CN101802404B - Closed type compressor and freezing apparatus using the same - Google Patents

Abstract

A bearing part (120) and a compression chamber (115) are disposed so that a first central line (141) showing the axial center of the bearing part (120) and a second central line (142) showing the axial center of the compression chamber (115) may intersect with each other, angle a1 formed between the first central line (141) and the second central line (142), and predetermined angle b1 may satisfy the relation of formula 1 and angle b1 is set by relating to absolute value c1 of inclination angle of a shaft (110) with respect to the bearing part (120) based on the clearance of the bearing part (120) and the main shaft part (111), and thereby prying between a piston and the compression chamber (115) can be prevented.

Description

Hermetic compressor and refrigeration equipment using the hermetic compressor

technical field

The present invention relates to a hermetic compressor used in a refrigerating cycle of a freezer, refrigerator, etc., and freezing and refrigerating equipment using the hermetic compressor.

Background technique

Recently, hermetic compressors for freezers, refrigerators, and other freezing and refrigerating equipment are required to increase efficiency to reduce power consumption, and to reduce noise and improve reliability. Among such conventional hermetic compressors, some have improved efficiency and stability by changing an oil supply method to a joint between a connecting rod and a piston (see, for example, PTL1).

An example of the conventional hermetic compressor will be described below with reference to the drawings. FIG. 20 is a longitudinal sectional view of a conventional hermetic compressor disclosed in Patent Document 1. As shown in FIG. Fig. 21 is an enlarged cross-sectional view of a main part of Fig. 20 . FIG. 22 is a sectional view of the main part of FIG. 20 .

As shown in FIGS. 20 and 21 , the airtight container 1 accommodates a motor drive element 4 having a stator 2 and a rotor 3 , and a compression element 5 driven by the motor drive element 4 . Lubricating oil 6 is stored at the bottom of the airtight container 1 . The shaft 10 has a main shaft portion 11 , and an eccentric shaft portion 12 formed eccentrically at one end of the main shaft portion 11 to move integrally with the main shaft portion 11 . The main shaft portion 11 is fixed to the axis of the rotor 3 .

The cylinder block 14 has an approximately cylindrical compression chamber 15 and a bearing portion 20 arranged to be fixed to each other at a specific position. In the compression chamber 15, a piston 23 is reciprocatably inserted.

The piston 23 has a piston pin 25 fitted parallel to the eccentric shaft portion 12 . The bearing portion 20 forms a cantilever bearing by supporting the end portion of the main shaft portion 11 of the shaft 10 on the side of the eccentric shaft portion 12 .

The link 26 is composed of a large end hole 28 , a small end hole 29 and a rod 30 . The large end hole portion 28 is closely fitted to the eccentric shaft portion 12 , and the small end hole portion 29 is connected to the piston pin 25 . Therefore, the eccentric shaft portion 12 and the piston 23 are connected together. The inner wall of the small end hole portion 29 has a convex spherical portion 31 so that when the piston pin 25 and the small end hole portion 29 contact each other in the vicinity of the axial center of the small end hole portion 29, the small end hole portion 29 in the axial direction A gap is formed at both ends of the top.

An oil supply passage 35 is provided inside the shaft 10 , and an oil spout 36 is fitted to an end portion of the oil supply passage 35 on the eccentric shaft portion 12 side. The lower end 40 , which is the end opposite to the eccentric shaft portion 12 of the main shaft portion 11 , protrudes so that the lubricating oil 6 can penetrate into the oil supply passage 35 to a predetermined depth.

In the hermetic compressor having this configuration, its operation is explained as follows. The rotor 3 of the motor drive element 4 rotates the shaft 10 . Therefore, the rotational movement of the eccentric shaft portion 12 is transmitted to the piston 23 through the connecting rod 26 . Thus, the piston 23 reciprocates in the compression chamber 15 . By the reciprocating motion of the piston 23, refrigerant gas is sucked from the cooling system (not shown) into the compression chamber 15, compressed and discharged into the cooling system again.

The lower end portion of the oil supply passage 35 is designed to function as a pump by the rotation of the shaft 10 . By this pumping action, the lubricating oil 6 at the bottom of the airtight container 1 is sucked upward through the oil supply passage 35 . The lubricating oil 6 that has reached the upper portion of the oil supply passage 35 is sprayed horizontally over the entire circumference of the airtight container 1 by centrifugal force from the upper portion of the oil sprinkling pipe 36 as indicated by the arrow X. A part of the sprayed lubricating oil 6 is supplied to lubricate the piston pin 25, the piston 23, and the like.

Since the inner wall of the small end hole portion 29 has a convex spherical portion 31, if a force to pry the connecting rod 26 up and down is generated, the contact portion of the spherical portion 31 deviates, preventing the piston pin 25 from contacting the small end hole portion 29. Local prying. In addition, a large amount of lubricating oil 6 can be supplied to the sliding portion of the piston pin 25 and the small end hole portion 29 , thereby achieving high reliability and high efficiency.

However, in this conventional hermetic compressor, it is insufficient to prevent the prying between the piston 23 and the inner wall 15a of the compression chamber 15 which occurs when the compression load of compressing refrigerant gas acts.

Generation of levering between the piston 23 and the inner wall 15a of the compression chamber 15 will be described with reference to the sectional view of main parts in FIG. 22 .

As shown in FIG. 22 , the compression load F generated on the piston 23 in the compression stroke of the refrigerant gas acts on the eccentric shaft portion 12 through the connecting rod 26 . Since there is a gap between the main shaft part 11 and the bearing part 20, when the compressive load F acts on the eccentric shaft part 12, the shaft 10 is located at the shaft center 20A of the bearing part 20, and the main shaft part 11 is inclined inside the bearing part 20 to The maximum degree of angle c. Therefore, the eccentric shaft portion 12 is also inclined by the angle dc from the shaft center of the main shaft portion 11 (ie, based on the shaft center 12A of the eccentric shaft portion 12 parallel to the shaft center of the main shaft portion 11 ), and a gap between the compression chamber 15 and the bearing portion 20 The relative angle of the axis of the axis also changes. Therefore, the piston 23, as shown in FIG. 22, tilts its axial center.

In this conventional hermetic compressor, by forming a convex shape on the inner wall of the small end hole portion 29, the inclination of the piston 23 can be suppressed, but the occurrence of prying between the piston 23 and the inner wall 15a of the compression chamber 15 cannot be prevented. .

Due to the prying generated between the piston 23 and the inner wall 15a of the compression chamber 15, a part of the sliding surface on which the piston 23 slides with the inner wall 15a of the compression chamber 15, that is, the edge of the upper end surface shown by P in the figure Part of , the surface pressure increases locally. Therefore, even in the conventional hermetic compressor having a convex-shaped inner wall in the small end hole portion 29, there are still problems such as early wear of the piston 23, an increase in the amount of wear, and an increase in sliding loss. reference list

patent documents

PTL 1: Patent Document 1: Japanese Patent Application Laid-Open No. 09-317644

Contents of the invention

The present invention was developed to solve the above problems, and therefore its object is to provide a hermetic compressor capable of preventing prying between the piston and the compression chamber, suppressing wear of the piston, reducing sliding loss, and further improving reliability and efficiency.

The present invention provides a hermetic compressor in which a motor drive element and a compression element driven by the motor drive element are accommodated in a hermetic container, wherein the compression element includes: a shaft having a main shaft portion rotated and driven by the motor drive element , and an eccentric shaft portion formed at one end of the main shaft portion to move integrally with the main shaft portion; a bearing portion forming a cantilever bearing by supporting the main shaft portion of the shaft; a cylinder block arranged to be fixed at a specific position in the bearing portion, And form a cylindrical compression chamber; a piston inserted so as to reciprocate in the compression chamber; and a connecting rod for connecting the eccentric shaft portion and the piston, and the bearing portion and the compression chamber are arranged so that the shaft center of the bearing portion Or a line parallel to the shaft center of the bearing portion may intersect with the shaft center of the compression chamber, an angle a1 (rad) formed by the shaft center of the bearing portion or a line parallel to the shaft center of the bearing portion and the shaft center of the compression chamber and The predetermined angle b1(rad) satisfies formula (1), and the angle b1 is set by being associated with the absolute value c1(rad) of the inclination angle of the shaft relative to the bearing part based on the gap between the bearing part and the main shaft part.

a1=π/2+b1(rad) (1)

The present invention also provides a hermetic compressor in which a motor-driven element and a compression element driven by the motor-driven element are accommodated in an airtight container, wherein the compression element includes: a shaft having a main shaft rotated and driven by the motor-driven element part, and an eccentric shaft part formed at one end of the main shaft part to move integrally with the main shaft part; a bearing part, which forms a cantilever bearing by supporting the main shaft part of the shaft; and a cylinder block, which is arranged to be fixed at a specific position in the bearing part , and form a cylindrical compression chamber; a piston inserted to be capable of reciprocating in the compression chamber and having a pin hole; a piston pin inserted and fixed in the pin hole; and a piston pin for connecting the eccentric shaft portion and the piston, and For a connecting rod having a large end hole portion at one end and a small end hole portion at the other end, the angle a2(rad) formed by the axis center of the piston and the axis center of the pin hole and the predetermined angle b2(rad) satisfy the formula (2), And the angle b2 is set by being associated with the absolute value c2 (rad) of the inclination angle of the shaft with respect to the bearing part based on the clearance between the bearing part and the main shaft part.

a2=π/2+b2(rad) (2)

The present invention also provides a hermetic compressor in which a motor-driven element and a compression element driven by the motor-driven element are accommodated in an airtight container, wherein the compression element includes: a shaft having a main shaft rotated and driven by the motor-driven element part, and an eccentric shaft part formed at one end of the main shaft part to move integrally with the main shaft part; a bearing part, which forms a cantilever bearing by supporting the main shaft part of the shaft; and a cylinder block, which is arranged to be fixed at a specific position in the bearing part , and form a cylindrical compression chamber; a piston inserted so as to reciprocate in the compression chamber and having a pin hole; a piston pin inserted and fixed in the pin hole; and a piston pin for connecting the eccentric shaft portion and the piston pin, and In a connecting rod having a large end hole at one end and a small end hole at the other end, the angle a3 (rad) formed by the axes of the large end hole and the small end hole is configured based on the bearing and 0.5 times or more to 3.3 times or less the absolute value c3 (rad) of the inclination angle of the shaft with respect to the bearing part in the gap between the main shaft parts.

In this configuration, prying between the piston and the compression chamber can be prevented. Therefore, piston wear is reduced and reliability is improved, and sliding loss is reduced and high efficiency is obtained.

Description of drawings

Fig. 1 is a longitudinal sectional view of a hermetic compressor in a preferred embodiment 1 of the present invention.

Fig. 2 is an enlarged sectional view of main parts when a compressive load does not act in the same preferred embodiment.

Fig. 3 is an enlarged sectional view of main parts when a compressive load acts in the same preferred embodiment.

Fig. 4 is a sectional view of main parts showing relative positions of a bearing portion and a compression chamber in the same preferred embodiment.

Fig. 5 is a characteristic diagram showing the results of experiments based on the same preferred embodiment.

Fig. 6 is a sectional view of the upper surface showing the relative positions of the bearing portion and the compression chamber in the same preferred embodiment.

Fig. 7 is a cross-sectional view of main parts in the vicinity of a compression chamber in preferred embodiment 2 of the present invention.

Fig. 8 is a sectional view of main parts near the compression chamber in the same preferred embodiment.

Fig. 9 is a characteristic diagram showing the results of experiments based on the same preferred embodiment.

Fig. 10 is a longitudinal sectional view of a hermetic compressor in preferred embodiment 3 of the present invention.

Fig. 11 is an enlarged sectional view of main parts when a compressive load does not act in the same preferred embodiment.

Fig. 12 is an enlarged sectional view of main parts when a compressive load acts in the same preferred embodiment.

Fig. 13 is a sectional view of main parts showing the relative positions of the piston and the pin hole in the same preferred embodiment.

Fig. 14 is a characteristic diagram showing the results of experiments based on the same preferred embodiment.

Fig. 15 is an enlarged sectional view of a main part when a compressive load does not act in Preferred Embodiment 4 of the present invention.

Fig. 16 is an enlarged sectional view of main parts when a compressive load acts in the same preferred embodiment.

Fig. 17 is a sectional view of main parts showing the relative positions of the large end hole and the small end hole of the connecting rod in the same preferred embodiment.

Fig. 18 is a characteristic diagram showing the results of experiments based on the same preferred embodiment.

Fig. 19 is a schematic configuration diagram of a freezer refrigerator in a preferred embodiment 5 of the present invention.

Fig. 20 is a longitudinal sectional view of a conventional hermetic compressor.

Fig. 21 is an enlarged sectional view of a main part in Fig. 20 .

Fig. 22 is a sectional view of the main part in Fig. 20 .

Detailed ways

Preferred embodiments of the present invention will be specifically described below with reference to the accompanying drawings. However, it must be noted that the present invention is not limited to these preferred embodiments.

Example 1

Fig. 1 is a longitudinal sectional view of a hermetic compressor in a preferred embodiment 1 of the present invention. Fig. 2 is an enlarged sectional view of main parts when a compressive load does not act in the same preferred embodiment. Fig. 3 is an enlarged sectional view of main parts when a compressive load acts in the same preferred embodiment. Fig. 4 is a sectional view of main parts showing relative positions of a bearing portion and a compression chamber in the same preferred embodiment. Fig. 5 is a characteristic diagram showing the results of experiments based on the same preferred embodiment.

In FIGS. 1 to 3 , an airtight container 101 accommodates a motor driving element 104 having a stator 102 and a rotor 103 , and a compression element 105 driven by the motor driving element 104 . Lubricating oil 106 is contained at the bottom of the airtight container 101 .

The shaft 110 has a main shaft portion 111 , and an eccentric shaft portion 112 formed eccentrically at one end of the main shaft portion 111 to move integrally with the main shaft portion 111 . The main shaft portion 111 is fixed to the axis of the rotor 103 . Oil supply passages 113 are formed inside and outside of the shaft 110 . The lower end portion of the shaft 110 is extended so that the lubricating oil 106 can immerse into the oil supply passage 113 to a prescribed depth.

The cylinder block 114 has a cylindrical (or nearly cylindrical) compression chamber 115 and a bearing portion 120 arranged to be fixed at a specific position with each other. The bearing portion 120 forms a cantilever bearing by supporting the end portion of the main shaft portion 111 of the shaft 110 on the side of the eccentric shaft portion 112 .

A piston 123 is reciprocally inserted into the compression chamber 115 . The piston 123 has a piston pin 125 parallel to the eccentric shaft portion 112 as shown in FIGS. 2 and 3 .

The valve plate 150 is assembled on the end surface of the cylinder 114 . A cylindrical hole portion 116 is formed in the cylinder 114 so as to form a compression chamber 115 together with the piston 123 and the valve plate 150 .

As shown in FIGS. 2 and 3 , the connecting rod 126 is composed of a large end hole portion 128 , a small end hole portion 129 and a rod portion 130 . The large end hole portion 128 is fitted onto the eccentric shaft portion 112 , and the small end hole portion 129 is connected to the piston 123 through the piston pin 125 . The eccentric shaft portion 112 and the piston 123 are connected together by a connecting rod 126 and a piston pin 125 .

In this preferred embodiment, when a compression load for compressing refrigerant gas acts, the axis C of the piston 123 is inclined due to the inclination of the shaft 110 as in the conventional example. However, in the present preferred embodiment, the compression chamber 115 is formed by inclining the axis D of the compression chamber 115 corresponding to the inclination of the piston 123 .

That is, in the present preferred embodiment, when the compression load is not acting, the axis C of the piston 123 is not inclined toward the compression chamber 115 formed by inclining the axis D as shown in the enlarged sectional view in FIG. 2 . On the other hand, when a compression load acts, the piston 123 is inclined such that the axis D of the compression chamber 115 and the axis C of the piston 123 can coincide with each other as shown in the enlarged sectional view in FIG. 3 .

The inclination of the compression chamber 115 is explained by referring to FIG. 4 . The bearing part 120 and the compression chamber 115 are arranged such that a first centerline 141 showing the axis of the bearing part 120 and a second centerline 142 showing the axis of the compression chamber 115 may intersect each other. The angle a1 formed between the first centerline 141 and the second centerline 142 is π/2 in a conventional hermetic compressor, however in this preferred embodiment, the angle a1 satisfies the formula (1) together with the predetermined angle b1 .

In the hermetic compressor having this configuration, its operation and action are explained below. In FIG. 1 , a rotor 103 of a motor drive element 104 rotates a shaft 110 . Along with the rotation of the shaft 110 , the rotational movement of the eccentric shaft portion 112 is transmitted to the piston 123 through the connecting rod 126 . Accordingly, the piston 123 reciprocates in the compression chamber 115 . By the reciprocating motion of the piston 123 , refrigerant gas is sucked into the compression chamber 115 from a not-shown cooling system having a refrigeration cycle. The refrigerant gas is compressed once in the compression chamber 115, and then is discharged into the cooling system again.

The lower end portion of the oil supply passage 113 functions like a pump by the rotation of the shaft 110 . By this pump action, the lubricating oil 106 at the bottom of the airtight container 101 passes through the oil supply passage 113 and is sucked upward, and is sprayed horizontally over the entire circumference in the airtight container 101 . Sprayed lubricating oil 106 is supplied to lubricate piston pin 125 and piston 123 .

In the cantilever bearing, only one side of the main shaft portion 111 on the eccentric shaft portion 112 of the shaft 110 supports the compression load for compressing refrigerant gas. Therefore, the shaft 110 is inclined in the gap between the main shaft portion 111 and the bearing portion 120 . Thus, the angle a1 between the axis 144 of the main shaft portion 111 of the shaft 110 inclined in the gap of the bearing portion 120 and the second centerline 142 showing the axis of the compression chamber 115 is smaller than π/2.

In order to prevent the piston 123 from prying against the compression chamber 115 caused by the inclination of the shaft 110, in this preferred embodiment, the first centerline 141 showing the shaft center of the bearing part 120 and the shaft showing the compression chamber 115 are aligned. The angle a1 between the second centerlines of the cores is set to be slightly larger than π/2.

In FIG. 4 , an intersection point of a first centerline 141 showing the axis of the bearing portion 120 and a second centerline 142 showing the axis of the compression chamber 115 is assumed to be O. The absolute value of the inclination angle of the shaft 110 relative to the bearing portion 120 based on the gap between the bearing portion 120 and the main shaft portion 111 is assumed to be c1. The value of the predetermined angle is an angle b1. At this time, the compression chamber 115 is formed such that the angle a1 formed by the first centerline 141 showing the axis of the bearing portion 120 and the second centerline 142 showing the axis of the compression chamber 115 can satisfy the formula (1 ) and formula (3).

b1=f(c1); f is the function of independent variable c1 (3)

An experimental value may be adopted as a specific value associating the angle b1 with the absolute value c1 of the inclination angle of the shaft 110 . FIG. 5 shows the measurement results of the efficiency of the hermetic compressor in which four types of cylinders 114 having different angles of the axial centers of the compression chambers 115 were prepared and these cylinders 114 were assembled. In FIG. 5 , the axis of abscissa represents the expansion from π/2 of the second centerline 142 showing the axis of the compression chamber 115 relative to the first centerline 141 showing the axis of the bearing portion 120 (in Figure 5 shows the angle b1) of the compression chamber relative to the bearing. The axis of ordinates represents the efficiency COP (coefficient of performance) with respect to the angle b1. That is, FIG. 5 is a quadratic approximation characteristic diagram of the measured value of the efficiency COP with respect to the angle b1.

Here, the line P1 indicates that the angle b1 is 0 (rad), and the efficiency at this time shows an average value of a conventional hermetic compressor. In this experiment, the absolute value c1 of the inclination angle of the shaft 110 due to the gap was about 3.7×10 ^-4 (rad) as indicated by the line Q1 . It can be seen from FIG. 5 that the efficiency is high when the angle b1 is in the range (A) of about 3.7 to 10×10 ⁻⁴ (rad). Similarly, when the angle b1 is in the range (B) of about 2 to 12×10 ^-4 (rad), the efficiency is higher than that in the conventional hermetic compressor.

Using the absolute value c1 of the inclination angle of the shaft 110 to represent the range of this angle b1, and when the angle b1 is in the range of 1.0c1 to 2.7c1, the efficiency is very high, especially in the range of 0.5c1 to 3.3c1, Efficiency is higher than in conventional hermetic compressors.

Therefore, when the angle a1 formed by the first centerline 141 showing the axis of the bearing portion 120 and the second centerline 142 showing the axis of the compression chamber 115 is expressed by formula (1), it is desired that the angle b1 and The absolute value c1 of the angle satisfies the relationship of formula (4).

0.5c1≤b1≤3.3c1 (4)

More preferably, the desired angle b1 and the absolute value c1 of the angle satisfy the relationship of formula (5).

1.0c1≤b1≤2.7c1 (5)

Therefore, by defining the angle a1 represented by the formula (1) as a design value of the angle of the axis center of the compression chamber 115, and by associating with the absolute value c1 of the inclination angle of the shaft 110 with respect to the bearing portion 120, the predetermined angle b1 Setting it closer to the actual value can prevent prying between the piston 123 and the compression chamber 115 more surely.

In addition, in order to improve efficiency, the arrangement may be determined to avoid the intersection between the second centerline 142 showing the axis of the compression chamber 115 and the first centerline 141 showing the bearing portion 120 .

This configuration will be described more specifically below by referring to the sectional view of the upper surface in FIG. 6 showing the relative positions of the bearing portion and the compression chamber in the present preferred embodiment.

With respect to the second centerline 142 showing the axis of the compression chamber 115, the first centerline 141 (a point in FIG. 6 ) showing the bearing portion 120 is parallelly offset by a dimension "e", which is generally referred to as offset. shift.

In FIG. 6, a third centerline 143 (a point in FIG. 6) parallel to a first centerline 141 (a point in FIG. 6) showing the axis of the bearing portion 120, that is, parallel to The line of the axis intersects with the second center line 142 showing the axis of the compression chamber 115 . According to experiments, the same results as those shown in Fig. 5 are also obtained in this configuration as long as the dimension "e" is within 3 mm.

Therefore, as long as the offset (dimension "e") of the compression chamber 115 relative to the bearing portion 120 is within 3 mm, the same effect as above can be obtained. That is, when the bearing portion 120 and the compression chamber 115 are arranged such that the second centerline 142 showing the axis of the compression chamber 115 and the third centerline 141 parallel to the first centerline 141 showing the axis of the bearing portion 120 When 143 can intersect with each other, the following can be known. The angle a1' (rad) formed between the third centerline 143 and the second centerline 142 is represented by formula (6), and at this time, preferably, the angle b1 and the absolute value c1 of the angle can satisfy the formula (4) relation. More preferably, the angle b1 and the absolute value c1 of the angle should satisfy the relationship of formula (5).

a1'＝π/2+b1(rad) (6)

In the cantilever bearing of this preferred embodiment, when the piston 123 is located at the bottom dead center, it is configured such that at least a part of the piston 123 can be exposed from the cylinder 114 . Specifically, it is formed such that at least 1/3 or more of the overall length of the piston 123 can be exposed in the axial direction.

In the second half stage of the suction stroke or in the early stage of the compression stroke, when the compression load caused by the pressure of the refrigerant gas acts on the end surface 123a of the piston 123 is not very large, the shaft 110 is held between the main shaft portion 111 and the bearing portion. 120 and doesn't lean much. Therefore, by setting the relative angle between the first centerline 141 showing the axis of the bearing portion 120 and the second centerline 142 showing the axis of the compression chamber 115 to be slightly larger than π/2, the piston 123 and the compression chamber The prying between 115 increases, and the sliding loss is afraid to increase.

However, in this preferred embodiment, when the piston 123 is located at the bottom dead center, it is designed such that at least 1/3 or more of the overall length in the axial direction of the piston 123 can be exposed. That is, the axial length of the piston 123 that causes prying is formed in a short size, and prying between the piston 123 and the compression chamber 115 can be suppressed.

Therefore, if the piston 123 is positioned near the bottom dead center, levering between the piston 123 and the compression chamber 115 can be prevented. Therefore, higher reliability can be achieved by reducing wear of the piston 123, and higher efficiency can be achieved by reducing sliding loss.

Example 2

In preferred embodiment 1, the compression chamber 115 is formed by inclining the axis D of the compression chamber 115 corresponding to the inclination of the piston 123 . However, in the present preferred embodiment, in addition to the configuration of the preferred embodiment 1, a tapered portion for forming the compression chamber 115 is formed in the cylindrical hole portion 116 . Therefore, in this preferred embodiment, explanations about the same configuration as in preferred embodiment 1 are omitted, and configurations different from preferred embodiment 1 are mainly explained.

Figures 1 to 4 are also applicable to this preferred embodiment. Fig. 7 is a sectional view of main parts near the compression chamber in this preferred embodiment, showing a state where the piston is located at the bottom dead center. Fig. 8 is a sectional view of main parts near the compression chamber in the same preferred embodiment, showing a state where the piston slides along the tapered portion. Fig. 9 is a characteristic diagram showing the results of experiments based on the same preferred embodiment.

In this preferred embodiment, as in preferred embodiment 1, a cylindrical hole portion 116 is formed in a cylinder 114 so as to form a compression chamber 115 together with a piston 123 and a valve plate 150 . As shown in FIG. 7 , the cylindrical hole portion 116 has a tapered portion 117 whose inner diameter increases from Dt to Db (>Dt) from the side where the piston 123 is located at the top dead center to the side located at the bottom dead center. The cylindrical hole portion 116 further has a straight portion 118 whose inner diameter is constant within a section of the length L in the axial direction at a position corresponding to the end portion of the piston 123 that reaches the top dead center on the compression chamber 115 side. The piston 123 is formed with the same outer diameter throughout the entire length.

The cylinder 114 has a notch cut out in a part of the peripheral wall of the cylindrical hole portion 116, that is, in the upper wall portion 119, so that the piston 123 is exposed when the piston 123 is located at the bottom dead center as shown in FIG. 123 on the anti-compression chamber 115 side.

In this configuration of the preferred embodiment, the compression chamber 115 is formed by inclining the axis D of the compression chamber 115 corresponding to the inclination of the piston 123 caused by the inclination of the shaft 110 when the compression load for compressing refrigerant gas acts. , and a tapered portion 117 for forming the compression chamber 115 is also formed in the cylindrical hole portion 116 .

The arrangement in which the compression chamber is formed by inclining the axis D of the compression chamber will be specifically described. As illustrated in FIG. 4 in Preferred Embodiment 1, the bearing portion 120 and the compression chamber 115 are arranged such that a first centerline 141 showing the axis of the bearing portion 120 and a second centerline 141 showing the axis of the compression chamber 115 are arranged. The two centerlines 142 may intersect each other. Among the angles formed between the first centerline 141 and the second centerline 142 , the angle between the bearing portion 120 side below the first centerline 141 and the compression chamber 115 side of the second centerline 142 is assumed to be a1. In a conventional hermetic compressor, as described in Preferred Embodiment 1, the angle a1 is π/2. In this preferred embodiment, as in preferred embodiment 1, assuming that the angle of the predetermined value is b1, the angle a1 and the angle b1 satisfy the formula (1).

The following is a specific description of the arrangement of the tapered portion 117 and the straight portion 118 forming the cylindrical hole portion 116 of the compression chamber 115 . As shown in FIGS. 7 and 8 , the angle formed between the axis of the piston 123 when the outer periphery of the piston 123 slides along the tapered portion 117 and the second centerline 142 showing the axis of the compression chamber 115 is assumed to be d1. At this time, as can be seen from FIGS. 7 and 8 , the angle formed between the tapered portion 117 and the second centerline 142 showing the axis of the compression chamber 115 corresponds to d1.

In the hermetic compressor having this configuration, the operations and effects are basically the same as those described in Preferred Embodiment 1. Therefore, the shaft 110 is inclined in the gap between the main shaft portion 111 and the bearing portion 120 . Thus, an angle a1 between the axis 144 of the main shaft portion 111 of the shaft 110 inclined in the gap of the bearing portion 120 and the second centerline 142 showing the axis of the compression chamber 115 is smaller than π/2.

In order to prevent the piston 123 from prying against the compression chamber 115 caused by the inclination of the shaft 110, in this preferred embodiment, the first centerline 141 showing the shaft center of the bearing part 120 and the shaft showing the compression chamber 115 are aligned. The angle a1 between the second centerlines 142 of the cores is set to be slightly larger than π/2.

In FIG. 4 , as in preferred embodiment 1, an intersection point of a first centerline 141 showing the axis of the bearing portion 120 and a second centerline 142 showing the axis of the compression chamber 115 is assumed to be O. The absolute value of the inclination angle of the shaft 110 relative to the bearing portion 120 based on the gap between the bearing portion 120 and the main shaft portion 111 is assumed to be c1. Assuming that the value of the predetermined angle is angle b1, in this preferred embodiment, as in preferred embodiment 1, the compression chamber 115 is formed such that the first center line 141 showing the shaft center of the bearing portion 120 and the first center line 141 shown in FIG. The angle a1 formed by the second centerline 142 exiting the axis of the compression chamber 115 may satisfy formula (1) and formula (3).

As described above, in the present preferred embodiment, prying of the piston 123 against the compression chamber 115 due to inclination of the shaft 110 is prevented. At the same time, also in the compression stroke, up to the middle point of the upper dead center side movement, the sliding loss is suppressed low, and when the piston 123 is close to the upper dead center position, the gas leakage due to the pressure increase of the refrigerant gas is prevented happened. Therefore, in this preferred embodiment, as shown in FIGS. 7 and 8 , the cylindrical hole portion 116 forming the compression chamber 115 has a straight portion 118 with a constant inner diameter in the axial direction, which is formed at a position opposite to the piston 123 . The position corresponding to the upper end portion of the piston 123 on the side of the compression chamber 115 at the top dead center. In addition, the cylindrical hole portion 116 has a tapered portion 117 formed adjacent to the straight portion 118 whose inner diameter increases from the side where the piston 123 is at the top dead center to the side where the piston 123 is at the bottom dead center.

In addition, a predetermined angle b1 added to the axis C of the piston 123 when the outer periphery of the piston 123 slides along the tapered portion 117 and the second centerline showing the axis of the compression chamber 115 are set by being associated with the angle c1. The value obtained on the angle d1 formed between 142. That is, the compression chamber 115 is formed such that the sum of the angle b1 and the angle d1 can satisfy formula (7).

(b1+d1)=f’(c1); f’ is a function about the independent variable c1 (7)

Therefore, in this preferred embodiment, as the value of the predetermined angle b1, or the value obtained by adding the angle b1 to the set angle d1 of the tapered portion 117, an experimental value can be used as the absolute value of the angle of inclination to the shaft 110. The concrete value associated with the value c1. Fig. 9 shows the measurement results of the efficiency of the hermetic compressor in this preferred embodiment, in which several kinds of cylinder blocks 114 having different angles of the second center line 142 showing the axis of the compression chamber 115 are prepared, and assembled these cylinders 114.

That is, the expansion angle b1 from π/2 of the second centerline 142 showing the axis of the compression chamber 115 relative to the first centerline 141 showing the axis of the bearing portion 120 and the angle of the tapered portion 117 The sum of the angles d1 (b1+d1) is divided by the absolute value c1 of the angle of inclination of the shaft 110, and the obtained dimensionless number is plotted on the axis of abscissa. The efficiency COP corresponding to each angle on the axis of abscissa is shown on the axis of ordinate. That is, FIG. 9 is a quadratic approximation characteristic diagram of each measured value of efficiency at (b1+d1)/c1.

Here, the efficiency at a value of 0 on the axis of abscissas represents an average value in a configuration without the tapered portion 117 in a conventional hermetic compressor. The absolute value c1 of the inclination angle of the shaft 110 in the gap in this experiment was about 3.7×10 ⁻⁴ (rad). Therefore, in FIG. 9, these values are represented by lines P2 and Q2.

As can be seen from FIG. 9, when the value of (b1+d1)/c1 is in the range (A) of about 1 to 3.2, the efficiency is high. It is also known that when the value of (b1+d1)/c1 is in the range (B) of about 0.3 to 4, the efficiency is higher than that of the conventional hermetic compressor.

Therefore, when the angle a1 of the second centerline 142 showing the axis of the compression chamber 115 with respect to the first centerline 141 showing the axis of the bearing portion 120 is expressed by formula (1), the angle b1 and the angle c1 should be The relationship of formula (8) is preferably satisfied.

0<b1≤2.5c1 (8)

Meanwhile, by setting the angle b1 to a positive value excluding 0 (rad), especially in the compression stroke, it is possible to effectively prevent the Leverage between the straight portion 118 and the piston 123. In addition, by setting the angle b1 to 2.5c1 or less, when the shaft 110 is not inclined much in the gap between the main shaft part 111 and the bearing part 120 in the second half stage of the suction stroke or in the early stage of the compression stroke, it is possible to Effectively prevent prying between the piston 123 and the compression chamber 115 .

Meanwhile, the angle d1 formed by the axis C of the piston 123 when the outer periphery of the piston 123 slides along the tapered portion 117 and the second centerline 142 showing the axis of the compression chamber 115 preferably satisfies the angle b1, angle Equation (9) related to c1 and angle d1.

0.3c1≤(b1+d1)≤4c1 (9)

More preferably, angle b1, angle d1, and angle c1 should have a relationship satisfying formula (10).

c1≤(b1+d1)≤3.2c1 (10)

Here, the effect of setting the angle of the axis 142 of the compression chamber 115 with respect to the axis 141 of the bearing 120 larger than π/2 and the effect of forming the tapered portion 117 on the side of the connecting rod 126 of the compression chamber 115 will be described.

First, the effect of setting the angle of the second centerline 142 showing the axis of the compression chamber 115 relative to the first centerline 141 showing the axis of the bearing portion 120 to be greater than π/2 is the same as in the preferred embodiment 1. same as described in . That is, it is possible to effectively prevent the piston 123 from levering against the compression chamber 115 due to the inclination of the shaft 110 in the gap of the bearing portion 120 due to the compression load when compressing the refrigerant gas by the cantilever bearing.

However, when the piston 123 reciprocates in the compression chamber 115 , the sliding loss becomes relatively large due to the sliding between the outer periphery of the piston 123 and the inner peripheral wall of the compression chamber 115 .

In order to reduce the sliding loss between the outer circumference of the piston 123 and the inner peripheral wall of the compression chamber 115, in this preferred embodiment, a straight portion 118 with a constant inner diameter in the axial direction is provided on the top dead center side of the compression chamber 115, and Also formed on the side of the connecting rod 126 of the compression chamber 115 is a tapered portion 117 provided so that the inner diameter increases from the top dead center side to the bottom dead center side.

Therefore, in the intermediate state of moving up to the upper dead center side in the compression stroke, gas leakage (that is, the refrigerant compressed in the compression chamber 115 leaks from the gap between the outer periphery of the piston 123 and the inner wall of the compression chamber 115) hardly occurs. The phenomenon). In addition, the sliding resistance (sliding loss) of the piston 123 becomes smaller. Furthermore, in a state where the compression stroke proceeds until the piston 123 approaches the top dead center, generation of gas leakage of refrigerant gas caused by an increase in air pressure can be reduced compared to the case where the tapered portion 117 is formed over the entire length.

Here, in the compression stroke, it can be considered that the outer circumference of the piston 123 can slide along the tapered portion 117 . As shown in the sectional view of the main part in the vicinity of the compression chamber in FIG. The inclination of the first centerline 141 of the axis of the 1st axis is greater than π/2 (b1+d1). Therefore, in the case of considering not only the angle b1 but also the angle d1 of the tapered portion 117, it is possible to consider the absolute value of the angle of inclination of the shaft 110 relative to the bearing portion 120 based on the gap between the bearing portion 120 and the main shaft portion 111. The relationship between the value c1 is optimized.

Alternatively, in the case of considering only the angle d1 of the tapered portion 117, if the relationship between the absolute value c1 of the inclination angle of the shaft 110 relative to the bearing portion 120 based on the gap between the bearing portion 120 and the main shaft portion 111 As designed, if a straight portion 118 with a constant inner diameter in the axial direction is provided on the top dead center side of the compression chamber 115, the sliding between the straight portion 118 and the piston 123 cannot be prevented from being caused by the shaft 110 to the bearing portion. Tilting of piston 120 causes levering between piston 123 and compression chamber 115 .

When the inclination of the axis C of the piston 123 with respect to the first center line 141 showing the axis of the bearing portion 120 is maintained at π/2 as in a conventional hermetic compressor, the bearing portion 120 and the main shaft When designing the angle d1 of the tapered portion 117 in relation to the absolute value c1 of the inclination angle c1 of the shaft 110 relative to the bearing portion 120 in the clearance of the shaft 111, if the angle d1 of the tapered portion 117 is large, the piston 123 is compressed. Behavior in chamber 115 is erratic and noise may increase. At the same time, retention of lubricating oil 106 between piston 123 and compression chamber 115 becomes insufficient, and leakage of refrigerant gas may increase.

Conversely, if the angle value d1 of the tapered portion 117 is small, the effect of reducing the sliding loss between the outer periphery of the piston 123 and the inner peripheral wall of the compression chamber 115 is weakened.

Therefore, prying between the piston 123 and the compression chamber 115 caused by inclination of the shaft 110 with respect to the bearing portion 120 can be prevented. At the same time, the sliding resistance (sliding loss) of the piston 123 in the intermediate state in which it moves up to the upper dead center side in the compression stroke can also be effectively reduced. In addition, in a state where the compression stroke is performed until the piston 123 approaches the top dead center position, generation of gas leakage of refrigerant gas caused by an increase in air pressure is reduced. In order to meet these requirements, the angle of the axis of the compression chamber 115 with respect to the axis of the bearing portion 120 is set to be larger than π/2, and at the same time, the tapered portion 117 is provided on the side of the connecting rod 126 of the compression chamber 115, so that synergy can be obtained. Effect.

However, only by setting the angle of the axis of the compression chamber 115 with respect to the axis of the bearing portion 120 to be greater than π/2 and providing the tapered portion 117 on the side of the connecting rod 126 of the compression chamber 115 cannot complement each other's problems. That is, in consideration of both the angle a1 of the axis of the compression chamber 115 with respect to the axis of the bearing portion 120 and the angle d1 of the tapered portion 117, the angles b1, d1, and c1 can be defined to satisfy the formula ( 9) or formula (10), and can be set closer to The actual value, and achieve the above effect.

At this time, additionally, when the angle b1 and the angle d1 satisfy the relationship of formula (11), according to the experimental results, the effect is further improved, and the reliability and efficiency are much higher than in conventional hermetic compressors.

0.5b1≤d1≤1.5b1 (11)

If the angle d1 of the tapered portion 117 is less than 0.5 times the angle b1, the effect of reducing the sliding loss between the outer circumference of the piston 123 and the inner peripheral wall of the compression chamber 115 is weakened. On the contrary, if the angle d1 of the tapered portion 117 is greater than the angle 1.5 times of b1, the noise increases due to the unstable behavior of the piston 123 in the compression chamber 115, and it is intended to be optimized from the perspective of two characteristics.

In this preferred embodiment, also, as in preferred embodiment 1, in order to obtain higher efficiency, components may be arranged such that the second centerline 142 showing the axis of the compression chamber 115 may not be the same as that shown The first centerline 141 of the axis of the bearing part 120 intersects. In this case, also in the present preferred embodiment, the angle a1' and the angle b1 may be defined to satisfy the formula (6) as described in the preferred embodiment 1 by referring to FIG. 6 .

Also in this preferred embodiment, at least a part of the piston 123 is formed to be exposed from the cylinder 114 when the piston 123 is located at the bottom dead center. More specifically, more than 1/3 of the overall length of the piston 123 is exposed in its axial direction. Therefore, as in the preferred embodiment 1, in the present preferred embodiment as well, prying between the piston 123 and the compression chamber 115 when the piston 123 is located near the bottom dead center can be prevented.

In this preferred embodiment, at the same time, on the inner peripheral wall of the compression chamber 115 corresponding to the upper end portion of the compression chamber 115 side of the piston 123 when the piston 123 is located at the top dead center, a straight portion 118 having a constant inner diameter in the axial direction is formed. . However, in the case where the straight portion 118 is not formed, the present invention is applicable as long as the tapered portion 117 is provided. That is, if only the tapered portion 117 is formed, although the leakage of refrigerant gas from the compression chamber 115 increases and the efficiency tends to decrease, it is possible to use the shaft 110 for the These problems are solved by setting the angle d1 closer to the actual value in relation to the absolute value c1 of the inclination of the bearing portion 120 .

Example 3

In preferred embodiments 1 and 2, the compression chamber 115 is formed by inclining the axis of the compression chamber 115 corresponding to the inclination of the piston 123 . However, in the present preferred embodiment, the pin hole is formed by inclining the axis center of the pin hole corresponding to the inclination of the connecting rod which is caused to inclination by the inclination of the shaft 110 when the compression load of compressing refrigerant gas acts.

Fig. 10 is a longitudinal sectional view of the hermetic compressor in this preferred embodiment. Fig. 11 is an enlarged sectional view of main parts when a compressive load does not act in the same preferred embodiment. Fig. 12 is an enlarged sectional view of main parts when a compressive load acts in the same preferred embodiment. Fig. 13 is a sectional view of main parts showing the relative positions of the piston and the pin hole in the same preferred embodiment. Fig. 14 is a characteristic diagram showing the results of experiments based on the same preferred embodiment. The basic configuration of the hermetic compressor of this preferred embodiment is the same as in preferred embodiments 1 and 2, but will be described again.

In FIGS. 10 to 12 , an airtight container 101 accommodates a motor driving element 104 having a stator 102 and a rotor 103 , and a compression element 105 driven by the motor driving element 104 . Lubricating oil 106 is contained at the bottom of the airtight container 101 .

The shaft 110 has a main shaft portion 111 , and an eccentric shaft portion 112 formed eccentrically at one end of the main shaft portion 111 to move integrally with the main shaft portion 111 . The main shaft portion 111 is fixed to the axis of the rotor 103 . Oil supply passages 113 are formed inside and outside of the shaft 110 . The lower end portion of the shaft 110 is extended so that the lubricating oil 106 can immerse into the oil supply passage 113 to a prescribed depth.

The cylinder block 114 has an approximately cylindrical compression chamber 115 and a bearing portion 120 arranged to be fixed at a specific position with each other. The bearing portion 120 forms a cantilever bearing by supporting the end portion of the main shaft portion 111 of the shaft 110 on the side of the eccentric shaft portion 112 .

A piston 123 is reciprocally inserted into the compression chamber 115 . The piston 123 has a pin hole 124 , and a piston pin 125 is inserted and fixed in the pin hole 124 .

As shown in FIGS. 11 and 12 , the connecting rod 126 is composed of a large end hole portion 128 , a small end hole portion 129 and a rod portion 130 . The large end hole portion 128 is fitted onto the eccentric shaft portion 112 . The small end hole portion 129 is connected to the piston 123 via the piston pin 125 . The eccentric shaft portion 112 and the piston 123 are connected together by a connecting rod 126 and a piston pin 125 .

In the preferred embodiment, the connecting rod 126 also tilts due to the tilt of the shaft 110 when the compression load of compressing the refrigerant gas acts. However, the pin hole 124 is formed by inclining the axis center of the pin hole 124 corresponding to the inclination of the link 126 .

This tilted state will be described with reference to FIGS. 11 and 12 . In FIG. 11 , no compression load acts, and the figure shows an enlarged sectional view of a state of the axis C of the piston 123 formed by inclining the axis C of the pin hole 124 with respect to the axis D of the compression chamber 115 . In FIG. 12 , a compression load acts, and the figure shows an enlarged sectional view of a state of the piston 123 such that the axis D of the compression chamber 115 can coincide with the axis C of the piston 123 .

The inclination of the pin hole 124 is shown in FIG. 13 , wherein the angle formed between a first centerline 141 showing the axis C of the piston 123 and a second centerline 142 showing the axis C of the pin hole 124 a2, is π/2 in the conventional hermetic compressor, but is defined to satisfy formula (2) together with the predetermined angle b2 in this preferred embodiment.

In the hermetic compressor having this configuration, its operation and action are explained below. The rotor 103 of the motor drive element 104 rotates the shaft 110 . Along with the rotation of the shaft 110 , the rotational movement of the eccentric shaft portion 112 is transmitted to the piston 123 through the connecting rod 126 . Accordingly, the piston 123 reciprocates in the compression chamber 115 . By the reciprocating motion of the piston 123, refrigerant gas is sucked into the compression chamber 115 from a cooling system not shown, is compressed once, and is discharged into the cooling system again.

The lower end portion of the oil supply passage 113 functions like a pump by the rotation of the shaft 110 . By this pump action, the lubricating oil 106 at the bottom of the airtight container 101 passes through the oil supply passage 113 and is sucked upward, and is sprayed horizontally over the entire circumference in the airtight container 101 . Sprayed lubricating oil 106 is supplied to lubricate piston pin 125 and piston 123 .

In the cantilever bearing, only one side of the main shaft portion 111 on the eccentric shaft portion 112 of the shaft 110 supports the compression load for compressing refrigerant gas. Therefore, the shaft 110 is inclined in the gap between the main shaft portion 111 and the bearing portion 120 . Therefore, the relative angle between the axis center 144 of the main shaft portion 111 of the shaft 110 inclined in the gap of the bearing portion 120 and the axis center D of the compression chamber 115 is smaller than π/2.

In order to prevent the piston 123 from prying against the compression chamber 115 caused by the inclination of the shaft 110, in this preferred embodiment, the first centerline 141 showing the axis of the piston 123 and the axis showing the pin hole 124 are connected to each other. The relative angle between the second centerlines 142 is set to be slightly larger than π/2.

In FIGS. 12 and 13 , an intersection point of a first centerline 141 showing the axis C of the piston 123 and a second centerline 142 showing the axis of the pin hole 124 is assumed to be O. The absolute value of the inclination angle of the shaft center 144 of the main shaft part 111 with respect to the shaft center of the bearing part 120 based on the gap between the bearing part 120 and the main shaft part 111 is assumed to be c2. The value of the predetermined angle is angle b2, and the pin hole 124 is formed such that the angle formed by the first center line 141 showing the axis C of the piston 123 and the second center line 142 showing the axis C of the pin hole 124 a2 can satisfy formula (2) and formula (12).

b2=f(c2); f is a function about the independent variable c2 (12)

An experimental value may be adopted as a specific value associating the predetermined angle b2 with the absolute value c2 of the inclination angle of the shaft 110 . FIG. 14 shows the measurement results of the efficiency of the hermetic compressor in which pistons 123 having different angles of the axis centers of the pin holes 124 were prepared, and these pistons 123 were assembled. That is, the axis of abscissa represents the expansion from π/2 of the second centerline 142 showing the axis of the pin hole 124 relative to the first centerline 141 showing the axis of the piston 123 (described in FIG. 14 ). is the angle b2) between the axis of the pin hole and the axis of the piston. The axis of ordinate represents the efficiency COP with respect to the angle b2. That is, FIG. 14 is a quadratic approximation characteristic diagram of the measured value of the efficiency COP with respect to the angle b2.

Here, the efficiency at which the angle b2 shown by the line P3 is 0 shows the average value of the conventional hermetic compressor. In this experiment, the absolute value c2 of the inclination angle of the shaft 110 caused by the gap was about 3.7×10 ⁻⁴ . As can be seen from FIG. 14, when the angle b2 is in the range (A) of about 3.7 to 10×10 ^-4 , the efficiency is high. Similarly, when the angle b2 is in the range (B) of about 2 to 12×10 ^-4 , the efficiency is higher than that in the conventional hermetic compressor.

Using the absolute value c2 of the inclination angle of the shaft 110 to represent the range of this angle b2, and when the angle b2 is in the range of 1.0c2 to 2.7c2, the efficiency is very high, especially in the range of 0.5c2 to 3.3c2, Efficiency is higher than in conventional hermetic compressors.

Therefore, when the angle a2 formed by the first centerline 141 showing the axis of the piston 123 and the second centerline 142 showing the axis of the pin hole 124 is expressed by formula (2), the desired angle b2 and angle The absolute value of c2 satisfies the relationship of formula (13).

0.5c2≤b2≤3.3c2 (13)

More preferably, it is desired that the angle b2 and the angle c2 satisfy the relationship of formula (14).

1.0c2≤b2≤2.7c2 (14)

Therefore, in this preferred embodiment, by defining the angle a2 represented by the formula (2) as the design value of the angle of the axis center of the pin hole 124, and by the absolute value c2 of the angle of inclination of the shaft 110 relative to the bearing portion 120 In association with setting the predetermined angle b2 closer to the actual value, prying between the piston 123 and the compression chamber 115 can be prevented.

In addition, in the cantilever bearing of this preferred embodiment, when the piston 123 is located at the bottom dead center, it is designed so that at least a part of the piston 123 can be exposed from the cylinder 114 . More specifically, more than 1/3 of the total length in the axial direction of the piston 123 may be exposed.

In the second half stage of the suction stroke or in the early stage of the compression stroke, when the compression load caused by the pressure of the refrigerant gas acts on the end surface 123a of the piston 123 is not very large, the shaft 110 is held between the main shaft portion 111 and the bearing portion. 120 and doesn't lean much. Therefore, by setting the relative angle between the first centerline 141 showing the axis of the piston 123 and the second centerline 142 showing the axis of the pin hole 124 to be slightly larger than π/2, the piston 123 and the compression chamber 115 The prying between them increases, and the sliding loss may increase.

However, in this preferred embodiment, when the piston 123 is located at the bottom dead center, it is designed such that at least 1/3 or more of the overall length in the axial direction of the piston 123 can be exposed. That is, the axial length of the piston 123 that causes prying is formed in a short size, and prying between the piston 123 and the compression chamber 115 can be suppressed.

Therefore, if the piston 123 is positioned near the bottom dead center, levering between the piston 123 and the compression chamber 115 can be prevented. Therefore, higher reliability can be achieved by reducing wear of the piston 123, and higher efficiency can be achieved by reducing sliding loss.

In the preferred embodiment, the piston 123 is vertically asymmetric so that upper and lower can be easily distinguished during assembly. Specifically, a judgment hole 146 a is formed at an upper portion of the piston 123 . By assembling so that this judging hole 146a can be on the upper side, the piston 123 is not assembled upside down. Therefore, the effect of preventing prying between the piston 123 and the compression chamber 115 can be surely obtained.

Also in this preferred embodiment, as described in preferred embodiment 2, by forming the tapered portion 117 for forming the compression chamber 115 in the cylindrical hole portion 116, the same as that in the preferred embodiment 2 is obtained. same effect. That is, by applying the configurations shown in FIGS. 7 and 8 in addition to the configurations explained in FIGS. 10 to 13 , characteristics as shown in FIG. 9 are obtained. In FIGS. 7 to 9 , the same components as in the preferred embodiment 2 are identified by the same reference numerals, and the same symbols as in the preferred embodiment 2 are used to describe angles. In this preferred embodiment, adding a predetermined angle b2 to the axis C of the piston 123 when the outer periphery of the piston 123 slides along the tapered portion 117 and the axis center showing the compression chamber 115 is set by being associated with the angle c2. The sum obtained on the angle d2 formed between the second centerline 142 of . The compression chamber 115 is formed such that the sum of the angle b2 and the angle d2 can satisfy formula (15).

(b2+d2)=f”(c2); f” is a function about the independent variable c2 (15)

In this preferred embodiment, also, as the predetermined angle b2 or the sum of the angle b2 and the predetermined angle d2 of the tapered portion 117, an experimental value can be used as a specific value associated with the absolute value c2 of the inclination angle of the shaft 110. Through the same experiment as in Preferred Embodiment 2, the same measurement results as in FIG. 9 were obtained.

Therefore, in this preferred embodiment, similarly, the axis C of the piston 123 when the outer periphery of the piston 123 slides along the tapered portion 117 and the second centerline 142 showing the axis of the compression chamber 115 are formed between The angle d2 preferably satisfies the relationship of formula (16) with respect to the angle b2, the angle c2, and the angle d2.

0.3c2≤(b2+d2)≤4c2 (16)

In addition, angle b2, angle d2, and angle c2 should preferably satisfy the relationship of formula (17).

c2≤(b2+d2)≤3.2c2 (17)

Furthermore, when the angle b2 and the angle d2 satisfy the formula (18), the same effect as in the preferred embodiment 2 is obtained, and the reliability and efficiency are much higher than those in the conventional hermetic compressor.

0.5b2≤d2≤1.5b2 (18)

Example 4

In preferred embodiments 1 and 2, the compression chamber 115 is formed by inclining the axis of the compression chamber 115 corresponding to the inclination of the piston 123 . In preferred embodiment 3, the pin hole 124 is formed by inclining the axis of the pin hole 124 corresponding to the inclination of the connecting rod 126 caused by the inclination of the shaft 110 when the compression load of compressing refrigerant gas acts. However, in this preferred embodiment, the axis of the small end hole 129 is inclined relative to the axis of the large end hole 128 in accordance with the inclination of the shaft 110 when the compression load for compressing refrigerant gas acts.

The basic configuration of the hermetic compressor of this preferred embodiment is the same as that in preferred embodiment 3 illustrated in FIG. 10 . Fig. 15 is an enlarged sectional view of main parts when a compressive load does not act in this preferred embodiment. Fig. 16 is an enlarged sectional view of main parts when a compressive load acts in the same preferred embodiment. Fig. 17 is a sectional view of main parts showing the relative positions of the large end hole and the small end hole of the connecting rod in the same preferred embodiment. Fig. 18 is a characteristic diagram showing the results of experiments based on the same preferred embodiment.

Explanation of the overall configuration of this preferred embodiment with reference to FIGS. 10 , 15 and 16 is the same as in Preferred Embodiment 3, and thus omitted. In this preferred embodiment, as described above, the axis of the small end hole 129 is inclined relative to the axis of the large end hole 128 corresponding to the inclination of the shaft 110 when the compression load for compressing refrigerant gas acts.

This tilted state will be described with reference to FIGS. 15 and 16 . FIG. 15 is an enlarged cross-sectional view showing a state of the axis C of the piston 123 relative to the axis D of the compression chamber 115 when the compression load is not acting. 16 is an enlarged sectional view showing a state of the piston 123 and the connecting rod 126 such that the axis D of the compression chamber 115 and the axis C of the piston 123 can coincide with each other when a compression load acts.

FIG. 17 shows the inclination relationship between the axis of the large end hole 128 and the axis of the small end hole 129 . As shown in FIG. 17, among the angles formed between the first centerline 141 showing the axis of the large end hole 128 and the second centerline 142 showing the axis of the small end hole 129, the The angle formed between the eccentric shaft portion 112 side (counter-main shaft portion 111 side) above the first center line 141 and the eccentric shaft portion 112 side (counter main shaft portion 111 side) above the second center line 142 or line 143 is assumed to be a3. The absolute value of the inclination angle of the shaft 110 relative to the bearing portion 120 based on the gap between the bearing portion 120 and the main shaft portion 111 is assumed to be c3. In a conventional hermetic compressor, the angle a3 is 0. In the preferred embodiment, angle a3 is defined by formula (19).

0.5c3≤a3≤3.3c3 (19)

That is, the axes of the large end hole 128 and the small end hole 129 are slightly inclined toward each other as they go from the eccentric shaft 112 side (upper) to the main shaft 111 side (lower).

In the hermetic compressor having this configuration, the basic operations and functions are the same as in the preferred embodiment 3, and descriptions thereof are omitted. In this preferred embodiment, also in the cantilever bearing, the compression load when compressing the refrigerant gas is supported only by the main shaft portion 111 on one side of the eccentric shaft portion 112 of the shaft 110 . Accordingly, the shaft 110 is inclined within the gap between the main shaft portion 111 and the bearing portion 120 .

Therefore, the relative angle between the shaft center 144 of the main shaft portion 111 of the shaft 110 inclined in the gap of the bearing portion 120 and the shaft center D of the compression chamber 115 is smaller than π/2.

In order to prevent the piston 123 from prying against the compression chamber 115 caused by the inclination of the shaft 110, in this preferred embodiment, the first centerline 141 showing the axis of the large end hole 128 and the first centerline 141 showing the small end hole The relative angle between the axes of the portions 129 and the second centerline 142 is set to be slightly greater than zero.

In FIGS. 16 and 17 , the large end hole portion 128 and the small end hole portion 129 are formed such that the first center line 141 showing the axis of the large end hole portion 128 is the same as the axis of the small end hole portion 129 . The angle a3 between the second centerlines 142 of , and the absolute value c3 of the inclination angle of the shaft center 144 of the main shaft part 111 relative to the shaft center of the bearing part 120 based on the gap between the bearing part 120 and the main shaft part 111 can satisfy the formula (15). In FIG. 17 , in order to easily understand the angle a3, a line 143 parallel to the second centerline 142 showing the axis of the small end hole 129 is marked, and the angle a3 is used to represent the line 143 and the line 143 showing the large end hole. The angle between the first centerline 141 of the axis of the portion 128.

An experimental value can be adopted as a specific value associating the angle a3 with the absolute value c3 of the inclination angle of the shaft 110 . Fig. 18 shows the measurement results of the efficiency COP of the hermetic compressor, wherein the connecting rod 126 in which the relative angle a3 between the axis center of the large end hole portion 128 and the axis center of the small end hole portion 129 is changed is prepared, and assembled These connecting rods 126 are removed. That is, the angle between the first centerline 141 showing the axis of the large end hole 128 and the second centerline 142 showing the axis of the small end hole 129 is plotted on the axis of abscissa (in FIG. 18 is the angle a3) between the axis of the big end hole of the connecting rod and the axis of the small end hole. The efficiency COP is plotted on the axis of ordinates for each value of the angle a3. That is, FIG. 18 is a quadratic approximation characteristic diagram of each measured value of the efficiency COP at each angle a3 value.

Here, the efficiency at which the angle a3 shown by the line P4 is 0 shows the average value of the conventional hermetic compressor. The absolute value c3 of the inclination angle of the shaft 110 caused by the gap in this experiment shown by the line Q4 is about 3.7×10 ⁻⁴ . As can be seen from FIG. 18, the efficiency is high when the angle a3 is in the range (A) of about 3.7 to 10×10 ^-4 . Similarly, when the angle a3 is in the range (B) of about 2 to 12×10 ^-4 , the efficiency is higher than that in the conventional hermetic compressor.

Using the absolute value c3 of the inclination angle of the shaft 110 to represent the range of this angle a3, and when the angle a3 is in the range of 1.0c3 to 2.7c3, the efficiency is very high, especially in the range of 0.5c3 to 3.3c3, Efficiency is higher than in conventional hermetic compressors.

Therefore, the angle a3 and the angle c3 formed by the first centerline 141 showing the axis of the large end hole portion 128 and the second centerline 142 showing the axis of the small end hole portion 129 should preferably satisfy the formula (19 )Relationship. More preferably, it is expected that angle a3 and angle c3 satisfy the relationship of formula (20).

1.0c3≤a3≤2.7c3 (20)

However, if the angle a3 is set too small for the angle c3, especially in the compression stroke, it cannot prevent the friction between the straight portion 118 and the piston 123 when the shaft 110 is inclined much in the gap between the main shaft portion 111 and the bearing portion 120. Prying, or conversely, if the angle a3 is set too large for the angle c3, in the second half of the suction stroke or in the early stage of the compression stroke, when the shaft 110 is not in the gap between the main shaft part 111 and the bearing part 120 When the tilt is large, prying between the piston 123 and the compression chamber 115 cannot be prevented.

Therefore, in this preferred embodiment, the angle a3 between the axis center of the large end hole portion 128 and the axis center of the small end hole portion 129 is defined by being associated with the absolute value c3 of the inclination angle of the shaft 110 relative to the bearing portion 120 To get closer to the actual value, it is possible to prevent prying between the piston 123 and the compression chamber 115 .

In addition, in the cantilever bearing of this preferred embodiment, when the piston 123 is located at the bottom dead center, it is designed so that at least a part of the piston 123 can be exposed from the cylinder 114 . More specifically, more than 1/3 of the total length in the axial direction of the piston 123 may be exposed.

In this preferred embodiment, as in preferred embodiment 3, in the latter half of the suction stroke or in the early stage of the compression stroke, the first center line 141 showing the axis of the large end hole 128 If the relative angle of the second center line 142 showing the axis of the small end hole portion 129 is set slightly larger than 0, the prying between the piston 123 and the compression chamber 115 increases, and the sliding loss may increase.

However, in this preferred embodiment, when the piston 123 is located at the bottom dead center, it is designed such that at least 1/3 or more of the overall length in the axial direction of the piston 123 can be exposed. That is, the axial length of the piston 123 that causes prying is formed in a short size, and prying between the piston 123 and the compression chamber 115 can be suppressed.

Therefore, if the piston 123 is positioned near the bottom dead center, levering between the piston 123 and the compression chamber 115 can be prevented. Therefore, higher reliability can be achieved by reducing wear of the piston 123, and higher efficiency can be achieved by reducing sliding loss.

In the preferred embodiment, the link 126 is vertically asymmetric so that upper and lower can be easily distinguished during assembly. Specifically, a judging projection 146 b is formed at an upper portion of the link 126 . By assembling such that the judging projection 146b can be on the upper side, the link 126 is not assembled upside down. Therefore, the effect of preventing prying between the piston 123 and the compression chamber 115 can be surely obtained.

For higher efficiency, components may be arranged such that the centerline showing the axis of the compression chamber 115 may not intersect the axis of the bearing part 120 . In this case as well, as in the preferred embodiment 1, as long as the compression chamber 115 is offset from the bearing portion 120 within 3 mm, the same effect as in the present preferred embodiment can be obtained.

In this preferred embodiment, also, as described in preferred embodiments 2 and 3, by forming the tapered portion 117 for forming the compression chamber 115 in the cylindrical hole portion 116, the same as the preferred embodiment is obtained. Same effect as in example 2 and 3.

Therefore, in this preferred embodiment, also, when the outer periphery of the piston 123 slides along the tapered portion 117, the center line 142 formed between the axis C of the piston 123 and the axis center of the compression chamber 115 The angle d3 preferably satisfies the relationship of formula (21) with respect to the predetermined angle b3, angle c3, and angle d3.

0.3c3≤(b3+d3)≤4c3 (21)

In addition, angle b3, angle d3, and angle c3 should preferably satisfy the relationship of formula (22).

c3≤(b3+d3)≤3.2c3 (22)

In addition, when the angle b3 and the angle d3 satisfy the formula (23), the same effect as in the preferred embodiment 2 is obtained, and the reliability and efficiency are much higher than those in the conventional hermetic compressor.

0.5b3≤d3≤1.5b3 (23)

Example 5

Fig. 19 is a schematic configuration diagram of a freezer refrigerator in a preferred embodiment 5 of the present invention using any one of the hermetic compressors described in preferred embodiments 1 to 4. In FIG. 19 , a freezer refrigerator 200 of this preferred embodiment includes a plurality of storage compartments 202 disposed on the front of a box body 201 , and a machine compartment 203 disposed on the rear. The machine room 203 accommodates the hermetic compressor 204 as described in the preferred embodiments 1 to 4. The hermetic compressor 204 is connected to a refrigeration cycle constituent element 205 such as a condenser through a pipe 206 . The hermetic compressor 204 is controlled by a control device 207, and operates an appropriate refrigeration cycle. Therefore, according to the present preferred embodiment, a high reliability and high efficiency freezer refrigerator is obtained.

Industrial applicability

As described herein, the hermetic compressor of the present invention can achieve high reliability and high efficiency, and thus is suitable for use in freezing and refrigerating equipment operating a refrigeration cycle such as an air conditioner or a vending machine.

List of reference signs

101 airtight container

102 stator

103 rotor

104 motor drive components

105 compression elements

106 lubricating oil

110 axis

111 spindle part

112 eccentric shaft

113 oil supply passage

114 cylinder

115 compression chamber

116 cylindrical hole

117 tapered part

118 straight department

120 Bearing Department

123 pistons

123a end face

124 pin holes

125 piston pin

126 connecting rod

128 large end hole

129 small end hole

130 stem

141 First Centerline

142 Second Centerline

143 Third Centerline

144 The axis of the main shaft

146a judgment hole

146b judgment raised

150 valve plate

200 freezer refrigerator

201 cabinet

202 storage room

203 Mechanical Room

204 sealed compressor

205 Refrigeration cycle components

206 tube

207 control device

Claims (26)

1. hermetic type compressor comprises:

The compressing member that is contained in the motor-driven components in the seal container and drives by said motor-driven components,

Wherein, said compressing member comprises: axle, and it has the main shaft part by said motor-driven components rotation and driving, and is formed on an end of said main shaft part and the eccentric axial portion that said main shaft part is integrally moved; Bearing portion, it forms cantilever bearings through the said main shaft part that supports said axle; Cylinder body, it is arranged to be fixed on the special position in the said bearing portion, and forms columnar pressing chamber; Be inserted into can be in said pressing chamber pistons reciprocating; And the connecting rod that is used to connect said eccentric axial portion and said piston; And; The 3rd center line that said bearing portion and said pressing chamber are arranged such that first center line in the axle center that said bearing portion is shown or are parallel to said first center line intersects each other with second center line that the axle center of said pressing chamber is shown

The angle a1 (rad) and the predetermined angle b1 (rad) that are formed by said first center line or said the 3rd center line and said second center line satisfy formula a1=pi/2+b1 (rad), and through setting said angle b1 with being associated with respect to the absolute value c1 (rad) at the angle of inclination of said bearing portion based on the axle gap between said bearing portion and the said main shaft part, said.

2. hermetic type compressor as claimed in claim 1,

Wherein said angle b1 be set to said angle absolute value c1 more than 0.5 times to below 3.3 times.

3. hermetic type compressor as claimed in claim 1,

Wherein said angle b1 be set to said angle absolute value c1 more than 1.0 times to below 2.7 times.

4. hermetic type compressor as claimed in claim 1,

Wherein said angle b1 be set to said angle absolute value c1 below 2.5 times do not comprise 0 (rad) on the occasion of; And said pressing chamber has and is formed the tapered portion that a side internal diameter that a side direction that is positioned at upper dead center from said piston is positioned at lower dead centre increases, and the angle d1 that between the axle center of the axle center of said piston and said pressing chamber, forms during along said tapered portion slip when the periphery of said piston and the said angle b1 sum absolute value c1 that is set to said angle more than 0.3 times to below 4 times.

5. hermetic type compressor as claimed in claim 4,

Wherein said angle b1 and said angle d1 sum be set to said angle absolute value c1 more than 1.0 times to below 3.2 times.

6. hermetic type compressor as claimed in claim 5,

Wherein said angle d1 be set to said angle b1 more than 0.5 times to below 1.5 times.

7. hermetic type compressor as claimed in claim 4,

The straight portion that also is included in corresponding position, the upper end portion of the said pressing chamber side of said piston when being positioned at upper dead center, forms adjacent to said tapered portion with said piston.

8. hermetic type compressor as claimed in claim 1,

Wherein when said piston was positioned at lower dead centre, at least a portion of said piston was exposed from said cylinder body.

9. hermetic type compressor comprises:

The compressing member that is contained in the motor-driven components in the seal container and drives by said motor-driven components,

Wherein, said compressing member comprises: axle, and it has the main shaft part by said motor-driven components rotation and driving, and is formed on an end of said main shaft part and the eccentric axial portion that said main shaft part is integrally moved; Bearing portion, it forms cantilever bearings through the said main shaft part that supports said axle; Cylinder body, it is arranged to be fixed on the special position in the said bearing portion, and forms columnar pressing chamber; Be inserted into can be in said pressing chamber to-and-fro motion and have the piston of pin-and-hole; Be inserted and secured on the wrist pin in the said pin-and-hole; And connecting rod, it is used to connect said eccentric axial portion and said piston, and at one end has big stomidium portion and have small end hole portion at the other end,

Satisfy formula a2=pi/2+b2 (rad) by first center line in the axle center that said piston is shown with angle a2 (rad) and the predetermined angle b2 (rad) that second center line that the axle center of said pin-and-hole is shown forms, and through be associated set angle b2 based on the gap between said bearing portion and the said main shaft part, said absolute value c2 (rad) with respect to the angle of inclination of said bearing portion.

10. hermetic type compressor as claimed in claim 9,

Wherein said angle b2 be set to said angle absolute value c2 more than 0.5 times to below 3.3 times.

11. hermetic type compressor as claimed in claim 9,

Wherein said angle b2 be set to said angle absolute value c2 more than 1.0 times to below 2.7 times.

12. hermetic type compressor as claimed in claim 9,

Wherein said angle b2 be set to said angle absolute value c2 below 2.5 times do not comprise 0 (rad) on the occasion of; Said pressing chamber has and is formed the tapered portion that the side internal diameter that makes a side direction that is positioned at upper dead center from said piston be positioned at lower dead centre increases, and the angle d2 that between the axle center of the axle center of said piston and said pressing chamber, forms during along said tapered portion slip when the periphery of said piston and the said angle b2 sum absolute value c2 that is set to said angle more than 0.3 times to below 4 times.

13. hermetic type compressor as claimed in claim 12,

Wherein said angle b2 and said angle d2 sum be set to said angle absolute value c2 more than 1.0 times to below 3.2 times.

14. hermetic type compressor as claimed in claim 13,

Wherein said angle d2 be set to said angle b2 more than 0.5 times to below 1.5 times.

15. hermetic type compressor as claimed in claim 9,

Said pressing chamber has: be formed the tapered portion that the side internal diameter that makes a side direction that is positioned at upper dead center from said piston be positioned at lower dead centre increases; The straight portion that forms with corresponding position, the upper end portion of the said pressing chamber side of said piston when being positioned at upper dead center, adjacent to said tapered portion with said piston.

16. hermetic type compressor as claimed in claim 9,

Wherein when said piston was positioned at lower dead centre, at least a portion of said piston was exposed from said cylinder body.

17. hermetic type compressor as claimed in claim 9,

Wherein in the vertical direction is formed asymmetrically said piston.

18. a hermetic type compressor comprises:

The compressing member that is contained in the motor-driven components in the seal container and drives by said motor-driven components,

Wherein, said compressing member comprises: axle, and it has the main shaft part by said motor-driven components rotation and driving, and is formed on an end of said main shaft part and the eccentric axial portion that said main shaft part is integrally moved; Bearing portion, it forms cantilever bearings through the said main shaft part that supports said axle; Cylinder body, it is arranged to be fixed on the special position in the said bearing portion, and forms columnar pressing chamber; Be inserted into can be in said pressing chamber to-and-fro motion and have the piston of pin-and-hole; Be inserted and secured on the wrist pin in the said pin-and-hole; And connecting rod, it is used to connect said eccentric axial portion and said wrist pin, and at one end has big stomidium portion and have small end hole portion at the other end,

By first center line in the axle center that said big stomidium portion is shown and illustrate angle a3 that second center line in the axle center of said small end hole portion forms be set to based on the axle gap between said bearing portion and the said main shaft part, said with respect to the absolute value c3 at the angle of inclination of said bearing portion more than 0.5 times to below 3.3 times.

19. hermetic type compressor as claimed in claim 18,

Wherein said angle a3 be set to said angle absolute value c3 more than 1.0 times to below 2.7 times.

20. hermetic type compressor as claimed in claim 18,

Said pressing chamber has and is formed the tapered portion that the side internal diameter that makes a side direction that is positioned at upper dead center from said piston be positioned at lower dead centre increases, and the angle d3 that between the axle center of the axle center of said piston and said pressing chamber, forms during along said tapered portion slip when the periphery of said piston and the predetermined angle b3 sum absolute value c3 that is set to said angle more than 0.3 times to below 4 times.

21. hermetic type compressor as claimed in claim 20,

Wherein said angle b3 and said angle d3 sum be set to said angle absolute value c3 more than 1.0 times to below 3.2 times.

22. hermetic type compressor as claimed in claim 21,

Wherein said angle d3 be set to said angle b3 more than 0.5 times to below 1.5 times.

23. hermetic type compressor as claimed in claim 18,

Said pressing chamber has: be formed the tapered portion that the side internal diameter that makes a side direction that is positioned at upper dead center from said piston be positioned at lower dead centre increases; The straight portion that forms with corresponding position, the upper end portion of the said pressing chamber side of said piston when being positioned at upper dead center, adjacent to said tapered portion with said piston.

24. hermetic type compressor as claimed in claim 18,

Wherein when said piston was positioned at lower dead centre, at least a portion of said piston was exposed from said cylinder body.

25. hermetic type compressor as claimed in claim 18,

Wherein in the vertical direction is formed asymmetrically said connecting rod.

26. freezing and refrigerating equipment that is equipped with like any one the described hermetic type compressor in the claim 1 to 25.

Images