JPH109167A - Rotary compressor - Google Patents

Abstract

(57) [Problem] To provide a rotary compressor capable of solving tribological problems and improving performance and reliability even when a high-pressure refrigerant is used in a contact portion between a roller and a vane of the rotary compressor. I do. A roller is provided with a non-uniform mass portion by providing a hole in an end surface of a roller, embedding a different material, or performing a process such as element injection on a part of the roller. The crankshaft 9 is shifted from the rotation center with respect to the eccentric portion 10.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotary compressor.

[0002]

2. Description of the Related Art A conventional rotary compressor will be described with reference to FIG.

[0003] An electric element having a stator 2 and a rotor 3 and a compression element driven by the electric element are housed in a closed container 1. As a compression element, a roller 11 rotatably fitted to an eccentric portion 10 of a crankshaft 9 eccentrically rotates within the cylinder 4 by rotation of the crankshaft 9. The inside of the cylinder is partitioned by the vanes 12 pressed by the rollers 11, and the working fluid (refrigerant gas) sucked from the suction pipe 15 is compressed. The compressed gas is discharged into the closed container and discharged from the discharge pipe 19 to an external refrigeration cycle.

In the rotary compressor having such a configuration, the most important in terms of reliability are problems relating to tribology such as lubrication between the roller 11 and the vane 12 and the cylinder 4 and prevention of wear. Normally, roller 11 and vane 1
The cylinder 2 and the cylinder 4 are used in combination of metal materials, and in the case of poor lubrication, there is a problem that abnormal wear occurs and the compression performance is reduced.

[0005] There are quite a number of known examples of improving lubrication between a roller, a vane and a cylinder, but most of them are intended to increase the amount of oil supplied to the sliding surfaces of the roller and the vane to improve wear resistance. It is. Japanese Patent Application Laid-Open No. 6-257576 is an example of such a device.

[0006] The compressor described in Japanese Patent Application Laid-Open No. 6-257576 has diagonal grooves for holding lubricating oil provided on side walls of rollers and vanes. For this reason, the lubricating oil is easily retained, but if the supply of the lubricating oil continues to be interrupted, there is lubricating oil in the groove, but there is no lubricating oil on the contact surface between the roller and the vane, Adhesion between the vanes is likely to occur. Therefore, the rotational movement of the roller stops,
It is feared that the relative movement between the roller and the vane does not occur, and local abnormal wear of the roller occurs.

[0007]

In the conventional rotary compressor, the contact portion between the roller and the vane is in linear contact, so that the surface pressure is very high and the temperature is high and the pressure is high. For this reason, the contact interface becomes a boundary lubrication region where it is difficult to form an oil film, and abnormal wear is likely to occur.

In addition, Freon CFC12 and HCFC2 which have been conventionally used as working fluids for refrigeration / air conditioning equipment
2 and the like have chlorine in the molecule, and have been pointed out as destroying the ozone layer in the stratosphere, which has become a social problem. Therefore, it is necessary to switch to alternative chlorofluorocarbons which do not have to worry about depletion of the ozone layer, and as such alternative chlorofluorocarbons, HFC-based refrigerants having no chlorine in the molecule are the most promising candidates.
Among these alternative chlorofluorocarbons, when a high-pressure refrigerant such as an azeotropic two-type refrigerant mixture of HFC32 and HFC125 is used, the working pressure is about 1.5 times higher than that of the conventional refrigerant. Since the pressing of the vane against the roller is performed by the discharge pressure of the compressor, the contact pressure between the roller and the vane becomes about 1.5 times as large as the conventional pressure. For this reason, the frictional force between the roller and the vane becomes large, and there is a problem that the roller does not rotate and comes into contact with the vane at only one place.

An object of the present invention is to solve the problem of tribology at the contact portion between the roller and the vane and to achieve high compression performance even in the case of using a high-pressure refrigerant in which the pressure applied to the vane increases under severe lubrication conditions. An object of the present invention is to provide a rotary compressor.

[0010]

Means for Solving the Problems In order to solve the above-mentioned object, there are the following technical means.

(1) An electric element having a stator and a rotor in a closed container, a crankshaft driven by the electric element, a roller rotatably fitted to an eccentric portion of the crankshaft, and a tip attached to the roller. The compression is formed by a main bearing having a vane that reciprocates in contact with each other to partition the inside of a cylinder into a low-pressure suction chamber and a high-pressure compression chamber, supports the crankshaft, and has an end plate that closes both end openings in the cylinder. In the rotary compressor in which the components are housed, a non-uniform portion having a mass that shifts a center of mass of the roller from a rotational axis with respect to an eccentric portion of the crank shaft of the roller is provided.

(2) An electric element having a stator and a rotor in a closed container, a crankshaft driven by the electric element, a roller rotatably fitted to an eccentric portion of the crankshaft, and a tip on the roller. The compression is formed by a main bearing having a vane that reciprocates in contact with each other to partition the inside of a cylinder into a low-pressure suction chamber and a high-pressure compression chamber, supports the crankshaft, and has an end plate that closes both end openings in the cylinder. In the rotary compressor containing the components, the center of mass of the roller is set at 1.0 mm from the rotation axis with respect to the eccentric portion of the crankshaft of the roller.
Provide a non-uniform mass of eccentricity in the range of × 10 to ⁴ kg · m or more and 2.0 × 10 to ³ kg · m or less.

(3) In (1) or (2), a hole is made in a part of the roller end face.

(4) In (1) or (2), a material different from the roller material is embedded in a part of the end face of the roller.

(5) In (1) or (2), an element different from the element forming the roller material is applied to only a part of the circumferential surface of the roller by sputtering, vapor deposition, injection, or the like. Apply another surface treatment to the entire circumference.

[0016]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to the drawings.

FIG. 6 is a longitudinal sectional view of a part of a horizontal rotary compressor embodying the present invention, and FIG. 7 is a sectional view taken along line CC of FIG. 6 and 7, the closed casing 1 contains an electric element including a stator 2 and a rotor 3, and a compression element driven by the electric element. The cylinder 4 has a main bearing 5 and a sub-bearing 6 that close the openings at both ends of the cylinder 4 to form a working chamber including a suction chamber 7 and a compression chamber 8. Crankshaft 9
Has an eccentric portion 10, and a roller 11 is rotatably fitted to the eccentric portion 10. The vane 12 divides the inside of the cylinder 4 into a low-pressure suction chamber 7 and a high-pressure compression chamber 8 by being pressed by a roller 11 with a gas pressure (discharge pressure) in the closed container 1 and a spring 13.

With this configuration, the compression operation of the rotary compressor is performed as follows. When the electric element is energized, the rotation of the rotor 3 drives the crankshaft 9, and the roller 11 fitted to the eccentric portion 10 eccentrically rotates in the cylinder 4.
The cylinder 4 is moved by the vane 12 pressed by the roller 11.
By partitioning the inside into a suction chamber 7 and a compression chamber 8, the working fluid (refrigerant gas) sucked into the suction chamber 7 from the suction pipe 15 is compressed, and the compressed gas passes through the discharge valve 16 from the discharge port 16 a. Then, it enters a discharge chamber 18 formed by the sub bearing 6 and the discharge cover 17, is thereafter discharged into the closed container 1, and is discharged to an external refrigeration cycle (not shown) by a discharge pipe 19.

The lubrication of the bearing sliding portion is performed as follows. The rotation of the crankshaft 9 causes the vane 12 pressed by the roller 11 to reciprocate, changing the volume of the space on the back surface of the vane where the spring 13 is mounted. The lubricating oil 14 stored at the bottom of the sealed container 1 is sucked from the suction fluid diode 20 by the reciprocating pump action due to this volume change, and formed on the crankshaft 9 through the discharge fluid diode 21 and the oil supply pipe 22. The oil is supplied to the oil supply hole 23 and the oil supply groove 24 to lubricate the sliding portion of the bearing.

Next, lubrication of the contact portion between the roller 11 and the vane 12 and the cylinder 4 is caused by leakage of the lubricating oil supplied to the sliding portion of the bearing from both end surfaces of the roller 11 into the cylinder 4 and the refrigerating cycle. The amount of lubricating oil contained in the refrigerant in the cylinder 4 is sucked into the cylinder 4 and the amount of the lubricating oil on the back surface of the vane leaks into the cylinder 4 from the gap between the cylinder 4 and the vane 12. It is on the order of milliliters.
Also. All of the lubricating oil is from roller 11 and vane 12
Instead of contributing to the lubrication of the sliding surface, a very small amount actually contributes, and the remainder becomes mist in the cylinder 4 and is discharged into the refrigeration cycle together with the refrigerant gas.

In the rotary compressor having this configuration, the rollers 1
1 and the vane 12 behave as follows. The roller 11 and the eccentric part 10 are rotatably fitted with each other.
Due to the balance between the frictional force between the roller and the eccentric and the frictional force between the roller and the vane 12, the roller rotates or stands still with respect to the vane. Therefore, in order to improve the lubrication state between the roller and the vane and to prevent wear, the roller must always rotate and relatively move with respect to the vane without standing still. Since the roller and the vane have a relative speed, an oil film is easily formed between the roller and the vane, and the vane does not stay in contact at one point of the roller, so that abnormal wear does not occur. However, when the roller rotates at such a speed as to be fixed to the crankshaft, the mechanical loss between the roller and the vane increases, which reduces the efficiency of the compressor. Therefore, the rollers must be rotating at an appropriate speed without standing still with respect to the vane.

In particular, when a high-pressure refrigerant such as an azeotropic two-type refrigerant mixture of HFC32 and HFC125 is used, the working pressure is about 1.5 times higher than that of the conventional refrigerant. Closed container 1
The gas pressure (discharge pressure) inside the vane and the vane pressed by the spring 13 are pressed against the roller with a load about 1.5 times that in the case where a conventional refrigerant is used. So roller,
The frictional force between the vanes increases, so that the roller does not rotate and easily comes into contact with the vane at only one point.

In this case, since it is difficult to rotate the roller only by the frictional force between the roller 11 and the eccentric portion 10, it is necessary to rotate the roller 11 to an appropriate speed by other means.

According to the present invention, as a means for rotating the roller 11, the center of mass of the roller 11 is eccentric from the center of rotation of the roller 11 with respect to the eccentric portion 10 of the crankshaft 9, so that centrifugal force acts on the roller 11 and the effect is obtained. Roller 1
1 is rotated with respect to the vane 12. At this time, the rotational force of the roller 11 due to the action of the centrifugal force is
And the amount of eccentricity is in the range of 1.0 × 10 to ⁴ kg · m or more and 2.0 × 10 to ³ kg · m or less.

The mechanism, operation and effect will be described below.

An embodiment of the present invention will be described with reference to FIG. 1 or FIG.

FIG. 1 is a perspective view showing the structure of a cylinder 4 portion of a rotary compressor embodying the present invention.
In this example, the center of mass of the roller is shifted from the center of rotation of the roller with respect to the eccentric portion 10 of the crankshaft 9 by providing a hole 11a in a part of the shaft. In this embodiment, the roller 11 has the hole 11
a, and the hole is not provided on the entire circumference along the end face of the roller, but only a part is left without forming a hole, so that the mass of the portion is made larger than the other portions, and the mass of the roller is increased. Non-uniform distribution. Thus, when the roller rotates due to the rotation of the crankshaft 9, a centrifugal force acts on the roller, and the roller easily rotates with respect to the eccentric portion of the crankshaft. Furthermore, since the rotation speed is determined by the balance between the centrifugal force acting on the roller and the frictional force between the roller and the vane, and the frictional force between the roller and the eccentric part of the crankshaft, the hole speed depends on the material of the roller or the operating conditions of the compressor. diameter, and the number appropriately provided, the eccentric amount 1.0 × 10 ~ ⁴ k
By setting the range of g × m to 2.0 × 10 to ³ kg · m or less, the rotational force of the roller is set to the increase in the pressing force of the vane 12, and the relative movement can be performed at an appropriate speed. As a result, the lubrication state between the roller and the vane can be improved, abnormal wear can be prevented, and the compression performance is not impaired.

In this embodiment, the number of the holes 11a is nine, but the number and the diameter of the holes are determined by the material of the roller material,
Determined according to the operating conditions of the compressor.

The embodiment shown in FIG. 3 is an example in which the roller 11 has a non-uniform mass portion, a hole is provided in a part of the end face of the roller 11, and another material 11b different in density from the roller material is embedded therein. It is. In the case of this embodiment, when the density of the embedding material 11b is higher than the density of the roller material, there is an advantage that the number of processing steps of piercing the roller and embedding another material is reduced. In the embodiment shown in the figure, embedding processing is performed at three places of the roller,
This number is determined by the effect of the centrifugal force of the roller, which is determined by the density and the number of the embedding materials, and embedding is not limited to three places. Further, when a material having a density lower than that of the roller material is embedded, the number of processing locations must be increased.

In the embodiment shown in FIG. 4, an element having a density different from that of the roller material is segregated on the circumferential surface of the roller as a non-uniform mass of the roller 11 by a technique such as sputtering, vapor deposition or driving. This is an example in which a portion 11d is provided. In this case, since there is a possibility that the friction and wear behavior may be different between the portion where the other element is not segregated and the portion where the other elements are not segregated, the abrasion resistant coating 11c is applied to the roller surface over the entire circumference of the roller cylindrical surface. In the embodiment shown in the figure, other elements are implanted on a surface of about 1/4 circumference of the roller cylindrical surface, but this is the case where the implanted element is an element heavier than the roller material. The range of implantation is determined by the mass and density of the element to be implanted and the implantation depth.

In the embodiment shown in FIG. 5, the roller 11 is divided into two parts, an outer peripheral side and an inner peripheral side, so that the embedding material 11b, which is different from the roller material, has a function as a key for preventing rotation. This is an example of providing a simple shape. In this case, a key groove must be provided on the inner peripheral surface on the outer peripheral side and the outer peripheral surface on the inner peripheral side of the roller. In this case, the filling material 11b must be a material having a higher density than the roller material. In this embodiment, since the inner peripheral side and the outer peripheral side of the roller are divided, the inner peripheral side is made of a material having a lower density than the outer peripheral side, so that the weight of the entire roller can be reduced and a non-uniform portion of the mass is provided. The effect of the centrifugal force that induces the rotation of the roller can be further increased.

In the present invention, a one-cylinder type rotary compressor has been described as an example, but the present invention can also be applied to a two-cylinder rotary compressor. Further, in addition to the compressor, the present invention is applicable to an expander and a vacuum pump having the same rotary type as the present invention.

[0033]

According to the present invention, the lubrication state between the roller and the vane is greatly improved by the relative movement of the roller and the vane even in an alternative Freon environment where the lubrication state is severe, and the compression performance and reliability are improved. Can be provided.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a configuration of a cylinder portion of a rotary compressor according to an embodiment of the present invention.

FIG. 2 is a perspective view of a roller used in the rotary compressor of FIG.

FIG. 3 is a perspective view of a roller showing a second embodiment of the present invention.

FIG. 4 is a perspective view of a roller showing a third embodiment of the present invention.

FIG. 5 is a perspective view of a roller according to a fourth embodiment of the present invention.

FIG. 6 is a partial cross-sectional view of the rotary compressor of the present invention.

FIG. 7 is a sectional view taken along line CC of FIG. 6;

[Description of References] 4 ... Cylinder, 11 ... Roller, 11a ... Hole, 11b ... Different material embedding part, 11c ... Different element segregation part, 12 ... Vane.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Hirokatsu Kasogabe 502, Kandachicho, Tsuchiura-shi, Ibaraki Pref.Mechanical Research Laboratories, Inc. Within Hitachi, Ltd.

Claims (5)

[Claims] An electric element having a stator and a rotor in a closed container, a crankshaft driven by the electric element,
A roller rotatably fitted to the eccentric portion of the crankshaft, a reciprocating motion in contact with the tip of the roller, a vane for partitioning a cylinder into a low-pressure suction chamber and a high-pressure compression chamber, and supporting the crankshaft; In a rotary compressor containing a compression element formed by a main bearing having an end plate that closes both end openings in the cylinder, a center of mass of the roller is eccentric from a rotation axis with respect to an eccentric portion of the crankshaft of the roller. A rotary compressor using a roller provided with a nonuniform portion of mass to be applied. 2. An electric element having a stator and a rotor in a closed container, a crankshaft driven by the electric element,
A roller rotatably fitted to the eccentric portion of the crankshaft, a reciprocating motion in contact with the tip of the roller, a vane for partitioning a cylinder into a low-pressure suction chamber and a high-pressure compression chamber, and supporting the crankshaft; In a rotary compressor containing a compression element formed by a main bearing having an end plate that closes an opening at both ends in the cylinder, the center of mass of the roller is set at 1 from the rotational axis with respect to the eccentric portion of the crank shaft of the roller. A rotary compressor characterized by using a roller provided with a non-uniform mass portion that is eccentric within a range of from 0.0 × 10 to ⁴ kg · m to 2.0 × 10 to ³ kg · m. 3. The rotary compressor according to claim 1, wherein a hole is formed in a part of the roller end surface. 4. The rotary compressor according to claim 1, wherein a material other than a roller material is embedded in a part of an end face of the roller. 5. The roller according to claim 1, wherein an element different from the element forming the roller material is subjected to a process such as sputtering, vapor deposition or injection on only a part of the circumferential surface of the roller, and further, the entire surface of the roller circumference. Rotary compressor with different surface treatment.