JPH05312171A - Rolling piston type compressor - Google Patents

Abstract

(57) [Summary] [Purpose] To prevent fluid leakage between the outer peripheral surface of the roller and the inner peripheral surface of the cylinder. [Constitution] In contrast to a rolling piston type compressor in which the roller rotates while the roller outer peripheral surface is in contact with the cylinder inner peripheral surface (5e) to compress the refrigerant, when the high pressure chamber is in a high pressure state, the roller outer peripheral surface and the cylinder inner Cylinder inner peripheral surface (5e) so that the gap with the peripheral surface (5e) becomes small.
Is formed into a non-perfect circle. That is, on the high pressure chamber side, the crank rotation axis (3
Reduce the distance to g). As a result, refrigerant leakage from the high pressure side to the low pressure side can be reduced and the compressor efficiency can be improved.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rolling piston type compressor, and more particularly to improvement of measures for preventing fluid leakage between an outer peripheral surface of a roller and an inner peripheral surface of a cylinder.

[0002]

2. Description of the Related Art Generally, as one type of compressor provided in a refrigerator or the like, for example, a rolling piston type compressor as disclosed in Japanese Patent Laid-Open No. 63-167095 is known. This type of compressor is configured such that an electric motor and a compressor body connected to the electric motor via a crankshaft are housed in a casing. As shown in FIG. 4, in the compressor body, rollers (b) as rolling pistons are arranged in a cylinder (a), and a front surface (not shown) is provided on each of upper and lower end surfaces of the cylinder (a). A head and a rear head are attached, and a compression chamber (c) is formed between the inner peripheral surface of the cylinder (a) and the outer peripheral surface of the roller (b). A crankshaft extending from the electric motor is inserted through the inside of the roller (b), and a portion of the crankshaft through which the roller (b) is inserted is formed by an eccentric cam portion. The roller (b) is eccentrically arranged with respect to the cylinder (a) by inserting the cam portion into the roller (b). Further, the cylinder (a) is provided with a fluid suction passage (d) and a fluid discharge passage (e), and a blade () is provided between the suction passage (d) and the discharge passage (e). f) is the compression chamber (c)
The blade (f) is provided so as to be able to project and retract inside, and the tip end surface of the blade (f) is brought into contact with the outer peripheral surface of the roller (b) so that the compression chamber (c) becomes the high pressure chamber (c1). It is partitioned into a low pressure chamber (c2).

When the compressor is driven, the volumes of the compression chambers (c1) and (c2) are changed by the rotation of the roller (b) (see the arrow in FIG. 4) accompanying the rotation of the crankshaft. A fluid such as a refrigerant gas flows into the compression chamber (c) from the suction passage (d), compresses this fluid, and then discharges it from the discharge passage (e).

[0004]

By the way, as shown in FIG. 5, in such a rolling piston type compressor, as described above, the roller (b) as an individual member is provided inside the cylinder (a). Therefore, a gap (g) (generally called a CP gap) is formed between the outer peripheral surface of the roller (b) and the inner peripheral surface of the cylinder (a). This gap (g) is generated not only due to the processing precision and assembly precision of each component, but also the bearing gap and the gap between the cam portion and the roller (b) are biased according to the pressure change in the compression chamber due to the compression process. It is caused by something and is unavoidable.

When such a gap (g) is generated, this gap (g) serves as a leakage passage that connects the high pressure chamber (c1) and the low pressure chamber (c2), and the fluid is in the high pressure chamber (c1). ) To the low pressure chamber (c2), and the fluid efficiency reduces the compressor efficiency. Further, such a fluid leakage is caused by the high pressure chamber (c
The situation is such that the pressure in 1) becomes high, that is, it tends to occur as the compression process by the roller (b) progresses.

The present invention has been made in view of this point, and an object thereof is to prevent fluid leakage between the outer peripheral surface of the roller and the inner peripheral surface of the cylinder.

[0007]

In order to achieve the above-mentioned object, the present invention improves the shape of the cylinder inner peripheral surface so that the outer peripheral surface of the roller and the inner peripheral surface of the cylinder can be prevented in the situation where fluid leakage is likely to occur. The gap generated between and is made as small as possible. Specifically, the invention according to claim 1 accommodates a drive means (3) and a compression means (4) connected to the drive means (3) in a casing (2),
The cylinder (5) is formed by accommodating the roller (6) in the cylinder (5) and disposing the head portions (7) and (8) on both end surfaces of the cylinder (5). ) Inner peripheral surface (5e) and roller (6) outer peripheral surface (6)
It is formed by forming a compression chamber (9) with a). Then, the drive shaft (3) of the drive means (3) is attached to the roller (6).
By inserting an eccentric portion (3f) formed eccentrically in a predetermined direction from the rotational axis (3g) of b), the roller (6) is eccentric with respect to the cylinder (5), and the roller (6) A part of the outer peripheral surface (6a) of the cylinder is brought into contact with the inner peripheral surface (5e) of the cylinder (5). Further, in the compression chamber (9),
The fluid suction passage (5a) and the fluid discharge passage (5d) are connected to each other, and the roller (6) is rotated in the cylinder (5) in accordance with the driving of the driving means (3), so that the fluid is drawn from the suction passage (5a). It is premised on a rolling piston type compressor configured to suck a fluid into the compression chamber (9), compress the fluid, and then discharge the fluid from the discharge passage (5d). The radius (R) of the drive shaft (3b) with respect to the rotation axis (3g) of at least a part of the cylinder inner peripheral surface (5e) with which the roller outer peripheral surface (6a) contacts between the time when the fluid is compressed and the time when the fluid is discharged. Is set to be smaller than the radius (RR) of the drive shaft (3b) with respect to the rotation axis (3g) of the other cylinder inner peripheral surface (5e), thereby making the cylinder inner peripheral surface (5e) non-circular. It was configured to be formed by.

According to a second aspect of the present invention, in the rolling piston type compressor according to the first aspect, the roller outer peripheral surface (6a) is in contact with the roller outer peripheral surface (6a) at the start of fluid compression, and the roller outer peripheral surface ( The radius (R) of the drive shaft (3b) with respect to the rotational axis (3g) of at least a part of the cylinder inner peripheral surface (5e) up to the position where 6a) contacts is expressed by the formula R = RR- (ε / 2) [ 1-sin {(4θ / 3)-(7π
/ 4)}] (ε: maximum reduction in radius of inner peripheral surface of cylinder, θ: roller rotation angle (90 ° ≦ θ ≦ 360 °)).

[0009]

With the above construction, the present invention has the following effects. In the invention according to claim 1, the roller (6) of the compression means (4) is driven by the drive of the drive means (3).
Rotates in the cylinder (5), which causes the suction passage (5
The fluid is sucked into the compression chamber (9) from (a), compressed, and then discharged from the discharge passage (5d). In such a compression operation, the radius of the drive shaft (3b) with respect to the rotation axis (3g) of a part of the cylinder inner peripheral surface (5e) with which the roller outer peripheral surface (6a) contacts between the time when the fluid is compressed and the time when the fluid is discharged. Since (R) is smaller than the radius (RR) of the other portion, when the roller (6) passes through this portion, the roller outer peripheral surface (6a) and the cylinder inner peripheral surface (5)
In the situation where the gap between the compression chamber (e) and e) becomes small and the high pressure chamber of the compression chamber (9) is in a high pressure state, fluid leakage from the high pressure side to the low pressure side is reduced.

According to the second aspect of the present invention, the radius (R) of the cylinder inner peripheral surface (5e) is set by the above equation, so that the position where the roller outer peripheral surface (6a) is in contact with the fluid when the compression of the fluid is started. The radius (R) is minimized at a position intermediate with the position where the roller outer peripheral surface (6a) contacts at the end of the discharge. Therefore, in the connecting portion of the region where the radius of the cylinder inner peripheral surface (5e) is set to be small and the region where the radius is not set to be small, the rate of change of the radius per unit dimension in the circumferential direction is not significantly changed, and both of them are changed. It is possible to make the radial dimensions close to each other, and it becomes easy to ensure the continuity of the inner peripheral surfaces (5e) of both cylinders.

[0011]

Embodiments of the present invention will now be described with reference to the drawings. As shown in FIG. 1, a rolling piston compressor (1) according to the present invention is provided in an air conditioner, and has a casing (2) in which a driving means (3) and a compression means are provided. The machine body (4) is housed and configured.

The drive means (3) comprises an electric motor (3a) and a crankshaft (3b) as a drive shaft.
The electric motor (3a) is disposed above the internal space (2a) of the casing (2), and the stator (3c) fixed to the inner peripheral surface of the casing (2) and the stator (3).
c) and the rotor (3d) arranged in the central part. The crankshaft (3b) has its upper end connected to the center of the rotor (3d), and has its lower end extended downward and linked to the compressor body (4). Lubricating oil (O) is stored in the bottom of the casing (2), and the lower end of the crankshaft (3b) is immersed in the lubricating oil (O). A centrifugal pump (3e) is arranged at the lower end of the crankshaft (3b), and an oil supply passage (not shown) extending in the vertical direction is formed through the crankshaft (3b).
When the compressor (1) is driven, the lubricating oil (O) is pumped to the oil supply passage by the centrifugal pump (3e) and then supplied to each sliding portion of the compressor (1). ..

On the other hand, the compressor body (4) has a fixed blade shape and is arranged below the electric motor (3a). As shown in FIGS. 1 and 2, the compressor body (4) has rollers (6) housed in a cylindrical cylinder (5) fixed to the inner wall of the casing (2). A front head (7) as a head portion is attached to the upper end surface of the cylinder (5), and a rear head (8) as a head portion is attached to the lower end surface thereof, respectively. The front head (7) and the rear head (8) ), A compression chamber (9) is formed between the inner peripheral surface (5e) of the cylinder (5) and the outer peripheral surface (6a) of the roller (6). The front and rear heads (7), (8) are formed with through holes (7a), (8a) which have a diameter substantially the same as that of the crankshaft (3b) and extend in the vertical direction. A crankshaft (3b) is rotatably supported in the holes (7a) and (8a) via a metal seal or the like. Also,
The cylinder (5) is formed with a refrigerant gas suction passage (5a) opening to the compression chamber (9).
A suction pipe (10) extending from an accumulator (not shown) is connected to a). On the other hand, an eccentric portion formed integrally with the crankshaft (3b) at the center of the roller (6) and eccentric in a predetermined direction with respect to the rotational axis (3g) of the crankshaft (3b). The cam portion (3f) is fitted. Thereby, the roller (6) is provided eccentrically with respect to the cylinder (5), and a part of the outer peripheral surface (6a) of the roller (6) is provided on the inner peripheral surface (5e) of the cylinder (5).
Is always in contact with.

A blade groove (5) is provided in the vicinity of the position of the suction passage (5a) in the cylinder (5).
b) is formed. The blade groove (5b) extends in the radial direction of the cylinder (5), penetrates both upper and lower end surfaces of the cylinder (5), and its outer peripheral side is closed by an outer peripheral wall (5c). .. The blade (11) is inserted into and retracted from the cylinder (5) in the blade groove (5b). The blade (11)
The tip end is pressed against the outer peripheral surface (6a) of the roller (6) by the urging force of the spring (12) arranged between the back surface (11a) and the outer peripheral wall (5c), and the compression is performed. The chamber (9) is divided into a low pressure chamber (9a) and a high pressure chamber (9b).

Further, a discharge passage (5d) is provided on the high pressure chamber (9b) side from the position where the blade (11) is arranged. One end of the discharge passage (5d) is opened to the inner peripheral surface (5e) of the cylinder (5), and a reed valve that can be opened with an increase in pressure in the high-pressure chamber (9b) at this opening. (13) is provided. On the other hand, this discharge path (5
The other end of d) is the inner space (2) of the casing (2).
It is opened in a). And the casing (2)
A discharge pipe (14) connected to a condenser (not shown) is connected to the upper surface of the compressor, and the high-temperature high-pressure refrigerant gas discharged from the compressor body (4) is discharged from the discharge pipe (14) to the condenser side. It is supposed to be done. With this configuration,
When the compressor is driven, the roller (6) rotates in the cylinder (5) along with the rotation of the crankshaft (3b) driven by the electric motor (3a), and the compression chambers (9a) and (9b) rotate.
Is designed to contract.

Next, the characteristic configuration of this example will be described. The feature of this example is the shape of the inner peripheral surface (5e) of the cylinder (5). The inner peripheral surface (5e) of the cylinder (5) is formed in a non-perfect circle in plan view. Specifically, as shown in FIG. 3, the position (point A) where the roller (6) contacts at a roller rotation angle of 0 °.
Between the position (point B) where the roller (6) comes into contact with the roller rotation angle of 90 °, it is formed in an arc shape with a radius (RR) centered on the rotation axis (3g) of the crankshaft (3b). ing. The value of this radius (RR) is determined in the same manner as in the conventional rolling piston type compressor. On the other hand, from the position (point B) where the roller (6) contacts at the rotor rotation angle of 90 °, the roller (6) at the roller rotation angle of 360 °.
Between the positions (point A) where the two contact with each other, the shape of the cylinder inner peripheral surface (5e) is set by the radius (R) set based on the following equation. R = RR- (ε / 2) [1-sin {(4θ / 3)-(7π / 4)}] (1) (RR: Cylinder inner surface up to roller rotation angle 90 ° (5
Radius to the crankshaft center (3 g) in e), ε:
Maximum decrease amount of the inner radius of the cylinder, θ: Roller rotation angle (90 ° ≦ θ ≦ 360 °)) Since the radius (R) of the inner radius of the cylinder is set by such a formula, from FIG. As can be seen, the rotation axis center (3g) of the crankshaft (3b) and the cylinder inner peripheral surface (5
The distance from the roller e) gradually decreases from the position where the roller rotation angle exceeds 90 ° (the position of point B), and becomes the minimum at the position where the rotation angle of the roller (6) is around 210 ° (the position of point C). become. When the rotation angle of the roller (6) exceeds the position of the point C, this value gradually increases and returns to the original radius (RR) at the position of 360 °. That is, at least a part of the cylinder inner peripheral surface (5e) from the position where the roller outer peripheral surface (6a) contacts at the start of refrigerant gas compression to the position where the roller outer peripheral surface (6a) contacts at the end of refrigerant gas discharge. The radius (R) of the crankshaft (3b) with respect to the rotation axis (3g) is greater than the radius (RR) of the crankshaft (3b) with respect to the rotation axis (3g) of the other cylinder inner peripheral surface (5e). By setting it small, the cylinder inner peripheral surface (5e) is formed in a non-perfect circle.

According to the above equation, the radius is at an intermediate position between the position where the roller outer peripheral surface (6a) is in contact at the start of fluid compression and the position where the roller outer peripheral surface (6a) is in contact at the end of fluid discharge. (R) will be minimized. Therefore, in the connecting portion (near the roller rotation angle of 90 ° and around 360 °) where the radius of the cylinder inner peripheral surface (5e) is set to be small and the region where the radius is not set to be small, the change of the radius per unit dimension in the circumferential direction. The radius dimensions of the both can be made close to each other without greatly changing the ratio, and the continuity of the inner peripheral surfaces (5e) of the both cylinders can be easily ensured. It should be noted that what is indicated by an imaginary line D in FIG. 3 is a perfect circle having a radius (RR).

Since the inner peripheral surface (5e) of the cylinder (5) is formed in such a shape, when the roller rotation angle exceeds 90 ° when the compressor (1) is driven, the cylinder (5) of the cylinder (5) is driven. The inner peripheral surface (5e) slightly protrudes toward the roller side, and the outer peripheral surface (6a) of the roller (6) is relatively pressed against the inner peripheral surface (5e) of the cylinder (5). , A gap (CP gap) formed between the outer peripheral surface (6a) of the roller (6) and the inner peripheral surface (5e) of the cylinder (5).
Becomes smaller as the compression process by the roller (6) progresses. Then, at the roller rotation angle where the roller (6) contacts the point C, this CP gap is minimized.

Next, the operation of the rolling piston compressor (1) will be described. First, when the electric motor (3a) is driven, this driving force is applied to the crankshaft (3a).
It is transmitted to the roller (6) of the compressor body (4) via the cam portion (3f) of b), and the roller (6) rotates in the cylinder (5) so as to contract the compression chamber (9). .. As a result, the refrigerant gas flows from the suction pipe (10) into the low pressure chamber (9a) of the compressor body (4) through the suction passage (5a). Then, as the roller (6) rotates, the refrigerant gas is compressed as the low-pressure chamber (9a) becomes the high-pressure chamber (9b), and when the pressure of the refrigerant gas reaches a predetermined value, the pressure causes the lead to flow. The valve (13) is opened, and the high pressure refrigerant gas is discharged from the discharge passage (5d) into the internal space (2) of the casing (2).
It is discharged to a) and then discharged to the condenser side by a discharge pipe (14). In addition, the lubricating oil (O) pumped to the oil supply passage by the centrifugal pump (3e) as the crankshaft (3b) rotates is supplied to each sliding portion in the compressor (1), Lubricate each part.

The characteristic operation of this example is as follows.
Roller outer peripheral surface (6a) in the operating state as described above
The operation of preventing refrigerant leakage between the cylinder and the inner peripheral surface (5e) of the cylinder. That is, when the roller (6) rotates inside the cylinder (5) and the roller rotation angle exceeds 90 °, as described above, the radius of the cylinder inner peripheral surface (5e) gradually decreases, Cylinder (5) is roller (6)
The outer peripheral surface (6a) of the roller (6) is relatively pressed against the inner peripheral surface (5e) of the cylinder (5), and the outer peripheral surface (6a) of the roller (6) is pushed out. ) And the inner peripheral surface (5e) of the cylinder (5), the gap (CP clearance) becomes smaller as the compression process by the roller (6) progresses, and the outer peripheral surface (6a) of the roller which has been conventionally generated. ) And the cylinder inner peripheral surface (5e) are reduced, and the refrigerant leakage between the high pressure side and the low pressure side between them is reduced. Then, in the vicinity of the roller rotation angle of 210 °, this CP gap becomes the minimum and the high pressure chamber (9
When the inside of b) is in a high pressure state, the leakage amount of the refrigerant gas from the high pressure chamber (9b) to the low pressure chamber (9a) is reduced. After that, when the rotation of the roller (6) further progresses, the radius of the inner peripheral surface of the cylinder (5) gradually increases, and at the roller rotation angle of 360 °, the outer peripheral surface of the roller (6a) and the inner peripheral surface of the cylinder (5e) are separated. During that time, it will be restored to its original condition.

As described above, according to the configuration of this example, the inner peripheral surface (5e) of the cylinder (5) is formed in a non-perfect circle, and the inside of the high pressure chamber (9b) is in a high pressure state. Under the circumstances, the roller outer peripheral surface (6a) and the cylinder inner peripheral surface (5e)
Since the gap between and becomes small and the refrigerant leakage from the high pressure side to the low pressure side between them becomes small, the efficiency of the compressor can be improved.

Although the present embodiment has been described with respect to the compressor provided in the air conditioner, the present invention is not limited to this, but can be applied to various fluid compressors. Also, the inner surface of the cylinder (5
The shape of e) is not limited to that of this example, and for example, the rotation axis center (3g) of the crankshaft (3b) and the cylinder inner peripheral surface (5e).
The distance from the roller (6) may be minimized at a position where the rotation angle of the roller (6) is 270 °. In short, the reed valve (13) is moved from the position where the rotation angle of the roller (6) is 180 °.
The configuration may be such that it is minimized up to the position where is opened. Further, the radius (R) may be changed over the entire area of the cylinder inner peripheral surface (5e) with which the roller outer peripheral surface (6a) is in contact between the time when the fluid is compressed and the time when the fluid is discharged.

[0023]

As described above, according to the present invention, the following effects are exhibited. According to the first aspect of the present invention, the rotational axis (3g) of the drive shaft (3b) in a part of the cylinder inner peripheral surface (5e) with which the roller outer peripheral surface (6a) is in contact between the start of fluid compression and the end of discharge. ) Is set to be smaller than the radius (RR) of the other portion, and when the roller (6) passes through the area where the radius (R) is set small, the roller outer peripheral surface ( Since the gap between 6a) and the cylinder inner peripheral surface (5e) is made small, the outer peripheral surface () of the roller (6) is in a high pressure state in the compression chamber (9). 6
Fluid leakage between a) and the inner peripheral surface (5e) of the cylinder (5) can be reduced, and the compressor efficiency can be improved.

According to the second aspect of the present invention, the intermediate position between the position where the roller outer peripheral surface (6a) is in contact at the start of fluid compression and the position where the roller outer peripheral surface (6a) is in contact at the end of fluid discharge is set forth above. Since the radius (R) is minimized, the rate of change of the radius per unit dimension in the circumferential direction at the connecting portion between the region where the radius of the cylinder inner peripheral surface (5e) is set small and the region where it is not set small. It is possible to bring the two radial dimensions closer to each other without making a large change, it is easy to ensure continuity of both cylinder inner peripheral surfaces (5e), and the rotation of the roller (6) is performed smoothly. An accurate compression operation can be performed.

[Brief description of drawings]

FIG. 1 is a vertical sectional view of a rolling piston compressor.

FIG. 2 is a cross-sectional view at a position corresponding to a line II-II in FIG.

FIG. 3 is a diagram showing a shape of an inner peripheral surface of a cylinder.

FIG. 4 is a view corresponding to FIG. 2 in a conventional rolling piston type compressor.

5 is a cross-sectional view at a position corresponding to line VV in FIG.

[Explanation of symbols]

 (1) Rolling piston type compressor (2) Casing (3) Drive means (3b) Crankshaft (drive shaft) (3f) Cam part (eccentric part) (3g) Rotating shaft center (4) Compressor body (compression means) ) (5) Cylinder (5a) Suction path (5d) Discharge path (5e) Inner peripheral surface (6) Roller (6a) Outer peripheral surface (7) Front head (head part) (8) Rear head (head part) (9) Compression chamber

Claims (2)

[Claims] 1. A drive means (3) in the casing (2).
And a compression means (4) connected to the drive means (3) are housed, and the compression means (4) contains a roller (6) in a cylinder (5) and the cylinder (5).
Head portions (7) and (8) are disposed on both end surfaces of the compression chamber (9) between the inner peripheral surface (5e) of the cylinder (5) and the outer peripheral surface (6a) of the roller (6). ) Is formed, and an eccentric portion (3f) is formed in the roller (6) so as to be eccentric in a predetermined direction from the rotation axis (3g) of the drive shaft (3b) of the drive means (3). By being
The roller (6) is eccentric with respect to the cylinder (5) so that a part of the outer peripheral surface (6a) of the roller (6) is brought into contact with the inner peripheral surface (5e) of the cylinder (5). A fluid suction passage (5a) and a fluid discharge passage (5d) are connected to the compression chamber (9), and the roller (6) is moved to the cylinder (5) by the driving of the driving means (3). Rotate inside,
A rolling piston compressor configured to suck a fluid from the suction passage (5a) into the compression chamber (9), compress the fluid, and then discharge the fluid from the discharge passage (5d). The radius (R) of the drive shaft (3b) with respect to the rotation axis (3g) of at least a part of the cylinder inner peripheral surface (5e) with which the roller outer peripheral surface (6a) is in contact between the time and the end of discharge is the other cylinders. Inner surface (5
The rolling is characterized in that it is set to be smaller than the radius (RR) of the drive shaft (3b) with respect to the rotation axis center (3g) in e), and the cylinder inner peripheral surface (5e) is formed in a non-perfect circle. Piston type compressor. 2. The rolling piston type compressor according to claim 1, from a position where the roller outer peripheral surface (6a) contacts at the time of starting compression of the fluid to a position where the roller outer peripheral surface (6a) contacts at the end of discharge of the fluid. The drive shaft (3b) on at least a part of the cylinder inner peripheral surface (5e)
The radius (R) with respect to the rotation axis (3g) of the formula is R = RR− (ε / 2) [1-sin {(4θ / 3) − (7π
/ 4)}] (ε: maximum reduction amount of cylinder inner peripheral surface radius, θ: roller rotation angle (90 ° ≦ θ ≦ 360 °)).