JPH10141271A - Rotary compressor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce leakage of a fluid on the end surface of a piston as well as to stabilize the behavior of the piston by offsetting load applied to both upper and lower end surfaces of the piston, in a two-cylinder rotary compressor. SOLUTION: Bearings 40, 50 contacting with cylinders 11, 31 are provided on both upper and lower end surfaces of a compression means 4. Stepped parts 41, 51 coaxial with a crank shaft 5 are provided on the center parts of the bearings 40, 50. Thrust bearings 15, 35 eccentric from each other are provided between cams 14, 34 and the stepped parts 41, 51. High-pressure refrigerant is introduced into spaces formed by cylinders 11, 31, the steeped parts 41, 51 and thrust bearings 15, 35, and pressing force having the same magnitude in an opposite direction as that by high-pressure refrigerant in a space near a through hole 21 of a middle plate 20 acts on the pistons 12, 32.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotary compressor, and more particularly, to a high efficiency compressor having a plurality of compressor bodies.

[0002]

2. Description of the Related Art Conventionally, as a rotary compressor used for a refrigerator or the like, for example, as shown in FIG. 8, a two-cylinder type compressor disclosed in Japanese Patent Application Laid-Open No. 4-143483 is used. Are known. In this compressor, two casings (c) and (d) connected to an electric motor (b) are housed in a casing (a). The compressor bodies (c) and (d) are disposed on upper and lower sides of a middle plate (e) fixed to the inner peripheral surface of the casing (a). In the compressor body (c) and (d), the cylinder (f)
A rolling piston (g) is eccentrically provided in the inside, and an upper bearing is provided on the upper end surface of the cylinder (f) of the upper compressor body (c).
(h), a lower bearing (i) is attached to the lower end surface of the cylinder (f) of the lower compressor body (d). As a result, compression chambers (j) and (k) are formed between the inner peripheral surface of the cylinder (f) and the outer peripheral surface of the rolling piston (g).
The cylinder (f) is provided with a blade (not shown) which can be retracted inside the cylinder, and a drive shaft (l) extending from the electric motor (b) is inserted into a shaft hole of the rolling piston (g). A fluid suction passage (m) and a discharge passage (not shown) are connected to each of the compression chambers (j) and (k).

[0003] When the compressor is driven, the fluid flows through a suction passage.
(m) flows into the cylinder (f). Then, the volumes of the compression chambers (j) and (k) change due to the rotation of the rolling piston (g). Due to this volume change, the fluid is compressed. After being compressed, the fluid is discharged from the discharge path to the internal space (n) of the casing (a).

[0004] During the compression operation, the middle plate (e)
In the vicinity of the through hole, a high-pressure fluid discharged into the internal space (n) of the casing (a) is in a high-pressure state. On the other hand, in the upper and lower bearings (h) and (i), an annular high-pressure groove (o) is formed around a through hole through which the drive shaft (l) passes,
This high pressure groove (o) is also in a high pressure state. Therefore, since the high pressure in the high-pressure groove (o) acts as a pressing force, an unbalanced load is not applied to the rolling piston (g).

[0005]

However, in the compressor as described above, the high pressure grooves (o) of the bearings (h) and (i) are
Since it is formed by a circumferential groove having a U-shaped cross section, the pressure receiving area of the upper surface or the lower surface of the piston (g) generated by the through hole of the middle plate (e) and the piston generated by the high pressure groove (o)
The pressure receiving area on one side of (g) does not match. Therefore, the piston (g) is biased toward the bearings (h) and (i), and there is a problem that the leakage of the fluid cannot be sufficiently prevented.

Further, since the strength of the portion between the high pressure groove (o) and the through hole is weak, this portion is easily deformed with the rotation of the rolling piston (g), and as a result, the rolling piston (g) Fluid leakage at the end face sometimes occurred. In particular, since the lower bearing (i) receives the axial load of the drive shaft (l), the above-mentioned problem is remarkable.

SUMMARY OF THE INVENTION The present invention has been made in view of the foregoing, and has as its object to cancel the loads applied to the upper and lower end surfaces of the piston, to stabilize the behavior of the piston and reduce mechanical loss. Another object of the present invention is to reduce fluid leakage at the end face of the piston.

[0008]

In order to achieve the above object, the present invention provides a bearing (40, 50) having a step (41, 51),
The pressure receiving area on the upper surface of the piston (12, 32, 112, 32) was made equal to the pressure receiving area on the lower surface. Further, the thrust force is received at the step (51).

More specifically, the invention according to claim 1 is characterized in that a casing (2) is configured to have a high-pressure atmosphere and a compression means (4, 104) is accommodated in the casing (2). The compression means (4, 104) includes a plurality of compressors in which pistons (12, 32, 112, 132) into which drive shafts (5) are fitted are housed in cylinders (11, 31) eccentrically from the axis of the drive shaft (5). Body (10,
30,110,130), the compressor body (10,30,110,130) is arranged side by side with a middle plate (20) in the axial direction of the drive shaft (5), and a drive shaft is provided at the center of the middle plate (20). (Five)
In a rotary compressor having a through hole (21) through which a side plate (4) is provided at both end surfaces of the compression means (4, 104) to close the end surface of the cylinder (11, 31).
(0,50), a disc-shaped surface into which high-pressure fluid is introduced by notching the edges of the shaft holes (42, 52) supporting the drive shaft (5) on the facing surface of the pistons (12, 32, 112, 132). Step portions (41, 51) are formed, and the outer diameter of the step portions (41, 51) is formed to be the same diameter as the outer diameter of the through hole (21) of the middle plate (20). It is.

According to the above-mentioned invention specifying matter, the bearing (40,5
(0), the high-pressure gas refrigerant is introduced into the space defined by the step (41, 51) and the piston (12, 32, 112, 132).
The high-pressure gas in the space near the through hole (21) of the middle plate (20) acts on the piston (12, 32, 112, 132) with a pressing force opposite to the pressing force acting on the piston (12, 32, 112, 132). Therefore, the one-sided contact state of the piston (12, 32, 112, 132) is eliminated, and the behavior of the piston (12, 32, 112, 132) is stabilized. And the leakage of the fluid at the end face of the piston (12, 32, 112, 132) is reduced.

According to a second aspect of the present invention, in the rotary compressor according to the first aspect, a blade (112a) is integrally formed with a piston (112, 132) of each compressor body (110, 130), The blade (112a) is a cylinder (11, 31)
Are supported via a swinging bush (120) so as to freely and reciprocate in a supporting hole (121) formed in the cylinder, and the piston (112, 132) is rotated in the cylinder (11, 31) by rotation of the drive shaft (5). Is revolved to compress the fluid.

According to the above-mentioned invention specifying matter, the blade (112)
Since a) is integrated with the pistons (112, 132), the blade (112a) is held at an intermediate position between the bearings (40, 50) and the middle plate (20). Therefore, the blade (112a)
Significantly reduces fluid leakage at the end face of the device. In addition, the sliding loss between the blade (112a) and the oscillating bush (120) is reduced, the piston behavior is stabilized, and the piston (112, 132)
Combined with the effect of reducing the fluid leakage loss at the end face, the efficiency of the compressor is improved.

According to a third aspect of the present invention, there is provided a rotary compressor according to the first aspect, wherein
(4,104) is configured vertically, and at least a lower portion of the drive shaft (5) has a thrust bearing (3) in contact with the lower step portion (51).
5) is provided.

According to the above-mentioned invention specific matter, the lower step portion (51) supports the axial load via the thrust bearing (35), so that the lower piston (32, 132) and the lower bearing (50) are connected between the lower piston (32, 132) and the lower bearing (50). No large friction is generated by the thrust force.

[0015]

Embodiment 1 Hereinafter, embodiments of the present invention will be described with reference to the drawings.

The rotary compressor (1) of the first embodiment is a so-called rolling piston type compressor (1). As shown in FIG. 1, the rotary compressor (1) of the first embodiment has a configuration in which a driving unit (3) and a compressor body (4) as a compression unit are housed in a closed casing (2). Have been.

The driving means (3) comprises an electric motor (3a) and a crankshaft (5) as a driving shaft. The electric motor (3a) is disposed above the internal space (2a) of the casing (2), and is fixed to an inner peripheral surface of the casing (2).
(3c) and a rotor (3d) disposed at the center of the stator (3c).
And is constituted by. The crankshaft (5) extends vertically, and its upper end is connected to the center of the rotor (3d), and its lower end extends downward and is connected to the compressor body (4).

The bottom of the casing (2) is an oil reservoir (6), in which lubricating oil (O) is stored. Then, the lower end of the crankshaft (5) and the compressor body (4)
Is immersed in the lubricating oil (6). A centrifugal oil pump (not shown) is provided at the lower end of the crankshaft (5). The oil pump supplies the lubricating oil (O) of the oil reservoir (6) to the crankshaft according to the rotation of the crankshaft (5). The water is sucked into the oil supply passage (7) formed in (5). Lubricating oil that has passed through the oil supply passage (7)
(O) is supplied to a sliding portion of the compressor body (4).

The compressor body (4) is configured such that a first compressor body (10) and a second compressor body (30) are vertically arranged below an electric motor (3a). A middle plate (20) fixed to the inner peripheral surface of the casing (2) is provided between the first compressor body (10) and the second compressor body (30).

As shown in FIGS. 1 and 2, the first compressor body (10) has an annular rolling piston (11) fixed in an annular cylinder (11) fixed to the upper surface of a middle plate (20). 1
2) is housed, and an upper bearing (40) is attached to the upper end surface of the cylinder (11). A first compression chamber (16) is formed between the upper surface of the middle plate (20), the lower surface of the upper bearing (40), the inner peripheral surface of the cylinder (11), and the outer peripheral surface of the rolling piston (12). Have been. A refrigerant suction passage (17) opening to the first compression chamber (16) is formed in the cylinder (11), and a suction pipe (60) extending from an accumulator (not shown) is connected to the refrigerant suction passage (17). I have.

On the other hand, a shaft hole (13) is formed in the center of the rolling piston (12), and a crankshaft is formed in the shaft hole (13).
An eccentric cam (14) integrally formed with (5) is fitted. As a result, the rolling piston (12)
It is eccentric with respect to (11), and a part of the outer peripheral surface of the rolling piston (12) is in contact with the inner peripheral surface of the cylinder (11). Further, as shown in FIG. 2, the refrigerant suction passage in the cylinder (11)
A blade groove (18) extending in the radial direction of the cylinder (11) is formed in the vicinity of the disposition position of (17), and the blade (19) projects into and out of the cylinder (11) in the blade groove (18). It is arranged freely. The tip of the blade (19) is pressed against the outer peripheral surface of the rolling piston (12) by the pressure of the spring and the refrigerant gas or the like, and the first compression chamber (16) is divided into the low pressure chamber (16L) and the high pressure chamber (16H). And is divided into: In addition, blade (19)
A discharge path (19a) is provided on the high-pressure chamber (16H) side near the disposition position. One end of the discharge path (19a) is a cylinder (11).
It is open on the inner peripheral surface of. This opening has a high-pressure chamber (1
A reed valve (19b) is provided which can be opened as the pressure inside 6H) increases. The other end of the discharge path (19a) opens into the internal space (2a) of the casing (2).

The middle plate (20) has a crankshaft (5)
And a through-hole (21) through which the crankshaft (5) is inserted is formed. Note that this through hole (2
1) is formed to have a smaller diameter than the outer diameter of the rolling pistons (12), (32).

On the other hand, the structure of the second compressor body (30) is the same as the structure of the first compressor body (10) described above, and the cylinder (31) fixed to the lower surface of the middle plate (20). The rolling piston (32) is housed inside the cylinder (3
A lower bearing (50) is attached to the lower end surface of 1). Thereby, a second compression chamber (36) is formed between the outer peripheral surface of the rolling piston (32) and the inner peripheral surface of the cylinder (31). The cylinder (31) is provided with a refrigerant suction passage (37) opening to the second compression chamber (36), and the refrigerant suction passage (37) is connected to a suction pipe (61). On the other hand, an eccentric cam (34) integrally formed with the crankshaft (5) is fitted into the shaft hole (33) of the rolling piston (32), whereby the rolling piston (32) is inserted into the cylinder (31). The rolling piston (32) is partly eccentric to the inner peripheral surface of the cylinder (31). The rolling piston (32) and the rolling piston of the first compressor body (10)
(12) is set so that the eccentric direction with respect to the axis of the crankshaft (5) is in the opposite direction position, whereby
The dynamic balance during rotation of each of the rolling pistons (12) and (32) is maintained. Also, this second
A cylinder (31) of the compressor body (30) is also provided with a blade (not shown) that can be retracted and retracted in the cylinder (31),
A discharge path (not shown) is provided to pass through the second compression chamber (36) and the internal space (2a) of the casing (2).

The compressor body (4) is integrally fastened by a plurality of bolts (not shown). That is,
Upper bearing (40), cylinder (11), middle plate (20),
The cylinder (31) and the lower bearing (50) are fixed by a plurality of bolts extending vertically.

A discharge pipe (62) connected to a condenser (not shown) is connected to the upper surface of the casing (2).
The high-temperature and high-pressure refrigerant discharged from (4) is supplied to the discharge pipe (62).
From the condenser.

-Upper bearing (40) and lower bearing (50)-Next, the upper bearing (40) and the lower bearing (50), which are characteristic parts of the present invention, will be described. First, the upper bearing (40) will be described.

As shown in FIG. 3, the upper bearing (40) includes a bearing (43) and a plate (44).

The bearing portion (43) is formed to extend in the vertical direction so as to cover the periphery of the crankshaft (5). That is, the bearing portion (43) is formed with a shaft hole (42) that is slightly larger in diameter than the shaft diameter of the crankshaft (5) and extends in the vertical direction, and the crankshaft (5) is inserted into the shaft hole (42). It is rotatably supported.

On the other hand, the plate portion (44) extends in the radial direction of the cylinder (11) and is formed concentrically with the crankshaft (5). The plate portion (44) is in contact with the cylinder (11) and the rolling piston (12) of the first compressor body (10), and forms one of the partition walls of the first compression chamber (16). And
A disk-shaped step portion (41) having the same diameter as the diameter (D) of the through hole (21) of the middle plate (20) is provided at the center of the plate portion (44). In other words, the step portion (41) is formed in a disk shape in which the edge of the shaft hole (21) is cut in a circular shape. The bottom surface (41a) of the step portion (41) is continuous with the shaft hole (42). That is, one opening of the shaft hole (42) is formed in the center of the bottom surface (41a) of the step portion (41). This step (4
The side surface (41b) of (1) is formed so as to be parallel to the crankshaft (5), and the bottom surface (41a) of the step portion (41) is orthogonal to the crankshaft (5).

A thrust bearing (15) in which the crankshaft (5) is fitted is provided between the cam (14) and the step (41). This thrust bearing (15) is formed in an eccentric annular shape, and the longest distance (OL) from the axis (P) of the crankshaft (5) to the end face is the bottom surface (41a) of the step portion (41). And the shortest distance (OS) is set equal to the shaft diameter of the crankshaft (5). Both upper and lower surfaces of the thrust bearing (15) are formed flat so as to be in close contact with the bottom surface (41a) of the upper bearing (40) and the cam (14), respectively. The thickness of the crank bearing (15), that is, the length in the vertical direction, depends on the upper bearing (4
0) is equal to the distance between the bottom surface (41a) of the step (41) and the upper surface of the cam (14) in a state where the rolling piston (12) is in contact with the rolling piston (12). In other words, the thrust bearing (15)
During operation of (1), rolling piston (12) and upper bearing
(40), and the bottom (41) of the cam (14) and the upper bearing (40).
This is formed so that no gap is generated between the rolling piston (12) and the upper bearing (40), thereby suppressing fluid leakage between the rolling piston (12) and the upper bearing (40).

The lower bearing (50) is basically obtained by inverting the upper bearing (40) in the vertical direction.
Is shorter than the bearing portion (43) of the upper bearing (40), except that it is formed shorter than the upper bearing (40). Therefore,
The bottom surface (51a) of the lower bearing (50) is also formed flat, and supports the axial load of the crankshaft (5) via the thrust bearing (35).

-Operation of Rolling Piston Compressor (1)-Next, the operation of the rolling piston compressor (1) will be described.

First, when the electric motor (3a) is driven, the driving force is applied to each compressor body (10), (30) via the crankshaft (5).
Is transmitted to the rolling pistons (12) and (32), and the rolling pistons (12) and (32) rotate in the cylinders (11) and (31). Thereby, the refrigerant gas flows from each suction pipe (60), (61) through each refrigerant suction passage (17), (37), and the first and second compressor main bodies.
It flows into the low pressure chamber (16L) of (10), (30). Thereafter, as the rolling pistons (12), (32) rotate, the refrigerant gas is compressed as the low-pressure chamber (16L) becomes a high-pressure chamber (16H). When the pressure of the refrigerant gas reaches a predetermined value, the reed valve (19b) is opened by the pressure, and the refrigerant gas in a high pressure state is discharged.
It is discharged from (19a) into the internal space (2a) of the casing (2), and then flows into the condenser through the discharge pipe (62).

In such an operating state, the casing
The internal space (2a) of (2) is filled with a high-pressure refrigerant gas to form a high-pressure atmosphere. At this time, the high-pressure refrigerant gas is supplied to the shaft holes (13), (33) of the rolling pistons (12), (32) and the middle plate.
It is introduced into the through hole (21) of (20). Then, the high-pressure refrigerant gas introduced into the through hole (21) of the middle plate (20)
As shown by an arrow (FD), a part of the lower end surface of the rolling piston (12) of the first compressor body (10) facing the through hole (21) is pressed upward. Therefore, the rolling piston (1
Part of the upper end surface of 2) is pressed by the upper bearing (40).

However, in the rolling piston type compressor (1) of the first embodiment, the high pressure space (45) divided by the step (41) of the upper bearing (40), the thrust bearing (15) and the rolling piston (12). ), High-pressure refrigerant gas is introduced into the rolling piston (12).
The force shown in 1) acts. That is, in the rolling piston (12) of the first compressor body (10), the upper end face located above the lower end face on which the pressure (FD) is acting is located in the high-pressure space (4).
It is pressed downward by the high-pressure refrigerant gas (F1) in 5). In the first embodiment, since the step portion (41) of the upper bearing (40) is formed to have the same diameter as the through hole (21) of the middle plate (20), the rolling piston ( 12) Rolling piston on which the lower end area and pressure (F1) act
The area of the upper end face of (12) is equal. As a result, the pressure (FD) pressing the rolling piston (12) upward is offset by the pressure (F1) pressing downward.

The same applies to the second compressor main body (30) in the same manner as in the step (51) of the lower bearing (50), the thrust bearing.
(35) and high-pressure space partitioned by rolling piston (32)
Since the high-pressure refrigerant gas is introduced into (55), an upward pressing force (F2) acts on the rolling piston (32). As a result, for the same reason as above, the rolling piston (32)
Is the pressure that presses upwards (FE).
Offset by (F2).

The rolling piston type compressor
In (1), the thrust force of the crankshaft (5) is mainly transmitted through the thrust bearing (35) to the bottom surface of the step portion (51) of the lower bearing (50).
It depends on (51a).

-Effects of Rolling Piston Type Compressor (1)-As described above, the pressing forces acting on the end faces of the rolling pistons (12) and (32) are offset, so that each rolling piston (12) , (32) is not affected by an unbalanced load, and the dynamic balance is not disturbed by one-side contact. Therefore, the behavior of each rolling piston (12), (32) is stabilized.

Further, the frictional force between each end face and the middle plate (20) or each of the bearings (40) and (50) is reduced. As a result, mechanical losses are reduced and compressor efficiency is improved.

Furthermore, volumetric efficiency is increased because fluid leakage between each end face and the middle plate (20) or each bearing (40), (50) is significantly reduced. Therefore, the efficiency of the compressor is improved.

Further, the thrust force of the crankshaft (5) mainly acts on the bottom surface (51a) of the step portion (51) of the lower bearing (50), so that the rolling piston (32) of the second compressor body (30). ) And the lower bearing (50) do not generate large friction due to thrust force. Therefore, a decrease in mechanical efficiency due to the thrust force can be suppressed, and the compressor efficiency can be further improved.

Also, since the bearings (40) and (50) are hardly deformed, the rolling pistons are deformed by the deformation of the bearings (40) and (50).
Fluid leakage at the end faces of (12) and (32) hardly occurs.

-Modification- The rolling piston compressor (1) is a so-called vertical compressor in which a first compressor body (10) and a second compressor body (30) are arranged vertically. However, the compressor according to the first embodiment is not limited to a vertical compressor, and may be a so-called horizontal compressor as shown in FIG. In other words, the drive means (3) and the compression means are provided in the casing (2) whose longitudinal direction is the transverse direction.
(4) and the first compressor body (10) and the second
The compressor body (30) may be disposed on the left and right.

[0044]

Second Embodiment A rotary compressor according to a second embodiment.
(101) is a rolling piston type compressor (1) of Embodiment 1.
The compression means (4) is a compression means (104) that compresses a fluid by revolving the piston (112) in the cylinder (11), in which the blade (112a) and the piston (112) are integrally formed. It has been replaced. That is, the rotary compressor (2) of the second embodiment is a so-called swing compressor (101).

Therefore, in the following description, the same elements as those of the rolling piston type compressor (1) of the first embodiment are denoted by the same reference numerals as those of the first embodiment, and the description thereof will be omitted.

-Structure of Swing Compressor (101)-As shown in FIG.
4) includes a first compressor body (110) located above the middle plate (20) and a second compressor body (130) located below.

As shown in FIG. 6, the first compressor body (110)
Has a substantially annular piston (112) housed in a cylinder (11) having an annular cross section.

In the cylinder (11), a refrigerant suction passage (17) connected to the suction pipe (60) is formed, and an oscillating bush (120) is fitted near the refrigerant suction passage (17). A bush hole (121) as a circular support hole is provided. The bush hole (121) has an opening (107) that opens toward the cylinder chamber (106). A discharge port (not shown) is formed on the inner peripheral wall of the cylinder (11) so as to communicate with the high-pressure chamber (116H). The discharge port is provided with a discharge valve (not shown) similar to that of the first embodiment.

A cam (14) is rotatably fitted inside the piston (112), and the axis of the cam (14) is a crankshaft.
It is offset by a predetermined amount from the center point of (5).

The piston (112) is integrally formed with a blade (112a) that protrudes from the outer peripheral surface in the radial direction and extends. The blade (112a) is formed integrally with the piston (112), or is formed as a separate member from the piston (112), and is connected to the piston (112) by a fitting structure of unevenness, or an adhesive or the like. Are connected.

In the bush hole (121), a pair of swinging bushes (120) having a substantially semicircular cross section are arranged so as to be swingable. The tip of the blade (112a) is
20) is inserted between. In other words, this double swing bush
The (120) is arranged so as to sandwich the tip side of the blade (112a), allows the blade (112a) to move in and out of the bush hole (121), and is integrated with the blade (112a). It is provided so as to swing in the bush hole (121).

With such a configuration, the blade (112)
a) is a cylinder chamber (106) between the inner peripheral surface of the cylinder (11) and the outer peripheral surface of the piston (112), a low-pressure chamber (116L) communicating with the refrigerant suction passage (17), and a discharge port (FIG. High-pressure chamber (1 not shown)
16H).

The structure of the second compressor body (130) is also the same as that of the first compressor.
The description is omitted because it is the same as the compressor body (110).

-Operation of Swing Compressor (101)-When the electric motor (3a) is driven in the same manner as in the first embodiment, the driving force is applied to each compressor body via the crankshaft (5).
The power is transmitted to the pistons (112) and (132) of the (110) and (130), and the pistons (112) and (132) revolve in the cylinders (11) and (31) without substantially rotating. And each refrigerant suction path (17), (37)
Refrigerant gas sucked from the compressor is compressed. When the pressure of the compressed refrigerant gas reaches a predetermined value, the refrigerant gas is discharged from a discharge port (not shown) to the internal space (2a) of the casing (2), and then discharged through the discharge pipe (62). (Not shown)
Flows into.

Even in the above-described operating state of the swing compressor (101) according to the second embodiment, the internal space (2a) of the casing (2) is filled with the high-pressure refrigerant gas to have a high-pressure atmosphere. The high-pressure refrigerant gas is supplied to the shaft holes (13), (3) of the pistons (112), (132).
3) and into the through hole (21) of the middle plate (20).
Then, the high-pressure refrigerant gas introduced into the through hole (21) of the middle plate (20), as shown by an arrow (FD) in FIG.
A part of the lower end surface of the piston (112) of the first compressor body (10) facing (21) is pressed upward, and a part of the upper end surface of the piston (112) is pressed against the upper bearing (40).

However, the swing compressor (10
Also in (1), the high pressure space (4) defined by the step (41) of the upper bearing (40), the thrust bearing (15) and the piston (112).
Since high-pressure refrigerant gas is introduced into 5), the piston (11
A force indicated by an arrow (F1) acts on a part of the upper end surface of 2). As a result, the pressure (FD) pressing the piston (112) upward is offset by the pressure (F1) pressing downward. The same applies to the second compressor body (30).

-Effects of Swing Compressor (101)-Accordingly, the same effect as the rolling piston type compressor (1) of the first embodiment is exerted also in the swing compressor (101) of the second embodiment. Further, the following effects can be obtained.

That is, the pistons (112) and (132) can be held at the upper and lower intermediate positions between the middle plate (20) and the bearings (40) and (50). Can also be held at the intermediate position, so that the end face leakage of the fluid can be sufficiently suppressed.

Specifically, the leakage of the fluid is caused by the gap area A of 3
It is known to be proportional to the power. Therefore, for example, as shown in FIG.
When the blade (39) is held at an intermediate position between the lower bearing (50) and the lower bearing (50) as shown in FIG. For reasons
Fluid leakage is reduced.

In FIG. 7A, the middle plate (20)
If the height of the gap between the blade and the blade (112a) is t, and the length in the radial direction is s, the gap area is s × t (= A). Also,
The clearance area between the bearing (50) and the blade (112a) is also s × t (=
A). As a result, since both the upper fluid leak and the lower fluid leak are proportional to A ³ , the total leak is 2 ×
A ³ is proportional to 2A ³ .

On the other hand, in the case of a rolling piston type compressor, the piston (32) is different from the blade (39). Even if it is held, the blade (39) is not always held at the intermediate position, but is left to the operating state. Thus, for example, the blade (39) may be located below. In this case, as shown in FIG. 7B, the height of the gap between the middle plate (20) and the blade (39) is 2t.
And a large gap is formed above the blade (39). The area of this gap is s × 2t (= 2A). As a result,
Fluid leakage is proportional to (2A) ³ = 8A ³ , which is four times the value of the swing compressor in FIG. 7A.

In order to facilitate understanding of the above description, the gaps are exaggerated in FIG.

From the above, in the case of the swing compressor,
By holding the pistons (112) and (132) at the intermediate position by the steps (41) and (51), the blade (112a) can also be held at the intermediate position. As a result, fluid leakage can be significantly reduced.

Further, in the conventional swing compressor, since the piston and the blade are integrated, there is an adverse effect that the disturbance of the dynamic balance due to one-sided contact of the piston is amplified and transmitted to the blade. Machine (1
In 01), there is no such adverse effect. Therefore, the behavior of the piston (112) is stabilized, so that the sliding loss between the blade (112a) and the swing bush (120) is reduced, and the mechanical efficiency is improved. As a result, the compressor efficiency is improved in combination with the effect described in the first embodiment.

Further, since the prying of the blade (112a) is suppressed, the durability of the blade (112a) is improved.

-Modification- The swing compressor (101) of the second embodiment is the same as that of the first embodiment.
Similarly to the above, the compressor is not limited to a vertical compressor, and may be a horizontal compressor.

[0067]

As described above, according to the present invention, the following effects are exhibited.

According to the first aspect of the present invention, since the high-pressure fluid is introduced into the space defined by the step portion of the bearing and the piston, the high-pressure fluid in the space near the through hole of the middle plate acts on the piston. The pressing force opposite to the pressing force acts on the piston. In addition, the area of the end face of the piston on which the high pressure acts is the same on both upper and lower end faces, so that the pressing forces acting on the piston are balanced. Therefore, an unbalanced load does not act on the piston, and the one-sided contact state of the piston is eliminated. Therefore, the behavior of the piston is stabilized, and the friction at the end face of the piston is reduced. Further, leakage of fluid at the end face of the piston is reduced. As a result, the efficiency of the compressor is improved.

According to the second aspect of the present invention, since the blade is held at an intermediate position between the bearing and the middle plate, fluid leakage at the end face of the blade is significantly reduced. Further, since the behavior of the piston is stabilized, the sliding loss between the blade and the swing bush is reduced. Further, since the blade is prevented from prying, the durability of the blade is improved. Therefore, the efficiency of the compressor is improved in combination with the improvement of the mechanical efficiency by stabilizing the piston behavior and the improvement of the volume efficiency by reducing the leakage of the fluid at the piston end face.

According to the third aspect of the present invention, since the step portion of the lower bearing supports the axial load via the thrust bearing, a large friction is generated between the lower piston and the lower bearing due to the thrust force. do not do. As a result, the compressor efficiency is improved.

[Brief description of the drawings]

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

FIG. 2 is a cross-sectional view of a first compression means of the rolling piston compressor.

FIG. 3 is a partial longitudinal sectional view of a compression unit.

FIG. 4 is a longitudinal sectional view of a horizontally arranged rolling piston type compressor.

FIG. 5 is a longitudinal sectional view of a compression means of the swing compressor.

FIG. 6 is a cross-sectional view of a first compressor body of the swing compressor.

FIGS. 7A and 7B are diagrams illustrating fluid leakage, in which FIG. 7A shows a case of a swing compressor, and FIG. 7B shows a case of a rolling piston type compressor.

FIG. 8 is a longitudinal sectional view of a conventional rotary compressor.

[Explanation of symbols]

 (2) Casing (3) Driving means (4) Compression means (5) Crankshaft (7) Oil supply path (10) First compressor body (11) Cylinder (12) Rolling piston (13) Shaft hole (14) Cam (15) Thrust bearing (16) First compression chamber (16H) High pressure chamber (16L) Low pressure chamber (20) Middle plate (30) Second compressor body (40) Upper bearing (41) Step (45) High pressure space

Claims (3)

[Claims] A casing (2) is configured to have a high-pressure atmosphere, and a compression means (4,104) is accommodated in the casing (2). The compression means (4,104) has a drive shaft (5) fitted therein. Piston (1
2, 32, 112, 132) are housed in the cylinder (11, 31) eccentrically from the axis of the drive shaft (5).
10, 130), the compressor body (10, 30, 110, 130) is a drive shaft
A rotary member which is provided side by side with a middle plate (20) in the axial direction of (5), and has a through-hole (21) through which the drive shaft (5) penetrates in the center of the middle plate (20). In the compressor, cylinders (1) are provided on both end faces of the compression means (4, 104).
The side plates (40, 50) for closing the end faces of the (1, 31) are provided around the edges of the shaft holes (42, 52) supporting the drive shaft (5) on the surfaces facing the pistons (12, 32, 112, 132). A disc-shaped step portion (41, 51) into which the high-pressure fluid is introduced is formed in a notch shape, and the outer diameter of the step portion (41, 51) is formed in the through hole of the middle plate (20).
A rotary compressor formed to have the same diameter as the outer diameter of (21). 2. The rotary compressor according to claim 1, wherein a blade (112a) is integrally formed on a piston (112, 132) of each compressor body (110, 130), and the blade (112a) is The swinging bush (12) is swingably and reciprocally movable in a support hole (121) formed in the
0), and the pistons (112, 132) are rotated by the rotation of the drive shaft (5).
A rotary compressor characterized by revolving inside 1,31) to compress a fluid. 3. The rotary compressor according to claim 1, wherein the compression means (4, 104) is configured vertically, and at least a lower portion of the drive shaft (5) has a thrust contact with a lower step portion (51). A rotary compressor provided with a bearing (35).