JPH0988852A - Swing compressor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To realize the high efficiency of a swing compressor by reforming a structure of a fitting part of a piston, and eliminating an offset of upper and lower clearances when the piston is revolved to minimize the sum of the internal leakage of the fluid. SOLUTION: A piston 9 is revolved in a cylinder chamber by the lubricating oil to be fed in the cylinder chamber 6a as a drive shaft is rotated. The cylinder chamber 6a is formed in an enclosed space keeping upper and lower clearances 41, 42 to enable revolution of the piston 9 on each side of the cylinder 6 in the axial direction. A bearing means 43 to approximately equalize the upper and lower clearances 41, 42 by the dynamic pressure effect of the lubricating oil in revolving the piston is provided on the piston 9. The bearing means 43 consists of upper and lower tapered surface 44, 45 formed on the inner circumference side of upper and lower end faces of the piston 9. Each tapered surface is of unbalanced shape in which the area is different in the vertical direction so that the dynamic pressure effect of the lubricating oil is applied more to the upper tapered surface than to the lower tapered surface 45.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a swing compressor used in a refrigeration system or the like, and more particularly to a structure of a piston fitting portion fitted to an eccentric shaft portion of a drive shaft.

[0002]

2. Description of the Related Art Generally, this swing compressor is disclosed in, for example, Japanese Unexamined Patent Publication No. 6-58276.
A motor and a compression element driven by the motor are housed in a closed casing. The compression element is arranged in the cylinder chamber and a cylinder having a cylinder chamber in which an intake port and a discharge port are opened, and an inner peripheral portion is rotatably fitted to an eccentric shaft portion of a drive shaft driven by the motor. A piston, a blade radially outwardly coupled to the outer periphery of the piston, and a blade for partitioning the cylinder chamber into a low-pressure chamber communicating with the suction port and a high-pressure chamber communicating with the discharge port; It is provided between the suction port and the discharge port,
The drive is provided with a hole having an opening that opens into the cylinder chamber, and a swing bush that is swingably provided in the hole and that supports the protruding tip side of the blade swingably and reciprocally. As the shaft rotates, the piston revolves along the inner peripheral wall of the cylinder chamber so that it oscillates around the oscillating bush via the blade as a fulcrum, and due to this revolution, the fluid such as refrigerant gas sucked from the suction port into the low pressure chamber. Is compressed to a high pressure, and the high-pressure fluid is discharged from the high pressure chamber through the discharge port. And, the cylinder chamber is
The front head and the rear head, which are arranged on both sides in the axial direction of the drive shaft, form a closed space in the closed space, and the lubricating oil supplied to the cylinder chamber through the oil supply passage causes the cylinder inner peripheral wall, the front head and the inner wall of the rear head to be in contact with each other. The sliding resistance is reduced so that the piston can revolve smoothly.

[0003]

In the swing compressor, in a normal arrangement, the front head and the rear head form the upper and lower inner walls of the cylinder chamber, and the upper and lower inner walls of the cylinder chamber and the upper and lower end surfaces of the piston are the same. In between, upper and lower clearances necessary for smoothly revolving the piston are provided, for example, about 20 μm in total in the vertical direction. However, it is unavoidable that high-pressure fluid leaks from such a clearance to the low-pressure chamber side from the high-pressure chamber in the cylinder chamber, and the internal leakage amount in the cylinder chamber includes the upper and lower clearances, respectively. Leakage of the sum of the cubes is expected. In that case, the actual clearance between the upper and lower end surfaces of the piston with respect to the upper and lower inner walls of the cylinder chamber is small due to the weight of the piston, and the lower clearance is minute, while the upper clearance is unilaterally greatly increased. It will be biased. Therefore, when the sum of the upper and lower clearances, which are vertically combined, is H, the upper clearance is almost H, and internal leakage of the high-pressure fluid is performed only through the upper clearance. There is a problem that the internal leakage amount of the high-pressure fluid is converted into the cube of H by only one-sided leakage from this upper clearance, which naturally increases and the efficiency of the swing compressor deteriorates.

The present invention has been made in view of the above points, and an object thereof is to improve the structure of the fitting portion of the piston fitted to the eccentric shaft portion of the drive shaft so that the piston can be revolved during its revolution. By revolving the upper and lower clearances so that there is no offset, the total amount of internal leakage of the high-pressure fluid is minimized to improve the efficiency of the swing compressor.

[0005]

[Means for Solving the Problems] In order to achieve the above-mentioned object, a solution means of the invention according to claim 1 is a suction port (2
1) and a cylinder (6) having a cylinder chamber (6a) with the discharge port (22) opening, and an eccentric shaft portion (5) of the drive shaft (5), which is disposed inside the cylinder chamber (6a). 5a) is rotatably fitted to a piston (9) and a low pressure chamber (34) that is connected to the outer periphery of the piston (9) in a protruding manner and communicates the cylinder chamber (6a) with the suction port (21). ) And the high pressure chamber (35) communicating with the discharge port (22), and between the suction port (21) and the discharge port (22) of the cylinder (6) and the cylinder (31). A hole (24) having an opening (24a) opening to the chamber (6a) and a swingable member provided in the hole (24), and the protruding tip side of the blade (31) is swingable and reciprocates. An oscillating bush (32) that freely supports and an oil supply passage (10) for supplying lubricating oil into the cylinder chamber (6a) are provided, and the piston (9) is moved by the rotation of the drive shaft (5). A swing compressor (1 configured to revolve in the cylinder chamber (6a) ) Is assumed. Then, on the piston (9),
When the piston (9) revolves, the dynamic pressure of the lubricating oil causes the upper clearance (41) between the upper end surface of the piston (9) and the lower end surface of the piston (9) in the cylinder chamber (6a). Bearing means (4
3), (52), (61), (72), and (82) are provided.

As a result, the lubricating oil that has entered the lower clearance (42) by the dynamic pressure action of the lubricating oil when the piston (9) revolves causes a wedge effect so as to lift the piston (9) against its own weight. When the upper and lower clearances (41) and (42) are made substantially uniform and the upper and lower clearances (41) and (42) are vertically arranged to be H (for example, about 20 μm). In the cylinder chamber (6a) that leaks from the high pressure chamber (35) to the low pressure chamber (34) through the clearances (41) and (42), the internal leakage amount is ), (42) are almost equal, the sum of cubed half of H, that is, (H / 2) ³ × 2
= (H / 4) ³ and the total amount of leakage is one fourth (25
%) And the efficiency of the swing compressor (1) is increased.

[0007] The solution taken by the invention of claim 2 is as follows.
The bearing means (43) of the invention according to claim 1 is specified, and the piston
When the piston (9) revolves, it is formed on the inner peripheral side of both upper and lower end surfaces of the piston (9) so that the inner peripheral side of the upper end surface and the lower end surface of the piston (9) are respectively subjected to the dynamic pressure action of the lubricating oil. It is composed of tapered surfaces (44) and (45). Then, the respective tapered surfaces (44) and (45) are connected to the tapered surface (45) on the inner peripheral side of the lower end surface of the piston (9) (the tapered surface on the inner peripheral side of the upper end surface of the piston (9) ( It is configured to have an unbalanced shape above and below each other so that the dynamic pressure effect of the lubricating oil has a greater effect than in 44).

As a result, when the piston (9) revolves, a large dynamic pressure action of the lubricating oil that has entered the taper surface (45) (the lower clearance (42) side) on the inner peripheral side of the lower end surface of the piston (9). Causes the piston (9) to levitate against its own weight, while
A small dynamic pressure effect of the lubricating oil that has entered the taper surface (44) (upper clearance (41) side) on the inner peripheral side of the upper end surface of the piston (9) suppresses excessive surfacing of the piston (9), and the upper and lower sides of the piston (9) are suppressed. The side clearances (41) and (42) can be equalized more accurately.

The solving means taken by the invention of claim 3 is
The bearing means (52) of the invention according to claim 1 is specified, and the piston
When the piston (9) revolves, the piston (9) is subjected to dynamic pressure of the lubricating oil only on the inner peripheral side of the lower end surface of the piston (9).
The taper surface (51) is formed on the inner peripheral side of the lower end surface of (9).

Thus, when constructing the bearing means (52), it is only necessary to form the tapered surface (51) on the inner peripheral side of the lower end surface of the piston (9) from one direction, and the processing operation is simple. To be done.

A solution taken by the invention according to claim 4 is as follows.
The bearing means (61) of the invention according to claim 1 is specified, and the piston
A plurality of grooves (62) formed on the upper and lower end surfaces of the piston (9) so that the upper end surface and the lower end surface of the piston (9) are subjected to the dynamic pressure action of the lubricating oil, respectively, when the piston (9) revolves.
Consists of (63). The grooves (62) and (63) on the upper and lower end surfaces of the piston (9) are opened at the inner end of the piston (9) and extend radially to the middle position of the outer circumference. , The upper and lower sides of the piston (9) so that the dynamic pressure effect of the lubricating oil affects the grooves (63) on the lower end surface of the piston (9) more than the grooves (62) on the upper end surface of the piston (9). Both ends are unbalanced from each other.

As a result, when the piston (9) revolves, the lubricating oil that has entered the grooves (62), (63) (lower clearance (42) side) on the inner peripheral side of the lower end surface of the piston (9) While the piston (9) floats against its own weight due to the large dynamic pressure,
The small dynamic pressure action of the lubricating oil that has entered the grooves (62) (upper clearance (41) side) on the inner peripheral side of the upper end surface of the piston (9) suppresses excessive surfacing of the piston (9), and allows The side clearances (41) and (42) can be equalized more accurately. Moreover, the grooves (62), (6
With 3), it is possible to unbalance the piston (9) by changing the quantity on the upper and lower ends of the piston (9).
The machining work of the grooves (62) and (63) on the upper and lower end surfaces of (9) is simplified with the reduction of the number.

The means for solving the problems according to the invention of claim 5 is as follows.
The bearing means (72), (82) of the invention according to claim 1 is specified, and when the piston (9) revolves, the dynamic pressure action of the lubricating oil is exerted only on the lower end surface of the piston (9).
It is composed of a plurality of grooves (71), (81) formed in the lower end surface of (9). The grooves (71) and (81) are arranged such that their inner ends open at the inner peripheral portion of the piston (9) and extend radially to a midpoint of the outer peripheral portion.

As a result, when the bearing means (72), (82) are constructed, a plurality of grooves (71), (8) are formed in the lower end surface of the piston (9).
1) Only one process is required to form, and the work is simple.

Furthermore, the solution means taken by the invention of claim 6 is, in addition to the constituent features of the invention of claim 4 or claim 5, each groove (62), (63), (71), (). The depth of the bottom surface of 81) is formed so that it becomes shallower as it approaches the midway position of the outer circumference of the piston (9).

As a result, when the piston (9) revolves, each groove
The lubricating oil that has entered (62), (63), (71), (81) is the piston.
(9) The piston is pushed smoothly into the clearances (41), (42) on the outer peripheral side without any difficulty, and the dynamic pressure of the lubricating oil acts.
The effect of (9) on both upper and lower end surfaces appears promptly and without waste.

[0017]

Embodiments of the present invention will be described below with reference to the drawings.

FIG. 4 shows the entire structure of the swing compressor according to the first embodiment of the present invention.
In (1), the motor (3) is installed in the upper inner part of the closed casing (2), and the compression element (4) is installed in the lower side of the motor (3). ) Drive shaft (5)
The compression element (4) is driven to rotate. The compression element (4) is arranged in contact with a cylinder (6) having a cylinder chamber (6a) inside and upper and lower open portions of the cylinder (6), and the front opening for closing the upper and lower open portions is closed. The head (7) and rear head (8) and the cylinder chamber (6
and a lower portion of the drive shaft (5) is supported by bearings provided on the heads (7) and (8).

Further, as shown in FIG. 3, the cylinder chamber
The inner peripheral wall of (6a) is formed to have a substantially circular cross section, the piston (9) is formed in an annular shape, and the eccentric shaft portion (5a) is rotatably fitted to the inner peripheral side thereof. ing. Above eccentric shaft
The shaft center of (5a) is offset from the center point of the drive shaft (5) by a predetermined amount, and when the drive shaft (5) rotates, the piston (9) does not rotate but at one place on the outer peripheral surface of the cylinder chamber. (6a)
It revolves along the outer peripheral wall while coming into contact with or close to the outer peripheral wall. Further, on the center side of the drive shaft (5), an oil supply passage (10) opening to the bottom oil sump (2a) of the casing (2) is provided. This oil supply channel (10)
A pump element (11) is provided on the inlet side,
The intermediate outlet is opened in the sliding contact surface between the eccentric shaft part (5a) and the piston (9), that is, in the cylinder chamber (6a), and the lubrication pumped from the bottom oil sump (2a) by the pump element (11). Oil is supplied into the cylinder chamber (6a) from the intermediate outlet via the oil supply passage (10).

Further, the cylinder (6) is provided with a suction port (21) and a discharge port (22) which open respectively on the outer peripheral wall of the cylinder chamber (6a), and the suction port (21) has a closed casing ( 2)
While the suction pipe (2b) is connected from the outside of the
Cylinder chamber (6a) in 2) (High pressure chamber (35) which will be described later in detail)
A discharge valve (23) is provided that opens when the internal pressure exceeds a predetermined value. A cylinder-shaped bush hole (24) (hole) penetrating in the axial direction is formed in the cylinder (6) at a position between the suction port (21) and the discharge port (22). )
Has an opening (24a) that opens to face the cylinder chamber (6a) in a part of the circumference.

The piston (9) is integrally provided with a blade (31) extending radially from the outer peripheral surface of the piston (9). The blade (31) is integrally formed with the piston (9), or is made of a separate member and is formed by connecting the two with a concavo-convex fitting structure or an adhesive or the like. The protruding tip side of the blade (31) is inserted into the bush hole (24), while in the bush hole (24), a pair of rocking bushes (32) having a substantially semicircular cross section, ( 32) is arranged, and a receiving groove (33) for receiving the protruding tip side of the blade (31) so as to be able to move forward and backward is formed between the flat opposing surfaces of the both swing bushes (32), (32). Has been done. Both swing bushes (3
2) and (32) allow the projecting tip side of the blade (31) to move forward and backward while the blade (31) is sandwiched in the receiving groove (33) and to be integrated with the blade (31). Bush hole
It is provided so as to swing within (24). The blade (31) is formed on the inner peripheral surface of the cylinder (6) and the piston (9).
The cylinder chamber (6a) between the outer peripheral surface of the piston is divided into a low pressure chamber (34) communicating with the suction port (21) and a high pressure chamber (35) communicating with the discharge port (22). 9) so that it swings with the swing bush (32) as a fulcrum via the blade (31).
It revolves along the outer peripheral wall of (6a), and the intake port (21)
A fluid such as a refrigerant gas sucked from is compressed and discharged from the discharge port (22). In addition, (2c) in FIG.
It is an external discharge pipe connected to the upper part of the closed casing (2).

Further, the cylinder chamber (6a) is a piston
There are upper and lower clearances (41) and (42) that enable the piston (9) to revolve between the upper and lower end surfaces of (9) and the inner walls of the heads (7) and (8). It is formed in a closed space.
In this case, the upper and lower clearances (41), (42) are
For example, both clearances (41) and (42) are set to about 20 μm, but due to the weight of the piston (9), the lower clearance (42) is about 2 μm, while the upper clearance (42) is about 2 μm. 41) is about 18 μm, which is offset.

As a characteristic part of the present invention, as shown in FIGS. 1 and 2, the piston (9) fitted to the eccentric shaft portion (5a) has a piston on the inner peripheral portion as a fitting portion.
A bearing means (43) is provided which makes the upper clearance (41) and the lower clearance (42) substantially equal by the dynamic pressure action of the lubricating oil during the revolution of (9). The bearing means (43) is
When the piston (9) revolves, chamfering is performed on the inner peripheral side of both upper and lower end surfaces of the piston (9) so that the inner peripheral side of the upper end surface and the lower peripheral surface of the piston (9) are respectively subjected to the dynamic pressure action of lubricating oil. Formed upper and lower taper surfaces (44), (45), and each of the taper surfaces (44), (45) has a lower taper surface (45) than the upper taper surface (44). In order that the dynamic pressure effect of the lubricating oil has a great influence, the upper and lower surfaces are formed into unbalanced tapered surface shapes. That is, the lower taper surface
In order to make it easier to receive the dynamic pressure action of the lubricating oil, (45) has the outer taper angle of the upper taper surface (44) kept the same and the outer end of the upper taper surface (44) is located at the outer circumference of the piston (9) rather than the upper taper surface (44). A large area is secured by approaching the department side.

Therefore, in the first embodiment described above,
The lubricating oil that has entered the lower clearance (42) through the lower tapered surface (45) due to the dynamic pressure of the lubricating oil when the piston (9) revolves causes the piston (9) to float against its own weight. Playing a wedge effect, the upper and lower clearances (41), (42) are almost even when the piston (9) revolves, and the upper and lower clearances (41), (42) are vertically aligned to make H When it is provided (about 20 μm), the internal leakage amount in the cylinder chamber (6a) that leaks from the high pressure chamber (35) to the low pressure chamber (34) side through the clearances (41) and (42) is ,
Since the upper and lower clearances (41), (42) are almost equal, half of H is the cube of (3)
^{2) 3 × 2 = (1/4} ) H 3 , and the total sum of the amount of leakage,
It is possible to improve the efficiency of the swing compressor (1) by suppressing leakage to the third power of H, which is a one-way leakage amount, to a quarter (25%). Moreover, the lower taper surface (4
5) has a larger area than the upper tapered surface (44) so that the dynamic pressure effect of the lubricating oil has a greater effect, so the piston
When revolving (9), lower taper surface (45) (lower clearance (4
(2) side) Lubricating oil that has entered the upper tapered surface (44) (upper clearance (41) side) due to excessive surfacing of the piston (9) that floats against its own weight due to the large dynamic pressure action of the lubricating oil It can be suppressed by a small dynamic pressure effect of the above, and the upper and lower clearances (41), (42) can be equalized more accurately.

In the first embodiment, the bearing means
Although (43) is composed of tapered surfaces (44) and (45) formed on the inner peripheral side of the upper and lower end surfaces of the piston (9), respectively, as shown in Fig. 5, when the piston (9) revolves, The bearing means (52) is formed by the tapered surface (51) formed on the inner peripheral side of the lower end surface of the piston (9) so that the dynamic pressure of the lubricating oil is exerted only on the inner peripheral side of the lower end surface of (9). In this case, in forming the bearing means (52), the taper surface (51) is only formed from one direction on the inner peripheral side of the lower end surface of the piston (9). Only the processing work is required, and the processing work can be simplified.

Next, a second embodiment of the present invention will be described with reference to FIGS. 6 and 7.

In the second embodiment, the bearing means is changed.

That is, in this embodiment, as shown in FIGS. 6 and 7, the bearing means (61) has a lubricating oil on the upper end surface and the lower end surface of the piston (9) when the piston (9) revolves. So that it receives the dynamic pressure of
A plurality of rectangular upper grooves (62) formed on the upper end surface of (9),
... and a plurality of rectangular lower grooves (63) formed on the lower end surface,
It consists of and.

[0029] Each groove (6
Each of 2) and (63) has an inner end opened to the inner peripheral portion of the piston (9) and extends radially to a midway position on the outer peripheral portion. The lower grooves (63) are formed in unbalanced shapes on the upper and lower end surfaces of the piston (9) so that the dynamic pressure effect of the lubricating oil has a greater effect than the upper grooves (62). In other words, each lower groove (63) has a larger radial length and bottom surface depth than each upper groove (62) in order to make it easier to receive the dynamic pressure action of the lubricating oil, and the volume into which the lubricating oil enters. Is increasing. Further, the depth of the bottom surface of each groove (62), (63) is formed in a tapered surface (64), which becomes shallower as it approaches an intermediate position on the outer peripheral portion of the piston (9).

Therefore, in the second embodiment,
The lubricating oil entering the lower clearance (42) through each lower groove (63) due to the dynamic pressure of the lubricating oil when the piston (9) revolves does not allow the lubricating oil to float up against the piston (9) against its own weight. It acts as a rust effect, and makes the upper and lower clearances (41), (42) almost even when the piston (9) revolves.
The internal leak amount in the cylinder chamber (6a) that leaks from the high pressure chamber (35) to the low pressure chamber (34) side via the upper and lower clearances (41) and (42) becomes a unilateral leak amount. Similarly, the swing compressor (1) is suppressed to 25% of that of the cube of H.
It is possible to achieve high efficiency. Moreover, each lower groove (63)
In order to increase the dynamic pressure action of the lubricating oil more than each upper groove (62), the length in the radial direction and the bottom surface depth are increased to increase the volume of the lubricating oil entering. When the piston (9) revolves, the large dynamic pressure of the lubricating oil that has entered the lower grooves (63) floats against the weight of the piston (9). It is suppressed by a small dynamic pressure effect of the upper side and lower side clearances (41) and (42) can be equalized more accurately.
Further, since the depth of the bottom surface of each of the upper groove (62) and each of the lower groove (63) is formed on the tapered surface (64) which becomes shallower as it approaches the middle position of the outer peripheral portion of the piston (9), the piston
The lubricating oil that has entered the grooves (62) and (63) during the revolution of (9) is smoothly and reasonably pushed into the clearances (41) and (42) on the outer peripheral side of the piston (9), and The dynamic pressure action of the lubricating oil can be quickly and efficiently applied to the upper and lower end surfaces.

In the second embodiment, the bearing means
The (61) is composed of a plurality of grooves (62) and (63) formed on the inner peripheral side of the upper and lower end surfaces of the piston (9), respectively, as shown in Fig. 8, when the piston (9) revolves. The bearing means (71) is formed by a plurality of grooves (71) formed on the inner peripheral side of the lower end surface of the piston (9) so that the dynamic pressure action of the lubricating oil is exerted only on the inner peripheral side of the lower end surface of the piston (9). 72) may be formed.In this case, when forming the bearing means (72), a plurality of grooves (71), on the inner peripheral side of the lower end surface of the piston (9),
It is possible to simplify the machining work because the machining work from only one direction is required to form.

In the second embodiment, each upper groove (62) and each lower groove (63) are formed in a rectangular shape, but at least each lower groove of each upper groove and each lower groove is formed. It is needless to say that the piston may be formed in a triangular shape with a sharp tip or a circular arc shape with a rounded tip at an intermediate position on the outer peripheral side of the piston. Moreover, as shown in FIG. 9, at least each lower groove (81) is formed into a spiral shape in which the tip is uniformly curved in the circumferential direction.
(82) may be configured, and in this case, each of the pistons (9) that revolves with the rotation of the eccentric shaft portion (5a) (the rotation in the direction of the dashed line shown in the figure). The lubricating oil that has entered the lower groove (81) is pushed into the lower clearance (42) more smoothly and reasonably, and the lower end surface of the piston (9) is quickly and effectively affected by the dynamic pressure of the lubricating oil. Can be made.

Further, in the second embodiment, the lower grooves (63) are made larger in the radial length and the bottom depth, so that the volume of lubricating oil entering is smaller than that of the upper grooves (62). Although it has been increased, the number of grooves on both end faces of the piston may be unbalanced by varying the number on each end face of the piston. It is simplified with the reduction of

[0034]

As described above, according to the swing compressor of the first aspect of the invention, since the upper and lower clearances are made substantially equal by the dynamic pressure action of the lubricating oil when the piston revolves, the lower side when the piston revolves. The wedge effect of the lubricating oil that enters the clearance causes the piston to float, making the upper and lower clearances substantially even, and minimizing the total amount of internal leakage of high-pressure fluid to improve the efficiency of the swing compressor.

According to the swing compressor of the second aspect of the present invention, the tapered surfaces on the inner peripheral side of the upper and lower end surfaces of the piston are unbalanced with each other, and the tapered surface on the inner peripheral side of the lower end surface of the piston. Since the dynamic pressure effect of the lubricating oil was greatly affected by the large dynamic pressure effect of the lubricating oil on the tapered surface on the inner peripheral side of the lower end surface of the piston when the piston revolved It is possible to suppress the lubrication oil by a small dynamic pressure action on the tapered surface on the peripheral portion side, and to more accurately equalize the upper and lower clearances.

According to the swing compressor of the third aspect of the invention, since the bearing means is constituted only by the taper surface on the inner peripheral side of the lower end surface of the piston, the tapered surface is formed on the inner peripheral side of the lower end surface of the piston. It is only necessary to form the taper from one direction, and the working operation can be simplified.

According to the swing compressor of the fourth aspect of the invention, the grooves on the upper and lower end surfaces of the piston are unbalanced with each other, and the dynamic pressure action of the lubricating oil is increased in the grooves on the lower end surface of the piston. As it is affected, excessive floating of the piston due to large dynamic pressure action of lubricating oil on each groove on the lower end surface of the piston during revolution of the piston is suppressed by small dynamic pressure action of lubricating oil on each groove on the upper end surface of the piston. However, the upper and lower clearances can be equalized more accurately. Moreover, the grooves on the both end faces of the piston are made unbalanced by making the numbers on both end faces of the piston different from each other, so that the machining work of the grooves on both end faces of the piston can be simplified with the reduction in the number.

According to the swing compressor of the fifth aspect of the present invention, since the bearing means is constituted only by each groove on the lower end surface of the piston, a plurality of grooves are formed in one direction with respect to the lower end surface of the piston. Only grooving is required, and the machining work can be simplified.

Further, according to the swing compressor of the sixth aspect of the invention, since the depth of the bottom surface of each groove is formed so as to become shallower as it approaches the intermediate position of the outer peripheral portion of the piston, the lubricating oil is used when the piston revolves. Can be smoothly and reasonably pushed into the clearance on the outer peripheral side of the piston, and the dynamic pressure effect of the lubricating oil can be quickly and efficiently exerted on the end surface of the piston.

[Brief description of drawings]

FIG. 1 is a vertical sectional view of a piston according to a first embodiment of the present invention.

FIG. 2 is a plan view of the piston viewed from above.

FIG. 3 is a cross-sectional plan view of the compression element, which is also cut in the vicinity of the eccentric shaft portion.

FIG. 4 is also a vertical side view of the swing compressor.

FIG. 5 is a view corresponding to FIG. 1 according to a modified example of the first mode.

FIG. 6 is a view corresponding to FIG. 1 according to a second embodiment of the present invention.

FIG. 7 is a view equivalent to FIG.

FIG. 8 is a view corresponding to FIG. 1 according to a modified example of the second mode.

FIG. 9 is a bottom view of a piston according to another modification of the second embodiment, as viewed from below.

[Description of symbols] (1) Swing compressor (5) Drive shaft (5a) Eccentric shaft (6) Cylinder (6a) Cylinder chamber (9) Piston (10) Oil supply passage (21) Suction port (22) Discharge port (24) Bush hole (hole) (24a) Opening (31) Blade (32) Swing bush (34) Low pressure chamber (35) High pressure chamber (41) Upper clearance (42) Lower clearance (43), (52) ), (61), (72), (82) Bearing means (44), (45), (51) Tapered surface (62), (63), (71), (81) Groove

Front page continuation (72) Inventor Katsumi Kato 1304 Kanaoka-cho, Sakai City, Osaka Prefecture Daikin Industries, Ltd.Kanaoka Plant, Sakai Manufacturing Co., Ltd. (72) Katsumi Kawahara 1304, Kanaoka-cho, Sakai City, Osaka Prefecture Daikin Industries, Inc. In-house (72) Inventor Takeyoshi Okawa 1304 Kanaoka-cho, Sakai-shi, Osaka Daikin Industry Co., Ltd.Kanaoka Factory (72) In-house Takashi Hirouchi 1304, Kanaoka-machi, Sakai-shi, Osaka Daikin Industry Co., Ltd. Inside the factory (72) Inventor Founder, 1304 Kanaoka-cho, Sakai City, Osaka Prefecture Daikin Industries, Ltd. Sakai Works Kanaoka Factory

Claims (6)

[Claims] 1. A cylinder (6) having a cylinder chamber (6a) in which an intake port (21) and a discharge port (22) are open, and a cylinder (6a) disposed in the cylinder chamber (6a), the inner peripheral portion of which is a drive shaft. (Five)
Piston (9) rotatably fitted to the eccentric shaft (5a) of
And a low pressure chamber (34) and a discharge port (2) which are connected to the outer periphery of the piston (9) in a protruding manner and communicate the cylinder chamber (6a) with the suction port (21).
It is provided between the blade (31) that divides the high pressure chamber (35) communicating with 2) and the suction port (21) and discharge port (22) of the cylinder (6), and the cylinder chamber (6a) A hole (24) having an opening (24a) that opens, and a swinging member that is swingably provided in the hole (24) and that swingably and advancingly supports the protruding tip side of the blade (31). A dynamic bush (32) and an oil supply passage (10) for supplying lubricating oil into the cylinder chamber (6a) are provided, and the piston (9) is rotated by the drive shaft (5) to move the cylinder chamber (6a). In the swing compressor (1) configured to revolve inside the piston (9), the piston (9) has a piston (9a) in the cylinder chamber (6a) due to the dynamic pressure action of the lubricating oil when the piston (9) revolves. Bearing means (43), (52), (61), which make the upper clearance (41) to the upper end surface of the piston) and the lower clearance (42) to the lower end surface of the piston (9) almost equal. (72), (82) are provided Swing compressor, characterized in that there. 2. The bearing means (43) is adapted to receive dynamic pressure of lubricating oil on the inner peripheral side of the upper end surface and the lower end surface of the piston (9) when the piston (9) revolves. It consists of tapered surfaces (44) and (45) formed on the inner peripheral side of both upper and lower end surfaces of (9), and these tapered surfaces (44) and (45) are inside the lower end surface of the piston (9). Circumferential taper surface (45)
The upper and lower surfaces of the piston (9) are unbalanced so that the dynamic pressure action of the lubricating oil has a greater effect than the tapered surface (44) on the inner peripheral side of the upper end surface of the piston (9). Swing compressor. 3. The bearing means (52) is arranged such that when the piston (9) revolves, the piston (9) receives the dynamic pressure of the lubricating oil only on the inner peripheral side of the lower end surface of the piston (9). The swing compressor according to claim 1, wherein the swing compressor is constituted by a taper surface (51) formed on the inner peripheral side of the lower end surface of the. 4. The bearing means (61) is configured so that the piston (9) is subjected to dynamic pressure action of lubricating oil at the upper end surface and the lower end surface thereof when the piston (9) revolves.
It consists of a plurality of grooves (62), (63) formed on both upper and lower end surfaces of (9), and each groove (62), (63) on the upper and lower end surfaces of this piston (9) is a piston (9) respectively. The inner end of the piston (9) is open at its inner end and extends radially to the middle position of the outer periphery, and each groove (63) on the lower end face of the piston (9) is fitted to each groove on the upper end face of the piston (9). The swing compressor according to claim 1, wherein the upper and lower end surfaces of the piston (9) are unbalanced from each other so that the dynamic pressure action of the lubricating oil has a greater effect than the (62). 5. The bearing means (72), (82) are pistons.
The grooves (71) and (81) formed in the lower end surface of the piston (9) are used so that the dynamic pressure of the lubricating oil is applied only to the lower end surface of the piston (9) when the piston (9) revolves. 2. The swing compressor according to claim 1, wherein each of the grooves (71) has an inner end opening at an inner peripheral portion of the piston (9) and is radially extended to a middle position of an outer peripheral portion. 6. The depth of the bottom surface of each groove (62), (63), (71), (81) is formed so that it becomes shallower as it approaches the middle position of the outer peripheral portion of the piston (9). The swing compressor according to claim 4 or 5.