KR100506901B1 - Variable Capacity Rotary Compressor - Google Patents

Abstract

As the rotating shaft rotates, the outer circumferential surface of the eccentric bush and the inner circumferential surface of the roller are worn and provide a capacity variable rotary compressor that can prevent the sintering phenomenon. The rotary compressor has upper and lower compression chambers, rotary shafts, and upper and lower eccentric cams which are eccentrically installed in the same direction in the same direction. A locking pin for selectively converting the eccentric bush to the maximum eccentric rotation position, and the upper and lower rollers disposed on the outer circumferential surface of the upper and lower eccentric bush to perform a compression action. The outer circumferential surface of the upper and lower eccentric bushes in contact with the upper and lower rollers is provided with a surface coating formed by tungsten carbide coating or tin coating to have high hardness to prevent sintering at the contact surface.

Description

Variable Capacity Rotary Compressor

The present invention relates to a rotary compressor, and more particularly, to a rotary compressor capable of varying the capacity by selectively performing compression operation in any one of two compression chambers having different contents by an eccentric device disposed on the rotary shaft. will be.

A cooling device for cooling a specific space using a refrigeration cycle such as an air conditioner and a refrigerator is provided with a compressor for compressing a refrigerant circulating in a closed circuit of the refrigeration cycle. The cooling capacity of such a cooling device is usually determined according to the compression capacity of the compressor. Therefore, when the compressor is configured to vary the compression capacity of the compressor, the cooling device is optimally optimized according to the surrounding conditions such as the difference between the actual temperature and the set temperature. By operating in a state, it is possible to appropriately cool a specific space and at the same time save energy.

Compressors used in the cooling system include a rotary compressor and a reciprocating compressor, and the present applicant selectively compresses only one of two compression chambers having different contents through Korean Patent Application No. 10-2002-0061462. This has been applied for a variable displacement rotary compressor to vary the capacity.

In each compression chamber of the variable displacement rotary compressor, an eccentric device is arranged so that the compression operation is performed only in one compression chamber according to the rotation direction of the rotation shaft. The eccentric device includes two eccentric cams provided on the outer surface of the rotating shaft passing through the compression chambers, two eccentric bushes rotatably disposed on the outer surface of the eccentric cams, and rotatably disposed on the outer surface of the eccentric bushes. And two rollers for compressing the refrigerant gas, and a locking pin installed so that one eccentric bushing is shifted to an eccentric position with respect to the center line of the rotating shaft and the other eccentric bushing is shifted to a concentric position according to the direction in which the rotating shaft is rotated. It is configured to include.

Therefore, when the rotating shaft rotates in the forward or reverse direction, the compression operation is performed only in any one of the two compression chambers having different contents by the eccentric device configured as described above, thereby changing the capacity of the compressor.

In this compression operation of the variable displacement compressor, each eccentric bush rotates eccentrically with the rotating shaft while being in contact with the inner circumferential surface of each roller. Accordingly, each roller rotates along the inner circumferential surface of each compression chamber with rotation. You lose.

However, in the conventional variable displacement compressor, since the surface hardness of the eccentric bushes and the rollers is not sufficiently high, wear and tear occur on the outer circumferential surface of each eccentric bush and the inner circumferential surface of each roller when repeated compression operation is performed, There is a possibility that the phenomenon that the wear part is sintered occurs.

The present invention is to solve the above-mentioned problems of the prior art, an object of the present invention is to provide a variable displacement rotary compressor that can prevent the phenomenon that the outer circumferential surface of the eccentric bush and the inner circumferential surface of the roller is squeezed as the rotating shaft rotates; It is.

Capacity variable rotary compressor according to the present invention for achieving this object,

Upper and lower compression chambers divided into different contents, rotation shafts penetrating the upper and lower compression chambers, upper and lower eccentric cams provided on the rotation shafts, and upper and lower circumferential surfaces of the upper and lower eccentric cams, respectively; Upper and lower rollers disposed on outer circumferential surfaces of the upper and lower eccentric bushes, respectively, and rotating along inner circumferential surfaces of the upper and lower compression chambers, slots provided between the upper and lower eccentric bushes; And engaging pins for selectively shifting the upper and lower eccentric bushes to a maximum eccentric position by working with a slot, wherein surface coatings are formed on the surfaces of the upper and lower eccentric bushes to be relatively higher than the surface hardness of the upper and lower rollers. It is characterized by having a high surface hardness.

Preferably, the surface coatings of the upper and lower eccentric bushes are formed by tungsten carbide coating treatment or tin coating treatment.

Preferably, the surface hardness of the upper and lower eccentric bushes is approximately 800 Vickers hardness or more.

In addition, the upper and lower eccentric bushes are made by turning a surface of a predetermined material, followed by tungsten carbide coating or tin coating, and then grinding.

Hereinafter, with reference to the accompanying drawings will be described in detail a preferred embodiment of the present invention.

1 is a longitudinal sectional view showing an approximate internal structure of a variable displacement rotary compressor according to the present invention. As shown therein, the variable displacement rotary compressor according to the present invention is installed in the sealed container 10 to generate a rotational force, and a compression unit for compressing gas by the rotational force of the drive unit 20. 30 is provided. The driving unit 20 includes a cylindrical stator 22 fixed to an inner surface of the sealed container 10, a rotor 23 rotatably installed in the stator 22, and the rotor 23. It is provided so as to extend from the center portion and is composed of a rotating shaft 21 which rotates forward (first rotation direction) or reverse rotation (second rotation direction) together with the rotor 23.

The compression unit 30 is disposed at the upper and lower ends of the housing 33 having a cylindrical upper compression chamber 31 and a lower compression chamber 32 having different contents in upper and lower portions, respectively. It is disposed between the upper flange 35 and the lower flange 36 to rotatably support the rotating shaft 21, and the upper compression chamber 31 and the lower compression chamber 32, the upper compression chamber 31 and the lower compression Intermediate plate 34 to allow the seals 32 to be partitioned from one another.

The height of the upper compression chamber 31 is formed larger than the height of the lower compression chamber 32 so that the contents of the upper compression chamber 31 are larger than the contents of the lower compression chamber 32, and thus the upper compression chamber ( 31, it is possible to compress the gas of a higher flow rate than the lower compression chamber 32, so that the rotary compressor according to the present invention has a variable capacity.

Of course, if the height of the lower compression chamber 32 is greater than the height of the upper compression chamber 31, the contents of the lower compression chamber 32 may be increased so that the gas in the lower compression chamber 32 can be compressed at a higher flow rate. It becomes larger than the content of the compression chamber 31.

The inside of the upper compression chamber 31 and the lower compression chamber 32 may be selectively compressed only in any one of the upper compression chamber 31 and the lower compression chamber 32 according to the rotational direction of the rotary shaft 21. The eccentric device 40 is disposed, the structure and operation of the eccentric device 40 will be described later with reference to FIGS.

The upper compression chamber 31 and the lower compression chamber 32 are also provided with an upper roller 37 and a lower roller 38 rotatably disposed on the outer circumferential surface of the eccentric device 40, respectively, and in the housing 33. Upper and lower suction ports 63 and 64 and upper and lower discharge ports 65 and 66 (refer to FIGS. 4 and 6) are arranged to communicate with the upper compression chamber 31 and the lower compression chamber 32, respectively.

The upper roller 37 and the lower roller 38 rotate in contact with the outer circumferential surface of the eccentric device 40 and revolve along the inner circumferential surfaces of the upper compression chamber 31 and the lower compression chamber 32, respectively. Inhale the gas to allow it to be compressed and discharged.

The upper vane 61 is radially disposed between the upper suction port 63 and the upper discharge port 65 in a state in which the upper vane 61 is in close contact with the upper roller 37 by the support spring 61a (see FIG. 4). Between the 64 and the lower discharge port 66, the lower vanes 62 are radially arranged in close contact with the lower roller 38 by the support spring 62a (see Fig. 6).

In addition, in the outlet tube 69a of the accumulator 69 which separates the liquid refrigerant and allows only the gas refrigerant to flow into the compressor, only the suction port side of the upper and lower suction inlets 63 and 64 formed in the housing 33 is compressed. A flow path switching device 70 for selectively opening and closing each suction flow path 67 and 68 so that a gas refrigerant is supplied is provided. The suction flow paths 67 and 68 are formed inside the flow path switching device 70 by the pressure difference between the suction flow path 67 connected to the upper suction port 63 and the suction flow path 68 connected to the lower suction port 64. The valve device 71 which opens only one of them and is supplied with the refrigerant gas is arranged to be movable left and right.

Next will be described with reference to Figures 2 and 3 the structure of the rotating shaft and the eccentric device which constitutes a characteristic configuration of the present invention.

Figure 2 shows the eccentric device and the upper and lower rollers of the present invention separated from the rotating shaft, Figure 3 shows the eccentric device and the upper and lower rollers are coupled to the rotating shaft according to the present invention.

As shown in FIG. 2, the eccentric device 40 includes an upper eccentric cam 41 and a lower eccentric cam (34) provided at positions corresponding to the upper compression chamber 31 and the lower compression chamber 32, respectively, on the rotation shaft 21. 42) an upper eccentric bush 51, a lower eccentric bush 52, an upper eccentric cam 41 and a lower eccentric cam 42 disposed on the outer circumferential surfaces of the upper eccentric cam 41 and the lower eccentric cam 42, respectively. A locking pin 43 installed between the upper and lower eccentric bushes 51 and the lower eccentric bush 52 is provided with a predetermined length so that the locking pins 43 are provided.

The upper eccentric cam 41 and the lower eccentric cam 42 protrude integrally in the transverse direction from the outer circumferential surface of the rotating shaft 21 and are vertically disposed in an eccentric state with respect to the center line C1-C1 of the rotating shaft 21. In addition, the upper and lower eccentric cams (41, 42) are each projected to the maximum from the upper and lower eccentric cams 41, 42 of the upper and lower eccentric cams (41) 42 and the uppermost projecting to the minimum. And an upper eccentric line L1-L1 and a lower eccentric line L2-L2 connecting the minimum eccentric portions of the lower eccentric cams 41 and 42.

The locking pin 43 is composed of a threaded body 44 and a head 45 formed with a diameter slightly larger than the body 44 at the tip of the body 44, the upper eccentric cam 41 The body portion (3) in a screw hole (46) formed at a position to form an approximately 90 degree angle with the eccentric lines (L1-L1) (L2-L2) on the rotation shaft (21) between the lower eccentric cam (42). 44 is screwed to the rotary shaft 21 is fastened.

The upper eccentric bush 51 and the lower eccentric bush 52 are integrally formed by a connecting portion 54 connecting them, and having a width slightly larger than the diameter of the head 45 of the locking pin 43. The slot 53 is formed in the connecting portion 54 in the circumferential direction.

Therefore, the upper eccentric bush 51 and the lower eccentric bush 52 formed integrally connected by the connecting portion 54 are inserted into the rotating shaft 21, and the locking pin 43 is rotated through the slot 53. When fastened to the screw hole 46 of the locking pin 43 is installed in the rotating shaft 21 in the state fitted to the slot (53).

In this state, when the rotating shaft 21 is rotated forward or reverse, the upper and lower portions thereof until the engaging pin 43 is caught by any one of the first end 53a and the second end 53b of the slot 53. The eccentric bushes 51 and 52 do not rotate, and when the engaging pin 43 is caught by the first end 53a or the second end 53b, the upper eccentric bushes 51 and the lower eccentric bushes 52 The rotating shaft 21 is rotated forward or reverse.

On the other hand, the angle between the eccentric line (L3-L3) connecting the maximum eccentric portion and the minimum eccentric portion of the upper eccentric bush (51) and the line connecting the center of the first end (53a) of the slot 53 and the connecting portion (54) Is formed to form approximately 90 degrees, the eccentric line (L4-L4) and the second end (53b) of the slot 53 and the connecting portion (54) connecting the maximum eccentric portion and the minimum eccentric portion of the lower eccentric bush (52) The angle between the lines connecting the center is likewise formed to be approximately 90 degrees.

In addition, the eccentric line (L3-L3) of the upper eccentric bush (51) and the eccentric line (L4-L4) of the lower eccentric bush (52) are located on the same plane, but the maximum eccentric portion of the upper eccentric bush (51) and The maximum eccentric portions of the lower eccentric bush 52 are eccentrically disposed to face opposite sides, and connect the first end 53a and the second end 53b of the slot 53 formed in the circumferential direction to the connecting portion 54. The line is formed to form an angle of 180 degrees.

The locking pin 43 is caught by the first end 53a of the slot 53 by the arrangement structure as described above, so that the upper eccentric bush 51 rotates in the first rotation direction together with the rotation shaft 21 (of course, the lower portion). The eccentric bush is rotated together with the upper eccentric bush 51 at each position where the eccentric bush 51 rotates together with the maximum eccentric portion of the upper eccentric bush 41 and the maximum eccentric bush of the upper eccentric bush 51. While the forward rotation is performed in the maximum eccentric state (see FIG. 4), the lower eccentric bush 52 has the maximum eccentric portion of the lower eccentric cam 42 and the minimum eccentric portion of the lower eccentric bush 52 abut against each other. Forward rotation is made in concentric with (21) (see Fig. 5).

Contrary to the above, the lower eccentric at the angular position where the engaging pin 43 is caught by the second end 53b of the slot 53 so that the lower eccentric bush 52 rotates in the second rotation direction together with the rotation shaft 21. The bush 52 has the maximum eccentric portion of the lower eccentric cam 42 and the maximum eccentric portion of the lower eccentric bush 52 come into contact with each other to be reversely rotated in the state of being eccentrically with the rotation shaft 21 (FIG. 6). The upper eccentric bush 51 is rotated in a state in which the maximum eccentric portion of the upper eccentric cam 41 and the minimum eccentric portion of the upper eccentric bush 51 abut on each other and are concentric with the rotating shaft (see FIG. 7). ).

Meanwhile, as shown in FIG. 3, when the upper eccentric bush 51 and the lower eccentric bush 52 rotate in the forward or reverse directions, the inner circumferential surfaces of the upper eccentric bush 51 and the lower eccentric bush 52 are respectively. The upper roller 37 and the lower roller 38 disposed in contact with each other rotate in the same direction as the rotational direction of the upper and lower eccentric bushes 51 and 52, and the upper compression chamber 31 and the lower compression chamber. Along the inner circumferential surface of (32).

Therefore, when the above operation is repeated for a long time, the contact portion between the upper and lower eccentric bushes 51 and 52 and the upper and lower rollers 37 and 38, that is, the outer circumferential surface of the upper eccentric bush 51 and the upper roller 37 In the inner circumferential surface, and the outer circumferential surface of the lower eccentric bush 52 and the inner circumferential surface of the lower roller 38, abrasion occurs, while the wear portion may be sintered by the frictional heat at the contact portion due to the high speed rotation.

The upper eccentric bush 51 and the lower eccentric bush in order to prevent the occurrence of adhesion between the upper and lower eccentric bushes 51 and 52 and the upper and lower rollers 37 and 38 by preventing or minimizing such wear. The surface coating part 80 is formed in the surface of 52 so that hardness may be high.

The upper and lower eccentric bushes 51 and 52 by the surface coating part 80 have a relatively high surface hardness than the upper and lower rollers 37 and 38 so that abrasion does not occur on the surface thereof, thereby rotating. Due to the high frictional heat caused by the sintering in the contact portion does not occur.

Preferably, the surface coating portion 80 is formed to a predetermined thickness by tungsten carbide coating treatment or tin coating treatment so that the surface hardness of the surface coating portion 80 can be maintained at about 800 or more in Vickers hardness.

The upper and lower eccentric bushes 51 and 52 are first made by turning a predetermined material, and then applying the tungsten carbide coating or tin coating on the surface thereof, and then grinding the surface again.

Therefore, the upper eccentric bush 51 and the lower eccentric bush 52 according to the present invention are able to have a hardness of Hv 800 or more with a higher hardness, that is, a Vickers hardness, than a conventional heat treatment.

Hereinafter, an operation of selectively compressing refrigerant gas in the upper compression chamber or the lower compression chamber by the eccentric device and the upper and lower rollers configured as described above will be described with reference to FIGS. 4 to 7.

Figure 4 is a view showing that the rotation axis is rotated in the first rotation direction by the eccentric apparatus according to the invention the compression action in the upper compression chamber, Figure 5 is a view corresponding to Figure 4, the rotation axis in the first rotation direction It is shown that the compression action is not made in the lower compression chamber by the eccentric device according to the invention by rotating to.

As shown in FIG. 4, the engaging pin 43 protruding from the rotating shaft 21 by rotating the rotary shaft 21 in the first rotational direction (counterclockwise in FIG. 4) has an upper eccentric bush 51 and a lower eccentric. When the locking pin 43 is caught by the first end 53a of the slot 53 when the locking pin 43 is rotated at a predetermined angle while being inserted into the slot 53 formed between the bushes 52, the upper eccentric bush 51 is rotated 21. Will rotate).

In the state where the locking pin 43 is engaged with the first end 53a of the slot 53, as described above, the maximum eccentric portion of the upper eccentric cam 41 is brought into contact with the maximum eccentric portion of the upper eccentric bush 51. The upper eccentric bush 51 is rotated in a state where the upper eccentric bush 51 is switched to the maximum eccentric position with respect to the center line C1-C1 of the rotating shaft 21, whereby the inner circumferential surface of the upper roller 37 is the upper eccentric bush 51. While rotating in contact with the outer circumferential surface of the, while the outer circumferential surface is in contact with the inner circumferential surface of the housing 33 forming the upper compression chamber 31 to perform the compression operation.

At the same time, as shown in FIG. 5, the maximum eccentric portion of the lower eccentric cam 42 abuts the minimum eccentric portion of the lower eccentric bush 52 such that the lower eccentric bush 52 is the centerline C1- of the rotation shaft 21. C1) is rotated in a state in which it is switched to a concentric position, thereby the lower roller 38 rotates while its inner circumferential surface is in contact with the outer circumferential surface of the lower eccentric bush 52, and its outer circumferential surface is Since the revolving spaced apart from the inner circumferential surface of the housing 33 forming the compression chamber 32 at a predetermined interval, the compression operation is not made.

Therefore, when the rotating shaft 21 rotates in the first rotation direction, the refrigerant gas introduced into the upper suction port 63 by the upper roller 37 is compressed in the upper compression chamber 31 having a relatively high content, and thus the upper discharge port 65. In the lower compression chamber 32, which is relatively small in content, the compression operation is not performed, so that the rotary compressor operates in a state where the compression capacity is large.

In this case, since the upper eccentric bush 51 and the lower eccentric bush 52 according to the present invention have a surface coating 80 formed by tungsten carbide coating or tin coating on the surface thereof and have a very high surface hardness, the Even if the operation continues for a long time, the upper and lower eccentric bushes 51 and 52 are hardly worn, and thus, the squeezing phenomenon does not occur between the upper and lower eccentric bushes 51 and 52 and the upper and lower rollers 37 and 38. Will not.

6 is a view showing that the rotation axis is rotated in the second rotation direction by the eccentric apparatus according to the invention the compression action in the lower compression chamber, Figure 7 is a view corresponding to Figure 6, the rotation axis in the second rotation direction It is shown that the compression action is not made in the upper compression chamber by the eccentric device according to the present invention by rotating to.

As shown in FIG. 6, when the rotating shaft 21 is rotated in the second rotation direction (clockwise in FIG. 6), the compression operation is performed only in the upper compression chamber 31 as in FIGS. 4 and 5. In operation, the compression is performed only in the lower compression chamber 32.

That is, the locking pin 43 protruding from the rotary shaft 21 is caught by the second end 53b of the slot 53 by the rotation of the rotary shaft 21 in the second rotation direction, thereby lowering the eccentric bush 52. And the upper eccentric bush 51 are rotated in the second rotation direction by the rotation shaft 21.

This switching operation causes the maximum eccentric portion of the lower eccentric cam 42 to contact the maximum eccentric portion of the lower eccentric bush 52 so that the lower eccentric bush 52 is maximum with respect to the center line C1-C1 of the rotation shaft 21. It is converted to the eccentric state and rotated, so that the lower roller 38 is rotated in contact with the inner circumferential surface of the housing 33 forming the lower compression chamber 32 to perform the compression operation.

At the same time, as shown in FIG. 7, the maximum eccentric portion of the upper eccentric cam 41 abuts against the minimum eccentric portion of the upper eccentric bush 51 such that the upper eccentric bush 51 is the center line C1- of the rotation shaft 21. It is converted into a concentric state with respect to C1) and rotates, so that the upper roller 37 rotates while being spaced at a predetermined interval from the inner circumferential surface of the housing 33 forming the upper compression chamber 31. This will not be done.

Therefore, in the lower compression chamber 32 having a relatively small inner content, the refrigerant gas introduced into the lower suction port 64 by the lower roller 38 is compressed and discharged through the lower discharge port 66. Since the compression operation is not performed in the compression chamber 31, the rotary compressor is operated in a state where the compression capacity is small.

Even in the above operation, since the upper eccentric bush 51 and the lower eccentric bush 52 according to the present invention have a very high surface hardness because the surface coating portion 80 is formed on its surface, the upper and lower eccentric bushes 51 The squeeze phenomenon does not arise between 52 and the upper and lower rollers 37 and 38.

As described in detail above, the capacity-variable rotary compressor according to the present invention has a structure capable of varying the compression capacity by the eccentric device which rotates in the forward or reverse direction in the upper compression chamber and the lower compression chamber having different contents, the surrounding space In addition to being able to cool properly, there is an effect that can save energy.

In particular, in the variable displacement compressor according to the present invention, since the surface of the upper eccentric bush and the lower eccentric bush is provided with a surface coating formed by tungsten carbide coating or tin coating, delamination does not occur between the upper and lower eccentric bushes and the upper and lower rollers. It works stably and extends the lifespan.

1 is a longitudinal sectional view showing an approximate internal structure of a variable displacement rotary compressor according to the present invention.

Figure 2 is a perspective view showing a state in which the eccentric device and the roller according to the present invention is separated from the rotating shaft.

3 is a cross-sectional view showing a state in which the eccentric device and the roller according to the present invention is coupled to the rotating shaft.

4 is a view showing that the rotation axis is rotated in the first direction of rotation in the upper compression chamber by the eccentric apparatus according to the present invention.

FIG. 5 is a view corresponding to FIG. 4, in which the rotating shaft rotates in the first rotation direction, and thus the compression operation is not performed in the lower compression chamber by the eccentric apparatus according to the present invention.

6 is a view showing that the rotation axis is rotated in the second direction of rotation in the lower compression chamber by the eccentric apparatus according to the present invention.

FIG. 7 is a view corresponding to FIG. 6, in which the rotating shaft is rotated in the second rotation direction so that the compression action is not performed in the upper compression chamber by the eccentric apparatus according to the present invention.

* Description of symbols on the main parts of the drawings *

21: rotating shaft 31: upper compression chamber

32: lower compression chamber 37: upper roller

38: lower roller 40: eccentric device

41: upper eccentric cam 42: lower eccentric cam

43: engaging pin 51: upper eccentric bush

52: lower eccentric bush 53: slot

80: surface coating

Claims (5)

Upper and lower compression chambers divided into different contents, rotation shafts penetrating the upper and lower compression chambers, upper and lower eccentric cams provided on the rotation shafts, and upper and lower circumferential surfaces of the upper and lower eccentric cams, respectively; Upper and lower rollers disposed on outer circumferential surfaces of the upper and lower eccentric bushes, respectively, and rotating along inner circumferential surfaces of the upper and lower compression chambers, slots provided between the upper and lower eccentric bushes; And engaging pins for selectively shifting the upper and lower eccentric bushes to a maximum eccentric position by working with a slot, wherein surface coatings are formed on the surfaces of the upper and lower eccentric bushes to be relatively higher than the surface hardness of the upper and lower rollers. A variable displacement rotary compressor characterized by high surface hardness. 2. The variable displacement rotary compressor according to claim 1, wherein the surface coatings of the upper and lower eccentric bushes are formed by a tungsten carbide coating process. The variable displacement rotary compressor according to claim 1, wherein the surface coatings of the upper and lower eccentric bushes are formed by tin coating treatment. The variable displacement rotary compressor according to claim 1, wherein the surface hardness of the upper and lower eccentric bushes is approximately Vickers hardness of 800 or more. The variable displacement rotary compressor according to claim 1, wherein the upper and lower eccentric bushes are made by turning tungsten carbide coating or tin coating on a surface of the material and then grinding the material.