KR20230071955A - Variable swash plate compressor with variable refrigerant drain structure in response to amount of stroke of swashplate - Google Patents

Abstract

The present invention relates to a variable swash plate compressor with a variable refrigerant discharge structure in accordance with a size of a stroke of a swash plate. The variable swash plate compressor comprises: a housing forming a crank chamber; a driveshaft supported in the housing to be rotatable around a longitudinal axis; a rotor fastened with the driveshaft to rotate along with the driveshaft; and a swash plate unit including a swash plate arranged in the crank chamber with a variable inclined angle and fastened with the rotor to rotate along with the rotor. The driveshaft forms a refrigerant passage to discharge a refrigerant in the crank chamber. The refrigerant passage includes: a center hole extended along the longitudinal axis of the driveshaft; and a first side hole and a second side hole respectively formed at different positions of the driveshaft to allow the center hole and the crank chamber to communicate with each other. Therefore, durability can be increased.

Description

Variable swash plate compressor with variable refrigerant drain structure in response to amount of stroke of swashplate}

The present invention relates to a variable swash plate type compressor.

A variable swash plate type compressor used in a vehicle air conditioner is configured to have a variable capacity by changing an inclination angle of a swash plate according to a cooling load. When there is a request for a change in cooling load, the discharge gas of a control valve injected into the crankcase is adjusted to change the pressure in the crankcase so that the angle of the swash plate is adjusted based on the pressure in the cylinder.

The drive shaft of the variable swash plate type compressor forms a refrigerant passage connecting a crank chamber formed in a crankcase and a suction chamber for refrigerant discharge, and the refrigerant passage is formed in a center hole extending longitudinally from the center of the drive shaft and a center hole. It includes a side hole extending in the radial direction of the drive shaft and connected to the crank chamber. This side hole serves to separate the oil contained in the refrigerant by centrifugal force when the refrigerant flows through the refrigerant passage when the drive shaft rotates. By allowing the oil contained in the refrigerant to be separated and remaining in the crankcase, the oil is discharged together with the refrigerant and circulated inside the air conditioning system, thereby improving the overall cooling performance.

However, due to the increase in the number of rotations of the drive shaft when the compressor rotates at high speed and the cooling load decreases, the oil separation function by the side hole becomes larger than necessary, so that too much oil remains in the crankcase, resulting in frictional heat between the swash plate and oil, which are rotating elements. This occurs excessively, which leads to a decrease in durability.

US Registered Patent Publication US5836,748 (1998.11.17.) US Registered Patent Publication US8,348,632 (2013.01.08.) US Registered Patent Publication US7,458,785 (2008.12.02.)

An object to be solved by the present invention is to provide a method capable of variably realizing a flow rate of oil through a refrigerant passage of a drive shaft according to the size of a cooling load.

A variable swash plate compressor according to an embodiment of the present invention includes a housing forming a crankcase, a drive shaft supported in the housing so as to be rotatable about a longitudinal axis, and a rotating body fastened to the drive shaft to rotate together with the drive shaft. and a swash plate unit including a swash plate disposed in the crankcase with a variable inclination angle and fastened to the rotating body to rotate together with the rotating body. The drive shaft forms a refrigerant passage for discharging the refrigerant in the crankcase. The refrigerant passage includes a center hole extending along the longitudinal axis of the drive shaft, and first and second side holes respectively formed at different positions of the drive shaft to communicate the center hole and the crank chamber. includes

The first side hole may be formed at a position that is always open regardless of the inclination angle of the swash plate, and the second side hole may be formed at a position that can be opened or closed according to the inclination angle of the swash plate.

The second side hole may be configured to be closed by the swash plate unit when the swash plate has an inclination angle with a maximum stroke and not closed by the swash plate unit when the swash plate has an inclination angle with a minimum stroke and open. there is.

The second side hole may be formed to be eccentric from the center of the drive shaft.

The second side hole may be formed to be eccentric upward from the center of the drive shaft based on the rotation direction of the drive shaft.

According to the present invention, the second side hole is closed when the angle of the swash plate increases as the cooling load increases, and the second side hole is opened when the angle of the swash plate decreases as the cooling load decreases, so that the cooling load is increased. Cooling efficiency can be improved by reducing the discharge of oil in a large state, and durability can be improved by reducing friction between the oil and the swash plate by increasing the discharge of oil in a state where the cooling load is small.

1 is a cross-sectional view of a variable swash plate type compressor according to an embodiment of the present invention.
2 is a view showing a drive shaft of a variable swash plate type compressor according to an embodiment of the present invention.
3 is a cross-sectional view taken along line III-III of FIG. 2;
4 is an exploded perspective view of a rotating body and a swash plate unit of a variable swash plate type compressor according to an embodiment of the present invention.
5 is a view showing a state in which the rotating body and the swash plate unit of the variable swash plate compressor according to an embodiment of the present invention close the auxiliary side hole.
Figure 6 is a longitudinal cross-sectional view of Figure 4;
7 is a view showing a state in which the rotation body and the swash plate unit of the variable swash plate compressor according to an embodiment of the present invention open an auxiliary side hole.
8 is a longitudinal cross-sectional view of FIG. 7 .

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

Referring to FIG. 1 , a variable swash plate type compressor 1 includes a compressor housing 10 . The compressor housing 10 may include a cylinder block 13, and a front housing 11 and a rear housing 12 fastened to both ends of the cylinder block 13, respectively. Cylinder block 13 forms a plurality of cylinder bores 15 . The plurality of cylinder bores 15 are each formed to extend in a direction parallel to the longitudinal axis X of the variable swash plate type compressor, and the plurality of cylinder bores 15 may be radially arranged at equal intervals.

A plurality of pistons 17 are respectively arranged to be capable of linear reciprocating movement within the plurality of cylinder bores 15 . A compression chamber in which the refrigerant is compressed is formed by the piston 17 and the cylinder bore 15, and the refrigerant is sucked, compressed, and discharged by the reciprocating motion of the piston 17.

The front housing 11 and the rear housing 12 are connected to the front and rear ends of the cylinder block 13, respectively. For example, the front housing 11 may be connected to the front end of the cylinder block 13 to form a crank chamber 19, and the rear housing 12 may be connected to the rear end of the cylinder block 13. It can be connected to form the suction chamber 21 and the discharge chamber 23. At this time, the front housing 11, the cylinder block 13, and the rear housing 12 may be fastened to each other by fastening bolts 25.

A valve assembly 26 forming a refrigerant passage for refrigerant movement is disposed between the cylinder block 13 and the rear housing 12 . The valve assembly 26 may include a valve plate 27 and gaskets 28 and 29 . The refrigerant in the suction chamber 21 flows into the compression chamber through the valve plate 27 and gaskets 28 and 29, and the refrigerant compressed in the compression chamber passes through the valve plate 27 and gaskets 28 and 29 to the discharge chamber. (23) is discharged. For the movement of the refrigerant, the valve plate 27 and the gaskets 28 and 29 have a refrigerant passage.

A drive shaft 31 is rotatably supported on the front housing 11 and the cylinder block 13 so as to be able to rotate about the longitudinal axis X. The drive shaft 31 may pass through the front housing 11 and be disposed to extend to the cylinder block 13, and may be connected to the drive pulley 33 to transmit power so as to rotate together with the drive pulley 33. there is. The drive pulley 33 may be disposed on one side of the front housing 11 as shown in FIG. 1, and the drive shaft 31 selectively transmits power by a clutch 37 implementing selective power transmission. Possibly connected to the drive pulley 33 . For example, the clutch 37 is configured to have a clutch coil to which current can be applied and to dynamically connect or disconnect the drive shaft 31 and the drive pulley 33 depending on whether or not current is applied. It can be.

A rotor 41 is fastened to the drive shaft 31 so as to rotate together with the drive shaft 31 while being located in the crank chamber 19 . The rotation body 41 may have a substantially disk shape, and as shown in FIG. 1 , the drive shaft 31 is installed in a state in which the through hole 43 of the rotation body 41 passes through.

The drive shaft 31 may be radially supported by the front housing 11 and the cylinder block 13 by radial bearings 45 and 46, respectively. In addition, one end of the drive shaft 31 is supported on the cylinder block 13 in the direction of the longitudinal axis X by a thrust bearing 48 elastically supported by a coil spring 47. The rotating body 41 coupled to the driving shaft 31 may be supported in the direction of the longitudinal axis X with respect to the front housing 11 by the thrust bearing 49 .

The swash plate unit 50 is configured to reciprocate the piston 17 by rotation. The swash plate unit 50 may include a journal 54 and a swash plate 51 . The swash plate unit 50 is configured to be rotatable about the longitudinal axis X together with the drive shaft 31 .

The swash plate unit 50 is connected to the rotating body 41 by a hinge mechanism 53. The swash plate unit 50 is connected to the drive shaft 31 so as to rotate together about the drive shaft 31 and the longitudinal axis X through a hinge structure 53, and the swash plate unit 50 on the other hand It is configured so that the angle of the rotating body 41 and the driving shaft 31 can be changed. 4 and 6 each show a state in which the swash plate unit 50 has different angles with respect to the rotating body 41 and the drive shaft 31 . A change in the angle of the swash plate unit 50 with respect to the rotating body 41 and the drive shaft 31 leads to a change in the stroke of the piston 17, resulting in variable displacement compression. The swash plate unit 50 may be elastically supported in both directions by coil springs 58 and 59 installed on the drive shaft 31, respectively.

4 and 5, the journal 54 has a through hole 56 into which the drive shaft 31 is inserted, and the swash plate 51 is fastened to the journal 54 to act together with the journal 54. do. The journal 54 includes a lug 55 protruding toward the rotating body 41 for connection with the rotating body 41, and the lug 55 is attached to the rotating body 41 through the hinge structure 53. Connected. The hinge structure 53 enables the hinge behavior of the swash plate unit 50 to adjust the inclination angle of the swash plate unit 50 while the swash plate unit 50 rotates together with the rotating body 41, that is, the pivoting behavior. (41) and the swash plate unit (50) are configured to connect. On the other hand, the swash plate 51 is connected to each piston 17 through a shoe 57 fastened to the edge, and the rotation of the swash plate 51 causes the piston 17 to move in a straight line within the cylinder bore 15. reciprocating motion

The hinge structure 53 is provided on the rotating body 41 and is fastened to a pair of guide arms 61 each having a guide slot 64 extending in an inclined direction, and a lug 55 It may be provided with a guide pin 63 fastened to the guide slot 64 to be movable in an inclined direction. Both ends of the guide pin 63 may be disposed in the guide slot 64, respectively, and thereby the journal 54 may be hinged. Meanwhile, the hinge structure 53 may be implemented in various ways widely known in the variable swash plate type compressor, and a detailed description thereof will be omitted. The angle of the swash plate 51 can be changed by the hinge structure 53 .

One side of the piston 17 is exposed to the compression chamber and the other side is exposed to the crankcase 19, so that the net force acting on the piston 17 depends on the pressure in the compression chamber and the pressure in the crankcase 19. Size and direction are determined. With this structure, when the pressure in the crank chamber 19 is changed by the operation of the control valve, the pressure difference between the compression chamber and the crank chamber 19 changes, and according to the pressure difference between the compression chamber 18 and the crank chamber 19 The inclination angle of the swash plate 51 changes. A change in the inclination angle of the swash plate 51 causes a change in the stroke of the piston 17, and a change in the stroke of the piston 17 leads to a change in compression capacity. A variable capacity structure can be implemented in this way, and since a detailed structure for implementing the variable capacity function is general in the technical field to which the present invention belongs, a detailed description thereof will be omitted. Although not shown in the drawings, a control valve (not shown) may be configured to supply discharged gas from the discharge chamber 23 to the crankcase 19 through the control passage. The discharge gas discharged from the control valve may be supplied to the crank chamber 19 through the control passage.

The valve assembly 26 may form a bleed hole 74 connecting the crank chamber 19 and the suction chamber 21 . For example, the cylinder block 13 may form a connection space 75 in which a coil spring 47 supporting the drive shaft 31 is disposed, and the drive shaft 31 may form a crankcase 19 and a coil A refrigerant passage 70 communicating with the connection space 75 where the spring 47 is disposed is included. The bleed hole 74 formed in the valve assembly 26 extends along the longitudinal axis X to communicate the connection space 75 where the coil spring 47 is disposed with the suction chamber 21 .

The refrigerant passage 70 may include a center hole 73 and first and second side holes 71 and 72 . The center hole 73 may extend from the center of the drive shaft 31 along the longitudinal axis X, and the first and second side holes 71 and 72 extend in the radial direction of the drive shaft 31. can be formed. The center hole 73 may extend to one end of the drive shaft 31 and extend to the connection space 75 described above. Inner ends of the first and second side holes 71 and 72 are connected to the center hole 73 and outer ends are connected to the outer circumferential surface of the driving shaft 31 . The first and second side holes 71 and 72 may be formed at different positions along the longitudinal axis X of the drive shaft 31 and may be positioned to communicate with the crank chamber 19, respectively. A refrigerant passage connecting the crank chamber 19 and the suction chamber 21 is formed by the refrigerant passage including the first and second side holes 71 and 72 and the center hole 73, and the refrigerant passage Some of the refrigerant containing oil in the crankcase 19 may be discharged to the suction chamber 21 through the.

The first side hole 71 is formed at a position that can always remain open when the angle of the swash plate unit 50 changes, and the second side hole 72 is formed in the swash plate unit 50, that is, the swash plate 51 ) is formed at a position that can be opened or closed according to the change in angle. Specifically, the outer end of the second side hole 72 is closed by the journal 54 in a specific angle range among possible angle ranges of the swash plate unit 50 and not closed by the journal 54 in another specific angle range. It consists of 4 and 5 show a state in which the swash plate unit 50 is at an angle where the second side hole 72 is closed by the journal 54, and in FIGS. 6 and 7, the swash plate unit 50 is The state in which the two side holes 72 are at an angle not closed by the journal 54 is shown.

5 and 6 show a state in which the swash plate unit 50 is inclined at the largest inclination angle, that is, a state in which the swash plate 51 is inclined with respect to the rotating body 41 at the largest angle. This is a state in which the maximum stroke of the piston is achieved when the swash plate 51 rotates, and when the cooling load is large, the inclination angle of the swash plate unit 50 can be controlled to be implemented. In this case, as shown in FIG. 5 , the second side hole 72 is closed by the journal 54 of the swash plate unit 50, and thus the crank chamber 19 is opened only through the first side hole 71. The refrigerant containing oil is discharged into the suction chamber (21). This can improve the cooling efficiency of the cooling system.

Meanwhile, FIGS. 7 and 8 show a state in which the swash plate unit 50 maintains the smallest inclination angle, that is, a state in which the swash plate 51 is substantially parallel to the rotating body 41 . This is a state in which the stroke of the piston connected to the swash plate 51 is reduced, and when the cooling load is small, the inclination angle of the swash plate unit 50 can be controlled to be realized. In this case, as shown in FIG. 7, the second side hole 72 is in an open state that is not closed by the journal 54 of the swash plate unit 50, and thus the first side hole 71 and Also through the second side hole 72, the refrigerant containing the oil in the crank chamber 19 is discharged to the suction chamber 21. As a result, the amount of oil discharged from the crankcase 19 increases, and accordingly, frictional heat generated between the swash plate 51 and the oil is reduced, so that the durability of the device can be improved.

The characteristics of the second side hole 72 according to an embodiment of the present invention will be further described with reference to FIGS. 2 and 3 . 2 and 3, the drive shaft 31 is formed to have a circular cross section as a whole, and the second side hole 72 is formed on a cut surface 74 formed by removing a part of the outer circumferential surface of the drive shaft 31. can be formed At this time, the second side hole 72 may be formed to be eccentric by a predetermined distance from the center of the driving shaft 31 . That is, as shown in FIG. 3 , the line c1 passing through the center of the second side hole 72 may be spaced apart from the line c2 passing through the center of the drive shaft 31 by a predetermined distance d. . In addition, the second side hole 72 may be located at an upper portion based on the direction of rotation of the drive shaft 31 and the direction of the arrow shown in FIG. 2 . That is, referring to FIG. 3, the inlet of the second side hole 72 passes through the center of the drive shaft 31 and is located in the first quadrant on the Cartesian coordinate system with two mutually perpendicular lines c1 and c3 as axes, and is located in the second quadrant. can be extended towards Meanwhile, in another embodiment, the inlet of the second side hole may be located on the third quadrant and extend toward the fourth quadrant. Accordingly, when the drive shaft 31 rotates, the inflow of the refrigerant and the oil can be better achieved.

Although the embodiments of the present invention have been described above, the scope of the present invention is not limited thereto, and it is recognized that the embodiments of the present invention are easily changed by those skilled in the art to which the present invention belongs and are equivalent. It includes all changes and modifications within the scope of

1: variable swash plate type compressor
10: compressor housing
11: front housing
12: rear housing
13: cylinder block
15: cylinder bore
17: piston
21: suction chamber
23: discharge chamber
26: valve assembly
31: drive shaft
33: driving pulley
35: clutch coil
37: Clutch
41: rotating body
50: Sapphire unit
51: Sapan
54: Journal
63: guide pin
64: guide slot
70: refrigerant passage
71: first side hole
72: second side hole
73: center hall

Claims (5)

a housing forming a crankcase;
a drive shaft supported within the housing to be rotatable about a longitudinal axis;
A rotating body fastened to the drive shaft to rotate together with the drive shaft, and
A swash plate unit including a swash plate disposed in the crankcase with a variable inclination angle and fastened to the rotating body to rotate together with the rotating body
including,
The drive shaft forms a refrigerant passage for discharging the refrigerant in the crankcase;
The refrigerant passage includes a center hole extending along the longitudinal axis of the drive shaft, and first and second side holes respectively formed at different positions of the drive shaft to communicate the center hole and the crank chamber. containing
Variable swash plate type compressor. In paragraph 1,
The first side hole is formed at a position that is always open regardless of the inclination angle of the swash plate, and the second side hole is formed at a position that can be opened or closed according to the inclination angle of the swash plate. In paragraph 2,
The second side hole is a variable type configured to be closed by the swash plate unit when the swash plate has an inclination angle with a maximum stroke and not closed by the swash plate unit when the swash plate has an inclination angle with a minimum stroke to be opened. swash plate compressor. In paragraph 2,
The second side hole is formed to be eccentric from the center of the drive shaft. In paragraph 4,
The second side hole is formed to be eccentric upward from the center of the drive shaft based on the rotation direction of the drive shaft.

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