JP4684166B2 - Swash plate type variable displacement compressor - Google Patents

Description

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

  A conventional swash plate type variable displacement compressor of this type is disclosed in Patent Document 1. The swash plate type variable displacement compressor 100 has a cylinder housing 101 as shown in FIG. In the cylinder housing 101, a cylinder block 101a, a front head 101b arranged on one end side of the cylinder block 101a, and a rear head 101c arranged on the other end side of the cylinder block 101a via a valve plate 102 are assembled. It is mainly composed by.

  A drive shaft 103 is disposed at the center of the cylinder housing 101. The drive shaft 103 is configured to receive a drive input from one end side, and one end side thereof is rotatably supported by the cylinder housing 101 via a radial bearing portion 120. The other end side of the drive shaft 103 is rotatably supported via a radial bearing portion 121. A thrust bearing 122 and a coil spring 123 that urges the thrust bearing 122 toward one end are disposed on the other end surface of the drive shaft, and the thrust direction is absorbed while absorbing backlash in the thrust direction of the drive shaft 103. Is supported.

  In the cylinder block 101a, a plurality of cylinder bores 104 are formed on a circumference centered on the drive shaft 103, and pistons 105 are slidably disposed in the cylinder bores 104, respectively. A crank chamber 106 communicating with the plurality of cylinder bores 104 is formed in the front head 101b. A rotor 107 and a swash plate 108 that rotate integrally with the drive shaft 103 are disposed in the crank chamber 106. When the drive shaft 103 rotates, each piston 105 reciprocates in the cylinder bore 104 by the rotor 107, the swash plate 108, etc., and the reciprocating stroke of each piston 105 is varied by the inclination angle of the swash plate 108. ing. A suction chamber 110 and a discharge chamber 111 are formed in the rear head 101c.

  A valve plate 102 interposed between the cylinder block 101 a and the rear head 101 c partitions the plurality of cylinder bores 104 from the suction chamber 110 and the discharge chamber 111. In the valve plate 102, a suction hole 112 with a suction valve and a discharge hole 113 with a discharge valve are formed corresponding to each cylinder bore 104.

  The cylinder block 101 a is formed with a suction port 114 that guides the refrigerant into the swash plate type variable displacement compressor 100. The suction port 114 and the suction chamber 110 communicate with each other via a suction communication path 115. The rear head 101 c is formed with a discharge port 116 that guides the refrigerant out of the swash plate type variable displacement compressor 100. The discharge port 116 and the discharge chamber 111 communicate with each other via a discharge communication path 117.

  In the above configuration, the refrigerant in the refrigeration cycle enters the swash plate type variable displacement compressor 100 through the suction port 114 and is supplied to the suction chamber 110 through the suction communication passage 115. The refrigerant in the suction chamber 110 is supplied into the cylinder bore 104 through the suction hole 112 during the suction stroke of the piston 105. The refrigerant supplied into the cylinder bore 104 is compressed in the compression stroke of the piston 105, is heated to a high temperature and a high pressure, and is discharged from the discharge hole 113 to the discharge chamber 111. The high-temperature and high-pressure refrigerant discharged into the discharge chamber 111 is discharged out of the swash plate type variable displacement compressor 100 from the discharge port 116 through the discharge communication passage 117.

When the load is high, the pressure in the crank chamber 106 is low, and the inclination angle of the swash plate 108 is increased. Then, the reciprocating stroke of each piston 105 increases, the refrigerant discharge capacity increases, and the cooling capacity increases. Further, when the load is low, the pressure in the crank chamber 106 is increased, and the inclination angle of the swash plate 108 is reduced. Then, the reciprocating stroke of each piston 105 becomes small, the refrigerant discharge capacity becomes small, and the cooling capacity becomes small. The swash plate type variable displacement compressor 100 saves power by such operation.
JP 2004-92648 A

  However, in the conventional swash plate type variable displacement compressor 100, when the pressure in the crank chamber 106 is high, the pressure acts as a thrust load toward the other end of the drive shaft 103, and this large thrust load is directly applied to the thrust bearing portion. 122, it is necessary to have a structure that can withstand a large thrust load. Therefore, the other end side of the drive shaft 103 is composed of a radial bearing portion 121, a thrust bearing portion 122, and a coil spring 123 for absorbing backlash, and the bearing structure is complicated.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a swash plate type variable displacement compressor that can support the radial and thrust directions of a drive shaft without play with a simple structure without being affected by the high pressure of the crank chamber.

  According to the first aspect of the present invention, which achieves the above object, a plurality of cylinder bores and a crank chamber communicating with the cylinder bore are provided in the cylinder housing, and a swash plate that is rotated by rotation of a drive shaft is disposed in the crank chamber. A plurality of pistons reciprocate in the cylinder bore by the rotation of the plate, and the reciprocating stroke of each piston is varied according to the inclination angle of the swash plate, and the inclination angle of the swash plate is adjusted to the back to each piston. In the swash plate type variable displacement compressor that is adjusted by the pressure of the crank chamber that is a pressure, the drive shaft is disposed in a shaft insertion hole that penetrates the crank chamber, and is configured to input a drive force from one end side thereof. And one end side of the drive shaft is rotatably supported by the cylinder housing via a bearing portion, and the other end side of the drive shaft is The other end of the shaft is rotatably supported, and is supported by the cylinder housing via a support member that is slidably disposed in the shaft insertion hole. The discharge chamber communicates with the discharge chamber.

  According to a second aspect of the present invention, in the swash plate type variable displacement compressor according to the first aspect, the support member is provided with a refrigerant supply path that communicates between a tip end surface thereof and a shaft support inner surface that receives the drive shaft. It is characterized by that.

  A third aspect of the present invention is the swash plate type variable displacement compressor according to the first or second aspect, wherein an oil retaining groove is provided on a sliding surface of the support member that slides within the shaft insertion hole. It is characterized by that.

  The invention according to claim 4 is the swash plate type variable displacement compressor according to claim 1 or 2, wherein a seal ring is provided on a sliding surface of the support member that slides in the shaft insertion hole. It is characterized by that.

  A fifth aspect of the present invention is the swash plate type variable displacement compressor according to any one of the first to fourth aspects, wherein a sliding bearing portion is provided on an inner surface of the support member that supports the drive shaft. It is characterized by that.

  A sixth aspect of the present invention is the swash plate type variable displacement compressor according to any one of the first to fifth aspects, wherein the support member is constituted by a single plunger.

  According to the first aspect of the invention, since the high pressure of the discharge chamber acts on the other end surface of the drive shaft via the support member, the drive shaft can be supported without play by this thrust load. In addition, since the high pressure of the discharge chamber acts on the other end surface of the drive shaft via the support member, even when a large thrust load acts on the drive shaft due to the high pressure of the crank chamber, the drive shaft has only a small total thrust load. It may be a structure that can withstand low thrust load without acting on. As described above, the radial and thrust directions of the drive shaft can be supported without play with a simple structure without being affected by the high pressure of the crank chamber. Further, since the thrust load acting on the drive shaft is reduced, noise from the drive shaft is reduced and wear resistance is improved.

  According to the invention of claim 2, in addition to the effect of the invention of claim 1, since the oil in the high-pressure refrigerant gas is supplied from the refrigerant supply path to the gap between the drive shaft and the support member, the drive shaft smoothly rotates. Can be secured, and defects such as baking can be prevented.

  According to the invention of claim 3, in addition to the effect of the invention of claim 1 or 2, the oil in the refrigerant gas is held in the oil holding groove, and the held oil causes the high pressure in the discharge chamber to be applied to the crank chamber. It can prevent leaking. Therefore, the crank chamber pressure can be adjusted smoothly and appropriately. Further, it is possible to seal between the sliding surface of the support member and the cylinder housing with a simple structure.

  According to the invention of claim 4, in addition to the effect of the invention of claim 1 or 2, it is possible to prevent the discharge chamber pressure from leaking into the crank chamber, so that the pressure adjustment of the crank chamber is smooth and appropriate. Can be done.

  According to the invention of claim 5, in addition to the effects of the inventions of claims 1 to 4, smooth rotation of the drive shaft can be secured with a simple configuration, and problems such as burning can be prevented.

  According to the invention of claim 6, in addition to the effects of the inventions of claims 1 to 5, it is sufficient to assemble only the plunger on the other end side of the drive shaft, and the assembly is very simple.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. 1 to 5 show a first embodiment of the present invention. FIG. 1 is an overall sectional view of a swash plate type variable displacement compressor 1. FIG. 3 is a side view of the plunger 24, FIG. 4 is a cross-sectional view of the plunger 24, and FIG. 5 is an enlarged cross-sectional view of the plunger 24 near the oil holding groove 27.

  As shown in FIG. 1, the swash plate type variable displacement compressor 1 has a cylinder housing 2. The cylinder housing 2 is assembled with a cylinder body 2a, a front head 2b disposed on one side surface of the cylinder body 2a, and a rear head 2c disposed on the other side surface of the cylinder body 2a via a valve body 3. It is configured by being.

  A plurality of cylinder bores 6 arranged at equal intervals on the same circumference and a crank chamber 7 communicating with the plurality of cylinder bores 6 are formed in the cylinder housing 2.

  The cylinder housing 2 has a shaft insertion hole 4 penetrating the crank chamber 7, and a drive shaft 5 disposed in the shaft insertion hole 4 is rotatably supported. This detailed support structure will be described in detail below. One end side 5a of the drive shaft 5 protrudes outside the cylinder housing 2, and a pulley (not shown) for receiving the rotation of the engine is fixed to the protruding portion. The drive shaft 5 is configured to rotate by receiving a driving force from a pulley (not shown) fixed to one end side in this way.

  A piston 8 is slidably disposed in each cylinder bore 6. In the crank chamber 7, a rotor 10, a sleeve (not shown), a journal 12, and a swash plate 13 through which the drive shaft 5 passes are arranged. The rotor 10 is fixed to the drive shaft 5 and is rotated integrally with the drive shaft 5. The sleeve (not shown) is supported so as to be movable in the axial direction of the drive shaft 5 and returns the swash plate 13 to the initial position after the operation is stopped by the balance position of the spring force of the left and right springs S1, S2. The journal 12 is fixed to the rotor 10 via a connecting link 14. The swash plate 13 is fixed to the journal 12. An engaging portion 8 a of the piston 8 is engaged with the outer peripheral portion of the swash plate 13 via a shoe 15.

  As described above, the swash plate 13 rotates together with the rotor 10 by the rotation of the drive shaft 5, and the differential pressure between the crank chamber pressure Pc that is the back pressure of each piston 8 and the suction chamber pressure Ps on the front side of each piston 8 ( The inclination angle changes depending on the pressure balance. The piston 8 reciprocates in the cylinder bore 6 by the rotation of the swash plate 13 whose swing angle is variable as described above, and its stroke is changed by the swing angle of the swash plate 13. That is, if the crank chamber pressure is adjusted, the inclination angle of the swash plate 13 can be varied, the stroke of the piston 8 can be varied, and finally the refrigerant discharge capacity can be varied.

  On the other hand, a refrigerant gas suction chamber 16 and a discharge chamber 17 are formed on the rear head 2 c side of the cylinder housing 2. The suction chamber 16 is connected to the outlet side of the evaporator of the refrigeration cycle. The discharge chamber 17 is connected to the inlet side of the condenser of the refrigeration cycle. The suction chamber 16 and the discharge chamber 17 are partitioned by the cylinder bores 6 through the valve body 3. A suction hole (not shown) with a suction valve and a discharge hole (not shown) with a discharge valve are formed in the valve body 3 partitioning both chambers.

  In addition, a bleed passage (not shown) that is always in communication is formed between the crank chamber 7 and the suction chamber 16. An air supply passage 19 in which a pressure control valve 18 is interposed is formed between the crank chamber 7 and the discharge chamber 17. The pressure control means controls the opening degree of the pressure control valve 18 and adjusts the inclination angle of the swash plate 13 by adjusting the pressure in the crank chamber 7, thereby varying the refrigerant gas discharge capacity. Specifically, when the load is high, the pressure in the crank chamber 7 is low, and the inclination angle of the swash plate 13 is increased. Then, the reciprocating stroke of each piston 8 becomes large, the discharge capacity of the refrigerant becomes large, and the cooling capacity becomes large. Further, when the load is low, the pressure in the crank chamber 7 is increased, and the inclination angle of the swash plate 13 is reduced. Then, the reciprocating stroke of each piston 8 becomes small, the refrigerant discharge capacity becomes small, and the cooling capacity becomes small.

  Next, the support structure of the drive shaft 5 will be described in detail. As shown in FIG. 1, the shaft insertion hole 4 includes an end side hole 20 disposed at one end side from the crank chamber 7 and a stepped other end side hole 21 disposed at the other end side from the crank chamber 7. It is configured. The other end side hole 21 includes a large-diameter large-diameter hole portion 21a that opens to the crank chamber 7 side, and a small-diameter small-diameter hole portion 21b that is positioned on the valve body 3 side.

  One end side of the drive shaft 5 is rotatably supported by the front head 2b of the cylinder housing 2 via two bearing portions 22 and 23. The other end side of the drive shaft 5 holds the other end portion 5b of the drive shaft 5 in a rotatable manner, and via a plunger 24 that is a support member that is slidably disposed in the one end side hole 20. Is supported by the cylinder body 2a.

  As shown in FIGS. 2 to 5, the plunger 24 is integrally composed of a large diameter cylindrical portion 24 a and a small diameter cylindrical portion 24 b. The large diameter cylindrical portion 24a is disposed in a state where there is a gap in the large diameter hole portion 21a. A shaft support chamber 25 into which the other end portion 5b of the drive shaft 5 is inserted is formed in the large diameter cylindrical portion 24a. A sliding bearing portion 26 made of a low friction material is attached to the inner surface of the shaft support chamber 25, and the inner surface of the sliding bearing portion 26 is the shaft supporting inner surface. The small-diameter cylindrical portion 24b is inserted in the small-diameter hole portion 21b without a gap, so that the plunger 24 is slidably disposed in the other end side hole 21 of the shaft insertion hole 4. A plurality of V-shaped oil retaining grooves 27 are formed on the outer peripheral surface of the small-diameter cylindrical portion 24b. The plunger 24 is formed with a refrigerant supply path 28 that communicates between the tip surface of the small diameter cylindrical portion 24b and the shaft support inner surface.

  The distal end side of the plunger 24 of the small diameter hole 21b and the discharge chamber 17 are communicated with each other through a high pressure introduction hole 29 (shown in FIG. 1) provided in the valve body 3. As a result, the high pressure of the discharge chamber 17 acts on the distal end surface of the plunger 24.

  In the above configuration, when the drive shaft 5 rotates, the rotational force causes the swash plate 13 to rotate, and the plurality of pistons 8 reciprocate within the cylinder bore 6. In the suction stroke of the piston 8 (stroke moving from the top dead center to the bottom dead center), a suction hole (not shown) is opened due to the reduced pressure in the cylinder bore 6. As a result, the refrigerant gas is supplied from the suction chamber 16 to the cylinder bore 6.

  In the compression stroke of the piston 8 (stroke moving from the bottom dead center to the top dead center), the suction hole (not shown) is closed, and the refrigerant gas in the cylinder bore 6 is adiabatically compressed by the piston 8. The compressed high-temperature and high-pressure refrigerant gas is discharged into the discharge chamber 17 through a discharge hole (not shown). The high-temperature and high-pressure refrigerant discharged into the discharge chamber 17 is discharged out of the swash plate variable displacement compressor 1 through a discharge port (not shown).

  When the load is high, the pressure in the crank chamber 7 is low, and the inclination angle of the swash plate 13 is increased. As a result, the reciprocating stroke of each piston 8 increases, the refrigerant discharge capacity increases, and the cooling capacity increases. Further, when the load is low, the pressure in the crank chamber 7 is increased, and the inclination angle of the swash plate 13 is reduced. Then, the reciprocating stroke of each piston 8 becomes small, the refrigerant discharge capacity becomes small, and the cooling capacity becomes small.

  In the above operation process, since the high pressure Pd of the discharge chamber 17 acts on the other end surface of the drive shaft 5 via the plunger 24, the drive shaft 5 can be supported without play by this thrust load. Further, since the high pressure Pd of the discharge chamber 17 acts on the other end surface of the drive shaft 5 via the plunger 24, even when a large thrust load acts on the drive shaft 5 due to the high pressure of the crank chamber 7, Only a small thrust load acts on the drive shaft 5, and a structure capable of withstanding a low thrust load may be used. As described above, the radial and thrust directions of the drive shaft 5 can be supported without backlash with a simple structure without being affected by the high pressure of the crank chamber 7. In addition, since the thrust load acting on the drive shaft 5 is reduced, noise from the drive shaft 5 is reduced and wear resistance is also improved.

  In the first embodiment, the plunger 24 is provided with a refrigerant supply path 28 that communicates between the tip end surface and the shaft support inner surface that receives the drive shaft 5, so that the oil in the high-pressure refrigerant gas is the refrigerant. Since the supply path 28 supplies the gap between the drive shaft 5 and the plunger 24, smooth rotation of the drive shaft 5 can be ensured, and problems such as burning can be prevented.

  In the first embodiment, since the oil holding groove 27 is provided on the sliding surface that slides in the small diameter hole portion 21b of the plunger 24, the oil in the refrigerant gas is held in the oil holding groove 27, This retained oil can prevent the high pressure in the discharge chamber 17 from leaking into the crank chamber 7. Therefore, the pressure of the crank chamber 7 can be adjusted smoothly and appropriately. Further, it is possible to seal between the sliding surface of the plunger 24 and the cylinder body 2a with a simple structure.

  In the first embodiment, since the slide bearing portion 26 is provided on the inner surface of the plunger 24 that supports the drive shaft 5, smooth rotation of the drive shaft 5 can be secured with a simple configuration, and defects such as seizure are caused. Can be prevented.

  In the first embodiment, since the support member is composed of a single plunger 24, only the plunger 24 needs to be assembled to the other end side of the drive shaft 5, and the assembly is very simple.

  6 to 8 show a second embodiment of the present invention, FIG. 6 is a cross-sectional view of a main part showing a support structure on the other end side of the drive shaft 5, FIG. 7 is a side view of the plunger 30, and FIG. FIG.

  The second embodiment is different from the first embodiment only in the configuration of the plunger 30 that is a support portion and the arrangement position thereof. Since the other configuration is the same, the description is omitted to avoid redundant description. In addition, the same code | symbol is attached | subjected to the same structure location of drawing, and the clarity is aimed at.

  That is, as shown in FIGS. 6 to 8, the plunger 30 has a single cylindrical shape and is slidably disposed in the large-diameter hole portion 21 a of the other end side hole 21. Therefore, the outer peripheral surface of the plunger 30 is a sliding surface, and several ring holding grooves 30a are formed on the sliding surface. A seal ring 31 is fitted in each of the ring holding grooves 30a.

  Also in the second embodiment, since the high pressure Pd of the discharge chamber acts on the other end face of the drive shaft 5 via the plunger 30 as in the first embodiment, the drive shaft 5 is not rattled by this thrust load. I can support it. Further, since the high pressure Pd of the discharge chamber acts on the other end surface of the drive shaft 5 via the plunger 30, even if a large thrust load acts on the drive shaft 5 due to the high pressure of the crank chamber, the thrust load is small as a whole. However, the structure may be such that it acts on the drive shaft 5 and can withstand low thrust loads. As described above, the radial and thrust directions of the drive shaft 5 can be supported without play with a simple structure without being affected by the high pressure of the crank chamber. In addition, since the thrust load acting on the drive shaft 5 is reduced, noise from the drive shaft 5 is reduced and wear resistance is also improved.

  In the second embodiment, since the seal ring 31 is provided on the sliding surface that slides within the large-diameter hole portion 21a of the plunger 30, it is possible to prevent the discharge chamber pressure from leaking into the crank chamber. The crank chamber pressure can be adjusted smoothly and appropriately.

1 is a general sectional view of a swash plate type variable displacement compressor according to a first embodiment of the present invention. It is principal part sectional drawing which shows 1st Embodiment of this invention and shows the support structure of the other end side of a drive shaft. 1 shows a first embodiment of the present invention and is a side view of a plunger. FIG. 1 shows a first embodiment of the present invention and is a sectional view of a plunger. FIG. FIG. 2 is an enlarged cross-sectional view of the vicinity of the oil retaining groove of the plunger, showing the first embodiment of the present invention. It is principal part sectional drawing which shows 2nd Embodiment of this invention and shows the support structure of the other end side of a drive shaft. It is a side view of a plunger showing a second embodiment of the present invention. It is sectional drawing of a plunger which shows 2nd Embodiment of this invention. It is a whole sectional view of a swash plate type variable capacity compressor of a conventional example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Swash plate type variable capacity compressor 2 Cylinder housing 4 Shaft insertion hole 5 Drive shaft 5b The other end part of a drive shaft 6 Cylinder bore 7 Crank chamber 8 Piston 13 Swash plate 16 Suction chamber 17 Discharge chamber 22 Bearing portion 23 Bearing portion 24 Plunger (support member) )
26 Sliding bearing portion 27 Oil retaining groove 28 Refrigerant supply path 29 High-pressure introduction hole 30 Plunger 31 Seal ring

Claims (6)

A cylinder housing (2) is provided with a plurality of cylinder bores (6) and a crank chamber (7) communicating with the cylinder bores (7). The plurality of pistons (8) reciprocate in the cylinder bore (6) by the rotation of the swash plate (13), and each piston (8) according to the inclination angle of the swash plate (13). In the swash plate type variable displacement compressor, the reciprocating stroke of the swash plate (13) is variable, and the inclination angle of the swash plate (13) is adjusted by the pressure of the crank chamber (7) which is the back pressure to each piston (8).
The drive shaft (5)
It is arranged in the shaft insertion hole (4) that penetrates the crank chamber (7), and is configured to receive an input of driving force from one end side,
One end side of the drive shaft (5) is rotatably supported by the cylinder housing (2) through bearing portions (22, 23),
On the other end side of the drive shaft (5), the other end portion (5b) is rotatably held, and a support member (24, 30) is slidably disposed in the shaft insertion hole (4). Supported by the cylinder housing (2) through
A swash plate type variable displacement compressor, characterized in that a front end surface side of the support member (24, 30) of the shaft insertion hole (4) communicates with the discharge chamber (17). A swash plate type variable displacement compressor according to claim 1,
The support member (24, 30) is provided with a refrigerant supply path (28) that communicates between a tip end surface thereof and a shaft support inner surface that receives the drive shaft (5). Capacity compressor. A swash plate type variable displacement compressor according to claim 1 or 2,
A swash plate type variable displacement compressor characterized in that an oil retaining groove (27) is provided on a sliding surface of the support member (24) sliding in the shaft insertion hole (4). A swash plate type variable displacement compressor according to claim 1 or 2,
A swash plate type variable displacement compressor characterized in that a seal ring (31) is provided on a sliding surface of the support member (30) sliding in the shaft insertion hole (4). A swash plate type variable displacement compressor according to any one of claims 1 to 4,
A swash plate type variable displacement compressor, wherein a sliding bearing (26) is provided on an inner surface of the support member (24) for supporting the drive shaft (5). A swash plate type variable displacement compressor according to any one of claims 1 to 5,
The swash plate type variable displacement compressor, wherein the support member is composed of a single plunger (24, 30).

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