This application claims priority to Japanese Patent Application No. 2021-011311 filed on Jan. 27, 2021, the entire disclosure of which is incorporated herein by reference.
The present disclosure relates to a scroll compressor.
The scroll compressor includes a housing, a rotary shaft, a fixed scroll, and an orbiting scroll. The rotary shaft is rotatably supported by the housing. The fixed scroll includes a fixed base plate, a fixed spiral wall, and an outer peripheral wall. The fixed base plate includes a discharge port at the center thereof. The fixed spiral wall extends from the fixed base plate. The outer peripheral wall extends from the fixed base plate and surrounds the fixed spiral wall. The orbiting scroll includes an orbiting base plate and an orbiting spiral wall. The orbiting base plate is opposed to the fixed base plate. The orbiting spiral wall extends from the orbiting base plate and engages with the fixed spiral wall. The orbiting scroll is configured to revolve relative to the fixed scroll as the rotary shaft rotates.
A compression chamber is defined between the fixed spiral wall and the orbiting spiral wall. The outer peripheral wall includes a suction port. The outer peripheral wall also has a suction chamber that is formed inside the outer peripheral wall and communicates with the suction port. The housing includes a discharge chamber communicating with the discharge port. A refrigerant compressed in the compression chamber is discharged into the discharge chamber. The scroll compressor, as disclosed in Japanese Patent Application Publication No. 2020-165362, for example, includes an oil storage chamber that stores an oil separated from the refrigerant discharged into the discharge chamber and an oil supply passage that supplies the oil in the oil storage chamber to the suction chamber.
However, in the above-described scroll compressor, a flow rate of the oil supplied from the oil supply passage is unstable because the flow rate is likely to vary depending on an operating status of a compression device, which may partially cause poor lubrication between the fixed scroll and the orbiting scroll. In particular, in a case where a pair of suction ports is provided interposing the discharge port therebetween and if the oil is unlikely to be supplied uniformly to both of the pair of the suction ports, the poor lubrication is likely to occur. In order to improve lubricity between the fixed scroll and the orbiting scroll as a whole, it is desirable that the oil supplied from the oil supply passage is temporarily stored in an oil storage chamber that communicates with the suction chamber inside the compression device.
The present disclosure has been made in view of the above circumstances and is directed to providing a scroll compressor that improves lubricity between a fixed scroll and an orbiting scroll.
In accordance with an aspect of the present disclosure, there is provided a scroll compressor that includes a housing, a rotary shaft, a fixed scroll, an orbiting scroll, a compression chamber, a suction port, a suction chamber, a discharge chamber, an oil storage chamber, and an oil supply hole. The rotary shaft is rotatably supported by the housing. The fixed scroll includes a fixed base plate including a discharge port at a center of the fixed base plate, a fixed spiral wall extending from the fixed base plate, and an outer peripheral wall extending from the fixed base plate and surrounding the fixed spiral wall. The orbiting scroll includes an orbiting base plate opposed to the fixed base plate, and an orbiting spiral wall extending from the orbiting based plate and engaging with the fixed spiral wall. The orbiting scroll is configured to revolve relative to the fixed scroll as the rotary shaft rotates. The compression chamber is defined between the fixed spiral wall and the orbiting spiral wall. The suction port is formed in the outer peripheral wall. The suction chamber is formed inside the outer peripheral wall and communicates with the suction port. The discharge chamber is defined inside the housing, communicates with the discharge port. The discharge chamber is a chamber into which a refrigerant compressed in the compression chamber is discharged. The oil storage chamber stores oil separated from the refrigerant discharged into the discharge chamber. The oil supply hole is formed in the fixed scroll. The fixed scroll includes a groove disposed at the same position as the oil supply hole or on an outer side with respect to the oil supply hole in a radial direction of the rotary shaft. At least part of the groove is configured to be closed by the orbiting base plate as the orbiting scroll revolves relative to the fixed scroll. The oil supply hole and the groove form part of an oil supply passage that supplies the oil in the oil storage chamber to the suction chamber.
Other aspects and advantages of the disclosure will become apparent from the following description, taken in conjunction with the accompanying drawings, illustrating by way of example the principles of the disclosure.
The disclosure, together with objects and advantages thereof, may best be understood by reference to the following description of the embodiments together with the accompanying drawings in which:
An embodiment of a scroll compressor according to the present disclosure will be described with reference to
As illustrated in
The motor housing 12 has a bottomed cylindrical shape and includes a disc-shaped end wall 12a and a peripheral wall 12b that cylindrically extends from an outer peripheral edge of the end wall 12a. An axial direction of the peripheral wall 12b coincides with an axial direction of the rotary shaft 15. The peripheral wall 12b includes a female screw hole 12c at an opening end of the peripheral wall 12b. The peripheral wall 12b also includes a suction hole 12h that takes in a refrigerant gas. The suction hole 12h is disposed at a position of the peripheral wall 12b close to the end wall 12a. The suction hole 12h provides communication between an inside and an outside of the motor housing 12.
The end wall 12a includes a boss 12d having a cylindrical shape and protruding from an inner surface of the end wall 12a. A first end of the rotary shaft 15, i.e., one of ends of the rotary shaft 15 in the axial direction, is inserted inside the boss 12d. A rolling bearing 16 is interposed between an inner peripheral surface of the boss 12d and an outer peripheral surface of the first end of the rotary shaft 15. The first end of the rotary shaft 15 is rotatably supported by the motor housing 12 via the rolling bearing 16.
The shaft support housing 13 has a bottomed cylindrical shape and includes an end wall 17 having a disc shape and a peripheral wall 18 that extends from an outer peripheral portion of the end wall 17. An axial direction of the peripheral wall 18 coincides with the axial direction of the rotary shaft 15. The shaft support housing 13 includes a flange wall 19 that has an annular shape and extends, in a radially outward direction of the rotary shaft 15, from an end of an outer peripheral surface of the peripheral wall 18 opposite to the end wall 17. An outer peripheral portion of the flange wall 19 is in contact with the opening end of the peripheral wall 12b of the motor housing 12. The outer peripheral portion of the flange wall 19 includes a bolt insertion hole 19a. The bolt insertion hole 19a is formed through the flange wall 19 in a thickness direction of the flange wall 19. The bolt insertion hole 19a of the flange wall 19 communicates with the female screw hole 12c of the motor housing 12. The motor housing 12 and the shaft support housing 13 define a motor chamber 20 inside the housing 11. The refrigerant gas is taken into the motor chamber 20 through the suction hole 12h.
The end wall 17 includes an insertion hole 17a having a circular hole shape at a center portion thereof. The insertion hole 17a is formed through the end wall 17 in a thickness direction of the end wall 17. The rotary shaft 15 is inserted through the insertion hole 17a. An end surface 15e of a second end of the rotary shaft 15, i.e., the other of the ends of the rotary shaft 15 in the axial direction, is disposed inside the peripheral wall 18. A rolling bearing 21 is interposed between an inner peripheral surface of the peripheral wall 18 and an outer peripheral surface of the rotary shaft 15. The rotary shaft 15 is rotatably supported by the shaft support housing 13 via the rolling bearing 21. The rotary shaft 15 is thus rotatably supported by the housing 11.
The motor chamber 20 accommodates an electric motor 22. The electric motor 22 includes a stator 23 having a cylindrical shape and a rotor 24 disposed inside the stator 23. The rotor 24 rotates integrally with the rotary shaft 15. The stator 23 surrounds the rotor 24. The rotor 24 includes a rotor core 24a fixedly attached to the rotary shaft 15, and a plurality of permanent magnets (not illustrated) provided in the rotor core 24a. The stator 23 includes a stator core 23a having a cylindrical shape and fixed to an inner peripheral surface of the peripheral wall 12b of the motor housing 12, and a coil 23b wound around the stator core 23a. By supplying power controlled by a driving circuit (not illustrated) to the coil 23b, the rotor 24 rotates and the rotary shaft 15 rotates integrally with the rotor 24.
The discharge housing 14 includes an end wall 14a having a disc shape and a peripheral wall 14b that cylindrically extends from an outer peripheral edge of the end wall 14a. An axial direction of the peripheral wall 14b coincides with the axial direction of the rotary shaft 15. An opening end of the peripheral wall 14b is in contact with the outer peripheral portion of the flange wall 19. The peripheral wall 14b includes a bolt insertion hole 14c that communicates with the bolt insertion hole 19a of the flange wall 19.
In a state where the outer peripheral portion of the flange wall 19 is in contact with the opening end of the peripheral wall 12b of the motor housing 12 and the opening end of the peripheral wall 14b of the discharge housing 14 is in contact with the outer peripheral portion of the flange wall 19, a bolt B1 passing through the bolt insertion hole 14c and the bolt insertion hole 19a is screwed into the female screw hole 12c of the motor housing 12. This enables the shaft support housing 13 to be coupled to the peripheral wall 12b of the motor housing 12 and the discharge housing 14 to be coupled to the flange wall 19 of the shaft support housing 13. The motor housing 12, the shaft support housing 13, and the discharge housing 14 are aligned in this order in the axial direction of the rotary shaft 15.
The scroll compressor 10 includes a fixed scroll 25 and an orbiting scroll 26. The fixed scroll 25 and the orbiting scroll 26 are disposed inside the peripheral wall 14b of the discharge housing 14. The fixed scroll 25 is located closer to the end wall 14a than the orbiting scroll 26 is, in the axial direction of the rotary shaft 15.
As illustrated in
As illustrated in
The orbiting base plate 26a includes a boss 26c having a cylindrical shape and protruding from an end surface 26e of the orbiting base plate 26a opposite to the fixed base plate 25a. An axial direction of the boss 26c coincides with the axial direction of the rotary shaft 15. The end surface 26e of the orbiting base plate 26a includes a plurality of recesses 26d each having a circular hole shape around the boss 26c. The recesses 26d are disposed at predetermined intervals in a circumferential direction of the rotary shaft 15. The recesses 26d are fitted with ring members 28 each having an annular shape, respectively. Pins 29 to be inserted into the ring members 28, respectively, protrudes from an end surface 13e of the shaft support housing 13 on a side of the shaft support housing 13 close to the discharge housing 14.
A valve member 25v is installed to a surface of the fixed base plate 25a on a side of the fixed base plate 25a opposite to the orbiting scroll 26. The valve member 25v is configured to open and close the discharge port 25h. The opening end surface of the fixed outer peripheral wall 25c includes a plurality of positioning recesses 25d. Positioning pins 30 to be inserted in the positioning recesses 25d protrude, respectively, from the end surface 13e of the shaft support housing 13. By the positioning pins 30 being inserted in the respective positioning recesses 25d, the fixed scroll 25 is positioned with respect to the shaft support housing 13 in a state where a rotation of the rotary shaft 15 around an axial line L1 inside the peripheral wall 14b of the discharge housing 14 is restricted. The end surface 13e of the shaft support housing 13 and the opening end surface of the fixed outer peripheral wall 25c securely interpose an elastic plate having an annular and plate shape (not illustrated) therebetween. The elastic plate continuously presses the orbiting scroll 26 toward the fixed scroll 25. The fixed scroll 25 is disposed inside the peripheral wall 14b of the discharge housing 14 in a state where the fixed scroll 25 is interposed between the end surface 13e of the shaft support housing 13 and the end wall 14a of the discharge housing 14 so that a movement of the rotary shaft 15 in the axial direction inside the peripheral wall 14b of the discharge housing 14 is restricted.
An eccentric shaft 31 protruding from the end surface 15e of the rotary shaft 15 toward the orbiting scroll 26, at a position decentered from the axial line L1 of the rotary shaft 15, is integrally formed with the rotary shaft 15. An axial direction of the eccentric shaft 31 coincides with the axial direction of the rotary shaft 15. The eccentric shaft 31 is inserted inside the boss 26c. A bush 33 integrated with a balancing weight 32 is fitted to an outer peripheral surface of the eccentric shaft 31. The balancing weight 32 is integrally formed with the bush 33. The balancing weight 32 is accommodated inside the peripheral wall 18 of the shaft support housing 13. The orbiting scroll 26 is supported by the eccentric shaft 31 so as to be relatively rotatable to the eccentric shaft 31 via the bush 33 and a rolling bearing 34.
The rotation of the rotary shaft 15 is transmitted to the orbiting scroll 26 via the eccentric shaft 31, the bush 33, and the rolling bearing 34, which causes the orbiting scroll 26 to rotate on its axis. However, the pins 29 contacting inner peripheral surfaces of the respective ring members 28 stop the orbiting scroll 26 from rotating on its axis and thus only allows the orbiting scroll 26 to revolve. The orbiting scroll 26 revolves with the orbiting spiral wall 26b contacting the fixed spiral wall 25b so that a volumetric capacity of the compression chamber 27 reduces to compress the refrigerant gas. Therefore, the orbiting scroll 26 revolves according to the rotation of the rotary shaft 15. The balancing weight 32 reduces an unbalanced state of the orbiting scroll 26 by offsetting a centrifugal force acting upon the orbiting scroll 26 when the orbiting scroll 26 revolves.
The peripheral wall 12b of the motor housing 12 includes a plurality of first grooves 35 on part of the inner peripheral surface of the peripheral wall 12b. Each of the first grooves 35 is open at the opening end of the peripheral wall 12b. The outer peripheral portion of the flange wall 19 of the shaft support housing 13 includes first holes 36. The first holes 36 communicate with the first grooves 35, respectively. Each of the first holes 36 is formed through the flange wall 19 in the thickness direction. The peripheral wall 14b of the discharge housing 14 includes second grooves 37 on part of an inner peripheral surface of the peripheral wall 14b. The second grooves 37 communicate with the first holes 36, respectively. The first grooves 35, the first holes 36, and the second grooves 37 are illustrated only by one each in
As illustrated in
As illustrated in
The direction of gravity is indicated by an arrow Z1 in
As illustrated in
The connecting portion 53 includes a sliding surface 54 with which the orbiting base plate 26a intermittently comes into sliding contact as the orbiting scroll 26 revolves relative to the fixed scroll 25. The sliding surface 54 is an end surface of the connecting portion 53 on a side of the connecting portion 53 opposite to the fixed base plate 25a. The sliding surface 54 has a flat surface. The sliding surface 54 is disposed at a position closer to the fixed base plate 25a than to the opening end surface of the fixed outer peripheral wall 25c. The sliding surface 54 is continuous with the inner peripheral surface of the fixed outer peripheral wall 25c. The sliding surface 54 is flush with the tip end surface of the fixed spiral wall 25b. The sliding surface 54 is continuous with the tip end surface of the fixed spiral wall 25b located at the outermost peripheral portion.
As illustrated in
As illustrated in
The end portion of the groove 56 on a side of the groove 56 close to the second suction port 52 is not opened to a portion of the connecting portion 53 on a side of the connecting portion 53 close to the second suction port 52 in the circumferential direction of the fixed outer peripheral wall 25c. In other word, the end portion of the groove 56 on the side of the groove 56 close to the second suction port 52 is closed. Part of the sliding surface 54 is interposed, in the circumferential direction of the fixed spiral wall 25b, between the groove 56 and the portion of the connecting portion 53 on the side of the connecting portion 53 close to the second suction port 52 in the circumferential direction of the fixed outer peripheral wall 25c. Part of the sliding surface 54 is interposed, in the radial direction of the fixed outer peripheral wall 25c, between the groove 56 and the fixed spiral wall 25b. At least part of the groove 56 is configured to be closed by the orbiting base plate 26a as the orbiting scroll 26 revolves relative to the fixed scroll 25.
As illustrated in
The scroll compressor 10 includes a discharge chamber 41. The discharge chamber 41 is defined inside the housing 11. The discharge chamber 41 is defined by the discharge housing 14 and the fixed scroll 25. The discharge chamber 41 communicates with the discharge port 25h. The refrigerant gas compressed in the compression chamber 27 is discharged through the discharge port 25h into the discharge chamber 41.
A gasket 70 having an annular shape is interposed between the discharge housing 14 and the fixed scroll 25. The gasket 70 is a thin plate made of metal. An outer peripheral portion of the gasket 70 extends along the outer peripheral portion of the fixed base plate 25a. A gap between the discharge housing 14 and the fixed scroll 25 is sealed by the gasket 70.
The discharge housing 14 includes an oil separating chamber 43. The oil separating chamber 43 is formed inside an external cylinder 44 having an elongated cylindrical shape that is part of the end wall 14a of the discharge housing 14. One of end portions of the external cylinder 44 in an axial direction, i.e., a first end portion, is opened to an outer peripheral surface of the end wall 14a of the discharge housing 14. The first end portion of the external cylinder 44 and the suction hole 12h are connected via an external refrigerant circuit 49. The external refrigerant circuit 49 includes a condenser 49a, an expansion valve 49b, and an evaporator 49c. The scroll compressor 10 and the external refrigerant circuit 49 form an air-conditioning system for a vehicle.
The scroll compressor 10 includes an oil separator 45. The oil separator 45 separates oil from the refrigerant gas that has been discharged into the discharge chamber 41. The oil separator 45 has a cylindrical shape. The oil separator 45 is installed inside the external cylinder 44 by being fitted to an inner peripheral surface of the external cylinder 44 with an axial direction of the oil separator 45 aligned with an axial direction of the external cylinder 44.
The discharge housing 14 includes a guiding hole 47 that provides communication between the discharge chamber 41 and the oil separating chamber 43. The guiding hole 47 guides the refrigerant gas, which has been discharged into the discharge chamber 41, to the oil separating chamber 43. The scroll compressor 10 includes an oil storage chamber 42. The oil storage chamber 42 is disposed at a lower part of the discharge housing 14. The oil storage chamber 42 stores the oil separated from the refrigerant gas by the oil separator 45.
The scroll compressor 10 includes an oil supply passage 60. The oil supply passage 60 includes a communication groove (not illustrated) formed on the outer peripheral portion of the gasket 70 and communicating with the oil storage chamber 42, and an oil supply hole 25f communicating with the communication groove. The oil supply hole 25f is formed in the fixed scroll 25. A first end of the oil supply hole 25f communicates with the communication groove of the gasket 70.
As illustrated in
As illustrated in
The oil supply hole 25f and the groove 56 form part of the oil supply passage 60 that supplies the oil in the oil storage chamber 42 to the suction chamber 55. The oil supplied from the oil supply hole 25f is temporarily storable in a space formed by the groove 56 and the orbiting base plate 26a when at least part of the groove 56 is closed by the orbiting base plate 26a according to the revolution of the orbiting scroll 26.
Operational effects of the embodiment of the present disclosure will now be described in the following paragraphs.
The refrigerant gas after compressed in the compression chamber 27 is discharged through the discharge port 25h into the discharge chamber 41, and then is guided through the guiding hole 47 into the oil separating chamber 43. The refrigerant gas guided into the oil separating chamber 43 turns around in the oil separator 45. This gives a centrifugal force to the oil included in the refrigerant gas so that the oil is separated from the refrigerant gas in the oil separating chamber 43. The refrigerant gas from which the oil is separated flows into the oil separator 45 through an opening at a lower part of the oil separator 45, passes through the oil separator 45 and the external cylinder 44, and flows out to the external refrigerant circuit 49.
The refrigerant gas having flowed out to the external refrigerant circuit 49 passes through the condenser 49a, the expansion valve 49b, and the evaporator 49c of the external refrigerant circuit 49. The refrigerant gas passing through the condenser 49a, the evaporator 49c, and the like is a refrigerant gas from which the oil has been separated in the oil separating chamber 43. This reduces a likelihood of the oil attaching to the condenser 49a, the evaporator 49c, and the like, and thus, reduces deterioration in an efficiency of heat exchange of the condenser 49a, the evaporator 49c, and the like. The refrigerant gas after having passed the condenser 49a, the expansion valve 49b, and the evaporator 49c returns to the motor chamber 20 through the suction hole 12h.
The oil separated from the refrigerant gas in the oil separating chamber 43 is stored in the oil storage chamber 42. The oil stored in the oil storage chamber 42 flows through the oil supply hole 25f, i.e., the part of the oil supply passage 60, to the sliding surface 54. Some of the oil having flowed out from the oil supply hole 25f to the sliding surface 54 flows along the sliding surface 54 to flow into the groove 56. As illustrated in
The oil having flowed into the groove 56 flows toward a portion of the suction chamber 55, which have an inlet pressure, on a side of the suction chamber 55 closer to the first suction port 51 than to the second suction port 52 because the groove 56 communicates with the portion of the suction chamber 55 on the side of the suction chamber 55 closer to the first suction port 51 than to the second suction port 52. As a result, the oil in the groove 56 flows out from the groove 56 toward the first suction port 51, and flows into the suction chamber 55. Therefore, the oil from the oil supply hole 25f flows through the groove 56 toward the first suction port 51 to flow into the suction chamber 55.
Some of the oil having flowed out from the oil supply hole 25f to the sliding surface 54 flows along the sliding surface 54 toward the second suction port 52 by own weight and flows into the suction chamber 55 without flowing into the groove 56. Therefore, the oil from the oil supply hole 25f flows along the sliding surface 54 toward the second suction port 52 to flow into the suction chamber 55.
As described above, the oil supply passage 60 supplies the oil stored in the oil storage chamber 42 to the suction chamber 55. The oil supplied to the suction chamber 55 is supplied between the fixed scroll 25 and the orbiting scroll 26, which improves lubricity between the fixed scroll 25 and the orbiting scroll 26. This smooths the revolution of the orbiting scroll 26, and improves a compression efficiency of the scroll compressor 10.
The embodiment of the present disclosure has the following advantageous effects.
The embodiment according to the present disclosure may be modified as follows. The embodiment described above and modification examples to be described below may be implemented in combination with each other as long as they are not technically inconsistent.
As illustrated in
The oil supply hole 25f of the embodiment illustrated in
The oil supply hole 25f of the embodiment, with respect to the sliding surface 54, need not be opened and closed by the orbiting base plate 26a according to the revolution of the orbiting scroll 26, but may be opened to a portion that is continuously open.
The scroll compressor 10 of the embodiment may include another suction port 50 in the fixed outer peripheral wall 25c of the fixed scroll 25, in addition to the first suction port 51 and the second suction port 52.
The fixed scroll 25 of the embodiment need not include, for example, the second suction port 52 in the fixed outer peripheral wall 25c. The suction port 50 in the fixed outer peripheral wall 25c of the fixed scroll 25 may be provided by a single suction port 50.
The scroll compressor 10 of the present embodiment need not be driven by the electric motor 22, but may be driven by, for example, an engine of a vehicle.
Number | Date | Country | Kind |
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2021-011311 | Jan 2021 | JP | national |