Scroll-type compressor

Abstract

A shaft support member (30) for supporting, via a bearing (34), a rotary shaft (20) extending in the vertical direction partitions off an upper suction space (17a) which has disposed therein a fixed scroll (50) and a movable scroll (60), and a lower suction space (17b) which has disposed therein an electric motor (40) and an oil storage chamber (18). Between the shaft support member (30) and the movable scroll (60), a back pressure chamber (19) for applying, to the movable scroll (60), a back pressure opposing the pressure within a compression chamber is formed. A pump (75) feeds oil pumped up from the oil storage chamber (18) to the upper suction space (17a) via an oil feed passage (70) which connects the oil storage chamber (18) and the upper suction space (17a). The oil feed passage (70) is disposed in a region partitioned off the back pressure chamber (19) by seal mechanisms (35, 36, 38) that seal between the rotary shaft (20) and the shaft support member (30) and that separate the back pressure chamber (19) from the lower suction space (17b).

Description

Scroll-type compressor

[0001] The present invention relates to a scroll-type compressor.

[0002] A conventional scroll-type compressor is disclosed in Patent Document 1. This scroll-type compressor is a so-called vertical compressor, and includes a housing, a rotating shaft, a shaft support member, an electric motor, a fixed scroll, and a movable scroll.

[0003] The housing has a circumferential wall extending cylindrically in the vertical direction. The interior of the housing serves as a discharge space. The rotating shaft is disposed inside the housing and has a rotational axis extending in the vertical direction. The shaft support member is disposed inside the housing and rotatably supports the rotating shaft via a bearing. The electric motor is disposed below the shaft support member and drives the rotating shaft to rotate. The fixed scroll is disposed above the shaft support member and is fixed to the housing. The movable scroll is disposed between the shaft support member and the fixed scroll, and forms a compression chamber for compressing fluid between itself and the fixed scroll vertically opposing thereto, while rotating together with the rotating shaft. On the outer circumferential side of the movable scroll, between the shaft support member and the fixed scroll, there is formed a suction chamber through which fluid is sucked in from the outside.

[0004] This scroll-type compressor further includes an oil storage chamber, a back pressure chamber, an oil supply passage, and a pump.

[0005] The oil storage chamber is disposed in the lower part of the housing and stores oil separated from the fluid. The back pressure chamber is formed between the movable scroll and the shaft support member, and applies a back pressure opposing the pressure inside the compression chamber to the movable scroll by means of oil supplied from the oil storage chamber. The bearing is disposed in the back pressure chamber. The oil supply passage communicates the oil storage chamber with the back pressure chamber, and also communicates the back pressure chamber with the suction chamber. The pump pumps up oil from the oil storage chamber and supplies the oil to the suction chamber via the oil supply passage and the back pressure chamber.

[0006] Thus, in the above-mentioned conventional scroll-type compressor, oil pumped up from the oil storage chamber by the pump is supplied to the suction chamber, and the oil lubricates sliding portions of the bearing and the compression chamber.

[0007] Japanese Unexamined Patent Application Publication No. 2010-138749

[0008] Incidentally, in the conventional scroll compressor described above, the inside of the housing serves as the discharge space, and the electric motor is positioned in the discharge space where the discharge pressure of the fluid, which has been compressed in the compression chamber and become high temperature and high pressure, acts. As a result, in the conventional scroll compressor described above, the operating environment of the electric motor becomes hot, and the coil is more prone to heat loss when the electric motor is under high load. Consequently, the durability of the electric motor may decrease. Therefore, in the case of compressors mounted on vehicles, protective control is usually implemented to stop the operation of the compressor when the electric motor exceeds its limit temperature.

[0009] Therefore, it is conceivable to create an intake space within the housing and place the electric motor in the intake space, which is less prone to high temperatures. However, in this case, the oil storage chamber would be located in the intake space, making it difficult to supply the oil pumped from the oil storage chamber to the intake chamber and, consequently, the compression chamber, via the back pressure chamber, which is at a higher pressure than the intake space in the conventional scroll compressor configuration described above. As a result, the lubricity of the sliding parts may decrease.

[0010] If the pressure in the back pressure chamber is maintained below the intake pressure, oil can be supplied to the compression chamber; however, in that case, the back pressure chamber cannot function as a back pressure chamber. Thus, it is difficult to achieve both the formation of a back pressure chamber and the supply of oil to the compression chamber.

[0011] This invention has been made in view of the above-mentioned conventional circumstances, and aims to solve the problem of providing a scroll-type compressor that can achieve both the formation of a back pressure chamber and the supply of oil to the compression chamber while avoiding the use of the electric motor in a high-temperature environment.

[0012] The scroll compressor of the present invention comprises: a housing having a circumferential wall extending vertically in a cylindrical shape and having an intake space formed inside; a rotating shaft disposed within the housing and extending vertically; a support member that rotatably supports the rotating shaft via a bearing, the support member dividing the intake space into an upper intake space above the support member and a lower intake space below the support member; an electric motor disposed in the lower intake space for rotating the rotating shaft; a fixed scroll disposed in the upper intake space; and a movable scroll disposed between the support member and the fixed scroll, rotating together with the rotating shaft and forming a compression chamber between itself and the vertically opposing fixed scroll for compressing fluid drawn in from the upper intake space, the scroll compressor comprising: a back pressure chamber formed between the support member and the movable scroll, which applies a back pressure to the movable scroll to counteract the pressure in the compression chamber by introducing a portion of the fluid compressed in the compression chamber; and an oil storage chamber disposed in the lower intake space for storing oil separated from the fluid. The device comprises: a fuel supply passage connecting the oil storage chamber and the upper suction space; a pump that supplies oil pumped from the oil storage chamber to the upper suction space via the fuel supply passage; and a sealing mechanism that seals the space between the rotating shaft and the shaft support member, thereby separating the back pressure chamber from the lower suction space, wherein the fuel supply passage is located in a region partitioned from the back pressure chamber by the sealing mechanism.

[0013] The scroll compressor of the present invention is a so-called vertically mounted compressor, installed in such a manner that the rotating shaft extends in the vertical direction. In this scroll compressor, the intake space formed inside the housing is divided into an upper intake space and a lower intake space by a shaft support member. The oil reservoir is located in the lower intake space. In such a case, it is difficult to pump oil from the oil reservoir and supply it to the back pressure chamber, which has a higher pressure than the lower intake space, or to supply oil to the upper intake space and, consequently, to the compression chamber via the back pressure chamber.

[0014] In this regard, in the scroll compressor of the present invention, the back pressure chamber is separated from the lower suction space by a sealing mechanism, and the oil supply passage is located in the area partitioned from the back pressure chamber by the sealing mechanism. Therefore, the sealing mechanism can suppress the high pressure in the back pressure chamber from acting on the oil supply passage. As a result, oil pumped from the oil storage chamber can be suitably supplied to the upper suction space and, consequently, to the sliding parts of the compression chamber via the oil supply passage.

[0015] Furthermore, in the scroll-type compressor of the present invention, the electric motor is located in the lower suction space, which is less prone to becoming extremely hot.

[0016] Therefore, the scroll compressor of the present invention makes it possible to achieve both the formation of a back pressure chamber and the supply of oil to the compression chamber while avoiding the use of the electric motor in high-temperature environments.

[0017] The bearing is preferably positioned in an area partitioned from the back pressure chamber by a sealing mechanism and exposed to the lubrication passage.

[0018] In this case, oil passing through the lubrication passage can be supplied to the bearing, thereby effectively lubricating the bearing.

[0019] Preferably, the lubrication passage has an internal passage within the rotating shaft that is formed inside the rotating shaft and connected to the oil storage chamber, and an internal passage within the support member that is formed inside the support member and connects the internal passage within the rotating shaft to the upper suction space. Furthermore, it is preferable that at least a portion of the internal passage within the support member and the internal passage within the rotating shaft are located below the seal mechanism. And, preferably, the bearing is exposed in the portion of the internal passage within the support member that is located below the seal mechanism.

[0020] In this case, the oil pumped up from the oil storage chamber is supplied to the upper suction space through the internal passage of the rotating shaft and the internal passage of the support member. The oil passing through the internal passage of the support member is then supplied to the bearing, thereby effectively lubricating the bearing.

[0021] According to the scroll-type compressor of the present invention, it is possible to achieve both the formation of a back pressure chamber and the supply of oil to the compression chamber while avoiding the use of the electric motor in high-temperature environments.

[0022] Figure 1 is a longitudinal cross-sectional view of the scroll compressor of Example 1. Figure 2 is a longitudinal cross-sectional view of the scroll compressor of Example 2. Figure 3 is a longitudinal cross-sectional view of the scroll compressor of Example 3.

[0023] Examples 1 to 3 embodying the present invention will be described below with reference to the drawings. Specifically, the scroll compressors (hereinafter simply referred to as "compressors") in Examples 1 to 3 are scroll-type electric compressors. The compressors in Examples 1 to 3 are mounted in a vehicle (not shown) and constitute the vehicle's refrigeration circuit.

[0024] In Examples 1 to 3, the vertical and longitudinal directions of the compressor are defined by the solid arrows shown in Figures 1 to 3. Note that this vertical direction refers to the vertical direction in the mounting position of the compressor when mounted on a vehicle. This vertical direction coincides with or approximately coincides with the vertical direction. Furthermore, this longitudinal direction is an example for the sake of explanation; the longitudinal and lateral directions of the compressor in the mounting position are appropriately changed according to the vehicle on which it is mounted.

[0025] As shown in Figure 1, the compressor of Embodiment 1 comprises a housing 10, a rotating shaft 20, a support member 30, an electric motor 40, a fixed scroll 50, and a movable scroll 60.

[0026] The housing 10 is made of aluminum alloy and includes a compressor housing 11, a motor housing 12, a shaft support housing 13, and a housing cover 14. The compressor housing 11 constitutes the substantially upper portion of the housing 10, while the motor housing 12, the shaft support housing 13, and the housing cover 14 constitute the substantially lower portion of the housing 10.

[0027] The compressor housing 11 has an upper wall 11a and a first circumferential wall 11b. The upper wall 11a is located at the upper end of the compressor housing 11 and extends radially. The first circumferential wall 11b is connected to the upper wall 11a and extends downward from the upper wall 11a in a substantially cylindrical shape. Due to these upper wall 11a and first circumferential wall 11b, the compressor housing 11 has a bottomed cylindrical shape with an open bottom.

[0028] The compressor housing 11 has an oil separation chamber 11d, a discharge recess 11e, a discharge passage 11f, and a discharge opening 11g. The oil separation chamber 11d is formed inside the upper wall 11a and extends radially to the compressor housing 11. The discharge recess 11e is formed in the upper wall 11a. The discharge recess 11e has a shape that is recessed upward toward the oil separation chamber 11d. The discharge passage 11f is formed inside the upper wall 11a and extends in the direction of the rotation axis O between the oil separation chamber 11d and the discharge recess 11e. Thus, the discharge passage 11f connects the oil separation chamber 11d and the discharge recess 11e. The discharge opening 11g is formed in the upper wall 11a. The discharge opening 11g is in communication with the front end of the oil separation chamber 11d and opens toward the front of the upper wall 11a. The discharge opening 11g is connected to a condenser (not shown) by piping.

[0029] Furthermore, a separation cylinder 11h is fixed inside the oil separation chamber 11d. The inner surface of the oil separation chamber 11d and the outer surface of the separation cylinder 11h constitute an oil separator. In addition, a filter 11j is provided inside the oil separation chamber 11d, rearward of the separation cylinder 11h.

[0030] The motor housing 12 is positioned below the compressor housing 11, with the shaft support member 30 in between. The motor housing 12 is substantially cylindrical and has a second circumferential wall 12a and a first flange 12b. The second circumferential wall 12a extends substantially cylindrical in the vertical direction. The first flange 12b protrudes radially outward from the lower end of the second circumferential wall 12a.

[0031] Furthermore, an intake opening 12c is formed in the motor housing 12. The intake opening 12c is formed in the lower part of the second peripheral wall 12a and penetrates the second peripheral wall 12a radially while communicating with the lower intake space 17b, which will be described later. The intake opening 12c is connected to an evaporator (not shown) by piping (not shown), and the refrigerant gas that has passed through the evaporator is drawn into the lower intake space 17b. The refrigerant gas is an example of a "fluid" in this invention.

[0032] The support member 30 is provided between the compressor housing 11 and the motor housing 12. The support member 30 has a roughly disc-shaped main body 31 and a first boss 32. The main body 31 has approximately the same diameter as the first circumferential wall 11b of the compressor housing 11 and the second circumferential wall 12a of the motor housing 12, and is sandwiched vertically by the first circumferential wall 11b and the second circumferential wall 12a. In this compressor, the outer circumferential surface of the support member 30 is exposed to the outside of the compressor, but for example, the support member 30 may be fixed to the motor housing 12 without exposing the outer circumferential surface of the support member 30 to the outside of the compressor.

[0033] The main body portion 31 has a recess 31a and an intake hole 31b formed therein.

[0034] The recess 31a is a cylindrical recess formed in the center of the main body 31, extending downward from the upper end surface of the main body 31 with the rotation axis O as the center. The intake hole 31b penetrates the main body 31 in the vertical direction and connects the upper intake space 17a and the lower intake space 17b, which will be described later.

[0035] Six swivel pins 33 are fixed to the main body 31. Each swivel pin 33 protrudes above the upper end surface of the main body 31. The swivel pins 33 are arranged at equal intervals in the circumferential direction of the main body 31. Note that Figure 1 shows one of the six swivel pins 33.

[0036] The first boss 32 is integrally formed with the main body 31 and protrudes downward from the main body 31 in a bottomed cylindrical shape. An annular bottom wall 32a is integrally formed at the lower end of the first boss 32. The inner circumferential surface of the bottom wall 32a is an axle hole 32b through which the rotating shaft 20 is inserted. The axle hole 32b communicates with the interior of the first boss 32. The interior of the first boss 32 communicates with the recess 31a. A first radial bearing 34 is provided inside the first boss 32. The first radial bearing 34 is an example of a "bearing" in the present invention. Details of the first radial bearing 34 will be described later.

[0037] The pivot housing 13 is located below the motor housing 12. The pivot housing 13 is substantially cylindrical and has a third circumferential wall 13a, a second flange 13b, a support portion 13c, and four connecting arms 13d. The pivot housing 13 may be formed integrally with the motor housing 12.

[0038] The third circumferential wall 13a extends in a substantially cylindrical shape in the vertical direction. The second flange 13b protrudes radially outward from the upper end of the third circumferential wall 13a.

[0039] The support portion 13c extends vertically in a short cylindrical shape coaxially with the third circumferential wall 13a. A second radial bearing 13e is provided inside the support portion 13c.

[0040] Each connecting arm 13d extends radially from the support portion 13c, connecting the third circumferential wall 13a and the support portion 13c. The connecting arms 13d are arranged at equal intervals in the circumferential direction of the third circumferential wall 13a. Four oil passage openings 13f are formed between the connecting arms 13d, allowing oil 77 to flow. Each oil passage opening 13f is fan-shaped and extends vertically, connecting the oil storage chamber 18 (described later) and the lower suction space 17b.

[0041] The housing cover 14 is positioned below the pivot housing 13. The housing cover 14 is roughly disc-shaped and abuts against the lower end of the third peripheral wall 13a, closing off the lower part of the pivot housing 13. In this way, an oil storage chamber 18 is formed inside the housing 10 at its lower part, partitioned by the pivot housing 13 and the housing cover 14. Oil 77 separated from the refrigerant gas is stored in the oil storage chamber 18.

[0042] The rotating shaft 20 is provided within the housing 10, extending in the vertical direction. The rotating shaft 20 is cylindrical in shape, extending in the direction of the rotation axis O with the rotation axis O as its center. The rotating shaft 20 has a large diameter portion 20a, a medium diameter portion 20b, and a small diameter portion 20c. The upper end of the rotating shaft 20 is the large diameter portion 20a, and the lower end of the rotating shaft 20 is the small diameter portion 20c.

[0043] The rotating shaft 20 is rotatably supported by the shaft support member 30 and the shaft support housing 13 via the first radial bearing 34 and the second radial bearing 13e. Specifically, the upper end of the large-diameter portion 20a is inserted into the shaft hole 32b of the first boss 32, and enters the interior of the first boss 32. Inside the first boss 32, the upper end of the large-diameter portion 20a is rotatably supported by the first radial bearing 34. Further, the lower end of the medium-diameter portion 20b is rotatably supported by the second radial bearing 13e provided on the support portion 13c of the shaft support housing 13. In this way, the rotating shaft 20 is rotatable about the rotation axis O within the housing 10. The small-diameter portion 20c is disposed in the oil storage chamber 18.

[0044] At the upper end of the rotating shaft 20, a columnar eccentric pin 21 is provided to protrude upward at a position eccentric from the rotation axis O. A cylindrical bush 22 is fitted to and supported by the eccentric pin 21.

[0045] A balance weight 23 is fixed to the rotating shaft 20 at a position below the shaft support member 30. The balance weight 23 extends radially outward from the large-diameter portion 20a at a position opposite to the eccentric pin 21 across the rotation axis O. The balance weight 23 cancels out the centrifugal force generated by the orbiting motion of the movable scroll 60 as the rotating shaft 20 rotates.

[0046] The fixed scroll 50 is disposed above the shaft support member 30, and is clamped between the shaft support member 30 and the compressor housing 11. The fixed scroll 50 includes a fixed end plate 51, a fixed peripheral wall 52, and a fixed spiral wall 53.

[0047] The fixed end plate 51 is located at the upper end of the fixed scroll 50 and formed into a substantially disc shape. The outer peripheral surface of the fixed end plate 51 is fitted to the first peripheral wall 11b, and the upper end surface of the fixed end plate 51 is in contact with the lower end surface of the upper wall 11a. A discharge port 54 is formed in the fixed end plate 51. The discharge port 54 penetrates the fixed end plate 51 in the direction of the rotation axis O. Further, a discharge reed valve 56 and a retainer 57 are attached to the fixed end plate 51 by a fixing bolt 55. The discharge reed valve 56 opens and closes the discharge port 54 by elastic deformation. The retainer 57 adjusts the amount of elastic deformation of the discharge reed valve 56.

[0048] The fixed peripheral wall 52 is formed into a cylindrical shape extending in the direction of the rotation axis O. The fixed peripheral wall 52 is connected to the fixed end plate 51 at the outer periphery of the fixed end plate 51, and extends downward from the fixed end plate 51. The fixed peripheral wall 52 is located radially outward of the fixed scroll 50 relative to the fixed spiral wall 53. A suction port 58 is formed in the fixed peripheral wall 52. The suction port 58 penetrates the fixed peripheral wall 52 in the radial direction of the fixed peripheral wall 52. A gap extending in a substantially annular shape in the direction of the rotation axis O is formed between the outer peripheral surface of the fixed peripheral wall 52 and the inner peripheral surface of the first peripheral wall 11b.

[0049] The fixed spiral wall 53 is formed integrally with the fixed end plate 51, and extends downward from the lower end surface of the fixed end plate 51 in the direction of the rotation axis O. The fixed spiral wall 53 extends spirally from the center side of the fixed end plate 51 toward the radially outer side of the fixed scroll 50.

[0050] The movable scroll 60 is disposed between the shaft support member 30 and the fixed scroll 50. The movable scroll 60 is disposed radially inward of the fixed peripheral wall 52. The movable scroll 60 includes a movable end plate 61 and a movable spiral wall 62.

[0051] The movable end plate 61 is roughly disc-shaped and faces the fixed end plate 51 in the vertical direction. The movable spiral wall 62 is formed integrally with the movable end plate 61 and extends upward from the upper end surface of the movable end plate 61 in the direction of the rotation axis O. The movable spiral wall 62 extends spirally from the center side of the movable end plate 61 radially outward from the movable scroll 60. The movable spiral wall 62 is engaged with the fixed spiral wall 53.

[0052] A third radial bearing 24 is provided radially inward of a cylindrical second boss portion 63 located on the lower end surface of the movable end plate 61. A bush 22 is rotatably supported on the movable end plate 61 via the third radial bearing 24. As a result, the movable scroll 60 is connected to the rotation axis 20 at an eccentric position from the rotation axis O via the bush 22 and the eccentric pin 21.

[0053] Six rings 64 are fixed to the lower end surface of the movable end plate 61. Each ring 64 is arranged at equal intervals in the circumferential direction of the movable end plate 61 to correspond to each pivot pin 33. Note that Figure 1 shows one of the six rings 64.

[0054] Between the vertically opposing fixed scroll 50 and movable scroll 60, a compression chamber 66 is formed, partitioned by a fixed end plate 51, a fixed peripheral wall 52, a fixed spiral wall 53, a movable end plate 61, and a movable spiral wall 62.

[0055] A ring-shaped metal plate 25 is interposed between the fixed scroll 50 and the pivot member 30. The plate 25 is sandwiched between the main body 31 of the pivot member 30 and the fixed peripheral wall 52 of the fixed scroll 50. The plate 25 can bias the movable scroll 60 upward, that is, toward the fixed scroll 50, by the restoring force during elastic deformation.

[0056] Oil passage holes 26 are formed in the fixed scroll 50 and the support member 30. The oil passage holes 26 consist of a first hole 26a that penetrates the fixed end plate 51 and the fixed peripheral wall 52 of the fixed scroll 50, a second hole 26b that penetrates the plate 25, and a third hole 26c that penetrates the support member 30. The upper end of the first hole 26a opens to the upper end surface of the fixed end plate 51. The second hole 26b connects the first hole 26a and the third hole 26c. The lower end of the third hole 26c opens to the lower end surface of the main body portion 31 of the support member 30. In this way, the oil passage holes 26 connect the oil separation chamber 11d and the lower suction space 17b, which will be described later, through the filter 11j.

[0057] The electric motor 40 is located inside the housing 10, more specifically in the lower intake space 17b. In other words, the lower intake space 17b also serves as a motor chamber for housing the electric motor 40. The electric motor 40 is located below the shaft support member 30 and below the balance weight 23 fixed to the rotating shaft 20.

[0058] The electric motor 40 has a stator 41 and a rotor 42. The stator 41 is connected to an inverter (not shown) located outside the housing 10.

[0059] The stator 41 has a stator core 41a and a coil end 41b. The stator core 41a is formed in a cylindrical shape and is fixed to the inner surface of the second peripheral wall 12a of the motor housing 12. A coil 41c made of conductive wire is wound around the stator core 41a. The coil end 41b is an annular shape that protrudes vertically from the stator core 41a in the direction of the rotation axis O. The coil end 41b is formed by a part of the coil 41c.

[0060] The rotor 42 is formed in a cylindrical shape extending in the direction of the rotation axis O and is located inside the stator 41. The rotor 42 is fixed to the lower end of the large-diameter portion 20a by press-fitting. As a result, the rotation of the rotor 42 inside the stator 41 causes the rotation shaft 20 to rotate around the rotation axis O.

[0061] Although not shown in the diagram, in this compressor, the compressor housing 11, the support member 30, and the motor housing 12 are fastened and fixed in the direction of the rotation axis O by multiple bolts. Also, although not shown in the diagram, the motor housing 12 and the support housing 13 are fastened together by multiple bolts, and the support housing 13 and the housing cover 14 are fastened together by multiple bolts.

[0062] As described above, inside the compressor housing 11, the outer circumferential surface of the fixed end plate 51 of the fixed scroll 50 fits into the first circumferential wall 11b, and the upper end surface of the fixed end plate 51 abuts against the upper wall 11a. As a result, the discharge chamber 15 is formed by the discharge recess 11e and the fixed end plate 51. The discharge chamber 15 is in communication with the discharge port 54 and the discharge passage 11f. In other words, the discharge chamber 15 is in communication with the compression chamber 66 through the discharge port 54.

[0063] Furthermore, the area above the fixed scroll 50 inside the housing 10 is designated as the discharge space 16, and the remaining area is designated as the suction space 17.

[0064] In this compressor, the intake space 17 is divided into an upper intake space 17a above the support member 30 and a lower intake space 17b below the support member 30, by a support member 30 sandwiched between the compressor housing 11 and the motor housing 12 in the direction of the rotation axis O. In other words, the upper intake space 17a is the gap between the fixed peripheral wall 52 of the fixed scroll 50 and the first peripheral wall 11b of the compressor housing 11, above the support member 30. The upper intake space 17a is in communication with the compression chamber 66 through the intake port 58. The upper intake space 17a may be formed between the support member 30 and the fixed scroll, in the gap between the fixed peripheral wall 52 and the movable spiral wall 62 in the radial direction.

[0065] Furthermore, a back pressure chamber 19 is formed by the recess 31a of the pivot member 30, the movable end plate 61 of the movable scroll 60, and the plate 25. The back pressure chamber 19 is formed in a substantially annular shape on the outside of the rotation axis 20 and is located below the movable end plate 61 of the movable scroll 60, with the plate 25 in between. The back pressure chamber 19 is in communication with the air supply hole 67. The air supply hole 67 penetrates the movable scroll 60 in the direction of the rotation axis O on the central side of the movable scroll 60. The upper end of the air supply hole 67 opens to the tip surface of the movable spiral wall 62, and the lower end of the air supply hole 67 opens to the lower end surface of the movable end plate 61. In this way, the compression chamber 66 and the back pressure chamber 19 are in communication with each other by the air supply hole 67.

[0066] The first radial bearing 34, provided within the first boss 32 of the support member 30, is a so-called sealed bearing, with a rubber seal plate 35 attached to its upper end. The rubber seal plate 35 is an example of a "sealing mechanism" in the present invention.

[0067] Furthermore, the first radial bearing 34 is a ball bearing having an outer ring, an inner ring, and a plurality of rolling elements. The rubber seal plate 35 is annular in shape and covers the gap between the outer ring and the inner ring. In this way, the rubber seal plate 35 mounted on the first radial bearing 34 seals the space between the first boss 32 of the shaft support member 30 and the rotating shaft 20. As a result, the back pressure chamber 19 located above the rubber seal plate 35 is separated from the lower suction space 17b located below the rubber seal plate 35.

[0068] The outer edge of the rubber seal plate 35 is in contact with the outer ring, but the inner edge of the rubber seal plate 35 is not in contact with the inner ring. In other words, this first radial bearing 34 is a so-called non-contact type sealed bearing, but it could also be a contact type sealed bearing in which the inner edge of the rubber seal plate 35 is in contact with the inner ring, or a non-contact type shielded bearing in which a metal seal plate is installed instead of the rubber seal plate 35.

[0069] Furthermore, this compressor is equipped with a fuel supply passage 70 and a pump 75.

[0070] The lubrication passage 70 includes a passage 71 inside the rotating shaft and a passage 72 inside the support member.

[0071] The rotating shaft internal passage 71 is formed inside the rotating shaft 20. The lower end of the rotating shaft internal passage 71 opens to the lower end surface of the rotating shaft 20, and the upper end of the rotating shaft internal passage 71 opens to the outer circumferential surface near the upper end of the rotating shaft 20. The rotating shaft internal passage 71 consists of an axial portion 71a and a radial portion 71b. That is, the lower end of the axial portion 71a opens to the lower end surface of the small diameter portion 20c. The axial portion 71a extends upward from its lower end along the direction of the rotation axis O, and its upper end extends to near the upper end of the large diameter portion 20a. One end of the radial portion 71b is connected to the upper end of the axial portion 71a. The radial portion 71b extends radially outward from one end to the other end, and the other end opens to the outer circumferential surface of the large diameter portion 20a.

[0072] The internal passage 72 of the pivot member is formed inside the pivot member 30. The internal passage 72 of the pivot member consists of an annular recess 72a and an obliquely upward portion 72b. The annular recess 72a is formed on the entire upper surface of the bottom wall 32a and the inner circumferential surface of the first boss 32. The annular recess 72a is located at the same height as the radial portion 71b of the internal passage 71 of the rotating shaft, and the inner circumferential end of the annular recess 72a faces the radial portion 71b in the radial direction. That is, the inner circumferential end of the annular recess 72a communicates with the other end of the radial portion 71b. The inner circumferential end of the annular recess 72a coincides with the inner circumferential end of the bottom wall 32a, and the annular recess 72a extends horizontally from its inner circumferential end toward the outer circumference. The outer circumferential end of the annular recess 72a is located further outward than the first radial bearing 34. One end of the obliquely upward portion 72b is connected to the outer circumferential end of the annular recess 72a. The diagonally upward portion 72b extends diagonally upward toward the outer circumference from one end of the annular recess 72a. The other end of the diagonally upward portion 72b opens to the upper end surface of the main body portion 31 at a position corresponding to the upper intake space 17a.

[0073] Thus, the oil storage chamber 18 and the upper suction space 17a are connected by the rotating shaft internal passage 71 and the pivot member internal passage 72 of the oil supply passage 70. The back pressure chamber 19 is separated from the lower suction space 17b by the rubber seal plate 35, which functions as a sealing mechanism, and the oil supply passage 70 and the first radial bearing 34 are arranged in the area partitioned from the back pressure chamber 19 by the rubber seal plate 35. Furthermore, the annular recess 72a of the pivot member internal passage 72 and the rotating shaft internal passage 71 are positioned below the rubber seal plate 35. The lower end of the first radial bearing 34 is exposed in the annular recess 72a of the pivot member internal passage 72. Depending on the shape of the pivot member 30, the entire pivot member internal passage 72 may be positioned below the rubber seal plate 35, which acts as a sealing mechanism.

[0074] Pump 75 is mounted on the small-diameter portion 20c of the rotating shaft 20. Pump 75 is, for example, a two-rotor trochoid pump. Although not shown in the figures, pump 75 has an inner rotor fixed to the outer circumferential surface of the small-diameter portion 20c and having outer teeth formed thereon, and an outer rotor rotatably supported on the inner circumferential surface of the support portion 13c and having inner teeth formed thereon. The axis of the inner rotor is eccentric with respect to the axis of the outer rotor, and a portion of the outer teeth and a portion of the inner teeth mesh together. As a result, the outer rotor rotates in conjunction with the rotation of the inner rotor. As the rotating shaft 20 rotates, pump 75 draws up oil 77 from the oil storage chamber 18 and supplies the oil 77 to the upper suction space 17a via the oil supply passage 70.

[0075] In this compressor configured as described above, the rotating shaft 20 rotates around the rotation axis O as the electric motor 40 operates under the control of the inverter. As a result, the movable scroll 60 rotates eccentrically from the rotation axis O, and the volume of the compression chamber 66 is reduced. Therefore, the refrigerant gas supplied from the evaporator to the lower intake space 17b via the intake opening 12c is introduced into the upper intake space 17a through the intake through hole 31b, and is then drawn into the compression chamber 66 from the upper intake space 17a via the intake port 58 and compressed. The refrigerant gas, compressed to the discharge pressure, is discharged from the discharge port 54 into the discharge chamber 15 and discharged to the condenser via the discharge passage 11f, the oil separation chamber 11d, and the discharge opening 11g.

[0076] Furthermore, the refrigerant gas introduced into the oil separation chamber 11d is separated from the oil 77 by centrifugal force using an oil separator. The separated oil 77 then falls by gravity through the oil passage hole 26 into the lower suction space 17b and is stored in the oil storage chamber 18 through the oil passage opening 13f.

[0077] The oil 77 in the oil storage chamber 18 is pumped up by the pump 75 and supplied to the upper suction space 17a via the oil supply passage 70. The oil 77 passing through the oil supply passage 70 lubricates the first radial bearing 34 via the annular recess 72a of the shaft support member internal passage 72. The oil 77 supplied to the upper suction space 17a is then drawn into the compression chamber 66 and lubricates the sliding parts of the compression chamber 66.

[0078] Furthermore, a portion of the refrigerant gas compressed in the compression chamber 66 is introduced into the back pressure chamber 19 through the air supply port 67. This causes the back pressure chamber 19 to act as a back pressure on the movable scroll 60 that counteracts the pressure in the compression chamber, biasing the movable scroll 60 toward the fixed scroll 50. In addition, oil 77 is supplied from the compression chamber 66 to the back pressure chamber 19 through the air supply port 67 along with the refrigerant gas, and the third radial bearing 24 is lubricated by this oil 77.

[0079] In this compressor, the back pressure chamber 19 is separated from the lower suction space 17b by a rubber seal plate 35 that functions as a sealing mechanism, and the oil supply passage 70 is located in the area partitioned from the back pressure chamber 19 by the rubber seal plate 35. Therefore, the high pressure in the back pressure chamber 19 can be prevented from acting on the oil supply passage 70 by the rubber seal plate 35. As a result, the oil 77 pumped up from the oil storage chamber 18 by the pump 75 can be suitably supplied to the upper suction space 17a and, consequently, to the sliding parts of the compression chamber 66 via the oil supply passage 70.

[0080] Furthermore, in this compressor, the electric motor 40 is positioned in the lower intake space 17b, which is less prone to becoming hot. Therefore, heat loss in the coil 41c can be suppressed when the electric motor 40 is under high load.

[0081] Therefore, this scroll-type compressor makes it possible to avoid using the electric motor 40 in high-temperature environments while simultaneously achieving both the formation of a back pressure chamber 19 and the supply of oil to the compression chamber 66.

[0082] In particular, in this compressor, the first radial bearing 34 is positioned below the rubber seal plate 35 and is exposed to the annular recess 72a in the internal passage 72 of the support member of the oil supply passage 70. Therefore, oil 77 passing through the annular recess 72a of the internal passage 72 of the support member can be supplied to the first radial bearing 34, thereby effectively lubricating the first radial bearing 34. As a result, the decrease in the lubricity of the first radial bearing 34 can be further suppressed.

[0083] As shown in Figure 2, in the compressor of Example 2, a rubber elastic body 36 is used as the sealing mechanism instead of the rubber seal plate 35 in the compressor of Example 1.

[0084] The rubber elastic body 36 is annular in shape and positioned directly above the first radial bearing 34. Furthermore, an annular, substantially disc-shaped retaining member 37 is fitted to the inner circumferential surface of the first boss 32 of the pivot member 30, directly above the first radial bearing 34. The inner circumferential surface of the rubber elastic body 36 abuts against the outer circumferential surface of the rotating shaft 20, while the outer circumferential surface of the rubber elastic body 36 abuts against the inner circumferential surface of the retaining member 37.

[0085] In this way, the rubber elastic body 36 separates the back pressure chamber 19 from the lower suction space 17b. Furthermore, the fuel supply passage 70 is located below the rubber elastic body 36. Therefore, the rubber elastic body 36 can suppress the high pressure in the back pressure chamber 19 from acting on the fuel supply passage 70.

[0086] The other configurations and effects are the same as in Example 1.

[0087] As shown in Figure 3, in the compressor of Embodiment 3, a narrow gap 38 is used as the sealing mechanism instead of the rubber seal plate 35 in the compressor of Embodiment 1.

[0088] In this compressor, an annular disc-shaped member 39 is fitted to the inner circumferential surface of the first boss 32 of the support member 30, directly above the first radial bearing 34. A narrow gap 38 is formed between the inner circumferential surface of the disc-shaped member 39 and the outer circumferential surface of the rotating shaft 20. The disc-shaped member 39 may be formed integrally with the support member 30.

[0089] In this way, the narrow gap 38 separates the back pressure chamber 19 from the lower intake space 17b. Furthermore, the fuel supply passage 70 is located below the narrow gap 38. Therefore, the narrow gap 38 can prevent the high pressure in the back pressure chamber 19 from acting on the fuel supply passage 70.

[0090] The other configurations and effects are the same as in Example 1.

[0091] Although the present invention has been described above in reference to Examples 1 to 3, it goes without saying that the present invention is not limited to Examples 1 to 3, and can be applied with appropriate modifications without departing from its spirit.

[0092] This invention is applicable to scroll compressors.

[0093] 10 Housing 11b First peripheral wall (peripheral wall) 12a Second peripheral wall (peripheral wall) 13a Third peripheral wall (peripheral wall) 17 Intake space 17a Upper intake space 17b Lower intake space 18 Oil storage chamber 19 Back pressure chamber 20 Rotating shaft 30 Support member 34 First radial bearing (bearing) 35 Rubber seal plate (sealing mechanism) 36 Rubber elastic body (sealing mechanism) 40 Electric motor 50 Fixed scroll 60 Movable scroll 66 Compression chamber 70 Oil supply passage 71 Passage inside rotating shaft 72 Passage inside support member 75 Pump � Rotating shaft center

Claims

1. A scroll compressor comprising: a housing having a circumferential wall extending vertically in a cylindrical shape and having an intake space formed inside; a rotating shaft disposed within the housing and extending vertically; a support member that rotatably supports the rotating shaft via a bearing, the support member dividing the intake space into an upper intake space above the support member and a lower intake space below the support member; an electric motor disposed in the lower intake space for rotating the rotating shaft; a fixed scroll disposed in the upper intake space; and a movable scroll disposed between the support member and the fixed scroll, rotating together with the rotating shaft and forming a compression chamber between itself and the vertically opposing fixed scroll for compressing fluid drawn in from the upper intake space, wherein the compressor comprises: a back pressure chamber formed between the support member and the movable scroll, which applies a back pressure to the movable scroll to counteract the pressure in the compression chamber by introducing a portion of the fluid compressed in the compression chamber; and an oil storage chamber disposed in the lower intake space for storing oil separated from the fluid. A scroll compressor comprising: a fuel supply passage connecting the oil storage chamber and the upper suction space; a pump that supplies oil pumped from the oil storage chamber to the upper suction space via the fuel supply passage; and a sealing mechanism that seals the space between the rotating shaft and the shaft support member, thereby separating the back pressure chamber from the lower suction space, wherein the fuel supply passage is located in a region partitioned from the back pressure chamber by the sealing mechanism.

2. The scroll compressor according to claim 1, wherein the bearing is located in the region partitioned from the back pressure chamber by the sealing mechanism and is exposed to the lubrication passage.

3. The scroll compressor according to claim 2, wherein the oil supply passage has an internal passage for the rotating shaft formed inside the rotating shaft and connected to the oil storage chamber, and an internal passage for the support member formed inside the support member and communicating the internal passage for the rotating shaft and the upper suction space, at least a portion of the internal passage for the support member and the internal passage for the rotating shaft are located below the seal mechanism, and the bearing is exposed in the portion of the internal passage for the support member located below the seal mechanism.

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