Patent Application
20050169787
The present invention relates to a compressor, for example, for use in a vehicle air conditioner.
For example, a motor compressor, which accommodates an electric motor and a scroll type compression mechanism in a housing thereof, discharges refrigerant gas through a discharge port, which is formed in a fixed scroll member of the compression mechanism, to a discharge chamber. There are various kinds of conventional structures of the discharge chamber in the housing.
As disclosed in
Also, as disclosed in
In a compressor that employs carbon dioxide as refrigerant gas, the maximum pressure of the compressor is approximately ten times as high as that of a compressor that employs fluorocarbon gas. For the reason, a pressure difference of the refrigerant gas between an outermost compression chamber of a scroll type compression mechanism and a discharge chamber may cause an annular portion, that is, the back surface of the fixed scroll member except the center thereof, to deform toward a movable scroll member. If the fixed scroll member deforms, each scroll wall of the scroll member needs a larger clearance between each distal end, thus decreasing the compression efficiency of the compression mechanism. Additionally, since each distal end of the scroll wall of the scroll member is pressed against the facing scroll member by the deformation of the fixed scroll member, each scroll wall needs to increase in strength.
To prevent such deformation of the fixed scroll member, the discharge chamber may be reduced in volume so as to face only the center of the fixed scroll member. Accordingly, the pressure of the refrigerant gas is not applied to the fixed scroll member on the outer peripheral side of the compression chamber, thus preventing the deformation of the fixed scroll member. However, as the discharge chamber is reduced in volume, the refrigerant gas discharged from the scroll type compression mechanism to the discharge chamber increases in pulsation. Additionally, when the refrigerant gas employs carbon dioxide, the pulsation of the refrigerant gas is distinct because the maximum pressure of the refrigerant gas is huge.
As the discharge camber is formed to face only the center of the fixed scroll member while ensuring the volume thereof, the discharge chamber needs to be elongated in the axial direction of the fixed scroll member, or the discharge chamber needs to be reduced in the radially cross-sectional area on the side adjacent to the fixed scroll member while being increased in the radially cross-sectional area at a position away from the fixed scroll member. Thus, the housing should be enlarged, thereby enlarging the compressor.
It is not only occurred to the scroll type compression mechanism, but there also is a problem in a compressor having a piston type compression mechanism that the above mentioned pressure difference causes deformation of a valve plate that is provided to isolate the compression chamber from the discharge chamber. As the valve plate is thickened for preventing the deformation thereof, the volume of the discharge chamber is limited, the housing of the compressor is enlarged, or the compressor is increased in weight. Therefore, there is a need for a compressor that prevents a compression mechanism from being deformed by high-pressure compressed refrigerant gas and that also increases the volume of a discharge chamber without enlarging the housing thereof.
In accordance with the present invention, a compressor has a housing, a compression mechanism and a partition member. The housing defines therein a discharge chamber. The compression mechanism is located adjacent to the discharge chamber in the housing. The partition member faces a predetermined region, which is a portion of the compression mechanism that faces the discharge chamber except a specific region where a gas discharge port opens, for restraining pressure of refrigerant gas in the discharge chamber to be applied to the predetermined region.
Other aspects and advantages of the invention will become apparent from the following description, taken in conjunction with the accompanying drawings, illustrating by way of example the principles of the invention.
The features of the present invention that are believed to be novel are set forth with particularity in the appended claims. The invention together with objects and advantages thereof, may best be understood by reference to the following description of the presently preferred embodiments together with the accompanying drawings in which:
A first preferred embodiment of a scroll type motor compressor 10 for use in a vehicle air conditioner according to the present invention will now be described with reference to
As shown in
In the first housing component 12, a small-diameter portion 14a on the side of the small-diameter cylindrical portion 15 and a large-diameter portion 14b on the side of the opening end are formed inside the large-diameter cylindrical portion 14, and a first holding surface 14c is formed at a step therebetween. On the other hand, a second holding surface 17b is formed inside the second housing component 13 on the radially inner side relative to an inner peripheral surface 17a of the cylindrical portion 17 and on the radially inner side relative to the first holding surface 14c.
The first housing component 12 forms therein a plurality of fitting portions 19, which is integrally formed at intervals on the outer peripheral surface of the opening side of the large-diameter cylindrical portion 14. The second housing component 13 forms therein a plurality of fitting portions 20, which is integrally formed at positions that correspond to the plurality of fitting portions 19 on the outer peripheral surface of the opening side of the cylindrical portion 17. As shown in
The inner periphery of the joint surface 13a of the second housing component 13 extends radially inward relative to the joint surface 12a of the first housing component 12. Then, the inner periphery of the joint surface 13a faces the first holding surface 14c of the first housing component 12. Also, the gasket 22 is substantially formed to the same shape as the joint surface 13a of the second housing component 13. The inner periphery of the gasket 22 also faces the first holding surface 14c of the first housing component 12.
As shown in
The first housing component 12 accommodates therein a rotary shaft 28, which is rotatably supported at one end by the shaft support portion 24 through a bearing 29 and also rotatably supported at the other end in the through hole 26a of the shaft support member 25 through a bearing 30. A motor chamber 31 is defined between the shaft support member 25 and the bottom portion 16. A stator core 33, around which an exciting coil 32 wound, is fixedly fitted in the small-diameter cylindrical portion 15 of the first housing component 12. A rotor 34, which is made of a multipolar magnet, is fixed to the rotary shaft 28 so as to face the stator core 33. The exciting coil 32, the stator core 33, the rotor 34 and the like cooperatively form an inner rotor type electric brushless motor.
The first housing component 12 accommodates therein a scroll type compression mechanism 35 inside the large-diameter cylindrical portion 14. That is, a fixed scroll member 36 is fixedly fitted in the large-diameter portion 14b of the first housing component 12. The fixed scroll member 36 has a disc-shaped base plate 37, a cylindrical outer peripheral wall 38 and a fixed scroll wall 39. The cylindrical outer peripheral wall 38 is integrally formed on the outer periphery of the base plate 37. The fixed scroll wall 39 is integrally formed with the base plate 37 inside the outer peripheral wall 38. The distal end of the outer peripheral wall 38 of the fixed scroll member 36 is in contact with the flange 27 of the shaft support member 25, which is in contact with the first holding surface 14c of the first housing component 12.
A crankshaft 40 extends from the end surface of the rotary shaft 28 on the side of the fixed scroll member 36. A bushing 41 having a balance weight 41a is fixedly fitted around the crankshaft 40. A movable scroll member 42, which faces the fixed scroll member 36, is supported rotatably with respect to the fixed scroll member 36 by the bushing 41 through a bearing 43, which is placed in a boss 42a. The crankshaft 40, the bushing 41 and the bearing 43 cooperatively form an orbiting mechanism to orbit the movable scroll member 42 by the rotation of the rotary shaft 28.
The movable scroll member 42 has a disc-shaped base plate 44 and a movable scroll wall 45, which is integrally formed with the base plate 44. As shown in
The compression chamber 47 is in communication with an inner space of the second housing component 13 through a (gas) discharge hole 37a that extends through the center of the base plate 37 of the fixed scroll member 36 and opens at a back surface 37b of the base plate 37. The outer peripheral wall 38 of the fixed scroll member 36 and the outermost peripheral portion of the movable scroll wall 45 of the movable scroll member 42 define therebetween a suction chamber 48. The suction chamber 48 is in communication with the motor chamber 31 through a passage (not shown), and is connected to an evaporator of an external refrigerant circuit (not shown) through a suction port 49 (shown in
A plurality of fixed pins 50 are secured on the same circumference to the base plate 37 of the fixed scroll member 36, and a plurality of movable pins 51 are correspondingly secured to the base plate 44 of the movable scroll member 42 relative to the respective fixed pins 50. Then, the fixed pins 50 and the movable pins 51 cooperatively form a known self-rotation blocking mechanism for the movable scroll member 42.
A discharge valve 52 is provided at the center of the back surface 37b of the base plate 37 of the fixed scroll member 36 for opening and closing the discharge hole 37a. The opening degree of the discharge valve 52 is regulated by a retainer 53, which is fixed to the base plate 37.
The inner periphery of the gasket 22 and the inner periphery of the joint surface 13a of the second housing component 13, in this order, are in contact with the outer periphery of the back surface 37b of the base plate 37 of the fixed scroll member 36. The fixed scroll member 36, the shaft support member 25 and the gasket 22 are held between the first holding surface 14c of the first housing component 12 and the second holding surface 17b of the second housing component 13. That is, the fixed scroll member 36 is held between the gasket 22 and the shaft support member 25.
An annular partition member 60 is placed in the second housing component 13. The partition member 60 is held between the fixed scroll member 36 and the second housing component 13. As shown in
As shown in
The peripheral wall 62 of the partition member 60 is supported through the rubber layer 64 onto the inner peripheral surface 17a of the cylindrical portion 17 of the second housing component 13. Also, the distal end of the peripheral wall 62 is in contact with the second holding surface 17b of the second housing component 13. The partition wall 61 faces an annular region (a predetermined region) of the back surface 37b of the base plate 37 of the fixed scroll member 36 (a portion that faces the discharge chamber of the compression mechanism) except the center thereof (a region where the gas discharge hole opens). At the same time, the O-ring 66 is in close contact with the inner peripheral surface 17a of the second housing component 13, while the O-ring 67 is in close contact with the back surface 37b of the base plate 37 of the fixed scroll member 36. That is, the partition member 60, the shaft support member 25 and the fixed scroll member 36 are held between the first housing component 12 and the second housing component 13. Thus, the partition member 60 is positioned in the axial direction of the rotary shaft 28.
The second housing component 13 defines therein a discharge chamber 68, with which the compression chamber 47 communicates through the discharge hole 37a of the fixed scroll member 36. The discharge chamber 68 is isolated in airtight from the annular region, that is, the back surface 37b of the base plate 37 of the fixed scroll member 36 except the center thereof, by the partition member 60 and the O-rings 66, 67. In other words, the space between the annular region, that is, the back surface 37b of the base plate 37 except the center thereof, and the partition wall 61 of the partition member 60 is isolated in airtight from the discharge chamber 68 by the gasket 22 and the O-rings 66, 67. The suction chamber 48 is in communication with the above space through a through hole 37c, which is formed in the base plate 37 of the fixed scroll member 36. On the other hand, the discharge chamber 68 is connected to a condenser of the external refrigerant circuit (not shown) through a discharge port 69, which is formed in the second housing component 13.
In the motor compressor 10 as described above, as the motor is driven, the movable scroll member 42 is orbited around the axis of the fixed scroll member 36 through the crankshaft 40 of the rotary shaft 28. Then, as the compression chamber 47 progressively reduces in volume and moves inward from the outer peripheral side of the scroll walls 39, 45 by the orbital motion of the movable scroll member 42, refrigerant gas introduced from the suction chamber 48 into the compression chamber 47 is compressed. After the compressed refrigerant gas is discharged to the discharge chamber 68 through the discharge hole 37a of the fixed scroll member 36, the refrigerant gas is supplied to the condenser of the external refrigerant circuit through the discharge port 69.
According to the first preferred embodiment of the present invention, the following advantageous effects are obtained.
(1) The partition member 60 is provided in the housing 11, in which the scroll type compression mechanism 35 and the discharge chamber 68 that is adjacent to the back surface 37b of the fixed scroll member 36, and faces the annular region, that is, the base plate 37 of the fixed scroll member 36 except the center thereof. The partition member 60 prevents the pressure of the refrigerant gas in the discharge chamber 68 from being applied to the annular region.
Therefore, the base plate 37 of the fixed scroll member 36 is hard to be deformed toward the movable scroll member 42 even by the high-pressure of the refrigerant gas in the discharge chamber 68. Accordingly, the variation of the clearances between the distal end of the fixed scroll wall 39 of the fixed scroll member 36 and the base plate 44 of the movable scroll member 42 and between the distal end of the movable scroll wall 45 of the movable scroll member 42 and the base plate 37 of the fixed scroll member 36 become small. Thus, the distal end of the scroll wall 39 (or 45) is not tightly pressed against the base plate 44 (or 37), so that excessive stress does not occur at the proximal portions of the scroll walls 39, 45 thereby improving reliability.
Additionally, the iron partition member 60, which has more strength than the aluminum alloy, is located at the side of the opening end of the aluminum alloy cylindrical second housing component 13 having a bottom at one end, and the partition member 60 prevents the pressure of the refrigerant gas in the discharge chamber 68 from being applied to the annular region, that is, the back surface 37b of the base plate 37 of the fixed scroll member 36 except the center thereof. Accordingly, the thickness of the partition member 60 may be thinned unlike in the case of the partition member 60 integrally formed with the second housing component 13, so that limitations on the volume of the discharge chamber 68 is reduced.
Consequently, the compression mechanism 35 is prevented from being deformed due to the high-pressure compressed refrigerant gas, and the volume of the discharge chamber 68 may be increased without enlarging the housing 11.
The iron partition member 60, which has a lower thermal conductivity than aluminum alloy and the air layer between the partition member 60 and the base plate 37 of the fixed scroll member 36, reduces heat transmitted from the refrigerant gas in the discharge chamber 68 to the refrigerant gas in the suction chamber 48 through the fixed scroll member 36. Thus, the refrigerant gas in the suction chamber 48 is prevented from decreasing in density, and the compression efficiency of the compression mechanism 35 is improved.
(2) The partition member 60 is integrally composed of the cylindrical partition wall 61 and the cylindrical peripheral wall 62 that extends from the outer periphery of the partition wall 61 in the axial direction thereof. Then, the partition wall 61 faces the annular region, that is, the back surface 37b of the fixed scroll member 36 except the center thereof, and the peripheral wall 62 is inserted in the inner peripheral surface 17a of the second housing component 13 and supported thereon.
Therefore, as the partition member 60 is accommodated in the housing 11, the conventional housing may basically be employed. Furthermore, as the cylindrical peripheral wall 62 that extends from the outer periphery of the partition wall 61 in the axial direction thereof is inserted in the housing 11 and supported thereon, the partition wall 61 is improved in strength against deformation in the axial direction thereof in comparison to a structure that the outer periphery of the partition member formed merely in a disc-shape is supported in the housing 11. Thus, the base plate 37 of the fixed scroll member 36 is further efficiently prevented from being deformed.
(3) Since the rubber layer 64 is provided as the insulation material between the peripheral wall 62 of the partition member 60 and the second housing component 13, it reduces heat transmitted from the refrigerant gas in the discharge chamber 68 to the refrigerant gas in the suction chamber 48 and the motor chamber 31 through the partition member 60, the second housing component 13 and the first housing component 12. Thus, the refrigerant gas in the suction chamber 48 is prevented from decreasing in density, and the compression efficiency of the compression mechanism 35 is further improved.
Additionally, since the O-ring 67 is interposed between the partition member 60 and the base plate 37 of the fixed scroll member 36, it reduces heat transmitted from the partition member 60 to the fixed scroll member 36, thus further improving the compression efficiency of the compression mechanism 35.
(4) The partition member 60 is elastically supported on the housing 11 by the rubber layer 64, which is interposed between the peripheral wall 62 of the partition member 60 and the second housing component 13. Thus, noise or vibration of the compressor 10 due to pulsation of the refrigerant gas discharged from the compression chamber 47 to the discharge chamber 68 is reduced.
A second preferred embodiment of the scroll type motor compressor 10 that is similar to that of the first preferred embodiment according to the present invention will now be described with reference to
A third holding surface 17c, instead of the second holding surface 17b in the first preferred embodiment, is provided in the second housing component 13 according to the second preferred embodiment. The third holding surface 17c is formed near the opening end of the cylindrical portion 17 so as to face the first holding surface 14c of the first housing component 12.
The joint surface 13a of the second housing component 13 does not extend radially inward relative to the joint surface 12a of the first housing component 12, which is different from the first preferred embodiment. However, the inner periphery of the gasket 22 extends radially inward relative to the joint surfaces 12a, 13a. Then, the inner periphery of the gasket 22 is in contact with the outer periphery of the back surface 37b of the base plate 37 of the fixed scroll member 36.
A discharge gas casing 80, which forms the discharge chamber 68, is located in the second housing component 13. The discharge gas casing 80, as shown in
The partition member 81 includes a flange 83 near the fixed scroll member 36 so as to extend outward. The partition member 81 is covered with a rubber layer 84, which functions as a heat insulation and elastic material, on its outer peripheral surface 81 a including the flange 83.
The partition member 81 is integrally composed of a disc-shaped partition wall 85 and a cylindrical peripheral wall 86 that extends from the outer periphery of the partition wall 85 in the axial direction of the partition wall 85. The inner peripheral surface of the corner between the partition wall 85 and the peripheral wall 86 forms a circular arc in shape, thus enhancing the strength against bending of the partition wall 85 in the axial direction of the peripheral wall 86. It is noted that the partition member 81 is integrally formed by forging iron material.
An annular recess 87 is formed around the opening 85a of the partition wall 85 and on an end surface of the partition wall 85, which is opposite to the peripheral wall 86 in the partition wall 85 of the partition member 81. An annular groove 88 is formed along the inner periphery of the partition wall 85 on the end surface of the partition wall 85, which is opposite to the peripheral wall 86. An O-ring 89 is fitted into the annular groove 88. In the second preferred embodiment, the O-ring 89 functions as a sealing member.
The peripheral wall 86 of the discharge gas casing 80 is inserted and supported through the rubber layer 84 on the inner peripheral surface 17a of the cylindrical portion 17 of the second housing component 13. Also, the flange 83 of the partition member 81 is in contact with the third holding surface 17c through the rubber layer 84. The partition wall 85 faces an annular region (a predetermined region), that is, the back surface 37b of the base plate 37 (a portion) of the fixed scroll member 36 except the center (a specific region) thereof. At this time, the O-ring 89 is in close contact with the back surface 37b of the base plate 37 of the fixed scroll member 36. Additionally, the inner periphery of the gasket 22 is interposed between the flange 83 of the partition member 81 and the outer periphery of the back surface 37b of the base plate 37 of the fixed scroll member 36. That is, the discharge gas casing 80, the shaft support member 25 and the fixed scroll member 36 are held between the first holding surface 14c of the first housing component 12 and the third holding surface 17c of the second housing component 13. Thus, the discharge gas casing 80 is positioned in the axial direction of the rotary shaft 28.
The discharge chamber 68, which is defined in the discharge gas casing 80, is isolated inside the second housing component 13 by the cover portion 82, which is connected to the partition member 81. Then, the discharge chamber 68 is partitioned in airtight from the annular region, that is, the back surface 37b of the base plate 37 of the fixed scroll member 36 except the center thereof, by the partition member 81 and the O-ring 89. In other words, the space between the annular region, that is, the back surface 37b of the base plate 37 except the center thereof, and the partition wall 85 of the partition member 81 is isolated in airtight from the discharge chamber 68 by the gasket 22 and the O-ring 89. This space is in communication with the suction chamber 48 through the through hole 37c, which is formed in the base plate 37 of the fixed scroll member 36.
As shown in
As shown in
As shown in
In the above described motor compressor 10, the refrigerant gas discharged from the compression chamber 47 to the discharge chamber 68 in the discharge gas casing 80 through the discharge hole 37a is supplied to the condenser of the external refrigerant circuit through the communication hole 92 of the internal seat 91 and the internal passage 96a of the communicating tube 96.
According to the second preferred embodiment, in addition to the paragraph (1) through (4) mentioned in the first preferred embodiment, the following advantageous effects are obtained.
(5) The partition member 81 that corresponds to the partition member 60 of the first preferred embodiment includes the cover portion 82, which isolates the discharge chamber 68 inside the second housing component 13. Then, the refrigerant gas is discharged outside the housing 11 from the discharge chamber 68 through the communicating tube 96, which is sealed against the boundary surface between the discharge gas casing 80 and the second housing component 13. The gap 90 having substantially the same spacing is formed as a heat insulation space between the cover portion 82 and the second housing component 13. Therefore, heat transmitted from the refrigerant gas in the discharge chamber 68 to the refrigerant gas in the suction chamber 48 and the motor chamber 31 through the second housing component 13 and the first housing component 12 is reduced. Accordingly, the refrigerant gas in the suction chamber 48 is prevented from decreasing in density, thereby further enhancing compression efficiency of the compression mechanism 35.
Furthermore, since the cover portion 82 is made of iron material that has a higher strength than aluminum alloy, the thickness of the second housing component 13 may be thinned in comparison to the structure in which the second housing component 13 directly forms therein the discharge chamber 68 as in the first preferred embodiment. Therefore, the same volume discharge chamber 68 is obtained by the housing 11 having a smaller size. Additionally, the cover portion 82 made of iron material that has a lower thermal conductivity than aluminum alloy reduces heat transmitted from the refrigerant gas in the discharge chamber 68 to the second housing component 13 through the cover portion 82.
The present invention is not limited to the embodiments described above but may be modified into the following alternative embodiments.
In an alternative embodiment to the first preferred embodiment, the partition member 60 is made of other metal materials, such as magnesium alloy, titanium alloy. Additionally, the partition member 60 may be made of non-metallic materials. This may also be applied to the partition member 81 and the cover portion 82 of the discharge gas casing 80 in the second preferred embodiment.
In an alternative embodiment to the second preferred embodiment, a rubber layer or an insulation means occupies the gap between the cover portion 82 of the discharge gas casing 80 and the bottom portion 18 of the second housing component 13. The rubber layer may be inserted in a fluid state into the gap between the discharge gas casing 80 and the second housing component 13 during assembling of the compressor 10, or may previously be applied on outer surface of the cover portion 82 of the discharge gas casing 80 or the inner surface of the bottom portion 18 of the second housing component 13.
In an alternative embodiment to the first preferred embodiment, the housing 11 includes a first housing component which accommodates a motor, and a second housing component, which includes a shaft support member that supports one end of a rotary shaft and is formed to accommodate a compression mechanism, the partition member 81 and the discharge chamber 68. This may also be applied to the second preferred embodiment.
In an alternative embodiment to the first preferred embodiment, a partition member is a disc-shaped partition wall member that faces a back surface of the fixed scroll member except the center thereof, and is held between the first housing component 12 and the second housing component 13.
The present invention may be applied to a motor compressor that employs fluorocarbon series refrigerant as refrigerant gas.
The present invention may be applied to a compressor that has a piston type compression mechanism as shown in
In a compressor having such a compression mechanism, a partition member 113 is provided to face an annular region (a predetermined region), that is, the valve port assembly 104 facing the discharge chamber 112 (a portion facing the discharge chamber in the compression mechanism) except the center thereof where the discharge valves are located (a specific region where a gas discharge port opens). The partition member 113 forms cylinder in shape, and is inserted into the discharge chamber 112 and supported therein. On the other hand, no sealing member for isolating in airtight the space between the annular region of the valve port assembly 104 and the partition member 113 from the discharge chamber 112 is provided between the partition member 113 and the valve port assembly 104. However, the clearance between the valve port assembly 104 and the partition member 113 is sufficiently small, so that the pressure of the refrigerant gas in the discharge chamber 112 is limited to be applied to the annular region of the valve port assembly 104.
In this case, since the partition member 113 controls the pressure of the refrigerant gas in the discharge chamber 112 to be applied to the annular region of the valve port assembly 104, the valve port assembly 104 substantially does not deform toward the compression chamber 105. Therefore, the communication between the discharge chamber 112 and the suction chamber 111 due to the deformation of the valve port assembly 104 is prevented, and the leakage of the refrigerant gas from the discharge chamber 112 to the suction chamber 111 is prevented, thereby preventing decrease in compression efficiency of the compression mechanism.
The present invention is not limited to be applied to a motor compressor for use in a vehicle air conditioner, but may, for example, be applied to a motor compressor for use in a domestic air conditioner.
The present invention is not limited to be applied to a motor compressor for use in an air conditioner, but may be applied to a refrigeration cycle other than the air conditioner, namely, a motor compressor for use in a refrigeration cycle for a refrigerator or a freezer.
The present invention is not limited to be applied to a motor compressor for use in a refrigeration cycle, but may, for example, be applied to a motor air compressor for use in an air-suspension system for a vehicle, or the like.
The present invention is not limited to be applied to a motor compressor, but may, for example, be applied to a scroll type compressor that is driven by a gasoline engine of a vehicle or a gas engine of a gas heat pump.
Therefore, the present examples and embodiments are to be considered as illustrative and not restrictive, and the invention is not to be limited to the details given herein but may be modified within the scope of the appended claims.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2004-007129 | Jan 2004 | JP | national |
