BACKGROUND OF THE INVENTION 0001 The present invention relates to a compressor. In particular, the present invention relates to a compressor that is used as a part of a refrigeration cycle of a vehicular air-conditioner and compresses refrigerant gas. 0002 Japanese Laid-Open Patent Publication No. 7-174084 discloses a compressor. The compressor of the publication includes a compression mechanism, which is housed in a housing assembly. The housing assembly is formed by securing a plurality of housing members to each other. The gap between the inner surface of the housing assembly and the compression mechanism defines a discharge chamber, to which compressed gas is discharged from the compression mechanism. 0003 In the compressor, the housing members are coupled to each other through a sealing member. The compression mechanism is abutted to the inner surface of the housing member by way of another sealing member. However in the above prior art, these sealing members are separated from one another by a significant distance. Accordingly it was not possible to use a single sealing member to seal both between the housing members and between the housing assembly and the compression mechanism. This increases the number of the parts forming the compressor.

SUMMARY OF THE INVENTION 0004 Accordingly, it is an objective of the present invention to provide a compressor that simplifies the sealing structure and reduces the number of parts. 0005 To achieve the above objective, the present invention provides a compressor that receives gas from an outer circuit, said compressor comprising: 0006 a housing having a first housing member and a second housing member coupled to the first housing member, the first housing member having an opening end surface, and the second housing member having an opening end surface; 0007 a compression mechanism disposed in the first housing member, the compression mechanism compressing gas supplied to the compressor, said compression mechanism has a contact surface; and 0008 a circular sealing member which includes a first portion and a second portion, said first portion of said sealing member being interposed between the opening end surface of the first housing member and the projections of the second housing member, said second portion extending radially inwardly from the first portion to be interposed between the contact surfaces of the compression mechanism and the second housing member. 0009 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.

BRIEF DESCRIPTION OF THE DRAWINGS 0010 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: 0011 FIG. 1 is a cross-sectional view illustrating an electric compressor according to a preferred embodiment of the present invention; and 0012 FIG. 2 is an enlarged partial cross-sectional view illustrating the vicinity of the compression mechanism shown in FIG. 1.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 0013 An electric compressor according to a preferred embodiment of the present invention will now be described. The electric compressor is used in a vehicular air-conditioner. 0014 As shown in FIG. 1, a housing assembly 11 of the electric compressor includes a first housing member 21 and a second housing member 22, which are secured to each other. The first housing member 21 includes a cylindrical portion 23 and a first closing wall 24 closing the left side of the cylindrical portion 23 as viewed in FIG. 1. The right side of the cylindrical portion 23, as viewed in FIG. 1, remains open and constitutes a first opening. The first housing member 21 is made of die cast aluminum alloy. The second housing member 22 includes a cylindrical portion 25 and a second closing wall 26, which closes the right side of the cylindrical portion 25 as viewed in FIG. 1. The left side of the cylindrical portion 25, as viewed in FIG. 1, remains open and constitutes a second opening. The second housing member 22 is also made of die cast aluminum alloy. Constituting the first and the second housing members 21, 22 from aluminum based metal such as aluminum alloy is advantageous for reducing the weight of the electric compressor as compared to a case where the first and the second housing members 21, 22 are made of, for example, iron based metal. 0015 The axial length of the cylindrical portion 23 of the first housing member 21 is longer than the outer diameter of the cylindrical portion 23. In contrast, the axial length of the cylindrical portion 25 of the second housing member 22 is shorter than the outer diameter of the cylindrical portion 25. Therefore, the first housing member 21 constitutes the most part of the housing assembly 11. 0016 Compressor supports 27 are integrally formed with the outer circumferential surface of the cylindrical portion 23 of the first housing member 21. Each compressor support 27 has a through hole 27a. A bolt is inserted through each through hole 27a to mount the electric compressor to the vehicle body. 0017 As shown in FIGS. 1 and 2, the inner diameter of the inner circumferential surface 23a of the cylindrical portion 23 discretely increases from the wall 24 toward the opening end. The section of the inner circumferential surface 23a close to the wall 24 is the smallest diameter section. A medium diameter section is formed adjacent to the smallest diameter section. A step formed between the smallest diameter section and the medium diameter section serves as a step 23b. The section of the inner circumferential surface 23a close to the opening is the largest diameter section. An inner shoulder 23c formed between the largest diameter section and the medium diameter section serves as a part of the clamp means clamping the compression mechanism. The inner circumferential surface 23a of the cylindrical portion 23, the diameter of which varies step by step, is formed by grinding after the casting of the first housing member 21. 0018 An opening end surface 28a is an end surface of the cylindrical portion 23 of the first housing member 21. Joint portions 28 are formed in the outer circumferential surface of the cylindrical portion 23 of the first housing member 21 on the side close to the opening end. Each joint portion 28 has a cylindrical shape with an end surface 28a facing the second housing member 22. Each end surface 28a is continuous to and flush with the opening end surface 23d. The end surfaces 28a and the opening end surface 23d of the cylindrical portion 23 form a contact surface of the first housing member 21. Each joint portion has a threaded bore 28b extending in its axial direction from the end surface 28a. 0019 An opening end surface 25a is an end surface of the cylindrical portion 25 of the second housing member 22. Likewise, projections 29 project from the outer circumferential surface of the cylindrical portion 25 of the second housing member 22 on the side close to the opening end. Each projection 29 has an end surface 29a, which faces the first housing member 21. Each end surface 29a is continuous to and flush with the opening end surface 25a of the cylindrical portion 25. The end surfaces 29a and the opening end surface 25a of the cylindrical portion 25 form a contact surface of the second housing member 22. A through hole 29b is formed in each projection 29 from the second housing member 22 toward the first housing member 21. Joint portions 28 and projections 29 are provided to conform to each other. 0020 The first housing member 21 is secured to the second housing member 22 at the contact surfaces 23d, 28a, 25a, and 29a. A bolt 30 is inserted through the through hole 29b of each projection 29 of the second housing member 22. The bolt 30 is then threaded through the threaded bore 28b of the corresponding joint portion 28 of the first housing member 21. Thus, the first housing member 21 is secured to the second housing member 22. 0021 A sealing member, which is a plate-like gasket 31 in the preferred embodiment, is located between the contact surface 23d, 28a of the first housing member 21 and the contact surface 25a, 29a of the second housing member 22. Thus, a sealed chamber 12 is defined in the housing assembly 11 surrounded by the first housing member 21 and the second housing member 22, sealed by a first portion 31a of the gasket 31 as shown in FIG. 2. 0022 The contact surface 25a, 29a of the second housing member 22 extend radially inward (toward the sealed chamber 12) from the edge of the contact surface 23d, 28a of the first housing member 21, as shown by an extended edge 25b of FIG. 2. The extended edge 25b faces the inner shoulder 23c of the first housing member 21 to serve as a part of clamp means for clamping the compression mechanism. 0023 The sealing of the circular gasket 31 has substantially the same shape as the contact surface 25a, 29a of the second housing member 22. Therefore, the gasket 31 also extends radially inward from the edge of the contact surface 23d, 28a of the first housing member 21 as shown by a second portion 31b of the gasket of FIG. 2. 0024 As shown in FIG. 1, a cylindrical shaft support projection 24a is integrally formed at the center of the inner wall of the wall 24 of the first housing member 21. A shaft support member 32 is arranged in the first housing member 21 on the side close to the opening of the cylindrical portion 23. The shaft support member 32 has a through hole 32a at its center. The shaft support member 32 is press fitted to the cylindrical portion 23 of the first housing member 21. The periphery of the shaft support member 32 abuts against the inner shoulder 23c. 0025 A drive shaft 33 is accommodated in the first housing member 21. The end, shown in left hand side of FIG. 1, of the drive shaft 33 is rotatably supported by the shaft support projection 24a with a radial bearing 34. The right hand side end of the drive shaft 33 is inserted through the through hole 32a of the shaft support member 32. The drive shaft 33 is rotatably supported by the shaft support member 32 with a radial bearing 35. That is, both ends of the drive shaft 33 are rotatably supported by the first housing member 21 inside the sealed chamber 12. 0026 A stator 36 is arranged in the first housing member 21 close to the wall 24. The stator 36 includes a cylindrical iron core 36a and a coil 36b, which is wound about the iron core 36a. The iron core 36a of the stator 36 is press fitted into the cylindrical portion 23 of the first housing member 21 until the periphery of the iron core 36a abuts against the step 23b. A magnet 37 is secured to the drive shaft 33 to be arranged radially inward of the stator 36. 0027 The stator 36 and the magnet 37 constitute a brushless DC motor, which is a motor 13 in the preferred embodiment. When power is supplied to the coil 36b of the stator 36 from the outside, the motor 13 rotates the magnet 37 integrally with the drive shaft 33. 0028 As shown in FIGS. 1 and 2, a scroll type compression mechanism 14 is used in the electric compressor in the preferred embodiment. 0029 A fixed scroll 41 is arranged in the first housing member 21 on the side close to the opening end (the first opening) of the cylindrical portion 23. The fixed scroll 41 has a disk-like fixed base plate 41a and a cylindrical outer circumferential wall 41b, which extends from the periphery of the fixed base plate 41a. A fixed volute portion 41c is arranged on the fixed base plate 41a inside the outer circumferential wall 41b. 0030 The end surface on the side of support member 32 of the outer circumferential wall 41b of the fixed scroll 41 abuts against the inner shoulder 23c of the first housing member 21 via the periphery of the shaft support member 32. The end surface 41f, on the side near the second housing member 22 of the outer circumferential wall 41b of the fixed scroll 41 abuts against the extended edge 25b of the second housing member 22 via the inner circumferential portion of the gasket 31. The end surface 41f (which is a contact surface abutting against the second housing member 22) is flush with the contact surface 23d, 28a of the first housing member 21. Thus, when the first housing member 21 is secured to the second housing member 22, the fixed scroll 41 is held between the inner shoulder 23c and the extended edge 25b inside the sealed chamber 12 with the shaft support member 32 connected thereto, which forms a part of the compression mechanism 14. 0031 An annular recess 41d is formed in the outer circumferential surface of the outer circumferential wall 41b of the fixed scroll 41. When both ends of the outer circumferential wall 41b abut the largest diameter section of the first housing member 21, a heat insulation chamber 42 is defined by the outer circumferential wall 41b and the inner circumferential surface 23a of the first housing member 21. 0032 The heat insulation chamber 42 is interposed between the first housing member 21 and the fixed scroll 41 to slow the heat conduction between the first housing member 21 and the fixed scroll 41. The heat insulation chamber 42 is provided in this embodiment especially for this purpose. 0033 An eccentric shaft 43, the axis of which is offset from the axis of the drive shaft 33, is arranged on the end surface of the drive shaft 33 close to the fixed scroll 41. A bush 44 is fitted to the eccentric shaft 43. A movable scroll 45 is supported by the bush 44 via a bearing 46. The movable scroll 45 faces the fixed scroll 41 and is rotated relative to the fixed scroll 41. The movable scroll 45 has a base plate 45a and a movable volute portion 45b, which is located on the base plate 45a and extends toward the fixed scroll 41. 0034 The fixed scroll 41 and the movable scroll 45 are engaged with each other by the fixed and the movable volute portions 41c, 45b. The distal end of the fixed volute portion 41c contacts the base plate 45a of the movable volute portion 45. The distal end of the movable volute portion 45b contacts the fixed base plate 41a of the fixed scroll 41. Therefore, a compression chamber 47 is defined by the fixed base plate 41a and the fixed volute portion 41c of the fixed scroll 41, and the base plate 45a and the movable volute portion 45b of the movable scroll 45. 0035 A conventional anti-rotation mechanism 48 is located between the base plate 45a of the movable scroll 45 and the shaft support member 32, which faces the base plate 45a. The anti-rotation mechanism 48 includes an annular bore 48a, which is formed in the shaft support member 32, and a pin 48b, which projects from the movable scroll 45 and is loosely fitted in the annular bore 48a. 0036 A suction chamber 49 is defined between the outer circumferential wall 41b of the fixed scroll 41 and the outermost peripheral portion of the movable volute portion 45b of the movable scroll 45. A suction flange 50, which includes an inlet 50a, is integrally formed with the outer circumferential surface of the first housing member 21. The inlet 50a is connected to an evaporator of an external refrigerant circuit, which is not shown, by an external pipe. The inlet 50a is connected to the suction chamber 49 by a suction passage 51, which is formed through the suction flange 50 and the fixed scroll 41. 0037 The suction passage 51 is formed through the fixed scroll 41 such that the suction passage 51 does not overlap with the heat insulation chamber 42. That is, the heat insulation chamber 42 is formed in the housing assembly 11 such that the heat insulation chamber 42 is not exposed to the refrigerant gas. 0038 A discharge chamber 52 is defined in the sealed chamber 12 by the fixed scroll 41 abutting against the second housing member 22. The discharge chamber 52 is disconnected from the outside by the abutment of the fixed scroll 41 against the extended edge 25b of the second housing member 22 via the inner circumferential portion of the gasket 31. That is, the sealed chamber 12 and the discharge chamber 52 are sealed by the common gasket 31 in one plane. 0039 A discharge flange 53, which has an outlet 53a, is integrally formed with the outer circumferential surface of the second housing member 22. The outlet 53a is connected to a condenser of the external refrigerant circuit, which is not shown, by an external pipe. The outlet 53a is connected to the discharge chamber 52 by a discharge passage 54, which is formed through the discharge flange 53. A discharge bore 41e is formed at the center of the fixed scroll 41. The section of the compression chamber 47 that is at the center is connected to the discharge chamber 52 by the discharge bore 41e. A lead valve, which is a discharge valve 55 in the preferred embodiment, is arranged on the fixed scroll 41 in the discharge chamber 52. The discharge valve 55 selectively opens and closes the discharge bore 41e. The opening degree of the discharge valve 55 is restricted by a retainer 56 secured to the fixed scroll 41. 0040 When the drive shaft 33 is rotated by the motor 13, the movable scroll 45 orbits about the axis of the fixed scroll 41 via the eccentric shaft 43. The anti-rotation mechanism 48 prevents the movable scroll 45 from rotating, while permitting the movable scroll 45 to orbit. As the movable scroll 45 orbits, the compression chamber 47 moves toward the center of the volute portions 41c, 45b of the scrolls 41, 45. As it moves, the volume of the compression chamber 47 decreases. The refrigerant gas drawn into the compression chamber 47 from the suction chamber 49 is thus compressed. The compressed refrigerant gas is then discharged to the discharge chamber 52 through the discharge bore 41e and the discharge valve 55. After being discharged to the discharge chamber 52, the refrigerant gas is sent to the external refrigerant circuit through the discharge passage 54 and the outlet 53a. 0041 The preferred embodiment of the present invention provides the following advantages. 0042 (1) The common gasket 31 is used to seal the contact portion between the first housing member 21 and the second housing member 22 (that is, it seals the sealed chamber 12), and it is used to seal the contact portion between the compression mechanism 14 and the second housing member 22 (that is, it seals the discharge chamber 52). This simplifies the sealing structure of the electric compressor and reduces the number of parts. 0043 (2) The space in the sealed chamber 12 that is defined by the compression mechanism 14 abutting against the second housing member 22 serves as the discharge chamber 52. Therefore, the pressurized gas in the discharge chamber 52 presses the compression mechanism 14 (fixed scroll 41) toward the inner shoulder 23c of the first housing member 21. Thus, the compression mechanism 14 is reliably secured to the first housing member 21. The inner shoulder 23c of the first housing member 21 and the extended edge 25b of the second housing member 22 need not be manufactured with high accuracy. This reduces the manufacturing cost of the first and the second housing members 21, 22. 0044 (3) In the second housing member 22, the contact surface 25a, 29a, which abuts against the first housing member 21, is flush with the contact surface (extended edge) 25b, which abuts against the compression mechanism 14 (fixed scroll 41). Therefore, the plate-like gasket 31 is easily applied as the sealing member. (That is, each projection of the second housing member has a contact surface abutting the first housing member on substantially the same plane as the extended edge of the second housing member.) Thus, the common sealing member as described in the advantage (1) is easily embodied at low cost. 0045 (4) The contact surface 23d, 28a of the first housing member 21 abuts against the second housing member 22. The contact surface 41f of the compression mechanism 14 abuts against the second housing member 22. The contact surface 23d, 28a and the contact surface 41f are flush with each other. Therefore, the plate-like gasket 31 is easily applied as the sealing member. Thus, the common sealing member as described in the advantage (1) is easily embodied at low cost. 0046 (5) The compression mechanism 14 is held between the inner shoulder 23c and the extended edge 25b of the first and the second housing members 21 and 22 inside the sealed chamber 12. Therefore, fasteners such as bolts are not required for securing the compression mechanism 14 to the housing assembly 11. This simplifies the structure of the electric compressor. Also, the compression mechanism 14 is secured to the housing assembly 11 as the first housing member 21 is secured to the second housing member 22. This simplifies the assembling procedure of the electric compressor. 0047 (6) The compression mechanism 14 is scroll type. As compared to a piston type compression mechanism, the scroll type compression mechanism 14 is small and has high efficiency and low noise. 0048 It should be apparent to those skilled in the art that the present invention may be embodied in many other specific forms without departing from the spirit or scope of the invention. Particularly, it should be understood that the invention may be embodied in the following forms. 0049 In the second housing member 22, there may be a small step between the contact surface 25a, 29a, which abuts against the first housing member 21, and the contact surface (extended edge) 25b, which abuts against the compression mechanism 14 (fixed scroll 41). The gasket 31 deforms to compensate for the step. Thus, the plate-like gasket 31 can still be used as the sealing member. 0050 There may be a small step between the contact surface 23d, 28a of the first housing member 21, the contact surface 23d abutting against the second housing member 22, and the contact surface 41f of the compression mechanism 14, the contact surface 41f abutting against the second housing member 22. The gasket 31 deforms to compensate for the step. Thus, the plate-like gasket 31 can still be used as the sealing member. 0051 The housing assembly 11 need not be structured by two housing members 21, 22. For example, the first housing member 21 may be divided into the cylindrical portion 23 and the wall 24. That is, the housing assembly 11 may be structured with more than two housing members. 0052 The present invention need not be embodied in a scroll type compression mechanism. For example, the present invention may be embodied in a piston type compression mechanism, a vane type compression mechanism, or a helical type compression mechanism. 0053 The present invention is not limited to an electric compressor, which has a built-in electric motor. For example, the present invention may be embodied in a compressor that is driven by an internal combustion engine of a vehicle. 0054 The present invention is not limited to compressors that are used in vehicular air-conditioners. The present invention may be embodied in compressors that are used in home air-conditioners. 0055 The present invention is not limited to compressors used in air-conditioners. The present invention may be used in compressors used in refrigeration cycles other than air-conditioners such as refrigeration cycles of refrigerators and freezers. 0056 The present invention is not limited to compressors used in refrigeration cycles. For example, the present invention may be embodied in air compressors used in air suspension devices in vehicles. 0057 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 and equivalence of the appended claims.