Motor compressor

Abstract

To provide a motor compressor that enables downsizing and has excellent durability and quietness.SOLUTION: An electric compressor comprises a housing 1, a rotational shaft 5, a motor 7, and a compression unit 10. The housing 1 has a boss 4 that protrudes cylindrically toward the rotational shaft 5. A bearing 19 that supports the rotational shaft 5 is provided on an inner peripheral surface 42 of the boss 4. The boss 4 has an asymmetric shape with an outer peripheral surface 41 at different distances from the inner peripheral surface 42 in a radial direction of the rotational shaft 5. The rotational shaft 5 is press-fitted into the bearing 19, and the bearing 19 is clearance-fitted against the inner peripheral surface 42 of the boss 4.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to an electric compressor. [Background technology]

[0002] Patent Document 1 discloses a conventional electric compressor. This electric compressor includes a housing, a rotating shaft rotatably supported inside the housing, a motor for rotating the rotating shaft, and a compression section for compressing a fluid by the rotation of the rotating shaft. The housing has a cylindrical boss protruding toward the outer circumferential surface of the rotating shaft. A bearing for supporting the rotating shaft is provided on the inner circumferential surface of the boss.

[0003] Specifically, the bearing is a ball bearing, and has an inner ring, an outer ring, and a number of spherical bearing balls disposed between the inner ring and the outer ring. Although the details are unclear in the document, in this type of electric compressor, it is common for the rotating shaft to be clearance-fitted into the inner ring, and for the outer ring to be press-fitted against the inner peripheral surface of the boss. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2012-57504 A Summary of the Invention [Problem to be solved by the invention]

[0005] In recent years, there has been a demand for further miniaturization of electric compressors, and so the diameter of the housing has been made smaller. On the other hand, the smaller diameter of the housing makes it difficult to secure a sufficient space for forming a boss on the housing. For this reason, the boss is formed in a shape that avoids interference with other components provided in the motor chamber, or conversely, is formed in a shape that is integrated with a part of the other components. This makes the boss have a complex shape, and an asymmetric shape with an outer circumferential surface that is at different distances from the inner circumferential surface in the radial direction of the rotating shaft. In other words, the thickness of the boss is not uniform, and there are thick and thin parts.

[0006] When a bearing is press-fitted into a boss having such a difference in thickness, the boss is likely to deform unevenly during press-fitting, making the boss prone to distortion. As a result, the bearing held by the boss is also susceptible to distortion due to the influence of the boss deformation.

[0007] This results in a problem of reduced durability of the bearing. In addition, when the bearing is distorted, it is no longer able to properly hold the rotating shaft, which makes it more likely for the rotating shaft to vibrate when rotating. This also results in a problem of increased noise.

[0008] The present invention has been made in consideration of the above-mentioned conventional circumstances, and has an object to be achieved by providing an electric compressor that is compact, durable, and quiet. [Means for solving the problem]

[0009] The electric compressor of the present invention comprises a housing and a rotating shaft rotatably supported within the housing; A motor that rotates the rotary shaft; a compression unit that compresses a fluid by rotation of the rotating shaft, The housing has a boss that protrudes cylindrically toward the rotation shaft, an inner circumferential surface of the boss is provided with a bearing for supporting the rotating shaft; the boss has an asymmetric shape having an outer circumferential surface at different distances from the inner circumferential surface in a radial direction of the rotation shaft, The rotating shaft is press-fitted into the bearing, and the bearing is clearance-fitted against the inner circumferential surface.

[0010] In the electric compressor of the present invention, the boss has an asymmetric shape with an outer circumferential surface that is at different distances from the inner circumferential surface in the radial direction of the rotating shaft, and therefore the thickness of the boss is not uniform.

[0011] Here, in this electric compressor, the rotating shaft is press-fitted into the bearing, while the bearing is clearance-fitted against the inner peripheral surface of the boss. As a result, even if the boss has an asymmetric shape and is not uniform in thickness, this does not pose a problem when mounting the bearing on the inner peripheral surface of the boss. As a result, even if the bearing is mounted on the inner peripheral surface of the boss, the bearing is unlikely to be distorted. As a result, the durability of the bearing, and therefore the electric compressor, can be increased.

[0012] On the other hand, in this electric compressor, although the rotating shaft is press-fitted into the bearing, the cross section of the rotating shaft is originally formed to be nearly a perfect circle to ensure proper rotation. Therefore, if the shape of the bearing is affected by the shape of the rotating shaft through press-fitting, the bearing will become closer to a perfect circle. This allows the bearing to properly support the rotating shaft in this electric compressor. As a result, the rotating shaft is less likely to wobble in this electric compressor, and noise during operation can be suppressed.

[0013] Therefore, the electric compressor of the present invention is compact and has excellent durability and quietness.

[0014] The boss preferably has a supply passage that penetrates from the outer circumferential surface to the inner circumferential surface in the radial direction of the rotating shaft and supplies lubricating oil to the bearing.

[0015] In this case, the lubricating oil can be suitably supplied to the bearing through the supply passage, thereby improving the durability of the bearing and the rotating shaft. Also, although the boss is likely to have an asymmetric shape and a difference in thickness is likely to occur due to the formation of the supply passage in this manner, in this electric compressor, the bearing is loosely fitted onto the inner peripheral surface of the boss as described above, so that the bearing is less likely to deform.

[0016] The housing may be provided with an inverter located on the opposite side of the motor from the compression unit and electrically connected to the motor. The housing may have a motor chamber that accommodates the motor, an inverter chamber that accommodates the inverter, and a partition wall that separates the motor chamber from the inverter chamber and in which the boss is provided. The partition wall may be provided with a through hole into which an airtight terminal that electrically connects the motor and the inverter is inserted. The motor may have a stator core around which a coil is wound, and a rotor that rotates integrally with the rotating shaft. The coil may have a coil end that protrudes from an end of the stator core, a terminal box that is electrically connected to the airtight terminal, and a lead wire that extends from the coil end to the terminal box. The boss is preferably asymmetric in shape by cutting out the outer circumferential surface so that the distance from the inner circumferential surface is different from that of at least one of the through hole and the terminal box in the radial direction of the rotating shaft.

[0017] In this case, the housing and therefore the electric compressor can be made smaller, while preventing interference between the terminal box connected to the airtight terminal and the boss, so that the electric compressor can be suitably connected to the motor and the inverter via the airtight terminal and the terminal box.

[0018] The inner circumferential surface may have a fitting portion into which the bearing is clearance-fitted, and a guide portion that guides the bearing into the fitting portion. The guide portion preferably has a first tapered portion that gradually increases in diameter as it moves away from the fitting portion in the axial direction of the rotating shaft, a second tapered portion that is disposed apart from the first tapered portion in the axial direction of the rotating shaft and gradually increases in diameter beyond the maximum inner diameter of the first tapered portion as it moves away from the first tapered portion, and a connection portion that is located between the first tapered portion and the second tapered portion and connects the first tapered portion and the second tapered portion while maintaining the maximum inner diameter of the first tapered portion.

[0019] When the bearing is provided on the inner peripheral surface of the boss, the bearing, which is press-fitted and assembled to the rotating shaft, is clearance-fitted into the fitting portion on the inner peripheral surface. In order to clearance-fit the bearing into the fitting portion, the fitting portion is formed with a larger diameter than the bearing. In addition, since the rotating shaft is attached to a motor, the rotating shaft is inevitably affected by the magnetism of the motor. For this reason, it is often difficult to clearance-fit the rotating shaft and the bearing assembled to the rotating shaft into the fitting portion in a state parallel to the axis of the rotating shaft.

[0020] In this regard, in this electric compressor, the inner peripheral surface of the boss has a guide portion that guides the bearing into the fitting portion, and the guide portion has a first tapered portion, a second tapered portion, and a connection portion. Therefore, in this electric compressor, even if the rotating shaft is affected by the magnetism of the motor, the guide portion can guide the bearing into the fitting portion in a state parallel to the axial direction of the rotating shaft. Thus, in this electric compressor, the bearing can be easily clearance-fitted into the fitting portion.

[0021] The bearing preferably has an inner ring into which the rotating shaft is press-fitted, an outer ring that is clearance-fitted against the inner circumferential surface, and a plurality of spherical bearing balls provided between the inner ring and the outer ring.

[0022] In this case, the inner ring is influenced by the shape of the rotating shaft into which it is pressed, and so approaches a perfect circle, allowing the bearing to suitably support the rotating shaft through the inner ring. Meanwhile, the outer ring is loosely fitted onto the inner peripheral surface of the boss, making it less likely to deform. This can increase the durability of the bearing. Effect of the Invention

[0023] The electric compressor of the present invention is compact and has excellent durability and quietness. [Brief description of the drawings]

[0024] [Figure 1] FIG. 1 is a cross-sectional view of the electric compressor according to the first embodiment. [Diagram 2] FIG. 2 is a cross-sectional view taken along line AA in FIG. 1, showing the electric compressor of the first embodiment. [Diagram 3] FIG. 3 is a cross-sectional view taken along line BB of FIG. 2, showing the electric compressor of the first embodiment, in a state in which a rotating shaft is supported by a bearing and the bearing is housed and held in a boss. [Figure 4] FIG. 4 is an enlarged view of a main part of the electric compressor of the first embodiment, showing a boss, as shown in FIG. [Diagram 5] FIG. 5 is a schematic cross-sectional view of the electric compressor of the first embodiment taken along line CC of FIG. [Figure 6] FIG. 6 is a cross-sectional view similar to FIG. 2 showing the electric compressor of the first embodiment, in which an inverter and a motor are connected through a cluster block. [Figure 7] FIG. 7 is a cross-sectional view similar to FIG. 3 showing an electric compressor according to a second embodiment, in which a rotating shaft is supported by a bearing and the bearing is housed and held in a boss. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0025] Hereinafter, first and second embodiments of the present invention will be described with reference to the drawings. The electric compressors (hereinafter simply referred to as compressors) of the first and second embodiments are specifically scroll-type electric compressors. These compressors are mounted on a vehicle (not shown) and form a refrigeration circuit of the vehicle.

[0026] Example 1 As shown in FIG. 1, the compressor of the first embodiment includes a housing 1, an inverter 3, a rotating shaft 5, a motor 7, and a compression unit 10.

[0027] In this embodiment, the front-rear direction of the compressor is defined by the solid arrow shown in Fig. 1. In Fig. 3 and subsequent figures, the front-rear direction of the compressor is defined in accordance with Fig. 1. Note that this front-rear direction is an example provided for convenience of explanation, and the attitude of the compressor is appropriately changed in accordance with the vehicle in which it is installed, etc.

[0028] As shown in Fig. 1, the housing 1 is made up of a motor housing 13, a compressor housing 14, a fixed block 15, and an inverter cover 2. The motor housing 13, the compressor housing 14, the fixed block 15, and the inverter cover 2 are all made of an aluminum alloy. The inverter cover 2 forms the front portion of the housing 1, and the compressor housing 14 forms the rear portion of the housing 1.

[0029] The motor housing 13 has a first front wall 13a and a first peripheral wall 13b. The first front wall 13a is an example of the "partition wall" in the present invention. The first front wall 13a is located at the front end of the motor housing 13 and extends in the radial direction of the rotating shaft 5 and therefore in the radial direction of the motor housing 13. The first peripheral wall 13b is connected to the first front wall 13a and extends rearward from the first front wall 13a in the direction of the rotation axis O. The direction of the rotation axis O is parallel to the front-rear direction of the compressor.

[0030] The first front wall 13a and the first peripheral wall 13b form the motor housing 13 in a cylindrical shape with a bottom that is open at the rear. A motor chamber 17 is formed in the motor housing 13 by the first front wall 13a and the first peripheral wall 13b.

[0031] The first front wall 13a has a front surface 131 and a rear surface 132. The front surface 131 faces the front of the motor housing 13. The rear surface 132 is located on the opposite side to the front surface 131 and faces the inside of the motor chamber 17.

[0032] As shown in Fig. 2, the first front wall 13a is formed with a first boss 4, a bulge 6, and a through hole 8. The first boss 4 is an example of the "boss" in the present invention. In Fig. 2, for ease of explanation, the rotating shaft 5, the motor 7, and a first radial ball bearing 19 described later are omitted. The same applies to Fig. 6.

[0033] As shown in FIG. 2, the first boss 4 is integrally formed with the first front wall 13a. As shown in FIG. 1 and FIG. 3, the first boss 4 protrudes from the rear surface 132 toward the outer circumferential surface 501 of the rotating shaft 5 in the direction of the rotation axis O. That is, the first boss 4 protrudes rearward from the rear surface 132 into the motor chamber 17. The first boss 4 has a substantially cylindrical shape centered on the rotation axis O. The first boss 4 holds a first radial ball bearing 19. The first radial ball bearing 19 is an example of the "bearing" in the present invention. The configurations of the first boss 4 and the first radial ball bearing 19 will be described in detail later.

[0034] As shown in FIG. 2, the bulge 6 is disposed outside the first boss 4 and in close proximity to the first boss 4. The bulge 6 bulges from the rear surface 132 toward the inside of the motor chamber 17. The bulge 6 has a rear end surface 6a located at the rear end. A portion of the rear end surface 6a is formed flat. The through hole 8 is disposed so as to overlap the bulge 6, and penetrates the first front wall 13a in the direction of the rotation axis O in the shape of an elongated hole. In other words, the through hole 8 penetrates from the front surface 131 of the first front wall 13a to the rear end surface 6a of the bulge 6. In this way, the through hole 8 communicates between the outside of the motor housing 13 and the inside of the motor chamber 17.

[0035] 1, a suction opening 13c is formed in the first peripheral wall 13b of the motor housing 13. The suction opening 13c extends through the first peripheral wall 13b in the radial direction of the motor housing 13 and communicates with the motor chamber 17. The suction opening 13c is connected to an evaporator (not shown) by a pipe (not shown), and allows the refrigerant gas that has passed through the evaporator to be sucked into the motor chamber 17. The refrigerant gas is an example of the "fluid" in the present invention.

[0036] Furthermore, as shown in Fig. 2, six first bolt holes 13d are formed in the rear part of the first peripheral wall 13b, and two positioning pins 13e are fixed thereto. Each of the first bolt holes 13d extends forward from a rear end surface 133 of the first peripheral wall 13b (see Fig. 1). Each of the positioning pins 13e shown in Fig. 2 is fixed to the first peripheral wall 13b with a part of it protruding rearward from the rear end surface 133.

[0037] As shown in Fig. 1, the compressor housing 14 has a rear wall 14a and a second peripheral wall 14b. The rear wall 14a is located at the rear end of the compressor housing 14 and extends in the radial direction of the compressor housing 14. The second peripheral wall 14b is connected to the rear wall 14a and extends forward from the rear wall 14a. The rear wall 14a and the second peripheral wall 14b form the compressor housing 14 into a cylindrical shape with a bottom that is open at the front.

[0038] The compressor housing 14 is formed with an oil separation chamber 14c, a first discharge recess 14d, a discharge passage 14e, a discharge opening 14f, and six second bolt holes 14g. The oil separation chamber 14c is located on the rear side in the compressor housing 14 and extends in the radial direction of the compressor housing 14. The first discharge recess 14d is located on the front side of the oil separation chamber 14c in the compressor housing 14 and has a shape recessed toward the oil separation chamber 14c. The discharge passage 14e extends in the front-rear direction and connects the oil separation chamber 14c and the first discharge recess 14d. The discharge opening 14f is connected to the oil separation chamber 14c and opens toward the outside of the compressor housing 14. The discharge opening 14f is connected to a condenser (not shown) by a pipe (not shown). Each of the second bolt holes 14g is formed in the second peripheral wall 14b and penetrates the second peripheral wall 14b in the front-rear direction. Note that Fig. 1 illustrates only one of the six second bolt holes 14g.

[0039] A separation cylinder 21 is fixed inside the oil separation chamber 14c. A separator is formed by the inner peripheral surface of the oil separation chamber 14c and the outer peripheral surface of the separation cylinder 21. A filter 23 is provided in the oil separation chamber 14c at a position below the separation cylinder 21.

[0040] The fixed block 15 is provided between the motor housing 13 and the compressor housing 14. The fixed block 15 is provided with a second boss 15a that protrudes forward. An insertion hole 15b is formed at the tip of the second boss 15a. A second radial ball bearing 27 and a seal member 29 are provided in the second boss 15a. The fixed block 15 is further provided with six third bolt holes 15c. Each of the third bolt holes 15c is disposed outside the second boss 15a and penetrates the fixed block 15 in the front-rear direction. Although not shown, the fixed block 15 is provided with positioning recesses that correspond to each of the positioning pins 13e of the motor housing 13. Note that FIG. 1 illustrates one of the six third bolt holes 15c.

[0041] The motor housing 13, the compressor housing 14, and the fixed block 15 are aligned in the front-rear direction with the first bolt holes 13d, the second bolt holes 14g, and the third bolt holes 15c. The motor housing 13 and the fixed block 15 are also aligned with the positioning pins 13e inserted into the positioning recesses. In this way, the motor housing 13, the compressor housing 14, and the fixed block 15 are positioned. The motor housing 13, the compressor housing 14, and the fixed block 15 are fixed by six bolts 25 inserted from the compressor housing 14 side into the second bolt holes 14g, the third bolt holes 15c, and the first bolt hole 13d in this order. In this way, the motor housing 13, the compressor housing 14, and the fixed block 15 are integrated. The method of fixing the motor housing 13, the compressor housing 14, and the fixed block 15 can be designed as appropriate. Furthermore, the numbers of first bolt holes 13d, second bolt holes 14g, and third bolt holes 15c can be designed appropriately according to the number of bolts 25.

[0042] By fixing the motor housing 13, the compressor housing 14, and the fixed block 15 in this manner, the fixed block 15 is located between the motor chamber 17 and the compression section 10 in the front-rear direction, as shown in Fig. 1. The second boss 15a protrudes forward toward the motor chamber 17.

[0043] In addition, the fixed block 15 has a plurality of suction passages 55 formed therein, and also has a plurality of rotation prevention pins 31 fixed thereto. Each suction passage 55 is disposed at a position that is outside the second boss 15a and inside the third bolt holes 15c, and each passes through the fixed block 15 in the front-rear direction. As a result, each suction passage 55 communicates with the motor chamber 17 and the inside of the compressor housing 14. Each rotation prevention pin 31 is fixed to the fixed block 15 in a state where it protrudes rearward. Note that FIG. 1 illustrates one each of the suction passages 55 and each rotation prevention pin 31.

[0044] The inverter cover 2 is disposed in front of the motor housing 13. The inverter cover 2 has a second front wall 2a and a third peripheral wall 2b. The second front wall 2a is located at the front end of the inverter cover 2 and extends in the radial direction of the inverter cover 2. The third peripheral wall 2b is connected to the second front wall 2a and extends rearward from the second front wall 2a. The second front wall 2a and the third peripheral wall 2b form the inverter cover 2 into a cylindrical shape with a bottom that is open at the rear. The inverter cover 2 may be made of resin.

[0045] The inverter cover 2 has the rear end of the third peripheral wall 2b in contact with the front surface 131 of the first front wall 13a of the motor housing 13. The inverter cover 2 is fixed to the motor housing 13 in this state by a plurality of bolts (not shown). In this manner, the inverter cover 2, the motor housing 13, the fixing block 15, and the compressor housing 14 are fixed in this order from the front to the rear to form the housing 1. The inverter cover 2 forms an inverter chamber 18 between itself and the first front wall 13a. That is, the first front wall 13a divides the motor chamber 17 and the inverter chamber 18. The inverter chamber 18 communicates with the through hole 8 shown in FIG. 2. Although not shown, a connector portion is formed on the second front wall 2a of the inverter cover 2.

[0046] The inverter 3 shown in FIG. 1 is accommodated in the inverter chamber 18. The inverter 3 has a circuit board 3a, a switching element 3b, and an airtight terminal 3c shown in FIG. 2. The circuit board 3a is fixed to a front surface 131 of a first front wall 13a of the motor housing 13 by a bolt (not shown). The circuit board 3a is connected to a battery (not shown) provided in the vehicle through a connector portion. The switching element 3b is provided on the circuit board 3a. The switching element 3b faces the front surface 131 and abuts against the front surface 131 by fixing the circuit board 3a to the front surface 131. Thus, heat generated from the switching element 3b during operation is dissipated to the first front wall 13a. The switching element 3b and the first front wall 13a may be spaced apart from each other.

[0047] The airtight terminal 3c shown in Fig. 2 is connected to the circuit board 3a. The airtight terminal 3c is fixed to the first front wall 13a of the motor housing 13 by a bolt (not shown) while being disposed in the through hole 8. As a result, the airtight terminal 3c is inserted into the through hole 8 and faces the inside of the motor chamber 17 from the through hole 8. The airtight terminal 3c seals the inverter chamber 18 and the motor chamber 17. The shape of the airtight terminal 3c can be designed as appropriate. The shape of the through hole 8 can be designed as appropriate according to the shape of the airtight terminal 3c.

[0048] As shown in FIG. 1, the rotating shaft 5 is provided in the housing 1. The rotating shaft 5 is made of steel and has a cylindrical shape extending in the front-rear direction. The rotating shaft 5 is composed of a small diameter portion 5a, a large diameter portion 5b, and a tapered portion 5c. Although detailed illustration is omitted, the rotating shaft 5 is formed by cutting. As a result, the cross section of the small diameter portion 5a, the large diameter portion 5b, and the tapered portion 5c on a plane perpendicular to the rotating shaft has a shape of a nearly perfect circle. The rotating shaft 5 also has an outer circumferential surface 501. The outer circumferential surface 501 constitutes the outer circumferential surface of the small diameter portion 5a, the outer circumferential surface of the large diameter portion 5b, and the outer circumferential surface of the tapered portion 5c.

[0049] The small diameter portion 5a is located on the front end side of the rotary shaft 5. The large diameter portion 5b is located behind the small diameter portion 5a and is formed with a larger diameter than the small diameter portion 5a. A flat rear end surface 5d is formed at the rear end of the large diameter portion 5b. The tapered portion 5c is located between the small diameter portion 5a and the large diameter portion 5b. The tapered portion 5c is connected to the small diameter portion 5a at its front end. The tapered portion 5c expands in diameter toward the rear and is connected to the large diameter portion 5b at its rear end.

[0050] The small diameter portion 5a of the rotating shaft 5 is rotatably supported by the first boss 4 of the motor housing 13 via a first radial ball bearing 19. The rear end side of the large diameter portion 5b is inserted into an insertion hole 15b of the fixed block 15 and enters the second boss 15a. Inside the second boss 15a, the rear end of the large diameter portion 5b is rotatably supported by a second radial ball bearing 27. In this way, the rotating shaft 5 is rotatable around the rotation axis O within the housing 1. The gap between the fixed block 15 and the rotating shaft 5 is sealed by a seal member 29.

[0051] In addition, an eccentric pin 50 is fixed to the large diameter portion 5b of the rotating shaft 5. The eccentric pin 50 is disposed at a position eccentric from the rotation axis O on the rear end face 5d. The eccentric pin 50 is formed in a cylindrical shape having a smaller diameter than the rotating shaft 5, and extends rearward from the rear end face 5d. The eccentric pin 50 advances into the second boss 15a by inserting the rear end side of the large diameter portion 5b into the insertion hole 15b. The eccentric pin 50 is fitted into a bush 50a in the second boss 15a.

[0052] Furthermore, in the rotating shaft 5, a balance weight 33 is integrally formed on the large diameter portion 5b. The balance weight 33 is disposed in a position eccentric from the rotation axis O in the large diameter portion 5b. More specifically, the balance weight 33 is disposed in a position opposite the eccentric pin 50 across the rotation axis O.

[0053] Although detailed illustration is omitted, the balance weight 33 is formed in a plate shape having a substantially sector shape. The balance weight 33 extends in the radial direction of the rotating shaft 5 in a direction away from the large diameter portion 5b. The radial direction of the rotating shaft 5 is a direction perpendicular to the direction of the rotation axis O. That is, the balance weight 33 extends from the large diameter portion 5b toward the first peripheral wall 13b of the motor housing 13. The balance weight 33 is located in the motor chamber 17 by providing the rotating shaft 5 in the housing 1. More specifically, the balance weight 33 is located between the fixed block 15 and the motor 7 in the motor chamber 17. The shape of the balance weight 33 can be designed as appropriate.

[0054] The motor 7 is accommodated in the motor chamber 17. In this case, the motor 7 is accommodated in the motor chamber 17 forward of the balance weight 33. The motor 7 has a stator 7a and a rotor 7b.

[0055] The stator 7a has a stator core 71. The stator core 71 is formed in a cylindrical shape and is fixed to the inner peripheral surface of the first peripheral wall 13b. A coil 75 is wound around the stator core 71. The coil 75 has a cluster block 7c, a first lead wire 701, a second lead wire 702, and a third lead wire 703 shown in FIG. 6 in addition to a coil end 73. The cluster block 7c is an example of a "terminal box" in the present invention. The first to third lead wires 701 to 703 are an example of a "lead wire" in the present invention.

[0056] As shown in Fig. 1, the coil end 73 is a portion of the coil 75 that protrudes forward and backward in the axial direction from the stator core 71 and has an annular shape. The rear end of the coil end 73 is inclined on the inner circumferential side to avoid interference with the balance weight 33. For ease of explanation, the cluster block 7c and the first to third lead wires 701 to 703 are omitted from Fig. 1.

[0057] The cluster block 7c shown in FIG. 6 has a connection terminal (not shown) housed therein. Although not shown in detail, the first to third lead wires 701 to 703 extend from the coil end 73 toward the cluster block 7c. The cluster block 7c is connected to the coil end 73 by the first to third lead wires 701 to 703. The cluster block 7c is connected to the airtight terminal 3c in a state facing the rear end surface 6a of the bulging portion 6 from the rear. This allows the stator 7a and the inverter 3 to be electrically connected through the cluster block 7c. At this time, a part of the rear end surface 6a abuts against the cluster block 7c and supports the cluster block 7c.

[0058] 1, the rotor 7b is disposed within the stator 7a. The large diameter portion 5b of the rotating shaft 5 is fixed to the rotor 7b. The rotor 7b rotates within the stator 7a, thereby rotating the rotating shaft 5 around the rotation axis O.

[0059] The compression section 10 is specifically a scroll type compression mechanism, and is composed of a fixed scroll 9 and a movable scroll 11. The fixed scroll 9 is fixed to a compressor housing 14 and disposed within the compressor housing 14. The fixed scroll 9 has a fixed end plate 9a, a fixed peripheral wall 9b, and a fixed spiral wall 9c.

[0060] The fixed end plate 9a is located at the rear end of the fixed scroll 9 and is formed in a disk shape. The fixed end plate 9a is formed with a second discharge recess 9d and a discharge port 9e. The second discharge recess 9d is shaped to be recessed forward from the rear end surface of the fixed end plate 9a. The second discharge recess 9d faces the first discharge recess 14d by fixing the fixed scroll 9 to the compressor housing 14. Thus, the first discharge recess 14d and the second discharge recess 9d form a discharge chamber 35. The discharge chamber 35 is connected to the oil separation chamber 14c through the discharge passage 14e. The discharge port 9e penetrates the fixed end plate 9a in the front-rear direction and is connected to the discharge chamber 35.

[0061] In addition, a discharge reed valve 38 and a retainer 39 are fixed to the fixed end plate 9a by bolts 37. The bolts 37, the discharge reed valve 38, and the retainer 39 are disposed in the discharge chamber 35. The discharge reed valve 38 opens and closes the discharge port 9e by elastically deforming. The retainer 39 adjusts the amount of elastic deformation of the discharge reed valve 38.

[0062] The fixed peripheral wall 9b is connected to the fixed end plate 9a at the outer periphery of the fixed end plate 9a and extends forward in a cylindrical shape. An intake port 9f is formed in the fixed peripheral wall 9b. The intake port 9f penetrates the fixed peripheral wall 9b in the radial direction. As a result, the intake port 9f opens into the compressor housing 14. The fixed volute wall 9c is raised on the front surface of the fixed end plate 9a and is integral with the fixed peripheral wall 9b on the inside of the fixed peripheral wall 9b.

[0063] An oil supply passage 9g is formed in the fixed scroll 9. The oil supply passage 9g penetrates through the fixed end plate 9a and the fixed peripheral wall 9b. As a result, the rear end of the oil supply passage 9g opens at the rear end surface of the fixed end plate 9a, and the front end of the oil supply passage 9g opens at the front end surface of the fixed peripheral wall 9b. The oil supply passage 9g communicates with the oil separation chamber 14c through the filter 23. The shape of the oil supply passage 9g can be designed as appropriate.

[0064] The movable scroll 11 is provided in the compressor housing 14 and is located between the fixed scroll 9 and the fixed block 15. The movable scroll 11 has a movable end plate 11a and a movable spiral wall 11b. The movable end plate 11a is located at the front end of the movable scroll 11 and is formed in a disk shape. A bush 50a is rotatably supported by the movable end plate 11a via a third radial ball bearing 45. As a result, the movable scroll 11 is connected to the rotating shaft 5 at a position eccentric from the rotation axis O through the bush 50a and the eccentric pin 50. The movable spiral wall 11b is raised on the front surface of the movable end plate 11a and extends toward the fixed end plate 9a.

[0065] The movable end plate 11a is provided with rings 47, the number of which is the same as the number of rotation-prevention pins 31. Furthermore, an air supply hole 11d is formed near the center of the movable spiral wall 11b, which opens at the front end of the movable spiral wall 11b, extends in the front-rear direction within the movable spiral wall 11b, and reaches the movable end plate 11a.

[0066] The fixed scroll 9 and the movable scroll 11 are meshed with each other. As a result, a compression chamber 49 is formed between the fixed scroll 9 and the movable scroll 11 by the fixed end plate 9a, the fixed spiral wall 9c, the movable end plate 11a, and the movable spiral wall 11b. The volume of the compression chamber 49 changes as the movable scroll 11 rotates. As a result, the compression chamber 49 is communicated with the suction port 9f and the discharge port 9e, respectively.

[0067] Furthermore, each ring 47 is connected to each rotation prevention pin 31 by inserting each rotation prevention pin 31 into each ring 47. These rotation prevention pins 31 and rings 47 form the rotation prevention mechanism 16. In the rotation prevention mechanism 16, each rotation prevention pin 31 rolls while sliding on the inner circumferential surface of each ring 47, thereby restricting the rotation of the movable scroll 11 and allowing only revolution. Note that the number of each rotation prevention pin 31 and each ring 47 constituting the rotation prevention mechanism 16 can be designed as appropriate, so long as there are three or more of each.

[0068] Furthermore, a thrust plate 51 is provided between the movable scroll 11 and the fixed block 15. The thrust plate 51 is formed of a thin metal plate, and is in contact with the movable scroll 11 and the fixed block 15, respectively. The thrust plate 51 is capable of biasing the movable scroll 11 rearward, i.e., toward the fixed scroll 9, by a restoring force generated when elastically deformed. In addition, a back pressure chamber 53 is formed in the second boss 15a of the fixed block 15 by the movable end plate 11a and the thrust plate 51. The back pressure chamber 53 is in communication with the air supply hole 11d.

[0069] 2 to 4, the first boss 4 is made of a boss body 4a, a connection portion 4b, and a supply passage 4c. Since the motor housing 13 is made of an aluminum alloy, the first boss 4 formed integrally with the first front wall 13a of the motor housing 13 is also made of an aluminum alloy.

[0070] As shown in Fig. 3, the boss body 4a constitutes the rear portion of the first boss 4. The boss body 4a is formed in a substantially cylindrical shape centered on the rotation axis O, and has a first outer peripheral surface 41, a first inner peripheral surface 42, and a solid portion 43. The first outer peripheral surface 41 is an example of the "outer peripheral surface" in the present invention. Also, the first inner peripheral surface 42 is an example of the "inner peripheral surface" in the present invention.

[0071] 5, the first outer peripheral surface 41 constitutes the outer surface of the boss body 4a and faces the motor chamber 17. The first inner peripheral surface 42 is located inside the first outer peripheral surface 41 in the radial direction of the boss body 4a, i.e., in the radial direction of the rotation shaft 5. As a result, the first inner peripheral surface 42 constitutes the inner surface of the boss body 4a.

[0072] 3, the first inner circumferential surface 42 is composed of a fitting portion 42a and a guide portion 42b. The fitting portion 42a has an inner diameter length of a first length L1, and is larger than the outer diameter of the first radial ball bearing 19. The fitting portion 42a holds the first radial ball bearing 19 while accommodating it.

[0073] The guide portion 42b is located behind the fitting portion 42a and is connected to the fitting portion 42a. The inner diameter of the front end of the guide portion 42b, i.e., the connection point of the guide portion 42b with the fitting portion 42a, is the same as the inner diameter of the fitting portion 42a. The guide portion 42b has a tapered shape that gradually increases in diameter compared to the fitting portion 42a as it moves rearward from the fitting portion 42a in the axial direction of the rotating shaft 5, i.e., the direction of the rotation axis O. As a result, the inner diameter of the rear end of the guide portion 42b is larger than the inner diameter of the fitting portion 42a and the outer diameter of the first radial ball bearing 19.

[0074] As shown in Fig. 5, the meat portion 43 is located between the first outer peripheral surface 41 and the first inner peripheral surface 42 in the radial direction of the rotating shaft 5. In order to facilitate explanation, Fig. 5 shows a simplified shape of the boss body 4a, and omits illustration of the supply passage 4c, the rotating shaft 5, and the first radial ball bearing 19.

[0075] As shown in FIG. 3, the connection portion 4b is located in front of the boss body 4a. As a result, the connection portion 4b constitutes the front portion of the first boss 4. The connection portion 4b is connected to the front end of the boss body 4a. Then, as shown in FIG. 4, the connection portion 4b extends forward while expanding in diameter more than the boss body 4a, and is connected to the rear surface 132 of the first front wall 13a. Also, as shown in FIG. 3, a recess 44 is formed in the connection portion 4b. The recess 44 is recessed in a cylindrical shape centered on the rotation axis O. The recess 44 is connected to the fitting portion 42a. The inner diameter of the recess 44 is smaller than the inner diameter of the fitting portion 42a.

[0076] Here, in this compressor, the diameter of the motor housing 13 is reduced in order to achieve a compact size. As a result, although the first front wall 13a has the bulge 6 and the through hole 8 in addition to the first boss 4 as described above, it is no longer possible to provide a sufficient space between the first boss 4 and the bulge 6 and the through hole 8. For this reason, as shown in Fig. 6, the first boss 4 is formed with an interference avoidance portion 46 for preventing interference with the cluster block 7c when the cluster block 7c is connected to the airtight terminal 3c.

[0077] The interference avoidance portion 46 is formed in the boss body 4a and the connection portion 4b at locations on the bulging portion 6, through hole 8, and cluster block 7c side, i.e., at locations near the bulging portion 6, through hole 8, and cluster block 7c in the radial direction of the rotating shaft 5. The interference avoidance portion 46 extends in a plane in the direction of the rotation axis O.

[0078] Since the interference avoidance portion 46 is thus formed in the boss body 4a and the connecting portion 4b, the boss body 4a and the connecting portion 4b are spaced apart from the bulging portion 6, the through hole 8, and the cluster block 7c.

[0079] Furthermore, by forming the interference avoidance portion 46, the first outer peripheral surface 41 and the connection portion 4b of the boss main body 4a have a shape in which the portion where the interference avoidance portion 46 is formed is cut out in a flat shape. As a result, when the boss main body 4a is viewed from the rear in the direction of the rotation axis O, as shown in Figures 4 and 5, the first outer peripheral surface 41 of the boss main body 4a does not have a shape that forms an arc in the circumferential direction over its entirety, and the portion where the interference avoidance portion 46 is formed is linear. In contrast, the first inner peripheral surface 42 is not influenced by the shape of the interference avoidance portion 46, so there is no portion that is linear.

[0080] As a result, as shown in FIG. 5, in the boss body 4a, the thickness of the wall portion 43 is not uniform as a whole. That is, the wall portion 43 is provided with a first thick portion 43a having a first thickness t1 in the radial direction of the rotating shaft 5, and a second thick portion 43b having a second thickness t2 at the thinnest portion in the radial direction of the rotating shaft 5. The second thickness t2 is thinner than the first thickness t1. That is, the second thick portion 43b is thinner than the first thick portion 43a. In other words, the second thick portion 43b having a thinner thickness than the first thick portion 43a is provided in the wall portion 43, so that an interference avoidance portion 46 is formed in the first boss 4. Strictly speaking, the wall thickness is not constant at the second thickness t2 in all the portions of the second thick portion 43b, and there are also portions of the second thick portion 43b having different wall thicknesses. However, the thickness of the second thick portion 43b at any point is thinner than the first thickness t1.

[0081] Then, because the thickness of the second thick portion 43b is reduced, the distance of the first inner peripheral surface 42 in the radial direction of the rotation shaft 5 from the first outer peripheral surface 41 is shorter at the location of the boss body 4a where the second thick portion 43b exists, i.e., where the interference avoidance portion 46 is formed, than when the first thick portion 43a exists. Also, the distance of the first inner peripheral surface 42 in the radial direction of the rotation shaft 5 from the bulging portion 6, the through hole 8, and the cluster block 7c is shorter at the location where the interference avoidance portion 46 is formed, than when the first thick portion 43a exists (see FIG. 6). As a result, as shown in FIGS. 4 to 6, the first boss 4 has a target shape in which the shape of the side where the interference avoidance portion 46 exists and the shape of the side where the interference avoidance portion 46 does not exist are different with respect to the rotation axis O. In other words, the first boss 4 has an asymmetric shape in which the shape on the right side of the paper in FIGS. 4 to 6 is different from the shape on the left side of the paper in FIGS. 4 to 6.

[0082] As shown in FIG. 4, the supply passage 4c extends in the radial direction of the rotating shaft 5 and is recessed from the rear end of the first boss 4 toward the front. That is, the supply passage 4c is recessed from the boss body 4a to the connection portion 4b. In the guide portion 42b, the portion where the supply passage 4c is formed is cut out. Here, since the boss body 4a and therefore the first boss 4 are cylindrical, the supply passage 4c is composed of a first passage portion 401 located on the interference avoidance portion 46 side of the rotation axis O in the radial direction of the rotating shaft 5, and a second passage portion 402 located on the opposite side of the first passage portion 401 across the rotation axis O.

[0083] Furthermore, at the location of the boss body 4a where the supply passage 4c is formed, the first outer peripheral surface 41 and the fitting portion 42a of the first inner peripheral surface 42 are connected through the supply passage 4c. Similarly, at the connection portion 4b, the recess 44 is connected to the outer surface of the connection portion 4b through the supply passage 4c.

[0084] 3, the first radial ball bearing 19 is made of steel, and has an outer ring 191, an inner ring 192, and a number of bearing balls 193. The outer ring 191 constitutes a second outer peripheral surface 19a which is the outer peripheral surface of the first radial ball bearing 19. The inner ring 192 is disposed inside the outer ring 191, and constitutes a second inner peripheral surface 19b which is the inner peripheral surface of the first radial ball bearing 19. Each bearing ball 193 is formed in a spherical shape, and is provided between the outer ring 191 and the inner ring 192.

[0085] The length of the outside diameter of the outer ring 191, i.e., the diameter of the second outer peripheral surface 19a of the first radial ball bearing 19, is formed to be shorter than the length of the inside diameter of the fitting portion 42a. Also, the length of the inside diameter of the inner ring 192, i.e., the diameter of the second inner peripheral surface 19b of the first radial ball bearing 19, is formed to be shorter than the length of the outside diameter of the small diameter portion 5a of the rotating shaft 5. In other words, the outside diameter of the first radial ball bearing 19 is smaller than the inside diameter of the boss body 4a, and the inside diameter of the first radial ball bearing 19 is smaller than the outside diameter of the small diameter portion 5a.

[0086] The first radial ball bearing 19 is assembled to the rotating shaft 5 with the small diameter portion 5a inserted into the inner ring 192. Here, as described above, the inner diameter of the first radial ball bearing 19 is smaller than the outer diameter of the small diameter portion 5a, and therefore, in this compressor, when the small diameter portion 5a is inserted into the inner ring 192, the small diameter portion 5a is press-fitted into the inner ring 192. In this way, the first radial ball bearing 19 is assembled to the small diameter portion 5a. In this way, in this compressor, the small diameter portion 5a of the rotating shaft 5 is fixed to the second inner circumferential surface 19b of the first radial ball bearing 19 by press-fitting.

[0087] The first radial ball bearing 19, while mounted on the rotating shaft 5, enters the inside of the boss body 4a from the front of the first boss 4. At this time, in the boss body 4a, the guide portion 42b guides the first radial ball bearing 19 to the fitting portion 42a. Here, as described above, the inner diameter of the fitting portion 42a is larger than the outer diameter of the first radial ball bearing 19. Therefore, in this compressor, there is no need to press-fit the first radial ball bearing 19 when inserting it into the fitting portion 42a.

[0088] Thus, in this compressor, the second outer peripheral surface 19a of the first radial ball bearing 19 is clearance-fitted into the fitting portion 42a. As a result, the first boss 4 holds the first radial ball bearing 19 with the first radial ball bearing 19 housed in the fitting portion 42a. Then, the first radial ball bearing 19 rotatably supports the rotating shaft 5 while being held by the first boss 4.

[0089] In the compressor configured as above, low-temperature, low-pressure refrigerant gas that has passed through the evaporator is drawn into the motor chamber 17 through the suction opening 13c. As a result, in this compressor, the motor chamber 17 also serves as a suction chamber. The refrigerant gas drawn into the motor chamber 17 contains lubricating oil (not shown).

[0090] The inverter 3 also converts the DC current supplied from the battery into AC current using the switching element 3b, while supplying power to the stator 7a. In this way, the inverter 3 controls the operation of the motor 7. As a result, in the motor chamber 17, the rotor 7b rotates together with the rotating shaft 5 around the rotating axis O.

[0091] As a result, in the compression section 10, the movable scroll 11 rotates, the movable end plate 11a slides on the tip of the fixed scroll wall 9c, and the fixed scroll wall 9c and the movable scroll wall 11b slide against each other. At this time, the rotation prevention mechanism 16 restricts the rotation of the movable scroll 11, and the movable scroll 11 only revolves. In this way, as the movable scroll 11 rotates, the refrigerant gas in the motor chamber 17 flows through each suction passage 55 to the suction port 9f, and is sucked into the compression chamber 49 from the suction port 9f. Then, the volume of the compression chamber 49 decreases as the movable scroll 11 rotates, compressing the refrigerant gas therein.

[0092] The high-pressure refrigerant gas compressed in the compression chamber 49 is discharged from the discharge port 9e to the discharge chamber 35, and then passes through the discharge passage 14e from the discharge chamber 35 to the oil separation chamber 14c. The high-pressure refrigerant gas flows through the inside of the separation cylinder 21 while separating the lubricating oil as it circulates between the outer circumferential surface of the separation cylinder 21 and the inner circumferential surface of the oil separation chamber 14c, and is then discharged from the discharge opening 14f.

[0093] Meanwhile, the lubricating oil separated from the refrigerant gas is stored in the oil separation chamber 14c. This lubricating oil then passes through the filter 23 and flows through the oil supply passage 9g, whereby it is supplied to the sliding parts between the fixed scroll 9 and the movable scroll 11, lubricating the sliding parts between the fixed scroll 9 and the movable scroll 11. The lubricating oil flowing through the oil supply passage 9g is also supplied between the second radial ball bearing 27 and the rotating shaft 5, and also into the motor chamber 17.

[0094] A portion of the lubricating oil in the motor chamber 17 is supplied through the supply passage 4c of the first boss 4 to the first radial ball bearing 19 and to a space between the first radial ball bearing 19 and the small diameter portion 5a of the rotating shaft 5. In this manner, the first radial ball bearing 19 and the rotating shaft 5 are lubricated.

[0095] Furthermore, a portion of the high-pressure refrigerant gas compressed in the compression chamber 49 flows through the air supply hole 11d and is supplied into the back pressure chamber 53. This causes the pressure in the back pressure chamber 53 to increase. As a result, the movable scroll 11 is urged toward the compression chamber 49 by the pressure in the back pressure chamber 53 via the thrust plate 51. The movable scroll 11 is also urged toward the compression chamber 49 by the elastic force of the thrust plate 51. In this manner, in this compressor, the movable scroll 11 is prevented from rotating in an inclined state with respect to the rotation axis O.

[0096] In this compressor, the motor housing 13 is made smaller in diameter, thereby realizing a compact size. This allows the compressor to be easily mounted on a vehicle. Here, by making the motor housing 13 smaller in diameter, the distance between the first boss 4 and the bulging portion 6 and the through hole 8, and further between the first boss 4 and the cluster block 7c, is inevitably narrowed. In this respect, in this compressor, the interference avoidance portion 46 is formed in the first boss 4, so that the first boss 4 and the cluster block 7c are less likely to interfere with each other. Therefore, in this compressor, it is easy to connect the cluster block 7c to the airtight terminal 3c. In addition, in this compressor, the connection failure between the cluster block 7c and the airtight terminal 3c due to the interference between the first boss 4 and the cluster block 7c is also prevented.

[0097] On the other hand, since the interference avoidance portion 46 is formed in the first boss 4, the thickness of the wall portion 43 is not uniform in the boss body 4a of the first boss 4. That is, the wall portion 43 is provided with a first thick portion 43a and a second thick portion 43b, and the second thick portion 43b is thinner than the first thick portion 43a. Therefore, in the portion of the boss body 4a where the second thick portion 43b exists, i.e., where the interference avoidance portion 46 is formed, the distance in the radial direction of the rotation axis 5 of the first inner peripheral surface 42 to the first outer peripheral surface 41, and therefore the distance in the radial direction of the rotation axis 5 of the first inner peripheral surface 42 to the bulge portion 6, the through hole 8, and the cluster block 7c are shorter than in the portion where the first thick portion 43a exists. In this way, the first boss 4 has an asymmetric shape.

[0098] Incidentally, when the first radial ball bearing 19 is held in the fitting portion 42a of the first boss 4, it is possible to form the inner diameter of the fitting portion 42a to be smaller than the outer diameter of the first radial ball bearing 19, and press the first radial ball bearing 19 into the fitting portion 42a. However, if the first thick portion 43a and the second thick portion 43b are present in the wall portion 43 and the wall thickness of the wall portion 43 is not uniform as a whole, the first inner circumferential surface 42 including the fitting portion 42a is likely to be deformed unevenly when pressed. As a result, the fitting portion 42a of the boss main body 4a is likely to be deformed distorted, and the first radial ball bearing 19 is also likely to be deformed distorted due to this influence. In addition, since the first boss 4 is made of an aluminum alloy, while the first radial ball bearing 19 is made of steel, the thermal expansion coefficients of the first boss 4 and the first radial ball bearing 19 are also different. This also makes the first radial ball bearing 19 susceptible to distortion due to the influence of deformation of the fitting portion 42a. For these reasons, the roundness of the second outer peripheral surface 19a and the second inner peripheral surface 19b of the first radial ball bearing 19 decreases, and there is a concern that the durability of the first radial ball bearing 19 decreases and the first radial ball bearing 19 may become unable to properly support the rotating shaft 5.

[0099] In this regard, in this compressor, the second outer peripheral surface 19a of the first radial ball bearing 19 is loosely fitted into the fitting portion 42a of the boss body 4a. Therefore, even if the first boss 4 has an asymmetric shape and the thickness of the wall portion 43 of the boss body 4a is not uniform, there is no problem in holding the first radial ball bearing 19 in the first boss 4. Therefore, in this compressor, when the first radial ball bearing 19 is held in the fitting portion 42a, the first radial ball bearing 19 is unlikely to be distorted. As a result, the durability of the first radial ball bearing 19 and therefore the durability of the compressor are increased.

[0100] In this compressor, the small diameter portion 5a of the rotating shaft 5 is press-fitted and fixed to the second inner peripheral surface 19b of the first radial ball bearing 19. Here, since both the first radial ball bearing 19 and the rotating shaft 5 are made of steel, their thermal expansion coefficients are equal. Therefore, the small diameter portion 5a and the second inner peripheral surface 19b are unlikely to be distorted even by thermal expansion and thermal contraction. In addition, in order to ensure favorable rotation, the cross section of the rotating shaft 5, including the small diameter portion 5a, perpendicular to the direction of the rotation axis O is essentially formed into a nearly perfect circle. Therefore, if the shape of the second inner peripheral surface 19b is influenced by the shape of the small diameter portion 5a due to the interference fit, the second inner peripheral surface 19b will be closer to a perfect circle. As a result, in this compressor, the small diameter portion 5a is interference-fitted into the second inner peripheral surface 19b, so that the first radial ball bearing 19 can favorably support the rotating shaft 5 through the second inner peripheral surface 19b. As a result, in this compressor, vibration is less likely to occur in the rotating shaft 5, making it possible to suppress noise during operation.

[0101] Therefore, the compressor of the first embodiment is compact and has excellent durability and quietness.

[0102] In particular, in this compressor, because the first boss 4 has the supply passage 4c, lubricating oil can be suitably supplied to the first radial ball bearing 19 and the rotating shaft 5 through the supply passage 4c. This makes it difficult for wear to occur in the first radial ball bearing 19 and the rotating shaft 5. In this respect as well, in this compressor, the durability of the first radial ball bearing 19 is high, and the first radial ball bearing 19 can suitably support the rotating shaft 5.

[0103] In addition, in this compressor, the first inner circumferential surface 42 of the first boss 4 has a guide portion 42b. Here, in this compressor, when the first radial ball bearing 19 is held in the fitting portion 42a, the first radial ball bearing 19 mounted on the rotating shaft 5 is inserted into the fitting portion 42a from the front of the first boss 4. In addition, the rotating shaft 5 is fixed to the rotor 7b. For this reason, the rotating shaft 5 is affected by the magnetism of the rotor 7b and therefore the motor 7, and therefore the rotating shaft 5 and the first radial ball bearing 19 are likely to tilt with respect to the rotation axis O when the first radial ball bearing 19 is inserted into the fitting portion 42a. In this regard, in this compressor, the guide portion 42b has a tapered shape in which the inner diameter gradually decreases as it approaches the first inner circumferential surface 42 in the direction of the rotation axis O, so that the guide portion 42b can suitably guide the first radial ball bearing 19 to the fitting portion 42a while correcting the attitude of the rotating shaft 5 and the first radial ball bearing 19. As a result, in this compressor, the first radial ball bearing 19 can easily be inserted into the fitting portion 42a in a state parallel to the direction of the rotation axis O, making it easy to manufacture.

[0104] Example 2 In the compressor of the second embodiment, a first boss 40 shown in FIG. 7 is formed on the first front wall 13a instead of the first boss 4. The first boss 40 is also an example of the "boss" in the present invention. The first boss 40 has a first inner circumferential surface 48, which is composed of a fitting portion 42a and a guide portion 48a. Although not shown, the first boss 40 also has an interference avoidance portion 46 formed thereon. As a result, in the first boss 40 as well, the distance of the first inner circumferential surface 48 in the radial direction of the rotating shaft 5 relative to the first outer circumferential surface 41 is shortened at the location where the interference avoidance portion 46 is formed, and the first boss 40 has an asymmetric shape.

[0105] The guide portion 48a is located behind the fitting portion 42a and is connected to the fitting portion 42a. The guide portion 48a is composed of a first tapered portion 411, a second tapered portion 412, and a connection portion 413. The first tapered portion 411 constitutes a front portion of the guide portion 48a. The first tapered portion 411 is connected to the fitting portion 42a. The inner diameter of the front end of the first tapered portion 411, i.e., the connection portion of the first tapered portion 411 with the fitting portion 42a, is the same as the inner diameter of the fitting portion 42a. The first tapered portion 411 has a tapered shape that gradually becomes larger in diameter than the fitting portion 42a as it moves away from the fitting portion 42a rearward in the direction of the rotation axis O. As a result, the inner diameter of the rear end of the first tapered portion 411 is a first inner diameter L11 that is larger than the inner diameter of the fitting portion 42a and the outer diameter of the first radial ball bearing 19. In other words, the maximum inner diameter of the first tapered portion 411 is the first inner diameter L11.

[0106] The second tapered portion 412 is disposed rearwardly of the first tapered portion 411 and constitutes a rear portion of the guide portion 48a. As the second tapered portion 412 moves rearward from the first tapered portion 411 in the direction of the rotation axis O, the diameter of the second tapered portion 412 gradually increases from the maximum inner diameter of the first tapered portion 411. That is, the minimum inner diameter of the second tapered portion 412 is the first inner diameter L11, and as the second tapered portion 412 moves rearward from the first tapered portion 411 in the direction of the rotation axis O, the diameter of the second tapered portion 412 increases from the first inner diameter L11 to the second inner diameter L12. That is, the maximum inner diameter of the second tapered portion 412 is the second inner diameter L12. The rear end of the second tapered portion 412 is connected to the rear end of the boss main body 4a.

[0107] The connection portion 413 is located between the first taper portion 411 and the second taper portion 412. The connection portion 413 is connected to the first taper portion 411 at the front end and to the second taper portion 412 at the rear end. In this manner, the connection portion 413 connects the first taper portion 411 and the second taper portion 412. Here, the connection portion 413 linearly connects the first taper portion 411 and the second taper portion 412 without narrowing or widening the diameter. In other words, the connection portion 413 connects the first taper portion 411 and the second taper portion 412 while maintaining the first inner diameter L11, which is the maximum inner diameter of the first taper portion 411.

[0108] Furthermore, at the location of guide portion 48a where supply passage 4c is formed, first tapered portion 411, second tapered portion 412, and connection portion 413 are cut out by supply passage 4c. Other configurations of the compressor of embodiment 2, including other configurations of first boss 40, are similar to those of the compressor of embodiment 1, and the same configurations are denoted with the same reference numerals, and detailed description of the configurations will be omitted.

[0109] In this compressor, the connection portion 413 of the guide portion 48a connects the first tapered portion 411 and the second tapered portion 412 while maintaining the first inner diameter L11, so that even if the rotating shaft 5 and the first radial ball bearing 19 are inclined with respect to the direction of the rotation axis O, the attitude can be suitably corrected in the process of passing through the connection portion 413. Then, the first tapered portion 411 guides the rotating shaft 5 and the first radial ball bearing 19 that have passed through the connection portion 413 to the fitting portion 42a while gradually reducing in diameter from the first inner diameter L11. This allows the first tapered portion 411 to more reliably correct the attitude of the rotating shaft 5 and the first radial ball bearing 19 in the process of passing through.

[0110] Furthermore, since the guide portion 48a is composed of the first tapered portion 411, the second tapered portion 412, and the connection portion 413, in this compressor, the distance in the direction of the rotation axis O in the guide portion 48a, i.e., the length in the direction of the rotation axis O, can be suitably secured. As a result, in this compressor, the guide portion 48a can more suitably guide the first radial ball bearing 19 to the fitting portion 42a. This makes it easier to manufacture this compressor. Other functions of this compressor are the same as those of the compressor of the first embodiment.

[0111] In the above, the present invention has been described based on Examples 1 and 2. However, the present invention is not limited to the above Examples 1 and 2, and it goes without saying that the present invention can be modified as appropriate without departing from the spirit of the present invention.

[0112] For example, in the compressor of the first embodiment, the first radial ball bearing 19 is defined as the "bearing" in the present invention, but this is not limiting, and a sliding bearing may be defined as the "bearing" in the present invention. The same applies to the compressor of the second embodiment.

[0113] Furthermore, in the compressor of the first embodiment, the first boss 4 has an asymmetric shape by forming an interference avoidance portion 46 in the first boss 4. However, this is not limited thereto, and the first outer peripheral surface 41 of the boss main body 4a may be integrated with a part of another member formed in the first front wall 13a, thereby causing the first boss 4 to have an asymmetric shape. That is, even in this case, the first boss 4 will have a location where the distance from the first inner peripheral surface to the first outer peripheral surface 41 varies in the radial direction of the rotating shaft 5. The same applies to the compressor of the second embodiment.

[0114] In the compressor of the first embodiment, the supply passage 4c is composed of the first passage portion 401 and the second passage portion 402. However, the present invention is not limited to this, and the supply passage 4c may be composed of only one of the first passage portion 401 or the second passage portion 402, or the supply passage 4c may be composed of three or more passage portions. The same applies to the compressor of the second embodiment.

[0115] In the compressor of the first embodiment, the compression section 10 is a scroll type compression section. However, the present invention is not limited to this, and the compression section 10 may be a vane type compression section or the like. In addition, when the compression section 10 is a scroll type compression section, it may be a bi-rotating scroll type compression section in which both scrolls rotate. The same applies to the compressor of the second embodiment.

[0116] In the compressor of the first embodiment, the compression section 10 compresses a refrigerant gas as a fluid. However, this is not limiting, and the compression section 10 may compress a fluid such as air. The same applies to the compressor of the second embodiment.

[0117] This specification also includes the following inventions. (Appendix 1) Housing and a rotating shaft rotatably supported within the housing; A motor that rotates the rotary shaft; a compression unit that compresses a fluid by rotation of the rotating shaft, The housing has a boss that protrudes cylindrically toward the rotation shaft, an inner circumferential surface of the boss is provided with a bearing for supporting the rotating shaft; the boss has an asymmetric shape having an outer circumferential surface at different distances from the inner circumferential surface in a radial direction of the rotation shaft, 2. The electric compressor according to claim 1, wherein the rotating shaft is press-fitted into the bearing, and the bearing is clearance-fitted against the inner circumferential surface. (Appendix 2) 2. The electric compressor according to claim 1, wherein the boss has a supply passage that penetrates from the outer circumferential surface to the inner circumferential surface in a radial direction of the rotating shaft and supplies lubricating oil to the bearing. (Appendix 3) an inverter is provided in the housing, the inverter being located on the opposite side of the motor from the compression unit and electrically connected to the motor; the housing includes a motor chamber that accommodates the motor, an inverter chamber that accommodates the inverter, and a partition wall that separates the motor chamber from the inverter chamber and on which the boss is provided, the partition wall is provided with a through hole into which an airtight terminal for electrically connecting the motor and the inverter is inserted, The motor includes a stator core around which a coil is wound, and a rotor that rotates integrally with the rotary shaft, The coil has a coil end protruding from an end of the stator core, a terminal box electrically connected to the airtight terminal, and a lead wire extending from the coil end to the terminal box, 3. The electric compressor according to claim 1, wherein the boss has an asymmetric shape by cutting out the outer circumferential surface such that the distance from the inner circumferential surface to at least one of the through hole and the terminal box is different in a radial direction of the rotating shaft. (Appendix 4) The inner circumferential surface has a fitting portion into which the bearing is clearance-fitted and a guide portion that guides the bearing into the fitting portion, the guide portion has a first tapered portion that gradually increases in diameter as it moves away from the fitting portion in the axial direction of the rotating shaft; a second tapered portion disposed apart from the first tapered portion in the axial direction of the rotating shaft, the second tapered portion having a diameter gradually increasing from a maximum inner diameter of the first tapered portion as it moves away from the first tapered portion; 4. The electric compressor according to any one of claims 1 to 3, further comprising a connection portion located between the first tapered portion and the second tapered portion, the connection portion connecting the first tapered portion and the second tapered portion while maintaining a maximum inner diameter of the first tapered portion. (Appendix 5) 5. The electric compressor according to any one of claims 1 to 4, wherein the bearing includes an inner ring into which the rotating shaft is press-fitted, an outer ring that is gap-fitted against the inner circumferential surface, and a plurality of spherical bearing balls provided between the inner ring and the outer ring. [Industrial Applicability]

[0118] The present invention can be used in vehicle air conditioners and the like. [Explanation of symbols]

[0119] 1. Housing 3…Inverter 3c…Airtight terminal 4, 40…First boss (boss) 4c…Supply route 5...Rotation axis 7…Motor 7c...Cluster block (terminal box) 8...Through hole 10...Compression section 17…Motor room 19…First radial ball bearing (bearing) 41...First outer circumferential surface (outer circumferential surface) 42, 48...First inner circumferential surface (inner circumferential surface) 42a...Mating part 42b, 48a...Guidance department 411…First taper section 412…Second taper section 413…Connection part 701~703...1st~3rd lead wires (pull-out wires) O: Rotation axis

Claims

1. Housing and a rotating shaft rotatably supported within the housing; A motor that rotates the rotary shaft; a compression unit that compresses a fluid by rotation of the rotating shaft, The housing has a boss that protrudes cylindrically toward the rotation shaft, a bearing for supporting the rotating shaft is provided on an inner circumferential surface of the boss, the boss has an asymmetric shape having an outer circumferential surface at different distances from the inner circumferential surface in a radial direction of the rotation shaft, 2. The electric compressor according to claim 1, wherein the rotating shaft is press-fitted into the bearing, and the bearing is clearance-fitted against the inner circumferential surface.

2. 2. The electric compressor according to claim 1, wherein the boss has a supply passage extending radially from the outer circumferential surface to the inner circumferential surface of the rotary shaft and supplying lubricating oil to the bearing.

3. an inverter is provided in the housing, the inverter being located on the opposite side of the motor from the compression unit and electrically connected to the motor; the housing includes a motor chamber that accommodates the motor, an inverter chamber that accommodates the inverter, and a partition wall that separates the motor chamber from the inverter chamber and on which the boss is provided, the partition wall is provided with a through hole into which an airtight terminal for electrically connecting the motor and the inverter is inserted, The motor includes a stator core around which a coil is wound, and a rotor that rotates integrally with the rotary shaft, The coil has a coil end protruding from an end of the stator core, a terminal box electrically connected to the airtight terminal, and a lead wire extending from the coil end to the terminal box, 2. The electric compressor according to claim 1, wherein the boss has an asymmetric shape by cutting out the outer circumferential surface so that the distance from the inner circumferential surface to at least one of the through hole and the terminal box is different in the radial direction of the rotating shaft.

4. The inner circumferential surface has a fitting portion into which the bearing is clearance-fitted and a guide portion that guides the bearing into the fitting portion, the guide portion has a first tapered portion that gradually increases in diameter as it moves away from the fitting portion in the axial direction of the rotating shaft; a second tapered portion disposed apart from the first tapered portion in the axial direction of the rotating shaft, the second tapered portion having a diameter gradually increasing from a maximum inner diameter of the first tapered portion as it moves away from the first tapered portion; 3. The electric compressor according to claim 1, further comprising a connection portion located between the first tapered portion and the second tapered portion, the connection portion connecting the first tapered portion and the second tapered portion while maintaining a maximum inner diameter of the first tapered portion.

5. 3. The electric compressor according to claim 1, wherein the bearing comprises an inner ring into which the rotating shaft is press-fitted, an outer ring that is gap-fitted against the inner circumferential surface, and a plurality of spherical bearing balls provided between the inner ring and the outer ring.

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