Electric compressor

Abstract

The invention provides an electric compressor which realizes miniaturization and is excellent in durability and silence. This electric compressor is provided with a housing (1), a rotating shaft (5), a motor (7), and a compression unit (10). The housing (1) has a boss (4) protruding in a cylindrical shape toward the rotating shaft (5). A bearing (19) for supporting the rotating shaft (5) is provided on the inner peripheral surface (42) of the boss (4). The boss (4) has an asymmetric shape having an outer peripheral surface (41) having different distances from the inner peripheral surface (42) in the radial direction of the rotating shaft (5). The rotating shaft (5) is pressed in relative to the bearing (19), and the bearing (19) is in clearance fit with the inner circumferential surface (42) of the boss (4).

Description

Technical Field

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

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

[0003] The bearing is specifically a ball bearing, and has an inner ring, an outer ring, and a plurality of spherical bearing balls disposed between the inner ring and the outer ring. Although the details are unclear in the document, in such an electric compressor, the rotating shaft is usually loosely fitted with the inner ring, and the outer ring is pressed into the inner peripheral surface of the boss.

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent Document 1: Japanese Patent Application Publication No. 2012-57504 Summary of the invention

[0007] Problems to be solved by the invention

[0008] In recent years, there is a demand for further miniaturization of electric compressors, so the diameter of the housing is further reduced. On the other hand, due to the reduction in the diameter of the housing, it is difficult to fully ensure the space for forming the boss on the housing. Therefore, the boss is formed into a shape that avoids interference with other components arranged in the motor chamber, or conversely is formed into a shape that is integrated with a part of other components. As a result, the shape of the boss is complicated and becomes an asymmetric shape having an outer peripheral surface at different distances from the inner peripheral surface in the radial direction of the rotating shaft. That is, in the boss, the wall thickness becomes uneven, resulting in thicker and thinner parts.

[0009] Here, when a bearing is press-fitted into such a boss having a difference in wall thickness, deformation of the boss during press-fitting tends to fluctuate, and the boss tends to deform distortedly. Therefore, the bearing held by the boss tends to be affected by the deformation of the boss and deformed distortedly.

[0010] As a result, there is a problem of reduced durability of the bearing. In addition, since the bearing is deformed skewly, the bearing cannot properly hold the rotating shaft, so it is easy to generate vibration when the rotating shaft rotates. As a result, there is also a problem of worsening noise.

[0011] The present invention has been made in view of the above-mentioned conventional actual situation, and an object of the present invention is to provide an electric compressor which is downsized and excellent in durability and quietness.

[0012] Solutions to Solve Problems

[0013] The electric compressor of the present invention comprises:

[0014] case;

[0015] a rotating shaft rotatably supported inside the housing;

[0016] a motor that rotates the rotating shaft; and

[0017] a compression part that compresses the fluid by the rotation of the rotating shaft,

[0018] The housing has a boss protruding in a cylindrical shape toward the rotating shaft.

[0019] A bearing for supporting the rotating shaft is disposed on the inner circumferential surface of the boss.

[0020] The electric compressor is characterized in that

[0021] The boss has an asymmetric shape having an outer peripheral surface at different distances from the inner peripheral surface in the radial direction of the rotation axis,

[0022] The rotating shaft is press-fitted into the bearing, and the bearing is clearance-fitted with the inner peripheral surface.

[0023] In the electric compressor of the present invention, the boss has an asymmetric shape having an outer peripheral surface with different distances from the inner peripheral surface in the radial direction of the rotating shaft. Therefore, the wall thickness of the boss becomes uneven.

[0024] Here, in the electric compressor, the rotating shaft is pressed into the bearing, and the bearing is loosely fitted with the inner peripheral surface of the boss. Thus, in the electric compressor, even if the boss is assumed to be asymmetrical and the wall thickness becomes uneven, it will not be a problem when the bearing is arranged on the inner peripheral surface of the boss. Thus, in the electric compressor, even if the bearing is arranged on the inner peripheral surface of the boss, the bearing is unlikely to deform skewedly. As a result, the durability of the bearing and thus the electric compressor can be improved.

[0025] On the other hand, in this electric compressor, although the rotating shaft is pressed into the bearing, the cross section of the rotating shaft is originally formed into a substantially perfect circular shape in order to ensure proper rotation. Therefore, if the shape of the bearing is affected by the shape of the rotating shaft due to the pressing, the bearing will be closer to a perfect circular shape. Thus, in this electric compressor, the bearing can properly support the rotating shaft. As a result, in this electric compressor, it is difficult to generate vibration in the rotating shaft, so the noise during operation can be suppressed.

[0026] Therefore, the electric compressor of the present invention is downsized and has excellent durability and quietness.

[0027] Preferably, the boss has a supply passage that penetrates from the outer peripheral surface to the inner peripheral surface in the radial direction of the rotating shaft and supplies lubricating oil to the bearing.

[0028] In this case, lubricating oil can be appropriately supplied to the bearing through the supply path, thereby improving the durability of the bearing and the rotating shaft. In addition, although the boss is easily asymmetrically shaped and a difference in wall thickness is easily generated due to the formation of the supply path in this way, as described above, the bearing is loosely fitted with the inner peripheral surface of the boss in the electric compressor, so deformation of the bearing is unlikely to occur.

[0029] It may be that an inverter is provided in the housing, which is located on the side opposite to the compression part and sandwiches the motor and is electrically connected to the motor. It may be that the housing has a motor chamber for accommodating the motor, an inverter chamber for accommodating the inverter, and a partition wall that divides the motor chamber and the inverter chamber and on which the boss is provided. It may be that a through hole is provided in the partition wall for inserting an airtight terminal that electrically connects the motor and the inverter. It may be that the motor has a stator core for winding the coil and a rotor that rotates integrally with the rotating shaft. It may be that the coil has a coil end protruding from the 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. And, preferably, the boss is asymmetrically shaped by cutting off the outer peripheral surface in a manner that the distance of the inner peripheral surface relative to at least one of the through hole and the terminal box in the radial direction of the rotating shaft is different.

[0030] In this case, the housing and the electric compressor are miniaturized, and the terminal box connected to the airtight terminal and the boss are less likely to interfere with each other. Therefore, in this electric compressor, the motor and the inverter can be appropriately connected through the airtight terminal and the terminal box.

[0031] The inner peripheral surface may have a fitting portion for the bearing clearance fit and a guide portion for guiding the bearing to the fitting portion. Furthermore, preferably, the guide portion has: a first tapered portion, which gradually expands in diameter compared to the fitting portion as it separates from the fitting portion in the axial direction of the rotating shaft; a second tapered portion, which is arranged separately from the first tapered portion in the axial direction of the rotating shaft and gradually expands in diameter compared to the maximum inner diameter of the first tapered portion as it separates from the first tapered portion; and a connecting portion, which 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.

[0032] When the bearing is set on the inner circumferential surface of the boss, the bearing in a state of being pressed and assembled with the rotating shaft is loosely matched with the fitting portion of the inner circumferential surface. Here, in order to loosely match the bearing with the fitting portion, the fitting portion is formed to have a larger diameter than the bearing. In addition, the rotating shaft is installed in the motor, so the rotating shaft is inevitably affected by the magnetism of the motor. Therefore, it is easy to become difficult to loosely match the rotating shaft and the bearing assembled with the rotating shaft with the fitting portion in a state parallel to the axis of the rotating shaft.

[0033] In this regard, in the electric compressor, the inner peripheral surface of the boss has a guide portion for guiding the bearing to the fitting portion, and the guide portion has a first cone portion, a second cone portion, and a connection portion. Therefore, in the electric compressor, even if the rotating shaft is affected by the magnetism of the motor, the guide portion can be used to guide the bearing to the fitting portion in a state parallel to the axial direction of the rotating shaft. In this way, in the electric compressor, the bearing can be easily fitted with the fitting portion in a clearance.

[0034] Preferably, the bearing includes an inner ring into which the rotating shaft is press-fitted, an outer ring which is clearance-fitted with the inner peripheral surface, and a plurality of spherical bearing balls provided between the inner ring and the outer ring.

[0035] In this case, the inner ring is closer to a perfect circle due to the shape of the rotating shaft being pressed in, so the bearing can properly support the rotating shaft through the inner ring. On the other hand, the outer ring is loosely fitted with the inner circumference of the boss, so deformation of the outer ring is less likely to occur. Therefore, the durability of the bearing can be improved.

[0036] Effects of the Invention

[0037] The electric compressor of the present invention is compact and has excellent durability and quietness. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 It is a cross-sectional view of the electric compressor of Example 1.

[0039] Figure 2 The electric compressor of embodiment 1 is Figure 1 AA section view.

[0040] Figure 3 The electric compressor of the first embodiment is shown in a state where the rotating shaft is supported by the bearing and the bearing is accommodated and held by the boss. Figure 2 BB cross-sectional view.

[0041] Figure 4 The electric compressor of the embodiment 1 is shown in FIG. Figure 2 Enlarged view of the main part.

[0042] Figure 5 The electric compressor of embodiment 1 is shown Figure 3 Schematic cross-sectional view of CC section.

[0043] Figure 6 The electric compressor of the first embodiment is connected to the inverter and the motor through a cluster block. Figure 2 Same cross-section view.

[0044] Figure 7 The electric compressor of the second embodiment is a diagram showing a state in which the rotating shaft is supported by the bearing and the bearing is received and held by the boss. Figure 3 Same cross-section view.

[0045] Description of Reference Numerals

[0046] 1 Shell

[0047] 3 Inverter

[0048] 3c airtight terminal

[0049] 4.40 first boss (boss)

[0050] 4c supply road

[0051] 5 Rotation Axes

[0052] 7 Motor

[0053] 7c block (terminal box)

[0054] 8 through holes

[0055] 10Compression unit

[0056] 17 Motor room

[0057] 19 First radial ball bearing (bearing)

[0058] 41 first outer peripheral surface (outer peripheral surface)

[0059] 42, 48 first inner peripheral surface (inner peripheral surface)

[0060] 42a Fitting portion

[0061] 42b, 48a guide part

[0062] 411 first cone part

[0063] 412 Second cone part

[0064] 413 connection part

[0065] 701~703 first to third lead wires (lead wires)

[0066] O Rotation axis. DETAILED DESCRIPTION

[0067] Hereinafter, embodiments 1 and 2 of the present invention will be described with reference to the drawings. The electric compressors (hereinafter referred to as compressors) of embodiments 1 and 2 are specifically scroll-type electric compressors. The compressors are mounted on a vehicle (not shown) and constitute a refrigeration circuit of the vehicle.

[0068] (Example 1)

[0069] like Figure 1 As shown, the compressor of the first embodiment includes a housing 1 , an inverter 3 , a rotary shaft 5 , a motor 7 , and a compression unit 10 .

[0070] In this embodiment, using Figure 1 The solid arrows shown define the front-rear direction of the compressor. Figure 3 Later, with Figure 1 The front-rear direction of the compressor is defined accordingly. It should be noted that the front-rear direction is an example for convenience of description, and the compressor changes its posture appropriately in accordance with the vehicle on which it is mounted.

[0071] like Figure 1 As shown, the housing 1 is composed of a motor housing 13, a compressor housing 14, a fixing block 15 and an inverter cover 2. The motor housing 13, the compressor housing 14, the fixing block 15 and the inverter cover 2 are all made of aluminum alloy. The inverter cover 2 constitutes the front part of the housing 1, and the compressor housing 14 constitutes the rear part of the housing 1.

[0072] 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 a "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 the radial direction of the motor housing 13. The first peripheral wall 13b is connected to the first front wall 13a and extends from the first front wall 13a toward the rear in the direction of the rotation axis O. The direction of the rotation axis O is parallel to the front-to-back direction of the compressor.

[0073] The motor case 13 is formed into a bottomed cylindrical shape with an open rear side by the first front wall 13 a and the first peripheral wall 13 b. A motor chamber 17 is formed in the motor case 13 by the first front wall 13 a and the first peripheral wall 13 b.

[0074] 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 of the front surface 131 and faces the inside of the motor chamber 17.

[0075] In addition, if Figure 2 As shown in FIG. 1 , a first boss 4, a bulging portion 6, and a through hole 8 are formed on the first front wall 13a. The first boss 4 is an example of a "boss" in the present invention. Figure 2 In order to facilitate the description, the rotating shaft 5, the motor 7, and the first radial ball bearing 19 described later are omitted. Figure 6 The same is true.

[0076] like Figure 2 As shown in FIG. 1 , the first boss 4 is integrally formed on the first front wall 13a. Figure 1 as well as Figure 3 As shown in the figure, the first boss 4 protrudes from the rear surface 132 in the direction of the rotation axis O toward the motor 7. That is, the first boss 4 protrudes in the rear direction of the motor chamber 17 more than the rear surface 132. The first boss 4 is roughly cylindrical with the rotation axis O as the center. The first radial ball bearing 19 is retained on the first boss 4. The first radial ball bearing 19 is an example of a "bearing" in the present invention. The details of the structure of these first boss 4 and the first radial ball bearing 19 will be described later.

[0077] like Figure 2 As shown, the bulge 6 is arranged at a position closer to the outside of the first boss 4 and closer 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 face 6a located at the rear end. A portion of the rear end face 6a is formed flat. The through hole 8 is arranged in a manner overlapping with the bulge 6 and penetrates the first front wall 13a in the direction of the rotation axis O in the shape of a long hole. That is, the through hole 8 penetrates from the front surface 131 of the first front wall 13a to the rear end face 6a of the bulge 6. In this way, the through hole 8 connects the outside of the motor housing 13 with the inside of the motor chamber 17.

[0078] like Figure 1As shown in the figure, a suction opening 13c is formed on the first peripheral wall 13b of the motor housing 13. The suction opening 13c extends in the radial direction of the motor housing 13 on the first peripheral wall 13b and is connected to the motor chamber 17. The suction opening 13c is connected to the evaporator (not shown) through a pipe (not shown), and the refrigerant gas passing through the evaporator is sucked into the motor chamber 17. The refrigerant gas is an example of the "fluid" in the present invention.

[0079] And, if Figure 2 As shown in FIG. 1 , six first bolt holes 13d are formed at the rear of the first peripheral wall 13b, and two positioning pins 13e are fixed thereto. Each first bolt hole 13d extends forward from the rear end surface 133 of the first peripheral wall 13b (see FIG. 1 ). Figure 1 ). Figure 2 Each positioning pin 13 e shown is fixed to the first peripheral wall 13 b in a state where a part of the positioning pin 13 e protrudes rearward from the rear end surface 133 .

[0080] like Figure 1 As shown in the figure, 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 from the rear wall 14a toward the front. Through these rear wall 14a and second peripheral wall 14b, the compressor housing 14 is a bottomed cylindrical shape with an opening at the front.

[0081] An oil separation chamber 14c, a first discharge recess 14d, a discharge passage 14e, a discharge opening 14f and six second bolt holes 14g are formed in the compressor housing 14. 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 in the compressor housing 14 at a position closer to the front side than the oil separation chamber 14c and is in a shape that is recessed toward the oil separation chamber 14c. The discharge passage 14e extends in the front-to-back direction and connects the oil separation chamber 14c with the first discharge recess 14d. The discharge opening 14f is connected to the oil separation chamber 14c and opens to the outside of the compressor housing 14. The discharge opening 14f is connected to the condenser (not shown) through a pipe (not shown). Each second bolt hole 14g is formed in the second peripheral wall 14b and penetrates the second peripheral wall 14b in the front-to-back direction respectively. It should be noted that in Figure 1 , one of the six second bolt holes 14g is shown.

[0082] In addition, a separation cylinder 21 is fixed in 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. In addition, a filter 23 is provided below the separation cylinder 21 in the oil separation chamber 14c.

[0083] The fixing block 15 is disposed between the motor housing 13 and the compressor housing 14. A second boss 15a protruding forward is formed on the fixing block 15. An insertion hole 15b is formed at the front end of the second boss 15a. In addition, a second radial ball bearing 27 and a sealing member 29 are provided in the second boss 15a. Furthermore, six third bolt holes 15c are formed in the fixing block 15. Each third bolt hole 15c is arranged at a position closer to the outside than the second boss 15a, and penetrates the fixing block 15 in the front-to-back direction respectively. In addition, although not shown in the figure, positioning recesses corresponding to the positioning pins 13e of the motor housing 13 are formed in the fixing block 15. It should be noted that in Figure 1 In the figure, one of the six third bolt holes 15c is shown.

[0084] The motor housing 13, the compressor housing 14 and the fixing block 15 match each first bolt hole 13d, each second bolt hole 14g and each third bolt hole 15c in the front-rear direction. In addition, in the motor housing 13 and the fixing block 15, each positioning pin 13e is inserted into each positioning recess. In this way, the motor housing 13, the compressor housing 14 and the fixing block 15 are positioned. In addition, the motor housing 13, the compressor housing 14 and the fixing block 15 are fixed by 6 bolts 25 inserted from the compressor housing 14 side in the order of each second bolt hole 14g, each third bolt hole 15c and the first bolt hole 13d. In this way, the motor housing 13, the compressor housing 14 and the fixing block 15 are integrated. It should be noted that the fixing method of the motor housing 13, the compressor housing 14 and the fixing block 15 can be appropriately designed. In addition, the number of each first bolt hole 13d, each second bolt hole 14g and each third bolt hole 15c can be appropriately designed according to the number of bolts 25.

[0085] By fixing the motor housing 13, the compressor housing 14 and the fixing block 15 in this way, Figure 1 As shown, the fixing block 15 is located between the motor chamber 17 and the compression unit 10 in the front-rear direction. Thus, the second boss 15a is in a state of protruding forward toward the motor chamber 17.

[0086] In addition, a plurality of suction passages 55 are formed in the fixed block 15, and a plurality of rotation preventing pins 31 are also fixed thereto. Each suction passage 55 is arranged at a position on the outside of the second boss 15a and on the inside of each third bolt hole 15c, and penetrates the fixed block 15 in the front-to-back direction. Thus, each suction passage 55 connects the motor chamber 17 with the interior of the compressor housing 14. Each rotation preventing pin 31 is fixed to the fixed block 15 in a state of protruding toward the rear. It should be noted that in Figure 1 In the figure, each suction passage 55 and each rotation preventing pin 31 are shown one by one.

[0087] The inverter cover 2 is arranged 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 from the second front wall 2a toward the rear. Through these second front wall 2a and third peripheral wall 2b, the inverter cover 2 is a bottomed cylindrical shape with an opening at the rear. It should be noted that the inverter cover 2 can also be made of resin.

[0088] The inverter cover 2 makes the rear end of the third peripheral wall 2b abut against the front surface 131 of the first front wall 13a of the motor housing 13. And, in this state, the inverter cover 2 is fixed to the motor housing 13 by a plurality of bolts (not shown). In this way, 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, and constitute the housing 1. In addition, the inverter cover 2 forms an inverter chamber 18 between the first front wall 13a. That is, the first front wall 13a divides the motor chamber 17 and the inverter chamber 18. And, the inverter chamber 18 and Figure 2 The through hole 8 shown is communicated. Although not shown in the figure, a connector portion is formed on the second front wall 2a of the inverter cover 2.

[0089] Figure 1 The inverter 3 shown is housed in the inverter chamber 18. The inverter 3 includes a circuit board 3a, a switching element 3b, and Figure 2 The circuit substrate 3a is fixed to the front surface 131 of the first front wall 13a of the motor housing 13 by bolts not shown. In addition, the circuit substrate 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 substrate 3a. The circuit substrate 3a is fixed to the front surface 131, so that the switching element 3b is opposite to the front surface 131 and abuts against the front surface 131. As a result, the heat generated from the switching element 3b during operation is dissipated to the first front wall 13a. It should be noted that the switching element 3b can also be separated from the first front wall 13a.

[0090] Figure 2 The airtight terminal 3c shown is connected to the circuit board 3a. In addition, the airtight terminal 3c is fixed to the first front wall 13a of the motor housing 13 by bolts (not shown) in a state of being arranged in the through hole 8. As a result, the airtight terminal 3c is inserted into the through hole 8 and faces the motor chamber 17 from the through hole 8. In addition, the airtight terminal 3c seals the inverter chamber 18 and the motor chamber 17. It should be noted that the shape of the airtight terminal 3c can be appropriately designed. In addition, the shape of the through hole 8 can be appropriately designed according to the shape of the airtight terminal 3c.

[0091] like Figure 1As shown in the figure, the rotating shaft 5 is arranged in the housing 1. The rotating shaft 5 is made of steel and is cylindrically extended in the front-back direction. The rotating shaft 5 is composed of a small diameter portion 5a, a large diameter portion 5b and a tapered portion 5c. Although the 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 in the plane orthogonal to the rotating shaft 5 becomes a substantially circular shape. In addition, the rotating shaft 5 has an outer peripheral surface 501. The outer peripheral surface 501 constitutes the outer peripheral surface of the small diameter portion 5a, the outer peripheral surface of the large diameter portion 5b and the outer peripheral surface of the tapered portion 5c.

[0092] The small diameter portion 5a is located at the front end side of the rotating shaft 5. The large diameter portion 5b is located behind the small diameter portion 5a and is formed to have a larger diameter than the small diameter portion 5a. A planar 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 the front end. In addition, the tapered portion 5c expands in diameter as it moves toward the rear, and is connected to the large diameter portion 5b at the rear end.

[0093] The small diameter portion 5a of the rotating shaft 5 is rotatably supported by the first boss 4 of the motor housing 13 via the first radial ball bearing 19. In addition, the rear end side of the large diameter portion 5b is inserted into the insertion hole 15b of the fixed block 15 and enters the second boss 15a. And, in the second boss 15a, the rear end of the large diameter portion 5b is rotatably supported by the second radial ball bearing 27. In this way, the rotating shaft 5 can rotate around the rotation axis O in the housing 1. The fixed block 15 and the rotating shaft 5 are sealed by a sealing member 29.

[0094] In addition, in the rotating shaft 5, an eccentric pin 50 is fixed to the large diameter portion 5b. The eccentric pin 50 is arranged at a position eccentric from the rotating shaft center O in the rear end surface 5d. The eccentric pin 50 is formed in a cylindrical shape with a smaller diameter than the rotating shaft 5, and extends toward the rear from the rear end surface 5d. The eccentric pin 50 is inserted into the insertion hole 15b through the rear end side of the large diameter portion 5b, so that the eccentric pin 50 enters the second boss 15a. And the eccentric pin 50 is fitted with the bushing 50a in the second boss 15a.

[0095] Furthermore, the large diameter portion 5b of the rotating shaft 5 is integrally formed with a balance weight 33. The balance weight 33 is disposed at a position eccentric from the rotation axis O in the large diameter portion 5b. More specifically, the balance weight 33 is disposed at a position opposite to the eccentric pin 50 with respect to the rotation axis O.

[0096] Although detailed illustrations are omitted, the balancing weight 33 is formed into a plate-like shape that is roughly fan-shaped. Furthermore, the balancing weight 33 extends in a direction away from the large diameter portion 5b in the radial direction of the rotating shaft 5. The radial direction of the rotating shaft 5 is a direction orthogonal to the direction of the rotating axis O. That is, the balancing weight 33 extends from the large diameter portion 5b toward the first circumferential wall 13b side of the motor housing 13. The rotating shaft 5 is disposed in the housing 1, so that the balancing weight 33 is located in the motor chamber 17. More specifically, the balancing weight 33 is located between the fixed block 15 and the motor 7 in the motor chamber 17. It should be noted that the shape of the balancing weight 33 can be appropriately designed.

[0097] The motor 7 is accommodated in the motor chamber 17. At this time, the motor 7 is accommodated in the motor chamber 17 at a position forward of the balance weight 33. The motor 7 includes a stator 7a and a rotor 7b.

[0098] The stator 7a has a stator core 71. The stator core 71 is formed in a cylindrical shape and 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 coil end 73 and also has Figure 6 The block 7c, the first lead 701, the second lead 702, and the third lead 703 are shown. The block 7c is an example of a "terminal box" in the present invention. The first to third lead wires 701 to 703 are examples of "lead wires" in the present invention.

[0099] like Figure 1 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 end of the stator core 71 and is annular. The inner circumference of the coil end 73 at the rear end of the coil 75 is inclined to avoid interference with the balance weight 33. Figure 1 In order to facilitate the description, the block 7c and the first to third lead wires 701 to 703 are omitted from the illustration.

[0100] Figure 6 The block 7c shown has a connection terminal (not shown) accommodated inside. In addition, although detailed illustration is omitted, the first to third leads 701 to 703 extend from the coil end 73 at the front end of the coil 75 toward the block 7c. And the block 7c is connected to the coil end 73 at the front end of the coil 75 through the first to third leads 701 to 703. In addition, the block 7c is connected to the airtight terminal 3c in a state of being opposed from the rear to the rear end face 6a of the bulge 6. Thus, the stator 7a and the inverter 3 can be electrically connected through the block 7c. In addition, at this time, a part of the rear end face 6a abuts against the block 7c and supports the block 7c.

[0101] like Figure 1As shown, the rotor 7b is arranged in the stator 7a. The large diameter portion 5b of the rotating shaft 5 is fixed to the rotor 7b. The rotating shaft 5 rotates around the rotation axis O when the rotor 7b rotates in the stator 7a.

[0102] The compression unit 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 and arranged in 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.

[0103] The fixed end plate 9a is located at the rear end of the fixed scroll 9 and is formed in a disc shape. A second discharge recess 9d and a discharge port 9e are formed in the fixed end plate 9a. The second discharge recess 9d is in a shape that is recessed from the rear end surface of the fixed end plate 9a toward the front. The fixed scroll 9 is fixed to the compressor housing 14, so that the second discharge recess 9d is opposite to the first discharge recess 14d. In this way, a discharge chamber 35 is formed by the first discharge recess 14d and the second discharge recess 9d. 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-to-back direction and is connected to the discharge chamber 35.

[0104] In addition, a discharge needle reed valve 38 and a retainer 39 are fixed to the fixed end plate 9a by bolts 37. The bolts 37, the discharge needle reed valve 38 and the retainer 39 are arranged in the discharge chamber 35. The discharge needle reed valve 38 opens and closes the discharge port 9e by elastic deformation. The retainer 39 adjusts the elastic deformation amount of the discharge needle reed valve 38.

[0105] 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 in a cylindrical shape toward the front. A suction port 9f is formed on the fixed peripheral wall 9b. The suction port 9f penetrates the fixed peripheral wall 9b in the radial direction. Thus, the suction port 9f opens in the compressor housing 14. The fixed scroll wall 9c stands up on the front surface of the fixed end plate 9a and is integrated with the fixed peripheral wall 9b on the inner side of the fixed peripheral wall 9b.

[0106] In addition, an oil supply passage 9g is formed in the fixed scroll 9. The oil supply passage 9g penetrates the fixed end plate 9a and the fixed peripheral wall 9b. Thus, 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 is connected to the oil separation chamber 14c through the filter 23. It should be noted that the shape of the oil supply passage 9g can be appropriately designed.

[0107] The movable scroll 11 is arranged 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 scroll wall 11b. The movable end plate 11a is located at the front end of the movable scroll 11 and is formed in a disc shape. The movable end plate 11a is rotatably supported by a bushing 50a 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 bushing 50a and the eccentric pin 50. The movable scroll wall 11b stands up on the front surface of the movable end plate 11a and extends toward the fixed end plate 9a.

[0108] In addition, the movable end plate 11a is provided with the same number of rings 47 as the rotation preventing pins 31. Also, near the center of the movable scroll wall 11b, an air supply hole 11d is formed which opens at the rear end of the movable scroll wall 11b and extends in the front-rear direction inside the movable scroll wall 11b and extends to the movable end plate 11a.

[0109] The fixed scroll 9 and the movable scroll 11 are meshed with each other. Thus, a compression chamber 49 is formed between the fixed scroll 9 and the movable scroll 11 by the fixed end plate 9a, the fixed scroll wall 9c, the movable end plate 11a, and the movable scroll wall 11b. The compression chamber 49 changes its volume by the rotation of the movable scroll 11. Thus, the compression chamber 49 is communicated with the suction port 9f and the discharge port 9e, respectively.

[0110] In addition, each of the rotation preventing pins 31 is inserted into the rings 47, so that each of the rings 47 is connected to the respective rotation preventing pins 31. The rotation preventing mechanism 16 is formed by the respective rotation preventing pins 31 and the rings 47. In the rotation preventing mechanism 16, the rotation of the movable scroll 11 is restricted and only the revolution is allowed by rolling while the respective rotation preventing pins 31 slide on the inner circumferential surface of each ring 47. It should be noted that the number of the respective rotation preventing pins 31 and the respective rings 47 constituting the rotation preventing mechanism 16 can be appropriately designed as long as there are three or more of each.

[0111] 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 abuts against the movable scroll 11 and the fixed block 15, respectively. The thrust plate 51 can apply force to the movable scroll 11 toward the rear side, that is, toward the fixed scroll 9 side, under the action of the restoring force during elastic deformation. 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 communicated with the air supply hole 11d.

[0112] like Figure 2 to Figure 4As shown, the first boss 4 includes a boss body 4a, a connection portion 4b, and a supply path 4c. Here, the motor case 13 is made of aluminum alloy, so the first boss 4 integrally formed on the first front wall 13a of the motor case 13 is also made of aluminum alloy.

[0113] like Figure 3 As shown in the figure, the boss body 4a constitutes the rear portion of the first boss 4. The boss body 4a is formed into 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 wall portion 43. The first outer peripheral surface 41 is an example of the "outer peripheral surface" in the present invention. In addition, the first inner peripheral surface 42 is an example of the "inner peripheral surface" in the present invention.

[0114] like Figure 5 As shown, 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, that is, in the radial direction of the rotating shaft 5. Therefore, the first inner peripheral surface 42 constitutes the inner surface of the boss body 4a.

[0115] like Figure 3 As shown, the first inner peripheral surface 42 includes a fitting portion 42a and a guide portion 42b. The fitting portion 42a has an inner diameter of a first length L1 and is larger than the outer diameter of the first radial ball bearing 19. The fitting portion 42a accommodates and holds the first radial ball bearing 19.

[0116] 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, that is, the connecting portion of the guide portion 42b connected to 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 away from the fitting portion 42a toward the rear in the axial direction of the rotating shaft 5, that is, in 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.

[0117] like Figure 5 As shown in FIG. 4 , the wall 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. Figure 5 In order to facilitate the description, the shape of the boss body 4a is simplified in the figure, and the supply path 4c, the rotating shaft 5, and the first radial ball bearing 19 are omitted from the figure.

[0118] like Figure 3 As shown in FIG. 1 , the connecting portion 4b is located in front of the boss body 4a. Thus, the connecting portion 4b constitutes the front portion of the first boss 4. The connecting portion 4b is connected to the front end of the boss body 4a. Figure 4As shown in FIG. 4 , the connecting portion 4 b extends forward while being enlarged in diameter compared to the outer diameter of the boss body 4 a, and is connected to the rear surface 132 of the first front wall 13 a. Figure 3 As shown, a recessed portion 44 is formed in the connection portion 4b. The recessed portion 44 is recessed in a cylindrical shape with the rotation axis O as the center. The recessed portion 44 is connected to the fitting portion 42a. The inner diameter of the recessed portion 44 is smaller than the inner diameter of the fitting portion 42a.

[0119] Here, in this compressor, the motor housing 13 is reduced in diameter in order to achieve miniaturization. Therefore, although the first front wall 13a is provided with the bulged portion 6 and the through hole 8 in addition to the first boss 4 as described above, a sufficient space cannot be provided between the first boss 4 and the bulged portion 6 and the through hole 8. Figure 6 As shown, the first boss 4 has an interference avoiding portion 46 formed thereon for preventing interference with the block 7 c when the block 7 c is connected to the hermetic terminal 3 c.

[0120] The interference avoiding portion 46 is formed in the boss body 4a and the connecting portion 4b at a portion near the bulging portion 6, the through hole 8, and the block 7c, that is, at a portion near the bulging portion 6, the through hole 8, and the block 7c in the radial direction of the rotating shaft 5. The interference avoiding portion 46 extends in a planar shape in the direction of the rotation axis O.

[0121] As the interference avoiding portion 46 is formed in the boss body 4 a and the connecting portion 4 b in this manner, the boss body 4 a and the connecting portion 4 b are separated from the bulging portion 6 , the through hole 8 , and the block 7 c .

[0122] In addition, by forming the interference avoiding portion 46, the portion where the interference avoiding portion 46 is formed in the first outer peripheral surface 41 of the boss body 4a and the connecting portion 4b is cut out in a planar shape. The interference avoiding portion 46 is an example of a "notch" in the present invention. Figure 4 as well as Figure 5 As shown in the figure, when the boss body 4a is viewed from the rear in the direction of the rotation axis O, in the boss body 4a, the first outer peripheral surface 41 does not have an arc shape in the circumferential direction as a whole, but the portion where the interference avoiding portion 46 is formed is linear. In contrast, the first inner peripheral surface 42 is not affected by the shape of the interference avoiding portion 46, and therefore does not have a linear portion.

[0123] As a result, if Figure 5As shown in FIG. 1 , in the boss body 4a, the wall thickness of the wall portion 43 as a whole becomes uneven. That is, the wall portion 43 is provided with a first wall thickness portion 43a whose wall thickness in the radial direction of the rotating shaft 5 becomes the first thickness t1, and a second wall thickness portion 43b which is the thinnest part of the wall thickness in the radial direction of the rotating shaft 5 and becomes the second thickness t2. And the second thickness t2 is thinner than the first thickness t1. That is, the second wall thickness portion 43b is thinner than the first wall thickness portion 43a. In other words, by providing the wall portion 43 with a second wall thickness portion 43b whose wall thickness is thinner than the first wall thickness portion 43a, an interference avoidance portion 46 is formed on the first boss 4. It should be noted that, strictly speaking, the wall thickness in all parts of the second wall thickness portion 43b is not constant at the second thickness t2, and there are also parts with different wall thicknesses in the second wall thickness portion 43b. However, at any part of the second wall thickness portion 43b, its wall thickness is thinner than the first thickness t1.

[0124] Furthermore, by thinning the thickness of the second wall thickness portion 43b, in the portion of the boss body 4a where the second wall thickness portion 43b exists, i.e., the portion where the interference avoiding portion 46 is formed, the radial distance of the first inner peripheral surface 42 relative to the first outer peripheral surface 41 in the rotation axis 5 becomes shorter than that in the portion of the boss body 4a where the first wall thickness portion 43a exists. In addition, in the case where the interference avoiding portion 46 is formed, the radial distance of the first inner peripheral surface 42 relative to the bulge 6, the through hole 8, and the rotation axis 5 of the block 7c also becomes shorter than that in the case where the first wall thickness portion 43a exists over the entire circumference of the boss body 4a, i.e., the case where the interference avoiding portion 46 is not formed (see FIG. 1 ). Figure 6 ). Therefore, if Figures 4 to 6 As shown in FIG. 1 , the first boss 4 has an asymmetric shape with respect to the rotation axis O, in which the shape of the side where the interference avoiding portion 46 is present is different from the shape of the side where the interference avoiding portion 46 is not present. In other words, the first boss 4 has an asymmetric shape. Figures 4 to 6 The shape on the right side of the paper is Figures 4 to 6 The shape of the left side of the paper is a different asymmetrical shape.

[0125] like Figure 4 As shown in the figure, the supply path 4c extends along 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 path 4c is recessed from the boss body 4a to the connecting portion 4b. And, in the guide portion 42b, the portion where the supply path 4c is formed is in a cut-off state. Here, the boss body 4a and then the first boss 4 are cylindrical, so the supply path 4c is composed of a first passage portion 401 located on the side of the interference avoidance portion 46 compared to 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 with the rotation axis O sandwiched therebetween.

[0126] In the portion of the boss body 4a where the supply path 4c is formed, the fitting portion 42a of the first outer peripheral surface 41 and the first inner peripheral surface 42 is connected via the supply path 4c. Similarly, in the connection portion 4b, the recess 44 is connected to the outer surface of the connection portion 4b via the supply path 4c.

[0127] like Figure 3 As shown, the first radial ball bearing 19 is made of steel and has an outer ring 191, an inner ring 192, and a plurality of bearing balls 193. The outer ring 191 constitutes a second outer peripheral surface 19a as the outer peripheral surface of the first radial ball bearing 19. The inner ring 192 is arranged on the inner side of the outer ring 191 and constitutes a second inner peripheral surface 19b as 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.

[0128] The length of the outer diameter of the outer ring 191, that is, 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 inner diameter of the fitting portion 42a. In addition, the length of the inner diameter of the inner ring 192, that is, 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 outer diameter of the small diameter portion 5a of the rotating shaft 5. That is, the outer diameter of the first radial ball bearing 19 is smaller than the inner diameter of the boss body 4a, and the inner diameter of the first radial ball bearing 19 is smaller than the outer diameter of the small diameter portion 5a.

[0129] The first radial ball bearing 19 is assembled to the rotating shaft 5 in a state where the small diameter portion 5a is inserted through 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, so in this compressor, when the small diameter portion 5a is inserted into the inner ring 192, the small diameter portion 5a is pressed 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 by being pressed into the second inner peripheral surface 19b of the first radial ball bearing 19.

[0130] Furthermore, the first radial ball bearing 19 enters the interior of the boss body 4a from the front of the first boss 4 in a state of being assembled to the rotating shaft 5. 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, when the first radial ball bearing 19 is made to enter the fitting portion 42a, it is not necessary to press the first radial ball bearing 19.

[0131] Thus, in this compressor, the second outer peripheral surface 19a of the first radial ball bearing 19 is loosely fitted with the fitting portion 42a. Thus, the first boss 4 holds the first radial ball bearing 19 in a state where the first radial ball bearing 19 is accommodated in the fitting portion 42a. Furthermore, the first radial ball bearing 19 supports the rotating shaft 5 in a rotatable manner while being held by the first boss 4.

[0132] In the compressor constructed as described above, the low-temperature and low-pressure refrigerant gas that has passed through the evaporator is sucked into the motor chamber 17 through the suction opening 13c. Thus, in the compressor, the motor chamber 17 also serves as the suction chamber. It should be noted that the refrigerant gas sucked into the motor chamber 17 includes lubricating oil (not shown).

[0133] Inverter 3 converts the DC current supplied from the battery into AC current using switching element 3b and supplies power to stator 7a. In this way, inverter 3 controls the operation of motor 7. As a result, rotor 7b rotates around rotation axis O together with rotating shaft 5 in motor chamber 17.

[0134] As a result, in the compression section 10, the movable scroll 11 rotates, the movable end plate 11a slides on the front end of the fixed scroll wall 9c, and the fixed scroll wall 9c and the movable scroll wall 11b slide on each other. At this time, under the action of the self-rotation prevention mechanism 16, the movable scroll 11 is restricted from rotating and only revolves. In this way, through the rotation of the movable scroll 11, the refrigerant gas in the motor chamber 17 flows to the suction port 9f through each suction passage 55, and is sucked into the compression chamber 49 from the suction port 9f. In addition, the compression chamber 49 reduces its volume through the rotation of the movable scroll 11, and compresses the refrigerant gas inside.

[0135] The high-pressure refrigerant gas compressed in the compression chamber 49 is discharged from the discharge port 9e to the discharge chamber 35, and reaches the oil separation chamber 14c through the discharge passage 14e from the discharge chamber 35. The high-pressure refrigerant gas separates the lubricating oil while circulating between the outer circumferential surface of the separation cylinder 21 and the inner circumferential surface of the oil separation chamber 14c, and circulates inside the separation cylinder 21 and is discharged from the discharge opening 14f.

[0136] On the other hand, the lubricating oil separated from the refrigerant gas is stored in the oil separation chamber 14c. The lubricating oil passes through the filter 23 and flows through the oil supply passage 9g, thereby being supplied to the sliding part where the fixed scroll 9 and the movable scroll 11 slide, and lubricating the sliding part where the fixed scroll 9 and the movable scroll 11 slide. In addition, the lubricating oil flowing through the oil supply passage 9g is supplied to the space between the second radial ball bearing 27 and the rotating shaft 5, etc., and is also supplied to the motor chamber 17.

[0137] Part of the lubricating oil in the motor chamber 17 is supplied to the first radial ball bearing 19 and between the first radial ball bearing 19 and the small diameter portion 5a of the rotating shaft 5 through the supply passage 4c of the first boss 4. In this way, the first radial ball bearing 19 and the rotating shaft 5 are lubricated.

[0138] In addition, a part of the high-pressure refrigerant gas compressed in the compression chamber 49 flows through the air supply hole 11d and is supplied to the back pressure chamber 53. As a result, the pressure in the back pressure chamber 53 rises. As a result, the movable scroll 11 is urged toward the compression chamber 49 side by the thrust plate 51 and the pressure in the back pressure chamber 53. In addition, the movable scroll 11 is also urged toward the compression chamber 49 side by the elastic force of the thrust plate 51. In this way, in this compressor, the movable scroll 11 is restrained from rotating in a state tilted relative to the rotation axis O.

[0139] Furthermore, in this compressor, miniaturization is achieved by reducing the diameter of the motor housing 13. As a result, the mountability of the compressor on a vehicle becomes higher. Here, as the diameter of the motor housing 13 is reduced in this way, the space between the first boss 4 and the bulge 6 and the through hole 8, and further between the first boss 4 and the block 7c, inevitably becomes narrower. In this regard, in this compressor, since an interference avoidance portion 46 is formed on the first boss 4, it is difficult for the first boss 4 to interfere with the block 7c. Therefore, in this compressor, it is easy to connect the block 7c to the airtight terminal 3c. In addition, in this compressor, poor connection between the block 7c and the airtight terminal 3c due to interference between the first boss 4 and the block 7c is also prevented.

[0140] On the other hand, since the interference avoiding portion 46 is formed in the first boss 4, the wall thickness of the wall portion 43 becomes uneven in the boss body 4a of the first boss 4. That is, the wall portion 43 is provided with a first wall thickness portion 43a and a second wall thickness portion 43b, and the second wall thickness portion 43b is thinner than the first wall thickness portion 43a. Therefore, in the boss body 4a, in the portion where the second wall thickness portion 43b exists, that is, the portion where the interference avoiding portion 46 is formed, the radial distance of the first inner peripheral surface 42 with respect to the first outer peripheral surface 41 in the rotation axis 5 is shorter than that in the portion where the first wall thickness portion 43a exists. Furthermore, when the interference avoiding portion 46 is formed, the radial distance of the first inner peripheral surface 42 with respect to the first outer peripheral surface 41 in the rotation axis 5, and further the radial distance of the first inner peripheral surface 42 with respect to the bulging portion 6, the through hole 8, and the rotation axis 5 of the block 7c are shorter than that in the case where the first wall thickness portion 43a exists over the entire circumference of the boss body 4a, that is, the case where the interference avoiding portion 46 is not formed. In this way, the first boss 4 has an asymmetric shape.

[0141] In addition, it is also considered that when the first radial ball bearing 19 is held in the fitting portion 42a of the first boss 4, the inner diameter of the fitting portion 42a is formed to be smaller than the outer diameter of the first radial ball bearing 19, and the first radial ball bearing 19 is pressed into the fitting portion 42a. However, in the case where the wall portion 43 has a first wall thickness portion 43a and a second wall thickness portion 43b and the wall thickness of the wall portion 43 as a whole becomes uneven, the first inner peripheral surface 42 including the fitting portion 42a is prone to deformation fluctuations during press-fitting. As a result, in the boss body 4a, the fitting portion 42a is prone to skew deformation, and under this influence, the first radial ball bearing 19 is also prone to skew deformation. In addition, the first boss 4 is made of aluminum alloy, while the first radial ball bearing 19 is made of steel, so the thermal expansion coefficients of the first boss 4 and the first radial ball bearing 19 are also different. As a result, the first radial ball bearing 19 is also prone to skew deformation due to the influence of the deformation of the fitting portion 42a. Therefore, there is a concern that the durability of the first radial ball bearing 19 may be reduced due to the reduction in the roundness of the second outer peripheral surface 19 a and the second inner peripheral surface 19 b of the first radial ball bearing 19 , and the first radial ball bearing 19 may not be able to properly support the rotating shaft 5 .

[0142] In this regard, in the compressor, the second outer peripheral surface 19a of the first radial ball bearing 19 is loosely fitted with the fitting portion 42a of the boss body 4a. Therefore, in the compressor, even if the first boss 4 is assumed to have an asymmetric shape and the wall thickness of the wall portion 43 of the boss body 4a becomes uneven, there will be no problem in holding the first radial ball bearing 19 on the first boss 4. Therefore, in the compressor, when the first radial ball bearing 19 is held on the fitting portion 42a, it is difficult for the first radial ball bearing 19 to deform skewly. As a result, the durability of the first radial ball bearing 19 and thus the durability of the compressor is improved.

[0143] In addition, in this compressor, the small diameter portion 5a of the rotating shaft 5 is pressed into and fixed to the second inner peripheral surface 19b of the first radial ball bearing 19. Here, the first radial ball bearing 19 and the rotating shaft 5 are both made of steel, so the thermal expansion coefficients are equal. Therefore, even under the action of thermal expansion and thermal contraction, the small diameter portion 5a and the second inner peripheral surface 19b are difficult to deform skewly. In addition, in order to ensure proper rotation, the cross section of the surface orthogonal to the direction of the rotation axis O of the rotating shaft 5, including the small diameter portion 5a, is originally formed into a substantially perfect circular shape. Therefore, if the shape of the second inner peripheral surface 19b is affected by the shape of the small diameter portion 5a due to interference fit, the second inner peripheral surface 19b will be closer to a perfect circular shape. Therefore, in this compressor, by interference fitting the small diameter portion 5a on the second inner peripheral surface 19b, the first radial ball bearing 19 can properly support the rotating shaft 5 through the second inner peripheral surface 19b. As a result, in this compressor, it is difficult to generate vibration in the rotating rotating shaft 5, so that the noise during operation can be suppressed.

[0144] Therefore, the compressor of Example 1 is compact and excellent in durability and quietness.

[0145] In particular, in this compressor, the first boss 4 has the supply path 4c, so that lubricating oil can be appropriately supplied to the first radial ball bearing 19 and the rotating shaft 5 through the supply path 4c. As a result, it is difficult for the first radial ball bearing 19 and the rotating shaft 5 to be worn. Based on this point, in this compressor, the durability of the first radial ball bearing 19 can be increased, and the first radial ball bearing 19 can appropriately support the rotating shaft 5.

[0146] In addition, in this compressor, the first inner peripheral 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 in a state of being assembled to the rotating shaft 5 is made to enter the fitting portion 42a from the front of the first boss 4. In addition, the rotating shaft 5 is in a state of being fixed to the rotor 7b. Therefore, since the rotating shaft 5 is affected by the magnetism of the rotor 7b and further the motor 7, when the first radial ball bearing 19 is made to enter the fitting portion 42a, the rotating shaft 5 and the first radial ball bearing 19 are easily tilted relative to the rotation axis O. In this regard, in this compressor, the guide portion 42b is in a tapered shape in which the inner diameter gradually decreases as it approaches the first inner peripheral surface 42 in the direction of the rotation axis O, so that the guide portion 42b can be used to correct the posture of the rotating shaft 5 and the first radial ball bearing 19, and the first radial ball bearing 19 can be appropriately guided to the fitting portion 42a. As a result, in this compressor, the first radial ball bearing 19 can be easily inserted into the fitting portion 42a in a state parallel to the direction of the rotation axis O, so that the manufacturing is easy.

[0147] (Example 2)

[0148] In the compressor of the second embodiment, instead of the first boss 4, a Figure 7 The first boss 40 is shown. 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, and the first inner circumferential surface 48 includes a fitting portion 42a and a guide portion 48a. It should be noted that, although not shown in the figure, an interference avoiding portion 46 is also formed on the first boss 40. Therefore, in the first boss 40, in the portion where the interference avoiding portion 46 is formed, the radial distance of the first inner circumferential surface 48 relative to the first outer circumferential surface 41 of the rotating shaft 5 becomes shorter than that of the portion where the interference avoiding portion 46 is not formed, and the first boss 40 becomes an asymmetric shape.

[0149] The guide portion 48a is located behind the fitting portion 42a and is connected to the fitting portion 42a. The guide portion 48a includes a first tapered portion 411, a second tapered portion 412, and a connection portion 413. The first tapered portion 411 constitutes the 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, that is, the connection portion of the first tapered portion 411 connected to the fitting portion 42a is the same as the inner diameter of the fitting portion 42a. The first tapered portion 411 is in a tapered shape that gradually expands in diameter compared to the fitting portion 42a as it separates from the fitting portion 42a toward the rear in the direction of the rotation axis O. As a result, the inner diameter of the rear end of the first tapered portion 411 becomes 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. That is, the maximum inner diameter of the first tapered portion 411 is the first inner diameter L11.

[0150] The second cone portion 412 is arranged to be separated from the first cone portion 411 to the rear, and constitutes the rear portion of the guide portion 48a. The second cone portion 412 gradually expands in diameter compared to the maximum inner diameter of the first cone portion 411 as it separates from the first cone portion 411 to the rear in the direction of the rotation axis O. That is, the minimum inner diameter of the second cone portion 412 is the first inner diameter L11, and the second cone portion 412 expands in diameter from the first inner diameter L11 to the second inner diameter L12 as it separates from the first cone portion 411 to the rear in the direction of the rotation axis O. That is, the maximum inner diameter of the second cone portion 412 is the second inner diameter L12. In addition, the rear end of the second cone portion 412 is connected to the rear end of the boss body 4a.

[0151] The connection portion 413 is located between the first cone portion 411 and the second cone portion 412. The connection portion 413 is connected to the first cone portion 411 at the front end and to the second cone portion 412 at the rear end. In this way, the connection portion 413 connects the first cone portion 411 and the second cone portion 412. Here, the connection portion 413 does not reduce or expand in diameter, but extends linearly between the first cone portion 411 and the second cone portion 412. That is, the connection portion 413 connects the first cone portion 411 and the second cone portion 412 while maintaining the first inner diameter L11 which is the maximum inner diameter of the first cone portion 411.

[0152] In addition, in the portion of the guide portion 48a where the supply path 4c is formed, the first tapered portion 411, the second tapered portion 412, and the connecting portion 413 are in a state where the supply path 4c is cut off. The other structures of the compressor of the second embodiment, including the other structures of the first boss 40, are the same as those of the compressor of the first embodiment, and the same reference numerals are used for the same structures, and detailed descriptions of the structures are omitted.

[0153] 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 the rotation shaft 5 and the first radial ball bearing 19 can appropriately correct their postures in the process of passing through the connection portion 413 even if they are inclined relative to the direction of the rotation axis O. In addition, the first tapered portion 411 guides the rotation 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 the diameter from the first inner diameter L11. As a result, the first tapered portion 411 can more reliably correct the postures of the rotation shaft 5 and the first radial ball bearing 19 in the process of passing through.

[0154] In addition, the guide portion 48a is composed of the first tapered portion 411, the second tapered portion 412, and the connecting portion 413, so that in this compressor, the distance in the direction of the rotation axis O in the guide portion 48a, that is, the length in the direction of the rotation axis O can be appropriately ensured. Therefore, in this compressor, the first radial ball bearing 19 can be more appropriately guided to the fitting portion 42a by the guide portion 48a. Therefore, in this compressor, manufacturing becomes easier. Other functions in this compressor are the same as those of the compressor of Example 1.

[0155] As mentioned above, the present invention has been described in conjunction with Embodiments 1 and 2. However, the present invention is not limited to the above-mentioned Embodiments 1 and 2, and can be applied with appropriate changes without departing from the gist thereof.

[0156] For example, in the compressor of Example 1, the first radial ball bearing 19 is used as the "bearing" in the present invention, but the present invention is not limited thereto, and a sliding bearing may be used as the "bearing" in the present invention. The same is true for the compressor of Example 2.

[0157] In addition, in the compressor of the first embodiment, the first boss 4 is formed with the interference avoiding portion 46, so that the first boss 4 has an asymmetric shape. However, this is not limited to this, and the first boss 4 may be formed into an asymmetric shape by integrating the first outer peripheral surface 41 of the boss body 4a with a part of other components formed on the first front wall 13a. That is, in this case, a portion having a different distance from the first inner peripheral surface 42 to the first outer peripheral surface 41 in the radial direction of the rotating shaft 5 is also generated in the first boss 4. The same is true for the compressor of the second embodiment.

[0158] In the compressor of the first embodiment, the supply path 4c is composed of the first passage portion 401 and the second passage portion 402. However, the present invention is not limited thereto, and the supply path 4c may be composed of only one of the first passage portion 401 and the second passage portion 402, or may be composed of three or more passage portions. The same is true for the compressor of the second embodiment.

[0159] In addition, in the compressor of Example 1, the compression part 10 is set as a scroll type compression part. However, it is not limited to this, and the compression part 10 may also be an airfoil type compression part or the like. In addition, when the compression part 10 is a scroll type compression part, it may also be a double-rotating scroll type compression part in which the scrolls on both sides rotate. The same is true for the compressor of Example 2.

[0160] In the compressor of the first embodiment, the compression unit 10 compresses the refrigerant gas as a fluid. However, the present invention is not limited thereto, and the compression unit 10 may compress a fluid such as air. The same is true for the compressor of the second embodiment.

[0161] In addition, the present specification includes the following inventions.

[0162] (Note 1)

[0163] An electric compressor comprising:

[0164] case;

[0165] a rotating shaft rotatably supported inside the housing;

[0166] a motor that rotates the rotating shaft; and

[0167] a compression part that compresses the fluid by the rotation of the rotating shaft,

[0168] The housing has a boss protruding in a cylindrical shape toward the rotating shaft.

[0169] A bearing for supporting the rotating shaft is provided on the inner peripheral surface of the boss.

[0170] The electric compressor is characterized in that

[0171] The boss has an asymmetric shape having an outer peripheral surface at different distances from the inner peripheral surface in the radial direction of the rotation axis,

[0172] The rotating shaft is press-fitted into the bearing, and the bearing is clearance-fitted with the inner peripheral surface.

[0173] (Note 2)

[0174] The electric compressor according to Supplementary Note 1, wherein:

[0175] The boss has a supply path that penetrates from the outer peripheral surface to the inner peripheral surface in the radial direction of the rotating shaft and supplies lubricating oil to the bearing.

[0176] (Note 3)

[0177] The electric compressor according to Supplement 1 or 2, wherein:

[0178] The housing is provided with an inverter which is located on the opposite side of the compression unit and sandwiches the motor and is electrically connected to the motor.

[0179] The housing includes a motor chamber for accommodating the motor, an inverter chamber for accommodating the inverter, and a partition wall for dividing the motor chamber and the inverter chamber and for installing the boss.

[0180] The partition wall is provided with a through hole into which an airtight terminal for electrically connecting the motor and the inverter is inserted.

[0181] The motor includes a stator core around which a coil is wound and a rotor that rotates integrally with the rotating shaft.

[0182] 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.

[0183] The boss has the asymmetric shape by cutting away the outer peripheral surface so that the distance of the inner peripheral surface from at least one of the through hole and the terminal box is different in the radial direction of the rotating shaft.

[0184] (Note 4)

[0185] An electric compressor according to any one of Supplementary Notes 1 to 3, wherein:

[0186] The inner peripheral surface has a fitting portion for the bearing to be loosely fitted and a guide portion for guiding the bearing toward the fitting portion.

[0187] The guide portion has:

[0188] a first tapered portion whose diameter gradually increases compared to the fitting portion as it moves away from the fitting portion in the axial direction of the rotating shaft;

[0189] 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 compared to the maximum inner diameter of the first tapered portion as it separates from the first tapered portion; and

[0190] A connection portion is located between the first cone portion and the second cone portion and connects the first cone portion and the second cone portion while maintaining the maximum inner diameter of the first cone portion.

[0191] (Note 5)

[0192] An electric compressor according to any one of Supplementary Notes 1 to 4, wherein:

[0193] The bearing includes an inner ring into which the rotating shaft is press-fitted, an outer ring which is clearance-fitted with the inner peripheral surface, and a plurality of spherical bearing balls provided between the inner ring and the outer ring.

[0194] Industrial Applicability

[0195] The present invention can be utilized in a vehicle air conditioning device or the like.

Claims

1. An electric compressor comprising: case; a rotating shaft rotatably supported inside the housing; a motor that rotates the rotating shaft; and a compression part that compresses the fluid by the rotation of the rotating shaft, The housing has a boss that protrudes in a cylindrical shape toward the motor in the axial direction of the rotating shaft. A bearing for supporting the rotating shaft is provided on the inner peripheral surface of the boss. The electric compressor is characterized in that The boss has an asymmetric shape having an outer peripheral surface at different distances from the inner peripheral surface in the radial direction of the rotation axis, The rotating shaft is press-fitted into the bearing, and the bearing is clearance-fitted with the inner peripheral surface.

2. The electric compressor according to claim 1, wherein: The boss has a supply path that penetrates from the outer peripheral surface to the inner peripheral surface in the radial direction of the rotating shaft and supplies lubricating oil to the bearing.

3. The electric compressor according to claim 1, wherein: The housing is provided with an inverter which is located on the opposite side of the compression unit and sandwiches the motor and is electrically connected to the motor. The housing includes a motor chamber for accommodating the motor, an inverter chamber for accommodating the inverter, and a partition wall for dividing the motor chamber and the inverter chamber and for installing the boss. 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 rotating shaft. The coil has coil ends protruding from both ends of the stator core, a terminal box electrically connected to the airtight terminal, and a lead wire extending from one side of the coil end to the terminal box. The outer peripheral surface has a notch, and the boss is formed into the asymmetric shape by cutting off the outer peripheral surface in a manner such that the distance of the inner peripheral surface relative to at least one of the through hole and the terminal box in the radial direction of the rotating shaft is different when the notch is formed and when the notch is not formed.

4. The electric compressor according to claim 1 or 2, wherein: The inner peripheral surface has a fitting portion for the bearing to be loosely fitted and a guide portion for guiding the bearing toward the fitting portion. The guide portion has: a first tapered portion whose diameter gradually increases compared to the fitting portion as it moves away from the fitting portion in the axial direction of the rotating shaft; a second tapered portion, which is disposed apart from the first tapered portion in the axial direction of the rotating shaft and gradually increases in diameter compared to the maximum inner diameter of the first tapered portion as it is separated from the first tapered portion; as well as A connection portion is located between the first cone portion and the second cone portion and connects the first cone portion and the second cone portion while maintaining the maximum inner diameter of the first cone portion.

5. The electric compressor according to claim 1 or 2, wherein: The bearing includes an inner ring into which the rotating shaft is press-fitted, an outer ring which is clearance-fitted with the inner peripheral surface, and a plurality of spherical bearing balls provided between the inner ring and the outer ring.

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