Electric Compressor

Abstract

To provide an electric compressor which can increase a cooling effect of an inverter.SOLUTION: An inverter 16 has a plurality of electrolyte capacitors 71 having cylinder faces 710, and a holder 72 for holding the electrolyte capacitors 71. The electrolyte capacitors 71 are attached to the holder 72 so that center axes O being longitudinal directions become parallel with one another. An inner wall of an inverter accommodation chamber S1 has groove parts 30a which are recessed into fan shapes. In the holder 72, the plurality of electrolyte capacitors 71 are arranged at each stage, and the electrolyte capacitors 71 are held in a stuck manner so that intervals between the electrolyte capacitors 71 at each stage are sequentially expanded at each stage. The electrolyte capacitors 71 are thermally connected to the groove parts 30a at the cylinder faces 710, and accommodated in the groove parts 30a so that the intervals between the electrolyte capacitors 71 at each stage are expanded toward fan shape directions of the groove parts 30a.SELECTED DRAWING: Figure 3

Description

[Technical field]

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

[0002] The electric compressor includes a compression unit, an electric motor, an inverter, and a housing. The compression unit compresses a refrigerant. The electric motor drives the compression unit. The inverter drives the electric motor. The housing includes a cylindrical motor housing and an inverter housing. The motor housing accommodates the electric motor and defines a suction chamber into which the refrigerant is drawn. The inverter housing defines an inverter accommodating chamber that accommodates the inverter.

[0003] The inverter has a switching element and an LC circuit having a coil and a plurality of cylindrical electrolytic capacitors. In the electric compressor described in Patent Document 1, each electrolytic capacitor is arranged such that its central axis, which is the longitudinal direction of the electrolytic capacitor, extends along the axial direction of the motor housing. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] JP 2019-173656 A Summary of the Invention [Problem to be solved by the invention]

[0005] The switching elements, coils, and electrolytic capacitors are examples of heat generating elements that generate heat when the inverter is in operation. The heat generating elements are cooled, for example, as follows: Heat from the heat generating elements is transferred to the housing. The housing is cooled by the refrigerant drawn into the suction chamber. That is, the heat generating elements are cooled by the refrigerant drawn into the suction chamber. Therefore, it is preferable that the heat generating elements are arranged in line with the suction chamber in the axial direction of the motor housing so as to facilitate heat exchange with the suction chamber.

[0006] As in Patent Document 1, when the central axis of the electrolytic capacitor extends along the axial direction of the motor housing, the area of ​​the electrolytic capacitor when viewed from the suction chamber is unlikely to be large. For this reason, it is easy to arrange the heating element so as to be aligned with the suction chamber in the axial direction of the motor housing. However, for example, when the peripheral surface of the electrolytic capacitor is arranged along the wall separating the suction chamber and the inverter accommodating chamber in the housing, that is, when the axial direction of the electrolytic capacitor is arranged so as to be perpendicular to the axial direction of the motor housing, the area of ​​the electrolytic capacitor when viewed from the suction chamber is likely to be large. For this reason, it may be difficult to arrange the heating element so as to be aligned with the suction chamber in the axial direction of the motor housing. A heating element that is not aligned with the suction chamber in the axial direction of the motor housing is less likely to be cooled than a heating element that is aligned with the suction chamber in the axial direction of the motor housing. [Means for solving the problem]

[0007] The electric compressor for solving the above problems includes a housing having a compression unit that compresses a refrigerant, an electric motor that drives the compression unit, an inverter that drives the electric motor, a cylindrical motor housing that accommodates the electric motor and forms a suction chamber into which the refrigerant is sucked, and an inverter housing that is thermally connected to the motor housing and forms an inverter accommodating chamber that accommodates the inverter, the inverter has a plurality of electrolytic capacitors having a cylindrical surface, and a holder that holds the electrolytic capacitors, the electrolytic capacitors are attached to the holder such that their central axes which are longitudinal directions are parallel to each other, an inner wall of the inverter accommodating chamber has a groove that is recessed in a flared shape, the holder holds the electrolytic capacitors in a stacked state such that the plurality of electrolytic capacitors are arranged in each stage and the intervals between the electrolytic capacitors in each stage increase sequentially with each stage, and the electrolytic capacitors are accommodated in the groove such that the cylindrical surface is thermally connected to the groove and the intervals increase in the flaring direction of the groove.

[0008] The holder holds the electrolytic capacitors, so that the electrolytic capacitors are arranged in multiple stages. Therefore, the area of ​​the electrolytic capacitors as viewed from the suction chamber is reduced compared to when all the electrolytic capacitors are arranged in a row. Therefore, it is possible to easily arrange the heat generating elements other than the electrolytic capacitors in the inverter accommodating chamber so that they can easily exchange heat with the suction chamber. As a result, it is possible to increase the cooling effect of the heat generating elements other than the electrolytic capacitors compared to when all the electrolytic capacitors are arranged in a row. In addition, by being accommodated in the groove, the electrolytic capacitors are thermally connected to the groove and, by extension, to the inner wall of the inverter accommodating chamber. Therefore, it is possible to increase the contact area of ​​the electrolytic capacitor with the inner wall compared to when the electrolytic capacitors are not accommodated in the groove. Therefore, it is possible to increase the cooling effect of the electrolytic capacitors. As a result, it is possible to increase the cooling effect of the inverter.

[0009] In the above electric compressor, the inverter housing may have a wall portion that closes one axial end of the motor housing and constitutes part of the inner wall, the groove portion may be provided in the wall portion, and the holder may hold the electrolytic capacitors such that a plurality of the electrolytic capacitors in a step closer to an opening of the groove sandwich the electrolytic capacitor in a step closer to a bottom of the groove in the radial direction of the motor housing.

[0010] In this configuration, some of the electrolytic capacitors in the stage close to the opening of the groove and some of the electrolytic capacitors in the stage close to the bottom of the groove overlap in the radial direction of the motor housing, which makes it possible to reduce the size of the capacitors in the axial direction of the motor housing compared to a case in which the electrolytic capacitors in the stage close to the opening of the groove and the electrolytic capacitors in the stage close to the bottom of the groove are arranged so as not to overlap in the radial direction of the motor housing.

[0011] In the above electric compressor, the inverter may have a coil and a switching element which form an LC circuit together with the electrolytic capacitor, and the switching element, the coil, and the plurality of electrolytic capacitors may be fixed within the inverter accommodating chamber so as to be aligned with the suction chamber in the axial direction of the motor housing and thermally connected to the wall portion.

[0012] In this configuration, since the coil and the switching element, in addition to the electrolytic capacitor, are disposed within the inverter chamber so as to facilitate heat exchange with the suction chamber, the coil and the switching element can be easily cooled.

[0013] In the above electric compressor, the electrolytic capacitor may be fixed in the inverter chamber with one end facing the switching element, and a pair of lead wires of the electrolytic capacitor may extend from the one end.

[0014] This configuration can shorten the distance between the lead wires of the electrolytic capacitor and the switching element, thereby reducing the impedance between the electrolytic capacitor and the switching element. Effect of the Invention

[0015] The present invention can increase the cooling effect of the inverter. [Brief description of the drawings]

[0016] [Figure 1] 6 is a cross-sectional view of the electric compressor taken along line 1-1 in FIG. 5. [Diagram 2] FIG. 2 is a perspective view of a first component and a capacitor unit. [Diagram 3] 6 is a cross-sectional view of the electric compressor taken along line 3-3 in FIG. 5. [Figure 4] FIG. 2 is a perspective view of a first component, an inverter, and a third component. [Diagram 5] FIG. [Figure 6] FIG. 2 is a side view of the capacitor unit. [Figure 7]FIG. 2 is a side view of the capacitor unit. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0017] An embodiment of an electric compressor will now be described with reference to Figures 1 to 7. The electric compressor of the present embodiment is used, for example, in a vehicle air conditioner. <<Electric compressor>> As shown in Fig. 1, the electric compressor 10 includes a housing 11, a shaft support member 12, a rotating shaft 13, a compression unit 14, an electric motor 15, and an inverter 16. The housing 11 accommodates the shaft support member 12, the rotating shaft 13, the compression unit 14, the electric motor 15, and the inverter 16. The compression unit 14 compresses a refrigerant as a fluid. The electric motor 15 drives the compression unit 14 by rotating the rotating shaft 13. The inverter 16 drives the electric motor 15.

[0018] <Housing> The housing 11 has a first constituent body 21, a second constituent body 22, and a third constituent body 23. The first constituent body 21, the second constituent body 22, and the third constituent body 23 are made of metal. Therefore, the housing 11 is made of metal. In this embodiment, the first constituent body 21, the second constituent body 22, and the third constituent body 23 are made of aluminum.

[0019] The first component 21 has a cylindrical motor housing 24 and a cylindrical inverter housing 25 with a bottom. The inverter housing 25 is continuous with a first axial end of the motor housing 24. The inverter housing 25 is thermally connected to the motor housing 24.

[0020] As shown in FIG. 2, the inverter housing 25 has a bottom wall 26 and a peripheral wall 27 extending from the outer periphery of the bottom wall 26 in the thickness direction of the bottom wall 26. The thickness direction of the bottom wall 26 coincides with the axial direction of the motor housing 24. The outer shape of the bottom wall 26 is larger than the outer shape of the motor housing 24. The bottom wall 26 has a closing portion 26a and an extending portion 26b. The closing portion 26a is a portion that closes an opening located at a first end in the axial direction of the motor housing 24, and corresponds to the wall portion that closes one end of the motor housing 24 in the present invention. The extending portion 26b is a portion that is located outside the outer periphery surface 24a of the motor housing 24 in the radial direction of the motor housing 24. The extending portion 26b has a first surface 261 and a second surface 262. The first surface 261 and the second surface 262 are surfaces that are perpendicular to the axial direction of the motor housing 24. The first surface 261 is a part of the inner surface of the inverter housing 25. The second surface 262 is a surface located opposite to the first surface 261. The second surface 262 is a part of the outer surface of the inverter housing 25.

[0021] As shown in FIG. 1 and FIG. 2, the inverter housing 25 has a recess 28. The recess 28 is a portion recessed from the first surface 261 of the extending portion 26b. The recess 28 is provided in the closing portion 26a. The depth of the recess 28 is greater than the thickness of the extending portion 26b. The bottom 28a of the recess 28 protrudes toward the motor housing 24 beyond the second surface 262 of the extending portion 26b. The bottom 28a has a first surface 281 and a second surface 282. The first surface 281 and the second surface 282 are surfaces perpendicular to the axial direction of the motor housing 24. The first surface 281 is a part of the inner surface of the inverter housing 25. The second surface 282 is a surface located opposite to the first surface 281.

[0022] As shown in Fig. 1, the inverter housing 25 has a boss 29. The boss 29 is a portion that protrudes from the closing portion 26a toward the motor housing 24. The boss 29 has a bearing accommodating portion 29a. The bearing accommodating portion 29a is a portion that is recessed from the tip surface of the boss 29. The bearing accommodating portion 29a accommodates the first bearing 17.

[0023] As shown in Figures 2 and 3, the inverter housing 25 has a protruding portion 30. The protruding portion 30 is a portion that protrudes in the axial direction of the motor housing 24 from a first surface 281 of the bottom portion 28a. The tip surface of the protruding portion 30 is flush with the first surface 261 of the extension portion 26b. The protruding portion 30 has a groove portion 30a that is recessed in a flared shape. The groove portion 30a is composed of two first grooves 31 and two second grooves 32.

[0024] Here, the axial direction of the motor housing 24 is defined as a first direction. The direction perpendicular to the first direction is defined as a second direction. The direction perpendicular to both the first and second directions is defined as a third direction. The second and third directions each coincide with the radial direction of the motor housing 24.

[0025] Each of the first grooves 31 and each of the second grooves 32 extends along the second direction. Each of the grooves 31, 32 is arranged in two stages in the first direction. The two first grooves 31 are provided in a stage different from the two second grooves 32 in the first direction. The two first grooves 31 are located on the base end side of the protruding portion 30. The two second grooves 32 are located on the tip side of the protruding portion 30. In other words, the two first grooves 31 are located on the bottom 28a side of the recess 28. The two second grooves 32 are located on the opening side of the recess 28. The two first grooves 31 are aligned in the third direction. The two second grooves 32 are aligned in the third direction. In this embodiment, the two first grooves 31 are located between the two second grooves 32 in the third direction. That is, the groove 30a in this embodiment has a flared shape in which the width of the groove 30a in the third direction increases from the bottom of the groove 30a toward the opening.

[0026] 1, the second component 22 is connected to a second axial end of the motor housing 24. The second axial end of the motor housing 24 is an end located opposite to the first end in the axial direction of the motor housing 24. The second component 22 closes an opening located at the second axial end of the motor housing 24.

[0027] 4, the third component 23 has a shape corresponding to the peripheral wall 27 of the inverter housing 25. The third component 23 is connected to the peripheral wall 27 of the inverter housing 25. The third component 23 closes the opening of the inverter housing 25. The third component 23 is thermally connected to the second component 22. An inner surface 23a of the third component 23 is a surface perpendicular to the axial direction of the motor housing 24.

[0028] 1 and 3, an inverter accommodating chamber S1 is defined by the inner surface of the inverter housing 25 and the inner surface 23a of the third component 23. In other words, the inner surface of the inverter housing 25 and the inner surface 23a of the third component 23 are the inner walls of the inverter accommodating chamber S1.

[0029] As shown in FIG. 1, the housing 11 has a suction port 11a and a discharge port 11b. The suction port 11a is provided in the motor housing 24. The suction port 11a is provided in a portion of the motor housing 24 close to the inverter housing 25 in the axial direction. A first end of an external refrigerant circuit is connected to the suction port 11a. The discharge port 11b is provided in the second component 22. A second end of the external refrigerant circuit, which is an end opposite to the first end, is connected to the discharge port 11b.

[0030] <Support member> The shaft support member 12 is accommodated in a motor housing 24. The shaft support member 12 has a shaft insertion hole 12a and a communication hole 12b. A second bearing 18 is accommodated in the shaft insertion hole 12a.

[0031] The suction chamber S2 is defined by the inner circumferential surface of the motor housing 24, the shaft support member 12, and the closing portion 26a of the inverter housing 25. The closing portion 26a separates the inverter accommodating chamber S1 and the suction chamber S2. The closing portion 26a is exposed to the suction chamber S2. The closing portion 26a is thermally connected to the suction chamber S2. The closing portion 26a and a portion of the third component 23 are aligned with the suction chamber S2 in the axial direction of the motor housing 24.

[0032] <Rotation axis> The rotating shaft 13 is accommodated in the motor housing 24. The rotating shaft 13 extends along the axial direction of the motor housing 24. One end of the rotating shaft 13 is inserted into the bearing accommodating portion 29a. One end of the rotating shaft 13 is rotatably supported by the boss 29 via the first bearing 17. The other end of the rotating shaft 13 is inserted into the shaft insertion hole 12a of the shaft support member 12. The other end of the rotating shaft 13 is rotatably supported by the shaft support member 12 via the second bearing 18.

[0033] <Compression section> The compression section 14 is accommodated in the motor housing 24. The compression section 14 is disposed between the shaft support member 12 and the second component 22 in the axial direction of the rotary shaft 13. The compression section 14 in this embodiment is of a scroll type. The compression section 14 has a fixed scroll 14a and a movable scroll 14b. The fixed scroll 14a is fixed to the inner peripheral surface of the motor housing 24. The movable scroll 14b is disposed so as to face the fixed scroll 14a. A volume-changeable compression chamber S3 is defined between the fixed scroll 14a and the movable scroll 14b. The compression chamber S3 communicates with the suction chamber S2 via the communication hole 12b. A discharge chamber S4 is defined by the fixed scroll 14a and the inner surface of the second component 22. The compression chamber S3 and the discharge chamber S4 communicate with each other.

[0034] <Electric motor> The electric motor 15 is accommodated in the suction chamber S2. That is, the suction chamber S2 also serves as a motor accommodating chamber that accommodates the electric motor 15. The electric motor 15 has a rotor 41 and a stator 42. The rotor 41 has a cylindrical rotor core 41a and a plurality of permanent magnets 41b. The rotor core 41a is fixed to the rotating shaft 13. The plurality of permanent magnets 41b are embedded in the rotor core 41a. The permanent magnets 41b are provided at equal pitches in the circumferential direction of the rotor core 41a. The stator 42 surrounds the rotor 41. The stator 42 has a cylindrical stator core 42a and a motor coil 42b. The stator core 42a is fixed to the inner circumferential surface of the motor housing 24. The motor coil 42b is wound around the stator core 42a. The rotor 41 rotates when a current flows through the motor coil 42b. The rotating shaft 13 rotates integrally with the rotor 41 .

[0035] <Inverter> As shown in FIGS. 4 and 5, the inverter 16 has a three-phase switching element 61, a coil 62, a capacitor unit 63, a three-phase conductive member 64, a resin plate 65, and a circuit board 66.

[0036] The three-phase switching elements 61 perform switching operations to drive the electric motor 15. The capacitor unit 63 has a plurality of electrolytic capacitors 71 and a resin holder 72. The capacitor unit 63 of this embodiment has four electrolytic capacitors 71 as the plurality of electrolytic capacitors 71. The holder 72 holds the plurality of electrolytic capacitors 71. The plurality of electrolytic capacitors 71 and the coil 62 form an LC circuit. The LC circuit is a filter circuit for reducing noise contained in an input current from the outside. The three-phase switching elements 61, the coil 62, and the electrolytic capacitor 71 are heating elements that generate heat when the inverter 16 is operating. The three-phase conductive members 64 are each made of metal. The three-phase conductive members 64 electrically connect the electric motor 15 and the inverter 16.

[0037] The configuration of the capacitor unit 63 will now be described in detail. 6 and 7, each electrolytic capacitor 71 is cylindrical. Each electrolytic capacitor 71 has a cylindrical surface 710 as its outer circumferential surface. The outer diameter and axial dimension of each electrolytic capacitor 71 are the same for all electrolytic capacitors 71. The axial dimension of each electrolytic capacitor 71 is greater than the outer diameter of the electrolytic capacitor 71. In other words, the direction in which the central axis O of each electrolytic capacitor 71 extends is the longitudinal direction of the electrolytic capacitor 71. Two lead wires 73 extend from one axial end of each electrolytic capacitor 71.

[0038] The holder 72 has two first capacitor housing portions 74 and two second capacitor housing portions 75. Each of the first capacitor housing portions 74 and each of the second capacitor housing portions 75 is a substantially cylindrical space. The axial direction of each of the first capacitor housing portions 74 and each of the second capacitor housing portions 75 coincides with each other. One axial end of each of the first capacitor housing portions 74 and each of the second capacitor housing portions 75 is closed, and the other axial end is open.

[0039] The capacitor accommodating portions 74, 75 are arranged in two stages in a direction perpendicular to the axial direction of the capacitor accommodating portions 74, 75. The two first capacitor accommodating portions 74 are arranged in a stage different from the two second capacitor accommodating portions 75 in the direction perpendicular to the axial direction of the capacitor accommodating portions 74, 75.

[0040] The direction in which capacitor accommodating portions 74, 75 are arranged in two tiers is defined as the thickness direction of holder 72. The thickness direction of holder 72 is a direction perpendicular to the axial direction of capacitor accommodating portions 74, 75. In addition, the direction perpendicular to both the axial direction of capacitor accommodating portions 74, 75 and the thickness direction of holder 72 is defined as the width direction of holder 72.

[0041] The two first capacitor accommodating portions 74 are aligned in the width direction of the holder 72. The two second capacitor accommodating portions 75 are aligned in the width direction of the holder 72. In this embodiment, the two first capacitor accommodating portions 74 are located between the two second capacitor accommodating portions 75 in the width direction of the holder 72. The distance between the two second capacitor accommodating portions 75 is wider than the distance between the two first capacitor accommodating portions 74.

[0042] Holder 72 has a window 76. Window 76 connects each of capacitor housing portions 74, 75 to the outside of holder 72. Each electrolytic capacitor 71 is accommodated in a first capacitor accommodating portion 74 or a second capacitor accommodating portion 75. More specifically, of the four electrolytic capacitors 71, two electrolytic capacitors 71 are accommodated in the first capacitor accommodating portion 74, and the other two electrolytic capacitors 71 are accommodated in the second capacitor accommodating portion 75. When it is necessary to distinguish between the four electrolytic capacitors 71, the electrolytic capacitor 71 accommodated in the first capacitor accommodating portion 74 will be referred to as a first electrolytic capacitor 71a. Also, the electrolytic capacitor 71 accommodated in the second capacitor accommodating portion 75 will be referred to as a second electrolytic capacitor 71b.

[0043] Each electrolytic capacitor 71 has a first portion 711 accommodated in a capacitor accommodating portion 74, 75, and a second portion 712 protruding from holder 72. Lead wire 73 extends from first portion 711. Lead wire 73 is drawn out to the outside of holder 72.

[0044] In a state where the four electrolytic capacitors 71 are held by the holder 72, the axial directions of all the electrolytic capacitors 71 are the same. The central axes O of the electrolytic capacitors 71 are parallel to each other. The axial direction of each electrolytic capacitor 71 is the same as the axial direction of the capacitor accommodating portions 74, 75. The two first electrolytic capacitors 71a and the two second electrolytic capacitors 71b are arranged in two stages in the thickness direction of the holder 72. The two first electrolytic capacitors 71a are lined up in the width direction of the holder 72. The two second electrolytic capacitors 71b are lined up in the width direction of the holder 72. In this embodiment, the two first electrolytic capacitors 71a are arranged between the two second electrolytic capacitors 71b in the width direction of the holder 72. The distance between the two second electrolytic capacitors 71b is wider than the distance between the two first electrolytic capacitors 71a. That is, holder 72 holds electrolytic capacitors 71 in a stacked state, with a plurality of electrolytic capacitors 71 arranged in each stage, and the intervals between electrolytic capacitors 71 in each stage increasing successively.

[0045] 7, the first electrolytic capacitor 71a and the second electrolytic capacitor 71b are disposed so as to partially overlap in the axial direction of the electrolytic capacitor 71. More specifically, a first portion 711 of the first electrolytic capacitor 71a protrudes in the axial direction of the electrolytic capacitor 71 more than a first portion 711 of the second electrolytic capacitor 71b. A second portion 712 of the second electrolytic capacitor 71b protrudes in the axial direction of the electrolytic capacitor 71 more than the second portion 712 of the first electrolytic capacitor 71a.

[0046] 6, first electrolytic capacitor 71a and second electrolytic capacitor 71b are disposed so as to partially overlap in the thickness direction of holder 72. More specifically, one end of first electrolytic capacitor 71a in the thickness direction of holder 72 is positioned between one end and the other end of second electrolytic capacitor 71b in the thickness direction of holder 72.

[0047] The first electrolytic capacitor 71a and the second electrolytic capacitor 71b are arranged to partially overlap in the width direction of the holder 72. In particular, one end of the first electrolytic capacitor 71a in the width direction of the holder 72 is located between one end and the other end of the second electrolytic capacitor 71b in the width direction of the holder 72.

[0048] 4, the plate 65 has a first surface 65a and a second surface 65b. The first surface 65a and the second surface 65b are surfaces perpendicular to the thickness direction of the plate 65. The second surface 65b is a surface located opposite to the first surface 65a. The plate 65 holds the three-phase switching elements 61, the coil 62, the capacitor unit 63, and the three-phase conductive members 64 on the first surface 65a.

[0049] As shown in FIG. 5, the plate 65 has a through hole 65c that passes through the plate 65 in the plate thickness direction. In a state where the three-phase switching element 61, the coil 62, the capacitor unit 63, and the three-phase conductive member 64 are held by the plate 65, the three-phase switching element 61 and the capacitor unit 63 are arranged in the axial direction of the electrolytic capacitor 71. Each electrolytic capacitor 71 is arranged in a state where one end in the axial direction of the electrolytic capacitor 71 faces the three-phase switching element 61. As described above, the pair of lead wires 73 extend from one end in the axial direction of the electrolytic capacitor 71. Therefore, the lead wires 73 extending from each electrolytic capacitor 71 are arranged between the electrolytic capacitor 71 and the three-phase switching element 61 in the axial direction of the electrolytic capacitor 71. In addition, the capacitor unit 63 and the three-phase switching element 61 are arranged between the coil 62 and the three-phase conductive member 64 in the width direction of the holder 72.

[0050] 4, plate 65 is disposed so as to overlap circuit board 66. The thickness direction of plate 65 coincides with the thickness direction of circuit board 66. The outer shape of circuit board 66 is larger than the outer shape of plate 65. Circuit board 66 has a portion that overlaps with plate 65 and a portion that protrudes beyond plate 65.

[0051] The second surface 65b of the plate 65 faces the circuit board 66. The portion of the holder 72 in which the window 76 is formed faces the circuit board 66 via the through hole 65c of the plate 65. A part of the first portion 711 of each electrolytic capacitor 71 faces the circuit board 66 via the window 76 and the through hole 65c.

[0052] The plate 65 is disposed between the three-phase switching elements 61, the coils 62, the capacitor unit 63, the three-phase conductive members 64, and the circuit board 66. The three-phase switching elements 61, the coils 62, the electrolytic capacitors 71, and the three-phase conductive members 64 are mounted on the circuit board 66 via insertion holes (not shown) formed in the plate 65.

[0053] 1 and 3, the inverter 16 is accommodated in the inverter accommodating chamber S1. The inverter 16 is fixed in the inverter accommodating chamber S1. The three-phase switching elements 61, the coils 62, most of the capacitor unit 63, and the three-phase conductive members 64 are accommodated inside the recess 28 in the inverter accommodating chamber S1. The plate 65 and the circuit board 66 are accommodated outside the recess 28 in the inverter accommodating chamber S1. The three-phase switching elements 61, the coils 62, the capacitor unit 63, and the three-phase conductive members 64, the plate 65, and the circuit board 66 are arranged in this order in the axial direction of the motor housing 24.

[0054] As shown by the two-dot chain line in Fig. 5, a region obtained by projecting the outer circumferential surface 24a of the motor housing 24 in the axial direction of the motor housing 24 is defined as a projected region A. Since the motor housing 24 in this embodiment is cylindrical, the projected region A is circular. The three-phase switching elements 61, the coils 62, the capacitor unit 63, and the three-phase conductive members 64 are located within the projected region A. Therefore, the three-phase switching elements 61, the coils 62, the capacitor unit 63, and the three-phase conductive members 64 are aligned with the suction chamber S2 in the axial direction of the motor housing 24.

[0055] 1, the three-phase switching element 61 is thermally connected to the blocked portion 26a via an insulating member 67. The coil 62 is disposed in contact with the blocked portion 26a. The coil 62 is thermally connected to the blocked portion 26a.

[0056] As shown in FIG. 3 and FIG. 5, the electrolytic capacitor 71 is accommodated in the groove 30a. More specifically, the second portion 712 of the first electrolytic capacitor 71a is accommodated in the first groove 31. The second portion 712 of the second electrolytic capacitor 71b is accommodated in the second groove 32. By accommodating each electrolytic capacitor 71 in the groove 30a, the cylindrical surface 710 in the second portion 712 is thermally connected to the groove 30a. As described above, the groove 30a is formed in the protruding portion 30. The protruding portion 30 is thermally connected to the blocking portion 26a. That is, each electrolytic capacitor 71 is thermally connected to the blocking portion 26a via the groove 30a and the protruding portion 30.

[0057] The thickness direction of the holder 72 coincides with the first direction. The axial direction of the electrolytic capacitor 71 coincides with the second direction. The width direction of the holder 72 coincides with the third direction. That is, the electrolytic capacitors 71 are arranged in two stages in the first direction. The first electrolytic capacitor 71a is the electrolytic capacitor 71 in the stage close to the bottom of the groove 30a. The second electrolytic capacitor 71b is the electrolytic capacitor 71 in the stage close to the opening of the groove 30a. The electrolytic capacitors 71 are arranged such that the interval between the electrolytic capacitors 71 in each stage is wider in the direction in which the groove 30a widens. The direction in which the groove 30a widens is the direction in which the width of the groove 30a widens in the third direction. The direction in which the groove 30a widens coincides with the first direction. In this embodiment, the interval between the second electrolytic capacitors 71b arranged in the wide portion of the groove 30a is wider than the interval between the first electrolytic capacitors 71a arranged in the narrow portion of the groove 30a.

[0058] The holder 72 holds the electrolytic capacitors 71 such that the two second electrolytic capacitors 71b sandwich the two first electrolytic capacitors 71a in the second direction. In other words, the holder 72 holds the electrolytic capacitors 71 such that the two second electrolytic capacitors 71b sandwich the two first electrolytic capacitors 71a in the radial direction of the motor housing 24. Therefore, a part of the first electrolytic capacitor 71a in the first direction and a part of the second electrolytic capacitor 71b in the first direction overlap in the third direction. In addition, a part of the first electrolytic capacitor 71a in the second direction and a part of the second electrolytic capacitor 71b in the second direction partially overlap in the first direction. Furthermore, a part of the first electrolytic capacitor 71a in the third direction and a part of the second electrolytic capacitor 71b in the third direction partially overlap in the first direction.

[0059] The portion of the circuit board 66 protruding beyond the plate 65 is accommodated between the extension portion 26b of the inverter housing 25 and the third component 23 in the axial direction of the motor housing 24. The plate 65 and the circuit board 66 are fixed to the inverter housing 25 by bolts B.

[0060] <<Operation of electric compressor>> The refrigerant is sucked into the suction chamber S2 through the suction port 11a. The refrigerant sucked into the suction chamber S2 flows into the compression chamber S3 through the communication hole 12b. The refrigerant that flows into the compression chamber S3 is compressed by changing the volume of the compression chamber S3. The compressed refrigerant is discharged into the discharge chamber S4. The refrigerant discharged into the discharge chamber S4 flows out from the discharge port 11b into the external refrigerant circuit. The refrigerant that flows out into the external refrigerant circuit passes through a heat exchanger and an expansion valve of the external refrigerant circuit, and flows back into the suction chamber S2 through the suction port 11a. The electric compressor 10 and the external refrigerant circuit constitute a vehicle air conditioner.

[0061] The operation of this embodiment will be described. The three-phase switching elements 61, the coils 62, and the electrolytic capacitors 71 generate heat when the inverter 16 is in operation. The heat of each switching element 61 is transferred to the blocked portion 26a via the insulating member 67. The heat of the coils 62 is transferred directly to the blocked portion 26a. The heat of each electrolytic capacitor 71 is transferred to the blocked portion 26a via the protruding portion 30. The blocked portion 26a is thermally connected to the suction chamber S2. Therefore, the blocked portion 26a is cooled by the refrigerant drawn into the suction chamber S2. In this way, the switching elements 61, the coils 62, and the electrolytic capacitors 71 are cooled by the refrigerant drawn into the suction chamber S2 via the blocked portion 26a.

[0062] The effects of this embodiment will be described. (1) The holder 72 holds the electrolytic capacitors 71, so that the electrolytic capacitors 71 are arranged in two stages in the first direction. Therefore, the area of ​​the capacitor unit 63 as viewed from the suction chamber S2 is reduced compared to when all the electrolytic capacitors 71 are arranged in a row. Therefore, it is possible to easily arrange the heat generating elements other than the electrolytic capacitors 71 in the inverter accommodating chamber S1 so as to facilitate heat exchange with the suction chamber S2. As a result, it is possible to increase the cooling effect of the heat generating elements other than the electrolytic capacitors 71 compared to when all the electrolytic capacitors 71 are arranged in a row. In addition, each electrolytic capacitor 71 is accommodated in the groove portion 30a, and is thermally connected to the groove portion 30a and the inner wall of the inverter accommodating chamber S1. Therefore, it is possible to increase the contact area of ​​the electrolytic capacitor 71 with the inner wall of the inverter accommodating chamber S1 compared to when each electrolytic capacitor 71 is not accommodated in the groove portion 30a. Therefore, it is possible to increase the cooling effect of the electrolytic capacitors 71. As a result, it is possible to increase the cooling effect of the inverter 16.

[0063] (2) Holder 72 holds electrolytic capacitors 71 such that the two second electrolytic capacitors 71b on the step closer to the opening of groove 30a sandwich first electrolytic capacitor 71a on the step closer to the bottom of groove 30a in the radial direction of motor housing 24. As a result, a portion of first electrolytic capacitor 71a and a portion of second electrolytic capacitor 71b overlap in the radial direction of motor housing 24. Therefore, the capacitor unit 63 can be made smaller in size in the axial direction of motor housing 24 than when the first electrolytic capacitor 71a and the second electrolytic capacitor 71b do not overlap in the radial direction of motor housing 24.

[0064] (3) The switching element 61, the coil 62, and the electrolytic capacitors 71 are fixed in the inverter accommodating chamber S1 so as to be aligned with the suction chamber S2 in the axial direction of the motor housing 24 and thermally connected to the blocking portion 26a. In this case, in addition to the electrolytic capacitor 71, the switching element 61 and the coil 62 are arranged in the inverter accommodating chamber S1 so as to facilitate heat exchange with the suction chamber S2. Therefore, the switching element 61 and the coil 62 can be easily cooled.

[0065] (4) The electrolytic capacitor 71 is fixed inside the inverter accommodating chamber S1 with one end facing the switching element 61. The pair of lead wires 73 of the electrolytic capacitor 71 extend from one end of the electrolytic capacitor 71. This makes it possible to shorten the distance between the lead wires 73 of the electrolytic capacitor 71 and the switching element 61. This makes it possible to reduce the impedance between the electrolytic capacitor 71 and the switching element 61.

[0066] (5) The blocking portion 26a is exposed to the suction chamber S2. Therefore, the cooling effect of the inverter 16 is increased compared to a case in which the blocking portion 26a is not exposed to the suction chamber S2 and is thermally connected to another wall portion exposed to the suction chamber S2.

[0067] (6) Holder 72 holds multiple electrolytic capacitors 71 such that a portion of first electrolytic capacitor 71a in the second direction and a portion of second electrolytic capacitor 71b in the second direction overlap in the first direction. Therefore, it is easier to ensure insulation between lead wire 73 extending from first electrolytic capacitor 71a and lead wire 73 extending from second electrolytic capacitor 71b, compared to a case in which the entire first electrolytic capacitor 71a in the second direction and the entire second electrolytic capacitor 71b in the second direction overlap in the first direction.

[0068] This embodiment can be modified as follows: The embodiment and the modified examples can be combined with each other to the extent that there is no technical contradiction. The configuration of the housing 11 may be modified as appropriate. For example, the motor housing 24 and the inverter housing 25 may be separate bodies. When the motor housing 24 and the inverter housing 25 are separate bodies, the motor housing 24 may have the following configuration.

[0069] The motor housing 24 has a peripheral wall and an end wall that closes an opening located at one axial end of the peripheral wall. The end wall of the motor housing 24 is exposed to the suction chamber S2 and is thermally connected to the suction chamber S2. The inverter housing 25 is disposed such that the closing portion 26a is adjacent to the end wall of the motor housing 24. The closing portion 26a is thermally connected to the end wall of the motor housing 24. That is, the closing portion 26a is thermally connected to the suction chamber S2 via the end wall of the motor housing 24.

[0070] In the above configuration, the protrusion 30 having the groove 30a may be formed to protrude from the end wall of the motor housing 24 toward the inverter housing 25. The protrusion 30 is disposed in the inverter accommodating chamber S1 via a through hole that penetrates the blocking portion 26a. In this case, the end wall of the motor housing 24, which is the wall portion having the grooves 31 and 32, is exposed to the suction chamber S2, thereby further increasing the cooling effect of the inverter 16.

[0071] The groove 30a may be formed as a flared recess in a surface of the inner surface 23a of the third component 23 that is aligned with the suction chamber S2 and the motor housing 24 in the axial direction, instead of in the closed portion 26a.

[0072] The surface of the inner wall of the inverter accommodation chamber S1 on which the groove 30a is provided does not have to be perpendicular to the axial direction of the motor housing 24 as long as it intersects with the axial direction of the motor housing 24. The motor housing 24 does not have to be cylindrical as long as it is cylindrical. The motor housing 24 may be, for example, a rectangular cylindrical shape.

[0073] The inverter housing 25 does not have to have the recess 28. That is, the closing portion 26a may have a surface that is flush with the first surface 261 of the extending portion 26b. In this case, for example, the protrusion 30 may be formed on the surface of the closing portion 26a that is flush with the first surface 261 of the extending portion 26b. Also, without forming the protrusion 30, the groove 30a may be formed on the surface of the closing portion 26a that is flush with the first surface 261 of the extending portion 26b.

[0074] The recess 28 may be provided around the first bearing 17. That is, a part of the inverter 16 may be disposed around the first bearing 17. In this case, the dead space of the suction chamber S2 is utilized as an inverter accommodating chamber, so that the electric compressor 10 can be made smaller in size in the axial direction of the motor housing 24.

[0075] Holder 72 may hold a plurality of electrolytic capacitors 71 such that electrolytic capacitors 71 are stacked in three or more tiers depending on the number of electrolytic capacitors 71. In this case, holder 72 also holds electrolytic capacitors 71 such that a plurality of electrolytic capacitors 71 are arranged in each tier, and the intervals between electrolytic capacitors 71 in each tier increase sequentially with each tier.

[0076] Holder 72 may hold three or more first electrolytic capacitors 71a in the third direction. When three or more electrolytic capacitors 71 are lined up in a single row in this manner, the distance between central axes O of electrolytic capacitors 71 located at both ends is defined as the spacing between electrolytic capacitors 71 in the present invention.

[0077] The holder 72 may hold a plurality of electrolytic capacitors 71 such that the electrolytic capacitors 71 located in different stages do not overlap each other in the radial direction of the motor housing 24 . Holder 72 may hold multiple electrolytic capacitors 71 such that electrolytic capacitors 71 located in different stages are entirely overlapped in the first direction in the second direction. In this case, holder 72 holds multiple electrolytic capacitors 71 such that insulation between lead wires 73 of electrolytic capacitors 71 located in different stages is ensured. For example, holder 72 holds multiple electrolytic capacitors 71 such that lead wire 73 of second electrolytic capacitor 71b is positioned on the opposite side of electrolytic capacitor 71 from lead wire 73 of first electrolytic capacitor 71a.

[0078] The electrolytic capacitor 71 does not have to be disposed such that one end of the lead wire 73 in the axial direction faces the switching element 61. In other words, the lead wire 73 extending from the electrolytic capacitor 71 does not have to be located between the electrolytic capacitor 71 and the switching element 61.

[0079] The compression section 14 is not limited to a scroll type. The compression section 14 may be, for example, a piston type or a vane type. The electric compressor 10 may be used for purposes other than vehicle air conditioning systems. For example, the electric compressor 10 may be mounted on a fuel cell vehicle. The electric compressor 10 is used to compress air, which serves as a fluid to be supplied to a fuel cell, by the compression unit 14. [Explanation of symbols]

[0080] 10...electric compressor, 11...housing, 14...compression section, 15...electric motor, 16...inverter, 24...motor housing, 25...inverter housing, 26a...blocking section as wall section, 30a...groove section, 61...switching element, 62...coil, 71...electrolytic capacitor, 72...holder, 73...lead wire, 710...cylindrical surface, O...central axis, S1...inverter accommodating chamber, S2...suction chamber.

Claims

1. A compression section that compresses a refrigerant; an electric motor that drives the compression unit; an inverter that drives the electric motor; a housing including a cylindrical motor housing that accommodates the electric motor and defines a suction chamber into which the refrigerant is drawn, and an inverter housing that is thermally connected to the motor housing and defines an inverter accommodating chamber that accommodates the inverter; Equipped with the inverter includes a plurality of electrolytic capacitors having cylindrical surfaces and a holder for holding the electrolytic capacitors; The electrolytic capacitors are attached to the holder so that their central axes, which are longitudinal directions, are parallel to each other; an inner wall of the inverter accommodating chamber has a groove portion recessed in a flared shape, the holder holds the electrolytic capacitors in a stacked state such that a plurality of the electrolytic capacitors are arranged in each stage and the intervals between the electrolytic capacitors in each stage are successively increased from stage to stage; the electrolytic capacitor is accommodated in the groove such that the cylindrical surface is thermally connected to the groove and the interval between the cylindrical surface and the electrolytic capacitor becomes wider in a direction in which the groove expands; the inverter housing has a wall portion that closes one axial end of the motor housing and constitutes a part of the inner wall, The groove is provided in the wall, The holder holds the electrolytic capacitors such that the electrolytic capacitors in a stage closer to the opening of the groove sandwich the electrolytic capacitors in a stage closer to the bottom of the groove in the radial direction of the motor housing.

2. 2. The electric compressor according to claim 1, wherein the inverter has a coil and a switching element which form an LC circuit together with the electrolytic capacitor, and the switching element, the coil, and the plurality of electrolytic capacitors are fixed in the inverter accommodating chamber so as to be aligned with the suction chamber in the axial direction of the motor housing and thermally connected to the wall portion.

3. 3. The electric compressor according to claim 2, wherein the electrolytic capacitor is fixed in the inverter chamber with one end facing the switching element, and a pair of lead wires of the electrolytic capacitor extend from the one end.

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