JP2023096978A - electric compressor - Google Patents

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

The present invention relates to an electric compressor.

The electric compressor includes a compressing section, an electric motor, an inverter, and a housing. The compression section compresses the refrigerant. The electric motor drives the compression section. The inverter drives the electric motor. The housing has a cylindrical motor housing and an inverter housing. The motor housing accommodates the electric motor and defines a suction chamber into which refrigerant is sucked. The inverter housing forms an inverter housing chamber that houses the inverter.

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 Literature 1, each electrolytic capacitor is arranged such that the central axis, which is the longitudinal direction of the electrolytic capacitor, extends along the axial direction of the motor housing.

JP 2019-173656 A

Switching elements, coils, and electrolytic capacitors are examples of heat generating elements that generate heat during operation of the inverter. A heating element is cooled, for example, as follows. Heat from the heating element is transmitted to the housing. The housing is cooled by refrigerant sucked into the suction chamber. That is, the heat generating element is cooled by the refrigerant sucked into the suction chamber. Therefore, it is preferable that the heating element is arranged so as to be aligned with the suction chamber in the axial direction of the motor housing so as to facilitate heat exchange with the suction chamber.

When the central axis of the electrolytic capacitor extends along the axial direction of the motor housing as in Patent Document 1, the area of the electrolytic capacitor when viewed from the suction chamber is unlikely to increase. Therefore, it is easy to arrange the heating element so as to line up with the suction chamber in the axial direction of the motor housing. However, for example, when the circumferential surface of the electrolytic capacitor is arranged along the wall separating the suction chamber and the inverter housing chamber in the housing, that is, the axial direction of the electrolytic capacitor is arranged perpendicular to the axial direction of the motor housing. If so, the area of the electrolytic capacitor when viewed from the inhalation chamber tends 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 cooled than a heating element that is aligned with the suction chamber in the axial direction of the motor housing.

An electric compressor for solving the above problems includes a compression section that compresses a refrigerant, an electric motor that drives the compression section, an inverter that drives the electric motor, an electric motor, and the refrigerant. a housing having a cylindrical motor housing forming a suction chamber for inhalation and an inverter housing thermally connected to the motor housing and forming an inverter housing chamber for housing the inverter; 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 longitudinal central axes are parallel; The inner wall of the electrolytic capacitor has a recessed groove in a widening shape, and the holder has a plurality of the electrolytic capacitors arranged in each stage, and the electrolytic Capacitors are held in a stacked state, and the electrolytic capacitor is housed in the groove such that the cylindrical surface is thermally connected to the groove, and the interval widens in the direction in which the groove widens. This is the gist of it.

A holder holds a plurality of electrolytic capacitors, so that the electrolytic capacitors are arranged in a plurality of stages. Therefore, compared to the case where all electrolytic capacitors are arranged in a line, the area of the plurality of electrolytic capacitors when viewed from the suction chamber is reduced. Therefore, the heating element other than the electrolytic capacitor can be easily arranged in the inverter accommodating chamber so as to facilitate heat exchange with the suction chamber. As a result, compared to the case where all the electrolytic capacitors are arranged in a line, the cooling effect of the heating elements other than the electrolytic capacitors can be increased. Further, the electrolytic capacitor is thermally connected to the inner wall of the groove and thus the inverter housing chamber by being accommodated in the groove. Therefore, the contact area of the electrolytic capacitor with the inner wall can be increased compared to the case where the electrolytic capacitor is not accommodated in the groove. Therefore, the cooling effect of the electrolytic capacitor can be increased. As a result, the cooling effect of the inverter can be increased.

In the above electric compressor, 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 portion is provided in the wall portion, and the holder The electrolytic capacitors may be held so that a plurality of the electrolytic capacitors at a stage near the opening of the groove sandwich the electrolytic capacitor at a stage near the bottom of the groove in a radial direction of the motor housing.

In this configuration, a portion of the plurality of electrolytic capacitors on a stage near the opening of the groove and a portion of the electrolytic capacitor on a stage near the bottom of the groove overlap in the radial direction of the motor housing. Therefore, compared to the case where a plurality of electrolytic capacitors on a stage near the opening of the groove and electrolytic capacitors on a stage near the bottom of the groove are arranged so as not to overlap in the radial direction of the motor housing, the motor housing A plurality of capacitors can be miniaturized in the axial direction of .

In the above electric compressor, the inverter has a coil and a switching element that form an LC circuit together with the electrolytic capacitor, and the switching element, the coil, and the plurality of electrolytic capacitors are arranged in the axial direction of the motor housing. It may be fixed in the inverter housing chamber so as to be aligned with the suction chamber and thermally connected to the wall portion.

In this configuration, in addition to the electrolytic capacitor, the coil and the switching element are arranged in the inverter accommodating chamber so as to facilitate heat exchange with the suction chamber, so that the coil and the switching element can be easily cooled.

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

This configuration can shorten the distance between the leads of the electrolytic capacitor and the switching element. Therefore, the impedance between the electrolytic capacitor and the switching element can be reduced.

The present invention can increase the cooling effect of the inverter.

FIG. 6 is a cross-sectional view of the electric compressor taken along line 1-1 in FIG. 5; FIG. 4 is a perspective view of a first structure and a capacitor unit; FIG. 6 is a cross-sectional view of the electric compressor taken along line 3-3 in FIG. 5; It is a perspective view of a 1st structure, an inverter, and a 3rd structure. It is a front view of an inverter. It is a side view of a capacitor unit. It is a side view of a capacitor unit.

An embodiment embodying an electric compressor will be described below with reference to FIGS. 1 to 7. FIG. The electric compressor of this 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 compressing section 14 , an electric motor 15 and an inverter 16 . The housing 11 accommodates the shaft support member 12 , the rotary shaft 13 , the compression section 14 , the electric motor 15 and the inverter 16 . Compressor 14 compresses the refrigerant as a fluid. The electric motor 15 drives the compression section 14 by rotating the rotating shaft 13 . Inverter 16 drives electric motor 15 .

<Housing>
The housing 11 has a first structure 21 , a second structure 22 and a third structure 23 . The 1st structure 21, the 2nd structure 22, and the 3rd structure 23 are metal. Therefore, housing 11 is made of metal. In this embodiment, the first structure 21, the second structure 22, and the third structure 23 are made of aluminum.

The first structure 21 has a cylindrical motor housing 24 and a bottomed cylindrical inverter housing 25 . The inverter housing 25 is connected to the first axial end of the motor housing 24 . The inverter housing 25 is thermally connected with the motor housing 24 .

As shown in FIG. 2 , the inverter housing 25 has a bottom wall 26 and a peripheral wall 27 extending from the outer peripheral edge 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 extension portion 26b. The closing portion 26a is a portion that closes the opening positioned at the axial first end of the motor housing 24, and corresponds to a wall portion that closes one end of the motor housing 24 in the present invention. The extending portion 26 b is a portion located outside the outer peripheral surface 24 a of the motor housing 24 in the radial direction of the motor housing 24 . The extending portion 26 b has a first surface 261 and a second surface 262 . The first surface 261 and the second surface 262 are surfaces orthogonal to the axial direction of the motor housing 24 . The first surface 261 is 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 part of the outer surface of the inverter housing 25 .

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

As shown in FIG. 1, inverter housing 25 has bosses 29 . The boss 29 is a portion protruding toward the motor housing 24 from the closing portion 26a. The boss 29 has a bearing accommodating portion 29a. The bearing accommodating portion 29 a is a portion recessed from the tip end surface of the boss 29 . The bearing accommodating portion 29 a accommodates the first bearing 17 .

As shown in FIGS. 2 and 3, the inverter housing 25 has a protrusion 30. As shown in FIG. The projecting portion 30 is a portion projecting in the axial direction of the motor housing 24 from the first surface 281 of the bottom portion 28a. The tip surface of the projecting portion 30 is flush with the first surface 261 of the extending portion 26b. The projecting portion 30 has a groove portion 30a that is recessed in a widening shape. The groove portion 30 a is composed of two first grooves 31 and two second grooves 32 .

Here, the axial direction of the motor housing 24 is defined as the first direction. A direction perpendicular to the first direction is defined as a second direction. A direction perpendicular to both the first direction and the second direction is defined as a third direction. The second direction and the third direction respectively match the radial direction of the motor housing 24 .

Each first groove 31 and each second groove 32 extend along the second direction. Each groove 31, 32 is arranged in two stages in the first direction. The two first grooves 31 are provided at different stages from the two second grooves 32 in the first direction. The two first grooves 31 are located on the base end side of the projecting portion 30 . The two second grooves 32 are located on the tip side of the projecting portion 30 . In other words, the two first grooves 31 are positioned on the bottom 28a side of the recess 28 . The two second grooves 32 are positioned on the opening side of the recess 28 . The two first grooves 31 are arranged in the third direction. The two second grooves 32 are arranged in the third direction. In this embodiment, the two first grooves 31 are positioned between the two second grooves 32 in the third direction. In other words, the groove portion 30a of the present embodiment has a shape that widens toward the opening in the third direction from the bottom of the groove portion 30a.

As shown in FIG. 1, the second structure 22 is connected to a second axial end of the motor housing 24 . The second axial end of the motor housing 24 is the end of the motor housing 24 located axially opposite to the first end. The second structure 22 closes the opening located at the second axial end of the motor housing 24 .

As shown in FIG. 4 , the third structure 23 has a shape corresponding to the peripheral wall 27 of the inverter housing 25 . The third structure 23 is connected to the peripheral wall 27 of the inverter housing 25 . The third structure 23 closes the opening of the inverter housing 25 . The third structure 23 is thermally connected to the second structure 22 . An inner surface 23 a of the third structure 23 is a surface orthogonal to the axial direction of the motor housing 24 .

As shown in FIGS. 1 and 3, the inner surface of the inverter housing 25 and the inner surface 23a of the third structure 23 define an inverter housing chamber S1. In other words, the inner surface of the inverter housing 25 and the inner surface 23a of the third structure 23 are the inner walls of the inverter housing chamber S1.

As shown in FIG. 1, the housing 11 has an inlet 11a and an outlet 11b. The intake port 11 a is provided in the motor housing 24 . The suction port 11a is provided at a portion of the motor housing 24 that is 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 outlet 11 b is provided in the second structure 22 . A second end opposite to the first end of the external refrigerant circuit is connected to the discharge port 11b.

<Pivot member>
The pivot member 12 is housed within the 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.

A suction chamber S<b>2 is defined by the inner peripheral surface of the motor housing 24 , the shaft support member 12 , and the closed portion 26 a of the inverter housing 25 . The closing portion 26a separates the inverter housing 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 26 a and a portion of the third structure 23 are aligned with the suction chamber S<b>2 in the axial direction of the motor housing 24 .

<Rotating axis>
The rotary shaft 13 is accommodated within 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 a boss 29 via a first bearing 17 . The other end of the rotary shaft 13 is inserted through the shaft insertion hole 12 a of the shaft support member 12 . The other end of the rotary shaft 13 is rotatably supported by the shaft support member 12 via a second bearing 18 .

<Compressor>
Compressor 14 is housed within motor housing 24 . The compressing portion 14 is arranged between the axial support member 12 and the second structure 22 in the axial direction of the rotating shaft 13 . The compression unit 14 of this embodiment is of scroll type. The compression section 14 has a fixed scroll 14a and a movable scroll 14b. The fixed scroll 14 a is fixed to the inner peripheral surface of the motor housing 24 . The movable scroll 14b is arranged to face the fixed scroll 14a. A variable volume 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 through the communication hole 12b. A discharge chamber S<b>4 is defined by the fixed scroll 14 a and the inner surface of the second structure 22 . The compression chamber S3 and the discharge chamber S4 are communicated with each other.

<Electric motor>
The electric motor 15 is housed in the suction chamber S2. That is, the suction chamber S2 is also a motor accommodation 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 41 a is fixed to the rotating shaft 13 . A plurality of permanent magnets 41b are embedded in the rotor core 41a. Each permanent magnet 41b is provided at equal pitches in the circumferential direction of the rotor core 41a. Stator 42 surrounds rotor 41 . The stator 42 has a cylindrical stator core 42a and a motor coil 42b. The stator core 42 a is fixed to the inner peripheral 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 .

<Inverter>
As shown in FIGS. 4 and 5, the inverter 16 includes 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. have.

The three-phase switching element 61 performs 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 . A holder 72 holds a plurality of electrolytic capacitors 71 . A plurality of electrolytic capacitors 71 and coils 62 form an LC circuit. The LC circuit is a filter circuit for reducing noise contained in the input current from the outside. The three-phase switching element 61, coil 62, and electrolytic capacitor 71 are heating elements that generate heat when the inverter 16 operates. Each of the three-phase conductive members 64 is made of metal. A three-phase conductive member 64 electrically connects the electric motor 15 and the inverter 16 .

A configuration of the capacitor unit 63 will be described in detail.
As shown in FIGS. 6 and 7, each electrolytic capacitor 71 is cylindrical. Each electrolytic capacitor 71 has a cylindrical surface 710 as an outer peripheral surface. All the electrolytic capacitors 71 have the same outer diameter and axial dimension. The axial dimension of electrolytic capacitor 71 is larger than the outer diameter of electrolytic capacitor 71 . That is, the direction in which the central axis O of the 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 .

The holder 72 has two first capacitor housing portions 74 and two second capacitor housing portions 75 . Each first capacitor accommodating portion 74 and each second capacitor accommodating portion 75 are substantially cylindrical spaces. The axial direction of each first capacitor accommodating portion 74 and the axial direction of each second capacitor accommodating portion 75 match. One end in the axial direction of each first capacitor accommodating portion 74 and each second capacitor accommodating portion 75 is closed, and the other end is open.

The capacitor housing portions 74 and 75 are arranged in two stages in a direction perpendicular to the axial direction of the capacitor housing portions 74 and 75 . The two first capacitor housing portions 74 are arranged at different stages from the two second capacitor housing portions 75 in the direction perpendicular to the axial direction of the capacitor housing portions 74 and 75 .

The direction in which the capacitor accommodating portions 74 and 75 are arranged in two stages is defined as the thickness direction of the holder 72 . The thickness direction of the holder 72 is perpendicular to the axial direction of the capacitor accommodating portions 74 and 75 . A direction orthogonal to both the axial direction of the capacitor accommodating portions 74 and 75 and the thickness direction of the holder 72 is defined as the width direction of the holder 72 .

The two first capacitor accommodating portions 74 are arranged in the width direction of the holder 72 . The two second capacitor accommodating portions 75 are arranged in the width direction of the holder 72 . In this embodiment, the two first capacitor housing portions 74 are positioned between the two second capacitor housing portions 75 in the width direction of the holder 72 . The interval between the two second capacitor accommodating portions 75 is wider than the interval between the two first capacitor accommodating portions 74 .

Holder 72 has a window 76 . The windows 76 allow the capacitor housing portions 74 and 75 and the outside of the holder 72 to communicate with each other.
Each electrolytic capacitor 71 is accommodated in a first capacitor accommodating portion 74 or a second capacitor accommodating portion 75 . 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. there is When it is necessary to distinguish between the four electrolytic capacitors 71, the electrolytic capacitor 71 housed in the first capacitor housing portion 74 will be referred to as the first electrolytic capacitor 71a. Also, the electrolytic capacitor 71 housed in the second capacitor housing portion 75 is referred to as a second electrolytic capacitor 71b.

Each electrolytic capacitor 71 has a first portion 711 housed in the capacitor housing portions 74 and 75 and a second portion 712 protruding from the holder 72 . Lead wire 73 extends from first portion 711 . The lead wire 73 is drawn outside the holder 72 .

When 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 coincides with the axial direction of the capacitor accommodating portions 74 and 75 . The two first electrolytic capacitors 71 a and the two second electrolytic capacitors 71 b are arranged in two stages in the thickness direction of the holder 72 . The two first electrolytic capacitors 71 a are arranged in the width direction of the holder 72 . The two second electrolytic capacitors 71b are arranged in the width direction of the holder 72 . In this embodiment, the two first electrolytic capacitors 71 a are arranged between the two second electrolytic capacitors 71 b in the width direction of the holder 72 . The interval between the two second electrolytic capacitors 71b is wider than the interval between the two first electrolytic capacitors 71a. In other words, the holder 72 holds the electrolytic capacitors 71 in a stacked state such that a plurality of electrolytic capacitors 71 are arranged in each stage and the intervals between the electrolytic capacitors 71 in each stage are gradually increased.

As shown in FIG. 7 , the first electrolytic capacitor 71 a and the second electrolytic capacitor 71 b are arranged so as to partially overlap in the axial direction of the electrolytic capacitor 71 . Specifically, the first portion 711 of the first electrolytic capacitor 71a protrudes in the axial direction of the electrolytic capacitor 71 more than the first portion 711 of the second electrolytic capacitor 71b. The 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.

As shown in FIG. 6, the first electrolytic capacitor 71a and the second electrolytic capacitor 71b are arranged so as to partially overlap in the thickness direction of the holder 72. As shown in FIG. Specifically, one end of the first electrolytic capacitor 71 a in the thickness direction of the holder 72 is positioned between one end and the other end of the second electrolytic capacitor 71 b in the thickness direction of the holder 72 .

The first electrolytic capacitor 71 a and the second electrolytic capacitor 71 b are arranged so as to partially overlap in the width direction of the holder 72 . Specifically, one end of the first electrolytic capacitor 71 a in the width direction of the holder 72 is positioned between one end and the other end of the second electrolytic capacitor 71 b in the width direction of the holder 72 .

As shown in FIG. 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 plate thickness direction of the plate 65 . The second surface 65b is a surface located opposite to the first surface 65a. The plate 65 holds a three-phase switching element 61, a coil 62, a capacitor unit 63, and a three-phase conductive member 64 on a first surface 65a.

As shown in FIG. 5, the plate 65 has a through hole 65c penetrating through the plate 65 in the plate thickness direction.
In a state in which 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 form an electrolytic capacitor 71 are aligned along the axis of Each electrolytic capacitor 71 is arranged with one axial end of the electrolytic capacitor 71 facing the three-phase switching element 61 . As described above, the pair of lead wires 73 extends from one axial end of the electrolytic capacitor 71 . Therefore, the lead wire 73 extending from each electrolytic capacitor 71 is arranged between the electrolytic capacitor 71 and the three-phase switching element 61 in the axial direction of the electrolytic capacitor 71 . 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 .

As shown in FIG. 4, the plate 65 is placed over the circuit board 66 . The plate thickness direction of the plate 65 and the plate thickness direction of the circuit board 66 match. The outer shape of the circuit board 66 is larger than the outer shape of the plate 65 . The circuit board 66 has a portion that overlaps the plate 65 and a portion that protrudes beyond the plate 65 .

A second surface 65 b of the plate 65 faces the circuit board 66 . A portion of the holder 72 where the window 76 is formed faces the circuit board 66 via the through hole 65c of the plate 65. As shown in FIG. A portion of the first portion 711 of each electrolytic capacitor 71 faces the circuit board 66 via the window 76 and the through hole 65c.

The plate 65 is arranged between the three-phase switching element 61 , the coil 62 , the capacitor unit 63 , the three-phase conductive member 64 and the circuit board 66 . The three-phase switching element 61 , the coil 62 , the electrolytic capacitor 71 , and the three-phase conductive member 64 are mounted on the circuit board 66 through insertion holes (not shown) formed in the plate 65 .

As shown in FIGS. 1 and 3, the inverter 16 is accommodated in the inverter accommodation chamber S1. The inverter 16 is fixed inside the inverter housing chamber S1. The three-phase switching element 61, the coil 62, most of the capacitor unit 63, and the three-phase conductive member 64 are accommodated inside the recess 28 in the inverter accommodation chamber S1. The plate 65 and the circuit board 66 are accommodated outside the recess 28 in the inverter accommodation chamber S1. The three-phase switching element 61, the coil 62, the capacitor unit 63, the three-phase conductive member 64, the plate 65, and the circuit board 66 are arranged in this order in the axial direction of the motor housing 24. FIG.

As indicated by a two-dot chain line in FIG. 5 , a projection area A is defined as an area obtained by projecting the outer peripheral surface 24 a of the motor housing 24 in the axial direction of the motor housing 24 . Since the motor housing 24 of this embodiment is cylindrical, the projected area A is circular. A three-phase switching element 61 , a coil 62 , a capacitor unit 63 , and a three-phase conductive member 64 are located within the projection area A. FIG. Therefore, the three-phase switching element 61, the coil 62, the capacitor unit 63, and the three-phase conductive member 64 are aligned with the suction chamber S2 in the axial direction of the motor housing .

As shown in FIG. 1, the three-phase switching element 61 is thermally connected to the closing portion 26a through an insulating member 67. As shown in FIG. The coil 62 is arranged in contact with the closing portion 26a. The coil 62 is thermally connected to the closing portion 26a.

As shown in FIGS. 3 and 5, the electrolytic capacitor 71 is housed in the groove 30a. Specifically, the second portion 712 of the first electrolytic capacitor 71 a is accommodated within the first groove 31 . A second portion 712 of the second electrolytic capacitor 71 b is accommodated in the second groove 32 . By accommodating each electrolytic capacitor 71 in groove portion 30a, cylindrical surface 710 in second portion 712 is thermally connected to groove portion 30a. As described above, the groove portion 30a is formed in the projection portion 30. As shown in FIG. The projecting portion 30 is thermally connected to the closing portion 26a. That is, each electrolytic capacitor 71 is thermally connected to the closed portion 26a through the groove portion 30a and the projecting portion 30. As shown in FIG.

The thickness direction of the holder 72 matches the first direction. The axial direction of the electrolytic capacitor 71 matches the second direction. The width direction of the holder 72 matches 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 on the stage near the bottom of the groove 30a. The second electrolytic capacitor 71b is the electrolytic capacitor 71 on the stage near the opening of the groove portion 30a. The electrolytic capacitors 71 are arranged so that the interval between the electrolytic capacitors 71 in each stage becomes wider toward the widening direction of the groove portion 30a. The diverging direction of the groove 30a is the direction in which the width of the groove 30a widens in the third direction. The expanding direction of the groove portion 30a 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. there is

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 so that the two second electrolytic capacitors 71 b sandwich the two first electrolytic capacitors 71 a in the radial direction of the motor housing 24 . Therefore, a portion of the first electrolytic capacitor 71a in the first direction and a portion of the second electrolytic capacitor 71b in the first direction overlap in the third direction. A portion of the first electrolytic capacitor 71a in the second direction and a portion of the second electrolytic capacitor 71b in the second direction partially overlap in the first direction. Furthermore, a portion of the first electrolytic capacitor 71a in the third direction and a portion of the second electrolytic capacitor 71b in the third direction partially overlap in the first direction.

A portion of the circuit board 66 that protrudes beyond the plate 65 is housed between the extending portion 26 b of the inverter housing 25 and the third component 23 in the axial direction of the motor housing 24 . The plate 65 and circuit board 66 are fixed to the inverter housing 25 with bolts B. As shown in FIG.

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

The operation of this embodiment will be described.
The three-phase switching element 61, coil 62, and electrolytic capacitor 71 generate heat when the inverter 16 operates. The heat of each switching element 61 is transferred to the closing portion 26a through the insulating member 67. As shown in FIG. The heat of the coil 62 is directly transmitted to the closing portion 26a. The heat of each electrolytic capacitor 71 is transferred to the closed portion 26a through the projecting portion 30. As shown in FIG. The closing portion 26a is thermally connected to the suction chamber S2. Therefore, the closed portion 26a is cooled by the refrigerant sucked into the suction chamber S2. Thus, each switching element 61, each coil 62, and each electrolytic capacitor 71 are cooled by the refrigerant sucked into the suction chamber S2 through the closed portion 26a.

Effects of the present embodiment will be described.
(1) The holder 72 holds the plurality of 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 when viewed from the suction chamber S2 is reduced compared to the case where all the electrolytic capacitors 71 are arranged in a line. Therefore, the heat generating elements other than the electrolytic capacitor 71 can be easily arranged in the inverter housing chamber S1 so as to facilitate heat exchange with the suction chamber S2. As a result, compared to the case where all the electrolytic capacitors 71 are arranged in a line, the cooling effect of the heating elements other than the electrolytic capacitors 71 can be increased. Further, each electrolytic capacitor 71 is accommodated in the groove portion 30a, so that it is thermally connected to the groove portion 30a and the inner wall of the inverter housing chamber S1. Therefore, the contact area of the electrolytic capacitors 71 with the inner wall of the inverter housing chamber S1 can be increased compared to the case where each electrolytic capacitor 71 is not housed in the groove portion 30a. Therefore, the cooling effect of the electrolytic capacitor 71 can be increased. As a result, the cooling effect of inverter 16 can be increased.

(2) The holder 72 is configured so that the two second electrolytic capacitors 71b on the stage near the opening of the groove 30a sandwich the first electrolytic capacitor 71a on the stage near the bottom of the groove 30a in the radial direction of the motor housing 24. It holds a capacitor 71 . Therefore, part of the first electrolytic capacitor 71 a and part of the second electrolytic capacitor 71 b overlap in the radial direction of the motor housing 24 . Therefore, the size of the capacitor unit 63 can be reduced in the axial direction of the motor housing 24 compared to the case where the first electrolytic capacitor 71 a and the second electrolytic capacitor 71 b do not overlap in the radial direction of the motor housing 24 .

(3) The switching element 61, the coil 62, and the plurality of electrolytic capacitors 71 are fixed in the inverter housing 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 closed portion 26a. ing. In this case, in addition to the electrolytic capacitor 71, the switching element 61 and the coil 62 are arranged in the inverter housing chamber S1 so as to facilitate heat exchange with the suction chamber S2. Therefore, it is easy to cool the switching element 61 and the coil 62 .

(4) The electrolytic capacitor 71 is fixed in the inverter housing chamber S1 with one end facing the switching element 61 . A pair of lead wires 73 of the electrolytic capacitor 71 extend from one end of the electrolytic capacitor 71 . Therefore, the distance between the lead wire 73 of the electrolytic capacitor 71 and the switching element 61 can be shortened. Therefore, the impedance between the electrolytic capacitor 71 and the switching element 61 can be reduced.

(5) The blocking portion 26a is exposed to the suction chamber S2. Therefore, the cooling effect of the inverter 16 is increased as compared with the case where the closed portion 26a is not exposed to the suction chamber S2 and is thermally connected to another wall portion exposed to the suction chamber S2.

(6) The holder 72 holds the plurality of electrolytic capacitors 71 such that a portion of the first electrolytic capacitors 71a in the second direction and a portion of the second electrolytic capacitors 71b in the second direction overlap in the first direction. ing. Therefore, compared to the case where the entirety of the first electrolytic capacitor 71a in the second direction and the entirety of the second electrolytic capacitor 71b in the second direction overlap in the first direction, the lead wire 73 extending from the first electrolytic capacitor 71a It is easy to ensure insulation from the lead wire 73 extending from the second electrolytic capacitor 71b.

This embodiment can be implemented with the following modifications. This embodiment and modifications can be implemented in combination with each other within a technically consistent range.
(circle) the structure of the housing 11 may be changed suitably. 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 be configured as follows.

The motor housing 24 has a peripheral wall and an end wall that closes an opening positioned at one axial end of the peripheral wall. An 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 arranged such that the closing portion 26 a is adjacent to the end wall of the motor housing 24 . The closing portion 26 a 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 through the end wall of the motor housing 24. As shown in FIG.

Note that, in the case of the above configuration, the projecting portion 30 having the groove portion 30 a may be formed so as to project from the end wall of the motor housing 24 toward the inverter housing 25 . The protruding portion 30 is arranged in the inverter housing chamber S1 via a through hole penetrating through the closing portion 26a. In this case, since 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, the cooling effect of the inverter 16 is further increased.

The groove portion 30a may be recessed in a widening shape in the surface of the inner surface 23a of the third structure 23 in which the suction chamber S2 and the motor housing 24 are aligned in the axial direction instead of the closing portion 26a.

(circle) the surface in which the groove part 30a is provided in the inner wall of the inverter accommodating chamber S1 does not need to be orthogonal as long as it crosses the axial direction of the motor housing 24. As shown in FIG.
(circle) the motor housing 24 does not need to be cylindrical as long as it is cylindrical. The motor housing 24 may have, for example, a square tubular shape.

(circle) the inverter housing 25 does not need to have the recessed part 28. FIG. 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 projecting portion 30 may be formed on a surface flush with the first surface 261 of the extending portion 26b of the closing portion 26a. Also, instead of forming the projecting portion 30, the groove portion 30a may be formed in a surface flush with the first surface 261 of the extending portion 26b of the closing portion 26a.

(circle) the recessed part 28 may be provided around the first bearing 17 . That is, a portion of inverter 16 may be arranged around first bearing 17 . In this case, the dead space of the suction chamber S<b>2 is used as an inverter housing chamber, so that the electric compressor 10 can be made smaller in the axial direction of the motor housing 24 .

O The holder 72 may hold a plurality of electrolytic capacitors 71 so that the electrolytic capacitors 71 are stacked in three or more stages according to the number of the electrolytic capacitors 71 . In this case also, the holder 72 holds the electrolytic capacitors 71 such that a plurality of electrolytic capacitors 71 are arranged in each stage, and the intervals between the electrolytic capacitors 71 in each stage are gradually widened for each stage.

O The holder 72 may hold three or more first electrolytic capacitors 71a in the third direction. Thus, when three or more electrolytic capacitors 71 are arranged in one row, the distance between the central axes O of the electrolytic capacitors 71 positioned at both ends is defined as the interval between the electrolytic capacitors 71 in the present invention.

O The holder 72 may hold a plurality of electrolytic capacitors 71 so that the electrolytic capacitors 71 positioned in different stages do not overlap in the radial direction of the motor housing 24 .
O The holder 72 may hold a plurality of electrolytic capacitors 71 such that the entirety of the electrolytic capacitors 71 positioned in different stages in the second direction overlap in the first direction. In this case, holder 72 holds a plurality of electrolytic capacitors 71 so as to ensure insulation between lead wires 73 of electrolytic capacitors 71 positioned in different stages. For example, the holder 72 holds the plurality of electrolytic capacitors 71 such that the lead wire 73 of the second electrolytic capacitor 71b is positioned opposite to the lead wire 73 of the first electrolytic capacitor 71a with the electrolytic capacitor 71 interposed therebetween.

O The electrolytic capacitor 71 may not be arranged so that one axial end of the lead wire 73 extends toward the switching element 61 . That is, lead wire 73 extending from electrolytic capacitor 71 does not have to be positioned between electrolytic capacitor 71 and switching element 61 .

(circle) the compression part 14 is not limited to a scroll type. The compression part 14 may be of a piston type, a vane type, or the like, for example.
(circle) the electric compressor 10 may be used for uses other than a vehicle air conditioner. For example, the electric compressor 10 may be mounted on a fuel cell vehicle. The electric compressor 10 is used to compress air, which is a fluid to be supplied to the fuel cell, using the compression section 14 .

DESCRIPTION OF SYMBOLS 10... Electric compressor, 11... Housing, 14... Compression part, 15... Electric motor, 16... Inverter, 24... Motor housing, 25... Inverter housing, 26a... Closing part as a wall part, 30a... Groove part, 61... Switching Elements 62 Coil 71 Electrolytic capacitor 72 Holder 73 Lead wire 710 Cylindrical surface O Central axis S1 Inverter chamber S2 Suction chamber.

Claims (4)

a compression section that compresses the 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 accommodation chamber that accommodates the inverter. a housing;
with
The inverter has a plurality of electrolytic capacitors having cylindrical surfaces and a holder that holds the electrolytic capacitors,
The electrolytic capacitors are attached to the holder so that their longitudinal central axes are parallel to each other,
The inner wall of the inverter housing chamber has a groove portion that is recessed in a widening 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 gradually widened for each stage,
The electric compressor, wherein the electrolytic capacitor is housed in the groove such that the cylindrical surface is thermally connected to the groove, and the interval widens in a direction in which the groove widens. 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 so that a plurality of the electrolytic capacitors on a stage near the opening of the groove sandwich the electrolytic capacitor on a stage near the bottom of the groove in a radial direction of the motor housing. 1. The electric compressor according to 1. The inverter has a coil and a switching element that form an LC circuit together with the electrolytic capacitor, and the switching element, the coil, and the plurality of electrolytic capacitors are aligned with the suction chamber in the axial direction of the motor housing. 3. The electric compressor according to claim 2, wherein the electric compressor is fixed inside the inverter accommodating chamber so as to be thermally connected to the wall. 4. The electric compressor according to claim 3, wherein said electrolytic capacitor is fixed in said inverter housing chamber with one end facing said switching element, and a pair of lead wires of said electrolytic capacitor extend from said one end.

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