Electric compressor

Abstract

The present invention relates to an electric compressor capable of improving heat dissipation performance. The conductor has a first metal plate and a second metal plate. The first metal plate has a main body portion disposed on the opposite side from the second metal plate with respect to the pair of windings, and a pair of extension portions extending from the main body portion toward the second metal plate. The second metal plate has a pair of facing portions facing each of the pair of extending portions, and a connecting portion connecting the pair of facing portions to each other. The conductor has a welding portion in which the facing portion is welded to the extending portion. A groove in which the welding part and the connecting part are disposed is formed in the housing. The groove is provided with a heat dissipation member for transmitting heat generated from the welding part and the connecting part to the housing. The induction current flows through the welding part and the connecting part arranged in the groove.

Description

Technical Field

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

[0002] An electric compressor includes a housing, a compressor, a motor, and an inverter. The housing houses the compressor, motor, and inverter. The compressor compresses the fluid. The motor drives the compressor. The inverter is housed in the metal housing and drives the motor.

[0003] The inverter device includes an inverter circuit unit and a noise reduction unit. The inverter circuit unit converts direct current into alternating current. The noise reduction unit is provided on the input side of the inverter circuit unit. The noise reduction unit reduces common-mode noise and normal-mode noise contained in the direct current input to the inverter circuit unit. The noise reduction unit includes a common-mode choke coil and a smoothing capacitor that together with the common-mode choke coil forms a low-pass filter. The common-mode choke coil includes an annular core, a pair of windings wound around the core, and an annular conductor surrounding both sides of the pair of windings. The conductor is configured so that an induced current flows circumferentially to hinder changes in leakage magnetic flux from the core.

[0004] For example, in the electric compressor disclosed in Japanese Patent Application Laid-Open No. 2021-168561, a ring-shaped metal plate serving as a conductor includes a first metal plate and a second metal plate divided along the circumference of the metal plate. The first metal plate includes a main body and a pair of upright portions bent so as to extend from the opposite ends of the main body. A through-hole is formed in the main body of the first metal plate.

[0005] The second metal plate includes a main body and a pair of bent upright portions extending from the opposite ends of the main body. Furthermore, the main body and upright portions of the second metal plate are positioned between the upright portions at the distal ends of the pair of upright portions of the first metal plate. The upright portions of the first and second metal plates are welded to each other, thereby forming the metal plates into a ring shape.

[0006] The main body of the first metal plate is arranged in contact with the housing and is positioned between the housing and the pair of windings. Furthermore, a heat dissipation member is positioned within the through-hole of the main body. The second metal plate is electrically connected to the first metal plate and is positioned between the circuit substrate and the pair of windings. Summary of the Invention

[0007] Problems to be solved by the invention

[0008] In the aforementioned publication, when an induced current flows in the circumferential direction of the metal plates, the metal plates heat up. This also heats the welded portion where the upright portions of the first and second metal plates are welded together. The second metal plate, placed between the welded portions, transfers heat from the welded portion, easily reaching a high temperature.

[0009] Means for solving problems

[0010] An electric compressor according to one embodiment of the present disclosure includes a compressor configured to compress a fluid; an electric motor configured to drive the compressor; an inverter configured to drive the electric motor; and a metal housing that houses the compressor, electric motor, and inverter. The inverter includes an inverter circuit configured to convert direct current (DC) into alternating current (AC); and a noise reduction unit disposed on the input side of the inverter circuit and configured to reduce common-mode noise and normal-mode noise contained in the DC power input to the inverter circuit. The noise reduction unit includes a common-mode choke coil and a smoothing capacitor that, together with the common-mode choke coil, forms a low-pass filter. The common-mode choke coil includes an annular core; a pair of windings wound around the core; and a conductor, an annular conductor surrounding both of the pair of windings, configured to allow induced current to flow in the circumferential direction to counteract changes in leakage magnetic flux from the core. The conductor includes a first metal plate and a second metal plate. The first metal plate includes: a main body portion, which is arranged on the opposite side of the second metal plate relative to the pair of windings; and a pair of extension portions, which extend from the main body portion toward the second metal plate. The second metal plate includes: a pair of opposing portions, which are respectively opposed to the pair of extension portions, and a connecting portion, which connects the pair of opposing portions to each other. The conductor includes a welding portion where the opposing portion is welded to the extension portion. The housing is formed with a groove for arranging the welding portion and the connecting portion. A heat sink is provided in the groove to transfer heat generated from the welding portion and the connecting portion to the housing. The induced current flows in the welding portion and the connecting portion arranged in the groove. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 It is a partially cutaway cross-sectional view showing the electric compressor.

[0012] Figure 2 yes Figure 1 Circuit diagram of the electric motor of the electric compressor.

[0013] Figure 3 It shows Figure 1 A top view of the groove of the end wall portion of the electric compressor.

[0014] Figure 4 It shows Figure 1 A three-dimensional diagram of the common-mode choke coil and conductors of an electric compressor.

[0015] Figure 5 It shows Figure 1 Exploded perspective view of the common mode choke coil and conductors of an electric compressor.

[0016] Figure 6 It shows Figure 1 Top view of the common-mode choke coil and conductor of the electric compressor.

[0017] Figure 7 It shows Figure 1 A cross-sectional view of a portion of an electric compressor.

[0018] Figure 8 It shows Figure 1 A cross-sectional view of a portion of an electric compressor. DETAILED DESCRIPTION

[0019] The following, according to Figures 1 to 8 An embodiment in which an electric compressor is embodied will be described. The electric compressor of this embodiment is used in, for example, a vehicle-mounted air conditioner.

[0020] like Figure 1 As shown, a vehicle air conditioner 10 includes an electric compressor 11 and an external refrigerant circuit 12. The external refrigerant circuit 12 includes a heat exchanger and an expansion valve (not shown). The vehicle air conditioner 10 cools and heats the vehicle interior by compressing a refrigerant (a fluid) via the electric compressor 11 and performing heat exchange and expansion of the refrigerant via the external refrigerant circuit 12.

[0021] The vehicle air conditioning system 10 includes an air conditioning ECU 13 that controls the entire vehicle air conditioning system 10. The air conditioning ECU 13 monitors the vehicle interior temperature and the target temperature set by the user. Based on parameters such as the vehicle interior temperature and the target temperature, the air conditioning ECU 13 sends various commands, such as on / off commands, to the electric compressor 11.

[0022] <Electric compressor>

[0023] The electric compressor 11 includes a housing 14 , a rotating shaft 17 , a compression unit 18 that compresses refrigerant, an electric motor 19 that drives the compression unit 18 , and an inverter device 30 that drives the electric motor 19 .

[0024] The housing 14 is made of a heat-conductive metal (eg, aluminum) and is in contact with the vehicle body.

[0025] The housing 14 includes an intake housing member 15, an exhaust housing member 16, and an inverter housing member 25, which are mounted on each other. The intake housing member 15 is cylindrical with one end closed. The intake housing member 15 includes a plate-shaped end wall portion 15a and a peripheral wall portion 15b that rises cylindrically from the peripheral edge of the end wall portion 15a toward the exhaust housing member 16.

[0026] like Figure 3 As shown, a groove 151 is formed in the end wall 15a of the suction housing member 15. The groove 151 is recessed from the outer surface 15c of the end wall 15a. The groove 151 is in the shape of a rectangular frame and has a pair of long grooves 151a and a pair of short grooves 151b.

[0027] The groove 151 is defined by a pair of inner side surfaces 151d and an inner bottom surface 151c serving as the bottom surface of the groove 151. The pair of inner side surfaces 151d are connected to the outer surface 15c of the end wall portion 15a, and the inner bottom surface 151c is connected to each inner side surface 151d. The shortest distance between the pair of inner side surfaces 151d is defined as the opening width W. The opening width W at the long groove portion 151a of the groove 151 is the same as the opening width W at the short groove portion 151b. In addition, as Figure 7 and Figure 8 As shown, the depth F of the groove 151 is the same at the long groove portion 151a and the short groove portion 151b. It should be noted that the depth F of the groove 151 is the shortest distance from the outer surface 15c of the end wall portion 15a to the inner bottom surface 151c of the groove 151.

[0028] like Figure 1 As shown, the discharge housing member 16 is assembled to the suction housing member 15 in a state of closing the opening of the suction housing member 15. Thus, an internal space is formed in the housing 14.

[0029] The housing 14 has a suction port 14a for drawing refrigerant from the external refrigerant circuit 12. The suction port 14a is formed in a peripheral wall portion 15b of the suction housing member 15. The housing 14 has a discharge port 14b for discharging refrigerant to the external refrigerant circuit 12. The discharge port 14b is formed in the discharge housing member 16.

[0030] The inverter housing member 25 is cylindrical and closed at one end. The inverter housing member 25 is attached to the end wall 15a using bolts 26, with its open end abutting against the end wall 15a. The opening of the inverter housing member 25 is sealed by the end wall 15a. The inverter housing member 25 and the end wall 15a form a storage chamber So.

[0031] A connector 27 is attached to the inverter case member 25. The connector 27 is electrically connected to a storage device 28 mounted on the vehicle. The storage device 28 is a DC power source mounted on the vehicle, such as a secondary battery, a capacitor, or the like.

[0032] The housing 14 houses the rotating shaft 17, the compression unit 18, and the electric motor 10. Furthermore, the housing chamber So of the housing 14 houses the inverter device 30. Therefore, the housing 14 houses the compression unit 18, the electric motor 19, and the inverter device 30.

[0033] The rotating shaft 17 is supported in a rotatable state with respect to the housing 14. The rotating shaft 17 is arranged so that the axial direction of the rotating shaft 17 coincides with the plate thickness direction of the end wall portion 15a.

[0034] The compression unit 18 compresses the refrigerant drawn from the suction port 14a and discharges the compressed refrigerant from the discharge port 14b by the rotation of the rotary shaft 17. The compression unit 18 may be of any structure such as a scroll type, a piston type, or a vane type.

[0035] The electric motor 19 is arranged between the compression section 18 and the end wall section 15a in the axial direction of the rotating shaft 17. The electric motor 19 drives the compression section 18 by rotating the rotating shaft 17. The electric motor 19 has a rotor 20 fixed to the rotating shaft 17 and a stator 21 fixed to the housing 14. The stator 21 has a cylindrical stator core 22, a u-phase coil 23u, a v-phase coil 23v, and a w-phase coil 23w wound around the stator core 22. The stator core 22 is fixed to the inner circumferential surface of the peripheral wall section 15b of the suction housing member 15. The u-phase coil 23u, the v-phase coil 23v, and the w-phase coil 23w are, for example, Y-connected. The connection method of the u-phase coil 23u, the v-phase coil 23v, and the w-phase coil 23w is not limited to Y-connection, and can also be, for example, delta connection.

[0036] The rotor 20 rotates by energizing the u-phase coil 23u, the v-phase coil 23v, and the w-phase coil 23w in a predetermined pattern. Rotating the rotor 20 rotates the rotary shaft 17, thereby driving the compression unit 18.

[0037] <Inverter unit>

[0038] like Figure 1 As shown in FIG. 3 , the inverter device 30 includes an inverter circuit unit 31 and a noise reduction unit 32. Figure 2 The control unit 33 and the holder 39 are shown. The inverter circuit unit 31 converts direct current into alternating current.

[0039] like Figure 1 As shown in FIG. 1 , the circuit board 29 included in the inverter circuit unit 31 is plate-shaped and is disposed at a predetermined distance from the end wall 15 a in the axial direction of the rotation shaft 17 .

[0040] The retainer 39 is made of resin. It is positioned between the circuit board 29 and the end wall 15a of the suction housing member 15. The retainer 39 includes a plate portion 39a and a cylindrical portion 39b. The thickness of the plate portion 39a coincides with the thickness of the circuit board 29. The cylindrical portion 39b extends from the plate portion 39a toward the end wall 15a.

[0041] The inverter circuit unit 31 is held by the plate portion 39a of the holder 39 and is mounted on the circuit board 29. The inverter circuit unit 31 includes two connection lines EL1 and EL2.

[0042] like Figure 2 As shown, the inverter circuit unit 31 includes u-phase switching elements Qu1 and Qu2 corresponding to the u-phase coil 23u, v-phase switching elements Qv1 and Qv2 corresponding to the v-phase coil 23v, and w-phase switching elements Qw1 and Qw2 corresponding to the w-phase coil 23w. Each switching element Qu1-Qw2 is a power switching element such as an IGBT. It should be noted that each switching element Qu1-Qw2 has a freewheeling diode (body diode) Du1-Dw2.

[0043] The u-phase switching elements Qu1 and Qu2 are connected in series via a connecting line connected to the u-phase coil 23u. The series connection of the u-phase switching elements Qu1 and Qu2 is electrically connected to the connecting lines EL1 and EL2, and DC power from the storage device 28 is input to the series connection.

[0044] It should be noted that the other switching elements Qv1 , Qv2 , Qw1 , and Qw2 have the same connection method as the u-phase switching elements Qu1 and Qu2 , except that the corresponding coils are different.

[0045] The control unit 33 controls the switching operation of each switching element Qu1-Qw2. The control unit 33, as a processing circuit, can be implemented, for example, by one or more dedicated hardware circuits and / or one or more processors operating according to a computer program. A processor includes a CPU and memory such as RAM and ROM. The memory stores, for example, program code or instructions that cause the processor to perform various processes. Memory, or computer-readable media, includes all available media that can be accessed by a general-purpose or special-purpose computer.

[0046] The control unit 33 is electrically connected to the air conditioning ECU 13 via the connector 27. Based on commands from the air conditioning ECU 13, the control unit 33 periodically turns on and off each switching element Qu1 to Qw2. Specifically, based on the commands from the air conditioning ECU 13, the control unit 33 performs pulse width modulation control (PWM control) on each switching element Qu1 to Qw2. More specifically, the control unit 33 generates a control signal using a carrier signal (carrier signal) and a command voltage value signal (comparison target signal). The control unit 33 then uses the generated control signal to turn on and off each switching element Qu1 to Qw2, thereby converting DC power into AC power.

[0047] like Figure 1As shown, the noise reduction unit 32 is provided on the input side of the inverter circuit unit 31. The noise reduction unit 32 reduces the common mode noise and normal mode noise contained in the direct current input to the inverter circuit unit 31. Specifically, the noise reduction unit 32 includes a common mode choke coil 34 mounted on the circuit substrate 29 and a smoothing capacitor 35 that forms a low-pass filter together with the common mode choke coil 34. In addition, the noise reduction unit 32 includes a conductor 80 and two Y capacitors 37 and 38. The low-pass filter is provided on the connecting lines EL1 and EL2. The low-pass filter is provided between the connector 27 and the inverter circuit unit 31 in the circuit.

[0048] like Figure 2 As shown, a common-mode choke coil 34 is provided on the two connecting lines EL1 and EL2. A smoothing capacitor 35 is provided between the common-mode choke coil 34 and the inverter circuit unit 31. Smoothing capacitor 35 is electrically connected to the two connecting lines EL1 and EL2. Common-mode choke coil 34 and smoothing capacitor 35 form an LC resonant circuit. In other words, the low-pass filter of this embodiment is an LC resonant circuit including the common-mode choke coil 34.

[0049] The two Y capacitors 37 and 38 are connected in series. A bypass line EL3 connecting one end of the Y capacitor 37 and one end of the other Y capacitor 38 is connected to the ground of the vehicle body.

[0050] Furthermore, a series connection of two Y capacitors 37 and 38 is provided between the common mode choke coil 34 and the smoothing capacitor 35 , and is electrically connected to the common mode choke coil 34 .

[0051] Common Mode Choke Coils

[0052] The common-mode choke coil 34 suppresses the high-frequency noise generated on the vehicle side from being transmitted to the inverter circuit unit 31 of the electric compressor 11. The common-mode choke coil 34 reduces the common-mode noise. In addition, the common-mode choke coil 34 uses leakage inductance as normal-mode inductance. Thus, the common-mode choke coil 34 is used as the L component in a low-pass filter for removing normal-mode noise, so-called differential-mode noise. That is, the common-mode choke coil 34 can cope with common-mode noise and normal-mode noise. Therefore, the electric compressor 11 does not use a common-mode choke coil and a normal-mode choke coil separately, but uses a common-mode choke coil 34 to cope with two-mode noise.

[0053] like Figure 4 and Figure 5 As shown, the common mode choke coil 34 includes a ring-shaped core 50, an insulating member 60 that houses the core 50, a pair of windings 70 wound around the core 50 with the insulating member 60 interposed therebetween, and a ring-shaped conductor 80 surrounding both sides of the pair of windings 70. The core 50 is an endless ring. The conductor 80 is configured to allow an induction current to flow in the circumferential direction, thereby resisting changes in the leakage magnetic flux from the core 50.

[0054] A pair of windings 70 are wound around an insulating member 60 that houses a core 50. The pair of windings 70 are surrounded by a conductor 80. The core 50 is made of a ferromagnetic material. For example, the core 50 is a ferrite core. In the following description, one of the pair of windings 70 may be referred to as a first winding 701, and the other as a second winding 702.

[0055] like Figure 6 As shown, the core 50 is in an oblong ring shape and has a pair of straight portions 51 and a pair of arc portions 52 .

[0056] In the following description, one of the pair of straight portions 51 may be referred to as a first straight portion 511 and the other as a second straight portion 512 . Also, one of the pair of arc portions 52 may be referred to as a first arc portion 521 and the other as a second arc portion 522 .

[0057] Each straight portion 51 extends in a straight line. A pair of straight portions 51 extend parallel to each other. Each arc portion 52 extends in an arc shape. The pair of arc portions 52 connect the corresponding ends of the pair of straight portions 51. Specifically, the first arc portion 521 connects one end of the first straight portion 511 and one end of the second straight portion 512, and the second arc portion 522 connects the other end of the first straight portion 511 and the other end of the second straight portion 512.

[0058] like Figure 7 and Figure 8 As shown, the core 50 has a first end face 50a and a second end face 50b. The first end face 50a is one end face of the core 50 in the axial direction, and the second end face 50b is the other end face of the core 50 in the axial direction.

[0059] Of the pair of windings 70 , the first winding 701 is wound around the first straight portion 511 , and the second winding 702 is wound around the second straight portion 512 .

[0060] like Figure 7 As shown, each of the pair of windings 70 has a central axis L of the winding 70 at the center of the winding. The extending direction of the central axis L is defined as the axial direction Y of the winding 70. The pair of windings 70 are wound around the core 50 so that the central axes L are parallel to each other. The pair of windings 70 are arranged in a parallel arrangement direction X. The parallel arrangement direction X coincides with the direction in which the pair of straight portions 51 are arranged. Therefore, the common mode choke coil 34 includes a pair of windings 70 wound around the core 50 and arranged in the parallel arrangement direction X.

[0061] like Figure 5 and Figure 6As shown, each winding 70 has a first coil portion 71 wound around the straight portion 51. In the present embodiment, each winding 70 is also wound around a portion of a pair of arc portions 52. Each winding 70 has a pair of second coil portions 72 wound around the pair of arc portions 52. The pair of second coil portions 72 are located on both sides of the first coil portion 71. Each winding 70 has a pair of lead portions 73 drawn out from the second end surface 50b of the core 50. The core 50 has a non-winding portion 53 around which the winding 70 is not wound. The non-winding portion 53 in the present embodiment is the portion of each arc portion 52 around which the winding 70 is not wound.

[0062] The insulating member 60 includes a pair of core insulating portions 61 , a winding insulating portion 62 , and four connecting portions 63 .

[0063] Each core insulating portion 61 is annular. A pair of core insulating portions 61 covers the portion of the core 50 around which the windings 70 are wound. Each core insulating portion 61 includes a first covering portion 61a that covers the entirety of each straight portion 51, and a second covering portion 61b located on both sides of the first covering portion 61a and covering a portion of the pair of arc portions 52. The pair of windings 70 are wound around the core 50 to which the insulating member 60 is attached. The pair of core insulating portions 61 are sandwiched between the core 50 and the pair of windings 70. The pair of core insulating portions 61 insulate the pair of windings 70 from the core 50. The non-wound portion 53 of the core 50 is not covered by the insulating member 60.

[0064] The winding insulation portion 62 is flat and located inside the core 50. It is interposed between the first winding 701 and the second winding 702. The winding insulation portion 62 insulates the first winding 701 from the second winding 702. The winding insulation portion 62 is larger in the axial direction of the core 50 than the axial dimensions of each winding 70.

[0065] The four connecting portions 63 connect the pair of core insulating portions 61 and the winding insulating portion 62. The pair of core insulating portions 61 and the winding insulating portion 62 are integrated by the four connecting portions 63.

[0066] like Figure 7 and Figure 8 As shown, the insulating member 60 is composed of a first split body 60a and a second split body 60b that are split into two parts along the axial direction of the core 50. The first split body 60a is assembled to the core 50 so as to cover the first end face 50a of the core 50. The second split body 60b is assembled to the core 50 so as to cover the second end face 50b of the core 50.

[0067] Conductors

[0068] like Figure 4 and Figure 7 As shown, the conductor 80 is annular. In other words, the conductor 80 is an endless ring. Figure 5As shown, the conductor 80 includes a first metal plate 81 and a second metal plate 92, which are divided in a direction perpendicular to the axial direction Y of the winding 70 and the parallel arrangement direction X. The first metal plate 81 and the second metal plate 92 are made of brass with a tinned surface. The tin plating is for corrosion resistance. The thickness of the first metal plate 81 is constant. The thickness of the second metal plate 92 is constant. The thickness of the first metal plate 81 and the thickness of the second metal plate 92 can be the same or different.

[0069] The first metal plate 81 includes a main body 83 and a pair of extensions 84. The main body 83 is rectangular. The pair of extensions 84 extend from both ends of the main body 83 in the thickness direction of the main body 83. The pair of extensions 84 extend parallel to each other. Each extension 84 is rectangular. The first metal plate 81 is formed by stamping a single metal plate.

[0070] Each extension 84 includes a connecting plate portion 85 at its front end. The connecting plate portion 85 is formed in the center of the extension 84 in the short-side direction. The connecting plate portion 85 extends from the front end of the extension 84 in parallel with the extension 84. The connecting plate portion 85 has a connecting plate portion outer surface 85a and a connecting plate portion inner surface 85b located on opposite sides of each other in the plate thickness direction. The connecting plate portion outer surface 85a is also the outer surface of the extension 84, and the connecting plate portion inner surface 85b is also the inner surface of the extension 84.

[0071] The second metal plate 92 is shaped as a quadrilateral frame. It includes a pair of rectangular opposing portions 94 and a pair of rectangular connecting portions 93 that connect the opposing portions 94. The opposing portions 94 face each other in the thickness direction, and the connecting portions 93 face each other in the thickness direction. The central axis of the quadrilateral frame formed by the second metal plate 92 extends in a direction that coincides with the short sides of the connecting portions 93 and the opposing portions 94. Therefore, the second metal plate 92 is shaped as a quadrilateral frame, including a pair of opposing portions 94 and a pair of connecting portions 93 that connect the opposing portions 94. Each opposing portion 94 has an opposing portion outer surface 94a and an opposing portion inner surface 94b that are located on opposite sides of the opposing portion 94 in the thickness direction. Each connecting portion 93 has a connecting portion outer surface 93a and a connecting portion inner surface 93b that are located on opposite sides of the connecting portion 93 in the thickness direction. The connecting portion outer surface 93 a and the facing portion outer surface 94 a form the outer surface of the second metal plate 92 , and the connecting portion inner surface 93 b and the facing portion inner surface 94 b form the inner surface of the second metal plate 92 .

[0072] like Figure 7As shown, the second metal plate 92 is located between the connecting plate portions 85 of the pair of extensions 84 of the first metal plate 81. The direction in which the pair of extensions 84 extend from the main body 83 is the same as the short-side direction of the connecting portion 93 and the opposing portion 94. The pair of opposing portions 94 overlap with the connecting plate portions 85 of the corresponding extensions 84. Furthermore, the pair of opposing portions 94 are welded to the connecting plate portions 85 of the corresponding extensions 84. Specifically, the opposing portion outer surface 94a of the opposing portion 94 and the connecting plate portion inner surface 85b of the connecting plate portion 85 are welded to each other. Therefore, the conductor 80 has a welded portion 99 formed by welding the opposing portion 94 and the extension 84 to each other. In this embodiment, the pair of opposing portions 94 and the pair of extensions 84 are respectively joined to each other by resistance welding. Therefore, the conductor 80 is integrated by the pair of extensions 84 and the corresponding opposing portions 94 being joined to each other, and is formed into a rectangular frame shape when viewed from the front. The pair of connection portions 93 extends along the parallel arrangement direction X between the pair of extension portions 84 .

[0073] The conductor 80 surrounds both sides of the pair of windings 70. Furthermore, in the conductor 80, the first metal plate 81 includes a main body 83 disposed on the opposite side of the pair of windings 70 from the second metal plate 92, and a pair of extensions 84 extending from the main body 83 toward the second metal plate 92. Furthermore, in the conductor 80, the second metal plate 92 includes a pair of opposing portions 94 that oppose the connecting plate portions 85 of the pair of extensions 84, respectively, and at least one connecting portion 93 that connects the pair of opposing portions 94.

[0074] like Figure 8 As shown, a pair of connecting parts 93 have a connecting part outer surface 93a and a connecting part inner surface 93b that are orthogonal to the axial direction Y extending from the central axis L of each winding 70. The pair of connecting parts 93 are separated from each other in the axial direction Y of the winding 70. Therefore, the first coil portion 71 of a pair of windings 70 is exposed from between the pair of connecting parts 93 toward the outer surface 15c of the end wall portion 15a. In addition, the pair of connecting parts 93 are arranged at the boundary corresponding to the first coil portion 71 and the pair of second coil portions 72. Therefore, the entirety of each first coil portion 71 faces the outer surface 15c of the end wall portion 15a. It should be noted that the pair of connecting parts 93 are separated from each other in the axial direction Y, and the position of the pair of connecting parts 93 can be appropriately changed.

[0075] Furthermore, the pair of opposing portions 94 connect the pair of connecting portions 93 to each other in the axial direction Y. Therefore, the second metal plate 92 has a quadrilateral frame shape having a pair of connecting portions 93 separated in the axial direction Y and a pair of opposing portions 94 connecting the pair of connecting portions 93 to each other in the axial direction Y.

[0076] like Figure 3 and Figure 8As shown, the plate thickness D1 of each connecting portion 93 is smaller than the opening width W of the long groove portion 151a of the groove 151. The plate thickness D1 is approximately 1 / 10 of the opening width W, but this ratio can be arbitrarily changed. In addition, the dimension G of each connecting portion 93 in the short-side direction is smaller than the depth F of the long groove portion 151a of the groove 151.

[0077] In addition, if Figure 3 and Figure 7 As shown, the total thickness D2 of the connecting plate portion 85 and the opposing portion 94 is smaller than the opening width W of the short groove portion 151b of the groove 151. In addition, the dimension G of the opposing portion 94 in the short side direction is smaller than the depth F of the short groove portion 151b of the groove 151.

[0078] like Figure 7 As shown, viewing the conductor 80 along the axial direction Y of the winding 70 is referred to as the front view of the conductor 80. In the front view, the conductor 80 has a quadrilateral frame shape. The direction in which the central axis of the quadrilateral frame formed by the conductor 80 extends is defined as the axial direction of the conductor 80. The axial direction of the conductor 80 coincides with the direction in which the pair of straight portions 51 of the core 50 extend, and also coincides with the axial direction Y of the winding 70.

[0079] The pair of straight portions 51 of the core 50 and the first coil portion 71 of each winding 70 are located inside the quadrilateral frame of the conductor 80. The pair of arc portions 52 of the core 50 and the pair of second coil portions 72 of each winding 70 are located on either side of the axis of the conductor 80. In other words, the pair of arc portions 52 of the core 50 and the pair of second coil portions 72 of each winding 70 are located outside the conductor 80.

[0080] <Common mode choke coil placement>

[0081] The axial direction of the core 50 coincides with the thickness direction of the plate portion 39a and the axial direction of the cylindrical portion 39b. The first end face 50a of the core 50 faces the end wall portion 15a of the suction housing member 15. The second end face 50b of the core 50 faces the plate portion 39a. The pair of lead portions 73 of each winding 70 penetrates the plate portion 39a. These lead portions 73 are soldered to the circuit board 29, for example. This electrically connects the common mode choke coil 34 to the circuit board 29.

[0082] The common mode choke coil 34 and the conductor 80 are housed in a space surrounded by the plate portion 39 a and the cylindrical portion 39 b of the holder 39 between the circuit board 29 and the end wall portion 15 a of the housing 14 .

[0083] The main body 83 of the conductor 80 is sandwiched between the first coil portion 71 of the pair of windings 70 and the plate portion 39a. The portion of each core insulating portion 61 that covers the first end surface 50a of the core 50 is located on the opposite side of the circuit substrate 29 relative to the first coil portion 71 of each winding 70. A pair of extensions 84 of the conductor 80 extend from the main body 83 toward the end wall portion 15a, further outward of the pair of windings 70 in the side-by-side arrangement direction X, and cover the pair of windings 70 from the outside of the side-by-side arrangement direction X. A pair of connecting plate portions 85 extend from the corresponding extensions 84 toward the end wall portion 15a of the suction housing member 15. The second metal plate 92 is located between the first coil portion 71 of the pair of windings 70 and the end wall portion 15a.

[0084] like Figure 7 and Figure 8 As shown, the groove 15 formed in the end wall portion 15a is in the shape of a quadrilateral frame that opens toward the second metal plate 92. In other words, the groove 151 is in the shape of a quadrilateral frame that opens toward the common mode choke coil 34. In addition, the groove 151 is filled with heat dissipation grease 56 as a heat sink. The second metal plate 92 is inserted into the groove 151. Specifically, a pair of connecting portions 93 are inserted into the corresponding long groove portions 151a, and a pair of connecting plate portions 85 of the opposing portions 94 and the extension portion 84 are inserted into the corresponding short groove portions 151b. Therefore, the welding portion 99 between the opposing portions 94 and the extension portion 84 is inserted into the short groove portion 151b. The length direction and the plate thickness direction of the connecting portion 93 are respectively consistent with the length direction and the short side direction of the long groove portion 151a. In addition, the length direction and the plate thickness direction of the opposing portion 94 are respectively consistent with the length direction and the short side direction of the short groove portion 151b. The width of the long groove portion 151 a along the short side direction and the width of the short groove portion 151 b along the short side direction are consistent with the opening width W of the groove 151 .

[0085] Heat dissipation grease 56 is provided between the first coil portion 71 and the second coil portion 72 of each winding 70 and the end wall portion 15a. Heat dissipation grease 56 is provided inside the quadrilateral frame formed by the second metal plate 92. Thus, the heat dissipation grease 56 electrically insulates the winding 70 from the end wall portion 15a, and thus the housing 14, while enabling heat transfer between the winding 70 and the end wall portion 15a.

[0086] In the following description, of the pair of inner side surfaces 151d of groove 151, the inner side surface 151d located on the outer periphery of groove 151 is referred to as first inner side surface 151d1, and the inner side surface 151d located on the inner periphery of groove 151 is referred to as second inner side surface 151d2. First inner side surface 151d1 faces connecting portion outer surface 93a, opposing portion outer surface 94a, and connecting plate portion outer surface 85a. Second inner side surface 151d2 faces connecting portion inner surface 93b and opposing portion inner surface 94b.

[0087] Heat dissipating grease 56 is interposed between the first inner side surface 151d1 and the connecting portion outer surface 93a, and between the second inner side surface 151d2 and the connecting portion inner surface 93b, respectively. Therefore, the connecting portion 93 is inserted into the groove 151 so that both surfaces in the plate thickness direction face the pair of inner side surfaces 151d of the groove 151 with the heat dissipating grease 56 interposed therebetween, and are spaced apart from the pair of inner side surfaces 151d.

[0088] Heat dissipation grease 56, serving as a heat sink, is interposed between the first inner side surface 151d1 and the connecting plate portion outer surface 85a, and between the second inner side surface 151d2 and the opposing portion inner surface 94b. Therefore, the connecting plate portion 85 and the opposing portion 94 are inserted into the groove 151 so as to face and be spaced apart from the pair of inner side surfaces 151d of the groove 151 via the heat dissipation grease 56. Consequently, the heat dissipation grease 56 is also inserted into the weld 99 between the extension portion 84 and the opposing portion 94.

[0089] like Figure 3 As shown, the second metal plate 92 is inserted into the groove 151 so that the shortest distances between the first inner side surface 151d1 and the connecting portion outer surface 93a, and between the second inner side surface 151d2 and the connecting portion inner surface 93b, are both the first distance M1. The second metal plate 92 is inserted into the groove 151 so that the shortest distances between the first inner side surface 151d1 and the connecting plate portion outer surface 85a, and between the second inner side surface 151d2 and the opposing portion inner surface 94b, are both the second distance M2. The opening width W of the groove 151 is the same at all positions within the groove 151. Therefore, the second distance M2 is smaller than the first distance M1.

[0090] In addition, if Figure 8 As shown, the shortest distance between the first coil portion 71 of the winding 70 and the outer surface 15c of the end wall portion 15a is defined as the spacing distance N. The first distance M1 and the second distance M2 are each less than the spacing distance N. Therefore, the connecting portion outer surface 93a and the connecting portion inner surface 93b are respectively arranged closer to the end wall portion 15a than the first coil portion 71. Similarly, the connecting plate portion outer surface 85a, the opposing portion outer surface 94a, and the opposing portion inner surface 94b are respectively arranged closer to the end wall portion 15a than the first coil portion 71.

[0091] The second metal plate 92 is inserted into the groove 151 so that the connecting portion 93 is located at the center of the short side of the long groove portion 151a. Therefore, the first distance M1 is the same on both sides of the connecting portion 93. Furthermore, the second metal plate 92 is inserted into the groove 151 so that the connecting plate portion 85 and the opposing portion 94 are located at the center of the short side of the short groove portion 151b. Therefore, the second distance M2 is the same on both sides of the connecting plate portion 85 and the opposing portion 94.

[0092] [Effects of Implementation Methods]

[0093] The effects of the embodiment will be described.

[0094] The noise reduction unit 32 includes a conductor 80 surrounding a pair of windings 70 of the common-mode choke coil 34. When a normal-mode current flows through the pair of windings 70, leakage magnetic flux is generated from the core 50. Consequently, in the conductor 80, an induced current flows in the circumferential direction of the conductor 80 to counteract changes in the leakage magnetic flux from the core 50. That is, the induced current flows through the first metal plate 81 and the second metal plate 92. Therefore, the induced current also flows through the weld 99, the connecting portion 93, and the opposing portion 94. Furthermore, the induced current flowing through the conductor 80 is converted into heat energy, thereby producing a damping effect. As a result, the resonance peak of the low-pass filter is suppressed.

[0095] When the induced current flows through the conductor 80, the conductor 80 generates heat. Specifically, the first metal plate 81 and the second metal plate 92 of the conductor 80 generate heat, and the weld 99 also generates heat. The heat generated in the weld 99 is transferred from the opposing portion 94 to the connecting portion 93. Therefore, when the induced current flows through the conductor 80, heat is generated from the weld 99 and the connecting portion 93.

[0096] Heat generated from weld 99 is transferred from the connecting plate outer surface 85a and the opposing portion inner surface 94b, respectively, via heat dissipation grease 56, to the inner side surface 151d defining the short groove 151b. Furthermore, heat generated from connection portion 93 is transferred from the connection portion outer surface 93a and the connection portion inner surface 93b, respectively, via heat dissipation grease 56, to the inner side surface 151d defining the long groove 151a. Therefore, groove 151 is formed in suction housing member 15 for positioning weld 99 and connection portion 93. Heat dissipation grease 56 is provided in groove 151 to transfer heat generated from weld 99 and connection portion 93 to suction housing member 15. Furthermore, an induced current flows through weld 99 and connection portion 93, which are positioned in groove 151.

[0097] When current flows through the pair of windings 70 , the pair of windings 70 generates heat. The heat of the first coil portions 71 of the pair of windings 70 is transferred to the suction housing member 15 via the heat dissipating grease 56 .

[0098] [Effects of this embodiment]

[0099] The effects of this embodiment will be described.

[0100] (1) The welded portion 99 and the connecting portion 93 of the conductor 80 are arranged in the groove 151 of the suction housing member 15, and the heat dissipation grease 56 is provided in the groove 151. When the induced current flows through the conductor 80 and causes the conductor 80 to heat up, the welded portion 99 also generates heat, and the heat is also transferred to the connecting portion 93 connected to the welded portion 99. The heat generated from the welded portion 99 and the connecting portion 93 is dissipated to the suction housing member 15 via the heat dissipation grease 56. Therefore, the electric compressor 11 can improve the heat dissipation performance of the conductor 80 formed by joining the first metal plate 81 and the second metal plate 92 at the welded portion 99.

[0101] (2) The second metal plate 92 is in the shape of a quadrilateral frame having a pair of opposing portions 94 and a pair of connecting portions 93 that connect the pair of opposing portions 94 to each other. For example, compared to a case where the connecting portion 93 is a single piece, the area over which heat can be dissipated from the connecting portion 93 is increased. Thus, compared to a case where the connecting portion 93 is a single piece, the heat dissipation performance of the second metal plate 92 can be improved.

[0102] (3) The first distance M1 and the second distance M2 from the second metal plate 92 to the pair of inner side surfaces 151 d of the groove 151 are each set to be smaller than the spacing distance N from the winding 70 to the end wall portion 15 a of the suction housing member 15. This improves the heat dissipation effect from the second metal plate 92 and, by extension, the welded portion 99 and the connecting portion 93 to the end wall portion 15 a.

[0103] (4) The connecting portion 93 is inserted into the groove 151 so that the first distance M1 between the connecting portion and the inner side surface 151d of the groove 151 is the same on both sides in the plate thickness direction. Therefore, the heat generated from the connecting portion 93 can be dissipated uniformly from both the connecting portion outer surface 93a and the connecting portion inner surface 93b to the corresponding inner side surface 151d of the groove 151. In addition, due to component tolerances, etc., there is a case where the first distance M1 between the first inner side surface 151d1 and the connecting portion outer surface 93a and the first distance M1 between the second inner side surface 151d2 and the connecting portion inner surface 93b are different. Even in this case, the surface of the connecting portion outer surface 93a and the connecting portion inner surface 93b where the first distance M1 is set smaller can be used to compensate for the reduction in heat dissipation performance due to the surface where the first distance M1 is set larger, so that heat can be dissipated efficiently from the connecting portion 93.

[0104] (5) The connecting plate portion 85 and the opposing portion 94 are inserted into the groove 151 so that the second distance M2 between the connecting plate portion outer surface 85a and the first inner side surface 151d1 and the second distance M2 between the opposing portion inner surface 94b and the second inner side surface 151d2 are the same. Therefore, heat generated from the weld 99 can be dissipated uniformly from both the connecting plate portion outer surface 85a and the opposing portion inner surface 94b to the corresponding inner side surface 151d of the groove 151. In addition, due to component tolerances, etc., there is a case where the second distance M2 between the first inner side surface 151d1 and the connecting plate portion outer surface 85a and the second distance M2 between the second inner side surface 151d2 and the opposing portion inner surface 94b are different. Even in this case, the surface of the connecting plate portion outer surface 85a or the opposing portion inner surface 94b with the smaller second distance M2 can be used to compensate for the reduction in heat dissipation performance caused by the surface with the larger second distance M2, thereby enabling efficient heat dissipation from the weld 99.

[0105] (6) The second metal plate 92 is in the shape of a quadrilateral frame having a pair of opposing portions 94 and a pair of connecting portions 93. For example, compared to a case where the second metal plate 92 and the pair of opposing portions 94 are connected by a single connecting portion 93, the strength of the second metal plate 92 can be increased, and thus the strength of the conductor 80 can also be increased.

[0106] [Change Example]

[0107] The embodiment and the following modified examples can be implemented in combination with each other within the scope of no technical contradiction.

[0108] The heat sink may be a structure other than the heat dissipation grease 56 , for example, heat dissipation paste, heat dissipation filler, etc. may be used.

[0109] The connecting portion 93 may be inserted into the groove 151 so that the first distance M1 is different on both sides in the plate thickness direction. The connecting plate portion 85 and the facing portion 94 may be inserted into the groove 151 so that the second distance M2 is different on both sides in the plate thickness direction.

[0110] The conductor 80 may be made of an aluminum plate, a stainless steel plate, or the like in addition to the brass plate.

[0111] The connecting plate portion 85 may not be formed in the extension portion 84 .

[0112] The first distance M1 and the second distance M2 from the second metal plate 92 to the inner side surface 151 d of the groove 151 may be equal to or greater than the spacing distance N from the winding 70 to the end wall portion 15 a of the suction housing member 15 .

[0113] The groove 151 and the second metal plate 92 do not need to be rectangular frames. For example, the second metal plate 92 may have an H-shaped configuration, including a pair of opposing portions 94 and a connecting portion 93 connecting the pair of opposing portions 94. In this case, the groove 151 is formed by a pair of first groove-forming portions, which accommodate the pair of opposing portions 94 and the connecting plate portion 85, and a second groove-forming portion, which connects the pair of groove-forming portions and extends linearly to accommodate the connecting portion 93.

[0114] Alternatively, the second metal plate 92 may have a shape including a pair of opposing portions 94 and three or more connecting portions 93 connecting the pair of opposing portions 94. In this case, the groove 151 is formed by a pair of first groove-forming portions for accommodating the pair of opposing portions 94 and the connecting plate portion 85, and a second groove-forming portion connecting the pair of groove-forming portions and extending linearly so as to accommodate the three or more connecting portions 93.

Claims

1. An electric compressor comprising: a compression portion configured to compress the fluid; an electric motor configured to drive the compression unit; an inverter device configured to drive the electric motor; and a metal housing that houses the compression unit, the electric motor, and the inverter device; in, The inverter device comprises: an inverter circuit unit configured to convert direct current into alternating current; and a noise reduction unit provided on the input side of the inverter circuit unit and configured to reduce common mode noise and normal mode noise included in the direct current input to the inverter circuit unit; The noise reduction unit includes: Common mode choke coils; and a smoothing capacitor, which together with the common mode choke coil constitutes a low-pass filter, The common mode choke coil has: annular core; a pair of windings wound around the core; as well as A conductor is a ring-shaped conductor surrounding both sides of the pair of windings, the conductor being configured to allow an induced current to flow in a circumferential direction so as to resist changes in leakage magnetic flux from the core. The conductor has a first metal plate and a second metal plate, The first metal plate has: a main body portion disposed on a side opposite to the second metal plate with respect to the pair of windings; and a pair of extensions extending from the main body toward the second metal plate, The second metal plate has: a pair of opposing portions, which are respectively opposed to the pair of extending portions; as well as a connecting portion connecting the pair of opposing portions to each other, The conductor has a welding portion for welding the opposing portion to the extending portion. The housing is formed with a groove for arranging the welding portion and the connecting portion. The groove is provided with a heat sink for transferring heat generated from the welding portion and the connecting portion to the housing. The induced current flows through the weld portion and the connecting portion arranged in the groove.

2. The electric compressor according to claim 1, wherein The connecting portion is one of a pair of connecting portions, The second metal plate is in a quadrilateral frame shape having a pair of the opposing portions and a pair of connecting portions connecting the pair of the opposing portions to each other. The groove is in the shape of a quadrilateral frame opening toward the second metal plate. The second metal plate is disposed in the groove.

3. The electric compressor according to claim 1 or claim 2, wherein: The shortest distance between the second metal plate and an inner side surface of the slot is smaller than the shortest distance between the winding wire and the housing.

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