Electric compressor

Abstract

To provide an electric compressor capable of improving heat radiation performance of a conductor in which a first metal plate and a second metal plate are joined by a welding unit.SOLUTION: A conductor 80 includes a plate-shaped first metal plate 81 and a plate-shaped second metal plate 92. The first metal plate 81 has a main body portion 83 disposed with a pair of windings 70 interposed therebetween with respect to the second metal plate 92 and a pair of extension portions 84 extending from the main body portion 83 toward the second metal plate 92. The second metal plate 92 includes a pair of facing portions 94 respectively facing the pair of extending portions 84, and a coupling portion 93 coupling the pair of facing portions 94. The facing portion 94 and the extending portion 84 have a welded portion 99 to be welded to each other, a welded portion 99 and the coupling portion 93 are disposed in a bottom wall portion 15a, and a groove 151 is formed in which heat dissipation grease 56 for transferring heat generated from the welded portion 99 and the coupling portion 93 to the bottom wall portion 15a is provided. An induced current flows through the welded portion 99 and the coupling portion 93 disposed in the groove 151.SELECTED DRAWING: Figure 7

Description

[Technical Field]

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

[0002] The electric compressor has a housing, a compression unit, a motor, and an inverter device. The housing accommodates the compression unit, the motor, and the inverter device. The compression unit compresses the fluid. The motor drives the compression unit. The inverter device is accommodated in a metal housing. The inverter device drives the motor.

[0003] The inverter device has an inverter circuit unit and a noise reduction unit. The inverter circuit unit converts DC power into AC power. 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 DC power input to the inverter circuit unit. The noise reduction unit has 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 has an annular core, a pair of windings wound around the core, and an annular conductor that surrounds both of the pair of windings and allows an induced current to flow circumferentially to resist changes in leakage magnetic flux from the core.

[0004] For example, in an electric compressor disclosed in Patent Document 1, an annular metal plate serving as a conductor has a first metal plate and a second metal plate divided in the circumferential direction of the metal plate. The first metal plate has a main body portion and a pair of upright portions formed by bending the main body portion and extending from both ends of the main body portion. A through hole is formed in the main body portion of the first metal plate.

[0005] The second metal plate has a main body and a pair of bent upright portions extending from both ends of the main body. The upright portions of the second metal plate are disposed between the pair of upright portions of the first metal plate on the tip side of the pair of upright portions. The upright portions of the first metal plate and the second metal plate are welded together, forming the metal plate into a ring shape.

[0006] The first metal plate is disposed with the main body in contact with the housing and is disposed between the housing and the pair of windings. A heat dissipation member is disposed within the through hole of the main body. The second metal plate is electrically connected to the first metal plate and is disposed between the circuit board, the core, and the pair of windings. [Prior art documents] [Patent documents]

[0007] [Patent Document 1] Patent Publication No. 2021-168561 Summary of the Invention [Problem to be solved by the invention]

[0008] In Patent Document 1, when an induced current flows in the circumferential direction of a metal plate, the metal plate generates heat. At this time, the welded portion between the upright portions of the first metal plate and the second metal plate also generates heat, and the second metal plate spanning the welded portion is easily heated to a high temperature due to the heat transferred from the welded portion. [Means for solving the problem]

[0009] An electric compressor that solves the above problem includes a compression unit that compresses a fluid, an electric motor that drives the compression unit, an inverter device that drives the electric motor, and a metal housing that houses the compression unit, the electric motor, and the inverter device, wherein the inverter device includes an inverter circuit unit that converts DC power to AC power, and a noise reduction unit that is provided on the input side of the inverter circuit unit and reduces common mode noise and normal mode noise contained in the DC power input to the inverter circuit unit, and the noise reduction unit includes a common mode choke coil and a smoothing capacitor that forms a low pass filter together with the common mode choke coil, and the common mode choke coil includes an annular core, a pair of windings wound around the core, and a smoothing capacitor that surrounds both of the pair of windings and is arranged on the core. and a conductor formed in a ring shape so that an induced current flows circumferentially to resist changes in leakage magnetic flux from a housing, the conductor having a first metal plate and a second metal plate, the first metal plate having a main body portion arranged relative to the second metal plate with the pair of windings sandwiched therebetween, and a pair of extending portions extending from the main body toward the second metal plate, the second metal plate having a pair of opposing portions facing the pair of extending portions respectively, and a connecting portion connecting the pair of opposing portions, the opposing portions and the extending portions having welded portions welded to each other, the housing having grooves in which the welded portions and the connecting portions are arranged and in which heat dissipation material is provided to transfer heat generated from the welded portions and the connecting portions to the housing, the induced current flows through the welded portions and the connecting portions arranged in the grooves.

[0010] According to this, an induced current flows through the conductor, resisting the change in leakage magnetic flux from the core, causing the conductor to heat up. At this time, the welded portion also heats up, and the heat from the welded portion is transferred to the connecting portion connected to the welded portion. The heat generated from the welded portion and the connecting portion is released to the housing via the heat dissipation material. As a result, the electric compressor can improve the heat dissipation performance of the conductor, which is made by joining the first metal plate and the second metal plate at the welded portion.

[0011] In the above electric compressor, the second metal plate may be a rectangular frame having a pair of the opposing portions and a pair of connecting portions that respectively connect the pair of opposing portions, the groove may be a rectangular frame that opens toward the second metal plate, and the second metal plate may be disposed in the groove.

[0012] This increases the heat dissipation area of the second metal plate compared to when the second metal plate has only one connecting portion, thereby improving heat dissipation performance compared to when the second metal plate has only one connecting portion, for example.

[0013] In the electric compressor, the shortest distance between the second metal plate and an inner side surface of the groove may be smaller than the shortest distance between the winding and the housing. This improves the heat dissipation performance from the second metal plate to the groove compared to when the shortest distance between the second metal plate and the inner surface of the groove is greater than the shortest distance between the winding and the end face of the housing. [Effects of the Invention]

[0014] The present invention can improve the heat dissipation performance of a conductor in which a first metal plate and a second metal plate are joined at a welded portion. [Brief explanation of the drawings]

[0015] [Figure 1] FIG. 1 is a partially cutaway cross-sectional view showing an electric compressor. [Figure 2] FIG. 2 is a circuit diagram of the electric motor. [Figure 3] FIG. 3 is a plan view showing the grooves in the bottom wall portion. [Figure 4] FIG. 4 is a perspective view showing the common mode choke coil and the conductor. [Figure 5] FIG. 5 is an exploded perspective view showing the common mode choke coil and the conductor. [Figure 6] FIG. 6 is a plan view showing the common mode choke coil and the conductor. [Figure 7] FIG. 7 is a cross-sectional view showing a part of the electric compressor. [Figure 8] FIG. 8 is a cross-sectional view showing a part of the electric compressor. DETAILED DESCRIPTION OF THE INVENTION

[0016] An embodiment of an electric compressor will now be described with reference to Figures 1 to 8. The electric compressor of this embodiment is used in, for example, an air conditioner for a vehicle. 1, the vehicle air conditioner 10 has an electric compressor 11 and an external refrigerant circuit 12. The external refrigerant circuit 12 has a heat exchanger and an expansion valve (not shown). The vehicle air conditioner 10 cools or heats the interior of the vehicle by compressing a refrigerant as a fluid by the electric compressor 11 and then exchanging heat and expanding the refrigerant by the external refrigerant circuit 12.

[0017] The vehicle air conditioner 10 has an air conditioning ECU 13 that controls the entire vehicle air conditioner 10. The air conditioning ECU 13 grasps the vehicle interior temperature, the set temperature of the car air conditioner, etc. The air conditioning ECU 13 transmits various commands, such as ON / OFF commands, to the electric compressor 11 based on parameters such as the vehicle interior temperature and the set temperature of the car air conditioner.

[0018] <Electric compressor> The electric compressor 11 has a housing 14, a rotary shaft 17, a compression section 18 that compresses the refrigerant, an electric motor 19 that drives the compression section 18, and an inverter device 30 that drives the electric motor 19.

[0019] The housing 14 is made of a metal such as aluminum, which is a heat-conductive material, and is grounded to the body of the vehicle. The housing 14 includes an assembled suction housing 15, a discharge housing 16, and an inverter housing 25. The suction housing 15 is cylindrical and has a bottom that opens in one direction. The suction housing 15 includes a plate-shaped bottom wall 15a and a cylindrical side wall 15b that extends from the periphery of the bottom wall 15a toward the discharge housing 16.

[0020] 3, a groove 151 recessed from an outer surface 15c of bottom wall 15a is formed in bottom wall 15a of suction housing 15. Groove 151 has a rectangular frame shape. Groove 151 has a pair of long groove portions 151a and a pair of short groove portions 151b.

[0021] The groove 151 is defined by an inner side surface 151d connected to the outer surface 15c of the bottom wall 15a, and an inner bottom surface 151c connected to the inner side surface 151d and forming the bottom surface of the groove 151. The shortest distance between the inner sides 151d facing each other in the lateral direction of the groove 151 is defined as the opening width W. The opening width W of each long groove portion 151a is the same as the opening width W of each short groove portion 151b in the lateral direction. Furthermore, as shown in FIGS. 7 and 8, the depth F of the groove 151 is the same for the long groove portion 151a and the short groove portion 151b. The depth F of the groove 151 is the shortest distance from the outer surface 15c of the bottom wall 15a to the inner bottom surface 151c of the groove 151.

[0022] 1, discharge housing 16 is assembled to suction housing 15 in a state where it closes the opening of suction housing 15. This forms an internal space within housing 14.

[0023] The housing 14 is formed with an intake port 14a through which refrigerant is drawn from the external refrigerant circuit 12. The intake port 14a is formed in a side wall portion 15b of the intake housing 15. The housing 14 is formed with a discharge port 14b through which refrigerant is discharged to the external refrigerant circuit 12. The discharge port 14b is formed in the discharge housing 16.

[0024] The inverter housing 25 is cylindrical and has a bottom that opens toward the bottom wall 15a of the suction housing 15. The inverter housing 25 is attached to the bottom wall 15a with bolts 26, with the open end abutting against the bottom wall 15a. The opening of the inverter housing 25 is closed by the bottom wall 15a. The accommodation chamber So is formed by the inverter housing 25 and the bottom wall 15a.

[0025] A connector 27 is attached to the inverter housing 25. The connector 27 is electrically connected to an electric storage device 28 mounted on the vehicle. The electric storage device 28 is a DC power source mounted on the vehicle, such as a secondary battery or a capacitor.

[0026] The housing 14 accommodates a rotating shaft 17, a compression unit 18, and an electric motor 19. The housing 14 also accommodates an inverter device 30 in an accommodation chamber So. Therefore, the housing 14 accommodates the compression unit 18, the electric motor 19, and the inverter device 30 inside.

[0027] The rotary shaft 17 is supported in a rotatable state relative to the housing 14. The rotary shaft 17 is disposed such that the axial direction of the rotary shaft 17 coincides with the thickness direction of the bottom wall portion 15a. Compression section 18 compresses the refrigerant drawn in through suction port 14a by rotation of rotary shaft 17, and discharges the compressed refrigerant from discharge port 14b. Compression section 18 may have any configuration, such as a scroll type, a piston type, or a vane type.

[0028] The electric motor 19 is disposed between the compression unit 18 and the bottom wall 15a in the axial direction of the rotary shaft 17. The electric motor 19 drives the compression unit 18 by rotating the rotary shaft 17. The electric motor 19 includes a rotor 20 fixed to the rotary shaft 17 and a stator 21 fixed to the housing 14. The stator 21 includes a cylindrical stator core 22 and 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 side wall 15b of the suction housing 15. The u-phase coil 23u, the v-phase coil 23v, and the w-phase coil 23w are wound around the stator core 22. The u-phase coil 23u, the v-phase coil 23v, and the w-phase coil 23w are, for example, Y-connected. The connection of the u-phase coil 23u, the v-phase coil 23v, and the w-phase coil 23w is not limited to a Y connection, but may be, for example, a delta connection.

[0029] The rotor 20 rotates when current is applied in a predetermined pattern to the u-phase coil 23u, the v-phase coil 23v, and the w-phase coil 23w. When the rotor 20 rotates, the rotary shaft 17 rotates, thereby driving the compression unit 18.

[0030] <Inverter device> As shown in Fig. 1, the inverter device 30 includes an inverter circuit unit 31 and a noise reduction unit 32. The inverter device 30 also includes a control unit 33 and a holder 39 shown in Fig. 2. The inverter circuit unit 31 converts DC power into AC power.

[0031] 1, the circuit board 29 provided in the inverter circuit unit 31 is plate-shaped and is disposed opposite the bottom wall portion 15a in the axial direction of the rotary shaft 17 with a predetermined gap therebetween.

[0032] The holder 39 is made of resin. The holder 39 is disposed between the circuit board 29 and the bottom wall 15a of the suction housing 15. The holder 39 has a plate-shaped portion 39a and a cylindrical portion 39b. The thickness direction of the plate portion 39a coincides with the thickness direction of the circuit board 29. The cylindrical portion 39b extends cylindrically from the plate portion 39a toward the bottom wall 15a.

[0033] The inverter circuit section 31 is held by a plate section 39a of a holder 39, and is mounted on the circuit board 29. The inverter circuit section 31 has two connection lines EL1 and EL2.

[0034] 2, 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 of the switching elements Qu1 to Qw2 is a power switching element such as an IGBT. Each of the switching elements Qu1 to Qw2 includes freewheeling diodes (body diodes) Du1 to Dw2.

[0035] The u-phase switching elements Qu1, Qu2 are connected in series to each other via connection lines, which are connected to the u-phase coil 23u. The series connection of the u-phase switching elements Qu1, Qu2 is electrically connected to both connection lines EL1, EL2, and DC power is input to the series connection from the power storage device 28.

[0036] The other switching elements Qv1, Qv2, Qw1, and Qw2 are connected in the same manner as the u-phase switching elements Qu1 and Qu2, except that the corresponding coils are different.

[0037] The control unit 33 controls the switching operation of each of the switching elements Qu1 to Qw2. The control unit 33 can be realized, for example, by one or more dedicated hardware circuits and / or one or more processors operating according to a computer program. The processor includes a CPU and memory such as RAM and ROM. The memory stores, for example, program code or instructions configured to cause the processor to perform various processes. The memory, i.e., computer-readable medium, includes any available medium that can be accessed by a general-purpose or special-purpose computer.

[0038] The control unit 33 is electrically connected to the air conditioning ECU 13 via the connector 27. The control unit 33 periodically turns on / off each of the switching elements Qu1 to Qw2 based on a command from the air conditioning ECU 13. Specifically, the control unit 33 performs pulse width modulation control (PWM control) on each of the switching elements Qu1 to Qw2 based on a command from the air conditioning ECU 13. More specifically, the control unit 33 generates a control signal using a carrier signal (carrier wave signal) and a command voltage value signal (comparison signal). Then, the control unit 33 converts DC power to AC power by performing ON / OFF control on each of the switching elements Qu1 to Qw2 using the generated control signal.

[0039] As shown in FIG. 1 , the noise reduction unit 32 is provided on the input side of the inverter circuit unit 31 and reduces common-mode noise and normal-mode noise contained in the DC power input to the inverter circuit unit 31. Specifically, the noise reduction unit 32 includes a common-mode choke coil 34 mounted on the circuit board 29 and a smoothing capacitor 35 that, together with the common-mode choke coil 34, forms a low-pass filter. The noise reduction unit 32 also includes a conductor 80 and two Y capacitors 37 and 38. The low-pass filter is provided on the connection lines EL1 and EL2. The low-pass filter is provided between the connector 27 and the inverter circuit unit 31 in terms of the circuit.

[0040] As shown in Fig. 2, the common mode choke coil 34 is provided on both connection lines EL1 and EL2. The smoothing capacitor 35 is provided on the inverter circuit unit 31 side of the common mode choke coil 34. The smoothing capacitor 35 is electrically connected to both connection lines EL1 and EL2. The common mode choke coil 34 and the 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.

[0041] The two Y capacitors 37 and 38 are connected in series. A bypass line EL3 connecting one end of the Y capacitor 37 to one end of the other Y capacitor 38 is grounded to the vehicle body.

[0042] Furthermore, the series connection of the two Y capacitors 37 and is provided between the common mode choke coil and the smoothing capacitor 35, and is electrically connected to the common mode choke coil .

[0043] <Common mode choke coil> The common mode choke coil 34 prevents 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 common mode noise. Furthermore, the common mode choke coil 34 uses leakage inductance as normal inductance. As a result, the common mode choke coil 34 is used as the L component in a low-pass filter for removing normal mode noise, also known as differential mode noise. In other words, the common mode choke coil 34 can handle both 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 instead handles both modes of noise with the common mode choke coil 34.

[0044] As shown in Figures 4 and 5, the common mode choke coil 34 has an annular core 50, a pair of windings 70 wound around the core 50, and an annular conductor 80 that surrounds both of the pair of windings 70 and allows an induced current to flow circumferentially to resist changes in leakage magnetic flux from the core 50.

[0045] A pair of windings 70 are wound around the insulating member 60 that houses the core 50, and a conductor 80 is wound around the pair of windings 70. The core 50 is made of a ferromagnetic material. The core 50 is, for example, a ferrite core.

[0046] As shown in FIG. 6 , the core 50 has a track shape. The core 50 has a pair of straight portions 51 and a pair of arc portions 52. Each straight portion 51 extends linearly. The 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 both ends of the pair of straight portions 51. One arc portion 52 connects one end of one straight portion 51 to one end of the other straight portion 51, and the other arc portion 52 connects the other end of one straight portion 51 to the other end of the other straight portion 51.

[0047] 7 and 8, 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.

[0048] One of the pair of windings 70 is wound around one of the straight portions 51 , and the other of the pair of windings 70 is wound around the other straight portion 51 . As shown in Figure 7, each of the pair of windings 70 has a central axis L of the winding 70 at its center. The direction in which this central axis L extends is defined as the axial direction Y of the winding 70. The pair of windings 70 are wound around the core 50 with their central axes L parallel to each other and are arranged side by side in the juxtaposition direction X. The juxtaposition direction X coincides with the direction in which the pair of straight portions 51 are arranged. Therefore, the common mode choke coil 34 has a pair of windings 70 wound around the core 50 and arranged side by side in the juxtaposition direction X.

[0049] As shown in Figures 5 and 6, each winding 70 has a first coil portion 71 wound around the straight portion 51. In this embodiment, each winding 70 is also wound around a portion of the 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 an unwound portion 53 around which the winding 70 is not wound. In this embodiment, the unwound portion 53 is the portion of each arc portion 52 around which the winding 70 is not wound.

[0050] The insulating member 60 has a pair of core insulating portions 61 , a winding insulating portion 62 , and four connecting portions 63 . Each core insulating portion 61 is annular. The pair of core insulating portions 61 cover the portion of the core 50 around which the windings 70 are wound. Each core insulating portion 61 has a first covering portion 61a that covers the entire straight portion 51, and second covering portions 61b that are located on both sides of the first covering portion 61a and cover portions of the pair of arcuate 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 interposed between the core 50 and the pair of windings 70. The pair of core insulating portions 61 insulate the core 50 from the pair of windings 70. The non-wound portion 53 of the core 50 is not covered by the insulating member 60.

[0051] The winding insulation portion 62 is flat. The winding insulation portion 62 is located inside the core 50. The winding insulation portion 62 is interposed between one winding 70 and the other winding 70. The winding insulation portion 62 insulates one winding 70 from the other winding 70. The dimension of the winding insulation portion 62 in the axial direction of the core 50 is larger than the dimension of each winding 70 in the axial direction of the core 50.

[0052] The four connection portions 63 connect the pair of core insulating portions 61 and the winding insulating portions 62. The four connection portions 63 integrate the pair of core insulating portions 61 and the winding insulating portions 62. 7 and 8, the insulating member 60 is composed of a first divided body 60a and a second divided body 60b that are divided into two in the axial direction of the core 50. The first divided body 60a is attached to the core 50 from the first end face 50a side of the core 50. The second divided body 60b is attached to the core 50 from the second end face 50b side of the core 50.

[0053] <Conductors> As shown in Figures 4 and 7, the conductor 80 is annular. As shown in Figure 5, the conductor 80 has a plate-shaped first metal plate 81 and a plate-shaped second metal plate 92 that are divided in a direction perpendicular to the axial direction Y and the juxtaposition direction X of the winding 70. The first metal plate 81 and the second metal plate 92 are made of brass with tin plating on the 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 may be the same or different.

[0054] The first metal plate 81 has a main body portion 83 and a pair of extending portions 84. The main body portion 83 is in the shape of a rectangular plate. The pair of extending portions 84 extend in the plate thickness direction of the main body portion 83 from both longitudinal end portions of the main body portion 83. The pair of extending portions 84 extend parallel to each other. Each extending portion 84 is in the shape of a rectangular plate. The first metal plate 81 is formed by pressing a single metal plate.

[0055] Each extension portion 84 includes a connecting plate portion 85 at its tip. The connecting plate portion 85 is formed in the center of the extension portion 84 in the short direction. The connecting plate portion 85 is located at the tip of the extension portion 84 and extends in the plate thickness direction of the main body portion 83. The connecting plate portion 85 has a connecting plate portion outer surface 85a and a connecting plate portion inner surface 85b that are opposite surfaces in the plate thickness direction. The connecting plate portion outer surface 85a is the outer surface of the extension portion 84, and the connecting plate portion inner surface 85b is also the inner surface of the extension portion 84.

[0056] The second metal plate 92 has a rectangular frame shape overall. The second metal plate 92 has a pair of rectangular opposing portions 94 and a pair of rectangular connecting portions 93 connecting the pair of opposing portions 94. The pair of opposing portions 94 face each other in the plate thickness direction, and the pair of connecting portions 93 face each other in the plate thickness direction. The second metal plate 92 has a rectangular frame shape with the central axis of the rectangular frame aligned with the short sides of the connecting portions 93 and the opposing portions 94. Therefore, the second metal plate 92 has a rectangular frame shape with a pair of opposing portions 94 and a pair of connecting portions 93 connecting the pair of opposing portions 94. Each opposing portion 94 has an opposing portion outer surface 94a and an opposing portion inner surface 94b that are opposite each other in the plate thickness direction. Each connecting portion 93 has a connecting portion outer surface 93a and a connecting portion inner surface 93b that are opposite each other in the plate thickness direction. The connecting portion outer surface 93 a and the opposing 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 opposing portion inner surface 94 b form the inner surface of the second metal plate 92 .

[0057] As shown in FIG. 7 , the second metal plate 92 is located between the connecting plate portions 85 of the pair of extending portions 84 of the first metal plate 81. The direction in which the pair of extending portions 84 extend from the main body portion 83 is the same as the short-side direction of the coupling portion 93 and the facing portion 94. The pair of facing portions 94 overlap with the extending portions 84 at the pair of connecting plate portions 85. One of the pair of facing portions 94 is welded to one of the connecting plate portions 85 of the pair of extending portions 84, and the other of the pair of facing portions 94 is welded to the other connecting plate portion 85 of the pair of extending portions 84. Specifically, the facing portion outer surface 94a of the facing portion 94 is welded to the connecting plate portion inner surface 85b of the connecting plate portion 85. Therefore, the facing portion 94 and the extending portion 84 have welded portions 99 where they are welded to each other. In this embodiment, the pair of facing portions 94 and the pair of extending portions 84 are joined to each other by resistance welding. Therefore, the conductor 80 is formed into a rectangular frame shape when viewed from the front, by joining the pair of extending portions 84 and the pair of opposing portions 94. The pair of connecting portions 93 extend in the juxtaposition direction X between the pair of extending portions 84.

[0058] The conductor 80 surrounds both of the pair of windings 70. In the conductor 80, the first metal plate 81 has a main body portion 83 disposed relative to the second metal plate 92 with the pair of windings 70 sandwiched therebetween, and a pair of extending portions 84 extending from the main body portion 83 toward the second metal plate 92. In the conductor 80, the second metal plate 92 has a pair of opposing portions 94 that respectively face the connecting plate portions 85 of the pair of extending portions 84, and a connecting portion 93 that connects the pair of opposing portions 94.

[0059] As shown in FIG. 8 , the pair of connecting portions 93 have connecting portion outer surfaces 93a and connecting portion inner surfaces 93b that are perpendicular to the axial direction Y along which the central axis L of each winding 70 extends. The pair of connecting portions 93 are spaced apart in the axial direction Y of the winding 70. Therefore, the first coil portions 71 of the pair of windings 70 are exposed between the pair of connecting portions 93 toward the outer surface 15c of the bottom wall 15a. Each of the pair of connecting portions 93 is disposed at the boundary between the first coil portion 71 and the second coil portion 72. Therefore, the entirety of each first coil portion 71 faces the outer surface 15c of the bottom wall 15a. Note that as long as the pair of connecting portions 93 are spaced apart in the axial direction Y, the positions of each connecting portion 93 can be changed as needed.

[0060] Additionally, the pair of opposing portions 94 connect the pair of connecting portions 93 in the axial direction Y. Therefore, the second metal plate 92 has a rectangular frame shape having a pair of connecting portions 93 spaced apart in the axial direction Y and a pair of opposing portions 94 connecting the pair of connecting portions 93 in the axial direction Y.

[0061] 3 and 8, the thickness D1 of each connecting portion 93 is smaller than the short-side opening width W of the long groove portion 151a. The thickness D1 is approximately 1 / 10 of the opening width W, but this ratio can be changed as desired. Furthermore, the short-side dimension G of each connecting portion 93 is smaller than the depth F of the long groove portion 151a.

[0062] 3 and 7, the total thickness D2 of the connecting plate portion 85 and the opposing portion 94 is smaller than the longitudinal opening width W of the short groove portion 151b. Also, the lateral dimension G of the opposing portion 94 is smaller than the depth F of the short groove portion 151b.

[0063] As shown in Figure 7, the front view of the conductor 80 refers to the view of the conductor 80 in the axial direction Y of the winding 70. When viewed from the front, the conductor 80 has a rectangular frame shape. The direction in which the central axis of the rectangular frame of the conductor 80 extends is referred to 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.

[0064] The pair of straight portions 51 of the core 50 and the pair of first coil portions 71 of each winding 70 are located inside the rectangular 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 both sides of the axial direction 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.

[0065] <Common mode choke coil placement> 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 surface 50a of the core 50 is located on the bottom wall portion 15a side of the suction housing 15. The second end surface 50b of the core 50 is located on the plate portion 39a side. A pair of lead portions 73 of each winding 70 penetrates the plate portion 39a, and the penetrated pair of lead portions 73 are soldered to the circuit board 29, for example. In this way, the common mode choke coil 34 is electrically connected to the circuit board 29.

[0066] The common mode choke coil 34 and the conductor 80 are interposed between the plate portion 39a and the cylindrical portion 39b of the holder 39, and between the circuit board 29 and the bottom wall portion 15a of the housing 14.

[0067] The main body 83 of the conductor 80 is interposed between the first coil portions 71 of the pair of windings 70 and the circuit board 29 and plate portion 39a. The portion of each core insulating portion 61 covering the first end face 50a of the core 50 is located on the opposite side of the first coil portion 71 of each winding 70 from the circuit board 29. The pair of extension portions 84 of the conductor 80 extend from the main body 83 toward the bottom wall 15a outside the windings 70 in the juxtaposition direction X, covering each winding 70 from the outside in the juxtaposition direction X. The pair of connection plate portions 85 extend from the main body 83 toward the bottom wall 15a of the suction housing 15. The second metal plate 92 is located between the first coil portions 71 of the pair of windings 70 and the bottom wall 15a.

[0068] As shown in FIGS. 7 and 8, the groove 151 formed in the bottom wall portion 15a has a rectangular frame shape that opens toward the second metal plate 92. The groove 151 is filled with thermal grease 56 as a heat dissipation material. The rectangular frame of the second metal plate 92 is inserted into the groove 151. Specifically, each connecting portion 93 is inserted into each long groove portion 151a, and the connecting plate portions 85 of each facing portion 94 and the extending portion 84 are inserted into each short groove portion 151b. Therefore, the welded portions 99 of the facing portion 94 and the extending portion 84 are inserted into the short groove portions 151b. The longitudinal direction and thickness direction of the connecting portion 93 coincide with the longitudinal direction and width direction of the long groove portion 151a, respectively. The longitudinal direction and thickness direction of the facing portion 94 coincide with the longitudinal direction and width direction of the short groove portion 151b, respectively.

[0069] Thermal grease 56 is provided between the bottom wall 15a and the first coil portion 71 and second coil portion 72 of each winding 70. The thermal grease 56 is provided inside the rectangular frame of the second metal plate 92. As a result, the winding 70 and the bottom wall 15a, i.e., the housing 14, are electrically insulated by the thermal grease 56, and heat can be transferred via the thermal grease 56.

[0070] Of the inner surfaces 151d of the groove 151, thermal grease 56 as a heat dissipation material is interposed between the inner surface 151d facing the connecting portion outer surface 93a and between the inner surface 151d facing the connecting portion inner surface 93b. Therefore, each connecting portion 93 is inserted into the groove 151 with both surfaces in the plate thickness direction facing the inner surface 151d of the groove 151 with the thermal grease 56 interposed therebetween, and spaced apart from the inner surface 151d.

[0071] Of the inner surfaces 151d of the groove 151, thermal grease 56 as a heat dissipation material is interposed between the inner surface 151d facing the connecting plate portion outer surface 85a and the inner surface 151d facing the facing portion inner surface 94b. Therefore, the connecting plate portion 85 and the facing portion 94 of each extension portion 84 are inserted into the groove 151 so as to face the inner surface 151d of the groove 151 with the thermal grease 56 interposed therebetween, while being spaced apart from the inner surface 151d. Therefore, the welded portion 99 between the extension portion 84 and the facing portion 94 is also inserted into the thermal grease 56.

[0072] As shown in Figure 3, the shortest distance in the short direction of the groove 151 to the inner side surface 151d of the groove 151 that faces each of the connecting portion outer surface 93a and the connecting portion inner surface 93b is defined as a first distance M1. The shortest distance in the short direction of the groove 151 to the inner side surface 151d of the groove 151 that faces each of the connecting plate portion outer surface 85a and the opposing portion inner surface 94b is defined as a second distance M2. The opening width W of the groove 151 in the short direction is the same at any position in the groove 151. Therefore, the second distance M2 at the portion where the connecting plate portion 85 and the opposing portion 94 are inserted is shorter than the first distance M1.

[0073] 8, if the shortest distance between first coil portion 71 of winding 70 and the opposing surface of bottom wall portion 15a is defined as separation distance N, then first distance M1 and second distance M2 are each smaller than separation distance N. Therefore, coupling portion outer surface 93a and coupling portion inner surface 93b are each positioned closer to bottom wall portion 15a than first coil portion 71. Similarly, connecting plate portion outer surface 85a, opposing portion outer surface 94a, and opposing portion inner surface 94b are each positioned closer to bottom wall portion 15a than first coil portion 71.

[0074] The second metal plate 92 is inserted into the groove 151 so that the connecting portion 93 is located at the center of the long groove portion 151a in the short direction. Therefore, the first distance M1 is the same on both sides of each 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 groove portion 151b in the short direction. Therefore, the second distance M2 is the same on both sides of the connecting plate portion 85 and the opposing portion 94.

[0075] [Operation of the embodiment] The operation of the embodiment will be described. The noise reduction unit 32 has a conductor 80 surrounding the 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. Then, an induced current flows in the conductor 80 in the circumferential direction thereof, resisting the change 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 welded portion 99, the connecting portion 93, and the opposing portion 94. The induced current flowing through the conductor 80 is converted into thermal energy, which generates a damping effect. As a result, the resonance peak of the low-pass filter is suppressed.

[0076] When an induced current flows through the conductor 80, the conductor 80 generates heat. Furthermore, when an induced current flows, heat is generated from the first metal plate 81 and the second metal plate 92 of the conductor 80, and the welded portion 99 also generates heat. The heat generated in the welded portion 99 is transferred from the opposing portion 94 to the connecting portion 93. Therefore, when an induced current flows through the conductor 80, heat is generated from the welded portion 99 and the connecting portion 93.

[0077] Heat generated from the welded portion 99 is conducted from each of the connecting plate portion outer surface 85a and the opposing portion inner surface 94b via the thermal grease 56 to the inner surface 151d that defines the short groove portion 151b. Heat generated from the connecting portion 93 is conducted from each of the connecting portion outer surface 93a and the connecting portion inner surface 93b via the thermal grease 56 to the inner surface 151d that defines the long groove portion 151a. Therefore, the suction housing 15 is formed with a groove 151 in which the welded portion 99 and the connecting portion 93 are disposed and in which the thermal grease 56 is provided that conducts heat generated from the welded portion 99 and the connecting portion 93 to the suction housing 15. The induced current flows through the welded portion 99 and the connecting portion 93 that are disposed in the groove 151.

[0078] When a current flows through the pair of windings 70, the pair of windings 70 generates heat. The heat from the first coil portion 71 of the pair of windings 70 is transferred to the suction housing 15 via the thermal grease 56. [Effects of this embodiment] The effects of this embodiment will be described.

[0079] (1) The welded portion 99 and the connecting portion 93 of the conductor 80 are disposed in a groove 151 of the suction housing 15, and the groove 151 is provided with thermal grease 56. When an induced current flows through the conductor 80 and the conductor 80 heats up, the welded portion 99 also heats up, and the heat from the welded portion 99 is 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 released to the suction housing 15 via the thermal grease 56. Therefore, the electric compressor 11 can improve the heat dissipation performance of the conductor 80, which is formed by joining the first metal plate 81 and the second metal plate 92 with the welded portion 99.

[0080] (2) The second metal plate 92 has a rectangular frame shape and includes a pair of opposing portions 94 and a pair of connecting portions 93 that connect the pair of opposing portions 94. For example, compared to when there is only one connecting portion 93, the area that can dissipate heat from the connecting portion 93 can be increased. This improves the heat dissipation performance of the second metal plate 92 compared to when there is only one connecting portion 93.

[0081] (3) Each of the first distance M1 and the second distance M2 from the second metal plate 92 to the inner surface 151d of the groove 151 is arranged to be smaller than the distance N from the winding 70 to the bottom wall portion 15a of the intake housing 15. This improves the heat dissipation effect from the second metal plate 92, and therefore from the welded portion 99 and the connecting portion 93 to the bottom wall portion 15a.

[0082] (4) The connecting portion 93 is inserted into the groove 151 with the first distance M1 from the inner surface 151d of the groove 151 being the same on both sides in the plate thickness direction. Therefore, heat can be dissipated equally from both the connecting portion outer surface 93a and the connecting portion inner surface 93b to the inner surface 151d of the groove 151. Furthermore, due to component tolerances and the like, the connecting portion 93 may be inserted into the groove 151 with different first distances M1 on the connecting portion outer surface 93a side and the connecting portion inner surface 93b side. Even in this case, the surface with the smaller first distance M1 can compensate for the reduced heat dissipation performance caused by the surface with the larger first distance M1, so heat can be dissipated efficiently from the connecting portion 93.

[0083] (5) The connecting plate portion 85 and the opposing portion 94 are inserted into the groove 151 with the second distance M2 between the connecting plate portion outer surface 85a and the inner surface 151d being the same as the second distance M2 between the opposing portion inner surface 94b and the inner surface 151d. Therefore, heat generated from the welded portion 99 can be dissipated in the same manner from both the connecting plate portion outer surface 85a and the opposing portion inner surface 94b to the inner surface 151d of the groove 151. Furthermore, due to component tolerances and the like, the connecting plate portion may be inserted into the groove 151 with different second distances M2 on the connecting plate portion outer surface 85a side and the opposing portion inner surface 94b side. Even in this case, the surface with the smaller second distance M2 can compensate for the reduced heat dissipation performance caused by the surface with the larger second distance M2, thereby allowing the heat generated from the welded portion 99 to be dissipated efficiently.

[0084] (6) The second metal plate 92 has a rectangular frame shape having a pair of opposing portions 94 and a pair of connecting portions 93. For example, compared to when the second metal plate 92 connects the pair of opposing portions 94 with a single connecting portion 93, the strength of the second metal plate 92 can be increased, and the strength of the conductor 80 can also be increased.

[0085] [Example of change] The embodiment can be modified as follows: The embodiment and the following modifications can be combined with each other within the scope of technical compatibility.

[0086] The heat dissipating material may be other than the heat dissipating grease 56, such as heat dissipating paste or heat dissipating filler. The connecting portion 93 may be inserted into the groove 151 with the first distance M1 being different on both sides in the plate thickness direction. The connecting plate portion 85 and the opposing portion 94 may be inserted into the groove 151 with the second distance M2 being different on both sides in the plate thickness direction.

[0087] The conductor 80 may be made of an aluminum plate, a stainless steel plate, or the like, in addition to a brass plate. The connecting plate portion 85 does not have to be formed on the extending portion 84 .

[0088] The first distance M1 and the second distance M2 from the second metal plate 92 to the inner surface 151d of the groove 151 may be equal to or greater than the distance N from the winding 70 to the bottom wall portion 15a of the suction housing 15.

[0089] The groove 151 and the second metal plate 92 do not have to be rectangular frame-shaped. For example, the conductor 80 may have the second metal plate 92 in an H-shape having a pair of opposing portions 94 and a single 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 in which the pair of opposing portions 94 and the connecting plate portion 85 are disposed, and a second groove-forming portion that connects the pair of groove-forming portions and extends linearly so that the single connecting portion 93 is disposed therein.

[0090] Furthermore, the conductor 80 may have a shape in which the second metal plate 92 has a pair of opposing portions 94 and three or more connecting portions 93 connecting the pair of opposing portions 94. In this case as well, the groove 151 is formed by a pair of first groove forming portions in which the pair of opposing portions 94 and the extending portion 84 are arranged, and a second groove forming portion that connects the pair of groove forming portions and extends linearly so that three or more connecting portions 93 are arranged. [Explanation of symbols]

[0091] M1...first distance, M2...second distance, N...separation distance, 11...electric compressor, 14...housing, 18...compression section, 19...electric motor, 30...inverter device, 31...inverter circuit section, 32...noise reduction section, 34...common mode choke coil, 35...smoothing capacitor, 50...core, 56...thermal grease as heat dissipation material, 70...pair of windings, 80...conductor, 81...first metal plate, 83...main body section, 84...extension section, 92...second metal plate, 93...connection section, 94...opposing section, 99...welded section, 151...groove, 151d...inner surface.

Claims

1. a compression section that compresses the fluid; an electric motor that drives the compression unit; an inverter device that drives the electric motor; a metal housing that accommodates the compression unit, the electric motor, and the inverter device therein; The inverter device is an inverter circuit unit that converts DC power into AC power; a noise reduction unit that is provided on the input side of the inverter circuit unit and that reduces common mode noise and normal mode noise contained in the DC power input to the inverter circuit unit, The noise reduction unit A common mode choke coil, a smoothing capacitor that configures a low-pass filter together with the common mode choke coil, The common mode choke coil comprises: an annular core; a pair of windings wound around the core; a conductor formed in an annular shape that surrounds both of the pair of windings and allows an induced current to flow in a circumferential direction so as to resist a change 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 relative to the second metal plate with the pair of windings sandwiched therebetween, 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 opposing portions that respectively face the pair of extending portions, and a connecting portion that connects the pair of opposing portions, the facing portion and the extending portion have a welded portion welded to each other, the housing has grooves in which the welded portions and the connecting portions are disposed and in which heat dissipation materials are provided to transfer heat generated from the welded portions and the connecting portions to the housing; The electric compressor, wherein the induced current flows through the welding portion and the connecting portion disposed in the groove.

2. the second metal plate has a rectangular frame shape including a pair of the opposing portions and a pair of connecting portions that respectively connect the pair of opposing portions, the groove has a rectangular frame shape that opens toward the second metal plate, The electric compressor according to claim 1 , wherein the second metal plate is disposed in the groove.

3. 3. The electric compressor according to claim 1, wherein the shortest distance between the second metal plate and the inner surface of the groove is shorter than the shortest distance between the winding and the housing.

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