Electric compressor

Abstract

The invention provides an electric compressor which can easily ensure damping resistance when a large current is input to a common mode choke coil. An electric compressor is provided with a noise reduction unit (50) that reduces common-mode noise and normal-mode noise. The noise reduction section (50) has a common mode choke coil (51) for reducing common mode noise and a magnetic damping section (55) for reducing normal mode noise. The common mode choke coil (51) has an annular iron core (60), a first winding wire (61) wound around the iron core (60), and a second winding wire (62) wound around the iron core (60) and arranged at a distance from the first winding wire (61). The magnetic body damping part (55) is composed of a plate-shaped magnetic body. Eddy current is generated in the magnetic damping part (55) by means of leakage magnetic flux leaked from the iron core (60). The noise reduction section (50) has a plurality of magnetic damping sections (55). The plurality of magnetic damping parts (55) are laminated with an insulating layer (73) interposed therebetween.

Description

Technical Field

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

[0002] In Patent Document 1, an in-vehicle electric compressor mounted on a vehicle such as an electric vehicle is described. The in-vehicle electric compressor includes a compression unit that compresses a fluid, a motor that drives the compression unit, and an inverter device that drives the motor. 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.

[0003] The noise reduction unit includes a common-mode choke coil, a smoothing capacitor, and a damping unit. The common-mode choke coil has an annular iron core, a first winding wound around the iron core, and a second winding wound around the iron core and arranged at an interval from the first winding. The common-mode choke coil reduces common-mode noise. The smoothing capacitor and the common-mode choke coil together form a low-pass filter circuit. The damping unit is made of a magnetic material. The damping unit is disposed around the common-mode choke coil.

[0004] When a normal-mode current flows through the first winding and the second winding, leakage magnetic flux leaks from the iron core. If the leakage magnetic flux leaking from the iron core flows through the damping unit, eddy currents are generated in the damping unit. The eddy currents generated in the damping unit are converted into heat energy. Thereby, a damping effect is obtained. The damping unit reduces normal-mode noise.

[0005] Prior Art Documents

[0006] Patent Documents

[0007] Patent Document 1: Japanese Patent No. 6673468 Summary of the Invention

[0008] Problems to be Solved by the Invention

[0009] Due to the high voltage of the power supply voltage accompanying the popularization of electric vehicles and the like, in recent years, the current input to the common-mode choke coil (hereinafter referred to as "input current") has increased. Therefore, it is desired to ensure a damping resistance when a large current is input to the common-mode choke coil.

[0010] Means for Solving the Problems

[0011] An electric compressor for solving the above problems includes: a compression part that compresses a fluid; a motor that drives the compression part; and an inverter device that drives the motor. The inverter device has: an inverter circuit part that converts DC power into AC power; and a noise reduction part that is provided on the input side of the inverter circuit part and reduces common-mode noise and normal-mode noise. The noise reduction part has: a common-mode choke coil that has an annular iron core, a first winding wound around the iron core, and a second winding wound around the iron core and arranged at an interval from the first winding, and reduces the common-mode noise; a smoothing capacitor that together with the common-mode choke coil forms a low-pass filter circuit; and a magnetic damping part that is composed of a plate-shaped magnetic body, generates eddy currents using leakage magnetic flux leaking from the iron core, and reduces the normal-mode noise. The gist of the electric compressor is that the noise reduction part has a plurality of the magnetic damping parts, and the plurality of the magnetic damping parts are laminated with an insulating layer therebetween.

[0012] According to the above structure, since a plurality of magnetic damping parts are laminated with an insulating layer therebetween, it is difficult to generate magnetic saturation. Therefore, even if the input current to the common-mode choke coil increases, it is difficult for the damping resistance to decrease. Thus, it is easy to ensure the damping resistance when a large current is input to the common-mode choke coil.

[0013] In the above electric compressor, it may also be that the plurality of the magnetic damping parts respectively extend along the circumferential direction of the iron core so as to surround the outer periphery of the iron core.

[0014] According to the above structure, each magnetic damping part extends along the circumferential direction of the iron core so as to surround the outer periphery of the iron core. In this case, a more excellent damping effect is obtained.

[0015] In the above electric compressor, the noise reduction part has a non-magnetic damping part that is composed of a plate-shaped non-magnetic body, is arranged so as to surround the first winding and the second winding, and an induced current flows in the non-magnetic damping part to generate a magnetic flux that resists the change of the leakage magnetic flux, and reduces the normal-mode noise. The plurality of the magnetic damping parts are respectively arranged with the non-magnetic damping part sandwiched therebetween on the side opposite to the first winding and the second winding, and extend along the circumferential direction of the iron core so as to surround the outer periphery of the iron core.

[0016] According to the above structure, the noise reduction part has a non-magnetic damping part composed of a non-magnetic body. The non-magnetic damping part surrounds the first winding and the second winding. Therefore, an induced current flows in the non-magnetic damping part to generate a magnetic flux that resists the change of the leakage magnetic flux leaking from the iron core. And the induced current flowing in the non-magnetic damping part is converted into heat energy. Thus, a damping effect is also obtained.

[0017] In addition, the noise reduction unit has a plurality of magnetic body damping parts. Thus, compared with the case where the noise reduction unit has one magnetic body damping part, the induced current flowing in the non-magnetic body damping part increases correspondingly as the leakage magnetic flux increases. Therefore, the damping resistance when a small current is input to the common mode choke coil can be increased.

[0018] For example, when the magnetic body damping part is disposed between the first winding and the second winding and the non-magnetic body damping part, the leakage magnetic flux leaking from the iron core branches into a loop passing through the magnetic body damping part inside the non-magnetic body damping part and a loop passing through the outside of the non-magnetic body damping part. In this way, due to the magnetic flux passing through the magnetic body damping part, the magnetic flux linked with the non-magnetic body damping part decreases, and thus the induced current flowing in the non-magnetic body damping part also decreases. As a result, the damping effect brought by the non-magnetic body damping part decreases.

[0019] In contrast, according to the above structure, a plurality of magnetic body damping parts are respectively disposed on the side opposite to the first winding and the second winding with the non-magnetic body damping part sandwiched therebetween. In this case, the situation where the magnetic flux linked with the non-magnetic body damping part decreases due to the magnetic flux passing through the magnetic body damping part is avoided, and thus the induced current flowing in the non-magnetic body damping part does not decrease. Therefore, a decrease in the damping effect brought by the non-magnetic body damping part can be avoided.

[0020] Moreover, each magnetic body damping part extends in the circumferential direction of the iron core so as to surround the outer periphery of the iron core. In this case, a more excellent damping effect is obtained.

[0021] In the above electric compressor, it may also be that when the direction in which the first winding and the second winding are arranged is set as the first direction and the direction orthogonal to both the axial direction of the iron core and the first direction is set as the second direction, a plurality of the magnetic body damping parts respectively include a pair of side parts configured to sandwich the space between the first winding and the second winding in the second direction, and at least one of the plurality of magnetic body damping parts has a void part that increases the magnetic resistance in the extending direction on at least one of the pair of side parts.

[0022] According to the above structure, at least one of the plurality of magnetic body damping parts has a void part that increases the magnetic resistance in the extending direction. The leakage magnetic flux leaking from the iron core is more likely to flow through the path without the void part than through the path with the void part in the magnetic body damping part. In addition, according to the above structure, the void part is provided on at least one of the pair of side parts configured to sandwich the space between the first winding and the second winding in the second direction. Therefore, the magnetic flux passing through the part of the iron core where the first winding is wound and the magnetic flux passing through the part of the iron core where the second winding is wound can respectively depict loops passing through the magnetic body damping part without being obstructed by the void part.

[0023] In the above-described electric compressor, the insulating layer may be a resin layer provided on the surface of the magnetic damping portion.

[0024] According to the above structure, the insulating layer is a resin layer provided on the surface of the magnetic damping portion. Therefore, compared with the case where the insulating layer is provided in the gap between the magnetic damping portions, it is possible to easily ensure insulation between the magnetic damping portions.

[0025] Advantageous Effects of the Invention

[0026] According to the present invention, it is easy to ensure the damping resistance when a large current is input to the common mode choke coil. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 is a side cross-sectional view showing an electric compressor according to a first embodiment.

[0028] Figure 2 is a circuit diagram showing the electrical structure of the electric compressor.

[0029] Figure 3 is a perspective view showing a part of a holding member and a magnetic damping portion.

[0030] Figure 4 is a perspective view showing a common mode choke coil.

[0031] Figure 5 of (a) is a partial front view showing a part of the electric compressor according to the first embodiment, Figure 5 of (b) is Figure 5 an enlarged view of (a).

[0032] Figure 6 is a partial cross-sectional view showing a part of the electric compressor according to the first embodiment.

[0033] Figure 7 is a graph showing the relationship between the input current to the common mode choke coil and the damping resistance.

[0034] Figure 8 is an exploded perspective view showing a common mode choke coil and a non-magnetic damping portion.

[0035] Figure 9 of (a) is a partial front view showing a part of the electric compressor according to the second embodiment, Figure 9 of (b) is Figure 9 an enlarged view of (a).

[0036] Figure 10 is a partial cross-sectional view showing a part of the electric compressor according to the second embodiment.

[0037] Figure 11It is a graph showing the relationship between the input current of the common mode choke coil and the total damping resistance brought by the magnetic damping part and the non-magnetic damping part.

[0038] Description of Reference Numerals

[0039] 10: Electric compressor, 13: Compression part, 14: Motor, 15: Inverter device, 43: Inverter circuit part, 50: Noise reduction part, 51: Common mode choke coil, 52: Smoothing capacitor, 53: Low-pass filter circuit, 55: Magnetic damping part, 56: Non-magnetic damping part, 60: Iron core, 61: First winding, 62: Second winding, 71: First resin layer as a resin layer, 72: Second resin layer as a resin layer, 73: Insulating layer, 552a: Side part, G: Gap part. Detailed Description of the Embodiment

[0040] Hereinafter, Figures 1 to 7 an embodiment of embodying the electric compressor will be described. The electric compressor is mounted on a vehicle such as an electric vehicle. The electric compressor of this embodiment is used for a vehicle air conditioner.

[0041] As Figure 1 shown, the vehicle air conditioner 100 includes an electric compressor 10 and an external refrigerant circuit 101. The external refrigerant circuit 101 supplies a refrigerant as a fluid to the electric compressor 10. The external refrigerant circuit 101 has, for example, a heat exchanger (not shown) and an expansion valve. The vehicle air conditioner 100 compresses the refrigerant using the electric compressor 10, and performs heat exchange and expansion of the refrigerant using the external refrigerant circuit 101, thereby performing cooling and heating inside the vehicle.

[0042] The vehicle air conditioner 100 includes an air conditioner ECU 102. The air conditioner ECU 102 controls the whole vehicle air conditioner 100. The air conditioner ECU 102 is configured to be able to grasp the inside temperature of the vehicle, the set temperature of the vehicle air conditioner 100, etc. And, the air conditioner ECU 102 sends various commands such as on / off commands to the electric compressor 10 based on parameters such as the inside temperature of the vehicle and the set temperature of the vehicle air conditioner 100.

[0043] <Electric Compressor>

[0044] The electric compressor 10 includes a housing 11, a rotating shaft 12, a compression part 13 that compresses the refrigerant, a motor 14 that drives the compression part 13, and an inverter device 15 that drives the motor 14.

[0045] The housing 11 houses the rotating shaft 12, the compression part 13, the motor 14, and the inverter device 15. The housing 11 is made of metal. The housing 11 of this embodiment is made of aluminum. The housing 11 is grounded to the vehicle body. The housing 11 has a suction housing 21, a discharge housing 22, and an inverter housing 23.

[0046] The suction housing 21 has a plate-shaped end wall 21a and a peripheral wall 21b that extends cylindrically from the outer peripheral portion of the end wall 21a. The discharge housing 22 is connected to the end portion on the opening side of the suction housing 21. The discharge housing 22 closes the opening of the suction housing 21. The suction housing 21 and the discharge housing 22 define a suction chamber S1. The rotating shaft 12, the compression section 13, and the motor 14 are housed in the suction chamber S1. The motor 14 is disposed in the suction chamber S1 between the compression section 13 and the end wall 21a of the suction housing 21.

[0047] The inverter housing 23 has a plate-shaped end wall 23a and a peripheral wall 23b that extends cylindrically from the outer peripheral portion of the end wall 23a. The inverter housing 23 is connected to the end wall 21a of the suction housing 21 by bolts B. The end wall 21a of the suction housing 21 and the inverter housing 23 define an inverter accommodation chamber S2. The inverter device 15 is housed in the inverter accommodation chamber S2.

[0048] A connector 16 is mounted on the end wall 23a of the inverter housing 23. The connector 16 is electrically connected to the power storage device 103 mounted on the vehicle. The power storage device 103 is a power source that supplies power to the devices mounted on the vehicle. The power storage device 103 is a DC power source. The power storage device 103 is, for example, a secondary battery or a capacitor.

[0049] The housing 11 has a suction port 11a. The suction port 11a is formed in the peripheral wall 21b of the suction housing 21. The suction port 11a is formed in a portion of the peripheral wall 21b of the suction housing 21 that is closer to the end wall 21a than the discharge housing 22. In addition, the housing 11 has a discharge port 11b. The discharge port 11b is formed in the discharge housing 22. The suction port 11a is connected to one end of the external refrigerant circuit 101, and the discharge port 11b is connected to the other end of the external refrigerant circuit 101.

[0050] The rotating shaft 12 is supported in a state capable of rotating relative to the housing 11. The axial direction of the rotating shaft 12 is the same as the axial direction of the peripheral wall 21b of the suction housing 21.

[0051] The compression section 13 is connected to the rotating shaft 12. The compression section 13 compresses the refrigerant when the rotating shaft 12 rotates. The compression section 13 is, for example, a scroll type composed of a fixed scroll (not shown) fixed to the suction housing 21 and a rotating scroll (not shown) disposed opposite to the fixed scroll.

[0052] The motor 14 has a rotor 31 and a stator 32.

[0053] The rotor 31 has a cylindrical rotor core 33 and permanent magnets (not shown) provided on the rotor core 33. The rotating shaft 12 is inserted through the rotor core 33. The rotating shaft 12 is fixed to the rotor core 33. The rotating shaft 12 can rotate integrally with the rotor 31.

[0054] The stator 32 and the rotor 31 are opposed to each other in the radial direction of the rotation shaft 12. The stator 32 has a stator core 34 having a cylindrical shape, a u-phase coil 35u, a v-phase coil 35v, and a w-phase coil 35w. The stator core 34 is fixed to the inner peripheral surface of the peripheral wall 21b of the suction housing 21. The u-phase coil 35u, the v-phase coil 35v, and the w-phase coil 35w are respectively wound around the stator core 34.

[0055] As Figure 2 shown, the u-phase coil 35u, the v-phase coil 35v, and the w-phase coil 35w are, for example, connected in Y. The connection method of the u-phase coil 35u, the v-phase coil 35v, and the w-phase coil 35w is not limited to Y connection and is arbitrary. The connection method of the u-phase coil 35u, the v-phase coil 35v, and the w-phase coil 35w can also be, for example, delta connection.

[0056] The u-phase coil 35u, the v-phase coil 35v, and the w-phase coil 35w are energized in a prescribed pattern, whereby the rotor 31 rotates. When the rotor 31 rotates, the rotation shaft 12 rotates. Thereby, the compression section 13 is driven. Therefore, the motor 14 drives the compression section 13. The compression section 13 compresses the refrigerant sucked into the suction chamber S1 from the external refrigerant circuit 101 via the suction port 11a. The refrigerant compressed by the compression section 13 is discharged to the external refrigerant circuit 101 via the discharge port 11b.

[0057] <Inverter device>

[0058] As Figure 1 and Figure 2 shown, the inverter device 15 includes a circuit board 41, a holding member 42, an inverter circuit section 43, a control section 44, and a noise reduction section 50.

[0059] As Figure 1 shown, the circuit board 41 is arranged axially of the rotation shaft 12 between the end wall 21a of the suction housing 21 and the end wall 23a of the inverter housing 23. The thickness direction of the circuit board 41 coincides with the axial direction of the rotation shaft 12.

[0060] The holding member 42 is made of resin. The holding member 42 is arranged between the circuit board 41 and the end wall 21a of the suction housing 21.

[0061] The holding member 42 has a plate-shaped main body portion 45. The plate thickness direction of the main body portion 45 coincides with the axial direction of the rotation shaft 12. The main body portion 45 has a first surface 45a and a second surface 45b. The first surface 45a and the second surface 45b are surfaces orthogonal to the plate thickness direction of the main body portion 45, respectively. The first surface 45a of the main body portion 45 is located on the side of the end wall 21a of the suction housing 21. The second surface 45b of the main body portion 45 is located on the side of the circuit board 41.

[0062] As Figure 3 shown, the holding member 42 has a cylindrical portion 46 erected from the first surface 45a of the main body portion 45. The first surface 45a of the main body portion 45 and the inner peripheral surface 46a of the cylindrical portion 46 define a receiving space 47.

[0063] The cylindrical portion 46 of the present embodiment has an octagonal cylindrical shape. The cylindrical portion 46 has a pair of first wall portions 461, a pair of second wall portions 462, and four third wall portions 463. The pair of first wall portions 461 are opposed to each other. The pair of second wall portions 462 are opposed to each other in a direction orthogonal to the direction in which the pair of first wall portions 461 are opposed. The third wall portions 463 connect the first wall portion 461 and the second wall portion 462.

[0064] As Figure 1 shown, in the present embodiment, the inverter circuit portion 43 is disposed between the main body portion 45 of the holding member 42 and the end wall 21a of the suction housing 21 in the axial direction of the rotating shaft 12. The inverter circuit portion 43 is mounted on the circuit board 41. The inverter circuit portion 43 converts DC power into AC power.

[0065] As Figure 2 shown, the inverter circuit portion 43 has two connection lines EL1, EL2. The inverter circuit portion 43 includes a u-phase switching element Qu1, Qu2 corresponding to the u-phase coil 35u. The inverter circuit portion 43 includes a v-phase switching element Qv1, Qv2 corresponding to the v-phase coil 35v. The inverter circuit portion 43 includes a w-phase switching element Qw1, Qw2 corresponding to the w-phase coil 35w. Each of the switching elements Qu1 to Qw2 is a power switching element such as an IGBT. It should be noted that freewheeling diodes Du1, Du2, Dv1, Dv2, Dw1, Dw2 are respectively connected to the switching elements Qu1, Qu2, Qv1, Qv2, Qw1, Qw2.

[0066] Each of the u-phase switching elements Qu1, Qu2 is connected in series. Between each of the u-phase switching elements Qu1, Qu2, the u-phase coil 35u is connected. And, the series connection body of each of the u-phase switching elements Qu1, Qu2 is electrically connected to the two connection lines EL1, EL2.

[0067] Each of the v-phase switching elements Qv1, Qv2 is connected in series. Between each of the v-phase switching elements Qv1, Qv2, the v-phase coil 35v is connected. And, the series connection body of each of the v-phase switching elements Qv1, Qv2 is electrically connected to the two connection lines EL1, EL2.

[0068] Each of the w-phase switching elements Qw1, Qw2 is connected in series. Between each of the w-phase switching elements Qw1, Qw2, the w-phase coil 35w is connected. And, the series connection body of each of the w-phase switching elements Qw1, Qw2 is electrically connected to the two connection lines EL1, EL2.

[0069] The control unit 44 controls the inverter circuit unit 43. The control unit 44 controls the switching operations of the respective switching elements Qu1 to Qw2. The control unit 44 can be implemented, for example, by one or more processors (control circuits) that operate according to one or more dedicated hardware circuits and / or computer programs (software). The processor includes a CPU and memories such as RAM and ROM. The memories store, for example, program codes or instructions configured to cause the processor to execute various processes. The memories, i.e., computer-readable media, include all available media that can be accessed by a general-purpose or special-purpose computer.

[0070] The control unit 44 is electrically connected to the air conditioner ECU 102 via the connector 16. Based on an instruction from the air conditioner ECU 102, the control unit 44 periodically turns on / off the respective switching elements Qu1 to Qw2. Specifically, the control unit 44 performs pulse width modulation control (PWM control) on the respective switching elements Qu1 to Qw2 based on an instruction from the air conditioner ECU 102. More specifically, the control unit 44 generates a control signal using a carrier signal and an instruction voltage value signal (comparison object signal). And the control unit 44 performs on / off control of the respective switching elements Qu1 to Qw2 by using the generated control signal, thereby converting DC power into AC power.

[0071] <Noise reduction unit>

[0072] The noise reduction unit 50 is provided on the input side of the inverter circuit unit 43. The noise reduction unit 50 reduces common-mode noise and normal-mode noise.

[0073] As Figure 1 shown, in the present embodiment, the noise reduction unit 50 is arranged in the axial direction of the rotating shaft 12 between the main body portion 45 of the holding member 42 and the end wall 21a of the suction housing 21. The noise reduction unit 50 is mounted on the circuit board 41.

[0074] As Figure 2 shown, the noise reduction unit 50 has a common-mode choke coil 51 and a smoothing capacitor 52. The smoothing capacitor 52 and the common-mode choke coil 51 together constitute a low-pass filter circuit 53. The low-pass filter circuit 53 is provided on the connection lines EL1, EL2. The low-pass filter circuit 53 is provided circuitously between the connector 16 and the inverter circuit unit 43. The common-mode choke coil 51 is provided on the two connection lines EL1, EL2.

[0075] The smoothing capacitor 52 is disposed on the inverter circuit unit 43 side with respect to the common mode choke coil 51. The smoothing capacitor 52 is an X capacitor connected in parallel with the inverter circuit unit 43. The smoothing capacitor 52 is electrically connected to the two connection lines EL1 and EL2. And, an LC resonance circuit is constituted by the common mode choke coil 51 and the smoothing capacitor 52. Therefore, the low-pass filter circuit 53 of the present embodiment is an LC resonance circuit including the common mode choke coil 51.

[0076] The noise reduction unit 50 has two Y capacitors 54. The two Y capacitors 54 are connected in series. The two Y capacitors 54 are grounded to the vehicle body via the housing 11. The two Y capacitors 54 are disposed on the inverter circuit unit 43 side with respect to the common mode choke coil 51. The two Y capacitors 54 are connected in parallel with respect to the common mode choke coil 51. The two Y capacitors 54 are connected in parallel with respect to the smoothing capacitor 52. The two Y capacitors 54 are located between the common mode choke coil 51 and the smoothing capacitor 52.

[0077] The common mode choke coil 51 suppresses the transmission of high-frequency noise generated on the vehicle side to the inverter circuit unit 43 of the electric compressor 10. The common mode choke coil 51 reduces the common mode noise. In addition, the common mode choke coil 51 uses the leakage inductance as the normal mode inductance. Thus, the common mode choke coil 51 is used as the L component in the low-pass filter circuit (LC filter) 53 for removing the normal mode noise (differential mode noise). That is, the common mode choke coil 51 can cope with the common mode noise and the normal mode noise (differential mode noise). Therefore, in the electric compressor 10 of the present embodiment, instead of using a common mode choke coil and a normal mode (differential mode) choke coil separately, the common mode choke coil 51 is used to cope with the two-mode noise.

[0078] <Common mode choke coil>

[0079] As Figure 4 shown, the common mode choke coil 51 has an iron core 60, a first winding 61, and a second winding 62.

[0080] The iron core 60 is annular. The iron core 60 is made of a ferromagnetic material. The iron core 60 is, for example, a ferrite core. The iron core 60 has a first winding portion 601, a second winding portion 602, and a pair of connecting portions 603. The first winding portion 601 and the second winding portion 602 each extend linearly. The first winding portion 601 and the second winding portion 602 extend in parallel. One connecting portion 603 connects one end portion of the first winding portion 601 and one end portion of the second winding portion 602, and the other connecting portion 603 connects the other end portion of the first winding portion 601 and the other end portion of the second winding portion 602. The iron core 60 has a first end face 60a and a second end face 60b. The first end face 60a is one end face in the axial direction of the iron core 60, and the second end face 60b is the other end face in the axial direction of the iron core 60.

[0081] The first winding 61 is wound around the first winding portion 601 of the iron core 60. In the present embodiment, a part of the first winding 61 is also wound around a pair of connecting portions 603 of the iron core 60. Both end portions of the first winding 61 are led out from the first end face 60a of the iron core 60 as a pair of first lead portions 63.

[0082] The second winding 62 is wound around the second winding portion 602 of the iron core 60. In the present embodiment, a part of the second winding 62 is also wound around a pair of connecting portions 603 of the iron core 60. The second winding 62 is arranged at an interval from the first winding 61. In the following description, the direction in which the first winding 61 and the second winding 62 are arranged is defined as the first direction, and the direction orthogonal to both the axial direction of the iron core 60 and the first direction is defined as the second direction. Both end portions of the second winding 62 are led out from the first end face 60a of the iron core 60 as a pair of second lead portions 64.

[0083] The first winding 61 and the second winding 62 each have a first portion 65 located on the first end face 60a of the iron core 60, a second portion 66 located on the second end face 60b of the iron core 60, and a third portion 67 located on the outer peripheral surface 60c of the iron core 60.

[0084] As Figure 5 shown in (a) and Figure 6 as shown, the common mode choke coil 51 is housed in the housing space 47 of the holder 42. The axial direction of the iron core 60 coincides with the axial direction of the cylindrical portion 46. The first end face 60a of the iron core 60 is located on the side of the first face 45a of the main body portion 45. The second end face 60b of the iron core 60 is located on the side of the end wall 21a of the suction housing 21.

[0085] As Figure 6 shown, each first lead portion 63 and each second lead portion 64 are inserted through an insertion hole 45h that penetrates the main body portion 45. Each first lead portion 63 and each second lead portion 64 are, for example, soldered to the circuit board 41. Thus, the first winding 61 and the second winding 62 are electrically connected to the circuit board 41, respectively.

[0086] <Magnetic damping portion>

[0087] As Figure 3 and Figure 5As shown in (a) of [reference], the noise reduction unit 50 has a plurality of magnetic damping units 55 that reduce common-mode noise. The noise reduction unit 50 of the present embodiment has three magnetic damping units 55. In the present embodiment, the three magnetic damping units 55 have the same structure. When differentiating the three magnetic damping units 55, they are referred to as the first magnetic damping unit 55a, the second magnetic damping unit 55b, and the third magnetic damping unit 55c. Each magnetic damping unit 55 is composed of a plate-shaped conductive magnetic body. Each magnetic damping unit 55 is made of, for example, iron or electromagnetic steel. Each magnetic damping unit 55 is plate-shaped. The thickness of each magnetic damping unit 55 is several hundred μm. However, in the drawings, the thickness of each magnetic damping unit 55 is exaggeratedly illustrated.

[0088] Each magnetic damping unit 55 is disposed outside the cylindrical portion 46. The first magnetic damping unit 55a is provided along the outer peripheral surface 46b of the cylindrical portion 46. The second magnetic damping unit 55b is provided along the outer peripheral surface of the first magnetic damping unit 55a. The third magnetic damping unit 55c is provided along the outer peripheral surface of the second magnetic damping unit 55b. The three magnetic damping units 55 are stacked in a direction orthogonal to the axial direction of the iron core 60.

[0089] Each magnetic damping unit 55 extends along the circumferential direction of the iron core 60 so as to surround the outer periphery of the iron core 60. Each magnetic damping unit 55 has a pair of first portions 551, a pair of second portions 552, and four third portions 553. The pair of first portions 551 are arranged so as to sandwich the common-mode choke coil 51 in the first direction. The pair of second portions 552 are arranged so as to sandwich the common-mode choke coil 51 in the second direction. The pair of second portions 552 include a pair of side portions 552a arranged so as to sandwich the space between the first winding 61 and the second winding 62 in the second direction. The third portion 553 connects the first portion 551 and the second portion 552.

[0090] As shown in Figure 5 As shown in (b) of [reference], each magnetic damping unit 55 has a first surface 70a and a second surface 70b. The first surface 70a and the second surface 70b are the surfaces of the magnetic damping unit 55 that are orthogonal to the thickness direction of the magnetic damping unit 55, respectively. The first surface 70a constitutes the inner peripheral surface of the magnetic damping unit 55. The second surface 70b constitutes the outer peripheral surface of the magnetic damping unit 55. In the present embodiment, a first resin layer 71 as a resin layer is provided on the first surface 70a of each magnetic damping unit 55. A second resin layer 72 as a resin layer is provided on the second surface 70b of each magnetic damping unit 55. It should be noted that in Figure 3 and Figure 5 In (a) of [reference], the illustration of the first resin layer 71 and the second resin layer 72 is omitted.

[0091] The first magnetic damping portion 55a and the second magnetic damping portion 55b are insulated by the second resin layer 72 of the first magnetic damping portion 55a and the first resin layer 71 of the second magnetic damping portion 55b. That is, the second resin layer 72 of the first magnetic damping portion 55a and the first resin layer 71 of the second magnetic damping portion 55b constitute an insulating layer 73 interposed between the stacked magnetic damping portions 55.

[0092] The second magnetic damping portion 55b and the third magnetic damping portion 55c are insulated by the second resin layer 72 of the second magnetic damping portion 55b and the first resin layer 71 of the third magnetic damping portion 55c. That is, the second resin layer 72 of the second magnetic damping portion 55b and the first resin layer 71 of the third magnetic damping portion 55c constitute an insulating layer 73 interposed between the stacked magnetic damping portions 55. Thus, the three magnetic damping portions 55 are stacked with the insulating layer 73 therebetween.

[0093] In each magnetic damping portion 55 of the present embodiment, a gap portion G that increases the magnetic resistance in the extending direction of the magnetic damping portion 55 is provided. In the present embodiment, the gap portions G are respectively provided at a pair of side portions 552a. Specifically, the gap portions G are provided on an imaginary straight line L that extends along the second direction and is located between the first winding 61 and the second winding 62 in the first direction. The gap portions G of the first magnetic damping portion 55a, the gap portions G of the second magnetic damping portion 55b, and the gap portions G of the third magnetic damping portion 55c are arranged in the second direction.

[0094] In the present embodiment, the gap portions G are provided in the entire range in the thickness direction of the magnetic damping portion 55. In addition, the gap portions G are provided in the entire range of the magnetic damping portion 55 in the axial direction of the iron core 60. Therefore, the magnetic damping portion 55 becomes discontinuous in the extending direction of the magnetic damping portion 55 due to the gap portions G. Therefore, in each magnetic damping portion 55, the portion located on one side of the imaginary straight line L in the first direction and the portion located on the other side of the imaginary straight line L in the first direction are not electrically connected.

[0095] [Function of the present embodiment]

[0096] Explain the function of the present embodiment.

[0097] The noise reduction portion 50 has a magnetic damping portion 55 made of a plate-shaped magnetic body. If leakage magnetic flux leaking from the iron core 60 when normal mode current flows in the first winding 61 and the second winding 62 flows in the magnetic damping portion 55, eddy currents are generated in the magnetic damping portion 55. The eddy currents generated in the magnetic damping portion 55 are converted into heat energy. Thereby, a damping effect is obtained.

[0098] Figure 7FIG. is a graph showing the relationship between the input current to the common mode choke coil 51 and the damping resistor for Comparative Example 1, Example 1-1, and Example 1-2. The larger the damping resistor, the more excellent the damping effect. In Figure 7 FIG., the graphs of Comparative Example 1, Example 1-1, and Example 1-2 are shown by a solid line, a dotted line, and a one-dot chain line, respectively.

[0099] In Comparative Example 1, Example 1-1, and Example 1-2, the conditions are set to be the same except for the number of stacked magnetic body damping portions 55. In Comparative Example 1, the noise reduction portion 50 has one magnetic body damping portion 55. That is, in Comparative Example 1, the magnetic body damping portions 55 are not stacked. In Example 1-1, the noise reduction portion 50 has two magnetic body damping portions 55, and the two magnetic body damping portions 55 are stacked with an insulating layer 73 therebetween. In Example 1-2, the noise reduction portion 50 has three magnetic body damping portions 55, and the three magnetic body damping portions 55 are stacked with an insulating layer 73 therebetween. That is, Example 1-2 is an example corresponding to the first embodiment.

[0100] According to Figure 7 it is clearly understood that the larger the input current to the common mode choke coil 51, the smaller the damping resistor. This is a common tendency in Comparative Example 1, Example 1-1, and Example 1-2. However, in Example 1-1 and Example 1-2, the damping resistor decreases more gently than in Comparative Example 1. And, in Example 1-2, the damping resistor decreases more gently than in Example 1-1. That is, the larger the number of stacked magnetic body damping portions 55, the more gently the damping resistor decreases. In other words, the larger the number of stacked magnetic body damping portions 55, the more difficult it is for the damping resistor to decrease even when the input current to the common mode choke coil 51 increases. This is because the larger the number of stacked magnetic body damping portions 55, the more difficult it is for the magnetic body damping portions 55 to be magnetically saturated. Therefore, in the present embodiment in which a plurality of magnetic body damping portions 55 are stacked with an insulating layer 73 therebetween, it is easy to ensure the damping resistor when a large current is input to the common mode choke coil 51.

[0101] It should be noted that, as Figure 7 shown, when a small current is input to the common mode choke coil 51, the damping resistors in Example 1-1 and Example 1-2 are smaller than in Comparative Example 1. This is because if the number of stacked magnetic body damping portions 55 increases, the leakage inductance of the common mode choke coil 51 increases, and thus the resonance frequency of the LC resonance circuit decreases. Generally, in the characteristics of a coil, the impedance of the higher frequency side is larger. Therefore, when a small current is input to the common mode choke coil 51, the larger the number of stacked magnetic body damping portions 55, the smaller the damping resistor.

[0102] On the other hand, when a large current is input to the common-mode choke coil 51, the damping resistances of Example 1-1 and Example 1-2 are larger than that of Comparative Example 1. For example, the required damping resistance is set to Figure 7 X shown. The current value of the input current when the damping resistance is less than X in Example 1-1 and Example 1-2 is larger than the current value of the input current when the damping resistance is less than X in Comparative Example 1. That is, in Example 1-1 and Example 1-2, even when the input current is a large current, it is easy to ensure the required damping resistance.

[0103] [Effects of the present embodiment]

[0104] Explain the effects of the present embodiment.

[0105] (1-1) In the present embodiment, the three magnetic body damping portions 55 are laminated with the insulating layer 73 therebetween, so that the magnetic body damping portions 55 are difficult to be magnetically saturated. Therefore, even if the input current to the common-mode choke coil 51 increases, the damping resistance is difficult to decrease. Thus, it is easy to ensure the damping resistance when a large current is input to the common-mode choke coil 51.

[0106] It should be noted that in the case of thickening the thickness of one magnetic body damping portion 55 instead of increasing the number of laminations of the magnetic body damping portions 55, eddy currents are generated on the surface of the magnetic body damping portion 55 due to the skin effect, but it is difficult to generate eddy currents inside the magnetic body damping portion 55. Therefore, even if the thickness of one magnetic body damping portion 55 is the same as the total thickness of the plurality of laminated magnetic body damping portions 55, the damping effect is worse than that of the present embodiment. In other words, by laminating a plurality of magnetic body damping portions 55 with the insulating layer 73 therebetween as in the present embodiment, eddy currents can be effectively generated in each magnetic body damping portion 55, and thus a more excellent damping effect is obtained.

[0107] (1-2) Each magnetic body damping portion 55 of the present embodiment extends along the circumferential direction of the iron core 60 so as to surround the outer periphery of the iron core 60. In this case, a more excellent damping effect is obtained.

[0108] (1-3) Each magnetic body damping portion 55 of the present embodiment has a gap portion G that increases the magnetic resistance in the extending direction. The leakage magnetic flux leaking from the iron core 60 is more likely to flow through the path where the gap portion G is not provided than through the path where the gap portion G is provided in the magnetic body damping portion 55. In addition, in the present embodiment, the gap portion G is provided in a pair of side portions 552a arranged so as to sandwich the space between the first winding 61 and the second winding 62 in the second direction. Therefore, in Figure 5 the magnetic fluxes passing through the first winding portion 601 of the iron core 60 and the magnetic fluxes passing through the second winding portion 602 of the iron core 60 shown by the arrows of the one-dot chain line in (a) can respectively depict loops passing through the magnetic body damping portion 55 without being hindered by the gap portion G.

[0109] (1-4) The insulating layer 73 of the present embodiment is a first resin layer 71 provided on the first surface 70a of the magnetic damping portion 55 and a second resin layer 72 provided on the second surface 70b. Therefore, compared with the case where the insulating layer 73 is provided in the gap between the magnetic damping portions 55, it is possible to easily ensure insulation between the magnetic damping portions 55.

[0110] (1-5) The inverter device 15 of the present embodiment includes a resin holding member 42 having a plate-shaped main body portion 45 and a cylindrical portion 46 erected from the main body portion 45. The common mode choke coil 51 is housed in a housing space 47 defined by the main body portion 45 and the cylindrical portion 46 such that the axial direction of the iron core 60 extends along the axial direction of the cylindrical portion 46. Thus, the position of the common mode choke coil 51 is less likely to shift. In addition, the magnetic damping portion 55 of the present embodiment is disposed on the outer periphery of the cylindrical portion 46 of the holding member 42. Therefore, the magnetic damping portion 55 can be insulated from the common mode choke coil 51 by the cylindrical portion 46.

[0111] [Second Embodiment]

[0112] Hereinafter, Figures 8 to 11 a second embodiment in which an electric compressor is embodied will be described. It should be noted that the main difference from the first embodiment is that the electric compressor further includes a non-magnetic damping portion. Therefore, detailed description of the same structure as that of the first embodiment will be omitted.

[0113] <Non-magnetic Damping Portion>

[0114] As shown in (a) of Figure 8 and Figure 9 the noise reduction portion 50 has a plate-shaped non-magnetic damping portion 56 that reduces common mode noise. The non-magnetic damping portion 56 is made of a plate-shaped conductive non-magnetic material. The non-magnetic damping portion 56 is made of, for example, copper or aluminum.

[0115] The non-magnetic damping portion 56 of the present embodiment is annular. The non-magnetic damping portion 56 has a first covering portion 56a, a second covering portion 56b, a third covering portion 56c, and a fourth covering portion 56d. The first covering portion 56a, the second covering portion 56b, the third covering portion 56c, and the fourth covering portion 56d are each in the shape of a rectangular flat plate. The first covering portion 56a is parallel to the second covering portion 56b. A through hole 56h is formed in the second covering portion 56b. The through hole 56h penetrates the second covering portion 56b in the plate thickness direction. The third covering portion 56c connects one end portion in the long side direction of the first covering portion 56a and one end portion in the long side direction of the second covering portion 56b. The fourth covering portion 56d connects the other end portion in the long side direction of the first covering portion 56a and the other end portion in the long side direction of the second covering portion 56b. The third covering portion 56c is parallel to the fourth covering portion 56d.

[0116] As Figure 9 shown in (a) of Figure 10 and as shown in, the non-magnetic damping portion 56 and the common mode choke coil 51 are housed together in the housing space 47 of the holding member 42. A part of the common mode choke coil 51 is disposed inside the non-magnetic damping portion 56. The axial direction of the non-magnetic damping portion 56 coincides with the second direction. The first winding portion 601 and the second winding portion 602 of the iron core 60, the portion of the first winding 61 wound around the first winding portion 601, and the portion of the second winding 62 wound around the second winding portion 602 are located inside the non-magnetic damping portion 56. The pair of connecting portions 603 of the iron core 60, the portion of the first winding 61 wound around the connecting portion 603, and the portion of the second winding 62 wound around the connecting portion 603 are located outside the non-magnetic damping portion 56. The pair of first lead portions 63 and the pair of second lead portions 64 are respectively located on both sides in the axial direction of the non-magnetic damping portion 56.

[0117] The first covering portion 56a and the second covering portion 56b are arranged so as to sandwich the common mode choke coil 51 in the axial direction of the iron core 60. The first covering portion 56a is located on the side of the first end face 60a of the iron core 60. The second covering portion 56b is located on the side of the second end face 60b of the iron core 60. The first covering portion 56a covers the first portion 65 of the first winding 61 and the second winding 62. The second covering portion 56b covers the second portion 66 of the first winding 61 and the second winding 62. The third covering portion 56c and the fourth covering portion 56d are arranged so as to sandwich the common mode choke coil 51 in the first direction. The third covering portion 56c covers the third portion 67 of the first winding 61. The fourth covering portion 56d covers the third portion 67 of the second winding 62. In this way, the non-magnetic damping portion 56 surrounds the first winding 61 and the second winding 62. The non-magnetic damping portion 56 covers the first portion 65, the second portion 66, and the third portion 67 of the first winding 61 and the second winding 62.

[0118] As Figure 10 shown, the surface of the first covering portion 56a on the side opposite to the surface facing the common mode choke coil 51 faces the first surface 45a of the main body portion 45 of the holding member 42. Between the surface of the second covering portion 56b on the side opposite to the surface facing the common mode choke coil 51 and the outer surface of the end wall 21a of the suction housing 21, there is a heat dissipation grease (not shown). The surfaces of the third covering portion 56c and the fourth covering portion 56d on the side opposite to the surfaces facing the common mode choke coil 51 face the inner surfaces of the pair of first wall portions 461 of the cylindrical portion 46.

[0119] As Figure 9 shown in (a) of Figure 9 and (b) of Figure 9 three magnetic body damping portions 55 are laminated with an insulating layer 73 therebetween. It should be noted that, similarly to the first embodiment, in

[0120] (a) of

[0121] the illustration of the insulating layer 73 is omitted.

[0122] The operation of this embodiment will be described.

[0123] The noise reduction portion 50 has a non-magnetic body damping portion 56 made of a plate-shaped non-magnetic body. The non-magnetic body damping portion 56 surrounds the first winding 61 and the second winding 62. Therefore, an induced current flows in the non-magnetic body damping portion 56 to generate a magnetic flux that resists the change in the leakage magnetic flux leaking from the iron core 60. And the induced current flowing in the non-magnetic body damping portion 56 is converted into heat energy. Thus, a damping effect is also obtained.

[0124] Figure 11 is a graph showing the relationship between the input current to the common mode choke coil 51 and the damping resistance for Comparative Example 2-1, Comparative Example 2-2, Example 2-1, and Example 2-2. In Figure 11 the graphs of Comparative Example 2-1, Comparative Example 2-2, Example 2-1, and Example 2-2 are shown by double-dot dash lines, solid lines, dashed lines, and single-dot dash lines, respectively.

[0125] In Comparative Example 2-1, Comparative Example 2-2, Example 2-1, and Example 2-2, the conditions were set to be the same except for the number of stacked magnetic damper portions 55. In Comparative Example 2-1, Comparative Example 2-2, Example 2-1, and Example 2-2, the noise reduction portion 50 has a non-magnetic damper portion 56. In Comparative Example 2-1, the noise reduction portion 50 does not have a magnetic damper portion 55. In Comparative Example 2-2, the noise reduction portion 50 has one magnetic damper portion 55. That is, in Comparative Example 2-1 and Comparative Example 2-2, the magnetic damper portions 55 are not stacked. In Example 2-1, the noise reduction portion 50 has two magnetic damper portions 55, and the two magnetic damper portions 55 are stacked with an insulating layer 73 therebetween. In Example 2-2, the noise reduction portion 50 has three magnetic damper portions 55, and the three magnetic damper portions 55 are stacked with an insulating layer 73 therebetween. That is, Example 2-2 is an example corresponding to the second embodiment.

[0126] According to Figure 11 It is clearly understood that in Comparative Example 2-2, Example 2-1, and Example 2-2, the damping resistance is larger than that in Comparative Example 2-1. That is, by having both the magnetic damper portion 55 and the non-magnetic damper portion 56 in the noise reduction portion 50, the damping effect is increased compared to the case where only the non-magnetic damper portion 56 is provided.

[0127] In Example 2-1 and Example 2-2, the damping resistance decreases gently compared to Comparative Example 2-2. That is, as in the first embodiment, the more the number of magnetic damper portions 55, the more gently the damping resistance decreases. In other words, the more the number of magnetic damper portions 55, the more difficult it is for the damping resistance to decrease even when the input current to the common mode choke coil 51 increases. Therefore, in the present embodiment in which a plurality of magnetic damper portions 55 are stacked with an insulating layer 73 therebetween, it is easy to ensure the damping resistance when a large current is input to the common mode choke coil 51.

[0128] In addition, in Example 2-1 and Example 2-2, the damping resistance is larger than that in Comparative Example 2-2 regardless of the input current. And in Example 2-2, the damping resistance is larger than that in Example 2-1 regardless of the input current. That is, different from the first embodiment, when the noise reduction portion 50 has a non-magnetic damper portion 56, the more the number of magnetic damper portions 55, the larger the damping resistance. This is because, as the number of magnetic damper portions 55 increases, the leakage magnetic flux leaking from the iron core 60 increases accordingly, and the induced current flowing in the non-magnetic damper portion 56 increases. Therefore, in the present embodiment having a non-magnetic damper portion 56, it is possible to increase the damping resistance when a small current is input to the common mode choke coil 51.

[0129] [Effect of the present embodiment]

[0130] Explain the effects of this embodiment. In this embodiment, in addition to the effects (1-1) to (1-5) of the first embodiment, the following effects are obtained.

[0131] (2-1) The noise reduction unit 50 of this embodiment has a non-magnetic damping unit 56 made of a non-magnetic material. The non-magnetic damping unit 56 surrounds the first winding 61 and the second winding 62. Therefore, an induced current flows in the non-magnetic damping unit 56 to generate a magnetic flux that resists the change in the leakage magnetic flux leaking from the iron core 60. And the induced current flowing in the non-magnetic damping unit 56 is converted into heat energy. Thus, a damping effect is also obtained.

[0132] In addition, the noise reduction unit 50 has a plurality of magnetic damping units 55. Thus, compared with the case where the noise reduction unit 50 has one magnetic damping unit 55, the induced current flowing in the non-magnetic damping unit 56 increases correspondingly as the leakage magnetic flux increases. Therefore, the damping resistance when a small current is input to the common mode choke coil 51 can be increased.

[0133] (2-2) For example, when the magnetic damping unit 55 is disposed between the windings 61, 62 and the non-magnetic damping unit 56, the leakage magnetic flux leaking from the iron core 60 branches into a loop passing through the magnetic damping unit 55 inside the non-magnetic damping unit 56 and a loop passing through the outside of the non-magnetic damping unit 56. In this way, due to the magnetic flux passing through the magnetic damping unit 55, the magnetic flux linked to the non-magnetic damping unit 56 decreases, so the induced current flowing in the non-magnetic damping unit 56 also decreases. As a result, the damping effect brought by the non-magnetic damping unit 56 decreases.

[0134] In contrast, in this embodiment, the plurality of magnetic damping units 55 are respectively disposed on the opposite side of the first winding 61 and the second winding 62 with the non-magnetic damping unit 56 sandwiched therebetween. In this case, the situation where the magnetic flux linked to the non-magnetic damping unit 56 decreases due to the magnetic flux passing through the magnetic damping unit 55 is avoided, so the induced current flowing in the non-magnetic damping unit 56 does not decrease. Therefore, a decrease in the damping effect brought by the non-magnetic damping unit 56 can be avoided.

[0135] (2-3) The non-magnetic damping unit 56 and the common mode choke coil 51 are housed together in the housing space 47 of the holder 42. Thus, the position of the non-magnetic damping unit 56 is difficult to shift. In addition, the magnetic damping unit 55 of this embodiment is disposed on the outer periphery of the cylindrical portion 46 of the holder 42. Therefore, the magnetic damping unit 55 can be insulated from both the common mode choke coil 51 and the non-magnetic damping unit 56 by the cylindrical portion 46.

[0136] [Modification Example]

[0137] Note that the above-described embodiments can be implemented with the following changes. The above-described embodiments and the following modification examples can be implemented in combination with each other within a technically non-contradictory range.

[0138] ○ The inverter device 15 may not have the holding member 42.

[0139] ○ As long as the cylindrical portion 46 of the holding member 42 is cylindrical, it does not have to be an octagonal cylindrical shape.

[0140] ○ The number of the magnetic damping portions 55 laminated with the insulating layer 73 therebetween is not limited to three. The number of the magnetic damping portions 55 laminated with the insulating layer 73 therebetween may be two, or may be four or more.

[0141] ○ As long as eddy currents are generated in the magnetic damping portion 55 by the leakage magnetic flux leaking from the iron core 60, the shape of the magnetic damping portion 55 and the arrangement of the magnetic damping portion 55 with respect to the common mode choke coil 51 can also be appropriately changed. However, it is assumed that a plurality of magnetic damping portions 55 are laminated with the insulating layer 73 therebetween.

[0142] The magnetic damping portion 55 may also be, for example, a flat plate shape, an L shape, or a U shape.

[0143] The magnetic damping portion 55 may also be arranged, for example, so as to cover only the third portion 67 of the first winding 61, or may be arranged so as to sandwich the common mode choke coil 51 in the axial direction of the iron core 60.

[0144] ○ The shape of the magnetic damping portion 55 and the arrangement of the magnetic damping portion 55 with respect to the common mode choke coil 51 do not have to be the same in all the magnetic damping portions 55. The shape of the magnetic damping portion 55 and the arrangement of the magnetic damping portion 55 with respect to the common mode choke coil 51 may be different for each magnetic damping portion 55. However, it is assumed that a plurality of magnetic damping portions 55 are laminated with the insulating layer 73 therebetween. It may be that the whole of the magnetic damping portion 55 and a part of other magnetic damping portions 55 are laminated with the insulating layer 73 therebetween, or it may be that a part of the magnetic damping portion 55 and a part of other magnetic damping portions 55 are laminated with the insulating layer 73 therebetween.

[0145] ○ In the above-described embodiment, the insulating layer 73 is the first resin layer 71 provided on the first surface 70a of the magnetic damping portion 55 and the second resin layer 72 provided on the second surface 70b, but it is not limited thereto. The insulating layer 73 may be arbitrary as long as it is interposed between the magnetic damping portions 55 to insulate the magnetic damping portions 55 from each other.

[0146] As an example, the insulating layer 73 may also be a gap provided between the magnetic damping portions 55.

[0147] As other examples, the insulating layer 73 may also be an insulating member separate from the magnetic damping portion 55.

[0148] ○ In the above-described embodiment, the resin layer is provided on both surfaces of the magnetic damping portion 55, but it may be provided only on one surface of the magnetic damping portion 55.

[0149] For example, it may be that a first resin layer 71 is provided on the first surface 70a of each magnetic damping portion 55, and the second resin layer 72 is not provided on the second surface 70b. In this case, the insulating layer 73 is constituted only by the first resin layer 71.

[0150] For example, it may be that a second resin layer 72 is provided on the second surface 70b of each magnetic damping portion 55, and the first resin layer 71 is not provided on the first surface 70a. In this case, the insulating layer 73 is constituted only by the second resin layer 72.

[0151] ○ In the above-described embodiment, the void portion G is provided in all of the three magnetic damping portions 55, but it is not limited thereto.

[0152] The void portion G may also be provided in at least one of the plurality of magnetic damping portions 55 laminated with the insulating layer 73 interposed therebetween. The expression "at least one" used in this specification means "more than one" of the desired alternatives. As an example, when the number of alternatives is two, the expression "at least one" used in this specification means "only one alternative" or "both of the two alternatives". As other examples, when the number of alternatives is three or more, the expression "at least one" used in this specification means "only one alternative" or "any combination of two or more alternatives".

[0153] The void portion G may not be provided in all of the plurality of magnetic damping portions 55 laminated with the insulating layer 73 interposed therebetween.

[0154] ○ In the above-described embodiment, the void portion G is provided on both of the pair of side portions 552a of the magnetic damping portion 55, but it may be provided only on one of the side portions 552a. As long as the void portion G is provided on at least one of the pair of side portions 552a, the effects (1-3) of the first embodiment are obtained. It should be noted that "at least one of the pair of side portions 552a" means "only one of the side portions 552a", "only the other side portion 552a", or "both of the side portions 552a".

[0155] ○ In the above-described embodiment, the void portion G is provided on the imaginary straight line L, but it may be provided at a position shifted in the first direction with respect to the imaginary straight line L.

[0156] ○In the above-described embodiment, the gap portion G is provided in the side portion 552a of the magnetic damping portion 55, but it may also be provided in a portion other than the side portion 552a in the first portion 551, the third portion 553, and the second portion 552.

[0157] ○The position of the gap portion G in the magnetic damping portion 55 may not be the same in all of the magnetic damping portions 55. For example, the position of the gap portion G in the magnetic damping portion 55 may also be different for each magnetic damping portion 55.

[0158] ○In the above-described embodiment, the gap portion G is provided over the entire range in the thickness direction of the magnetic damping portion 55, but it is not limited thereto. The gap portion G may also be provided in a part of the thickness direction of the magnetic damping portion 55.

[0159] ○In the above-described embodiment, the gap portion G is provided over the entire range of the magnetic damping portion 55 in the axial direction of the iron core 60, but it is not limited thereto. The gap portion G may also be provided in a part of the magnetic damping portion 55 in the axial direction of the iron core 60.

[0160] ○A plurality of magnetic damping portions 55 may also be arranged inside the cylindrical portion 46. In this case, insulation between the magnetic damping portion 55 and the common mode choke coil 51 is ensured. As a method for ensuring insulation, for example, a method of ensuring an insulation distance between the magnetic damping portion 55 and the common mode choke coil 51, a method of performing an insulation treatment on the surface of the magnetic damping portion 55 facing the common mode choke coil 51, etc. may be cited. When the magnetic damping portion 55 is arranged inside the cylindrical portion 46 in the second embodiment, in addition to the insulation between the magnetic damping portion 55 and the common mode choke coil 51, insulation between the magnetic damping portion 55 and the non-magnetic damping portion 56 is also ensured.

[0161] In this case, the cylindrical portion 46 can ensure insulation between the magnetic damping portion 55 and other electronic components mounted on the circuit board 41 and located outside the cylindrical portion 46. And, compared with the case where the magnetic damping portion 55 is arranged outside the cylindrical portion 46, the magnetic damping portion 55 can be brought closer to the iron core 60, and thus a more excellent damping effect can be obtained.

[0162] ○All of the magnetic damping portions 55 may not be arranged outside or inside the cylindrical portion 46.

[0163] For example, it may be that one of the two magnetic damping portions 55 is arranged outside the cylindrical portion 46 and the other magnetic damping portion 55 is arranged inside the cylindrical portion 46. In this case, the cylindrical portion 46 functions as an insulating layer 73 that insulates one magnetic damping portion 55 from the other magnetic damping portion 55.

[0164] ○As long as the iron core 60 is annular, the shape of the iron core 60 can also be appropriately changed. For example, the iron core 60 can also be circular.

[0165] ○In the above-described embodiment, the iron core 60 is composed of one component, but it can also be composed of two or more components.

[0166] ○As long as the non-magnetic damping portion 56 surrounds the first winding 61 and the second winding 62, the shape of the non-magnetic damping portion 56 can also be appropriately changed. For example, the non-magnetic damping portion 56 can also be circular.

[0167] ○In the above-described embodiment, the non-magnetic damping portion 56 is composed of one component, but it can also be composed of two or more components.

[0168] ○The noise reduction portion 50 can also have a plurality of common mode choke coils 51. In addition, in the second embodiment, the noise reduction portion 50 can also have the same number of non-magnetic damping portions 56 as the common mode choke coils 51.

[0169] ○The compression portion 13 is not limited to a scroll type, and can be, for example, a piston type, a vane type, or the like.

[0170] ○The electric compressor 10 can also be mounted on a fuel cell vehicle. In this case, the electric compressor 10 can also compress air, which is a fluid supplied to the fuel cell, by using the compression portion 13.

[0171] [Supplementary Note]

[0172] The following describes the technical idea that can be grasped from the above-described embodiments and modification examples.

[0173] <Supplementary Note 1>

[0174] An electric compressor includes: a compression portion that compresses a fluid; a motor that drives the compression portion; and an inverter device that drives the motor. The inverter device has: an inverter circuit portion that converts DC power into AC power; and a noise reduction portion that is provided on the input side of the inverter circuit portion and reduces common mode noise and normal mode noise. The noise reduction portion has: a common mode choke coil that has an annular iron core, a first winding wound around the iron core, and a second winding wound around the iron core and arranged at an interval from the first winding, and reduces the common mode noise; a smoothing capacitor that forms a low-pass filter circuit together with the common mode choke coil; and a magnetic damping portion that is composed of a plate-shaped magnetic body, generates eddy currents by using leakage magnetic flux leaking from the iron core, and reduces the normal mode noise. The electric compressor is characterized in that the noise reduction portion has a plurality of the magnetic damping portions, and the plurality of magnetic damping portions are laminated with an insulating layer interposed therebetween.

[0175] <Supplementary Note 2>

[0176] The electric compressor according to Note 1, wherein the plurality of magnetic damping portions respectively extend in the circumferential direction of the iron core so as to surround the outer circumference of the iron core.

[0177] <Supplementary Note 3>

[0178] The electric compressor according to Note 1, wherein the noise reduction portion has a non-magnetic damping portion formed of a plate-shaped non-magnetic body, and is arranged so as to surround the first winding and the second winding, and an induced current flows in the non-magnetic damping portion to generate a magnetic flux that resists the change in the leakage magnetic flux, and reduces the common-mode noise. The plurality of magnetic damping portions are respectively arranged with the non-magnetic damping portion interposed therebetween on the side opposite to the first winding and the second winding, and extend in the circumferential direction of the iron core so as to surround the outer circumference of the iron core.

[0179] <Supplementary Note 4>

[0180] The electric compressor according to Note 2 or Note 3, wherein when the direction in which the first winding and the second winding are arranged is set as the first direction, and the direction orthogonal to both the axial direction of the iron core and the first direction is set as the second direction, the plurality of magnetic damping portions respectively include a pair of side portions arranged so as to sandwich the space between the first winding and the second winding in the second direction, and at least one of the plurality of magnetic damping portions has a void portion that increases the magnetic resistance in at least one of the pair of side portions in the extending direction.

[0181] <Supplementary Note 5>

[0182] The electric compressor according to any one of Notes 1 to 4, wherein the insulating layer is a resin layer provided on the surface of the magnetic damping portion.

Claims

1. An electric compressor comprising: a compression portion that compresses a fluid; a motor that drives the compression portion; and an inverter device that drives the motor, The inverter device comprises: an inverter circuit portion that converts DC power into AC power; and a noise reduction unit, which is provided at the input side of the inverter circuit unit and reduces common mode noise and normal mode noise, The noise reduction unit comprises: A common mode choke coil having a ring-shaped iron core, a first winding wound on the iron core, and a second winding wound on the iron core and arranged at a distance from the first winding, and reducing the common mode noise; a smoothing capacitor which, together with the common mode choke coil, forms a low-pass filter circuit; as well as a magnetic damping part, which is composed of a plate-shaped magnetic body and generates an eddy current by utilizing the leakage magnetic flux leaking from the iron core to reduce the normal mode noise; The electric compressor is characterized in that The noise reduction unit has a plurality of magnetic damping units. The plurality of magnetic damping parts are stacked with insulating layers interposed therebetween.

2. The electric compressor according to claim 1, wherein: The plurality of magnetic damping portions extend along the circumferential direction of the core so as to surround the outer circumference of the core.

3. The electric compressor according to claim 1, wherein: The noise reduction unit includes a non-magnetic damping unit, the non-magnetic damping unit is formed of a plate-shaped non-magnetic body and is arranged in a manner of surrounding the first winding and the second winding, and an induced current flows in the non-magnetic damping unit to generate a magnetic flux that resists the change of the leakage magnetic flux and reduces the normal mode noise. The plurality of magnetic damping parts are disposed on the side opposite to the first winding and the second winding with the non-magnetic damping parts interposed therebetween, and extend in the circumferential direction of the core so as to surround the outer circumference of the core.

4. The electric compressor according to claim 2 or 3, wherein: When the direction in which the first winding and the second winding are arranged is defined as a first direction, and a direction orthogonal to both the axial direction of the core and the first direction is defined as a second direction, The plurality of magnetic damping parts each include a pair of side portions arranged so as to sandwich a space between the first winding and the second winding in the second direction. At least one of the plurality of magnetic damping parts has a gap portion that increases magnetic resistance in at least one of the pair of side portions in the extending direction.

5. The electric compressor according to any one of claims 1 to 4, wherein: The insulating layer is a resin layer provided on the surface of the magnetic damping part.

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