Electric motor, power conversion device, and electric motor system

Abstract

To achieve a higher rotational speed.SOLUTION: A motor 2 comprises: a rotor 22; a stator 23 provided with a plurality of coils; a plurality of electric power lines 8U, 8V, and 8W which supply electric power to the plurality of coils; and a noise reduction member 5, made of a magnetic material, which has a plurality of through-holes 51 provided for the plurality of electric power lines 8U, 8V, and 8W.SELECTED DRAWING: Figure 9

Description

[Technical field]

[0001] The present invention relates to an electric motor, a power conversion device, and an electric motor system. [Background technology]

[0002] Patent Documents 1 and 2 disclose technologies related to sensorless drive motors. Both of the technologies disclosed in Patent Documents 1 and 2 address noise that occurs in induced voltages. Patent Document 1 employs a method of incorporating electrical elements such as capacitors and resistors into the circuit as a countermeasure against noise. Patent Document 2 employs a method using signal processing as a countermeasure against noise. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2019-126103 A [Patent Document 2] JP 2014-166097 A Summary of the Invention [Problem to be solved by the invention]

[0004] There is a demand for electric motors to rotate at even higher speeds. To achieve higher speeds, it is important to take measures against noise, as signals with superimposed noise interfere with the rotation control of the motor. As mentioned above, noise countermeasures include a method of incorporating electric elements into the circuit and a method using signal processing. The method of incorporating electric elements into the circuit converts noise components into electrical loss and releases them as heat. Therefore, the electric elements that convert noise components into electrical loss become very hot. Furthermore, with the method using signal processing, there are cases where the signal processing cannot keep up with the high rotation speed of the motor. Therefore, it has been difficult to increase the rotation speed of electric motors.

[0005] Therefore, the present invention provides an electric motor capable of high speed rotation, a power conversion device, and an electric motor system. [Means for solving the problem]

[0006] One form of the present invention relates to an electric motor that includes a rotor, a stator having a plurality of coils, a plurality of power lines that supply power to each of the plurality of coils, and a noise reduction section formed of a magnetic material and having a plurality of through holes provided for each of the plurality of power lines.

[0007] This electric motor can reduce noise components superimposed on signals used to control the rotation of the electric motor due to iron loss caused by the noise reduction section, and therefore can achieve high speed rotation of the electric motor.

[0008] The electric motor may further include a housing that houses the rotor and the stator and has an opening through which the power lines pass, and the noise reduction unit may be disposed in the opening of the housing. This configuration also makes it possible to reduce high-frequency noise components superimposed on signals used to control the rotation of the electric motor.

[0009] The above electric motor may further include a housing that accommodates the rotor and the stator, the housing having a first portion including a noise reduction portion and a second portion not including the noise reduction portion, and the thickness of the first portion may be different from the thickness of the second portion. The housing has a first portion including a noise reduction portion and a second portion not including the noise reduction portion, and the thickness of the first portion may be different from the thickness of the second portion. This configuration also makes it possible to reduce high-frequency noise components superimposed on a signal used to control the rotation of the electric motor.

[0010] The electric motor further includes a housing that houses the rotor and the stator, and the noise reduction unit is a member attached to the housing, or the noise reduction unit may be a separate unit from the housing. This configuration also makes it possible to reduce high-frequency noise components superimposed on signals used to control the rotation of the electric motor.

[0011] Another form of the present invention is a power conversion device that includes a circuit section that converts received power into power required by an electric motor, a plurality of power lines that provide power to each of a plurality of coils possessed by the electric motor, and a noise reduction section formed of a magnetic material and with a plurality of through holes provided for each of the plurality of power lines.

[0012] This power conversion device can reduce noise components superimposed on signals used to control the rotation of the electric motor by iron loss caused by the noise reduction section.

[0013] An electric motor system according to yet another embodiment of the present invention includes an electric motor, a power conversion device that provides the electric power required by the electric motor to the electric motor, a plurality of power lines for electrically connecting the power conversion device to the electric motor, and a noise reduction section formed of a magnetic material and having a plurality of through holes provided for each of the plurality of power lines.

[0014] This electric motor system can reduce noise components superimposed on signals used to control the rotation of the electric motor due to iron loss caused by the noise reduction section, thereby enabling the electric motor to rotate at higher speeds. Effect of the Invention

[0015] According to the electric motor, power conversion device, and electric motor system of the present invention, high speed rotation is possible. [Brief description of the drawings]

[0016] [Figure 1] FIG. 1 is a schematic diagram of an electric motor system according to an embodiment. [Diagram 2] FIG. 2 is a circuit diagram of the inverter shown in FIG. [Diagram 3] FIG. 3 is a table for explaining the operation of the inverter and the motor shown in FIG. [Figure 4] Figure 4(a) is a graph showing the rotor phase, Figure 4(b) is a graph showing the U-phase voltage, Figure 4(c) is a graph showing the V-phase voltage, and Figure 4(d) is a graph showing the W-phase voltage. [Diagram 5] FIG. 5 is a circuit diagram showing a first operation of the inverter and the motor shown in FIG. [Figure 6] FIG. 6 is a circuit diagram showing a second operation of the inverter and the motor shown in FIG. [Figure 7] FIG. 7 is an equivalent circuit diagram for explaining the operation of the inverter and the motor shown in FIG. [Figure 8] FIG. 8 is a graph for explaining electrical problems in the inverter and the motor. [Figure 9] Fig. 9(a) is a configuration diagram of an electric motor system including a motor to which a noise reduction component is applied. Fig. 9(b) is a configuration diagram of an electric motor system including an inverter to which a noise reduction component is applied. Fig. 9(c) is a configuration diagram of an electric motor system to which a noise reduction component is applied. Fig. 9(d) is a configuration diagram of an electric motor system including a motor to which another noise reduction unit is applied. [Figure 10] FIG. 10 is a simplified perspective view for explaining the function of the noise reduction component. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0017] Hereinafter, embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. In the description of the drawings, the same elements are given the same reference numerals and duplicated descriptions will be omitted.

[0018] 1 is a two-stage centrifugal compressor. The rotating machine system 100 includes a rotating machine 1 and an inverter 9 (power conversion device).

[0019] The rotating machine 1 has a motor 2 (electric motor), a cooling jacket 3, a cooling device 4, and a pair of compressors 6. The motor 2 is provided with a rotating shaft 21, and impellers 61 of the compressor 6 are connected to both ends of the rotating shaft 21. The cylindrical rotating shaft 21 is supported by a pair of bearings 7 and rotates about its axis L relative to a motor housing 26. The cooling jacket 3 recovers heat generated by the operation of the motor 2 using a cooling medium supplied from the cooling device 4. The cooling medium is, for example, water.

[0020] The motor 2 has a motor housing 26. The motor housing 26 accommodates the motor 2, the cooling jacket 3, and the like. The cooling device 4 may be disposed outside the motor housing 26 as shown in FIG. 1, or may be accommodated inside the motor housing 26. The motor housing 26 has, for example, a cylindrical shape. The integrated motor 2 and the cooling jacket 3 are fixed to the inner circumferential surface of the motor housing 26. The motor housing 26 is made of, for example, ductile cast iron (Ferrum Casting Ductile: FCD), etc. A bearing casing 63 supporting the bearings 7 is provided on the inner circumferential side of the motor housing 26 at both ends in the axial direction D.

[0021] The motor 2 is a so-called brushless DC motor. The motor 2 has a rotor 22 and a stator 23. An alternating current is provided to the stator 23. An interaction between the rotor 22 and the stator 23 generates a torque in the rotor 22. As a result, the rotating shaft 21 fixed to the rotor 22 rotates.

[0022] The rotor 22 is attached to the rotating shaft 21. The position where the rotor 22 is fixed is approximately the center of the rotating shaft 21 in the axial direction D (hereinafter simply referred to as the "axial direction D").

[0023] The stator 23 surrounds the rotor 22 along the circumferential direction of the rotating shaft 21. The stator 23 includes a stator core 231 and a stator coil 232. The cylindrical stator core 231 extending along the axis L is provided so as to surround the rotor 22. The stator coil 232 is formed of a conductor wound around the stator core 231. In the stator coil 232, a portion protruding from the stator core 231 is a so-called coil end 232a. The coil end 232a protrudes in the axial direction D beyond both ends of the stator core 231.

[0024] The cooling jacket 3 is provided around the stator 23. That is, the cooling jacket 3 surrounds the stator 23 in the circumferential direction. The cooling jacket 3 also surrounds a part of the rotating shaft 21 and the rotor 22 that protrudes in the axial direction D beyond the end of the stator 23. The cooling jacket 3 is formed with a cooling flow passage 30 through which a cooling medium flows.

[0025] The cooling flow passage 30 is formed to revolve around the axis L of the rotating shaft 21. The cooling flow passage 30 has a flow passage inlet and a flow passage outlet. The flow passage inlet of the cooling flow passage 30 is connected to a supply pipe 41. The flow passage outlet is connected to a discharge pipe 42.

[0026] The cooling jacket 3 has a cylindrical inner housing 31 surrounding the stator 23, and a cylindrical outer housing 32 that is fitted to the inner housing 31. The inner housing 31 and the outer housing 32 are, for example, cast metal, and examples of materials include aluminum (Al) or cast iron. The cooling jacket 3 made by casting has a cast surface, and therefore has a relatively large surface roughness. When the surface roughness is large, the surface area tends to increase, which is advantageous from the viewpoint of heat transfer. The cooling jacket 3 may be made by three-dimensional molding instead of casting. The outer housing 32 surrounds the inner housing 31. The inner housing 31 is fixed to the outer housing 32 by bolts.

[0027] The inner housing 31 has a spiral flow passage groove 311 provided on the outer circumferential surface of the inner housing 31. In other words, the flow passage grooves 311 are each formed continuously so as to revolve around the axis L of the rotating shaft 21 as the center.

[0028] The opening of the flow passage groove 311 is closed by the inner circumferential surface of the outer housing 32. In other words, the inner circumferential surface of the outer housing 32 is in close contact with the outer circumferential surface of the inner housing 31.

[0029] The inverter 9 supplies so-called three-phase AC power to the motor 2. The inverter 9 is connected to the motor 2 via three power lines 8. The three power lines 8 correspond to the so-called U phase, V phase, and W phase.

[0030] Fig. 2 is a circuit diagram of the inverter 9 shown in Fig. 1. The inverter 9 outputs three-phase AC power by controlling the on / off of multiple switching elements. The inverter 9 has a power supply unit 91, a U-phase leg 92, a V-phase leg 93, and a W-phase leg 94.

[0031] The power supply unit 91 includes DC power supplies 911 and 912. The DC power supply 911 generates a positive voltage (+Vdc / 2). The DC power supply 912 generates a negative voltage (-Vdc / 2). The negative electrode of the DC power supply 911 is connected to the positive electrode of the DC power supply 912, and the negative electrode of the DC power supply 911 and the positive electrode of the DC power supply 912 are both connected to a reference potential 913.

[0032] U-phase leg 92 has a U-phase upper arm 921 and a U-phase lower arm 922. U-phase upper arm 921 and U-phase lower arm 922 are each formed by a switching element. U-phase upper arm 921 and U-phase lower arm 922 are connected in series. A U-phase output terminal 923 is provided on a line connecting U-phase upper arm 921 to U-phase lower arm 922. U-phase output terminal 923 is connected to U-phase power line 8U.

[0033] The V-phase leg 93 and the W-phase leg 94 have the same configuration as the U-phase leg 92. That is, the V-phase leg 93 has a V-phase upper arm 931 and a V-phase lower arm 932. A V-phase output terminal 933 is provided on the line connecting the V-phase upper arm 931 to the V-phase lower arm 932. The V-phase output terminal 933 is connected to the V-phase power line 8V. The W-phase leg 94 has a W-phase upper arm 941 and a W-phase lower arm 942. A W-phase output terminal 943 is provided on the line connecting the W-phase upper arm 941 to the W-phase lower arm 942. The W-phase output terminal 943 is connected to the W-phase power line 8W.

[0034] 2 also shows an equivalent circuit of the motor 2, which includes the inductor 24 and an induced voltage generating element 25. The induced voltage generating element 25 visualizes the induced voltage generated by the rotation of the rotor 22 for the purpose of explanation.

[0035] The inverter 9 shown in Fig. 2 repeats six operation modes M1 to M6 shown in the table of Fig. 3. Fig. 4(a) shows the phase of the rotor 22 in each of the operation modes M1 to M6. Fig. 4(b), Fig. 4(c), and Fig. 4(d) show the U-phase voltage, V-phase voltage, and W-phase voltage in each of the operation modes M1 to M6.

[0036] When "voltage detection" is written in the table of Fig. 3, the inverter 9 does not operate, but performs an operation of detecting the induced voltage from the motor 2. For example, in the operation mode M1, the U phase is in "voltage detection". Therefore, the pulse-shaped graphs G4b, G4c, and G4d shown in Fig. 4(b), Fig. 4(c), and Fig. 4(d) show the induced voltage of the motor 2.

[0037] The operation modes M1 to M6 are switched in sequence based on the timing when the reference voltage is exceeded. For example, when the phase advances by 30 degrees from the timing when the induced voltage exceeds zero, the operation modes are switched in sequence to the next operation modes M1 to M6. The timing when the induced voltage exceeds zero can be known by judging the so-called zero crossing. The zero crossing can be judged from the induced voltage output by each phase that detects the voltage.

[0038] In the examples shown in Figures 4(b), 4(c), and 4(d), the induced voltage is shown as a pulse-like waveform. Zero-crossings can be determined by either an analog circuit or digital processing. When using an analog circuit, the pulse-like signal indicating the induced voltage is passed through a low-pass filter. When using digital processing, a microcomputer is used to obtain the detected voltage in accordance with the MWM period.

[0039] The reason why the induced voltage is output as a pulse waveform as shown in FIGS. 4(b), 4(c) and 4(d) will be described.

[0040] For example, operation mode M1 will be taken as an example for detailed description. In operation mode M1, the U phase is in a voltage detection operation for detecting an induced voltage, the V phase is in a switching operation for outputting a PWM signal, and the W phase is in a conductive operation in which the W-phase upper arm 941 is always ON. In operation mode M1 in which these operations are performed, the V-phase lower arm 932 repeatedly turns ON or OFF. The V-phase upper arm 931 and the V-phase lower arm 932 operate in a complementary manner. This complementary operation makes it possible to suppress inverter loss during reflux.

[0041] First, when the switching element constituting V-phase lower arm 932 is ON, switching element 931S constituting V-phase upper arm 931 is OFF. Fig. 5 shows a first state in which V-phase lower arm 932 is ON and V-phase upper arm 931 is OFF in operation mode M1. In the first state shown in Fig. 5, the average value of the output voltage of inverter 9 is the reference potential (GND). Furthermore, in the first state, the intermediate potential of motor 2 is also the reference potential (GND). In the first state, the voltage detected in U-phase is only the induced voltage.

[0042] Next, when the switching element constituting V-phase lower arm 932 is OFF, switching element 931S constituting V-phase upper arm 931 is ON. Fig. 6 shows a second state in which V-phase lower arm 932 is OFF and V-phase upper arm 931 is ON in operation mode M1. In the second state shown in Fig. 6, the average value of the output voltage of inverter 9 is a positive voltage (+Vdc / 2). Furthermore, in the second state, the intermediate potential of motor 2 is also a positive voltage (+Vdc / 2). And, in the second state, the voltage detected in U-phase is a positive voltage (+Vdc / 2).

[0043] Here, if the induced voltage is positive, a positive voltage (+Vdc / 2) is added to the induced voltage, which exceeds the positive voltage (+Vdc / 2) output by DC power supply 911. In this case, a flywheel diode (not shown) provided in U-phase upper arm 921 is energized. As a result, the maximum value of the voltage detected in the U-phase becomes a positive voltage (+Vdc / 2).

[0044] To summarise the first and second states, the ON / OFF switching operation of the V-phase lower arm 932 in the operation mode M1 causes the intermediate potential of the motor 2 to become a pulsed signal which goes back and forth between the reference potential (GND) and a positive voltage (+Vdc / 2). As a result, the voltage detected in the U-phase also becomes a pulsed signal.

[0045] As described above, the operation modes M1 to M6 shown in Fig. 2 are switched sequentially based on the zero-cross timing. Therefore, accurately grasping the zero-cross timing is an important issue in controlling the motor 2 in sensorless operation.

[0046] According to an ideal circuit, the waveform of the induced voltage for obtaining the timing of the zero crossing is as shown in FIG. 4(b), FIG. 4(c), and FIG. 4(d). However, in an actual circuit, so-called parasitic resistance and parasitic capacitance exist. FIG. 7 is a circuit diagram showing an equivalent circuit when the U-phase is the voltage detection phase. As shown in FIG. 7, the equivalent circuit for detecting the induced voltage includes an inductor 24 caused by the winding of the motor 2, a parasitic resistance element 8R caused by the U-phase power line 8U connecting the motor 2 and the inverter 9, and parasitic capacitance elements 931C and 932C caused by the switching elements 931S and 932S.

[0047] These electrical elements form a so-called LCR series circuit. The LCR series circuit has a natural resonant frequency. When the switching frequency of the switching element approaches the resonant frequency of the equivalent circuit, the induced voltage contains noise caused by the resonance.

[0048] The graph in Figure 8 is an example of the measured value of the induced voltage. Graph G8 includes several peaks P8. The multiple peaks P8 are high-frequency noise components caused by resonance. If such noise components are included in the waveform of the induced voltage, it will affect the determination of the zero crossing.

[0049] In other words, if the switching frequency of the inverter 9 is increased in accordance with the increased speed of the motor 2, the frequency approaches the resonant frequency of the circuits included in the inverter 9 and the motor 2, and as a result, noise caused by resonance is superimposed on the induced voltage. When noise is superimposed on the induced voltage, it affects the determination of the zero crossings required for controlling the motor 2. As a result, the motor 2 is prevented from rotating at a higher speed.

[0050] Therefore, the rotating machine system 100 of the embodiment has a configuration for suppressing noise caused by resonance. Specifically, the Q value, which indicates the degree to which the amplitude increases due to resonance, is reduced. Refer again to the equivalent circuit shown in Fig. 7. The Q value of this equivalent circuit is expressed by equation (1). Q = ω × L / R (1) Q: Quality factor. ω: switching frequency. L: Motor 2 inductor. R: Parasitic resistance.

[0051] According to the formula (1), it is understood that in order to reduce the Q value on the left side, the parasitic resistance R included in the denominator on the right side should be increased. Therefore, the rotating machine system 100 is provided with a configuration for increasing the value of the parasitic resistance element 8R shown in the equivalent circuit of FIG.

[0052] First Embodiment 9(a) is a diagram showing a schematic diagram of a connection configuration between the motor 2 and the inverter 9. The inverter 9 is connected to the motor 2 via power lines 8U, 8V, and 8W.

[0053] The inverter 9 has a power conversion circuit 95 (circuit section), an inverter housing 96, and an inverter terminal block 97. The inverter housing 96 accommodates the power conversion circuit 95. The power conversion circuit 95 is connected to the inverter terminal block 97 by an internal cable 98. One ends of power lines 8U, 8V, and 8W are further connected to the inverter terminal block 97. The other ends of the power lines 8U, 8V, and 8W extend to the motor 2.

[0054] The motor 2 has a motor housing 26, a rotor 22, a stator 23, and a noise reduction member 5. The motor housing 26 is provided with an opening 26h that receives the power lines 8U, 8V, and 8W. For example, the opening 26h may be a single opening having a rectangular shape in a plan view. In other words, the three power lines 8U, 8V, and 8W are drawn into the motor housing 26 from the single opening 26h.

[0055] Here, the noise reducing member 5 is disposed so as to cover the opening 26h provided in the motor housing 26. The noise reducing member 5 is provided with three through holes 51U, 51V, 51W (see FIG. 10 ). Therefore, the power lines 8U, 8V, 8W are drawn into the motor housing 26 through the noise reducing member 5 and the opening 26h of the motor housing 26.

[0056] FIG. 10 is an enlarged perspective view of the noise reducing member 5. The noise reducing member 5 is a plate-shaped member. For example, the noise reducing member 5 may be an aluminum plate. The noise reducing member 5 has three through holes 51U, 51V, and 51W. The three through holes 51 may be arranged at equal intervals along a linear reference line. One power line 8U, 8V, and 8W is inserted into each of the through holes 51U, 51V, and 51W. In other words, the noise reducing member 5 is provided with the through holes 51U, 51V, and 51W for each of the power lines 8U, 8V, and 8W of each phase of the motor 2.

[0057] The inner diameters of the through holes 51U, 51V, 51W are the same as or larger than the outer diameters of the power lines 8U, 8V, 8W. As shown in Fig. 10, when the inner diameters of the through holes 51U, 51V, 51W are larger than the outer diameters of the power lines 8U, 8V, 8W, a small gap may be formed between the inner wall surfaces of the through holes 51U, 51V, 51W and the outer circumferential surfaces of the power lines 8U, 8V, 8W.

[0058] In the example of Fig. 10, a U-phase current flows through the power line 8U. A V-phase current flows through the power line 8V. A W-phase current flows through the power line 8W. For example, when a U-phase current flows through the power line 8U, a magnetic flux 5S is generated in a part of the noise reducing member 5 present around the power line 8U. Similarly, a magnetic flux 5S is generated around the power line 8V through which the V-phase current flows and the power line 8W through which the W-phase current flows.

[0059] This magnetic flux 5S generates so-called iron loss. This iron loss suppresses the generation of high-frequency current. As a result, it becomes possible to suppress the noise components superimposed on the induced voltage.

[0060] Furthermore, the noise reducing member 5 is provided so as to be exposed from the motor housing 26. In other words, the noise reducing member 5 is not surrounded by other components, and is disposed in a position that is advantageous for cooling, exposed to the outside air. As a result, heat generated by iron loss in the noise reducing member 5 is efficiently dissipated to the air surrounding the noise reducing member 5. Furthermore, there is no other member in the motor housing 26 that could be a heat source other than the noise reducing member 5. Therefore, since the noise reducing member 5 is naturally cooled, there is no need to add any component for cooling the noise reducing member 5. However, this description does not prevent the addition of a component for cooling the bus bar 81.

[0061] The motor 2 includes a rotor 22, a stator 23 having a plurality of coils, a plurality of power lines 8U, 8V, 8W which supply power to each of the plurality of coils, and a noise reduction member 5 which is made of a magnetic material and has a plurality of through holes 51U, 51V, 51W provided for each of the plurality of power lines 8U, 8V, 8W.

[0062] The motor 2 can reduce noise components superimposed on signals used to control the rotation of the motor 2 due to iron loss caused by the noise reducing member 5. This allows the electric motor to rotate at high speed.

[0063] <Second embodiment> In the first embodiment, the noise reducing member 5 is provided in the motor 2. That is, the noise reducing member 5 in the first embodiment is a component of the motor 2. If the noise reducing member 5 is provided between the power conversion circuit 95 and the stator 23, it will have the effect of reducing noise components. Therefore, as a second embodiment, a configuration in which the noise reducing member 5 is provided in the inverter 9A as shown in FIG. 9(b) will be described. That is, the noise reducing member 5 in the second embodiment is a component of the inverter 9A. Note that the configuration of the noise reducing member 5 alone is the same as that of the noise reducing member 5 in the first embodiment, and therefore a detailed description thereof will be omitted.

[0064] First, the motor 2A has a rotor 22, a stator 23, a motor housing 26, and a motor terminal block 27. The motor terminal block 27 is connected to the coil of the stator 23 by an internal cable 28. Furthermore, one ends of the power lines 8U, 8V, and 8W are connected to the motor terminal block 27.

[0065] The inverter 9A has a power conversion circuit 95, an inverter housing 96, and a noise reduction member 5. The inverter housing 96 is provided with an opening 96h that receives the power lines 8U, 8V, and 8W. For example, the opening 96h may be a single opening having a rectangular shape in a plan view. That is, the three power lines 8U, 8V, and 8W are led into the inverter housing 96 through the single opening 96h. The noise reduction member 5 is provided to cover the opening 96h.

[0066] The inverter 9A includes a power conversion circuit 95 that converts the received power into the power required by the motor 2A, a plurality of power lines 8U, 8V, 8W that provide power to each of the plurality of coils possessed by the motor 2A, and a noise reduction member 5 formed of a magnetic material and having a plurality of through holes 51 provided for each of the plurality of power lines 8U, 8V, 8W.

[0067] The inverter 9A can reduce noise components superimposed on a signal used to control the rotation of the motor 2A due to iron loss caused by the noise reducing member 5.

[0068] <Third embodiment> In the first embodiment, the noise reducing member 5 was a component of the motor 2, and in the second embodiment, the noise reducing member 5 was a component of the inverter 9. The noise reducing member 5 does not have to be a component of either the motor 2 or the inverter 9. Therefore, as shown in FIG. 9(c), a third embodiment will be described in which the noise reducing member 5 is a component of a rotating machine system 100. As in the first embodiment, the configuration of the noise reducing member 5 alone is the same as that of the noise reducing member 5 of the first embodiment, and therefore a detailed description thereof will be omitted.

[0069] The inverter 9B has a power conversion circuit 95, an inverter housing 96, and an inverter terminal block 97. The power conversion circuit 95 is connected to the inverter terminal block 97 by an internal cable 98. The inverter terminal block 97 is further connected to one ends of power lines 8U, 8V, and 8W.

[0070] The motor 2B has a rotor 22, a stator 23, a motor housing 26, and a motor terminal block 27. The motor terminal block 27 is connected to the coil of the stator 23 by an internal cable 28. Furthermore, one ends of the power lines 8U, 8V, and 8W are connected to the motor terminal block 27.

[0071] That is, in the third embodiment, the power lines 8U, 8V, 8W are not led into the motor housing 26, nor into the inverter housing 96.

[0072] The noise reducing member 5 is disposed between the motor terminal block 27 and the inverter terminal block 97. That is, the noise reducing member 5 of the third embodiment is not attached to the motor housing 26, and is not attached to the inverter housing 96 either.

[0073] The rotating machine system 100 includes a motor 2B, an inverter 9B that provides the motor 2B with the power required by the motor 2B, a plurality of power lines 8U, 8V, 8W for electrically connecting the inverter 9B to the motor 2B, and a noise reducing member 5 formed of a magnetic material and having a plurality of through holes 51U, 51V, 51W provided for each of the plurality of power lines 8U, 8V, 8W.

[0074] The rotating machine system 100 can reduce noise components superimposed on a signal used for controlling the rotation of the motor 2B due to iron loss in the noise reducing member 5. This allows the motor 2B to rotate at higher speeds.

[0075] The present disclosure is not limited to the above-described embodiment, and various modifications as described below are possible without departing from the gist of the present disclosure.

[0076] 9(d) shows a rotating machine system 100 including a motor 2C that is a modification of the first embodiment. The noise reduction member 5 of the motor 2C of the first embodiment is separate from the motor housing 26. The noise reduction part 5C of the motor 2C of the modification is integrated with the motor housing 26.

[0077] The motor housing 26 includes a first portion 26a and a second portion 26b. The first portion 26a includes the noise reduction portion 5C. The second portion 26b does not include the noise reduction portion 5C. The first portion 26a and the second portion 26b can be distinguished from each other by the difference in thickness. That is, the thickness of the first portion 26a including the noise reduction portion 5C is different from the thickness of the second portion 26b not including the noise reduction portion 5C. In the example shown in FIG. 9(d), the thickness of the first portion 26a is thinner than the thickness of the second portion 26b.

[0078] Even in this modified motor 2C, the noise components can be reduced by the iron loss caused by the noise reduction section 5C. [Explanation of symbols]

[0079] 1 Rotating Machinery 2. Motor (electric motor) 22 Rotor 23 Stator 26 Motor housing (housing) 26h opening 5 Noise reduction components (noise reduction parts) 8U,8V,8W power line 9. Inverter (power conversion device) 95 Power conversion circuit (circuit section) 96 Inverter housing (housing) 96h opening

Claims

1. A rotor; A stator provided with a plurality of coils; a plurality of power lines for providing power to each of the plurality of coils; a noise reducing portion formed of a magnetic material and having a plurality of through holes provided for each of the plurality of power lines.

2. a housing that accommodates the rotor and the stator and has an opening through which the power lines pass; The electric motor according to claim 1 , wherein the noise reduction portion is disposed in the opening of the housing.

3. a housing for accommodating the rotor and the stator; the housing has a first portion including the noise reduction portion and a second portion not including the noise reduction portion, 2. The electric motor of claim 1, wherein a wall thickness of said first portion is different than a wall thickness of said second portion.

4. a housing for accommodating the rotor and the stator; the noise reduction portion is a member attached to the housing, The electric motor according to claim 1 , wherein the noise reduction portion is separate from the housing.

5. a circuit section for converting the received electric power into electric power required by the electric motor; a plurality of power lines for supplying the electric power to each of a plurality of coils included in the electric motor; a noise reducing section formed of a magnetic material and having a plurality of through holes provided for each of the plurality of power lines.

6. An electric motor; a power converter for providing the electric motor with the electric power required by the electric motor; a plurality of power lines for electrically connecting the power converter to the electric motor; a noise reducing section formed of a magnetic material and having a plurality of through holes provided for each of the plurality of power lines.

Images