WO2024104481A1 - 一种电机及电器 - Google Patents

一种电机及电器 Download PDF

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Publication number
WO2024104481A1
WO2024104481A1 PCT/CN2023/132449 CN2023132449W WO2024104481A1 WO 2024104481 A1 WO2024104481 A1 WO 2024104481A1 CN 2023132449 W CN2023132449 W CN 2023132449W WO 2024104481 A1 WO2024104481 A1 WO 2024104481A1
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WO
WIPO (PCT)
Prior art keywords
end cover
motor
rotating shaft
stator
capacitor
Prior art date
Application number
PCT/CN2023/132449
Other languages
English (en)
French (fr)
Inventor
胡建
黎明
钟贵烈
彭潮炜
Original Assignee
广东美的白色家电技术创新中心有限公司
美的集团股份有限公司
广东美的制冷设备有限公司
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Priority claimed from CN202211441808.4A external-priority patent/CN115800647A/zh
Priority claimed from CN202211469857.9A external-priority patent/CN115765325A/zh
Priority claimed from CN202211469859.8A external-priority patent/CN115955040A/zh
Application filed by 广东美的白色家电技术创新中心有限公司, 美的集团股份有限公司, 广东美的制冷设备有限公司 filed Critical 广东美的白色家电技术创新中心有限公司
Publication of WO2024104481A1 publication Critical patent/WO2024104481A1/zh

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Classifications

    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02K—DYNAMO-ELECTRIC MACHINES
    • H02K11/00—Structural association of dynamo-electric machines with electric components or with devices for shielding, monitoring or protection
    • H—ELECTRICITY
    • H02—GENERATION; CONVERSION OR DISTRIBUTION OF ELECTRIC POWER
    • H02K—DYNAMO-ELECTRIC MACHINES
    • H02K11/00—Structural association of dynamo-electric machines with electric components or with devices for shielding, monitoring or protection
    • H02K11/40—Structural association with grounding devices

Definitions

  • the present application relates to the field of motor technology, and in particular to a motor and an electrical appliance.
  • the existing technology is mainly based on the research on motor electrical corrosion suppression technology under DC power supply, which mainly suppresses the shaft voltage formed by the common mode voltage generated by PWM (Pulse Width Modulation) at the bearing, thereby reducing the risk of electrical corrosion.
  • PWM Pulse Width Modulation
  • the present application mainly provides a motor and an electrical appliance to solve the problem of poor electrical corrosion suppression effect of the motor in a non-isolated AC power supply system.
  • the motor includes a rotor, a stator, a rotating shaft, a first end cover and a second end cover, wherein the rotor is arranged on the rotating shaft, the stator and the rotor are arranged to be nested with each other, the first end cover and the second end cover are arranged at both ends of the rotor and the stator along the axial direction of the rotating shaft, and the rotating shaft is rotatably supported by the first end cover and the second end cover, and the first end cover, the second end cover and the stator core of the stator are short-circuited.
  • the motor further includes a capacitor, and the stator core is further grounded through the capacitor.
  • the capacitor is an adjustable capacitor, and the capacitance value of the capacitor is adjusted according to the distance between the capacitor and the external metal member.
  • first end cover and the second end cover are metal end covers, and a radial dimension of the first end cover along the rotating shaft is greater than a radial dimension of the second end cover along the rotating shaft.
  • a radial dimension of the first end cover is greater than or equal to a radial dimension of the stator, and a radial dimension of the second end cover is smaller than a radial dimension of the stator.
  • the motor further comprises a first bearing and a second bearing, the first bearing comprising a first outer ring and a first inner ring which are insulated and isolated, the first outer ring being fixed to the first end cover and in electrical contact with the first end cover, and the first inner ring being fixed to the rotating shaft and in electrical contact with the rotating shaft;
  • the second bearing comprises a second outer ring and a second inner ring which are insulated and isolated, and the second outer ring is fixed to The second end cover is in electrical contact with the second end cover, and the second inner ring is fixed on the rotating shaft and in electrical contact with the rotating shaft.
  • the motor further includes an electronic control device, which is electrically connected to the stator winding of the stator, and is disposed between the rotor and the first end cover, and is insulated from the first end cover, the rotor, the rotating shaft, and the second end cover.
  • the motor further comprises a frame, the first end cover and the second end cover are disposed at both ends of the frame to form a receiving cavity, the rotor, the stator and the rotating shaft are disposed in the receiving cavity, and the rotating shaft further extends from the first end cover or the second end cover to outside the receiving cavity;
  • the motor further includes a conducting member, which is arranged on the frame and electrically connects the first end cover, the second end cover and the stator core.
  • the conductive member includes a first conductive portion and a second conductive portion, the first conductive portion is disposed on the frame and short-circuits the first end cover and the second end cover, and the second conductive portion short-circuits the stator core and the first conductive portion and is led out of the frame.
  • the electrical appliance comprises: the above-mentioned motor; a heat exchanger, which is spaced apart from the motor and grounded; a driving device, which is used to connect to the mains and supply power to the motor and control the operation of the motor; wherein the motor further comprises a capacitor, which is electrically connected between the stator core of the stator and the heat exchanger.
  • the beneficial effect of the present application is that, different from the prior art, the present application discloses a motor and an electrical appliance.
  • the first end cover, the second end cover and the stator core of the stator, the first end cover, the second end cover and the stator core are made to be at the same potential, so as to change the model topology of the motor, so that the motor can be applied to a non-isolated AC power supply system and can approach to achieve a bridge balance condition, so that the shaft voltage and shaft current can be significantly reduced, thereby effectively inhibiting the electrical corrosion of the motor.
  • FIG1 is a schematic diagram of a motor power supply model under a grid-powered and non-isolated solution
  • FIG2 is a schematic diagram of a shaft current waveform detected under the motor power supply model shown in FIG1 ;
  • FIG3 is a schematic diagram of the waveform of the shaft current detected by the first electro-corrosion inhibition scheme applied to the model shown in FIG1 ;
  • FIG4 is a schematic diagram of the waveform of the shaft current detected by the second electro-corrosion inhibition scheme applied to the model shown in FIG1 ;
  • FIG5 is a schematic diagram of the structure of a motor without adopting electrical corrosion suppression measures
  • FIG6 is a schematic diagram of a system equivalent distributed parameter model of the motor shown in FIG5 when it is applied to a grid-powered and non-isolated solution;
  • FIG7 is a schematic diagram of the structure of the equivalent DC power supply E2 after non-isolated AC/DC conversion in FIG6;
  • FIG8 is a schematic diagram of an equivalent circuit of the model in FIG6 after ⁇ -Y conversion
  • FIG9 is a schematic structural diagram of an embodiment of an electric corrosion suppression measure for a motor provided by the present application.
  • FIG10 is a schematic diagram of a system equivalent distributed parameter model of the motor shown in FIG9 applied to a grid-powered and non-isolated solution;
  • FIG11 is a schematic diagram of the shaft current waveform detected under the model shown in FIG10 ;
  • FIG12 is a schematic structural diagram of another embodiment of a motor provided by the present application that adopts an electrical corrosion suppression measure
  • FIG13 is a schematic diagram of a system equivalent distributed parameter model of the motor shown in FIG12 when it is applied to a grid-powered and non-isolated solution;
  • FIG14 is a schematic diagram of the shaft current waveform detected under the model shown in FIG13;
  • FIG15 is a schematic structural diagram of another embodiment of a motor provided by the present application that adopts an electro-corrosion inhibition measure
  • FIG16 is a schematic diagram of a system equivalent distributed parameter model of the motor shown in FIG15 when it is applied to a grid-powered and non-isolated solution;
  • FIG17 is a schematic diagram of the shaft current waveform detected under the model shown in FIG16;
  • FIG. 18 is a schematic structural diagram of an electrical appliance according to an embodiment of the present application.
  • first”, “second”, and “third” in the embodiments of the present application are only used for descriptive purposes and cannot be understood as indicating or implying relative importance or implicitly indicating the number of indicated technical features.
  • the features defined as “first”, “second”, and “third” can expressly or implicitly include at least one of the features.
  • the meaning of “multiple” is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.
  • the terms “including” and “having” and any of their variations are intended to cover non-exclusive inclusions.
  • a process, method, system, product, or device comprising a series of steps or units is not limited to the listed steps or units, but optionally also includes steps or units that are not listed, or optionally also includes other steps or units inherent to these processes, methods, products, or devices.
  • the brushless DC motor drive uses PWM modulation (Pulse Width Modulation).
  • PWM modulation Pulse Width Modulation
  • the sum of the three-phase output voltage, that is, the common mode voltage (zero sequence voltage) is not zero.
  • the common mode voltage will generate shaft voltage at the bearing.
  • EDM electrical discharge machining
  • FIG2 is a schematic diagram of the shaft current waveform detected under the motor power supply model shown in FIG1 , wherein the peak shaft current value is relatively large, there is a breakdown shaft current, and electrical corrosion is likely to occur.
  • FIG. 4 is a schematic diagram of the waveform of the shaft current detected under the scheme of short-circuiting the end covers on both sides of the motor with an electrical connector.
  • the electrical properties of the motor 100 without adopting the electrical corrosion suppression measures may be firstly analyzed to obtain a schematic diagram of the system equivalent distributed parameter model under the grid-powered and non-isolated scheme.
  • FIG5 is a schematic diagram of the structure of a motor without adopting electrical corrosion suppression measures.
  • the motor 100 includes a rotor 10, a stator 20 and a rotating shaft 30, wherein the rotor 10 is disposed on the rotating shaft 30, and the rotor 10 and the stator 20 are arranged to be spaced apart and nested with each other.
  • the motor 100 is powered on, the rotor 10 and the stator 20 rotate relative to the stator 20 due to the electromagnetic effect, and drive the rotating shaft 30 to output power.
  • the motor 100 further includes a first end cover 40, a first bearing 50, a second bearing 60, a second end cover 70 and a frame 80.
  • the first end cover 40 and the second end cover 70 are spaced apart along the axial direction of the rotating shaft 30.
  • the first end cover 40 and the second end cover 70 are covered at both ends of the frame 80 to form an accommodating cavity 82.
  • the rotor 10, the stator 20 and the rotating shaft 30 are arranged in the accommodating cavity 82, that is, the first end cover 40 and the second end cover 70 are respectively arranged at both ends of the rotor 10 and the stator 20 along the axial direction of the rotating shaft 30.
  • the rotating shaft 30 further extends from the first end cover 40 or the second end cover 70 to the outside of the accommodating cavity 82, and the rotating shaft 30 is rotatably supported on the first end cover 40 through the first bearing 50, and the rotating shaft 30 is rotatably supported on the second end cover 70 through the second bearing 60.
  • the rotor 10 includes a rotor core 12 and a rotor magnet 14, wherein the rotor magnet 14 is disposed on the rotor core 12, and a rotating shaft 30 is fixed in an axial hole of the rotor core 12, wherein at least the rotor core 12 and the rotor magnet 14 can be fixed together by plastic packaging, and the rotating shaft 30 can be interference fit with the axial hole, so that the rotating shaft 30 and the rotor core 12 are in direct contact, and the rotating shaft 30 and the rotor core 12 are both made of conductive materials to form electrical contact, and the rotor magnet 14 is electrically isolated from the rotor core 12 and the rotating shaft 30 due to the isolation of the plastic packaging material.
  • the stator 20 includes a stator core 22 and a stator winding 24.
  • the stator winding 24 is wound around the stator core 22.
  • the stator winding 24 generates an alternating magnetic field when powered on, and the electromagnetic effect between the stator winding 24 and the rotor 10 causes the rotor 10 to rotate.
  • the stator 20 is sleeved on the outer circumference of the rotor 10 and is spaced apart from the rotor 10 , that is, there is a gap between the stator 20 and the rotor 10 to form electrical isolation.
  • first end cover 40 and the second end cover 70 may be integrally formed with the frame 80 by injection molding, and the other may be detachably connected to the frame 80.
  • both the first end cover 40 and the second end cover 70 may be detachably connected to the frame 80.
  • the first end cover 40 and the second end cover 70 are both conductive end covers, and are insulated and isolated from the rotor 10, the stator 20 and the rotating shaft 30.
  • the first end cover 40 and the second end cover 70 may not be in contact with the rotor 10, the stator 20 and the rotating shaft 30, or may be isolated from each other by an insulating member made of an insulating material.
  • the first end cap 40 and the second end cap 70 may be metal end caps or composite material end caps.
  • the composite material end caps may contain conductive particles uniformly mixed therein, which may realize a conductive function.
  • the radial dimension of the first end cover 40 along the rotating shaft 30 is larger than the radial dimension of the second end cover 70 along the rotating shaft 30, so that the distributed capacitance formed between the first end cover 40 and the stator core 22 is larger, and the distributed capacitance formed between the second end cover 40 and the stator core 22 is smaller.
  • the radial dimension of the first end cover 40 is greater than the radial dimension of the stator 20 , and even its outer contour can be used as the outer contour of the motor 100 .
  • the first end cover 40 completely covers the frame 80 in the axial direction, covers the rotor 10 and the stator 20 , and its radial dimension is the radial dimension of the motor 100 .
  • the radial dimension of the second end cover 70 is roughly the radial dimension of the rotor 10 .
  • the rotating shaft 30 is rotatably supported on the first end cover 40 and the second end cover 70 through the first bearing 50 and the second bearing 60 respectively, wherein the first bearing 50 includes a first outer ring 51 and a first inner ring 52 which are insulated and isolated, the first outer ring 51 is fixed to the first end cover 40 and is in electrical contact with the first end cover 40, the first inner ring 52 is fixed to the rotating shaft 30 and is in electrical contact with the rotating shaft 30, that is, the rotating shaft 30 and the first end cover 40 are insulated and isolated by the first bearing 50; the second bearing 60 includes a second outer ring 61 and a second inner ring 62 which are insulated and isolated, the second outer ring 61 is fixed to the second end cover 70 and is in electrical contact with the second end cover 70, the second inner ring 62 is fixed to the rotating shaft 30 and is in electrical contact with the rotating shaft 30, that is, the rotating shaft 30 and the second end cover 70 are insulated and isolated by the second bearing 60.
  • the first bearing 50 includes a first outer ring 51
  • the motor 100 also includes an electronic control device 90, which is arranged in the accommodating cavity 82.
  • the electronic control device 90 is electrically connected to the stator winding 24 of the stator 20 and serves as the negative pole of the DC bus of the motor 100, wherein the stator winding 24 is a three-phase winding, and the neutral point of the three-phase winding serves as the positive pole of the DC bus of the motor 100, and supplies current after non-isolated AC/DC conversion.
  • the electric control device 90 is disposed between the rotor 10 and the first end cover 40 , and is insulated from the first end cover 40 , the rotor 10 , the rotating shaft 30 and the second end cover 70 .
  • the current motor 100 is applied to the application scenario of "AC power supply from the power grid + non-isolated AC/DC conversion + DC motor", and a specific system analysis is performed taking into account the more practical situation in the application environment, that is, the existence of external metal parts around the motor 100.
  • the motor 100 can be used in equipment such as air conditioning systems, air purifiers, range hoods or dishwashers.
  • the external metal parts are condensers.
  • the first end cover 40, the second end cover 70 and the rotating shaft 30 located outside the motor 100 are all There is an equivalent capacitance with the external metal part.
  • the scenario in which the external metal parts around the motor 100 are condensers is analyzed. Based on this actual application scenario, its circuit model is equivalent to obtain a system equivalent distributed parameter model as shown in Figure 6, wherein the power grid E1 supplies power to the entire system.
  • the power grid E1 is the mains electricity, and its remote end is directly grounded.
  • E2 is an equivalent DC power supply after non-isolated AC/DC conversion, which is supplied to the subsequent motor 100.
  • the motor 100 is the motor shown in Figure 5.
  • the positive pole of the DC power supply E2 is electrically connected to the neutral point of the stator winding 24, and the negative pole of the DC power supply E2 is electrically connected to the electronic control device 90, which can be equivalent to the negative pole of the DC bus in the model;
  • the first end cover 40, the stator core 22, the rotor magnet 14, the rotating shaft 30 and the second end cover 70 are all insulated and isolated from the stator winding 24, thereby forming equivalent capacitors Csb1, Cs, Cm and Csb2 respectively;
  • the first end cover 40, the rotating shaft 30 and the second end cover 70 are all insulated and isolated from the electronic control device 90, thereby forming equivalent capacitors Cn1, Csn and Cn2 respectively;
  • the stator core 22 is arranged between the first end cover 40 and the second end cover 70, and is insulated from the first end cover 40 and the second end cover 70.
  • the sub-core 22 forms equivalent capacitors Cg1 and Cg2 with the first end cover 40 and the second end cover 70 respectively;
  • the rotating shaft 30 is insulated and isolated from the first end cover 40 and the second end cover 70, thereby forming equivalent capacitors Cb1 and Cb2 with the first end cover 40 and the second end cover 70 respectively, and the resistance of the rotating shaft 30 itself is divided into L1 and L2, respectively corresponding to its parts located at the first end cover 40 and the second end cover 70;
  • the rotor magnet 14 is also isolated and insulated from the rotating shaft 30 and the stator core 22, and forms equivalent capacitors Cmg and Cg respectively;
  • the first end cover 40, the rotating shaft 30 and the second end cover 70 also form equivalent capacitors Cn3, Cn4 and Cn5 with external metal parts, and the external metal parts are also grounded in specific equipment.
  • the first outer ring 51 is electrically in contact with the first end cover 40
  • the first inner ring 52 is electrically in contact with the rotating shaft 30
  • the equivalent capacitor Cb1 is the bearing capacitance of the first bearing 50
  • the second outer ring 61 is electrically in contact with the second end cover 70
  • the second inner ring 62 is electrically in contact with the rotating shaft 30
  • the equivalent capacitor Cb2 is the bearing capacitance of the second bearing 60; therefore, once the shaft voltage allocated to the equivalent capacitors Cb1 and Cb2 is too large, the lubricating oil film in the bearing will be broken down to generate electrospark machining (EDM) current, causing electrical corrosion.
  • EDM electrospark machining
  • the equivalent DC power supply E2 after the non-isolated AC/DC conversion specifically includes a rectifier unit 1 and an inverter unit 2.
  • the rectifier unit 1 is used to convert AC power into DC power
  • the inverter unit 2 is used to receive a control signal to regulate the on/off status of each phase winding in the stator winding 24, so as to utilize the electromagnetic effect to drive the rotor 10 to rotate.
  • the rectifier unit 1 includes a first rectifier branch, a second rectifier branch and a capacitor branch connected in parallel, the first rectifier branch includes a first diode D1 and a second diode D2 connected in series, the second rectifier branch includes a third diode D3 and a fourth diode D4 connected in series, the capacitor branch includes a capacitor C, a node a1 derived from the first rectifier branch is used to connect the live wire of the power grid E1, and the node a1 is connected between the first diode D1 and the second diode D2, a node a2 derived from the second rectifier branch is used to connect the neutral wire of the power grid E1, and the node a2 is connected between the third diode D3 and the fourth diode D4, and one end of the capacitor branch is also derived to connect to an electronic control device 90 that serves as the negative pole of the DC bus.
  • the inverter unit 2 includes a first switch branch, a second switch branch and a third switch branch connected in parallel, and the first switch branch, the second switch branch and the third switch branch are connected in parallel with the capacitor branch.
  • the first switch branch includes a first switch tube Q1 and a second switch tube Q2 connected in series
  • the second switch branch includes a third switch tube Q3 and a fourth switch tube Q4 connected in series
  • the third switch branch includes a fifth switch tube Q5 and a sixth switch tube Q6 connected in series. Leads are respectively drawn out from the first switch branch, the second switch branch and the third switch branch to connect the stator.
  • resistance R1 and inductance Ln1 are the equivalent resistance and equivalent inductance on the neutral point line of the first switch branch connected to the stator winding
  • resistance R2 and inductance Ln2 are the equivalent resistance and equivalent inductance on the neutral point line of the second switch branch connected to the stator winding
  • resistance R3 and inductance Ln3 are the equivalent resistance and equivalent inductance on the neutral point line of the third switch branch connected to the stator winding 24.
  • the rectifier unit 1 and the inverter unit 2 may also have other forms, which are more common technical means and can be designed by referring to public information. This application does not limit their specific forms.
  • the distributed capacitance model of the current motor 100 is now simplified according to the ⁇ -Y conversion.
  • the ⁇ -Y conversion is the step-down starting conversion relationship of the motor.
  • the model can be gradually simplified into an equivalent circuit as shown in FIG8 .
  • the bridge balance voltage division condition can be achieved by adjusting the capacitance of some equivalent capacitors to reduce the shaft voltage, thereby reducing the shaft current on the shaft 30 and achieving the purpose of inhibiting electrical corrosion.
  • FIG 9 is a structural schematic diagram of an embodiment of an electric motor provided in the present application using an electro-corrosion suppression measure.
  • the motor shown in Figure 9 is modified based on Figure 5 to change its topological structure in the current system model, thereby achieving electro-corrosion suppression.
  • the first end cover 40, the second end cover 70 and the stator core 22 of the stator 20 are further short-circuited, and the motor 100 shown in Figure 9 is applied to the grid power supply and non-isolation scheme to obtain the system equivalent distributed parameter model schematic diagram as shown in Figure 10, wherein the first end cover 40, the second end cover 70 and the stator core 22 are at the same potential, the equivalent capacitance Cg1 between the first end cover 40 and the stator core 22 is eliminated, and the equivalent capacitance Cg2 between the second end cover 70 and the stator core 22 is also eliminated to change the model topology of the motor 100, and actual measurement verification is carried out. It is found that compared with the model topology of the original motor 100, the shaft voltage of the motor 100 shown in Figure 9 is significantly reduced, and the actual measurement results verify that there is no shaft current peak value of breakdown.
  • the first end cover 40 and the second end cover 70 are metal end covers, and the radial dimension of the first end cover 40 along the rotating shaft 30 is larger than the radial dimension of the second end cover 70 along the rotating shaft 30. Therefore, relatively speaking, the equivalent capacitance formed by the first end cover 40 and the second end cover 70 and the adjacent components on the motor 100 is more conducive to achieving the bridge balance condition.
  • the radial dimension of the first end cover 40 is greater than or equal to the radial dimension of the stator 20, and the radial dimension of the second end cover 70 is less than the radial dimension of the stator 20.
  • the radial dimension of the first end cover 40 is the radial dimension of the motor 100, that is, the first end cover 40 covers the stator 20 and the frame 80
  • the radial dimension of the second end cover 70 can be equal to the radial dimension of the rotor 10, which can effectively adjust the distributed capacitance model in the motor 100, so as to be more conducive to achieving or approaching the bridge balance condition through the above means.
  • the motor 100 further includes a capacitor C1 , and the stator core 22 is further grounded through the capacitor C1 to further promote the bridge balance condition, thereby reducing the shaft current on the rotating shaft 30 and avoiding the occurrence of breakdown shaft current.
  • the motor 100 is used in an air conditioner
  • the condenser is an external metal part near the motor 100, and the condenser is grounded
  • the stator core 22 is connected to the condenser through the capacitor C1 to The device is grounded.
  • the capacitor C1 may be an adjustable capacitor, and the capacitance value of the capacitor C1 is adjusted according to the distance from the external metal member. For example, in practical applications, the shaft current may be detected, and the capacitance value of the capacitor C1 may be adjusted to achieve a bridge balance condition, reduce the shaft current on the rotating shaft 30, and avoid a breakdown shaft current.
  • the capacitance value of the capacitor C1 is adjusted by adjusting the overlapping area of the two metal plates.
  • the capacitance value of the capacitor C1 can also be adjusted by adjusting the distance between the two metal plates.
  • the capacitor C1 may also be a fixed capacitor.
  • the positions of components such as the motor 100 and the condenser are determined, and the required capacitance value of the capacitor C1 can also be determined.
  • the required capacitance value of the capacitor C1 is a fixed value, that is, the capacitor C1 may also be a fixed capacitor.
  • the capacitor C1 may not be added, and the shaft current on the rotating shaft 30 can also be effectively reduced to avoid the occurrence of breakdown shaft current.
  • the motor 100 further includes a conducting member 101 , which is disposed on the frame 80 and electrically connects the first end cover 40 , the second end cover 70 and the stator core 22 , and is also grounded through the capacitor C1 .
  • the conductive member 101 may be a conductive sheet, a conductive pin or a conductive tape, which may be partially embedded in the frame 80 or partially attached to the inner surface or outer surface of the frame 80 .
  • the conductive member 101 includes a first conductive portion 102 and a second conductive portion 103, the first conductive portion 102 is buried in the frame 80 and short-circuit the first end cover 40 and the second end cover 70, the second conductive portion 103 passes through the frame 80 and short-circuit the stator core 22 and the second conductive portion 103, and the second conductive portion 103 is led outward from the frame 80 to electrically connect the capacitor C1 and is grounded through an external metal member, for example, through a condenser.
  • the first conductive part 102 can be a conductive sheet, a conductive tape, a conductive wire or a conductive pin
  • the second conductive part 103 can be a conductive sheet, a conductive wire or a conductive pin.
  • the first conductive part 102 is a conductive tape, it can also be attached to the inside or outside of the frame 80.
  • FIG 11 is a schematic diagram of the shaft current waveform detected under the model shown in Figure 10, wherein the peak value of the shaft current is 12mA during actual measurement, which can reduce the shaft current by 500% compared with the existing schemes one and two, and there is no breakdown shaft current, which can effectively avoid the phenomenon of electrical corrosion in the application scenario of "grid AC power supply + non-isolated AC/DC conversion + DC motor", and greatly improve the reliability of the motor 100 and its system.
  • FIG 12 is a structural schematic diagram of another embodiment of the motor provided in the present application using electrical corrosion suppression measures.
  • the motor shown in Figure 12 is modified based on Figure 5 to change its topological structure in the current system model, thereby achieving electrical corrosion suppression.
  • the radial dimension of the first end cover 40 along the rotating shaft 30 is greater than or equal to the radial dimension of the rotor 10 along the rotating shaft 30 and is smaller than the radial dimension of the stator 20 along the rotating shaft 30.
  • the stator core 22 of the stator 20 is grounded.
  • the motor 100 shown in Figure 12 is applied to the grid power supply and non-isolated scheme to obtain the system equivalent distributed parameter model schematic diagram as shown in Figure 10, wherein the motor 100 shown in Figure 12 is relative to the motor 100 shown in Figure 5, by reducing the area of the original first end cover 40 to reduce the distributed capacitance between the first end cover 40 and the stator core 22 and the stator winding 24, that is, the original equivalent capacitance Cg1 is reduced to the equivalent capacitance Cg1', the equivalent capacitance Csb1 is reduced to the equivalent capacitance Csb1', and the stator core 22 is directly grounded to change the model topology of the motor 100 and the equivalent capacitance between the system model, reduce the shaft voltage of the motor 100 in the case of non-isolated system application, inhibit the electrical corrosion phenomenon, and conduct actual measurement verification.
  • the motor 100 further includes a conducting member 101, which is electrically connected to the stator core 22 and leads out of the accommodating cavity 82 through the frame 80, and is used for grounding. By setting the conducting member 101 to lead out of the frame 80, the stator core 22 can be directly grounded.
  • the conductive member 101 is formed by the core laminations of the stator core 22 being led out of the frame 80, that is, at least one of the core laminations forming the stator core 22 is also led out of the frame 80 to serve as the grounding terminal of the stator core 22, so as to facilitate the grounding of the stator core 22.
  • the conductive member 101 may also be a conductive sheet or a conductive pin, one end of which is short-circuited with the stator core 22, and the other end is led out through the frame 80 to serve as the grounding terminal of the stator core 22 to facilitate grounding of the stator core 22.
  • the conductive member 101 may be grounded through an external metal member, for example, through a condenser.
  • Figure 15 is a structural schematic diagram of another embodiment of the motor provided in the present application using electrical corrosion suppression measures.
  • the motor shown in Figure 15 is modified on the basis of Figure 5 to change its topological structure in the current system model, thereby achieving electrical corrosion suppression.
  • first end cover 40 and the second end cover 70 are metal end covers.
  • the radial dimension of the first end cover 40 and the second end cover 70 along the rotating shaft 30 is larger than the radial dimension of the second end cover 70 along the rotating shaft 30, so that relatively speaking, the equivalent capacitance formed by the first end cover 40 and the second end cover 70 and the adjacent components on the motor 100 is more conducive to achieving the bridge balance condition.
  • the first end cover 40 and the stator core 22 are also grounded via a capacitor C1 to further promote the bridge balance condition, thereby reducing the shaft current on the rotating shaft 30 and avoiding the occurrence of breakdown shaft current.
  • the motor 100 is applied to an air conditioner
  • the condenser is an external metal part near the motor 100
  • the condenser is grounded
  • the first end cover 40 is connected to the condenser through the capacitor C1 to be grounded through the condenser.
  • the capacitance value of the capacitor C1 is adjusted by adjusting the overlapping area of the two metal plates.
  • the capacitance value of the capacitor C1 can also be adjusted by adjusting the distance between the two metal plates.
  • the capacitance value of capacitor C1 is greater than or equal to 50pF and less than or equal to 70pF. After short-circuiting the first end cover 40 and the stator core 22, the required smaller grounding capacitance value can obviously approach the bridge balance condition, thereby reducing the shaft current and avoiding electrical corrosion in system applications.
  • the capacitance range of the capacitor C1 may be an adjustable capacity range of the adjustable capacitor, which may be adjusted based on the actual condition of the motor 100 .
  • the capacitance value of the capacitor C1 may be 50 pF, 55 pF, 60 pF, 65 pF, or 70 pF, and the capacitance value may be adaptively adjusted when the motor 100 is used in different system environments.
  • the motor 100 further includes a conductive member 101 , which short-circuits the first end cover 40 and the stator core 22 , and can also be connected to the capacitor C1 through the conductive member 101 to achieve grounding, or the first end cover 40 is directly grounded through the capacitor C1 .
  • the conductive member 101 may be a conductive sheet, a conductive pin or a conductive tape, which may be partially embedded in the frame 80 or partially attached to the inner surface or outer surface of the frame 80 .
  • the conductive member 101 includes a first conductive portion 102 and a second conductive portion 103.
  • the first conductive portion 102 passes through the frame 80 and short-circuits the stator core 22.
  • the second conductive portion 103 is buried in the frame 80 and short-circuits the first end cover 40 and the first conductive portion 102.
  • the first conductive portion 102 can be led outward from the frame 80 to electrically connect the capacitor C1 and be grounded through an external metal member, such as being grounded through a condenser, or the first end cover 40 is directly grounded through the capacitor C1.
  • the first conductive portion 102 may be a conductive sheet, a conductive line or a conductive pin
  • the second conductive portion 103 may be
  • the second conductive portion 103 may be a conductive sheet, a conductive tape, a conductive wire or a conductive pin.
  • the second conductive portion 103 is a conductive tape, it may also be attached to the inner side or the outer side of the frame 80 .
  • FIG 17 is a schematic diagram of the shaft current waveform detected under the model shown in Figure 16, wherein the peak value of the shaft current is 40mA during actual measurement, which can reduce the shaft current by about 200% compared with the existing schemes one and two, and the breakdown frequency is significantly reduced, which can effectively avoid the phenomenon of electrical corrosion in the application scenario of "grid AC power supply + non-isolated AC/DC conversion + DC motor", and greatly improve the reliability of the motor 100 and its system.
  • FIG18 is a schematic diagram of the structure of an embodiment of the electrical appliance 200 provided by the present application.
  • the electrical appliance 200 includes the motor 100, a heat exchanger 201 and a drive device 202 as described above, the heat exchanger 201 is spaced apart from the motor 100, and the heat exchanger is grounded; the drive device 202 is used to connect to the mains, and to supply power to the motor 100 and control the operation of the motor 100; wherein the motor 100 also includes a capacitor C1, which is electrically connected between the stator core 22 of the stator 20 and the heat exchanger 201.
  • the heat exchanger 201 may specifically be an evaporator or a condenser.
  • the line L connected to the driving device 202 represents the live line of the power grid
  • the line N connected to the driving device 202 represents the neutral line of the power grid
  • the line PE connected to the heat exchanger 201 represents the ground line.
  • the electrical appliance 200 may be an air conditioner, a refrigerator, an air purifier, a range hood or a dishwasher, etc.
  • the driving device 202 includes the above-mentioned non-isolated AC/DC conversion device.
  • the capacitance value of the capacitor C1 may be adaptively adjusted based on the distance value between the motor 100 and the heat exchanger 201 to avoid breakdown shaft current and inhibit electrical corrosion.
  • the capacitor C1 may be omitted.

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  • Motor Or Generator Frames (AREA)

Abstract

本申请公开了一种电机及电器。该电机包括转子、定子、转轴、第一端盖和第二端盖，转子设置于转轴上，定子与转子间隔嵌套设置，第一端盖和第二端盖沿转轴的轴向分设于转子和定子的两端，且转轴转动支撑于第一端盖和第二端盖，第一端盖、第二端盖和定子的定子铁芯短接。通过上述方式，本申请提供的电机能够有效地抑制电机的电腐蚀现象。

Description

一种电机及电器
本申请要求于2022年11月17日提交的申请号2022114698579，发明名称为“一种电机及电器”的中国专利申请的优先权；本申请要求于2022年11月17日提交的申请号2022114418084，发明名称为“一种电机及电器”的中国专利申请的优先权；本申请要求于2022年11月17日提交的申请号2022114698598，发明名称为“一种电机及电器”的中国专利申请的优先权，其通过引用方式全部并入本申请。
【技术领域】
本申请涉及电机技术领域，特别是涉及一种电机及电器。
【背景技术】
现有技术主要基于直流供电情况下电机电腐蚀抑制技术研究，主要抑制由于PWM(Pulse Width Modulation，脉宽调制)产生的共模电压在轴承处分压形成的轴电压，从而降低电腐蚀风险。
然而在研究中发现，电机在非隔离的交流供电系统中使用时，轴电压上会叠加工频成分，现有技术方案的抑制效果有限。
【发明内容】
本申请主要提供一种电机及电器，以解决电机在非隔离的交流供电系统中的电腐蚀抑制效果不佳的问题。
为解决上述技术问题，本申请采用的一个技术方案是：提供一种电机。所述电机包括转子、定子、转轴、第一端盖和第二端盖，所述转子设置于所述转轴上，所述定子与所述转子间隔嵌套设置，所述第一端盖和所述第二端盖沿所述转轴的轴向分设于所述转子和所述定子的两端，且所述转轴转动支撑于所述第一端盖和所述第二端盖，所述第一端盖、所述第二端盖和所述定子的定子铁芯短接。
在一些实施例中，所述电机还包括电容器，所述定子铁芯还通过所述电容器接地。
在一些实施例中，所述电容器为可调电容器，所述电容器的电容值根据其与外部金属件的距离大小进行调整。
在一些实施例中，所述第一端盖和所述第二端盖为金属端盖，所述第一端盖沿所述转轴的径向尺寸大于所述第二端盖沿所述转轴的径向尺寸。
在一些实施例中，所述第一端盖的径向尺寸大于等于所述定子的径向尺寸，所述第二端盖的径向尺寸小于所述定子的径向尺寸。
在一些实施例中，所述电机还包括第一轴承和第二轴承，所述第一轴承包括绝缘隔离的第一外圈和第一内圈，所述第一外圈固定于所述第一端盖并与所述第一端盖电性接触，所述第一内圈固定于所述转轴上并与所述转轴电性接触；
所述第二轴承包括绝缘隔离的第二外圈和第二内圈，所述第二外圈固定于 所述第二端盖并与所述第二端盖电性接触，所述第二内圈固定于所述转轴上并与所述转轴电性接触。
在一些实施例中，所述电机还包括电控器件，所述电控器件电连接所述定子的定子绕组，所述电控器件设置于所述转子和所述第一端盖之间，且与所述第一端盖、所述转子、所述转轴和所述第二端盖绝缘隔离。
在一些实施例中，所述电机还包括机架，所述第一端盖和所述第二端盖设置于所述机架的两端，以形成一容置腔，所述转子、所述定子和所述转轴设置于所述容置腔内，所述转轴进一步从所述第一端盖或所述第二端盖延伸至所述容置腔外；
其中，所述电机还包括导通件，所述导通件设置于所述机架且电连接所述第一端盖、所述第二端盖和所述定子铁芯。
在一些实施例中，所述导通件包括第一导通部和第二导通部，所述第一导通部设置于所述机架上且短接所述第一端盖和所述第二端盖，所述第二导通部短接所述定子铁芯和所述第一导通部并向所述机架外引出。
为解决上述技术问题，本申请采用的另一个技术方案是：提供一种电器。所述电器包括：如上述的电机；换热器，与所述电机间隔设置，且所述换热器接地；驱动器件，所述驱动器件用于外接市电，并给所述电机供电和控制所述电机运行；其中，所述电机还包括电容器，所述电容器电连接于所述定子的定子铁芯和所述换热器之间。
本申请的有益效果是：区别于现有技术的情况，本申请公开了一种电机及电器。通过将第一端盖、第二端盖和定子的定子铁芯短接，使得第一端盖、第二端盖和定子铁芯为等电势位，以改变电机的模型拓扑结构，使得电机应用于非隔离的交流供电系统中是可趋近于达成电桥平衡条件，以使得轴电压和轴电流能够明显地降低，从而有效地抑制电机电腐蚀现象。
【附图说明】
为了更清楚地说明本申请实施例或现有技术中的技术方案，下面将对实施例或现有技术描述中所需要使用的附图作简单地介绍，显而易见地，下面描述中的附图仅仅是本申请的一些实施例，对于本领域普通技术人员来讲，在不付出创造性劳动的前提下，还可以根据这些附图获得其他的附图，其中：
图1是电网供电且非隔离方案下的电机供电模型示意图；
图2是图1所示电机供电模型下检测得到的轴电流波形示意图；
图3是应用于如图1所示模型下的电腐蚀抑制方案一所检测得到的轴电流的波形示意图；
图4是应用于如图1所示模型下的电腐蚀抑制方案二所检测得到的轴电流的波形示意图；
图5是电机未采用电腐蚀抑制措施的结构示意图；
图6是图5所示电机应用于电网供电且非隔离方案下的系统等效分布参数模型示意图；
图7是图6中经非隔离AC/DC变换后等效的直流电源E2的结构示意图；
图8是图6模型经Δ-Y转换后的等效电路示意图；
图9是本申请提供的电机采用电腐蚀抑制措施一实施例的结构示意图；
图10是图9所示电机应用于电网供电且非隔离方案下的系统等效分布参数模型示意图；
图11是图10所示模型下检测得到的轴电流波形示意图；
图12是本申请提供的电机采用电腐蚀抑制措施另一实施例的结构示意图；
图13是图12所示电机应用于电网供电且非隔离方案下的系统等效分布参数模型示意图；
图14是图13所示模型下检测得到的轴电流波形示意图；
图15是本申请提供的电机采用电腐蚀抑制措施又一实施例的结构示意图；
图16是图15所示电机应用于电网供电且非隔离方案下的系统等效分布参数模型示意图；
图17是图16所示模型下检测得到的轴电流波形示意图；
图18是本申请提供的电器一实施例的结构示意图。
【具体实施方式】
下面将结合本申请实施例中的附图，对本申请实施例中的技术方案进行清楚、完整地描述，显然，所描述的实施例仅是本申请的一部分实施例，而不是全部的实施例。基于本申请中的实施例，本领域普通技术人员在没有做出创造性劳动前提下所获得的所有其他实施例，都属于本申请保护的范围。
本申请实施例中的术语“第一”、“第二”、“第三”仅用于描述目的，而不能理解为指示或暗示相对重要性或者隐含指明所指示的技术特征的数量。由此，限定有“第一”、“第二”、“第三”的特征可以明示或者隐含地包括至少一个该特征。本申请的描述中，“多个”的含义是至少两个，例如两个，三个等，除非另有明确具体的限定。此外，术语“包括”和“具有”以及它们任何变形，意图在于覆盖不排他的包含。例如包含了一系列步骤或单元的过程、方法、系统、产品或设备没有限定于已列出的步骤或单元，而是可选地还包括没有列出的步骤或单元，或可选地还包括对于这些过程、方法、产品或设备固有的其他步骤或单元。
在本文中提及“实施例”意味着，结合实施例描述的特定特征、结构或特性可以包含在本申请的至少一个实施例中。在说明书中的各个位置出现该短语并不一定均是指相同的实施例，也不是与其他实施例互斥的独立的或备选的实施例。本领域技术人员显式地和隐式地理解的是，本文所描述的实施例可以与其他实施例相结合。
直流无刷电机驱动采用PWM调制(Pulse Width Modulation，脉宽调制)，三相输出电压之和，即共模电压(零序电压)不为零。共模电压会在轴承处分压产生轴电压。轴电压过大时会击穿轴承内的润滑油膜产生电火花加工(EDM)电流，造成电腐蚀问题，影响系统可靠性。
针对这一问题，现如今已有技术方案针对电机单体进行研究，该研究中，电机直接采用直流电源供电，所测得轴电压主要为开关频率的高频噪声，且经 研究获得的电腐蚀抑制方案针对电机直流供电条件下，其抑制效果表现良好。
但在进一步研究中发现，在如图1所示情况下，电机前端采用个电网供电且AC/DC变换采用非隔离方案时，轴电压会由工频和开关频率噪声相叠加，使得现有电腐蚀抑制方案的作用效果明显变差。
如图2所示，图2图1所示电机供电模型下检测得到的轴电流波形示意图，其峰值轴电流的值较大，存在击穿轴电流，容易产生电腐蚀。
然而采用“电网交流供电+非隔离AC/DC变换+直流电机”的应用场景非常广泛，使得这一问题被显著放大，现有针对电机单体的电腐蚀抑制方案明显不适应这一场景，存在较大的电腐蚀风险。
针对这一模型下所存在的电腐蚀问题，存在对电机进行电腐蚀抑制的方案一，方案一中采用导通插针短接端盖和定子铁芯，如图3所示，图3是导通插针短接端盖和定子铁芯方案下所检测得到的轴电流的波形示意图，经测试发现，其在这一应用场景下，其轴承仍存在击穿轴电流，其中轴电流峰值为82mA。
针对这一模型下所存在的电腐蚀问题，还存在对电机进行电腐蚀抑制的方案二，方案二采用电连接件短接电机的两侧端盖，如图4所示，图4是电连接件短接电机的两侧端盖方案下所检测得到的轴电流的波形示意图，经测试发现，其在这一应用场景下，其轴承仍存在击穿轴电流，其中轴电流峰值为112mA。
可见，在这一应用场景下，现有方案已不足以解决电机的电腐蚀问题。
针对这一应用场景和发现的问题，申请人组织并投入大量人力物力进行研发，获得可有效降低轴电压抑制电腐蚀的方案。
可先对未采用电腐蚀抑制措施的电机100进行电性分析，得出其在电网供电且非隔离方案下的系统等效分布参数模型示意图。
参阅图5，图5是电机未采用电腐蚀抑制措施的结构示意图。
该电机100包括转子10、定子20和转轴30，其中转子10设置于转轴30上，转子10与定子20彼此间隔嵌套设置。电机100通电后，转子10与定子20之间由于电磁效应而使得转子10相对定子20转动，并带动转轴30以进行动力输出。
电机100还包括第一端盖40、第一轴承50、第二轴承60、第二端盖70和机架80，第一端盖40和第二端盖70沿转轴30的轴向间隔设置，第一端盖40和第二端盖70盖设于机架80的两端，以形成一容置腔82，转子10、定子20和转轴30设置于容置腔82内，即第一端盖40和第二端盖70沿转轴30的轴向分设于转子10和定子20的两端，转轴30进一步从第一端盖40或第二端盖70延伸至容置腔82外，且转轴30通过第一轴承50转动支撑于第一端盖40，转轴30通过第二轴承60转动支撑于第二端盖70。
转子10包括转子铁芯12和转子磁体14，转子磁体14设置于转子铁芯12上，转轴30固定于转子铁芯12的轴孔内，其中至少转子铁芯12和转子磁体14可通过塑封方式固定于一体，转轴30可与轴孔过盈配合，从而转轴30和转子铁芯12直接接触，而转轴30和转子铁芯12均采用导电材料制成而形成电性接触，转子磁体14因塑封材料的隔离而与转子铁芯12及转轴30形成电性隔离。
定子20包括定子铁芯22和定子绕组24，定子绕组24缠绕于定子铁芯22 的定子齿上，定子绕组24在上电时产生交变磁场，而与转子10之间由于电磁效应而使得转子10转动。
定子20套设于转子10的外周，而与转子10间隔设置，即定子20和转子10之间具有间隙而形成电性隔离。
其中第一端盖40和第二端盖70中的一者可与机架80一体注塑形成，另一者可与机架80可拆卸连接。或者，第一端盖40和第二端盖70均与机架80可拆卸连接。
第一端盖40和第二端盖70均为导电端盖，且均与转子10、定子20和转轴30绝缘隔离。其中第一端盖40和第二端盖70可以与转子10、定子20和转轴30不接触，或者彼此之间通过绝缘材质制成的绝缘件隔离。
第一端盖40和第二端盖70可以为金属端盖或复合材料端盖，例如复合材料端盖内均匀混合有导电粒子，其可实现导电功能。
第一端盖40沿转轴30的径向尺寸大于第二端盖70沿转轴30的径向尺寸，从而第一端盖40和定子铁芯22之间形成的分布电容较大，第二端盖40和定子铁芯22之间形成的分布电容较小。
参阅图5，第一端盖40的径向尺寸大于定子20的径向尺寸，甚至其外轮廓可以作为电机100的外轮廓。
本实施例中，第一端盖40沿轴向上全覆盖机架80，遮盖转子10和定子20，其径向尺寸为电机100的径向尺寸，第二端盖70的径向尺寸大致为转子10的径向尺寸。
转轴30通过第一轴承50和第二轴承60分别转动支撑于第一端盖40和第二端盖70，其中第一轴承50包括绝缘隔离的第一外圈51和第一内圈52，第一外圈51固定于第一端盖40并与第一端盖40电性接触，第一内圈52固定于转轴30上并与转轴30电性接触，即转轴30和第一端盖40之间通过第一轴承50绝缘隔离；第二轴承60包括绝缘隔离的第二外圈61和第二内圈62，第二外圈61固定于第二端盖70并与第二端盖70电性接触，第二内圈62固定于转轴30上并与转轴30电性接触，即转轴30和第二端盖70之间通过第二轴承60绝缘隔离。
进一步地，电机100还包括电控器件90，电控器件90设置于容置腔82中，电控器件90电连接定子20的定子绕组24，并作为电机100的直流母线负极，其中定子绕组24为三相绕组，该三相绕组的中性点作为电机100的直流母线正极，并由非隔离AC/DC变换后供给电流。
其中，电控器件90设置于转子10和第一端盖40之间，且与第一端盖40、转子10、转轴30和第二端盖70绝缘隔离。
将目前的电机100应用于“电网交流供电+非隔离AC/DC变换+直流电机”这一应用场景中，同时考虑到其在所应用环境中，即电机100周围存在外部金属件这一更实际的情况，进行具体的系统分析。
例如在家电或新能源汽车等领域，电机100可应用于空调系统、空气净化器、烟机或洗碗机等设备中，电机100周围存在外部金属件，例如该外部金属件为冷凝器，则电机100中位于外部的第一端盖40、第二端盖70和转轴30均 与该外部金属件存在等效电容。
以空调系统中，电机100周围存在的外部金属件为冷凝器这一场景进行分析，基于这一实际应用场景，将其电路模型进行等效，得到如图6所示的系统等效分布参数模型，其中电网E1为整个系统供电，电网E1为市电，其远端直接接地，E2为经非隔离AC/DC变换后等效的直流电源，供给后级电机100使用，电机100为如图5所示的电机。
参阅图5和图6，直流电源E2的正极电连接定子绕组24的中性点，直流电源E2的负极电连接电控器件90，电控器件90可等效于该模型中的直流母线负极；第一端盖40、定子铁芯22、转子磁体14、转轴30和第二端盖70均与定子绕组24绝缘隔离，从而分别形成等效电容Csb1、Cs、Cm和Csb2；第一端盖40、转轴30和第二端盖70均与电控器件90绝缘隔离，分别形成等效电容Cn1、Csn和Cn2；定子铁芯22设置于第一端盖40和第二端盖70之间，且与第一端盖40和第二端盖70绝缘设置，定子铁芯22与第一端盖40和第二端盖70分别形成等效电容Cg1和Cg2；转轴30与第一端盖40和第二端盖70绝缘隔离，从而分别与第一端盖40和第二端盖70形成等效电容Cb1、Cb2，且转轴30自身电阻划分成L1和L2，以分别对应于其位于第一端盖40和第二端盖70的部分；转子磁体14还分别与转轴30和定子铁芯22隔离绝缘，并分别形成等效电容Cmg和Cg；第一端盖40、转轴30和第二端盖70还均与外部金属件形成等效电容Cn3、Cn4和Cn5，该外部金属件在具体设备中还进行接地处理。
其中，第一外圈51与第一端盖40电性接触，第一内圈52与转轴30电性接触，等效电容Cb1为第一轴承50的轴承电容；第二外圈61与第二端盖70电性接触，第二内圈62与转轴30电性接触，等效电容Cb2为第二轴承60的轴承电容；因而一旦等效电容Cb1、Cb2所分配到的轴电压过大，将会击穿轴承内的润滑油膜产生电火花加工(EDM)电流，造成电腐蚀。
参阅图7，经非隔离AC/DC变换后等效的直流电源E2具体包括整流单元1和逆变单元2，整流单元1用于将交流电转变为直流电，逆变单元2用于接受控制信号调控定子绕组24中各相绕组的通断电状况，以利用电磁效应驱动转子10转动。
本实施例中，整流单元1包括并联的第一整流支路、第二整流支路和电容支路，第一整流支路包括串联的第一二极管D1和第二二极管D2，第二整流支路包括串联的第三二极管D3和第四二极管D4，电容支路包括电容C，由第一整流支路引出的节点a1用于连接电网E1的火线，节点a1连接于第一二极管D1和第二二极管D2之间，由第二整流支路引出的节点a2用于连接电网E1的零线，节点a2连接于第三二极管D3和第四二极管D4之间，电容支路的一端还引出连接作为直流母线负极的电控器件90。
逆变单元2包括并联的第一开关支路、第二开关支路和第三开关支路，第一开关支路、第二开关支路和第三开关支路且与电容支路并联，第一开关支路包括串联的第一开关管Q1和第二开关管Q2，第二开关支路包括串联的第三开关管Q3和第四开关管Q4，第三开关支路包括串联的第五开关管Q5和第六开关管Q6，第一开关支路、第二开关支路和第三开关支路中分别引出引线连接定子 绕组24的中性点，电阻R1和电感Ln1为第一开关支路连接至定子绕组24的中性点线路上的等效电阻和等效电感，电阻R2和电感Ln2为第二开关支路连接至定子绕组24的中性点线路上的等效电阻和等效电感，电阻R3和电感Ln3为第三开关支路连接至定子绕组24的中性点线路上的等效电阻和等效电感。
整流单元1和逆变单元2还可以有其他形式，其为较通用的技术手段，可查阅公开的资料进行设计，本申请对其具体形式不作限制。
在如图6所示的当前该系统等效分布参数模型中，轴电压会由工频和开关频率噪声相叠加，现有对电腐蚀抑制的方案效果在该模型系统中会变差。
现对当前电机100的分布电容模型进行简化，按照Δ-Y转换进行简化，Δ-Y转换为电机的降压启动转换关系，可将模型逐步简化为如图8所示的等效电路，基于电桥平衡条件Z1/Z3＝Z2/Z4时，轴电容两端电压Vz5＝0，所以可通过调整部分等效电容容值，达到电桥平衡分压条件，以降低轴电压，即可降低转轴30上的轴电流，以达到抑制电腐蚀的目的。
具体而言，需要采用一些技术手段改变当前系统模型的拓扑结构，从而改变轴承电容两端的分压，最终达到抑制电腐蚀的目的。
参阅图9，图9是本申请提供的电机采用电腐蚀抑制措施一实施例的结构示意图，图9所示电机时在图5的基础上进行更改，以改变其在当前系统模型的拓扑结构，从而达到抑制电腐蚀。
本实施例中，如图9所示，进一步将第一端盖40、第二端盖70和定子20的定子铁芯22短接，图9所示的电机100应用于电网供电且非隔离方案下得到如图10所示的系统等效分布参数模型示意图，其中第一端盖40、第二端盖70和定子铁芯22为等电势位，第一端盖40和定子铁芯22之间的等效电容Cg1被消除，第二端盖70与定子铁芯22之间的等效电容Cg2也被消除，以改变电机100的模型拓扑结构，并进行实测验证，发现相较于原电机100的模型拓扑结构，图9所示电机100的轴电压明显降低，经实测结果验证未出现击穿的轴电流峰值。
本实施例中，第一端盖40和第二端盖70为金属端盖，第一端盖40沿转轴30的径向尺寸大于第二端盖70沿转轴30的径向尺寸，从而相对而言，第一端盖40和第二端盖70与电机100上相邻各部件所形成的等效电容更利于达到电桥平衡条件。
具体地，第一端盖40的径向尺寸大于等于定子20的径向尺寸，第二端盖70的径向尺寸小于定子20的径向尺寸。例如，第一端盖40的径向尺寸为电机100的径向尺寸，即第一端盖40覆盖定子20及机架80，第二端盖70的径向尺寸可以等于转子10的径向尺寸，可有效地调整电机100内的分布电容模型，以更利于通过上述手段达到或趋近达到电桥平衡条件。
进一步地，参阅图10，电机100还包括电容器C1，定子铁芯22还通过电容器C1接地，以进一步地促使达到电桥平衡条件，从而降低转轴30上的轴电流，避免出现击穿轴电流。
例如，该电机100应用于空调中，冷凝器为电机100附近的外部金属件，且冷凝器进行接地处理，定子铁芯22通过电容器C1连接冷凝器，以通过冷凝 器接地。
电容器C1可以为可调电容器，电容器C1的电容值根据其距离外部金属件的距离大小进行调整。例如，在实际应用时，可检测轴电流，通过调节电容器C1的电容值，以促使达到电桥平衡条件，降低转轴30上的轴电流，避免出现击穿轴电流。
本实施例中，电容器C1的电容值通过调整两块金属平板的重叠面积进行调整。电容器C1的电容值还可以通过调两块金属平板的间距进行调整。
可选地，电容器C1还可以是固定电容器。例如在空调场景中，电机100和冷凝器等器件的位置是确定，所需的电容器C1的电容值也是可以确定的，在此条件下，所需电容器C1的电容值为定值，即电容器C1还可以是固定电容器。
在一些场景下，电机100经第一端盖40、第二端盖70和定子20的定子铁芯22短接后，所需电容器C1的电容值较小时，也可不增加电容器C1，也能够有效地降低转轴30上的轴电流，避免出现击穿轴电流。
本实施例中，如图9所示，电机100还包括导通件101，导通件101设置于机架80且电连接第一端盖40、第二端盖70和定子铁芯22，且还通过电容器C1接地。
其中，导通件101可以为导通片、导通插针或导电胶带，其可以部分埋设于机架80内，或部分贴设于机架80的内表面或外表面。
例如，导通件101包括第一导通部102和第二导通部103，第一导通部102埋设于机架80内且短接第一端盖40和第二端盖70，第二导通部103穿过机架80并短接定子铁芯22和第二导通部103，且第二导通部103自机架80向外引出，以电连接电容器C1，并通过外部金属件接地，例如通过冷凝器接地。
第一导通部102可以为导通片、导电胶带、导通线或导通插针，第二导通部103可以为导通片、导通线或导通插针，第一导通部102为导电胶带时，其还可以贴设于机架80的内侧或外侧。
基于本申请所提供的方案，进行模型验证，可得到较小的轴电压，并实际验证轴电流无击穿，可有效地抑制在“电网交流供电+非隔离AC/DC变换+直流电机”的应用场景电机100的电腐蚀现象，突破了现有方案电机单体上电腐蚀抑制的研究局限，使得能够以更符合实际应用场景的技术方案来达到有效抑制在这一场景下的电腐蚀。
参阅图11，图11是图10所示模型下检测得到的轴电流波形示意图，其中实测时轴电流的峰值为12mA，其相对现有方案一和二能够降低轴电流500％，且不存在击穿轴电流，可有效地避免在“电网交流供电+非隔离AC/DC变换+直流电机”的应用场景仍存在电腐蚀的现象，大幅提升了电机100及其在该系统下的可靠性。
参阅图12，图12是本申请提供的电机采用电腐蚀抑制措施另一实施例的结构示意图，图12所示电机时在图5的基础上进行更改，以改变其在当前系统模型的拓扑结构，从而达到抑制电腐蚀。
本实施例中，如图12所示，进一步限定第一端盖40沿转轴30的径向尺寸大于等于转子10沿转轴30的径向尺寸，且小于定子20沿转轴30的径向尺寸， 且定子20的定子铁芯22接地。
结合参阅图5、图6、图12和图13，图12所示的电机100应用于电网供电且非隔离方案下得到如图10所示的系统等效分布参数模型示意图，其中图12所示的电机100相对于图5所示的电机100而言，通过减小原本第一端盖40的面积，以减小第一端盖40与定子铁芯22和定子绕组24之间的分布电容，即原本的等效电容Cg1减小为等效电容Cg1'，等效电容Csb1减小为等效电容Csb1'，并将定子铁芯22直接接地，以改变电机100的模型拓扑结构和系统模型间的等效电容，降低在非隔离系统应用情况下电机100的轴电压，抑制电腐蚀现象，并进行实测验证，发现相较于原方案一和二下电机的模型拓扑结构，图12所示电机100的轴电压明显降低，实际验证轴电流明显减少，表明本申请提供的方案在系统应用中的电腐蚀抑制效果明显。
如图12所示，电机100还包括导通件101，导通件101与定子铁芯22电连接并穿过机架80向容置腔82外引出，导通件101用于接地。通过设置导通件101向机架80外引出，以便于将定子铁芯22直接接地。
本实施例中，导通件101为定子铁芯22的铁芯叠片向机架80外引出所形成，即形成定子铁芯22的铁芯叠片中的至少一个还向机架80外引出，以作为定子铁芯22的接地端，以便于定子铁芯22接地。
可选地，导通件101还可以是导通片或导通插针，导通片或导通插针的一端与定子铁芯22短接，另一端穿过机架80向外引出，以作为定子铁芯22的接地端，以便于定子铁芯22接地。
导通件101可通过外部金属件接地，例如通过冷凝器接地。
参阅图14，图14是图13所示模型下检测得到的轴电流波形示意图，基于本申请所提供的方案，进行模型验证，可得到较小的轴电压，经实测得到轴电流峰值为52mA，相比于原方案一和二，轴电流明显减小，本申请所提供的方案能够降低轴电流约100％，轴电流峰值明显降低，可有效地改善在“电网交流供电+非隔离AC/DC变换+直流电机”的应用场景电机100的电腐蚀现象，大幅提升电机100及系统的可靠性，突破了现有方案电机单体上电腐蚀抑制的研究局限，使得能够以更符合实际应用场景的技术方案来达到有效抑制在这一场景下的电腐蚀。
参阅图15，图15是本申请提供的电机采用电腐蚀抑制措施又一实施例的结构示意图，图15所示电机时在图5的基础上进行更改，以改变其在当前系统模型的拓扑结构，从而达到抑制电腐蚀。
本实施例中，如图15所示，进一步将第一端盖40与定子20的定子铁芯22短接，且第一端盖40进一步通过电容器C1接地，图15所示的电机100应用于电网供电且非隔离方案下得到如图16所示的系统等效分布参数模型示意图，第一端盖40和定子铁芯22为等电势位，并将第一端盖40通过电容器C1接地，以改变电机100的模型拓扑结构，并进行实测验证，发现相较于原电机100的模型拓扑结构，图15所示电机100的轴电压明显降低，可有效抑制电机100的电腐蚀现象。
本实施例中，第一端盖40和第二端盖70为金属端盖，第一端盖40沿转轴 30的径向尺寸大于第二端盖70沿转轴30的径向尺寸，从而相对而言，第一端盖40和第二端盖70与电机100上相邻各部件所形成的等效电容更利于达到电桥平衡条件。
具体地，第一端盖40的径向尺寸大于等于定子20的径向尺寸，第二端盖70的径向尺寸小于定子20的径向尺寸。例如，第一端盖40的径向尺寸为电机100的径向尺寸，即第一端盖40覆盖定子20及机架80，第二端盖70的径向尺寸可以等于转子10的径向尺寸，可有效地调整电机100内的分布电容模型，以更利于通过上述手段达到或趋近达到电桥平衡条件。
参阅图16，第一端盖40及定子铁芯22还通过电容器C1接地，以进一步地促使达到电桥平衡条件，从而降低转轴30上的轴电流，避免出现击穿轴电流。
例如，该电机100应用于空调中，冷凝器为电机100附近的外部金属件，且冷凝器进行接地处理，第一端盖40通过电容器C1连接冷凝器，以通过冷凝器接地。
电容器C1可以为可调电容器，电容器C1的电容值根据其距离外部金属件的距离大小进行调整。例如，在实际应用时，可检测轴电流，通过调节电容器C1的电容值，以促使达到电桥平衡条件，降低转轴30上的轴电流，避免出现击穿轴电流。
本实施例中，电容器C1的电容值通过调整两块金属平板的重叠面积进行调整。电容器C1的电容值还可以通过调两块金属平板的间距进行调整。
可选地，电容器C1还可以是固定电容器。例如在空调场景中，电机100和冷凝器等器件的位置是确定，所需的电容器C1的电容值也是可以确定的，在此条件下，所需电容器C1的电容值为定值，即电容器C1还可以是固定电容器。
电容器C1的电容值大于等于50pF且小于等于70pF，将第一端盖40和定子铁芯22短接后，所需较小的接地电容值即可明显地趋近于电桥平衡条件，从而降低轴电流，避免在系统应用中存在电腐蚀的现象。
例如，电容器C1的电容值范围可以是可调电容器的可调容置范围，其可基于电机100的实际状况进行调整。
在一些实施例中，电容器C1的电容值可以是50pF、55pF、60pF、65pF或70pF，电机100在不同系统环境中应用时电容值可适应性调整。
本实施例中，如图15所示，电机100还包括导通件101，导通件101短接第一端盖40和定子铁芯22，且还可以通过导通件101连接电容器C1，以实现接地，或者第一端盖40通过电容器C1直接接地。
其中，导通件101可以为导通片、导通插针或导电胶带，其可以部分埋设于机架80内，或部分贴设于机架80的内表面或外表面。
例如，导通件101包括第一导通部102和第二导通部103，第一导通部102穿过机架80并短接定子铁芯22，第二导通部103埋设于机架80内且短接第一端盖40和第一导通部102，第一导通部102可自机架80向外引出，以电连接电容器C1，并通过外部金属件接地，例如通过冷凝器接地，或者第一端盖40通过电容器C1直接接地。
第一导通部102可以为导通片、导通线或导通插针，第二导通部103可以 为导通片、导电胶带、导通线或导通插针，第二导通部103为导电胶带时，其还可以贴设于机架80的内侧或外侧。
基于本申请所提供的方案，进行模型验证，可得到较小的轴电压，并实际验证轴电流无击穿，可有效地抑制在“电网交流供电+非隔离AC/DC变换+直流电机”的应用场景电机100的电腐蚀现象，突破了现有方案电机单体上电腐蚀抑制的研究局限，使得能够以更符合实际应用场景的技术方案来达到有效抑制在这一场景下的电腐蚀。
参阅图17，图17是图16所示模型下检测得到的轴电流波形示意图，其中实测时轴电流的峰值为40mA，其相对现有方案一和二能够降低轴电流约200％，且击穿频率显著降低，可有效地避免在“电网交流供电+非隔离AC/DC变换+直流电机”的应用场景仍存在电腐蚀的现象，大幅提升了电机100及其在该系统下的可靠性。
基于此，本申请还提供一种电器200，图18是本申请提供的电器200一实施例的结构示意图。该电器200包括如上述的电机100、换热器201和驱动器件202，换热器201与电机100间隔设置，且换热器接地；驱动器件202用于外接市电，并给电机100供电和控制电机100运行；其中，电机100还包括电容器C1，电容器C1电连接于定子20的定子铁芯22和换热器201之间。
其中，换热器201具体可以为蒸发器或冷凝器。
如图18所示，与驱动器件202连接的线L表示电网火线，与驱动器件202连接的线N表示电网零线，与换热器201连接的线PE表示地线。
该电器200可以是空调、冰箱、空气净化器、烟机或洗碗机等，驱动器件202包括有上述的非隔离AC/DC变换器件，电容器C1的电容值可基于电机100与换热器201之间的距离值进行适应性调整，以避免出现击穿轴电流，抑制电腐蚀。
在一些场景下，当所需电容器C1的电容值足够小时，还可取消设置电容器C1。
区别于现有技术的情况，本申请公开了一种电机及电器。通过将第一端盖、第二端盖和定子的定子铁芯短接，使得第一端盖、第二端盖和定子铁芯为等电势位，以改变电机的模型拓扑结构，使得电机应用于非隔离的交流供电系统中是可趋近于达成电桥平衡条件，以使得轴电压和轴电流能够明显地降低，从而有效地抑制电机电腐蚀现象。
以上所述仅为本申请的实施例，并非因此限制本申请的专利范围，凡是利用本申请说明书及附图内容所作的等效结构或等效流程变换，或直接或间接运用在其他相关的技术领域，均同理包括在本申请的专利保护范围内。

Claims (10)

  1. 一种电机，其特征在于，所述电机包括转子、定子、转轴、第一端盖和第二端盖，所述转子设置于所述转轴上，所述定子与所述转子间隔嵌套设置，所述第一端盖和所述第二端盖沿所述转轴的轴向分设于所述转子和所述定子的两端，且所述转轴转动支撑于所述第一端盖和所述第二端盖，所述第一端盖、所述第二端盖和所述定子的定子铁芯短接。
  2. 根据权利要求1所述的电机，其特征在于，所述电机还包括电容器，所述定子铁芯还通过所述电容器接地。
  3. 根据权利要求2所述的电机，其特征在于，所述电容器为可调电容器，所述电容器的电容值根据其与外部金属件的距离大小进行调整。
  4. 根据权利要求1所述的电机，其特征在于，所述第一端盖和所述第二端盖为金属端盖，所述第一端盖沿所述转轴的径向尺寸大于所述第二端盖沿所述转轴的径向尺寸。
  5. 根据权利要求4所述的电机，其特征在于，所述第一端盖的径向尺寸大于等于所述定子的径向尺寸，所述第二端盖的径向尺寸小于所述定子的径向尺寸。
  6. 根据权利要求1所述的电机，其特征在于，所述电机还包括第一轴承和第二轴承，所述第一轴承包括绝缘隔离的第一外圈和第一内圈，所述第一外圈固定于所述第一端盖并与所述第一端盖电性接触，所述第一内圈固定于所述转轴上并与所述转轴电性接触；
    所述第二轴承包括绝缘隔离的第二外圈和第二内圈，所述第二外圈固定于所述第二端盖并与所述第二端盖电性接触，所述第二内圈固定于所述转轴上并与所述转轴电性接触。
  7. 根据权利要求6所述的电机，其特征在于，所述电机还包括电控器件，所述电控器件电连接所述定子的定子绕组，所述电控器件设置于所述转子和所述第一端盖之间，且与所述第一端盖、所述转子、所述转轴和所述第二端盖绝缘隔离。
  8. 根据权利要求7所述的电机，其特征在于，所述电机还包括机架，所述第一端盖和所述第二端盖设置于所述机架的两端，以形成一容置腔，所述转子、所述定子和所述转轴设置于所述容置腔内，所述转轴进一步从所述第一端盖或所述第二端盖延伸至所述容置腔外；
    其中，所述电机还包括导通件，所述导通件设置于所述机架且电连接所述第一端盖、所述第二端盖和所述定子铁芯。
  9. 根据权利要求8所述的电机，其特征在于，所述导通件包括第一导通部和第二导通部，所述第一导通部设置于所述机架上且短接所述第一端盖和所述第二端盖，所述第二导通部短接所述定子铁芯和所述第一导通部并向所述机架外引出。
  10. 一种电器，其特征在于，所述电器包括：
    如权利要求1至9任一项所述的电机；
    换热器，与所述电机间隔设置，且所述换热器接地；
    驱动器件，所述驱动器件用于外接市电，并给所述电机供电和控制所述电机运行；
    其中，所述电机还包括电容器，所述电容器电连接于所述定子的定子铁芯和所述换热器之间。
PCT/CN2023/132449 2022-11-17 2023-11-17 一种电机及电器 WO2024104481A1 (zh)

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Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2011205724A (ja) * 2010-03-24 2011-10-13 Panasonic Corp 空気調和機
CN112821678A (zh) * 2021-03-22 2021-05-18 广东威灵电机制造有限公司 无刷电机及电气设备
CN115765325A (zh) * 2022-11-17 2023-03-07 广东美的白色家电技术创新中心有限公司 一种电机及电器

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2011205724A (ja) * 2010-03-24 2011-10-13 Panasonic Corp 空気調和機
CN112821678A (zh) * 2021-03-22 2021-05-18 广东威灵电机制造有限公司 无刷电机及电气设备
CN115765325A (zh) * 2022-11-17 2023-03-07 广东美的白色家电技术创新中心有限公司 一种电机及电器

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