Single-phase asynchronous motor with adaptive adjustable capacitor

Abstract

A single-phase asynchronous motor with a self-adaptive adjustable capacitor relates to the technical field of motors and comprises a stator, a rotor, a single-phase alternating current power supply and the self-adaptive adjustable capacitor. The stator is provided with a main winding and an auxiliary winding, the first leading-out ends of the two phases of windings are connected, the two ends of the self-adaptive adjustable capacitor are respectively connected to the second leading-out ends of the two phases of windings, one power supply terminal of the single-phase alternating-current power supply is connected to the second leading-out end of the main winding, and the other power supply terminal of the single-phase alternating-current power supply is connected to the first leading-out ends of the two phases of windings. The single-phase asynchronous motor with the self-adaptive adjustable capacitor provided by the utility model is suitable for high-efficiency and low-vibration noise operation under multiple working conditions.

Description

Technical Field

[0001] The utility model relates to the technical field of motors, in particular to the technology of a single-phase asynchronous motor with an adaptive adjustable capacitor. Background Art

[0002] Single-phase asynchronous motors are powered by a single-phase power supply and have the advantages of low manufacturing cost, durability and high reliability. They are widely used in residential, office, medical and other places.

[0003] An ordinary single-phase asynchronous motor has two-phase windings, the main winding and the auxiliary winding. The auxiliary winding is connected in series with the starting capacitor and the centrifugal switch, and then connected in parallel with the main winding to the single-phase power supply. When starting, the centrifugal switch is in a closed state, and the current generates a rotating magnetic field in the motor after passing through the two-phase winding, forming a starting torque; when the motor speed reaches more than two-thirds of the rated speed, the centrifugal switch is disconnected, and the motor keeps running under the action of the pulsating magnetic field generated by the main winding. During operation, due to the large negative sequence component, the motor efficiency is poor, the vibration noise is large, and the output torque is low.

[0004] Some single-phase asynchronous motors are also equipped with starting capacitors and running capacitors. The running capacitor is used to run at rated speed, so that the two-phase windings are energized to generate a circular rotating magnetic field in the motor, increase the output torque, and ensure high-efficiency operation. When the motor is not at rated speed, the magnetic field generated by the two-phase windings after energization is asymmetric, the negative sequence component is large, and the motor still has poor efficiency and large vibration noise.

[0005] In order for a single-phase asynchronous motor to achieve high efficiency and low vibration and noise operation, the two-phase windings need to generate symmetrical magnetomotive force to form a circular rotating magnetic field with zero negative sequence component. This depends on the current of the auxiliary winding, which is determined by the capacitance value of the capacitor in series. Using two fixed capacitors cannot meet the high efficiency and low vibration and noise operation of the motor under multiple working conditions. Utility Model Content

[0006] In view of the defects existing in the above-mentioned prior art, the technical problem to be solved by the utility model is to provide a single-phase asynchronous motor with an adaptive adjustable capacitor which can operate with high efficiency and low vibration and noise under multiple working conditions and improve the output torque.

[0007] In order to solve the above technical problems, the utility model provides a single-phase asynchronous motor with an adaptive adjustable capacitor, comprising a stator, a rotor and a single-phase AC power supply, characterized in that: it also includes an adaptive adjustable capacitor;

[0008] The stator is provided with a main winding and an auxiliary winding, the first lead ends of the two-phase windings are connected, the two ends of the adaptive adjustable capacitor are respectively connected to the second lead ends of the two-phase windings, one power supply terminal of the single-phase AC power supply is connected to the second lead end of the main winding, and the other power supply terminal is connected to the first lead end of the two-phase windings;

[0009] The adaptive adjustable capacitor is composed of a left part, a middle part and a right part from left to right, and the three parts are all sleeved on the rotating shaft of the motor, and there is a certain gap between the parts. The inner side of the motor housing is provided with an annular U-shaped groove and an annular L-shaped groove protruding radially inward, and the housing is penetrated with a first positioning pin and a second positioning pin for axial positioning of the U-shaped groove and the L-shaped groove respectively, and the right part of the L-shaped groove is bent downward;

[0010] The left part of the adaptive adjustable capacitor is installed on the rotor, and the part includes an annular steel plate, and sector-shaped permanent magnets are fixed at intervals around the rotating shaft on the right side of the annular steel plate, and the polarities of adjacent sector-shaped permanent magnets are different;

[0011] The middle part of the adaptive adjustable capacitor is installed on the stator, and the part is formed by the eddy current disk on the left and the first capacitor plate on the right being joined by an insulating adhesive. The eddy current disk and the first capacitor plate are both in a semicircular ring shape. The first capacitor plate can be stuck in the U-shaped groove to move circumferentially. A coil spring is provided on the left side of the first capacitor plate, and the other end of the coil spring is fixed on the housing. The coil spring is used for the circumferential initial positioning of the first capacitor plate.

[0012] The right part of the adaptive adjustable capacitor is mounted on the stator, and the part is formed by joining the dielectric on the left and the second capacitor plate on the right. The dielectric and the second capacitor plate are both in a semicircular ring shape. The second capacitor plate is provided with a circumferential positioning notch for the second positioning pin to extend into, and the dielectric and the capacitor plate are inserted into the L-shaped groove.

[0013] The outer diameters of the annular steel plate, the eddy current disk and the sector-shaped permanent magnet are the same.

[0014] The utility model provides a single-phase asynchronous motor with an adaptive adjustable capacitor, which adopts a structure with a built-in adaptive adjustable capacitor. The axial overlapping area of ​​the first capacitor plate and the second capacitor plate is controlled by the rotation of the rotor, and the capacitance value can be adaptively adjusted according to the rotor speed. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a structural axial half-section diagram of a single-phase asynchronous motor with an adaptive adjustable capacitor according to an embodiment of the utility model;

[0016] Figure 2 This is a full axial cross-sectional view of the structure of the adaptive adjustable capacitor of the embodiment of the utility model;

[0017] Figure 3 This is a radial view of the annular steel plate and the sector-shaped permanent magnet of the embodiment of the utility model;

[0018] Figure 4 is a radial view of the eddy current disk and the first capacitor plate of the embodiment of the utility model;

[0019] Figure 5 is a radial view of the dielectric and the second capacitor plate of an embodiment of the utility model;

[0020] Figure 6 It is a circuit wiring diagram of an embodiment of the utility model. DETAILED DESCRIPTION

[0021] The following is a further detailed description of an embodiment of the utility model in conjunction with the accompanying drawings, but the embodiment is not intended to limit the utility model. All similar structures and similar changes of the utility model should be included in the protection scope of the utility model. The semicolons in the utility model all represent the relationship of and.

[0022] like Figure 6 As shown, a single-phase asynchronous motor with an adaptive adjustable capacitor provided in an embodiment of the utility model comprises a stator 1, a rotor 2 and a single-phase AC power supply U1, and also comprises an adaptive adjustable capacitor C R ;

[0023] The stator 1 is provided with a main winding X1 and an auxiliary winding X2. The first lead-out ends of the two-phase windings are connected. The adaptive adjustable capacitor C R The two ends of are respectively connected to the second lead-out end of the two-phase winding, one power supply terminal of the single-phase AC power supply U1 is connected to the second lead-out end of the main winding X1, and the other power supply terminal is connected to the first lead-out end of the two-phase winding;

[0024] like Figure 1-Figure 2 As shown, the adaptive adjustable capacitor C R It is composed of a left part, a middle part and a right part from left to right. The three parts are all sleeved on the rotating shaft 3 of the motor, and there is a certain gap between the parts. The inner side of the motor housing 4 is provided with an annular U-shaped groove 51 and an annular L-shaped groove 61 protruding radially inward. The housing 4 is penetrated by a first positioning pin 52 and a second positioning pin 62 for axial positioning of the U-shaped groove 51 and the L-shaped groove 61 respectively. The right part of the L-shaped groove 61 is bent downward;

[0025] like Figure 3 As shown, the adaptive adjustable capacitor C R The left part is installed on the rotor 2, and the part includes an annular steel plate 711. The right side of the annular steel plate 711 is fixed with sector-shaped permanent magnets 712 at intervals around the rotation axis, and the polarities of adjacent sector-shaped permanent magnets 712 are different;

[0026] like Figure 4 As shown, the adaptive adjustable capacitor C R The middle part is installed on the stator 1, which is formed by the eddy current disk 721 on the left and the first capacitor plate 722 on the right through an insulating adhesive. The eddy current disk 721 and the first capacitor plate 722 are both semi-circular ring-shaped. The first capacitor plate 722 can be stuck in the U-shaped groove 51 to make circumferential movement. A coil spring 8 is provided on the left side of the first capacitor plate 722. The other end of the coil spring 8 is fixed on the housing 4. The coil spring 8 is used for the circumferential initial positioning of the first capacitor plate 722.

[0027] like Figure 5 As shown, the adaptive adjustable capacitor C R The right part is installed on the stator 1, which is formed by the dielectric 731 on the left and the second capacitor plate 732 on the right. The dielectric 731 and the second capacitor plate 732 are both semicircular. The second capacitor plate 732 is provided with a circumferential positioning notch for the second positioning pin 62 to extend into. The dielectric 731 and the capacitor plate 732 are inserted into the L-shaped groove 61;

[0028] The outer diameters of the annular steel plate 711 , the eddy current disk 721 and the sector-shaped permanent magnet 712 are the same.

[0029] In an embodiment of the utility model, the eddy current disk is made of thick steel plate, the first capacitor plate and the second capacitor plate are made of conductive material, the U-shaped groove and the L-shaped groove are made of insulating composite materials such as polyimide or carbon fiber, and the first positioning pin and the second positioning pin are made of insulating high-strength plastic.

[0030] The working principle of the embodiment of the utility model is as follows:

[0031] When the motor is stationary, the installation positions of the coil spring 8, the first capacitor plate 722 and the second capacitor plate 732 are set so that the axial overlap area of ​​the two plates is maximized, so that the capacitance value of the capacitor is also maximized, which meets the needs of a large current amplitude and a 90-degree phase in the auxiliary winding when the motor is started, and generates a circular rotating magnetic field;

[0032] When the motor rotates, the magnetic flux lines generated by the fan-shaped permanent magnet 712 cut the eddy current disk 721. Since the eddy current disk 721 is made of a thick steel plate that is both magnetic and conductive, an eddy current torque is generated inside, causing the eddy current disk 721 and the first capacitor plate 722 to rotate a certain angle to overcome the tension of the spiral spring 8, thereby changing the axial overlap area between the first capacitor plate 722 and the second capacitor plate 732, causing the capacitance value to change.

[0033] As the speed of the motor increases, the speed at which the magnetic flux lines cut the eddy current disc 721 increases, the eddy current torque generated increases, the angle at which the eddy current disc 721 and the first capacitor plate 722 rotate to overcome the tension of the spiral spring 8 increases, the axial overlapping area of ​​the first capacitor plate 722 and the second capacitor plate 732 decreases, and the capacitance value of the capacitor decreases;

[0034] When the motor stops, there is no relative movement between the sector permanent magnet 712 and the eddy current disk 721 , and there is no eddy current torque. The circumferential moving part returns to the initial position under the pulling force of the spiral spring 8 .

[0035] In the embodiment of the utility model, when the motor generates a circular rotating magnetic field, the capacitance value of the capacitor required to be connected in series with the auxiliary winding decreases linearly with the increase of the motor speed. The capacitance value of the capacitor is adaptively adapted by relying on the proportional relationship between the eddy current torque and the speed and the proportional relationship between the capacitance value of the capacitor and the overlapping area of ​​the plates. The utility model has the characteristics of high efficiency, low vibration and noise, and high torque output under multiple working conditions.

Claims

1. A single-phase asynchronous motor with an adaptive adjustable capacitor, comprising a stator, a rotor and a single-phase AC power supply, characterized in that: Also included is an adaptive adjustable capacitor; The stator is provided with a main winding and an auxiliary winding, the first lead ends of the two-phase windings are connected, the two ends of the adaptive adjustable capacitor are respectively connected to the second lead ends of the two-phase windings, one power supply terminal of the single-phase AC power supply is connected to the second lead end of the main winding, and the other power supply terminal is connected to the first lead end of the two-phase windings; The adaptive adjustable capacitor is composed of a left part, a middle part and a right part from left to right, and the three parts are all sleeved on the rotating shaft of the motor, and there is a certain gap between the parts. The inner side of the motor housing is provided with an annular U-shaped groove and an annular L-shaped groove protruding radially inward, and the housing is penetrated with a first positioning pin and a second positioning pin for axial positioning of the U-shaped groove and the L-shaped groove respectively, and the right part of the L-shaped groove is bent downward; The left part of the adaptive adjustable capacitor is installed on the rotor, and the part includes an annular steel plate, and sector-shaped permanent magnets are fixed at intervals around the rotating shaft on the right side of the annular steel plate, and the polarities of adjacent sector-shaped permanent magnets are different; The middle part of the adaptive adjustable capacitor is installed on the stator, and the part is formed by the eddy current disk on the left and the first capacitor plate on the right being joined by an insulating adhesive. The eddy current disk and the first capacitor plate are both in a semicircular ring shape. The first capacitor plate can be stuck in the U-shaped groove to move circumferentially. A coil spring is provided on the left side of the first capacitor plate, and the other end of the coil spring is fixed on the housing. The coil spring is used for the circumferential initial positioning of the first capacitor plate. The right part of the adaptive adjustable capacitor is mounted on the stator, and the part is formed by joining the dielectric on the left and the second capacitor plate on the right. The dielectric and the second capacitor plate are both in a semicircular ring shape. The second capacitor plate is provided with a circumferential positioning notch for the second positioning pin to extend into, and the dielectric and the capacitor plate are inserted into the L-shaped groove. The outer diameters of the annular steel plate, the eddy current disk and the sector-shaped permanent magnet are the same.

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