Improved structure of motor

Abstract

An improved structure of a motor comprises two coils which drive a rotor to rotate and are arranged on a stator, and a power supply circuit, the two coils are respectively a main stator coil and a starting auxiliary coil, and the power supply circuit comprises a micro control unit (MCU), two groups of driving circuits which output sine wave power supplies and are controlled by the MCU, and a direct current power supply circuit. The two groups of driving circuits for outputting sine wave power supplies are respectively connected with one end of the main stator coil and one end of the starting auxiliary coil and respectively output the sine wave power supplies to the main stator coil and the starting auxiliary coil, and the sine wave frequencies of the sine wave power supplies of the two groups of driving circuits for outputting sine wave power supplies controlled by the MCU are the same. And therefore, the power supply is matched with the two coils which are vertically arranged to generate a rotating magnetic field to drive the rotor to rotate. Compared with the prior art, a common starting capacitor is eliminated, the torque stability of the motor and the utilization rate of the coil are improved, the power factor is improved, and the motor has the advantages of simple circuit, few components and low manufacturing cost.

Description

Technical Field

[0001] The utility model relates to a motor control technology, in particular to an improved structure of a motor. Background Art

[0002] For a general single-phase motor, the prior art is to set an auxiliary starting winding in the direction perpendicular to the main winding and connect a starting capacitor in series to create two power supplies with different phases, so that the two windings generate a rotating magnetic field, enabling the motor to enter the rotating state from the stationary state. After the motor rotates, in some occasions with low power, the starting capacitor is designed to remain online, while in some designs, the power supply of the capacitor and the auxiliary winding is disconnected to avoid affecting the efficiency and normal operation of the motor due to the instability and inaccuracy of the phase difference generated by the capacitor. In this way, only the main stator coil works to drive the rotor to rotate. For such a single-phase motor, since the rotor is only driven by a group of main stator coils, the acting force will tend to one side (the direction of the force driving the rotor to rotate is elliptical), and the resulting adverse phenomena are that the motor rotates unstably and makes a relatively large noise. At the same time, since the auxiliary coil stops working after the motor starts, the auxiliary coil is in a useless state. If the auxiliary coil is not disconnected, it will waste electric energy and interfere with the operation of the main winding.

[0003] Therefore, the inventor of the present invention invented a patented technology with the patent number 202010569207.6, enabling the auxiliary coil to continue working after the motor starts, not only improving the balance of the coil driving force to effectively reduce the noise during motor rotation, but also increasing the power of the motor without adding working coils of the motor. However, this technology requires two groups of four pairs of triodes, a total of 8 triodes. Firstly, the circuit is complex, with many components and high costs. An 8-channel control is required using a relatively expensive control chip, which is not conducive to large-scale promotion. Moreover, in the existing wiring rules of general asynchronous motors, one end of the main winding and the auxiliary winding are connected in parallel, and the other end of the auxiliary winding is connected in series with a capacitor and then connected in parallel with the other end of the main winding. That is to say, when a common single-phase motor is not connected to the starting capacitor, there are three wiring terminals. It is rather troublesome to disconnect the wiring of the three terminals and change it to the four wirings of the above patent, which is not conducive to transformation. Summary of the Invention

[0004] The purpose of the utility model is to provide an improved structure of a motor that can overcome more than one of the above-mentioned disadvantages, has a simple circuit, few components, low manufacturing cost, and requires less modification to the existing single-phase motor.

[0005] The present utility model is realized as follows. It includes two coils arranged on a stator for driving a rotor to rotate and a power supply circuit. The two coils are a main stator coil and an auxiliary coil respectively. The power supply circuit includes a micro-control unit (MCU), two driving circuits for outputting sinusoidal power supplies controlled by the MCU, and a DC power supply circuit. The special feature is that the two driving circuits for outputting sinusoidal power supplies are respectively connected to one end of the main stator coil and the auxiliary coil, and output sinusoidal power supplies to the main stator coil and the auxiliary coil respectively. The sinusoidal frequencies of the sinusoidal power supplies of the two driving circuits controlled by the MCU are the same, but the phases differ by 90 degrees.

[0006] During operation, since the sinusoidal currents driving the main stator coil and the auxiliary coil differ by 90 degrees, the motor can be effectively driven to rotate. Since two-phase drive is achieved and only two driving circuits for outputting sinusoidal power supplies are used, the electronic control circuit is simplified and the cost is reduced.

[0007] Preferably, the MCU used is an MCU that can output a sinusoidal electronic control signal with a positive voltage. The driving circuit for the sinusoidal power supply is a first amplification circuit that amplifies the sinusoidal electronic control signal into a sinusoidal power supply. The first amplification circuit includes a first triode or a first MOS transistor. The output signal of the MCU is connected to the base of the first triode or the gate of the first MOS transistor. The collector of the first triode or the source of the first MOS transistor is connected to one end of the main stator coil and the auxiliary coil. The emitter of the first triode or the drain of the first MOS transistor is grounded;

[0008] Or, the MCU used is an MCU that can output a PWM square-wave electronic control signal with a modulated duty cycle. The driving circuit includes a PWM switch control circuit and a low-pass filter circuit. The PWM square-wave power supply output by the PWM switch control circuit is converted into a sinusoidal power supply by the low-pass filter circuit and then connected to one end of the main stator coil and the auxiliary coil. The other ends of the main stator coil and the auxiliary coil are grounded.

[0009] Compared with the prior art, the present utility model has the advantages of simple circuit, few components, and low manufacturing cost. Description of the Drawings

[0010] Figure 1 It is a schematic structural diagram of Embodiment 1 of the improved structure of the motor of the present utility model;

[0011] Figure 2 It is a waveform diagram of the sinusoidal electronic control signal output by the MCU in Embodiment 1;

[0012] Figure 3 It is a schematic structural diagram of Embodiment 2 of the improved structure of the motor of the present utility model;

[0013] Figure 4 Waveform diagram of the PWM square-wave electronic control signal with modulated duty cycle output by the microcontroller unit (MCU) in Embodiment 2;

[0014] Figure 5 Waveform diagram of the output sine-wave power supply in Embodiments 1 and 2;

[0015] Figure 6 Schematic diagram of one of the structures of the improved structure of the motor of the present invention for the full waveform in Embodiment 3;

[0016] Figure 7 Schematic diagram of another structure of the improved structure of the motor of the present invention for the full waveform in Embodiment 3;

[0017] Figure 8 Power supply waveform processed by the third amplifier circuit

[0018] Figure 9 Waveform diagram of the output sine-wave power supply in Embodiment 3.

[0019] Explanation of the reference numerals in the attached drawings: a - power supply circuit; L1 - main stator coil; L2 - auxiliary coil; MCU - microcontroller unit; VCC - DC power supply; 1 - drive circuit; G1 - first triode; G2 - second MOS tube; G3 - third MOS tube; G4 - fourth MOS tube; L - inductor; C - capacitor Detailed implementation manners

[0020] The improved structure of the motor of the present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments:

[0021] Embodiment 1: As shown in Figure 1 , the improved structure of the motor of the present invention includes two coils provided on the stator for driving the rotor to rotate and a power supply circuit a. The two coils are respectively the main stator coil L1 and the auxiliary coil L2. The power supply circuit includes a microcontroller unit MCU and two drive circuits 1 for outputting sine-wave power supplies controlled by the microcontroller unit MCU. The power supply circuit a outputs a DC power supply VCC. The special feature is that the two drive circuits 1 for outputting sine-wave power supplies are respectively connected to one end of the main stator coil L1 and the auxiliary coil L2, and output sine-wave power supplies to the main stator coil L1 and the auxiliary coil L2 respectively. As shown in Figure 5 , the sine-wave frequencies of the sine-wave power supplies I1 and I2 of the two drive circuits 1 controlled by the microcontroller unit MCU are the same, but the phases differ by 90 degrees.

[0022] Preferably, the microcontroller unit MCU used is an MCU capable of outputting sine-wave electronic control signals. As shown in Figure 2As shown, the sine-wave electronic control signal is a sine-wave electronic control signal I0 of positive voltage (the sine-wave electronic control signals I0 of two positive voltages with a 90-degree phase difference output by the microcontroller unit MCU respectively control the drive circuits 1 of two sets of output sine-wave power supplies), as Figure 1 As shown, the drive circuit of the sine-wave power supply is a first amplifier circuit that amplifies the sine-wave electronic control signal I0 into a sine-wave power supply. The first amplifier circuit includes two npn-type first triodes G1. The sine-wave electronic control signal output terminal of the microcontroller unit MCU is connected to the base of one of the npn-type first triodes G1. The emitter of one of the npn-type first triodes G1 is grounded through a resistor R1. The collectors of the two npn-type first triodes G1 are connected to one end of the main stator coil and the auxiliary coil. The emitter of one of the npn-type first triodes G1 is connected to the base of the other npn-type first triode G1. The emitter of the other npn-type first triode G1 is grounded. The other end of the main stator coil and the auxiliary coil is connected to the DC power supply VCC.

[0023] Of course, the first triode G1 can be replaced with a first MOS tube of the corresponding type.

[0024] An adjustment circuit F for adjusting the frequency is provided on the microcontroller unit MCU.

[0025] During operation, as Figure 2 shown, the microcontroller unit MCU outputs a sine-wave electronic control signal I0 of positive voltage. Through two-stage amplification by two npn-type triodes G1, as Figure 5 shown, sine-wave drive power supplies I1 and I2 of positive voltage are output to the main stator coil L1 and the auxiliary coil L2. Since the sine-wave currents driving the main stator coil L1 and the auxiliary coil L2 differ by 90 degrees, the motor is effectively driven to rotate. Since two-phase drive is achieved and only two sets of drive circuits for output sine-wave power supplies are used, the electronic control circuit is simplified and the cost is reduced.

[0026] Embodiment 2: As Figure 3As shown in the figure, this embodiment is based on Embodiment 1. The microcontroller unit (MCU) used is a microcontroller unit that can output a PWM square-wave electronic control signal with a modulated duty cycle. The drive circuit of the sine-wave power supply includes a second amplifier circuit and a low-pass filter circuit (including a series-connected inductor L and capacitor C). The second amplifier circuit includes a second MOS transistor G2. The control signal output terminal of the microcontroller unit MCU is connected to the gate of the second MOS transistor G2. The DC power supply VCC is connected to the source of the second MOS transistor G2. The drain of the second MOS transistor G2 is connected to the low-pass filter circuit. The PWM square-wave power supply with a modulated duty cycle output by the amplifier circuit is converted into a sine-wave power supply by the low-pass filter circuit and then supplies a drive power supply to one end of the main stator coil L1 and the auxiliary coil L2 (one end of the main stator coil and the auxiliary coil is connected between the series-connected inductor L and capacitor C). The other ends of the main stator coil L1 and the auxiliary coil L2 are grounded.

[0027] During operation, as Figure 4 shown, as Figure 4 shown, the microcontroller unit MCU outputs a PWM square-wave electronic control signal with a modulated duty cycle (the PWM square-wave electronic control signals for driving the main stator coil L1 and the auxiliary coil L2 are t1 and t2 respectively). After being amplified by the second MOS transistor G2 and processed by the low-pass filter circuit to become a positive-voltage sine-wave power supply, as Figure 5 shown, a positive-voltage sine-wave drive power supply is output to the main stator coil L1 and the auxiliary coil L2. Since the sine-wave currents for driving the main stator coil and the auxiliary coil are 90 degrees out of phase, the motor can be effectively driven to rotate. Since two-phase drive is achieved and only two sets of drive circuits for outputting sine-wave power supplies are used, the electronic control circuit is simplified and the cost is reduced.

[0028] Of course, a second triode of a corresponding type can be used to replace the second MOS transistor.

[0029] Embodiment 3: As Figure 6 、 7 shown, this embodiment is based on Embodiment 2. The drive circuit of the sine-wave power supply includes a third amplifier circuit and a low-pass filter circuit (including a series-connected inductor L and capacitor C). The third amplifier circuit includes an N-type third MOS transistor G3 and a P-type fourth MOS transistor G4. The control signal output terminal of the microcontroller unit MCU is connected to the gates of the N-type third MOS transistor G3 and the P-type fourth MOS transistor G4. The DC power supply +VCC and -VCC are respectively connected to the sources of the N-type third MOS transistor G3 and the P-type fourth MOS transistor G4. The drains of the N-type third MOS transistor G3 and the P-type fourth MOS transistor G4 are connected to the low-pass filter circuit. As Figure 9As shown, the PWM square wave power supply with a modulated duty cycle output by the amplifier circuit is converted into a sine wave power supply through a low-pass filter circuit and then supplies a driving power supply to one end of the main stator coil L1 and the auxiliary coil L2 (one end of the main stator coil and the auxiliary coil is connected between the series-connected inductor L and capacitor C), and the other ends of the main stator coil L1 and the auxiliary coil L2 are grounded.

[0030] During operation, as Figure 8 shown, the microcontroller MCU outputs PWM square wave electronic control signals with a modulated duty cycle (the PWM square wave electronic control signals for driving the main stator coil L1 and the auxiliary coil L2 with a modulated duty cycle are t1 and t2 respectively), as Figure 9 shown, the square wave power supply amplified by the N-type third MOS transistor G3 and the P-type fourth MOS transistor G4 is processed into a sine wave power supply through a low-pass filter circuit (as Figure 9 shown, the sine wave power supplies for driving the main stator coil L1 and the auxiliary coil L2 are I1 and I2 respectively), and outputs a sine wave driving power supply to the main stator coil L1 and the auxiliary coil L2. Since the sine wave currents for driving the main stator coil and the auxiliary coil are 90 degrees out of phase, the motor can be effectively driven to rotate. Since two-phase drive is realized, only two sets of driving circuits for outputting sine wave power supplies are used, thus simplifying the electronic control circuit and reducing the cost.

Claims

1. An improved structure of an electric motor, comprising two coils arranged on a stator for driving a rotor to rotate, and a power supply circuit. The two coils are respectively a main stator coil and an auxiliary coil. The power supply circuit includes a microcontroller unit (MCU), two driving circuits controlled by the MCU for outputting sinusoidal power supplies, and a DC power supply circuit. It is characterized in that, The driving circuits of the two groups of output sine wave power supplies are respectively connected to one end of the main stator coil and the auxiliary coil, and output sine wave power supplies to the main stator coil and the auxiliary coil respectively. The frequencies of the two groups of sine wave power supplies output by the microcontroller unit (MCU) are the same, but the phases are 90 degrees different.

2. The improved structure of the motor according to claim 1, characterized in that, The MCU used is a microcontroller unit that can output a sine wave electronic control signal with a positive voltage. The driving circuit of the sine wave power supply is a first amplification circuit that amplifies the sine wave electronic control signal into a sine wave power supply. The first amplification circuit includes a first triode or a first MOS transistor. The output signal of the MCU is connected to the base of the first triode or the gate of the first MOS transistor. The collector of the first triode or the source of the first MOS transistor is connected to one end of the main stator coil and the auxiliary coil. The emitter of the first triode or the drain of the first MOS transistor is grounded.

3. The improved structure of the motor according to claim 2, characterized in that, The first amplification circuit includes two npn-type first triodes. The sine wave electronic control signal output terminal of the microcontroller unit is connected to the base of one of the npn-type first triodes. The emitter of one of the npn-type first triodes is grounded through a resistor. The collectors of the two npn-type first triodes are connected to one end of the main stator coil and the auxiliary coil. The emitter of one of the npn-type first triodes is connected to the base of the other npn-type first triode. The emitter of the other npn-type first triode is grounded. The other ends of the main stator coil and the auxiliary coil are connected to a DC power supply.

4. The improved structure of the motor according to claim 1, characterized in that, The MCU used is a microcontroller unit that can output a PWM square wave electronic control signal with a modulated duty cycle. The driving circuit includes a PWM switch control circuit and a low-pass filter circuit. The PWM square wave power supply with a modulated duty cycle output by the PWM switch control circuit is converted into a sine wave power supply by the low-pass filter circuit and then connected to one end of the main stator coil and the auxiliary coil. The other ends of the main stator coil and the auxiliary coil are grounded.

5. The improved structure of the motor according to claim 4, characterized in that, The PWM switch control circuit with a modulated duty cycle is a second amplification circuit. The second amplification circuit includes a second MOS transistor. The control signal output terminal of the microcontroller unit is connected to the gate of the second MOS transistor. The DC power supply is connected to the source of the second MOS transistor. The drain of the second MOS transistor is connected to the low-pass filter circuit. The square wave power supply output by the second amplification circuit is converted into a sine wave power supply by the low-pass filter circuit and then supplies driving power to one end of the main stator coil and the auxiliary coil. The other ends of the main stator coil and the auxiliary coil are grounded.

6. The improved structure of the motor according to claim 4, characterized in that, The drive circuit of the sine wave power supply includes a third amplifier circuit and a low-pass filter circuit. The third amplifier circuit includes an N-type third MOS transistor and a P-type fourth MOS transistor. The control signal output terminal of the micro control unit is connected to the gates of the N-type third MOS transistor and the P-type fourth MOS transistor. The +VCC and -VCC of the DC power supply are respectively connected to the sources of the N-type third MOS transistor and the P-type fourth MOS transistor. The drains of the N-type third MOS transistor and the P-type fourth MOS transistor are connected to the low-pass filter circuit. The square wave power supply output by the amplifier circuit is converted into a sine wave power supply by the low-pass filter circuit and then supplies the drive power to one end of the main stator coil and the auxiliary coil, and the other ends of the main stator coil and the auxiliary coil are grounded.

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