Two-in-one coaxial direct current brushless motor

Abstract

The invention discloses a two-in-one coaxial direct current brushless motor. The two-in-one coaxial direct current brushless motor is an integrated motor formed by combining two direct current brushless motors which are basically identical in power in a coaxial mode, wherein the performance of the integrated motor is improved obviously. The two-in-one coaxial direct current brushless motor comprises a common rotating shaft, a first motor and a second motor. The first motor and the second motor are both direct current brushless motors. The first motor and the second motor are arranged on the common rotating shaft in a series connection mode. Through process control, when the two-in-one coaxial direct current brushless motor is started, the synthesized torque of the two-in-one coaxial direct current brushless motor is always greater than zero, and the minimum synthesized torque is the maximum torque of one of the motors. Therefore, the torque amplitude of the whole motor is effectively reduced, no dead angle exists during motor operation, the starting performance is better, vibrations caused by electromagnetic switching between the motors are reduced, and noise is lowered; meanwhile, under the condition that the outer diameters of the motors do not change basically, the motors are overlapped coaxially and then operate simultaneously to achieve the effect of outputting higher torque.

Description

technical field [0001] The present invention relates to the technology in the field of DC brushless motors, in particular to a high-efficiency motor with low cost and better performance, which is a two-in-one coaxial DC brushless motor that outputs superimposed torque through a common rotating shaft. Background technique [0002] Existing brushless DC motors usually include an outer rotor brushless DC motor (such as figure 1 shown) and inner rotor brushless DC motor (such as figure 2 shown) two types, they all include rotor assembly, stator assembly and connectors; the main parts of rotor assembly are permanent rotor magnet 6 (6'), rotor frame 7 (7') and shaft 8, etc., rotor frame 7 ( 7') is the main part connecting the rotating shaft 8 and the permanent rotor magnet 6 (6'), and the position of the rotor magnet 6 (6') and the rotating shaft 8 is fixed by connecting and assembling, ( image 3 It is a schematic diagram of the mutual position of the stator and the rotor in t...

AI Technical Summary

Problems solved by technology

[0003] The number of stator teeth and the number of rotor magnetic poles of ordinary DC brushless motors are the same in number, and they are distributed symmetrically along the center of the rotating shaft; The neutral point is in the aligned phase, therefore, at the moment the motor starts, the force generated by the stator magnetic field and the rotor magnetic field reaches the maximum in the radial direction, but is zero in the circumferential direction, that is, the starting torque of the motor is zero, and the motor is difficult to start; and , when the motor is running, the moment the stator switches polarity every time, the output torque of the motor is zero, so the brushless DC motor has a dead angle in the process of stalling (Note: the brushless DC motor has no dead angle problem during operation); at the same time , since the maximum torque value of the motor is the maximum amplitude value of the torque, the torque changes greatly when the motor is running, the motor is easy to shake, and the running noise is large

[0004] Aiming at the problem that the brushless DC motor cannot be started, the current practice is to design the pole teeth of the stator as an asymmetrical shape on both sides, so that when the motor is stationary, the polarity teeth of the stator and the rotor magnet will attract the polarity of the rotor. The point deviates from the midpoint of the polar teeth of the stator by a certain phase, so as to ensure that the torque of the motor is not zero when the power is turned on, so as to achieve the purpose of starting the motor. During operation, the motor can run continuously by relying on inertial force; through this design, although the motor can start Start and run, but the torque at start is relatively small, so it is difficult to start when the load is heavy, the zero torque of the motor still exists, and the torque amplitude of the motor has not been improved, so the dead angle still exists when the rotor is locked, the motor is easy to shake, and the motor The operation noise is high, and the motor is only suitable for occasions with small loads and low quality requirements

[0005] Aiming at the above-mentioned problems of starting the brushless DC motor difficultly, running stalls with dead angles, and motor vibration and noise caused by large torque amplitude, the most commonly used solution is to use a three-phase motor circuit, but this solution is due to the three-phase motor circuit. The circuit cost is expensive, the circuit is complicated, and the circuit space is relatively large. In the micro motor, the circuit needs to be plugged in, and its application and promotion are limited.

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