Brushless direct current motor

Abstract

The invention discloses a brushless direct current motor. The advantages are that complex structures are designed on the rotor punching sheet and the stator punching sheet; and the rotor punching sheet is designed into an irregular circle. Non-uniform motor air gap design is adopted; a magnetic circuit sine wave design idea is imitated to optimize polar arc coefficients, meanwhile, a circle defined by the inner surfaces of the boot parts of the stator punching sheets is also designed into an irregular circle, so that the pole-arc coefficient is further optimized, the waveform of the counter electromotive force of the brushless direct current motor is smooth and closer to a sine wave through the combination of the irregular circle and the pole-arc coefficient, the vibration of the rotor issmaller, and the noise is correspondingly lower; and the magnetic steel structure is simplified, only a square strip structure is adopted, no arc design is adopted, the utilization rate of magnetic steel processing materials is high, the number of used magnetic steel does not need to be increased, and the total cost is low.

Description

technical field [0001] The invention relates to a brushless direct current motor. Background technique [0002] The brushless DC motor consists of a motor body and a driver, and is a typical mechatronic product. The brushless DC motor uses semiconductor switching devices to realize electronic commutation, that is, electronic switching devices are used to replace traditional contact commutators and brushes; it has the advantages of high reliability, no commutation sparks, and low mechanical noise. Widely used in high-end audio recorders, video recorders, electronic instruments and automated office equipment. The brushless DC motor will generate a back EMF during electronic commutation. If the back EMF is not sinusoidal (also known as sine wave distortion), the operation will not be smooth, and the rotor will vibrate, which is one of the main sources of noise in the brushless DC motor. [0003] Existing BLDC motor back-EMF sine wave design schemes mostly focus on the transfo...

AI Technical Summary

Problems solved by technology

Among them, the shortcomings of the surface-mounted rotor design scheme are: the design of the magnetic steel is bread-shaped, the processing cost of the magnetic steel is relatively high, and the rotor needs to be designed with a magnetic steel sleeve, and the motor assembly process and cost are relatively high; the embedded rotor design scheme The disadvantage is that the design of magnetism gathering schemes is mostly used, and the number of magnets increases, which increases the cost of materials and assembly process costs.

The improvement points of these two schemes are all in the aspect of magnetic steel, and the cost is relatively high.

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