Permanent magnet direct current motor

Abstract

The invention relates to a permanent magnet direct current motor. The motor comprises a stator assembly and a rotor assembly. The stator assembly comprises a shell and a magnetic cylinder. The rotor assembly comprises a rotor, and the rotor, the magnetic cylinder and the shell are sequentially arranged from inside to outside; the ratio of an angle corresponding to the reversing interval of the surface magnetic curve of the magnetic cylinder to an angle corresponding to the surface magnetic curve of a corresponding magnetic pole is smaller than or equal to 15%, the peripheral contour of the magnetic cylinder is based on a regular polygon, and curves are arranged at the connecting positions of the edges of the regular polygon so that the edges of the regular polygon can be smoothly connected. According to the motor, the noise and vibration of the motor are reduced, and the EMC grade of the motor is improved.

Description

technical field [0001] The invention belongs to the field of motors, in particular to a permanent magnet DC motor. Background technique [0002] Permanent magnet DC motors are widely used in various portable electronic equipment or other devices. With the continuous improvement of automobile intelligence and comfort, permanent magnet DC motors are widely used in automobiles, such as multi-directional adjustment of seats and window adjustment. The application environment of permanent magnet DC motors determines the need for the lowest possible noise and vibration. In addition, when applied to automobiles, since there are many electronic devices in automobiles, there are high requirements for the electromagnetic compatibility (EMC, Electro Magnetic Compatibility) level of permanent magnet DC motors, so as not to affect the normal operation of automobiles. EMC can be divided into electromagnetic interference (EMI) and electromagnetic susceptibility (EMS) according to its cont...

AI Technical Summary

Problems solved by technology

For the circular structure, although it is easy to manufacture and requires relatively less space for installation, since its shell is circular, in order to prevent the motor from rotating as a whole, additional fixing elements are required to fix it. This increases the need for installation space and the complexity of the installation

[0005] The square structure can naturally prevent the motor from rotating due to the existence of square sides, but this shape has two problems: for some irregular installation spaces, it may be difficult to install due to the interference of a certain corner; However, because the shape of the rotor is circular, the volume of the outer and inner circle of the magnetic cylinder at the corner is much larger than the volume between the two adjacent corners, making the distribution of the magnets extremely uneven, which significantly reduces the performance of the motor. , and lead to waste of magnetic material at the corners of the magnetic cylinder

Images