CN2938550Y

CN2938550Y - Structure for reducing torque pulsation of brushless DC motor

Info

Publication number: CN2938550Y
Application number: CN 200620043381
Authority: CN
Inventors: 李军丽; 李秀英; 苗国辉
Original assignee: Shanghai Electrical Apparatus Research Institute Group Co Ltd
Current assignee: Shanghai Dianke Motor Technology Co Ltd
Priority date: 2006-06-29
Filing date: 2006-06-29
Publication date: 2007-08-22
Anticipated expiration: 2016-06-29

Abstract

The utility model relates to a structure for reducing torque ripple of brush-less DC motor, comprising a magnetic steel (1), a rotor magnetic yoke (2), a key (3) and a rotating shaft (4). It is characterized in that the pole arc width of the magnetic steel (1) is reduced from 90 degrees to 76.9 degrees, the positions of the rotor magnetic yoke (2), the key (3) and the rotating shaft (4) remain unchanged. Since the pole arc width of the magnetic steel is changed, the rear spline torque is improved to 1.5 percent of the rated torque. By changing the pole arc width of the permanent magnet, the spatial mechanical angle occupied by the permanent magnet is changed, reducing the spline torque greatly and thereby the torque ripple. Thus, not only the vibration and noise of the brush-less DC motor are improved, but also the magnetic steel is omitted, reducing total loss and improving motor efficiency.

Description

Reduce the structure of brshless DC motor torque pulsation

Technical field

The utility model relates to a kind of structure that reduces the brshless DC motor torque pulsation, reduces the method for brshless DC motor torque pulsation in other words, belongs to technical field of motors.

Background technology

The magnetic field that permanent magnet produced on the brshless DC motor rotor attracts each other with the tooth in the stator armature iron core, and its active force makes rotor that a kind of trend of aliging with stator along a certain specific direction be arranged in the torque that component produced of circumferencial direction.

This torque is exactly a cogging torque, also is referred to as reluctance torque.It is the one of the main reasons that the brshless DC motor torque produces pulsation.Rotor structure is magnet steel, rotor yoke, machine shaft as shown in Figure 1 from outside to inside successively.Magnet steel sticks on the rotor yoke surface, and rotor yoke links up by key and machine shaft.

In variable speed drives, when the natural machanical frenquence of the frequency of cogging torque and stator or rotor is identical, just caused resonance, make the vibration of motor and noise increase.The existence of cogging torque influenced equally motor in speed control system low-speed performance and hi-Fix in the Position Control.

On structural design, reduce cogging torque, make torque pulsation reach desirable situation by improving the polar arc width.

Structure before improving, cogging torque is about 23% of a nominal torque, situation is Cui not, for this reason, must be improved the polar arc width of permanent magnet, reduces the torque pulsation of motor.

Summary of the invention

The utility model relates to the structure that reduces the brshless DC motor torque pulsation, and cogging torque is about 1.5% of a nominal torque after this architecture advances.

For achieving the above object, the technical solution of the utility model is: rotor is made up of magnet steel, rotor yoke, key, rotating shaft, and rotating shaft is in the bosom, and magnet steel has key on the surface of rotor yoke between rotating shaft and the rotor yoke.By improving the polar arc width of permanent magnet, promptly change the permanent magnet mechanical angle shared in the space, make cogging torque reduce significantly, thereby torque pulsation also reduce.

The beneficial effects of the utility model: by improving the polar arc width of permanent magnet, make cogging torque reduce significantly, thereby torque pulsation has also reduced, the vibration and the noise of brshless DC motor have so not only been improved, also saved magnet steel, reduce iron loss and copper loss, thereby improved efficiency of motor, had certain economic benefits.

Below in conjunction with drawings and Examples to the utility model detailed explanation of making comparisons.

Description of drawings

Fig. 1 is the rotor structure schematic diagram of prior art;

Fig. 2 is a rotor structure schematic diagram of the present utility model.

Embodiment

With reference to Fig. 2, this is a rotor structure schematic diagram of the present utility model.

As shown in the figure, rotor structure comprises magnet steel 1, rotor yoke 2, key 3, rotating shaft 4, and rotating shaft has key in the bosom between rotating shaft and the rotor yoke, changes magnet steel 1 polar arc width, reduces to 76.9 degree, rotor yoke 2, key 3, rotating shaft 4 invariant positions from 90 degree.Owing to change magnet steel 1 polar arc width, improving the back cogging torque is 1.5% of nominal torque.

By improving the polar arc width of permanent magnet, promptly change the permanent magnet mechanical angle shared in the space, make cogging torque reduce significantly, thereby torque pulsation has also reduced.Like this, not only improve the vibration and the noise of brshless DC motor, also saved magnet steel, reduced iron loss and copper loss, improved efficiency of motor.

Claims

1, a kind of structure that reduces the brshless DC motor torque pulsation, this structure comprises that magnet steel (1), rotor yoke (2), key (3), rotating shaft (4), rotating shaft are in the bosom, between rotating shaft and magnet steel, the rotor yoke key is arranged, it is characterized in that: magnet steel (1) polar arc width reduces to 76.9 degree from 90 degree, rotor yoke (2), key (3), rotating shaft (4) invariant position, improving the back cogging torque is 1.5% of nominal torque.