Permanent magnet bearing-free auto-suspension three-degree-of-freedom spherical motor and control method thereof

Abstract

The invention belongs to the technical field of design and control of motors and relates to a permanent magnet bearing-free auto-suspension three-degree-of-freedom spherical motor. The permanent magnet bearing-free auto-suspension three-degree-of-freedom spherical motor comprises a base, a spherical stator wall, stator coils and a rotor, wherein the rotor is positioned in the stator wall; the output shaft of the rotor extends out of an opening above the stator wall; the spherical motor is characterized in that: the stator coils have columnar ironless structures; three layers of stator coils are uniformly distributed along the equator of the spherical stator wall and wefts parallel to the equator and radially fixed on the spherical stator wall; permanent magnet poles are embedded on the surface of the rotor and divided into two layers, namely an upper layer and a lower layer, along the equator; the poles N and the poles S on each layer are staggered; and each stator coil is independently controlled by a driving circuit. The invention also provides a control method for the motor. By the motor and the control method thereof, controllability of a magnetic suspension force and bearing-free running of the motor are realized; furthermore, the movement characteristic of the motor and the flexibility of design of a motor control system are improved.

Description

technical field [0001] The invention belongs to the technical field of motor design and control, and relates to a multi-degree-of-freedom spherical motor. Background technique [0002] With the advancement of science and technology, the application range of multi-degree-of-freedom motion mechanisms is becoming wider and wider. The traditional multi-degree-of-freedom motion mechanism is realized by combining multiple single-degree-of-freedom motors, which has a large mechanism, low transmission precision, and difficult control. The spherical motor can realize the movement of the rotor in three degrees of freedom, and has broad application prospects in high-precision control systems such as robots and nano-working platforms. The permanent magnet spherical motor also has the characteristics of small size and high torque density. [0003] Due to the special structure and movement mode, the supporting device of the spherical motor rotor is also different from ordinary motors. I...

AI Technical Summary

Problems solved by technology

There are some problems in these contact methods. In the direct contact method, the rotor is directly placed on the inner wall of the stator or on the slip ring. Although the coating with a low friction coefficient is used to reduce the sliding friction, the friction torque will still be generated by the movement of the rotor. Impact, as mentioned in patent 200810053083.5; the universal ball bearing uses rolling friction instead of sliding friction, although the friction torque is reduced, but because the bearing and the rotor are in point contact, the pressure is high, and the rotor surface may be damaged; The joint bearing can better realize the three-degree-of-freedom movement of the rotor, but this kind of bearing is more suitable for the low-speed movement of the motor; the air bearing can realize the non-contact between the stator and the rotor, which greatly reduces the friction, but requires additional air pressure device

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