Calculation And Analysis Of Torque-Angle Characteristic Of Two-Degree-of-Freedom Motor

After comparing and analyzing the many model spherical motors, which were made by some countries, we have decided to adopt orthogonal cylinder structure in design of two-degree-of-freedom motor. The motor can be divided into two special structure two-phase hybrid step motors, separately, which are inner small motor, that is, external-rotor two-phase hybrid step motor, and outer big motor, that is, fan-shaped two-phase hybrid step motor.In this dissertation, based on tooth-layer specific permeability method, an analysis and calculating of torque-angle curves is carried out. It will be helpful for optimizing the dimension of the motor by comparing the torque from calculation with the torque that is required in qualification.Firstly, a scalar and vector potential analysis models of tooth-layer magnetic field in a two-degree-of-freedom motor is developed, which is the same as standard hybrid step motor. By applying the finite element method, the distribution of the tooth-layer magnetic field is studied in detail. It provides an effective means for further calculation of performance and parameters of the motor. On the basis of the scalar potential analysis model and calculation of the tooth-layer magnetic field, a data bank of the equivalent magnetic parameters of tooth-layer with different structure sizes is established. A nonlinear equivalent magnetic circuit model of the tooth-layer in this motor is also developed. All above prepare for CAD and optimal design of the motor.Secondly, comparing to common hybrid step motor, a unifying nonlinear magnetic network of a two-degree-of-freedom motor is constituted. The difficult problems of accurate and quantitative calculation of the motor are solved successfully. After resolving the magnetic network, a torque-angle characteristic procedure is programmed.Finally, referring to structure parameters of two-degree-of-freedom motor, example calculation is given. The results prove that Fortran program of static characteristic in two-degree-of-freedom motor is correct and available. Consequently,an important development and improvement on the tooth-layer specific permeability method for step motor calculation is accomplished.