The Study of Permanent Magnet Brushless DC Motor for Machine ARM Joint

　　The Study of Permanent Magnet Brushless DC Motor for Machine ARM Joint
　　Along with the progress of capacity control and robot technology, machine arms, which are not so easy to be effected by the environment, easy operated, have taken place of human in more and more field. Recently, it makes more and more progress in this field. The motor used in the joint of machine arm is always the point in the research of machine arm field. The neodymium magnets choice of the motor and relative method of control has more or less effect on the cost, operating precision and the reliable of the arm. Among all the motors that can be used in the joints, Brushless DC motor (BLDCM), which has advantages as low cost, light quality and high reliable etc., has taken more and more attentions. In this paper, we analysis the characters of BLDCM according to environment and its structures.At first, the designing index and principle of the BLDCM and its controlling system is presented. And the mathematic model also has been set up.Secondly, the whole FEM analysis model of static and transient operating are made, and the data of electromagnetism has been. The calculation has taken the saturation into account.
　　Thirdly, by using FEM, we can design the http://www.chinamagnets.biz motor more effectively. Experiment and analysis results show that BLDCM has high power-density, high T-n character and can complete the work of machine arms. It is so valuable that can optimize the motor’s structure and the load capability.At last, for being high power density, the thermal load of BLDCM is also higher. So more attention must be paid to the temperature rising. In this paper we use FEM 3D software to analysis the thermal field of the motor. And we get the temperature distribution and temperature rise process when the motor is on static or transient operating. Through block experiments at vacuum and normal statement ,we get that if we deal with the time and load of BLDCM well, machine arm would operate more safe and reliable.