Study On Magnetic Suspension Feed Mechanism For NC Machine Tools

As a new technique of manufacture, high-speed machining has developed just more than ten years, besides rotational speed, setting accuracy of feed unit and response ability of control system of high-speed NC machine tools all need to be improved correspondingly. Compared with traditional feeding system, magnetic suspension feeding system has following superiorities, such as untouched, frictionless, free-lubrication, more advanced setting accuracy, higher feeding velocity and acceleration and so on. All above characteristics are needed for making high-speed machining of NC machine possible.In this thesis, the operating principle and system composition are introduced on details, magnetic suspension feed device is designed and structure parameter design process of suspension magnet and drive magnet is represented. On the condition of maximum electromagnetic force and minimum electromagnet weight, electromagnet optimum design is set up. By MATLAB, complex method is employed to design electromagnet parameters, and structural dimension of magnetic suspension device is designed.Control system is an important part of magnetic suspension feed system. Single-magnet suspension mathematic model is built according to the analysis on electromagnetic suspension force. Linearity processing near the balance point is needed because of system's nonlinear and parameter uncertainty so as to get sate law and transfer function of system. System's visible and controllable are analyzed and linear state controller and PID controller of magnetic suspension feed system are designed, control algorithm corresponding to two kind controller is present and MATLAB is used to emulate how the controller work.Instead of formula analysis which can lead to inaccuracy for leakage, finite element analysis to electromagnetic field by ANSYS to calculate the...