Design And Thermal Characteristic Research On High Speed Permanent Magnetic Synchronous Motorized Spindle

High speed machining is a promising technology for significantly increasing productivity ratio and reducing production costs. Development of high-speed spindle technology is strategically critical to the implementation of HSM. Compared to conventional spindles, and motorized spindles are equipped with built-in motors for better power transmission and balance to achieve high-speed operation. The motorized spindle is equipped with a built-in motor, so that "zero transmission" is realized. It has simple structure, small power loss, small rotational inertia, fast response and easy to achieve precise control of variable speed, but the motorized spindle used to adopt asynchronous induction motor which has large power loss, resulting in large heating, high temperature-rise and large thermal deformation of the motor spindle, then influence on the machining precision of high-speed machine tools seriously. In order to reduce the temperature-rise of motorized spindle and improve it's thermal characteristic, we select PMS motor which has little calorific value, completing the overall structure designing of permanent magnetic synchronous motorized spindle. Then analysis the thermal characteristic of motorized spindle deeply. Special details of the thesis are as follows:(1) Completed the overall structure design of motorized spindle. Calculate the interference between the spindle and the rotor, analysis the static stiffness of motorized spindle in FEM based on the software ANSYS.(2) Calculated the loss and fever of PMSM and the frictional heating of bearing in motorized spindle, study the influence of various factors on bearing's frictional heating. Analysis the heat dissipation characteristics of internal spindle, water cooling system and oil-gas lubrication system. Then calculated the corresponding heat transfer coefficient.(3) Establish finite element model of high-speed spindle's thermal analysis, analysis the temperature field and thermal deformation of motorized spindle in FEM based on the software ANSYS. Discuss the influence of various conditions on temperature rise of bearing and thermal deformation of spindle. Finally, comparison study the thermal characteristic of PMS motor spindle and asynchronous motor spindle.