Research On Electromagnetic And Thermal Properties Of Permanent Magnet Synchronous Spindle Motor For Turning

The motorized spindle is high-tech products widely applied in the high-grade CNC machine tools with the advantage of compact structure, light weight, small inertia, and good dynamic characteristics, which integrated the machine tool shaft and pindle motor together.With the improving of performance, control precision and speed range, permanent magnet motor is more and more applied to the the high speed motorized spindle of processing center.The spindle nose is sensitive to temperature changes, and temperature rise can affect machining precision of the cutting tool, even cause the component deformation and insulation damage. So the accurate calculation and analysis of the temperature distribution is very important. This dissertation is applied to the study of the turning motorized spindle motor.Firstly, the electromagnetic design plan such as the electromagnetic load, the main dimensions of turning motorized spindle motor is determined according to the installation dimensions and performance specifications with the reference of SIEMENS 1FE1 motor. And the flux field, the no-load EMF and the load torque are obtained by finite element calculation,which verify the rationality of the design plan.Secondly, the flux weaken field characteristics, the inductance of d-axis and q-axis and the maximum speed are calculated and obtained. Then the calculation method of the iron loss,the copper loss, the mechanical loss and the stray loss is given, and the iron loss of stator, the iron loss of rotor, the solidloss of permanent magnet is caculated by finite element analysis and compared under rated operation and flux weaken operation.Finally, the temperature of the motorized spindle is calculated by the finite volume method after the reasonable equivalent, the caculation of equivalent heat transfer coefficient and heat generation rate with the fit-up gap in consideration. The temperature distribution and the highest temperature pointis are obtained with different water speed and different slot insulation. And a method to reduce temperature rise of hottest part of motor is put forward,that is to encapsulate winding ends with epoxy. This dissertation provides a certain reference value for the same type of permanent magnet spindle motor design and optimization.