Prediction of Thermal Deflection at Spindle Nose-tool Holder Interface
Loss of machining accuracy is a major problem in machine tool spindles under high speed machining (HSM) conditions due to thermal deflections of the spindle nose. Frictional losses in the spindle bearings which contribute for the temperature rise and hence thermal deflection of the spindle nose are estimated. A 2-D axisymmetric finite element model of high speed spindle assembly is developed using ANSYS to determine the temperature distribution considering oil-mist lubricated bearings. Spindle nose thermal deflection is determined by performing a sequential thermal-structural coupled field analysis. The effects of spindle speed and cooling on the spindle nose deflection are investigated so as to minimize the same. The effect of conduction through tool holder on spindle nose deflection is also investigated.