Thermal monitoring and thermal deformation prediction for spherical machine tool spindles

Abstract

Machine tool operations and processing can cause temperature changes in vari-ous components because of internal and external thermal effects. Thermal defor-mations caused by thermal effect in machine tools can result in errors in pro-cessing size or shape and decrease processing precision. Thus, this paper focuses on the analysis of heating during machine tool spindle's high speed operation, which is the heat source that causes component and structural deformation. In this paper, thermal monitoring was used to build a thermal error prediction mod-el. Temperature change around the spindle was measured with a DS18B20, then multiple regression analysis was used to establish the relationship between ther-mal deformation quantity and temperature fields at specific points. Finally, finite element analysis was used to build the thermal error model. A solution for the correlation coefficient was obtained using the least squares method. The result of this study verified that finite element analysis can predict front bearing and rear bearing temperature rise, and is consistent with laboratory results. The error in thermal steady-state deformation prediction was less than 2 μm. This information can be used by the controller to effectively compensate the processing and im-prove processing precision.