Motorized spindle is one of the core components of precision machine tool. The precision of the motorized spindle will be subjected to thermal load and force load during its operation. These two kinds of loads will be coupled with the machining process, leading to the deformation error of a motorized spindle. So, a method of thermal- mechanical coupling calculation for deformation error of motorized spindle is proposed. Firstly, the thermal load and force load during operation of the motorized spindle are calculated, and the effect of force load on thermal load is also analyzed. On this basis, the changes of thermal load, force load and thermal boundary condition of motorized spindle are analyzed. With the increase of temperature, the heat generation and thermal boundary conditions of the bearing will change. Through iterative updating of heat generation and thermal boundary conditions, the deformation of the motorized spindle can be calculated in a thermal steady state. Finally, the thermal-mechanical coupling calculation method is verified by finite element simulation and experiment.

电主轴是精密机床的核心部件之一。电主轴的精度在其运行过程中会受到热负荷和力负荷。这两种载荷会与加工过程耦合，导致电主轴的变形误差。为此，提出了一种电主轴变形误差的热-机耦合计算方法。首先计算了电主轴运行过程中的热负荷和力负荷，分析了力负荷对热负荷的影响。在此基础上，分析了电主轴热负荷、力负荷和热边界条件的变化。随着温度的升高，轴承的发热和热边界条件会发生变化。通过发热和热边界条件的迭代更新，可以在热稳态下计算电主轴的变形。最后，通过有限元仿真和实验验证了热力耦合计算方法。