Thermal Behavior of Bearing Surroundings in Machine Tool Spindle System.

The thermal deformation of the machine tool spindle has recently become the most important problem to materialize the manufacturing system for a product with higher accuracy and performance. In order to solve such problems, a large number of investigations have so far been dealt with. Of these, the thermal deformation of the spindle, mainly caused by the internal heat sources such as a bearing, is a major subject. However, there is no effective model to express the dynamic and thermal behavior of the spindle bearing system in the actual rotational condition. In this paper, therefore, to establish the dynamic simulation model of thermal characteristics in machine tool spindle systems with the rolling bearing, the thermal behavior of the main spindle system has been investigated by using the thermal closed-loop concept. Indeed, the effects of the bearing surroundings, i.e., those of the quill and bearing housing structures, have been experimentally clarified. In addition, the cooling effects of air blown to such bearing surroundings have been investigated.