Analysis On The Thermo-Mechanical Coupling Properties Of High Speed Grinding Motorized Spindle

The traditional machining has been taken in a new era when the high-speed machining technology appearing. As the main supporter and machine tools of the high-speed machining, the traditional cutting machine is increasingly replaced by the higher ones which is becoming the mainstream of the modern mechanical processing industry. As the core component of the high-speed cutting machine, the degree of excellent on machining precision,surface quality and machining stability of motorized spindle is the main affection of the cutting machine.This paper takes the production of 3DL24 type of high-speed grinding motorized spindle as the research object, analysis the deformation and the distribution of temperature of the spindle in the finite element simulation software with the knowledge of the classical thermodynamics combining the simulating method. The following is the main work in this paper.First introducing the whole system of the main component and the theory of t he motorized spindle, and make the highlight on the main technology, including the inside structure of the spindle, the support structure, lubrication system, cooling system, electrical engineering system and etc.Making deep analysis of the classical thermodynamics and heat transfer, and the analysis of the mechanism and reason of the main heating resource. So that determine the main two heating resource: one is the power loss, another is the friction heating of the bearings with high speed in front and behind the spindle. With the knowledge of the heat transfer theory, the main heat transfer models of main heat are following: the cooling affection between the water in the cooling jacket and the stator; between the rotor and high speed air flow around it; between the motor and the air cross it; between the compressed air and the bearing and between the spindle shell and air near it. Loading all of the heat generation rate and coefficient of heat transfer on the simulating model in the Ansys workbench. Making thermal analysis of steady state and transient with the rotational speed of 15000r/m, in order to get the internal temperature distribution and the changing state of temperature in the cloud, including the curves of the bearing and motor.Loading the result in the analysis of thermal-structure coupling, the deformation in front of the spindle is big enough to make the structure improvement. So that introducing a special structure of back bearing room called ?bearing bowl‘ in order to change the back bearing room form the fully fixed to the float.Simulating the improved structure and contrast with the formal on the deformation ahead the spindle and the internal temperature again. The result is shown that ?bearing bowl‘ can efficiently reduce the deformation ahead the spindle and the increase of the internal temperature by contrasting the before and after.A result of the distribution of internal temperature and deformation ahead the spindle have been made from the thermal characteristics and thermal-structure coupling analysis. The improvement structure called ?bearing bowl‘ have been made and the feasibility of it verified. According to the result, simulation and theory on the system of motorized spindle can be provided and the theoretical basis of the research on the thermal error compensation can be established.