Analysis Of Thermal Characteristics Of High-speed Precision Electric Spindle And Research On Its Cooling Strateg

High-speed motorized spindle as the core component of numerical control machine tool,the precision influence on nc machine tools machining precision,but the key factor to spindle precision of heat is the most main factors that influence its from the high-speed operation of the state of physical phenomena,motorized spindle structure caused by the axial,radial and bending deformation,causing the processing precision is lower.Therefore,it is essential to analyze the thermodynamic characteristics of spindle.This paper will take AC8230026100 high-speed motorized spindle as the research object for thermal state analysis,and then reveal the heat generation mechanism,conduction characteristics and the impact on accuracy,and further put forward the optimal cooling strategy.The main research contents of this paper include:(1)Firstly,based on Hertz contact theory,the author comprehensively considers the interaction between the rolling body and raceway,cage and lubricant,and establishes a more comprehensive pseudo-dynamic theoretical model of angular contact ball bearings and bearing heating model.Then,based on thermal impedance method,the temperature rise transfer model of multi-node thermal resistance network is established,and the axial and radial thermal displacements of each part of the bearing system are calculated according to thermoelastic theory.Finally,the influence of rotational speed and preload on bearing thermal characteristics and the reverse influence of bearing thermal displacement on bearing parameters are analyzed.(2)Based on the analysis of the electromagnetic power loss and heating of the spindle motor and the deformation of the motor stator and rotor structure due to thermal stress and high-speed centrifugal motion,the deformation law of the spindle motor and its influence on the heat exchange of the spindle motor are obtained.(3)Based on the transient thermal characteristics of the spindle system,the fluidheat-solid coupling transient temperature field and structural field simulation analysis of the entire spindle is performed.And compare and analyze theoretical calculation and simulation to verify the effectiveness of the method.(4)Analysis on the influence of channel structure characteristics on heat transfer capacity,the optimized heat dissipation performance of spindle unit is obtained.It includes the cooling structure of the spindle unit,the initial flow rate in the passage,the roughness of the surface in the passage and the influence of the geometrical parameters of the passage on the cooling efficiency of the spindle,and then realizes the improvement of bearing,motor,spindle deformation and temperature rise.