Research On The Thermodynamics Of High-speed Spindle Based On Matlab

High speed machining can drastically increase productivity, surface finish andprecision, but the improvement of these cutting speeds will introduce large amounts ofheat which should have negative impacts on the machining. Spindle unit is the corecomponent of high speed cutting machine tool. In practice, it is important to researchthermal dynamic characteristics through analyzing the process of heat transfer, thermaldeformation and build up the spindle bearing’s quasi-dynamics analysis model with theinfluences of heating effect.This paper refers to three fields of rotor dynamics, tribology and transfer heat.Because angular contact ball bearing can withstand the axial and radial loads, while it hasthe advantage of high stiffness, simple and compact structure. In this paper, angularcontact ball bearings will be research models of high speed spindle bearings. Throughanalysing the movement of bearing rollers, dynamic loads and displacement, friction heat,heat transfer mechanism, the heat blance equation will be built to modify mathematicmodel of spindle units, and then study thermal characteristics of bearing and relevantparameters effect, while taking GWE3500A electrospindle as an example to analyse.From the results of analysis, computation and testing, the results show:1.The analysis of the quasi-dynamic model of angular contact ball bearings consideringthe influence of friction heat is more reliable, while the calculation results are more closeto the actual value.2.Spindle speed has significant effects for the motion performance of the spindle unit.With the increase of spindle speed, Because the contact loadings of inner ring and outerring is influenced by centrifugal force, the contact loadings of inner ring is falling whilethe contact loadings of outer ring constantly improves; The contact angle of inner ringincreases, the contact angle of outer ring decreases.3.In high speed, the frictional heat of the rotation speed can bring obvious influence tothe spindle unit. The thermal displacement of the inner ring groove center according tothe different bearings shows the different increasing trends.4.The influence of pre-loading to the temperature of inner and outer rings, the bearingstiffness and working frequency of spindle unit can be ignored at10000times per minute.But with the improvement of speed, the influence of pre-loading will become evident.5.The increase of lubricant viscosity will cause the corresponding rise of temperatureof inner and outer ring. According to the different geometry of bearing, the risingtendency of bearing temperature is also different.The paper comprehensively analyses thermal characteristics of spindle units and relevant parameters effect on dynamic characteristics, and then to generalize anddemonstrate. The results may be helpful to the research and design of spindle units andhave reference value for further research of thermal dynamic characteristics of highspeed spindle.