Electromechanical Coupled Characteristic And Thermal Characteristic Analysis And Reliability Research Of Motorized Spindle

Electromechanical coupled dynamical characteristic and thermal characteristic are important characteristics of motorized spindle system.Meanwhile,machining precision is an important performance evaluation indicator of motorized spindle.Based on the research object,electromechanical coupled dynamical model and the finite element model of thermal analysis were established,and then calculation was operated.On the basis of thermal-structure coupling analysis,this dissertation studied reliability and reliability sensitivity of machining precision.Then reliability optimization design and robust design were done.Specific research content is the following:(1)After the comprehensive analysis,motorized spindle system was simplified as mechanical rotor system and motor rotor system.The force acting on mechanical rotor disc was analyzed and subsequently mechanical model equations of motorized spindle system were established.Under the condition of natural coordinate system transformed into rotating coordinate system,the motion equations of motor rotor system were built.Based on electromechanical coupled dynamical modeling of motorized spindle,the experimental simulation analysis was done by using Matlab/Simulink.(2)Based on the finite element model of the motorized spindle system and the experimental simulation data from the first part,the steady-state and transient-state analysis were done respectively.Then thermal-structure coupling analysis was done and we could get displacement response of shaft end under the condition of temperature load and cutting load.And the response value was regarded as the important basis of reliability of motorized spindle's machining precision.(3)Considering the randomness of the thermal characteristic parameters of motorized spindle,we used Latin hypercube sampling,normal sampling and BP neural network technology to get the explicit function relation between machining error and thermal characteristic parameters.Then reliability and reliability sensitivity of every parameter were calculated by linear second moment method.(4)According to the actual working status of the motorized spindle system,the parameters that affected machining precision reliability mostly were regarded as variables,then variables were constrained in a reasonable range.Subsequently the objective function was created and reliability optimization design was done.Taken the minimum spindle parameter sensitivity values' square sum as design goal,reliability robust design of motorized spindle was calculated.In this dissertation,electromechanical coupled dynamical characteristic and thermal characteristic were analyzed,then the study of reliability problems associated with the machining accuracy was done.Its aim is to determine design parameters reasonably in the process of manufacture and improve system reliability and machining performance.