Research On The Driving Method Of Heavy Load And High Precision Fine Adjustment Mechanism

According to the requirement of OM2 fine adjustment mechanism of SG-III,its driving methods characteristics was analyzed and compared.The tuning mechanism have the requirements of heavy loading,high precision.And its friction force is too high to cause phenomenon of creeping.So the driving method selection of adjustment mechanism has a high demand.According to the requirement of heavy load and high precision of the OM2 fine adjustment mechanism,the three drive methods which are motor screw driving,hydraulic servo driving and hydraulic cylinder precision unit driving are determined,and the stability of hydraulic servo control system is simulated and analyzed in MATLAB Simulink.Then the driving precision of the three methods were analyzed.Analyzed the transmission error and return error of motor screw driving and hydraulic cylinder precision unit driving by analyzing its manufacturing error,assembly error and using error.And analyzed the controlling error of hydraulic servo control system by analyzing its static error and steady state error.Analyzed the creeping phenomenon of three methods because of their high friction force and slow speed.Put forward the calculation formula of the critical creeping speed of screw driving and hydraulic cylinder driving,and obtained their limited velocity of the three methods.Then established the simplified model for OM2 assembly tooling in ADAMS and AMESim,and simulated the creeping phenomenon of the three methods and mutual verified with the theoretical calculation.In the end,compared it's driving characteristics of three methods with different working condition.By analyzing and comparing their driving precision and limited velocity of different guide length,different driving mass and different tuning adjustment direction.The conclusion was concluded,when it has short position bearing length and heavy mass,suggested adopting the hydraulic cylinder precision driving unit method;and when it has long guide length and light mass,suggested adopting the hydraulic cylinder precision driving unit method only on the driving of around Y axis rotation and along the Z axis translation,and using servomotor screw driving in the other working conditions.