Theoretical Study On No-load Starting Torque Of Self-lubricating Spherical Plain Bearing And Design Of Its Detector

Self-lubricating spherical plain bearings are widely used in aerospace and construction machinery because of their simple structure,good self-tuning and no need to add lubricants.The no-load starting torque is an important index to evaluate the rotational flexibility and oscillational flexibility of self-lubricating joint bearings,and it directly affects the performance of joint bearings.At present,it is still impossible to calculate the starting torque accurately in theory,so the related research mostly focuses on the testing,while the equipment used in the testing still has some defects,such as low detection accuracy and single function.Therefore,this paper study the theory of no-load starting torque of joint bearings,and develop its detector.The analytical model for calculating the no-load rotational and oscillational breakway torque of joint bearings was established by analyzing the formation mechanism.The clamping process of joint bearings were numerically simulated,and the clamping effects of four kinds of clamping modes were analyzed qualitatively.The data of the compression of liner generated by the numerical simulation was brought into the breakway torque analytic model,and the additional starting torque and the measurement errors caused by clamping modes was calculated quantitatively.A no-load starting torque detector with two driving systems of inner and outer rings was developed,which can detect the rotational starting torque,the oscillational starting torque and the dynamic frictional torque.The flat scroll spring device was added to the drive system in order to distinguish the no-load starting torque and the dynamic frictional torque.Based on the measurement errors calculated in the preceding part,the clamping system was designed by choosing the clamping modes which meets the requirements.The selection of sensors and the design of main electrical control circuits in the detection and control system were completed.The error analysis of the detector was made.The dynamic simulation of the inner ring drive system of the detector was carried out,the motion state and torque change of the system were investigated.The test of the no-load starting torque of the joint bearings was carried out by using the detection device.The simulation results verified the feasibility of increasing the flat scroll spring device in the drive system.