The Research On Starting Torque’s Adjustment Of Self-lubricating Joint Bearing And On-line Testing Technology

Starting-torque-without-load of self-lubricating joint bearing is the frictionaltorque which inner and outer rings of bearing need to overcome from static state tothe relative rotation when the bearing is out of load. It comprehensively reflects thefitting degree of bearing’s inner and outer rings sphere, the preload condition andfriction property of self-lubricating liner, which is an important technical parameter ofself-lubricating joint bearing. Roll forming is the effective process to adjust integralself-lubricating joint bearing’s clearance and also the principal means of adjusting thestarting-torque-without-load. The involved technology of adjustment process of thisjoint bearing’s starting torque, combined with a small rolling mill’s development, isresearched in this paper.Firstly, the formation mechanism and influence factors of self-lubricating jointbearing’s no-load starting torque are theoretically analyzed in this paper.The factorson the no-load starting torque’s measurement precision, such as radial load, clampingway and clamping force, are considered with finite element analysis.Considering that the rolling force is critical to bearing clearance adjustment, aloading device using "electric cylinder" to replace traditional hydraulic cylinder is putforward in this paper, which consists of servo motor, lead screw and nut mechanism,force sensors, etc. The PID control algorithm of rolling force is designed to realize theaccurate control of rolling force on a larger scale and simplify mechanical structure atthe same time.The starting torque online testing system of self-lubricating joint bearing isdesigned to monitor starting torque’s changes while rolling bearing clearance. Aimingat the characteristics of online testing as starting torque’s significant changes androlling force seriously affect the start torque, the rolling clearance process mode withalternating rolling and testing is designed to separate the rolling and testing. Test is inthe process of unloading, the no-load starting torque is determined through continuoustesting inner and outer rings’ resistance torque, effectively weaken the impact of clamping force on the measuring result.The design of rolling mill’s control system with online testing function isdiscussed and hardware and software design of the system are introduced in this paper.The trial production shows that the rolling clearance process with alternaterolling-trial testing is feasible, which make the system has practical significance.