Analysis On The Tribology Performance Of The Large Four-point-contact Ball Bearing In Wind Turbine

The bearing friction torque has much influence on operation precision andplacidity and is an important parameter to the service performance of a bearing. It hasdirect influence on energy consumption of a system, temperature rise in operation,load capacity and lifetime.Based on the theory of static mechanics analysis, the influence of loads state andthe parameters of a bearing on friction torque are studied by numerical solution. Thechange law of the each part of friction torque is also studied. The analysis on theinfluencing factors of the friction torque can help designer to control friction torquebetter and ensure bearing working in security and reliability.In this paper, firstly, the static model of the bearing is established and the loaddistribution is solved. The influence of bearing geometric parameters and materialparameters on contact stress of the raceway are researched, and also the changing lawof the stress curve is obtained so as to provide a basis for improving load capacity ofthe bearing. The sources and the calculating method of friction torque of the slewingbearing are introduced. Based on the generation mechanism of friction torque, thefriction torque of the slewing bearing under various loads are calculated by the theoryof static mechanics analysis, and also the tribology performance of the bearing isanalyzed.Results show that the characteristic of load distribution on raceway is different atdifferent loads. With the increase of contact angle and the decrease of the coefficient ofthe groove curvature radius, the maximum loads on raceway decrease and the lifetimeof bearing increases. The loads have much influence on the various components of thefriction torque of the slewing bearing. The friction torque caused by elastic hysteresisincreases when bearing is under high loads. With the increase of the contact angle, thefriction torque of the slewing bearing decreases. With the increase of the coefficient ofthe groove curvature radius, the friction torque caused by elastic hysteresis increases and the friction torque caused by revolving sliding decreases.