风力发电机组主轴承温度计算与测试验证

Temperature calculation and test verification of wind turbine main bearing

测试了风力发电机组在发电状态时,发电机的主轴前、后轴承温度,得到了温度曲线和温升曲线.根据功率和温升的关系,在满功率发电状态时,计算了发电机主轴的前、后轴承的温升,根据叶片根部载荷,得到了轮毂中心载荷.计算了风机主轴前、后轴承的摩擦力矩及摩擦热量,根据摩擦热量,使用有限元方法计算了满功率发电状态下的主轴系前、后轴承的温度,分析了轴承理论温升与测试温升的差异.研究了径向载荷、轴承预紧力、轴承尺寸、润滑脂黏度和轴承转速等对轴承温度的影响.结果表明:前轴承比后轴承受到的径向载荷要大、温升大很多;在4种摩擦力矩中,滑动摩擦力矩产生的热功率损耗大大高于其他摩擦力矩产生的热工率损耗;轴承温升随预紧力的增大而增加,预紧力对前轴承温升影响较大,对后轴承温升影响很小.

During the generating of turbine,the temperature tests of the front and rear bearings on the generator were conducted to obtain temperature curve and temperature rise curve.According to the relationship between the power curve and the temperature rise curve,the temperature rise values of the front and rear bearings under the full power generation were calculated.The load at the center of the hub was obtained according to the blade root load.The frictional torques in the front and rear bearings and the generating heat by the frictional torque were calculated.Based on the calculated frictional heat,the temperature values of the front and rear bearings of the main shaft system under the full power generation were calculated by finite element method.The difference between the theoretical temperature and the test temperature was analyzed.The effects of radial load,bearing preload,bearing size,grease viscosity and bearing speed on bearing temperature were analyzed in detail.The results show that the radial load and the temperature rise of the front bearing are much larger than those of the rear bearing.Among the four friction torques,the thermal power loss caused by the sliding friction torque is significantly higher than those by other friction torques.The temperature rise of the bearing varies with the preload force,and the greater the pretension force is,the greater the temperature rises.The increasing of pretension force has great effect on the temperature rise of front bearing and has small effect on the temperature rise of rear bearing.