考虑热效应作用的浮环轴承润滑特性研究

Study on Lubrication Characteristics of Floating Ring Bearing Considering Thermal Effect

针对高速工况下浮环轴承润滑特性的理论预测和实验结果存在偏差的问题,在充分考虑热效应影响的基础上建立涡轮增压器径向浮环轴承的热流体动力润滑模型。该模型的理论计算结果和试验结果基本一致,验证其正确性。研究浮环内外层油膜间隙、浮环厚度和浮环宽度等浮环结构参数对浮环轴承润滑特性的影响。结果表明:在其他参数一定时,外层油膜间隙变大时,环速比和流量将变大,将带走更多的热量,轴承温升降低;内层油膜间隙变大,环速比将变小,但流量增大,轴承温升下降;浮环厚度变大,环速比将下降,但浮环厚度对内外膜温升几乎没有影响;浮环外接触表面宽度越大,环速比下降,温升将变大。

The theoretical prediction results of the lubrication characteristics of the floating ring bearing show significant discrepancies with test data at high speed condition. Aimed at this problem, the thermal fluid dynamic lubrication model considering the influence of thermal effect was established to investigate the lubrication performance of the floating ring bearing of a turbocharger.The simulation results of the thermal model are consistent with the test results, which verifies the rationality and feasibility of the thermal model.The effect on lubrication characteristics of floating ring bearing by the struc- ture parameters of inner and outer film oil clearance, thickness and width of ring was studied.The results show that while other parameters remain the same, with the increasing of outer bearing clearance, the ring speed ratio and oil flow rate will increase ,which will take away more heat and reduce the temperature rise.While with the increasing of inner bearing clearance ,the ring speed ratio will decrease and the flow rate will increase ,which will also reduce the temperature rise.The increasing of ring thickness will cause the decreasing of ring speed ratio ,but it has little effect on the temperature rise.The larger outer bearing width will cause the decreasing of ring speed ratio and the increasing of temperature rise.