三油楔轴承若干参数对刚性和弹性转子失稳转速的影响

Influences of Parameters of Three-Lobe Bearing on the Instability Speed of Rigid and Elastic Rotor Systems

分别以三油楔固定瓦滑动轴承-刚性Jeffcott转子系统和三油楔固定瓦滑动轴承-弹性Jeffcott转子系统为研究对象,采用有限差分法,通过数值计算联立求解系统自由振动方程、Reyn-olds方程和扰动Reynolds方程。研究了轴承的宽径比、最小间隙比和平均油温的变化对两种系统失稳转速的影响规律并进行了比较。结果表明:减小宽径比,弹性系统失稳转速上升,刚性系统则在小范围内有小幅波动;增大最小间隙比,两系统的失稳转速先减小后增大,最小间隙比的变化对刚性系统的稳定性影响更大;提高平均油温,两系统的失稳转速提高。

Taking three-lobe bearings supporting rigid and elastic Jeffcott rotor as the research subject respectively,free vibration equation, Reynolds equation and perturbation Reynolds equation of the systems were solved through numerical calculation by use of finite difference method. The influences of bearing parameters, such as length-to-diameter ratio, minimum clearance ratio and average oil temperature on the instability speeds of two systems were studied and compared. According the results, decreasing length-todiameter ratio, the instability speed of elastic system increases, but the instability speed of rigid system fluctuates in a small region. Increasing the minimum clearance ratio, the instability speed of the two systems first decreases and then increases and the influence change of minimum clearance ratio on rigid system is more than that on elastic system. Increasing the average oil temperature, the instability speed of the two systems increases.