转子不平衡量对角接触球轴承-刚性转子系统动力学耦合特性的影响

Influence of rotor unbalance on dynamic coupling characteristics of angular contact ball bearing-rigid rotor system

建立了高速角接触球轴承-刚性转子系统完全动力学数值仿真模型。以某仪表轴承支承的转子系统为例,分析了转子不平衡量对转子振动响应、轴承内部载荷分布以及保持架质心运动轨迹、频域幅值变化及其磨损的影响。结果表明:无转子不平衡量时,转轴振动仅包含保持架频率,而转子不平衡时,转轴振动除保持架频率,还包含内圈频率及其倍频。随着转子不平衡量的增大,内圈频率对应的转轴振动幅值逐渐增大,而保持架频率对应的转轴振动幅值先减小后增大。球与内外圈接触载荷波动随着转子不平衡量的增大而增大,且载荷包含了保持架频率与内圈频率的多种耦合频率。转子不平衡量越大,保持架质心运动越不稳定,而保持架磨损率反而逐渐降低。保持架质心运动除保持架频率外,还包含保持架频率与内圈频率的耦合频率,说明保持架运动受转子振动的影响。

A complete dynamic numerical simulation model of the high-speed angular contact ball bearing-rigid rotor system was established.Taking an instrument bearing-rotor system as an example,the influences of rotor unbalance on the vibration response of the rotor,the load distribution of the bearing,the movement trajectory and frequency domain amplitude change of the cage mass center and its wear were analyzed.The results showed that when there was no rotor unbalance,the shaft vibration only included the cage frequency,and when the rotor was unbalanced,the shaft vibration included the inner ring frequency and its multiples in addition to the cage frequency.As the rotor unbalance increased,the shaft vibration amplitude corresponding to the inner ring frequency gradually increased,while the shaft vibration amplitude corresponding to the cage frequency first decreased and then increased.The fluctuation of the contact load between the ball and rings increased with the rotor unbalance,and the contact load included multiple coupling frequencies of the cage frequency and the inner ring frequency.The greater rotor unbalance indicated the more unstable mass center movement of cage,but the lower cage wear rate.In addition to the cage frequency,the mass center movement of cage also included the coupling frequency of the cage frequency and the inner ring frequency,indicating that the cage movement was affected by the rotor vibration.