To measure the vibration caused by the random speed fluctuations superimposed on the constant speed,this paper discusses the dynamic characteristics of the rolling mill s drive system when the elastic driving shaft and motor shaft had speed oscillation,and an instantaneous speed measurement model of rolling mill s drive system was established.

The performance of high speed rolling bearing was studied under unstable conditions of rotation speed fluctuation, and the failure modes of the bearing were analyzed under such conditions.

Design of In-Cycle Speed Fluctuation Measurement System for High-Speed Gasoline Engines;

During the bench the test process,gasoline engine cycle variation leads to speed fluctuations that will reduce control precision of A/F and the credibility of the bench test.

The rattling model of a one stage gear system is established,in which mass unbalance,speed fluctuation of driving shaft and backlash of the gear pair are considered.