Study On Vibration Characteristics Of Grease-lubricated Bearings Used In High-speed Spindle

In recent years, the requirement of speed, output torque, power and other technical parameters of the electric spind le was raised to a new standard, which also brought a series of technical problems. The DN value of the grease- lubricated bearings used by DGZ-60 E, the glass grinding series of electric spindle of Dake international INC. is up to 1.56×106(mm·r/min), has been used beyond its limitation of general grease- lubricated bearings. Q ualified bearings tested by routine method often make an unsatisfactory causative performance at a higher speed, even the life cannot be effectively guaranteed sometimes. Thus, taking into account that the basic requirements of the existing standard on bearing vibration cannot meet the requirements of electric spindle under ultra- high speed condit ions, the subject takes a deep analysis of vibration characteristics of the bearings used in high- speed spindle, explores a more effective way to assess the high-speed bearing vibration, so as to provide a reliable basis for products bearing quality evaluation, control the qualit y of the products bearings, support the rapid and stable development of high-speed spindle technology.First, analyzes the influencing factors of bearing vibration on the structure, manufacture and work, especially analyzes the impact of speed and lubrication, claims that the increased speed will cause more intense collis ion, result ing in increased vibration; a good lubrication film thickness can ensure to produce reliable lubricant film on rolling ring contact region which plays a positive role to reduce bearing vibration. Analysis of bearing vibration characteristic parameters, the square root of the amplitude and variance are put into the bearing vibration detection index system. Analysis of bearing vibration testing standards, point ing out many flaws of its existence, and give reasonable amendments.Then, design and manufacturing of a high- speed bearing vibration detection bench according to the latter part of the test objects, test purposes, test content and test requirements. The bench not only can meet current national standards for vibration detection of bearings and and the test results has a consistency with the standard bearing vibration measuring instrument, but also can expand the test conditions, testing vibration of bearings under high speed operating conditions.Finally, finish high- speed bearing vibration testing, and analysis the discipline of bearing vibration characteristic parameter of the variation with the speed of bearings. bearings which has a poor level in standard detecting vibration is not necessarily bad at high speed, and sometimes even better than the other bearing, indicating that the current standard for bearing vibration detection does not represent vibration at high speed. Dimensional characteristic parameters inc lude a maximum rectified mean, rms and root magnitude are gradually increasing w ith the increase of bearing speed, and has a consistent trend, ans make no too big differences. Dimensionless characteristic parameters like crest factor, form factor and pulse factor generally fluctuation with change of speed, but there is no obvious rules to follow. Therefore it is not recommended as bearing vibration assessment indicators.