Papers by Keyword: Squeeze Film Damper

Abstract: The operation principle of SFD and the center moving orbit of grinding wheel spindle which under the operation of SFD are studied. Based on the theoretical research, the experiment is studied and analyzed. The study results show that the application of SFD technology can effectively restrain vibration which is caused by the imbalance quality when the grinding wheel spindle turning at ultrahigh speed. And it can remarkably improve the working quality and work efficiency of ultra high-speed grinder.

Abstract: A continuum model of the evolution of air ingestion and entrainment for open-ended squeeze film dampers is proposed in this paper. Hydrodynamic lubrication theory is extended to lubrication with mixture of a Newtonian liquid and an ideal gas. The solution to the universal Reynolds equation is determined numerically using a control volume method (Elrod algorithm) and the forth-order Range-Kutta method. This method conserves mass throughout the computational domain including air ingestion and entrainment. Excellent agreement is found with the experimental works of Diaz and San Andrès for the squeeze film damper [1, 2].

Abstract: A grinding wheel spindle with squeeze film damper—SFD is designed based on squeeze film damping theory and relevant grinding experiments have been performed. Experimental results indicate that the rationality of design for SFD can make the vibration of the grinding wheel spindle is reduced by 25%. The precision of hole machining is improved by 20%. At the same time, work efficiency of the grinder can be raised about 15%. So it has very important research value and wide application prospect in the field of machining.

Abstract: The response time of a rotor system on a magnetorheological(MR) fluid squeeze film damper was measured experimentally. The effects of rotating speed, step voltage and rotor imbalance on the response time were dealt with. It is shown that the MR fluid damper rotor system is a second-order dynamic system. The rapid response time defined by the time taken for the vibration amplitude to rise (fall) from 10 % (or 90%) to 90 % (or 10%) of the vibration amplitude difference between the initial and final states is 0.05~0.7s in applying a step voltage and 0.01~1.225s in dropping a step voltage, respectively. It is impossible for the response time to be within a few milliseconds. The response time is determined not only by magnetic field strength, MR fluid specification, rotational speed, but operation mode of the power supply. There is a zero initial delay time at either applying or dropping the step voltage, which is caused by the magnetizing or de-magnetizing process.

Abstract: Based on the shortcoming and deficiency of deep hole machining, a grinding wheel spindle with squeeze film damper—SFD is design based on squeeze film damped theory. The motion differential equation of SFD grinding wheel spindle is constituted according to D’ Ale mbert principle，and a lot of simulated research has been carried out about the locus of grinding wheel spindle affect by SFD. Founded on the simulated result, the SFD grinding wheel spindle of internal grinder have designed, and the grinding experiments have been performed. Experimental result indicate that the rationality of design for SFD can make the vibration of the grinding wheel spindle reduce 25% , and make machining precision of hole improve 20% , make work efficiency of the grinder raise 15%.