Research On Embedded Bearing Lubricating Device Based On Piezoelectric Microjet

The enhancement of comprehensive strength of a country is closely related tothe space technology. Therefore, in recent years, countries put much manpowerand finances into research and development of aerospace technology. Similarly, asthe successful launch of Tiangong-1space station, Shenzhou-9、Shenzhou-10spacecraft, it also indicates that，China ’s manned space project are in accordancewith the established strategy smoothly, while the successful launch of Chang-e I,II, III lunar orbiter and six-wheeled rover named Yutu indicates that China’s lunarexploration project is in the leading position of the world. But with the gradualdevelopment of space technology, the problem of aerospace equipment’s usefullife period is particularly prominent. As a spacecraft have the followingcharacteristics: longer production cycle, costs higher and lower reuse recyclingrate, the useful life period of an aerospace equipment has become an importantfactor which restrict the development of space technology. The thing whichdetermines spacecraft’s lifetime is usually the mechanical parts inside thespacecraft, After lots of failure analysis on the mechanical components inside thespacecraft, people find that one of its major failure modes is wear failure whichdue to not timely and inadequate lubrication of the bearing. At present, aerospacebearing’s lubrication is mainly dependent on passive lubrication, i.e. aerospacedevices rely on the limited lubricating oil which is carried before lift of. With theincrease of operating time in the space, there will come out problems such as oilvolatile, invalid of oil coating etc. And if inject too much oil, there will appear oilleak which will contaminate space environment. In recent years, The activelubrication is proposed as a new scheme to solve the aerospace lubrication device’swear failure. Active lubrication can increase the utilization of the limitedlubricating oil then greatly improving the useful life period of lubricants relativedto passive lubrication, by the way of supplying oil depend on the determination ofmotion state.According to the lubrication failure of bearing in Control Moment Gyroscopewhich has typical representativeness for aerospace devices, this paper design akind of bearing lubricating device based on piezoelectric micro jet, on the basis ofour team’s years of application of piezoelectric and the mature piezoelectrictheory.The device eject lubricating oil from the nozzle and then act on the bearingdue to the pressure waves which generated by piezoelectric vibrator. Firstly, thispaper designed one simple Control Moment Gyroscope, and then embeddedthe bairing lubrication device in.Secondly using the finite element simulationsoftware to simulate the vibration mode and the corresponding excitation parameters; Draw the timely varying motion curves of the key point on thevibrator;obtained the relationship between piezoelectric vibrator’s motion andexcitation parameters. Finally conduct an experiment to verify the theory. Bycomparing the experimental results and theoretical analysis,obtained the changeregulation between piezoelectric vibrator’s motion and excitation parameters. Andit demonstrated the feasibility of this scheme for the lubrication failure of bearingin Control Moment Gyroscope.