| Rotation speed stability is an important evaluation indicator of the performance of ahydro-viscous clutch (HVC). In order to improve the rotation speed stability of HVC inmixed lubrication and expand the speed range, the friction pair of HVC in mixedlubrication is studied theoretically and experimentally.The torsional vibration model of HVC in mixed lubrication is established to obtain thefrictional heat flux of the friction pair. Then, the distribution of heat flux is determined bysolving the thermal resistance model of the friction pair. The results show that the heattransfer coefficient can be increased by the following ways: increasing the outer diameter ofthe friction pair or decreasing that inner diameter, increasing the flow rate of the input oiland choosing a right oil type which has a higher thermal conductivity, a higher density, ahigher specific heat capacity or a lower kinematic viscosity.The3-D finite element model of the friction pair of a HVC in mixed lubrication isestablished. And the thermal field and the displacement field of the friction pair, obtainedby thermal-stress analysis method, are obviously affected by the diamond-like structures onfriction layer.The function of the wear rate of a HVC in mixed lubrication is built by performing thewear tests on Plint TE-92. And by derivating the displacement field of the friction pair, theexpansion rate is obtained. According to the thermoelastic stability theory, the phenomenonof rotation speed instability of a HVC in mixed lubrication is studied by comparing thewear rate and expansion rate. |
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