| According to the problems happened in the aviation transmission system,such as the decrease of oil film thickness,increase of pressure and temperature and frictional wear,deterioration of surface failure,which caused by the harsh load condition,like heavy load,high speed and temperature,surface topography,fuel injection direction and elastic-flow lubrication,this paper carried out the research on the lubrication performance of air transmission units under the influence of multi-scale parameters.The coupled lubrication model with multi-parameters has been established for air transmission unit including gears and bearings,and the influence rule of lubrication characteristics caused by multi-scale parameters including load,structure,speed,lubricating oil,surface roughness and profile modification has been analyzed,which provided the theoretical foundation and analytic method for the design and manufacture of air transmission unit with long life and high reliability.The main work of this paper including as follows:1)The second digital filtering method is used to simulate the gauss rough surface,and the lubrication model of the ball bearing is proposed considering the real surface,the thermal effect and the angular contact ball bearing with micro elastic-flow lubrication model.Reynolds equation,film thickness equation,energy equation and load balance equation are established synchronously to obtain pressure,film thickness and temperature distribution.The influence of load,self-spin speed,autocorrelation length and rough peak on its lubrication performance was studied,which proposed the technic approach of the life forecast of the aeronautic angular contact ball bearing2)A static model of angular contact ball bearing with oil film and self-spin characteristics was established,and the load distribution and spin speed of the rolling body are obtained.Combining quasi-statics and elastic-flow lubrication,this paper presents a model with variable volume absorption speed,spin speed,rough surface and thermal effect.The influence law of the speed direction,the volume and the load on the lubrication performance of the coil is analyzed,and the lubrication evolution mechanism of the micro-interface of the angular contact ball bearing under the complicated conditions of aviation is revealed.3)Considering the extreme situation of coexistence of micro-convex body direct contact and oil film lubrication,the model of spur gear with mixed lubrication considering thermal effect is built,and the strong coupling nonlinear stress field,film thickness and temperature field of rapid and stable solution is studied.The influence of working condition,structure and surface topography on themixed lubrication performance is discussed,and the analysis tool is provided for the lubrication performance of the spur gear.4)In this paper,a new type of generatrix and two-ends profile modification curve equations are presented in this paper.In this paper,a model with finite line contact micro elastic-flow lubrication is established considering the time-varying length of the contact line,the time-change of the winding speed,the surface topography,the heat and the modification factors.Explore the lubricating characteristics caused by roughness on both ends of the wavelength and amplitude,generatrix and radius of circular arc profile modification,modification of chamfer on both ends,and provide theoretical basis for profile modification method of high reliability and long-life helical gear.5)A new method for calculating the length of time varying contact line length is proposed,which break through the limitation of the shape,spiral angle and contact ratio.By using the finite element method,the gear tooth contact analysis model was established,and the load distribution law of the teeth was obtained.Based on the finite element load analysis method and elastic-flow lubrication method,the thermal effect,surface topography and the load distribution of the tooth surface are considered to establish the lubrication model of the helical gear.This paper analyzes the lubrication characteristics under the method of finite element load analysis,and provides a research method for the design and performance analysis of the helical gear. |
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