Theoretical And Experimental Study On Churning Loss Of Gear Pair

In recent years,with the development of electric vehicles,high speed and high efficiency,the efficiency of the transmission system has become one of the key factors influencing the cruising range of new energy vehicles.Gear transmission system is the main component of automobile transmission,and its transmission efficiency is particularly important for improving automobile economy.The loss of the gear transmission system is mainly composed of gear tooth meshing loss,bearing loss and oil churning loss.Under high-speed and light-load conditions,the oil churning loss accounts for the largest proportion.There are many factors influencing the oil stirring loss of the gear transmission system,such as the internal factors of the gear system such as gear parameters,working condition parameters and lubricating oil parameters,and external factors such as inclination angle,box size and internal cavity.However,there is still a lack of complete theoretical models at home and abroad to predict oil churning losses.Most of them are semi-empirical formulas obtained through experiments to predict oil churning losses,and the scope of application is limited.This subject is developed to solve the problem of insufficient quantification of oil churning loss in gear transmission systems.From a theoretical point of view,a hydrodynamic analysis model of the oil churning loss of the gear pair is established;an experimental bench for the oil churning loss of the gear pair is designed and built.It was verified,and based on the experimental data,the parameter influence law of the oil churning loss was studied;based on the theoretical model,the in-depth analysis of the influence law of the oil churning loss parameter under the high-speed working condition was carried out;finally,a new energy source was established in combination with the moving particle semi-implicit method The oil churning loss calculation model and fluid simulation analysis model of the reducer are used to analyze the change law of the oil churning loss of the reducer under different oil filling amounts and inclination angles through the calculation value and the distribution of lubricating oil.The specific content is as follows:1、According to the resistance principle during the relative movement of fluid and solid,combined with the contact state of the gear pair and the lubricating oil,the oil churning loss of the gear pair is divided into end surface friction loss,peripheral surface friction loss and squeeze loss in the meshing area.Using fluid theory,boundary layer principle,and tribological principle,the end-face friction loss and peripheral friction loss of the gear are derived;using fluid continuity equation,momentum conservation principle and Bernoulli principle,the extrusion of the gear pair meshing area is derived Then,a theoretical calculation model of hydrodynamics for gear pair churning oil loss was established.2、The influencing parameters of churning oil loss were extracted through theoretical calculation model,and the experiment platform for churning oil loss test was designed and built.Based on the bench test method,the churning loss under different speed,tooth width,transmission ratio,modulus,helix angle,oil immersion depth,lubricating oil density and viscosity was measured.Based on the experimental data,the theoretical model was verified and the influence law of gear pair churning loss parameters was analyzed.Based on the established theoretical calculation model of gear pair churning oil loss,study the influence of different speed,tooth width,transmission ratio,modulus,helix angle,oil immersion depth,lubricating oil density and viscosity on the churning oil loss at high speed.And the mechanism of action.Using orthogonal experiment design,design a seven-factor three-level orthogonal experiment,and analyze the influence proportion of each parameter.3、Based on the established theoretical calculation model of gear pair churning loss,the influence of gear pair speed,tooth width,transmission ratio,modulus,helix angle,oil immersion depth,lubricating oil density and viscosity on stirring oil loss at high speed is studied.And the mechanism of action.Using the principle of orthogonal experiment,a seven-factor three-level orthogonal experiment was designed,and the order of influence of each parameter was analyzed.4、Based on the theoretical calculation model of gear pair churning oil loss,combined with the moving particle semi-implicit method,the oil churning loss of the new energy reducer is analyzed.The calculation model of oil churning loss and fluid simulation analysis model of the reducer were established,the model was solved,and the value of oil churning loss of the reducer under different oil filling and inclination angles was obtained,and combined with the distribution of lubricating oil inside the reducer,The influence law of the oil filling amount and the inclination angle on the oil churning loss of the reducer is studied,which provides a reference for practical engineering applications.