| The power shift gearbox of the loader studied in this paper realizes the power shift by controlling the engagement and separation of the wet clutch.When the wet clutch friction plate separation spacing is not uniform,the friction plate spacing is too small,will lead to the clutch band row torque will increase sharply,and produce a lot of friction heat,resulting in the clutch thermal failure.This problem seriously affects the stability and reliability of the power shift transmission system.Based on the five groups improved wet clutch friction pair as the research object,aiming at the condition of the friction plate separation spacing uneven,improved wet clutch friction plate dynamics model is established,on the dynamic characteristics of friction plate separation process of theoretical research and calculation,the control system for the friction plate spacing,provides reference for the research and development of wet clutch.The main content of this paper is as follows:Firstly,the key parameters are extracted based on the traditional torque model with row.It is clear that the spacing of friction plates is an important factor affecting the torque of the strip row.The smaller the spacing is,the greater the influence on the torque of the strip row is.The larger the spacing is,the greater the influence of the relative speed on the torque of the strip row is.Secondly,through the dynamic model of the improved wet clutch friction plate,the variable design factors in the model are analyzed,and the results show that the mass of the friction plate,the stiffness of the return spring between the plates and the external engagement pressure may be the influencing factors of the separation distance of the friction plate.In order to study the damping force in the process of friction plate separation,the gap cooling lubricating oil model of friction pair was established based on the fluid continuity equation and momentum equation.The fluid dynamics calculation of the separation process of friction plate was carried out.Combined with Origin software,the calculated data were fitted and analyzed by polynomial fitting method.The relation of damping coefficient decreases with the increase of separation velocity is obtained.Finally,based on the improved dynamic model of the wet clutch using AMESim software to calculate the performance of the separation of friction plate spacing,analyses the quality of lining,slice junction return spring stiffness and the external pressure on the influence of the friction plate separation distance,it is concluded that the friction piece quality step by step change on the influence of the friction pair separation spacing smaller,but will increase friction plate separation time,The separation time will be significantly increased when the mass of the friction plate increases step by step.However,the gradual change of the mass of the dual steel has little effect on the separation distance and separation time.When the spring stiffness changes,the clutch separation time is similar,which has little effect on the separation time.The separation distance of friction plates decreases step by step with the spring stiffness increasing,and decreases with the spring stiffness increasing step by step.The separation distance of the friction plate is positively correlated with the joint pressure.The unloading mode of joint pressure has obvious influence on the separation distance and time between the friction plate and the dual steel plate,and the linear decrease of joint pressure makes the separation distance of the clutch plate have good uniformity,and the completion time of the separation is shorter. |
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