液黏调速离合器传动特性分析

Investigation on the transmission characteristics of hydroviscous drive

针对液黏调速离合器实验装置中一对摩擦副间隙内流体流动开展研究,建立定常、层流条件下的简化数学模型,在假设流体黏度为常数的基础上,分别获得流场的近似解析解和数值解.数值研究结果表明:1)惯性力使得摩擦副间隙内流体切向线速度呈非线性分布,且小于忽略惯性力条件下的速度值;2)液黏调速离合器传动过程中,转矩损耗始终存在,该值与摩擦副间隙大小及输入、输出转速等因素相关,且与摩擦副间隙值呈三次方比例关系;3)由于转矩损耗及转速差的存在,使得任一摩擦副间隙值都对应一个最佳输出转速工作区间,在此区间内,传动效率较高.在理论分析研究的基础上,进行转矩传递特性的实验测试,发现实验结果与理论计算结果在曲线变化趋势上基本一致.

The flow between a pair of frictional plates in hydroviscous drive experiment rig was investigated.A simplified mathematic model for the steady and laminar flow was established for the flow in the gap of frictional pairs,and it was solved analytically and numerically respectively under the assumption of constant viscosity.The numerical results show that 1） inertia force causes the distribution of tangential velocity to be nonlinear,and the velocity value is smaller than that with neglecting the inertia force;2） torque loss exists during the course of torque transmission,which is associated with the clearance,input and output rotational speed,and other factors.Furthermore,it is proportional to the 3rd power of the clearance;3） there is an optimum output rotational speed interval for any clearance,owing to torque loss and rotational speed differences,and in the interval,the transmission efficiency is higher.On the basis of theoretical analysis,the torque transferring characteristics of hydroviscous drive was tested on the test bench.It is found that the changing trend of experiments results is basically in accordance with the trend of numerical curves.