Abstract:The elastohydrodynamic lubrication (EHL) model of ferrofluid lubricated involute spur gears was established, and the full numerical solution of the unsteady elastohydrodynamic lubrication problem of spur gears was obtained by using multigrid method and multigrid integral method. The effects of different carrier fluids on elastohydrodynamic lubrication of spur gears under impact load were analyzed. Considering of impact load, the change rules of pressure profile and oil film thickness of two tooth contact points were obtained. The results show that the film thickness of two esterD01 ferrofluid is the largest, the pressure is the smallest, and the esterbased H01 magnetic fluid has the lowest film thickness and maximum pressure.The larger the ratio, the smaller the pressure and the greater the film thickness under the impact load of the D01 ferrofluid lubrication film. The larger the load on the tooth, the greater the pressure and the smaller the film thickness under the impact load of the D01 ferrofluid lubrication film.