Tribological Properties and Viscosity of Cast Iron in Low Viscous Oil(Machine Elements, Design and Manufacturing)

In order to preserve environment and save energy, some resembles using low viscous engine oils have been made. We examined the tribological properties in base oils with low viscosities of 8.3, 17.5 and 78.7mPa・s. Friction test was carried out using a lathe, similar to a block on ring tribometer. Block specimen and ring specimen was the same cast iron. Frictional force and temperature rise were measured. As a result, the type of frictional properties and the type of wear curve can respectively be classified into three. Those types corresponded. It is possible to divide by the classification like H type, T type, and B type. For T type, pressure from which oil is supported has lowered as the viscosity lowers. From the PV diagram, it is understood that the area of H type narrows from L3 of a high viscosity as for L1 and L2 of a low viscosity. Moreover, if L1 is compared with L2, the area of B type is growing in L1. This suggests that the possibility of transition to B type that friction and wear keeps increasing when the viscosity is lowered in excess rise.