Miyake, K., Nishida, T., Kurokawa, T., and Arai, H., "Sliding Properties of Polyamide Coating in High Temperature for Intermediate Shaft of Electric Power Steering," SAE Technical Paper 2016-01-0507, 2016, doi:10.4271/2016-01-0507.
Sliding intermediate shaft of Electric Power Steering (EPS) system is used for torque transmission from steering wheel or motor and buffering reverse input from tire. Polyamide coating material with good sliding properties is treated in the sliding types of intermediate shaft.Conventionally, sliding types of intermediate shaft with polyamide coating have been used in vehicle interior. On the other hand, extension of applied area to engine room is needed. However, in high temperature conditions, there is concerns about increase of friction coefficient and wear volume of polyamide by deterioration of sliding properties of polyamide. Therefore, improvement of sliding properties of polyamide in high temperature is necessary.In this research, we examined sliding properties of polyamide blended with metal stearate in high-temperature to use polyamide in high temperature compared to conventional environment. As resin material, we used polyamide 610 blended with metal stearates. It was confirmed that sliding properties in high temperature with metal stearate was superior to polyamide with no stearate. We have clarified that temperature dependence of sliding properties of polyamide blended with metal stearate were related to melting point of metal stearate. Polyamide resin material with improved sliding properties was developed by adding metal stearate.