Evaluation of Property Difference between Traction Oil and Traction Grease

Abstract

In this paper, the characteristics of traction grease are evaluated. The difference in film formation ability between traction oil and traction grease is focused on, and the state of film formation and the traction coefficient of traction oil and two types of traction grease with different consistencies are measured simultaneously while varying temperature, Hertzian pressure and rolling speed. The traction coefficient of traction grease at a low temperature, a low pressure and a high peripheral speed shows a value larger than that of traction oil. The film thickness of traction grease is measured by the contact ratio method and decreases markedly at a low temperature and a high peripheral speed compared with that of traction oil. An estimation formula for traction grease considering film thickness is developed. These results lead to the conclusion that the property change between traction oil and traction grease is caused by the change of the film formation state.

Keywords

• traction drive
• grease
• traction coefficient
• film thickness
• contact ratio