転がり軸受の撹拌損失エネルギーに及ぼすグリースのレオロジー特性

抄録

In recent years, demands for improving energy efficiency in industrial machinery and vehicles are increasing. Especially, bearing rotational torque in motors cannot be ignored and low torque property of ball bearings are required. Generally, rotational torque of ball bearings using grease lubrication is greatly affected by stirring resistance derived from grease. Although studies on torque of rolling bearings were mainly related to soap grease, few studies investigated urea grease. In future, the use of urea grease is expected to increase because of severe operating conditions such as high temperature. Thus, new grease design for low torque and long-life properties are needed. In this study, we evaluated rheological properties and bearing rotational torque of different types of urea grease prepared by changing amine composition, oil types and penetration. We found correlation between the new concept of viscosity reduction energy and stirring loss energy which is the time integral of torque. It is suggested that the higher the viscosity reduction energy, the lower the bearing rotational torque.