The Role of Microslip for Freely Rolling Bodies

Abstract

The energy required to roll a sphere in a cylindrical groove is shown to be partly a hysteresis loss and partly a microslip loss. Data for three different sphere-groove combinations are separated into the two types of losses by comparison with data for toroid-plane rolling combinations chosen to give identical stress fields. The microslip loss is accounted for by the Palmgren-Heathcote equation assuming a coefficient of sliding friction of 0.073. Once the microslip torque is subtracted from the total rolling torque, the remaining torque turns out to be proportional to the load and independent of the geometry of the rolling elements, which includes various diameter spheres in addition to the combinations mentioned previously.