Mean coefficient of friction

A constant, based on measurement or experience, can be specified.

Note: If μm is specified directly, the input options for the profile correction and the thermal contact coefficient are not affected. The background is that these parameters are also used in the flash temperature calculation equation.

A constant over the contact length. The equation for determining the constant calculates a typical value for gears located in a partial EHD area. For gears that are at the limit of solid state friction, the value determined here may be too low. For gears whose tooth flanks are completely separated by the oil, the value determined here may be too high.

The empirical equation according to Benedict and Kelley determines a coefficient of friction which is variable over the length of engagement.