Elastohydrodynamic Lubrication During Simultaneous Rolling and Boring Friction.

In stepwise-settable rolling gears, in addition to the rolling motion in the contact surface, a relative motion about the common normal (called a boring motion) also occurs. This boring motion and the forced slip caused by it are, in the case of most gear designs, very large at the limits of the setting range and thus have a decisive effect on the operational behavior. A test stand and a measurement system are described which make it possible to measure the lubricant film thickness and the friction coefficient under various boring velocity conditions.