A wedge gear is a specialized friction drive component that transmits torque without traditional involute teeth. Instead, the wheel periphery is machined with concentric, wedge-shaped grooves that mate with corresponding ridges on the driven wheel. The wedging action multiplies the normal force between the mating surfaces, allowing the drive to transmit higher torque before slipping compared to a flat friction wheel.
Heard on the job
The old hoist uses a wedge gear arrangement, so make sure the grooves are completely free of oil before you test it.
Insider tip
Because they rely entirely on friction rather than positive mechanical engagement, wedge gears are highly sensitive to surface contamination and require strict tensioning to prevent slippage.