10 Cast Net: Thrust Washer

Wednesday, 10 October 2012

Thrust Washer

Thrust washers can be found in almost every appliance, machine, transportation conveyance, power tool, and recreational device that has moving parts, axles, bolts, pins, bearings, and rotating components. In their simplest form, thrust washers are long-wearing flat bearings in the shape of a washer that transmit and resolve axial forces in rotating mechanisms to keep components aligned along a shaft. Thrust washers are an economical alternative to rolling thrust bearings whenever forces velocities are moderate. The need for thrust washers presented itself in antiquity almost as soon as the wheel was invented. These rugged washer shaped flat bearings are used to prevent wheels from moving sideways on axles whenever the bearing that handles the radial load such as a bushing or roller bearing has no specific provision for axial or thrust loads. Typical sideways or axial loads are encountered whenever turning a corner and the vehicle is thrust sideways towards the outside of the curve. Other applications from our ancestors would have been grain mills, water wheels, turntables, and rotary drills, wherever the primary movement may have had both radial and axial forces to contend with. Of course, propeller shafts on every propeller driven vessel from the largest to the tiniest must have thrust bearings to resolve the linear and axial propulsion forces of spinning propellers either forward or backward.