The invention of the wheel early in man’s history has resulted in many ways to reduce manual labor. Among these helpful applications are the automotive industry, bearings for rotating machinery and other time and energy-saving technologies. The use of wheels in manufacturing often includes the movement of materials from one location to another. Many factory floors require that heavy materials be regularly relocated for the stages of assembly or machining processes. The use of a crane is necessary for some of the instances. Others make use of carts set on heavy duty casters allowing equipment to be relocated by simply rolling it from one station to another. A caster makes use of the wheel in two different ways. Both applications overcome friction and allow for heavy loads to be moved with little energy. These two applications are the caster wheels themselves and the bearings inside each caster.
The roundness of a wheel translates linear motion into rotary motion and vice versa. In both cases, they reduce the surface area in contact with the ground to the footprint of the area of the tread of each wheel. Friction, that force that resists motion, is related directly to surface areas. The wheels of casters generally reduce this surface area to four points each located at a corner of the load, supporting its weight in a stable configuration.
These devices help distribute the forces of gravity acting on the loads. Essentially, spherical-shaped metal balls are trapped within a track that allows independent rotation to occur between the inner and outer portion of the wheel. Because the metal spheres in a ball bearing occupy most of the space between inner and outer wheels, the weight of the load is more equally born around the circumference of the circle. This reduces pressure on each individual ball in the bearing making for a long-lasting and durable mechanism.
Wheel applications can be found in almost every industry and reflect the notion that good ideas are simple. Occasionally it is good to revisit old ideas to better appreciate their value. Casters are a great example of the simple wheel being put to good use.