Bushings are necessary for optimal functioning of any wheel application. Without it, the bore of the wheel is subject to constant friction—wearing it out faster and shortening its life span. This is especially important in industrial wheels that carry heavy loads, such as metal wheels at lumber mills or manufacturing plants.
Bushings are shaped like a tube or sleeve, and help with motion by sliding, as opposed to the rolling motion of most bearing bushes. Still, bushings are a type of bearing, as they aid in the efficiency of rotating.
From cart wheels to Ferris wheels—all wheels need bearings or bushings to operate smoothly in the long run. However, the type and size of the bearing or bushing required will be specific to each application and must be carefully selected.