Thrust ball bearings, sometimes called plain track thrust bearings, are comprised of ball bearings supported in a snap ring and held between two thrust washers. Thrust bearings allow smooth rotation under high thrust loads at low and medium speeds. Whether the rolling element is a ball, needle or roller, they are designed for pure thrust loads and can handle little or no radial load. Complete thrust bearing assemblies typically include two thrust washers and a ball retainer and typically come in standard and metric sizes, with custom sizes available.
Depending on the conditions in which you will be using your thrust bearing, there are some considerations when choosing your materials of construction.
The ball retainer can also be made of different materials, such as nylon or metal. A nylon retainer offers several advantages over a metal one. Injection-molded, heat-set nylon retainers are lightweight and provide a natural lubricity that eliminates the need for lubrication. Nylon retainers are corrosion resistant, provide quieter operation and long life. Another important advantage is that nylon retainers are less expensive and are a great budget option.
The remaining components, the ball bearings and thrust washers, must be chosen to match the application and environment in which they will operate. Typical material choices include stainless steel or hardened carbon steel. Stainless steel works well in environments where moisture and corrosives may be present. They are widely used for food and beverage processing machinery, medical devices, and a wide range of applications where moisture may be present. A carbon steel thrust bearing with hardened steel components is an excellent choice for non-corrosive environments.
Combining the cost savings and performance advantages of a nylon ball retainer with the strength and durability of steel creates a new generation of high performance, economical thrust bearings. Typical applications include advertising signs, printing equipment, marine hardware, point-of-purchase displays, medical instruments, manual valves, and pharmacy automation.