In manufacturing, a pin bearing is a type of joint used to create a flexible connection between two elements. It consists of a metal pin or piston surrounded by a metal ring. The metal ring connects to one component, while a fastener joins the pin to a second component. As the ring rotates around the pin, each object can be moved while still remaining connected to the other. Today, the metal ring in a pin bearing most often consists of a steel ball bearing rather than a plain metal ring.
Manufacturers produce two basic types of pin bearing designs. The first is a center pin bearing, where the ball bearing fits around the center of the piston. The second is an end bearing, where the bearing rests at one end of the piston. Typically, the ends of the pin are capped on each of these models to prevent the pin from slipping out of the bearing.
A variety of applications rely on pin bearings. They are often used in engines and machinery to connect components to one another. They are also found in bridges and large-scale steel construction. On a bridge, the pin bearing allows adjacent sections to flex slightly while still maintaining a high level of structural integrity and strength.
Each pin bearing is rated by the manufacturer based on the type of load it is able to support. This load depends on factors such as the size of the bearing and the material used to make it. It also depends on the configuration of the bearing and the way the bearing is fastened to surrounding components.
The pin bearing is one of the oldest types of bearings, and tends to have greater limitations than other modern bearing designs. It allows rotation along only a single axis, and creates a great deal of friction and stress within the bearing. Rocker and roller bearings are often used as a stronger and more flexible alternative to traditional pin bearings.
Long-term performance depends on proper pin bearing maintenance. These bearings are likely to fail over time due to the high level of friction between the ring and the pin. Many pin bearings are self-lubricating, which helps to reduce friction automatically. Others must be lubricated often to minimize stress and friction. Pin bearings must also be cleaned regularly to prevent dirt and grease from building up and interfering with performance.
