What is Plain Bush Bearing

A plain bush bearing, also known as a plain bearing or bushing, is a type of bearing that provides a sliding contact between two surfaces to support and facilitate rotational or linear motion. Unlike rolling element bearings, which use balls or rollers, plain bush bearings rely on a layer of lubricant to reduce friction between the bearing surfaces.

The plain bush bearing consists of two main components: the bearing shell or sleeve, and the shaft or journal that rotates within the bearing. The bearing shell is typically made of a low-friction material, such as bronze, brass, or a composite material like PTFE (polytetrafluoroethylene) or Babbitt metal. The shaft is usually made of a harder material, such as steel.

The bearing shell is designed with a cylindrical inner diameter that matches the outer diameter of the rotating shaft. The clearance between the shaft and the bearing is filled with a lubricant, such as oil or grease, which forms a lubricating film between the two surfaces. This film of lubricant helps reduce friction and wear, ensuring smooth and efficient operation.

Plain bush bearings are commonly used in various applications, including automotive engines, industrial machinery, pumps, electric motors, and agricultural equipment. They provide benefits such as simplicity, low cost, high load capacity, and the ability to withstand harsh operating conditions. However, they may require regular maintenance to ensure an adequate supply of lubrication and prevent excessive wear.