What Is a Radial Bearing?

There are many types of sliding bearings, which can be divided into radial bearings (bearing radial load) and thrust bearings (bearing axial load) according to the way they bear loads.

The part of the shaft supported by the bearing is called the journal, and the part matching the journal is called the bearing bush. The whole cylindrical bearing is called the sleeve sleeve. The half is called the bearing seat. The cover and the seat are connected by studs, and the joint surface of the two is positioned by a stop or a pin. Spacers of different thicknesses can be placed to adjust the bearing clearance. The joint surface of most bearings is horizontal and inclined to meet the requirement that the load direction is close to the joint surface. In order to facilitate the lubricating oil to enter between the friction surfaces, the bearing cover is provided with an oil injection hole, and the bearing pad is provided with an axial oil groove for distributing the lubricating oil. The bearing caps and seats are mostly made of cast iron, and the heavy load is made of cast steel or steel plate welded structure.

(1) Integral radial sliding bearing

The structure of the integral radial sliding bearing is shown in Figure 12-1. It consists of a bearing seat and an integral bushing made of antifriction material. Above the bearing seat

Bearing bushes are made of sliding bearing materials with good friction reduction, including metallic materials (such as copper alloys, aluminum alloys, and pasteur alloys) and non-metallic materials (such as plastics, graphite, rubber, and wood). Some metal materials with good friction reduction have low strength (such as Babbitt alloy), and only one layer is cast on the surface of the bearing shell with higher material strength, which is called bearing lining. The part that supports the bearing bush is called the bearing back, and it is usually made of mild steel, cast iron or bronze. In order to further improve the surface properties of the bearing lining, a thin layer of metal (such as indium) with better friction reduction can be plated on the surface. Such bearings made of multiple layers of different metal materials are called multilayer metal bearings. Bearings whose inner hole shape is not substantially affected by the shape of the bearing seat hole are called thick-walled bearing bushes; those whose inner hole shape mainly depends on the shape of the bearing seat hole are called thin-walled bearing bushes. Thin-walled bearing pads are widely used in mass-produced machines such as internal combustion engines and air compressors.

Common lubricants are fluids such as oil, water, air, and solids such as graphite and molybdenum disulfide, depending on the application and requirements of the bearing. Radial bearings with liquid as lubricant are divided into thin film lubricated bearings and thick film lubricated bearings according to the thickness of the lubricating film. According to the mechanism of thick film formation in thick film lubricating bearings, they are further divided into hydrodynamic radial bearings and hydrostatic radial bearings.