The difference between rolling bearings and sliding bearings

- Jul 27, 2020-

Sliding bearing:

Sliding bearings, bearings that work under sliding friction. Sliding bearings work smoothly, reliably, and without noise. Under liquid lubrication conditions, the sliding surfaces are separated by lubricating oil without direct contact, and friction loss and surface wear can be greatly reduced. The oil film also has a certain vibration absorption capacity. But the starting frictional resistance is relatively large. The part of the shaft supported by the bearing is called the journal, and the parts matching the journal are called the bearing bush.

In order to improve the friction properties of the bearing pad surface, the anti-friction material layer cast on its inner surface is called a bearing lining. The materials of bearing bushes and bearing linings are collectively referred to as sliding bearing materials. Commonly used sliding bearing materials include bearing alloys (also called Babbitt alloys or white alloys), wear-resistant cast iron, copper-based and aluminum-based alloys, powder metallurgy materials, plastics, rubber, hardwood and carbon-graphite, polytetrafluoroethylene (PTFE) ), modified polyoxymethylene (POM), etc. Sliding bearing applications are generally under low-speed and heavy-duty conditions, or operating parts where maintenance and lubrication are difficult.

Rolling bearings:

The radial bearing (mainly bearing radial force) in the rolling bearing is usually composed of 4 parts: inner ring, outer ring, rolling element and rolling element cage. The inner ring is tightly sleeved on the journal and rotates with the shaft, and the outer ring is installed in the bearing seat hole. Raceways are formed on both the outer circumference of the inner ring and the inner circumference of the outer ring. When the inner and outer rings rotate relatively, the rolling elements roll on the raceways of the inner and outer rings. They are separated by the cage to avoid mutual friction. Thrust bearing is divided into two parts: tight ring and live ring. The tight ring and the shaft sleeve are tight, and the live ring is supported on the bearing seat. Rings and rolling elements are usually made of rolling bearing steel with high strength and good wear resistance, and the surface hardness after quenching should reach HRC60-65. The cage is mostly made of mild steel stamping, and can also be made of copper alloy laminated bakelite or plastic.