As the “joint” component of machinery, bearings play an important role in the use of machinery and machines. Bearings have been discovered since ancient times and work as simple rotational principles. However, with continuous research and exploration by humans, today’s bearings have made great breakthroughs in both performance requirements and working range. Moreover, different types of bearings can be selected according to their specific environmental conditions, thus achieving twice the result with half the effort.
Firstly, let’s understand the working principle of the bearing, as shown in the figure:
Rolling bearings, developed based on bearings, work by replacing sliding friction with rolling friction. They are generally composed of two rings, a set of rolling elements, and a cage, and are highly versatile, standardized, and serialized mechanical components. Due to the different working conditions of various machinery, different requirements have been put forward for rolling bearings in terms of load capacity, structure, and performance. Therefore, rolling bearings need to have various structures. However, the most basic structure consists of an inner ring, an outer ring, rolling elements, and a cage – commonly referred to as the four major components.
The components of bearings, the following editor mainly takes deep groove ball bearings as an example, as shown in the figure:
Bearing seals
Seals can be mainly divided into two categories: bearing seals and bearing dust covers. The bearing sealing ring is of great significance for its sealing performance and service life. The material used for production is rubber, mainly including nitrile rubber, hydrogenated nitrile rubber, and fluororubber; The bearing dust cover is used to prevent dust and other debris from entering the bearing and affecting its operation. It is made of thin metal plate and is a ring-shaped cover, usually stamped from thin metal plate. It is fixed on one ring or washer of the bearing and extends towards the other ring or washer, covering the internal space of the bearing but not in contact with the other ring or washer.
Bearing outer ring
The outer ring of the bearing, also known as the outer ring or outer sleeve of the bearing, is usually fixed on the bearing seat or machine housing to support the rolling elements. There are grooves on the outer surface of the outer ring for steel balls or rollers to roll, which are called outer grooves or outer raceways.
Rolling element
Rolling elements are the core components in rolling bearings, and due to their presence, there is rolling friction between the surfaces in relative motion. The types of rolling elements include balls, cylindrical rollers, tapered rollers, needle rollers, etc. The rolling elements of rolling bearings mainly include two types: steel balls and rollers.
Bearing inner ring
The inner ring of a bearing can also become a bearing inner ring or bearing inner sleeve, usually fixed on the shaft neck. The inner ring rotates together with the shaft, and there are grooves on the outer surface of the inner ring for steel balls or rollers to roll, called inner grooves or inner raceways.
Bearing cage
A bearing cage, also known as a bearing retainer, refers to a bearing component that partially wraps all or part of the rolling elements and moves with them, used to isolate the rolling elements and usually guide and hold them inside the bearing.
The interaction between the inner ring, outer ring, and cage and the rolling elements:
The inner ring is matched with the shaft to fix the bearing, providing half of the motion track of the rolling element and transmitting the load; The outer ring is matched with the bearing seat to fix the bearing, providing the other half of the rolling element’s motion track and transmitting the load; Keep all the shelves