The most basic knowledge of rolling bearings. Don't you still know these?

The bearing is a component that fixes and reduces the friction coefficient of the load during the mechanical transmission process. It has a pivotal position in contemporary machinery and equipment. Its main function is to support the mechanical rotating body to reduce the friction coefficient of the mechanical load during the transmission of the equipment. Bearings can be divided into rolling bearings and sliding bearings. Today we will talk about rolling bearings in detail.

Rolling bearing is a kind of precision mechanical component that changes the sliding friction between the rotating shaft and the shaft seat into rolling friction, thereby reducing friction loss. Rolling bearings are generally composed of four parts: inner ring, outer ring, rolling elements and cage. The function of the inner ring is to cooperate with the shaft and rotate with the shaft; the function of the outer ring is to cooperate with the bearing seat and play a supporting role; The cage evenly distributes the rolling elements between the inner ring and the outer ring, and its shape, size and quantity directly affect the performance and life of the rolling bearing; the cage can evenly distribute the rolling elements, prevent the rolling elements from falling off, and guide the rolling elements Rotation plays a role of lubrication.

Features of rolling bearings

1. Specialization

In the processing of bearing parts, a large number of special equipment for bearings are used. For example, ball mills, grinders and other equipment are used for steel ball processing. Specialization is also reflected in the production of bearing parts, such as a steel ball company specializing in the production of steel balls and a miniature bearing factory specializing in the production of miniature bearings.

2. Advancement

Due to the large-scale requirements of bearing production, it is possible to use advanced machine tools, tooling and technology. Such as CNC machine tools, three-jaw floating chucks and protective atmosphere heat treatment.

17 141'>3. Automation

The specialization of bearing production provides conditions for its production automation. In the production, a large number of fully automatic, semi-automatic dedicated and non-dedicated machine tools are used, and the production automatic line is gradually popularized and applied. Such as automatic heat treatment line and automatic assembly line.

Classified by structure type

According to the structure of rolling elements and rings, it can be divided into:

Deep groove ball bearings, needle roller bearings, angular contact bearings, self-aligning ball bearings, Spherical roller bearings, thrust ball bearings, thrust spherical roller bearings, cylindrical roller bearings, tapered roller bearings, outer spherical ball bearings with seat, etc.

Rolling bearings can be divided into:

1. Deep groove ball bearings

17 142'>Deep groove ball bearings are simple in structure and easy to use. They have the largest production batch and the widest application range. Class bearings. It is mainly used to bear radial load, but also can bear certain axial load. When the radial clearance of the bearing is enlarged, it has the function of angular contact bearing and can bear larger axial load. Used in automobiles, tractors, machine tools, motors, water pumps, agricultural machinery, textile machinery, etc.

2. Needle roller bearings

Needle roller bearings are equipped with thin and long rollers (the length of the roller is 3-10 times the diameter, and the diameter is generally not greater than 5mm), so the radial structure is compact, and its When the inner diameter and load capacity are the same as other types of bearings, the outer diameter is the smallest, which is especially suitable for supporting structures with restricted radial installation dimensions. Depending on the application, a bearing without an inner ring or a needle roller and cage assembly can be selected. At this time, the journal surface and the housing hole surface matching the bearing are directly used as the inner and outer rolling surfaces of the bearing to maintain the load capacity and running performance Same as the bearing with ring, the hardness of the surface of the shaft or housing hole raceway. The machining accuracy and surface and surface quality should be similar to the raceway of the bearing ring. This kind of bearing can only bear radial load. For example: universal joint shafts, hydraulic pumps, sheet rolling mills, rock drills, machine tool gearboxes, automobile and tractor gearboxes, etc.

3. Angular contact bearing

Angular contact ball bearing has a high limit speed, which can bear both longitudinal load and axial load, and can also bear pure axial load. Its axial load capacity is determined by the contact angle , And increase with the increase of the contact angle. Mostly used in: oil pumps, air compressors, various transmissions, fuel injection pumps, printing machinery.

4. Self-aligning ball bearing

The self-aligning ball bearing has two rows of steel balls, the inner ring has two raceways, and the outer ring raceway is an inner spherical surface, which has the performance of self-aligning. It can automatically compensate for the coaxiality error caused by the bending of the shaft and the deformation of the housing, and it is suitable for parts where strict coaxiality cannot be guaranteed in the support seat hole. The middle bearing mainly bears radial load. While bearing radial load, it can also bear a small amount of axial load. It is usually not used for bearing pure axial load. For example, bearing pure axial load, only one row of steel balls is stressed. Mainly used in agricultural machinery such as combine harvesters, blowers, paper machines, textile machinery, woodworking machinery, traveling wheels and drive shafts of bridge cranes.