Detailed Explanation Of Bearing Types And Classifications

As the core components of mechanical equipment, bearings are widely used in various mechanical devices. In particular, rolling bearings have become the first choice in many fields due to their high efficiency and durability.

This article will introduce the classification of bearings in detail, especially the classification code of rolling bearings, and compare and analyze rolling bearings and sliding bearings.

1. Types and classifications of bearings

Bearings can be divided into many types according to different classification standards. The following are the main classification methods:

Classification by load direction:

Radial bearings: mainly bear radial force and can withstand smaller axial force.
Thrust bearings: specially bear axial force, suitable for working conditions with large axial load.
Radial thrust bearings: can withstand both radial force and axial force, have high comprehensive load-bearing capacity, and are suitable for complex working conditions.

Classification by rolling element shape:

Ball bearings: rolling elements are spherical, such as deep groove ball bearings, self-aligning ball bearings, etc., suitable for high-speed operation and low friction requirements.
Roller bearings: The rolling element is cylindrical or conical, such as cylindrical roller bearings, tapered roller bearings, etc., suitable for working conditions with large loads.
Needle roller bearings: The rolling element is slender needle-shaped, suitable for occasions with limited radial space, and can provide higher load-bearing capacity.

Classification by working conditions:

Ordinary bearings: Suitable for general working conditions.
High-speed bearings: Designed for high-speed operation, with low friction and low heat generation characteristics.
High-temperature bearings/low-temperature bearings: Used in extremely high or low temperature environments respectively.
Special environment bearings: Such as vacuum bearings, anti-magnetic bearings, corrosion-resistant bearings, etc., designed for special working environments.
Precision miniature bearings/extra-large bearings: Used for precision machinery or large-scale mechanical equipment, respectively, to meet special size and load requirements.

2. Analysis of the classification code of rolling bearings

The classification code of rolling bearings is used to identify its specific type for quick identification and selection. The following are some common codes and their meanings:

“0”: Double-row angular contact ball bearings, suitable for working conditions that bear both radial and axial forces.
“1”: Self-aligning ball bearings, which have the function of self-aligning, are suitable for applications with large deviations between the shaft and the seat hole.
“2”: Spherical roller bearings and thrust spherical roller bearings, which have strong load-bearing capacity and are suitable for heavy-duty applications.
“3”: Tapered roller bearings, which can withstand large combined radial and axial loads.
“4”: Double-row deep groove ball bearings, which are suitable for applications with large radial forces.
“5”: Thrust ball bearings, which can only withstand axial forces.
“6”: Deep groove ball bearings, which are widely used in high-speed, low-friction conditions.
“7”: Angular contact ball bearings, which are suitable for applications with high axial forces.
“8”: Thrust cylindrical roller bearings, which are suitable for applications with large axial forces.
“9”: Thrust tapered roller bearings, which are suitable for applications with heavy loads and radial and axial forces at the same time.
“N”: Cylindrical roller bearings and needle roller bearings, the suffix letters indicate different flange structures or types.
“U”: Spherical ball bearings, which are suitable for applications with limited installation space.
“QJ”: Four-point contact ball bearing, suitable for occasions with high axial and radial forces.

3. Comparative analysis of rolling bearings and sliding bearings

Rolling bearings and sliding bearings are two common types of bearings, each with its own unique advantages and disadvantages. The following is a comparison between the two:

1. Advantages of rolling bearings:

Low friction resistance, sensitive starting, high efficiency, low heat generation, and low temperature rise.
Small radial clearance, high running accuracy, suitable for precision machinery.
Compact structure, suitable for applications with limited space.
Can withstand radial and axial loads at the same time, and the bearing combination is simple.
Low lubricant consumption, good sealing, and convenient maintenance.
High degree of standardization, easy to mass produce, low cost.

2. Disadvantages of rolling bearings:

Weak ability to withstand impact loads.
Under high speed and heavy load conditions, the bearing life may be short.
Large vibration and noise.
Large radial size, may occupy more space.

3. Advantages of sliding bearings:

Can withstand large impact loads and instantaneous loads.
Has good load-bearing capacity under low speed and heavy load.
In some cases, low noise.

4. Disadvantages of sliding bearings:

The friction coefficient is high and the working efficiency is relatively low.
More lubrication is required, and the lubrication effect is relatively dependent.
Compared with rolling bearings, the structure is more complex and the maintenance requirements are high.

Rolling bearings have been widely used in various types of mechanical equipment due to their superior performance. The selection of the appropriate bearing type requires comprehensive consideration based on specific working conditions, load requirements, space restrictions and other factors. In practical applications, rolling bearings and sliding bearings each have their own advantages and limitations. Reasonable selection and matching will greatly improve the working efficiency and service life of mechanical equipment.