Bearing designation and what it means

 

Now the bearing model gradually increases with the different needs of the current people, and now the network is very developed, the information transmission is also very rapid, and it is easier to know the bearing model. Next, we will introduce you to the basic code, post-code, pre-code and other related knowledge of the bearing

 

Bearing designation and its meaning Bearing designation components

 

The bearing model generally has a pre-code, a basic code and a post-code. In general, the bearing designation is only indicated by the basic designation. The basic model generally consists of three parts, the type code, the size code and the inner diameter code. The post-code is to use letters and numbers to indicate the structure, tolerance and special requirements of the material. The prefix code is used to indicate the sub-components of the bearing, which are indicated by letters.

 

General Purpose Bearing (Rolling Bearing) Designation Method

 

It is divided into: pre-code, basic code and post-code.

 

1. Basic codename

 

(Type code, size code, inner diameter code [2 digits])

 

The basic code is used to indicate the inner diameter, diameter series, width series and type of bearing, generally up to five digits, as follows:

 

1) The inner diameter of the bearing is indicated by the first digit from the right of the basic code. The inner diameter of the bearing with a common inner diameter of d=20~480mm is generally a multiple of 5, and these two digits represent the quotient of the bearing inner diameter size divided by 5, such as 04 means d=20mm; 12 means d=60mm, etc. For bearings with an inner diameter of 10mm, 12mm, 15mm and 17mm, the inner diameter codes are 00, 01, 02 and 03 respectively. For bearings with an inner diameter of less than 10mm and more than 500mm, the method of expressing the inner diameter is otherwise specified, please refer to GB/T272-93.

 

2) The diameter series of the bearing (i.e., the series of changes in the outer diameter and width of the bearing with the same structure and the same inner diameter) is indicated by the third digit from the right of the basic code. For example, for radial and radial thrust bearings, 0 and 1 indicate the extra light series; 2 indicates light series; 3 indicates the medium series; 4 indicates a heavy series. The size comparison between the series is shown in the figure below. Thrust bearings except for 1 to represent the light series, the rest and the radial bearings are the same.

 

3) The width series of the bearing (i.e., the series of changes in the width of the bearing with the same structure, inner diameter and diameter series) is indicated by the fourth digit from the right of the basic code. When the comparison of the diameter series of the width series in Figure 13-4 is listed as 0 series (normal series), the width series code O can not be marked in the code for most bearings, but for spherical roller bearings and tapered roller bearings, the width series code 0 should be marked.

 

Diameter series codes and width series codes are collectively referred to as dimension series codes.

 

4) The bearing type code is represented by the fifth digit from the right of the basic code (for cylindrical roller bearings and needle roller bearings, the code is a letter).

 

2. Post-code

 

The post-code of the bearing is to use letters and numbers to indicate the structure, tolerance and special requirements of the material. There are many contents of post-codes, and here are a few commonly used codenames.

 

1) The internal structure code is to indicate the different internal structure of the same type of bearing, which is indicated by letters followed by the basic code. For example, angular contact ball bearings with contact angles of 15°, 25° and 40° are respectively represented by C, AC and B to represent the difference in internal structure.

 

2) The tolerance grade of the bearing is divided into 2 grades, 4 grades, 5 grades, 6 grades, 6X grades and 0 grades, a total of 6 grades, in turn from high to low, and their codes are /PZ, /P4, /PS, /P6, /P6X and /PO. Among the tolerance classes, class 6X is only applicable to tapered roller bearings; Level 0 is an ordinary grade, which is not marked in the wheel bearing code.

 

3) The commonly used bearing radial clearance series is divided into 1 group, 2 groups, 0 groups, 3 groups, 4 groups and 5 groups, a total of 6 groups, and the radial clearance is from small to large. Group o clearance is a commonly used clearance group, which is not marked in the bearing code, and the rest of the clearance groups are represented by /CI, /CZ, /C3, /C4 and /CS in the bearing code.

 

3. Pre-code

 

The prefix designation of the bearing is used to indicate the sub-parts of the bearing, which are indicated by letters. For example, L is used to represent the separable ring of the separable bearing; K denotes the rolling elements and cage components of the bearing, etc.

 

There are many types of rolling bearings in practical applications, and the corresponding bearing codes are also more complex. The code introduced above is the most basic and most commonly used part of the bearing code, and you can identify and check the commonly used bearing if you are familiar with this part of the code. For the detailed code method of rolling bearings, please refer to GBT272-93.