Bearing code
The bearing models in the bearing exhibition are generally composed of front code, basic code and rear code. Generally, the bearing model is only represented by the basic model. The basic model generally includes three parts: type code, size code and inner diameter code. The post code refers to the special requirements of bearing structure, tolerance and material with letters and numbers. The preceding code is used to represent the sub parts of the bearing and is represented by letters.
The code method of general bearing (rolling bearing) is divided into: front code, basic code and rear code.
1. Basic code
The basic code is used to indicate the inner diameter, diameter series, width series and type of bearing. Generally, it is up to five digits. It is described as follows:
(1) The bearing inner diameter is represented by the first digit from the right of the basic code. For the bearing with common inner diameter d = 20 ~ 480mm, the inner diameter is generally a multiple of 5. These two digits represent the quotient obtained by dividing the inner diameter of the bearing by 5. For example, 04 represents d = 20mm; 12 means d = 60mm, etc. For bearings with inner diameters of 10mm, 12mm, 15mm and 17mm, the inner diameter codes are 00, 01, 02 and 03. For bearings with inner diameter less than 10mm and greater than 500mm, the expression method of inner diameter is otherwise specified. Refer to GB / t272-93.
(2) The diameter series of bearings (i.e. the variation series of outer diameter and width of bearings with the same structure and inner diameter) is represented by the third digit from the right of the basic code. For example, for radial bearings and radial thrust bearings, 0 and 1 represent ultra light series; 2 represents light series; 3 represents medium series; 4 represents the heavy series. The size comparison between the series is shown in the figure below. Except that 1 is used to represent the ultra light series, the representation of thrust bearing is consistent with that of radial bearing.
(3) The width series of bearing (i.e. the variation series of bearing width with the same structure, inner diameter and diameter series) is represented by the fourth digit from the right of the basic code. When the comparison of the diameter series in Figure 13-4 of the width series is listed as 0 series (normal series), the width series code o may not be marked in the code for most bearings, but for self-aligning roller bearings and tapered roller bearings, the width series code 0 shall 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 (the type codes of cylindrical roller bearing and needle roller bearing are letters).
2. Post code
The post code of bearing is to use letters and numbers to represent the structure, tolerance and special material requirements of bearing. There are many post codes. Here are some common codes.
(1) The internal structure code represents different internal structures of the same type of bearing, which is represented by letters followed by the basic code. For example, the internal structure of angular contact ball bearings with contact angles of 15 °, 25 ° and 40 ° is represented by C, AC and B respectively.
(2) The tolerance grade of bearing is divided into grade 2, grade 4, grade 5, grade 6, grade 6x and grade 0, with a total of 6 levels, from high level to low level, and their codes are / PZ, / P4, / PS, / P6, / p6x and / PO respectively. In the tolerance class, class 6x is only applicable to tapered roller bearings; Grade 0 is a common grade and is not marked in the wheel bearing code.
(3) The commonly used radial clearance series of bearings are divided into 1 group, 2 groups, 0 group, 3 groups, 4 groups and 5 groups, with a total of 6 groups. The radial clearance increases from small to large. O group clearance is a common clearance group, which is not marked in the bearing code, and the other clearance groups are represented by / CI, / CZ, / C3, / C4, / Cs in the bearing code.
3. Prefix code
The leading code of the bearing is used to represent the sub parts of the bearing and is represented by letters. For example, l represents the separable ring of the separable bearing; K represents the rolling element and cage assembly of the bearing, etc.
There are many types of rolling bearings in practical application, and the corresponding bearing code is also more complex. The codes introduced in the above bearing exhibition are the most basic and commonly used part of the bearing codes. Once you are familiar with these codes, you can identify and check the commonly used bearings. For the detailed code method of rolling bearing, please refer to gbt272-93.
