How to choose the right bearing?

     The bearing is a support for various mechanical rotating shafts or movable parts, and is widely used in agricultural machinery such as 

agricultural vehicles, tractors, diesel engines, electric motors, and threshers. The bearing code is commonly used to purchase bearings, but the 

bearing code is more complicated. If the agricultural machine masters the rules of identifying the bearing code, it is easy to purchase.

     Commonly used bearings are some standard models, codenamed “0”, tolerance class is “G” (normal grade), the first section of the 

general bearing can not be written, so its code number is mostly represented by 7 digits of the basic code. Now give an example of the meaning 

of the bearing code: Example 7002136 (135 series diesel engine shaft main bearing), the basic code is identified from right to left. The "36" two-

digit number indicates the inner diameter, and the calculation method is 36 × 5 = 180 mm; "1" indicates that the diameter series is extremely 

light; "2" indicates that the type is a cylindrical roller bearing; "00" indicates that the bearing structure has no outer ring. The rib; "7" indicates 

that the width series is narrow. If the operator buys 7-digit other standard model bearing code, it can be deduced.

      The bearing is multi-reference bearing inner diameter. The inner diameter of the bearing is indicated by the first and second digits in the 

right code in the basic code. The inner diameter of the bearing is divided into a standard and a non-standard inner diameter, and the difference 

between the non-standard inner diameter is not an integer or an integral multiple of 5. In order to facilitate the purchase of the machine, an 

example is given as follows: 1. The inner diameter of the bearing below 9 mm is expressed by the actual size of the first digit on the right end. 

For example, bearing number 18 has an inner diameter of 8 mm. 2. The inner diameter of the bearing is expressed in fixed numbers from 10 mm 

to 17 mm. For example, bearing numbers 100, 201, 302, and 403 have inner diameter codes of 00, 01, 02, and 03, respectively, and their inner 

diameters are fixed numbers of 10, 12, 15, and 17 mm, respectively. 3, the bearing inner diameter is 20 mm - 480 mm (except 22, 28, 32), 

expressed in terms of the inner diameter size divided by 5. 4. The inner diameter of the bearing is above 500 mm (22, 28, 32). The denominator 

indicates the inner diameter, and the numerator indicates the size series, type and structure of the bearing. For example, bearing 30031/560 has 

an inner diameter of 560 mm, and so on.