Rolling bearings are a standard component of support shafts. Due to the advantages of compact structure, low friction and long life, it is widely used in modern mechanical equipment. When used, it can be selected according to the design requirements and the code specified by the national standard.

First, the structure, classification and code of rolling bearings

Rolling bearings are composed of four parts: outer ring, inner ring, rolling body, and spacer. As shown in Figure 1. Generally, the outer ring is installed in the hole of the machine base, and the inner ring is sleeved on the shaft. In most cases, the outer ring is fixed and the inner ring rotates with the shaft.

There are three types of rolling bearings commonly used according to their load capacity:

(1) Deep groove ball bearings, which mainly bear radial loads.

(2) The thrust bearing mainly bears the axial load.

(3) Tapered roller bearings, which mainly bear radial and axial loads.

See Figure 2.

* Code of rolling bearing

(1) The code of rolling bearing is to use letters and numbers to indicate the structure, size, tolerance level, technology of the bearing Product symbols for characteristics such as performance.

Rolling bearing code consists of basic code, front code and rear code.

The front and rear codes are supplementary codes added to the left and right of the basic code when the bearing changes in structural shape, size, tolerance, technical requirements, etc. The specific standards of the tombs of Neizheng, Shaqiao, and Xie Di tomb.

(2) The basic code represents the basic type, structure and size of the bearing, which is the basis of the bearing code.

The basic code of bearing consists of bearing type code, dimension series code and inner diameter code, arranged as follows:

Type code size series code Inner diameter code

（a） The type code of the bearing is represented by numbers or letters, as shown in Table 1.

Table 1: Type code of rolling bearing

(b) The dimension series code of the bearing consists of the bearing's width (height) series code and diameter series code. The dimension series codes of radial bearings and thrust bearings are shown in Table 2.

Table 2: Size series code of radial bearing and thrust bearing

(c) The inner diameter code of the bearing is represented by numbers (numbers/numbers), according to Table 3.

Table 3: The inner diameter code of rolling bearing and its example

Second, the drawing method of rolling bearing.

The rolling bearing can adopt the general drawing method, the characteristic drawing method and the prescribed drawing method.

1. General drawing method

In the cross-sectional view, when the outline, load characteristics and structural features of the rolling bearing do not need to be accurately represented, the rectangular wire frame and the center of the wire frame can be used. An upright cross symbol indicates that the cross should not touch the section outline. Both the rectangular wireframe and the cross are drawn with thick solid lines.

Please see Figure 3, an example of the size ratio of the general drawing method for rolling bearings.

2. Feature drawing

In the cross-sectional view, if it is necessary to more vividly represent the structural features of the rolling bearing, the rectangular line can be used. The method of drawing the symbols of its structural elements in the box. An example of the size ratio of the feature drawing method of commonly used rolling bearings is shown in Figure 4.

3. The prescribed drawing method

The prescribed drawing method is generally drawn on one side of the axis, and the other side is drawn according to the general drawing method.

When drawing the sectional view of the rolling bearing with the prescribed drawing method, the rolling element of the bearing is not drawn with hatching lines, and each ring can be drawn with hatching lines with the same direction and interval. As shown in Figure 5.

In the assembly drawing, the Cages, chamfers, etc. can be omitted and not drawn; in order to ensure that the shaft and housing of the rolling bearing are installed, in order to ensure the contact between the bearing end face and the shoulder, the maximum fillet radius (rs) of the shaft and housing hole should be smaller than the bearing fillet radius (ras); The height of the shoulder should not be too large. Considering the convenience of installation and disassembly, the amount of g should be reserved. Please see Figure 6.