The first point of using the rolling bearing well

Rolling bearing is a kind of precise mechanical support element. Bearing users deeply hope that the bearing installed on the main engine will not be damaged and maintain its Dynamic performance, but the objective facts are sometimes not satisfactory, and sudden bearing failure accidents will cause heavy losses to users. Through a large number of rolling bearing failure analysis studies, it has been shown that short bearing life or premature loss of accuracy is sometimes caused by material defects or improper manufacturing, but to a considerable extent, it is due to the failure to strictly follow the bearing requirements for installation, maintenance, or Abnormal bearing damage is caused by improper bearing selection or the actual load exceeding the rated load of the bearing itself. For example, the fatigue spalling of bearing parts is largely caused by impurities in the lubricating oil. It can be seen that in order to achieve a longer life and accuracy retention period for rolling bearings, in addition to requiring bearing manufacturers to improve product quality, bearing users must also use scientific methods and procedures to use bearings, otherwise, no matter how good the bearing will be. Died under random conditions of use.

Chapter 1 Selection and Substitution of Rolling Bearings

1. Selection Methods and Steps

Whether the rolling bearings can be correctly selected and whether the main engine can obtain good performance Work performance, prolong the service life; whether the enterprise can shorten the maintenance time, reduce the maintenance cost, and improve the operation rate of the machine, it has a very important role. Therefore, whether it is a design and manufacturing unit or a maintenance and user unit, great attention must be paid to the selection of rolling bearings. The entire selection procedure is shown in Figure 1u0026#0;1.

Generally speaking, the steps for selecting a bearing may be summarized as follows:

1. According to the working conditions of the bearing (including load direction and load type, speed, lubrication method, Positioning or non-positioning, installation and maintenance environment, ambient temperature, etc.), select the basic type of bearing, tolerance level and clearance; Determine the bearing model, or select the bearing model according to the use requirements, and then check the life;

3. Check the rated load and limit speed of the selected bearing.

The main considerations in selecting bearings are the limiting speed, required good life and load capacity, other factors help to determine the final solution of bearing type, structure, size and tolerance class and clearance requirements.

1. Type selection

Various types of rolling bearings have different characteristics and are suitable for different use conditions of various machines. When selecting a bearing type,

The following factors should generally be considered. In general: Thrust bearings and angular contact bearings are used when bearing thrust loads, ball bearings are usually used for high-speed applications, and roller bearings are used when bearing heavy radial loads. Choose the appropriate type of bearing products.

? The space and position of the machine occupied by the bearing

In the mechanical design, the size of the shaft is generally determined first, and then the rolling bearing is selected according to the size of the shaft. Usually, ball bearings are used for small shafts, and roller bearings are used for large shafts. However, when the bearing is limited in the diameter direction of the machine, it is a ball or roller bearing of the light series; when the bearing is limited in the axial position of the machine, narrow or Extra narrow range of ball or roller bearings.

? The magnitude, direction and nature of the load on the bearing

Load is the most important factor in selecting bearings. Roller bearings are used to withstand heavier loads, ball bearings are used to withstand lighter or medium loads, and can withstand shock and vibration loads.

In terms of the direction of action of the load, deep groove ball bearings, cylindrical roller bearings or needle roller bearings can be selected when bearing pure radial loads. When bearing a small pure axial load, a thrust ball bearing can be selected; when bearing a large pure axial load, a thrust roller bearing can be selected. When the bearing is subjected to combined radial and axial loads, angular contact ball bearings or tapered roller bearings are generally used.

? Bearing alignment performance