The functions of rolling bearings required each are not identical

Rolling bearing the different functions: according to the bearing applications. These functions should be carried out for a long time. Even if the bearing installed correctly, correct operation, they eventually can't satisfactorily perform noise and vibration increase, run lose accuracy, grease spoiled or fatigue spalling rolling surface. Bearing life, in the broad sense, the word is bearing during continue to run to meet the required functions. This kind of life, bearing life can be defined as noise wear life, the life of grease or rolling fatigue life, which depends on the reason for bearing service losses. In addition to the function of bearing failure natural deterioration, bearing may be failure conditions such as grading ring, seal or damage or other damage to the cage. These conditions should not be interpreted as normal bearing failure, because they often as a result of bearing selection error, improper design or manufacturing bearing surroundings, improper installation or maintenance. 5. 1 rolling fatigue life and basic rating life, when the rolling bearing runs under the load, inner ring and outer ring raceway run and components undergo repeated cyclic stress. As a result of the rolling contact surface metal fatigue, raceway and rolling body, scaly particles may be related to the bearing material separation ( Figure 5. 1) 。 This phenomenon is called 'peeling off. Rolling fatigue life is a total revolution represented by bearing surface will start peeling stress at this time. This is known as the fatigue life. As shown. Rolling bearing the different functions: even the seemingly the same bearing, so it is of the same type, size and material, and subject to the same heat treatment processing, such as rolling fatigue under the same operating conditions of life difference is very big. This is because the material fatigue spalling is influenced by many other variables. Therefore, 'basic rating life of rolling fatigue life is seen as a statistical phenomenon, is better than that of the actual rolling fatigue life. Suppose that some of the same type bearing is under the condition of the same operating separately. After a period of time, 10% of them failed because of failure to scroll caused fatigue spalling. Revolution is defined as the basic rating, at this time in life, or if the speed is constant, the basic rating life is often expressed in total operating time when 10% of bearing into complete not operating due to spalling. In determining the bearing life, the basic rated life is often the only factor. However, other factors must also take into account. For example, the life of the grease prelubricated bearing grease ( See section 12, lubrication, pp A107) Can be estimated. Because of the noise of life and wear life standard, according to the personal judgment on different application specific value noise or wear life must be determined by experience.