Factors that Affect Bearing Life

In addition to structural design, there are four main aspects of materials, manufacturing, use and lubrication technology

(1) The impact of materials: in the bearing material technology, mainly through the selection of materials, material assurance and heat treatment and other means to ensure the improvement of bearing life. Rolling bearings are generally made of high carbon chromium bearing steel, and the chemical composition is almost constant. However, the purity of different smelting methods materials is different, the impact on the life is great in the same contact should be conditions, screening IV.4 ceramic bearing contact fatigue life is better than bearing steel bearings; It can be seen that the effect of material on bearing fatigue life is very significant.

(2) The effect of surface roughness: fatigue cracks usually originate from the surface, so the surface has a great impact on the life of the part. The smoother the surface, the longer the fatigue crack will first. Surface treatment techniques for rolling bearing rollers and collars can change the hardness of the rolling body surface, residual stress distribution and the overall strength of the material, thereby increasing bearing life.

(3) The effect of temperature: whether it is based on the fatigue model of subsurface stress, or the model based on surface defects, the effect of heat in the bearing contact area on fatigue life is not taken into account. In fact, the bearing after continuous operation, will inevitably be accompanied by a certain temperature rise, the magnitude of this temperature rise should be related to the thickness of the lubricant film between the contact sub-contact, the surface characteristics of the contact parts and the load, running speed and other parameters. At the same time, after the temperature increases, there must be a temperature distribution in the bearing collar and rolling body, and will produce thermal deformation due to the effect of thermal expansion, which affects the running accuracy of the bearing. Therefore, the effect of temperature rise and heat on fatigue life can not be ignored.

(4) The impact of lubrication technology: in bearing lubrication technology, mainly through the selection of lubricants and lubrication methods, to improve the life of bearings. Lubrication technology has become one of the most critical factors to improve bearing life. Especially for sealed bearings, grease life has become another "pronoun" for bearing life, that is, grease life is bearing life.

(5) Effect of running speed: bearing fatigue life is related to instantaneous contact time. Instant contact time refers to the time required for the rolling body to roll over the sleeve and the collar raceway to touch the width of the ellipse at maximum load. As the speed increases and the momentary contact time increases, the bearing fatigue life decreases. The slower the operation of the bearing, the longer the life in the number of revolutions. On the other hand, the length of instantaneous contact time also affects surface residual stress, which indirectly affects fatigue life.

(6) The effect of load: the effect of rolling body parameters and curvature coefficient on the fatigue life of deep groove ball bearings, the study shows that the size of the load has a very large impact on bearing fatigue. The fatigue life of rolling bearings depends to a large extent on the maximum rolling body load. Therefore, the increase of load leads to a significant increase in the load of the maximum rolling body and a decrease in fatigue life.