Based on the structural characteristics of the shaft bearing, the shaft as the inner ring of the bearing should have the contact fatigue life corresponding to the bearing. When the bearing is running, the raceway and the surface of the rolling body form cracks and expand under the long-term action of the periodic load, until the raceway or the surface of the rolling body fatigue spalling. Once this situation occurs in the operation of shaft bearing, its vibration and noise will increase sharply, so that the whole machine loses its working capacity. It can be seen that in order to improve the service life of shaft connected bearings, in addition to considering the wear resistance and fatigue strength required as shafts, it is necessary to have a higher contact fatigue life.

 

High carbon chromium bearing steel (GCr15) is used for conventional shaft connection bearings (including shaft, outer ring and ball roller). Because the smelting of high quality bearing steel through vacuum deoxidation, electromagnetic stirring, less oxide content, can withstand the larger contact compressive stress at the same time can also withstand the larger high tensile stress, after heat treatment, the raceway hardness of the shaft is 58-62HRC. The hardness of the raceway of the ring is 60-64HRC, and the hardness of the ball and roller is 61-65HRC. When the shaft and outer ring are made of carburized bearing steel, the raceway hardness is 60-64HRC. Cage material is usually used to enhance nylon 66, the sealing ring material is generally used butadiene rubber, when the requirements are higher, fluorine rubber sealing ring can also be selected.

 

Because the pump shaft bearing works at high speed and high temperature, lubrication conditions directly affect the life of the shaft shaft, usually the drop point is higher, better consistency of imported advanced grease, the seal ring usually also uses the radial contact seal with large interference, to ensure that the bearing does not lose oil for a long time.