The right choice of fit, must know the actual load conditions of large SNL bearing housing, operating temperature and other requirements, but in fact it is very difficult.Therefore, most of the cases are based on the use of choice.
The over-win between the ring and the shaft or housing depends on the size of the load. The heavier load adopts the larger over-win, while the lighter load adopts the smaller over-win.
With the development of science and technology, the spindle speed of machine tool is getting higher and higher, and the range of speed change is getting larger and larger. Therefore, the requirement for the stability of high-speed operation of bearing is getting higher and higher.Temperature rise of large SNL bearing housing is an important factor to limit the speed of bearing.Under normal circumstances, correct selection of non-standard bearing type, tolerance grade, configuration mode, clearance (pre-load) size, lubricant and lubrication mode can improve the high-speed performance of large SNL bearing seat to a certain extent.
For general machine tools, the life of the spindle component mainly refers to the life of its spindle precision maintenance, therefore, the precision maintenance performance of the bearing is required to meet the requirements of the life of the spindle component.For heavy-duty machine tools or heavy-duty cutting machines, the bearing capacity of non-standard bearings should be considered first.
1, on the surface, it is a large SNL housings in the process of rolling contact, because of the work in the plastic deformation and strain hardening on the surface of the contact stress on the surface of the cyclical changes caused by the effect of external load, and finally on the inner surface of the small crack from the development, the formation of surface crack between the two, because Xie into the lubricant on the surface of the work, the power of the open, crack down on the wall, crack force to move forward;
2, from the surface, under repeated pressure, the surface contact, initially at a certain depth of the exposed surface crack crack, and along the surface direction of the Angle, to a certain depth, from the surface of the contact surface, and beyond the surface, and eventually formed erosion stripping, leaving a horse pit.
From large SNL housings on the surface, or from the surface of the crack, these two goals (part carburizing, quenching and other surface heat treatment, if after have uneven hardness, organization, and the internal stress of non-uniform and other adverse, the contact stress is generally have the opposite under the influence of ground fissure, if parts surface quality is poor, there is a defect (oxidation and decarburization), friction or poor lubrication, from the surface crack.
The methods to control raceway sound are as follows: the low noise large SNL bearing seat is selected, namely the bearing with very small ripple, and the operating conditions are selected carefully.Raceway noise often affects the noise of the whole machine. Reducing raceway noise can reduce the noise of the whole machine.