When applying bearing preload, it is recommended to measure the deformation continuously. It should be noted that this deformation is nonlinear. The load in the high deformation stage is increased in the low deformation stage, and the linear pretension load is increased in the high deformation stage. There is a linear relationship between the principal deformation and the load. The increase in preload will stop immediately and a constant stiffness can be obtained. Thereafter, there is a fixed relationship between the stiffness of the axial and radial bearings, independent of external loads.

1. With bearings, the bearing structure has a great impact on the bearing stiffness. In general, the outer race of radial ball and roller bearings has a large end face to resist the overturning torque of the bearing. When the temperature changes, the preload adjustment will not change too much.

2. With the axial position allowed, the support stiffness can be increased by providing multiple bearing supports and two or more journal bearing supports at each fulcrum. In recent years, axial preload and multiple groups of radial thrust bearings have been widely used in machine tool spindle assembly.

3. In order to meet the requirements of bearing mating surface in Sweden, the shape of shaft and seat hole and the installation position and position precision of bearing are better, the surface roughness is lower and the bearing rigidity is higher. Case hardening helps to increase hardness. Under lubricating conditions, pressing the plug with extremely low hardness into and out of the seat hole for several times will have certain interference, which is also beneficial to improving the bearing stiffness. If necessary, this is similar to treating the journal with clamping rings.