One of the important performance indicators of Slewing Ring Bearing as a mechanical component is the bearing stiffness. Usually we do this by preloading the bearings. Preload is to adjust the bearing through a specific method during installation to maintain a certain axial force to eliminate the axial clearance of the bearing. Next, Zhiyuan factory will introduce to you the influence of slewing bearing preload on bearing stiffness.
1. Influence of slewing bearing preload on bearing stiffness
The preloading method of the bearing is mainly divided into two methods: constant pressure preloading and positioning preloading. The positioning preloading is a screw nut that adjusts the axial clearance by combining the axial relative position of the bearing without changing its relative position. method to adjust. The constant pressure preload is a method of applying appropriate preload to the bearing through a cylindrical spring and a disc spring.
1). Constant pressure preload and axial stiffness: The stiffness of the preload spring is generally smaller than the bearing stiffness, so the displacement line of the spring is basically parallel to the horizontal axis, so the stiffness of the constant pressure preload is the same as the pre-applied axial preload. The stiffness of each bearing is basically the same.
2). Positioning preload and axial stiffness: After the inner ring of the combined bearing is axially tightened, bearing A and bearing B have a certain degree of displacement respectively, and the clearance between the inner rings is also eliminated. A preload is obtained. For the axial load applied to the preloaded bearing, the stiffness of the bearing is the change of the load and displacement with the change of the axial load.
After comparison, in terms of increasing the rigidity of the slewing bearing, the displacement caused by the positioning preload is smaller than that caused by the constant pressure preload, which is more advantageous. However, the temperature change is larger, which may affect the centrifugal force and radial thermal expansion difference of the rolling elements, while the constant pressure preload will hardly cause the change of the spring conformity. Suitable for preloading with constant pressure.
2. the relationship between the stiffness of the slewing bearing and the preload
The preload of the bearing in the spindle bearing increases, and the adverse effects of the bearing caused by centrifugal force and gyroscopic moment during high-speed operation will reduce the rotational speed and increase the stiffness of the spindle. Bearing stiffness trend With the increase of bearing preload, the radial stiffness of the bearing increases, the machining accuracy and work efficiency of the machine are greatly improved, and the work performance is improved. However, there are limitations to the increase in preload that should be noted. With the increase of preload, the bearing temperature will also increase. Too high bearing temperature will affect the working life and performance of the bearing, so the larger the preload, the worse it is. According to the specific situation, it should be adjusted to the appropriate range.
This is Zhiyuan slewing bearing factory's introduction to the influence and relationship of slewing bearing preload on bearing stiffness. Typically, slewing bearing points require preload. Just doing interference fit and spring auto-adjustment etc in a different way. In this case, it must be decided according to the actual working conditions. In addition, if you encounter other problems during use, please contact slewing bearing manufacturer. We will provide appropriate questions and technical support. Welcome to call.