The matters needing attention in the process of INA needle roller bearing assembly

Bearing clearance is to point to in a ring under the condition of fixed, another ring along the radial or axial of maximum flow, so the clearance is divided into radial clearance and axial clearance. To move the needle roller bearing assembly, clearance cannot too big, also not too small. Clearance is too large, the number of moving body will cause the load at the same time, a single move body load increase, thereby reducing the rotating precision of bearing, reduce the service life; Clearance is too small, can make the friction force increases, the heat generated by the increased, aggravate wear, also can reduce the service life of INA bearings. Therefore, bearing in the assembly to strictly control and adjust the clearance. The cause of the high bearing temperature are: lubricating oil quality does not conform to the requirements or metamorphism, lubricating oil viscosity is too high; The assemble tight ( Inadequate clearance) ; Bearing assembly too tight; Bearing race in internal rotation shaft or housing; Too much load; INA bearing cage or rolling body fracture, etc. 1) , shaft and hole of the roundness, and retaining shoulder perpendicularity to according to the corresponding precision of bearing requirements. 2) , as well as the calculation of the rotating ring with quantity, also to accurate calculation of the fixed ring with right quantity. The rotating ring burning interference quantity within may also should be made smaller. As long as to ensure that work under the temperature of thermal expansion effect, and under the maximum speed of centrifugal force effect, not cause peristalsis or sliding on the surface of the tight fit. Fixed ring according to the size of the working load and bearing size, choose the smallest clearance fit or interference fit, too loose or too tight is unfavorable to keeping the original precise shape. 3) , needle roller bearings, such as under the condition of high speed running, and working temperature is higher, should pay special attention to the matching of the rotating ring is too loose, to prevent the eccentric vibration, and the matching of the fixed ring is a gap, in order to prevent the ferrule deformation and vibration under load. The functioning of the rolling bearing in the work to allow a slight noise, if you have any abnormal noise or excessive noise or sound, suggests that the bearing failure. When is preloaded bearing assembly, for inner ring and outer ring an axial force, to eliminate the needle roller bearing clearance, and make the move body contact with the inner and outer ring at the beginning of deformation. Preloaded can you improve bearing in the working status of the stiffness and rotation accuracy and load is larger, higher bearing rotating accuracy requirement is mostly in the absence of clearance there is even a small amount of work under the interference of the state, this situation requires the INA bearing pre-tightening when it is assembled. Adjustment of clearance and preload is usually by inner ring external circle for appropriate axial relative displacement method. From the above concept does not lose face technology, through the adjustment of move the bearing clearance, bearing capacity and can progress rotating accuracy, bearing service life. But at the same time can make the bearing friction intensified, fever to increase, so the clearance or preload adjustment when necessary to ensure good lubrication and cooling. If improper or poor lubrication, can in turn exacerbated bearing wear, reduce the service life.