angular contact ball bearing installation more complicated than the deep groove ball bearings, are installed in pairs, and adopts the preload. install well, can make the host the working accuracy, bearing life is greatly increased; otherwise, not only accuracy can not meet the requirements, life would also be affected.
type of installation
the installation form of angular contact ball bearing, a back to back, face to face and order three series. two bearing the wide end back to back (relatively) when installation, bearing of the line of contact angle along the rotation axis direction spread, can increase the angle of the radial and axial bearing rigidity, resistance to deformation ability; face to face (two bearing the narrow end relative) when installation, bearing contact angle of the line in the direction of the rotary axis convergence, the bearing angle rigidity is small. due to the bearing inner ring out of outer ring, when two bearing outer ring clamp together, outer ring of the original clearance eliminated, can increase of bearing preload lotus; tandem arrangement (two bearing the wide end in one direction) of the installation, bearing in a parallel direction and the contact angle, can make the two share the same direction of work load. but when using this type of installation, in order to ensure the installation of axial stability, two series of bearing must be installed on both ends of the shaft to the.
preload to get in
preloading load through a ring end face grinding bearing, or with two different thickness of the baffle on a pair of bearing between the inner and outer ring, the bearing is clamped together, make steel ball and raceway close contact.
preload size in a great influence on the service life of the bearings, according to the relevant information, when the bearing assembly is 0.012 mm interference quantity, service life is reduced by 38%, with a 0.016 mm interference quantity, service life by 50%; when the bearing assembly is 0.004 mm clearance, the service life of the significant decline, with 0.008 mm clearance, the service life of the 70% decline. therefore, the preload size in a reasonable choice, is very important. generally high speed appropriate chooses small preloading, preloading of low speed appropriate chooses big. at the same time, the preloading load should be slightly greater than or equal to the axial load.
preloading load calculation
choosing preloading charge, the minimum preload computation formula is as follows: in
aomin tgar = 1.58 + / - 0.5 a (n)
effect on the bearing radial load (n)
effect on the bearing axial load (n)
through the ball and raceway contact points in the plane of the straight line and through the steel ball center line the angle between the two (that is, the nominal contact angle) :
a = 15 ° 7000 c
7000 ac a = 25 °
a = 40 ° 7000 b
pairs of each bearing in the bearing are calculated according to the type. type "+" in the work for the axial load the disappearance of the original forecast and surplus value that a bearing; "work for the axial load makes the original pre and surplus value increases the one bearing. two bearings in pairs, the minimum preload loadings of two bearing two values obtained by the maximum selection (according to the experience of the assembly, generally take about 50 n the preload of the netherlands).
preload adjustment in
empty running test. angular contact ball bearing after assembly inspection, do you want to work with speed short running test, the time is not less than 2 h, the temperature rise shall not exceed 15 ℃.
