When choosing the angular contact bearing of NSK bearings,we need to clear that the bearing we need whether have precision.Since there is a big difference between the angular contact bearing with precision and the angular contact bearing without precision.

(1)Measure the size between shaft and bore of bearing housing,in order to make sure the  matching precision of bearing,the mating require as follow:Inner ring and shaft are fit to take to lead a surplus match,and the amount of 0 ~ +4 μm (in light-load, high-precision for 0); the outer ring and the bearing clearance to take the hole with the volume of space 0 ~ +6 μm (However, in a free-end bearings the use of angular contact ball bearing, the gap can be increased);The erroe between axis and the surface of the hole roundness is below 2μm, the following lap Parallelism that the bearings used is below 2μm , the beating that below the shoulder axis within the external end face is below 2μm; Bearing hole on the axis of the shoulder block in 4μm following the beating; spindle inside the front cover of the axis-side facing the beating in the following 4μm.

(2) fixed-end bearings in the shaft before the installation will be clean cleaning bearings with kerosene to carry out thorough cleansing, for resin lubrication, first containing 3% ~ 5% organic grease Bearings for degreasing solvent into the cleaning, then oil of the grease gun to fill in quantitative bearing (or bearing space volume of 10% ~ 15%); heating bearings to make up 20 ~ 30 ℃, oil presses will load bearing shaft; will bear fixed sets of pressure in the axis and to resist the pressure of a suitable end bearings enable axially positioning; will spring balance of the tape volumes .In the bearing outer ring, and with the measurement method of starting torque required by checking whether there is a substantial pre-load change (even if the bearings are correct, but because with or maintain. Plane deformation, pre-load also has the possibility of change).

(3) Take the combinations of bearing - shaft into the heating hole,then make the temperature up to 20 ~ 30 ℃, continuous pressure on the combinations into the hole; adjust the front cover, So that the front cover of the fastening of 0.02 ~ 0.05μm, to bearing pedestal outside the end as the benchmark dial gauge table will be inconsistent in the first journal surface, to measure its rotation axis beating Require the following error in the 10μm; will dial gauge positioning in the axis, the first conflict with the rear table surface hole will be to measure the bearing rotation axis around the Block, Block coaxiality hole.(4) Take the free end bearing on a location which may offset the deviation selective , installation on the bearing housing rear load position, as much as possible offset between roundness deviation and with axis deviation.