PRODUCT
The accuracy of precision bearing after installation
by:Waxing
2020-11-20
The precision of precision bearing installed 1.
Improve the precision of method of bearing in the host after the installation, such as the measurement of spindle radial runout, can be found that the measured values of each turn has certain change;
Continuous measurement, can be found that after a certain number of revolution, this change will approximately duplicated.
Measure for cyclic rotation accuracy degree of the change, change the approximately duplicated the revolution, on behalf of cyclic rotation accuracy 'cycle', the value of the amplitude changed in quasi cycle, is the cycle rotation accuracy is poor.
Such as the proper preload on the spindle, the higher speed step by step to near work speed, on bearing the 'break-in' effect, can improve the circulation of the spindle rotation accuracy.
2.
A method for increasing accuracy of bearing manufacture precision instruments in one power plant, the type 6202 / P2 bearing spindle and its precision is still cannot meet the requirements, the bold shaft neck and on the race to replace the inner ring, and the steel ball, the measurement of waxy secret, to size every three grain of a group, each group of steel ball in nearly 120 � are separated, due to reduced a heavy processing surface, reduce the heavy blend surface, at the same time improve the axial stiffness of the bearing system, and the three largest grain and minimum three grain of steel ball nearly equidistant distribution, and improves the precision of drive shaft rotation, thus satisfying the requirements of the precision of the instrument.
3.
The comprehensive check method of fitting accuracy after angular contact ball bearing in the spindle, installation precision calibration sequence is as follows (
Trunnion as 60?
100 mm engine lathe as an example)
:(
1)
Measuring the size of the shaft and bearing hole, to determine with precision of the bearing, cooperate with requirements as follows: take the interference fit, inner ring on the shaft interference was 0 ~ + 4 � � m (
At light load, high precision of 0)
;
Outer ring and bearing hole clearance fit, the interval 0 ~ + 6 � � m (
But on the free end bearing with angular contact ball bearing, still can increase the clearance)
;
Shaft and hole surface roundness error in 2 � � m below, bearing the face of baffle used parallelism in 2 � � m below the shaft shoulder end foreign face beat in 2 � � m the following;
Axis bearing hole block shoulder to beat in the 4 � � m the following;
Spindle axis cover inner end face before beating in 4 � � m below.
(
2)
Fixed end before the installation of the bearings on the shaft bearing with clean to clean a thorough cleaning of kerosene, the grease lubrication, to contain 3% ~ 5% of organic solvent injection bearing grease for degreasing, cleaning and quantitative grease oil gun will fill in the bearing inner (
Accounts for 10% ~ 15%) of the bearing space volume
;
Heat bearing the heat up 20 ~ 30 ℃, using hydraulic press the bearing into shaft end;
Will set casing pressure on the shaft and with appropriate pressure against bearing face makes its axial positioning;
The lace will spring balance volume on the bearing outer ring, use the method of measuring start torque check is the preload of the regulation for substantial changes (
Even if the bearing is correct, but due to cooperate or cage, the deformation of the preload is also has the potential to change)
。
(
3)
Bore the bearing spindle assembly into a heated seat made up of 20 ~ 30 ℃, with a continuous gentle pressure of bearing spindle assembly into a hole;
Adjust the front cover, make the front cover of fastening is 0.
02 ~ 0.
05 � � m to bearing outer end face as a benchmark, the dial gauge meter resistance on shaft neck surface, will beat measuring the rotation axis, request error in 10 � � m the following;
Will be located on the shaft, dial gauge meter resistance in the back seat hole surface, the axis of rotation to measure before and after bearing hole of the alignment.
(
4)
Put free end bearing selectively may offset the position of the deviation, after installed to the bearing support position, offset each other as much as possible of roundness error and axiality deviation.
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