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NSK bearings improve the accuracy of
NSK Bearings installed in the host, such as the measurement of NSK bearing spindle runout, can be found in the measured value of each turn to have some changes; continuous measurements, can be found after a certain number of revolutions, this change will approximately repeated. Indicators to measure the degree of this change for the circular rotation accuracy, changes in approximate repeat accuracy required for the transfer on behalf of the cyclic rotation "quasi-periodic, the magnitude of changes in amplitude in the quasi-periodic cycle rotation accuracy is .
Be properly pre-load, such as NSK bearing spindle speed will be gradually increased to close to operating speed, to "run" the role of the implementation of the bearing can improve the accuracy of cyclic rotation of the spindle.
A way to improve the accuracy of NSK Bearings
A factory trial precision instruments, spindle 6202/P2 type bearing its accuracy still can not meet the requirements of the journal after the bold and produced on the raceway to replace the inner ring, and carried the ball to the precision measurement of the size a group of three, the ball of each group to take close to 120 ° intervals to separate due to the reduction of re-machined surface, but also to reduce a heavy mating surface, while the stiffness of the shaft bearing system, a maximum of three with minimum three the ball close to equidistant distribution, but also improves the axis of rotational accuracy, then meet the requirements of the precision of the instrument.
3.NSK bearing installation accuracy calibration method
Angular contact ball bearing into the spindle of the NSK Bearings, installation accuracy of the calibration sequence is as follows (shaft diameter 60-100mm ordinary lathe, for example):
(1) measuring the size of the shaft and the bearing hole, to determine with precision bearings to meet the requirements are as follows: the inner ring and the shaft to take the interference fit, the amount of interference the 0 ~~ +4 μm (light load, high-precision, 0) ; take the outer ring and the bearing hole gap with the gap amount ~~ +6 μm (in the free end bearing angular contact ball bearings, but also increase the gap); axis and the surface of the bore roundness error below 2μm, bearing used parallel to the spacer end degrees below 2μm, the external end face of the shaft shoulder beating in the following 2μm; bearing hole block shoulder axis beating the 4μm below; spindle inside the front cover side face of the axis of the beating 4μm below.
(2) Installation: fixed end bearings in the shaft bearings to be thoroughly cleaned with clean cleaning kerosene For grease lubrication, the first organic solvent containing 3% ~ 5% of the grease into the bearings for the degreasing cleaning, and then oil gun will fill in the quantitative grease bearing (% of bearing space volume of 10% to 15%); heating bearing heating 20 to 30 ℃, oil press bearing into the shaft end; adapter sleeve pressure on the shaft and suitable pressure against the bearing face so that the axial position; spring balance of the tape volume in the bearing outer ring, using the method of calibration to measure the starting torque required by the pre-load significant changes (even if the bearings are correct , but due to the tie or cage deformation, pre-load changes possible).
(3) NSK Bearings - Shaft combination into the bore: heated seat hole temperature of 20 to 30 ℃ with continuous gently pressure bearing - shaft combination load bore; adjust the front cover, front cover fastening the amount of 0.02 ~ 0.05μm, bearing outer face, in contravention of the header of the dial gauge on the journal surface, the axis of rotation measured beating, requirements errors dial gauge positioned below 10μm; axis, the header is inconsistent with the surface of the rear seat hole axis to measure the bearing of the front and rear seat hole concentricity.
(4) The free end bearing selectively on the deviation of the position may be offset, to install the bearing after the supporting position, as much as possible to offset the roundness deviation and inter-coaxial deviation.
| Product Model | Inside Diameter | Outside Diameter | Thickness |
| 6912 NSK | 60 | 85 | 13 |
| 6812 NSK | 60 | 78 | 10 |