After the installation of precision precision bearings

1. improve the accuracy of Law
After the bearings installed in the host, such as measuring spindle radial runout, the measured values can be found in each of its turn has some changes; continuous measurements, can be found after a certain number of revolutions, the repetition of this change will be approximately appears. Indicators to measure the extent of this change for the precision rotation cycle, approximately repeated changes in the number of revolutions required for precision rotation cycle representative "quasi-periodic" magnitude of change in the amplitude of the quasi-periodic big difference is the precision rotation cycle .
If properly pre-load on the spindle, the speed gradually increased to nearly the speed of work to implement the "run-in" effect of the bearing can improve the accuracy of spindle rotation cycle.
2. A method for improving the accuracy of dental bearing
Precision instruments factory trial, spindle 6202 / P2-bearing and its accuracy still can not meet the requirements, and after making the bold journal on which to replace the inner ring raceways and balls were waxy dense measurements to size each set of three tablets, each taking the ball close to the interval of 120 ° apart, due to the reduction of a heavy machined surface, but with a weight reduction of the surface, while improving the rigidity of the shaft-bearing system, and the maximum and minimum three tablets three equally spaced ball close grain, but also improves the accuracy of the axis of rotation, so the instrument meets the accuracy requirements.
3. Install a comprehensive calibration method precision
After the angular contact ball bearing manufacturer into the spindle mounting accuracy of calibration sequence is as follows (with a shaft diameter of 60 100mm lathe, for example?):
(1) Measure the shaft and the slewing bearing hole size to determine with precision bearings, with the following requirements:
Take the inner ring and the shaft interference fit, the amount of interference 0 ~ + 4μm (at light load, when high precision is 0); the outer ring and the bearing hole to take a clearance fit, clearance volume 0 ~ + 6μm (but at the free end of the bearing when using angular contact ball bearings, but also increase the gap); the shaft and housing bore surface roundness error 2μm or less parallel to the end face of the bearing cage used in 2μm or less, the external end face of the inner shaft shoulder end beating in 2μm or less; retaining shoulder of the housing bore axis beating 4μm below; cover the face before the end of the axis of the spindle runout at 4μm below.
(2) the fixed end of the front bearing mounted on the shaft
After the bearings were cleaned thoroughly washed with clean kerosene, grease lubrication, the first containing 3% to 5% of the grease into the bearing organic solvents for degreasing, and then quantitative grease gun oil filled bearings (accounting bearing space volume of 10% to 15%); heating bearings make heating 20 ~ 30 ℃, oil press the bearing into the shaft; the tight sets against the shaft and bearing a suitable pressure against the end face axially the spring balance tape volumes on the bearing outer ring, the pre-load starting torque measuring method prescribed check whether a substantial change (even if the bearings are correct, but the fit or maintain deformation frame, preload there; positioning change may be).
(3) the bearing? Shaft assembly into the housing bore
Heated seat hole so heated 20 ~ 30 ℃, with continuous gentle pressure on the bearing shaft assembly into the housing bore;? Before adjusting cover, tighten the amount of the front cover of 0.02 ~ 0.05μm, to the outer face of the bearing housing benchmark indicator of the conflict in the journal header surface, the axis of rotation measured beating error 10μm following requirements; the dial gauge positioned on the shaft, the first table inconsistent backseat hole surface, the axis of rotation front and rear seat to measure the thrust roller bearing bore concentricity.
(4) the free end of the bearing may be selectively placed in a position offset bias, is mounted to the support position after the bearing, as much as possible to offset the roundness and concentricity deviation deviation between each other.
4. tapered bore double row cylindrical roller bearings installed
When installing NN3000K series tapered bore double row cylindrical roller bearings, must pay attention to the shaft bearing bore and taper fit properly in the case of the production of less coloring method available contact check, but in the production of large quantities of , preferably with a precision taper gauge calibration.
In the bearing mounted on a tapered shaft, the inner ring should be transferred to the appropriate position in the axial direction, so that the radial clearance is close to zero.