1, Accuracy is improved law

After bearing installed in the host, as measured radially spindle runout, measured values ​​can be found in each of its revolution has some changes. Continuous measurements can be found after a certain number of revolutions after this change will be approximately repeated. This change is a measure of the degree of precision rotation cycle indicators, approximately repeated changes in the number of revolutions required on behalf of the rotation cycle accuracy "quasi-periodic", the magnitude of the change in the quasi-periodic large amplitude, rotation accuracy is poor circulation .

If properly pre-load on the spindle, the speed gradually increased to close to the operating speed, in order to implement "run" function of the bearing can be improved cycle rotation accuracy of the spindle.

2, The installation of integrated precision calibration method

After the angular contact ball bearings into the spindle mounting accuracy of the calibration sequence is as follows (in shaft diameter is lathe 60-100mm example):

(1) Measurement of the shaft and the 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 precision is 0);

Take the outer ring and the bearing hole gap with the clearance amount 0 ~ + 6μm (but in the free end bearings angular contact ball bearings, but also increase the gap);

Shaft and housing bore surface roundness error in 2μm or less,

The parallelism of the bearing end face of the spacer in 2μm or less,

The inner shaft shoulder end of the end face of foreign beating 2μm or less;

Retaining shoulder on the housing bore axis beating 4μm or less;
The front end face of the spindle axis cover beating 4μm or less,

(2) Fixed to the front end of the bearing mounted on the shaft.

Bearing thorough cleaning with a clean wash kerosene,

For grease lubrication, the first containing 3% to 5% of the grease into the bearing organic solvent for degreasing, and then quantitative grease gun grease filled within the bearing (10% to 15% of the bearing space volume);

Heating the bearing temperature elevation 20 ~ 30 ℃, hydraulic press bearing onto the shaft;

The adapter sleeve bears on the shaft and a suitable pressure against the end face bearing axially positioned;

The spring scale tape volumes on the bearing outer ring, starting torque measuring method specified preload check whether there is a significant change (even if the bearing is correct, but to keep fit or deformed frame, there are changes in preload may).

(3) Bearing - axle assembly mounted seat hole.

Heated seat hole so warm 20 ~ 30 ℃, with continuous gentle pressure bearing - axle assembly mounted housing bore;

Before adjustment cover so that the amount of fastening the front cover of 0,02 ~ 0,05μm,

In the outer end face of the bearing as a reference, the dial gauge on the journal header inconsistent surface, the axis of rotation measured beating error of 10μm the following requirements;

The dial gauge positioned on the shaft, the first table in the back seat contradict the interior surface, the axis of rotation of the front and rear seat to measure the bearing bore concentricity.