1. The accuracy of the method
Bearing in the installation is completed in the host, such as measuring the spindle radial beat, but found its every turn measurements are certain change; Continuous measurement can be found after a certain number of turn after, this change will approximate the repetition. Measure the degree of this change for cycle rotation precision index, change the approximately the repetition of the number needed to represent the accuracy of the spin cycle "quasi-periodic", among a cycle of amplitude value change, namely for cycle rotation precision is poor.
As to the appropriate advance of spindle load, and will gradually rise to near work speed speed to implement bearing "integration" function, can improve the circulation of the spindle rotation precision.
2. Improve the accuracy of the bearing a method
A factory manufacture precision instruments, spindle use 6202 / P2 type bearings and its precision is still cannot meet the requirements, bold shaft neck after and the production groove instead of inner circle, and its dense ball for measurements to size every three grain by a group, each group of steel ball close to 120 ° from the separated, due to reduced a heavy processing surface, and reduces the heavy with surface, and at the same time, improve the shaft bearing the stiffness of a system, and the largest three goals and minimum three goals of steel ball close to isometric distribution, and also to improve the axis of rotation precision, and meet the demand for the accuracy of the instrument.
3. The installation precision is comprehensive calibration method
Will Angle contact ball bearing load spindle, installation precision calibration of the following order (for 60-100 mm trunnion ordinary lathe as an example) :
(1) measure shaft bearing and the size of the hole to determine with precision bearings, cooperate requirement as follows,
Inner circle take over surplus with shaft, a surplus quantity of 0 ~ + 4 μ m (in light load, high precision for 0);
Outer ring and the bearing hole take clearance fit, clearance is 0 ~ + 6 μ m (but in the bearings use free Angle contact ball bearing, still can increase clearance);
Axis and a hole surface roundness error in 2 μ m the following,
Bearing the face of every lap parallel degree in 2 μ m the following,
Shaft shoulder end in foreign end of the 2 μ m jump below;
The bearing hole to the beat of block shoulder axis in 4 μ m the following;
The front cover the face in the main shaft axis beat μ m in 4 below,
(2) the fixed end bearing on the shaft before installation.
With clean cleaning bearings are thoroughly clean kerosene,
To grease lubrication, the first contains 3% ~ 5% of the organic solvent grease injection bearing be skimmed cleaning after another, oil gun will quantitative grease fill in the bearings inside (volume of the space of bearing 10% ~ 15%);
Heating bearing that warming 20 ~ 30 ℃, with hydraulic press will load bearing axial end;
Will close on the shaft will set of pressure and pressure at the right end to withstand bearing the axial location;
Will DanHuangCheng band of roll bearing outer ring in, with the method of measuring start torque calibration regulations or whether there is a big change of load (even if bearing is correct, but due to cooperate or maintains a deformation, the load also has change may).
(3) will bearing axial load a hole-combination.
Heating a hole that warming 20 ~ 30 ℃, with the continuous light slow pressure will bearing axial load a hole-combination;
Adjust the front cover, make the front cover is tightening 0.02 ~ 0.05 u m,
In the end the bearing as a benchmark, will the header in the shaft resistance dial indicators on the surface of the neck, will axis rotation measuring the beating and requirements in 10 μ m the following error;
Dial indicators will be located in the shaft, headers to conflict with the back seat hole surface axis rotation to measure before and after the bearing a hole of the coaxial degrees.
(4) will the bearing on free selective may be offset by the position of the deviation, installation to after the bearing support position, as far as possible to offset the roundness error and between the coaxial tolerance of deviation.
4. Cone KongShuang column short cylindrical roller bearing installation
In the installation of NN3000K series cone KongShuang column short cylindrical roller bearing, must pay attention to bearing inner and shaft of the design of the correct match and in the production of colour can be less of calibration contact, but in the production batch is bigger, better use of precision taper gauge calibration.
In the bearings are mounted on tapered shaft, should be in circle along the axial moves to a proper position, make its radial clearance close to zero.




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