What should be paid attention to when installing precision bearings?

Precision bearings are mainly used in high-speed rotation occasions with light load, requiring high precision, high speed, low temperature rise and low vibration, and a certain service life. It is often used as the supporting parts of the high-speed electric spindle to be installed in pairs, and is the pivotal accessory of the high-speed electric spindle of the inner surface grinder. So what should be paid attention to when installing precision bearings?

The service life of high-speed precision bearings has a lot to do with installation. The following items should be noted:

1. The bearing installation should be carried out in a dust-free and clean room. The bearing should be carefully selected and the bearing spacer should be ground. The parallelism of the spacer should be controlled at 1um while keeping the same height of the inner and outer ring spacers. the following;

2. The bearing should be cleaned before installation. When cleaning, the inner ring slopes upwards, the hand feels flexible, and there is no sense of stagnation. After drying, put in a certain amount of grease, if it is oil mist lubrication, put a small amount of oil mist oil;

3. Special tools should be used for bearing installation, and the force should be even, and beating is strictly prohibited;

4. Bearing storage should be clean and ventilated, no corrosive gas, relative humidity should not exceed 65%, long-term storage should be rust-proof on schedule.

In order to improve the actual matching accuracy during the installation of precision bearings, it is necessary to use measuring methods and measuring tools that do not deform the precision bearings to carry out actual precision measurement of the matching surface dimensions of the inner hole and outer circle of the precision bearing. The relevant inner diameter and outer diameter can be measured. The measurement items of the diameter are all measured, and the measured data is analyzed comprehensively. Based on this, the precision matched the size of the precision bearing installation part of the shaft and the seat hole. The actual measurement of the corresponding size and geometry of the shaft and the seat hole should be carried out under the same temperature conditions as when measuring the precision bearing.

In order to ensure a higher actual matching effect, the roughness of the matching surface of the shaft and the seat hole and the precision bearing should be as small as possible.

When making the above measurement, two sets of marks should be made on the outer circle and inner hole of the precision bearing, and on the corresponding surface of the shaft and the seat hole, on the two sides close to the assembly chamfer, which can show the direction of significant deviation. In order to align the deviation between the two matching parties in the same orientation during actual assembly, the deviation between the two parties can be partially offset after assembly.

The purpose of making two sets of orientation marks is that the compensation of deviation can be considered comprehensively. Even if the rotation accuracy of the two ends of the support is improved, the coaxiality error of the seat hole between the two supports and the journal at both ends is partially eliminated. . The implementation of surface strengthening measures on the mating surface, such as sandblasting, using a precision plunger with a slightly larger diameter to plug the primary inner hole, etc., are all conducive to improving the accuracy of the mating.


Post time: May-07-2021