Four points of attention to improve the running accuracy of angular contact ball bearings

The precision of angular contact ball bearings seems to be not too high, is there any way to improve it? Rolling bearing precision can be improved, the following are the four major methods commonly used in rolling bearings to improve bearing precision.

1, the number of rolling load generated in the excitation, when a load-bearing radial load, the amount of rolling of its load will be slightly changed in operation, where: 2-3-2-3 .... This causes a shift in the direction of the load. The resulting vibration is unavoidable, but can be pre-loaded to reduce the axial loading of all rolling bodies.

2, local damage

In operation, rolling across a damaged bearing component will generate a specific vibration frequency. Frequency analysis can identify the damaged bearing components. This principle has been used in condition monitoring equipment to detect bearing damage. Temperatures can rise sharply and abnormally high temperatures can occur. Causes such as excessive lubricant, small bearing clearance, poor mounting, excessive friction in seals, etc. The occasion of high speed rotation, bearing structure, the wrong choice of lubrication method, etc. are also its causes.

3, the accuracy of the relevant parts

The relationship between the shaft and the bearing, close contact with the bearing collar can be compatible with the shape deformation of the neighboring parts. In the operation if there is distortion may produce vibration. Therefore, the tolerance of the bearing and shaft processing requirements is very important.

4, Contaminants

If you operate in a polluted environment, impurities may enter the rolling of the bearing. Vibration depends on the number, size and composition of rolling impurity particles, although the frequency does not produce the typical form, the cause of poor lubrication, poor shaft or bearing seat accuracy, bearing damage, foreign body intrusion, etc., but you can hear an annoying noise.

Measure the size of the shaft and bearing housing hole to determine the fit accuracy of the bearing, with the following requirements: inner ring and shaft to take interference fit, interference amount 0 ~ +4μm (in light load, high precision for 0); outer ring and bearing housing hole to take clearance fit, clearance amount 0 ~ +6μm (but in the free end of the bearing using angular contact ball bearings, but also to increase the clearance); shaft and housing hole surface roundness error in 2μm or less The parallelism of the end face of the spacer used in the bearing is below 2μm, the runout of the inner end face of the shaft shoulder to the outer end face is below 2μm; the runout of the bearing housing shoulder to the axis is below 4μm; the runout of the inner end face of the spindle front cover to the axis is below 4μm.

Fixed end of the front bearing in the shaft installation: the bearing with clean cleaning kerosene for thorough cleaning, for grease lubrication, first containing 3% to 5% grease organic solvent injected into the bearing for degreasing cleaning, and then use the oil gun to fill the quantitative grease into the bearing (accounting for 10% to 15% of the bearing space volume); heating the bearing to warm up 20 ~ 30 ℃, with oil press will be installed into the shaft end of the angular contact ball bearing; will be Fastening sleeve pressed on the shaft and with suitable pressure against the bearing end face to make its axial positioning; spring scale tape rolled on the outer ring of the bearing, with the method of measuring the starting torque to verify whether the specified preload has a substantial change (even if the bearing is correct, but because of the fit or cage deformation, the preload may also change).