The accuracy of angular contact ball bearings does not seem very high. Is there any way to improve it? The accuracy of rolling bearings can be improved. The following are four common methods to improve the accuracy of rolling bearings.

1. The number of rolling loads generated during excitation, when a bearing radial load is applied, the rolling amount carried by it will change slightly during operation, including 2-3-2-3.... This causes the deviation of the load direction. The resulting vibration is unavoidable, but can be preloaded to reduce axial loading of all rolling elements.

2. Local damage

During operation, rolling across a damaged bearing component produces a specific vibration frequency. Frequency analysis can identify damaged bearing components. This principle has been applied to condition monitoring equipment to detect bearing damage. The temperature will rise sharply, resulting in abnormal high temperature. The causes include too much lubricant, too small bearing clearance, poor installation, excessive friction of sealing device, etc. In the case of high-speed rotation, the wrong choice of bearing structure and lubrication mode is also the reason.

3. Accuracy of relevant parts

The relationship between the shaft and the bearing is compatible with the shape deformation of adjacent parts when it is in close contact with the bearing ring. Distortion during operation may cause vibration. Therefore, the tolerance required for the processing of bearings and shafts is very important.

4. Pollutants

If you operate in a polluted environment, impurities may enter the rolling of the bearing. The vibration depends on the quantity, scale and composition of rolling impurities. Although the frequency does not produce a typical form, it is caused by poor lubrication, poor accuracy of shaft or bearing seat, bearing damage, foreign matter intrusion, etc., you can hear an annoying noise.

Measure the size of the shaft and bearing seat hole to determine the fitting accuracy of the bearing. The fitting requirements are as follows: the inner race and the shaft adopt an interference fit with an interference amount of 0~+4 μ M (0 for light load and high precision); Clearance fit is adopted between outer ring and bearing seat hole, with clearance of 0~+6 μ M (but when angular contact ball bearings are used for bearings at free ends); The roundness error between shaft and seating hole surface is 2 μ Below m, the parallelism of the end face of the spacer used for the bearing is 2 μ Below m, the runout of the inner end face of the shaft shoulder and the outer end face is 2 μ M below; The runout of the bearing seat hole shoulder to the axis is 4 μ M below; The runout of the inner end of the spindle front cover to the axis is 4 μ M below.

Installation of the front bearing at the fixed end on the shaft: clean the bearing with clean cleaning kerosene. For grease lubrication, inject organic solvent containing 3%~5% grease into the bearing for degreasing cleaning, and then fill the bearing with quantitative grease with an oil gun (accounting for 10%~15% of the bearing space volume); Heat the bearing to make the temperature rise 20~30 ℃, and install the angular contact ball bearing into the shaft end with an oil press; Press the locking sleeve on the shaft and press it against the end face of the bearing with appropriate pressure to make it axial positioning; Wrap the tape of the spring scale on the outer ring of the bearing, and check whether the specified preload changes significantly by measuring the starting torque (even if the bearing is correct, the preload may also change due to the deformation of the fit or cage).