SIBCO

The accuracy of angular contact ball bearings seems to be not very high. Is there any way to improve it? The accuracy of rolling bearings can be improved, and the following are the four commonly used methods to improve the accuracy of rolling bearings.

1. In terms of the number of rolling loads generated by excitation, the rolling amount carried by a radial load will slightly change during operation, where: 2-3-2-3 This caused a deviation in the direction of the load. The resulting vibration is inevitable, but it can be preloaded to reduce axial loading on all rolling elements.

2. Local damage

During operation, rolling across damaged bearing components will generate specific vibration frequencies. 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 temperatures. The reasons for this include excessive lubricant, small bearing clearance, poor installation, and excessive friction in the sealing device. In situations of high-speed rotation, incorrect selection of bearing structure and lubrication method are also reasons for this.

3. Accuracy of relevant parts

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

4. Pollutants

If you operate in a polluted environment, impurities may enter the rolling of the bearings. The vibration depends on the number, scale, and composition of rolling impurity particles. Although the frequency does not produce a typical form, its causes include poor lubrication, poor accuracy of the shaft or bearing seat, bearing damage, foreign object intrusion, etc., but you can hear an annoying noise.

Measure the dimensions of the shaft and bearing seat holes to determine the fitting accuracy of the bearing. The fitting requirements are as follows: the inner ring and shaft adopt an interference fit, with an interference fit of 0 to+4 μ m (0 at light load and high precision); The outer ring and bearing seat hole adopt a clearance fit, with a clearance of 0~+6 μ m (but when using angular contact ball bearings on the free end bearings, the clearance can also be increased); The roundness error between the shaft and the seat hole surface is below 2 μ m, the parallelism of the end face of the spacer used in the bearing is below 2 μ m, and the runout of the inner end face of the shaft shoulder to the outer end face is below 2 μ m; The runout of the bearing seat hole shoulder to the axis is below 4 μ m; The runout of the inner end of the spindle front cover towards the axis is below 4 μ m.

Installation of fixed end front bearing on shaft: Thoroughly clean the bearing with clean cleaning kerosene. For grease lubrication, first inject an organic solvent containing 3% to 5% grease into the bearing for degreasing and cleaning, and then use an oil gun to fill a certain amount of grease into the bearing (accounting for 10% to 15% of the bearing space volume); Heat the bearing to raise the temperature by 20-30 ℃, and use a hydraulic press to install the angular contact ball bearing into the shaft end; Press the clamping sleeve onto the shaft and apply appropriate pressure to the bearing end face to position it axially; Roll the strap of the spring scale onto the outer ring of the bearing and use the method of measuring the starting torque to verify whether there is a significant change in the specified preload (even if the bearing is correct, the preload may also change due to deformation of the fitting or retaining frame).