What are the universal matching requirements for angular contact ball bearings, and how to improve matching accuracy?

Currently, the commonly used matched bearings for machine tool spindles are angular contact ball bearings. Usually, complete sets of matched bearings are used. In some cases, non-complete sets of angular contact ball bearings may be used for universal matching. However, universal matching faces inconsistent accuracy. , inconsistent ruler time, inconsistent angle, etc., what are the universal matching requirements for angular contact ball bearings? And how to improve the matching accuracy? The following editor has compiled relevant content for you, hoping to be helpful to you.

What are the universal matching requirements for angular contact ball bearings?

When pairing angular contact ball bearings, in addition to relying on high-precision equipment during the production process to directly ensure the mutual differences in the inner and outer diameter groove dimensions, groove curvature, and groove position, the contact angle, the mutual difference in the inner and outer diameter dimensions, and the protrusion amount must also be ensured. Wait for the request.

1. Contact angle

The contact angle of universal matched angular contact ball bearings directly affects the stress state of the bearing under working conditions. The contact angle difference between two matched sets of bearings should be as small as possible. Generally, the contact angle difference between precision and ultra-precision matched bearings is About 1°. When selecting, the contact angle is controlled by controlling the radial clearance according to the relationship between the radial clearance and the contact angle.

cosβ= 1-Y/2 (Re+ Ri-2Rw)

In the formula:

β – contact angle

Y – radial clearance

Re – outer ring groove curvature radius

Ri – inner ring groove curvature radius

Rw – steel ball radius

As can be seen from the above formula, the difference in curvature radius of the inner and outer ring grooves can be effectively controlled during processing. Using the same set of steel balls for assembly can reduce the impact on the contact angle. Controlling the contact angle by fine-tuning the radial clearance can improve the angular contact Universal matching accuracy of ball bearings.

2. The inner and outer diameters are different from each other.

When two angular contact ball bearings are universally matched, in addition to meeting tolerance requirements during the processing process, the inner and outer diameter dimensions should be minimized to minimize the dispersion difference. A high-precision internal cylindrical grinder and an outer diameter lapping machine are used to control the inner and outer diameter dimensions. Differentiate each other to increase the success rate of matching.

3. Output

The so-called protrusion refers to the distance by which the end face of the inner ring protrudes from the end face of the outer ring at the same end face of the bearing after the angular contact ball bearing is subjected to a certain axial preload.

The key to the successful universal pairing of two angular contact ball bearings lies in whether the protrusions of the two sets of bearings match under a certain axial load, because only two sets of bearings with matching protrusions can obtain the same preload force , and work normally under the action of preload. From a certain perspective, universal matched angular contact ball bearings are actually selected with appropriate protrusion amount and assembled within the range of +1μm. At present, the measured protrusion amount of 60% to 70% of the bearings can meet the needs of universal matching without grinding, while 30% to 40% of the bearings require the measured protrusion to be processed on a high-precision grinder. Sharpened to meet universal matching requirements.

Regarding the universal matching requirements for angular contact ball bearings, the above is all the content compiled by the editor. I hope it can be helpful to everyone. Our company focuses on the R&D, design and production of various precision bearings. In addition to providing various complete sets of matched angular contact ball bearings, we can also provide various types of matched pairs. A single set of angular contact ball bearings is used. If necessary, please write to us for consultation.