Can the Bearing be Repaired after Damage?

After the bearing is damaged, not all parts can be repaired. Only those bearing damage with maintenance value need to be repaired. The damaged bearing sleeves should be inspected and identified. If it has approached or reached the expected useful life, there is no need to repair it. In addition, it is necessary to judge whether the repair conditions are met, such as understanding the performance and manufacturing requirements of the bearing structure, the various tools, equipment, measurement and mastery of repair technology required for repair. In addition, it is necessary to analyze whether the repair cost and the bearing performance after repair can meet the requirements of the main engine. If some bearing spare parts are not well prepared or difficult to purchase due to cost and procurement conditions, and it is difficult to replace bearings in time in case of failure, repairs need to be considered. For some bearings with repair value, such as rolling mill bearings, the price is generally high. After use, it is damaged. After professional testing and processing, the bearings can continue to be used normally. This is a common "repair and use" method for large and extra-large bearings, including mill bearings.

The judgment on whether the bearing is available is mainly determined by considering the degree of bearing damage, mechanical performance, importance, operation conditions, and the period until the next maintenance. Parts with the following defects are of no repair value and can no longer be used. These bearings should generally be scrapped and new bearings must be replaced.

1. Any one of the rings, rolling bodies and veils is broken.

2. Bearing edge block drops, and there are significant jams on the rolling road surface, edge block and rolling body.

3. The keptension wears significantly or the rivets are obviously loose.

4. The bearing raceway is peeled off, and there is serious rust on the raceway surface and rolling body.

5. There are serious indentations and marks on the raceway surface and rolling body.

6. There is obvious creep in the inner radial or outer radial.

7. The discoloration caused by heat is obvious.

8. Bearings sealed with grease are obviously damaged by sealing rings or dust cover.

The price of some large bearings is generally higher. For bearings damaged in use but with repair value, the bearings continue to be used normally through professional testing and processing. This is a common "repair use" method for large and extra-large bearings, including mill bearings. In summary, there are two main types of bearing repair methods, one is the selection method of old parts, and the other is the processing method.

The selection method of old parts is the easiest way to repair bearings. It is to collect a batch of scrap bearings of the same model. After disassembly, cleaning, testing and identification, the size group the sleeves and rolling bodies that are slightly worn and can continue to be used without grinding and repair, or replace some new rolling bodies. And reassemble the cage to restore the bearing to its standard clearance and assembly height.

Machining method is to use different processing processes to process damaged rings and rolling bodies, change or restore the original size, and then select them, or make a batch of rings and rolling bodies, which are selected together with available old rings and rolling bodies or repaired rings and rolling bodies.

The processing and repair of sleeve rings generally include:

1. Sleeve welding method - that is, using electric welding or oxygen welding to weld the falling block, restore it to its original shape.

2. Restructuring method of sleeve rings -- that is, choose old bearing inner rings with larger inner diameter and diameter series. Modification and repair to meet the accuracy requirements of the original ring.

3. Sleeve preparation method - that is, according to the wear amount of the outer ring raceway and rolling body of the bearing, the preparation. A new inner ring that increases the diameter of the raceway is assembled and used with the original outer ring and rolling body.

The repair method of rolling body is generally as follows: for rolling bodies with light wear, the steel ball can be polished with buckets, and the roller can be polished with a heartless grinder, for rolling bodies with serious wear, the steel ball can be polished with a finishing machine, and the roller can be polished with a roller grinder.

The author of this article is Shaanxi Gainhui Heavy Industries Co., Ltd., which is a professional bearing manufacturer and distributor in China. The company supplies many types of the bearings, such as INA roller bearings, NTN roller bearings, etc. With high quality and competitive bearing products, we sincerely provide services to customers all over the world.

Contact us for more details:

E-mail: emily@gainhui.com

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