How to repair the wear grooves on the journal surface of NRV075-35H8-60 reducer shaft

The repair method for the wear groove of the NRV075-35H8-60 reducer shaft neck is as follows:

1. First, disassemble and clean the worn parts of the shaft neck, including oil stains, rust, grooves, and burrs. Measure the depth and width of the wear to determine if it can be repaired.

2. Slight wear (shallow grooves, depth<0.5mm): Polish the shaft neck with fine sandpaper and oilstone to eliminate sharp grooves, ensure the roundness and roughness of the shaft neck, and use it with a new oil seal.

3. Moderate wear (obvious grooves but not out of roundness): Use electric brush plating, cold spraying, or polymer repair coating to repair the journal, restore the standard size, and after curing, polish to the original tolerance to ensure a tight fit with the oil seal.

4. Severe wear and tear (deep grooves, out of roundness of shaft neck, steps): Remove the worn section from the upper bed by precision machining, reduce the diameter, and then weld a repair sleeve, or directly replace the shaft with a new one to ensure that the shaft neck size, coaxiality, and surface hardness meet the standards.

5. After repair, it is necessary to ensure that the surface roughness Ra of the shaft neck is ≤ 0.8 μ m, without scratches, grooves, or deflection, to avoid further abrasion of the oil seal.

6. Replace the oil seal with a new one, apply lubricating grease to the lip of the oil seal, install it correctly, prevent tilting or flanging, and ensure that the sealing preload is moderate.

7. Check the clearance between the bearing positions, and ensure that the inner ring of the bearing and the shaft neck are not loose to prevent further wear of the shaft neck due to movement or jumping.

8. After assembly, if there is no jamming or uneven wear during manual turning, and there is no leakage or abnormal temperature rise during no-load operation, the repair is considered qualified.