To eliminate the axial movement of the RX121-37KW reducer, the core is to start from the three dimensions of 'positioning, tightening, and compensation' and take corresponding measures to target the root causes of the movement (such as bearing failure, loose positioning parts, and excessive clearance).
1. Repair or replace core positioning components (the most direct and effective)
The main cause of axial movement is the failure of positioning components such as bearings, shaft shoulders, thrust rings, etc. Prioritize inspection and replacement of these wearing parts.
Bearing-related repairs : If the movement is caused by excessive bearing clearance or damage to the thrust bearing, it is necessary to replace the same type of high-precision bearing (it is recommended to choose P6 and above precision). During installation, ensure that the matching clearances between the inner ring of the bearing and the shaft, and the outer ring and the box meet the design requirements (usually H7/js6 fit).
Adjustment of the shaft shoulder and positioning ring : If the shaft shoulder is worn or the positioning ring is loose, the shoulder can be repaired and re-welded and reprocessed to standard size, or a new positioning ring can be replaced to ensure that it can firmly hold the inner ring of the bearing and limit the axial movement of the shaft.
Lock nut reinforcement : If the lock nut at the end of the gear shaft is loose, you need to disassemble the nut first, clean the oil stains and wear marks on the threads, and then use a torque wrench to retighten according to the design torque (usually 200-300N·m, refer to the equipment manual for details). If necessary, install a lock washer or apply thread locking glue.
2. Optimize the axial clearance compensation structure (for design or long-term wear)
If the axial clearance accumulates in the reducer due to long-term operation, the clearance can be eliminated by installing or adjusting compensation parts.
Install adjustment shims : Install copper or steel heat-shrinkable shims of different thicknesses (thickness accuracy must reach 0.01mm) between the bearing end cover and the box according to the actual movement amount. Control the axial gap within the range of 0.05-0.1mm by increasing or decreasing the number of shims.
Use double-row angular contact ball bearings : If the original reducer uses deep groove ball bearings (which can only bear radial loads), they can be replaced with double-row angular contact ball bearings, which can bear both radial and axial loads, and can eliminate axial clearance and improve shaft stability by adjusting the preload of the bearing inner ring.
Add a thrust bearing assembly : For scenarios with large axial loads, an additional set of thrust bearings (such as thrust ball bearings or thrust roller bearings) can be installed on the non-stressed end of the gear shaft to specifically bear the axial force and fundamentally limit the movement of the shaft.
