ZL115-8 soft tooth surface reducer has loud noise. Can replacing the gear solve this problem

1、 Suitable for gear replacement scenarios

The noise characteristics are periodic "clicking" metal impact sounds, with significantly intensified abnormal noises during start stop and load, and a large amount of metal iron filings found during oil discharge.

Upon dismantling and inspection, it was found that the tooth surface had worn more than one-third, with extensive pitting and peeling, broken teeth, or root cracks. The hardness of the tooth surface of the soft tooth gear had significantly decreased, and the meshing clearance exceeded the standard severely.

The machining accuracy of gears is inherently insufficient, with large tooth profile errors and pitch deviations, resulting in persistent meshing impact that cannot be improved by conventional adjustments.

In such situations, it is necessary to replace the paired gear pair as a whole, not just a single gear, otherwise the meshing surfaces of the new and old gears will not match and abnormal noise will occur again; When replacing, it is necessary to synchronously check the status of the matching bearings to avoid the jumping of the old bearings damaging the meshing accuracy of the new gears.

2、 Common scenarios where there is no need to replace gears

Bearing failure: continuous buzzing and vibration accompanied by pitting corrosion and excessive clearance on the bearing raceway. The gear itself is intact, and only replacing the bearing and correcting the shaft runout can reduce noise.

Lubrication failure: sharp and high-frequency whistling, often due to oil shortage, oil emulsification/deterioration, or mismatched oil viscosity. After draining the old oil and cleaning the box, add the specified model of L-CKD series gear oil to eliminate the noise.

Installation and base issues: Loose anchor bolts and coupling coaxiality deviation exceeding 0.05mm can cause overall resonance. Tightening the bolts and using a laser alignment instrument to correct coaxiality can solve the problem without the need to move gears.

Foreign object intrusion: Residual iron filings and assembly debris in the body make irregular rolling impact sounds. Immediately stop the machine, clean the box, check the tooth surface for any damage, and restore it without replacing the gears.

Misalignment of meshing clearance: The gear itself is intact, but the side clearance exceeds the standard due to long-term bearing wear. By adjusting the bearing end cover gasket, the side clearance can be corrected to the standard range of 0.1~0.3mm, which can eliminate the impact noise.

3、 Key acceptance points after gear replacement

After the installation of the new gear, the tooth clearance must be adjusted to the design allowable range, ensuring that the tooth surface contact area is ≥ 70%, to avoid impact caused by excessive clearance and dry friction whistling caused by insufficient clearance; Monitor temperature rise and vibration during 1-hour no-load operation, confirm no abnormal noise before gradually loading to prevent early wear and noise rebound of new gears.