How to repair or replace the core components of the ZLY560-12.5-III hard tooth surface gear reducer after it is damaged

For damaged repair or replacement of core components (such as gears, bearings, shafts, etc.) of the ZLY560-12.5-III hardened gear reducer, a plan needs to be formulated based on the damage type and working condition requirements. The specific process is as follows:

‌1. Gear damage assessment‌

• ‌Broken teeth/chipped corners‌ : Visually inspect the fracture shape (brittle fractures are crystalline, fatigue fractures have ridge lines), magnetic particle inspection to detect tooth surface cracks, and ultrasonic inspection to check for internal defects.

• ‌Wear /pitting‌ : Measure the amount of tooth thickness reduction (>5% needs to be replaced), check the contact marks on the tooth surface (unilateral meshing indicates axis misalignment)‌.

2. Bearing fault judgment‌

• Detect the clearance (rolling bearings >0.03mm need to be replaced), auscultate abnormal sounds (high-frequency sharp sounds indicate raceway damage), and check the integrity of the cage.

3.Shafting problem

• If the straightness deviation is >0.05mm/m, it needs to be straightened. If the journal wear exceeds 0.02mm, it can be repaired by chrome plating. If the keyway is worn, it can be re-milled.

2. Repair or replacement plan

(1) Gear processing

1. ‌Mild damage repair‌ (chip ≤10% tooth surface)

• Repair welding process: Use J507 electrode, preheat at 150~200℃, grind the tooth shape after welding (error ≤ 0.05mm), and restore hardness by surface quenching (deviation ≤ ±20HBW).

• Applicable conditions: non-critical transmission, low speed and light load conditions.

• ‌Serious damage replacement‌

• Spare parts requirements: Purchase according to original parameters (module, pressure angle, number of teeth, accuracy level), with priority given to original manufacturers or ISO 9001 certified suppliers.

• Assembly points: Adjust the tooth clearance (axial clearance ≤ 0.1mm) to ensure that the meshing contact area is ≥ 60% of the tooth width‌.

(2) Bearing and shaft maintenance

1. ‌Bearing replacement‌

• Use the same type of bearings and heat them to 80~100℃ during installation to avoid knocking.

• ‌Shaft Repair‌

• Journal wear: chrome plating or coating repair, the matching dimensions must meet the roughness requirements of the drawing.

• Keyway wear: Re-insert the keyway, and the fit tolerance is in accordance with H9/h8 standards.

3. Assembly and debugging

1. ‌Assembly process‌

• Install the shafts in sequence (passive shaft → three-axis → two-axis → high-speed shaft), apply sealant to prevent oil leakage, and tighten the tapered pins and bolts.

• Lubrication requirements: Add N120# industrial gear oil to the center line of the oil mark, and clean the impurities in the oil circuit.

• ‌Test Standard‌

• No-load operation: no abnormal sound, vibration (amplitude ≤ 0.05mm), temperature rise (bearing temperature ≤ 40°C).

• Load test: output torque fluctuation ≤±5%, efficiency ≥98%‌.