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
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
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
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).
