To repair the uneven wear of ZD gear reducer gears, you need to follow the process of 'first diagnose the root cause - then repair according to the situation - and then prevent recurrence'. The specific steps are as follows:
1. Accurately locate the source of wear
(1) Stop the machine and cut off the power, disassemble the reducer end cover and bearing end cover, take out the gear set, and check the worn parts: common uneven wear locations are one side of the gear tooth surface, tooth top or tooth root.
(2) Check the core causes: ① Installation deviation, the coaxiality of the input shaft and the output shaft is out of tolerance, or the connection with the motor and load is not concentric; ② Lubrication failure, inconsistent lubricating oil grade, insufficient oil volume, and oil contamination, leading to rupture of the lubricating film on the tooth surface; ③ Abnormal load, long-term unbalanced load, impact load or overload operation, causing uneven force on the gear; ④ Bearing damage, bearing clearance is too large or stuck, causing gear axis deviation; ⑤ Gear manufacturing defects, insufficient tooth profile accuracy, and uneven tooth surface hardness.
(3) Record the degree of wear: measure the tooth thickness reduction and tooth surface roughness to determine the wear level (slight wear: tooth surface smoothness decreases, no obvious pits; moderate wear: scratches and pitting on the tooth surface; severe wear: tooth surface peeling, tooth shape deformation).
2. Repair according to the degree of wear and tear
(1) Slight uneven wear (no tooth deformation)
① Cleaning: Use kerosene or special cleaning agent to clean the oil dirt and iron filings on the gear surface and the inner wall of the gear box to ensure that there are no residual impurities.
② Grinding: Use fine-grained oilstone or abrasive paste to manually grind the worn parts to eliminate tiny scratches on the tooth surface and restore the smoothness of the tooth surface; clean again after grinding to avoid residual abrasive particles.
③ Adjustment: Recalibrate the coaxiality of the input shaft, output shaft and coupling to ensure radial runout ≤ 0.05mm; replace damaged seals and bearings, and adjust bearing clearance to the standard range.
④ Oil change: Change the lubricating oil that meets the technical requirements of the ZD reducer (usually medium-load industrial gear oil). Add the oil amount to the middle of the oil mark line to avoid too much or too little.
(2) Moderate uneven wear (pitting and scratches on the tooth surface)
① Turning/grinding repair: If the gear material is 45 steel or quenched and tempered alloy steel, the gear can be clamped on a lathe, and the worn side tooth surface can be slightly turned to remove pitting and scratch layers; the tooth surface can then be finely ground with a gear grinding machine to ensure that the tooth profile accuracy and tooth direction accuracy meet the requirements of the drawing.
② Repair welding (partially severely worn parts): Use argon arc welding and use a welding rod that matches the gear base material to repair the local peeling and defective parts; after repair welding, annealing is required to eliminate the welding stress, and then turning and grinding are performed to restore the tooth shape size.
③ Assembly inspection: After the repaired gear is assembled, a no-load test run is required, and a dial indicator is used to detect the gear meshing clearance to ensure uniform meshing and no one-sided contact.
