What are the maintenance precautions for single-stage and multi-stage reducers

The core practices of lubrication, sealing, temperature/vibration monitoring, alignment, and fastening are consistent between the two; Due to the complexity of multi-level structure and oil pool stratification, more detailed stratification management and operational verification are needed in oil level control, oil injection sequence, temperature rise gradient, and leakage point investigation.
General maintenance points (applicable to both single level and multi-level)

Lubrication and oil management: Select oil according to working conditions and environment (ISO VG 150-1000, fully synthetic for extreme temperature zones); Change the oil for the first 1500-2000 hours, followed by 4000-8000 hours or annually thereafter; The oil level is at 2/3 of the window; Drain the oil while it is hot, clean the drain plug and respirator; Abnormal viscosity/moisture/metal shavings exceeding the standard should be dealt with immediately.

Temperature and heat dissipation: oil pool ≤ 90 ℃; The temperature rise of the bearing seat is controlled according to the insulation level; Fin dust accumulation>1 mm can reduce heat dissipation efficiency by about 35%, and blowing should be done quarterly.

Vibration and noise: Bearing position axial ≤ 4.5 mm/s, radial ≤ 7.1 mm/s; Abnormal whistling/impact/periodic abnormal noise indicates gear/bearing damage, immediately stop the machine for evaluation.

Sealing and Leakage: Inspect shaft seals, mating surfaces, end caps, and respirators; Replace the lip shaped oil seal in a timely manner if it hardens/cracks or if the joint surface is permanently deformed; A clogged respirator can cause an imbalance in internal and external pressure and oil leakage.

Alignment and fastening: Regularly tighten the anchor and end cap bolts to the specified torque; Poor alignment of couplings is one of the main causes of vibration and bearing failure.

Environment and safety: encrypted breathing apparatus and sealing inspection in dusty/humid/corrosive environments; Consider buffering/flywheel when starting and stopping frequently or when there is a large impact; Power off, hang out, lock before maintenance, and ensure complete protection against burns and PPE.

Additional considerations for multi-stage reducers (compared to single-stage reducers)

Layered oil injection and oil level management: First inject about 1/3 of the oil into the high-speed stage, turn or run at low speed for 30 minutes, and then replenish to the standard oil level to ensure the formation of oil film in each layer.

Temperature rise and gradient monitoring: Multi point infrared or thermal imaging, focusing on the temperature difference between the bearing seat and the stage; Prioritize checking for cooling and load matching in case of abnormal oil pool temperature.

The investigation of leakage points is more intensive: the focus is on shaft seals, multi-stage joint surfaces, end caps and respirators, oil cooler joints, etc; Breather blockage is more likely to cause layered oil leakage.

Stricter operational verification: When unloaded and stepped loaded to 25%/50%/75%/100% for 30 minutes each, the efficiency drop is ≤ 2% of the design value; The contact spots and modification requirements for multi-stage gear pairs are the same as those for single-stage gear pairs.