Maintenance Methods for the B3SH Series Industrial Gearbox

1、 Fault diagnosis before maintenance

Preliminary shutdown investigation: Shutdown and cool down to below 40 ℃, clean the surface oil stains, check for external abnormalities such as cracks in the box, loose bolts, and oil leakage points, and synchronously retrieve the equipment's operating time and historical overload records.

Accurately locate the fault point: Identify the characteristic fault frequency of gears and bearings through vibration spectrum analysis, combined with oil detection to determine the content of metal abrasive particles. If necessary, use magnetic particle/ultrasonic testing to check for hidden cracks in tooth roots and shaft necks.

2、 Targeted maintenance for common faults

1. Maintenance of abnormal vibration faults

Minor tooth surface wear: Perform micrometer level gear shaping, correct tooth load distribution, and recalibrate gear coaxiality and parallelism to ≤ 0.03mm/m.

Bearing failure: Replace the same type of heavy-duty bearing directly, control the axial displacement of the bearing within the qualified range of 0.01~0.03mm according to the specifications, and recalibrate the preload force.

Gear tooth breakage/severe eccentricity: Immediately stop the machine for disassembly, replace the damaged gear, investigate the torque impact source at the input and output ends, and avoid overloading and fracture of the new gear again.

2. Oil leakage fault repair

Oil leakage on the joint surface of the box: Remove the bolts in diagonal order, replace the oil resistant fluororubber gasket, apply a thin layer of Loctite 518 sealant on both sides, and tighten the bolts in three times according to the standard torque.

Shaft end seal oil leakage: Replace the worn oil seal. If the shaft neck has worn grooves, use laser cladding to repair the surface of the shaft neck to ensure that the oil seal lip fits without gaps.

Breather/oil level gauge oil leakage: Clean the clogged respirator, replace the aging and deformed O-ring, control the oil level at the middle of the upper and lower limits of the oil gauge, and avoid excessive oil replenishment.

3. Maintenance of lubrication system faults

Oil contamination/emulsification: Immediately drain the old oil, clean the sediment and impurities at the bottom of the oil tank with a silk cloth (cotton yarn is prohibited to prevent fiber residue), and replace with the same model of ISO VG 320/460 industrial gear oil.

Oil pump/pipeline malfunction: Disassemble and clean the lubrication pipeline, replace the clogged filter element, calibrate the oil pump outlet pressure to stabilize at 0.1~0.3MPa, and ensure that the fuel injector is accurately aligned with the gear meshing area for oil supply.

3、 Core Operating Standards for Major Maintenance

When any of the following situations occur, a major overhaul of the entire machine must be arranged: gear damage area exceeding 30% of the tooth surface, effective vibration velocity continuously exceeding 4.5mm/s, lubricating oil temperature exceeding 90 ℃ for a long time, and deformation cracks appearing in the box body.

1. Completely disassemble all components in the specified order and thoroughly clean oil stains and metal debris with specialized cleaning agents.

2. Repair the damaged and deformed parts of the bearing seat hole by boring and inserting sleeves, and replace all failed bearings and seals.

3. Re calibrate the gear meshing backlash and contact spots to ensure that the contact area is ≥ 40% along the tooth height and ≥ 70% along the tooth length.

4. After completing the assembly, conduct a 2-hour air load test run to confirm that the vibration, temperature, and oil pressure are all normal, and then gradually load to the rated working condition.