I. Core Common Faults and Repair Solutions
1. Leakage/Seal Failure Fault
Symptoms: Obvious liquid leakage at the pump body mating surface and shaft extension.
Causes: Aging and damage of the seal ring, wear of the pump shaft, foreign matter entering the bearing parts and damaging the sealing surface.
Repair Method: Disassemble the pump body and replace with a new seal ring of the same specification; grind and repair the worn pump shaft; thoroughly clean foreign matter from inside the pump chamber.
2. Abnormal Noise and Vibration Fault
Symptoms: Sharp abnormal noise during operation; excessive vibration amplitude of the entire machine.
Causes: Shaft... 1. Wear and tear, rough stator inner surface/wear in the transition zone, misalignment of pump and motor shafts, cavitation caused by air entering the oil.
Repair methods: Replace worn bearings, polish and repair worn stator surfaces, adjust pump and motor coaxiality to ≤0.05mm, check all joint seals to eliminate air inlet points.
3. Poor water/oil output, insufficient flow rate.
Symptoms: Output flow rate does not reach rated value, system pressure does not reach.
Causes: Clogged inlet/oil filter, excessively high oil viscosity, excessive oil suction height, individual blades sliding and stuck.
Repair methods: 1. Clean the inlet screen and remove clogged oil filters; replace with hydraulic oil of recommended viscosity or increase oil temperature; reduce oil suction height; disassemble and clean the rotor slots and adjust blade clearance.
4. Failure to start normally, no oil output, no pressure fault
Fault symptoms: The pump does not run after power is applied, or there is no medium output or system pressure after running.
Causes: Motor burnout, rotor jammed by foreign objects, motor reverse rotation, starting speed far below the nominal value.
Repair methods: Inspect the motor windings, replace the burnt-out motor, disassemble and clean foreign objects from the pump cavity, correct the motor rotation direction, and increase the operating speed to the nominal range.
5. Pressure Major Vibration Fault
Fault Symptoms: Frequent and significant fluctuations in system pressure, unable to stabilize at the set value.
Causes: Air leakage at the inlet connector; unstable performance of the hydraulic system relief valve.
Repair Methods: Tighten the inlet connector or seal the leak point with sealing tape; disassemble, repair, or replace the faulty relief valve.
II. Key Points for Daily Preventive Maintenance
1. Clean the pump body and inlet mesh promptly after each use and store in a cool, dry environment.
2. Regularly check the wear condition of the seals and bearings; replace them in advance to avoid sudden failures.
3. Control the oil cleanliness to below NAS 9; use ISO VG32 or ISO VG46 anti-wear hydraulic oil to avoid oil contamination causing blade jamming.
