Rotan gear pump fault analysis and troubleshooting

DESMI ROTAN Gear Pump Troubleshooting and Troubleshooting

1. Oil Seal Wear and Aging

The rubber oil seal on the unloading plate ages and deteriorates, losing its elasticity and losing its sealing and isolation function

 between the high-pressure and low-pressure oil chambers. This causes oil pressure from the high-pressure chamber to flow into 

the low-pressure chamber, known as "internal leakage," which reduces the operating pressure and flow rate of the oil pump. The

 CB46 gear pump has a normal operating pressure of 100-110 kg/cm² and a normal oil flow rate of 46 L/min. The standard 

unloading plate rubber oil seal is 57×43. The self-locking oil seal is a PG25×42×10 skeleton-type oil seal. Damage or aging 

can cause air to be drawn into the oil pump through the gap between the oil seal and the main shaft journal or through the

 junction between the oil inlet plate and the pump housing. This air enters the oil tank through the return line, generating 

a large number of bubbles in the tank. This will cause the oil in the fuel tank to decrease and the oil in the engine oil sump 

to increase, making the implement lift slowly or impossible. This fault must be corrected by replacing the oil seal.

2. Wear of Internal Pump Components

Wear of internal pump components can cause internal leakage. The area between the floating sleeve and the

 gear end face is the largest, making it the primary source of internal leakage. This area accounts for approximately

 50% to 70% of all internal leakage. A worn and leaking gear pump reduces its volumetric efficiency, resulting in 

significantly lower output power than input power. All of this loss is converted into heat, causing the pump to 

overheat. If the mating surfaces are tightened, the floating sleeve will experience slight movement during operation, 

causing wear. This can result in slow or ineffective lifting of the implement. Such floating sleeves must be replaced or repaired.

3. Wear of the Oil Pump Housing

This primarily involves wear of the floating sleeve bore (the normal clearance between the gear shaft and sleeve is 0.09

 to 0.175 mm, with a maximum limit of 0.20 mm). The gears are subjected to the pressure of oil, and the gear tips approach

 the pump housing, causing wear on the low-pressure chamber. Another type of wear is circular wear on the working surface

 within the housing. This wear is primarily caused by impure oil addition, so only impurity-free oil must be added.

DESMI ROTAN Gear Pumps