Gear pump failure analysis and troubleshooting: 1, oil seal wear, plastic sealing aging. Unloading sheet rubber seal aging deterioration, loss of elasticity, the high pressure oil chamber and the low pressure oil chamber lost seal isolation, will produce high pressure oil chamber oil Pressure to the low-pressure oil chamber, known as "internal leakage", which reduces the working pressure and flow of the pump. CB46 gear pump its normal working pressure of 100 ~ 110kg / cm2, the normal oil volume is 46L / min, the standard unloading sheet rubber seal is 57 × 43. Since the tight seal is PG25 × 42 × 10 of the skeleton oil seal, its damage or long-term failure, the air from the seal and the journal of the gap between the shaft or from the inlet plate and the oil pump housing junction is sucked into the pump, The return pipe into the tank, a large number of bubbles in the tank. Will cause the tank of oil to reduce the engine oil tank in the phenomenon of increased oil, so that agricultural tools to enhance slow or can not be improved. You must replace the oil seal to eliminate this fault. 2, the wear of the pump housing is mainly the wear of the floating sleeve hole (gear shaft and sleeve of the normal gap is 0.09 ~ 0.175mm, the maximum shall not exceed 0.20mm). Gear work by the role of pressure oil, the gear tip close to the pump housing, wear low pressure chamber part of the pump. Another kind of wear is the circumferential wear of the working surface in the shell. This wear is mainly caused by the net oil added, so the oil without impurities must be added. 3, gear pump internal parts wear pump internal parts wear will cause internal leakage. Among them, the leakage area between the floating bushing and the gear end face is large, which is the main part of the internal leakage. This part of leakage accounted for 50% of the total internal leakage of about 70%. The wear and tear of the lost circulation gear pump volumetric efficiency decreased, pump output power is much lower than the input power. The loss of all the heat into the heat, it will cause the pump overheating. If the combination of flat compression, due to work floating sleeve will be a small amount of exercise caused by wear and tear, resulting in slow or can not enhance the farm tools, such a floating sleeve must be replaced or repaired. Gear pump is through a pair of parameters and structure of the same involute gear rolling mutual engagement, the tank of low pressure oil to work can be an important part of high pressure oil. Is the engine of mechanical energy into hydraulic power unit.