1. The oil level of the oil tank is shallow, the oil inlet of the oil pump sucks air, and the bearing in the oil pump is damaged;
2. The suction port is small, blocked, and the spring force of the proportional valve is not adjusted;
3. The coupling connecting the motor and the oil pump is damaged, the motor is noisy, the viscosity of the hydraulic oil is high, and the oil temperature is too high, which changes the viscosity of the hydraulic oil.
How to solve these problems?
1. Remove the filter screen of the oil inlet of the oil pump and clean it; check the place where the air is sucked in, and reseal it; replace the bearing.
2. Increase the hydraulic oil so that the filter screen of the oil inlet of the oil pump is immersed in not less than 100mm of the oil surface; replace the spring.
3. Replace the hydraulic oil and repair the motor; add cooling water circulation to reduce the oil temperature.