The output pressure of the pump is determined by the load and is approximately proportional to the input torque. Abnormal output pressure has two kinds of faults.
(1) the output pressure is too low
When the pump in the self-priming state, if the oil pipeline leakage or the system in the hydraulic cylinder, one-way valve, reversing valve and other large leakage, the pressure will not rise up. This needs to find the leak, tighten, replace the seal, can increase the pressure. Overflow valve fault or low adjustment pressure, system pressure is not up, should be re-adjusted pressure or overhaul the overflow valve. If the hydraulic pump cylinder and the valve plate deviation resulting in a large number of leakage, serious, the cylinder may be broken, should be re-grinding mating surface or replace the hydraulic pump.
(2) the output pressure is too high
If the loop load continues to rise, the pump pressure also continues to rise, should be normal. If the load is constant and the pressure of the pump exceeds the pressure value required by the load, the hydraulic components other than the pump should be checked, such as direction valve, pressure valve, transmission device and return oil pipeline. If the large pressure is too high, should adjust the overflow valve.
Vibration and noise
Vibration and noise occur simultaneously. They not only do harm to the operators of the machines, but also pollute the environment.
(1) mechanical vibration and noise
If the pump shaft and motor shaft are different centers or dead, rotating shaft bearing, coupling damage, elastic pad damage and loose assembly bolts will produce noise. For pumps running at high speed or transmitting large amounts of energy, check periodically to record the amplitude, frequency and noise of each component. If the rotation frequency of the pump and the natural frequency of the pressure valve at the same time, will cause resonance, can change the speed of the pump to eliminate resonance.
(2) noise generated by liquid flow in the pipe
If the oil inlet pipe is too thin, the flow capacity of the oil inlet filter is too small or blocked, the air in the oil inlet pipe is inhaled, the oil gap is too high, the oil surface is too low and the oil absorption is insufficient, and the liquid strike occurs in the high-pressure pipe, etc. Therefore, the correct design of the tank, the correct selection of filters, tubing and direction valves.
