I. Small pump truck Noise from plunger pump or motor
(1) Suction phenomenon is one of the main causes of excessive noise in hydraulic pumps. When air is mixed into the oil, it is easy to form cavitation in its high pressure area and propagate in the form of pressure waves, causing the oil to oscillate and cause cavitation noise in the system. The main reasons are:
① The oil filter of the hydraulic pump of the small pump truck, the blockage of the oil inlet pipe, or the oil viscosity is too high, can cause the vacuum at the pump inlet to be too high, allowing air to penetrate.
② The small oil pump hydraulic pump and pilot pump shaft end oil seal is damaged, or the oil pipe is not well sealed, causing air to enter.
When high noise occurs in the concrete pump truck hydraulic pump, the above parts should be checked first, and problems should be dealt with in time.
(3) The hydraulic pump distribution plate of the small concrete pump truck is also one of the important components that are prone to cause noise. Due to surface wear or sludge deposits at the opening of the unloading tank during use, the distribution plate will shorten the unloading tank and change the unloading position, resulting in oil traps, which will cause higher noise. In the normal repairing process, the distribution plate repaired by flat grinding will also have the effect of shortening the unloading groove. At this time, if it is not properly lengthened in time, it will also generate a lot of noise. During the assembly process, the large unloading groove of the distribution plate must be installed in the high-pressure chamber of the pump, and its sharp angle must be opposite to the rotation direction of the cylinder, otherwise it will bring greater noise to the system.
Noise of the relief valve
The small pump truck relief valve is prone to high frequency noise, which is mainly caused by the unstable performance of the pilot valve, that is, the noise caused by the high frequency oscillation of the pressure in the front cavity of the pilot valve. The main reasons are:
Air is mixed in the oil, and cavitation is formed in the front cavity of the pilot valve, which causes high-frequency noise. At this time, exhaust air in time and prevent outside air from re-entering.
(2) The needle valve is frequently worn due to frequent opening during use, which makes the cone surface of the needle valve and the valve seat unable to closely contact with each other.
(3) The pilot valve’s pressure regulating function is unstable due to fatigue deformation of the spring, which causes large pressure fluctuations and causes noise. At this time, the spring should be replaced.
Third, the noise of small pump truck hydraulic cylinder
(1) Air is mixed in the oil or the air in the hydraulic cylinder is not completely exhausted, and cavitation occurs under the action of high pressure, which causes large noise. In this case, exhaust the air in time.
(2) The cylinder head oil seal is too tight or the piston rod is bent, and it will also generate noise due to other forces during the movement. In this case, you must replace the oil seal or straighten the piston rod in time.
Fourth, pipeline noise
Excessive bends in the sky pump pipe or loose fixing clips can also generate vibration and noise. Therefore, dead bends should be avoided as far as possible in the pipeline layout, and loosened clamps must be tightened in time.
Post time: Mar-26-2020