1. The piston pump or motor noise

(1) the phenomenon is caused by hydraulic pump suction empty high noise is one of the main reasons why. When the oil mix after air, easy in its high cavitation is formed, and with pressure wave form of communication, cause the oil oscillation, cause the system produce cavitation noise.

(2) the hydraulic pump the internal components excessive wear, such as piston pump cylinder and assignment dish, piston and piston hole and cooperate with pieces of wear, strain, make the hydraulic pump internal leakage serious, when output high pressure, small hydraulic pump the oil flow will generate traffic pulse, cause higher noise. This time can be appropriately increased system variables of the institutions PianJiao guide to improve internal leakage to pump the influence of output flow. The servo valve pump valve disc, control the flow of the piston in local wear, strain, driving the piston moves in the process of pulse, cause hydraulic pump output flow and pressure fluctuations, thus in the pump discharge produce larger vibration and noise. At this point, to wear the strain of the components are serious, brush plating inquiry with or replace processing.

(3) the hydraulic pump assignment dish is also easy cause the important components of noise. Assignment in use by the surface plate of wear or sludge deposition in the unloading slot open place, can make unloading slot short and change the unloading location, produce trapped oil phenomenon, leading to higher noise. In normal repair match means process, the PingMo repair match flow dish also can appear unloading slot short consequences, if it does not at this time the slender appropriate, will also have great noise. In the assembly process, with the big flow plate unloading slot must install on pump high-pressure chamber, and the direction of the cylinder block and pointed to spin must be relative, or it will bring greater noise to the system.

2. The noise of the relief valve

Relief valve easy generation of high frequency noise, mainly is the pilot valve performance instability is caused by pilot valve for high frequency oscillation cavity pressure before cause air of the noise and vibration. The main reasons are:

(1) the oil mix air in a pilot valve inside the cavity before forming cavitation and cause high-frequency noise. At this time, should be timely row do and to prevent the air outside air to enter.

(2) needle valve in use process for frequent opens and excessive wear, make needle valve cone and seat can't closed, cause leading flow instability, produce pressure fluctuations and cause noise, at this time, should timely repair or replacement.

(3) pilot valve for spring fatigue cause its pressure regulating function not deformation stability, make pressure fluctuations caused a big noise, at this time, should replace the spring.

3. Hydraulic cylinder of noise

(1) in the oil mixed with air or hydraulic cylinder is not completely row of air, as in the high pressure the influence of cavitation noise and causes larger. At this time, all shall be promptly row air.

(2) of cylinder head oil seal too close or piston rod bending, in athletic process because don't strength and noise. At this time, must be replaced oil seal or straightening the piston rod.