How to achieve control of the hydraulic system noise?

1. A piston pump or motor noise

(1) Air suction phenomenon is one of the main hydraulic pump noise is too high. When mixed with air in the fluid, easy formation of cavitation in its high-pressure zone, and the form of pressure wave propagation, resulting in fluid oscillation, causing the system to produce cavitation noise. The main reason:

① Pump oil filter, inlet pipe is clogged or the oil viscosity is too high can cause the pump oil into the mouth of the vacuum through the air infiltration.

② Hydraulic pump, the pilot shaft end oil seal damage, or inlet pipe seal bad, causing air to enter.

③ Oil tank level is too low, so that the hydraulic pump into the tubing to direct air suction.When higher noise in the hydraulic pump work, the above-mentioned parts of the examination, identify problems in time.

(2) Internal pump components, excessive wear, such as piston pump cylinder block and valve plate, piston and plunger holes, such as mating parts wear and tear, injury, a serious leak in the hydraulic pump, hydraulic pump output high voltage, small flow pulsation, the flow of oil will lead to higher noise. May be appropriate to increase the declination of the pilot system variables agencies, to improve the leakage of the pump output flow. Servo valve spool of the hydraulic pump, flow control piston will be due to local wear, strain, so that the piston during the move pulse, causing the hydraulic pump output flow and pressure fluctuations, which at the pump outlet greater vibration and noise . Wear and tear, the strain components of the plating spotting or replacement processing.

(3) One of the important components of the hydraulic pump valve plate is also easy to cause noise. The valve plate is in use due to surface wear or sludge deposited in the unloading slot open at will the unloading groove shorter and change the location of the unloading, resulting in the phenomenon of trapped oil, which led to higher noise. Level grinding to repair the valve plate in the normal repair process will be shorter unloading groove consequences, if not to timely appropriate slender, will also have a greater noise. During assembly, the valve plate unloading groove must be installed in the high-pressure chamber of the pump and the sharp corners of the direction of cylinder rotation to be relative, otherwise it will bring more noise.

2. Relief valve noise

The relief valve is easy to produce high-frequency noise, mainly to instability in the pilot valve performance, that is, the noise generated by vibrations in the air before the pilot valve chamber pressure caused by high frequency oscillation. The main reason:

(1) Oil mixed with air, in front of the pilot valve cavity to form cavitation caused by high frequency noise. At this point, should be promptly drained the air and to prevent outside air to re-enter.

(2) The needle valve during use due to frequent open excessive wear, so that the valve cone and valve seat can not close together, causing the pilot flow instability and pressure fluctuations caused by noise, should be promptly repaired or replaced.

(3) Of the pilot valve spring fatigue deformation caused by the instability of its regulator function, making the pressure fluctuations caused by noise, and you should replace the spring.

3 hydraulic cylinder noise

(1) Oil mixed with air or hydraulic cylinder, the air is not fully drained cavitation under high pressure caused by the larger noise. At this point, shall be promptly drained the air.

(2) Cylinder head oil seal too tight or piston rod bent in the course of the campaign will do fresh produce noise. At this point, shall promptly replace the seal or straightening the piston rod.

4. Piping noisePipe bending die too much or fixed clamp loose vibration and noise. Therefore, the piping layout should avoid bending die, the loosening of the clamp should be tighten.