The noise of hydraulic transmission system is caused by the closed circuit composed of motor, hydraulic pump, valve auxiliary device and hydraulic pipe. Because in this closed loop system, the hydraulic oil working state produced fluid flow and pressure pulsation noise due to the impact of turbulence and vortex cavitation, and to support basic parts and mechanical noise caused by vibration, the formation of.

Noise sources of hydraulic transmission system and their influencing factors

Generally speaking, the noise of hydraulic transmission system includes liquid dynamic noise, mechanical vibration noise, pipeline resonance noise, and resonance noise caused by vibration and noise.

The motor of the motor is the power source, and the noise of the motor is the main factor of the mechanical noise.

Motor noise of oil pump

The noise is the main source of aerodynamic noise by the cooling fan, rotor unbalance operation, electromagnetic vibration, commutator, commutator and various parts (such as casing, end cover) noise caused by vibration.

Noise of hydraulic pump and hydraulic motor:

Mechanical noise. Because the hydraulic pump and hydraulic motor working process, periodic sharp change of each working chamber pressure cycles and pressure oil chamber shell parts produced from touching quasi Jin Road Noise mountain in the insufficient fuel hole produced, cavitation phenomenon, caused by the intense vibration, the vibration force is a gear pump without rules in the gear noise increases with the load speed of tooth surface roughness increases, a great relationship with the viscosity of gear machining.

Fluid noise. Hydraulic pump and hydraulic motor in the work process, will produce energy pulses in different degrees, the ripple resistance is transformed into pressure pulsation, resulting in forced vibration of container. The liquid noise has a wide frequency spectrum, and the pulsation frequency is proportional to the flow pulsation times per unit time. In addition, the high frequency noise of hydraulic pump and hydraulic motor is caused by eddy current, cavitation or impact in the course of work. It has no regularity and less intensity.

Hydraulic valve noise:

The hydraulic valve of all kinds of bodies is a moving body, and many valve cores depend on the function of spring when they are working, so it is easy to produce vibration, so as to produce mechanical noise. According to these different functions in the system, the mechanical vibration generated is not the same, the impact of the sound when the valve is instantaneous; high frequency vibration when leaking oil overflow valve spool is continuous, if damping frequency interference rate just as a meal condition, it will cause resonance, increase noise. Resonance caused by high-frequency noise, the frequency range of 1-8kHz, the sound pressure level is above 90dB, with a significant peak.