Vibration and noise caused by valve components
Impurities in the oil block the damping hole of the valve, the spring in the valve is fatigued or damaged, and too many impurities make the movement of the valve core inflexible, which will cause vibration and noise.
The spool is not well matched with the valve body or the surface is rough. If the fit gap is too loose, the internal leakage will be serious, resulting in noise and vibration; if the valve core is too tight, it will be difficult to move, resulting in vibration and noise. Therefore, it is necessary to master the appropriate clearance during assembly, so that the valve core can move freely in the valve hole but not loose or astringent.
Noise is generated when the reversing valve is reversing. a. Rapid reversing causes pressure shock and mechanical vibration that spreads to the pipeline; b. There is dirt on the suction end surface of the reversing valve iron core and the armature rod, and the suction is not good; c. The reversing valve iron core and the armature rod are sucked The joint end surface is uneven, and the suction is poor; d. The armature rod is too long or too short.
Solution: avoid or reduce rapid reversing, clean the end face of the reversing valve core and the armature rod, improve the flatness of the end face, and correct the length of the armature rod.
The vibration and noise of the electromagnet, the electromagnet is stuck due to the valve core, the electric signal is intermittent, and the two pairs of electromagnets of the solenoid valve are energized at the same time, resulting in obvious vibration and noise.
Cavitation in the control valve creates fluid noise. This is due to the throttling effect of the oil flow through the valve body, which produces a high flow velocity at the orifice, and the pressure changes as the flow velocity changes. When the pressure is lower than the atmospheric pressure, the air dissolved in the oil is separated to generate a large amount of gas. Bubbles, the noise frequency at this time will be very high. In addition, in the state of jet flow, the speed of oil flow is not uniform and vortex occurs, or noise is also generated due to oil flow being cut off. The way to solve this kind of noise is to increase the back pressure on the downstream side of the orifice to make it higher than the threshold of air separation pressure, and the multi-section decompression method can be used to prevent the occurrence of cavitation.
Loose connections between control elements can also cause noise and vibration.