Analysis of sources and causes of vibration and noise in hydraulic systems
There are many sources of vibration and noise in the hydraulic system. There are many sources of vibration and noise in the hydraulic system. There are several mechanical systems, hydraulic pumps, hydraulic valves and piping. ShaoXing Change Auto Synchronizer Ring Co.,Ltd , https://www.sxcjautoparts.com
1. The vibration and noise of the mechanical system are mainly caused by the mechanical transmission system that drives the hydraulic pump, mainly in the following aspects.
1 imbalance of the body of revolution
In practical applications, most of the motors work through the coupling-driven hydraulic pump. It is very difficult to make these rotary bodies completely balanced. If the unbalanced force is too large, a large shaft will be generated during the rotation. Bending vibrations to generate noise.
2 improper installation
Hydraulic systems often cause vibration and noise due to problems with the installation. If the system piping is poorly supported and the basic defects or the hydraulic pump is not concentric with the motor shaft, and the coupling is loose, these will cause large vibration and noise.
2. Hydraulic pumps (hydraulic motors) are usually the most important hydraulic components that generate vibration and noise throughout the hydraulic system.
The causes of vibration and noise generated by hydraulic pumps are mainly reflected in the following three aspects:
1 Hydraulic pump pressure and flow cycle changes
The gears, blades and plungers of the hydraulic pump in the process of oil absorption and pressure oil cause the corresponding work to generate periodic flow and pressure during the process, so that the corresponding working chamber generates periodic flow and pressure changes, which in turn causes the pump The flow and pressure pulsation cause the components of the hydraulic pump to vibrate, and the vibration of the member causes the air in contact with it to generate a densely varying vibration, and the sound pressure wave that generates the noise propagates out.
2 cavitation of hydraulic pump
When the hydraulic pump is working, if the resistance of the hydraulic oil suction pipe is too large, at this time, the hydraulic oil does not have enough to fill the suction chamber of the pump, causing partial vacuum in the oil suction chamber to form a negative pressure. If this pressure just reaches the air separation pressure of the oil, the air originally dissolved in the oil will be precipitated in a large amount to form a bubble in a free state. As the pump moves, the bubble-like oil is transferred to the high pressure zone, at which time the bubble shrinks due to the high pressure, ruptures and disappears, forming a high local high frequency pressure shock.
3 mechanical vibration in the hydraulic pump
Hydraulic pumps are made up of many parts. Due to manufacturing errors of parts, improper assembly may cause vibration and noise of the hydraulic system.
1. Vibration and noise of hydraulic valves
The noise generated by the hydraulic valve varies depending on the type of valve and the conditions of use. According to the reasons for its occurrence, it can be roughly divided into two categories: mechanical sound and fluid sound:
1 mechanical sound
Most of the hydraulic valves are composed of valve core, valve body, regulating parts, fasteners, seals, etc. It is the external force to make the valve core move, and the spool moves to the corresponding position to change the flow, satisfying Work requirements. During this process, mechanical contact of the movable parts within the valve creates noise.
2 fluid sound
Due to the throttling, reversing, and overflow of the hydraulic valve, various changes occur in the flow, direction, and back pressure of the liquid flow in the valve body, causing vibrations on the wall surfaces of the valve member and the pipe, thereby generating noise. According to the reasons for the pressure vibration, it can be divided into cavitation sound, flowing sound, hydraulic shock sound and shock sound.
2. Vibration and noise of the pipeline
This is mainly due to the interaction of the vibration of hydraulic components such as pumps and valves on the pipeline. Studies have shown that when the length of the pipe is exactly equal to an integral multiple of half the wavelength of the vibration pressure, the pipeline produces intense high frequency noise.
In addition, the external source may also cause the pipeline to resonate; when the cross-sectional area of ​​the pipeline suddenly changes (rapidly expands and shrinks or sharply turns), the liquid flow changes, and turbulence is generated and noise is generated.
----- Editor-in-Chief: Dalan Oil Pump Motor 02-Procurement Consultant
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