Noise, shaking - phenomena unpleasant to man. Annoying their constant presence. Vibration isolators for fans eliminate negativity, both emotional and completely objective. Vibrations are not harmless processes.
Where do the
fan vibrations come from? Working fans do not have an efficiency of 100%.Since energy is spent on side effects:
- heating of rubbing surfaces;
- knocks, backlashes;
- acoustic noise.
Noise does not occur independently. They are a consequence of the vibrations of the fan, generating sound vibrations perceived by the human ear. Not all phenomena occur due to knocks, backlash and other defects of a mechanical nature. For example, the wire in the transmission line can vibrate. This happens when an electric current interacts with the Earth’s magnetic field. As a result, the wire vibrates at a frequency of 50 Hz and emits a low buzzing sound corresponding to the note salt.
The rotating blades in the fan will certainly cause shaking. Moving in a circle, the material is influenced by centrifugal force. Despite the name, seemingly meaning movement inside, the molecules of the substance tend to break out. As long as the part is strictly symmetrical, the fan runs silently and does not create vibrations. But it is necessary to outweigh a fraction of a gram, and beats arise with the frequency of rotation of the blades. This is how the fan vibration is born.
This immediately responds with a sinusoidal-type load transmitted to the supporting structures. The process described is called fan vibration. Shaking parts transmit air movement, in addition there is acoustic noise. It is shown that vibrations are accompanied by acoustic phenomena. An exception is the case when the latter are intentionally extinguished by means of sound protection.
Vibration Characteristics
In order to assess how great the vibration is, there are special quantities and methods for estimating them. Special standards have been developed that regulate noise and vibration levels. Including, and from household fans.
According to human physiology, there are ranges of especially dangerous vibration frequencies. On them measurements are taken and restrictions are raised. The level depends on the location of the observed vibration. The rustle of foliage in the woods in a quiet room will seem like a roar. It is clear that in a factory where workers work, permissible vibrations are more important than in an apartment.
The following concepts were introduced to quantify the oscillations:
- Vibration Acceleration.
- Shifting.
- Vibration Speed.
Imagine the end of the board, which oscillates in a vertical plane. That goes down, then goes up. The speed of movement of the oscillating edge, and will be vibration velocity, amplitude - vibration displacement, finally, vibration acceleration characterizes the change in speed at each point of movement.
Optionally, the speed varies sinusoidally or is uniform. Therefore, we introduced the concept of vibration acceleration. Exclusively taken together, these parameters accurately characterize the vibration. For an ordinary room in a residential building, regarding vibration acceleration, it looks like this:
- 2 Hz - 74 dB.
- 4 Hz - 75 dB.
- 8 Hz - 77 dB.
- 16 Hz - 83 dB.
- 31.5 Hz - 89 dB.
- 63 Hz - 95 dB.
The regulations on fan vibration are closely intertwined with legislation. All vibration levels are for a period of time from 7 to 23 hours. The vibration of the fan goes into acoustic oscillation, and "making noise after eleven is prohibited."
Why do we need to suppress the vibrationsPseudo-Reynaud syndrome is first described by Russian scientists in the 19th century. Then the first factory mechanisms began to appear and new unusual occupational diseases developed in people. Medicine divides the vibrations into local and general. These species can act together, and this form is called combined. About local vibrations in question, if part of the body is exposed to intense exposure. For example, when working on a lathe type machine. Vibration is transmitted to the floor, but turners often stand on special stages, and as a result, the impact is reduced. Continuous vibrations affecting the hands of the worker cause changes in the bone, nervous, circulatory, muscular systems.
General vibrations are said if the whole body is affected. This is true for machine-tool enterprises and those who work on ships, especially in engine rooms. Engine shivering is given throughout the body.
The first symptoms manifest themselves in circulatory disorders, dizziness, weakness, nausea, and other unpleasant conditions. Twitching of the limbs, numbness may occur. In the later stages, the blood hardly reaches the fingers, and they turn white. This syndrome is called white finger syndrome.
With timely treatment, the prognosis is favorable, it is possible to fully restore the functionality of the body. You can not assume that the constant action of noise is completely harmless to humans, there are various norms that limit this factor.
Vibration isolators for
fans. Vibration isolators are used to mitigate the negative effects of vibrations. These are elastic materials that neutralize the harmful factor. At frequencies up to 1800 Hz, rubber is considered effective, and all that is higher is suppressed by steel structures on springs. Naturally, there were people who offered to equip steel springs at both ends with rubber dampers, and so there was a universal vibration insulation, suitable for any range.
Foam rubber gasket perfectly isolates the PC case from cooler vibrations. Springs sandwiched between two plates are used in industry. In an apartment like the use of vibration isolators is problematic to find. And in the shop they belong.
For the evaluation of the effectiveness of vibration isolation, a special value of the same name is introduced, expressed in decibels, as well as vibration acceleration. It shows how much the vibration level is reduced when using this type of product.
When it comes to industrial fans, there are often two types of vibration insulators:
- .
- BP.
The first ones are performed according to the scheme with a spring between two steel plates, and the second ones resemble a keg from a rubber lotto holed along the axial line.
In ventilation systems, air duct sections fitted with inserts made of elastic materials are used as vibration insulators. It turns out an accordion that cuts off the turbine from the steel structures, preventing the transmission of vibrations.
Do not think that the spring or rubber gasket is designed for light weight. In fact, there is a model range, and similar vibration supports for fans can withstand up to 380 kg.
Vibration isolators for
coolers Not everyone installs industrial equipment professionally, but everyone is interested in reading about anti-vibration nails for the fan.
A curious thing made in China was discussed at the Ukrainian forum. This is a set of screws and gaskets. According to the manufacturer, should make the personal computer silent, eliminating the vibrations of the fans. A lot of lines were written about this thing for 50 hryvnias( about 200 rubles), where everyone argued. It was said that the rotation could not be made noiseless, it was told about the aerodynamic effect and it was proved that the movement of the hard disk head cannot be suppressed at all.
Supporters of Chinese vibration isolation for fans said that any knock was caused by unlubricated bearings. It is enough to add a drop of oil, buy a bag with screwdrivers and rubber, install according to the instructions, and the noise will disappear. Or it will be significantly less. Installing fans on vibration isolators will reduce noise.
But, probably, the point of view expressed on the second site is more correct. For example, it was proposed to get out of the package a new cooler and run it in hand. Food is taken from any source, for example, computer. On weight, the motor runs silently. But it is worth putting on the table how the vibrations and noise will begin. Vibration isolation is part of the measure. Need more care.
Finally, anti-vibration nails appear to be silicone shaped products resembling cooler fastening screws. The nail is passed through the openings outside the system unit and pulled out by the elastic nose inwards, until both slots, under the case and the cooler, are in place.
