In fact it is the source of rotating force consisting of:
It appears when mass body (in our case unbalanced elements) starts to rotate around axis of rotation when the gravity center is not situated on this axis. The extent of the force is given by:
Basically it is the product of:
The measure unit is kg.mm.
The value given in the vibrator property sheet is the sum of static momentum of all (four) counterweights when adjusted to 100% effect.
Double value of the static momentum is usually given as vibrator property in German speaking countries. It is because a peak-to-peak amplitude is being applied in this region while we use only single amplitude value.
Revolutions and a maximum centrifugal force, which is vibrator able to reach. The power input is not an important factor. The centrifugal force is not unique identificator and we cannot be sure if the momentum of the unbalanced counterweights is static or working (see above).
Kindly refer to us and we will suggest an option for replacement. Ideally, when a machine plate is readable, we must get some information from the following list:
If you do not want to study the machine plate, take a picture and send it to us. Do not bother if the plate is missing. Revolutions are measurable and the counterweight is possible to draw on paper and we can estimate its properties.
Having a storage tank or silo or feeder with a small slant and your material is not loosing as you wish? Then application of surface vibrator for shaking solve such problem in most cases!
When required, the size of centrifugal force and thus the amplitude of oscillation is possible to change by adjustment of the unbalanced eccentric counterweights.
We recommend following combination:
The bold nut of the coupling must be tightened by momentum key according up to indicated values according to following table:
|Nominal thread [Nz]||Tightening moment [N.m]|
Tightening of the vibrator is necessary to check after 1, 8, 100 and then after each 300 running hours (especially when applied on vibratory machines) according to manual and technical specifications for use of vibrator and machine. The same must be executed when you replace the vibratory drive unit with another one.
From the user’s point of view is none.
We have decided to use these marks to follow the previous line and description of VO and VA line. The difference is in the construction of the body casing and for the end user is not significant.
It is a special construction of selected NO vibrators that enables to run it up to 6000 rpm (which responds to working frequency 100Hz). Vibrator itself cannot reach such RPM level - it must be used together with frequency converter!.
For various purpose of use different operating frequency is necessary! Usual operating frequency corresponds to rounds-per-minute value of asynchronous electromotor:
|Frequency [Hz]||RPM [1/min]||Construction of motor||Example of VIBROS vibrator|
|100||6000||(with frequency inverter)||FO22|
Take note - the last digit in our vibrator name gives the number of poles of electric motor.
The standard execution of vibrators is for voltage input 3x400 AC. Different execution on customer’s demand is available also for another three-phase systems. Recently we do not produce vibrators for 1x230V AC, 12 and 24V DC.
Standard design is for input frequency 50 Hz. All technical specifications indicated in description sheets are stated for this working frequency. A construction on demand is possible also for 60 Hz frequency.
Mechanical protection IP65 according to CSN EN 6034-5. In other words, it does not matter, if vibrator is exposed to rain. There are not ventilation slots as on usual electromotor, thus no water can leak inside.
Our produced vibrators are not designed for applications in explosive atmosphere (exclusive special construction of vibrator NA66). Nevertheless, we are able to arrange supply of vibrator with such certification to you.
Vibrators are produced in the temperature class “F” according to CSN 33 0250.
On customer’s demand we can arrange our vibrators with thermistors implemented on coil winding for detecting high temperature.
The need of PTC thermistor rises in case of vibratory control by frequency converter (and is often demanded by customers in such case). Usual electromotor is decreasing cooling intensity with decreasing rpm. Our surface vibrators have no cooling, and on the opposite, their protection is IP65, thus the use of PTC thermistor protection is disputable. Anyway, when requested, we satisfy the customer’s demand.
Standard paint coating is done by synthetic color S2029 in yellow color shade 6401. If requested, we can arrange another shade or color finish, e.g. applicable in food industry.
The working frequency of the most of vibrating machines driven by surface vibrators is usually high above their own resonance frequency. During slow rundown of the machine, when the frequency of vibrators meets this machine own resonance the oscillation amplitude will reach several times higher value for few seconds. This phenomenon is not acceptable both for various applications and machines, but it may be eliminated by shortening the rundown time.
It is suitable to brake all over-resonance machines. However, the brake is necessary for following machine groups:
For elimination of higher dynamic effects during the rundown of the machine a d.c. brake block is being utilized.
The coil winding of the stator (one of its phase) is connected to direct current. Such magnetic field does not rotate and induced magnetic field in rotor cause to run-down within few (1-2) seconds. We supply an electronic element to activate this process - d.c. converter DCBB (BSB). Wiring circuit must be realized according to circuit scheme (next switch and time-relay are necessary). We can supply also switchboard case for the vibratory machine, which will include the DCBB with appropriate wiring.