Drives of D.G.R.

Technical characteristics

The coupling based on the known electromagnetic effect of induced currents, acquired from the asynchronous machine, includes all its merits and advantages, not least of which is itsrobust construction and inherent simplicity.
Its characteristic action on torque in a purely electromagnetic manner substantially eliminates wear compared to common mechanical drives.
This thus results in savings for the customer, as this type of product does not require burdensome maintenance.

 

An example of its use

The example presented here is a fixed field (see drawing in point 4), which excludes the presence of slip rings in its mechanical aspect.
The machine's structure has been designed in order to obtain very high thermal conductance. This ensures very contained standard temperatures and ample possibilities of temporary overload. The considerable increase in thermal conductivity was obtained by means of a fan (2) fixed to the induced constant speed of the asynchronous engine, generating forced air circulation.
This solution is particular thanks to the presence of a hollow shaft coupling (1) with which, with immediate simplicity, the UNEL IEC-B5 engine can be connected.
The not inconsiderable advantage that results is the ability to connect and disconnect the engine at any time and with maximum rapidity.

An example of its use
1. Shaft cable for insertion in engine UNEL-MEC-IEC-B5

 

2. Fan in constant rotation with the engine, generating forced cooling air

 

3. Induced in asynchronous speed

 

4. FIXED FIELD Toroidal Coil impregnated with synthetic resins with high insulating properties (IP55)

 

5. Polar expansion, sifted to shaft 7 in rotation at variable speed

 

6. PICK-UP tachogenerator output voltage proportional to the speed (only for GMV)

 

7. GMV variable speed output shaft GMC controlled torque
D.G.R. COSTRUZIONI DIVISIONE TRASMISSIONI INDUSTRIALI snc

Induced current couplings (controlled torque)

The need to wrap materials originating from rolling machines, drawing machines, cables, pipes, plastic film fabrics, paper, aluminium, etc. at speeds with constant tension, makes GMC the absolutely most suitable solution for its characteristic curves of the induced current coupling, which follow the ideal winding curve within a certain field.
The material's tension is obtained by varying the GMC supply voltage through a simple apparatus (ALC). Once the excitation voltage is set, the torque automatically adapts to vary the diameter of the coil without requiring any external intervention. This avoids the use of diameter sensors, encoders for speed measurement, load cells for tension measurement and dancer rollers for tension control.
In this way, the coupling's natural torque adjustment sees to, in a completely automatic way, a function which must otherwise be programmed with the use of sophisticated and expensive controls.

Induced current couplings (controlled speed)

The core group is made up of an Asynchronous, B5 form three-phase or single-phase UNEL-MEC-IEC engine powered directly by the network.
This excludes, unlike with classic continuous currents, the presence of expensive and bulky intermediate power equipment.
The variable speed engine has got a tachometer generator (6) mounted within it that provides a voltage proportional to the output shaft speed; comparing this voltage with the reference one, corresponding to a predetermined speed, an adjustment is obtained with accuracy up to 0.2% with constant loads and 1% with variable loads with 20% of the maximum torque. With a 4-pole engine, the speed is adjusted from 0 to 1300 revolutions/1' and with a 2-pole engine, from 0 to 2700 revolutions/1' with controlled acceleration.

Control equipment

Thanks to the low power level required, it is possible to employ highly reliable circuits.
We design and build all the necessary electronic equipment, whose operating safety is guaranteed and confirmed by years of continuous service and is verified through minimal maintenance requirements.

D.G.R. COSTRUZIONI DIVISIONE TRASMISSIONI INDUSTRIALI snc

Induced current couplings

B3 Form

GMV (*) induced current coupling for speed control

GMV (*) induced current coupling for speed control.

B3 Form

GMV (*) induced current coupling for torque control

GMV (*) induced current coupling for torque control.

B5 Form

GMVF (*) induced current coupling for speed control

GMVF (*) induced current coupling for speed control.

B5 Form

GMCF series (*) induced current coupling for torque control

GMCF series (*) induced current coupling for torque control.

GAV/GAVF B3/B5

Induced current coupling with input shaft

Induced current coupling with input shaft. These groups with an input shaft are used when the rotation is taken directly from the machine and not from the engine.

GMVEF(*)/GMCEF(*)

Coupling controlled in speed and torque, with triggering current

Coupling controlled in speed and torque, with triggering current "E" brake. This is applied in machines where a triggering current brake may be necessary in addition to speed control. Applications: machines that need instant triggering current braking.

D.G.R. COSTRUZIONI DIVISIONE TRASMISSIONI INDUSTRIALI snc

Electronics

Electronics
Our induced current couplings are controlled by a very simple and intuitive electronic device that is convenient for several reasons: its small postcard size, its great ease of use for connecting and starting the machine, and the fact that it does not require the presence of specialised personnel.

 

These characteristics make it particularly appreciated by our customers.
  • ALC: electronic equipment for torque control.
  • ALV: electronic equipment for speed control.
  • ALV/RC: electronic device designed to control speed and torque in a single device.
The greatest benefit of this extraordinary tool is the fact that the equipment remains the same, regardless of varying size and, consequently, drive power.
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