Torque motors 0,5 - 23 Nm

Construction:

• standard motor design IP 55 with die cast squirrel
  cage rotor
• insulation for the tropics and moisture-proof
  insulation through vacuum varnish impregnation
• insulation material class F
• noise-tested anti-friction bearings (lifetime
  lubrication)
• not ventilated - forced-ventilated

Special advantages:

• continued standstill-proof
  
• high operating frequency.

Options:

• special shafts
• brakes
• gearings
• special voltages / frequencies
• reverse current operation (e.g. unwinding
  brake)

Torque motors are asynchronous motors which are constructed for a continuous standstill operation.
The motors are designed in a way that they can dissipate the occurring heat without any problems.
All torque motors are provided with specially selected bearings for the higher temperatures. High-temperature grease is generally used.

Special applications for torque motors are

• actuators
• support drives
• winding drives
• drives with extreme operating frequency

The speed-torque characteristics of the torque motors in the main correspond to the opposite figure (a). By variating the terminal voltage, lower torque's can be attained (b-e). In order to adjust the terminal voltage, variable transformers or electronic voltage controllers can be applied. Please request the corresponding particulars from us.

Nomenklatur
sign	dimension	meaning
	1	mechanical efficiency
F	N	tractive force
M	Nm	torque
Pe	Watt	transition power
Pn	Watt	nominal power
d	mm	diameter of friction roll
d1	mm	diameter of tube
d2	mm	final diameter of coil
i	1	speed ratio = torque motor speed/machine
n	min¨¹	speed of machine shaft
n0	min¨¹	no-load speed torque motor
q	1	winding ratio
V	m / min	material speed

Layout of torque motors
The speed-torque characteristics of the individual types differ with regard to steepness so that in many drive cases, an exact layout is only possible by using the characteristics. Please, if necessary, request the characteristics from us.
As an estimation, it is possible to lay out the drives according to the data listed in the following.
Note! The list data refer to the machines at operating temperature. Torques and currents are approx. 30% higher in a cold condition.

Actuators
With actuators, drives are meant which are operated in the continuous standstill mode or at very low speeds.
The selection of the torque motor is effected according to the listed torque.
The application of 12-pole torque motors some- times with preceding gearing is customary. When actuating the actuators, one should calculate with more than 2/3 of the no-load speed. Up to this speed, the torque decreases, depending on the type, by 25 to 50%; then the decrease in steepness of the torque takes place.

Support drives
Torque motors are especially suitable for driving guide rolls and similar parts for manufacturing processes, so that the self friction torque does not have to be genera- ted by the material.
The torque must be determined in order to lay out the drive resp. the circumferential force must be measured (string, spring balance). The nominal power of the torque motor then can be ascertained as follows:

estimated with

The nominal power of the torque motors always refers to 2/3 of the no-load speed, therefore the following results for the speed ratio of the subsequent mechanical parts:

estimated

 

Winding drives
From the numerous drive possibilities for winding continuous filaments, we only want to mention the indirectly tractive force-controlled (without dancer or similar device) drives. In this case, the torque of the winding motor must be determined as precisely as possible as too large selected motors can lead to considerable problems due to the limited controlling range.

Contact winder, circumferential winder
The coil is driven via a contact roll at the circum- ference. The speed of the coil drive remains constant during the winding procedure. Layout same as with the support drives.

Axle winder, central winder
The coil is driven via the winding shaft. The speed is high at the beginning with a small torque and decreases with increasing winding diameter with an increasing torque.
The drive power is constant.
The 'transition power' is required for the layout.

Corresponding reserves must also be calculated for accelerating procedures. With winding ratios q<4, the above mentioned formulas cannot be applied. Please contact us.