Drive systems


MRA 2 - Motor belt drive


The MRA 2 replaces the complete QAP assembly. Servo motors set new standards. Every drive belt is controlled, adjusted and monitored separately via the central terminal.
The MRA 2 can be used for all circular knitting machines. Set-up takes just a tenth of the previous time.

Main features

  • ​Closer adherence to stitch size, not otherwise possible with conventional processes
  • Improved fabric quality due to uniform yarn inlet rate for all machine series
  • Greater productivity with lower costs thanks to shorter set-up times

MRA 2: The components


1. Servomotors

These power the drive belts at exactly the speed required for the present yarn feed rate.

2. Operator panel

Is used to enter all the installation and operating parameters.

3. Control unit

This feeds the power supply to the servomotors and can power up to 6 servomotors. The control unit stores data received from the operator panel and the encoder and transmits this data to the servomotors.

4. Capacitors

In the event of a mains power failure, the capacitors ensure that the system continues running until the machine has come to a complete standstill; this prevents yarn breakage.

5. Encoder

The encoder detects cylinder movements and transmits the corresponding pulses to the control unit.

Technische DatenTechnical data

Line voltage

3 x 400 V AC, other voltages possible with upstream step-down transformer

Line frequency

45 – 66 Hz


250 VA per servo motor

Max. number of driven feeders

60 MPF units per belt / servo motor
24 MER units per belt / servo motor

Max. belt speed

360 m/min (with 30-tooth drive pulley)
500 m/min (with 40-tooth drive pulley)
576 m/min (with 48-tooth drive pulley)

Length of connecting cable between control unit and servo motor

1,8 m or 3,0 m



Servo motors

Used to drive belts according to specified yarn feed rate.

Operation terminal

Used to enter all parameters necessary for installation and operation.

Control unit

Used to supply power to the max. 6 servo motors. Data from operation terminal and encoder are saved and transmitted to servo motors.


Ensure with a mains power failure that the system continues running until the machine comes to a complete standstill, so preventing yarn breakage.


Detects cylinder movements and transmits them to the control unit in the form of pulses.