Other Process Control

Tendency Drive Roller Systems

Torque clutch driven tendency roller from Dynaspede: We bring you a unique solution to meet challenges of web handling in printing, conversion, publishing and flexible packing industry.

Web handling with chiller rolls or supporting idler rolls of dryer section or high inertia roller applications demands ability to convey web at normal tension levels. The disadvantage of conventional roll systems is the amount of drag on web that is created by over all friction components… including that of support bearings. Each roller requires certain amount of power to rotate expectation is that web/ driving system has to deliver it.

Problems in conventional driven / non-driven rollers:

  • Loss of material tension and associated problems
  • Web shifting
  • Heavier ground rolls, its inertia and roller friction adds to handling problems… typical of Chillier applications
  • Small contact angle may not serve the purpose

These problems can easily be overcome by Torque clutch driven tendency roller that functions to remove the inherent friction of the roller assembly.

Tendency Drive

Torque clutch tendency drive is an electro-mechanical assembly which transmits only enough torque to remove all roller friction and just barely turn the roller. The excitation to the clutch is set such that the roller friction is overcome and the roller is just turning.

Tendency Drive Roller Systems
  • Motor, clutch driven mechanical transmission, which removes effects of self weight and bearing friction on the web
  • Can over come Speed matching problems… often associated with positively driven rollers
  • Specific high inertia rollers working in variable speed can be easily addressed to
  • TMost converters find tendency rollers better than conventional driven/non driven rollers

Though, dual bearing tendency rollers can meet some of application demands… construction restriction like in chilled rollers do not permit a dual bearing roller. Also, high temperature experienced by the bearings in the case of dryer rollers makes it complex to adopt. In view of these complexities, converting machines are compelled to employ a driven roller in place of dual bearing tendency roller. A driven roller can no doubt aid the transport of web; but a perfect speed, torque matching makes it a difficult reposition…resulting in sliding of the web over the roller causing web damage, static charges and its natural effects.

Dynaspede has yet again brought in a unique solution to meet these challenges with a torque clutch driven tendency drive. This would include a compact arrangement of gear-motor and torque clutch. The clutch could be rated as low as 0.06kgm (6kgcm) and controlled up to 0.006kgm (0.6kgcm) to over come the bearing friction. The torque clutch arrangement comes with a host of control options for friction and inertia compensation.