Gearboxes GS

AUMA worm gearboxes are used for the operation of part-turn valves and special valves (dampers, flue gas dampers, etc.).


  • Type of duty: Short-time duty S2 – 15 min (Open-close duty) and inching/positioning
  • Intermittent duty S4 – 25 % (Modulating duty only bronze)
  • They can either be operated in:
    – manual operation directly via handwheel
    – motor operation (electric multi-turn actuator)
  • Swing angle 0° to 190° or multi-turn without endstop


Design features

  • Torque range up to 675,000 Nm
  • Reduction ratios from 39:1 to 3328:1
  • Swing angles up to 190°
  • With or without primary reduction gearing
  • 360° worm wheel
  • End stops with travelling nut principle in accordance with AWWA C504
  • Output drive according to ISO standard
  • adjustable end stops
  • All parts within the power drive have been subjected to thermal hardening


  • Swing angle > 100 ° or multi-turn (without end stops)
  • Worm wheel made of bronze for modulating applications
  • Clockwise rotation at the input shaft results in counterclockwise rotation at the output drive
  • Base and lever
  • Chain drive
  • Housing made of spheroidal cast iron
  • Version for drinking water applications
  • Version for nuclear power plants
  • Fireproof K-MASS® coating
  • Extension flange IM1 to IM3 version in accordance with EN ISO 12944-2
  • Housing made of spheroidal cast iron
  • Functional safety: Up to SIL 2 in selected configurations

Ambient conditions

  • Enclosure protection IP68
  • High quality corrosion protection
  • –60 °C to +120 °C