FLENDER transmissions for water snails

Water snails rotate in a semicircular concrete shell. In waste water plants and in drainage installations they serve the purpose of lifting the water. The snail works according to the “Archimedean principle” at an angle of inclination of approx. 38o C. Water snails are able to transport heavily polluted fluids even then when small solids are present. Generally there is a delivery pressure of only a few meters at a relatively high flow rate. The tilted driven shaft of the gear located in the snail’s helix angle does not absorb additional forces and transfers the torque to the worm shaft by means of an elastic coupling.

FLENDER transmission units are specially designed for these special operating conditions. Consequently the gear unit must have an adapted oil level and a corresponding shaft seal, an oil drain and a ventilation system. When the engine is switched off the “return acceleration” of the snail through the push back of the water is preempted through the installation of a non-return device.

Technical Data

Design Helical gear units
Sizes 28
Transmission Ratios/ Stages 2-, 3- und 4-stage
Performance up to 10,500 kW
Translation Area / Gear Ratios i = 6,3 ... 450
Rated gear torque 5.8 ... 1,400 kNm
Installation position Tilted position 30 ... 38°


  • Low noise levels
  • Low vibration
  • High efficiency
  • Complete solution
  • Constructed on base frame
  • Non-return device
  • Protective hood as coupling guard
  • Monitoring / supervision possible
  • Immersion lubrication

Areas of application

  • Municipal waste water plants
  • Drainage installations
  • Irrigation systems
  • Wherever water has to be conveyed from one level to a higher one