S and W gear units

The gearings of the helical-worm and SPIROPLAN® gear units cause a high amount of sliding friction. Because of this, these gear units have greater tooth friction losses and thus lower efficiency than the R, F, or K gear units.

Other factors influencing the efficiency:

  • Gear ratio of the helical-worm or SPIROPLAN® stage
  • Input speed
  • Ambient temperature

SEW-EURODRIVE's helical-worm gear units are helical gear-helical worm combinations and therefore have far better efficiency than a pure helical-worm gear unit.

Efficiency can reach η < 0.5 for very large gear ratios of helical-worm stages.