The decision depends on where the output shaft sits relative to the motor, the torque to be transmitted, daily running time and how much loss is acceptable. A worm gearbox gives a high ratio in a single stage and its output is perpendicular to the motor axis, which makes it practical for small and medium drives that must fit into tight spaces. Helical gearboxes have lower losses; on machines that run continuously and need large torque, that difference shows up in operating temperature and energy use.

  • Worm (HEM30–HEM130): right-angle output, ratios from 1/7.5 to 1/100; according to the tables on the product pages they pair with motors from 0.06 to 11 kW.
  • Bevel-helical (K series): also right-angle output, but through helical and bevel gear stages; preferred for heavy, continuous loads.
  • Foot-mounted helical (M-HEM) and parallel-shaft (HF): the output points the same way as the motor; wide ratio and torque range.

In a worm gearbox, efficiency generally falls as the ratio rises, so a high-ratio worm unit may need a larger motor for the same output torque. In that case it makes sense to compare it with a bevel-helical alternative. Series pages: worm gearboxes and bevel-helical gearboxes.