Advice on choice of worm gear

Selecting the correct worm gear can be a challenge. There is a lot you need to know. BEVI's transmission experts are happy to help you make the right choice.

The following factors should be considered when choosing the right gear for a given application:

  • Type of machine to be commissioned
  • Ambient temperature
  • Surroundings (dust, moisture, acid, frost, tropical heat etc)
  • Drive motor (type and characteristics)
  • Type of coupling between drive motor and gear, i.e. belt, friction, direct or variable speed
  • Desired output torque required at output shaft
  • Input and output speed
  • Mounting positions
  • Service factor

Determining the service factor (Sf) 

The service factor is determined by the following characteristics:

  • Working hours per day
  • Workload
  • Life span
  • Work cycle

Formula for calculating the service factor (SF): 

 SF = F1 x F2 x F3

Factor F- working hours and workload 

Working hours/day Even  workload Variable workload Very variable workload
3–4 0,8 1 1,5
8–10 1,0 1,2 1,8
10–24 1,4 1,6 2


Factor F2 - desired life span

Desired life span (Hours) F2
10 000 0,8
15 000 1,0
20 000 1,4


Factor F- work cycle

Number of start/stop per hour F3
6 1,0
60 1,2
120 1,4


Anders Holgert

Anders Holgert, Product manager transmission
Direct: +46 499-271 28


Related products