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 F1 – 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 lifespan
| Desired lifespan (Hours) | F2 |
| 10 000 | 0,8 |
| 15 000 | 1,0 |
| 20 000 | 1,4 |
Factor F3 – work cycle
| Number of start/stop per hour | F3 |
| 6 | 1,0 |
| 60 | 1,2 |
| 120 | 1,4 |
