Advice on choice of worm gear

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)

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 - 3-4
• Even workload - 0,8
• Variable workload - 1
• Very variable workload - 1,5

• Working hours/day - 8-10
• Even workload - 1,0
• Variable workload - 1,2
• Very variable workload - 1,8

• Working hours/day - 10-24
• Even workload - 1,4
• Variable workload - 1,6
• Very variable workload - 2

Factor F2 - desired lifespan Redigera

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

Contact

Pontus Adolfsson, Product manager electric motors:

• Direct: +46 499-271 71
• Mobile: +46 70-224 02 83
• E-mail: pontus.adolfsson@bevi.com

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