Gear Box Sizing & Selection Guide
Determination of the Duty Cycle (ED)
Sample Output Profile
If ED<60% and (ta + tc + td) <20 minutes, perform a cycle operation selection (S5)
If ED>60% or (ta + tc + td) >20 minutes, perform a continuous operation selection (S1)
Selection of Optimum Gear box for a Continuous Operation (S1)
Data needed before selection can be performed:
1. Output profile
2. Desired ratio (i)
Calculations to be performed:
1. Mean Output Speed
2. Root – Mean Output Torque
Selection Criteria for Gearbox:
1. Mean Output Speed must not exceed the nominal speed rating of the gearbox.
2. Mean Output Torque must not exceed the nominal torque rating of the gearbox.
See gear box data tables for values of n1n and T2n
Formula Key Tables
| Index | |
| 1 | Input |
| 2 | Output |
| a | Acceleration |
| B | Maximum Acceleration |
| c | Constant |
| d | Deceleration |
| m | Mean |
| max | Maximum |
| n | Nominal |
| p | Pause |
| Symbol | Unit | Description |
| ED | % | Duty Cycle |
| fs | – | Shock Factor |
| i | – | Ratio |
| J | kg-cm2 | Moment of Inertia |
| n | RPM | Speed |
| t | s | Time |
| T | Nm | Torque |
| Zh | – | Number of Cycles |
 |
% | Efficiency |
For Cycle Operation (S5)
Data needed before selection can be performed:
1. Maximum Torque of the motor (T1B)
2. Output profile
3. Desired ratio (i)
4. Inertia of the load (JL)*
5. Inertia of the motor (Jmotor)* * optional
Sample Output Profile
Calculations to be performed:
1. Shock Factor (fs)
2. Maximum Output Torque
Selection Criteria for Gearbox:
1. Maximum Output Speed must not exceed the maximum speed rating of the gearbox.
2. Maximum Output Torque must not exceed the maximum torque rating of the gearbox.
3. (optional) Match inertia of the motor to the inertia of the load.
See technical data tables for values of , n1max, T2B, and J1
