Epicyclic gear train simulation using SolidWorks (Multi-body Dynamics)
Aim:
To model epicyclic gearset using toolbox in SolidWorks. Perform motion analysis for different configurations of the gearset and to compare the angular velocities.
Objective:
- model the ring gear using toolbox in SolidWorks.
- model the sun gear using toolbox in SolidWorks
- model the planetary gears using toolbox in SolidWorks
- model carrier for planetary gears
- model a shaft for the sun gear
- Perform motion analysis for 3 configurations of the system
| Sl.No | Input | Output | Fixed |
| 1 | Sun Gear | Carrier | Ring Gear |
| 2 | Ring Gear | Carrier | Sun Gear |
| 3 | Sun Gear | Ring Gear | Carrier |
Theory:
A planetary gear set is made up of three types of gears; a sun gear, planet gears, and a ring gear. The sun gear is located at the center, and transmits torque to the planet gears which are typically mounted on a moveable carrier. The planet gears orbit around the sun gear and mesh with an outer ring gear. Planetary gear systems can vary in complexity from very simple to intricate compound systems, depending on the application.
To calculate the number of tooth in planetary gear we use the following formula:
For convenience, let's denote R, S, and P as the number of teeth on the gears.
| R | Number of teeth in ring gear |
| S | Number of teeth in sun (middle) gear |
| P | Number of teeth in planet gears |
The first constraint for a planetary gear to work out is that all teeth have the same pitch, or tooth spacing. This ensures that the teeth mesh.
The second constraint is:
R = 2 × P + S
Model:
Ring gear
Sun gear:
Planetary gears:
Planetary gear carrier:
Sun gear shaft:
Assembly:
Plots
Case 1 :
| Input | Output | Fixed |
| Sun Gear | Carrier | Ring Gear |
Case 2:
| Input | Output | Fixed |
| Ring Gear | Carrier | Sun gear |
Case 3:
| Input | Output | Fixed |
| Sun Gear | Ring gear | Carrier |
Observations:
From the above plots its evident that case 2 has the highest angular velocity amongst the other configurations.
Case 1 - 266-304 Rpm
Case 2 - 890-942 Rpm
Case 3 - 340-390 Rpm
Conclusion:
Hence, the epicyclic gear assembly was moddeled using toolbox and motion analysis was carried out to gather data of angular velocities of the configurations.
Reference: