Planetary Gear
Aim:- Motion analysis on the planetary gear Assembly with different Gears fixed conditions.
Introduction :- This project is about the motion study of planetary gear train for following conditions-
- Ring Gear Fixed
- Sun Gear Fixed
- Carrier Fixed
Theory:- A Planetary gear (also known as epicyclic gear train) consists of a larger Ring gear, planet gears, and a sun gear. The sun gear is mounted at the center around which the Planet gears are mounted which can revolve around them. The planet gears are meshing internally with the Ring gear which is an internal gear. A carrier is mounted to the planet gears as shown in the image. The combination of epicycle gear trains with a planet engaging both a sun gear and a ring gear is called a planetary gear train.
Calculation:-
Pitch circle diameter of Ring gear=Pitch circle diameter of Sun gear + 2*Pitch circle diameter of planet gear ........eq1
Pitch circle diameter of Ring gear= Module* No.of Teeth
=2.5*46=115
Pitch circle diameter of Sun gear= Module* No.of Teeth
=2.5*14=35
By Eq 1
115=35+ 2*Pitch circle diameter of planet gear
Pitch circle diameter of planet gear=40
=>No.of Teeth= 40/2.5
=16
Creating the 3D model :-
For creating gear following steps to be followed
For sun and planet gears
Design library --> Toolbox --> ANSI metric --> Power transmission --> gears -->Spur gear
For Ring gear
Design library --> Toolbox --> ANSI metric --> Power transmission --> gears -->Internal Spur Gear
Choose Pressure angle = 20 degree full depth
Face Width = 20 mm
Sun Gear
Planet Gear:
Ring Gear:
Motion analysis -
There are total 8 contact pairs -
4 contact pairs - associating with a sun gear and 4 planetary gears (material -apply dry steel)
4 contact pairs - associating with a Ring gear and 4 planetary gears (material -apply dry steel)
Accroding to problem statement, there are 3 cases -
| Sl.No | Input | Output | Fixed |
| 1 | Sun Gear | Carrier | Ring Gear |
| 2 | Ring Gear | Carrier | Sun Gear |
| 3 | Sun Gear | Ring Gear | Carrier |
Let's see them one by one
Ring gear Fixed:
Input sun gear - 100 rpm
The plot of an angular velocity of the carrier against time.
Simulation:
Sun gear Fixed
Input Ring gear - 100 rpm
The plot of an angular velocity of the carrier against time.
Simulation:
Carrier Fixed
Input Sun gear - 100 rpm
The plot of an angular velocity of the Ring against time.
Simulation:
Results and explanation:
If we fixed Ring Gear then Carrier (output) speed is more than Sun (input) speed.
If we fixed Sun Gear then Carrier (output) speed is more than Ring (input) speed and also more than previous one.
and If we fixed carrier then Ring gear (output) speed is reversed and less than Sun Gear (input) speed.