1. Mechanical Design II
Spring 2013

2. Note how planet gear orbits around sun gear
Lecture 12
Planetary Gear Trains
The conventional gear trains described in the previous lectures are all one-degree-of-freedom devices.
Planetary gear trains are two-DOF devices  two inputs are needed to obtain a predictable output.
Planetary gear trains are used because they can obtain very large or small gear ratios and are able to transmit more power than ordinary gear trains.
Note how planet gear orbits around sun gear

3. Lecture 12
The Formula Method
Usually an input
Usually an unknown

4. Lecture 12
The Formula Method

5. Lecture 12
The Formula Method

6. Lecture 12
The Formula Method

7. Lecture 12
The Formula Method