1. Learning with Purpose February 19, 2013 Learning with Purpose February 19, 2013 22.322 Mechanical Design II Spring 2013

2. Learning with Purpose February 19, 2013 Let’s determine the angular velocity ratio, m v, for the gear train as shown: Lecture 11 Simple Gear Trains The gears N 3, N 4, N 5 are called idlers. The idlers only affect the sign of the overall ratio. Having more than one idler does not make much sense. External mesh!

3. Learning with Purpose February 19, 2013 To get a train ratio of greater than about 10:1, it is usually necessary to use a compound gear train. A compound gear train is one in which at least one shaft carries more than one gear. Lecture 11 Compound Gear Trains

4. Learning with Purpose February 19, 2013 Lecture 11 Compound Gear Trains

5. Learning with Purpose February 19, 2013 Lecture 11 Example #1

6. Learning with Purpose February 19, 2013 Lecture 11 Example #2

7. Learning with Purpose February 19, 2013 Lecture 11 Example #2

8. Learning with Purpose February 19, 2013 Lecture 11 Example #2 Of course we now would have to find the appropriate gears in a catalog that have the correct number of teeth for a given diametral pitch.

9. Learning with Purpose February 19, 2013 Lecture 11 Example #3

10. Learning with Purpose February 19, 2013 Lecture 11 Example #3