L9-Gear Train (kinematics of mechanisms and robots).ppt

Theory and examples of gear trains

1. Kinematics of Mechanisms and
Robots
(ME-2202)
Gear Trains

2. Gear Trains
•Two or more gears are combined to transmit power from one shaft to other.
•Four types of gear trains
–Simple
–Compound
–Reverted
–Epicyclic

3. Simple gear train
•Each shaft carries only one gear.

4. Simple Gear Train

5. Simple Gear Train with Idler
Speed ratio is
independent of no.
of teeth on the
intermediate shaft

6. Compound Gear Train
•When intermediate shaft contains two or more gears.
An ideal application when the
center distance is large and gear
ratio is larger than 1:10 or 10:1

7. Reverted Gear Train

8. Epicyclic gear train
Sun gear
Planet gear

9. Velocity ratio of epicyclic gear train
•Tabular method
•Algebraic method

10. Tabular method
Now if motion of two of the elements are given the
motion of the third one is easily calculated.

11. Algebraic method
The speed of gear A relative to arm C is
Since A and B are meshing they revolve in opposite direction

19. Differential in Automobiles

20. How do trains turn without
differential?