The document discusses gear trains, which consist of multiple gears meshing to transmit power, reduce speed, and increase torque. It outlines various types of gear trains, including simple, compound, and epicyclic gear trains, detailing their configurations and applications. Additionally, it covers concepts like speed ratios, train values, and methods for calculating these parameters.

1. GEAR TRAIN
UN IT-4

2. GEAR TRAIN
• Two or more gears are made to mesh with each
other to transmit power from one shaft to
another.
• Such a combination is called gear train or
train of toothed wheels.
• It reduces speed and increases torque
• Electric motors are used with the gear systems
to reduce the speed and increase the torque

3. .
Application

4. GEAR TRAINS
Simple Gear
Train
Ordinary Gear
Train
Epicyclic Gear
Train
.
Compound
Gear Train
.
Simple
Epicyclic Gear
Train
Non-Reverted Gear
Train
Reverted
Gear Train
Compound
Epicyclic Gear
Train

5. Introduction
Velocity Ratio AND Train Value Of Gear Train
TRAIN VALUE
Positive value of train value indicates both driver and driven
rotates in same direction
Negative value of train value indicates driver and driven
rotates in opposite direction

6. SIMPLE GEAR TRAIN
.
When there is only one gear on each shaft.
Gear 1 is called Driver
Gear 2 is called Driven or Follower
NI TI = N2T2

7. IDLE or INTERMEDIATE GEAR TRAIN
.

8. PROBLEM
Two parallel shafts are connected by a simple gear train. The speed of the driving gear
and the driven gear is 360 rpm and 120 rpm respectively. The number of teeth on the
driving gear is 30. Determine i) Speed ratio ii) The Train Value iii) Number of teeth on
the driven or Follower

9. Compound Gear Train
• For large velocities,
compound
arrangement is
preferred
• Two or more gears
may rotate about a
single axis

11. Reverted Gear Train
• The compound gear trains can be subdivided
into two types;
1.Reverted gear train: In which the first and last
gears are co-axial
2.Non-reverted gear train: In which the first and
last gears are not co-axial

12. COMPOUND GEAR TRAIN
.
ADVANTAGES
1. Larger speed ratio can be obtained
with smaller gears
2. Different gears can be used in order to
suit the given conditions.
3. Motion can be transmitted in the
round bends and corners

13. .
COMPOUND
GEAR TRAIN

14. .
PROBLEM

15. .
PROBLEM

16. .
PROBLEM

17. .
PROBLEM

21. REVERTED GEAR TRAIN
.

22. The centre distance between the shaft of gears 1 and 2 and 3 and
4 are the same
REVERTED GEAR TRAIN

23. .
.

24. EPICYCLIC GEAR TRAIN
A gear train that consists of one or more outer
gears rotating around a central gear. Epicylic
gear trains are also known as planetary gear
trains.

25. APPLICATIONS

26. TYPES
TYPES
1. SIMPLE EPICYCLIC GEAR TRAIN
2. COMPOUND EPICYCLIC GEAR TRAIN

27. SIMPLE EPICYCLIC GEAR TRAIN
When only one gear on each shaft in any
epicyclic gear train is called simple epicyclic
gear train

28. COMPOUND EPICYCLIC GEAR TRAIN
When there are more than one gear on a shaft in
any epicyclic gear train is called as compound
epicyclic gear train

29. METHODS TO FIND VELOCITY RATIO
1. Tabulation Method
2. Algebraic or Formula Method