kinematic of machinery

1. KINEMATICS OF MACHINERY
DEPARTMENT OF MECHANICAL ENGINEERING SLIDE NUMBER 1
• Introduction to gear Trains, Train value, Types - Simple and reverted
wheel train - Epicyclic gear Train. Methods of finding train value or
velocity ratio - Epicyclic gear trains.
• Selection of gear box-Differential gear for an automobile.

2. Gear Trains
DEPARTMENT OF MECHANICAL ENGINEERING SLIDE NUMBER 2

3. 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.
DEPARTMENT OF MECHANICAL ENGINEERING SLIDE NUMBER 3
The nature of the train used
depends upon
1. Velocity ratio required and
2. Relative position of the axes of shafts.

4. Types of Gear Trains:
Following are the different types of gear trains, depending upon the
arrangement of wheels:
1. Simple gear train,
2. Compound gear train,
3. Reverted gear train, and
4. Epicyclic gear train
DEPARTMENT OF MECHANICAL ENGINEERING SLIDE NUMBER 4

5. Simple Gear Train:
• When there is only one gear on each shaft, it is
known as simple gear train.
• Since the gear 1 drives the gear 2, therefore gear 1
is called the driver and the gear 2 is called the
driven or follower.
• The motion of the driven gear is opposite to the
motion of driving gear
DEPARTMENT OF MECHANICAL ENGINEERING SLIDE NUMBER 5

6. speed ratio (or )velocity ratio
 The ratio of the speed of the driver to the speed of the driven
 Ratio of speeds of any pair of gears in mesh is the inverse of their number
of teeth
Let N1 = Speed of gear 1(or driver) in r.p.m.,
N2 = Speed of gear 2 (or driven or follower) in r.p.m.,
T1 = Number of teeth on gear 1, and
T2 = Number of teeth on gear 2
DEPARTMENT OF MECHANICAL ENGINEERING SLIDE NUMBER 6

7. • Train value
Ratio of the speed of the driven or follower to the speed of the driver
DEPARTMENT OF MECHANICAL ENGINEERING SLIDE NUMBER 7
Sometimes, the distance between the two gears is large.
in such a case, The motion from one gear to another, may be transmitted by
either of the following two methods :
1. By providing the large sized gear, or
2. By providing one or more intermediate gears.

8. 1. By providing the large sized gear
***** very inconvenient and uneconomical method
2. By providing one or more intermediate gears
****** very convenient and economical
DEPARTMENT OF MECHANICAL ENGINEERING SLIDE NUMBER 8

9. Consider a Simple Train of Gears with One Intermediate Gear
DEPARTMENT OF MECHANICAL ENGINEERING SLIDE NUMBER 9

10. DEPARTMENT OF MECHANICAL ENGINEERING SLIDE NUMBER 10

11. DEPARTMENT OF MECHANICAL ENGINEERING SLIDE NUMBER 11

12. Compound Gear Train
DEPARTMENT OF MECHANICAL ENGINEERING SLIDE NUMBER 12

13. DEPARTMENT OF MECHANICAL ENGINEERING SLIDE NUMBER 13

14. DEPARTMENT OF MECHANICAL ENGINEERING SLIDE NUMBER 14

15. DEPARTMENT OF MECHANICAL ENGINEERING SLIDE NUMBER 15

16. Reverted Gear Train
DEPARTMENT OF MECHANICAL ENGINEERING SLIDE NUMBER 16

17. DEPARTMENT OF MECHANICAL ENGINEERING SLIDE NUMBER 17

18. DEPARTMENT OF MECHANICAL ENGINEERING SLIDE NUMBER 18

19. DEPARTMENT OF MECHANICAL ENGINEERING SLIDE NUMBER 19

20. DEPARTMENT OF MECHANICAL ENGINEERING SLIDE NUMBER 20

21. DEPARTMENT OF MECHANICAL ENGINEERING SLIDE NUMBER 21
 Given Data :
NA = 975 r.p.m. ; To find:- NF?
TA = 20; TB = 50; TC = 25; TD = 75; TE = 26; TF = 65
drivers
on
teeth
of
no.
of
Product
drivens
on
teeth
of
no.
of
Product

driven
last
the
of
Speed
driver
first
the
of
Speed
E
C
A
F
D
B
F
A
T
T
T
T
T
T
N
N




 75
.
18
26
25
20
65
75
50






.
.
.
52
75
.
18
m
p
r
N
N A
F 
