Machine Dynamic 231 Lab 3 Report

1. Objective
To become familiar with epicyclic gearing systems and to be able to experimentally and
analytically determine velocity ratios of epicyclic gear systems.
Apparatus
Epicyclic Gear Apparatus
The arrangement of the number of teeth for the two sets of epicyclic gear is as follows:
Set 1
Sun gear = 36 teeth
Planet gear = 17 teeth
Ring gear = 70 teeth
Set 2
Sun gear = 46 teeth
Planet gear = 15 teeth
Ring gear = 76 teeth
Procedure
First Experiment
The locking nut on shaft at gear set 1 is released and the gear set 1 is locked by
inserting a pin between the teeth of the planet gear of gear set 1. The pulley at gear set 2 is the
driver (input) and the pulley at gear set 1 is the follower (output). The driver pulley and the
follower pulley are rotated to the zero degree marks on the protractor. The driver is then
rotated by ¼ revolutions (90°). The number of revolution (in terms of degrees)that the
follower pulley makes is recorded. The driver shaft is then rotated a few complete revolutions
and the results are recorded and tabulated.
Second Experiment
The locking nut on shaft at gear set 2 is released and the gear set 2 is locked by
inserting a pin between the teeth of the planet gear of gear set 2. The pulley at gear set 1 is the
driver (input) and the pulley at gear set 2 is the follower (output). The driver pulley and the

2. follower pulley are rotated to the zero degree marks on the protractor. The driver is then
rotated by ¼ revolutions (90°). The number of revolution (in terms of degrees)that the
follower pulley makes is recorded. The direction of rotation of the follower pulley (clockwise
orcounter-clockwise) is noted from the driver side. The driver shaft is then rotated a few
complete revolutions and the results are recorded and tabulated.
Third Experiment
The locking nut on shaft at gear set 1 and gear set 2 are locked. The pulley at gear set
2 is the driver (input) and the pulley at gear set 1 is the follower (output). The driver pulley
and the follower pulley are rotated to the zero degree marks on the protractor. The driver is
then rotated by ¼ revolutions (90°). The number of revolution (in terms of degrees)that the
follower pulley makes is recorded. The direction of rotation of the follower pulley (clockwise
orcounter-clockwise) is noted from the driver side. The driver shaft is then rotated a few
complete revolutions and the results are recorded and tabulated.
Data and Analysis
Data
First Experiment
Input Output Velocity
Degree Revolutions Degree Revolutions Ratio
90 1/4 34 17/180 0.3778
180 1/2 68 17/90 0.3778
270 3/4 101 101/360 0.3741
360 1 136 17/45 0.3778
Table 1: recorded data of experiment 1.
Second Experiment
Input Output Velocity
Degree Revolutions Degree Revolutions Ratio
90 1/4 46 23/180 0.5111
180 1/2 92 23/90 0.5111
270 3/4 138 23/60 0.5111
360 1 185 37/72 0.5139
Table 2: recorded data of experiment 2.

3. Third Experiment
Input Output Velocity
Degree Revolutions Degree Revolutions Ratio
90 1/4 66 11/60 0.7333
180 1/2 132 11/30 0.7333
270 3/4 198 11/20 0.7333
360 1 264 11/15 0.7333
Table 3: recorded data of experiment 3.
Data Analysis
First Experiment
160
y = 0.376x
140
Output Revolutions (Degrees)
120
100
80
60
40
20
0
0 50 100 150 200 250 300 350 400
Input Revolutions (Degrees)
Graph 1: the gradient of the graph is 0.3767.

4. Second Experiment
200
180
160
Output Revolutions (Degrees)
y = 0.512x
140
120
100
80
60
40
20
0
0 50 100 150 200 250 300 350 400
Input Revolutions (Degrees)
Graph 2: the gradient of the graph is 0.5126.
Third Experiment
300
250
Output Revolutions (Degrees)
y = 0.733x
200
150
100
50
0
0 50 100 150 200 250 300 350 400
Input Revolutions (Degrees)
Graph 1: the gradient of the graph is 0.7333.