Planetary Gear
Given:
- Ring Gear
- Module = 2.5 (You must use the metric system in design modeler)
- Number of teeth = 46
- Sun Gear
- Number of teeth = 14
- Input Speed of the Gear = 200 rpm.
- Number of planet gears = 4
Theory:
An epicyclic gear train (also known as planetary gear) consists of two gears mounted so that the centre of one gear revolves around the centre of the other. A carrier connects the centres of the two gears and rotates to carry one gear, called the planet gear or planet pinion, around the other, called the sun gear or sun wheel. The planet and sun gears mesh so that their pitch circles roll without slip. A point on the pitch circle of the planet gear traces an epicycloid curve. In this simplified case, the sun gear is fixed and the planetary gear(s) roll around the sun gear.
Dynamics:
The diameter of the Planet gear:
The radius of Ring gear= Diameter of the Planet gear + radius of the sun gear
Rr = Dp + Rs
Therefore,
Dp =Rr - Rs
Dp=115/2 - 35/2 = 40mm
Number of teeth’s of Planet gear:
Pitch diameter, D=m*T
where m=module
T= Number of teeth
3D model :
Motion analysis
In the motion study, make contacts between the followings.
- Carrier and the Planet gears
- Sun gear and the Planet gears
- Ring gear and the Planet gears
Material: Steel (Dry)
There are 3 cases
|
S NO. |
INPUT |
OUTPUT |
FIXED COMPONENT |
|
1 |
Sun Gear |
Carrier |
Ring Gear |
|
2 |
Ring Gear |
Carrier |
Sun Gear |
|
3 |
Sun Gear |
Ring Gear |
Carrier |
Input Speed: 200 RPM
Time: 5 Seconds
Case 1:
Ring gear fixed. Motor - sun gear.
The plot of an angular velocity of the carrier against time.
Case 2:
Sun gear fixed. Motor - Ring gear.
The plot of an angular velocity of the carrier against time.
Case 3 :
Carrier fixed. Motor - Sun gear.
The plot of an angular velocity of the Ring against time.
Observation and conclusion:
Case 01: The angular velocity obtained for this case is between 235-313 deg/sec.
Case 02: The angular velocity obtained for this case is between 800-1017 deg/sec.
Case 03: The angular velocity obtained for this case is around 340-402 deg/sec.
Animation :
Case 01:
Case 02:
Case 03: