Planetary Gear
AIM
To run the motion analysis on the Epicyclic gear system consisting of a sun gear, a ring gear and four planetary gears.
INTRODUCTION
An epicyclic gear or planetary gear system consists of a carrier which connects the centers of the planet gear , around the other, called the sun gear or sun wheel. 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 gears roll around the sun gear.
An epicyclic gear train can be assembled so the planet gear rolls on the inside of the pitch circle of a fixed, outer gear ring, or ring gear. In this case, the curve traced by a point on the pitch circle of the planet is a hypocycloid.
The combination of epicycle gear trains with a planet engaging both a sun gear and a ring gear is called a planetary gear train. In this case, the ring gear is usually fixed and the sun gear is driven.
Epicyclic gears get their name from their earliest application, which was the modelling of the movements of the planets in the heavens. Believing the planets, as everything in the heavens, to be perfect, they could only travel in perfect circles, but their motions as viewed from Earth could not be reconciled with circular motion.
DATA AND CALCULATION
Module for every gear is same
Module=2.5
RING GEAR:
Number of of teeth= 46
PCD= 46*2.5= 115
SUN GEAR:
Number of teeth= 14
PCD= 14*2.5= 35
PLANETARY GEAR:
We know
(PCD of ring gear)/2= (PCD of planetary gear)+ (PCD of sun gear)/2
There fore PCD of planetary gear= 40
Number of teeth of planetary gear= 40/2.5= 16
Number of planetary gear= 4
PARTS
Ring gear
Sun gear
planetary gear
planetary carrier
After assembly
Link to the parts and assembly: https://drive.google.com/drive/folders/1h7KWewSqQFsQ7Uv2TnAllLrhX8QmyjXt?usp=sharing
PROCEDURE
After the assembly go to motion analysis. Then select the motor and feed 200 rpm. Then select the contacts and provide material as steel dry.
Now go to the motion analysis and conduct the study for follwing conditions
PLOTS
Case 1:
Fixing the ring gear, providing input to sun gear and output from carrier
Input
Output
Case 2:
Fixing the sun gear, providing input to ring gear and output from carrier
Input
Output
Case 3:
Fixing the carrier, providing input to sun gear and output from ring gear
Input
Output
RESULT
Case 1:
Fixing the ring gear, providing input of 200 rpm to sun gear and output from carrier. Here we can see the angular velocity of carrier is around 296 deg/sec.
Case 2:
Fixing the sun gear, providing input of 200 rpm to ring gear and output from carrier. Here we can see the angular velocity of carrier is around 932 deg/sec.
Case 3:
Fixing the carrier, providing input of 200 rpm to sun gear and output from ring gear. Here we can see the angular velocity of ring gear is around 394 deg/sec.
CONCLUSION
The angular velocity is maximum in case 2.