Planetary Gear

Aim:

To simulate the Planetary Gear Train with Sun, Ring and Planet gears and to study the angular velocity at the output.

Introduction:

Planetary gear or epicycle gear are gear trains used in automotive power transmission.

Planetary gear has following parts:

• Sun Gear
• Ring Gear
• Planet Gear
• Carrier

Sun Gear is Input component and Carrier is output component generally.

Ring gear is the big gear in ring shape. Sun Gear will be in the centre. Sun and Ring gear is connected by Planet gears which may be one or more in numbers. Planet gears are mounted onto Carrier.

These components form Planetary gear train.

By varying the input speed given either to Sun gear or Ring gear and fixing on or another gear , variable speed is achieved.

CONDITION FOR POWER TRANSMISSION USING GEARS:

1. Module of the mating gear should be same

2. Veloctity of gears should be same at mating point.

3D model:

RING GEAR :

PLANET GEAR

CARRIER

SUN GEAR:

Input Condition:

Simulation Cases with formula:

N = 200 rpm

Angular speed formula ( deg / sec ) : 6 * Speed (in rpm ).

OUTPUT PLOTS:

INPUT ANGULAR SPEED: 1200 deg/sec

CASE 1: OUTPUT PLOT

CASE 2: OUTPUT PLOT

CASE 3: OUTPUT PLOT

Conclusion:

( Note: Negative Gear ratio indicates Output component rotation is in opposite direction of Input )

Angular velocity of component varies for different output component, as gear ratio varies. Generally there is reduction in speed when input is given to Sun Gear and output taken at Carrier. This is due to change in number of teeth in both gears.

In first two cases , Output gear ratio is independent of Planet gears teeth.

As we see when input is given to Ring gear , angular speed found to be increased comparing to the input given to Sun gear when Output is taken at Carrier. This is due to fact that Pitch circe diameter & no.of teeth of the Ring is greater than Sun gear.

For reverse gear: Input given to Sun gear and Output is taken at Ring gear making carrier fixed.