PLANETARY GEAR MOTION ANALYSIS USING SOLIDWORKS

AIM: Motion analysis of Planetary Gear system for different conditions for angular velocities.

OBJECTIVES:

1) To obtain Outputs of Angular velocity vs time for different three cases as following:

SR. NO.	Input	Output	Fixed
1	Sun Gear	Carrier	Ring Gear
2	Ring Gear	Carrier	Sun Gear
3	Sun Gear	Ring Gear	Carrier

2) Calculate Pitch Circle Diameter & Number of teeths for the Planetary Gear.

PLANETARY GEAR:

> Planetary gearing is a gear system consisting of one or more outer, or planet, gears or pinions, revolving about a central sun gear or sun wheel. Typically, the planet gears are mounted on a movable arm or carrier, which itself may rotate relative to the sun gear. Epicyclic gearing systems also incorporate the use of an outer ring gear or annulus, which meshes with the planet gears. Planetary gears (or epicyclic gears) are typically classified as simple or compound planetary gears. Simple planetary gears have one sun, one ring, one carrier, and one planet set.

> Epicyclic gearing is also available which consists of a sun, a carrier, and two planets which mesh with each other. One planet meshes with the sun gear, while the second planet meshes with the ring gear. For this case, when the carrier is fixed, the ring gear rotates in the same direction as the sun gear, thus providing a reversal in direction compared to standard epicyclic gearing.

CALCULATION OF PITCH CIRCLE DIAMETER & NUMBER OF TEETHS FOR PLANETARY GEAR:

> MODULE `m` = 2.5

> RPM = 200

> FOR RING GEAR:

1) NUMBER OF TEETH `T_r` = 4

2) PITCH CIRCLE DIAMETER `D_r` = `m*T_r` = 115 mm

> FOR SUN GEAR:

1) NUMBER OF TEETH `T_s` = 14

2) PITCH CIRCLE DIAMETER `D_s` = `m*T_s` = 35 mm

> FOR PLANET GEAR:

1) PITCH CIRCLE DIAMETER

`D_p = (D_r - D_s)/2`

`D_p = (115 - 35)/2`

`D_p = 40` mm

2) NUMBER OF TEETH

`T_p = D_p/m = 40/2.5 = 16`

CASE 1 RESULT:

CASE 2 RESULT:

CASE 3 RESULT:

CONCLUSION:

> When Sun gear is input gear, the required speed is achieved within a short duration of time. But when ring gear is input gear, the required speed is achieved linearly with time.

> The output speed has small disturbances due to collisions between the gear tooth.

> The output speed in all cases is smaller than input speed.