Planetary Gear

|| SIMULATION AND MOTION ANALYSIS OF PLANETARY GEAR SYSTEM ||

Objective

Constructing a 3D model of planetary gear system with four planet gears fixed to a carrier and analyzing the angular velocities of the gears using SOLIDWORKS.

Introduction

Gear Terminology :

Generally, gear is identified by the pitch circle diameter, Module and Number of teeth. if we have any two-parameter between the module, pitch of circle and number of teeth we can find the third one.

In order to mate gear properly and correct power transmission, the pitch circle of both mating gears are should be tangent to each other. Also, the module of the two gear should be the same.

For our problem, we need to understand ring gear and spur gear. The ring gear is also called as an internal spur gear. So, the spur gear is the simplest form of gear having teeth parallel to the gear axis. the contact of two teeth takes place over the entire width along with a line parallel to axes of rotation.

Fig : Simple Ring Gear and Spur Gear

Planetary Gear System :

Planetary Gear System or an epicyclic gear train is used to set different gear ratios by using three sets of gear sun gear, planet gear, and ring gear.
All the planet gears are mounted to a single rotating member, called a cage, arm, or carrier where the output is obtained.
Planet gears, for their size, engage a lot of teeth as they circle the sun gear, therefore they can easily accommodate numerous turns of the driver for each output shaft revolution
With more planets gears comes an increase in load capacity and torsional rigidity; the more divided the load, the less deflection, and wear of gear teeth.

Fig : Simple Planetary Gear System

DATA USED :

	Module	No. of Teeths	Pitch Diameter
Ring Gear	2.5	46	115
Sun Gear	2.5	14	35
Planetary Gear	2.5	16	40

PLANETARY GEAR SYSTEM :

Here, I have used the in-built lilbrary of SOLIDWORKS for getting Gears with the required parameters.

CARRIER :

Carrier is separately made as a part by sketching and then extruding.

ASSEMBLY :

And Finally, the carrier and the gear system is assembled in an assembly file.

MOTION ANALYSIS :

The analysis is made in three different cases -

	Fixed Link	Input Link	Output Link
Case 1	Sun Gear	Carrier	Ring Gear
Case 2	Carrier	Sun Gear	Ring Gear
Case 3	Ring Gear	Carrier	Sun Gear

CASE 1 :

Fixed Link - Sun Gear

Input Link - Carrier

Output Link - Ring Gear

CASE 2 :

Fixed link - Carrier

Input Link - Sun Gear

Output Link - Ring

CASE 3 :

Fixed Link - Ring Gear

Input Link - Carrier

Ouput Link - Sun Gear

FILE LINK - https://drive.google.com/open?id=1ZQb5mgXOKZ8UBYJCkuSubLuD7Jsg0GVM