Planetary Gear

AIM -

To run the motion analysis on the planetary gear with a sun gear a carrier and four planet gears.

• To access the gears from the toolbox in solidworks present in the ANSI metric system.
• Provide the required parameters for defining each and every gear.
• Designing the carrier depending upon the shaft diameter of the planet gears.
• Assembling them in solidworks and giving correct constraints to all the parts so that the assembly is perfect for running the motion analysis study.

THEORY -

Planetary gears are the heart of modern engineering and are used in gearboxes that power everythingfrom basic plant machinery to cutting edge elecric vehicles. The simple configration of a central drive and orbiting gears was developed thousands of years ago model the movements of planets.

A simple planetary gear set is made up of three main components:

1. The sun gear that sits in the centre(central gear).
2. Multiple planet gears.
3. The ring gear(outer gear)

The load from the sun gear is distributed to several planeteary gears which can either be used to drive an outer ring or a shaft or spindle. The central sun gear takes a high speed, low torqueinput. it drives several rotating external gears which increases the torque.

CALCULATIONS:

GIVEN

Ring gear

• Module = 2.5(You must use 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

for calculating diameter of pitch diameter of sun gear and ring gear

D= m*T

d - pitch diameter

m - module

T - no. of teeth

for Ring gear -

d = (2.5)*(46)

d = 115

for sun gear - (module is same for all gears)

d = (2.5)*(14)

d = 35

for planet gears -

To fing pitch diameter

radius of ring gear = Radius of sun gear + diameter of planet gear

(115/2) = (35/2) + diameter of planet gear

d = 40

from above pitch diameter

d = m * t

no.of teeth(t) = 16

Gear	module(m)	No.of teeth (t)	Pitch diameter(d)
Ring gear	2.5	46	115
Sun gear	2.5	14	35
Planet gear	2.5	16	40

3D models -

Ring gear

module = 2.5, no.of teeth =46, Pitch diameter = 115.

Sun gear -

module = 2.5, no.of teeth =14, Pitch diameter = 35,Nominal shaft diameter = 10

Planet gear

module = 2.5, no.of teeth =16, Pitch diameter = 40,Nominal shaft diameter = 10

Carrier -

Final assembly -

MOTION STUDY SETUP -

• The carrier is designed as part file by using the obtained dimensions
• In solidworks assembly from design library the required number and types of gears like internal spur gear and spur gear are choosen from the ANSI metric system.
• The gears are constrained according to the requirment.
• The motion study is conducted by following steps

1. Solidworks motion is enabled from the solidworks add ins.
2. In each of the 3 cases the input element is provided a rotary motor with a constant speed 200RPM.
3. Then the element to be fixed using the fix option.
4. Then solid contact should be provided using contact option and material should be selected as steel(Dry).
5. Then calculate option is used and simulation was done
6. The required plots were obtained.

Results -

Conditions to carry out simulation , Input - 200 RPM

Sl.No	Input	Output	Fixed
1	Sun Gear	Carrier	Ring Gear
2	Ring Gear	Carrier	Sun Gear
3	Sun Gear	Ring Gear	Carrier

CASE -1

CASE -2

CASE -3

Animation links -

case 1 - https://drive.google.com/file/d/1Ca31CoI4Ykd9ET9odZ0m327akGWQGaUd/view?usp=sharing

case 2 - https://drive.google.com/file/d/17eK1cYtk2LGcQx4l8TJGarvx-77VW0N5/view?usp=sharing

case 3 - https://drive.google.com/file/d/1chcRwHAPjdEOEVbs5jVQD0qQkwiY3bZb/view?usp=sharing

CONCLUSION -

So, the motion analysis was sucessfully and working of planetary gear system was studied.