Planetary Gear
Aim :
The aim of this experiment is to calculate the design parameters of the given problem such as PCD, Teeth number
and plot the graphs for the obtaied results by fixing various components at a time.
Introduction:
An epicyclic gear train (also known as planetary gear) consists of two gears mounted so that the center of one gear revolves around the center of the other. A carrier connects the centers of the two gears and rotates to carry one gear, called the planet gear or planet pinion, around the other, called the sun gear or sun wheel. The planet and sun gears mesh so that their pitch circles roll without slip. 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 gear(s) 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, sometimes called an annular 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. (source : Wiki)
Calculation:
Given:
For Ring gear, module = 2.5 mm
No of Teeth,`Z` = 46
For Sun gear, No of teeth, `Z = 14
Input Speed of the Gear = 200 RPM
WKT, `m=d/z`
where m is module in mm
z is no of teeth
=> PCD of ring gear = `Dr = mr*Zr`
= 2.5*46 = 115 mm
=> PCD of Sun gear = `Ds = ms*Zs`
= 2.5*14 = 35 mm (Since module remains constant)
=> PCD of Planetary gear = `Dp = (Dr-Ds)/2` = (115-35)/2 = 40 mm
No of teeth on Planetary gear = `Zp = (Dp)/m`
= 40/2.5 = 16 mm for each planetary gear
Link to the Parts and Assembly:
https://drive.google.com/drive/folders/1vgsX9JRCK062AfqDL6DNw_sp072Enr9J?usp=sharing
Procedure:
- Based on the scenarios the input and output are specified for the respective gear and the other gear is fixed
- The motor and the contacts are set and the speed of driving gear is specified as 200 RPM and the motion study is run.
For the first scenario where the input is given to the Sun gear and Output to the Carrier with Ring gear being fixed plots obtained are as follows:
Assembly Picture:
Plot obtained:
Link to the animation Video:
For the second scenario where the input is given to the Ring gear and Output to the Carrier with Sun gear being fixed plots obtained are as follows:
Link to the animation Video:
For the Third scenario where the input is given to the Sun gear and Output to the Ring Gear with Carrier being fixed plots obtained are as follows:
Link to the animation Video:
Conclusion:
From the Plots obtained the Angular Velocity obtained in first area is about 293 deg/sec
the Angular Velocity obtained in first area is about 939 deg/sec
the Angular Velocity obtained in first area is about 388 deg/sec