Planetary Gear

AIM:  STUDY MOTION ANALYSIS OF PLANETARY GEARS  IN SOLIDWORKS

OBJECTIVES:  

• Design & assemble planetary gears parts in Solidworks
• Run motion analysis
• Study motion analysis & generate plots between angular velocity Vs time for various cases:

1. Input- Sun gear, Output-Carrier, Fixed- Ring gear
2. Input- Ring gear, Output- Carrier, Fixed- Sun gear
3. Input-Sun gear, Output- Ring gear, Fixed- Carrier

 

BODY OF CONTENT:

Planetary Gear arrangement consist mainly four parts:

• Sun Gear
• Planet Gear
• Ring Gear
• Carrier
  

• As shown in figure the gear at the center is called sun gear. The gears rotated around the sun gear are called planet gears. These planet gears are connected to the link called carrier. The outer gear is called Ring gear.
• This type of arrangement also known as Epicyclic gear train.
• This type of gear box used when high torque is required in compact areas. It is used where precision is required.
  

• Application:
• Lathe machine
• Wrists watches
• Automobile transmission
• Used in gear box
  

Gear Terminology:

• P.C.D.: Pitch circle diameter is the diameter of the pitch circle. Gears are defined by this diameter.
• Module: It is the ratio of P.C.D. to the number of teeth. It must be the same for given transmission system in order to maintain constant velocity.

Given Data:

Module = 2.5

• Ring Gear:

      Teeth = 46

      P.C.D = m * teeth

              = 2.5 * 46

     P.C.D = 115 mm

• Sun Gear:

     Teeth = 14

     P.C.D = 2.5 * 14

             = 35 mm

Now, for Planetary gear

    We know from the geometry,

    Radius of the Ring gear = P.C.D. of planet gear + Radius of the sun gear

    57.5                            = P.C.D. of planet gear + 17.5

    Hence, P.C.D. of planet gear = 40 mm

    Now, Teeth of the planet gear = 40/2.5 = 16

DESIGN STEPS:

Now from this data we can design gears in Solidworks.

1. Open Solidworks Assembly.
2. Now go to the toolbox>>ANSI Metric>>Power transmission>>gears
3. Now , input the data to generate the gears.
4. Save each of them one by one as a part file.

• Sun Gear:

• Planetary gear:

• Ring gear:

• Carrier:
  

• Assembly:

Case:1

Input is given to Sun gear. So, apply motor to sun gear & speed is given as 200RPM.

Ring gear is fixed.

Output is recorded for the carrier which is attached to the planetary gears.

Result:

Plot of Angular Velocity Vs Time(Carrier).

Here we can analyze from the plot that the average value of Angular velocity for the carrier is 285 degree/sec.

Video link for case-01:

https://drive.google.com/file/d/1ha0A1N8ZdUhjeCcV5mDebvDQ4oadN-UW/view?usp=sharing

Case:2

Input is given to Ring gear. So, apply motor to Ring gear & speed is given as 200RPM.

Sun gear is fixed.

Output is recorded for the carrier which is attached to the planetary gears.

Result:

Plot of Angular Velocity Vs Time(Carrier).

Here we can analyze from the plot that the average value of Angular velocity for the carrier is 920 degree/sec.

Video link for case-02:

https://drive.google.com/file/d/1EvakxpDHc8olj5oBELeJguSug4xVAONN/view?usp=sharing

Case:3

Input is given to Sun gear. So, apply motor to Sun gear & speed is given as 200RPM.

Carrier is fixed.

Output is recorded for the Ring gear.

Result:

Plot of Angular Velocity Vs Time(Ring gear).

Here we can analyze from the plot that the average value of Angular velocity for the Ring gear is 365 degree/sec.

Video link for case-03:

https://drive.google.com/file/d/1aqn4fhMhoMvpo6UB5VphSTr3PoJ4-l8m/view?usp=sharing

CONCLUSION:

Hence, from all the three cases we can conclude that by changing input member & output member for same given input speed one can get different output speed.

CAD files:

https://drive.google.com/drive/folders/1ghg88AVqXU8qbUNfYkMxWHf80Iz7bDfp?usp=sharing