Planetary Gear

Aim: Motion analysis of Planetary gear using Solid works Multi-Body Dynamics.

Theory: An epicyclical 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 career connects the centers of the two gears and rotates to carry one gear, called the planet gear or planet pinion, round 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 epicycloids curve. In this simplified case, the sun gear is fixed and the planetary gear(s) roll around the sun gear.

An epicycle 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. 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. In this case, the ring gear is usually fixed and the sun gear is driven.

Procedure:

1. For the Planetary Gear analysis, We will first open the Solidworks part modeling to make the 3D CAD model of the carrier in which the planetary gears and Sun Gear is fitted.
2. Then We will go for Solidworks assembly to start assembling the CAD model for motion analysis.
3. Now we will go to the design library and go for ANSI metric and then power transmission and then gears and then we will select the Spur Gears and define them and then the Internal Spur Gears for the Ring Gears.
4. The process of dragging and defining the Spur Gear will be repeated 5 times as one for the Sun Gear and four times for the Planetary Gears.
5. The process of dragging Internal Spur Gear is repeated one time and then we will define its specification.
6. Then we will define the Gear relation and we will make them constraint such that they can only rotate about their axis.
7. Now since constraining had been done we will go for motion analysis.
8. We will click on Solidworks motion to go for motion analysis.
9. Now we will define the contact between the gears and carriers.
10. Now using the motor option we will define the input as an input with 200rpm.
11. Now we will hit on the calculator to calculate and then using results and plots we can get our desired results and plots

Carrier:

Planet gear is mounted to the carrier shaft and it guide to rotate the planet gear at its own axis. Creating a 3D model of a sun gear, ring gear, planet gear, carrier Assembling the 3d model of a sun gear, ring gear, planet gear, carrier, as planetary gear by use of constraints. Using Multibody Dynamics to find the Motion Analysis for Planetary gear. In Input gear, the motor is fixed to rotate at a constant speed of 200 rpm. Input gear is different for different case studies. Fixing the contact type as Solid bodies of gears and assigning material as STEEL, and calculating the motion analysis.

Planet Gear:

Planetary gears is meshed with both sun gear and ring gear,and at the same time they rotate about their own axis.

Parameters required for Planet gear

Module:: 2.5

Number of Teeth : 16

Pressure Angle: 20

Face Width:10

Nominal shaft diameter : 22

Pitch circle diameter : (pcd of ring gear/2) - (pcd of sun gear / 2): (115/2) (35/ 2)

: (57.5) - (17.5)

:40

Number of gears: 4

Parameters required for Ring gear:

Module : 2.5

Number of Teeth : 46

Pressure Angle: 20

Face Width : 10

Outside Diameter: 135

Pitch circle diameter : no of teeth x module

:46 x 2.5 = 115

Number Of Gears: 1

Parameters required for Sun gear

Module : 2.5

Number of Teeth : 14

Pressure Angle: 20

Face Width : 10

Nominal shaft diameter: 18

Pitch circle diameter: no of teeth x module

: 14 x 2.5 = 35

Number of gears: 1

Assembly pictures of planetary gear:

Case 1: Ring gear is fixed. Input is given to sun gear.

Angular velocity of sun gear :

Angular velocity of ring gear :

Angular velocity of planetary gear :

Angular velocity of the carrier :

Case 2: sun gear is fixed. Input is given to ring gear.

Angular velocity of sun gear :

Angular velocity of ring gear :

Angular velocity of planetary gear :

Angular velocity of the carrier :

Case 3: carrier gear is fixed. Input is given to sun gear.

Angular velocity of sun gear :

Angular velocity of ring gear :

Angular velocity of planetary gear:

Angular velocity of the carrier:

Result:

In the first case where Input is given to Sun gear while Output is achieved at Carrier when Ring gear is fixed. The output angular velocity of the carrier is 281 deg/sec.

In the second case where Input is given to Ring gear while Output is achieved at Carrier when Sun gear is fixed. The output angular velocity of the carrier is 935 deg/sec.

In the third case where Input is given to Sun gear while Output is achieved at Ring gear when Carrier is fixed. The output angular velocity of the ring gear is 392 deg/sec.

CAD Models and Assembly file Link: https://drive.google.com/drive/folders/1PeOY1vGf-AyZL8Zerp7oFktFXXN2c5-W

Animation Link:https://www.youtube.com/playlist?list=PLgFSZcr_6YgxM4bLSf_DmuDdPlrWkaDqy