Planetary Gear
AIM: -
To create a 3D model of Epicyclic gear system and do its motion analysis.
OBJECTIVE: -
Our objective is to create a 3D model of Epicyclic gear system in solidwork and plot the variation of angular velocity for the following different constraint condition from result.
Sl.No Input Output Fixed
1 Sun Gear Carrier Ring Gear
2 Ring Gear Carrier Sun Gear
3 Sun Gear Ring Gear Carrier
Components:-
1- Sun gear
4 -Planetary gears
1 -Ring gear
1 Carrier
BODY: -
Calculation of Pitch Circle Diameter and No. of Teeth in Planet Gears:
- The module is the same for all the gears.
The relation between the pitch circle diameter and no. of teeth is as follows:-
D= m *T
D = pitch diameter
m = module
T= no. of teeth
(Dia of ring) / 2= (Dia of planetary gear)+( Dia of sun gear) / 2
From above equation we can calculate number of teeth in planetary gear .Here, we have got 16.
Here we have used the inbuilt design library of solidwork to design gear. We have imported all six gear from design library. We have saved all three type of gear individually. While assembling the gear We have imported one ring gear having 46 teeth, one sun gear having 14 teeth and we have imported planetary gear four times which is having 16 teeth. Then we have provided certain constraints and saved it.
While doing motion analysis , we have provided 8 contacts and input of 10 RPM.
- Variation of angular velocity at carrier when ring gear is fixed
- Variation of angular velocity at carrier when sun gear is fixed
- Variation of angular velocity at ring gear when carrier is fixed
CONCLUSION: -
In case 1 when the input is given rotation to the sun gear and output is obtained at the carrier keeping the ring gear fixed. The planet gear not only rotates about their axis but are also forced to roll on the inside of the ring gear since it is fixed (rolling action is present)
In case 2 when the input is given to the ring gear and output is obtained from the carrier keeping the sun gear fixed. The angular velocity achieved is maximum since the internal gear is big and planet gears are small comparatively so when a large gear meshes with a small gear the velocity achieved from the small gear is high because the velocity ratio is high A this can be seen in the plot of angular velocity.
In case 3 when a carrier is fixed and output is to be obtained from the ring gear the opposite happens. The planet gears rotate only about their axis and transmit motion from sun to the ring and since the ring gear is big in diameter the angular velocity achieved is less.
The deviations that are visible in the graphs show that there are points where sliding is occurring between the gears. For making the graph more smoother we can use precise contact.
#LINK
Sun is fixed:
ring is fixed:
carrier is fixed: