Need help with a Planetary Gear Arrangement

[manjot_singh]

Hi all,


I need help with a Gear Train described below. A rough sketch is attached.


I have a Round Plate above which there is a 88 Tooth Gear (Gear A). Both have their own drive and the ratio is 1:4. For every 1 turn of the plate, the Gear A rotates 4 times. They both rotate in the same clockwise direction.


On the plate is fixed a Gear B which meshes with the 88 Tooth Gear A.


I want it such that for every 1 rotation of the Plate, the Gear B rotates 18 times.


I am unable to figure out the no. of Teeth for Gear B, and would be grateful for any help with the formula/calculation.
If required, I can change the ratio between the Plate and the Gear A and/or the No. of Teeth on Gear A.

[mike_willard]

Isn't it 22? 88/22 Give a 4:1 ratio

[manjot_singh]

Isn't it 22? 88/22 Give a 4:1 ratio

Hi,
With 88/22 I get a ratio of 2.5:1 using the following formula:

(R+S) x Ty = Ts x S

R= Ring Gear Teeth (Calculated to be 132 [R=2 x P + S])
S= Sun Teeth (88)
P=Planet Teeth (22)
Ty=Turns of Planetary Gear Carrier (1)
Ts=Turn of Sun Gear (2.5)

Does this seem correct?