Epicyclic Gear Train, why is net radial force near 0
Epicyclic Gear Train, why is net radial force near 0
(OP)
Dear Experts,
I have a query regarding tangential and radial forces present in an epicyclic gear train.
I understand that the tangential force is responsible for transferring torque between the mating gears, while the radial forces tend to push the gears apart etc.
I read articles stating that the radial force is irrelevant in epicyclic gear trains but does not give a concise explanation why.
Can anyone shed some light on this query?
Even better, are there good books/ web sources that explain loading on epicyclic gears? I have machinery's handbook and Machine Design by Robert Norton but they are not useful for epicyclic systems.
Something is telling me the radial forces cancel each other outer at the ring / planet and planet/sun interfaces but I need solid proof in terms of references etc.
Any information will be appreciated.
Kind Regards
Ed
I have a query regarding tangential and radial forces present in an epicyclic gear train.
I understand that the tangential force is responsible for transferring torque between the mating gears, while the radial forces tend to push the gears apart etc.
I read articles stating that the radial force is irrelevant in epicyclic gear trains but does not give a concise explanation why.
Can anyone shed some light on this query?
Even better, are there good books/ web sources that explain loading on epicyclic gears? I have machinery's handbook and Machine Design by Robert Norton but they are not useful for epicyclic systems.
Something is telling me the radial forces cancel each other outer at the ring / planet and planet/sun interfaces but I need solid proof in terms of references etc.
Any information will be appreciated.
Kind Regards
Ed





RE: Epicyclic Gear Train, why is net radial force near 0
You list your field as mechanical, so it should be obvious. Draw a free body diagram and resolve the forces at the gear tooth faces into tangential and radial components for the gear train. This will demonstrate that the radial forces on the planet gears cancel.
Timelord
RE: Epicyclic Gear Train, why is net radial force near 0
Thanks you for your response. Yes, I have drawn the FBD of planet gear mating with the internal ring gear and the sun gear.
I have resolved the applied force acting along the line of the pressure angle into its radial and tangential components. I can see that the radial forces cancel but the tangential forces also eliminate each other since they are opposite and equal.
Perhaps I am missing something.
Regards
Ed
RE: Epicyclic Gear Train, why is net radial force near 0
RE: Epicyclic Gear Train, why is net radial force near 0
Good luck.
Terry
RE: Epicyclic Gear Train, why is net radial force near 0
RE: Epicyclic Gear Train, why is net radial force near 0
RE: Epicyclic Gear Train, why is net radial force near 0
RE: Epicyclic Gear Train, why is net radial force near 0
You are correct. I should have been more specific.
Regards,
Terry
RE: Epicyclic Gear Train, why is net radial force near 0
The free body diagram is always the key to the solution.
Now when we covered all configurations (I hope