Mailing List flyrotary@lancaironline.net Message #23876
From: Tracy Crook <lors01@msn.com>
Subject: Re: [FlyRotary] planetary gear ratios
Date: Wed, 15 Jun 2005 00:01:22 -0400
To: Rotary motors in aircraft <flyrotary@lancaironline.net>
The formula is not the same for both locked ring gear and locked planetary gear.   This formula is for the locked ring gear and you probably have the locked planetary.  Remove the 1 from the equation and it will come out right for yours. 
 
Tracy (making a lot of assumptions about your drive)
----- Original Message -----
Sent: Tuesday, June 14, 2005 11:24 PM
Subject: [FlyRotary] planetary gear ratios

I ran across some information in one of the scientific newsgroups on how
to calculate the gear ratio of a planetary gear set.

ratio = 1 + r / s

where: r = number of ring gear teeth
           s = number of sun gear teeth.

I haven't replace my 3-pinion gear set with a 6-pinion set, because I've
not been able to positively identify it to where I could call out a part
number.  Order strange gearset from the internet is not what I consider
an efficient way to spend money.  So I went out and counted.  74 teeth
on the ring and 34 on the sun.

1+74/34 = 3.176

That is not the 2.17 OR the 2.85 from the Ford gear sets.  Is it
possible that the one isn't added in standard practice, so that what I
actually have is the 2.17 gear set?

--
This is by far the hardest lesson about freedom. It goes against
instinct, and morality, to just sit back and watch people make
mistakes. We want to help them, which means control them and their
decisions, but in doing so we actually hurt them (and ourselves)."


>>  Homepage:  http://www.flyrotary.com/
>>  Archive:   http://lancaironline.net/lists/flyrotary/List.html
Subscribe (FEED) Subscribe (DIGEST) Subscribe (INDEX) Unsubscribe Mail to Listmaster