Received-SPF: none
 receiver=logan.com; client-ip=68.230.241.40; envelope-from=dale.r@cox.net
Message-ID: <47AF1723.2040400@cox.net>
Date: Sun, 10 Feb 2008 08:24:19 -0700
From: Dale Rogers <dale.r@cox.net>
User-Agent: Thunderbird 2.0.0.9 (Windows/20071031)
MIME-Version: 1.0
To: Rotary motors in aircraft <flyrotary@lancaironline.net>
Subject: Re: [FlyRotary] Re: Rotor Weight Codes
References: <list-2723043@logan.com>
In-Reply-To: <list-2723043@logan.com>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
Content-Transfer-Encoding: 7bit

Ernest Christley wrote:
> OK.  You caught me.
>
> I always thought there was some back and forth motion in that rotary 
> rotation.  But I've just spend the last few minutes staring at 
> http://www.keveney.com/Wankel.html
>
> There has to be some recipricating motion.  If there wasn't, the apex 
> seals would all trace a perfect circle.  I should go to bed.
>


Not reciprocating.  There is acceleration and deceleration; and the 
vectors are complex - the e-shaft makes a complete rotation every time a 
new face of the rotor is presented to the spark plugs.  Think of it like 
being in slow-and-go traffic on the freeway - you keep going forward, 
but sometimes not by much.  In fact, the path of the valve stem on your 
wheel as you roll down the freeway is a "classic" trochoid. 

Take a look at: http://mathworld.wolfram.com/Trochoid.html

Dale R.
COZY MkIV  #0497
Ch. 13