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Date: Sun, 28 Jun 2009 15:17:46 -0700
From: Dale Rogers <dale.r@cox.net>
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To: Rotary motors in aircraft <flyrotary@lancaironline.net>
Subject: Re: [FlyRotary] Re: More progress, more questions....
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Berniehb7448@wmconnect.com wrote:
> ...
> BTW, does anyone have a list of PSRU's that are also made for 
> rotaries? The emphasis today seems to be on geared PSRUs, why is that? 
> What scientific factual reasons prevent us from considering cog belts 
> or chains?
>

Dunno about "scientific", but generally a planetary drive is more
compact than a belt or chain drive.  An added plus is that it is
likely to eliminate the need for an $300++ prop hub extension.

There is a lot to like about a cog belt drive, as it is likely to
weigh less than an equivalent planetary drive.  Then again, the
necessary sealed bearings won't be cheap. Nor are the belts
that are capable of transmitting that much horsepower.  Will
they last 2,000 hours at 6000 RPM?

Somp'in to think about
Dale R.
COZY MkIV #0497
Mesa, AZ