X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from poplet2.per.eftel.com ([203.24.100.45] verified) by logan.com (CommuniGate Pro SMTP 5.2.14) with ESMTP id 3631119 for flyrotary@lancaironline.net; Mon, 04 May 2009 05:43:09 -0400 Received-SPF: none receiver=logan.com; client-ip=203.24.100.45; envelope-from=lendich@aanet.com.au Received: from mail.aanet.com.au (mail.aanet.com.au [203.24.100.34]) by poplet2.per.eftel.com (Postfix) with ESMTP id 506C8173962 for ; Mon, 4 May 2009 17:42:20 +0800 (WST) Received: from ownerf1fc517b8 (203.171.92.134.static.rev.aanet.com.au [203.171.92.134]) by mail.aanet.com.au (Postfix) with SMTP id C4177149C805 for ; Mon, 4 May 2009 17:40:45 +0800 (WST) Message-ID: From: "George Lendich" To: "Rotary motors in aircraft" References: Subject: Re: [FlyRotary] Re: Harley Davidson Generator Date: Mon, 4 May 2009 19:40:21 +1000 MIME-Version: 1.0 Content-Type: multipart/related; type="multipart/alternative"; boundary="----=_NextPart_000_000D_01C9CCF0.297CC570" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2900.5512 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.5579 X-Antivirus: avast! (VPS 0617-3, 04/28/2006), Outbound message X-Antivirus-Status: Clean This is a multi-part message in MIME format. ------=_NextPart_000_000D_01C9CCF0.297CC570 Content-Type: multipart/alternative; boundary="----=_NextPart_001_000E_01C9CCF0.297F0F60" ------=_NextPart_001_000E_01C9CCF0.297F0F60 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Todd, The heat actually affects the rare earth magnets, a search on the = internet should confirm this. I just can't remember the details. I guess = the glue is another matter. George (down under) Hi Ernest; From Georges comment, I gather that the heat sensitivity would = likely be due to the glue that bonds the magnets to the inside of the = rotor. This makes sense and also means that I shouldn't have much of an = issue if no air blows under the rotor and onto the stator. Air movement = around the rotor should be enough. I really am a lot less satisfied with "should" than I used to be. Todd C-FSTB =20 On Sun, 2009-05-03 at 21:01 -0400, Ernest Christley wrote:=20 Todd Bartrim wrote: > I'm thinking about the cooling issue that you are addressing with fan=20 > blades. How much heat do you think it will generate? I'm=20 > thinking/hoping not much. I don't know about the original Harley=20 > install, but as this is commonly used source of power, I got to=20 > looking at my Ski-Doo, ATV and dirt bike. In everyone of them the=20 > stator/rotor is completely sealed up and is not liquid or oil cooled.=20 > And I've never had issues with them. It would be a simple matter for=20 > me to put a small baffle at the exit of one of the evap cores that I=20 > use for cooling and direct some of the air over the rotor, but due to=20 > the tight fit, not much air would find it's way under to the stator. I don't know what sort of heat load it'll generate, but it is almost=20 immaterial to my installation. For me, he intake air will be flowing=20 over it regardless. I've been told that PM alternators are only 50%=20 efficient. I find that hard to believe; that would be a 500W heat=20 source for a 40A generator. But even at that worst case, it isn't an=20 issue for me. ------=_NextPart_001_000E_01C9CCF0.297F0F60 Content-Type: text/html; charset="UTF-8" Content-Transfer-Encoding: quoted-printable =EF=BB=BF

Todd,

The heat actually affects the rare = earth magnets, a=20 search on the internet should confirm this. I just can't remember the = details. I=20 guess the glue is another matter.

George (down under)

Hi=20 Ernest;
From Georges comment, I gather that the = heat=20 sensitivity would likely be due to the glue that bonds the magnets to = the=20 inside of the rotor. This makes sense and also means that I shouldn't = have=20 much of an issue if no air blows under the rotor and onto the stator. = Air=20 movement around the rotor should be = enough.
I=20 really am a lot less satisfied with "should" than I used to be.

Todd
C-FSTB

On Sun, 2009-05-03 at 21:01 = -0400,=20 Ernest Christley wrote:=20
Todd Bartrim wrote:
> I'm thinking about the cooling issue that you are addressing with =
fan=20
> blades. How much heat do you think it will generate? I'm=20
> thinking/hoping not much. I don't know about the original Harley=20
> install, but as this is commonly used source of power, I got to=20
> looking at my Ski-Doo, ATV and dirt bike. In everyone of them the=20
> stator/rotor is completely sealed up and is not liquid or oil =
cooled.=20
> And I've never had issues with them. It would be a simple matter =
for=20
> me to put a small baffle at the exit of one of the evap cores that =
I=20
> use for cooling and direct some of the air over the rotor, but due =
to=20
> the tight fit, not much air would find it's way under to the =
stator.
I don't know what sort of heat load it'll generate, but it is almost=20
immaterial to my installation.  For me, he intake air will be flowing=20
over it regardless.  I've been told that PM alternators are only 50%=20
efficient.  I find that hard to believe;  that would be a 500W heat=20
source for a 40A generator.  But even at that worst case, it isn't an=20
issue for me.

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