Date:         Mon, 29 Aug 2016 22:18:09 -0600
Reply-To:     Steve Williams <steve@WILLIAMSITCONSULTING.COM>
Sender:       Vanagon Mailing List <vanagon@gerry.vanagon.com>
From:         Steve Williams <steve@WILLIAMSITCONSULTING.COM>
Subject:      Re: Solution - Re: Dometic fridge (external) fan replacement...
Comments: To: "C. Abney" <tsudonimh@GMAIL.COM>
In-Reply-To:  <CALsWj8=fU5SRGBP_scZBmyCRHoTgwZOVTV6LnYwGAsme0=rQyQ@mail.gmail.com>
Content-Type: text/plain; charset=utf-8; format=flowed

Hi,

What an interesting tidbit of information!  That's quite a rabbit hole I
went down, researching computer fan (and hard disk) bearings!

I got a high quality fan... all of $17 CDN, but it's rated for 160,000 MTBF.

The literature for the fan I bought claims it's a "Loop Dynamic Bearing"
and looking at the manufacturer website, it's some kind of fluid dynamic
bearing.  The manufacturer's website doesn't mention mounting orientation.

Other web sites that I found seem to indicate that orientation doesn't
matter for a fluid dynamic bearing.

More reading would seem to indicate that the direction of air flow in
relation to gravity will affect the longevity of the bearing... pushing
air down would reduce the weight (force) on a thrust bearing.  The
orientation my fan is mounted with the air pushing up has 2 forces
working together, gravity and the force of the air forcing the fan into
the case.  Hum...  This will be an interesting experiment.  Not too
expensive of one either!

Thanks very much for pointing this out.  There are subtleties to everything!

Cheers,
Steve Williams


On 29/08/2016 6:03 PM, C. Abney wrote:
> I wasn't going to say anything since I don't have that (a) fridge and
> couldn't know the fan layout, but if that has a sleeve bearing the
> only way to use it and expect any life expectancy is to mount it
> vertically and not horizontally.  For that application you are better
> off with a ball bearing fan.
>
> On 8/29/16, Steve Williams <steve@williamsitconsulting.com> wrote:
>
>> http://www.williamsitconsulting.com/misc/DometicFan.jpg
> -Chuck
> --
> It seems my TO-DO list is a FITO (faster-in-than-out)