X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from mail-bk0-f52.google.com ([209.85.214.52] verified) by logan.com (CommuniGate Pro SMTP 5.4.4) with ESMTPS id 5475384 for flyrotary@lancaironline.net; Tue, 10 Apr 2012 09:47:05 -0400 Received-SPF: pass receiver=logan.com; client-ip=209.85.214.52; envelope-from=msteitle@gmail.com Received: by bkcjm19 with SMTP id jm19so4138080bkc.25 for ; Tue, 10 Apr 2012 06:46:29 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:in-reply-to:references:date:message-id:subject:from:to :content-type; bh=BrAanmwIu6R2wBpxBtRdaZD6ngGNDtkLlOlIvulTKio=; b=R8Y09uJd2E1SVOHdvdG4BtkMHrXjwK3q7RSO6s0SGGCn6Tr/oFinb8VbIo1LnPBJ32 Iaw0nV0531+aTDk/qdlYULbevR5X0ruAPIUDNck8UuNpwF7AXd8AL6x36cByF+aEmS1B JQdH5rStZ6seh/TOG8E3a+ObYMg/yTjmw10cULk4HI2Ugi5I/h4DHVftsTqXpD59EpDI VbSvPBwuWfajZZ+33Bng19Z7+qti4HyomRwP1Lms3dlPUCZCaGBSCxihFAIAVfWLzgpZ LIcndQaAs0oYIvuw/+vlfY/UXrxOvOdlvxuoxCm0yfsZX2BCxToPOSy+5478u1aFpPMU b5eQ== MIME-Version: 1.0 Received: by 10.205.133.210 with SMTP id hz18mr4575572bkc.117.1334065588971; Tue, 10 Apr 2012 06:46:28 -0700 (PDT) Received: by 10.205.118.139 with HTTP; Tue, 10 Apr 2012 06:46:28 -0700 (PDT) In-Reply-To: References: Date: Tue, 10 Apr 2012 08:46:28 -0500 Message-ID: Subject: Re: [FlyRotary] Re: OMP From: Mark Steitle To: Rotary motors in aircraft Content-Type: multipart/alternative; boundary=000e0ce0294a89a92804bd535955 --000e0ce0294a89a92804bd535955 Content-Type: text/plain; charset=ISO-8859-1 Steve, That drawing really helped me understand how the the OMP works. The 20b OMP is very similar, although the lever has been replaced with a stepper motor and a solenoid. Also, the 20B plunger and ports are larger, which makes sense as it must pump 50% more oil. So, it looks like I'll be using the 20b pump after all. Regarding the plugged port, this was done by Mazda. So, I'll leave it as is. Maybe they used the 2-rotor casting for the 3-rotor engines... just a guess. Mark On Tue, Apr 10, 2012 at 2:09 AM, Steven W. Boese wrote: > Mark, > > > > The 13B OMP is a positive displacement pump not a valve requiring constant > pressure differential and constant viscosity for flow control. Drilling > out the ports may change the flow rate if it causes overlap between the > supply and delivery ports, but the result would be the loss of accurate > flow control. The flow rate would decrease unless the oil reservoir were > pressurized. The attached drawing is an attempt to show how the pump > works. It delivers oil to only two of the four delivery ports on > one stroke and then delivers oil to the other two ports on the next > stroke. The sleeve completes two strokes each time it completes one > revolution. Although the drawing doesn't state it, the speed of the worm > gear (engine RPM) as well as the length of stroke determines the flow rate. > > > > Since this pump is positive displacement, simply plugging a port would not > be recommended. The oil needs some place to go because the pressure is > developed by the rotation of the sleeve against the stroke control cam, not > by limited spring pressure. > > > > Steve > ------------------------------ > *From:* Rotary motors in aircraft [flyrotary@lancaironline.net] on behalf > of Mark Steitle [msteitle@gmail.com] > *Sent:* Monday, April 09, 2012 9:04 PM > *To:* Rotary motors in aircraft > *Subject:* [FlyRotary] Re: OMP > > Steve, > > I disassembled both the 13b and 20b OMPs tonight. Best I can tell, the > OMP doesn't actually pump oil as much as it "meters" the oil. It appears > to be a small spool valve device. Instead of the spool moving, the lever > moves the outer part back and forth in relation to the spool valve. Moving > the lever full open causes the outer body to move in relation to the spool > valve allowing oil to flow through the passages providing maximum oil flow. > Move the lever the other way and the outer body moves the other direction > (in relation to the spool valve) reducing oil flow. When the outer body > moves from closed to open, its holes come into alignment with the outlet > holes in the OMP. Excess oil is routed through the pump body to the > crankcase. At least that's how I think it works, but then I could be wrong. > > If I could drill out one of the smaller outlets to equal the larger > ones, then this may work just fine for the 3-rotor. Following the 20b > design, I could then plug the 4th hole. > > > Mark > > > On Mon, Apr 9, 2012 at 8:49 PM, Steven W. Boese wrote: > >> Mark and all, >> >> >> >> The information that I previously gave on the '86 OMP delivery is in >> error. After further analysis of the disassembled OMP, I realized that the >> delivery rate for the front two ports depends on the DIFFERENCE between the >> diameters of the two sections of the pump piston. The result is that all >> four of the ports deliver the same flow rate. This would make the >> application of this OMP to a three rotor engine more difficult, in my >> opinion. Of course I could be wrong about that, too. >> >> >> >> I apologize for the mistake. >> >> >> >> Steve >> >> > > -- > Homepage: http://www.flyrotary.com/ > Archive and UnSub: > http://mail.lancaironline.net:81/lists/flyrotary/List.html > > --000e0ce0294a89a92804bd535955 Content-Type: text/html; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable Steve,=A0

That drawing really helped me understand how t= he the OMP works. =A0The 20b OMP is very similar, although the lever has be= en replaced with a stepper motor and a solenoid. =A0Also, the 20B plunger a= nd ports are larger, which makes sense as it must pump 50% more oil. =A0So,= it looks like I'll be using the 20b pump after all.

Regarding the plugged port, this was done by Mazda. =A0= So, I'll leave it as is. =A0Maybe they used the 2-rotor casting for the= 3-rotor engines... just a guess.

Mark
<= br>
On Tue, Apr 10, 2012 at 2:09 AM, Steven W. Boese= <SBoese@uwyo.edu> wrote:

Mark,

=A0

The 13B=A0OMP is a positive displacement pump not a valve requiring cons= tant pressure differential=A0and constant viscosity for flow control.=A0 Dr= illing out the ports may change the flow rate if it causes overlap between = the supply and delivery ports, but the result=A0would be=A0the loss of accurate flow control.=A0 The flow rate wo= uld decrease unless the oil reservoir were pressurized.=A0 The attached dra= wing is an attempt to show how the pump works.=A0 It delivers oil to only t= wo of the four delivery ports=A0on one=A0stroke and then delivers oil to the other two ports on the next stroke.=A0The sle= eve completes two strokes each time it completes one revolution.=A0 =A0Alth= ough the drawing doesn't=A0state it, the speed of the worm gear (engine= RPM) as well as the length of stroke determines the flow rate.

=A0

Since this pump is positive displacement, simply plugging a port would n= ot be recommended.=A0 The oil needs some place to go=A0because the pressure= is developed by the rotation of the sleeve against the stroke control cam,= not by limited spring pressure.=A0

=A0

Steve

Fro= m: Rotary motors in aircraft [flyrotary@lancaironline.net] on behalf of Mark = Steitle [msteitle@g= mail.com]
Sent: Monday, April 09, 2012 9:04 PM
To: Rotary motors in aircraft
Subject: [FlyRotary] Re: OMP

Steve,=A0

I disassembled both the 13b and 20b OMPs tonight. =A0Best I can tell, = the OMP doesn't actually pump oil as much as it "meters" the = oil. =A0It appears to be a small spool valve device. =A0Instead of the spoo= l moving, the lever moves the outer part back and forth in relation to the spool valve. =A0Moving the lever full open causes the o= uter body to move in relation to the spool valve allowing oil to flow throu= gh the passages providing maximum oil flow. =A0Move the lever the other way= and the outer body moves the other direction (in relation to the spool valve) reducing oil flow. =A0When the = outer body moves from closed to open, its holes come into alignment with th= e outlet holes in the OMP. =A0Excess oil is routed through the pump body to= the crankcase. =A0At least that's how I think it works, but then I could be wrong.

If I could drill out one of the smaller outlets to equal the larger on= es, then this may work just fine for the 3-rotor. =A0Following the 20b desi= gn, I could then plug the 4th hole. =A0


Mark


--
Homepage: =A0http:/= /www.flyrotary.com/
Archive and UnSub: =A0 http://mail.lancaironline.net:81/lists= /flyrotary/List.html


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