Return-Path: Received: from access.aic-fl.com ([204.49.76.2] verified) by logan.com (CommuniGate Pro SMTP 4.2.4) with ESMTP id 457375 for flyrotary@lancaironline.net; Fri, 08 Oct 2004 08:31:08 -0400 Received-SPF: none receiver=logan.com; client-ip=204.49.76.2; envelope-from=unicorn@gdsys.net Received: from homep276y68tk5 (unverified [204.49.76.109]) by access.aic-fl.com (Rockliffe SMTPRA 4.5.6) with SMTP id for ; Fri, 8 Oct 2004 07:30:55 -0500 Message-ID: <002a01c4ad32$c84435e0$6d4c31cc@homep276y68tk5> From: "Richard" To: "Rotary motors in aircraft" References: Subject: Re: [FlyRotary] Re: OIL METERING PUMP Date: Fri, 8 Oct 2004 07:31:37 -0500 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_0027_01C4AD08.D896ED90" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2800.1106 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1106 This is a multi-part message in MIME format. ------=_NextPart_000_0027_01C4AD08.D896ED90 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Al, the oil entrance is right behind the relieve hole on the other side of = the shaft bore, coming out of the cover wall. Oil will leak out when the shaft is bad. Under normal condition, there = can be no pressure buildup in the pump, because it is all open to the = crank case via the oil inlet and relieve hole. BTW, the shaft has a flat = section on its running surface toward the pump for oil feed. The actual pump does not have a drive plate. The picture shown on the = ACRE site has no resemblance with the physical design of the real pump. = There are even functional differences. The most significant functional = difference is that the piston makes two strokes per revolution.=20 Richard Sohn N-2071U unicorn@gdsys.net ----- Original Message -----=20 From: Al Gietzen=20 To: Rotary motors in aircraft=20 Sent: Monday, October 04, 2004 7:05 PM Subject: [FlyRotary] Re: OIL METERING PUMP Subject: [FlyRotary] OIL METERING PUMP Richard; Thanks for input on this. That relieve hole looks very large and not = likely to blocked, especially on a newly rebuilt engine. Or am I looking = at the wrong thing; how does the oil get into the recess? Oil entering the pump can leak past the adjuster shaft if the seal was = bad, right? And what happens to the oil that enters the piston with the = blocked exit port as the piston moves to eject the oil? I was thinking = it gets forced back past the piston into the drive area where it can = then leak past the adjuster shaft, but I guess the feed oil is in that = area anyway. Still; it seems forcing the piston against the oil with no = exit port would put high stress on the drive plate, no? Al Al, here is some more info on the OMP oil feed. Oil is coming into a recess in the pump drive shaft. The thus formed = cavity has a relieve hole as shown in the pic, making the pressure in = the cavity practically even with the crank case pressure, depending = someway on the flow rate. The roll pin in the relieve hole is to make = sure there is no air pocket in the cavity, which is connected to the = pump intake. Each out put is driven by a separate piston and two are together per = stroke. Each stroke is small enough not to create a problem when you = block a line off. It Would not hurt the pump if two outputs are = connected for double oil flow. I hope it is clear, and not confusing. Richard Sohn N-2071U unicorn@gdsys.net ------=_NextPart_000_0027_01C4AD08.D896ED90 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable

Al,

the oil entrance is right = behind the=20 relieve hole on the other side of the shaft bore, coming out of the = cover=20 wall.

Oil will leak out when the = shaft is bad.=20 Under normal condition, there can be no pressure buildup in the pump, = because it=20 is all open to the crank case via the oil inlet and relieve hole. BTW, = the shaft=20 has a flat section on its running surface toward the pump for oil=20 feed.

The actual pump does not have a = drive=20 plate. The picture shown on the ACRE site has no resemblance with the = physical=20 design of the real pump. There are even functional differences. The most = significant functional difference is that the piston makes two strokes = per=20 revolution.

Richard Sohn
N-2071U
unicorn@gdsys.net

----- Original Message -----
From:=20 Al = Gietzen=20
To: Rotary motors in = aircraft

Sent: Monday, October 04, 2004 = 7:05=20 PM

Subject: [FlyRotary] Re: OIL = METERING=20 PUMP

Subject:=20 [FlyRotary] OIL METERING PUMP

Richard;

Thanks = for input on=20 this. That relieve hole looks very large and not likely to = blocked,=20 especially on a newly rebuilt engine. Or am I looking at the wrong = thing; how=20 does the oil get into the recess?

Oil = entering the=20 pump can leak past the adjuster shaft if the seal was bad, right? = And=20 what happens to the oil that enters the piston with the blocked exit = port as=20 the piston moves to eject the oil? I was thinking it gets forced = back=20 past the piston into the drive area where it can then leak past the = adjuster=20 shaft, but I guess the feed oil is in that area anyway. Still; = it seems=20 forcing the piston against the oil with no exit port would put high = stress on=20 the drive plate, no?

Al

Al,

here is some more info = on the OMP=20 oil feed.

Oil is coming into a = recess in the=20 pump drive shaft. The thus formed cavity has a relieve hole as shown = in the=20 pic, making the pressure in the cavity practically even with the crank = case=20 pressure, depending someway on the flow rate. The roll pin in the = relieve hole=20 is to make sure there is no air pocket in the cavity, which is = connected to=20 the pump intake.

Each out put is driven = by a=20 separate piston and two are together=20 per stroke. Each stroke is small enough not to = create=20 a problem when you block a line off. It Would not hurt the pump = if two=20 outputs are connected for double oil flow.

I hope it is clear, and = not=20 confusing.

Richard = Sohn
N-2071U
unicorn@gdsys.net
=

------=_NextPart_000_0027_01C4AD08.D896ED90--