You missed the point on this item. The GOVERNOR has the pump to do this, Tracy need only provide a transfer area for the pressure. He could do a port into the bearing near the front with a circrumfrencial groove and a through hole on the shaft under the groove. This can be on the same bearing surface. This amounts to a small loss of bearing area but not enough to be a problem.
Bill,
Tracy considered doing that at one point. I believe when he realized most Hydraulic controlled props required much higher oil pressure than the 60-70 psi our oil system produces, he decided he didn't want to have to produce a Prop controller to provide the required oil pressure.
Here is a excerpt from the MT propeller site regarding hydraulic pressure typically required.
The servo pressure necessary for changing pitch is generated by a gear pump located inside the propeller governor, which increases the oil pressure supplied by the engine by factor 6 or higher.
Ed
----- Original Message -----
Sent: Monday, December 18, 2006 11:46 PM
Subject: [FlyRotary] Re: hydraulic constant speed prop for rotarys
Dave, if you go with a Mistral PSRU you can run any Hyd/CS you want. I'm supprised Tracy hasn't gone to a hollow shaft on his PSRU since he runs a big plain bearing he could set up a port for a CS prop.
Bill Jepson
HEY! That's like saying that the store is giving out free ice cream but not telling us which store.. :-)
Dave Leonard
On 12/18/06, lou rubin <grdflyguy@yahoo.com> wrote:
While we are on the subject of props I want to bring
to the groups attention we are installing a constant
speed hydraulic prop on a SA2 hub with Tracys 2.17 RD
The prop is very similar to MT design except its about
half the price & actuated hydraulically instead of
electrically. Im the past we havnt had any other CS
prop options except the electric because we dont
incorporate a hollow crankshaft as our Lycoming &
Continental cousins . We are mounting the prop on a
20B in a Lancair ES however, it could be just as
easily installed on a 13B as well We will keep you
posted on our progress
We will be selling our IVO Magnum if there is anyone
interested & possibly the 2.17 RD in the future
Lou N117ES