|
Dave and all,
My prop shaft is on timken taper
bearings, so does not need the pressure feed. Matt is too polite
to tell the whole story. The initial run did not get enough oil
to the bronze bush between the input shaft and the prop shaft ---
so it did what all oil starved bearings do --- it melted.
Luckily Matt had his rubber cushion drive self destruct as well--
I say luckily as that caused the dismantle of the redrive which
found the cooked bronze bush. Fortunately no other damage. This
prompted us to make the unit self contained as for lubrication.
Heat may be a problem, but I doubt it and time will soon tell.
Rubber cushion drive --- Matt has really copped the "pineapple"
on this. Finally turns out that the rubber firm used the wrong
rubber --- Still chasing that problem down but appears lack of
communication between the office and the workman doing the job.
In ignorance and lack of knowledge he put the wrong rubber in---
totally different rubber to the one I am running currently. These
cushion drives will be subject to recall and the proper rubber
fitted. Very embarrassing and infuriating for me.
So as info becomes available I will post, but the self contained
oil should work well and will simplify things.
Neil.
Well said, Charlie. Here is Neil's page with
diagrams:
BTW, very nicely done Neil.
Best I can tell it is a pressure fed bearing just like
Tracys.
Dave Leonard
Matt,
I've not followed Neil's version of the drive carefully;
he may not be using a sleeve bearing. But Tracy's drive
*does* use one, under that oil feed hole in the 'fat' part
of the housing. Dave's telling you that if there's a
sleeve type bearing in there that's designed for pressure
feeding, lack of oil pressure is certain death, in short
order. If Neil is using a ball or roller bearing back
there, that's a different game entirely, and I'd want his
input on whether it needs pressurized flow, both for lube
and for cooling.
On 5/8/2019 3:44 PM, Matt Boiteau mattboiteau@gmail.com wrote:
Neil's. 3.17 ratio.
I've found the back gears push the oil
to the front pretty well.
- Matt Boiteau
Matt, is this one of Tracy Crooks
drives? If so, it will absolutely fail in short
order with no pressure feed to the main bearing.
Dave Leonard.
So far on the ground, static 2200 prop rpm
for 30seconds, temps only got to 135°F.
Haven't flown yet. Will advise in June.
- Matt Boiteau
Matt,
So you are trying using self
contained lube with no pressure feed
from the engine and no
drain...…...Watch your
temps......…….Let us know what
happens...…...
Kelly Troyer
I've been
experimenting on Neil's PSRU with
sealing it up. Only adding a
breather vent on the rear housing.
So far I've only done ground
testing, but all seems well enough
to fly with it soon enough. The
Tygon house in the picture was
only to see the oil flow, it's
capped off now. I ran gear oil
70w-140 and it was way to thick
and came out the breather vent, so
went back down to my normal engine
oil 20w-50. Filled half full, but
I think I can go a little less,
haven't tested the idle level yet.
I have a temp sensor (1/3 down),
and a digital level sensor (half
way) installed in the rear
housing as well.
-
Matt Boiteau
On
2019-05-07 12:32:26 PM, Steven
W. Boese SBoese@uwyo.edu
<flyrotary@lancaironline.net>
wrote:
If
the original return line was
not enlarged, the "vent" line
simply acted as an additional
return line and my gearboxes
operated completely filled
with oil.
Steve Boese
> On May 7, 2019, at 9:41
AM, Jeff Whaley jwhaley@datacast.com
wrote:
>
> ◆ This message was sent
from a non-UWYO address.
Please exercise caution when
clicking links or opening
attachments from external
sources.
>
>
> Hi Steve, is the
enlarging of the oil return
necessary?
> I thought you first tried
enlarging the return line
expecting it to improve
draining, only to find no
improvement until the vent
line was added.
> Jeff
>
> Jeff,
> At this point I have only
3 hr of flight time on the
gearbox with the modified
drain and vent. I have not
observed a significant effect
with respect to power
absorption or heat generation.
>
> Connecting the vent line
to the foot of the rotor
housing was ineffective even
though this location was above
the oil level. Connecting the
vent line to the area of the
oil filler opening at the top
of the center iron allowed the
gearbox to drain as intended.
>
> The most troublesome part
of the modification was
enlarging the oil return to
1/2" NPT in the rotor housing
foot.
>
> Steve Boese
>
>
> --
> Homepage: http://www.flyrotary.com/
> Archive and UnSub: http://mail.lancaironline.net:81/lists/flyrotary/List.html
--
Homepage: http://www.flyrotary.com/
Archive and UnSub: http://mail.lancaironline.net:81/lists/flyrotary/List.html
Homepage: http://www.flyrotary.com/
Archive and UnSub: http://mail.lancaironline.net:81/lists/flyrotary/List.html
|