Any progress on the simple PSRU? I have a neighbor that is a
retired millwright, and he has a 12" metal lathe in his basement.
He has been building mini steam engines in his basement for a
while- a steam powered mini ferris wheel, locomotive, etc.
Last I remember you were discussing using the ceramic bearings-
and were trying to get them from China. If I can get an idea of
the internal parts and where to get them, I can try to make one.
Have we made any progress lately?
Kevin Alderman
It will be awhile. We had a ceramic bearing supplier picked out
but there was some evidence he was less than reliable. We are
attempting to finding another source.
Paul Lamar
I assume the heart is a Ford planetary, but where does the splined
shaft come from? Do we have to machine the splines on a shaft?
Kevin Alderman
It must be welded up from a manual transmission, one inch
diameter, input shaft or Ford auto tranny splined part. Tracy uses
the auto tranny part.
Paul Lamar
OK, I guess I need to go get a used E4OD and tear it apart and see
what's inside. Sounds like fun!
Kevin Alderman
No need. New parts are cheap.
http://www.makcotransmissionparts.com/
I have ordered from them and I think Tracy also buys from them.
Here is an outfit on the west coast.
http://www.slauson.com/
We are in the process of ordering the bearings in china now.
The smart thing to do is let us build one and see if it works
first :)
Paul Lamar
\--------------------------------------------------
You can order thin section steel bearings from mcmaster carr
but steel thin section bearings are limited rpm wise.
we are using the 4 inch size.
This is why we are trying to buy ceramic thin section bearings.
Cost is the reason for buying them in china.
Paul Lamar
I just noticed the NOTE:. The max RPM is with grease as a
lubricant. High RPM would heat the grease due to the internal
friction in the viscous material. How will lubricating with oil
affect the RPM rating?
Dale Davies
Perhaps a bit higher but no way is steel going to live long enough
with grease or oil.
Here is the specs on Shanghi Lilly thin section ceramic bearings.
The success of this design depends on the high rpm capability of ceramic
bearings.
Paul Lamar
Paul, I was looking at the attachments and it appears that the 4"
standard all stainless construction thin section bearing is rated
at 4800 RPM (grease) and 5700 RPM (oil). The propshaft would be
turning 7500 RPM/ 2,85 or 2631 RPM, well in range of a 5700 RPM
bearing. It would seem that using silicon nitride balls in the
bearing for an 8000 RPM rating would be overkill. I understand
that the input shaft might be turning 7500 RPM but with a much
smaller diameter where the speed ratings are much higher. It would
seem that a standard size bearing with C3 clearance would be
appropriate on the input shaft.
george grimes
The Shanghi Lilly are ceramic balls.
What manufacture was that? Most all steel thin section bearings
that size are limited to below 1000 rpm.
Paul Lamar
Paul, I was looking at the attachments on the 8:51 am posting.
One chart was 4800/5700 and the other chart ranged from 8500 to
15000 RPM for the same size. It would seem either type could be used.
george
Those RPM numbers are for the silicon nitride balls not steel balls.
The last attached jpg shows a steel ball bearing that comes close.
The penalty is a smaller shaft and a much larger housing.
The shaft strength goes up with cube or the fourth power of the diameter.
Paul Lamar
------------------------------------------------------------------------
This company in general does not post the RPM.
Paul Lamar
---------------------------------------------------------------------
This one might be worth a try to validate the concept as Milo has
suggested.
The cost makes it unattractive.
Paul Lamar
==========================================================================
Paul, will this do the job? Milo
Buy online VD040CP0 Thin Section Bearing 4"x5"x1/2" inch Open Slim
Ball Bearings
VXB Home Thin Section Bearings
VD040CP0 Thin Section Bearing 4"x5"x1/2" inch Open Slim Ball Bearings
Quantity in Basket: None
Part Number: Kit13153
Our Low Price: $179.00
Shipping Weight: 0.10 pounds
========================================================================
No I don't think so there is no RPM specified.
It would only last a few hours.
Paul
Years ago I was rebuilding Allison powershift transmissions for off
highway
equipment. One rebuild I noticed a new bearing to repalce one I had used
numerous times. The part number on the box was different, but the bearing
had
the same numbers etched on it. I asked the manager who was also a
mechanic. He
did a bunch of checking as the price was almost double and found out there
is
a tolerance on bearings. The manufacturer part number is the same as the
dimensions are identical, but the closer tolerance goes in a different box
with a corresponding cost change.
Two bearings listed in previous posts;
1: RBC KD040 CPO List $389
2: VD040 CPO List $179
Question is, what would the difference be considering the dimensions are
the
same? Just the change in the first letter of the part number K or V. If
normal
economics apply, the more expensive bearing would be of better quality.
Dale Davies
Without looking it up again, I believe bearings have what is call an ABEC
rating. ABEC-7 appears to be the common spec for super precision bearings.
Ed Carver
Group,
The ABEC scale is an industry accepted standard for the tolerances of a ball bearing.
It was developed by the Annular Bearing Engineering Committee (ABEC) of the American
Bearing Manufacturers Association (ABMA). There are five classes from largest to
smallest tolerances: 1, 3, 5, 7, and 9. The higher ABEC classes provide better
precision, efficiency,[citation needed] and greater speed capabilities, but do not
necessarily make the components spin faster.[1] The ABEC rating does not specify many
other critical factors, such as smoothness of the rolling contact surfaces, ball
precision or quality/type of steel used.
The bearing material is not specified in the ABEC grades. Bearings not conforming to
at least ABEC 1 can not be classified as precision bearings as their tolerances are
too loose.
The scale is designed to allow a user to make an informed decision about the type of
bearing they are purchasing. High rated bearings are intended for precision
applications like aircraft instruments or surgical equipment. Lower grades are
intended for the vast majority of applications such as vehicles, mechanical hobbies,
skates, skateboards, fishing reels and industrial machinery. High ABEC rated bearings
allow optimal performance of critical applications requiring very high RPM and smooth
operation.
http://en.wikipedia.org/wiki/ABEC
Rotor Head
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