coupling for my single rotor 12 d

12 d

   Hi Paul,

   This is the cush drive I have built for my single rotor.

   It is machined out of 6061T6 billet on an old lathe and cheep Chinese
   mill. The diameter is approx 4.7 inches, the inserts are urethane rod
   at 1.25 inches in diameter. I am going to start with the green
   urethane which is the lowest Shore hardness available here. the photo
   shows a yellow grade which is slightly harder. The rod cuts well with
   a sharp tungsten blade on a drop saw.

   I have also had a new flywheel machined from billet 4140, as I was
   not happy with the flex plate. The whole assembly has been
   dynamically balanced.

   Andrew Campbell.

   Yes. That looks like it is going to work. Good idea. You should use
   silicone rubber. Good to 500 F. There is a certain amount of energy
   going into those dampers.

   Urethane is only good to about 200 F.

   Paul Lamar

   You will need a sleeve or something around the outside of the
   inserts. After they have deformed a little they will no longer be
   contained and will fly out.

   Bill Bradburry They will have to deform a great deal before that
   happens , if this becomes a problem I will use a slightly harder
   compound. I don't really have the machine tools for production but I
   am happy to supply a drawing. Andrew.

   Andrew, What format can you support with the drawing? I would be
   grateful for a copy. I have Rhino.

   Craig Smith

   Hi Craig, I machined this from a sketch, I don't have any cad
   drawing programs so the best I can do would be a drawing with
   dimensions. I am going to do some torque measurements shortly to
   decide on the Shore hardness that I will be using . Bill had a valid
   point, I am only going to produce 130hp max at 7500 rpm so the torque
   will be in the region of 91ft/lbs. this can be applied with a torque
   wrench no problem. I will then be able to measure the deformation of
   the compound and know the most appropriate grade to use.

   If urethane does not hold up in this application and I suspect that
   the way the compound is being loaded, it will, then I will look at
   other materials.

   The product is readily available in NZ so if you have a problem with
   sourcing it I would be happy to ship it to you.

   I will do a Drawing and post it, might take a few days. The
   dimensions are able to be modified to suit your particular set or
   conditions, the only thing to bear in mind is the way the rubbers
   are captured. The two halves are identical. The only thing that may
   vary would be the height and bolt fixings. The overall outside
   diameter could be increased and more rubbers inserted for higher
   torque requirements. As the rubbers are held in close contact with
   aluminum I am expecting a good rate of cooling on the compound.

   Andrew Campbell.

   The torque pulses are severe in a one rotor so urethane is not going
   to work for long. Our TTC coupling is working great with up to 650
   HP. Most power so far has been 500 HP. That is 500 degree Fahrenheit
   silicon rubber you see in the pictures.

   Paul Lamar

Are the most current versions of the CAD drawings available to share?
We have lots of CNC and fabrication resources here on the Space Coast.
I could get estimates on some small volume production runs.

Scott Gettings

The exact design depends on the gear box input shaft.
Here is the jpg and iges drawings for the design.

Paul Lamar

Andrew,

Here is some round silicone rubber rod you may be able to use from McMaster.
If you cannot have it shipped directly to NZ I can buy it for you and
ship it to NZ
Let me know what lengths you need to cut the cost of shipping.

Paul Lamar

Hi, from [Andrew] your photos; I would radius the inside and outside corners of the
metal pockets for the elastomer rods. In one of the charts that Paul sent
you can see that the peak torque of a single rotor is at least twice that of average
torque. The elastomer has to deform to work and sharp metal edges will chew
the rods up in short order.

Murry I. Rozansky

------------------------------------------------------------------
Please add your questions or comments at the end of the thread.
Not the beginning.

I am going to enforce that rule. If people don't do that it will not be
forwarded.
My ISP changed the rules.

The Rotary Engine free News Letter. Powered by Linux. If you want off
the list PLEASE let me know and I will remove you. ACRE NL web
site. http://www.rotaryeng.net You Tube http://tinyurl.com/beqqxas
Copyright 1998-2017 All world wide rights reserved.