Rotary Piston

Discussion in 'Architecture & Engineering' started by Emil, May 11, 2010.

  1. Echo3Romeo One man wolfpack Registered Senior Member

    Messages:
    1,196
    The Renesis engine in the RX-8 supposedly isn't too bad, but I don't know how much of that is due to improved seals and how much is due to it being naturally aspirated.

    I know a few people who've turbocharged their RX-8s without any issue, but they're all running low-ish levels of boost (0.5 bar or less).
     
  2. Google AdSense Guest Advertisement



    to hide all adverts.
  3. Emil Valued Senior Member

    Messages:
    2,789

    Tightness is one of the advantages of rotary piston.
    All contacts are on the surface.Not a line,a generator as the Wankel.
    Rotary blade has radius equal to radius cylindrical housing.
    Contact between rotary blade and cylindrical housing are on surface.
    Cylindrical piston is not tangential to the cylindrical housing,they are secant.
    Contact between cylindrical piston and cylindrical housing also are on surface.


    http://www.youtube.com/watch?v=MrbDU_n1jqM&NR=1

    http://www.youtube.com/watch?v=MXZuRB4P-x8&feature=related
     
    Last edited: May 30, 2010
  4. Google AdSense Guest Advertisement



    to hide all adverts.
  5. Echo3Romeo One man wolfpack Registered Senior Member

    Messages:
    1,196
    How would you balance something like that? The moment of the piston changes through the rotation. Would you use a balance shaft like a piston engine?

    It does seem like a neat idea. If they can get a Wankel engine to work, this thing should be a lot easier.
     
  6. Google AdSense Guest Advertisement



    to hide all adverts.
  7. Emil Valued Senior Member

    Messages:
    2,789

    What you've presented is operating principle.
    Rotary piston has features depending where it is used( pump, compressor, pneumatic motor, hydraulic motor or internal combustion engine)
    It is nonlinear and is not balanced.
    To linearized or balance:
    is mounted on the same shaft, one after another, two (or more) identical rotary pistons, but the blades are 180 degrees from one another.
    When one is up other is the minimum.When one increases the other decreases.
    Narrowing in valves area is a problem.
    For liquids valves will be placed elsewhere.


     
    Last edited: May 31, 2010
  8. Echo3Romeo One man wolfpack Registered Senior Member

    Messages:
    1,196
    The Wankel engines Mazda uses have two rotors opposed to each other. I don't think they use a balance shaft or harmonic balancer.

    How efficient is an engine like this? Brake-specific fuel consumption?

    I had a rotary piston compressor for airbrushing plastic models when I was a kid, which I took apart once, so I am familiar with how the parts work.
     
  9. Emil Valued Senior Member

    Messages:
    2,789
  10. Kernl Sandrs Registered Senior Member

    Messages:
    645
    May I present

    The most beautiful piston machine.



    Please Register or Log in to view the hidden image!




    I could watch those motions for hours...
     
    Last edited: Jun 2, 2010
  11. Emil Valued Senior Member

    Messages:
    2,789

    Yes, indeed it is a pleasure to watch.
    But also I'm like piston rotary.It is very simple and elegant.
    I started working for about nine years to rotary piston.
    I worked five years at the rotary piston.I have made many variations.Among the first was one like Minh Nguyen's.I was not happy either.
    I can now say that a technology has muse as artists.
    After five years working in a few hours I managed to make the rotary piston.
    I was lucky? It was a muse?
    Look, once again at the simplicity and the efficiency of the rotary piston.

    Please Register or Log in to view the hidden image!




    http://www.youtube.com/watch?v=MrbDU_n1jqM

    http://www.youtube.com/watch?v=MXZuRB4P-x8&NR=1
     
  12. Billy T Use Sugar Cane Alcohol car Fuel Valued Senior Member

    Messages:
    23,198
    Emil, as I understand you, your "blade" serves two functions:
    (1) It moves in and out thru the seal of the eccentric rotating piston, which is a circular cylinder, to seal the high pressure side from the low pressure side as the eccentric piston rotates.
    &
    (2) It transfers the rotational torque to the shaft.

    Even though in one 360 turn it travels much less than the Wankel's seal going around the full circumference, I think all this seal wear can be eliminated by separating these two functions. I will let your creative mind work on how to couple the rotation of eccentric piston to the shaft (It is my bed time in Brazil now.) Probably an eccentric gear on the shaft will do - just don't have time now to think more on this.

    The rotation is always in one direction. Thus for the high/low sides pressure seal function, why not have a small region of negative curvature on the outer circumference of the eccentric piston - I.e. a cavity into which the FLEXING seal (no seal friction sliding in and out) can recess entirely when the blade would normally be fully inside the eccentric piston. 180 degrees of rotation later, this flexing seal would be fully extended out of the rotating cavity of the eccentric piston.

    Of course the tip of your blade will wear as it "scrapes" around the ID of the stator cylinder so it needs to be spring loaded. Likewise the seal of that folds out of the cavity to touch the ID will wear and the folding out can also be spring action (not just flex) But make it a few mm thick so still makes a good seal with the ID even when a mm thinner.

    Hope this is clear and not too silly just because I am sleepy now. I will check back tomorrow if you have questions. If you take up my modification, you can cut me in on a tiny fraction of your profits - I think your idea has a lot of potential.
     
    Last edited by a moderator: Jun 28, 2010
  13. Billy T Use Sugar Cane Alcohol car Fuel Valued Senior Member

    Messages:
    23,198
    Emil, your YouTube demo with link in post 16 is excellent. However, I will give few words, for English readers which probably are in your patent to call attention to one easily over looked, but essential, aspect of your rotating piston machine.

    The exterior of the rotating piston is one solid piece but two circular cylinders of different radii. I.e. a single circular cylinder has had one end machined down to a smaller diameter. This smaller diameter section slips inside a cylinderical cavity that has been machined in the stator block, however, the axis of this cavity in the stator block is NOT concentric with the main larger cavity cylinder of the stator block (or the drive shaft axis). The radius of smaller end section of the rotating piston is very slightly smaller than the radius of the small cavity eccentrically located in the stator block, but the size of these two nearly equal radii is not critical. (could be larger or smaller).

    To be specific I will create some symbols:
    The main large block's cavity has radius R.
    The OD radius of the larger section of the eccentric rotating piston is r. (r < R)
    The separation or displacement of the axis of the small cavity machined in the stator block from the axis of the main shaft (and from the axis of the stator block's main cylinder with radius R) is d.

    The relationship between these three is: d+r is almost R. Thus as the piston rotates, d+r is always in contact with the ID of the larger stator block cylinder, except for thin oil film between whose thickness is f.

    I.e. the exact relationship between these four is:

    r+d+f = R.

    PS for Emil: In the unlikely case that you do not know, OD and ID are standard abbreviations in English for Outer Diameter and Inner Diameter.
     
    Last edited by a moderator: Jun 28, 2010
  14. Emil Valued Senior Member

    Messages:
    2,789

    Thanks for your attention.
    I ask you to write short sentences and no abbreviations.My English is pretty bad.
    My experience over the net with rotary piston is daunting.
    From Automotive Forum, after two posts, I was kicked out, with the following explanation:Spam endorsing concept engine.
    On eng-tips and engineeredge forums,I was kicked out after two posts, without saying why.
    I do not understand why.
    I post on rotaryforum ,energeticforum and physicsforum but I have not found anyone to inquire about the rotary piston.
    I'm not sure I understand what you wrote.

    Please look at a practical implementation:
    http://www.youtube.com/watch?v=MXZuRB4P-x8&feature=related



    I worked hard to make some files.Some essential things for rotary piston:

    Rotor "eccentric" is placed eccentric but his movement is not eccentric.
    The center of rotation of the vane is centered in the housing…..and not centered in the rotor . Also the vane dosen't need to rub on the housing walls as it rotates and so in this area is not rpm limited.
    The vane is fixed to the shaft,no need for spring or centrifugal force so in this area is not pressure limited.
    For the rotary piston ,contact between the vane and cylindrical hausing is a surface and not a line(generator).Very easy to sealed.


    What you've presented is operating principle.

    Rotary piston has features depending where it is used( pump, compressor, pneumatic motor, hydraulic motor or internal combustion engine)
    It is nonlinear and is not balanced.
    To linearized or balance:
    is mounted on the same shaft, one after another, two (or more) identical rotary pistons, but the blades are 180 degrees from one another.
    When one is up other is the minimum.When one increases the other decreases.
    Narrowing in valves area is a problem.
    For liquids valves will be placed elsewhere.

    If performed four basic functions of rotary piston: pump, compressor, pneumatic motor, hydraulic motor,we can talk about applications.
    I think that now I have given enough details and I expect your observation.

     
  15. Billy T Use Sugar Cane Alcohol car Fuel Valued Senior Member

    Messages:
    23,198
    I am sorry you have been "kicked out" at some other forums.
    I think your idea is very interesting.
    I will only discuss one misunderstanding we have here:

    I understand that the vane (or blade) does not really "scrape" the inner circumference of the stator cavity.

    There is a film of oil, which prevents the high pressure from leaking past the tip of the vane into the lower pressure region (the region with decreasing volume if your machine is serving as a motor).

    Normally for reasons of manufacturing economy (greater tolerances) there is some need to have the space between the tip of the moving vane and the stator cylinder too large for only an oil film to seal.

    For example in the standard linear piston engine the space between the moving piston and the static cylinder wall is filled with several thin rings. These rings do essentially scrape the wall of the static cylinder except for a very thin film of oil. We call these rings "piston rings."

    In principle one could avoid the use of these rings. Just make this space between moving piston and static cylinder wall very small (high tolerance - exact control of the piston size and cylinder size - their diameters) but that is too costly for mass production, so "piston rings" are used.

    What I was suggesting with your vane is that it be spring loaded to keep the tip of the vane very close to the cylinder wall to reduce the cost of very high tolerance manufacturing.

    I assume you know about standard linear motion piston rings, but will mention that they too are springs. I.e. They are not continuous rings, but have a small gap open in their circumference. This gap needs to be reduced, compressed, when they are inserted into the cylinder so they naturally expand to essentially scrape the cylinder wall.

    SUMMARY: I was suggesting the exact length of your vane is not constant. That it has an internal spring trying to make it longer than the radius of the static cylinder so that it always (even after wear) is essentially in contact with the cylinder wall - only a very thin film of oil away. This is very much like the use of piston rings in a linear motion piston. It is done to reduce the cost of manufacture. I.e. the bore and piston diameters do not need to be made with very high precision as the piston rings fill the "tolerance gap"

    Your vane could have very slight ability to lengthen or contract so your manufacturing costs could be lower too.

    I.e. the vane would be hollow with a spring loaded inner blade inside that expands to almost make contact with the cylinder wall even if there is slight manufacturing variation in the exact diameter of the cylinder wall.

    I plan to also trying to describe a more important improvement to your machine later. It is a conceptual change, not just a cost reduction suggestion. First I need to know if I can write English you can understand.

    Let me know if you could understand this cost reduction point about the vane in English.
     
    Last edited by a moderator: Jun 28, 2010
  16. Emil Valued Senior Member

    Messages:
    2,789


    Of course.

    When I started writing post 31, yet you have not posted number 30. (OD, ID). Now I understand.
    I do not have the opportunity to start a production or even to complete a fully functional prototype.(zero series)
    Therefore, I am open to any collaboration.

    A former colleague, mechanical engineer, made the drawing of execution in 20 hours,for the prototype what you saw on YouTube.
    For him was a routine work.But he said I should talk to an engineer with specialty pumps who knows the materials used in pumps.He specializes in sewing machines.

    I'm not a mechanical engineer Iam industrial automation engineer.So here I have opinions, but I'm not sure.
    It takes oil if it works with gas.But it might, because of modern materials, not need oil.All movements and forces are taken bearings.Friction is only between vane and two sealing elements.
    Yes, applies to internal combustion engines.Size variations should be compensated due to temperature variations.Guidance is between piston and cylinder walls.The wear that is oval and not circular.(and because Crank system)
    Guidance is on bearings,for rotary piston
    The engine, designed by me, has little operating temperature.It is not an Internal Combustion Engine.But I propose talking about the engine later.

    Are applications even more important than the engine.
    Yes, I understand.

    In my opinion,the easiest would be the water pump.Current pumps, high flow, have low efficiency.Consume much of energy to supply a city with drinking water.


     
    Last edited: Jun 28, 2010
  17. Stryder Keeper of "good" ideas. Valued Senior Member

    Messages:
    13,101
    Emil,
    Over time you are unfortunately going to have to learn English if you want to interact with the international community, it's one of the main languages used to communicate internationally now. So practive makes perfect.

    Why you might of been classed as spam, is you might have been misunderstood. If you get stuck trying to write something in English, write it in your native tongue and let us work out what you mean through translators.

    What you will require doing is getting some prototypes up and getting third-parties to apply them to their own applications. The condition you should have for these third-parties is that they collect data and write a summary report on their findings "as an independent" on your products capacity.

    Without third-party evaluation people might assume you are a "snake oil" salesman, so let the results speak for themselves.
     
  18. Emil Valued Senior Member

    Messages:
    2,789

    Few concrete results.
    Two gold medals.

    Please Register or Log in to view the hidden image!



    Please Register or Log in to view the hidden image!

     
  19. Emil Valued Senior Member

    Messages:
    2,789
  20. chaos1956 Banned Banned

    Messages:
    238
    Place two holes in the cylindrical housing at 45º angles to the rotary blade and extend the rotary blade across the whole diameter. Now cover up the left hole leading outward in you animated diagram. As pressure builds in the middle it would have only one escape and would also be pushing the rotary blade from both sides.
     
  21. Facial Valued Senior Member

    Messages:
    2,217
    Emil, I've taken a look at the videos, but how does it work?
     
  22. Emil Valued Senior Member

    Messages:
    2,789

    No, unfortunately is not possible.
    The "rotor" is driven by the blade and it has variable rotational speed,
    when the palette has a constant rotational speed.
    If the blade is equal to the diameter of the "stator",
    so there are two blades arranged at 180 degrees,
    the system would lock up.
     
  23. Emil Valued Senior Member

    Messages:
    2,789

    The space between "stator" and "rotor" is crescent-shaped,is the useful chamber.
    At first is placed the admission valve and at the end is placed the discharge valve.
    This chamber is divided in two by the blade,the intake chamber and the compression chamber.
    The intake chamber and the compression chamber have variable volume when
    the blade rotates.

     

Share This Page