Scrap bin motor

Discussion in 'Finished Projects' started by dvbydt, Dec 15, 2010.

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  1. Dec 15, 2010 #1
  2. Dec 15, 2010 #2

    itowbig

    itowbig

    itowbig

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    i just dont get it for some reason how it works
     
  3. Dec 16, 2010 #3

    dvbydt

    dvbydt

    dvbydt

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    Sid,

    Compressed air flows into the stator spindle via the copper tube, then via the transfer port to the two pistons. These are forced appart moving about 5mm. At maximum stroke (the rotor has moved about 90 degrees) the air is cut off and the pressure is bled off via the exhaust port in the outer sleve. The rotor has now moved 180 degrees and the cycle is repeated.

    The rotor is about 45mm OD, the pistons are 8mm and the rollers are Delrin.

    Ian
     
  4. Dec 18, 2010 #4

    1hand

    1hand

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    thats pretty cool.

    Matt
     
  5. Jan 1, 2011 #5

    cfellows

    cfellows

    cfellows

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    Interesting application. Took me awhile to figure out what the pistons look like, but I think I've got it.

    Chuck
     
  6. Jan 1, 2011 #6

    itowbig

    itowbig

    itowbig

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    i still dont get how it works but it is cool looking.
     
  7. Jan 2, 2011 #7

    dvbydt

    dvbydt

    dvbydt

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    Thanks for taking an interest. Not very good at explaining how it works, sorry, perhaps this is better. I didn't do any drawings, just made it up from scrap bits.

    Ian



    Air Path.jpg
     
  8. Jan 2, 2011 #8

    itowbig

    itowbig

    itowbig

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    OH ok now i see how the thing works those little wheel are pistons hahaha
    i just could not for the life of me figger out how that worked .
    Thank you for that. it makes sence now
     
  9. Jan 3, 2011 #9

    cfellows

    cfellows

    cfellows

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    That's really a pretty elegant little engine with some nice design features. I particulaly like the slotted cylinder sides to keep the rollers oriented correctly. Wonder how well it would scale up?

    Chuck
     
  10. Jan 11, 2011 #10

    dvbydt

    dvbydt

    dvbydt

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    itowbig,

    I'm pleased I managed to get the idea across.

    Chuck,

    It should scale up OK, but would probably need ball races rather than plastic rollers. It did cross my mind that the rotor might make a centrifugally supercharged, uniflow, 2 stoke a possibility, but just a pipe dream!

    The reason I was experimenting with porting was for a small air driven V8, but the elegant ball valve exhaust ports on your opposed 4, has caused a redesign and that engine is on hold for the time being.

    Ian
     
  11. Jan 11, 2011 #11

    cfellows

    cfellows

    cfellows

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    Glad you are trying the ball valve design. It's fun to see how other people adapt it to their own designs.

    Chuck
     
  12. Jan 12, 2011 #12

    imagineering

    imagineering

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    What is the actual shape of the Rotor cavity - is it 3 holes at offset spacing, or is it a more complex set of curves?

    Murray.
     
  13. Jan 12, 2011 #13

    dvbydt

    dvbydt

    dvbydt

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    Murray,

    Yes, just 3 bores. The concentric one done on the lathe, the two offsets done at the same setup on the mill with a
    flycutting tool.

    Ian
     
  14. Jan 12, 2011 #14

    imagineering

    imagineering

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    Hi Ian,

    Could you post a few basic dimensions please - this one intrigues ???

    Murray
     
  15. Jan 16, 2011 #15

    dvbydt

    dvbydt

    dvbydt

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    Murray,

    Drawing of the rotor for you, should give you most of the information. I didn't do any drawings before I started, just made it up as I went along, so the drawing is just measurements of the completed motor. Important is the 5mm hole size as it gives the correct spacing of 45 degrees for the porting.

    Ian

    RotorImage.jpg
     
  16. Jan 16, 2011 #16

    imagineering

    imagineering

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    Thanks Ian, it's now on my 'to-do' list.
    Am I right in assuming that the Porting Holes go all the way through the Rotor Shaft, (making 4 in total)?

    Murray
     
  17. Jan 17, 2011 #17

    dvbydt

    dvbydt

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    Murray,

    Two holes and two slots - the inlet transfer ports that get covered by the outer sleeve.

    Ian
     
  18. Jan 20, 2011 #18

    crueby

    crueby

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    That is the coolest thing. You were thinking outside the room holding the bag that the box was in!
     
  19. Feb 6, 2011 #19

    dvbydt

    dvbydt

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  20. Mar 10, 2011 #20

    dvbydt

    dvbydt

    dvbydt

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    With the number of views of this thread, I figured this little experimental air motor had earned a mount and a dust cover.

    Ian

    Dust Cover.jpg
     

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