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Thread: Oddball engines and prototypes

  1. #2716
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    I've had some problems with windows 10 and the computer would not stay online for more than 30 seconds, all due to a major update on 10th Nov. I just about pulled out all my remaining hair after trying fix after fix to try and correct it! .... but last night, a fix (update) from heaven! - maybe it was from Microsoft, I don't care, I now have a stable fast computer which actually stays online!

    Like the axial engine discussion but have only glanced it as yet, should be interesting.

    I have always been interested in the possibility of using them in the IC engine role since I worked at a factory producing parts for hydraulic axial piston swashplate pumps and came to certain conclusions about them (ie from the point of view of using the arrangement for IC engines).

    The hydraulic pumps work well at relatively slow revs and being flooded constantly with oil - but in the IC engine role the lubrication would become critical and of course the higher revs, frictional forces would come into play! Using curved swashplates or sinuosoidal ribs to engage with and move the pistons requires some very accurate machining (therfore expensive) techniques. - the wobble plate idea (like the two stroke engine) is deceptively simple looking but the Duke engine seems to have overcome most of the problems here.

    I really don't believe in their (Duke's) sliding OHV system, - ok when it's new, but 20,000 Kms down the track ??? - really, the common or garden old poppet valve still rules the roost and doesn't look at all like being knocked off it's perch, despite all the criticism that's pointed at it!

    The compact axial piston engine would fit the bill for use on a bike I reckon! (preferably two stroke of course!).


    I need to find some time to read all the previous stuff properly!
    Freedom of speech is important but if what we say is considered incorrect by our peers, they will quickly put us right.
    P.C. will eventually destroy our right to tell the truth.

  2. #2717
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    I gained interst in the swash plate engine back in the late 70's when Dyna-Cam designed one for an aircraft engine,it was FAA certified and installed in a Piper PA28R-200 Arrow for testing,looked like a great leap in engine technology,but it faded like many others have,,I read the swash plates had high loading and would wear/warp with time.Now its hard to find any info on that engine as it was bought by other companies and data deleted..Found this site that has some good pics of various designs;
    http://www.douglas-self.com/MUSEUM/P...al-IC.htm#tech

  3. #2718
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    That's the one I was thinking of when I mentioned the "sinusoidal rib" and although I would have liked to see it survive I had the feeling it wouldn't (hard to break into an established "adequate " market with new technology!) - I haven't had time to read the link you supplied -
    I believe that engine was a development of an original German "Hermann"?? design.

    BTW my Windows 10 has gone again! and I'm now back on my old faithful Windows 7!! (but Windows 7 is to be dumped at the end of the year! I believe).
    Freedom of speech is important but if what we say is considered incorrect by our peers, they will quickly put us right.
    P.C. will eventually destroy our right to tell the truth.

  4. #2719
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    Quote Originally Posted by Frits Overmars View Post
    And I've never seen endurance test results of a swashplate engine...
    Two of these Michell engines, built under license by the National Gas Engine Company of England, were still operating as gas pipeline boosters in 1974. Still running after 40 years of service, that's endurance.

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    If One were to assume that Anthony Michell & Phil Irving and the National Gas Engine Company of England and were not 'Hopeless Dreamers'
    but had proven that the design had mechanical merit, then what would we need to consider in producing a practical 3 piston (6 cyl) two stroke along the lines of the one in the video?

    Cheers, Daryl.

  5. #2720
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    The axial engine certainly has worked very well in some situations, but I don't think that they were ever developed properly in the small engine scene.
    I do think that it has been well and truly proven that round pistons in round cylinders is the best way for the IC engine to go and this axial layout makes for a very compact engine, obviously lending itself to "opposed piston" ideas which (to me) have a lot of merit - at least with my train of thought at the moment

    I wonder what Neil (AKA Flettner) thinks about it - he has had good experience with opposed pistons!

    I sometimes wish that I had grown up between the wars - it was a great time to experiment with all sorts of engines etc - nothing was completely established and the chances of success were much greater than they are today!

    Today, the huge corporations (and countries) have got us by the short and curlies and we just don't have the clout to change or compete with them (and never again will have, but....... let's not give up playing - for our own sakes!!).
    Freedom of speech is important but if what we say is considered incorrect by our peers, they will quickly put us right.
    P.C. will eventually destroy our right to tell the truth.

  6. #2721
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    As an example of how clever tech doesn't always find it's place first time around:

    Look at the valve mechanism from the 1920's industrial gas pump engine.
    Click image for larger version. 

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    40 years later Honda create an empire with SOHC engines configured just like this.
    Only difference..... looks like Michell was using roller cam followers.

    Cheers, Daryl

  7. #2722
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    Quote Originally Posted by 190mech View Post
    Found this site that has some good pics of various designs;
    http://www.douglas-self.com/MUSEUM/P...al-IC.htm#tech
    That's a great link, thanks. I enjoy browsing through such summaries. For me it's a spiritual form of 'walking the dog'. It takes the mind of everyday problems and once that mind is opened, new ideas sometimes emerge.

    It is also funny to see how some patent applications have been put together. Take a look at the two wobble-plate engines below.
    The picture on the left shows connecting rods that are hinged to the pistons in the usual way, as you would expect.
    The picture on the right shows that it can also be done without a hinge in the piston. On paper, yes ....
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    It is possible to omit the hinge, but it requires a peculiar type of piston, pictured below, a project from the late Henk van Veen, of Van Veen Kreidler fame, in which I was also a little involved. It's just a pity that it cannot work in conjunction with cylinder exhaust ports.
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  8. #2723
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    How it Works!

    Click image for larger version. 

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    Apparently oil was squirted under pressure at the leading edge of the slipper at particular points.
    I would expect that to be at the ends of strokes when the slippers were least loaded and the clearance greatest.

    From 190mechs link

    Cheers, Daryl.

  9. #2724
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    A long time ago when I was designing hydraulic winch drives, there was an axial piston hydraulic pump with semi spherical pistons like Frits pictured. It seemed to me that the line contact would leak more than the conventional designs. Parker still makes a pump with this design, so it looks like I was wrong. However, sealing pumps flooded in oil is a lot easier than in an IC engine.

    Lohring Miller

  10. #2725
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    In the link (described by Frits as "walking the dog") ie where all the axial engines are described by animation - the wobble plate engine at the beginning .....

    It seems that although it has been fairly successful had it's share of problems early on, with the anchor or "pan handle" used to prevent the wobble plate from turning. It gave them a bit of grief by wearing out prematurely. - The movement of the plate (and of course joints at the top of the arms where it all changed from linear to rotating movement ) moves in a quite convoluted figure of eight path which made it fight with the slot provided to stop rotation of the plate.

    If you study the animation you can just about see what I mean (my description may not be all that clear)! - I can't remember just how it was solved but it must have been! - Duke engines must have made some arrangement to solve that one too.
    Freedom of speech is important but if what we say is considered incorrect by our peers, they will quickly put us right.
    P.C. will eventually destroy our right to tell the truth.

  11. #2726
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    Here is a nice animation of the Michell mechanism, no rods, no links, no problems, simple as...



    cheers, Daryl

  12. #2727
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    Quote Originally Posted by Pursang View Post
    Here is a nice animation of the Michell mechanism, no rods, no links, no problems, simple as...
    cheers, Daryl
    Got to admit Daryl that is a very clever design, ......... but, relatively speaking it's quite complicated - a lot of machining and a lot of parts too - but definitely clever!
    I want to delve into it a bit more but I really would need to divorce myself from reality about thinking of it being used in the future!
    It really deserves to be outside doing a sterling job, instead of being in a glass case in a museum! - but I don't think it will ever achieve that, because although (as I see it) it's actually quite a great engineering feat, unfortunately few people will recognize just how good it is / was, or could have been! - especially the big manufacturers. ....... but let's live in hope!
    Freedom of speech is important but if what we say is considered incorrect by our peers, they will quickly put us right.
    P.C. will eventually destroy our right to tell the truth.

  13. #2728
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    Quote Originally Posted by Frits Overmars View Post
    It is possible to omit the hinge, but it requires a peculiar type of piston, pictured below, a project from the late Henk van Veen, of Van Veen Kreidler fame, in which I was also a little involved. It's just a pity that it cannot work in conjunction with cylinder exhaust ports.
    Click image for larger version. 

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    This type of piston is for a mechanism in which BORE > STROKE
    I find it more appropriate for an auxiliary pump, in the style of this: combustion cylinder bore 39 stroke 41.8 auxiliary pump bore 62 stroke 13.8
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  14. #2729
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    Yes, - probably best in a pump (pompe?)
    In an IC engine it would produce a natural trap for unburnt charge! - I can't see exactly where any benefit would be, whatever it is in - wouldn't it be a very expensive alternative to a normal piston/ring setup?.
    VanVeen of course actually knew what he was talking about! - ie with his Kriedlers!
    Freedom of speech is important but if what we say is considered incorrect by our peers, they will quickly put us right.
    P.C. will eventually destroy our right to tell the truth.

  15. #2730
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    Combined piston/rod like that are used in small oil-less air compressors, often used for airbrush. the bigend runs a ballbearing packed with grease and the piston ring is teflon running on a hard anodized sleeve. They are quiet, light, and have zero chance of contaminating the air with oil, but they do not last a long time.
    Patrick Owens
    www.OopsClunkThud.com

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