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  • Users: unclematt
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  1. unclematt

    Cardan gear vs. slider crank in IC engines

    An issue I am encountering while tryng to work on my cardan gear design is that you need a minimum crank element diameter to transmit all the torque and horsepower without failing or distorting. However, since the ring gear is twice the diameter of the pinion gear, this forces a relatively long...
  2. unclematt

    Opposing Piston Engines

    The extra connecting rods can be engineered from titanium and or take the form of thin wall tubes, adding little mass. If you change the crank to a cardan gear hypocycloidal system, the outer piston rockers, the inner piston rod connections, and the seperate crank journal pieces can all be...
  3. unclematt

    Opposing Piston Engines

    I think that the main attraction of the OPOC design is that it offers the efficiency of a diesel in a small package with a lot of power. Ecomotors estimate over 300 hp for their 2 cylinder, 4 piston version for automotive use. Even if that is off by a lot, and maintains diesel liek efficiency...
  4. unclematt

    Cardan gear vs. slider crank in IC engines

    Indeed, I have yet to find any evidence of any rollerized diesel engines at all. However, I have done quite a bit of research on silicon nitride bearings lately, and thought they might be able to make a rollerized diesel a possibility. The rolling elements are much harder and lighter, they run...
  5. unclematt

    Cardan gear vs. slider crank in IC engines

    Most of the motors on the road today don't run in trucks for a million miles... Look, I am just having fun with this and exploring some ideas. I'm not saying what I am doing will introduce anything new in the world of engines, and I am sceptical as anyone else. If shown my concept is fatally...
  6. unclematt

    Cardan gear vs. slider crank in IC engines

    By the way, Timken has split shell bearings that they have used to rollerize crank slide motors with pretty good success. http://engineeringtv.com/blogs/etv/archive/2007/05/31/episode-42-rollerized-engines.aspx I don't even think the bearing elements are silicon nitride, as I would like to...
  7. unclematt

    Cardan gear vs. slider crank in IC engines

    And thats what I was trying to determine - if a cardan gear "built up" crankshaft could handle the loads of diesel engine operation. I am trying to figure out if commercially available bearings can withstand the pulses and loads, and if the general design I am working on is robust enough as...
  8. unclematt

    Cardan gear vs. slider crank in IC engines

    Thanks for the input on figuring out those forces. After doing the numbers using your inputs, I am getting approximately 49,000 psi. Does that sound like the upper limit of the forces that occur at the big end? As far as the problem I am trying to solve, I want to combine the surface area and...
  9. unclematt

    Cardan gear vs. slider crank in IC engines

    Well, you could use a boxer configuration, or an OPOC design, and there are a couple of designs at www.wiseman.com. The Wiseman site claims you can use counterweights to create hypocycloidal engines with as many cylinders as you like. I'm not saying they are the final word on the subject, far...
  10. unclematt

    Cardan gear vs. slider crank in IC engines

    https://oa.doria.fi/bitstream/handle/10024/36120/isbn9789522145345.pdf This paper compares the slider crank to the Cardan gear when used in internal combustion engines and was written just last year. The conclusion states that a cardan gear setup in IC engines would be superior to that of...
  11. unclematt

    Opposing Piston Engines

    I think if you work out a couple of refinements that the OPOC engine DOES have a lot to offer in the way of increased efficiency. The desireable characteristics of the engine have been spelled out in detail. No valvetrain, increased power density, etc. I too would like to see independent testing...
  12. unclematt

    Opposing Piston Engines

    I am curious, could the use of biodiesel in this kind of engine increase lubrication in the cylinder and perhaps help prevent piston ring scuffing? Though there seem to be some compatibility problems with some direct injection sytems, I have been reading that bidiesel has more lubrication...
  13. unclematt

    Silicon Nitride bearing tolerances

    Hi All, I am curious if anyone can share some info on how close of a tolerance you can achieve with full ceramic bearings (including ceramic races), preferably in silicon nitride. I am looking for both roller or ball configuration, and the ability to withstand heavy duty use. I am considering...
  14. unclematt

    Opposing Piston Engines

    I have a design I have been working on for a few months that would give the OPOC engine a hypocycloidal "cardan gear" crank system. The more I develop it, the more reluctant I am to post it in public. You know how that is... It uses silicon nitride bearings to save weight, to increase rpm and...
  15. unclematt

    Opposing Piston Engines

    I have suggested a hypocycloidal crank system to greatly reduce the friction created by side forces on the piston. If you water jacket the area of the cylinder around the exhaust ports at the same time, the oil won't flash off, and the oil that does make it above the ports should be enough for...
  16. unclematt

    Opposing Piston Engines

    Hey Meister, I did some checking and I think that maybe the gear tooth load thing in cardan gears has been overplayed. Especially if you use cryo treatment to further strengthen the gears, which is what some rotary racers have done to the stationary gear on their engine. They even use spur...
  17. unclematt

    Opposing Piston Engines

    I think that cost is more to blame for ceramics not being used more widely than their lack of desireable charecteristics. The same goes for using carbon-carbon, it is just too expensive to mass produce for the masses. Although, I did find several companies that produce carbon-carbon pistons for...
  18. unclematt

    Opposing Piston Engines

    Hey TDIMeister, Sorry if I missed some details in your posts. I wonder if utilizing some helical internal ring gears might work instead of spur gears. I have also been doing research into whether or not carbon-carbon gears might have the required strength and durability, especially if coated...
  19. unclematt

    Opposing Piston Engines

    If you will look at the engine on www.ecomotors.com, you will see that your statement outbout "outboard crankshafts" is not necessarily true. Their engine is the layout I had in mind when I came up with my hypocycloidal crank design. I also found Pattakon's OPRE design to be interesting, if not...

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