Brickley engine

[boonebucker]

Those of you with engine friction experience have any thoughts on the Brickley engine?

 

[ornerynorsk]

Interesting concept. Looks like more mass in motion than a conventional IC engine, and an extra set of main bearings, if they would be called that.

 

[MikeHalloran]

It has a lot of oscillating bearings.
I'm guessing they'd be in greatest need of hydrodynamic lubrication right where it's least likely available, near zero velocity.



Mike Halloran
Pembroke Pines, FL, USA

 

[boonebucker]

Actually, the velocity issue and hydrodynamic lubrication (squeeze film) are addressed on the website's blog.

 

[JWaterstreet]

I would suggest a zero-sum game; the large amount of mass in ever changing motion, (accel/decel) combined with a large amount of total bearings, would negate any implied improvement in friction. But what the heck to I know...

 

[patprimmer]

I don't see any advantage over a scotch yolk that is a much simpler system

Regards
Pat
See FAQ731-376 for tips on use of eng-tips by professional engineers &

http://eng-tips.com/market.cfm

for site rules

 

[tbuelna]

boonebucker,

Just my opinion, but I fail to see how a larger number of sliding joints combined with a significantly greater amount of dynamic mass and reciprocating inertias, for a given displaced engine volume, will result in lower mechanical losses and/or improved brake thermal efficiency.

It's interesting that you inquired about "engine friction". The largest friction loss fraction in a piston engine is due to pumping losses. And this design does not seem to address those losses.

To paraphrase the old joke, it's just a "complex solution to a non-existent problem".

Hopefully, Mr. Brickley hasn't spent the family nest egg on this boondoggle.

Regards,
T

 

[ornerynorsk]

Better mousetraps and rube goldberg mechanisms do have some purpose, if only to serve as a transient to spark some other idea. For the inventor or discoverer, the challenge is to acknowledge that your "baby" is mostly a novelty, and to discern well enough not to dump your life savings and someone else's into it. We've all got patents and outstanding ideas, and I would parlay a guess that few of us are going to retire on easy street anytime soon.

 

[boonebucker]

The example given on the blog uses a Willans line for a diesel. There are near zero pumping losses for the diesel at 1500 rpm. According to the graphs on the blog there is a huge difference between the friction at the at the wrist pin and the crank pin; approximately 1/15 the distance travelled per revolution and approximately the same load. Work lost equals FXd.

 

[franzh]

Its hard to conceive, but I think I counted 37 such wristpin type joints, including the large connecting rod little end.

Not all of the links have the same friction load while others have a disproportionately high load. I can see packaging such a beast as a real problem, something a modern 4 or V-6 does reasonably well.

Wait a moment! He lives in my town! Why havent I heard of such a marvel?

Franz


eng-tips, by professional engineers for professional engineers
Please see FAQ731-376 for tips on how to make the best use of Eng-Tips Fora.

 

[SomptingGuy]

I'm guessing that if a physical prototype existed, you'd have heard of it and heard it.

- Steve

 

[YvesLLewelyn]

Arranging the drive to the valve gear could be a bit tricky.

 

[btrueblood]

"The Brickley configuration reduces friction in several ways. First, it eliminates the piston skirts."

Ah, yes. Because the nodding motion of the end of the H-shaped links (visible in the animation on the home page) forces the piston to move not in a straight line, but in a rotating or wobbling motion thru the cylinder. So, you can't have a skirt. Nor piston rings, or at least not conventional ones. And the piston will then need to be a section of a sphere. How does the piston seal?

Eliminating piston rings will certainly help reduce friction. But it will play heck with efficiency due to blow-by, at least until the pistons seize...

 

[boonebucker]

The linkage at each piston is a Watt linkage. The center of the floating link is real real close to a straight line within the limits of the mechanism. This four bar linkage has been employed for it's linearity for over two centuries.

 

[patprimmer]

So it was well known and not selected for further development in ICs for over 10 years. I wonder why.

A Scotch Yolk has fully harmonic and zero side force on pistons and very few more parts but still was not used to any significant extent.

Regards
Pat
See FAQ731-376 for tips on use of eng-tips by professional engineers &

http://eng-tips.com/market.cfm

for site rules

 

[LionelHutz]

I must be missing something. What is the purpose of all the little linkages where the pistons attach, at the end of each of the large pieces? There must be a pivot pin through the holes in the middle of the big pieces and then the piston/rod pieces attach to pins on the ends of the same pieces. those other parts at each piston seem to do nothing?

Still, I don't see this living up to the hype. I see nothing about the energy required to continually reverse the direction of all those pieces, just claims about removing some of the rotating bearing losses in the crank.

 

[ornerynorsk]

That is a component of the watts linkage previously mentioned.

 

[MikeHalloran]

The little linkages are indeed Watt links, which kinematically drive the piston link in a straight line.
... if they are perfectly proportioned, and if the reaction hinges are stiff enough.

Given all that, the piston can use ordinary rings, doesn't need a huge skirt, and could probably have a round skirt, not an oval skirt.





Mike Halloran
Pembroke Pines, FL, USA

 

[btrueblood]

It's difficult to see the remainder of the linkage that is required to form a Watt's linkage. I will give benefit of doubt to the OP, that there are additional links hidden under/inside the H-shaped linkages, and not readily apparent at first glance. Having seen a lot of 3-D solid model animations, and knowing how simple it is to fake just about any motion you want using them, I am skeptical. I will be less skeptical of this one now.

 

[dicer]

Ring to cylinder is one of the main points of friction loss.
This is another one of those internet designs that will go nowhere. Too much monkey motion. For simple recip you can't improve on whats already there.