31 replies to this topic

[Cheater]

Even at 84 years old, Dan Gurney is still pushing the envelope. On August 11, 2015, he was granted US patent 9,103,277 for a "Moment-Cancelling 4-Stroke Engine" with the defining feature being two crankshafts rotating in opposite directions.

 

Dan explains more about the reasoning behind this new engine design in a "Message from Dan Gurney" found HERE.
 
From the AAR website, "The ‘Moment-Cancelling’ 4-stroke engine is Dan Gurney’s new, unique engine design that is still in a developmental stage. The first iteration is an 1800cc vertical twin that is slated to fire up for the first time toward the end of 2015. If simulation data is born out, it may prove to be a significant advancement compared to similar size engines."

 

Here's a couple of drawings from the patent.

 

 

 

There's no doubt that Dan Gurney has a vast amount of experience with engines of many different designs and while he's got as good a shot as anyone ever had at coming up with a fruitful new direction in internal combustion engines, the percentage of those who have been successful in such efforts over the last hundred plus years has been depressingly small. Best of luck to him!

[Half Fast]

Can you say Wankel?
 
Dan Gurney for president.

[Greg VanPeenen]

Old news. I did some performance coating work on a six-piston engine with two crankshafts for the military ten years ago. The engine had a crankshaft on both ends of the block in a flat plane. The pistons moved towards each other and formed the combustion chamber at TDC. It was also a two stroke and compression ignition. Very small and very powerful.
 
Regards,

GVP

[Cheater]

Well, Greg, they usually don't give patents out for old news... LOL!

I'm reminded of the King-Bugatti so-called U-16, but on that experimental aircraft engine the two crankshafts were geared to a common shaft that was to drive the propellor. It was a spectacular failure I've read...

[Cheater]

Greg, what you descibed is an opposed-piston engine and there were a number of such designs in use at one time in large ships and locomotives. The main advantage was said to be the absence of a cylinder head, typically a significant source of heat loss.

 

The wildest opposed-piston design was the famous Napier Deltic engine, which used three crankshafts.
 

[Half Fast]

The claims which define the novelty of the invention are quite narrow and detailed. For example:

 

1. An internal combustion engine comprising a first cylinder having a first piston and a second cylinder having a second piston, a first crankshaft operably connected to the first piston and a second crankshaft operably connected to the second piston, a cylinder head comprising at least one intake port and at least one exhaust port per cylinder, said at least one intake port connected to the first cylinder such that fluid can pass through the at least one intake port into the first cylinder and said at least one exhaust port connected to the first cylinder such that fluid can pass from the first cylinder through the at least one exhaust port, a movable intake valve positioned at least partially within the at least one intake port configured to control the flow of fluid through the intake ports, a movable exhaust valve positioned at least partially within the at least one exhaust port configured to control the flow of fluid through the at least one exhaust port, the at least one intake port having a minimum intake port diameter, a first inside radius positioned toward an intake port valve seat from the minimum intake port diameter, said first inside radius transitioning to a second inside radius positioned toward the intake port valve seat from the first radius so that the intake port expands to meet the intake port valve seat, the first inside radius being greater than 0.4 inches and less than 1.5 inches, the second inside radius being greater than 0.13 inches and less than 0.7 inches, the at least one intake port having a non-symmetric variable shape along at least a portion of a length of the at least one intake port, said movable intake valve defining an intake valve seat angle measured between the surface of the movable intake valve most distal from an intake valve stem of the movable intake valve and a plane perpendicular to the axis of movement of the movable intake valve, said intake valve seat angle being between about 40-52 degrees, said movable intake valve defining an intake valve undercut angle measured between the surface of the movable intake valve adjacent to an intake valve seating surface defined b the intake valve seat angle and positioned radially inward therefrom and a plane perpendicular to the axis of movement of the movable intake valve, said intake valve undercut angle being between about 30-42 degrees, said movable exhaust valve defining an exhaust valve seat angle measured between the surface of the movable exhaust valve most distal from an exhaust valve stem of the moveable exhaust valve and a plane perpendicular to the axis of movement of the movable exhaust valve, said exhaust valve seat angle between about 40-52 degrees, said movable exhaust valve defining_an exhaust valve undercut angle measured between the surface of the movable exhaust valve adjacent to an exhaust valve seating surface defined by the exhaust valve seat angle and positioned radially inward therefrom and a plane perpendicular to the axis of movement of the movable exhaust valve, said exhaust valve undercut angle being between about 30-48 degrees, and an intake port angle of the at least one intake port is between about 45 and 65 degrees, wherein the first crankshaft rotates in a first direction and the second crankshaft rotates in a second direction such that the second direction is an opposite direction from the first direction.

 

So that comments such as "old news" completely miss the point. As Greg said, they usually don't give patents out for old news..

 

Cheers,

[Cheater]

Even after carefully going through the patent, I am still unclear just exactly what exactly comprises the unique "invention" that is protected by the patent.

 

I don't pretend to be an engineer, but it seems to me that this particular engine optimizes a number of factors in a unique combination that may give the performance results being sought, but does a unique combination of "prior art" actually represent a patentable invention?

 

Find it interesting that 83 prior patents, from 1941 to 2013, both US and foreign, are cited.

[Half Fast]

I don't pretend to be an engineer, but it seems to me that this particular engine optimizes a number of factors in a unique combination that may give the performance results being sought, but does a unique combination of "prior art" actually represent a patentable invention?

 
Every invention is a combination of known parts.
 

Find it interesting that 83 prior patents, from 1941 to 2013, both US and foreign, are cited.

 
This actually makes the patent stronger as none of the prior art taken alone or in combination rendered the invention obvious.

Cheerio,

[Cheater]

Thanks for the insight, Bill, but I remain unsure of what is "uniquely" different about Gurney's engine such that it could be patented.

[racie35]

What's driving the cams? I cannot tell, other then it's on a different lay than the drive gears.

[Cheater]

I believe the cams are chain-driven.

[racie35]

How though? They're not turning on the same axis... I'm struggling to see how... but I like Dan Gurney!!

[Cheater]

They don't have to be on the same axis with skew gearing.

From the patent text: "The cam shafts are preferably chain driven off of the right end of the forward crankshaft."

And "... the crankshafts use gears and a chain as part of a chain drive system to drive the camshafts."

[Greg VanPeenen]

Well, Greg, they usually don't give patents out for old news... LOL!

I'm reminded of the King-Bugatti so-called U-16, but on that experimental aircraft engine the two crankshafts were geared to a common shaft that was to drive the propellor. It was a spectacular failure I've read...

 

The military engine was not patented for good reason and was never public information. It could be carried easily by one person and made amazing power for its size. I am sure it is in use somewhere in the military and am also sure we will never know where.

 

And yes, they do patent old news with minor changes to the design.

 

Regards,

 

GVP 

[TSR]

The main feature of this engine is its apparent total lack of vibration as a pair of counter-rotating mass negates each other quite effectively. Apparently a lot of BEMP is lost simply from engine vibration in most four-stroke designs. As in the 1979-1982 Kawasaki inline-twin motorcycle engines, the cranks are turned 90-degree from the engine axis, providing torsion-free crankshafts and less overall friction. The Kawasaki 250/350 GP motorcycles were reputedly completely vibration free, and won a total of six world championships during that period of time.

 

The Gurney engine's similarity stops there, as progress in metallurgy and electronics render 30-year old engines as stone-age technology.

There are all kinds of other interesting things in this engine, such as variable cam actuation, electronic timed direct injection, a novel combustion chamber design etc., the sum of which translates in a vastly greater amount of torque on the whole RPM range for its modest displacement while providing exceptionally advantageous fuel consumption.

 

That the US patent office granted one, means that there is a lot more than first catches the eye.

 

Let's wait until actual firing in three dimensions since all has been accomplished so far are simulations on a computer program, which look promising.

[A. J. Hoyt]

I see great utility in the moment canceling design that you described, GVP. It could be used for motion stability for UAV's (drones) for reduced or isolated motor affect on a fuselage-mounted camera or targeting system gimbals.

 

I think Dan's motor must be intended for his very cool motorcycle he has been working on for decades.

 

I love looking at new motor configurations. Patent attorneys once told me that anything patent-worthy regarding internal combustion engines was covered in mass filings from 1905 to 1935 of everything and anything that could constitute a practical heat pump or auxillary components, such as, camshaft drives, valve actuation, etc. Almost all forms of heat pumps (single to multiple up to 11 lobes, Wankel rotary engine is of a three-lobed variation) were cataloged by daVinci during his lifetime.

 

Everything since then (that has had "traction" and utility) has been in the areas of metallurgy, lubrication, and electronic controls. Again, these are the words of the patent attorneys.

 

It is impressive enough that he was granted a variation that was specific enough to be worthy of a patent and still vague enough that he could do some development work around the concept.

 

Kudos to Dan! He will always be one of my heros!

 

AJ

[Matt Sheldon]

No doubt I would have to think this is slated for the Alligator (his motorcycle involvement). There is some Yamaha and Buell technology in there as well. Visually it also looks as though they are utilizing the oil pump as a dampener.

[Half Fast]

Everything since then (that has had "traction" and utility) has been in the areas of metallurgy, lubrication, and electronic controls. Again, these are the words of the patent attorneys.

 
Most patent attorneys would not agree with that statement.
 
Cheers,

[Marty N]

What I see is a system capable of canceling rotating and reciprocating harmonics to the sixth order and combustion induced excitation nullification. Hammer strikes the bell and neither make a noise. Ultra-short power transmission path, enhanced torsional stability, and stabilizing ancillary systems. Very precise event timing.  

Yeah, pretty sure that's a patent. Boxer layouts employ canceling tech but do so with a rocking couple. Balance shafts are capable but absorb power and limit RPM. This liberates power and enhances range while dealing with the combustion dynamic influence.

Gurney made Eagles soar at Indy. This does not surprise me at all.

[Dave Crevie]

Fairbanks-Morse diesel railroad locomotives used an opposed piston engine, which had a crankshaft above the cylinder block, and one in the traditional location below the block. The cranks were geared together through a geartrain and timed so that the pistons TDC'ed at the same time. The idea was to get more power from less cylinders.

I can tell you from the ones I have worked on, they aren't really any smoother running. They are invariably very smoky, because some oil from the upper piston usually gets into the combustion area.

[beardogracing]

 
The British Commer "Knocker" motor powered many a truck. Notice the Roots supercharger.
 

[Marty N]

I love Brit engineering. Simplistic complexity.  (that's a complement gents)

[Mike Patterson]

I just liked seeing the engineering drawings in post #1. I miss drawing stuff like that, deciding which line weight to use for maximum clarity. Drafting is another lost art.

[Cheater]

Mike,

 

I took three years of drafting in HS and a year during my freshman year in college and liked it as well. I was tickled that my college drafting prof requested my drafting portfolio to use as exemples when I transferred to another school before my sophomore year.

 

Wonder if there is anyone still making the classic T-squares? If so, they are probably also making slide rules...

[Half Fast]

Those patent drawings do look hand drafted to me, and such draftsman are a dying breed.
 
Modern CAD/CAM programs like SolidWorks  now can make 2D renderings that approach hand drafting in appearance.
 
When I graduated Engineering school in '72, we were the last class of slide rule engineers.
 
Cheers,