Automotive

The spherical genius of the Hüttlin Kugelmotor

The spherical genius of the Hü...
Huttlin kugel motor prototype under testing
Huttlin kugel motor prototype under testing
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Kugel motor hybrid cutaway drawing
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Kugel motor hybrid cutaway drawing
Kugel motor generator cutaway drawing
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Kugel motor generator cutaway drawing
Kugel motor compressor cutaway drawing
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Kugel motor compressor cutaway drawing
Huttlin kugel motor prototype under testing
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Huttlin kugel motor prototype under testing
Kugel motor cutaway
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Kugel motor cutaway
Kugel motor prototype under testing
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Kugel motor prototype under testing
Dr Huttlin and the Kugel motor production prototype
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Dr Huttlin and the Kugel motor production prototype
Kugel motor prototype under testing
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Kugel motor prototype under testing
Kugel motor cutaway drawing
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Kugel motor cutaway drawing
Kugel motor cutaway drawing
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Kugel motor cutaway drawing
Kugel motor hybrid exterior drawing
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Kugel motor hybrid exterior drawing
Kugel motor generator exterior drawing
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Kugel motor generator exterior drawing
Kugel motor prototype under testing
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Kugel motor prototype under testing
Kugel motor cutaway showing the pistons
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Kugel motor cutaway showing the pistons
Kugel motor production prototype
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Kugel motor production prototype
Kugel motor cutaway showing the magnet ring
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Kugel motor cutaway showing the magnet ring
Kugel motor cutaway showing the generator coils
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Kugel motor cutaway showing the generator coils
Kugel motor cutaway
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Kugel motor cutaway
Dr Huttlin at the Geneva Motor Show
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Dr Huttlin at the Geneva Motor Show
Kugel motor cutaway
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Kugel motor cutaway
Kugel motor production prototype
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Kugel motor production prototype
Kugel motor production prototype
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Kugel motor production prototype
Dr Huttlin and the Kugel motor cutaway
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Dr Huttlin and the Kugel motor cutaway
Kugel motor production prototype
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Kugel motor production prototype
Kugel motor prototype under testing
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Kugel motor prototype under testing
Kugel motor prototype under testing
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Kugel motor prototype under testing

The car is not going to disappear anytime soon and neither is the combustion engine, despite the inevitable rise in fuel prices. We have said it before, electrical motors are an energy-efficient method for driving vehicles but battery technology is simply not going to advance quickly enough for all-electric vehicles to be a practical reality for most uses anytime soon. The near and mid-term future is undoubtedly a combination of compact combustion engine generators charging dense battery packs that drive electric motors - the "range extender" option. We reported on one possible candidate, the disc motor, a couple of months ago. Now, after nearly twenty years of development another candidate is going through final testing and it is a work of elegant genius - Dr. Herbert Hüttlin's Kugelmotor.

Dr Herbert Hüttlin is a 67 year old flow engineer with over 150 patents to his name, mostly in the field of pharmaceutical production machinery. In 1991 he began to look at the traditional "Otto/Diesel" combustion engine and how its efficiency could be improved. After twenty years and three design iterations the good doctor, with help from Freiburg University, has created a compact spherical motor/generator combination that is radically different from the traditional in-line combustion engine with significantly fewer moving parts. Its mode of operation is simple but hard to describe, the video at the bottom should help to make it clear.

Two opposing curved twin-piston heads rock on the same bearing. When two heads are pushed apart the opposing pistons are pushed together. Because this is four-stroke engine the cycle will be induction (apart), compression (together), combustion (apart) and exhaust (together). This obviously has the effect of rocking the cylinder heads back and forth. Here's the genius bit. On the top of each of the four piston heads is a large titanium ball bearing that runs in a channel that is circular in one axis and a sine wave in the other. The channel completely encompasses the pistons and their rocking causes them to rotate on an axis perpendicular to their bearing axis by "swimming" along the channel.

Genius bit #2. The ball-bearing guide channel is fixed to one side of the spherical aluminum housing whilst on the other side a permanent magnet ring is attached to the rotation axis of the cylinders. Fixed to the inside surface of the enclosing sphere is a ring of electromagnetic coils and the interaction with the spinning magnet causes the generation of electricity.

Kugel motor cutaway drawing
Kugel motor cutaway drawing

Genius bit #3. With the principal "kinematics" proven and working, three different variations can be created with simple design changes. The first is the basic generator that produces electricity from the combustion engine as described above. There's also a hybrid form that takes a drive shaft off the rotating pistons for traditional mechanical drive (plus the electricity generation). However the combustion pistons can be disengaged and drive reversed back to the engine (under braking for instance) to rotate the coils and generate electricity, or indeed the electrical flow reversed and the coils become an electric motor producing drive. There is a third variation where the pistons do not rotate but the guide channel is driven around them by the motor coils causing them to rock and become a compressor/pump. It's the simplicity yet ingeniousness and versatility of the arrangement that suggests the Kugelmotor (sphere-engine) has great potential longevity.

Pre-production prototypes of 1.18 liter capacity have been in testing for some months and power output at present is 74kW (100hp) at 3000rpm with torque up to 290Nm (213ft-lb). Dr Hüttlin expects efficiency to increase by another 40% with reduced bearing friction and optimization of the combustion. The engine weighs 62 kg and consists of only 62 parts, while a conventional engine has at least 240. The doctor has set up a corporation, Innomot AG, to license the engine design and expects to have a major car manufacturer on board before the end of the year.

49 comments
Oztechi
What a great invention! I really hope it succeeds and is not bought out by an greedy fuel company that will make sure it never gets produced (as has happened to many great motor designs in the past). So be careful who you license it to. I would like to know what fuels it can run on, Is Diesel an option? Will it be used in motorcycles too?
Pierre-André Aebischer
Very interesting indeed! I just wish the music in the video was a tad more inline with the innovative features of the engine :-) ( ie: a little more 2011!!)
Adrien
seems to me like the movement of the pistons is basically at right-angle to the rotation of the thing. That means the ball-bearings in the race will be under a lot of force and I would therefore expect friction in this engine to be high, and therefore reliability and longevity to suffer. It also doesn\'t show how the combustion is contained. Pity they didn\'t see fit to show us a video of the actual device in operation. I bet it is extremely loud.
Jelmer ten Hoeve
looks like an great improvement, maby now it will make it easier (more compact) to build in an electric engine in an former benzine/diesel car. if you want to turn it partly electric, right now I want to make an old citroen DS electric but thats looks impossible right now.
mboyd
But how efficient is it compared to current diesel engines? and how efficient does he expect it to be after some tuning? This thing is awesome, but if it\'s a gas hog then what was the point?
Maury Markowitz
How is this any different than any of the other swing-piston engines developed over the last 100 years? It\'s worth pointing out that every single one of them was a technical or financial failure. Usually both.
Will Ogden
At the end of the video it says it can be used in a wind turbine power station. Why would you want to use this in a wind mill to generate power from rotatory motion when you could just use a regular dynamo without the extraneous internal combustion engine components in it? Also, using it as a pump? As long as you don\'t mind getting gasoline/diesel and oil contamination in whatever liquid your pumping. They\'re just trying to make it look more useful than it really is.
Michael Taylor
So difficult not to be pessimistic after decades of seeing ideas like this with almost none of them ever making it into real-world consumer applications. Let\'s hope this one\'s viable and sees the light of day.
Slowburn
Re; Oztechi \"A greedy fuel company\" stands to make more money if through the long term selling at ever increasing prices that high efficiency engines offer. Unless people figure out that we are not really close to running out of oil.
ebrush870
This is extremely interesting. I love the idea. My question is: does the piston group rotate or does the track rotate? I would wonder if there is a possibility that the kugelmotor could be contained in a wheel with the piston group stationary and the track attached to the wheel so that it would spin. The possibilities are amazing. You could have a trike with one large back wheel with the motor in it and the rest of the trike could be shaped however the maker wants it to be. You cold have the gas tubes and air intake tubes run down the suspension for the wheel and run all the way down to the hub so that it\'s not exposed. I love this!