The spherical genius of the Hüttlin Kugelmotor


September 22, 2011

Huttlin kugel motor prototype under testing

Huttlin kugel motor prototype under testing

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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.

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.

About the Author
Vincent Rice Vincent Rice has been an audio-visual design consultant for almost 30 years including six years with Warner Brothers Cinemas. He has designed several large retail installations in London and a dozen major nightclubs across the world from Belfast to Brno to Beruit. An accomplished musician and 3D computer graphics artist, Vince also writes for AV Magazine in the U.K. and the Loudscreen digital signage blog. All articles by Vincent Rice

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?


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!!)

Pierre-André Aebischer

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.


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.

Jelmer ten Hoeve

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?


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.

Maury Markowitz

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.

Will Ogden

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.

Michael Taylor

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.


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!


The power/weight ratio seems very good. But the assertion in the article that batteries won\'t suffice for EVs is probably false. Tesla is putting out a 300-mile sports sedan next year, and there are LiIon innovations which could multiply that range many times in the pipeline (nano-electrodes, internal banding, etc. Check Stanford and MIT articles.)

Brian Hall

It looks like an alien, inexplicable machine designed by little green men. I congratulate the doctor, but who is going to re-tool an engine factory for this relatively untested, unrefined design? True, it has fewer parts than a typical piston engine, but so did the rotary engine. It had fewer parts, yet when the seals turned out to be problematic, it went away.

The question with something this new and different always is the same: What unpleasant engineering surprises await the company that buys this idea and invests a ton of money in its production? Will some part turn out to be its undoing?

Meanwhile, battery technology is forging ahead. How many years is the window of opportunity for any combustion engine before they are all swept away by the successor to today\'s lithium batteries?


overly complex. Keep it simple stupid. An engine like that will have a high mechanical vulnerability and a short life span. I\'ll pass.


You may also want to take a look at Duke Engines 5 Cylinder 4 Stroke 3 Injector Valveless Axial Engine. The site is

Gary Cartwright

This reminds me of the orbital engine, which came out in about 1962. The pistons were stationary and the engine wobulated around the pistons. You could stall the rotation of the engine and it would still run, if it could stand the vibration.

Douglas Rogers

i\'ve been following \'novel\' motors for a while.

they all have a pattern in common, which is basically just varying geometry of the pistons and their relationship to the torque generating shafts.

-----the obvious need for enhancing the combustion added energy to a battery powered engine is huge. however i would arge that the future is not in traditional high pressure pistons connected to shafts. the future is in low to medium temperature thermoelectric materials that will convert the heat of a NON-moving piston ( rather a burn chamber ) , directly into an electric current. removing nearly all noise and vibration from the engine, and drastically reducing the number of moving parts, if not eliminating them entirely .

that is the future. NO moving parts except for the electric motor. period. and that will be done by thermoelectric materials that replace the essential piston design that is common from sterling/steam/combustion designs, even the novel ones.

Facebook User

I\'m also interested what they do with getting the heat away from the combustion chambers..... much more difficult with this configuration.

I think it won\'t be able to run very long before overheating.


Re; DB Rogers\' comment: That was the Selden motor and correctly vibration was a major problem, And Yeah; Jimbo92107 hits the nail on the head, the retool costs are unreal. Many unusual engine profiles have failed because the consumer has a built in concept of what an engine \"should\" look like, and selling them something like this; well you need tio have a successful race car / team to sexify it. Oh, Wait does anybody remember the French \"MATRA\" race car that was banned for being too unusual?

Gerard René Supersad

As pointed out by others, combustion sealing may be an issue. The very fact that the motion imparts a 90 degree action implies reduced efficiency ( just imagine the energy \"lost\" while trying to force a gyroscope off its vector). While the reduced parts count is a plus, I wonder if this is any better than the Wankel. That particular engine seemed to run best at a steady state, although racing versions were made. Generators are typicaly operated at one speed. Seems like a natural application for the Wankel. one more thought: I wonder how space efficient ( as in energy density) a 2 stroke direct injected gas or diesel would be. While I really do like breakthrough technology, I suspect this is a unique design, but maybe a dead end. More data is necessary for a determination


I\'ll agree with most of the comenters. It doesn\'t seem like a practical solution. Moreover, its design is complicated which is an omen for reliability and durability issues. I would say hydrogen is the future but you\'ll say it\'s too expensive. And you\'ll be right. Scientist and Corporations need to shovel more manpower into battery and hybrid development. Hybrid designs are a solution but they need to get really cheap and fast first. One thing I\'m certain about. When I get old I\'ll be missing the sweet sound of a V8, V10, V12... Meh, I take that back. Ferrari, Lamborghini, Bugatti, Chevrolet will still be there. The day these companies stop making sweet engines is the day bees will extinct.


Another engine, don\'t we get one of these every couple of years and then it fades away. While it is interesting all the variations there are on internal combustion engines most of them are not enough better than a modern engine. No one will take a chance on something new, especially if there is not a working model to prove their point. I personally think a liquid fueled fuel cell will be the future but in the mean time here are 2 engine designs that have a better chance of seeing production. 1. could already be fading. 2. still looking like it has a chance.


For vibration free operation it is very hard to beat the pre Wankel rotary engine, because both the block, and pistons express perfect circles. Solving the lubrication, airflow, and exhaust linkage problems still represent a problem, and it still a better idea than this engine.


That\'s the most fascinating thing I\'ve seen in Gizmag in months. I studied it intently and finally have a basic picture of how goes the balls, pistons, etc. All you smart cynics are assuredly correct in your slide rule deductions as to why it won\'t work, but sooner are later we\'ve got to quit making the underwear washing, hybrid energy producing, tick repelling, quadravese cycle engine. One thing and do it seriously. Seems to me and based on my limited knowledge (I read the article & looked at the pictures!) If it works, it will sell itself at least as a chinese reversed engineered project. Concentrate on the one package hybrid even if does appear from the drawings there ain\'t enough Lock Tite in the world to hold that thing together.

Zappenfusen ther interesting video on Youtube from the engine We are still looking for investors! Further information on

Mario Lang

This reminds me of the Massive yet Tiny engine that could.

Why are we limited by battery technology on cars. Throughout our usage of batteries for ourelectronics we always charged and when we did not haveenouh time we replaced them with already charged ones. Why should our cars be any different. Companies like the Better Place have the right idea: create a battery that can be easily interchanged yet charged at home or in parking lots. It is like a AA or AAA battery for my flash light. We have the infrastructure already in place by using existing gas stations that can change some of the gas pumps into bays where cars can exchange the drained batteries for full ones in a matter of minutes. These stations can receive higher than normal electric current to speed up the charging of exchanged batteries and reuse those for other cars. Simple. Toe-Knee


A fascinating design by an original high-level thinker.

Now the hardest part must be answered, which the article did NOT list: THERMAL EFFICIENCY.

The article glaringly avoided listing that most key engineering parameter for any internal combustion engine, other than to speculate that an additional 40% efficiency could be obtained with design improvements.

The thermal efficiency compared to the newer high end diesel and diesel-gasoline hybrid combustion cycles must be nearly the same for this new design or it won\'t cut the mustard.

Burrell Clawson

I love trying to understand the motion and function of new concepts like this. How in the world does someone come up with this kind of \'kinematics\' layout? A great mind-bender. . As far as putting money on this concept, on the other hand, that\'s a long shot. The combustion chamber is a real question mark. How do you machine a cylindrical-toroidal shape for this with good tolerances and low friction and even heat-expansion characteristics and consistent sealing? And machining the circular-sinusoidal channels for the big balls - also a difficult problem. So, few moving parts, yes, okay - but fiendishly difficult shapes to manufacture. I\'m sure you could get an engine like this running, but what\'s the longevity? . Next, it takes decades to truly refine a combustion engine design. The current gas and diesel engines have had many many decades and tens of thousands of engineers testing, refining, testing, refining, so many layers of refinements and improvements. It\'s hard to see how any new and radically different engine can get ahead without that amount of evolutionary advancement. . Finally, it will only be for another 10 years, maybe 15, that we will need combustion engines in our cars. Battery technology is not that far an outlier, and will probably advance faster now that substantial demand for batteries in high production numbers has arrived with hybrid cars etc. We already have pure battery electric cars for sale and hybrid numbers are growing substantially. So it\'s likely that smaller and more efficient and refined conventional piston engines will be more than sufficient to see us through on the gradual process towards electrification of the transport sector.


I don\'t understand this fascination with reciprocating pistons. Why not a simple gas turbine genset?


re; Gadgeteer

To be efficient gas turbine have to run at ridiculously high temperatures, they burn almost as much fuel idling as they do running at full power (granted that is not a problem in this application).

Sterling engines are better suited for this application because they are more efficient, and produce less noxious exhaust (It is real hard to produce NOx at atmospheric pressure), especially if they use a catalytic burner.


I don\'t like it\'s queer \"rattley\" sound - sort of like the inside bit are a bit loose and slapping around a little.

Mr Stiffy

Big titanium balls. :) Seriously, won\'t they be a big titanium expense and a hot spot for failure? Large surface area, travelling quickly through a wiggly run sounds dodgy. I don\'t doubt you could probably eventually work out any such problems and find good applications for this engine, but will anyone want to retool their factory? Maybe this would work well as a portable generator rather than in a car? If you made a small, easy to transport 20KW version, you could use that in remote construction sites and all sorts.


a gas microturbine is far more efficient, simple, and with higher power density

Francesco Baldacchini

Interesting how many prejudices and experts opinion can be found without knowing anything. Long time ago lots of companies tried to develop gas microturbines and so far only Bladon's is somewhat promising. But even Jaguar will not bring a car on the streets with that concept because it is still gas guzzling and far too noisy which only can be solved by adding weight for insulation materials. And what about long term mechanical stability with a constant spinning of 80,000rpm? The ultra compact Huttlin Kugelmotor and generator in one turns at 3,000rpm only developping a rather high torque compared to normal engines and is quite "easy" to be built. There is no new field of material technology necessary e.g. Rotary Engines still existing problems and new ones with gas turbines that need very expensive high tech materials. I have seen a prototype already at the Geneva Motor Show this year and I never saw such an interesting concept before in near serial condition: a) Range Extender b) Generator c) Compressor d) Engine (direct link to a gearbox/wheels possible). It beats any comparable already available gas engine, e.g. Rotary Engine from Wankel/Mazda and is a far more practical solution than actual concepts used for Extended Range EV's e.g. Fisker, Volt, Jaguar C-X75 (nice but not serious to go in production the next 20 years) or even for EV's from LiIon Motors or Tesla. They would even offer enough room as the engine is from the size comparable to a Subaru/VW Boxer engine with the according low centre of gravity and size. The prototype has an engine volume of about 1.18 Liter or only 72 cubic inches and now compare yourself. I hope that I have added to a competent and serious discussion in view of interesting inputs and new positive solutions. Manybe that some serious engineers are also reading kind of platforms?

Roger Jean Zamofing

For those that have read down this far, if I remember right the Matra race car previously mentioned did not have a revolutionary engine, it had the fuel contained in the frame and was considered unsafe. It saved weight, but in a crash had the potential to be very messy.

Sandy Erickson

The\"Kugelmotor\" was already invented 1963 by Frank Berry (US-Pat. 3,075,506).

Richard Lachmann

peraves motor with added generator. Both based on the Berry engine.

3000rpm/60kw The 2nd generation has exhaust gases that fly with the euro norm. The 1st generation did not. There are no problems with seals or fact it is easier to machine and runs cleaner than the Otto Motor. It overcomes many of the design problems of previous kugelengines.

Its always difficult for English speaking journalists (and other people) to understand and find information about Euro inventions... Someone should educate the English speaking about that idea :) Heres the German Wiki...

Marcus Heavyweather

I can\'t imagine how to make repair in that engine, when it will get some run-out from wear.

Vladimir Evdokimov

Motor? This is an engine. Efficiency? How does this compare to existing diesels, or the disc engine?


Reading all comments I come to the conclusion that there are many prejudices and half-truth spread around without knowing nothing at all. Fact is that Huettlin as a young engineer went to Wankel to explain the great "guru" how to improve his engines major problem till today. On a 5-axis-CNC-milling machine it's done and could be built by any engine manufacturer so far. The pistons and engine use parts that are proven since the early OTTO engines and thermal problems have not been shown up so far. With less parts there is a better use of resources and thanks to the geometry of the engine it turns smooth like a Wankel - but without the known and still unsolved problems. There is no easier engine seriously working at test facilities and being ready to be produced. Probably the combustion engine will however only be second, because the compressor will go into production earlier. And do not forget that Huettlin was always working with his own money and had no time frame to finish work so everything is done with Swiss watchmakers precision to the point of perfection even in small details. So keep an eye on, it's really IMPRESSIVE and far ahead of other concepts you mentioned, that have even not one prototype working. The Huettlin is a pre-serial product that can be demonstrated. It's true however that it has been once badly copied by a "might be partner" company, which failed so far building any really functional machine in contrary to the Original that works fine.

Roger Jean Zamofing

Looks to me like a machinist's nightmare


Fact 1: This engine is everything but simple. It would have to be exceptionally efficient in order to be worthy of investing in it. Fact 2: 3 cylinder engine has less parts than 4 cylinder engine. Fact 3: 2 cylinder engine has less parts than 3 cylinder engine. Fact 4: 1 cylinder engine has less parts than 2 cylinder engine. Fact 5: gas turbine has only 1 moving part. Fact 6: the average consumer doesn't care/doesn't have a clue.

Andreja Sinadinovic Vijatovic
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