Like HowStuffWorks on Facebook!

How the Hüttlin Spherical Engine Works


Get This Ball Rolling
The Hüttlin-kugelmotor (spherical engine) on the test stand -- fueled by CNG
The Hüttlin-kugelmotor (spherical engine) on the test stand -- fueled by CNG
Courtesy of Innomot AG

The Hüttlin is designed to supplement the electrical power of a hybrid car, but for the sake of simplicity, pretend for a moment that it's a stand-alone engine. In practice, the power it produces will be routed according to that particular hybrid's power-sharing design, but for the purposes of understanding how the motor itself makes power, where the power goes afterward is basically irrelevant. It's hard enough to describe as it is.

Here's the simple stuff: The prototype Hüttlin that's been making the rounds produces about 104 horsepower, but unlike a traditional gasoline engine, Dr. Hüttlin claims the design is easy to scale to suit almost any power need. Modern automotives are liquid-cooled, but the kugelmotor can also be adapted for air-cooled setups. It's built from just a fraction of the parts of a traditional engine (about 60 components in the Hüttlin, as compared to about 250 in an average four-piston), which helps achieve the goals of efficiency and economy, since there are fewer parts to produce and assemble. That means, in part, that the Hüttlin achieves more than 30 percent efficiency (in other words, less than 70 percent of the power it produces is squandered to heat, noise and wasted friction), which, of course, means the engine will use less fuel, and will also give off fewer environment-harming emissions. Traditional engines, by comparison, achieve only about 20 percent efficiency. Think about that next time you fuel up.

Here's where it gets more complicated: The engine's movement, referred to as "three-dimensional kinematics," features gasoline combustion and a four-piston design, but after that, it's like being on another planet. The sight of the engine is a head-scratcher -- a silver ball with pipes coming out. Like Spaceship Earth at Epcot... how does that sphere encase what everyone claims is inside? Housed within the lightweight aluminum globe are more kugels that run in tracks inside the two pistons on the same bearing, which are inside the rotor, which rotates within the outer aluminum shell. As the rotor rotates, the pistons pump in opposition, and the kugels glide along their tracks...the movement of which makes the rotor spin. Got that? (The fact that the basic parts share names and roles with everyday engine parts really doesn't help at all.)

And along the way, some coils and magnets help generate power, and transfer the power outside the sphere to a set of batteries that act as temporary holding packs to move the power along the drivetrain as needed. The power is sent to another motor that directly drives the wheels (instead of sending the power directly down a traditional drivetrain), which Innomot AG says is more efficient.

Dr. Hüttlin has said that the kugelmotor took a couple of decades to figure out and develop, but expects to see it in production vehicles in about 2 to 5 years. The patents were filed in December 2010 (rounding out Dr. Hüttlin's portfolio of more than 150), and Innomot AG plans to license the technology, so the Hüttlin could soon be nestled in the engine bay of a range of hybrids.


More to Explore