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 top 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.