Photos courtesy of Capt. Bill Pike
A Steyr Motors Hybrid—its footprint is only 3.53" longer than a conventional engine's.
The idea behind the Steyr Motors Hybrid is as elegant as it is simple: tap a diesel's rotational energy by splicing a10-hp/5-kW electric motor/generator between the crankshaft and marine gear. Then employ the tap, via a computer-actuated levering mechanism that couples and uncouples the motor/generator, to either generate electricity and store it in a battery bank, engage silent, zero-emissions, all-electric operation, or boost the performance of the diesel.
Of course, the specifics are way more complicated. And Roland Streitner, the 28-year-old mechanical engineer who headed up the development of the hybrid for Austrian diesel manufacturer Steyr Motors, is a tad proprietary about the clever levering mechanism, with its sliding-shaft-mounted male and female splines that facilitate flywheel engagement and disengagement. But he is amenable to delving into at least the rudiments of "the rest of the electro-mechanic power unit," as he calls it.
A short summary starts with a green bell housing elongated just enough (approximately 3.5") to accommodate an array of extra componentry. A fixed, ring-like stator with electrical windings and sensor/senders processes pulse-modulated signals (much like the ones used to levitate and move super-fast magnetic trains overseas) sent from a computer or HCU (Hybrid Control Unit) installed remotely. The rotor—another ring-like part—spins freely within the stator at the behest of the pulse-modulated signals and their effects upon a series of brushless permanent magnets evenly distributed around the rotor's perimeter. Depending upon commands from the HCU, the stator-rotor combo functions either as a motor or a generator and connects with the diesel's flywheel via the levering mechanism already mentioned.
Ancillary aspects abound, of course. There's a dashboard touchscreen or SCC (Steyr Control Center) for monitoring and controlling the HCU, an electrically actuated, dashboard-mounted solenoid that engages and disengages the levering mechanism, and a bank of high-capacity, fast-charging batteries to store electrical energy.
This article originally appeared in the January 2009 issue of Power & Motoryacht magazine.