Exploded view of the OX2 Engine. Click to enlarge.|
Advanced Engine Technologies Inc. says it has reached the final development stage of its OX2 rotary engine, achieving a performance objective of more than 300 lb-ft (407 N·m) of torque along with 46 hp (34 kW) at an approximate operating speed of 760 rpm.
The OX2 engine was conceived in Australia by inventor Steve Manthey. The engine is an 8-cylinder barrel configuration, using a stationary head and cam plate, and rotating cylinder block and piston plates. Each cylinder fires twice per revolution and two cylinders fire simultaneously, resulting in four times the output per revolution of a conventional four-stroke engine at the same displacement. The engine can be adapted to run any combustible gas or liquid as fuel.
OX2 in a test rig. Click to enlarge.|
Advanced Engine Technologies was incorporated in 1996 to commercialize the OX2, with automotive racing pioneer Carroll Shelby on its Board of Directors and involved in the engine development.
With its expected higher power-to-weight ratio, multi-fuel capacity and anticipated low emissions and fuel efficiency, the OX2 is initially targeted at the commercial and industrial generator markets. Additional future applications may include marine, light-duty farm and construction equipment, light aircraft, and the hybrid electric vehicle market. However, the near term focus remains electrical generator applications.
The OX2 engine achieves considerable torque at all stages through its operating range. Consequently, in most engine applications there would be no need for the engine to operate at revs higher than 2,500 rpm. In some instances, this would eliminate the need for a gearbox and would certainly reduce engine wear.
However, in particular applications, if high engine revs were mandated, the OX2 engine could be adapted accordingly, AET says. A problem with higher revs is that the centrifugal force lifting the pistons from the track increases, requiring engineering modifications to keep the pistons on track.
The current OX2 is a 4-stroke, 1.1-liter engine that is 17 inches in diameter with a length of 13 inches and a total weight of 200 pounds (91 kg) in normally aspirated form. The compact engine weighs 75% less than and is half the size of traditional internal combustion engines.
The major parts of the engine are the housing; cylinder block; top piston plate; lower piston plate; cam track; and drive shaft. The moving parts are the cylinder block; top piston plate; and lower piston plate.
The combustion chambers are only slightly longer than the stroke and pistons need only to be thick enough to house the rings. The OX2 contains no piston skirts and the rings are the only contact point with the bore. In effect, at no time do the pistons touch the bore, and nor are they reliant on it for support. This system eliminates loading on the sides of the combustion chambers.
Engineers continue work on the commercialization package of the OX2 engine/generator with the fabrication of its finish enclosure and footprint. In addition, AET engineers have prototyped a version of the OX2 engine/generator operating in a vertical orientation.
This new vertical footprint reduces the surface footprint by 50%, allowing the majority of the OX2 engine/generator mass to occupy vertical airspace, not floor space. The company expects to demonstrate both its vertical and horizontal units in the future.
On the heels of AET’s new vertical platform development will be a new, smaller and more versatile power electronics unit. Upon failure of its previous power electronics unit, an outside electrical engineering firm was hired to write the new specifications. The company is poised to proceed with the production of two new power electronics units for fitment with the OX2 engine/generators.
The power electronics is the last mile of the OX2 engine/generator development. The OX2 engine/generator currently produces over 30 kW of power, however it is raw power. This new unit will condition the raw power and produce useable power for commercial connectivity and use.
—John Luft, Chief Operating Officer of AET
In addition to the exciting engineering progress made on the OX2 engine/generator, the company has initiated efforts to raise additional capital to fund the OX2’s 30 Kw Generator final development stage.