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Directory:Atkinson-Cycle Rotary Engine:Libralato Ruggero

Lasted edited by Andrew Munsey, updated on June 15, 2016 at 12:51 am.

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Rotary engine design by inventor, Libralato Ruggero of Italy, uses the Atkinson cycle to combine the best attributes of wankel rotaries and piston engines. Half the size of a conventional engine, it produces 30% more power and uses 10% less fuel.


Endothermic rotary engine with two parallel rotation axes.

R.A.C.E. Rotary Atkinson Cycle Engine (Independent of type of fuel used).

D.A.R.T. Diesel Asymmetric Rotary Technology (Diesel fuelled application).

H.A.R.T. Hydrogen Asymmetric Rotary Technology (Hydrogen fuelled application).

The Atkinson cycle engine is a type of Internal combustion engine invented by James Atkinson in 1882.


Official Website

Feature Sites - "There is something elegant about the concept of an ICE producing rotary motion in its simplest form. Apart from the Wankel none of the other designs have been a commercial success. When I first saw this engine, it appeared too good to be true. Like one of those perpetual motion machines, looks convincing but could not possibly work. The inventors claims where just not believable: Only half the size of a conventional engine yet produces 30% more power and uses 10% less fuel. Why is not everyone knocking at his door? After three weeks of simulating the engine design I was convinced that the invention was a truly remarkable breakthrough. The rotary engine technologies are currently undergoing independent computer simulated appraisals and assessments."


General Description

How it Works


Concepts and Comparisons

Main Attributes




Latest Developments

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How it Works

Image:Atkinson Rotory-Cycle Engine anim.gif

Quoting from wiki site

The engine consists of two interlaced circular chambers of slightly different diameters. Inside these chambers revolve two rotors about separate centres. Each rotor is located by its own bearings. The rotors do not rely on casing contact for their location as in a Wankel engine. Sealing of the rotors against the chamber walls is excellent because of their circular orbits and large sealing surfaces. The expansion of the engine is uniform. It does not have a hot and a cold side like the Wankel. Thus the engine does not require high tolerance manufacturing and wear of the rotors is not a factor. Induction air enters at the centre of the engine and compression/expansion occurs at the periphery producing uniform heat flow characteristics. The rotors are connected together by another component that has a quasi-circular orbit. These three components form the total internal mechanism of the engine. Each chamber within the engine is entirely separated from the others. This allows for the future development of alternative fuels like hydrogen to be used without the valve overlap and sealing problems associated with piston engines.

The engine does not have a traditional Otto or Diesel cycle. There are two compression phases. The first compression phase, which has a low compression ratio, controls the later scavenge of the exhaust gases. After the scavenge of the exhaust gases, the air is then partially re-circulated to act again in the next scavenge phase, the remainder of the air goes on to be compressed again in the second compression phase. In this second compression phase, the air is compressed at a higher compression ratio where the fuel is added. It is this fuel/air mixture that ignites to form the expansion phase. The inlet phase is in part contributed to by the scavenge gases. This all provides for an extremely efficient handling of the gases, with a significant reduction of exhaust emissions and excellent fuel economy. The expansion volume is larger than the second compression volume and this therefore increases the thermodynamic efficiency.

See also How it Works


Image:WO2004020791 250.gif


Abstract : The object of the invention is an endothermic engine of the rotating mass type. An innovative feature of the invention is that of presenting a kinematic mechanism based on a rotor comprising two parts (B1, B2) of semi-cylindrical shape and rotating in the same direction on two contiguous axes with interpositioning of a slider (B3) hinging the parts (B1, B2), said parts being contained in the hollows (1, 2) of a stator (A) in which is provided a combustion chamber (8) and an opposing exhaust pipe (90) for the burned gases. The inventive engine achieves an expansion stroke (MS) able to greatly exploit the power of the firing, while a conduit (25) assures the contemporary suction stroke, supported by the ability of the parts (B1, B2) to circumferentially diverge, and the part (Bl) provides for the consequent stroke of compression of a combustible mixture (ME).


The main attributes of the engine are:

Extremely compact

Uncomplicated design

High power and torque

Minimal vibration

High RPM

High fuel efficiency

Low Emissions

Reduced number of components

High thermodynamic efficiency

Multiple Fuel capability

Very flexible internal geometry

Noise Reduction

Company Profile

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In the News

Google News >

A true breath of fresh air: the 2008 Mazda Tribute Hybrid - A special 2.3-liter four-cylinder gasoline engine features Atkinson-cycle combustion for improved efficiency and produces 133 horsepower at 6000 rpm. (Global Auto Index, Hungary - Jan 7, 2007)

First Drive: 2007 Toyota Camry and Camry Hybrid - The engine half is the same 2.4-liter found in base Camrys, but this one uses an Atkinson cycle and makes 147 horsepower. ( Line, CA - Jan 3, 2007)



See Talk:Directory:Atkinson-Cycle Rotary Engine:Libralato Ruggero

See also


- Directory







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