Basic components of the Garric engine. Click to enlarge.
A pair of Florida entrepreneurs, Rick Ivas and Gary Kelley, are developing the concept of the Garric engine: a rotary, variable compression ratio engine promising a combination of high power and torque and low fuel consumption.
With a 3.8-inch piston bore (comparable to a contemporary midsize V6) and a 10-inch toroidal radius, the Garric engine is calculated to deliver more than 225 hp (168 kW) of power and 733 lb-ft (994 Nm) of torque while running at 1050 rpm. Fuel consumption is estimated to be approximately one-third to one-quarter of current production V-6 engines.
<!––>In August, Garric Engines reached an agreement in principal to utilize Cobra Design & Engineering, Inc. of St. Petersburg, Florida for engineering, drafting, design and manufacturing management functions for prototype development and production. The project will take the Garric design from its current advanced concept stage to development of a fully functional prototype, according to the company.
The Garric engine has been to operate on a wide variety of liquid and gaseous fuels.
The Garric engine divides the four elements of intake, compression, combustion and exhaust among multiple double-faced pistons moving in a constant direction. Each side of a double faced piston is continually performing one of the four elements. The central hub (or power shaft) is connected to a disc with one or more pistons attached. The pistons revolve around the central hub and are contained in a toroidal chamber. Along the path are multiple combustion areas, each of which has two gates (or valves) located on either side of the combustion area.
Each gate that is located following a combustion area along the piston’s path is responsible for controlling air or air-fuel intake and also for sealing the torus for compression. Each gate preceding the combustion area is responsible for sealing the toroidal chamber for combustion and for directing the forces of the expanding gasses behind the piston. It also directs the spent exhaust gasses out of the torus.
As a piston passes the second gate, the gate closes behind the piston sealing the torus and starting air intake. When the piston passes the second gate of the subsequent combustion area, the gate closes behind the piston sealing the torus and allowing for the subsequent compression of the air which was just ingested.
A following piston enters the area filled with fresh air through the previously closed gate which has now opened, simultaneously closing off the intake port. The piston, with its forward face, begins to compress the fresh air against the closed gate ahead. Additionally, the preceding intake/exhaust piston is simultaneously beginning to draw fresh air into the next combustion area along the path.
Compression by the compression/power piston continues against the closed gate. When the compression/power piston reaches Top Dead Center, both gates are closed and all of the compressed intake air is pushed into a combustion area adjacent to the toroidal chamber. The design of the piston shape aids in conducting the air through and around the piston into the combustion area.
A few degrees past Top Dead Center, fuel is injected into the compressed fresh air and ignition is accomplished (either by compression ignition or by spark).
As the piston is propelled along the toroidal path toward the next closed gate by the exhaust gasses, the fresh air ahead of it is again being compressed by the forward edge of the piston.
In a two-piston embodiment with three combustion areas, the process can complete three full power cycles in a single 360° revolution.
Variable Compression Ratio technology is designed into the Garric engine from the start through variable valve (gate) timing. The compression ratio of the engine can be adjusted in real time, as demand warrants, according to the developers.
A detailed animation of the cycle is available on the Garric Engine website.
Resources
- Company whitepaper: Inside the Non-Reciprocating, Variable Compression Internal Combustion Engine
http://www.greencarcongress.com/2009/09/garric-20090925.html
