Sanderson Engine Receives Patents on Mechanism for High-Efficiency Engine; Possible Hydraulic Hybrid Application
|Cutaway drawing of the Sanderson engine.|
Sanderson Engine Development Company (SED), which is developing a new engine that allows the conversion between reciprocating and rotational motion without the use of a conventional crankshaft, has been awarded three patents on critical elements of its technology.
The patents cover a piston assembly, an associated piston connecting joint, and a variable compression ratio mechanism. The piston joint and associated components are core components of the Sanderson Rocker Arm Mechanism (SRAM) invented by Robert and Albert Sanderson.
Among the applications for the engine currently being investigated is an integral hybrid hydraulic engine capable of powering a hydraulically-driven automobile.
In its simplest terms, the Sanderson Mechanism developed by SED is a variable-stroke system for single and multi-cylinder piston engines, using a patented configuration of universal joint and rocker arms to achieve remarkably low friction, small size, and high power-to-weight ratio. Other features are simple variable stroke adjustment, and very low noise and vibration.
The stroke is variable on all pistons simultaneously from a singe point control, easily controlled during engine operation even under all engine operating conditions. This feature is particularly valuable in increasing engine efficiency through higher CR, and reducing emissions, for example during cold-start and other conditions.
|Sanderson prototype. Click to enlarge.|
The SRAM concept allows the design and construction of a single integrated engine that incorporates a built-in hydraulic drive. This permits the elimination of numerous components normally required in hydraulically actuated vehicles such as log skidders and other commercial equipment.
Other potential applications being investigated for SRAM technology include pumps, compressors, refrigeration equipment, electric generators, agricultural and construction equipment, and hydraulic windmill systems.
The patent for the piston assembly covers both single- and double-ended pistons that are connected to a unique rocker arm mechanism in a manner that enables the engine’s compression ratio to be changed by varying the piston stroke while the engine is operating. The patent covers the application of the variable combustion ratio technology to various types of engines including two- and four-stroke, diesel, multi-fuelled, steam powered, and others.
The patent for the piston joint covers a new type of sliding joint assembly that couples a single- or double-ended piston to the Sanderson rocker arm, which in turn permits the virtual elimination of piston side-load, thus reducing friction, heat, and engine wear. The piston joint represents one of the principal breakthrough technologies of the Sanderson Rocker Arm Mechanism.
The patent for the piston assembly includes the incorporation of a drive gear and associated components to enable varying the stroke of a piston between zero and maximum stroke. This permits the compression ratio of an engine to be changed while the engine is running.
John Fox, president of Sanderson Engine Development, said that the company is working toward licensing its SRAM technology to several vertical industry segments.
With escalating gasoline prices, SRAM engines will enable accelerated development of ultra high-efficiency vehicles that are much lighter than today’s automobiles and may reach previously unattainable levels of fuel efficiency. SRAM engine technology could achieve up to 75 miles per gallon or more in a mid-sized sedan or SUV.—John Fox