CVD Engines

Technical Information

The AspireCVD Engine significantly reduces engine losses through simplified mechanics and reduced friction. This engine employs a wobble plate, a concept used by many hydraulic pumps. The piston stroke, hence the piston displacement, is changed by changing the wobble plate angle. By moving the wobble plate up or down the power shaft, the compression ratio can be increased, decreased, or held constant throughout a range of displacement volume.

This patented design eliminates the need for timing belts/timing chains, and easily allows independent valve timing. Plus it eliminates the skirt friction induced by pistons in traditional combustion engines. This technology can be adapted to virtually any internal combustion engine, including (but not limited to) school buses, utility trucks, RVs, long-haulers, military, marine and agricultural engines.

Single camshaft instead of multiple
Eliminates many efficiency losses due to friction
Uses many commercially available parts
Fewer parts means a less expensive engine build
Smaller engine size takes less space

AspireCVD 250HP engine cross section

Features

Independent intake and exhaust valve timing (part of reduction gears in hydraulic valve actuation system)
Greatly reduced intake air pressure loss at high power (2 intake valves, each with a short, straight, low loss intake air path for each cylinder)
Light engine weight (estimated to be about ½ of current combustible engines)
Greatly reduced need for steel and aluminum (largely foreign sources, especially aluminum. Both can be recycled when no longer usable)
Small engine profile of basic engine (about 13.50-inch diameter and 18.75-inch vertical length for about 250-horsepower and 16.98-inch diameter and 21.22-inch vertical length for about 700-horsepower)

• Use of ball or roller bearings instead of journal bearings on power shaft
• Lower mass

• Single, short camshaft and use of needle bearings
• Two efficient planetary gear cam drives instead of timing chain or belt and associated pulleys/gears
• Use of roller in cam follower and virtually no frictional loss in valve actuator assembly
• Virtually no loss in valve follower
• Use of only one intake and one exhaust valve per cylinder

• Independent intake and exhaust valve timing and tailored shape of cam; simple, short, straight intake ducts
• Reduced cylinder wall heat losses (proportional to displacement)

AspireCVD 250HP engine cross section

Compression Ratio

The AspireCVD design employs a wobble plate. Many hydraulic pumps use this concept today. The piston forces rotate a power shaft. By changing the wobble plate angle the piston stroke is changed. By moving the wobble plate up or down the power shaft compression ratio can be maintained, increased, or decreased throughout the range of displacement.

The complete AspireCVD engine uses a hydraulic valve actuation system that includes an actuator assembly, using one cam to actuate all intake valves and a second cam to actuate all exhaust valves. This patented design eliminates the need for timing belts/ timing chains and permits independent variable valve timing of intake and exhaust valves.

Specifications

• Virtually instant, continuously variable displacement from 3:1
• Constant or variable compression ratio through full range of displacement
• Variable independent intake and exhaust valve timing
• Variable valve stroke
• Aspirator engine design for rapid response to desired changes of engine speed

Cylinder arrangement	Axial
Combustion type	4-stroke
Maximum displacement	3.7 liter
Minimum displacement	1.2 liter
Number of cylinders	5
Cylinder bore	3.68 inch
Compression ratio	10
Displacement control	Hydraulic
Valve actuator	Planetary gear/Hydraulic, 2 cams
Fuel	Regular (87 octane) gasoline

Benefits

LIGHTER WEIGHT • FEWER PARTS • LOWER EMISSIONS

The CVD engine uses many commercially available parts:
• pistons after removal of the piston skirt
• cylinder sleeves
• direct fuel injection ignition systems engine control module lubricating oil pump
• bearings
• power shaft seal
• coolant pump
• exhaust ducting
• lubricating oil
• small starter (1/3 size of current combustible engines)

The CVD engine eliminates the need for unpopular options:
• piston/cylinder deactivation – not very effective
• high compression ratio – cost of high octane gasoline
• small benefit turbocharger – extremely high combustion pressure and temperature
• expensive transmissions with multiple gear speeds - displacement adjusts according to need
• stop/start – unpopular with drivers, virtually no benefit
• batteries for total electric or dual power trains – cost, recharge system, not recyclable

Reduction of Friction Loss

The AspireCVD engine eliminates most of the friction losses, and therefore creates a more powerful engine. At higher speeds, the losses are further eliminated.

• Reduced Engine Frictional Losses
• Reduced Engine Pumping Losses
• Avoid Over-Heat Problems At Maximum Power
• Reduced piston/ring friction at low displacement (low velocity & short stroke)
• Reduced wristpin loss due to little rotation
• Reduced connection rod / wobble plate bearing loss (reduced rotation, proportionalto displacement)

Piston Skirt losses appear to be the largest loss in conventional piston engines, especially at higher speeds. The piston skirt is the part of a piston that extends the lowest. It is tasked with balancing the side-force of the pistons inside the cylinder.

Piston Skirt losses are virtually eliminated because of how the connecting rod is designed in the AspireCVD Engine, especially at high RPM (little loss due to virtually no side-force).