Technology Overview

For more than 130 years, the crankshaft has been the mechanism utilized in internal combustion engines to convert the reciprocating linear motion of the pistons to rotary movement.

The CV design replaces the crankshaft with what we call the powershaft, which fundamentally alters the relationship of the motion of the piston stroke, the travel from top dead center (TDC) to bottom dead center (BDC), relative to the movement of the rotating shaft.

Crankshaft design engines are at the core of our industrial society, turning wheels in vehicles, spinning propellers in planes and boats, powering all manner of land, air and water based vehicles, moving air and fluids with pumps and/or compressors and powering devices as diverse as generators, cars, trucks, motorcycles, off-road and on-water recreational and commercial vehicles of all types, plus marine engines, both inboard and outboard, lawn and garden equipment, etc.

Modern crankshaft design has advanced significantly in terms of quality and durability, and the appendages connected to and/or related to the crankshaft design have evolved since its creation. As a result, power and fuel efficiency have been improved over time.

However, the mechanics of the crankshaft design, relating to the transfer of force of linear motion to rotational movement are simple but unchangeable. This presents a major shortcoming, as devices using crankshafts lose greater than 60% (sixty percent) of their mechanical transfer of power as a direct result of the inefficiencies associated with crankshaft geometry, and piston side load.

Lever Arm Length – The Key to Efficient Power Transfer

Lever arm length is the distance from the center of the rotating shaft to the point where the linear movement is applied. The lever arm length determines the amount of power transferred, from the force exerted on the piston, to the rotating shaft.

The CV design has its maximum lever arm length achieved within less than 10% of the piston stroke after TDC and maintains at maximum length until over 90% of stroke after TDC.  The crankshaft does not achieve its maximum lever arm length until 43% after TDC and instantly decreases.

Additionally, in the crankshaft design, the shorter the connecting rod length, the greater the off-center angle force vector, which increases both friction, heat and wear between the cylinder wall and the piston, decreasing fuel efficiency while increasing emissions. This results in the diversion of the transfer of the linear piston force away from the rotational movement and therefore, less piston power is transferred to rotation.

The Source of Dramatic Fuel Savings

The crankshaft design, because its maximum lever arm length is achieved only at about mid stroke, requires an over-fueling charge in order to make the presence of the expanding combustion gasses last to mid stroke. This is necessary to achieve transfer of power to the crankshaft from the piston force.

In the CV design, the maximum lever arm length is achieved just past TDC at about 8% of piston stroke.  The duration of the maximum lever arm length is considerably longer than the same stroke crankshaft design.  Therefore, the amount of fuel charge required to perform maximum transfer of power from the piston to the CV powershaft greatly reduces the amount of fuel used as compared to the same stroke crankshaft design.  This is expected to produce greater than twice the fuel efficiency.

Key CV Engine Mechanisms

Two major components of the CV Engine are the moving parts (assemblies):

1. A powershaft replaces the crankshaft.  The powershaft consists of a series of teeth arranged around its diameter, creating the connection for the majority of the stroke in each direction.  In each opposing direction of stroke, the teeth are offset, allowing for engagement in one direction and non-engagement in the opposite direction. A bearing race-way groove is in between the sets of teeth; this race-way allows for ramp up and ramp down creating a reversing point between each stroke.

There is always total engagement between the rodrack and the powershaft throughout the stroke and the reversing stroke.  The ramp up creates perfect alignment with the teeth, while providing additional strength at the highest concentration of force caused by combustion and stroke turn around.  Restated, the ramp down provides controlled deceleration to zero and the ramp up provides controlled acceleration to gain proper speed for engagement of the reverse stroke.

2. A rodrack assembly is the rigidly connected components of opposing pistons, linkrods, turning shafts, and rodrack. The pistons, linkrods and rodrack are all connected, and when assembled, the entire unit becomes rigid, as if made of one single piece.

The rodrack has two sets of teeth positioned at an offset from each side of the centerline of the linkrods, allowing for engagement with the powershaft.  Each end of the rodrack connects to the linkrods using the turning shaft axle. This is also rigidly attached as if made of one piece. The top and bottom of the rodrack have machined parallel surfaces, which fit into bearings, which are mounted to the case. This provides for a precise linear movement of the rodrack assembly.  The piston assemblies are mounted to the rodrack in a collinear position. The precise linear movement of the rodrack assembly maintains the pistons in the center of the cylinder in a collinear path. The rigid assembly is possible because there are no rotating linkages and unbalanced or eccentric loads.

The ideal engine would be comprised of two rodrack assemblies providing four cylinders (pistons). The linear direction of each rodrack would be opposite the other; this would help eliminate or counter balance their respective reciprocal forces.  The CV Engine can be reduced to two opposing cylinders if necessary for a particular application.

CV Engine Graphics

The following images are: (A) a cut-away, and (B) an assembly for a four-cylinder CV Engine showing some of the key features. Image (A) is the complete assembly, and Image (B) is an assembly highlighting the patented replacement of the crankshaft with a rodrack connected directly to the pistons, moving as one unit.

In both images, the linear motion of the pistons act with a linear force directly upon the gold colored rodrack, which turns the gray powershaft, thereby, replacing the crankshaft to convert linear motion to rotary movement.

In order to better visualize the interaction of the rodrack and powershaft, a video of the operating CV engine can be viewed at www.youtube.com/watch?v=DtKRI-SPGNU or accessed directly from YouTube by searching for “CV Engine Concept in Slow Motion.”

Recap of CV design verses crankshaft design

• The patented CV Engine/Technology (CVE) replaces the crankshaft completely. It continuously converts linear reciprocating piston motion to rotary movement and vice versa in the most efficient manner possible.
• The CV design replaces the crankshaft with what we call the powershaft, which fundamentally alters the relationship of the motion of the piston stroke (travel from TDC to BDC) relative to the movement of the rotating shaft.
• The CV piston stroke is maintained at a constant velocity to the rotation of the powershaft for over 80% of the piston stroke. The crankshaft piston stroke velocity is continuously changing throughout the rotation of the crankshaft and never achieves a true constant velocity with the crankshaft.  
• The CV powershaft rotates 90° per one direction of the piston stroke where the crankshaft rotates 180° per one direction of the piston travel.
• The maximum lever arm length of the CV design is over 80% of the piston stroke where the maximum lever arm length of the crankshaft is only at an instant close to mid piston stroke.
• The CV design has its maximum lever arm length achieved within 10% of the stroke after TDC and the crankshaft does not achieve its maximum lever arm length until just before mid-stroke. The connecting rod length determines the exact point where maximum lever arm length is achieved. The shorter the rod the closer the point gets to TDC. However, because of the crankshaft swing radius, the rod can only get so short. Also the shorter the rod length, the greater the off-center angle force vector which increases the friction, heat and wear between the cylinder wall and the piston. This also diverts the transfer of the linear piston force away from the rotational movement and therefore transfers less piston power to rotation, decreasing fuel efficiency while increasing emissions.

The benefits of the CV design over the crankshaft design, each design producing the same power, include:

• Size: A much more physically compact unit, on the order of one-quarter to one-half the size
• Weight: One-quarter to one-half the weight
• Power: Achieved with less than half the displacement
• Torque: Nearly twice the torque achieved at lower RPM; improving at higher RPM
• Fuel Consumption: Greater than twice the fuel efficiency
• Emissions: Greater than 50% reduction in harmful emissions. The reduced pollution comes from using less fuel, but also from unique combustion capabilities not possible with the crankshaft engine
• Efficiency: Quieter, cooler, less vibration
• Durability: Less wear, reduced maintenance and longer design life
• Complexity: Significantly fewer parts

Configuration Flexibility and Multiple Applications

The CVE can be configured as:

• A clean burning two-stroke (oil not required in the combustion area) or four-stroke engine
• Can be driven by spark ignition or compression ignition (diesel) and potentially homogeneous charge compression ignition
• The CV Internal Combustion (IC) Engine can be configured to run on gasoline, diesel or very fast burning fuels such as methane, alcohol and hydrogen
• The CVE is a high-torque, low-rpm engine and as such is not encumbered with the associated problems of shaft speed reduction devices
• Many applications such as cars, trucks, forklifts, motorcycles, watercraft, all-terrain vehicles etc. can be direct driven without the associated power losses and the maintenance of a gear reduction system
• The CV Engine/Technology also extends to air motors, compressors, fluid pumps and low-head and high-head positive-displacement hydro-generators (replacing turbine driven generators), electrical generators and air motors
• The CVE innovation recovers more than 270% of the lost mechanical conversion of power by the crankshaft resulting in greater fuel efficiency and lower pollution in a smaller package
• The CV Internal Combustion (IC) Engine operates as a high-torque and low-rpm engine in its preferred configuration; however, high rpm operation is not precluded.

Benefits of the CV Internal Combustion (IC) Engine

• The powershaft design, with its collinear through-hole construction, along with its continuously circular, compact and balanced design, is capable of producing higher torque and is lighter and stronger than the crankshaft design
• More than twice the torque of an equal bore and stroke crankshaft engine
• The CV IC Engine can have up to 270% more torque when friction and off axis connecting rod force vector loses are considered
• Less than half the size of an equal bore and stroke crankshaft engine
• High horsepower density from 2hp/lb to over 10hp/lb for large engines
• The sealed CV powercase prevents upper cylinder oil contamination and eliminates oil changes and does not require oil filters
• Low pollution from improved combustion and, for a 2-stroke, no oil required in the combustion chamber
• Very low friction due to full linear bearing mounted piston/rodrack assembly and no off-axis vector force loading by the pistons to the cylinder walls
• Low vibration due to a balanced, low mass assembly and minimal pulsations
• Operates at high torque and low rpm, without a gear reduction for many applications such as cars, trucks, aircraft and watercraft

• Low noise due to low rpm operation and constant volume combustion
• Low heat due to low friction, constant volume combustion and improved energy conversion near TDC
• Very long life cycle with low maintenance
• The hollow powershaft (front to back) allows a collinear shaft for alignment of multiple, diverse, clutched assemblies including a mixture of functions like an IC engine, air motor, compressor, pump, etc.
• As a prime mover, multiple engines provide redundancy, power modulation and an emergency mode 

Abbreviated Technical Summary

• The key benefit of the CV design is the increase in delivered torque to the powershaft, with the maximum lever arm length for the longest period during the piston stroke and particularly at the most favorable period of the combustion process.

  The cylinder pressure during combustion is greatest at the top of the piston stroke near top dead center (TDC). The graphic below is for an equal piston stroke and shows the relationship of the respective lever arms for the CV design and a crankshaft design.  The crankshaft loses more than 50% of the potential torque and worse, is not at maximum until greater than 40% of the piston stroke. To restate this, the CV design cylinder pressure force on the piston is acting on a longer lever arm length for a longer period to produce more power/torque and earlier than a crankshaft design can with equal bore and stroke. Torque is a direct relationship to the length of the lever arm or throw of a crankshaft.

The crankshaft is at maximum torque for only an instant at greater than 40% of the piston stroke after TDC. The CV design has constant torque starting in less than 10% of stroke after TDC and maintains until over 90% of stroke after TDC. Further, the crankshaft lever arm is always 50% of the piston stroke where the CV design lever arm length is greater than 62% of the piston stroke. This relates to a 25% increase in lever arm length for the CV design.

The crankshaft mass, with piston cycling, induces pulsating harmonics and vibration. In addition, the variable lever arm length of the crankshaft results in a highly variable piston velocity throughout the piston stroke. The mass of the crankshaft is much greater than the piston; therefore, the piston must change its relative velocity. In contrast, the CV Engine piston is at constant velocity relative to the powershaft for nearly the entire piston stroke. Therefore, the pulsating harmonics and vibration are nearly eliminated, producing a smoother, more consistent power output. The powershaft in the CV design is smaller in diameter, more balanced and stronger than a crankshaft.

US Patent

US Patent (Patents also held in EU, Japan, S. Korea and India)

Summary

The internal combustion engine has evolved for over 130 years (since the 1880’s) to a point where it has reached its limits of design efficiency.  One of the inherent design inefficiencies is in the geometry of the crankshaft, which is used to convert the linear motion to rotational movement.

The crankshaft has an inherent mechanical loss in the amount of force applied to the top of the piston that converts to rotational torque. The crankshaft loses over 50% of the force generated, plus 10 to 20% friction for losses, that increases with speed.

The CV design has three major mechanical improvements over the crankshaft design. These improvements relate to much greater power output using less fuel and having much less harmful exhaust emissions than the crankshaft with the same bore and stroke.

1. 58% greater transfer of piston power to shaft rotation
2. The maximum transfer of power occurs at 10% of piston stroke after TDC
3. The 58% increase of power transfer is present for greater than 80% of the piston stroke.

The CV Engine can deliver its benefits in one of two equally attractive ways:

1. The CV engine delivers more than twice the power, using significantly less fuel, when compared to the same bore and stroke (displacement) crankshaft engine.
2.  When comparing equal power output, the CV engine is a smaller, lighter, simpler and more fuel-efficient package, with less heat, noise, vibration and reduced emissions, requiring less maintenance and providing greater fuel flexibility and overall durability and longevity.