Angled Piston-Head Reciprocating Engine for High-Speed Long Strokes

Solution Overview

Problem

Traditional internal combustion engines are limited by maximum stroke due to piston, piston rod, and crank stress during high-speed operations, leading to designs with either increased stress or heat loss, making high-speed operation with low heat loss desirable.

Innovation Solution

An engine design with two banks of cylinders angled downwards from the crankshaft side, using synchronized crankshafts with angled piston heads to prevent oil entry and enable traditional poppet valves, achieving longer strokes and lower surface-to-volume ratios for increased power and thermal efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If a large crankshaft pulley radius is used for high efficiency, then thermal efficiency is improved, but stress on piston, piston rod, and crank increases due to high engine speeds

Engineering Contradiction:

Improvethermal efficiencyVSAvoidcomponent stress

Core Design Contradiction:

Use of energy by moving objectVSStress or pressure

Solution Approach 1:

The engine is divided into two separate banks of cylinders (first bank and second bank) with separate crankshafts for each bank. This segmentation allows independent optimization of each bank's stroke and crankshaft radius, enabling one bank to use a larger crankshaft radius for thermal efficiency while the other can be configured for lower stress conditions.

Inventive Principle:

Principle #1Segmentation

2Power

If a large cylinder radius is used for high peak power, then power output is improved, but heat loss increases due to large surface-to-volume ratio

Engineering Contradiction:

Improvepeak powerVSAvoidheat loss

Core Design Contradiction:

PowerVSLoss of energy

Solution Approach 1:

The two banks of cylinders are configured with different cylinder radii and stroke lengths to optimize for different performance characteristics. One bank uses larger cylinders for peak power while the other uses smaller cylinders with lower surface-to-volume ratios for reduced heat loss, allowing the engine to achieve both high power and high thermal efficiency simultaneously.

Inventive Principle:

Principle #3Local quality

3Power

If a small crankshaft pulley radius is used for high peak power, then power output is improved, but thermal efficiency decreases

Engineering Contradiction:

Improvepeak powerVSAvoidthermal efficiency

Core Design Contradiction:

PowerVSUse of energy by moving object

Solution Approach 1:

The engine is divided into two separate banks of cylinders (first bank and second bank) with separate crankshafts for each bank. This segmentation allows independent optimization of each bank's stroke and crankshaft radius, enabling one bank to use a larger crankshaft radius for thermal efficiency while the other can be configured for lower stress conditions.

Inventive Principle:

Principle #1Segmentation

4Duration of action of moving object

If engine stroke is increased for longer power delivery, then duration of action is improved, but maximum engine speed decreases due to excessive component stress

Engineering Contradiction:

Improvepower delivery durationVSAvoidmaximum engine speed

Core Design Contradiction:

Duration of action of moving objectVSSpeed

Solution Approach 1:

The engine is divided into two separate banks of cylinders (first bank and second bank) with separate crankshafts for each bank. This segmentation allows independent optimization of each bank's stroke and crankshaft radius, enabling one bank to use a larger crankshaft radius for thermal efficiency while the other can be configured for lower stress conditions.

Inventive Principle:

Principle #1Segmentation

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

The design allows for high-speed operation with increased power output and reduced unburnt emissions by balancing crankshaft radius and heat loss, achieving rotational speeds over 9400 RPM and compression ratios between 8.6:1 and 23.9:1.

Implementation Method 1

The planar surface of the piston head is configured to distribute forces from a corresponding combustion reaction to the corresponding piston rod

Methodology Applied

Scientific EffectForce distribution:

Implementation Method 2

at least one fuel injector that injects fuel into the cylinders where the fuel is mixed with air in the cylinders to form an air-fuel mixture

Methodology Applied

Scientific EffectFuel injection and mixing:

Implementation Method 3

The combustion chamber forms a containment boundary for a corresponding combustion reaction

Methodology Applied

Scientific EffectCombustion: Combustion

Data Source

PatentUS12421891B1High-speed long-stroke reciprocating engine

Publication Date: 2025.09.23 ARAMCO SERVICES CO

AI summary

An engine includes a first crankshaft and a second crankshaft, pistons, piston rods, cylinders, combustion chambers, and fuel injectors. The crankshafts each extend in a horizontal plane and form a first and second rotating power output shaft of the engine. The combustion chambers form containment boundaries for combustion reactions of an air-fuel mixture formed in the cylinders with fuel provided by the fuel injectors. The piston rods connect the pistons to the first or the second crankshaft. The pistons are disposed in the cylinders, and the planar surface of the piston head of each piston distributes forces from an associated combustion reaction to a corresponding piston rod. The piston heads are disposed at an angle between 7 and 15 degrees in the first bank of cylinders and −7 and −15 degrees in the second bank of cylinders relative to a vertical plane.