Variable Compression Ratio Engine Double Crank Drive

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing reciprocating piston internal combustion engines face challenges in achieving variable compression ratios, which are crucial for optimizing performance, reducing pollutant emissions, and minimizing engine wear, but current solutions are complex and limited in adjustability.

Innovation Solution

A reciprocating piston internal combustion engine with a double crank drive and variable compression mechanism, where the connecting rod connecting component is adjustable via an external thread and adjusting rod, allowing for precise control of the compression ratio through rotational and axial movements, enabling a wider range of compression adjustments.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If variable compression is implemented in known engines, then compression ratio can be adjusted, but the adjustment mechanism is complex and the adjustment range is very small

Engineering Contradiction:
Improvecompression ratio adjustabilityVSAvoidadjustment mechanism complexity
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The connecting rod connecting component is designed to be adjustable along the piston rod, allowing the compression ratio to be dynamically changed during operation. The component can be positioned at different locations on the piston rod to achieve different compression ratios, transforming a static system into a dynamic one that adapts to varying operational requirements.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The connecting rod connecting component is divided into distinct parts: the component itself, the piston rod with external thread, and the adjusting rod. This segmentation allows independent adjustment of the connecting rod connecting component's position along the piston rod, enabling precise control of the compression ratio through rotational movement of the adjusting rod.

Inventive Principle:
Principle #1Segmentation

2Use of energy by moving object

If high compression ratio is used, then fuel efficiency improves, but engine damage risk and friction increase

Engineering Contradiction:
Improvefuel efficiencyVSAvoidengine damage risk
Core Design Contradiction:
Use of energy by moving objectVSReliability

Solution Approach 1:

The compression ratio can be dynamically adjusted based on operating conditions. During high load operations, a higher compression ratio can be selected to maximize fuel efficiency. During low load or high-speed operations, the compression ratio can be reduced to minimize friction and prevent engine damage, thus optimizing the balance between energy efficiency and reliability.

Inventive Principle:
Principle #15Dynamics

3Loss of energy

If double crank drive is used, then friction and vibration are reduced, but the engine design becomes more complex

Engineering Contradiction:
Improvefriction lossVSAvoidcrank drive design
Core Design Contradiction:
Loss of energyVSDevice complexity

Solution Approach 1:

The adjusting rod is integrated into the hollow piston rod, and the connecting rod connecting component is mounted on the piston rod. This merging of functions reduces the number of separate parts and simplifies the overall structure, offsetting the added complexity of the double crank drive mechanism while maintaining its friction and vibration reduction benefits.

Inventive Principle:
Principle #5Merging (Combining)

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

This design simplifies engine design, reduces risk of damage, lowers friction and manufacturing costs, improves fuel efficiency, and reduces emissions, while allowing for optimized torque development and extended engine life.

Implementation Method 1

A reciprocating piston internal combustion engine with a double crank drive and variable compression mechanism, where the connecting rod connecting component is adjustable via an external thread and adjusting rod, allowing for precise control of the compression ratio through rotational and axial movements

Methodology Applied
Scientific EffectScrew mechanism: Screw

Data Source

PatentEP3362645B1Internal combustion engine with double crank drive and variable compression ratio
Publication Date: 2019.12.04 PELZ PETER
  • EP3362645B1 patent drawingFigure 1
  • EP3362645B1 patent drawingFigure 2
  • EP3362645B1 patent drawingFigure 3

AI summary

The invention relates to an internal combustion engine with a double crank drive and variable compression ratio, in which the force transmission occurs from the piston to the crank drive via a piston rod, secured to the piston and linearly moving following the movement of the piston, and via a connecting rod articulated on this piston rod and the double crank drive. To adjust the compression ratio, the engagement point of the connecting rod on the piston rod can be adjusted, even during operation of the internal combustion engine. The variable compression ratio is enabled with a minimal constructional output, by which means a cost-effective and simple internal combustion engine is created, which reduces consumption and operates at low emissions.