Counter-Rotating Shaft Transmission for Twin-Cylinder Engines

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Solution Overview

Problem

Existing twin-cylinder engines with camshafts housed in the cylinder head require numerous distinct mechanical components for each cylinder, increasing manufacturing and maintenance costs due to their complex and asymmetrical design.

Innovation Solution

The implementation of a primary stage with counter-rotating shafts allows for symmetrical design of both cylinders, using identical transmission components, including an idler gear driven by the crankshaft, timing shafts, and chain-driven camshafts with a tensioning system, reducing mechanical complexity and cost.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If separate mechanical components are used for each cylinder in twin-cylinder engines, then each cylinder can be independently optimized, but the number of parts increases and manufacturing cost rises

Engineering Contradiction:
Improveindependent cylinder optimizationVSAvoidnumber of mechanical components
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent applies universality by designing a single camshaft that serves both cylinders simultaneously. The camshaft includes cam lobes for both the first and second cylinders, eliminating the need for separate camshafts for each cylinder. This reduces the number of mechanical components while maintaining the ability to independently optimize valve timing for each cylinder through appropriately positioned cam lobes.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The patent merges the functions of multiple separate components into a single integrated camshaft assembly. By combining the cam lobes for both cylinders onto one camshaft, the invention reduces part count and simplifies manufacturing while preserving the independent control needed for each cylinder's valve operation.

Inventive Principle:
Principle #5Merging (Combining)

2Ease of manufacture

If identical transmission components are used for both high-engines, then manufacturing cost decreases, but the design becomes more constrained

Engineering Contradiction:
Improvemanufacturing costVSAvoiddesign flexibility
Core Design Contradiction:
Ease of manufactureVSAdaptability or versatility

Solution Approach 1:

The camshaft is designed as a universal component that can serve both high-engines with identical construction. The camshaft includes cam lobes positioned to control valves for both cylinders, allowing the same component design to be used in both engines without modification, thereby reducing manufacturing costs while maintaining design flexibility through proper cam lobe positioning.

Inventive Principle:
Principle #6Universality (Multi-functionality)

3Reliability

If camshafts are housed in the cylinder head, then valve control is improved, but the number of distinct mechanical components increases

Engineering Contradiction:
Improvevalve controlVSAvoiddistinct mechanical components
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent merges the camshaft housing within the cylinder head structure, integrating the camshaft into the existing cylinder head assembly. This eliminates the need for separate camshaft housings or mounting brackets, reducing the number of distinct mechanical components while maintaining effective valve control through the cam lobes.

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 solution enables a more compact and cost-effective engine design by utilizing identical components for both high-engines, reducing mechanical noise and maintaining efficiency with a balanced reduction ratio, thus lowering production and maintenance expenses.

Implementation Method 1

a gear secured to the crankshaft, said gear driving an idler gear, this idler gear driving a first timing shaft

Methodology Applied
Scientific EffectGear: Gear

Implementation Method 2

the second timing comprising a gear driven by a gear secured to said first timing shaft

Methodology Applied
Scientific EffectGear: Gear

Implementation Method 3

said chain receiving means comprises a tensioning system

Methodology Applied
Scientific EffectFriction: Friction

Data Source

PatentEP3094844B1Distribution system for a two-cylinder engine
Publication Date: 2019.10.30 RDMO
  • EP3094844B1 patent drawingFigure 1
  • EP3094844B1 patent drawingFigure 2
  • EP3094844B1 patent drawingFigure 3

AI summary

The invention relates to a two-cylinder engine comprising two separate cylinder heads each having at least one camshaft. The engine also comprises two drive means for transmitting torque between the crankshaft (4) and one of the camshafts (9, 10; 9', 10'), as well as comprising a primary stage and two counter-rotating shafts (21, 22) driven by the crankshaft (4) and each driving one of the transmission means, said two transmission means being formed by identical mechanical components.