Two-Stroke Engine Lubrication Upgrade With Common Rail Injection

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Solution Overview

Problem

Existing lubrication systems for large slow-running two-stroke engines, such as the Alpha lubricator, face challenges in increasing lubrication frequency without compromising lubricant volume or engine longevity, particularly when transitioning from compact jet injection to Swirl Injection Principle (SIP) systems, due to limitations in stroke length adjustment and synchronization with feedback sensors.

Innovation Solution

The modification involves introducing a lubricant accumulator and an upgrade valve system to decouple injectors from the lubricator's feed conduits, allowing for a common rail system where all injectors receive lubricant through a single supply line, enabling independent control of injection timing, frequency, and volume, and utilizing an upgrade controller to manage the flow, thereby allowing more frequent injections with reduced lubricant volume per injection.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If lubrication frequency is increased to improve lubrication effectiveness, then lubrication quality improves, but lubricant consumption increases

Engineering Contradiction:
Improvelubrication effectivenessVSAvoidlubricant consumption
Core Design Contradiction:
ReliabilityVSLoss of substance

Solution Approach 1:

The system changes the parameters of lubricant delivery by using a common rail to maintain high pressure and introducing an upgrade valve system to precisely control injection timing and duration. This allows frequent injections with optimized volume to achieve better lubrication without proportionally increasing total lubricant consumption.

Inventive Principle:
Principle #35Parameter changes

2Productivity

If lubrication frequency is increased by modifying the lubricator's actuator piston stroke, then injection frequency improves, but the system complexity and adjustment limitations worsen

Engineering Contradiction:
Improveinjection frequencyVSAvoidsystem complexity
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The system separates the lubricant storage and pressurization function (common rail) from the injection control function (upgrade valve system). This segmentation allows independent optimization of each subsystem, enabling frequent injections without requiring complex modifications to the actuator piston mechanism.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The common rail acts as an intermediary between the lubricator and injectors, decoupling them and allowing independent control of injection timing and frequency through the upgrade valve system without directly modifying the lubricator's mechanical components.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Reliability

If transition to SIP systems is made to improve lubrication distribution, then lubrication quality improves, but synchronization limitations with feedback sensors worsen

Engineering Contradiction:
Improvelubrication distribution qualityVSAvoidinjection timing precision
Core Design Contradiction:
ReliabilityVSManufacturing precision

Solution Approach 1:

The system uses feedback sensors to monitor engine position and the upgrade controller adjusts injection timing accordingly. This closed-loop control ensures precise synchronization of SIP injections with engine cycles, maintaining injection timing precision despite the transition to swirl injection technology.

Inventive Principle:
Principle #23Feedback

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 enhances lubrication frequency and reduces wear on engine components while maintaining minimal lubricant consumption, improving lubrication effectiveness without increasing overall lubricant use, and allows for seamless integration with existing systems, reducing costs and downtime.

Implementation Method 1

a lubricant accumulator and an upgrade valve system to decouple injectors from the lubricator's feed conduits

Methodology Applied
Scientific EffectHydraulic pressure: Pressure Increase

Implementation Method 2

an upgrade valve system to decouple injectors from the lubricator's feed conduits, allowing for a common rail system where all injectors receive lubricant through a single supply line

Methodology Applied
Scientific EffectFluid flow control: Valve

Implementation Method 3

injection of atomized droplets of lubricant into the scavenging air swirl inside the cylinder. The helically upwards directed swirl results in the lubricant being pulled towards the Top Dead Centre (TDC) of the cylinder and pressed outwards against the cylinder wall as a thin and even layer

Methodology Applied
Scientific EffectSwirl injection: Vortex Ring

Data Source

PatentEP3818256B1A method for upgrading a lubrication system in a large slow-running two-stroke engine
Publication Date: 2022.09.07 HANS JENSEN LUBRICATORS AS
  • EP3818256B1 patent drawingFigure 1
  • EP3818256B1 patent drawingFigure 2
  • EP3818256B1 patent drawingFigure 3

AI summary

A method for optimizing lubrication in a large slow-running two-stroke engine by which an existing lubrication system is upgraded by inserting an upgrade valve system downstream of an existing lubricator.