Cylinder Oil Injection Control for Two-Stroke Diesel Lubrication

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Solution Overview

Problem

Existing cylinder lubrication systems for large slow-running two-stroke diesel engines, such as those used in ship engines, face issues where the last part stroke before retraction often results in insufficient lubrication, leading to increased wear on pistons and liners due to inadequate lubrication, compromising engine maintenance and longevity.

Innovation Solution

The system employs a progressive partial stroke motion for the dosing plungers without immediate retraction, allowing lubrication oil to be injected over multiple engine revolutions before retraction, with a computer-controlled linear actuator and position sensors to ensure adequate lubrication by comparing the remaining oil volume with a predetermined threshold, allowing early retraction if insufficient for proper lubrication.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Duration of action of stationary object

If the dosing plunger is advanced in a full stroke to maximum extension, then the lifetime of the lubrication system is increased by even wear distribution, but the engine may receive insufficient lubrication in the last part stroke

Engineering Contradiction:
Improvelifetime of lubrication systemVSAvoidlubrication sufficiency
Core Design Contradiction:
Duration of action of stationary objectVSReliability

Solution Approach 1:

The system dynamically adjusts the dosing plunger stroke length based on real-time monitoring. Instead of always performing full strokes, the controller adapts the stroke length to ensure adequate lubrication is delivered, preventing the insufficiency issue while still distributing wear evenly through progressive partial strokes

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The system incorporates monitoring means that detect whether adequate lubrication has been delivered. This feedback mechanism allows the controller to determine when to retract the dosing plunger, ensuring that engine lubrication needs are met while still achieving even wear distribution through controlled partial strokes

Inventive Principle:
Principle #23Feedback

2Duration of action of stationary object

If the dosing plunger is retracted after insufficient lubrication in the last part stroke, then the lubrication system experiences reduced wear, but the engine suffers increased wear on pistons and liners

Engineering Contradiction:
Improvelifetime of lubrication systemVSAvoidwear on pistons and liners
Core Design Contradiction:
Duration of action of stationary objectVSObject-affected harmful factors

Solution Approach 1:

The monitoring means detects whether adequate lubrication has been delivered to the engine. This feedback prevents premature retraction that would cause insufficient lubrication, while still allowing the dosing plunger to be retracted in a controlled manner to distribute wear evenly, thus protecting both the lubrication system and engine components

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The system dynamically determines the optimal retraction timing based on actual lubrication delivery. By adapting the operation cycle to real-time conditions, it ensures adequate engine lubrication is maintained while still achieving even wear distribution on the dosing plunger and cylinder

Inventive Principle:
Principle #15Dynamics

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 approach reduces wear on the lubrication system components while maintaining proper engine lubrication, avoiding the compromise of engine maintenance seen in prior systems by ensuring sufficient lubrication is provided without relying on subsequent compensation strokes.

Implementation Method 1

a linear actuator (2) connected to the dosing plunger (21) and configured for driving said dosing plunger (21) progressively in successive partial strokes

Methodology Applied
Scientific EffectHydraulic actuation: Hydraulic Press

Implementation Method 2

A sensor is provided for determining the position of the dosing plunger, the position indicating a volume of lubrication oil that is left for potential pumping

Methodology Applied
Scientific EffectPosition sensing:

Data Source

PatentEP3640441B1A method for lubricating large slow running two-stroke diesel engines
Publication Date: 2022.09.07 HANS JENSEN LUBRICATORS AS
  • EP3640441B1 patent drawingFigure 1
  • EP3640441B1 patent drawingFigure 2
  • EP3640441B1 patent drawingFigure 3

AI summary

A method is provided where piston pumps are used for injection of oil into engine cylinders. The pistons in the piston pumps are advanced through a plurality of partial strokes over multiple engine revolutions before being retracted.