Lubricant Delivery Precision in Two-Stroke Marine Engines

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing lubrication systems for large slow-running two-stroke engines, particularly those using Swirl Injection Principle (SIP), face challenges in achieving precise lubricant delivery due to uncertainties in timing and volume caused by long conduits and external disturbances like pressure and temperature variations, leading to inefficiencies and potential mechanical failures.

Innovation Solution

A system with a controller and flowmeter for each injector, adjusting the stroke length of a plunger to regulate lubricant amount, and a common rail system for simultaneous lubricant feed to multiple injectors, allowing for precise and automatic lubricant delivery by calibrating injectors based on actual flow measurements and operational parameters.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If traditional lubrication systems with long conduits are used, then the system structure is simple, but the timing and volume precision of lubricant delivery deteriorates due to uncertainties caused by pressure and temperature variations

Engineering Contradiction:
Improvelubricant delivery precisionVSAvoidsystem complexity
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent implements feedback control by measuring actual lubricant flow with flowmeters and comparing it to desired flow values. The controller adjusts injector settings based on this feedback to compensate for deviations caused by pressure and temperature variations, thereby maintaining precise lubricant delivery despite environmental disturbances.

Inventive Principle:
Principle #23Feedback

Solution Approach 2:

The patent replaces traditional mechanical timing mechanisms with an electronically controlled system. Instead of relying on mechanical linkages and timing devices that are sensitive to pressure and temperature, the system uses electronic controllers, flowmeters, and adjustable valves to precisely control lubricant delivery timing and volume through electronic signals and feedback loops.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Loss of substance

If the amount of lubricant is reduced to lower operational costs, then oil consumption decreases, but engine reliability deteriorates due to insufficient lubrication

Engineering Contradiction:
Improveoil consumptionVSAvoidengine longevity
Core Design Contradiction:
Loss of substanceVSReliability

Solution Approach 1:

The patent dynamically adjusts lubricant delivery parameters (volume, pressure, timing) based on actual engine operating conditions measured by sensors. The controller modifies injection parameters in real-time to optimize lubrication efficiency, ensuring sufficient lubrication is provided only when and where needed, thereby reducing overall oil consumption while maintaining engine reliability.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent applies partial action by delivering lubricant only to specific areas and at specific times when it is most needed, rather than continuous or uniform lubrication. The system uses multiple injectors positioned at different locations and controls their operation individually or in groups, providing lubrication precisely when and where required, thus reducing total lubricant consumption while maintaining adequate protection.

Inventive Principle:
Principle #16Partial or excessive action

3Measurement precision

If multiple flowmeters are installed for each injector to achieve precise measurement, then measurement precision improves, but device complexity and cost increase

Engineering Contradiction:
Improveflow measurement accuracyVSAvoidnumber of flowmeters
Core Design Contradiction:
Measurement precisionVSDevice complexity

Solution Approach 1:

The patent merges measurement functions by using a single flowmeter to measure the total lubricant flow from multiple injectors rather than installing separate flowmeters for each injector. The controller calculates individual injector flow by subtracting the cumulative flow of previously measured injectors from the total, thereby achieving precise measurement of each injector's contribution while using only one physical flowmeter device.

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

The system ensures precise and consistent lubricant delivery, reducing deviations and mechanical failures, while adapting to changes in lubricant type, pressure, and temperature, thus enhancing engine longevity and reducing operational costs.

Implementation Method 1

at least one flowmeter for measuring the lubricant flow, wherein the controller is arranged for transforming the measured actual flow into an actual amount

Methodology Applied
Scientific EffectFlow measurement:

Implementation Method 2

an adjustable valve at the nozzle for opening and closing for flow of lubricant to the nozzle aperture from a pressure chamber in the injector during an injection-cycle

Methodology Applied
Scientific EffectMechanical force: Mechanical Force

Implementation Method 3

a pressure chamber in the injector during an injection-cycle

Methodology Applied
Scientific EffectPressure: Pressure Increase

Data Source

PatentEP4433742B1A large slow-running two-stroke engine, a method of lubricating it and a use of the engine and the method
Publication Date: 2025.11.05 HANS JENSEN LUBRICATORS AS
  • EP4433742B1 patent drawingFigure 1
  • EP4433742B1 patent drawingFigure 2
  • EP4433742B1 patent drawingFigure 3a

AI summary

A large engine, in particular a marine engine or engine for power plants, and a method of lubricating the engine with injectors. According to the method there are provided one flowmeter for all injectors in the engine, one flowmeter for all injectors in a cylinder or one flowmeter for each injector in the engine. The method comprises the steps of measuring with the at least one flowmeter the lubricant flow, transforming in the controller the measured actual flow into an actual amount, comparing the calculated actual amount to the desired value, and controlling the injectors and adjusting the setting thereof in order to regulate the amount to the desired value for lubricant amount to be injected for a specific operation mode.