Engine Oil Priming Control for Stop-Start Bearing Lubrication

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Solution Overview

Problem

Industrial vehicles with Stop and Start technology face challenges in lubricating large displacement engines due to frequent engine start events, leading to inadequate lubrication of bearings, which can result in excessive wear and energy consumption.

Innovation Solution

The implementation of a vehicle driver assist system that predicts upcoming engine load requests to prime the engine oil system using an electrical oil pump before engine start, ensuring bearings are lubricated at the time of hot-start, and switching off the pump when the engine is off to minimize energy consumption.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If the engine is equipped with Stop and Start technology to reduce energy consumption during idle, then energy efficiency is improved, but bearing lubrication is worsened due to frequent engine start events causing metal-to-metal contact

Engineering Contradiction:
Improveenergy consumption during idleVSAvoidbearing lubrication
Core Design Contradiction:
Loss of energyVSReliability

Solution Approach 1:

The system activates the electrical oil pump before the engine start event to pre-lubricate the bearings. The control unit receives a start request signal and triggers the pump to deliver oil to the bearing surfaces in advance, eliminating metal-to-metal contact during the critical start-up phase while maintaining the Stop and Start energy efficiency benefits

Inventive Principle:
Principle #10Preliminary action

2Reliability

If an electrical oil pump is activated continuously to ensure bearing lubrication, then bearing protection is improved, but energy consumption is worsened

Engineering Contradiction:
Improvebearing lubricationVSAvoidenergy consumption of oil pump
Core Design Contradiction:
ReliabilityVSLoss of energy

Solution Approach 1:

The electrical oil pump operates periodically rather than continuously, being activated only during specific phases: during engine operation and during the brief interval between detecting a start request and actual engine start. The pump is switched off when the engine is running at normal speed and during Stop and Start idle periods, significantly reducing energy consumption while maintaining bearing lubrication when needed

Inventive Principle:
Principle #19Periodic action

3Reliability

If the oil pump is activated earlier to prime the oil system, then bearing lubrication is improved, but energy consumption is worsened due to excessive anticipation

Engineering Contradiction:
Improvebearing lubricationVSAvoidenergy consumption of oil pump
Core Design Contradiction:
ReliabilityVSLoss of energy

Solution Approach 1:

The control unit continuously monitors engine status signals including crankshaft position, engine speed, and start request signals. Based on this real-time feedback, the control unit precisely determines when to activate and deactivate the oil pump, activating it only when a start request is detected and deactivating it when the engine reaches normal operating speed, thereby avoiding both insufficient lubrication and excessive energy consumption

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 approach reduces the time bearings and crankshaft are in metal-to-metal contact, enhancing bearing life and enabling efficient engine start with reduced energy consumption, while allowing for the integration of high compression ratio combustion engines and variable valve actuation systems.

Implementation Method 1

an electrical oil pump (13) arranged to deliver oil to at least one bearing (12) and to a crankshaft (14) of the internal combustion engine (1)

Methodology Applied
Scientific EffectLubrication: Lubrication

Data Source

PatentEP3536918B1Management method of an internal combustion engine lubrication and internal combustion engine implementing the method
Publication Date: 2021.12.29 FPT MOTORENFORSCHUNG AG
  • EP3536918B1 patent drawingFigure 1
  • EP3536918B1 patent drawingFigure 2
  • EP3536918B1 patent drawingFigure 3

AI summary

Management method of an internal combustion engine lubrication, the method comprising a step of automatically foresee a forthcoming engine start and a consequent electric oil pump activation before engine start.