Reversible Fuel Pumps with Redundant Flow Circuits

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Solution Overview

Problem

Existing fuel systems for internal combustion engines lack redundancy, leading to potential insufficient or non-existent fuel supply during operational disruptions, which can cause vehicles to suddenly stop, necessitating a solution to ensure continued movement to a garage.

Innovation Solution

A fuel system with a main supply pump and a transfer pump, both driven by electric engines and reversible, with three flow circuits that allow fuel to bypass either pump in case of failure, ensuring continuous fuel supply to the engine through redirection and sensor-activated control.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If only a mechanical fuel pump driven by the internal combustion engine is used, then the device complexity is reduced, but the reliability deteriorates because the fuel supply ceases when the pump fails or provides insufficient flow

Engineering Contradiction:
Improvefuel pump configurationVSAvoidfuel supply continuity
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The fuel supply function is segmented into two independent pumps: a mechanical fuel pump driven by the internal combustion engine and an electric fuel pump driven by an electric motor. This segmentation allows the system to maintain fuel supply through alternative means if one pump fails, thereby resolving the contradiction between device simplicity and reliability.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The system changes the operational parameters of the fuel pumps based on engine conditions. The mechanical pump operates during normal engine operation, while the electric pump is activated when the mechanical pump fails or during specific operating conditions, ensuring continuous fuel supply without requiring both pumps to operate simultaneously at full capacity.

Inventive Principle:
Principle #35Parameter changes

2Ease of operation

If only an electrically driven fuel pump is used, then the ease of operation is improved, but the reliability deteriorates due to operational disruptions and potential sudden vehicle stoppage

Engineering Contradiction:
Improvefuel pump controlVSAvoidfuel supply continuity
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The fuel supply function is segmented into two independent pumps: a mechanical fuel pump driven by the internal combustion engine and an electric fuel pump driven by an electric motor. This segmentation allows the system to maintain fuel supply through alternative means if one pump fails, thereby resolving the contradiction between device simplicity and reliability.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

A control unit acts as an intermediary between the mechanical and electric fuel pumps, monitoring their operational status and automatically switching between them or activating both as needed. This intermediary ensures seamless operation and maintains reliability while preserving the ease of automatic control.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Reliability

If two fuel pumps driven by electric motors are arranged to achieve redundancy, then the reliability is improved, but the device complexity increases

Engineering Contradiction:
Improvefuel supply redundancyVSAvoidfuel pump configuration
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The fuel supply function is segmented into two independent pumps: a mechanical fuel pump driven by the internal combustion engine and an electric fuel pump driven by an electric motor. This segmentation allows the system to maintain fuel supply through alternative means if one pump fails, thereby resolving the contradiction between device simplicity and reliability.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The mechanical fuel pump serves dual functions: it provides fuel supply during normal operation and acts as a backup when the electric pump fails. This multi-functionality reduces the need for dedicated backup systems, thereby reducing overall device complexity while maintaining reliability.

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

4Productivity

If a transfer pump is used to increase fuel flow during idling, then the productivity is improved, but the reliability deteriorates as the fuel pump driven by the internal combustion engine becomes a single point of failure

Engineering Contradiction:
Improvefuel flow during idlingVSAvoidfuel supply continuity
Core Design Contradiction:
ProductivityVSReliability

Solution Approach 1:

The fuel supply function is segmented into two independent pumps: a mechanical fuel pump driven by the internal combustion engine and an electric fuel pump driven by an electric motor. This segmentation allows the system to maintain fuel supply through alternative means if one pump fails, thereby resolving the contradiction between device simplicity and reliability.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

A control unit acts as an intermediary between the mechanical and electric fuel pumps, monitoring their operational status and automatically switching between them or activating both as needed. This intermediary ensures seamless operation and maintains reliability while preserving the ease of automatic control.

Inventive Principle:
Principle #24Intermediary (Mediator)

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 design reduces the risk of fuel supply disruptions, enabling the vehicle to be driven to a garage even with a failed pump, by using reversible pumps and sensor-activated control to redirect fuel flow, thus providing a 'limp home' function and maintaining engine operation.

Implementation Method 1

The fuel system comprises three flow circuits for a fuel flow, wherein the fuel flows at normal operation of the fuel system, wherein the fuel flows at an operational disruption in the main supply pump, and wherein the fuel flows at an operational disruption in the transfer pump

Methodology Applied
Scientific EffectHydraulic flow redirection:

Data Source

PatentEP3143273B1Fuel system for an internal combustion engine and a method for controlling a fuel system
Publication Date: 2018.03.21 SCANIA CV AB
  • EP3143273B1 patent drawingFigure 1
  • EP3143273B1 patent drawingFigure 2
  • EP3143273B1 patent drawingFigure 3

AI summary

The invention relates to a fuel system for an internal combustion engine (2), which fuel system (4) comprises a first fuel tank (20), a second fuel tank (22), a main supply pump (26) and a transfer pump (28), wherein a first electric engine (M1 ) is arranged to operate the main supply pump (26), and a second electric engine (M2) is arranged to operate the transfer pump (28). The main supply pump (26) and the transfer pump (28) are reversible, and the fuel system (4) comprises a first flow circuit (100) for the fuel flow, through which the fuel is led at normal operation, a second flow circuit (200) through which the fuel is led at an operational disruption in the main supply pump (26), and a third flow circuit (300) for the fuel flow, through which the fuel is arranged to flow at an operational disruption in the transfer pump (28). The fuel system reduces the risk of insufficient or non-existing fuel supply to the internal combustion engine in the event of an operational disruption, and enables a method for continued operation, albeit with potentially reduced power. This also secures the operation of the internal combustion engine (2) and a vehicle equipped with such a fuel system.