Hybrid Module Dual Pump System for Reduced Weight and Power Loss

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Solution Overview

Problem

Existing hybrid vehicle systems require significant modifications to vehicle drive trains and often result in power loss, making them inefficient for retrofitting and affecting fuel economy.

Innovation Solution

A self-sufficient hybrid module with a dual mechanical/electric pump system that includes a mechanical pump and an electric pump, allowing for independent lubrication and cooling, reducing the need for modifications to other systems and enabling efficient operation in various modes such as electric, transition, and cruise modes.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If a single mechanical pump is used to provide lubrication and cooling, then the system is simpler, but the pump size and weight must be larger to handle all workload

Engineering Contradiction:
Improvepump system complexityVSAvoidmechanical pump weight
Core Design Contradiction:
Device complexityVSWeight of stationary object

Solution Approach 1:

The patent divides the single pump function into two separate pumps: a mechanical pump and an electric pump. This segmentation allows each pump to be smaller and lighter, as they share the workload. The mechanical pump handles primary lubrication needs while the electric pump provides supplemental flow, particularly during transition modes, reducing the size requirements for each individual pump.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The dual pump system provides multi-functionality by enabling the system to operate in different modes (engine-only, electric-only, transition) and handle varying lubrication and cooling demands. The electric pump can independently operate during engine auto-stop to maintain lubrication and cooling when the mechanical pump is not running.

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

2Reliability

If hydraulic pumps operate at full capacity continuously, then lubrication and cooling needs are met, but power loss increases

Engineering Contradiction:
Improvelubrication and cooling adequacyVSAvoidpower loss
Core Design Contradiction:
ReliabilityVSLoss of energy

Solution Approach 1:

The system dynamically adjusts pump operation based on real-time engine conditions and operational mode. The control system monitors engine speed, load, and temperature to determine when the electric pump should supplement or replace the mechanical pump, optimizing power consumption while maintaining adequate lubrication and cooling.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The electric pump provides partial action by supplementing the mechanical pump only when needed, rather than operating continuously at full capacity. This partial action during specific transition periods reduces overall power loss while still meeting lubrication and cooling requirements.

Inventive Principle:
Principle #16Partial or excessive action

3Ease of manufacture

If the hybrid system integrates with existing vehicle systems, then modifications are reduced, but the hybrid system must share resources with other systems

Engineering Contradiction:
Improveretrofitting easeVSAvoidindependent operation capability
Core Design Contradiction:
Ease of manufactureVSAdaptability or versatility

Solution Approach 1:

The dual pump system is designed to be universally applicable across different operational modes and vehicle configurations. It can independently provide lubrication and cooling during engine auto-stop, during electric-only operation, and during transition periods, making the hybrid module self-sufficient while integrating with existing vehicle systems.

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

Solution Approach 2:

The hybrid module's dual pump system serves itself by independently managing its own lubrication and cooling needs without relying on the vehicle's existing hydraulic systems. The electric pump can operate autonomously during engine off-periods to maintain fluid circulation and temperature control.

Inventive Principle:
Principle #25Self-service

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 hybrid module reduces the size and weight of mechanical pumps, allows for electric-only operation, and minimizes power loss by balancing the workload between mechanical and electric pumps, enhancing fuel efficiency and ease of retrofitting.

Implementation Method 1

a mechanical pump for circulating a fluid

Methodology Applied
Scientific EffectHydraulic pump circulation: Pump

Implementation Method 2

an electric pump that supplements the workload for the mechanical pump when needed

Methodology Applied
Scientific EffectElectric pump circulation: Pump

Implementation Method 3

The fluid has been circulating through the hybrid module and has picked up heat from the eMachine and other components

Methodology Applied
Scientific EffectThermal conduction: Conduction (thermal)

Implementation Method 4

The cooler is in fluid communication with the sump and is configured to cool the fluid

Methodology Applied
Scientific EffectConvection: Convection

Data Source

PatentEP2675682B1Hydraulic system and method for a hybrid vehicle
Publication Date: 2019.12.11 ALLISON TRANSMISSION INC
  • EP2675682B1 patent drawingFigure 1
  • EP2675682B1 patent drawingFigure 2
  • EP2675682B1 patent drawingFigure 3

AI summary

A hydraulic system for a hybrid module which is located between an engine and a transmission includes a parallel arrangement of a mechanical pump and an electric pump. Each pump is constructed and arranged to deliver oil to other portions of the hydraulic system depending on the operational mode. Three operational modes are described including an electric mode, a transition mode, and a cruise mode. Various monitoring and control features are incorporated into the hydraulic system.