Vehicle Drivetrain Engine Start Using a Hydraulic Actuator Motor

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Solution Overview

Problem

Current drive trains with internal combustion engines face challenges in efficiently starting the engine while minimizing weight, cost, and energy consumption, particularly in hybrid systems where the electric starter motor's contribution to overall weight and energy storage state is significant, and existing solutions do not effectively address the need for starting the engine without a separate electric starter motor.

Innovation Solution

The drive train utilizes an electric actuator motor to drive a hydraulic pump, which hydraulically actuates a hydraulic motor to start the internal combustion engine, eliminating the need for a separate electric starter motor and allowing the electric drive machine to predominantly start the engine, with the hydraulic motor connected to the crankshaft or transmission to achieve starting speed.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If an electric starter motor is integrated into the drive train to start the internal combustion engine, then the engine can be reliably started from standstill, but the overall weight of the vehicle increases significantly

Engineering Contradiction:
Improveengine starting capabilityVSAvoidvehicle weight
Core Design Contradiction:
ReliabilityVSWeight of moving object

Solution Approach 1:

The electric drive machine is designed to perform multiple functions: it can drive the motor vehicle, generate electrical energy, and start the internal combustion engine. This eliminates the need for a separate electric starter motor, reducing vehicle weight while maintaining reliable engine starting capability

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

Solution Approach 2:

The patent combines the starting function with the existing electric drive machine by providing a mechanical coupling between the electric drive machine and the internal combustion engine. This merging of functions allows the same component to serve both propulsion and starting purposes

Inventive Principle:
Principle #5Merging (Combining)

2Reliability

If a separate electric starter motor is used to start the internal combustion engine, then the engine can be started reliably, but the cost and complexity of the drive train increases

Engineering Contradiction:
Improveengine starting capabilityVSAvoiddrive train complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The electric drive machine is designed to perform multiple functions: it can drive the motor vehicle, generate electrical energy, and start the internal combustion engine. This eliminates the need for a separate electric starter motor, reducing vehicle weight while maintaining reliable engine starting capability

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

Solution Approach 2:

The patent combines the starting function with the existing electric drive machine by providing a mechanical coupling between the electric drive machine and the internal combustion engine. This merging of functions allows the same component to serve both propulsion and starting purposes

Inventive Principle:
Principle #5Merging (Combining)

3Loss of energy

If the electric drive machine is used as a generator for recuperation, then energy recovery is achieved, but the machine cannot be used to restart the internal combustion engine

Engineering Contradiction:
Improveenergy recoveryVSAvoidstarting capability in hybrid modes
Core Design Contradiction:
Loss of energyVSAdaptability or versatility

Solution Approach 1:

The system dynamically switches between different operational modes of the electric drive machine. A switching arrangement enables the electric drive machine to operate as a generator during recuperation and as a motor during engine starting, allowing the same component to adapt to different hybrid drive modes

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The electric drive machine is designed to perform multiple functions including generation and motor operation, allowing it to serve both energy recovery and engine starting purposes depending on the operational mode

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

4Use of energy by moving object

If the internal combustion engine is frequently started and stopped in start-stop operation, then fuel consumption is reduced, but the state of charge of the electrical energy store deteriorates

Engineering Contradiction:
Improvefuel consumptionVSAvoidelectrical energy store state
Core Design Contradiction:
Use of energy by moving objectVSReliability

Solution Approach 1:

The electric drive machine serves itself by providing both the starting torque for the internal combustion engine and the electrical energy for the electrical energy store. During engine starting, it can simultaneously charge the energy store, making the system self-sufficient and eliminating the parasitic effect on the electrical energy store

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

This solution provides space, weight, and cost savings by using a hydraulic motor, which is cheaper and lighter than conventional electric starters, while maintaining efficient engine starting capabilities without affecting the transmission arrangement, and ensures the engine can be started in various hybrid modes, including start-stop operations.

Implementation Method 1

an electric actuator motor (52) which serves to actuate a component of the transmission arrangement and/or to start the internal combustion engine indirectly by driving a pump of a hydraulic circuit

Methodology Applied
Scientific EffectElectromagnetic conversion: Electromagnetic Induction

Implementation Method 2

the pump (50) provides a fluid volume flow for driving a hydraulic motor (64) in the fluid line

Methodology Applied
Scientific EffectHydraulic pump: Pump

Implementation Method 3

a hydraulic motor (64) which serves to start the internal combustion engine (12), the hydraulic motor being able to be connected to a fluid line of a hydraulic circuit

Methodology Applied
Scientific EffectHydraulic motor: Hydraulic Press

Data Source

PatentEP3740705B1Drivetrain for a motor vehicle and method for starting an internal combustion engine in such a drivetrain
Publication Date: 2022.02.02 MAGNA PT B V & CO KG
  • EP3740705B1 patent drawingFigure 1

AI summary

A drivetrain (10) for a motor vehicle, having an internal combustion engine (12) which can be started by means of a starter device, having a transmission arrangement (14) via which drive power can be conducted from the internal combustion engine (12) to an output (16) of the motor vehicle, which transmission arrangement (14) has at least one component (23; 32) which can be actuated in a way which can be automated, and having an actuator arrangement (40) which has at least one electric actuator motor (52; 78) by means of which the at least one component (23; 32) of the transmission arrangement can be actuated. In this context, the electric actuator motor (52; 78) is coupled to the starter device in order to be able to start the internal combustion engine (12) by means of the electric actuator motor (52; 78).