Electric Transmission Pump for Engine Stop-Start Fuel Savings

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Vehicles without electric motors face challenges in stopping the engine during low driver demand torque conditions due to the need for continuous engine operation to maintain transmission fluid pressure, which hinders fuel efficiency and transmission performance.

Innovation Solution

Activating an electric transmission pump and adjusting its speed based on accumulator pressure to maintain transmission operation and reduce energy consumption, allowing for quick gear engagement and reduced fuel consumption even when the engine is stopped.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If the engine is stopped to conserve fuel during low driver demand torque conditions, then fuel consumption is reduced, but transmission fluid pressure cannot be maintained and transmission operation fails

Engineering Contradiction:

Improvefuel consumptionVSAvoidtransmission operation

Core Design Contradiction:

Loss of energyVSReliability

Solution Approach 1:

The patent replaces the mechanical pump (which requires engine rotation to operate) with an electric transmission pump that can function independently of engine operation. This substitution allows the transmission to maintain fluid pressure and operate reliably even when the engine is stopped, thereby enabling fuel conservation without sacrificing transmission reliability.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The electric transmission pump serves multiple functions: it maintains transmission fluid pressure during engine stop-start conditions, enables transmission operation independent of engine rotation, and supports both fuel conservation mode and normal operation mode. This multi-functionality resolves the contradiction by providing a single component that addresses both fuel efficiency and transmission reliability requirements.

Inventive Principle:

Principle #6Universality (Multi-functionality)

2Loss of energy

If the engine is stopped to reduce fuel consumption, then fuel efficiency improves, but the transmission cannot shift gears properly due to lack of pressurized fluid

Engineering Contradiction:

Improvefuel consumptionVSAvoidgear shifting

Core Design Contradiction:

Loss of energyVSEase of operation

Solution Approach 1:

By replacing the mechanically-driven pump with an electric pump, the system ensures continuous availability of pressurized fluid for gear shifting operations even when the engine is stopped. This substitution eliminates the dependency between engine rotation and transmission fluid pressure, allowing smooth gear shifts during engine stop-start conditions.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The electric transmission pump acts as an intermediary component that decouples the transmission system from the engine. It provides the necessary pressurized fluid to the transmission independently of engine operation, thereby mediating between the stopped engine and the transmission's need for fluid pressure to perform gear shifts.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Reliability

If an electric transmission pump is activated to maintain transmission operation during engine stop, then transmission reliability improves, but electrical power consumption increases

Engineering Contradiction:

Improvetransmission operationVSAvoidelectrical power consumption

Core Design Contradiction:

ReliabilityVSUse of energy by stationary object

Solution Approach 1:

The electric transmission pump is activated periodically only when the engine is stopped and transmission operation is needed, rather than running continuously. This periodic activation reduces overall electrical power consumption while maintaining transmission reliability during the specific periods when the engine is off and fluid pressure is required.

Inventive Principle:

Principle #19Periodic action

Solution Approach 2:

The system dynamically adjusts pump operation based on real-time conditions: the electric pump is activated only when the engine is stopped and transmission fluid pressure is needed, and deactivated when the engine is running. This dynamic control optimizes the balance between transmission reliability and electrical power consumption.

Inventive Principle:

Principle #15Dynamics

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 enhances vehicle drivability by enabling rapid torque response and efficient gear shifting while reducing fuel and electrical power consumption, ensuring smooth transmission operation during engine stop-start cycles.

Implementation Method 1

activating an electric transmission pump in response to a request to stop an engine

Methodology Applied

Scientific EffectPump: Pump

Implementation Method 2

adjusting a speed of the electric transmission pump in response to a pressure in an accumulator

Methodology Applied

Scientific EffectHydraulic Accumulator: Hydraulic Accumulator

Data Source

PatentUS10336333B2System and method for performing an engine stop and start for a rolling vehicle

Publication Date: 2019.07.02 FORD GLOBAL TECH LLC

AI summary

Methods and systems for improving operation of a vehicle driveline that includes an engine and an automatic transmission with a torque converter are presented. In one non-limiting example, the engine may be stopped while a vehicle in which the engine operates is rolling. A transmission coupled to the engine may be shifted as the vehicle rolls so that vehicle response may be improved if a driver requests an increase of engine torque.