EV Propulsion Layout With Upstream Couplings for Flexible Modes

Solution Overview

Problem

Existing electric vehicle propulsion systems with two electric motors and two reducers lack flexibility in mode operation and are inefficient due to the need for selective-coupling systems positioned downstream of the reducers, leading to increased bulkiness, weight, and cost.

Innovation Solution

A propulsion system with two electric motors, each having two torque outputs axially opposed, and two reducers with selective or non-selective coupling systems positioned upstream, allowing for a wider range of operation modes and reduced torque transmission requirements, thereby reducing the bulkiness and cost of coupling systems.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If selective-coupling systems are positioned downstream of the reducers, then the system can switch between different operation modes, but the bulkiness, weight, and cost of the coupling systems increase

Engineering Contradiction:

Improvemode operation flexibilityVSAvoidcoupling system weight

Core Design Contradiction:

Adaptability or versatilityVSWeight of moving object

Solution Approach 1:

The patent inverts the conventional arrangement by positioning the selective-coupling systems upstream of the reducers rather than downstream. This inversion allows the coupling systems to handle only the motor's output torque directly, rather than the amplified torque after reduction, significantly reducing their size, weight, and cost while maintaining mode-switching capability

Inventive Principle:

Principle #13The other way round (Inversion)

Solution Approach 2:

The patent segments the torque transmission path into distinct sections: the coupling system handles only the motor output torque segment, while the reducer handles the torque multiplication segment. This segmentation allows each component to be optimized for its specific torque level, reducing the overall system bulkiness

Inventive Principle:

Principle #1Segmentation

2Adaptability or versatility

If selective-coupling systems are positioned downstream of the reducers, then mode switching is enabled, but the system becomes bulkier and more expensive

Engineering Contradiction:

Improveoperation modesVSAvoidsystem bulkiness

Core Design Contradiction:

Adaptability or versatilityVSVolume of stationary object

Solution Approach 1:

The patent inverts the conventional arrangement by positioning the selective-coupling systems upstream of the reducers rather than downstream. This inversion allows the coupling systems to handle only the motor's output torque directly, rather than the amplified torque after reduction, significantly reducing their size, weight, and cost while maintaining mode-switching capability

Inventive Principle:

Principle #13The other way round (Inversion)

Solution Approach 2:

The coupling systems perform the torque selection action before the torque enters the reducer. By selecting which motor torque to transmit upstream, the system avoids having to handle and switch between larger reduced torques, reducing the volume required for the coupling mechanisms

Inventive Principle:

Principle #10Preliminary action

3Adaptability or versatility

If selective-coupling systems are positioned downstream of the reducers, then different gear ratios can be selected, but the coupling systems become heavier and more costly

Engineering Contradiction:

Improvegear ratio selectionVSAvoidsystem cost

Core Design Contradiction:

Adaptability or versatilityVSEase of manufacture

Solution Approach 1:

The patent inverts the conventional arrangement by positioning the selective-coupling systems upstream of the reducers rather than downstream. This inversion allows the coupling systems to handle only the motor's output torque directly, rather than the amplified torque after reduction, significantly reducing their size, weight, and cost while maintaining mode-switching capability

Inventive Principle:

Principle #13The other way round (Inversion)

Solution Approach 2:

The patent segments the torque transmission path into distinct sections: the coupling system handles only the motor output torque segment, while the reducer handles the torque multiplication segment. This segmentation allows each component to be optimized for its specific torque level, reducing the overall system bulkiness

Inventive Principle:

Principle #1Segmentation

Data Source

PatentUS11738639B2Electric vehicle propulsion system

Publication Date: 2023.08.29 VALEO EMBRAYAGES SAS

AI summary

A propulsion system for an electric vehicle includes a first electric propulsion motor including a stator and a rotor that has a first and second output shafts that are axially opposed and define first and second torque outputs of the first electric motor. The system also includes a second electric propulsion motor including a stator and a rotor having a second output shaft with a torque output. Further, the system includes a first reduction gearbox to receive the torque supplied on the first torque output of the first electric motor where appropriate via a first selective or non-selective coupling system, a second reduction gearbox to receive the torque supplied by the second electric motor where appropriate via a second selective or non-selective coupling system, and a third coupling system for coupling the second torque output of the first electric motor to the torque output of the second electric motor.