Mechatronic Unit Lateral Layout for Lower EV Center of Gravity

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Solution Overview

Problem

The high center of gravity of the mechatronic unit in electric vehicles, due to the arrangement of power controllers above the transaxle, hinders efforts to lower the vehicle's center of gravity, and poses challenges in managing load distribution during frontal collisions.

Innovation Solution

The mechatronic unit is arranged in front of the cabin with power controllers positioned at the outer side of the transaxle, featuring a recessed surface on the external side surface to lower the center of gravity and facilitate controlled load distribution during collisions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If the power controller is disposed on the upper surface of the transaxle case, then the mechatronic unit is compactly arranged, but the center of gravity of the vehicle is raised

Engineering Contradiction:
Improvearrangement compactnessVSAvoidcenter of gravity position
Core Design Contradiction:
Device complexityVSTemperature

Solution Approach 1:

The power controller is relocated from the upper surface to the lateral outer side of the transaxle case, changing the spatial dimension of arrangement from vertical stacking to lateral distribution. This dimensional shift allows the center of gravity to be positioned lower while maintaining compact integration, as the controller extends in the lateral direction rather than vertically upward.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Temperature

If the power controller is arranged at the outer side of the transaxle, then the center of gravity is lowered, but the lateral dimension of the mechatronic unit increases

Engineering Contradiction:
Improvecenter of gravity positionVSAvoidlateral dimension
Core Design Contradiction:
TemperatureVSLength of moving object

Solution Approach 1:

The power controller is integrated with the transaxle case through unified outer shell design, where the controller housing merges with the transaxle case structure. This merging allows the lateral extension to be shared between both components, reducing the overall lateral dimension while accommodating both the transaxle and power controller in a consolidated lateral profile.

Inventive Principle:
Principle #5Merging (Combining)

3Ease of manufacture

If the external side surface is made flat, then manufacturing is simplified, but collision load distribution cannot be controlled

Engineering Contradiction:
Improvesurface fabrication simplicityVSAvoidcollision load management
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The external side surface transitions from a completely flat design to a locally varied geometry featuring a recessed portion. This local quality change creates a stepped configuration where different surface levels (first and second regions) can independently manage collision loads, allowing the majority of the surface to remain simple while providing localized load distribution control at the recessed area.

Inventive Principle:
Principle #3Local quality

4Volume of moving object

If the recessed surface is positioned at the upper area, then space utilization is improved, but the front side member cannot effectively abut during collision

Engineering Contradiction:
Improvespace utilizationVSAvoidcollision protection effectiveness
Core Design Contradiction:
Volume of moving objectVSReliability

Solution Approach 1:

The recessed surface configuration enables dynamic interaction during collision by creating a stepped surface that guides the deformation path of the front side member. The first and second regions at different heights allow progressive engagement and controlled deformation, transforming the static recessed structure into a dynamic collision management system that adapts to impact forces.

Inventive Principle:
Principle #15Dynamics

Data Source

PatentEP4663443A1Mechatronic unit and electric vehicle
Publication Date: 2025.12.17 TOYOTA JIDOSHA KK
  • EP4663443A1 patent drawingFigure 1~2
  • EP4663443A1 patent drawingFigure 3~4
  • EP4663443A1 patent drawingFigure 5~6

AI summary

A mechatronic unit (100) is integrally formed from a transaxle (110) and at least one power controller (120,130). The at least one power controller (120,130) is arranged at an outer side of the transaxle (110) in a lateral direction. The mechatronic unit (100) includes a recessed surface (F) located on an external side surface, above a horizontal line (L) lying along an uppermost portion of a drive shaft (90) in a vertical direction, and laterally inward from the lower area located below the horizontal line (L).