Vehicle Drive Unit Layout With Shared Coolant Channel Integration

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Solution Overview

Problem

Existing vehicle drive devices with multiple axes face challenges in reducing overall size in the up-down direction due to the offset placement of the inverter device relative to the rotating electrical machine, which complicates coolant channel configurations.

Innovation Solution

The vehicle drive device is configured with a case that integrates the rotating electrical machine, transmission mechanism, and inverter device, allowing for an efficient channel configuration by overlapping main components in the horizontal direction to minimize the overall size, particularly by positioning the inverter device closer to the middle of the vehicle and arranging the output gear to minimize its impact on overall dimensions.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Length of stationary object

If the inverter device is disposed offset with respect to the rotating electrical machine in the horizontal direction to reduce the overall size in the up-down direction, then the overall size in the up-down direction is reduced, but the coolant channel configuration becomes more complex and cannot use the common coolant channel configuration

Engineering Contradiction:
Improveoverall size in up-down directionVSAvoidcoolant channel configuration
Core Design Contradiction:
Length of stationary objectVSDevice complexity

Solution Approach 1:

The patent transitions from a vertical stacking arrangement (common coolant channel configuration) to a horizontal offset arrangement, utilizing the horizontal dimension more effectively. This dimensional change allows the inverter device to be positioned offset from the rotating electrical machine in the horizontal direction, reducing the overall height while accommodating separate coolant channels for each component.

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

Solution Approach 2:

The patent divides the coolant cooling system into separate, independent channels for the rotating electrical machine and the inverter device. Instead of using a single common coolant channel, the invention implements distinct coolant pathways that can be independently configured and optimized for each component's cooling requirements, thereby simplifying the overall system architecture despite the offset layout.

Inventive Principle:
Principle #1Segmentation

2Adaptability or versatility

If the inverter device is disposed offset with respect to the rotating electrical machine, then space utilization is improved, but the coolant channels cannot form a common configuration requiring separate channel arrangements

Engineering Contradiction:
Improvespace utilizationVSAvoidcoolant channel arrangement
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent applies local quality by providing dedicated coolant channels specifically tailored to the cooling needs of each component (rotating electrical machine and inverter device). Each component receives customized cooling through its own channel configuration, allowing optimal thermal management for each component's specific heat generation characteristics and spatial requirements.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The case structure serves multiple functions: it houses both the rotating electrical machine and inverter device, provides structural support, and integrates the coolant channel system. The universal case design accommodates the offset arrangement while incorporating built-in coolant channels that serve both components, reducing the need for additional external cooling infrastructure.

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

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 configuration enables a compact design that reduces the overall size of the vehicle drive device while maintaining efficient coolant channel arrangements, optimizing space utilization and component protection.

Implementation Method 1

a coolant channel through which a coolant for cooling a rotating electrical machine passes

Methodology Applied
Scientific EffectCooling: Cooling

Implementation Method 2

a coolant channel through which a coolant for cooling an inverter device passes

Methodology Applied
Scientific EffectCooling: Cooling

Data Source

PatentEP4385796B1Drive device for vehicle
Publication Date: 2025.12.10 AISIN CORP
  • EP4385796B1 patent drawingFigure 1
  • EP4385796B1 patent drawingFigure 2
  • EP4385796B1 patent drawingFigure 2A

AI summary

A vehicle drive device is disclosed that includes a rotating electrical machine, a transmission mechanism, and an inverter device. The rotating electrical machine and a pair of output members have a two-axis configuration. The transmission mechanism includes, coaxially with the pair of output members, an output gear drivingly connected to at least one of the pair of output members. The inverter device is disposed so as to overlap a first output member that is one of the pair of output members as viewed in a direction along an up-down direction. A first coolant channel through which a coolant for cooling the rotating electrical machine passes and a second coolant channel through which a coolant for cooling the inverter device passes are provided in the case so as to communicate with each other.