Integrated Drive Cooling Layout for Compact Heat Exchanger Packaging

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Solution Overview

Problem

Integrated drive apparatuses face challenges in downsizing due to the physical space required for mounting an oil cooler, which can increase the apparatus's size.

Innovation Solution

The drive apparatus incorporates a heat exchanger that overlaps with the gear and electric unit chambers, reducing the axial and radial dimensions required for the oil cooler, thereby allowing for a more compact design.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If an oil cooler is mounted on the drive apparatus, then cooling function is improved, but the physical size of the drive apparatus increases

Engineering Contradiction:
Improvecooling functionVSAvoidphysical size
Core Design Contradiction:
TemperatureVSVolume of moving object

Solution Approach 1:

The heat exchanger is integrated into the casing structure, merging the cooling function with the housing. The heat exchanger is positioned to overlap with the gear chamber in the axial direction and with the electric unit chamber in the radial direction, combining multiple spatial functions into a unified structure that provides cooling without increasing overall device volume.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The heat exchanger utilizes three-dimensional spatial overlap by extending in multiple directions - overlapping with the gear chamber in the axial direction and with the electric unit chamber in the radial direction. This multi-dimensional positioning allows the heat exchanger to fit within the existing spatial envelope of the drive apparatus rather than adding volume in a single direction.

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

2Length of moving object

If the heat exchanger is positioned to overlap with the gear chamber in the axial direction, then the width in the axial direction is reduced, but the spatial arrangement becomes more complex

Engineering Contradiction:
Improvewidth in axial directionVSAvoidspatial arrangement
Core Design Contradiction:
Length of moving objectVSDevice complexity

Solution Approach 1:

The heat exchanger is divided into multiple sections or segments that can be positioned in different spatial locations - one portion overlaps with the gear chamber in the axial direction while another portion overlaps with the electric unit chamber in the radial direction. This segmentation allows the heat exchanger to achieve compact overall dimensions while maintaining relatively simple positioning of each segment.

Inventive Principle:
Principle #1Segmentation

3Area of moving object

If the heat exchanger is positioned to overlap with the electric unit chamber in the radial direction, then the width in the radial direction is reduced, but the internal space arrangement becomes more complex

Engineering Contradiction:
Improvewidth in radial directionVSAvoidinternal space arrangement
Core Design Contradiction:
Area of moving objectVSDevice complexity

Solution Approach 1:

The heat exchanger serves multiple spatial functions simultaneously - it provides cooling while overlapping with both the gear chamber and the electric unit chamber in different directions. This multi-functionality allows a single component to achieve compact radial dimensions while the complex spatial arrangement is managed through the heat exchanger's dual positioning capability.

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 effectively reduces the increase in width due to the heat exchanger, enabling the downsizing of the drive apparatus while maintaining efficient cooling.

Implementation Method 1

The heat exchanger is configured to exchange heat between the first heat medium and the second heat medium

Methodology Applied
Scientific EffectHeat exchange: Heat Exchanger

Data Source

PatentEP4542830A1Drive apparatus
Publication Date: 2025.04.23 TOYOTA JIDOSHA KK
  • EP4542830A1 patent drawingFigure 1
  • EP4542830A1 patent drawingFigure 2
  • EP4542830A1 patent drawingFigure 3

AI summary

A drive apparatus (1) includes: a casing (10), an electric motor (40) comprising a central motor shaft (43), a gear unit (50), an electric unit (21), a first coolant route (74), a second coolant route (83) and a heat exchanger (73). The casing (10) includes a motor chamber (31), a gear chamber (SP1) and an electric unit chamber (SP2). The electric unit chamber (SP2) comprises a portion extending further to an one axial-direction side (AD1) of the motor shaft axis than the gear chamber (SP1). Said motor shaft (43) is retained at on one end (43e) in said one axial-direction side (AD1) and inside said gear chamber (SP1). The heat exchanger (73) does not extend further than said gear chamber (SP1) or said electric unit chamber (SP2) in order to enable a very compact drive apparatus (1).