Laminated Busbar Layout for Compact Motor Controller Cooling

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Solution Overview

Problem

Existing drive assemblies for new energy vehicles face challenges in optimizing the connection structures and layout between motors and motor controllers, cooling efficiency, and assembly ease, which limits their integration and space utilization.

Innovation Solution

A drive assembly with annularly arranged power transistors and a cylindrical housing that includes a partition wall dividing the housing into motor and controller chambers, featuring liquid cooling channels and heat-conducting surfaces, and a holding member to secure the transistors, facilitating efficient heat dissipation and compact integration.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Volume of moving object

If power transistors are arranged in an annular configuration around the rotor, then space utilization is improved and heat dissipation efficiency is enhanced, but device complexity increases due to the need for specialized mounting structures

Engineering Contradiction:
Improvespace utilizationVSAvoidmounting structure complexity
Core Design Contradiction:
Volume of moving objectVSDevice complexity

Solution Approach 1:

The power transistors are arranged in an annular configuration around the rotor, following a curved path rather than a linear arrangement. This curved layout optimizes space utilization within the motor controller housing and improves heat dissipation by distributing heat-generating components away from the center where heat accumulates, while the holding member adapts to this curved geometry to secure all transistors effectively

Inventive Principle:
Principle #14Spheroidality (Curvature)

Solution Approach 2:

The holding member serves multiple functions simultaneously: it secures the power transistors to the housing, provides thermal pathways for heat dissipation, and maintains the precise annular positioning of transistors. This multi-functional design reduces the need for separate mounting brackets, thermal interfaces, and positioning fixtures, thereby reducing overall device complexity despite the curved arrangement

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

2Temperature

If integrated liquid cooling channels are implemented in the housing, then heat dissipation efficiency is improved, but manufacturing complexity increases

Engineering Contradiction:
Improveheat dissipation efficiencyVSAvoidmanufacturing complexity
Core Design Contradiction:
TemperatureVSEase of manufacture

Solution Approach 1:

The liquid cooling channels are integrated directly into the motor controller housing structure, merging the cooling system with the structural component rather than being a separate attachment. This consolidation eliminates the need for separate cooling plates or heat sinks, reducing the number of parts and assembly steps while maintaining effective heat dissipation from the annularly arranged power transistors

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The housing acts as an intermediary thermal management system, containing the liquid cooling channels that absorb heat from the power transistors through thermal contact. The housing material and channel design facilitate efficient heat transfer from the high-power devices to the circulating coolant, managing thermal loads without requiring direct attachment of separate cooling components to each transistor

Inventive Principle:
Principle #24Intermediary (Mediator)

3Reliability

If holding members with elastic forces are used to secure power transistors, then reliability is improved under vibration, but device complexity increases

Engineering Contradiction:
Improvevibration resistanceVSAvoidholding mechanism complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The holding member incorporates elastic elements that provide dynamic, adaptive securing forces to the power transistors. Rather than rigid fixed positions, the elastic components allow for slight movements and adjustments, maintaining reliable electrical and thermal contact under varying conditions including vibration and thermal expansion, while the annular geometry distributes these dynamic forces evenly around all transistors

Inventive Principle:
Principle #15Dynamics

4Productivity

If the motor and motor controller are integrated into a single housing, then productivity is improved through compact design, but ease of operation for maintenance decreases

Engineering Contradiction:
Improveassembly efficiencyVSAvoidmaintenance accessibility
Core Design Contradiction:
ProductivityVSEase of operation

Solution Approach 1:

The integrated housing is divided into distinct functional chambers: a motor mounting chamber for the rotor and stator, and a controller mounting chamber for the circuit board assembly and power transistors. The partition wall separates these chambers while maintaining structural integrity. This segmentation allows for organized component placement and enables selective access to different subsystems for maintenance, reducing the complexity of servicing integrated systems

Inventive Principle:
Principle #1Segmentation

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 design enhances space utilization, improves heat dissipation efficiency, and stabilizes the drive assembly in severe vibration environments, enabling a highly integrated and efficient motor controller layout without additional heat conduction structures.

Implementation Method 1

an outer wall of the housing is provided with a liquid cooling channel which includes a motor cooling groove and a controller cooling groove that communicate with each other

Methodology Applied
Scientific EffectHeat conduction: Conduction (thermal)

Implementation Method 2

the controller cooling groove surrounds the power transistor

Methodology Applied
Scientific EffectConvection: Convection

Implementation Method 3

the holding portions abut between the ring wall and the power transistors so that the holding member exerts an elastic force on the power transistors toward the inner wall of the controller mounting chamber

Methodology Applied
Scientific EffectElastic force: Elasticity

Data Source

PatentEP4071979B1Laminated busbar assembly, motor controller, drive assembly and vehicle
Publication Date: 2024.02.28 ZHUHAI ENPOWER ELECTRIC
  • EP4071979B1 patent drawingFigure 1~2
  • EP4071979B1 patent drawingFigure 3
  • EP4071979B1 patent drawingFigure 4~5

AI summary

The present disclosure relates to the field of new energy, and provides a laminated busbar assembly, a motor controller, a drive assembly, and a vehicle. The present disclosure utilizes a space at a rear end in the axial direction of a motor, and designs a partition wall and a bearing, such that a rotor is rotatably provided in a motor mounting chamber and a motor controller is provided in a controller mounting chamber. The present disclosure designs a laminated arrangement of a busbar and other devices and an annular arrangement of a circuit and power transistors, thereby improving the device integration and space utilization, effectively reducing the occupied space, and realizing high integration of the motor controller and the drive assembly.