Bar-Winding Motor Cooling Plate Layout for High-Current Heat Dissipation

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Solution Overview

Problem

Electric motors with bar windings on the stator side require high current flow due to low inductance, leading to high heat generation and increased cooling requirements for components, which complicates the design and increases the need for efficient heat dissipation.

Innovation Solution

The motor design incorporates a stator with rod-like field conductors that penetrate cooling plates, with fluid lines routed along or around these conductors for enhanced heat dissipation, and multiple circuit boards arranged on cooling plates to manage heat and increase packing density.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Power

If high current flow is used to generate magnetic field in bar winding motors, then magnetic field strength is improved, but heat loss increases

Engineering Contradiction:
Improvemagnetic field strengthVSAvoidheat loss
Core Design Contradiction:
PowerVSLoss of energy

Solution Approach 1:

The patent extracts the cooling function from the general system and implements it through dedicated cooling plates positioned at specific locations (stator core, rotor core, and housing) to remove heat from critical areas, thereby managing the heat loss inherent in high-current bar winding operation

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent introduces cooling fluid as an intermediary substance that absorbs heat from the motor components through thermal contact with cooling plates, transferring thermal energy away from the system without directly contacting the heat-generating parts

Inventive Principle:
Principle #24Intermediary (Mediator)

2Device complexity

If circuit boards are positioned close to the motor for low voltage operation, then component packing density is improved, but heat dissipation becomes more difficult

Engineering Contradiction:
Improvecomponent packing densityVSAvoidheat dissipation
Core Design Contradiction:
Device complexityVSTemperature

Solution Approach 1:

The patent segments the cooling function into multiple independent cooling plates positioned at different locations (stator cooling plate, rotor cooling plate, housing cooling plate), allowing localized heat management that supports high component density without compromising thermal performance

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent employs a hydraulic cooling system with fluid lines and cooling plates that actively remove heat from densely packed components, using fluid circulation to manage thermal loads in the compact motor-inverter integration

Inventive Principle:
Principle #29Pneumatics and hydraulics

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

The design achieves improved heat dissipation through fluid cooling, reducing cooling requirements and allowing for a high packing density of electronic components while maintaining mechanical stability and efficient heat transfer.

Implementation Method 1

the field conductors or current conductors are in mechanical contact with the cooling plate, in particular, penetrate it

Methodology Applied
Scientific EffectThermal conduction: Conduction (thermal)

Implementation Method 2

at least one cooling device is present, which includes a fluid line that is routed externally along one or more of the field conductors and/or current conductors

Methodology Applied
Scientific EffectConvection: Convection

Data Source

PatentEP4454110B1Electric motor
Publication Date: 2026.03.11 INNOMOTICS GMBH
  • EP4454110B1 patent drawingFigure 1
  • EP4454110B1 patent drawingFigure 2
  • EP4454110B1 patent drawingFigure 3

AI summary

An electric motor with stator-side bar windings comprises a number of inverters for controlling the bars, wherein: the inverters are mounted on one or more circuit boards, the circuit boards are mounted on at least one cooling plate, and the cooling plates are attached directly to the bars or to bar-shaped current conductors attached to the bars. Between the stator/rotor block and the cooling plates the bars or the current conductors have cooling channels resting against the exterior of the bars or current conductors.