Electric Motor Cooling Channel Layout for Uniform Flow and Compact Housing

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Solution Overview

Problem

Existing electric motor designs face challenges in achieving uniform coolant flow and compact structure, leading to increased size and efficiency losses due to uneven coolant distribution and heat management issues, particularly in high-output applications like electric vehicles.

Innovation Solution

The electric motor incorporates a stator cooling channel and housing cooling channel system with strategically positioned end channels and connection channels, allowing for balanced coolant flow and reduced housing size by forming end channels along a tangent plane and utilizing axial and tangential direction channels for flexible positioning, which helps in efficient heat absorption and distribution.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the housing is enlarged to accommodate separate supply and discharge channels for two cooling systems, then the coolant flow paths can be established, but the motor size increases

Engineering Contradiction:
Improvecoolant flow distributionVSAvoidmotor size
Core Design Contradiction:
ReliabilityVSVolume of moving object

Solution Approach 1:

The patent merges the supply and discharge channels of two independent cooling systems (stator coil cooling and housing cooling) into a single integrated channel structure. The first and second channels serve as supply channels for both cooling systems, while the third and fourth channels serve as discharge channels, eliminating the need for separate channel structures and reducing motor size.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The channel structure is designed with multi-functionality where the same channels serve dual purposes: the first and second channels provide cooling for both the stator coil and housing, while the third and fourth channels handle discharge for both systems. This universal channel design reduces the overall number of channels needed and compactsthe motor structure.

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

2Temperature

If the supply and discharge channels are positioned to cool both stator and housing, then comprehensive cooling is achieved, but uneven coolant flow occurs

Engineering Contradiction:
Improvecooling effectivenessVSAvoidcoolant flow uniformity
Core Design Contradiction:
TemperatureVSManufacturing precision

Solution Approach 1:

The patent implements local quality by creating distinct channel regions with different functions: the first channel is positioned to primarily cool the stator coil, the second channel cools the housing, the third channel discharges from the stator cooling region, and the fourth channel discharges from the housing cooling region. This localized channel positioning ensures uniform coolant flow distribution to different thermal zones.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The cooling channel system is segmented into four distinct channels with specific positioning and functions. The channels are arranged in a predetermined pattern around the motor periphery, with each channel serving a specific cooling or discharge function. This segmentation prevents flow interference between channels and ensures uniform coolant distribution to both stator and housing cooling zones.

Inventive Principle:
Principle #1Segmentation

3Temperature

If multiple independent cooling channels are provided for stator and housing, then effective heat dissipation is achieved, but the device complexity increases

Engineering Contradiction:
Improveheat dissipation efficiencyVSAvoidchannel structure complexity
Core Design Contradiction:
TemperatureVSDevice complexity

Solution Approach 1:

The patent combines two independent cooling systems (stator cooling and housing cooling) into a unified channel architecture. By sharing the channel structure between both cooling systems, the patent reduces device complexity while maintaining effective heat dissipation from both the stator coil and housing through coordinated coolant flow management.

Inventive Principle:
Principle #5Merging (Combining)

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 enhances coolant flow uniformity, reduces motor size, and improves heat management, leading to increased efficiency and compactness, especially suitable for high-output applications such as electric vehicles and robots.

Implementation Method 1

a stator cooling channel that is defined inside an inner surface of the housing and is filled with coolant... a housing cooling channel that is formed between the inner surface and an outer surface of the housing and is filled with coolant

Methodology Applied
Scientific EffectThermal conduction: Conduction (thermal)

Implementation Method 2

the first end channel being formed in the housing protrusion and connecting to the first coil end accommodation channel, the second end channel being formed in the housing protrusion and connecting to the second coil end accommodation channel

Methodology Applied
Scientific EffectConvection: Convection

Data Source

PatentEP4391323A1Electric motor
Publication Date: 2024.06.26 YAMAHA MOTOR CO LTD
  • EP4391323A1 patent drawingFigure 1
  • EP4391323A1 patent drawingFigure 2
  • EP4391323A1 patent drawingFigure 3

AI summary

In an electric motor 10 a stator cooling channel F10 includes a first end channel F13 and a second end channel F14 that are formed in a housing protrusion 20c. The housing cooling channel F20 includes a third end channel F24 formed in the housing protrusion 20c and a fourth end channel F25 formed in the housing protrusion 20c. In this structure, the four end channels F13, F14, F24, and F25 are collectively formed in the housing protrusion 20c. This structure serves to reduce the size of the housing 20.