Spindle Support Axial Passages for Compact Wheel Motor Cooling

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Solution Overview

Problem

Existing motorized wheels in electric vehicles face challenges in integrating a traction-braking device within the wheel rim due to size constraints from electric cables and liquid cooling systems, which limit the compactness and efficiency of the braking system.

Innovation Solution

A spindle support with axial passages for fluid pipes and cables, allowing for a stator assembly with liquid cooling and electrical connections, enabling a compact integration of a conventional disc brake system within the wheel rim, along with a split gasket for sealing, facilitates efficient cooling and electrical connectivity without interfering with rotating parts.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Volume of moving object

If a conventional disc brake system is integrated into the wheel rim, then the braking function is achieved, but the size constraints from electric cables and liquid cooling systems limit the compactness

Engineering Contradiction:
Improvebraking system volumeVSAvoidsystem integration complexity
Core Design Contradiction:
Volume of moving objectVSDevice complexity

Solution Approach 1:

The patent merges the liquid cooling system and electrical cable passage into a single integrated spindle support structure. The spindle support contains both cooling fluid channels and cable passage routes within its body, eliminating the need for separate mounting structures and reducing overall system volume while maintaining all necessary functions.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The patent implements nesting by placing the stator assembly inside the wheel rim structure, with the rotor nested around the stator. The brake disc is positioned between the rotor and wheel rim, creating a compact nested arrangement where multiple components occupy overlapping spatial volumes, thereby minimizing the overall braking system footprint.

Inventive Principle:
Principle #7Nested doll (Nesting)

2Ease of operation

If the central shaft is positioned away from the axis to accommodate fluid pipes, then the braking device can be provided, but the compactness and efficiency are reduced

Engineering Contradiction:
Improvebraking device installationVSAvoidwheel rim interior space
Core Design Contradiction:
Ease of operationVSVolume of moving object

Solution Approach 1:

The patent extracts the fluid pipes and electrical cables from the traditional side-mounted configuration and relocates them through the central spindle support structure. The spindle support contains dedicated internal channels for cooling fluid and separate passage routes for cables, allowing these elements to be routed through the center rather than occupying lateral space that would increase the wheel rim interior volume.

Inventive Principle:
Principle #2Taking out (Extraction)

3Temperature

If the stator assembly is integrated with the spindle support, then the cooling performance is optimized, but the interference with rotating parts must be avoided

Engineering Contradiction:
Improvestator cooling performanceVSAvoidrotating parts operation
Core Design Contradiction:
TemperatureVSReliability

Solution Approach 1:

The patent applies local quality by providing cooling channels specifically within the spindle support structure that directly contact the stator assembly, while maintaining clear separation between the stationary spindle support and the rotating rotor. The cooling fluid channels are positioned to maximize thermal contact with the stator without extending into the rotational path of the rotor, ensuring effective cooling while preventing interference with rotating components.

Inventive Principle:
Principle #3Local quality

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 solution allows for a high-performance, compact traction-braking device that can be integrated within a standard wheel rim, suitable for various electric vehicles, optimizing cooling performance and minimizing cost while maintaining efficient electrical connectivity.

Implementation Method 1

liquid cooling device is provided

Methodology Applied
Scientific EffectLiquid cooling: Convection

Implementation Method 2

liquid fluid cooling of the stator

Methodology Applied
Scientific EffectHeat transfer: Conduction (thermal)

Implementation Method 3

stator assembly and to rotationally support the rotor and the motorized wheel

Methodology Applied
Scientific EffectElectromagnetic induction: Electromagnetic Induction

Data Source

PatentEP3152817B1Stator assembly for wheel motor and stub axle support therefor
Publication Date: 2021.01.27 VALEO SYSTEMES DE CONTROLE MOTEUR SAS
  • EP3152817B1 patent drawingFigure 1~2
  • EP3152817B1 patent drawingFigure 3
  • EP3152817B1 patent drawingFigure 4

AI summary

Traction/braking device (50) for electric wheel motor comprising a stator assembly (2), a rotor (3), a braking system (4) with brake disc (45) rotating as one with the rotor, the stator assembly comprising a stub axle support (1), a stator body (21) and a cover (22) delimiting a stator cooling chamber (5), the stub axle support comprising a securing base (12) intended for connecting the traction/braking device (50) to the vehicle, the stub axle support (1) comprising three axial passages for two fluid pipes (14, 15) and one for the passage of cables (16), these three passages opening into a central zone (11) of the securing base.