Blower Motor Shielding Cap Integration for EMI Reduction

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Solution Overview

Problem

Electric motors in HVAC systems for vehicles generate electromagnetic radiation that can interfere with other electronic devices, and existing solutions do not effectively confine this radiation.

Innovation Solution

An electric motor design featuring a rotor, stator, and support with a metal shielding cap that is integrated directly with the support and stator, providing a single-piece connection and electrical grounding to limit electromagnetic radiation propagation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If a shielding cap is added to confine electromagnetic radiation, then electromagnetic interference is reduced, but device complexity increases

Engineering Contradiction:
Improveelectromagnetic interferenceVSAvoiddevice complexity
Core Design Contradiction:
Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The shielding cap is integrated with the support structure to form a single unified component. The support structure serves dual functions: mechanical support for the rotor and stator, and electromagnetic shielding through the integrated shielding cap. This merging eliminates the need for separate shielding components while maintaining both structural and electromagnetic protection functions.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The support structure is designed to perform multiple functions simultaneously: providing mechanical support for rotating components, dissipating heat through its thermally conductive material, and confining electromagnetic radiation through the integrated shielding cap. This multi-functionality reduces the overall number of components needed in the motor assembly.

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

2Object-affected harmful factors

If a metal shielding cap is used to block electromagnetic radiation, then electromagnetic interference is reduced, but heat dissipation may be impaired

Engineering Contradiction:
Improveelectromagnetic radiationVSAvoidheat dissipation
Core Design Contradiction:
Object-affected harmful factorsVSTemperature

Solution Approach 1:

The shielding cap is designed with selective properties: it is made of electrically conductive material for electromagnetic shielding, while the support structure containing it is made of thermally conductive material for heat dissipation. The local quality of each component is optimized for its primary function, and the integration allows both functions to coexist without compromising either shielding or thermal management.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The integrated support and shielding structure utilizes composite material properties where the support structure is made of thermally conductive material and the shielding cap is made of electrically conductive material. This combination of materials with different primary properties (thermal conductivity vs. electrical conductivity) allows the system to simultaneously achieve effective heat dissipation and electromagnetic radiation confinement.

Inventive Principle:
Principle #40Composite materials

3Object-affected harmful factors

If multiple fixing means are used to attach the shielding cap, then shielding effectiveness is improved, but manufacturing complexity increases

Engineering Contradiction:
Improveshielding effectivenessVSAvoidmanufacturing complexity
Core Design Contradiction:
Object-affected harmful factorsVSEase of manufacture

Solution Approach 1:

The fixing means are integrated directly into the support structure as protrusions or attachment features formed as a single piece during manufacturing. This integration eliminates the need for separate fastening components and simplifies the assembly process while maintaining secure attachment of the shielding cap to the support structure.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The support structure is designed with segmented or modular features that facilitate easy attachment of the shielding cap. The fixing means are distributed at strategic locations to provide adequate mechanical and electrical connection while maintaining manufacturing simplicity through standardized integration methods.

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

The solution effectively confines electromagnetic radiation, reducing interference with nearby electronic devices and improving the motor's operational stability by using a metal shielding cap that is securely attached to the motor components.

Implementation Method 1

a shielding arranged between the rotor and the stator corresponding to a sheet of metal having an annular shape

Methodology Applied
Scientific EffectElectromagnetic radiation shielding: Faraday Cage

Implementation Method 2

a support for said rotor and said stator capable of dissipating heat

Methodology Applied
Scientific EffectThermal conduction: Conduction (thermal)

Data Source

PatentEP3314735B1Electric motor of a blower device and blower device
Publication Date: 2020.05.27 VALEO SYST THERMIQUES SAS
  • EP3314735B1 patent drawingFigure 1~2
  • EP3314735B1 patent drawingFigure 3~4
  • EP3314735B1 patent drawingFigure 5~6

AI summary

Electric motor (1) for an air blowing device, comprising a rotor (2), a stator (4), a support (12) for said rotor (2) and said stator (4) able to dissipate heat and a screening cap (26), characterized in that the screening cap (26) is fixed to the support (12) of said rotor (2) and of said stator (4) by a fixing means (28). The invention also relates to an air blowing device comprising such an electric motor (1).