BLDC Motor Stator Damping Structure for Resonance Control

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Solution Overview

Problem

Conventional electric power-assist steering systems using BLDC motors experience increased noise and erroneous operations due to resonance of the stator core caused by electromagnetic forces during rotor rotation, leading to decreased performance.

Innovation Solution

The motor design incorporates an insulation member coating the stator with coils and pressure ribs on the housing to absorb vibrations, altering the intrinsic frequency of the stator and reducing resonance, thereby minimizing noise and improving operational reliability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Power

If the motor operates with electromagnetic force generation during rotor rotation, then the motor produces necessary torque for power-assist steering, but resonance occurs on the stator core causing increased noise and erroneous operations

Engineering Contradiction:
Improvetorque generationVSAvoidoperational stability
Core Design Contradiction:
PowerVSReliability

Solution Approach 1:

The patent applies beforehand cushioning by introducing a damping structure (viscoelastic material or rubber damper) between the stator core and the housing before resonance occurs. This damping structure absorbs vibrational energy and prevents resonance from developing, thereby maintaining operational stability while allowing full torque generation during motor operation.

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

Solution Approach 2:

The patent uses an intermediary damping element positioned between the stator core and the housing. This intermediary structure acts as a mediator that decouples the vibrational transmission path, allowing the electromagnetic force to generate necessary torque while the damping intermediary absorbs resonant vibrations, preventing them from propagating to the housing and causing erroneous operations.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Device complexity

If the stator core is directly mounted in the housing, then the structure is simple and compact, but vibration from electromagnetic forces causes resonance and increased operational noise

Engineering Contradiction:
Improvestructural simplicityVSAvoidoperational noise
Core Design Contradiction:
Device complexityVSObject-generated harmful factors

Solution Approach 1:

The patent introduces a damping structure as an intermediary element between the stator core and the housing. This adds a minimal structural component that effectively absorbs vibrations generated by electromagnetic forces, significantly reducing operational noise while maintaining overall structural simplicity and compactness of the motor assembly.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent changes the mechanical parameters of the mounting system by introducing a viscoelastic material or rubber damper with specific damping characteristics. This parameter change transforms the rigid mounting connection into a vibration-absorbing connection, reducing resonant vibrations and operational noise while maintaining structural simplicity.

Inventive Principle:
Principle #35Parameter changes

3Stability of the object's composition

If the stator core is rigidly fixed to reduce vibration, then structural stability is improved, but resonance frequency shifts cause erroneous operations and decreased performance

Engineering Contradiction:
Improvestructural stabilityVSAvoidoperational accuracy
Core Design Contradiction:
Stability of the object's compositionVSReliability

Solution Approach 1:

The patent employs a damping structure as an intermediary that provides both structural stability and vibration absorption. The viscoelastic material or rubber damper maintains the stator core's positional stability while simultaneously absorbing resonant vibrations, preventing frequency shifts that would cause erroneous operations and performance degradation.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent uses composite material structures, particularly viscoelastic materials or rubber compounds with specific damping properties, to create a mounting system that provides both structural stability and vibration isolation. This composite approach ensures the stator core remains stable while resonance is suppressed, maintaining operational accuracy.

Inventive Principle:
Principle #40Composite materials

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 reduces operational noise and prevents erroneous operations by absorbing vibrations generated by electromagnetic forces, enhancing the motor's performance and reliability.

Implementation Method 1

a damping structure for absorbing vibrations generated by electromagnetic forces

Methodology Applied
Scientific EffectVibration absorption: Damping

Implementation Method 2

an insulation member coating the stator with coils and pressure ribs on the housing to absorb vibrations, altering the intrinsic frequency of the stator and reducing resonance

Methodology Applied
Scientific EffectFrequency alteration:

Data Source

PatentEP2675042B1Motor
Publication Date: 2021.08.04 LG INNOTEK CO LTD
  • EP2675042B1 patent drawingFigure 1~2
  • EP2675042B1 patent drawingFigure 3~4

AI summary

Disclosed is a motor, the motor according to a first exemplary embodiment of the present disclosure including a housing, a stator mounted on the housing and including a stator core having a plurality of teeth, an insulator and a coil, a rotor rotatably installed at a center of the stator by a rotation shaft, and an insulation member wrapping an entire surface except for a surface opposite to the rotor of the stator, wherein the insulation member is arranged therein with an insulator and a coil.