Motor Fan Damper Assembly for PWM Vibration Isolation

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Solution Overview

Problem

Existing electric motors with integrated fans face challenges in minimizing the mass and rigidity of rotating parts while maintaining effective aeraulic performance, particularly under PWM voltage signals that cause torque variations and vibration propagation.

Innovation Solution

Incorporating a shock absorber made of elastically deformable material that mechanically decouples the fan from the rotating shaft, reducing vibration transfer and allowing for reduced mass and rigidity of the fan, thereby enhancing aeraulic performance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If the fan is rigidly attached to the rotating shaft, then the structural strength is improved, but the mass and rigidity of rotating parts increase, reducing aerodynamic performance

Engineering Contradiction:
Improvestructural strengthVSAvoidmass of rotating parts
Core Design Contradiction:
StrengthVSWeight of moving object

Solution Approach 1:

The patent introduces a shock absorber as an intermediary element between the rotating shaft and the fan. This shock absorber is made of elastically deformable material and allows relative movement between the shaft and fan, thereby reducing the mass and rigidity requirements of the fan while maintaining structural integrity through the elastic connection.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Stability of the object's composition

If the fan is rigidly attached to the rotating shaft, then the structural stability is improved, but the aerodynamic performance deteriorates due to increased mass and rigidity

Engineering Contradiction:
Improvestructural stabilityVSAvoidaerodynamic performance
Core Design Contradiction:
Stability of the object's compositionVSProductivity

Solution Approach 1:

The shock absorber serves as a mediator that maintains structural stability through its elastic properties while allowing the fan to operate with reduced mass and rigidity, thereby improving aerodynamic performance. The elastic deformable material provides the necessary stability without requiring the fan to be rigidly connected to the shaft.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Power

If PWM voltage signal is applied to the motor, then the power control is improved, but vibration and torque variations increase, negatively affecting the fan

Engineering Contradiction:
Improvepower controlVSAvoidvibration and torque variations
Core Design Contradiction:
PowerVSObject-affected harmful factors

Solution Approach 1:

The shock absorber provides beforehand cushioning by being pre-installed between the rotating shaft and the fan. When PWM voltage signals cause torque variations and vibrations, the elastically deformable material of the shock absorber absorbs and dampens these harmful effects before they reach the fan, protecting it from the negative impacts of PWM control.

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

4Productivity

If the fan mass and rigidity are reduced for better aerodynamic performance, then the aerodynamic performance is improved, but the structural strength decreases

Engineering Contradiction:
Improveaerodynamic performanceVSAvoidstructural strength
Core Design Contradiction:
ProductivityVSStrength

Solution Approach 1:

The shock absorber acts as an intermediary that compensates for the reduced structural strength of the lighter fan. By providing elastic support and shock absorption, it allows the fan to be designed with lower mass and rigidity for improved aerodynamic performance while the shock absorber makes up for the strength deficiency through its load-bearing and damping capabilities.

Inventive Principle:
Principle #24Intermediary (Mediator)

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 mechanical dimensioning and improves aeraulic performance by absorbing vibrations, protecting the fan from torque variations and allowing for lighter, more efficient cooling systems in electric motors.

Implementation Method 1

a shock absorber made of an elastically deformable material, the fan bracket being attached to the hub only via the shock absorber

Methodology Applied
Scientific EffectElastic deformation: Elasticity

Implementation Method 2

Vibration transfer between the rotor and the fan is reduced. As a result, it becomes possible to reduce the fan's mass and rigidity

Methodology Applied
Scientific EffectVibration absorption: Damping

Data Source

PatentEP4246780A1Electric motor and method for producing same
Publication Date: 2023.09.20 ALSTOM HOLDINGS SA
  • EP4246780A1 patent drawingFigure 1
  • EP4246780A1 patent drawingFigure 2
  • EP4246780A1 patent drawingFigure 3

AI summary

The electric motor (1) comprises a stator (3), a rotor (5), a rotating shaft (7) driven in rotation about an axis of rotation (X) by the rotor (5), a fan (9), and a damper (13) linking in rotation the fan (9) to the rotating shaft (7), the damper (13) comprising: - a hub (15), mounted on the rotating shaft (7); - a fan support (17), on which the fan (9) is fixed; - a shock absorber (19) of an elastically deformable material, the fan support (17) being fixed to the hub (15) only by means of the shock absorber (19).