Thin Fan Using Magnetic Preload to Reduce Component Count

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Solution Overview

Problem

Conventional fans face challenges in achieving a thin structure with reduced components, as their height is difficult to be reduced below 5 mm due to the necessity of maintaining basic components like bearings and springs.

Innovation Solution

A thin type fan design incorporating an impeller with a hub and blade structure, a motor with a stator, magnetic assembly, and a single ball bearing, where magnetic elements are used to attract the bearing structure and rotational shaft, reducing the need for springs and enhancing mechanical strength, while maintaining a height of 5 mm or less and a total weight of 5 grams or less.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Length of stationary object

If conventional fan components (bearings, springs, fastening ring) are maintained, then reliability and structural stability are ensured, but the fan height cannot be reduced below 5 mm

Engineering Contradiction:

Improvefan heightVSAvoidnumber of components

Core Design Contradiction:

Length of stationary objectVSDevice complexity

Solution Approach 1:

The patent removes the fastening ring and preloading springs from the conventional fan structure. The magnetic element integrated into the bearing structure provides the necessary preloading force through magnetic attraction, eliminating the need for separate spring components and fastening rings, thereby reducing overall height and component count.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The magnetic element is integrated directly into the bearing structure, combining the bearing support function with the preloading function. This merging of functions eliminates the need for separate spring components and fastening rings, achieving both structural simplification and height reduction.

Inventive Principle:

Principle #5Merging (Combining)

2Length of stationary object

If the number of components is reduced to achieve thinning, then fan height decreases, but mechanical strength and reliability may be compromised

Engineering Contradiction:

Improvefan heightVSAvoidmechanical strength

Core Design Contradiction:

Length of stationary objectVSStrength

Solution Approach 1:

The patent replaces the mechanical spring preloading system with a magnetic field-based preloading system. The magnetic element generates magnetic attraction force to provide preloading on the bearing, substituting mechanical springs with a magnetic field mechanism, thereby reducing component count while maintaining preloading function and mechanical strength.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Length of stationary object

If springs are removed to reduce height, then fan thickness decreases, but preload provision becomes insufficient

Engineering Contradiction:

Improvefan heightVSAvoidpreload force

Core Design Contradiction:

Length of stationary objectVSForce

Solution Approach 1:

The magnetic element integrated into the bearing structure generates magnetic attraction force to provide the necessary preloading on the bearing. This magnetic field-based mechanism replaces the mechanical spring system, maintaining adequate preload force while eliminating the space required for spring components, thus achieving height reduction.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

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 design achieves a thinner and lighter fan structure by minimizing components, providing preload through magnetic attraction, and enhancing mechanical strength, thus overcoming the limitations of conventional fan designs.

Implementation Method 1

The magnetic assembly includes a magnet and a magnetically permeable shell. The magnetic assembly is disposed within the hub and around the stator structure.

Methodology Applied

Scientific EffectMagnetic attraction: Magnetism

Implementation Method 2

The bearing structure includes a bearing seat and a single ball bearing. The single ball bearing is disposed in the bearing seat and forms an accommodating space, and the rotational shaft is disposed in the accommodating space.

Methodology Applied

Scientific EffectRolling contact: Ball Bearing

Data Source

PatentUS9777734B2Thin fan

Publication Date: 2017.10.03 DELTA ELECTRONICS INC(CN)

AI summary

A thin type fan includes an impeller and a motor. The impeller includes a hub and a blade structure disposed around the hub. The motor includes a stator structure, a magnetic assembly, a bearing structure and a rotational shaft. The motor drives the impeller to rotate. The magnetic assembly is disposed within the hub and around the stator structure. The magnetic assembly includes a magnet and a magnetically permeable shell. The bearing structure includes a bearing seat and a single ball bearing. The single ball bearing is disposed in the bearing seat and forms an accommodating space, and the rotational shaft is disposed in the accommodating space.