Dual-Axis Rotary Fan for Variable Blade Attack Angle

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Solution Overview

Problem

Centrifugal fans with fixed rotational axes and blades have a fixed attack angle, limiting their ability to efficiently move air or gases at varying angles and velocities, which can lead to suboptimal performance in terms of air movement and increased drag.

Innovation Solution

A rotary fan system with dual rotation axes, where a driving arm rotates about a first axis and a trailing arm rotates about a second axis, allowing the attack angle of the blade to change based on its position along both circumferences, enabling variable angles and velocities of air or gas movement.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If the blade rotates about a fixed axis with a fixed rotational arc, then the structure is simple and stable, but the attack angle of the blade cannot be changed, limiting airflow efficiency

Engineering Contradiction:

Improveattack angle adjustmentVSAvoidrotation mechanism

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The patent applies the dynamics principle by transitioning from a fixed rotational arc to a variable rotational arc. The trailing arm is decoupled from rotational locking, allowing it to rotate freely about the second axis and change the blade's attack angle dynamically during operation. This enables the blade to adapt its orientation to optimize airflow at different positions in the rotation cycle.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The patent segments the rotation mechanism into two independent axes: the first axis (driving arm) provides the primary rotational motion, while the second axis (trailing arm) provides independent angular adjustment. This segmentation allows each axis to perform its specific function without interfering with the other, enabling both stable rotation and variable attack angle.

Inventive Principle:

Principle #1Segmentation

2Productivity

If the blade has a fixed attack angle, then the mechanical structure is simpler, but airflow efficiency is reduced due to inability to optimize for different positions

Engineering Contradiction:

Improveairflow efficiencyVSAvoidblade mechanism

Core Design Contradiction:

ProductivityVSDevice complexity

Solution Approach 1:

The trailing arm's free rotation about the second axis creates a dynamic attack angle that changes continuously as the blade moves through its rotation. This dynamic adjustment optimizes airflow efficiency at different positions without requiring complex active control systems, relying instead on the natural mechanics of the dual-axis rotation.

Inventive Principle:

Principle #15Dynamics

3Adaptability or versatility

If the trailing arm is rotationally locked, then the blade maintains a fixed orientation, but drag increases and airflow optimization is limited

Engineering Contradiction:

Improveblade orientationVSAvoiddrag

Core Design Contradiction:

Adaptability or versatilityVSLoss of energy

Solution Approach 1:

By allowing the trailing arm to rotate freely about the second axis, the blade can dynamically adjust its orientation to minimize drag at positions where the rotational arc brings it suboptimal alignment. This reduces energy loss due to drag while maintaining the structural simplicity of a passive mechanical system.

Inventive Principle:

Principle #15Dynamics

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 design allows for dynamic adjustment of the attack angle and direction of the blade, enhancing airflow efficiency by varying the speed of the trailing arm independently, thereby optimizing air movement and reducing drag.

Implementation Method 1

a driving axle that rotates and transfers energy and torque to the blade

Methodology Applied

Scientific EffectTorque: Torque

Implementation Method 2

a driving arm that rotates about a first axis responsive to receiving torque from the driving axle

Methodology Applied

Scientific EffectRotational motion:

Implementation Method 3

a trailing arm that rotates about a second axis, wherein the trailing arm is not rotationally locked with any other element allowing for the attack angle of the blade to change

Methodology Applied

Scientific EffectIndependent rotational motion: