Cycloidal Rotor Non-Circular Blade Orbit

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Solution Overview

Problem

Conventional cycloidal rotors with circular orbits are limited in their ability to adjust lift-to-thrust ratios and efficiency, particularly in varying flight conditions, and are susceptible to wind gusts and turbulence.

Innovation Solution

A cycloidal rotor system that allows blades to follow a non-circular orbit, such as elliptical or elongated paths, enabling dynamic adjustment of blade trajectory and spatial orientation, which enhances lift and thrust generation efficiency by optimizing orbit shape based on operational regimes.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If blades rotate in a circular orbit, then the rotor structure is simple and easy to manufacture, but the lift-to-thrust ratio cannot be dynamically adjusted and aerodynamic efficiency is limited

Engineering Contradiction:
Improverotor structure simplicityVSAvoidlift-to-thrust ratio adjustment capability
Core Design Contradiction:
Ease of manufactureVSAdaptability or versatility

Solution Approach 1:

The patent implements a dynamic blade orbit system where blades can transition between circular and non-circular (elliptical, figure-eight, etc.) orbits. This is achieved through a mechanism that allows radial movement of blades relative to the rotation axis, enabling the rotor to adapt its geometry dynamically based on flight conditions, thus resolving the contradiction between structural simplicity and adaptability.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The invention changes the orbital parameters of blade rotation from fixed circular paths to variable non-circular paths. By modifying the orbit shape parameter (circularity ratio), the system can optimize lift-to-thrust ratios for different flight regimes while maintaining a relatively simple base structure, addressing both manufacturing ease and operational versatility.

Inventive Principle:
Principle #35Parameter changes

2Adaptability or versatility

If blades follow a non-circular orbit, then lift-to-thrust ratio can be optimized for different flight conditions, but the rotor structure becomes more complex

Engineering Contradiction:
Improveflight condition adaptabilityVSAvoidblade positioning mechanism
Core Design Contradiction:
Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The rotor system is segmented into independent blade units, each capable of individual radial positioning. This segmentation allows complex non-circular orbit control to be achieved through simple, repeatable positioning mechanisms on each blade, rather than requiring a complex centralized control system, thus managing device complexity while maintaining flight condition adaptability.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The blade positioning mechanism serves multiple functions: it controls radial position for orbit shape, adjusts angle of attack, and enables transition between different flight regimes. This multi-functionality reduces the need for separate mechanisms for each function, thereby limiting the increase in device complexity while achieving comprehensive flight condition adaptability.

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

3Stability of the object's composition

If circular orbit is used, then the rotor is stable and easy to control, but efficiency in varying flight conditions deteriorates

Engineering Contradiction:
Improverotor operational stabilityVSAvoidaerodynamic efficiency
Core Design Contradiction:
Stability of the object's compositionVSProductivity

Solution Approach 1:

The system maintains stability through a controlled transition mechanism that smoothly changes blade orbits from circular to non-circular and back. The dynamic adjustment is performed in a controlled manner that preserves rotor stability while optimizing aerodynamic efficiency for varying flight conditions, resolving the contradiction between stability and productivity.

Inventive Principle:
Principle #15Dynamics

4Use of energy by moving object

If conventional circular cycloidal rotor is used, then power requirements are reduced, but lift and thrust generation efficiency is limited

Engineering Contradiction:
Improvepower consumptionVSAvoidlift and thrust generation
Core Design Contradiction:
Use of energy by moving objectVSPower

Solution Approach 1:

The invention optimizes the orbital parameters of blade rotation to maximize the ratio of useful work (lift and thrust) to energy input. By adjusting orbit shape, size, and blade positioning dynamically, the system extracts maximum aerodynamic efficiency from each unit of power consumed, resolving the contradiction between power consumption and power generation efficiency.

Inventive Principle:
Principle #35Parameter changes

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 system significantly improves lift and thrust capabilities, increases efficiency by allowing greater control over vortex formation and shedding, and enhances maneuverability and resistance to environmental changes.

Implementation Method 1

the blade can produce the desired aerodynamic effect... the kinds of aerodynamic effects that can be produced... lift or thrust generation... aerodynamic efficiency

Methodology Applied
Scientific EffectAerodynamic effect: Aerofoil

Implementation Method 2

When the rotor of the present invention works in a regime where vorticity based effects are utilised, the ability to select and dynamically adjust the blade's trajectory and spatial orientation allows control of the formation, spanwise movement, retention and shedding of the leading and trailing edge vortexes

Methodology Applied
Scientific EffectVortex formation and shedding: Vortex Ring

Data Source

PatentEP2307671B1Cycloidal rotor with non-circular blade orbit
Publication Date: 2019.08.28 BOGRASH PHILIP
  • EP2307671B1 patent drawingFigure 1~3
  • EP2307671B1 patent drawingFigure 4
  • EP2307671B1 patent drawingFigure 5

AI summary

A cycloidal rotor system having airfoil blades travelling along a generally non-circular, elongated and, in most embodiments, dynamically variable orbit. Such non-circular orbit provides a greater period in each revolution and an optimized relative wind along the trajectory for each blade to efficiently maximise lift when orbits are elongated horizontally, or thrust/propulsion when orbits are vertically elongated. Most embodiments, in addition to having the computer system controlled actuators to dynamically vary the blade trajectory and the angle of attack, can also have the computer system controlled actuators for dynamically varying the spatial orientation of the blades; enabling their slanting motion upward/downward and/or backsweep/forwardsweep positioning to produce and precisely control a variety of aerodynamic effects suited for providing optimum performance for various operating regimes, counter wind gusts and enable the craft to move sideways. Thus a rotor is provided, which when used in a VTOL rotorcraft, will require lower engine power to match or exceed the operating performance of VTOL rotorcrafts equipped with prior art rotors, this rotor also offers increased efficiency and decreased required power when used for generating the propulsive force for various vehicles or used as a fan.