Co-rotating Stacked Rotor Disks for Hover Lift
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Solution Overview
Problem
Existing rotor systems for rotorcraft face limitations in maximizing lift and thrust, particularly in hover performance, and often require additional anti-torque devices due to torque induction.
Innovation Solution
The implementation of a rotor hub design featuring multiple co-rotating co-axial rotor disk assemblies, with each disk assembly having three rotor blades, spaced to take advantage of 'wake contraction' to enhance air flow efficiency, allowing for increased lift and thrust without the need for a tail rotor.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If counter-rotating co-axial rotor systems are used, then hover performance is improved and torque cancellation occurs, but device complexity increases
Solution Approach 1:
The rotor system is divided into multiple independent rotor disk assemblies (upper and lower disks) that can rotate independently. Each disk assembly contains multiple rotor blades that are mechanically coupled to a common mast, allowing separate rotation of each disk while maintaining structural integration through the shared mast support system.
Solution Approach 2:
Multiple rotor disk assemblies are combined into a single integrated rotor system sharing a common mast. The upper and lower rotor disks are merged in space and time, rotating in opposite directions about the same axis, creating a compact co-axial configuration that provides torque cancellation while improving hover performance.
2Force
If a greater number of rotor blades are used, then lift and thrust are increased, but device complexity increases
Solution Approach 1:
The rotor system transitions from a single-plane rotor configuration to a three-dimensional co-axial arrangement with upper and lower rotor disks stacked vertically. This adds a vertical dimension to the rotor layout, allowing multiple blades to operate in different spatial planes while sharing a common rotation axis, thereby increasing total lift and thrust without proportionally increasing mechanical complexity.
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 improves rotorcraft performance by increasing lift and thrust while eliminating the need for anti-torque devices through counter-rotating co-axial rotors, optimizing air flow between disk assemblies for enhanced efficiency.
Implementation Method 1
thrust and/or lift is generated by air flowing through a rotor disk formed by a plurality of rotating rotor blades
Implementation Method 2
counter-rotating co-axial rotor systems on a helicopter do not need a tail rotor or other anti-torque device because each rotor acts to cancel the torque that would otherwise be induced into the helicopter
Data Source
AI summary
The system of the present application represents a rotor hub for a rotorcraft and a rotorcraft incorporating the rotor hub. The rotor hub is represented as having multiple rotor disk assemblies, each rotor disk assembly rotating in the same direction about the same mast axis of rotation. In the preferred embodiment, each rotor disk assembly has three rotor blades. The upper rotor disc assembly and the lower rotor disk assembly are separated by approximately 2.5% of the rotor disk diameter, at least to take advantage of “wake contraction”.