Proprotor Tilt Mechanism with Integrated Blade Pitch Control

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Solution Overview

Problem

Existing VTOL aircraft require dedicated blade pitch adjustment actuators to coordinate blade pitch with proprotor tilt, which adds weight, cost, and complexity.

Innovation Solution

A system that mechanically links the pitch of the blades of a proprotor to the tilt angle of the proprotor, eliminating the need for dedicated blade pitch adjustment actuators by using a cam and control rod mechanism.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If dedicated blade pitch adjustment actuators are used to coordinate blade pitch with proprotor tilt, then blade pitch control is achieved, but weight, cost, and complexity increase

Engineering Contradiction:
Improveblade pitch controlVSAvoidactuator system complexity
Core Design Contradiction:
Ease of operationVSDevice complexity

Solution Approach 1:

The patent combines the blade pitch control function with the existing proprotor tilt mechanism by integrating a cam and follower system into the tilt actuator assembly. The cam profile is specifically designed to convert the tilt actuator's linear motion into coordinated blade pitch rotation, eliminating the need for separate pitch actuators on each blade while maintaining precise pitch control throughout the tilt range.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The proprotor tilt actuator is designed to perform multiple functions: it simultaneously controls the proprotor tilt angle and coordinates the blade pitch adjustment. The cam mechanism embedded within the actuator converts a single actuator's linear motion into two coupled outputs (tilt and pitch), making the system more efficient by reducing the total number of actuators required.

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

2Ease of operation

If dedicated blade pitch adjustment actuators are used, then blade pitch control is achieved, but weight increases

Engineering Contradiction:
Improveblade pitch controlVSAvoidactuator system weight
Core Design Contradiction:
Ease of operationVSWeight of moving object

Solution Approach 1:

The patent combines the blade pitch control function with the existing proprotor tilt mechanism by integrating a cam and follower system into the tilt actuator assembly. The cam profile is specifically designed to convert the tilt actuator's linear motion into coordinated blade pitch rotation, eliminating the need for separate pitch actuators on each blade while maintaining precise pitch control throughout the tilt range.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The proprotor tilt actuator is designed to perform multiple functions: it simultaneously controls the proprotor tilt angle and coordinates the blade pitch adjustment. The cam mechanism embedded within the actuator converts a single actuator's linear motion into two coupled outputs (tilt and pitch), making the system more efficient by reducing the total number of actuators required.

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

3Ease of operation

If dedicated blade pitch adjustment actuators are used, then blade pitch control is achieved, but cost increases

Engineering Contradiction:
Improveblade pitch controlVSAvoidmanufacturing cost
Core Design Contradiction:
Ease of operationVSEase of manufacture

Solution Approach 1:

The patent combines the blade pitch control function with the existing proprotor tilt mechanism by integrating a cam and follower system into the tilt actuator assembly. The cam profile is specifically designed to convert the tilt actuator's linear motion into coordinated blade pitch rotation, eliminating the need for separate pitch actuators on each blade while maintaining precise pitch control throughout the tilt range.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The proprotor tilt actuator is designed to perform multiple functions: it simultaneously controls the proprotor tilt angle and coordinates the blade pitch adjustment. The cam mechanism embedded within the actuator converts a single actuator's linear motion into two coupled outputs (tilt and pitch), making the system more efficient by reducing the total number of actuators required.

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

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

Enables efficient proprotor performance across different flight regimes without the need for additional actuators, reducing weight, cost, and complexity while improving energy efficiency.

Implementation Method 1

A cam is connected to the pinion such that the cam rotates along with the pinion. A control rod is operatively coupled to the cam such that as the cam rotates the control rod follows the profile of the cam, which causes the control rod to translate depending on the profile.

Methodology Applied
Scientific EffectCam mechanism: Cam

Implementation Method 2

A pinion is rotatably connected to a tiltable frame to which the proprotor is mounted and is engaged with the fixed gear such that as the pinion gear moves with the tiltable frame, the pinion revolves around the fixed gear, which causes the pinion to rotate.

Methodology Applied
Scientific EffectGear mechanism: Gear

Data Source

PatentEP4507962B1Tilt rotor systems and methods for evtol aircraft
Publication Date: 2025.05.28 ARCHER AVIATION INC
  • EP4507962B1 patent drawingFigure 1
  • EP4507962B1 patent drawingFigure 2
  • EP4507962B1 patent drawingFigure 3

AI summary

A system includes a first frame for mounting to the aircraft; a second frame for mounting the proprotor, the second frame being rotatably mounted to the first frame; a first gear located along the rotation axis of the second frame and fixed in position relative to the first frame; a pinion that moves with the second frame and engages the first gear such that the pinion revolves around the first gear, causing the pinion to rotate; a cam that is fixedly connected to the pinion such that the cam rotates with the pinion; and a control rod operatively coupled at a first end with the cam such that rotation of the cam can cause translation of the control rod, wherein the control rod can be coupled at a second end to the blades of the proprotor such that translation of the control rod alters the pitch of the blades.