Rotorcraft Mechanical Control Combiner Parallelogram Linkage
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Solution Overview
Problem
Existing mechanical devices for combining control orders in rotorcraft flight control systems suffer from undue displacements and interference between cyclic and collective pitch commands, requiring compensatory actuators to maintain pilot control transparency.
Innovation Solution
A mechanical device with a return means featuring multiple articulations forming a parallelogram structure, allowing precise translation of movements without interference, where the elongated mechanical member and connecting rod arrangements ensure that input commands are faithfully transmitted without inducing unwanted rotations or displacements.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a conventional combiner with L-shaped return means is used to combine cyclic and collective pitch commands, then the control orders can be transmitted mechanically, but the rotation of main linkages during collective pitch lever movement causes undue displacement of the cyclic control handle
Solution Approach 1:
The invention divides the return means into two independent functional parts: a first return means (main linkages with L-shaped return) for collective pitch command transmission, and a second return means (secondary linkages with bellcrank) for cyclic pitch command transmission. This segmentation isolates the motion paths, preventing interference between collective and cyclic control orders while maintaining mechanical transmission for both functions.
2Manufacturing precision
If compensatory actuators are added to eliminate cyclic control handle displacement, then control position accuracy is improved, but device complexity and reliance on electric actuators increase
Solution Approach 1:
The invention employs passive mechanical design where the segmented return means inherently prevents undue displacement of the cyclic control handle during collective pitch operations. The system achieves control position accuracy through its geometric configuration and mechanical constraints alone, without requiring active compensatory actuators or complex control systems, thereby maintaining simplicity and reliability.
3Manufacturing precision
If the mechanical linkages are made more rigid to prevent displacement, then control position accuracy improves, but the device complexity and number of components increase
Solution Approach 1:
The invention achieves control position accuracy not through increased rigidity of individual components, but through the segmented architectural structure that separates collective and cyclic transmission paths. This allows each segment to maintain appropriate flexibility while the overall system prevents unwanted displacements, avoiding the need for overly rigid and complex individual components.
Data Source
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AI summary
The present invention relates to a mechanical device (1) equipped with a linkage (2), and an elongated mechanical member (30) extending from a first end (31) articulated by means of the linkage (2) to a second end (32). The elongated mechanical member (30) pivots about a fixed vertical axis of rotation (AX4). The mechanical device comprises a mechanical part (50) that is only movable in rotation about this axis of rotation (AX4), said mechanical part (50) having an input joint (55) connected to a mechanical linkage (152). A connecting rod (60) is articulated on one side to the linkage (2) and on the other side to the mechanical part (50).