Electronic Low-Pitch Stop Protection for Propeller Blades
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Solution Overview
Problem
Existing propeller pitch control systems face challenges due to the complexity and constraints of hydromechanical low pitch protection systems, including additional components, manual rigging requirements, and space limitations, which increase weight and manufacturing complexity.
Innovation Solution
A blade pitch control and protection system that integrates electronic sensors and control mechanisms, providing independent feedback channels for control and protection, eliminating the need for hydromechanical components and manual rigging, and allowing for electronic override of blade pitch commands.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a hydromechanical secondary low pitch stop system is used, then propeller pitch protection is provided, but device complexity increases due to additional components and manual rigging requirements
Solution Approach 1:
The patent replaces the hydromechanical secondary low pitch stop system with an electronic control system. The electronic unit receives signals from the primary position sensor and independently controls the pitch actuator through an electronic secondary control channel, eliminating the need for complex hydromechanical protection components, transfer tube modifications, and manual rigging procedures while maintaining reliable pitch protection.
2Reliability
If a hydromechanical low pitch protection system is implemented, then pitch control protection is achieved, but manufacturing complexity increases due to dedicated hydraulic piping and precise orifice requirements
Solution Approach 1:
The patent eliminates dedicated hydraulic piping and precise orifice manufacturing requirements by substituting the hydromechanical protection system with an electronic control architecture. The electronic unit processes position feedback and generates control commands digitally, removing complex manufacturing steps including hydraulic pipe installation, orifice machining, and precision assembly procedures.
3Reliability
If the transfer tube is extended to accommodate hydromechanical protection components, then pitch protection function is enabled, but space requirements increase in the constrained nacelle environment
Solution Approach 1:
The patent eliminates the need to extend the transfer tube by replacing the hydromechanical protection system with electronic controls. The electronic unit and position sensors utilize existing spatial arrangements, avoiding additional space requirements in the constrained nacelle environment while fully enabling pitch protection functionality.
4Measurement precision
If manual rigging of the transfer tube is performed, then accurate triggering threshold is achieved, but assembly time and potential for human error increase
Solution Approach 1:
The patent eliminates manual rigging operations by implementing an electronic secondary control system that receives position feedback from sensors and automatically determines the appropriate triggering threshold through electronic processing. This digital approach removes time-consuming manual adjustment procedures and reduces susceptibility to human error during assembly and calibration.
5Reliability
If a dual-channel electronic control system with independent protection sensing is implemented, then system reliability and redundancy are improved, but device complexity increases
Solution Approach 1:
The patent implements a dual-channel electronic control system where the electronic unit performs multiple functions: it processes primary control commands, monitors position feedback from sensors, independently evaluates pitch protection conditions, and generates both primary control and secondary protection commands. This multi-functional electronic architecture achieves high reliability and redundancy while avoiding the mechanical complexity of separate hydromechanical protection systems.
Data Source
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AI summary
A blade pitch control and protection system for a propeller is described herein comprising: an actuator (100) configured to be connectable to a propeller, such that displacement of said actuator (100) corresponds to a change in blade pitch of said propeller. The system further comprises: an electronic unit (200), a position control sensor (150) configured to interact with said actuator (100), said position control sensor (150) being configured to detect actuator (100) position and thereby said blade pitch of said propeller, and to send a control feedback signal to said electronic unit (200) via a first channel (151), based on said blade pitch, and a protection sensor (160) configured to interact with said actuator (100), configured to detect actuator (100) position and thereby said blade pitch of said propeller, and to send a protection feedback signal to said electronic unit (200) via a second channel (161), based on said blade pitch. The electronic unit (200) is configured to, based on said control feedback signal, control movement of said actuator (100) to alter said blade pitch through a control command. The electronic unit (200) is further configured to, based on said protection feedback signal, control movement of said actuator (100) through a protection command such that said blade pitch control command is overridden when said protection feedback signal indicates that the blade pitch has reached a predefined value.