Propeller Feedback Ring Position Detection Using LVDT Sensor
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Solution Overview
Problem
Existing methods for measuring the position of a feedback ring in propeller engines are vulnerable to magnetic noise, which can lead to inaccurate control of propeller blade angles and potentially serious failure conditions.
Innovation Solution
A feedback ring position detection system using a linear variable differential transformer (LVDT) sensor with a stationary sensor member comprising solenoidal coils and a moveable sensor member with a ferromagnetic core, generating a signal indicative of longitudinal displacement relative to a reference position, secured to the aircraft engine's gearbox, allowing accurate determination of the feedback ring's axial position.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If existing magnetic-based methods are used to measure feedback ring displacement, then the measurement system is simple, but the system becomes vulnerable to magnetic noise causing inaccurate measurements
Solution Approach 1:
The patent replaces magnetic-based displacement measurement with a mechanical linkage system. The feedback ring connects to a lever arm that pivots on a fixed axis, converting axial displacement into rotational motion. This mechanical approach eliminates vulnerability to magnetic noise while maintaining measurement capability through geometric relationships between the lever arm position and feedback ring displacement.
2Object-affected harmful factors
If a mechanical linkage system with lever arm is used to detect feedback ring position, then magnetic noise interference is eliminated, but the device complexity increases
Solution Approach 1:
The measurement system is segmented into distinct functional components: the feedback ring, the lever arm with pivot axis, and the position sensor. This segmentation allows each component to perform its specific function independently, simplifying the overall design while maintaining immunity to magnetic noise. The lever arm acts as an independent mechanical translator between the feedback ring and sensor.
3Reliability
If axial displacement of feedback ring is measured directly, then the measurement system is straightforward, but the system becomes vulnerable to interference and less reliable
Solution Approach 1:
The lever arm serves as a mechanical intermediary between the feedback ring and the position sensor. It translates axial displacement of the feedback ring into rotational motion that the sensor can measure accurately. This intermediary mechanism enhances reliability by providing a robust mechanical connection that is immune to magnetic interference while maintaining a relatively simple overall structure.
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 solution provides robust and accurate measurement of the feedback ring's position, reducing the risk of magnetic noise interference and ensuring precise control of propeller blade angles, thereby enhancing engine operation and safety.
Implementation Method 1
the sensor is a linear variable differential transformer, the stationary sensor member comprising a plurality of solenoidal coils and the moveable sensor member comprising a ferromagnetic core
Data Source
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AI summary
A system and method for determining a position of a feedback ring (104) of a propeller (30) of an aircraft engine (10) are provided. The feedback ring (104) is coupled to the propeller (30) to rotate with the propeller (30) and to be displaced along a longitudinal axis (A) with adjustment of a blade angle. An engagement member (210) is configured to engage the feedback ring (104) and to be displaced along a longitudinal direction substantially parallel to the longitudinal axis (A) with displacement of the feedback ring (104). A sensor (200) comprises a first member (202) coupled to the engine (10) and a second member (204) coupled to the engagement member (210). The second member (204) is moveable relative to the first member (202) along the longitudinal direction as the engagement member (210) is displaced. The sensor (200) generates a signal indicative of a longitudinal position of the second member (204) relative to the first member (202). A controller (400) determines an axial position of the feedback ring (104) from the sensor signal.