Angle of Attack Sensor With Integral Bearing Cage and Faceplate Heating
Solution Overview
Problem
Hindrance of the free rotation of the angle of attack vane or interference with aerodynamic characteristics due to icing conditions can degrade the accuracy of angle of attack determinations, and existing heating elements consume a significant portion of the electrical power budget.
Innovation Solution
The angle of attack sensor features a frustoconical faceplate with an integral bearing support cage, a vane assembly, and a rotational position sensor, where the faceplate heater provides direct thermal conduction to the rotational position sensor, optimizing heat distribution and reducing power consumption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If heating elements are added to prevent icing on the vane and faceplate, then reliability is improved, but use of energy deteriorates
Solution Approach 1:
The heating elements are strategically positioned only at the leading edge of the vane and specific areas of the faceplate where icing most commonly occurs, rather than heating the entire surfaces. This localized approach prevents icing in critical areas while minimizing overall power consumption.
Solution Approach 2:
The heating system is divided into separate heating elements for the vane and faceplate, allowing independent control and optimization of power consumption for each component based on its specific icing risk and operational requirements.
2Reliability
If heating elements are added to prevent icing on the vane and faceplate, then reliability is improved, but device complexity deteriorates
Solution Approach 1:
The heating elements are integrated directly into the structural components of the vane and faceplate during manufacturing, combining the heating function with the existing aerodynamic surfaces. This integration eliminates separate mounting structures and reduces overall system complexity.
Solution Approach 2:
The faceplate serves multiple functions: it protects internal components, provides a mounting surface for the vane, and incorporates heating elements for icing prevention. This multi-functionality reduces the need for additional separate components.
3Manufacturing precision
If the bearing support cage is made integral to the faceplate, then manufacturing precision is improved, but device complexity deteriorates
Solution Approach 1:
The bearing support cage is manufactured as an integral part of the faceplate using single-piece machining or molding processes. This integration ensures precise alignment of the bearing bores with the vane rotation axis while eliminating the need for separate assembly operations and reducing the number of parts.
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 effectively prevents icing on the faceplate and vane assembly, maintains accurate angle of attack measurements, and conserves electrical power by efficiently heating only the necessary areas, thus enhancing the sensor's performance and reliability in icing conditions.
Implementation Method 1
the faceplate heater provides direct thermal conduction to the rotational position sensor, optimizing heat distribution
Implementation Method 2
angle of attack sensors utilizing rotatable vanes typically include heating elements to prevent accretion of ice on the vane and faceplate
Data Source
AI summary
An angle of attack sensor includes a housing having an open end and a closed end. A faceplate is positioned on the open end of the housing. The faceplate comprises an integral bearing support cage that extends into the housing and is configured to accept a first bearing and a second bearing, a periphery at an outer edge of the faceplate, a central opening, and an exterior surface extending from the periphery to the central opening. A vane assembly extends through the central opening of the faceplate. A vane shaft extends into the housing and is connected to the vane assembly, and a rotational position sensor is connected to the vane shaft.