Thrust Reverser Translating Elements With Differential Lead Screw Actuation
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Solution Overview
Problem
Current thrust reverser systems for aircraft propulsion lack an efficient actuation mechanism that can effectively translate the thrust reverser components between stowed and deployed positions, requiring an improved system for faster and more precise control.
Innovation Solution
A lead screw mechanism is employed, comprising a lead screw sleeve, shaft, and shuttle nut, where the lead screw shaft is connected to the translating sleeve and the shuttle nut is connected to the translating cascade, with different threaded interfaces to achieve distinct actuation rates, allowing for faster translation of the sleeve compared to the cascade.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If a conventional actuation mechanism is used for thrust reverser systems, then the system structure is simpler, but the actuation speed and precision are insufficient
Solution Approach 1:
The actuation mechanism is segmented into two independent drive mechanisms: a first drive mechanism for actuating the translating sleeve and a second drive mechanism for actuating the translating cascade. This segmentation allows each mechanism to be optimized independently for its specific function, enabling faster actuation of the sleeve while maintaining control over the cascade, thus resolving the contradiction between actuation speed and system complexity.
Solution Approach 2:
The patent implements differential actuation rates where the first drive mechanism operates at a first actuation rate for the translating sleeve and the second drive mechanism operates at a second actuation rate for the translating cascade. This dynamic control allows the system to achieve faster overall actuation speed by optimizing the critical path (sleeve movement) while maintaining precise control, resolving the speed-complexity contradiction.
2Productivity
If the translating sleeve and cascade are actuated at the same rate, then the control system is simpler, but the deployment and stowing efficiency is reduced
Solution Approach 1:
The control system is segmented into two independent control paths: one controlling the translating sleeve at a first actuation rate and another controlling the translating cascade at a second actuation rate. This segmentation enables differential speed control where the sleeve can move faster during deployment/stowing, improving overall productivity without requiring complex coordinated control, thus resolving the contradiction between efficiency and control complexity.
Solution Approach 2:
The patent changes the actuation rate parameter differently for two components: the translating sleeve operates at a first actuation rate while the translating cascade operates at a second actuation rate. This parameter differentiation allows the critical path (sleeve movement) to be optimized for speed, improving deployment and stowing efficiency while the control system complexity is managed through independent rather than coordinated control.
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 configuration enables faster and more precise control of the thrust reverser components, allowing for efficient deployment and stowing, with the ability to tailor actuation rates independently, enhancing the overall performance of the thrust reverser system.
Implementation Method 1
The drive mechanism may be configured as or include a lead screw mechanism. The drive mechanism may include a lead screw sleeve, a lead screw shaft and a shuttle nut. The lead screw shaft may be within the lead screw sleeve and may be mated with the lead screw sleeve by a first threaded interface.
Data Source
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AI summary
A thrust reverser system (16) is provided with an axial centerline (18). This thrust reverser system (16) includes a first translating element, a second translating element and an actuator mechanism (48). The actuator mechanism (48) is attached to the first translating element and the second translating element. The actuator mechanism (48) is configured to translate the first translating element along the axial centerline (18) at a first rate. The actuator mechanism (48) is configured to translate the second translating element along the axial centerline (18) at a second rate, which may be different than the first rate.