RAT Latch Assembly Solenoid Actuation High G-Load Stability
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Solution Overview
Problem
The existing electromechanical actuator latch systems for ram air turbines face challenges in maintaining the latched position under high G-loads and stresses, requiring a reliable mechanism to ensure the latch assembly remains locked until actuated by the solenoid.
Innovation Solution
A latch assembly featuring a lever block with pivot axes and a latch pin, supported by bearings, which is rotated by a solenoid to initiate the deploy sequence, utilizing a deploy surface and a recock mechanism with a biasing spring to maintain the latched condition until solenoid activation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a latch assembly is designed to maintain latched position under high G-loads, then reliability is improved, but device complexity increases due to the need for robust locking mechanisms and bearings
Solution Approach 1:
The latch assembly is segmented into distinct functional components: a lever block with pivot axis, a latch pin, and needle bearings. This segmentation allows each component to be optimized independently for its specific function while maintaining overall reliability under high G-loads.
Solution Approach 2:
Needle bearings are introduced as intermediary elements between the latch pin and lever block. These bearings mediate the interaction by providing low-friction rotation support, enabling the latch to maintain position under high loads without requiring an overly complex mechanical structure.
2Ease of operation
If needle bearings are used to reduce friction, then ease of operation is improved, but manufacturing precision requirements increase
Solution Approach 1:
The needle bearings are designed to self-align within the lever block and latch pin structure. The bearing geometry and housing features work together to automatically position the bearings correctly during assembly, reducing the need for high-precision manual installation while still achieving smooth rotation.
3Extent of automation
If a solenoid is used to actuate the latch, then automation is improved, but power consumption increases under high stress conditions
Solution Approach 1:
The solenoid is designed to apply only the minimum necessary force required to initiate latch release under high stress conditions. Once the latch pin begins to rotate on its pivot axis, the stored mechanical energy in the system carries the remaining deployment action, reducing the total energy consumption of the solenoid.
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 ensures reliable and efficient deployment of the ram air turbine actuator by maintaining the latch in the latched position under high stresses and G-loads, allowing for precise control and reduced friction through the use of needle bearings and a self-energizing release mechanism.
Implementation Method 1
A solenoid is mounted to the housing and includes a rod having an end that engages the deploy surface. The solenoid is configured to push the lever block about the pivot axis during a deploy sequence.
Implementation Method 2
Each bearing receives an end of the latch pin and is configured to permit the latch pin to rotate relative to the lever block.
Implementation Method 3
utilizing a deploy surface and a recock mechanism with a biasing spring to maintain the latched condition until solenoid activation
Data Source
AI summary
A latch assembly for a RAT actuator includes a lever block having spaced apart first and second lateral walls interconnected to one another by a bridge wall. The first and second lateral walls provide a pivot axis at one end. A latch pin is at another end opposite the one end. The latch pin extends between the first and second lateral walls. A latch bearing is arranged in each of the first and second lateral walls. Each bearing receives an end of the latch pin and is configured to permit the latch pin to rotate relative to the lever block. A lever block is arranged within a housing and has first and second lateral walls interconnected to one another by a bridge wall. A solenoid is configured to push the lever block about the pivot axis during a deploy sequence.