Ratcheting Shape Memory Alloy Actuator for Compact Orientation Control
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Solution Overview
Problem
Traditional hydraulic and motorized actuators used in applications like aircraft are complex, bulky, and heavy, necessitating the development of simpler, smaller, and lighter alternatives to reduce manufacturing and maintenance costs, as well as fuel consumption.
Innovation Solution
The use of ratcheting shape memory alloy actuators, which incorporate a ratcheting assembly coupled with a shape memory alloy element, such as a nickel-titanium torque tube, to apply a motive force and adjust the orientation of structures through deformation between different conformations, with a selection mechanism and temperature control to manage the alloy's phase transitions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Force
If traditional hydraulic or motorized actuators are used, then reliable actuation force is achieved, but device complexity, weight, and volume increase
Solution Approach 1:
The patent replaces complex hydraulic or motorized actuation systems with a shape memory alloy (SMA) element that directly provides actuation force through its phase transition properties. The SMA element transforms thermal energy into mechanical work, eliminating the need for hydraulic fluids, motors, and associated control mechanisms, thereby reducing device complexity while maintaining actuation capability
Solution Approach 2:
The invention utilizes the phase transition of shape memory alloy material between austenite and martensite phases to generate actuation force. When heated, the SMA element transforms from martensite to austenite phase, causing reversible deformation that drives the ratcheting mechanism. This phase transition-based actuation provides reliable force with minimal mechanical complexity
2Force
If traditional hydraulic or motorized actuators are used, then sufficient actuation capability is achieved, but weight increases
Solution Approach 1:
The patent substitutes heavy mechanical actuation systems (motors, hydraulic pumps, reservoirs) with a lightweight shape memory alloy element. The SMA element's inherent ability to generate force through phase transition eliminates the need for power-intensive mechanical systems, dramatically reducing actuator weight while preserving actuation capability
Solution Approach 2:
The invention changes the actuation parameter from electrical or hydraulic energy input to thermal energy input. By controlling temperature (through heating elements or environmental temperature changes), the SMA element generates actuation force, eliminating the need for heavy electrical motors and hydraulic systems, thus reducing overall actuator weight
3Reliability
If traditional hydraulic or motorized actuators are used, then reliable actuation is achieved, but volume occupies significant space
Solution Approach 1:
The patent merges the actuation element (SMA), the transmission mechanism (ratcheting assembly), and the control system into a single integrated compact unit. The SMA element directly interfaces with the ratcheting mechanism, eliminating the need for separate hydraulic lines, motor mounts, and control electronics, thereby reducing overall actuator volume while maintaining reliability
Solution Approach 2:
The invention employs a nested configuration where the SMA element is positioned within or adjacent to the ratcheting assembly, and control components are integrated within the same housing. This compact nested arrangement minimizes the spatial footprint of the actuator while ensuring all components work together reliably
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
These actuators provide a compact, lightweight solution that effectively adjusts the orientation of structures, reducing complexity and weight while maintaining efficient operation, thereby decreasing costs and fuel consumption.
Implementation Method 1
a shape memory alloy element that is operatively coupled to the ratcheting assembly and to a second bracket. The shape memory alloy element is configured to apply a motive force to the ratcheting assembly upon deformation between a first conformation and a second conformation
Data Source
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AI summary
Ratcheting shape memory alloy actuators (100) and systems and methods including the same are disclosed herein. The ratcheting shape memory alloy actuators (100) include a ratcheting assembly (110) that is operatively coupled to a first bracket (62) and a shape memory alloy element (150) that is operatively coupled to the ratcheting assembly (110) and to a second bracket (72). The first bracket (62) is configured to be operatively coupled to a first structure (60), while the second bracket (72) is configured to be operatively coupled to a second structure (70). The shape memory alloy element (150) is configured to apply a motive force to the ratcheting assembly (110) upon deformation between a first conformation and a second conformation. The ratcheting assembly (110) is configured to utilize the motive force to selectively adjust an orientation of the first structure (60) relative to the second structure (70).