Screw-Driven Actuator With Helical Bearing Torque Conversion
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional hydraulic actuators used in aerospace applications for driving rotatable components like ailerons, elevators, and rudders are inefficient and require fluid transfer, which can be cumbersome and less precise.
Innovation Solution
An actuator system that converts rotational movement of a screw into axial movement of a nut and subsequently into rotational movement of a component, utilizing a bearing system with roller bearings on a helical track to drive the component, eliminating the need for hydraulic components and enhancing precision and efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If hydraulic systems are used to drive rotatable components, then power transmission capability is sufficient, but system complexity and fluid transfer requirements increase
Solution Approach 1:
The patent replaces the hydraulic system with a mechanical screw-nut actuation system. The screw (first member) converts rotational motion to axial motion of the nut (second member), which then drives the rotatable component through the bearing system, eliminating the need for hydraulic fluid transfer and associated complexity while maintaining adequate power transmission for flight control applications
Solution Approach 2:
The patent extracts and eliminates the hydraulic system from the actuator design. By removing the hydraulic reservoirs, fluid transfer mechanisms, and associated control systems, the invention simplifies the overall system architecture while achieving the same functional outcome through direct mechanical actuation
2Measurement precision
If hydraulic fluid transfer is used for control, then actuation capability is achieved, but precision and efficiency are reduced
Solution Approach 1:
The patent substitutes hydraulic control with direct mechanical control through the screw-nut mechanism. The threaded engagement provides inherent mechanical advantage and precise positioning capability, while the direct mechanical coupling eliminates fluid compressibility effects and transfer delays, resulting in both improved precision and efficiency
3Force
If conventional hydraulic actuators are used, then actuation function is provided, but torque efficiency is reduced
Solution Approach 1:
The patent employs a helical track with roller bearings that convert axial motion into rotational motion of the fourth member. The helical geometry provides mechanical advantage similar to a screw mechanism, multiplying the axial force from the nut into rotational torque, thereby improving torque efficiency while maintaining the required actuation power
Solution Approach 2:
The patent transforms the force transmission from a single-dimensional hydraulic pressure system to a multi-dimensional mechanical system. The screw converts rotation to axial motion, the nut translates this axial force, and the helical track converts axial motion back to rotation, creating a cascaded dimensional transformation that improves torque efficiency at each stage
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 a more efficient and precise method for driving rotatable components by converting rotational energy into axial and then rotational movement, suitable for aerospace applications, offering improved torque and reduced complexity compared to hydraulic systems.
Implementation Method 1
a first, rotating member comprising a screw; a second member comprising a nut threaded to the screw, wherein rotation of the first member causes axial movement of the first or second member
Implementation Method 2
one or a plurality of roller bearings moveable along a helical track located on said third or fourth member, wherein upon the axial movement of said first and third member, said roller bearings apply a force to said track, or said track applies a force to said roller bearings, so as to cause rotation of said fourth member
Data Source
AI summary
An actuator for driving a rotatable component includes a first, rotating member comprising a screw and a second member comprising a nut threaded to said screw, wherein rotation of said first member causes axial movement of said first or second member. The component also includes a third member coupled to the second member, wherein axial movement of said first or second member causes axial movement of said third member and a fourth, rotating member coupled to said third member and connectable to said component. The system also includes a bearing system located between said third member and said fourth member, said bearing system configured to cause said fourth member to rotate upon said axial movement of said third member so as to drive said component.