Aircraft Actuator With Sub-Turn Transmission Line
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The existing actuation systems for aircraft flight surfaces are complex and heavy due to the need for multiple actuators and synchronization of shafts, complicating assembly and maintenance, and requiring multiple turns to achieve desired positions.
Innovation Solution
An actuator system with a rotary motion transmission line allowing less than one revolution for flight surface movement between positions, using a single angular position between pinions and incorporating a motor with resolvers and brakes for precise control, along with a removable sliding connection for stress reduction and ease of assembly.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If multiple actuators are associated with each mobile flight surface to ensure sufficient force and control, then the reliability and control capability are improved, but the weight of the actuation system increases significantly
Solution Approach 1:
The patent combines multiple actuating members (first and second actuating members) into a single integrated actuator unit that shares common components including the motor, transmission line, and control electronics. This merging approach maintains the ability to independently control multiple flight surfaces while eliminating the weight penalty of duplicate actuators, as the shared components provide the necessary force and control for multiple surfaces without requiring separate motor assemblies for each
2Manufacturing precision
If shafts are wedged angularly together to ensure synchronization of actuating members, then the synchronization precision is improved, but the device complexity and difficulty of assembly increase
Solution Approach 1:
The patent introduces a transmission line as an intermediary mechanism that mechanically couples the first and second actuating members. This transmission line includes a shaft with splined sections that engage with corresponding splined sections on the actuating members, providing automatic angular synchronization without requiring complex wedging operations. The splined connection acts as a mediator that ensures precise angular alignment and synchronization while simplifying the assembly process, as the splined sections naturally guide the shafts into the correct relative positions during assembly
3Adaptability or versatility
If the transmission line allows multiple turns to achieve the desired angular position of flight surfaces, then the range of motion is improved, but the number of possible positions increases making assembly and maintenance more difficult
Solution Approach 1:
The patent changes the parameter of angular amplitude from multiple revolutions to less than one revolution (specifically, the shaft rotates through an angle of less than 360 degrees to achieve the full range of motion of the flight surfaces). This parameter change is made possible through the use of gear reduction mechanisms and the specific configuration of the transmission line, which amplifies the limited angular motion of the shaft into the larger angular displacement required by the flight surfaces. This reduction in the number of turns simplifies assembly by reducing the number of possible angular positions and makes maintenance easier by limiting the rotational travel required
Data Source
Figure 1
Figure 2
Figure 3
AI summary
An actuator (10) for at least one movable flight surface (3.1, 3.2, 4.1, 4.2) of an aircraft, comprising at least two members (30) for actuating the movable flight surface between two limit positions and a motor (20) linked to the actuation members by at least one rotational movement transmission line, each actuation member comprising a drive pinion (31.1, 31.2) and the actuator being arranged such that the transmission line has an angular amplitude of less than one turn when the movable flight surface moves between the two positions of same, and the movement transmission line is arranged to allow the drive pinions of the actuation member to assume a single angular position.