Aircraft Landing Gear Steering Device with Pivoting Bracket
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Solution Overview
Problem
Existing aircraft landing gear steering systems require large design spaces and heavy actuators due to their fixed pivot points, limiting achievable steering angles and increasing weight, while also risking clashes with other landing gear structures.
Innovation Solution
A steering device with a pivoting bracket and actuator system that allows actuators to move with the ground-contacting elements, reducing the need for large actuators and enabling smaller, more compact designs by using a steering arm that follows the contour of the landing gear leg, thus minimizing the risk of clashes and allowing for greater steering angles.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If fixed actuators are used with fixed pivot points, then the actuator structure is simple, but the actuator requires large clearance area and large design space
Solution Approach 1:
The patent applies the dynamics principle by making the actuator pivot point movable rather than fixed. The bracket pivots about a pivot location that moves with the ground-contacting elements, allowing the actuator to follow the motion path and reducing the required clearance area. This dynamic adjustment resolves the contradiction between structural simplicity and space requirements.
Solution Approach 2:
The bracket serves as an intermediary element between the actuator and the main fitting. It translates the actuator's linear motion into rotational motion of the steering collar while accommodating the changing geometry during steering. This intermediary mechanism enables compact actuator design without sacrificing steering capability.
2Reliability
If fixed actuators with large clearance are used, then the actuator can operate without clashes, but the maximum achievable steering angle is constrained
Solution Approach 1:
By making the pivot location dynamic and moving with the ground-contacting elements, the system achieves both clash avoidance and increased steering angle. The bracket's motion follows the steering collar's rotation, allowing the actuator to maintain proper clearance throughout the full range of motion without limiting the maximum steering angle.
3Force
If large actuators are used to provide sufficient steering torque, then the steering force is adequate, but the device size and weight increase
Solution Approach 1:
The dynamic pivot configuration creates a more favorable mechanical advantage ratio throughout the steering range. By allowing the actuator to follow the motion path, the system maintains optimal leverage, enabling smaller, lighter actuators to generate sufficient steering torque compared to fixed pivot systems.
Solution Approach 2:
The invention adds a rotational dimension to the actuator's motion by allowing the bracket to pivot. This transforms the actuator's linear motion into a combined linear-rotational motion, improving the mechanical efficiency and reducing the actuator size required to achieve the same steering torque.
4Ease of manufacture
If fixed pivot point actuators are used, then the actuator mounting is simple, but the actuator swings to large angles requiring large clearance
Solution Approach 1:
The system transitions from a simple fixed pivot mounting to a dynamic pivot mounting where the bracket rotates about a moving pivot location. While slightly more complex than a fixed pivot, this dynamic mounting significantly reduces the clearance area required by allowing the actuator to follow the natural motion path during steering operations.
Data Source
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AI summary
A steering device (20) for an aircraft landing gear leg including a main fitting has a steering collar (16) for rotatably mounting on the outside of the main fitting, and an actuator (40,50) having an actuator body (42,52) and an actuator arm (43,53) arranged to move between an extended position and retracted position with respect to the actuator body (42,52). The actuator arm (43,53) is pivoted to the main fitting. A bracket (29) is pivotally connected to the main fitting at a first pivot location (36), to the actuator body (52) at a second pivot location (34), and to one end (28) of a steering arm (26) at a third pivot location (32). The steering arm (26) is pivoted at its other end (27) to the steering collar (16). Also, an aircraft landing gear with the steering device (20) and aircraft having the landing gear.