Hydraulic Landing Gear Locking Mechanism With Rotary Indexing

Solution Overview

Problem

Conventional landing gear locking devices are bulky and heavy, lacking a reliable mechanism for checking their state and requiring separate control or dedicated fluid connections, which complicates their operation.

Innovation Solution

A landing gear locking device with a hydraulic actuator connected to a rotating distributor that mechanically indexes its state to the position of the landing gear, eliminating the need for separate control or dedicated fluid connections, and includes a system with multiple chambers and ports for fluid connection, enhancing reliability and compactness.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a stabilizing member is used to maintain the locking device in position, then the locking device can be stabilized, but the device becomes bulky and heavy

Engineering Contradiction:

Improvelocking device stabilityVSAvoidlocking device weight

Core Design Contradiction:

ReliabilityVSWeight of stationary object

Solution Approach 1:

The patent replaces the mechanical stabilizing member with a hydraulic control system. The hydraulic actuator uses fluid pressure to maintain the locking device in position, eliminating the need for heavy mechanical stabilizing components while achieving the same stabilization function.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent employs a hydraulic actuator connected to hydraulic supply lines to control the locking device. The hydraulic system provides the necessary force to maintain locking without requiring bulky mechanical stabilizing members, thus reducing weight while preserving reliability.

Inventive Principle:

Principle #29Pneumatics and hydraulics

2Reliability

If a stabilizing member is sized to deliver sufficient forces, then the locking device can be stabilized, but the device becomes bulky

Engineering Contradiction:

Improvelocking device stabilityVSAvoidlocking device size

Core Design Contradiction:

ReliabilityVSArea of stationary object

Solution Approach 1:

The patent replaces the mechanical stabilizing member with a hydraulic control system. The hydraulic actuator uses fluid pressure to maintain the locking device in position, eliminating the need for heavy mechanical stabilizing components while achieving the same stabilization function.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Solution Approach 2:

The patent employs a hydraulic actuator connected to hydraulic supply lines to control the locking device. The hydraulic system provides the necessary force to maintain locking without requiring bulky mechanical stabilizing members, thus reducing weight while preserving reliability.

Inventive Principle:

Principle #29Pneumatics and hydraulics

3Ease of operation

If separate control or dedicated fluid connections are used for the locking device, then the locking device can be controlled, but the operation becomes complicated

Engineering Contradiction:

Improvelocking device controlVSAvoidcontrol system complexity

Core Design Contradiction:

Ease of operationVSDevice complexity

Solution Approach 1:

The patent merges the control of the locking device with the existing hydraulic deployment system. The same hydraulic supply lines that control the deployment cylinder are used to control the locking device, eliminating the need for separate control systems and reducing operational complexity.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The hydraulic system is designed to serve multiple functions: it controls both the deployment cylinder and the locking device through the same supply lines and control mechanisms, reducing the overall system complexity and easing operation.

Inventive Principle:

Principle #6Universality (Multi-functionality)

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

The solution provides a compact and reliable locking mechanism that simplifies operation by indexing the distributor's state to the landing gear position, improving reliability and reducing the need for separate controls, while maintaining the locking device in the appropriate position during deployment and retraction.

Implementation Method 1

a hydraulic actuator connected to a rotating distributor

Methodology Applied

Scientific EffectHydraulic pressure: Hydraulic Press

Implementation Method 2

The rotating distributor comprises means for functionally connecting the rotating distributor to the landing gear, a first supply port fluidically connected to the first hydraulic supply and a first outlet port fluidically connected to the hydraulic actuator

Methodology Applied

Scientific EffectFluid flow control: Valve

Data Source

PatentEP4168309B1Landing gear locking mechanism

Publication Date: 2025.10.01 SAFRAN LANDING SYSTEMS

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AI summary

Locking device comprising a hydraulic actuator (21) connected to a rotary distributor (30), the rotary distributor (30) comprising: - means for operationally connecting the rotary distributor (30) to a landing gear; - a first supply port (35) fluidly connected to the first hydraulic supply (A1); - a second supply port (36) fluidly connected to the second hydraulic supply (A2); - a first outlet port (37) fluidly connected to the hydraulic actuator (21). Landing gear provided with such a device. Aircraft comprising such a landing gear.