Linear Actuator Backup Locking for Safe Rotor Pitch Holding
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Linear actuation devices in systems like aircraft rotor test benches are prone to failures, which can cause malfunctions leading to potential damage and safety risks.
Innovation Solution
A linear actuation device with a backup system that includes a secondary actuator and a hydraulic blocker, allowing the main rod to be immobilized in a safe position during failures, and a tracking system to ensure precise positioning.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a linear actuation device is used in nominal operating mode, then the main rod can move freely to control the rotor blade pitch, but the system becomes vulnerable to failures that can cause damage to the test bench
Solution Approach 1:
The backup system is pre-configured with the secondary actuator and hydraulic blocker in a ready state before any failure occurs. The secondary rod is positioned to potentially engage with the main rod, and the hydraulic blocker is pre-filled with hydraulic fluid, so that upon failure detection, the system can immediately transition to backup mode without requiring complex real-time decision-making or sequential activation steps
Solution Approach 2:
The hydraulic blocker acts as an intermediary mechanism between the secondary actuator and the main rod. It uses hydraulic fluid as a mediator to transmit force from the secondary rod to the main rod only when needed. The deformable clamping ring with functional clearance allows the hydraulic fluid to transmit pressure selectively, engaging the backup function only when the main system fails
2Reliability
If a backup system with secondary actuator and hydraulic blocker is added, then the safety and reliability of the test bench is improved, but the device complexity increases
Solution Approach 1:
The secondary actuator is designed to perform multiple functions: it can move the main rod to a safe position during failure, it provides structural support as part of the actuator assembly, and its rod serves as both a backup actuation element and a mechanical connector. The hydraulic blocker also serves dual purposes as both a locking mechanism and a force transmission element
Solution Approach 2:
The backup system components are nested within the existing actuator structure. The secondary rod is housed within the secondary actuator body, the hydraulic blocker is integrated into the actuator assembly, and the deformable clamping ring is positioned to engage with the main rod. This nested arrangement minimizes the overall space required and reduces the number of external components needed
3Ease of operation
If the hydraulic blocker uses a deformable clamping ring with functional clearance, then the main rod can slide freely during nominal operation, but the manufacturing precision requirements increase
Solution Approach 1:
The deformable clamping ring is designed with non-uniform properties: it has a functional clearance in specific regions to allow free sliding during nominal operation, while maintaining contact in other regions to provide guidance and support. The elasticity of the material allows different zones of the ring to have different degrees of engagement with the main rod, creating localized quality variations that satisfy both free movement and precision requirements
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 backup solution effectively addresses the safety and safety of the aircraft rotor test bench, ensuring the safety and safety of the aircraft rotor test bench, ensuring the pitch of the rotor blades is maintained at a predetermined value even in the event of a malfunction.
Implementation Method 1
a hydraulic blocker (26) attached to the secondary rod (23), the hydraulic blocker (26) comprising a deformable clamping ring (27) configured in the nominal operating mode to allow frictionless sliding of the main rod (13) within it
Implementation Method 2
elastic return means (32) jointly exerting a return force on a piston (29) to move each piston (29) from its first extreme position to a second extreme position when the fluid is no longer pressurized
Data Source
Figure 1
Figure 2
Figure 3~4
AI summary
The present invention relates to a linear actuator (1) comprising a main actuator (11) having a main body (12) and a main rod (13) movable with at least one degree of freedom in translation relative to said main body (12). According to the invention, the linear actuator (1) includes a backup system (20) configured to, in a nominal operating mode of the linear actuator (1), allow a displacement of the main rod (13) relative to the main body (12) and, in a backup operating mode of the linear actuator (1), return and then hold the main rod (13) in a predetermined safe position (PREF).