Passive Locking Actuator Using Motor-Driven Screw-Nut Locking
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional lockable thrust reverser actuators for turbojet engines are heavy and bulky due to the need for additional locking mechanisms, which increases weight and complexity, and are sensitive to vibrations and shocks, making them less reliable and more energy-intensive.
Innovation Solution
A compact and lightweight passive locking device is integrated into the electromechanical actuator, utilizing a screw and nut mechanism with a pinion and crown gear system, where the locking state is changed using the actuator motor, eliminating the need for a dedicated active locking actuator and reducing the weight and bulk of the device.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If an additional dedicated locking actuator is added to prevent accidental deployment, then reliability is improved, but weight and device complexity increase
Solution Approach 1:
The locking function is merged with the existing actuator motor by using the motor's own rotation to drive the locking mechanism through the pinion-crown gear system, eliminating the need for a separate dedicated locking actuator and reducing overall device complexity
Solution Approach 2:
The actuator motor serves dual functions: it provides the primary driving force for moving the extension tube and simultaneously acts as the locking actuator by engaging the pinion with the crown gear to secure the locking elements in position
2Stability of the object's composition
If traditional hydraulic cylinders are used for moving surfaces, then position stability is improved, but adaptability to new actuator designs deteriorates
Solution Approach 1:
The electromechanical actuator achieves position stability through its own integrated passive locking mechanism that automatically engages when the extension tube reaches the retracted position, eliminating the need for external hydraulic pressure to maintain position
3Weight of moving object
If a passive locking device using the actuator motor is used, then weight is reduced, but reliability may deteriorate due to vibration sensitivity
Solution Approach 1:
The passive locking mechanism is designed with inherent vibration resistance by using the motor's own structure and the mechanical engagement of the pinion with the crown gear, which provides stable locking that is not easily disrupted by vibrations or shocks during operation
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 reliable, compact, and lightweight locking mechanism that reduces the risk of accidental deployment and enhances the reliability of thrust reverser actuators by using the actuator motor to change the locking state, improving vibration resistance and reducing energy consumption.
Implementation Method 1
a screw connected in rotation with an output shaft of the motorization. An extension tube secured to a nut engaged on the screw
Implementation Method 2
a pinion and crown gear system, where the locking state is changed using the actuator motor
Data Source
Figure 1~2
Figure 3
Figure 4~6
AI summary
The invention relates to an electromechanical actuator (1) comprising: - a screw (15) extending along a longitudinal axis; - a nut (19) fitted on the screw (15) and provided with means (24) for connecting to an element (2) to be moved; - a passive locking device (40) for locking in the retracted position of the element (2) to be moved; the passive locking device (40) comprising means for actuating a lock that can selectively adopt a first position in which the lock prevents the screw and the nut from rotating relative to one another, which would result in extension of the element to be moved, and a second position in which the nut is free to rotate, the lock passing from one of the first and second positions to the other of the first and second positions when the element (2) to be moved is taken beyond its retracted position.