Multi-Disk Torque Coupling With Roller Interfaces to Prevent Glazing
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing torque transmission devices for electromechanical actuators in flight control surfaces suffer from performance issues such as high torque transmission when not intended, deterioration due to glazing effects, and require a compact design with high and low torque thresholds.
Innovation Solution
A torque transmission device using a solenoid and resilient member to switch between modes, featuring interdigitated friction and roller disks, allowing torque transmission through disk-to-roller interfaces in low torque mode and disk-to-disk interfaces in high torque mode, preventing glazing effects.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a solenoid-based clutch mechanism is used to selectively transmit torque, then the device can switch between torque transmission modes, but the device transmits too high torque when in non-transmission mode and deteriorates over time due to glazing effects
Solution Approach 1:
The friction transmission element is segmented into multiple friction disks (first plurality and second plurality) that are interdigitated with each other. This segmentation allows the creation of multiple friction interfaces, enabling more precise control over torque transmission characteristics and reducing the glazing effect by distributing contact pressure across multiple surfaces rather than a single interface.
Solution Approach 2:
A resilient member is introduced as an intermediary element between the solenoid actuation mechanism and the friction disks. This resilient member (such as a spring) mediates the force transmission, providing controlled axial loading that prevents excessive torque transmission in non-transmission mode while maintaining reliable torque transmission when activated, thereby reducing harmful glazing effects.
2Force
If the device is designed to transmit high torque, then torque transmission capability is improved, but the device size increases and cannot be compact
Solution Approach 1:
The friction disks are arranged in an interdigitated nested configuration where the first plurality of friction disks and second plurality of friction disks are stacked alternately along the axial direction. This nesting arrangement allows multiple friction interfaces to be packed into a compact axial space, enabling high torque transmission capability within a reduced device volume.
Solution Approach 2:
The torque transmission capability is enhanced by utilizing the axial dimension through multiple interdigitated friction disks rather than relying solely on radial expansion. By stacking friction disks axially in an interdigitated pattern, the device achieves high torque capacity in a compact radial footprint, effectively transitioning the scaling dimension from radial to axial.
3Adaptability or versatility
If the device allows free rotation without transmitting torque, then disconnection capability is improved, but torque transmission above threshold is not reliably prevented
Solution Approach 1:
The device utilizes parameter changes in the axial loading force applied by the resilient member to control torque transmission. By varying the axial pre-load parameter, the device can switch between different operational modes: below a first torque threshold for free rotation/disconnection, between first and second thresholds for limited torque transmission, and above the second threshold for full torque transmission. This parameter-based control enables reliable mode switching with distinct torque transmission characteristics.
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 device maintains high torque transmission capability without deterioration, ensuring efficient operation with low torque when needed and high torque when required, while minimizing glazing effects.
Implementation Method 1
The solenoid is configured to overcome the force from the first resilient member when energised
Implementation Method 2
The first resilient member is configured to provide an axial load through the first and second plurality of friction disks and roller disks
Implementation Method 3
a first axial load path through the device configured to transmit torque below a first transmittable torque threshold is provided through each of the first and second disk-to-roller interfaces
Data Source
AI summary
A device for selectively transmitting torque between an input shaft and an output shaft includes: a first plurality of friction disks configured to rotate with the input shaft; a second plurality of friction disks configured to rotate with the output shaft and interdigitated with the first plurality of friction disks; a plurality of roller disks wherein each of the plurality of roller disks includes a first disk-to-roller interface with one of the first plurality of friction disks and a second disk-to-roller interface with one of the second plurality of friction disks; a first resilient member configured to provide a force (FSPR) through the first and second plurality of friction disks and roller disks; a solenoid configured to overcome the force (FSPR) from the resilient member when energised. the device may be selectively placed in one of a first mode and a second mode depending on torque requirements.