Continuous-Rotation Stepper Relay for Vibration-Tolerant Switching
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Solution Overview
Problem
Stepper relays used in harsh environments, such as helicopter rotor-blade de-icing systems, face reliability issues due to heavy vibrations, which can disrupt the sequential operation of heating elements.
Innovation Solution
A multi-pole continuous-rotation stepper relay system with a rotatable disk, indexing members, ratcheting assembly, and control system that secures and releases the disk in a stepwise fashion to maintain alignment with switches, ensuring reliable operation despite vibrations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If a conventional stepper relay is used in harsh environments, then the system can operate in demanding conditions, but heavy vibrations disrupt the sequential operation of heating elements
Solution Approach 1:
The relay is divided into multiple independent poles, each with its own set of switches and cam actuation mechanism. This segmentation allows each pole to operate independently, so vibrations affecting one pole do not disrupt the entire system's sequential operation.
Solution Approach 2:
The relay employs a dynamic cam mechanism that rotates to sequentially actuate switches in a predetermined sequence. The cam's continuous rotation with controlled dwell positions provides inherent vibration tolerance while maintaining reliable sequential operation across multiple poles.
2Reliability
If the rotatable disk is secured at each step, then the alignment with switches is maintained, but the mechanism becomes more complex
Solution Approach 1:
A cam mechanism serves as an intermediary between the rotatable disk and the switches. The cam translates rotational motion into controlled linear actuation, providing reliable switch alignment through its geometric design rather than complex securing mechanisms.
Solution Approach 2:
The cam mechanism inherently maintains alignment through its own geometric constraints and rotational symmetry. Each cam lobe is designed to automatically align with the corresponding switch at the correct rotational position, eliminating the need for external securing devices.
Data Source
AI summary
Apparatus and associated methods relate to sequentially opening and/or closing a plurality of switches. A rotational securing assembly sequentially secures and releases a plurality of indexing members evenly distributed along a circular path centered on an axis of rotation of the rotatable disk, thereby sequentially securing and releasing the rotatable disk to and from a sequence of rotational positions. A ratcheting assembly sequentially engages a plurality of advancing members of the rotatable disk, thereby sequentially rotating the rotatable disk to a next one of the sequence of rotatable positions. A cam coupled to the rotatable disk sequentially either opens or closes a plurality of switches attached to an annular frame and distributed along a second circular path centered on the axis of rotation. Operations of the rotational securing assembly are coordinated with those of the ratcheting assembly so as to advance rotation of the rotatable disk in a stepwise fashion.