Rotatable Connector Gap Design for Foreign Object Protection
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Solution Overview
Problem
Conventional rotatable connector devices suffer from foreign objects entering the accommodation space, leading to cable breakage, delamination, and operational issues due to gaps between the stator and rotator, which increases the risk of short-circuiting and unusual sounds during pivoting.
Innovation Solution
The rotatable connector device features a gap between the stator and rotator that is oriented in a direction crossing the diametric direction, with one outer circumferential edge section having a longer diameter to cover the other, and optionally includes grooves to prevent foreign objects from entering the accommodation space effectively.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a gap is provided between the stator and rotator to enable pivoting motion, then the ease of operation is improved, but foreign objects can enter the accommodation space causing cable breakage and short-circuiting
Solution Approach 1:
A retainer is introduced as an intermediary component between the stator and rotator. The retainer includes a guide ring and rollers that actively guide the flat cables during pivoting motion, preventing foreign objects from entering the accommodation space while maintaining the necessary gap for operational movement.
Solution Approach 2:
The flat cables are covered with lamination covers that protect them from foreign object damage. The retainer structure with guide ring and rollers provides a protective barrier that keeps foreign objects away from the cables while allowing the flexible cables to move during pivoting.
2Device complexity
If the gap between stator and rotator is oriented in diametric direction, then the structural simplicity is improved, but foreign objects easily enter the accommodation space
Solution Approach 1:
The retainer structure introduces asymmetry to the gap configuration. The guide ring is positioned offset from the center, and the rollers are strategically placed to create an asymmetric barrier that effectively blocks foreign object entry while maintaining the pivoting function.
Solution Approach 2:
The retainer acts as an intermediary structure that modifies the gap's functional characteristics. It creates a controlled pathway that allows necessary motion while blocking harmful foreign object entry, effectively transforming the gap from a vulnerability into a controlled interface.
3Adaptability or versatility
If flat cables are wound around the rotator and stator to enable electrical connection, then the adaptability is improved, but the cables are susceptible to rubbing and breakage
Solution Approach 1:
The retainer with guide ring and rollers serves as a mediator between the cables and the external environment. It guides the cables through a controlled path that minimizes rubbing and prevents foreign objects from causing damage, thereby protecting cable strength while maintaining electrical connection adaptability.
Solution Approach 2:
The lamination covers on the flat cables provide a protective flexible shell that prevents delamination and short-circuiting. The retainer structure further protects these covered cables by guiding them away from potential damage zones during pivoting motion.
Data Source
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AI summary
The present invention has an object of providing a rotatable connector device capable of decreasing the amount of a foreign object entering an accommodation space. An outside outer circumferential cylindrical section 15o of a stator 12 is formed to have a longer diameter than a diameter of an outer circumferential edge 13a of a rotator 13. A top end 15a of the outside outer circumferential cylindrical section 15o is extended in an upward direction so as to cover a side surface of the outer circumferential edge 13a of the rotator 13, and a gap P formed between the stator 12 and the rotator 13 is opened upward. A foreign object Z, if invading when a steering lower cover K is pivoted, bypasses the top end 15a of the outside outer circumferential cylindrical section 15o and enters the gap P, opened upward, from above. Therefore, the foreign object Z cannot easily enter an accommodation space S directly, and thus the amount of the foreign object Z entering the accommodation space S can be decreased.