Rotary Connector Guide Structure for Steering Shaft Eccentricity

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing rotary connector devices in vehicles face issues with smooth rotation when the rotation axis of the steering shaft and the center axis of the rotary connector device are eccentric, leading to inefficient transfer of rotational motion.

Innovation Solution

The rotary connector device incorporates a configuration with guide target portions and guide portions that allow for loose fitting, enabling movement in specific directions to absorb eccentricity, ensuring the rotation axis can align and rotate smoothly, even when eccentric, by using recessed and protruding features on the rotating and stationary components.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Adaptability or versatility

If the rotation axis of the steering shaft and the center axis of the rotary connector device are eccentric to one another, then the rotary connector device can be installed in a vehicle, but the rotating portion at a portion of the fixed body cannot rotate smoothly

Engineering Contradiction:
Improveinstallation adaptabilityVSAvoidrotation smoothness
Core Design Contradiction:
Adaptability or versatilityVSEase of operation

Solution Approach 1:

The guide target portions are designed to move dynamically in radial directions relative to the guide portions, allowing the system to adapt to eccentric conditions. The guide target portions can shift position to accommodate misalignment between the steering shaft rotation axis and the rotary connector device center axis, maintaining smooth rotation despite installation variations.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The guide portions and guide target portions act as intermediary elements between the rotating and fixed bodies. These intermediary components absorb the eccentricity through their loose fitting configuration, enabling the rotation to be transmitted smoothly even when the axes are not perfectly aligned.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Strength

If guide target portions and guide portions are tightly fitted, then structural strength is improved, but movement to absorb eccentricity is restricted

Engineering Contradiction:
Improvestructural strengthVSAvoideccentricity absorption capability
Core Design Contradiction:
StrengthVSAdaptability or versatility

Solution Approach 1:

The connection between guide portions and guide target portions is designed with local quality variation - the fitting is loose in specific radial directions to allow movement for absorbing eccentricity, while maintaining sufficient strength for structural integrity. This localized adjustment capability enables the system to balance strength and adaptability.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The fitting parameters between guide portions and guide target portions are optimized to provide a loose fit in radial directions. This parameter change allows the guide target portions to move freely in radial directions while maintaining structural strength, enabling the system to adapt to eccentric conditions without compromising overall strength.

Inventive Principle:
Principle #35Parameter changes

Data Source

PatentEP3754795B1Rotary connector device and assembled structure comprising such rotary connector device
Publication Date: 2023.11.29 FURUKAWA ELECTRIC CO LTD
  • EP3754795B1 patent drawingFigure 1
  • EP3754795B1 patent drawingFigure 2
  • EP3754795B1 patent drawingFigure 3

AI summary

Object: The present invention provides a rotary connector device in which, when a rotation axis of a steering shaft and a center axis of the rotary connector device are eccentric to one another, a rotating portion at a portion of a fixed body can rotate smoothly. Resolution Means: A rotary connector device (1) includes a moving member (40) on a stator (30) side in an insertion direction of a steering shaft (200). The moving member (40) includes a first recessed portion (42) recessed in the insertion direction and located in a first direction (X) orthogonal to a center axis (Cx) of the stator (30), and a second recessed portion (43) recessed in a direction opposite to the first recessed portion (42) and located in a second direction (Y). A rotator (10) includes a first guide portion (23) configured to loosely fit together with and guide the first recessed portion (42). A rotating portion (70) provided in the stator (30) and configured to rotate about the center axis (Cx) includes a second guide portion (74) configured to loosely fit together with and guide the second recessed portion (43). The first recessed portion (42) and the second recessed portion (43) are capable of movement in the first direction (X) and the second direction (Y).