Rotating Device Radial Snap-Fit Cover Attachment
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Solution Overview
Problem
Conventional rotating devices, such as inner-rotor type brushless motors, face a challenge in reducing the dimension in the rotor axis direction due to the required space for fixing the cover to the substrate, which increases the overall length of the device.
Innovation Solution
The design incorporates a housing with a snap portion and a loop portion on an insulator, allowing for a snap-fit engagement between the substrate and the cover, reducing the radial dimension by arranging these features inside a recess portion, enabling a more compact structure.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of moving object
If the cover is fixed to the substrate using a conventional fixing structure, then the attachment strength is sufficient, but the dimension in the rotor axis direction increases
Solution Approach 1:
The patent transitions from axial fixing (along the rotor axis) to radial fixing (perpendicular to the rotor axis). The snap portion and loop portion are arranged in the radial direction, allowing the cover to be fixed to the substrate without increasing the axial dimension. This dimensional change resolves the contradiction by eliminating the need for axial space while maintaining attachment strength through radial engagement.
Solution Approach 2:
The snap portion is positioned inside the recess portion of the substrate, and the loop portion is arranged radially outward from the snap portion. This nested arrangement allows both fixing elements to be compactly integrated within the radial space, preventing axial dimension increase while ensuring secure attachment through the nested engagement structure.
2Length of moving object
If the snap portion and loop portion are arranged in the radial direction, then the rotor axis dimension is reduced, but the structural complexity increases
Solution Approach 1:
The snap portion and loop portion are integrated into a single engagement mechanism on the substrate, where both elements work together to fix the cover. This merging of functions into one compact radial arrangement reduces the overall structural complexity compared to having separate axial fixing mechanisms, while achieving the goal of reducing the rotor axis dimension.
3Reliability
If the cover and substrate are fixed with adequate attachment strength, then the reliability is improved, but the manufacturing cost increases
Solution Approach 1:
The snap portion and loop portion are designed to automatically engage and lock the cover to the substrate without requiring additional fasteners, adhesives, or complex assembly steps. This self-service fixing mechanism ensures reliable attachment through the elastic deformation and snap-fit engagement of the components, while keeping manufacturing costs low by eliminating the need for extra materials and assembly operations.
Data Source
AI summary
A rotating device has a housing having an opening portion opened to one side in a rotor axis direction, a rotor accommodated in the housing, a substrate coupling to the opening portion, and a cover covering a part of the substrate, and a snap portion and a loop portion are provided on an end portion, in the housing, forming the opening portion and are arranged in a radial direction. The substrate has an engaged portion engaging with the snap portion, and the cover has an engaged portion engaging with the loop portion.