Outer Rotor Motor Labyrinth Sealing Design
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Solution Overview
Problem
Existing motor designs fail to adequately improve waterproof and dustproof properties due to reduced gap widths and depths, which hinder effective prevention of moisture and dust ingress.
Innovation Solution
An outer-rotor-type motor design featuring a stator unit with a recess and a resin portion positioned radially outer than the recess, accommodating a rotor projection, forming a labyrinth structure that increases the path length for moisture and dust entry, thereby enhancing waterproof and dustproof properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If silicone rubber is used to cover the insulator in the gap, then waterproof properties are improved, but the gap width and depth are reduced, compromising sealing effectiveness
Solution Approach 1:
The invention transitions from a two-dimensional gap sealing approach to a three-dimensional labyrinthine path. The recess and projection combination creates a multi-level sealing structure that extends the sealing path in the axial direction, effectively increasing the gap dimensions while maintaining waterproof performance.
Solution Approach 2:
The sealing structure is divided into multiple segments: the recess in the stator, the projection on the rotor, and the resin portion. This segmentation creates a stepped labyrinthine structure that effectively increases the sealing path length without compromising the gap width and depth.
2Loss of substance
If the gap between insulator and bearing-supporting cylinder is reduced, then resin usage is decreased, but waterproof and dustproof properties are insufficiently improved
Solution Approach 1:
Instead of increasing resin quantity in the radial direction, the invention extends the sealing path in the axial direction through the recess and projection structure. This dimensional change allows effective sealing with reduced resin usage.
Solution Approach 2:
The projection on the rotor is nested within the recess in the stator, creating a compact labyrinthine structure. This nesting arrangement maximizes the sealing path length within a compact space, reducing the need for excessive resin material.
Data Source
AI summary
A motor includes a stator unit and a rotor rotatable relative to the stator unit. The stator unit includes a stator, a resin portion, a support portion, and an annular recess. The stator includes a stator core, an insulator, and a conducting wire wound around the stator core with the insulator interposed therebetween. The resin portion covers at least part of the stator. The support portion supports the stator. At an end portion of the stator unit on one side in an axial direction, the recess is recessed toward another side in the axial direction. The resin portion is positioned further in a radially outer direction than the recess. The rotor includes an annular projection extending toward the other side in the axial direction. At least part of the projection is accommodated in the recess.