Alternator Slip Ring Labyrinth Seal and Positioning

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Solution Overview

Problem

Conventional AC generator slip ring devices are prone to damage and contamination, with exposed components increasing size and assembly complexity, and suffer from positioning issues during molding and assembly.

Innovation Solution

The AC generator slip ring device incorporates a labyrinth structure formed by the partition ring and annular wall, with a flat portion on the outer circumference for conveyance positioning, preventing contamination and maintaining strength, and a compact design that reduces exposure to foreign substances.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If the ring portion made of insulation material is used as a place for grasping the slip ring device, then it provides a grasping function, but the projection portion and its vicinity are easily damaged

Engineering Contradiction:
Improvegrasping functionVSAvoiddamage resistance
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The grasping function is extracted from the ring portion and transferred to a dedicated protrusion structure. The protrusion is specifically designed as a grasping aid that does not compromise the structural integrity of the ring portion, thereby separating the grasping function from the potentially damaged areas.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The protrusion is provided locally at a specific position on the ring portion rather than modifying the entire ring structure. This localized addition provides the grasping function while minimizing impact on the overall structural strength and damage resistance of the ring portion.

Inventive Principle:
Principle #3Local quality

2Ease of operation

If the slip ring device has a configuration that excessively projects from the ring, then it provides necessary functional projections, but the device size increases and molding equipment becomes larger

Engineering Contradiction:
Improveassembly facilitationVSAvoiddevice size
Core Design Contradiction:
Ease of operationVSVolume of moving object

Solution Approach 1:

The connection elements are arranged in a compact configuration that utilizes three-dimensional space efficiently. The projections are oriented and positioned to provide necessary assembly facilitation while minimizing the overall envelope dimensions of the device, effectively using spatial arrangement to reduce volume.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

The connection elements and their projections are designed to nest within or alongside each other, maximizing space utilization. The structural components are arranged concentrically or in nested configurations that provide functional projections without increasing the external dimensions of the device.

Inventive Principle:
Principle #7Nested doll (Nesting)

3Manufacturing precision

If a circular through hole is provided for positioning the connection element during molding, then positioning is achieved, but almost half of it remains exposed to foreign substances

Engineering Contradiction:
Improvepositioning accuracyVSAvoidcontamination exposure
Core Design Contradiction:
Manufacturing precisionVSObject-affected harmful factors

Solution Approach 1:

The single large circular through hole is segmented into multiple smaller positioning features or a different positioning structure that provides the necessary positioning accuracy during molding. This segmentation allows the positioning function to be achieved while minimizing the exposed area to foreign substances.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

A protective covering or seal structure is introduced that closes or protects the positioning hole after molding, preventing exposure to foreign substances while maintaining the positioning function during the molding process. This could involve flexible seals or protective films that cover the positioning features.

Inventive Principle:
Principle #30Flexible shells and thin films

Data Source

PatentEP3151395B1Alternator slip ring device
Publication Date: 2019.09.04 MITSUBISHI ELECTRIC CORP
  • EP3151395B1 patent drawingFigure 1
  • EP3151395B1 patent drawingFigure 2
  • EP3151395B1 patent drawingFigure 3

AI summary

An AC generator slip ring device of the present invention includes: a shaft retatably supported by a front bracket and a rear bracket, and having a rotor arranged on the inner circumferential side of a stator; a sleeve fixed to an end portion on the rear bracket side of the shaft; and a conductive ring retained on the outer circumferential side of the sleeve, and connected to an excitation coil of the rotor. The AC generator slip ring device is provided with: a partition ring which is provided on the outer circumferential side of the sleeve, and in which one end portion is fixed to the rear bracket and the other end portion has a first flange that is projected in the outer diameter direction; a second flange which is provided on the side opposite to the rear bracket of the sleeve, and has an annular wall that is formed with a concave portion so that the other end portion of the partition ring is positioned, the end surface of the annular wall being opposed to the first flange of the partition ring; and a flat portion formed on an outer circumferential portion of the annular wall of the second flange as a conveyance positioning.