Brush Holder Cover Structure for Abrasion Powder Insulation

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Solution Overview

Problem

Existing rotating electric machines face insulation property deterioration due to abrasion powder accumulation between the brush and the housing, which is not adequately addressed by prior art.

Innovation Solution

A rotating electric machine design featuring a brush holder accommodating portion with a larger distance between the brush holder's lower surface and the inner peripheral wall, creating an abrasion powder accumulation space to maintain insulation distance, and a sealed structure to contain the abrasion powder.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If windings are inserted into slot openings of a laminated core, then the rotating electric machine can be constructed, but burrs on the inner circumferential surface of the slot opening cause insertion difficulty and may damage the insulating film

Engineering Contradiction:
Improveease of winding insertionVSAvoidinsulating film integrity
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The invention extracts and removes the harmful burrs from the slot opening inner circumferential surface before winding insertion. The burr removal device specifically targets and eliminates the burrs that cause insertion difficulty and potential insulating film damage, separating the harmful element from the system.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The invention performs burr removal as a preliminary action before the winding insertion process. By removing burrs in advance using the burr removal device, the system prevents potential damage to the insulating film and facilitates smoother winding insertion, addressing the problem before it can manifest during assembly.

Inventive Principle:
Principle #10Preliminary action

2Power

If a large number of laminated sheets are stacked to increase power output, then power output increases, but misalignment of tooth roots and slot openings occurs reducing assembly precision

Engineering Contradiction:
Improvepower outputVSAvoidslot opening alignment
Core Design Contradiction:
PowerVSManufacturing precision

Solution Approach 1:

The invention segments the stacking process by introducing guide pins that divide the laminated sheets into manageable sections. The guide pins are inserted into corresponding holes in adjacent laminated sheets, creating localized alignment references that prevent cumulative misalignment across large stacks, thereby maintaining precision even as power output increases through higher sheet counts.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The guide pins act as intermediary elements between the laminated sheets during stacking. These pins physically bridge adjacent sheets and enforce proper alignment through their fixed positions, serving as mediators that transfer and maintain alignment information across the entire stack without requiring direct contact between all sheet surfaces.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Device complexity

If conventional winding insertion methods are used without burr removal, then the process is simple, but windings cannot be inserted smoothly and insulating films may be damaged

Engineering Contradiction:
Improveprocess simplicityVSAvoidwinding insertion smoothness
Core Design Contradiction:
Device complexityVSEase of operation

Solution Approach 1:

The burr removal device is designed to be integrated into the existing stacking and winding insertion system. The guide pins automatically perform burr removal during the normal stacking process without requiring separate manual intervention, allowing the system to self-service the burr removal function while maintaining overall process simplicity.

Inventive Principle:
Principle #25Self-service

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

Prevents insulation property deterioration by ensuring a sufficient space for abrasion powder accumulation, maintaining insulation distance and preventing conductivity issues.

Implementation Method 1

a pressing device which presses the laminated core in a state in which the guide pins are inserted

Methodology Applied
Scientific EffectPressing force: Mechanical Force

Implementation Method 2

a rotor; and a stator which surrounds an outer circumferential surface of the rotor and generates a magnetic field, wherein the rotor rotates about a rotation axis in accordance with an electromagnetic force generated by the magnetic field

Methodology Applied
Scientific EffectElectromagnetic force: Lorentz Force

Data Source

PatentEP4472037B1Rotating electric machine
Publication Date: 2026.04.08 NISSAN MOTOR CO LTD
  • EP4472037B1 patent drawingFigure 1
  • EP4472037B1 patent drawingFigure 2
  • EP4472037B1 patent drawingFigure 3

AI summary

This invention relates to a rotating electric machine with a brush holder that holds brushes. A first cover through which a rotor shaft passes is provided on one end side in an axial direction. A brush holder accommodating portion that accommodates the brush holder is recessed in the first cover in the axial direction from an outer side of the first cover. The brush holder is disposed in the brush holder accommodating portion such that a distance between a lower surface of the brush holder and an inner peripheral wall of the brush holder accommodating portion is larger than a distance between another portion of the brush holder and another inner peripheral wall of the brush holder accommodating portion.