Grounding Body Layout for Unit Downsizing

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Solution Overview

Problem

Existing units cannot be sufficiently downsized by providing a grounding brush on the shaft due to layout constraints.

Innovation Solution

A layout structure is introduced where the grounding body is located at the inner side of the peripheral wall surrounding the inverter, allowing the grounding brush to be positioned within the inverter accommodating chamber, and the inverter is placed above the rotating electrical machine, reducing the overall unit size.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a grounding brush is provided on the shaft to achieve grounding function, then grounding reliability is improved, but the unit size cannot be sufficiently reduced due to layout constraints

Engineering Contradiction:
Improvegrounding reliabilityVSAvoidunit size
Core Design Contradiction:
ReliabilityVSVolume of moving object

Solution Approach 1:

The grounding brush is nested within the inverter housing cavity, specifically positioned at the inner side of the peripheral wall. This nesting arrangement allows the grounding body to utilize the existing housing space without requiring additional external space, thereby achieving grounding functionality while preventing unit size increase

Inventive Principle:
Principle #7Nested doll (Nesting)

Solution Approach 2:

The grounding brush is positioned in the radial direction (inner side of peripheral wall) rather than extending axially outward. This dimensional repositioning allows the grounding function to be achieved within the existing housing envelope, converting a potential axial space requirement into a radial space utilization that fits within the housing cavity

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

2Reliability

If the grounding body is positioned outside the inverter housing, then grounding function is achieved, but the overall unit dimensions increase

Engineering Contradiction:
Improvegrounding functionVSAvoidunit dimensions
Core Design Contradiction:
ReliabilityVSLength of stationary object

Solution Approach 1:

The grounding body positioning is merged with the inverter housing structure by placing it at the inner side of the peripheral wall. This merging eliminates the need for separate grounding components extending outside the housing, as the housing itself becomes part of the grounding path, thereby achieving grounding function without increasing unit dimensions

Inventive Principle:
Principle #5Merging (Combining)

Data Source

PatentEP4661259A1unit
Publication Date: 2025.12.10 JATCO LTD
  • EP4661259A1 patent drawingFigure 1
  • EP4661259A1 patent drawingFigure 2~3
  • EP4661259A1 patent drawingFigure 4

AI summary

[PROBLEMS] To provide a layout structure of a grounding body that contributes to downsizing of a unit. [SOLUTIONS] A unit includes a housing configured to accommodate an inverter, a rotating electrical machine, a shaft connected downstream of the rotating electrical machine, and a grounding body in contact with the shaft. The housing has a peripheral wall surrounding the inverter, and the grounding body is located at an inner side of the peripheral wall.