Bus Bar Unit Insulating Holder Segmentation

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Solution Overview

Problem

Conventional stator designs face challenges in ensuring creepage distance and insulation performance while maintaining motor miniaturization, leading to potential damage from external forces and limitations in durability and reliability of insulating holders.

Innovation Solution

The bus bar unit incorporates a molded portion with wall portions set lower than the bus bar height, and bus bar holding grooves with different opening directions to ensure insulation and strength, allowing for improved durability and reliability while maintaining insulation performance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the height of partition wall portions is increased to ensure creepage distance and insulation performance, then insulation performance is improved, but the insulating holder becomes more susceptible to damage from external forces and durability decreases

Engineering Contradiction:
Improveinsulation performanceVSAvoiddurability of insulating holder
Core Design Contradiction:
ReliabilityVSStrength

Solution Approach 1:

The insulating holder is divided into two functional parts: partition wall portions for insulation and molded portions for mechanical support. The partition wall portions maintain the required creepage distance for insulation, while the molded portions provide structural strength to resist external forces, resolving the contradiction between insulation height and durability.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The patent merges the partition wall portions with molded portions to form an integrated insulating holder structure. The molded portions are positioned adjacent to the partition wall portions and work together to provide both insulation and mechanical strength, eliminating the need to increase partition wall height for structural support.

Inventive Principle:
Principle #5Merging (Combining)

2Strength

If the width of partition wall portions is increased to improve durability, then strength is improved, but the motor size increases and miniaturization is compromised

Engineering Contradiction:
Improvedurability of insulating holderVSAvoidmotor size
Core Design Contradiction:
StrengthVSVolume of moving object

Solution Approach 1:

The structural support function is separated from the partition wall portions and assigned to dedicated molded portions. This allows the partition wall portions to maintain minimal width for insulation while the molded portions provide the necessary structural strength, enabling motor miniaturization without compromising durability.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Instead of increasing the width (horizontal dimension) of partition wall portions to improve strength, the patent adds molded portions in the same horizontal space, utilizing vertical integration to provide structural support without increasing the overall footprint or motor size.

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

3Volume of moving object

If the height of partition wall portions is reduced to enable motor miniaturization, then motor size is reduced, but insulation performance and creepage distance are compromised

Engineering Contradiction:
Improvemotor sizeVSAvoidinsulation performance
Core Design Contradiction:
Volume of moving objectVSReliability

Solution Approach 1:

The insulating holder is segmented into partition wall portions that provide creepage distance and molded portions that provide structural support. This segmentation allows reduced partition wall height for miniaturization while maintaining adequate insulation through the molded portions positioned adjacent to the bus bars.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The molded portions act as intermediary elements between the bus bars and the partition wall portions, providing additional insulation and structural support that compensates for the reduced height of partition wall portions, enabling miniaturization without sacrificing insulation performance.

Inventive Principle:
Principle #24Intermediary (Mediator)

4Ease of manufacture

If the insulating holder structure is simplified to reduce manufacturing complexity, then ease of manufacture is improved, but insulation performance and durability cannot be simultaneously ensured

Engineering Contradiction:
Improvemanufacturing complexity of insulating holderVSAvoidinsulation performance and durability
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The partition wall portions and molded portions are merged into a single integrated insulating holder structure that can be manufactured as one piece. This merging maintains the complex functional requirements for both insulation and durability while simplifying manufacturing compared to using multiple separate components that would need to be assembled.

Inventive Principle:
Principle #5Merging (Combining)

Data Source

PatentEP3509195B1Bus bar unit
Publication Date: 2023.01.25 NISSAN MOTOR CO LTD
  • EP3509195B1 patent drawingFigure 1
  • EP3509195B1 patent drawingFigure 2
  • EP3509195B1 patent drawingFigure 3

AI summary

To provide a bus bar unit capable of improving the durability and reliability of an insulating holder while ensuring insulation performance. Drive side bus bars (43U, 43V, 43W), and an insulating holder (43H) that holds the bus bars (43U, 43V, 43W) in a parallel arrangement and that insulates between the drive side bus bars (43U, 43V, 43W) are provided. In this bus bar unit (43), the drive side insulating holder (43H) includes a molded portion (431) that is molded about an entire periphery of one of the drive side bus bar (43U) from among the drive side bus bars (43U, 43V, 43W), a wall portion (432) that is provided at a position spaced apart from a side surface (431s) of the molded portion (431) and that insulates between the drive side bus bars (43U, 43V, 43W), and a bus bar holding groove (433) that hold a remaining drive side bus bar (43V, 43W) between the molded portion (431) and the wall portions (432). The height (H1) of the wall portion (432) is set to be lower than a height (H2) defined by a width of the drive side bus bars (43U, 43V, 43W).