Motor Coil End Isolation via Segmented Insulating Support

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Solution Overview

Problem

In vehicle motors with metallic bearing holders face challenges in isolating coil ends and preventing short circuits due to the rigidity of the material, which is exacerbated by strong vibrations.

Innovation Solution

A motor design featuring a rotor, stator, bearing, metallic bearing holder, busbar, and insulating coil support that includes through holes and insulating support portions with varying cross-sectional areas to securely pass and isolate coil ends, preventing short circuits and facilitating their positioning.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If a metallic bearing holder is used to support the bearing, then the rigidity and structural strength are improved, but the ability to provide electrical isolation between coil ends and the bearing holder deteriorates

Engineering Contradiction:

Improverigidity of bearing holderVSAvoidelectrical isolation of coil ends

Core Design Contradiction:

StrengthVSReliability

Solution Approach 1:

The bearing holder is segmented into a metallic bearing holder for structural support and a separate insulating support portion for electrical isolation. The insulating support portion includes through holes that guide coil ends while the metallic bearing holder provides bearing support, dividing the isolation function from the structural function.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The insulating support portion acts as an intermediary between the metallic bearing holder and the coil ends. It provides the necessary electrical isolation while mechanically guiding the coil ends through its through holes, mediating between the conductive bearing holder and the sensitive coil ends.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Stability of the object's composition

If a metallic bearing holder is used, then the structural stability under vibration is improved, but the ease of positioning and isolating coil ends deteriorates

Engineering Contradiction:

Improvestability under vibrationVSAvoidease of positioning coil ends

Core Design Contradiction:

Stability of the object's compositionVSEase of operation

Solution Approach 1:

The positioning function is segmented from the bearing support function. The insulating support portion with its through holes is specifically designed for guiding and positioning coil ends, while the metallic bearing holder is dedicated to bearing support, making each component specialized for its function.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The insulating support portion has local insulating properties where it contacts or guides the coil ends, while the metallic bearing holder has local structural strength where it supports the bearing. Each region of the assembly has the specific quality needed for its local function.

Inventive Principle:

Principle #3Local quality

Data Source

PatentUS10063120B2Motor and in-vehicle apparatus

Publication Date: 2018.08.28 NIDEC CORP(JP)

AI summary

A motor may include a rotor including a shaft having a central axis; a stator opposite to the rotor, and comprising coils; a bearing supporting the shaft; a metallic bearing holder covering the stator and supporting the bearing; at least one busbar on an opposite axial side of the bearing holder and including a connection terminal connected with a a coil wire extending from one of the coils; and a coil support between the stator and the bearing holder and fixed to the stator. The bearing holder may include at least one through hole. The coil support may include at least one insulating support portion comprising an opening portion. A portion of the opening portion of the insulating support portion having a smallest cross-sectional area in the opening portion lies inside of an edge of one of the through holes of the bearing holder.