Motor Bus Bar Segmentation for Corrosion Resistance

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

The reliability of electrical connections in motors with bus bars is compromised due to corrosion, and the large, heavy resin-insert molded terminal plates in brushless motors hinder assembly workability.

Innovation Solution

A motor design featuring a bus bar unit with multiple bus bars connected to coils, a holder, and a cover to prevent corrosion, improving handling and reliability, and a bracket system with resin components for structural support and assembly efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of manufacture

If bus bars are used to connect external power supply to coils, then electrical connection is facilitated, but reliability deteriorates due to corrosion of the bus bar

Engineering Contradiction:

Improveelectrical connection facilitationVSAvoidelectrical connection reliability

Core Design Contradiction:

Ease of manufactureVSReliability

Solution Approach 1:

The terminal plate is divided into multiple individual terminal plates (first terminal plate, second terminal plate, third terminal plate, fourth terminal plate) corresponding to each coil, rather than using a single integrated terminal plate. This segmentation allows each terminal plate to be independently handled and connected to its corresponding coil, improving assembly workability while maintaining electrical connection reliability through individual corrosion-resistant terminal plates

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Resin is used as an intermediary material to bond the terminal plates to the bracket and to provide corrosion protection. The resin-insert molding process creates a protective encapsulation around the terminal plates, preventing direct exposure to corrosive environments while maintaining electrical connectivity through the terminal plates

Inventive Principle:

Principle #24Intermediary (Mediator)

2Reliability

If terminal plates are formed by resin-insert molding as a single member, then corrosion resistance is improved, but assembly workability deteriorates due to large size and heavy weight

Engineering Contradiction:

Improvecorrosion resistanceVSAvoidassembly workability

Core Design Contradiction:

ReliabilityVSEase of operation

Solution Approach 1:

The terminal plate assembly is segmented into multiple individual terminal plates (first terminal plate for first coil, second terminal plate for second coil, third terminal plate for third coil, fourth terminal plate for fourth coil) that can be independently handled during assembly, significantly improving workability compared to a single large integrated terminal plate while each individual plate remains corrosion-resistant

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

Multiple terminal plates are combined with the bracket through resin-insert molding to create a unified corrosion-resistant structure, while maintaining the independence of each terminal plate for assembly purposes. The resin bonding merges the terminal plates and bracket into a single corrosion-resistant assembly

Inventive Principle:

Principle #5Merging (Combining)

Data Source

PatentUS11277051B2Motor with bus bars located between inlet of bracket and stator

Publication Date: 2022.03.15 NIDEC CORP(JP)

AI summary

A motor includes a shaft, a bearing supporting the shaft, an armature disposed radially outward of the bearing, a bracket to which the bearing and the armature are fixed, a covered cylindrical rotor connected to the shaft, and a bus bar unit. The armature includes a core back, teeth extending radially outward from the core back, an insulator covering surfaces of the, and a defined by a wire wound from above the insulator around the teeth. The bus bar unit includes bus bars to which the coils are connected, a bus bar holder holding the bus bars, and a bus bar cover covering portion of the bus bars.