Motor Terminal Guide Structure to Prevent Bus Bar Short Circuits

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

Conventional motors are prone to short circuits due to contact between the bus bar terminal and the connection terminal with the bracket.

Innovation Solution

The motor design includes a bus bar assembly with a bus bar terminal and a circuit terminal that are electrically connected and housed within a terminal guide portion, which prevents contact with the bracket and thus avoids short circuits.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the bus bar terminal and connection terminal are exposed in the welding work hole, then electrical connection is achieved, but short circuit risk increases due to contact with the bracket

Engineering Contradiction:

Improveelectrical connection reliabilityVSAvoidshort circuit risk

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent introduces a terminal guide portion as an intermediary component that guides and positions the bus bar terminal and connection terminal during assembly. This mediator ensures proper alignment and electrical connection while preventing direct contact with the bracket, thus resolving the contradiction between achieving reliable electrical connection and preventing short circuits

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent extracts the terminal guidance and positioning function from the bracket structure itself and creates a separate, dedicated terminal guide portion. This extracted component specifically handles the electrical terminals, isolating them from the bracket to prevent short circuits while maintaining proper electrical connection

Inventive Principle:

Principle #2Taking out (Extraction)

2Ease of manufacture

If the terminal through hole is open and accessible, then assembly is simplified, but insulation between terminals and bracket cannot be ensured

Engineering Contradiction:

Improveassembly easeVSAvoidelectrical insulation reliability

Core Design Contradiction:

Ease of manufactureVSReliability

Solution Approach 1:

The patent segments the terminal through hole into two functional zones: an upper open portion for easy assembly and insertion of terminals, and a lower enclosed portion within the terminal guide that provides insulation and prevents contact with the bracket. This segmentation maintains manufacturing ease while ensuring electrical insulation reliability

Inventive Principle:

Principle #1Segmentation

Data Source

PatentUS12323035B2Motor

Publication Date: 2025.06.03 NIDEC CORP(JP)

AI summary

A motor includes a rotor, a stator, a bearing, a motor housing, a bearing holder, a bus bar assembly, and a circuit board. The bearing holder holds the bearing to cover the opening of the motor housing, and includes a holder protrusion. The holder protrusion is located radially outside the motor housing and includes an axially penetrating terminal through hole. The bus bar assembly includes a bus bar terminal and a bus bar holder. The bus bar terminal is connected to the bus bar, extends axially downward, passes through the terminal through hole, and protrudes axially downward from the lower surface of the holder protrusion. The circuit board includes a circuit terminal extending axially downward, passing through the terminal through hole, protruding axially downward from the lower surface of the holder protrusion, and connected to the bus bar terminal.