Direct drive rotor with metal coupler

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Solution Overview

Problem

Direct drive clothes washing machine motors require a rotor that balances low cost, short axial length, and strong/durable coupling with the drive shaft, as existing steel rotors are heavy and costly, while plastic rotors are less durable and require longer axial lengths.

Innovation Solution

A rotor design featuring a metallic coupler with a polymeric frame, where the coupler has an inner axial surface for interfacing with a shaft and an outer axial surface with multiple outer teeth, engaging a hub to transmit torque, with specific dimensions optimizing strength and durability.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If steel rotors are used, then strength and durability are improved, but weight and cost increase

Engineering Contradiction:

Improvecoupling strengthVSAvoidrotor weight

Core Design Contradiction:

StrengthVSWeight of moving object

Solution Approach 1:

The rotor uses a composite structure combining a metallic coupler (steel) for strength and durability with a polymeric frame (plastic) for lightweight construction. The metallic coupler is integrally formed with the polymeric frame, creating a hybrid rotor that achieves the strength of steel with reduced weight and cost compared to full steel rotors.

Inventive Principle:

Principle #40Composite materials

2Weight of moving object

If plastic rotors are used, then weight and cost are reduced, but strength and durability deteriorate

Engineering Contradiction:

Improverotor weightVSAvoidcoupling strength

Core Design Contradiction:

Weight of moving objectVSStrength

Solution Approach 1:

Inventive Principle:

Principle #40Composite materials

3Weight of moving object

If plastic rotors are used, then weight and cost are reduced, but axial length increases

Engineering Contradiction:

Improverotor weightVSAvoidaxial length

Core Design Contradiction:

Weight of moving objectVSLength of moving object

Solution Approach 1:

Inventive Principle:

Principle #40Composite materials

4Strength

If steel rotors are used, then strength is improved, but axial length increases

Engineering Contradiction:

Improvecoupling strengthVSAvoidaxial length

Core Design Contradiction:

StrengthVSLength of moving object

Solution Approach 1:

Inventive Principle:

Principle #40Composite materials

Data Source

PatentUS9806584B2Direct drive rotor with metal coupler

Publication Date: 2017.10.31 NIDEC MOTOR CORP

AI summary

A rotor for an outer rotor-type motor is provided. The rotor includes a metallic coupler and a polymeric frame molded over at least part of the metallic coupler.