Motor Stator Seal Retention via Mechanical Interlock

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Solution Overview

Problem

Conventional fully-closed motors face issues with seal members being accidentally detached during assembly, and the use of adhesive agents is either ineffective or difficult to manage, especially in small motors where precise machining of tapered grooves is challenging.

Innovation Solution

A stator design featuring an annular seal member with radially extending protrusions and corresponding recessed parts in the stator parts, which securely retain the seal member without the need for adhesive agents, by forming groove parts and recessed parts that match the protrusions and seal member dimensions, ensuring firm attachment and preventing detachment.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If adhesive agent is used to secure the seal member in the annular groove, then the seal member is prevented from detaching, but the adhesive agent protrudes from the groove requiring additional wiping steps

Engineering Contradiction:

Improveseal member retentionVSAvoidmanufacturing process complexity

Core Design Contradiction:

ReliabilityVSEase of manufacture

Solution Approach 1:

The patent replaces the chemical bonding method (adhesive agent) with a mechanical retention system. The seal member is equipped with protrusions that fit into corresponding recesses formed in the stator parts, creating a mechanical interlock that secures the seal member without requiring adhesive agents or additional wiping steps.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

2Reliability

If the annular groove is made tapered to prevent seal member detachment, then the seal member is secured, but precise machining becomes extremely difficult in small motors

Engineering Contradiction:

Improveseal member retentionVSAvoidgroove machining precision

Core Design Contradiction:

ReliabilityVSManufacturing precision

Solution Approach 1:

The patent divides the retention function into multiple discrete elements: protrusions on the seal member and corresponding recesses in the stator parts. This segmentation replaces the need for a single complex tapered groove with multiple simpler rectangular or linear recesses that are much easier to machine precisely, even in small motor applications.

Inventive Principle:

Principle #1Segmentation

3Ease of manufacture

If no retention structure is provided for the seal member, then the manufacturing process is simple, but the seal member can be accidentally detached during assembly

Engineering Contradiction:

Improveassembly simplicityVSAvoidseal member retention

Core Design Contradiction:

Ease of manufactureVSReliability

Solution Approach 1:

The seal member is designed with integrated protrusions that automatically engage with the recesses in the stator parts during assembly. This self-service mechanism provides retention without requiring additional assembly steps, tools, or complex procedures, maintaining simplicity while ensuring reliable retention.

Inventive Principle:

Principle #25Self-service

Data Source

PatentUS10770946B2Stator having seal member, and motor

Publication Date: 2020.09.08 FANUC LTD

AI summary

A stator includes a first stator part, a second stator part, and an annular seal member. The annular seal member is provided with a plurality of protrusions extending radially outward. A groove part corresponding to the annular seal member, and a plurality of recessed parts, which correspond to the plurality of protrusions of the annular seal member and which are to be connected to the groove part, are formed in at least one of the first stator part and the second stator part.