Motor Device Connector Manufacturing Method for Reduced Thickness

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Solution Overview

Problem

Existing motor device manufacturing methods struggle to maintain a reduced thickness dimension while allowing the plug-in direction of an external connector to intersect the axial direction of the rotary shaft, leading to difficulties in precisely positioning sensor conductors and potential short-circuits due to complex three-dimensional bending.

Innovation Solution

A manufacturing method involving conductor molding, retention, and insert molding steps to form a connector member with precisely positioned drive and sensor conductors, where the conductors are bent and separated to ensure accurate placement and prevent short-circuits, while maintaining a reduced thickness dimension.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If the plug-in part opens in a direction intersecting the axial direction of the rotary shaft to improve assembly form and connector installation, then the adapter can be plugged in from the side direction, but the thickness dimension of the motor device in the axial direction of the output shaft increases

Engineering Contradiction:
Improveconnector installationVSAvoidthickness dimension
Core Design Contradiction:
Ease of operationVSLength of moving object

Solution Approach 1:

The patent changes the opening direction of the plug-in part from the axial direction of the output shaft to a direction intersecting the axial direction of the rotary shaft. This dimensional reorientation allows the external connector to be plugged in from the side direction, improving ease of operation and assembly form without increasing the thickness dimension in the output shaft axial direction

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Adaptability or versatility

If sensor conductors are formed by three-dimensional bending to accommodate the intersecting plug-in direction, then the connector can be installed sideways, but the sensor conductors may short-circuit due to complex bending and disordered positional relationships

Engineering Contradiction:
Improveconnector orientationVSAvoidshort-circuit prevention
Core Design Contradiction:
Adaptability or versatilityVSReliability

Solution Approach 1:

The patent performs preliminary positioning of the sensor conductors in the mold cavity before the insert molding process. The position holding member is provided in advance to maintain the correct spatial relationships of the sensor conductors, ensuring they do not short-circuit even when formed through complex three-dimensional bending to accommodate the intersecting plug-in direction

Inventive Principle:
Principle #10Preliminary action

3Length of moving object

If multiple sensor conductors are disposed closer to each other to maintain reduced thickness dimension, then the motor device remains compact, but it becomes difficult to prevent short-circuits between conductors

Engineering Contradiction:
Improvethickness dimensionVSAvoidconductor isolation
Core Design Contradiction:
Length of moving objectVSReliability

Solution Approach 1:

The patent introduces a position holding member as an intermediary element between the sensor conductors. This member is provided in the mold cavity to maintain precise spacing and positional relationships of the closely disposed sensor conductors, preventing short-circuits while allowing the conductors to be disposed closer to each other for maintaining a compact thickness dimension

Inventive Principle:
Principle #24Intermediary (Mediator)

Data Source

PatentEP3651321B1Motor device manufacturing method
Publication Date: 2023.02.01 MITSUBA CORP
  • EP3651321B1 patent drawingFigure 1
  • EP3651321B1 patent drawingFigure 2(a)~2(b)
  • EP3651321B1 patent drawingFigure 3(a)~3(b)

AI summary

In the present invention, a pair of drive conductive members 56a, 56b and four sensor conductive members 57a-57d are retained in a holder member 70. After installation in the holder member 70 and after insert molding, a first connection part JT1 and a second connection part JT2 are cut to separate the four sensor conductive members 57a-57d. Due to this configuration, the conductive members 56a, 56b, 57a-57d (six total) can be precisely disposed at the proper locations with respect to a connector member. Since the four sensor conductive members 57a-57d which are bent in a complex manner are used and can be disposed close to each other, an increase in the thickness dimension of a motor device along an opening direction of a connector connection part can be suppressed.