Single-Molded Motor Mounting Structure for Automated Assembly

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Solution Overview

Problem

Current mounting structures for low-power direct current motors with permanent magnet polar stator cores are costly and labor-intensive due to manual assembly requirements, particularly for brush holder sleeves and inductor housing seats, which are expensive and time-consuming to assemble.

Innovation Solution

A single, insulating plastic mounting element made from thermoplastic polymer reinforced with glass fibers, incorporating integral sleeves for brushes, inductor seats, circuit tracks, and soldering pads, allowing for automated soldering and reduced production costs by integrating components such as brushes, inductors, and capacitors into a single molded part.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Length of moving object

If a dish-like lid made of insulating plastic is used to mount multiple motor components, then the motor length is reduced and assembly is simplified, but the production cost increases due to manual assembly requirements

Engineering Contradiction:
Improvemotor lengthVSAvoidproduction cost
Core Design Contradiction:
Length of moving objectVSEase of manufacture

Solution Approach 1:

The patent combines multiple separate components (lid, brush holder, inductor housing, collector cover) into a single integrated plastic housing. This merging eliminates the need for manual assembly of these components while maintaining the compact motor design, thereby reducing production costs without increasing motor length.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The single plastic housing performs multiple functions simultaneously: it serves as the motor cover, brush holder, inductor housing, and collector cover. This multi-functionality reduces the number of parts and assembly steps, lowering production costs while maintaining the compact design.

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Strength

If brush holder sleeves are made by folding brass plates into tube shape, then the structural integrity is maintained, but the production cost increases significantly

Engineering Contradiction:
Improvebrush holder structural integrityVSAvoidproduction cost
Core Design Contradiction:
StrengthVSEase of manufacture

Solution Approach 1:

The patent uses a composite plastic housing that integrates the brush holder function. The plastic material provides sufficient structural integrity for the brush holder while being much cheaper to manufacture than folded brass plates, especially when produced through injection molding.

Inventive Principle:
Principle #40Composite materials

Solution Approach 2:

The plastic brush holder sleeve replaces the expensive brass construction. While plastic may be perceived as less durable, it provides adequate strength for the application at a fraction of the cost, and the integrated design eliminates the need for expensive metal forming processes.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

3Ease of operation

If multiple components are mounted separately on the lid, then the motor can be assembled manually, but the production speed decreases and labor costs increase

Engineering Contradiction:
Improveassembly easeVSAvoidproduction speed
Core Design Contradiction:
Ease of operationVSProductivity

Solution Approach 1:

By merging multiple components into a single integrated housing, the patent eliminates multiple manual assembly steps. The single-piece design can be produced through automated injection molding, dramatically increasing production speed while maintaining ease of installation in the motor.

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The housing is pre-manufactured as a complete integrated unit through injection molding, with all mounting features and structural elements formed during the molding process. This preliminary action eliminates the need for subsequent manual assembly operations, increasing productivity.

Inventive Principle:
Principle #10Preliminary action

Data Source

PatentEP2041857B1A mounting structure for electric motors
Publication Date: 2019.07.31 SPAL AUTOMOTIVE
  • EP2041857B1 patent drawingFigure 1~2
  • EP2041857B1 patent drawingFigure 3~4
  • EP2041857B1 patent drawingFigure 5~6

AI summary

A mounting structure for electric motors comprises a single element (3) for mounting a plurality of components of the motor (2), including at least the brushes (5), the inductors (6) and at least one printed circuit track (7, 8); the mounting element (3) is made as a single part by moulding a thermoplastic polymer reinforced with glass fibres, and incorporates, as an integral part of it, a plurality of sleeves (9) designed to accommodate and support the respective brushes (5), a plurality of first seats (15) designed to accommodate and support the respective inductors (6), a second seat (16, 17) for accommodating and supporting each printed circuit track (7, 8), a plurality of third seats (18) designed to accommodate respective solder points and clamping elements (19) for positioning and securing the electrical leads of the brushes (5) and/or of the inductors (6) inside the third seats (18) and in a position ready for soldering to the printed circuit track (7, 8).