Motor Stator With Grouped Teeth And Locking Pin

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Solution Overview

Problem

The existing methods for winding copper wire around stator teeth in motor stators are inefficient, particularly in solid lamination packs, requiring complex and expensive winding machines and resulting in suboptimal motor efficiency due to large gaps between teeth.

Innovation Solution

The stator teeth are formed in groups of three, with a central retaining tooth holding the two outer teeth, allowing for pre-winding of coils and a smaller clearance between teeth, utilizing a locking pin for secure mounting and angled surfaces for improved contact and retention.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Volume of moving object

If copper wire is wound around stems of stator teeth in a solid lamination pack, then the stator structure is compact, but the winding process becomes complex and expensive requiring sophisticated winding machines

Engineering Contradiction:
Improvestator compactnessVSAvoidwinding machine complexity
Core Design Contradiction:
Volume of moving objectVSDevice complexity

Solution Approach 1:

The stator teeth are divided into separate components: individual teeth with stems can be prepared separately from the main stator body. This segmentation allows simple winding machines to wind copper wire around individual tooth stems before assembly, eliminating the need for complex winding machines required for solid lamination packs while maintaining the compact stator structure when teeth are assembled together.

Inventive Principle:
Principle #1Segmentation

2Productivity

If gap between adjacent tooth heads is increased to facilitate machine winding, then winding speed improves, but motor efficiency decreases

Engineering Contradiction:
Improvewinding speedVSAvoidmotor efficiency
Core Design Contradiction:
ProductivityVSLoss of energy

Solution Approach 1:

The copper wire winding is performed in advance on individual tooth stems before the teeth are assembled into the final stator configuration. This preliminary action allows winding to be done on separately positioned teeth where spacing is not constrained, achieving high winding speed without requiring large gaps in the final assembled stator. The teeth are then brought together to form the compact structure with minimal gaps for optimal motor efficiency.

Inventive Principle:
Principle #10Preliminary action

3Ease of manufacture

If hand winding is used instead of machine winding, then employment costs are reduced in low-cost locations, but production speed and consistency decrease

Engineering Contradiction:
Improvelabor costVSAvoidwinding speed and consistency
Core Design Contradiction:
Ease of manufactureVSProductivity

Solution Approach 1:

By segmenting the stator into individual teeth that can be prepared separately, the invention enables the use of simple, inexpensive winding machines or even manual winding on individual tooth stems. This eliminates the need for complex automated winding machines while still allowing for reasonable production speed and consistency through standardized tooth designs and simplified winding processes on separate components.

Inventive Principle:
Principle #1Segmentation

Data Source

PatentEP2814138B1Motor stator
Publication Date: 2021.05.19 ROBERT BOSCH GMBH
  • EP2814138B1 patent drawingFigure 1~2
  • EP2814138B1 patent drawingFigure 3
  • EP2814138B1 patent drawingFigure 4A~4C

AI summary

A stator 100 for an electronically-commutated motor is disclosed. The stator comprises a stator body 110 and a plurality of stator teeth 120, 130 projecting radially inwardly from the stator body. The stator teeth are provided in groups of three, each group comprising a central retaining tooth 120 which retains the two adjacent teeth 130 either side, with a retaining means such as radially inwardly-directed projection 112 provided on the stator body in between each group of three teeth. The retaining tooth 120 is held in the mounted position by means of a locking pin 141 inserted in an axial direction, the locking pin engaging with a hook extending radially outward from the base portion of the retaining tooth 120. The present invention enables the stator coils to be wound onto each stator tooth before they are placed within the stator and also permits a smaller clearance between the head portions of adjacent teeth, which improves the motor efficiency.