Annular Stopper Radial Gap Design for Stator Resin Integrity

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Solution Overview

Problem

In electric machines, the resin used to fill gaps in stator windings often breaks and forms crumbs due to uneven gap sizes between the stopper and stator end disc, leading to uncontrolled distribution and potential malfunction.

Innovation Solution

An annular stopper design with a radial gap of constant thickness between the stopper and stator end disc, filled with the same resin as the stator windings, ensures complete resin curing without breaking, preventing resin crumbs from entering the machine.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the gap between stopper and stator end disc is large, then complete resin draining is achieved, but the cured resin breaks and forms crumbs

Engineering Contradiction:
Improveresin integrityVSAvoidresin residue
Core Design Contradiction:
ReliabilityVSLoss of substance

Solution Approach 1:

The patent changes the geometric parameters of the stopper by providing annular grooves at different radial positions, creating multiple smaller gaps instead of one large gap. This parameter modification allows the resin to be retained in controlled small volumes that cure without breaking, while still achieving sufficient draining to prevent harmful resin accumulation.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The stopper is segmented into multiple annular regions with grooves at different radial positions, dividing the single large gap into multiple smaller gaps. This segmentation prevents the formation of large resin clusters that would break during curing, while the combined effect of multiple gaps still achieves adequate resin drainage.

Inventive Principle:
Principle #1Segmentation

2Ease of manufacture

If the stopper is non-annular with local stoppers, then manufacturing is simpler, but the gap thickness is uneven causing resin breaking

Engineering Contradiction:
Improvestopper manufacturingVSAvoidgap thickness uniformity
Core Design Contradiction:
Ease of manufactureVSManufacturing precision

Solution Approach 1:

The stopper incorporates annular grooves at specific radial positions to create localized gaps of controlled thickness. This local quality modification allows the stopper to maintain a simple annular overall shape for easy manufacturing, while introducing localized features that ensure uniform gap thickness in critical areas to prevent resin breaking.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The invention transitions from a simple planar stopper design to a three-dimensional annular structure with grooves at varying radial positions. This dimensional enhancement allows precise control of gap thickness through radial positioning of grooves, achieving manufacturing precision without complicating the basic annular form that remains easy to manufacture.

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

3Strength

If resin is completely drained, then mechanical stability is improved, but resin crumbs are formed and distributed uncontrolled

Engineering Contradiction:
Improvestator winding stabilityVSAvoidresin crumbs
Core Design Contradiction:
StrengthVSObject-generated harmful factors

Solution Approach 1:

The annular grooves in the stopper beforehand cushion the resin by providing controlled retention zones. These grooves ensure that small amounts of resin are held in controlled environments where they can cure without breaking, preventing the formation of harmful crumbs while still achieving sufficient drainage for mechanical stability.

Inventive Principle:
Principle #11Beforehand cushioning (Prior cushioning)

Solution Approach 2:

The annular grooves act as intermediary structures between the large gap (which needs draining) and the stator windings (which need protection). These grooves mediate the resin drainage process by providing intermediate retention zones that control the curing process and prevent harmful crumb formation while maintaining mechanical stability.

Inventive Principle:
Principle #24Intermediary (Mediator)

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This solution prevents resin crumbs from entering the electric machine, ensuring proper function by maintaining a consistent gap size and ensuring complete resin curing, thus avoiding mechanical instability and malfunction.

Implementation Method 1

flooding the interior of the arrangement with a resin, draining the resin, wherein a radial gap between the stopper, which has an annular shape, and the stator end disc remains filled with the resin and curing the resin

Methodology Applied
Scientific EffectCuring: Photopolymerisation

Data Source

PatentEP3972098B1Arrangement for an electric machine with improved resin filling for stator windings
Publication Date: 2023.07.26 VALEO EAUTOMOTIVE GERMANY GMBH
  • EP3972098B1 patent drawingFigure 1~2
  • EP3972098B1 patent drawingFigure 3~4
  • EP3972098B1 patent drawingFigure 5~6

AI summary

An arrangement for an electric machine (1) is disclosed, which comprises a housing (12) with a stopper (13) and a stator (4) arranged in the housing (12). The stator (4) comprises a stator lamination stack (6), stator windings (7) and a stator end disc (8a, 8b) arranged on the axial end of the stator lamination stack (6). In the mounted position, the stator lamination stack (6) on the axial end, on which the stator end disc (8a, 8b) is arranged, is in body contact with the stopper (13) of the housing (12). In detail, the stopper (13) has an annular shape thereby providing a radial gap (b) between the stopper (13) and the stator end disc (8a, 8b). Moreover, the invention relates to a method for manufacturing such an arrangement, an electric machine (1) having such an arrangement and a vehicle (16) having such an electric machine (1).