Stator Slot Wedge Structure for Abrasion-Free Coil Securing

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

The insertion of wedges into the slots of a stator from the axial direction causes abrasion of components due to narrow spaces, leading to concerns about component wear.

Innovation Solution

A stator design with a plate-shaped wedge that can bend to reduce width, engagement portions on the teeth to restrict movement, and a seal member and reinforcement portion to facilitate installation and prevent radial movement, along with a method for assembling the rotary electric machine.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If wedges are inserted into slots from the axial direction, then the slots can be filled and coils can be secured, but the narrow space causes abrasion of components

Engineering Contradiction:

Improvecoil securingVSAvoidcomponent abrasion

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The patent inverts the conventional insertion direction of the wedge. Instead of inserting the wedge from the axial direction (where coils are already present), the wedge is inserted from the radial direction through opening portions of the slots. This reversal allows the wedge to be installed in a wider space without contacting and abrading the coils, while still achieving the function of securing the coils in the slots.

Inventive Principle:

Principle #13The other way round (Inversion)

2Ease of operation

If wedges are inserted from the axial direction, then installation is straightforward, but the remaining space in slots is narrow causing rubbing

Engineering Contradiction:

Improvewedge installationVSAvoidrubbing against components

Core Design Contradiction:

Ease of operationVSObject-affected harmful factors

Solution Approach 1:

The patent changes the insertion direction from axial to radial. The wedge is inserted through opening portions of the slots from the radial direction, utilizing the wider space available in the radial direction rather than the narrow axial space. This eliminates rubbing against components while maintaining ease of installation through the opening portions.

Inventive Principle:

Principle #13The other way round (Inversion)

Solution Approach 2:

The patent transitions the wedge insertion from one dimension (axial direction) to another dimension (radial direction). By utilizing the radial opening portions of the slots, the installation process accesses a different spatial dimension where there is sufficient clearance, avoiding contact with coils and other components that occupy the axial space.

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

3Ease of operation

If a plate-shaped wedge is used that can bend, then installation from radial direction is enabled, but the wedge structure becomes more complex

Engineering Contradiction:

Improveradial insertionVSAvoidwedge structure

Core Design Contradiction:

Ease of operationVSDevice complexity

Solution Approach 1:

The patent applies dynamics by making the wedge flexible rather than rigid. The plate-shaped wedge can bend elastically during radial insertion to navigate the slot opening portions, then maintains its shape to provide securing force. This dynamic flexibility enables radial insertion without requiring complex mechanical structures, achieving simplicity through material property utilization.

Inventive Principle:

Principle #15Dynamics

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

Facilitates easy installation of wedges while preventing component abrasion and ensuring secure positioning, enhancing mechanical strength and reducing eddy current loss.

Implementation Method 1

the wedge is formed in a plate shape capable of bending to reduce a width of the wedge in the circumferential direction

Methodology Applied

Scientific EffectElastic deformation: Elasticity

Implementation Method 2

the side surfaces have engagement portions that engage with both end portions of the wedge in the circumferential direction and restrict radially inward movement of the wedge

Methodology Applied

Scientific EffectMechanical engagement: Mechanical Fastener

Data Source

PatentUS20260031673A1Stator and rotary electric machine

Publication Date: 2026.01.29 IHI CORP

AI summary

A stator provided on the outer periphery of a rotor includes: teeth arranged in a circumferential direction around an axis; slots formed between each pair of adjacent teeth and having accommodation spaces for coils wound around each tooth; and a wedge inserted into each of opening portions of the slots that open radially inward. The wedge is formed in a plate shape capable of bending to reduce the width of the wedges in the circumferential direction. The pairs of teeth include side surfaces facing each other. The side surfaces have engagement portions that engage with both end portions of the wedge in the circumferential direction and restrict radially inward movement of the wedge.