Rotary Electric Machine Stator Winding Axial Length Reduction

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Solution Overview

Problem

Rotary electric machines used in vehicles face challenges in reducing their axial size while maintaining or increasing power, particularly when installed with dual mass flywheels, engines, and gears, where strict size reduction is necessary.

Innovation Solution

A rotary electric machine design featuring a stator winding with conductors that have their axial end portions tilted using a wedge inserted between the conductors and the stator core slots, reducing the axial height of the coil end portions and thus the overall stator length.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Length of moving object

If the axial length of the stator is reduced to meet space constraints in vehicle applications, then the size of the rotary electric machine is reduced, but the power output may be compromised

Engineering Contradiction:

Improveaxial length of statorVSAvoidpower output

Core Design Contradiction:

Length of moving objectVSPower

Solution Approach 1:

The patent tilts the conductors in the radial direction by inserting a wedge, transforming the conventional axial arrangement into a three-dimensional configuration. This dimensional change allows the coil end portions to be compacted axially while maintaining the necessary conductor length for power generation, thus reducing axial length without compromising power output

Inventive Principle:

Principle #17Another dimension (Dimensionality change)

Solution Approach 2:

The patent changes the geometric parameters of the conductor arrangement by tilting them at a specific angle using a wedge. This parameter change optimizes the space utilization within the stator, allowing for reduced axial length while maintaining the electrical characteristics necessary for power output

Inventive Principle:

Principle #35Parameter changes

2Length of moving object

If the coil end portions are made compact to reduce axial length, then the size is reduced, but the manufacturing complexity increases

Engineering Contradiction:

Improveaxial height of coil end portionsVSAvoidease of winding conductors

Core Design Contradiction:

Length of moving objectVSEase of manufacture

Solution Approach 1:

The patent inserts the wedge into the slots before winding the conductors, preparing the space in advance. This preliminary action guides the conductors into the tilted position during the winding process, making the manufacturing process more manageable despite the complex three-dimensional arrangement

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The wedge acts as an intermediary element that facilitates the tilted arrangement of conductors. By introducing this intermediate component, the patent enables the compact coil end configuration while providing a structured method for conductor placement, thereby managing manufacturing complexity

Inventive Principle:

Principle #24Intermediary (Mediator)

Data Source

PatentUS9337693B2Rotary electric machine with segment type of stator winding

Publication Date: 2016.05.10 DENSO CORP

AI summary

In a rotary electric machine provided with a rotor and a stator, a wedge is inserted between in-slot portions stacked in each of slots of the stator and a wall of each of the slots. The wedge has two edges and a length ranging from one of the edges to the other. The length of the wedge is smaller than an axial length of the stator core. The wall is located oppositely to an opening of each slot. By inserting the wedge, both end portions of the conductors are tilted so as to be oriented oppositely to the rotor in the radial direction. The tilted end portions starts from each of the two edges of the wedge in the axial direction.