Spiral Stator Coil Layout for Motor Cooling and Space Factor

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

The efficiency of motors is hindered by excessive heat generation due to reduced space factors in stator coils, which limits cooling effectiveness and increases mechanical losses, as the smaller space for refrigerant flow paths results in inadequate heat dissipation.

Innovation Solution

A spiral stator coil configuration with annular bodies having a quadrangular cross-sectional conductor and insulating coating, featuring recessed portions that increase heat dissipation areas and circulation passages for air, refrigerant, or oil, enhancing cooling efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If the space factor of the stator coil is improved by reducing dead space in the slot, then the current loss is reduced, but the refrigerant flow path is narrowed and cooling effectiveness deteriorates

Engineering Contradiction:
Improvecurrent lossVSAvoidcooling effectiveness
Core Design Contradiction:
Loss of energyVSTemperature

Solution Approach 1:

The stator coil is segmented into multiple coils arranged in parallel within the slot, creating multiple separate refrigerant flow paths. This segmentation allows the coil to maintain high space factor while preserving adequate flow paths for refrigerant circulation, thereby resolving the contradiction between reducing current loss and maintaining cooling effectiveness

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The invention transitions from a single large coil to multiple smaller coils arranged in parallel, effectively adding a dimensional aspect to the coil configuration. This multi-coil arrangement creates three-dimensional flow paths that accommodate refrigerant circulation while maximizing the conductor fill factor in the slot

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

2Productivity

If the dead space in the slot is reduced to improve space factor, then the conductor utilization is improved, but the refrigerant flow rate is reduced

Engineering Contradiction:
Improvespace factorVSAvoidrefrigerant flow rate
Core Design Contradiction:
ProductivityVSQuantity of substance

Solution Approach 1:

The stator coil is divided into multiple parallel coils, each creating its own refrigerant flow path. This segmentation maintains high space factor by reducing dead space while ensuring adequate refrigerant flow rate through multiple parallel channels, preventing flow restriction

Inventive Principle:
Principle #1Segmentation

3Productivity

If the thickness of the insulating coating is kept constant while reducing conductor diameter, then the space factor improves, but the ratio of insulating coating area increases

Engineering Contradiction:
Improvespace factorVSAvoidinsulating coating area ratio
Core Design Contradiction:
ProductivityVSLoss of energy

Solution Approach 1:

The invention changes the parameter of conductor geometry from circular to rectangular cross-section. This parameter change allows for more efficient space utilization in the slot while maintaining appropriate insulating coating thickness, improving space factor without excessively increasing the insulating coating area ratio

Inventive Principle:
Principle #35Parameter changes

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 configuration significantly improves cooling efficiency by increasing heat dissipation areas and circulation passages, leading to a highly efficient motor operation with reduced mechanical losses and improved thermal management.

Implementation Method 1

it is known to circulate a refrigerant inside the motor to inhibit a temperature rise

Methodology Applied
Scientific EffectConvection: Convection

Implementation Method 2

Heat is one of factors that lower the efficiency of the motor, and it is known to circulate a refrigerant inside the motor to inhibit a temperature rise

Methodology Applied
Scientific EffectThermal conduction: Conduction (thermal)

Data Source

PatentEP3826146B1motor
Publication Date: 2024.07.10 PANASONIC INTELLECTUAL PROPERTY MANAGEMENT CO LTD
  • EP3826146B1 patent drawingFigure 1A
  • EP3826146B1 patent drawingFigure 1B
  • EP3826146B1 patent drawingFigure 1C

AI summary

In a motor including a stator core including a mode of a laminated body where a plurality of stator core sheets is laminated, a stator including a stator coil that uses, as a part of a magnetic core, a tooth included in the stator core, and a rotor rotatably supported via a tip of the tooth of the stator core and a void, the stator coil has a mode of constituting a spiral coil including annular bodies having a predetermined number of turns.