Two-part coil insulator with heat-conducting insert

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Solution Overview

Problem

The existing coil insulation methods for electric machines, particularly in alternators used in range-extender systems for electric vehicles, face challenges in facilitating manufacturing and assembly while effectively transferring heat between the coil and the tooth, leading to inefficiencies in thermal management and potential performance limitations.

Innovation Solution

A two-part coil insulator design featuring a frame with side and end walls, incorporating a flexible heat-conducting material and a snap-fastening system, which allows for improved heat transfer and assembly efficiency by positioning a heat-conducting element between the coil and the tooth, and includes a foldable fin for electrical insulation and a heel to isolate coils from the yoke, enhancing thermal management and assembly ease.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If a single-piece coil insulator is used, then the insulation structure is simple, but the heat transfer between the coil and the tooth is insufficient

Engineering Contradiction:
Improveinsulator structureVSAvoidheat transfer efficiency
Core Design Contradiction:
Device complexityVSTemperature

Solution Approach 1:

The coil insulator is divided into two separate parts: an insulating body made of electrically insulating material and a heat-conducting element made of thermally conductive material. This segmentation allows each component to perform its specialized function - the insulating body provides electrical isolation while the heat-conducting element establishes thermal contact between the coil and the tooth, thereby resolving the contradiction between structural simplicity and heat transfer efficiency.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The invention combines two different materials with complementary properties - an electrically insulating material for the insulator body and a thermally conductive material for the heat-conducting element. This composite approach allows the system to simultaneously achieve both electrical insulation and effective heat transfer, resolving the contradiction between insulation requirements and thermal management needs.

Inventive Principle:
Principle #40Composite materials

2Temperature

If complex insulation methods are used to improve heat transfer, then thermal management improves, but manufacturing and assembly become more difficult

Engineering Contradiction:
Improvethermal managementVSAvoidassembly process
Core Design Contradiction:
TemperatureVSEase of manufacture

Solution Approach 1:

By separating the insulator into two distinct components with clear functional differentiation, the invention simplifies the manufacturing process for each part while enabling effective heat transfer. The insulating body and heat-conducting element can be manufactured independently using appropriate processes for each material type, then assembled together, avoiding the complexity of manufacturing a single integrated component with conflicting material requirements.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The heat-conducting element acts as an intermediary component between the coil and the tooth, facilitating thermal transfer without requiring complex direct contact arrangements. This mediator element simplifies the assembly process by providing a ready-made thermal pathway that can be easily positioned and secured within the insulator structure.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Productivity

If a two-part insulator design is used, then heat transfer and assembly efficiency improve, but the device complexity increases

Engineering Contradiction:
Improveassembly efficiencyVSAvoidinsulator structure
Core Design Contradiction:
ProductivityVSDevice complexity

Solution Approach 1:

The two-part design segments the insulator into functionally distinct components that can be manufactured and prepared separately, then quickly assembled. This segmentation improves assembly efficiency by allowing pre-manufacturing of standardized components that fit together, reducing on-site assembly complexity despite the increased number of parts.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The insulating body and heat-conducting element are merged into a single functional assembly that provides both electrical insulation and thermal conduction. This combining of functions into a integrated two-part system achieves better heat transfer and assembly efficiency compared to single-piece designs, while the modular nature keeps the overall complexity manageable.

Inventive Principle:
Principle #5Merging (Combining)

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

The two-part coil insulator design enhances heat transfer between the coil and the tooth, improves assembly efficiency, and increases the reliability and power density of electric machines by facilitating better thermal management and insulation, thus addressing the limitations of existing insulation methods.

Implementation Method 1

each comprising a window facing which is intended to be positioned an added element made of a flexible material that is a good heat conductor

Methodology Applied
Scientific EffectThermal conduction: Conduction (thermal)

Data Source

PatentEP2896117B1Mixed coil insulator made from two parts and corresponding element of an electrical machine
Publication Date: 2016.08.31 VALEO EQUIP ELECTRIC MOTEUR
  • EP2896117B1 patent drawingFigure 1~2b
  • EP2896117B1 patent drawingFigure 3~4
  • EP2896117B1 patent drawingFigure 5~6a

AI summary

The invention mainly concerns a coil insulator (20) intended to be positioned around a tooth (14) of a stator or of a rotor of an electrical machine. This coil insulator (20) comprises a body (23) having side walls (243, 244) and end walls (241, 242) forming a frame (24), the side walls (243, 244) each comprising a window (701, 702) opposite which an insert element (711, 712) made from a flexible material having good heat conducting properties is intended to be positioned. This coil insulator (20) comprises a front edge (261) and a rear edge (262) each formed by longitudinal edges (281, 282) linked together by transverse rims (291, 292). The body (23) is made from two parts (401, 402) separated vertically along a plane (Pm) substantially parallel to the side walls (243, 244) and passing through the end walls (241, 242) of the frame (24). The invention also concerns the corresponding element of an electrical machine that can consist of a stator or a rotor provided with teeth carrying the coil insulator made from two parts according to the invention.