Inflatable Bag Insulation for Electric Machine Retaining Rings

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Solution Overview

Problem

The existing methods for applying insulation to retaining rings for high power electric machines are complex and costly, requiring expensive tools like expansible steel cones or cylinders to achieve sufficient pressure for bonding, which complicates maintenance and replacement processes.

Innovation Solution

A method involving an inflatable bag made of chloroprene tissue with multiple glued layers is used to apply pressure to the insulation inside the retaining ring, utilizing a compressor to inflate the bag and exert pressure up to nine bars, facilitating a durable bond between the insulation and the retaining ring housing.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If expensive tools like expansible steel cones or cylinders are used to apply pressure to the insulation, then sufficient bond between the retaining ring and insulation is achieved, but the device complexity and cost increase

Engineering Contradiction:
Improvebond strengthVSAvoidtool complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The patent uses a pneumatic bag (inflatable element) to apply pressure to the insulation layers inside the retaining ring. By inflating the bag with compressed air, uniform radial pressure is exerted on the insulation, ensuring sufficient bonding between the insulation and the retaining ring without requiring complex mechanical pressing tools like expansible steel cones or cylinders.

Inventive Principle:
Principle #29Pneumatics and hydraulics

Solution Approach 2:

The patent employs a flexible inflatable bag made of elastomeric material that can conform to the internal geometry of the retaining ring. This flexible membrane distributes pressure uniformly across the insulation surface while remaining simple in structure, replacing the need for rigid and complex mechanical pressing devices.

Inventive Principle:
Principle #30Flexible shells and thin films

2Reliability

If expensive tools like expansible steel cones or cylinders are used to apply pressure to the insulation, then sufficient bond between the retaining ring and insulation is achieved, but the cost increases

Engineering Contradiction:
Improvebond strengthVSAvoidmanufacturing cost
Core Design Contradiction:
ReliabilityVSEase of manufacture

Solution Approach 1:

The patent uses a pneumatic bag (inflatable element) to apply pressure to the insulation layers inside the retaining ring. By inflating the bag with compressed air, uniform radial pressure is exerted on the insulation, ensuring sufficient bonding between the insulation and the retaining ring without requiring complex mechanical pressing tools like expansible steel cones or cylinders.

Inventive Principle:
Principle #29Pneumatics and hydraulics

Solution Approach 2:

The inflatable bag is a simple, inexpensive, and potentially disposable component compared to expensive expansible steel cones or cylinders. After use, the bag can be deflated, removed, and replaced if needed, eliminating the need for investing in costly durable tools while achieving the same bonding reliability.

Inventive Principle:
Principle #27Cheap short-living objects (Disposable)

3Device complexity

If simple tools are used to apply pressure to the insulation, then device complexity and cost are reduced, but sufficient bond between the retaining ring and insulation may not be achieved

Engineering Contradiction:
Improvetool complexityVSAvoidbond strength
Core Design Contradiction:
Device complexityVSReliability

Solution Approach 1:

The patent uses a pneumatic bag (inflatable element) to apply pressure to the insulation layers inside the retaining ring. By inflating the bag with compressed air, uniform radial pressure is exerted on the insulation, ensuring sufficient bonding between the insulation and the retaining ring without requiring complex mechanical pressing tools like expansible steel cones or cylinders.

Inventive Principle:
Principle #29Pneumatics and hydraulics

Solution Approach 2:

The patent controls the pressure parameter by adjusting the inflation pressure of the pneumatic bag. By varying the air pressure inside the bag, the desired bonding pressure can be precisely controlled to ensure adequate bond strength between the insulation and the retaining ring, maintaining reliability while using a simple device.

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 method simplifies the insulation application process, reduces costs, and ensures a secure, durable bond suitable for high operation requirements, making it easier and more efficient for maintenance and replacement.

Implementation Method 1

inflating a bag inside the retaining ring housing to apply pressure to the insulation

Methodology Applied
Scientific EffectPressure: Pressure Increase

Implementation Method 2

The bag is pressed against the insulation inside the retaining ring with a pressure of below nine bars by means of inflating the bag

Methodology Applied
Scientific EffectInflation: Pressure Increase

Data Source

PatentEP3217519B1A method to apply an insulation
Publication Date: 2018.10.03 GENERAL ELECTRIC TECH GMBH
  • EP3217519B1 patent drawingFigure 1

AI summary

The present disclosure relates to a method to apply an insulation to a retaining ring for end windings of an electric machine and to the use of an inflatable bag to apply an insulation to a retaining ring. Disclosed is a method to apply an insulation to a retaining ring for end windings of an electric machine, with the steps of providing a retaining ring housing, attaching an insulation at the inside of the retaining ring housing, and inflating a bag inside the retaining ring housing to apply pressure to the insulation. Also disclosed is the use of an inflatable bag to apply a pressure to an electric insulation inside a retaining ring for end windings of an electric machine.