Electric Machine Sealing System for Stator Dust Isolation

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

The circulation of cooling air in electric machines leads to dust deposition between the stator and rotor, potentially causing short circuits, which existing technologies fail to adequately prevent.

Innovation Solution

An electric machine design featuring a sealing system that channels cooling fluid between the inlet and outlet ports, preventing its entry into a reception space containing the stator, thereby isolating the stator from contaminants like dust transported by the cooling air.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If cooling air is circulated through the casing to cool the rotor, then the rotor cooling efficiency is improved, but dust is deposited between the stator and rotor leading to potential short circuits

Engineering Contradiction:
Improverotor temperatureVSAvoidelectric machine reliability
Core Design Contradiction:
TemperatureVSReliability

Solution Approach 1:

The internal space of the casing is segmented into a cooling circuit zone (where cooling air flows through rotor channels) and a stator reception space (where the stator is housed). This segmentation prevents dust-laden cooling air from contaminating the stator area, resolving the contradiction between effective rotor cooling and prevention of dust deposition that causes short circuits.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

A sealing system acts as an intermediary barrier between the cooling air flow path and the stator reception space. The sealing elements (such as labyrinth seals or contact seals) prevent dust particles transported by cooling air from entering the stator area, while allowing the cooling circuit to function effectively for rotor temperature control.

Inventive Principle:
Principle #24Intermediary (Mediator)

2Device complexity

If the stator is exposed to the cooling air circulation path, then the cooling system is simplified, but the stator becomes contaminated by dust transported by the cooling fluid

Engineering Contradiction:
Improvecooling system complexityVSAvoidstator contamination
Core Design Contradiction:
Device complexityVSObject-affected harmful factors

Solution Approach 1:

The cooling system is segmented into distinct zones: a cooling air circulation path that includes inlet ports, rotor cooling channels, and outlet ports; and a separate stator reception space that is isolated from the cooling air flow. This segmentation adds sealing components but prevents stator contamination by dust-laden cooling air.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

Sealing elements serve as intermediary barriers positioned between the cooling air flow path and the stator reception space. These seals (labyrinth seals, contact seals, or brush seals) prevent dust particles from the cooling air from contaminating the stator, while maintaining the simplicity of the overall cooling system architecture.

Inventive Principle:
Principle #24Intermediary (Mediator)

3Reliability

If the sealing system is added to prevent cooling fluid from entering the stator space, then the stator is protected from dust, but the device complexity increases

Engineering Contradiction:
Improvestator protection from short circuitVSAvoidsealing system complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

Sealing elements are introduced as intermediary components between the cooling air circulation path and the stator reception space. These seals (such as labyrinth seals, contact seals, or brush seals) provide effective protection against dust contamination while maintaining relatively simple integration into the existing cooling system architecture.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The sealing system utilizes flexible sealing elements (such as brush seals or elastomeric seals) that can adapt to slight variations in assembly tolerances and thermal expansion. This flexibility provides reliable dust protection without requiring complex rigid sealing structures, thereby limiting the increase in device complexity.

Inventive Principle:
Principle #30Flexible shells and thin films

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 design effectively limits the risk of stator contamination and malfunction by ensuring that cooling fluid does not enter the stator's reception space, maintaining the air gap and preventing dust deposition, thus enhancing the machine's reliability and longevity.

Implementation Method 1

a sealing system configured to channel cooling fluid between the inlet(s) and the cooling channel(s) and channel cooling fluid between the channel(s) cooling and the outlet port(s), preventing the entry of the cooling fluid into a delimited reception space inside the casing

Methodology Applied
Scientific EffectPressure differential: Pressure Gradient

Data Source

PatentEP4080733A1Electric machine with cooling channel and insulated stator
Publication Date: 2022.10.26 ALSTOM HOLDINGS SA
  • EP4080733A1 patent drawingFigure 1
  • EP4080733A1 patent drawingFigure 2
  • EP4080733A1 patent drawing

AI summary

An electric machine (10) comprising a housing (20), a stator (25) inside the housing (20), and a rotor (30) rotatably mounted inside the housing (20). The rotor (30) is provided with at least one cooling channel (100). The electric machine (10) includes at least one inlet port (35) for the entry of a cooling fluid (38) into the housing (20) for its circulation in each cooling channel (100) and at least one outlet port (45) for the exit of said fluid (38) to the outside of the housing (20). The electric machine includes a sealing system (110) configured to channel the cooling fluid (38) between the inlet port(s) (35) and the cooling channel(s) (100) and between the cooling channel(s) (100) and the outlet port(s) (45), preventing the entry of the cooling fluid (38) into a receiving space (115) in which the stator (25) is received.