Pump Group Stator Cooling via Sealed Oil Chamber

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing pump groups for engine cooling systems with electric drives, particularly those cooling the electric motor and its components, face inefficiencies in cooling due to complex structures that do not provide effective thermal management.

Innovation Solution

A pump group design featuring a radial impeller with an electric motor, where the stator is cooled by dielectric cooling oil in a sealed chamber that allows for both natural and forced convection, with a tubular wall dividing the chamber to accommodate thermal expansion and support the shaft, ensuring effective cooling of the stator and motor components.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If cooling liquid from the impeller chamber is used to cool the electric motor, then cooling effectiveness is improved, but structural complexity increases

Engineering Contradiction:
Improvecooling effectivenessVSAvoidstructural complexity
Core Design Contradiction:
TemperatureVSDevice complexity

Solution Approach 1:

The patent merges the cooling function with the existing cooling liquid circulation system by introducing a cooling liquid inlet into the rotor chamber and allowing cooling liquid to flow through the stator winding. This integrates the motor cooling function into the pump group's existing cooling system without adding separate cooling circuits or complex cooling apparatus, thereby improving cooling effectiveness while avoiding structural complexity

Inventive Principle:
Principle #5Merging (Combining)

Solution Approach 2:

The cooling liquid serves multiple functions simultaneously: it cools the impeller in the impeller chamber, cools the motor bearings through the rotor chamber, and cools the stator winding through the stator. This multi-functional use of a single cooling liquid stream eliminates the need for separate cooling systems for each component, resolving the contradiction between cooling effectiveness and structural complexity

Inventive Principle:
Principle #6Universality (Multi-functionality)

2Temperature

If a complex cooling structure is implemented, then cooling coverage is improved, but manufacturing complexity increases

Engineering Contradiction:
Improvecooling coverageVSAvoidmanufacturing complexity
Core Design Contradiction:
TemperatureVSEase of manufacture

Solution Approach 1:

The patent segments the motor chamber into a rotor chamber and a stator chamber using a partition wall, with the cooling liquid inlet positioned in the rotor chamber. This segmentation allows independent cooling of different motor components through a simple structural modification rather than a complex integrated cooling system, improving cooling coverage while maintaining ease of manufacture

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The cooling liquid naturally flows from the impeller chamber through the rotor chamber to the stator chamber, utilizing the existing pressure differential and gravity to achieve cooling without requiring additional pumps, valves, or complex flow control mechanisms. This self-service cooling approach expands cooling coverage while avoiding manufacturing complexity

Inventive Principle:
Principle #25Self-service

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 design achieves efficient cooling of the electric motor and stator, enhancing performance and reliability by utilizing convection methods and minimizing the need for additional cooling components, while maintaining a compact and simple structure.

Implementation Method 1

the cooling liquid present in the chamber where the impeller is housed is used to cool also the electric motor and the components thereof

Methodology Applied
Scientific EffectConvection: Convection

Implementation Method 2

the stator is cooled by dielectric cooling oil in a sealed chamber that allows for both natural and forced convection

Methodology Applied
Scientific EffectNatural convection: Free Convection

Implementation Method 3

the stator is cooled by dielectric cooling oil in a sealed chamber that allows for both natural and forced convection

Methodology Applied
Scientific EffectForced convection: Forced Convection

Data Source

PatentEP3861214B1Pump group
Publication Date: 2022.12.14 IND SALERI ITALO
  • EP3861214B1 patent drawingFigure 1
  • EP3861214B1 patent drawingFigure 2

AI summary

Pump group (1), for a cooling system of a vehicle engine, which extends with respect to an axis (X-X) and comprises an impeller (2), a shaft (3), on which is integrally mounted the impeller (2), and an electric motor (4), comprising a rotor (41) integrally mounted on the shaft (3) and a stator (42). The pump group (1) comprises a pump body (5) extending with respect to the axis (X-X) comprising: i) an impeller casing (51), which houses the impeller (2) in an impeller chamber (510); ii) a motor casing (52), which houses the electric motor (4) in a motor chamber (520), wherein the motor casing (52) comprises an intermediate tubular wall (526) positioned between the rotor (41) and the stator (42) so as to define a rotor chamber (521) and a stator chamber (522) which are sealingly separated from each other. The stator chamber (522) contains a predefined amount of cooling oil which fills it at least partially so that the stator (42) is cooled by convection.