Synchronous Machine Cooling Channels for Compact Boat Propulsion
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing electrical rotating machines in propulsion-oriented drive devices for boats face challenges in cooling, leading to increased volume and mass, reduced hydrodynamical efficiency, and the need for high-power converters due to limited space for power converters and inefficient cooling methods.
Innovation Solution
A synchronous electrical machine with a stator and rotor separated by an air gap, featuring stacks of laminations with channels and tie rods for compact design, and a bilateral cooling system that injects and extracts fluid to efficiently dissipate thermal losses, reducing the machine's volume and improving hydrodynamical efficiency.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Temperature
If the machine is shrunk into the housing to increase heat exchange surface, then cooling efficiency is improved, but the diameter increase deteriorates hydrodynamical efficiency
Solution Approach 1:
The patent transitions from radial heat exchange (through housing wall) to axial heat exchange (through end plates), utilizing the axial dimension for thermal management. This allows efficient cooling without increasing the radial diameter of the machine, thereby maintaining hydrodynamical efficiency while achieving effective heat dissipation.
Solution Approach 2:
The stator is divided into multiple segments with cooling channels distributed throughout the structure. This segmentation allows for efficient heat extraction from multiple locations simultaneously, improving overall cooling effectiveness without requiring a proportional increase in machine size.
2Temperature
If induction motor is used with forced air cooling, then cooling is achieved, but power converter size increases due to lower efficiency
Solution Approach 1:
The patent employs a liquid cooling system instead of air cooling, utilizing fluid circulation through channels in the stator and end plates. This hydraulic cooling approach provides superior heat transfer efficiency compared to pneumatic cooling, enabling better thermal management and allowing for more compact power converter design.
3Temperature
If synchronous machine with wounded rotor is shrunk into housing, then cooling through wall is achieved, but thermal losses increase
Solution Approach 1:
The patent extracts the primary cooling function from the housing wall and relocates it to dedicated cooling components (end plates with channels and stator segments). This separation allows the housing to maintain its structural and hydrodynamical functions while the specialized cooling components handle thermal management efficiently, reducing overall thermal losses.
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 solution enhances cooling efficiency, reduces the machine's volume, and improves hydrodynamical efficiency by effectively transferring thermal losses, maintaining overall propulsion system efficiency despite some electrical machine efficiency loss.
Implementation Method 1
a fluid injected in the air gap at the ends of the stator flows in the extraction duct and in the channel, and is extracted from the machine through the opening to cool the stator and the rotor
Implementation Method 2
the machine housing being configured to dissipate thermal losses generated by the stator
Data Source
AI summary
Provided is a synchronous electrical machine that includes a machine housing having a stator and a rotor lodged in the stator, the rotor being separated from the stator by an airgap, and the machine housing dissipating thermal losses generated by the stator. The stator having stacks of laminations and at least one channel extending along a longitudinal direction of the stator and formed in the laminations, two adjacent stacks of laminations being separated by pins or spacers to form an extraction duct connected to the channel, the machine housing further having an extraction opening so that a fluid injected in the air gap at the ends of the stator flows in the extraction duct and in the channel, and is extracted from the machine through the opening to cool the stator and the rotor.