Split Electric Machine Retrofit for Existing Propulsion Shafts
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Solution Overview
Problem
Existing vessels with conventional power systems face significant challenges and high costs when converting to hybrid propulsion systems, as conventional electric motor designs require disruptive modifications to the propulsion shaft line, making retrofitting unfeasible and costly.
Innovation Solution
A split permanent magnet electric machine design that can be fitted to existing propulsion shaft lines without interruption, featuring a hollow rotor and stator in multiple pieces, allowing for modular and scalable installation around existing shafts, reducing installation time and costs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If conventional electric motor design is used, then the motor can be integrated into the propulsion system, but the propulsion shaft line must be interrupted and modified, increasing installation complexity and cost
Solution Approach 1:
The electric motor is divided into two separate halves (stator half and rotor half) that can be assembled around the existing propulsion shaft without interrupting it. The stator is split into two stator halves that are positioned on opposite sides of the shaft, and the rotor is split into two rotor halves that are similarly positioned. This segmentation allows the motor to be installed without modifying the existing shaft line, directly resolving the technical contradiction.
2Productivity
If conventional electric motor design is used, then the motor can be integrated into the propulsion system, but installation time and costs increase due to disruptive modifications
Solution Approach 1:
The split design of the stator and rotor into two halves each enables parallel installation procedures. One half can be installed while the other is prepared, and the assembly can be positioned around the shaft without removing it from service. This significantly reduces installation time and vessel downtime compared to conventional motor installation that requires shaft line interruption.
Solution Approach 2:
The split electric motor components are designed to nest around the existing propulsion shaft in a concentric arrangement. The rotor halves are positioned around the shaft, with the stator halves enclosing the rotor, creating a nested configuration that fits within the existing propulsion system envelope without requiring shaft removal or extensive modifications.
3Adaptability or versatility
If conventional electric motor design is used, then the motor can be integrated into the propulsion system, but the cost of modification increases, removing the business case for hybrid conversion
Solution Approach 1:
By segmenting the motor into two halves that can be assembled around the existing shaft, the invention eliminates the need for costly shaft line modifications, welding, or structural changes to the vessel's propulsion system. This dramatically reduces installation costs and makes hybrid conversion economically viable for existing vessels.
Solution Approach 2:
The split electric motor design is created as a universal retrofit solution that can be adapted to various existing propulsion shaft configurations without custom shaft modifications. The standardized split design allows the same basic motor architecture to be installed on different vessel types, reducing overall system costs and improving the business case for hybrid conversion.
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
Enables the commercial viability of hybridizing existing vessels, reducing environmental impact by facilitating the integration of hybrid power systems into various vessel types without the need for costly shaft modifications, thus decreasing installation time and costs.
Implementation Method 1
a permanent magnet electric machine having a hollow rotor provided in at least two pieces... and a stator provided in at least two pieces
Implementation Method 2
permanent magnet electric machine
Data Source
AI summary
A device includes a first rotor segment and a second rotor segment, wherein the first rotor segment and the second rotor segment are configured to be directly coupled together about a shaft to form at least a portion of a unitary rotor. The device also includes a first stator segment and a second stator segment, wherein the first stator segment and the second stator segment are configured to be directly coupled together to form at least a portion of a unitary stator.