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Contra rotating double shaft brushless propulsion electric machine

IP.com Disclosure Number: IPCOM000248943D
Publication Date: 2017-Jan-24
Document File: 3 page(s) / 611K

Publishing Venue

The IP.com Prior Art Database

Related People

Ruohonen Antti: AUTHOR [+3]

Abstract

This invention combines the benefits of contra rotating shafts and brushless power supply with rotating transformer technology or with slip ring supply to inner rotating stator allowing the shafts to rotate freely in opposite rotating directions. These features will result in a doubled air gap speed which allows reduction of the size of the electric machine. The unit can be made with a slip ring supply. In that case the total diameter of the electric machine will be of the same size as the total diameter of a standard electric machine, but the output of the inventive electric machine will be (roughly) doubled compared to the output of a standard electric machine having the same diameter.

This text was extracted from a PDF file.
This is the abbreviated version, containing approximately 61% of the total text.

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© Copyright [2017] ABB. All rights reserved.

CONTRA ROTATING DOUBLE SHAFT BRUSHLESS PROPULSION ELECTRIC

MACHINE

Energy saving becomes more and more important and one of the largest energy saving

potential in marine vessels is within the propulsion system. The contra rotating propeller

(CRP) concept is as such a well-known solution in marine industry in order to improve

hydrodynamic efficiency.

This invention combines the benefits of contra rotating shafts and brushless power supply

with rotating transformer technology or with slip ring supply to inner rotating stator allowing

the shafts to rotate freely in opposite rotating directions. These features will result in a

doubled air gap speed which allows reduction of the size of the electric machine.

The unit can be made with a slip ring supply. In that case the total diameter of the electric

machine will be of the same size as the total diameter of a standard electric machine, but the

output of the inventive electric machine will be (roughly) doubled compared to the output of a

standard electric machine having the same diameter.

The invention provides at least some of the following advantages:

+ Improved power due to combined (doubled) air gap speed

+ Roughly 10% to 15% better propulsion efficiency on marine propulsion (may also be

applicable on wind mill applications)

+ Reduced motor diameter compared to current motor design about 25% which would

improve the propulsion efficiency further

+ No slip r...