Patent ID: 7041044

Claim:
A rotatable machine ( 1 ) having first and second ends, said machine ( 1 ) comprising a chamber ( 2 ) and a shaft ( 3 ), said shaft ( 3 ) mounted in said chamber ( 2 ) such that, upon rotation of said shaft ( 3 ) and said chamber ( 2 ), said shaft ( 3 ) and said chamber ( 2 ) each rotate about the same axis ( 4 ), a first motor ( 20 ) for driving the chamber ( 2 ) and a second motor ( 30 ) for driving the shaft ( 3 ), each said motor ( 20 , 30 ) having an axis, wherein the axes of the first and second motors ( 20 , 30 ) and the axis ( 4 ) of rotation of the chamber ( 2 ) and of the shaft ( 3 ) are coincident, the first motor ( 20 ) and the second motor ( 30 ) are both permanent-magnet synchronous motors comprising permanent magnets ( 22 , 32 ), wherein the first and the second motors ( 20 , 30 ) are both located at the same end of the machine ( 1 ), the rotatable machine further comprising a casing ( 50 ) containing both said first and said second motors ( 20 , 30 ) and first and second shafts ( 10 , 11 ) adapted for driving the chamber ( 2 ) and the shaft ( 3 ), respectively, wherein said shafts ( 10 , 11 ) are concentric and are push-fitted directly into corresponding rotors ( 21 , 31 ) of the respective motors ( 20 , 30 ).