Abstract: A rotor assembly comprises a rotor body defining a pole, a winding encircling the pole, a compression member located radially inwards of the winding, and compression means located between the compression member and the rotor body and operable to urge the compression member in an outward direction to apply a compressive load to the winding. A method of assembly of the rotor is also disclosed.

Abstract: A drive transfer device comprising: a first rotating element having a plurality of apertures therein; a second rotating element adjacent the first rotating element; a plurality of transfer elements; and a control element mounted for rotation with the first element and moveable with respect to the first element between a first position in which the control element holds the transfer elements in an engaged position where the transfer elements extend through the apertures of the first rotating element to engage with the second rotating element to urge them to rotate together, and a second position where the transfer elements are moved and held out of engagement with the second rotating element.