Abstract: A bearing assembly particularly suitable for the rotor arrangement of an electrical motor or generator includes a bearing located in a housing. The bearing has an inner race, an outer race, and a plurality of ball bearings between the inner and outer races. A portion of the housing is made up of a deformable flexible wall which permits the housing to conform to the shape of the outer race member, rather than forcing the outer race to conform to the shape of the housing, as was experienced hitherto.

Abstract: A rotor assembly for an electronic machine such as a motor includes a rotor on a shaft having a bearing at each end portion, the bearings being arranged to rotatably support the rotor and shaft. The assembly further includes a balancing member, from which material may be removed for balancing the rotor assembly. The balancing member is located in a predetermined position and orientation with respect to the rotor. The balancing member includes an encoder disk, arranged to permit positioning of the rotor with respect to a stator. The provision of a balancing member having an integral encoder disk facilitates the manufacture of the rotor assembly. As the balancing member is located in a predetermined position, the encoder automatically assumes a predetermined position and hence the position of the rotor can be determined with certainty.