Abstract: The invention provides a system for axially keying and adjusting in position on a shaft the stator of a rotating machine such as an electric motor. The shaft is mounted on bearings at either end and an insulating disc is disposed between one of the bearings and the stator. The insulating disc comprises a recess, the median plane of which is substantially orthogonal to the shaft and a communicating channel formed between this recess and an annular space between a sleeve of the insulating disc. A settable bonding material is introduced into this space and a spacing bush is fitted over the shaft between the insulating disc and the adjacent bearing which passes into the annular recess and acts as a piston when the parts are assembled to drive the bonding material into the recess and take up any free play. The assembly is bonded together when the material sets.