An intravascular blood pump comprises a pump casing having a blood flow inlet and a blood flow outlet, and an impeller arranged in said pump casing so as to be rotatable about an axis of rotation, wherein the impeller has blades sized and shaped for conveying blood from the blood flow inlet to the blood flow outlet. The blood pump further comprises a drive unit for rotating the impeller, the drive unit comprising a plurality of posts arranged about the axis of rotation, wherein each of the posts includes a shaft portion and a head portion. Coil windings around the posts are sequentially controllable so as to create a rotating magnetic field. The drive unit further comprises a back plate which engages ends of the shaft portions of the posts opposite the head portions.
