An improved drum motor, preferably electronically commutated, features a unitary stationary central shaft (18) supporting a stationary inner stator (52), and an external rotor (49), including permanent magnets (54), secured to an inner surface of a generally cylindrical rotatable casing part (18). This permits variable speed operation while avoiding any need for an internal gear linkage. Safety is improved by making sealing plates (76, 78) at respective axial ends of the casing (14) stationary, and providing an annular peripheral seal (90) around each sealing plate. Respective rolling bearings (24, 44) near each end of the casing (14) facilitate rotation of the external rotor (49) relative to the stator (52), and a clamping arrangement (30) minimizes noise from the bearings.