Abstract: A rotary electrical machine (1) has a least one stator (23). The stator is provided with at least one radial channel (107) for ducting cooling air. The channel (107) extends between a first position (113) at or substantially near the rim (109) of a winding region of the stator (23) and a second position (119) at or substantially near the center (51) of the winding region. The machine (1) has cooling means (91-97) for causing cooling air to enter the radial channel (107) via the second position (119) and exit via the first position (113). The stator may have electrical windings arranged as coil sectors (183-197) disposed substantially equi-angularly in a generally circular pattern. At least some of the coil sectors are wound in a generally spiral fashion when viewed axially. A rotor (13), for the machine may have a plurality of equi-angularly spaced magnets (127), which are generally circular but with a cut-away portion, when viewed axially.