It is also advantageous if a fluid-guiding element is provided which is formed by a free elevation that has the same extent in two orthogonal directions of a plane perpendicular to the axial direction. Such a fluid-guiding element, also referred to hereinafter as a second fluid-guiding element, is used expediently to support a radially outer permanent magnet. The free elevation is preferably circular.

The (first) fluid-guiding element formed by the protrusion is particularly preferably arranged radially further inwardly than the (second) fluid-guiding element formed by the free elevation. A partial cooling channel is thus formed between the first and the second fluid-guiding element and guides the cooling fluid to radially outer clearances of the magnet pockets.

A fluid-guiding element can also be provided which is formed by a free elevation which extends in an elongate manner in the radial direction. Such a fluid-guiding element, also referred to as a third fluid-guiding element, is used typically primarily in order to fluidically optimise the cooling channel.

A further fluid-guiding element symmetrical with respect to a plane extending in the radial direction through the middle of the cooling channel portion is particularly preferably provided in addition to the fluid-guiding element or one fluid-guiding element. In particular, the third fluid-guiding elements are mutually distanced radially inwardly not further than the first arc length and/or are mutually distanced radially outwardly further than radially inwardly. The third fluid-guiding elements thus form a partial cooling channel, in order to guide the cooling fluid to the inner clearances of the radially outer permanent magnets.