An axial flux rotating electrical machine is disclosed, the machine comprising a stator (10), a cooling jacket (22, 100) inside the stator for cooling the stator, and stator windings (24) around the stator and the cooling jacket. The cooling jacket comprises a plurality of independent protrusions (76) which extend radially outwards through the stator windings and which secure the stator to the machine. This can allow the stator to be secured without the need for direct contact with the stator.