Abstract: To attach a segmental stator, for example in the form of armature laminations, to the housing of a flywheel of an internal combustion engine, and permanent magnet rotor elements to the flywheel circumference, while permitting differential thermal expansion, the attachment elements include a shaft or web element (10, 210, 403, 403') which connects the respective magnetic structural component--stator laminations (1) or permanent magnet field (19)--to the engine structure housing (2) or flywheel (15), respectively, by two headed ends (8, 208, 408; 7, 207, 407) which may be in form of tapped cylindrical or spherical elements or cylindrical tubular portions fitted into holes (415) of the engine structure and expanded after placement, by driving a pin (FIG. 4c: 16) thereinto, or pulling a headed pin (FIG. 4d: 17) therethrough.