Abstract: A rotor disc assembly 10 for an AC machine includes a rotor disc 20, permanent magnets 30 and a spider 40. The rotor disc 10 has a circumferential lip 22 projecting from a surface thereof. The permanent magnets 30 are positioned in a circular array on the surface of the rotor disc 20, with constant angular pitch, and so as to lie against the lip 22. The spider includes an annular base portion 41, with a plurality of arms 42 projecting radially outwards therefrom. The spider 40 is fixed to the surface of the rotor disc 20 such that each arm 42 is between and abuts a respective juxtaposed pair of the permanent magnets 30. The arms 42 and the members 30 are each provided with cooperating wedge-shaped cross sections such that each arm 42 constrains the respective two permanent magnets 30 both axially and tangentially on the surface of the rotor disc 20.

Abstract: A toroidal AC generator includes an outer casing and an annular stator core of ferromagnetic material which is encased in a hollow annular cover of plastics material and which is fixed to the casing between the discs of a twin disc rotor. Each rotor disc carries a circular array of alternately polarised permanent magnets which face the stator core. The hollow annular cover is a two-part moulding and is formed of radially inner and outer ring portions which are joined by circular arrays of radial ribs which extend across the opposed radial faces of the annular core and form open-ended radial passages for the electrical phase windings which are wound around the cover. The ribs project radially beyond the radially outer ring portion and form hooks around which a winding may be retained temporarily during winding.

Abstract: A toroidal AC generator includes an outer casing (11) and an annular stator core (33) of ferromagnetic material which is encased in a hollow annular cover (34) of plastics material and which is fixed to the casing (11) between the discs (14 and 15) of a twin disc rotor (10). Each rotor disc (14, 15) carries a circular array of alternately polarised permanent magnets (23 and 24) which face the stator core (33). The hollow annular cover (34) is a two-part moulding and is formed of radially inner and outer ring portions which are joined by circular arrays of radial ribs which extend across the opposed radial faces of the annular core (33) and form open-ended radial passages for the electrical phase windings which are wound around the cover (34). The ribs project radially beyond the radially outer ring portion and form hooks around which a winding may be retained temporarily during winding.

Abstract: A rotor disc assembly (10) for an AC machine includes a rotor disc (20), permanent magnets (30) and a spider (40). The rotor disc (10) has a circumferential lip (22) projecting from a surface thereof. The permanent magnets (30) are positioned in a circular array on the surface of the rotor disc (20), with constant angular pitch, and so as to lie against the lip (22). The spider includes an annular base portion (41), with a plurality of arms (42) projecting radially outwards therefrom. The spider (40) is fixed to the surface of the rotor disc (20) such that each arm (42) is between and abuts a respective juxtaposed pair of the permanent magnets (30). The arms (42) and the members (30) are each provided with cooperating wedge-shaped cross sections such that each arm (42) constrains the respective two permanent magnets (30) both axially and tangentially on the surface of the rotor disc (20).

Abstract: An AC generator comprises a rotor 25 within a stator 24. The rotor carries a fan 27 at one end of the stator. The fan 27 is within a casing 30 which forms volute discharge passages 32. The fan 27 has blades 31 which project from the hub 28 at an angle which is oblique to the radial whereby those blades 31 trail the radial. The stator windings 23 form terminal leads 34 which are led from the end of the stator 24 remote from the fan 27. A circumferential array of cleats 35 which each have the form of a comb, support and guide the terminal leads 34 circumferentially, spaced from one another, to a certain location at the top from which the leads are taken and connected to terminals above. Those terminals are formed by the lower ends of busbars (56 to 58, 61 to 69) which extend through and which are supported by a structural panel of insulating material which forms an insulating barrier between the ends of those busbars.