An electric motor has efficient self-cooling. The electric motor contains a rotor that is rotatably mounted with respect to a stator. On a first sub-segment of an end face of the rotor, a first air-guiding contour is formed that, during rotation of the rotor in a reference rotation direction, generates an outwardly directed air flow. On a second sub-segment of the same end face, a second air-guide contour is formed that, during rotation of the rotor in a reference rotation direction, generates an inwardly directed air flow.

An electric motor has efficient self-cooling. The electric motor contains a rotor that is rotatably mounted with respect to a stator. On a first sub-segment of an end face of the rotor, a first air-guiding contour is formed that, during rotation of the rotor in a reference rotation direction, generates an outwardly directed air flow. On a second sub-segment of the same end face, a second air-guide contour is formed that, during rotation of the rotor in a reference rotation direction, generates an inwardly directed air flow.

A rotating shaft is attached rotatably to a front body and a rear body of an AC generator. Feeding brushes are disposed around a rear end portion of the rotating shaft. A heat radiating plate is attached to a rear end of the rear body. A control board is attached to a back of the heat radiating plate. External air flows in from an air inlet and advances in a radially inward direction after passing through a cooling fin disposed on the heat radiating plate by a first air flow passage. In addition, the external air passes through and around the rear end portion of the rotating shaft after flowing into a rear surface side of the heat radiating plate via a second air passage.

Rotating electric machine provided with an axis X. The machine comprises a front part and a rear part. The machine comprises a rotor of axis X comprising two axial end surfaces, each provided with fan blades. The axial surfaces located on the side of the front part and on the side of the rear part. A stator comprises a stator body having slots. The stator comprises a winding installed in the slots and forming a front winding head and a rear winding head. The rotor and the stator are placed in a casing. The front winding head completely masks the blades of the axial surface located on the front side of the machine, along a direction perpendicular to axis X.

Rotating electric machine provided with an axis X. The machine comprises a front part and a rear part. The machine comprises a rotor of axis X comprising two axial end surfaces, each provided with fan blades. The axial surfaces located on the side of the front part and on the side of the rear part. A stator comprises a stator body having slots. The stator comprises a winding installed in the slots and forming a front winding head and a rear winding head. The rotor and the stator are placed in a casing. The front winding head completely masks the blades of the axial surface located on the front side of the machine, along a direction perpendicular to axis X.

An electric machine is supplied with air for cooling purposes. The electric machine has a housing (40) with cooling ducts for cooling air. To improve and/or simplify the cooling of the electric machine, air-distributing ducts (71) are formed in the housing (40) and emerge from a common air supply duct (70).

Propulsion unit (8) for an electric, pedal-assisted bicycle comprising an electric machine (12) having a stator (14) and a rotor (16), rotatable about a motor axis (M-M), said rotor (16) being operatively connected to a crank pin (18), defining a crank axis (X-X), mechanically connected to pedals (20), and coaxial with the motor axis (M-M), wherein the rotor (16) is coaxial and external with respect to the stator (14) so-as radially enclose the rotor (16). The propulsion unit (8) comprises at least one electronic unit (32) for operating and controlling the functioning of the electric machine (12), and at least a pair of housings (24, 26) that define a containment space (28) which houses the electric machine (12) and at least partially the crank pin (18). The propulsion unit (8) comprises transmission means (36) of. the movement from the rotor (16) to the crank pin (18), said transmission means (36) being arranged in an asymmetrical position overall and decentralised from the crank axis (X-X) so as to be outside the projection of the rotor on a projection plane perpendicular to the crank axis (X-X).

Propulsion unit (8) for an electric, pedal-assisted bicycle comprising an electric machine (12) having a stator (14) and a rotor (16), rotatable about a motor axis (M-M), said rotor (16) being operatively connected to a crank pin (18), defining a crank axis (X-X), mechanically connected to pedals (20), and coaxial with the motor axis (M-M), wherein the rotor (16) is coaxial and external with respect to the stator (14) so-as radially enclose the rotor (16). The propulsion unit (8) comprises at least one electronic unit (32) for operating and controlling the functioning of the electric machine (12), and at least a pair of housings (24, 26) that define a containment space (28) which houses the electric machine (12) and at least partially the crank pin (18). The propulsion unit (8) comprises transmission means (36) of. the movement from the rotor (16) to the crank pin (18), said transmission means (36) being arranged in an asymmetrical position overall and decentralised from the crank axis (X-X) so as to be outside the projection of the rotor on a projection plane perpendicular to the crank axis (X-X).

There is provided a winding system for use in an electrical, electronic or electromagnetic device or component including: one or more set of windings, each set of windings including an electrically-conductive element arranged in a winding pattern with multiple turns, at least one pair of adjacent turns of the multiple turns being spaced apart to provide at least one channel therebetween for coolant fluid to flow therethrough; and a housing for housing the set of windings, the housing including a fluid inlet and a fluid outlet each in fluid communication with the at least one channel, the housing facilitating coolant fluid to flow from the fluid inlet to the fluid outlet, via the at least one channel in direct contact with exposed surfaces of the set of windings, the exposed surfaces at least partially defining the at least one channel.

An electric motor comprising a stator having a stator cavity with an axis extending in a longitudinal direction, said stator cavity having a stator inlet for receiving a fluid and a stator outlet for discharging said fluid, a rotor arranged inside the stator cavity and rotatable around said axis, a tubular sleeve, arranged between the stator and the rotor, coaxial with said axis, and attached to the stator through attachment members. The tubular sleeve is spaced from the stator by a first tubular gap, and from the rotor by a second tubular gap, the first tubular gap extends along the longitudinal direction between a first gap inlet and a first gap outlet, the second tubular gap extends along the longitudinal direction between a second gap inlet and a second gap outlet, the first and second gap inlets are in direct fluid communication with the stator inlet, and the first and second gap outlets are in direct fluid communication with the stator outlet, such that the fluid entering the stator cavity at said stator inlet divides into a first fluid flow and a second fluid flow respectively flowing through the first tubular gap and the second tubular gap and exiting the stator cavity at said stator outlet, the tubular sleeve is made of a thermal insulating material, thereby thermally insulating the first tubular gap from the second tubular gap.