A shroud includes a first shroud that covers a first side face to which a muffler is adjacent among four side faces that an engine has, a second shroud that covers a second side face adjacent to the first side face and a third side face, and a third shroud that sections a muffler space for housing the muffler with the first shroud, the first shroud and the second shroud form an upstream side air guide path that makes cooling air flow around the engine, and the muffler space is connected to a downstream side of the upstream side air guide path.

The present disclosure relates to electrical machines, cooling systems and methods for cooling active elements of electrical machines. More in particular, the present disclosure relates to cooling systems and methods for cooling active rotor and/or stator elements of a generator of a wind turbine, e.g. of a direct drive wind turbine. A cooling method comprises supplying a cooling fluid to an air gap through one or more primary inlets of an electrical machine for cooling a plurality of active elements of a rotor of the electrical machine and/or a plurality of active elements of a stator of the electrical machine separated by the air gap. The method further comprises reversing a direction of flow of the cooling fluid such that the cooling fluid is extracted from the electrical machine through one or more primary inlets.

A drive device includes an electric motor and a gear unit that is driven by the electric motor. The electric motor has a laminated stator core which includes stator windings and is accommodated in a stator housing. The stator housing has recesses that are axially uninterrupted, i.e. in particular in the direction of the rotor shaft axis, and the stator housing is surrounded, especially radially surrounded, by a housing of the drive device, in particular a tubular housing and/or a cup-shaped housing, and the housing is set apart from the stator housing, in particular such that an especially circulating airflow is able to be provided within the housing, the recesses in particular guiding the airflow through in the axial direction, and the airflow being returned in the opposite direction in the set-apart region between the stator housing part and the housing.

A drive device includes an electric motor and a gear unit that is driven by the electric motor. The electric motor has a laminated stator core which includes stator windings and is accommodated in a stator housing. The stator housing has recesses that are axially uninterrupted, i.e. in particular in the direction of the rotor shaft axis, and the stator housing is surrounded, especially radially surrounded, by a housing of the drive device, in particular a tubular housing and/or a cup-shaped housing, and the housing is set apart from the stator housing, in particular such that an especially circulating airflow is able to be provided within the housing, the recesses in particular guiding the airflow through in the axial direction, and the airflow being returned in the opposite direction in the set-apart region between the stator housing part and the housing.

An armature is presented. The armature includes an armature winding having a plurality of coils, wherein each coil of the plurality of coils is spaced apart from adjacent coils and comprise includes a first side portion and a second side portion. The armature further includes a first electrically insulating winding enclosure. Furthermore, the armature includes a second electrically insulating winding enclosure disposed at a radial distance from the first electrically insulating winding enclosure, wherein the armature winding is disposed between the first electrically insulating winding enclosure and the second electrically insulating winding enclosure. Moreover, the armature includes an electrically insulating coil side separator disposed between the first side portion and the second side portion of the plurality of coils of the armature winding. A superconducting generator including the armature and a wind turbine having such superconducting generator are also presented.

A stator for a brushless DC (BLDC) motor includes a stator core having stator teeth extending radially inwardly towards a center bore, stator windings respectively wound around the stator teeth, and insulating inserts having substantially the same longitudinal length as the stator core. The insulating inserts are longitudinally received between adjacent stator windings at or near inner tips of the adjacent stator teeth to substantially seal the center bore of the stator assembly from the stator windings.

A stator for a brushless DC (BLDC) motor includes a stator core having stator teeth extending radially inwardly towards a center bore, stator windings respectively wound around the stator teeth, and insulating inserts having substantially the same longitudinal length as the stator core. The insulating inserts are longitudinally received between adjacent stator windings at or near inner tips of the adjacent stator teeth to substantially seal the center bore of the stator assembly from the stator windings.

A rotor of a motor includes a cylindrical portion, a first plate portion, a second plate portion, and a side hole. The cylindrical portion is arranged on a radially outer side with respect to the stator and extends in the axial direction. The first plate portion is arranged on a first axial side with respect to the stator, and expands radially inward from a first axial end of the cylindrical portion. The second plate portion is arranged on a second axial side with respect to the stator, and expands radially inward from a second axial end of the cylindrical portion. The side hole penetrates the cylindrical portion in a radial direction. The stator holder has a holder through-hole. The holder through-hole is arranged on the radially inner side with respect to the stator and penetrates the stator holder in the axial direction.

A rotor of a motor includes a cylindrical portion, a first plate portion, a second plate portion, and a side hole. The cylindrical portion is arranged on a radially outer side with respect to the stator and extends in the axial direction. The first plate portion is arranged on a first axial side with respect to the stator, and expands radially inward from a first axial end of the cylindrical portion. The second plate portion is arranged on a second axial side with respect to the stator, and expands radially inward from a second axial end of the cylindrical portion. The side hole penetrates the cylindrical portion in a radial direction. The stator holder has a holder through-hole. The holder through-hole is arranged on the radially inner side with respect to the stator and penetrates the stator holder in the axial direction.

A power tool includes an electric motor having an output shaft, a transmission having a transmission housing, a spindle rotatable in response to receiving torque from the transmission and a pinion coupled to the output shaft. The pinion includes a bushing portion, a toothed portion for driving the transmission, and a cylindrical portion between the bushing portion and the toothed portion. The power tool further comprises a fan coupled to the bushing portion of the pinion and a bearing arranged between the cylindrical portion and the transmission housing for rotatably supporting the pinion and the output shaft.