Patent ID: 8597001
Filing Date: 2013-12-03
Classification: H02K

Abstract:
1. An electric machine, comprising: (a) a stator, comprising a stator core and a stator winding, that includes a first winding part accommodated in spaces of the stator core and an end winding as a second winding part, the end winding being located axially in front of a first front face and an opposed second front face of the stator core; (b) a housing that accommodates the stator; (c) a rotor that is rotatably supported; (d) an air gap that has a generally cylindrical configuration; (e) a plurality of circumferentially distributed first cooling gas ducts that are positioned at locations between the first and second front faces of the stator core and extend in generally radial direction between a respective outer inlet and the air gap; (f) the housing comprising a plurality of first holes directed towards the end winding in front of the first front face of the stator core to direct jets of cooling gas against the end winding for impingement cooling thereof; (g) the housing comprising a plurality of second holes directed towards the end winding in front of the second front face of the stator core to direct jets of cooling gas against the end winding for impingement cooling thereof; (h) the housing comprising a plurality of third holes directed towards the end winding in front of the first front face of the stator core to direct a flow of cooling gas through the end winding and towards a portion of the rotor behind the end winding; (i) the housing comprising a plurality of fourth holes directed towards the end winding in front of the second front face of the stator core to direct a flow of cooling gas through the end winding and towards a portion of the rotor behind the end winding; (j) the first and second holes having a smaller diameter than the third and fourth holes; (k) and at least one of: (k1) a blowing fan operable to provide a flow of cooling gas through the electric machine, the blowing fan being in cooling gas flow connection with the first cooling gas ducts, the first holes, the second holes, the third holes, and the fourth holes; (k2) or a sucking fan operable to provide a flow of cooling gas through the electric machine, the sucking fan being in cooling gas flow connection with those spaces in the electric machine, which receive cooling gas exiting from the air gap, the first holes, the second holes, the third holes, and the fourth holes; and wherein said housing further comprises a plurality of second cooling gas ducts that extend in a direction substantially parallel to an axis of rotation of said rotor and are circumferentially distributed around said stator, each second cooling gas duct being substantially continuous over the entire length of said stator and substantially perpendicular to, and in cooling gas flow connection with, at least one of said plurality of first cooling gas ducts and wherein at least one of said plurality of second cooling gas ducts are in cooling gas flow connection with at least one each of said first, second, third, and fourth holes and one of said blowing fan or said sucking fan.