Patent ID: 7714467

Claim:
An electric machine, comprising: a housing defining an axis; a coolant entry arranged on one side of the housing for entry of coolant; a cylindrical magnet arrangement received in the housing and defining a circumference, said magnet arrangement having axial bores; and a cooling device for cooling the magnet arrangement, wherein the cooling device has a ring-shaped coolant channel extending about an outer circumference of the magnet arrangement and being fluidly connected with the coolant entry such that incoming coolant from the coolant entry flows radially directly onto the magnet arrangement, and separate outer circumferential rectilinear axial channels in fluid communication with the coolant channel so that the coolant is guided in axial direction through the axial channels to an opposite side of the housing and from there is guided inwardly and back in opposite axial direction via the axial bores to the one side for expulsion through an outlet, wherein the ring-shaped coolant channel and the axial channels are configured such that incoming coolant is first distributed by the ring-shaped coolant channel in a circumferential direction before entering the axial channels and flowing essentially uniformly about the circumference of the cylindrical magnet arrangement.