Patent ID: 7633194

Claim:
A coaxial stack of laminations for a stator of an electrical machine comprising: substantially identical laminations with each lamination having an outer periphery and an inner periphery, the laminations directly abutting one another, wherein the outer periphery of each lamination is defined by an array of outwardly projecting pins that cooperate with a jacket surrounding the stack to provide a cooling space through which cooling fluid flows, wherein each of the pins has an end face and two side surfaces, and wherein the laminations are rotated, with respect to each other, so that the cooling fluid flowing in gaps between both of the two side surfaces of each of the pins of a first lamination impacts the end faces of pins of a second lamination that is adjacent to the first lamination, and wherein the two side surfaces of each of the pins slope from a base of the pin to a crown of the pin, and wherein the crown of the pin has a width less than a width of the base to provide channels between the pins of adjacent laminations, wherein the channels form axially extending grooves, and wherein the end faces are flat and without holes therethrough, and wherein the laminations are rotated so that an end face of a pin of any of the laminations is adapted to send undulating streams of the cooling fluid in an axial direction over both of the two surfaces of the pin and through the channels when the cooling fluid impacts the end face of the pin, and wherein each lamination is further defined by an array of teeth that project inwardly toward the inner periphery, and wherein the teeth provide aligned spaces therebetween for receiving stator windings.