Patent ID: 7832081
Filing Date: 2010-11-16
Classification: H02K,Y10T

Abstract:
1. A method of applying an outer groundwall insulation to a bare stator bar of an electric machine to form an insulated stator bar, the method comprising the steps of: forming a bare stator bar comprising strands of electrical conductors oriented parallel to each other and strand electrical insulation surrounding each of the strands of electrical conductors; extruding the outer groundwall insulation to comprise at least one extruded member containing an electrical insulation material, the at least one extruded member having an inner cavity extending a longitudinal length thereof and an opposing pair of edges parallel to the longitudinal length thereof; inserting the bare stator bar into the inner cavity of the outer groundwall insulation so that the outer groundwall insulation surrounds a perimeter of the bare stator bar and extends along a longitudinal length thereof; attaching together the opposing pair of edges of the at least one extruded member so that the perimeter of the bare stator bar is entirely enclosed by the at least one extruded member and the opposing pair of edges abut each other to define a seam that is substantially parallel to the longitudinal length of the bare stator bar; and then welding the opposing pair of edges together with a weld material deposited at the seam by a weld head; wherein the at least one extruded member is extruded so that the opposing pair of edges comprise interlocking features that physically secure the edges together as a result of the attaching step, and each of the interlocking features is continuous along a corresponding one of the edges so as to be substantially parallel to the longitudinal length of the bare stator bar.