# US 4,399,382 A · Electrical machine > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 4,399,382 A - Document ID: US4399382A - Status: Granted - Kind: A - Application number: 06/277,452 - Filed: 1981-06-25 - Granted: 1983-08-16 - Earliest claimed: 1980-07-16 - Inventors: Wolfgang Volkrodt - Web page: https://patentgrep.com/patent/US4399382A ## CPC - H02K 3/50: Fastening of winding heads, equalising connectors, or connections thereto - H02K 1/16: Stator cores with slots for windings - H02K 1/20: with channels or ducts for flow of cooling medium - H02K 5/15: Mounting arrangements for bearing-shields or end plates - H02K 5/225: {Terminal boxes or connection arrangements (specially adapted for submersible motors H02K5/132)} - H02K: DYNAMO-ELECTRIC MACHINES (dynamo-electric relays H01H53/00; conversion of DC or AC input power into surge output power {H03K3/53}) ## Abstract An electrical machine is provided which consists of a stator made up of stacks of plates and a rotor mounted at the ends of the machine in bearing plates and rotatable in the stator. The stator plates, which are asymmetrically designed so that one part has an arcuate outline corresponding to a circular stator contour while the opposite part has a rectangular contour with an arcuate separating line extending as far as possible into the described outline when the plates are being stamped from strip material, are arranged in respective separate stacks situated on one another, multiples of 90.degree. apart, in order to form a self-supporting stator. ## Claims ### Claim 1 An electrical machine comprising a stator having a cylindrical cavity extending therethrough; bearing means at opposite ends of said stator; a rotor in said cavity and mounted for rotation at opposite ends thereof in said bearing means; said stator comprising a plurality of stator plates having the same asymmetrical configuration and arranged in stacked relationship, each stator plate having a circular aperture therein of predetermined diameter, four secondary apertures arranged in a square configuration about said circular aperture, said secondary apertures being a predetermined distance from the perimeter of said circular aperture and the axes of said square configuration of said secondary apertures and of said circular aperture coinciding, a base edge spaced from one side of said circular aperture and from a pair of said secondary apertures, parallel side edges extending from opposite ends of said base edge, the distance of said side edges from each other being such that said side edges are a predetermined distance from the respective opposite sides of said circular aperture, and a top edge extending between said parallel side edges at the side of said circular aperture opposite said base edge, at least a major central portion of said top edge having a convex semicircular configuration concentric with and spaced a predetermined distance from the side of said circular aperture, said base edge having a central concave semicircular configuration complementary to said convex semicircular configuration of said top edge opposite said base edge and being spaced a greater distance from said one side of said circular aperture than said side and top edges; said stator plates of said stator being arranged in said stack with their circular apertures aligned to form said cylindrical cavity and with said stator plates arranged with their base edge sides offset from each other by 90.degree. and multiples thereof about the axis of said cylindrical cavity such that said secondary apertures of said stator plates are aligned to form four axial channels in said stator equally spaced about said cylindrical cavity; and means securing said bearing means and stator with said stator plates in said stacked relationship whereby the portions of said stator plates adjacent said base edge project radially about said stator and are spaced from each other to provide tangential cooling ribs. ### Claim 2 (depends on 1) An electrical machine according to claim 1 wherein said means securing said stator plates in said stacked relationship extends through said axial channels. ### Claim 3 (depends on 1) An electrical machine according to claim 1 wherein the base edge sides of adjacent successive stator plates are offset from each other by 90.degree. about said axis of said cylindrical cavity. ### Claim 4 (depends on 1) An electrical machine according to claim 1 further comprising a housing of substantially square configuration surrounding said stator, said housing including apertures therein, and fan means mounted on the interior of said housing for circulating air in a tangential direction between said cooling ribs and between the portions of said base edges having said central concave semicircular configuration and the interior of said housing and through said apertures in said housing. ### Claim 5 (depends on 1) An electrical machine according to claim 1 wherein said bearing means comprises bearing plates centered with respect to said cylindrical cavity at opposite ends of said stator. ### Claim 6 (depends on 5) An electrical machine according to claim 5 further comprising housing rings positioned at opposite ends of said stator and interposed between said bearing plates and said stator, each of said housing rings including feet for supporting said machine. ### Claim 7 (depends on 6) An electrical machine according to claim 6 further comprising a pressure ring disposed in each of said housing rings for pressing the ends of electrical coils against the internal surfaces of said housing rings.