Abstract: A method of manufacturing a squirrel-cage rotor includes: providing a laminated stack; attaching a plurality of rotor bars to the laminated stack, wherein the plurality of rotor bars each include opposite longitudinal ends; and die-casting a pair of end rings at the longitudinal ends of the plurality of rotor bars.

Abstract: The apparatus of the present invention provides a stator for an electric motor. The apparatus includes a plurality of stator components assembled together to form a generally annular stator core. A wire is wrapped around at least a portion of the stator core to form a stator winding. A first generally annular end plate and a second generally annular end plate are mounted to axially opposite sides of the stator core such that the stator core is axially trapped and retained therebetween. A fastener applies a clamping load to the first and second end plates such that the stator core is compressed therebetween. The clamping load from the fastener is applied directly to the first and second end plates which distribute the clamping load to the stator core such that the plurality of components are held together without the fastener directly applying the clamping load to the stator core. A corresponding method for providing a stator is similarly provided.

Abstract: The present invention provides a method for producing a stator assembly. The method initially includes providing an assembly mandrel having a generally cylindrical hub and a generally annular base circumscribing a terminal end portion of the hub. A first end ring and a stator shell are installed around the mandrel hub and onto the mandrel base. Thereafter, a plurality of poles are disposed on top of the first end ring and in a generally cylindrical pattern between the stator shell and the mandrel hub. A second end ring is disposed around the mandrel hub and on top of the plurality of poles. A plurality of stator shell tabs may then be bent in a radially inward direction to axially retain the first and second end rings.

Abstract: A permanent magnet machine includes a rotor and a stator including plurality of stator pole sections. Each stator pole section comprises a core section having an inner end piece disposed adjacent to the core section, the inner end piece comprising a first magnetic material that is adapted to saturate during exposure to a first magnetic field strength, and an outer end piece disposed adjacent to the core section radially outwardly relative to the inner end piece, the outer end piece comprising a second magnetic material that is adapted to be unsaturated during exposure to the first magnetic field strength and to saturate during exposure to a second magnetic field strength, wherein the second magnetic field strength is greater than the first magnetic field strength.

Abstract: A permanent magnet machine includes a stator, a rotor configured to coaxially rotate with respect to the stator and having a plurality of permanent magnets coupled thereto, and an air gap between the stator and the rotor having a magnitude that is continuously adjustable. The air gap may be adjusted to optimize torque, minimize back EMF, or optimize any characteristic of the permanent magnet machine during rotation.

Abstract: A permanent magnet machine includes a rotor and a stator including plurality of stator pole sections. Each stator pole section comprises a core section having an inner end piece disposed adjacent to the core section, the inner end piece comprising a first magnetic material that is adapted to saturate during exposure to a first magnetic field strength, and an outer end piece disposed adjacent to the core section radially outwardly relative to the inner end piece, the outer end piece comprising a second magnetic material that is adapted to be unsaturated during exposure to the first magnetic field strength and to saturate during exposure to a second magnetic field strength, wherein the second magnetic field strength is greater than the first magnetic field strength.

Abstract: Provided are stir-welded rotors and methods of making these. An exemplary stir-welded rotor may include a stack of laminations that each has spaced-apart slots arrayed on an outer circumference. The slots register with slot bars that each has a first extremity extending above the stack of laminations and a second extremity extending below the stack of laminations. A first weld extends between first extremities of adjacent slot bars, and a second stir weld extending between adjacent second extremities of adjacent slot bars.

Abstract: The apparatus of the present invention provides a stator for an electric motor. The apparatus includes a plurality of stator components assembled together to form a generally annular stator core. A wire is wrapped around at least a portion of the stator core to form a stator winding. A first generally annular end plate and a second generally annular end plate are mounted to axially opposite sides of the stator core such that the stator core is axially trapped and retained therebetween. A fastener applies a clamping load to the first and second end plates such that the stator core is compressed therebetween. The clamping load from the fastener is applied directly to the first and second end plates which distribute the clamping load to the stator core such that the plurality of components are held together without the fastener directly applying the clamping load to the stator core. A corresponding method for providing a stator is similarly provided.

Abstract: A method of manufacturing a squirrel-cage rotor includes: providing a laminated stack; attaching a plurality of rotor bars to the laminated stack, wherein the plurality of rotor bars each include opposite longitudinal ends; and die-casting a pair of end rings at the longitudinal ends of the plurality of rotor bars.

Abstract: A stator assembly is provided for an electric motor having a longitudinal axis. The stator assembly includes at least one stator segment having a first end member having a stator tooth and at least one of a stator shoe and a back iron. A second end member is positioned with respect to the first end member and has a stator tooth and at least one of a stator shoe and a back iron. A winding generally circumscribes the stator tooth of the first end member and the stator tooth of the second end member. The first and second end members have a parting line generally perpendicular to the longitudinal axis of the motor. A motor incorporating the stator assembly of the present invention is disclosed. Additionally, a method of forming the stator assembly of the present invention is described.

Abstract: A delta type inverter is used in conjunction with a closed-loop motor controller to provide a control device for driving a three phase brushless direct current motor. The delta inverter has one-half of the solid state switching devices and diodes required by conventional bridge type inventers, thereby improved reliability, and enabling the motor control device to have reduced size, cost and weight. The closed-loop motor controller may include a torque loop for reducing torque ripple during operation of the motor.

Abstract: The present invention relates to a cooling system and method for the concentrated motor stator windings of an electric motor. The cooling system and method provides coolant directly onto the motor stator windings and between each adjacent stator winding. The motor housing assists in distributing coolant between each stator winding of the electric motor assembly. Moreover, an insulated sheet and/or tube is insertable between the concentrated motor stator windings. Each is configurable to direct coolant directly on to the stator windings.

Abstract: A delta type inverter is used in conjunction with a closed-loop motor controller to provide a control device for driving a three phase brushless direct current motor. The delta inverter has one-half of the solid state switching devices and diodes required by conventional bridge type inventers, thereby improved reliability, and enabling the motor control device to have reduced size, cost and weight. The closed-loop motor controller may include a torque loop for reducing torque ripple during operation of the motor.

Abstract: Provided are stir-welded rotors and methods of making these. An exemplary stir-welded rotor may include a stack of laminations that each has spaced-apart slots arrayed on an outer circumference. The slots register with slot bars that each has a first extremity extending above the stack of laminations and a second extremity extending below the stack of laminations. A first weld extends between first extremities of adjacent slot bars, and a second stir weld extending between adjacent second extremities of adjacent slot bars.

Abstract: A stator assembly is provided having a generally annular stator core including a plurality of radially inwardly extending stator teeth. A stator wire is wound around each of the plurality of stator teeth to form a plurality of stator coils. Each of the plurality of stator coils are spaced apart to at least partially define a plurality of generally axially extending cooling channels through which a cooling medium, such as oil, flows. Additionally, the plurality of stator teeth each include a respective flanged end portion each adapted to retain an axially extending strip member. The strip member at least partially defines the cooling channel. The cooling medium operates to cool the plurality of stator coils. In the preferred embodiment, at least a portion of the flow of the cooling medium within the cooling channel is turbulent. Additionally, an electromechanical hybrid transmission is disclosed with the stator assembly provided.

Abstract: The present invention provides a method for producing a stator assembly. The method initially includes providing an assembly mandrel having a generally cylindrical hub and a generally annular base circumscribing a terminal end portion of the hub. A first end ring and a stator shell are installed around the mandrel hub and onto the mandrel base. Thereafter, a plurality of poles are disposed on top of the first end ring and in a generally cylindrical pattern between the stator shell and the mandrel hub. A second end ring is disposed around the mandrel hub and on top of the plurality of poles. A plurality of stator shell tabs may then be bent in a radially inward direction to axially retain the first and second end rings.

Abstract: A transmission includes a housing, an electric motor having a stator within the housing, and a member including a generally cylindrical portion that circumscribes at least part of the stator. The member cooperates with the housing to form an annular coolant flowpath therebetween, and the member includes a plurality of holes to provide radial inflow of coolant from the flowpath to the stator to provide significantly improved motor cooling compared to the prior art.

Abstract: A rotor assembly for a synchronous reluctance dynamo/motor machine has a plurality of axial laminations comprised of alternate magnetic and non-magnetic materials. The rotor has an end cap on each axial end which engages the stepped axial ends of the laminations.

Abstract: A reluctance motor control system is stabilized by a load angle feedback control loop provided by a computation of the load angle from sensed voltage and current on the terminals of the motor with the assist of a derived frequency signal. The motor is operated at most efficient load angle in motoring or braking, while the motor voltage is being controlled so as to maintain the desired load angle as the speed and/or load vary.

Abstract: A self-cascaded reluctance motor is provided with an axially laminated rotor. The motor includes a stator winding having two sets of terminals and wound such that the number of poles between one set of terminals differs from the number of poles between the other set of terminals by more than two. The rotor includes a plurality of axially disposed conductive sheets and magnetic material laminations which are interleaved within each rotor segment to form groups of magnetic material laminations which lie between two of the conductive sheets. The number of conductive laminations is equal to one half of the total number of stator winding poles or an integral submultiple thereof, while the number of groups of magnetic material laminations is equal to one half of the total number of stator pole pairs or an integral submultiple thereof. Short-circuited coils can be substituted for the conductive sheets to provide better coupling between the two stator component windings and thus more output power.