Abstract: A stator assembly for a rotating electrical machine is operatively associated with an internal cooling circuit including a plurality of cooling channels disposed through a stator core. To directed a liquid coolant medium through the stator core without leakage, the internal cooling circuit is formed from a plurality of cooling tubes including linear tubes and elbow tubes. Linear tubes are disposed in the cooling channels and can be expanded with a hydraulic expansion tool to frictionally fit the linear tube therein. The elbow tubes can fluidly couple two or more linear tubes and are disposed proximately beyond the first and second axial end faces of the stator core. To encapsulate the elbow tubes, first and second stator end castings of thermally conductive, electrically isolating material can be cast adjacent the first and second axial end faces.

Abstract: The present invention relates to high-resistivity permanent magnets, their preparation and their application in electrical machines. A permanent magnet according to the present invention comprises a permanent magnet comprising a magnetic material and a shaped inorganic insulating element, wherein a shape and a size of the shaped inorganic insulating element have been substantially unchanged by the sintering, wherein the shaped inorganic insulating element has a width and a length which are both at least 10 times larger than an average grain diameter of the magnetic material after sintering, and wherein an arithmetic average waviness Wa of an interface between the magnetic material and the shaped inorganic insulating element is less than 10% of a local wall thickness of the shaped inorganic insulating element after sintering.

Abstract: The present disclosure relates to electrical machines, such as liquid-cooled motors. The liquid-cooled motors can include a stator with cooling tube channels (e.g., corrugated channels) having tubes inserted and expanded. Lamination holes for each lamination in the lamination stack of the stator can have varying diameter along the axial direction to achieve a corrugated internal feature. The tubes for cooling liquid can be fitted in the lamination holes of the stator. In some embodiments, hydraulic expansion expands and plastically deforms the tubes to the contour of the corrugated internal feature of the corrugated channel. In some embodiments, the tube can also be inserted in the corrugated channel and a stator head plate, thereby helping create a compact stator by removing the need for tube connections to connect the corrugated channels.

Abstract: A rotor for a permanent magnet motor, including a rotor body having a cylindrical surface having a circumference. A plurality of magnets are disposed on the cylindrical surface at spaced intervals at the circumference, each of the magnets having a base disposed on the cylindrical surface and a top oriented radially away from the base, a sloping front side and a sloping rear side defining with the base and top an isosceles trapezoid shape in a cross sectional plane normal to an axis of rotation of the rotor, the isosceles trapezoid shape being broader at the base. A plurality of magnet retainers, each magnet retainer disposed between a neighboring pair of the plurality of magnets, include angled faces that engage respective front and rear sides of adjacent pairs of the plurality of magnets.

Abstract: A permanent magnet motor is provided that produces variable magnetic flux. The motor may include two different types of permanent magnets with different coercivities. The magnetic state of one of the magnets may be altered during use. In one state, the effective magnetic flux of the motor is greater, and in another state, the effective magnetic flux of the motor is less.

Abstract: A stator assembly for a rotating electrical machine is operatively associated with an internal cooling circuit including a plurality of cooling channels disposed through a stator core. To directed a liquid coolant medium through the stator core without leakage, the internal cooling circuit is formed from a plurality of cooling tubes including linear tubes and elbow tubes. Linear tubes are disposed in the cooling channels and can be expanded with a hydraulic expansion tool to frictionally fit the linear tube therein. The elbow tubes can fluidly couple two or more linear tubes and are disposed proximately beyond the first and second axial end faces of the stator core. To encapsulate the elbow tubes, first and second stator end castings of thermally conductive, electrically isolating material can be cast adjacent the first and second axial end faces.

Abstract: A rotor assembly includes a rotor member and a plurality of permanent magnets. The rotor member has a hub with a central axis and a plurality of spokes extending radially outward relative to the hub. Each spoke has a radially inward end and a radially outward end. Each spoke also has a body section, a mounting section, and a flux barrier section. The body section extends from the radially outward end towards the radially inward end. The mounting section is interconnected to the hub. The flux barrier section is disposed between the body section and the mounting section and has at least one flux restriction web extending between the body section and the mounting section. The flux restriction web magnetically isolates the body section from the mounting section. A permanent magnet is disposed within each magnet-receiving slot between pairs of adjacent spokes. A motor with the rotor assembly is also disclosed.

Abstract: A method for additive manufacturing of an article having a controlled magnetic anisotropy includes: forming a metallic layer of the article using additive manufacturing, the metallic layer having a magnetic anisotropy aligned in a first direction; forming a subsequent metallic layer of the article using additive manufacturing, the subsequent metallic layer having the magnetic anisotropy aligned in a second direction different from the first direction; and repeating the forming of subsequent metallic layers of the article to form at least a portion of the article, each subsequent metallic layer having the magnetic anisotropy aligned in a different direction than a previous metallic layer.

Abstract: An electric machine includes a rotor and a stator. The stator includes a stator core having a plurality of slots. The stator further includes a plurality of drive modules configured to collectively produce an aggregate rotating magnetic field. Each respective drive module includes a power supply configured to generate a respective poly-phase alternating current (AC) output and is connected to a plurality of respective conductor windings. Each respective conductor winding includes a plurality of respective conductors, each respective conductor configured to carry a respective phase of the respective poly-phase AC output. Each respective drive module is configured to generate a rotating, poly-phase, multipole magnetic field. The rotating, poly-phase, multipole magnetic field is a superimposition of a plurality of respective mono-phase, multiple magnetic fields being generated by a respective conductor of the respective conductor winding.

Abstract: A method of performing de-excitation of a brushless synchronous machine having a stator; and a rotor including: a field winding, an exciter armature, a rectifier having thyristors, the rectifier having input terminals connected to the exciter armature and output terminals connected to the field winding, a field discharge resistor connected in series with the field winding, and a bypass switch connected in parallel with the field discharge resistor, the bypass switch being operable between a closed state in which the field discharge resistor is bypassed, and an open state, wherein the method including: a) controlling the thyristors to fire only during a negative half-cycle of the armature voltage waveforms, and b) controlling the bypass switch to obtain the open state from the closed state to thereby discharge a field winding current through the field discharge resistor.

Abstract: A rotating electrical machine of the double stator configuration includes a rotor shaped as a hollow cylinder disposed concentrically between an outer stator and an inner stator. The rotor can include plurality of radially spaced magnet cavities configured to receive permanent magnetic bars. To provide sufficient stiffness and rigidity, the rotor may be made from fiber composite material. To simplify construction, the rotor can be assembled from a plurality of rotor segments radially arranged about an axis line in which the magnet cavities are disposed.

Abstract: A drive system is provided for propelling a ship through water. The drive system has two propellers. The propellers are coaxial so that one propeller engages the incoming water first, and the other propeller engages the water after it passes through the first propeller. The drive system has a stator that causes a first rotor to rotate. The first rotor is connected to, the first propeller to cause the first propeller to rotate. The first rotor also causes a second rotor to rotate. The second rotor is connected to the second propeller to cause the second propeller to rotate.

Abstract: An electrical machine includes a stator including a plurality of stator windings; and a rotor in magnetic cooperation with the stator. The rotor includes a plurality of cooling passages extending therethrough, each cooling passage including an inlet for receiving oil and an outlet for discharging the oil. The electrical machine includes a rotating oil distribution member coupled to the rotor, the oil distribution member including a radially inward portion and a radially outward portion, the radially outward portion being disposed adjacent to the inlets of the plurality of cooling passages. A stationary oil delivery nozzle is constructed to discharge oil toward the radially inward portion of the oil distribution member. The oil distribution member is constructed to receive the oil discharged by the oil delivery nozzle, and to direct the oil to the inlets of the cooling passages to cool the rotor.

Abstract: A drive system is provided for propelling a ship through water. The drive system has two propellers. The propellers are coaxial so that one propeller engages the incoming water first, and the other propeller engages the water after it passes through the first propeller. The drive system has a stator that causes a first rotor to rotate. The first rotor is connected to, the first propeller to cause the first propeller to rotate. The first rotor also causes a second rotor to rotate. The second rotor is connected to the second propeller to cause the second propeller to rotate.

Abstract: A rotating electrical machine of the double stator configuration includes a rotor shaped as a hollow cylinder disposed concentrically between an outer stator and an inner stator. The rotor can include plurality of radially spaced magnet cavities configured to receive permanent magnetic bars. To provide sufficient stiffness and rigidity, the rotor may be made from fiber composite material. To simplify construction, the rotor can be assembled from a plurality of rotor segments radially arranged about an axis line in which the magnet cavities are disposed.

Abstract: Unique systems, methods, techniques and apparatuses of exciterless synchronous machines are disclosed. One exemplary embodiment is a fractional slot synchronous machine comprising a rotor including a first pole pair including a first pole including a first plurality of slots having a first center point and arranged on a first outer surface in a slot pattern; a second pole pair including a second pole including a second plurality of slots having a second center point and arranged on a second outer surface in the slot pattern; energy harvest windings arranged in a winding pattern within a portion of the first plurality of slots and arranged in the same winding pattern within a portion of the second plurality of slots, the energy harvest winding being structured to receive a harmonic power from the stator; and a rectifier structured to receive the harmonic power from the energy harvest winding.

Abstract: Unique systems, methods, techniques and apparatuses of an exciterless synchronous generator are disclosed. One exemplary embodiment is an exciterless synchronous generator comprising a stator, a rotor, and a startup excitation system. The stator includes a set of stator windings. The rotor includes an energy harvest winding, a DC power supply including a DC bus and coupled to the energy harvest winding, and a field winding coupled to the DC power supply. The startup excitation system comprises one of a magnetic field generation system structured to generate a magnetic field received by the energy harvest winding in response to a rotation of the rotor, wherein the magnetic field is converted to DC power with the DC power supply and transmitted to the field winding; or a rotor DC power source including and diode coupled in series across the DC bus.

Abstract: A method for additive manufacturing of an article having a controlled magnetic anisotropy includes: forming a metallic layer of the article using additive manufacturing, the metallic layer having a magnetic anisotropy aligned in a first direction; forming a subsequent metallic layer of the article using additive manufacturing, the subsequent metallic layer having the magnetic anisotropy aligned in a second direction different from the first direction; and repeating the forming of subsequent metallic layers of the article to form at least a portion of the article, each subsequent metallic layer having the magnetic anisotropy aligned in a different direction than a previous metallic layer

Abstract: Unique systems, methods, techniques and apparatuses of an exciterless synchronous machine are disclosed. One exemplary embodiment is a salient pole rotor for an electric machine including one set of pole pairs including a first, second, and third pole pair; a field winding; a set of energy harvest windings, each winding mounted to each of the plurality of pole pairs and structured to receive a harmonic component of AC power from a stator; and a DC power supply structured to receive the harmonic component from the set of energy harvest windings, convert the harmonic component to DC power, and output the DC power to the field winding. The set of energy harvest windings are arranged in a first sequence on the first pole pair, a second sequence on the second pole pair, and a third sequence on the third pole pair, and each sequence is different.

Abstract: Unique systems, methods, techniques and apparatuses of exciterless synchronous machines are disclosed. One exemplary embodiment is a fractional slot synchronous machine comprising a rotor including a first pole pair including a first pole including a first plurality of slots having a first center point and arranged on a first outer surface in a slot pattern; a second pole pair including a second pole including a second plurality of slots having a second center point and arranged on a second outer surface in the slot pattern; energy harvest windings arranged in a winding pattern within a portion of the first plurality of slots and arranged in the same winding pattern within a portion of the second plurality of slots, the energy harvest winding being structured to receive a harmonic power from the stator; and a rectifier structured to receive the harmonic power from the energy harvest winding.