A rotor for an electrical machine includes a rotor core having a plurality of circumferentially spaced apart rotor poles. Windings are seated in gaps between circumferentially adjacent pairs of the rotor poles. A wedge secures the windings in each gap. The wedge includes a first member made of a first material and at least one second member made of a second material. The second material has a higher electrical conductivity than the first material. The wedge is configured to supply Q-axis damping. A pair of end plates is connected electrically to the at least one second member at opposing longitudinal ends thereof thereby completing a Q-axis winding circuit for each wedge.

A motor includes an annular core formed by stacking a plurality of electromagnetic steel sheets; end plates disposed at both ends of the core in an axial direction; a balance weight disposed on a side of one of the end plates, the side being opposite the core; and a spacer disposed between the one of the end plates and the balance weight, the spacer being configured to create a space between the one of the end plates and the balance weight. The motor is entirely fastened by allowing at least one of a plurality of rivets arranged in a circumferential direction of the core to pass through the core and the end plates in the axial direction, and allowing remaining at least one rivet to pass through the core, the end plates, the spacer, and the balance weight in the axial direction.

A compressor includes a rotor core, a stator configured to rotate the rotor core about a rotational axis, and a compressing unit that is driven as the rotor core is rotated, wherein the rotor core includes a stack of a plurality of core sheets, each core sheet of the core sheets has a balancing hole by which a center of a mass of the core sheet is offset in a radial direction from the rotational axis, the rotor core includes an eccentric portion and an eccentricity alleviating portion, the center of a mass of the eccentric portion is offset in the radial direction from the rotational axis, and in the eccentricity alleviating portion, the eccentricity of the balancing holes of some of the core sheets is canceled out by the eccentricity of the balancing holes of others of the core sheets.

An electric engine for a vertical takeoff-and-landing aircraft comprising an electric motor assembly including a stator and a rotor. The electric engine may comprise an inverter assembly, a gearbox assembly including a sun gear, and a main shaft including a length of the main shaft that extends from a first end of the main shaft through the gearbox assembly and through the electric motor assembly to a second end of the main shaft. The electric engine may include a hydrodynamic bearing located between the main shaft and sun gear, and a bearing including an inner race mechanically coupled to the main shaft and an outer race mechanically coupled to the rotor. The electric engine may include a bearing including an outer race mechanically coupled to an inner surface of the rotor.

A rotor assembly has a sleeve, a rotor hub, a lamination core, and a plurality of tapered magnets disposed circumferentially around an inner diameter of the sleeve. The plurality of tapered magnets are configured to abut on one another. The plurality of tapered magnets includes a first set of tapered magnets and a second set of tapered magnets. Insertion of the first set of tapered magnets axially relative to the second set of tapered magnets is configured to increase a diameter of the sleeve. The rotor hub is configured to retain at least one of the lamination core, the plurality of tapered magnets, or the sleeve.

A rotor assembly has a sleeve, a rotor hub, a lamination core, and a plurality of tapered magnets disposed circumferentially around an inner diameter of the sleeve. The plurality of tapered magnets are configured to abut on one another. The plurality of tapered magnets includes a first set of tapered magnets and a second set of tapered magnets. Insertion of the first set of tapered magnets axially relative to the second set of tapered magnets is configured to increase a diameter of the sleeve. The rotor hub is configured to retain at least one of the lamination core, the plurality of tapered magnets, or the sleeve.

An electric propulsion system for a vertical take-off and landing (VTOL) aircraft, the electric propulsion system including an electrical motor having a stator and a rotor. The electric propulsion system may include a main shaft possessing at least one shoulder on an outer surface of the main shaft. The electric propulsion system may include a gearbox assembly comprising a sun gear that is concentrically aligned with the main shaft at least one planetary gear that interfaces with the sun gear. The electric propulsion system may include a planetary carrier, wherein a center of the planetary carrier is concentrically aligned with the main shaft. The electric propulsion system may include a propeller flange assembly that travels through the rotor, and an axial buttress positioned in the at least one shoulder located on the main shaft.

A system for an aircraft includes a tiltable proprotor that is tiltable between a lift position for providing lift for the aircraft and a forward flight position for providing forward propulsion for the aircraft is provided. The system includes at least one actuator for adjusting a tilt angle of the tiltable proprotor; and at least one passive damper connected to the tiltable proprotor and configured to limit a rate of change of the tilt angle of the tiltable proprotor.

An electric propulsion system comprising an electric motor assembly. The electric motor assembly may include a housing having an internal volume, a stator ring disposed about a perimeter of the internal volume, and a rotor positioned within the stator. The electric motor assembly may include a main shaft connected to the rotor via a gear reduction, wherein the main shaft extends through the rotor. The electric motor assembly may include a collar connected to the main shaft, wherein the collar encircles the main shaft, and at least a portion of the collar is configured to direct a fluid away from the main shaft and toward the stator ring.

An electric propulsion system for a vertical take-off and landing (VTOL) aircraft having a heat exchanger to cool fluids used in an electrical engine, the electric propulsion system comprising at least one electrical engine mechanically connected directly or indirectly to a fuselage of the VTOL aircraft and electrically connected to an electrical power source. The electrical engine may comprise an electrical motor having a stator and a rotor; a gearbox assembly comprising a sun gear; at least one planetary gear; a ring gear; and a planetary carrier. The electric engine may include an inverter assembly comprising a thermal plate and an inverter assembly housing; an end bell assembly that is connected to the thermal plate of the inverter assembly; and a heat exchanger comprising an array of cooling fins and tubes.