Abstract: A propulsion system includes an engine having an engine output shaft, and an electric motor assembly including an electric motor having an output gear fixed to rotate with a driveshaft, and a disconnect clutch. The electric motor assembly further includes a common housing positioned around the electric motor and the disconnect clutch, and a fluid system including a fluid circuit for cooling and lubrication of the electric motor and the disconnect clutch. Related methodology including operating a propulsion system in a motor-only mode, an engine-only mode, and a hybrid mode is also disclosed.

Abstract: A propulsion system includes an electric motor assembly having an electric motor, a driveshaft, and a disconnect clutch. The disconnect clutch is structured to couple the driveshaft to an engine output shaft. The propulsion system further includes a fluid system having a cooling and lubrication fluid circuit fluidly connected to a first pump, and a clutch actuation fluid circuit fluidly connected to a second pump. The cooling and lubrication fluid circuit is fluidly connected to the clutch actuation fluid circuit via at least one of respective pump outgoing conduits from the first pump and the second pump or respective pump supply conduits to the first pump and the second pump. Related operating methodology is also disclosed.

Abstract: A carrier for a planetary gear train includes a hub disposed about an axis of rotation, the hub having an external cylindrical surface including a plurality of splines extending along a longitudinal direction, the longitudinal direction being parallel to the axis of rotation; and a deck extending away from the hub along a radial direction, the radial direction being transverse to the longitudinal direction. The deck defining a plurality of holes therethrough, each hole of the plurality of holes being configured to receive an axle of a planet gear of the plurality of planet gears, the hub being disposed between the plurality of holes and the axis of rotation along the radial direction. The splines have a value of a parameter (P) that is not less than 2.5 and not greater than 6.0.

Abstract: A carrier for a planetary gear train includes a hub disposed about an axis of rotation, the hub having an external cylindrical surface including a plurality of splines extending along a longitudinal direction, the longitudinal direction being parallel to the axis of rotation; and a deck extending away from the hub along a radial direction, the radial direction being transverse to the longitudinal direction. The deck defining a plurality of holes therethrough, each hole of the plurality of holes being configured to receive an axle of a planet gear of the plurality of planet gears, the hub being disposed between the plurality of holes and the axis of rotation along the radial direction. The splines have a value of a parameter (P) that is not less than 2.5 and not greater than 6.0.