A transmission assembly for a work vehicle having an engine includes a variator operably connected to the engine, a gear arrangement configured to provide a selective gear reduction for transmission of output power from the variator to an output shaft, and an electrical machine unit. The electrical machine unit further includes a main shaft operably connected to the variator, a first rotor configured to rotatably drive a first shaft, a second rotor configured to rotatably drive a second shaft, and a clutch configured to selectively couple the first shaft or the second shaft, or both the first shaft and the second shaft, to the main shaft. The clutch, the first rotor, and the second rotor are operable to control a speed and rotational direction of the main shaft in providing rotational power to the variator.