Electrical hybridization of hydromechanical variable transmission

A hybrid hydromechanical variable transmission (HVT) system, comprising:

• a hydrostatic assembly including a variable displacement hydraulic motor and a variable displacement hydraulic pump;
• a multi-speed gearbox mechanically coupled to the hydrostatic assembly and including a plurality of clutches configured to shift the system between a plurality of drive ranges;
• a planetary gear set mechanically coupled to the multi-speed gearbox, the hydrostatic assembly, and an output shaft;
• an electric machine directly rotationally coupled to an input shaft of the multi-speed gearbox via a dog clutch engaged in a first position, and directly rotationally coupled to the planetary gear set via the dog clutch engaged in a second position;
• a battery coupled to the electric machine;
• and,
• a controller including instructions stored in non-transitory memory that when executed in response to a battery charge request, cause the controller to adjust the dog clutch to the first position to rotationally couple the electric machine to the input shaft;
• and,
• in response to a power recovery or power boost request, cause the controller to adjust the dog clutch to the second position to rotationally couple the electric machine to the output shaft via the planetary gear set.