Hydrostatic torque modulation is a new, at moment theoretical approach, to developing advanced AWD4WD transmissions. The basic component is a rotational hydrostatic modulator. It is derived from a low-speed high-torque hydrostatic machine. As such, it can be integrated into a standard mechanical AWD4WD transmission as a replacement for the clutch, where torque is controlled through energy dissipation. Controlled by a simple solenoid valve, it provides torque vectoring with a reaction time shorter than 0.5 s, and it provides additional safety features that result in a more robust AWD4WD transmission. As it can modulate torque with energy flow control/transfer, it offers much more than existing systems based on controlled clutches. Specifically, hydrostatic torque modulation, when it is integrated into the AWD4WD transmission, brings CVT or ICT performance. As torque modulation is performed through the control of the energy flow, it provides torque control from 0 km/h without using a clutch. This option is relevant in extreme situations where standard solutions cause heat buildup that slows the advancement in order to protect the clutch from burning out. With the introduction of a hydrostatic torque modulator, for each wheel, allows for maneuvering similar to tracked vehicles i.e. the option of 180° spot turns. In addition, the technology can be integrated into mild hybrid vehicles with 48 V starter-generators. Such vehicles are thus transformed it into AWD4WD vehicles with ZEV options in traffic jams at speed limits of 40 km/h, and optional torque vectoring at speed limits well above 100 km/h. In addition, advanced suspensions can be developed.
