HYDRAULICALLY BALANCED STEPWISE VARIABLE DISPLACEMENT VANE PUMP

A binary vane pump providing a balanced, stepwise variable displacement is provided. The binary vane pump includes a pressure plate having first and second discharge ports configured to discharge fluid from the binary vane pump to a first discharge path and a thrust plate having third and fourth discharge ports configured to discharge fluid from the binary vane pump to a second discharge path. The binary vane pump also includes a ring positioned axially between the pressure plate and thrust plate, the ring having an inner cam surface, a rotor rotatably disposed within the ring, the rotor having a plurality of slots and a plurality of vanes received and movable within respective slots, and a shaft extending along an axis through the rotor and configured to rotate the rotor so that the vanes are rotatable within the ring.