Hydraulic regenerative braking and four wheel drive system

A hydraulic unit adapted for use with a wheel of a vehicle to act as either a pump to drive fluid or a motor to drive the wheel or both and to be connected to low and high pressure sources of fluid, the hydraulic unit comprising:

• A and B conduits connectible with the low and high pressure sources;
• a rotary cam adapted to be affixed to the wheel to turn therewith and having a plurality of lobes along its outer radial periphery and a pair of side sealing surfaces;
• a stationary member adapted to be affixed to the vehicle relative to the rotary member and having a plurality of circumferentially spaced radial cylinders, each of the cylinders being in fluid communication with the A and B conduits and having an radially inwardly extending inverted U-shaped seal portion;
• a plurality of pistons, each having a body and a follower, the bodies sealingly cooperating with the plurality of cylinders to bound variable volume chambers;
• and
• seal means adapted to seal between the side sealing surfaces of the rotary cam and the U-shaped seal portion thereby preventing fluid from leaking on brake pads.

A hydraulic unit adapted for use with a wheel of a vehicle having a disk and caliper brake to operate as pump to pump fluid or as a motor turn the wheel or both, the hydraulic unit comprising:

• a rotary cam adapted to be affixed to the wheel to turn therewith and having a plurality of lobes;
• a plurality of circumferentially spaced and radially extending cylinders;
• a plurality of pistons, each piston having a body and a follower, each body being reciprocable within a cylinder with the follower being cooperable with the lobes of the rotary cam;
• and
• a closed annular stationary member supporting the cylinders and being adapted to affix to the vehicle, the annular member having an inner and an outer periphery with the outer periphery having a recess extending radially inwardly reducing the radial thickness of the annular member, the recess partially receiving the caliper therein.

A hydraulic unit adapted for use with a wheel of a vehicle to operate as pump to pump fluid or as a motor turn the wheel or both, the hydraulic unit comprising:

• a rotary cam adapted to be affixed to the wheel to turn therewith and having a plurality of lobes;
• a plurality of circumferentially spaced and radially extending cylinders;
• a plurality of pistons, each piston having a body and a follower, each body being reciprocable within a cylinder with the follower being cooperable with the lobes of the rotary cam;
• a stationary member supporting the cylinders and being adapted to affix to the vehicle;
• and
• a seal means for fluidly sealing between the rotary cam and the stationary member;
• wherein the rotary cam cooperates with the stationary member to form a closed annular scavenge chamber which collects fluid escaping between the pistons and cylinders.