Hybrid Cart

The base vehicle was retrofited with a series hydraulic hybrid system. This hydraulic system included a fixed displacement hydraulic pump, 2 - 2.5 gallon accumulators, a bi-rotational fixed dispalcement hydraulic motor, and throttle control valves. A picture of the hydraulic schematic can be seen below. Hydraulic System Schematic

Frame Modifications

Several frame modifications were made to the base case cart to mount hydraulic components. First, a mounting rack for the accumulators was welded onto the frame just behind the back rests.

Next, a frame to bolt on the low pressure resevoir was welded onto the rear of the cart.

Other modifications to the cart included re-routing the gas engine exhaust, adjustinging acceleration and brake linkages, and reworking the jack-shaft into the rear end.

Drive Train

The drive train of the hydraulic hybrid cart consisted of the following major components: gasoline engine, fixed displacement hydraulic pump, restrictive flow control valves, and a fixed displacement bi-rotational hydraulic motor. The drive train was implemented following the projects hydraulic schematic.

Mounted Fixed Dispacement Hydraulic Pump

Restrictive Flow Control Valve

Bi-rotational Hydraulic Motor

Completed Hydraulic Hybrid Cart

After the retro-fit hydraulic hybrid system was implemented inot the cart, fuel consumption tests were performed. Under city driving conditions, the cart operated at 21 MPG ( a 52% improvement from the base case cart!).