| A pump test rig has been built to imitate the operation of the pumping portion of a Free-Piston Engine-Pump (FPEP). This test rig consists of two connected hydraulic pistons. One piston simulates the engine piston to drive the pumping piston. Check valves control flow in and out of the pumping chamber. The action of the suction check valve has been studied in detail. The dominant influence affecting flow into the pump chamber was the inertia of the fluid.; A hydro-pneumatic rebound system was designed and built for a FPEP with opposed pistons forming a combustion chamber between the pistons. A hydraulic cylinder was connected to each engine piston. Appropriate plumbing connected the cylinders to a poppet valve, which controlled the flow of oil from an accumulator to the cylinders. The design of the plumbing and location of the poppet valve influenced the operation of the rebound system. |
