Free piston pump assembly has a hollow zone in the piston to take a mechanical resonator suspended on coil springs with oscillation in the direction of piston movement for transfer of housing oscillation effectively to a low-mass piston

摘要

In the free piston pump assembly, the piston (4) has a hollow zone (20) to take a mechanical resonator (22) with oscillation in the direction of piston movement. It is a mass, suspended from a spring (24.26), with its natural frequency equal to the frequency of the pump housing (2) oscillation. The spring is a coil spring, and the mass body has a rotary symmetrical shape with its rotary axis aligned on that of the piston.