PISTON PUMP NOISE ATTENUATOIN THROUGH MODIFICATION OF PISTON TRAVEL TRAJECTORY

Piston pumps are widely used in industrial and mobile applications to transmit power. These pumps emit loud and objectionable noise when operated at high pressure and high speeds. It is generally accepted that large amplitude of flow ripple causes pumps to produce unacceptable noise level. The flow ripple could be thought of composed of two components a kinematic component resulting out of periodic nature of flow and a dynamic component resulting due to compression and decompression of fluid. There has been considerable research activity to reduce the noise induced by the dynamic component however very little is done to attenuate the noise generated due to the periodic nature of flow. This research investigated one method to reduce noise associated with kinematic component for axial and radial type piston pumps. A theoretical analysis is presented deriving the equations defining the motion of pistons on their regular trajectory as well as their modified trajectory. It is shown here that by altering the trajectory of the piston travel the amplitude of the kinematic flow component could be reduced by up to 85% in some conditions. While effectiveness of the techniques aimed at reducing the dynamic flow component are speed and pressure dependent, the techniques presented here work with same effectiveness throughout the entire spectrum of speed and pressure towards reducing the noise.