Abstract: An acoustic projector device having a piston exposed to pressure balanced air and water in an acoustically ideal position thereof within a piston chamber enclosing sleeve disposed in an outer housing to which deaerating water is selectively supplied in surrounding relation to the piston chamber sleeve while in communication with one side of the piston through axial slots in the sleeve uncovered by displacement of the piston from said acoustically ideal position.

Abstract: A fluidborne projector of sound derived from an electro-mechanical noise source translates acoustical energy through a piston subjected to balanced pressures of gas and liquid to enabled dynamic displacement thereof. Such displacement of the piston to a static position is regulated by controlled pressurization of gas, mechanically limited to prevent damage from changing pressures exerted on the piston.

Abstract: A crescent internal gear pump achieves greatly improved sealing against cter flow of fluid and greatly reduced noise by increase of the number of teeth of each of the ring and pinion gears which form discrete volumes of pumped fluid against a crescent-shaped member or insert. Reduction of the size of the teeth on the ring and pinion gears allows an increase in the angular extent of the crescent-shaped insert in order to increase the number of discrete volumes to be increased to a minimum of nineteen for each of the ring and pinion gears. The reduction in noise is accompanied by an increase in the fundamental frequency of the remaining noise, which can be more readily attenuated by acoustic filtering and isolation. Perfecting features of the invention include shaping of the crescent-shaped member to equalize the number of discrete volumes formed by each of the ring and pinion gears and shaping the teeth of the pinion gear to equalize the volumes of the discrete volumes formed by each gear.

Abstract: A control stator comprising a plurality of stationary vanes, ribs, or cavities is provided in a centrifugal pump having a shrouded impeller. The function of the control stator is to slow the swirl of fluid in the cavity between the casing and the impeller front shroud and thereby provide a very cost effective solution to the problem of excess axial thrust. The control stator is a simple, inexpensive non-rotating part that can be affixed in an existing space in the pump casing between the casing wall and the front shroud of the impeller.

Abstract: A mechanism for distributing axial thrust loads acting on a rotating shaft, ncluding dual thrust bearing assemblies concentrically mounted on the rotating shaft for transmitting axial thrust loads to the thrust load distributing mechanism. The thrust load distributing mechanism includes a stationary support member having at least one fulcrum to provide a reaction force to counterbalance the axial thrust loads acting on the rotating shaft, an annular load lever cooperating with each of the at least one fulcrum, at least two thrust transfer members cooperating with first and second segments on the annular load lever and the dual thrust bearing assemblies, and a force transmitting means.

Abstract: A recirculation diffuser for centrifugal pumps that produces a continuousrising head capacity curve and at the same time reduces levels of impeller vane-frequency sound and other high level acoustic flow tones. The conventional vane diffuser in the pump casing at the periphery of the rotary impeller is modified by separating one of the side shrouds from the diffuser vanes thereby creating a recirculation flow path around the vanes from the outside high pressure to the inside low pressure side.

Abstract: Pinion and ring gears intermeshed at one location within a pump chamber are rotationally supported therein by a cylindrical bearing portion of a housing sealingly enclosing said pump chamber between side plates of the housing within which stator windings are mounted in operative alignment with permanent magnets carried in one of the gears acting as a motor rotor as a result of interaction between such magnets and magnetic fields produced by electrical input power fed to the stator windings.