초록 ▼

A pump jet having a perforated wear liner inside the rotor housing for altering the spectrum of noise produced by the pump jet. The perforated wear liner is inserted in a circumferential recess formed on the inner surface of the rotor housing and surrounds the rotor tip region. The throughholes or p

A pump jet having a perforated wear liner inside the rotor housing for altering the spectrum of noise produced by the pump jet. The perforated wear liner is inserted in a circumferential recess formed on the inner surface of the rotor housing and surrounds the rotor tip region. The throughholes or perforations are preferably constant in size and regularly spaced. The perforated wear liner acts as a Helmholtz resonator liner which alters the spectrum of noise emitted from the pump jet during operation. Proper selection of the size, number and spacing of the holes permits the designer to control the specific noise spectrum range that is emitted from the front and rear lobes of the pump jet, thereby altering the hydrodynamic noise field.

대표청구항 ▼

[ What is claimed is:] [1.]1. A pump jet apparatus for a marine engine, comprising:a rotor assembly mounted on a rotatable shaft, said rotor assembly comprising a rotor hub coupled to said rotatable shaft and a plurality of rotor blades, each rotor blade being connected at one end to said rotor hub;

[ What is claimed is:] [1.]1. A pump jet apparatus for a marine engine, comprising:a rotor assembly mounted on a rotatable shaft, said rotor assembly comprising a rotor hub coupled to said rotatable shaft and a plurality of rotor blades, each rotor blade being connected at one end to said rotor hub;a rotor housing surrounding said rotor assembly, having an inlet and an outlet, and comprising a circumferential recess surrounding said rotor blades;a ring-shaped wear liner installed in said circumferential recess and having a multiplicity of holes extending radially therethrough;a stator housing coupled to said rotor housing and having an inlet and an outlet for water flow, said inlet of said stator housing being in flow communication with said outlet of said rotor housing; anda stator hub positioned rearwardly of said rotor hub and inside said stator housing.