Patent ID: 8298349

Claim:
A fluid nozzle for use in a high pressure water jetting system comprising: a housing configured to receive a source of high pressure water, said housing having defined therein an inner peripheral bore; a rotating member disposed within said inner peripheral bore, said rotating member including a shaft received at its rearward end within a bushing disposed in said housing, and a nozzle extending outwardly of said housing, said nozzle having openings extending along a direction that is oblique to an axis of rotation of said shaft and said nozzle; a central passage within said shaft for communicating high pressure fluid to the nozzle, and said shaft including leakage paths to provide leakage fluid from said central passage to an interface between an outer peripheral wall of said shaft and an inner peripheral wall of said bore in said housing, with said leakage paths communicating fluid to a forward fluid pressure chamber defined between the shaft and the housing, and to a first rearward fluid pressure chamber defined between the shaft and the housing; and a second rearward fluid pressure chamber defined between the shaft and the housing and adjacent to the bushing, the second rearward fluid pressure chamber configured to receive water that has leaked through the bushing and transport it to opposing thrust surfaces on the housing and the shaft, thereby applying a forward force to partially balance a rearward force generated by the forward fluid pressure chamber.