Patent ID: 6068460
Filing Date: 2000-05-30
Classification: F04C

Abstract:
A rotary fluid pressure device of the type including housing means defining a fluid inlet means and a fluid outlet means; fluid energy-translating displacement means defining expanding and contracting fluid volume chambers, stationary valve means defining stationary fluid passages in fluid communication with said expanding and contracting fluid volume chambers, a rotary disc valve member disposed rearwardly of said stationary valve means, and defining inlet and outlet valve passage means providing fluid communication between said fluid inlet and outlet means, respectively, and said stationary fluid passages, in response to rotation of said disc valve member; and a generally annular balancing ring member in engagement with a rear surface of said disc valve member, and adapted to maintain said disc valve member in sealing engagement with said stationary valve means; said housing means enclosing said disc valve member and said balancing ring member, and defining control fluid passage means; said disc valve member and said balancing ring member cooperating to define motor valve passage means operable to provide fluid communication between said control fluid passage means defined by said housing means and said inlet and outlet valve passage means defined by said rotary disc valve member; and control valve means selectively operable between a first low speed, high torque condition and a second high speed, low torque condition; characterized by:(a) said motor valve passage means comprising first, second, third, and fourth motor valve passages; and(b) said control valve means defining first, second, third, and fourth control valve passages, in fluid communication, respectively, with said first, second, third, and fourth motor valve passages whereby;(c) when said control valve means is in said high speed, low torque condition, said first control valve passage and said first motor valve passage provide fluid communication from said fluid inlet means to a plurality of said expanding fluid volume chambers, said second control valve passage and said second motor valve passage are in fluid communication with the remainder of said expanding fluid volume chambers, said fourth control valve passage and said fourth motor valve passage provide fluid communication from a plurality of said contracting fluid volume chambers to said fluid outlet means, and said third control valve passage and said third motor valve passage are in fluid communication with the remainder of said contracting fluid volume chambers, and said control valve means provides fluid communication between said second and third control valve passages.