Patent ID: 6810666
Filing Date: 2004-11-02
Classification: F01D

Abstract:
A variable geometry turbine comprising:a housing; a rotor supported in a rotary manner in said housing, said housing defining a spiral-shaped inlet channel for operating fluid, said inlet channel surrounding said rotor; a fluid control line; a fluid actuator; an auxiliary chamber connection means; and an annular vaned nozzle having a geometry interposed radially between the channel and the rotor, said annular vaned nozzle comprising an axially moving control member and a throat section, said control member being configured to control the flow of the operating fluid from the inlet channel to the rotor by varying said throat section, wherein said control member as constitutes an annular piston of said fluid actuator, and the control member being actuated directly by a control pressure via said fluid control line, wherein the control member further comprises a control surface subject to the control pressure and oriented axially so as to move the control member toward a closed configuration in response to an increase in this control pressure, the control member further having a reaction surface subject to the pressure of the operating fluid in the nozzle and oriented axially in a direction opposite to that of the control surface, and wherein the control member further comprises at least one auxiliary surface oriented axially in the same direction as the control surface, said control member being housed in said auxiliary chamber, and said connection means configured to supply the operating fluid from the annular vaned nozzle to the auxiliary chamber.