Rotary valve

Abstract

A rotary valve capable of high flow rates, minimal pressure drop, and rapid actuation is presented. According to one aspect, the rotary valve is characterized by a unique pressure balancing system operating on the rotary spool of the valve to reduce side force caused by pressure at the flow ports. According to another aspect, the rotary valve is characterized by a unique internal shiftable blocking spool in response to a failure condition or a modulating signal. According to another aspect, a unique interface is provided for sealing a port of a rotary valve to an outer surface of a rotary spool. According to another aspect, the rotary valve is characterized by a unique interface provided for sealing a port to an outer surface of the rotary spool. According to another aspect, a rotary valve is characterized by a unique three-way three-or-more-position configuration. According to another aspect, a rotary valve is characterized by a unique four-port three-position configuration.

1 - 7 . (canceled) 
     
     
         8 . A rotary valve comprising:
 a housing having a cavity;   a rotary spool positioned within and rotatably movable in the cavity of the housing about a rotation axis, the spool having a fluid passageway extending through the spool between first and second openings at an outer radial surface of the spool; and   a second spool movable with respect to the rotary spool for restricting flow through the fluid passageway of the rotary spool, and rotatably movable with the rotary spool about the rotation axis,   wherein the housing includes first and second flow ports opening to the cavity at radially spaced apart locations that respectively will align with the first and second openings at the outer radial surface of the spool at a first rotated position of the rotary spool,   wherein the second spool is positioned in a bore through the rotary spool, intersects the fluid passageway, is movable within the bore   wherein the second spool is configured to restrict flow through the fluid passageway in a first position and to not restrict flow through the fluid passageway in a second position, and   wherein the second spool is biased towards the first position.   
     
     
         9 - 10 . (canceled) 
     
     
         11 . The rotary valve of  claim 8 , wherein the second spool completely blocks flow through the fluid passageway when in the first position. 
     
     
         12 . (canceled) 
     
     
         13 . The rotary valve of  claim 8 , wherein the second spool is axially moveable within the bore for selectively opening and closing the passageway. 
     
     
         14 . The rotary valve of  claim 8 , wherein the axis of the bore and the second spool are perpendicular to the fluid passageway of the rotary spool. 
     
     
         15 . The rotary valve of  claim 14 , wherein the bore and the second spool are axially disposed within the rotary spool. 
     
     
         16 - 34 . (canceled) 
     
     
         35 . The rotary valve of  claim 8 , further comprising an actuator configured to actuate the rotary spool. 
     
     
         36 . The rotary valve of  claim 35  further comprising an actuator configured to actuate the second spool.