Dual-Concentric Control Valve with Direct Drive Control and Failed Motor Protection

Abstract

Systems and methods include providing an aircraft with a direct drive dual-concentric valve (D3V) having a body, an outer secondary spool coaxially located within a bore of the body and linearly displaceable relative to the body, an inner primary spool coaxially located within a bore of the secondary spool and linearly displaceable relative to the secondary spool and the body, and multiple motor assemblies coupled to the primary spool that provide selective displacement of the primary spool or the secondary spool. Each motor assembly includes a clutching mechanism that selectively couples a motor of the motor assembly to and from the primary spool.

What is claimed is: 
     
         1 . A spool valve, comprising:
 a body;   an outer secondary spool coaxially located within a bore of the body and linearly displaceable relative to the body;   an inner primary spool coaxially located within a bore of the secondary spool and linearly displaceable relative to the secondary spool and the body; and   a plurality of motor assemblies, each motor assembly comprising:
 a motor configured to provide selective displacement of the primary spool; and 
 a clutch configured to selectively couple the motor to the primary spool. 
   
     
     
         2 . The valve of  claim 1 , wherein the spool valve comprises a direct drive, dual concentric valve (D3V) comprising tandem flow-summing four-way valves at each end of the D3V. 
     
     
         3 . The spool valve of  claim 1 , further comprising: at least one primary spool position sensor configured to determine the position of the primary spool with respect to the secondary spool, and at least one secondary spool position sensor configured to determine the position of the secondary spool with respect to the body. 
     
     
         4 . The spool valve of  claim 1 , wherein the spool valve comprises at least two motor assemblies. 
     
     
         5 . The spool valve of  claim 1 , wherein each motor assembly comprises an eccentric drive unit, and wherein each clutch is configured to selectively coupled an associated motor to an associated eccentric drive unit. 
     
     
         6 . The spool valve of  claim 1 , wherein each motor assembly comprises a motor position sensor configured to determine the position of the respective motor. 
     
     
         7 . The spool valve of  claim 6 , wherein each clutch is configured to selectively decouple its associated motor from the primary spool in response to the associated motor position sensor detecting a motor fault. 
     
     
         8 . The spool valve of  claim 7 , wherein the clutches comprise rotary clutches. 
     
     
         9 . The spool valve of  claim 7 , wherein the clutches comprise linear clutches. 
     
     
         10 . The spool valve of  claim 7 , wherein the clutches comprise at least one of mechanically actuated, electromechanically actuated, hydraulically actuated, electromagnetically actuated, piezo-actuated, and magnetorheological-activated clutches. 
     
     
         11 . The spool valve of  claim 1 , wherein displacement of the primary spool alters a flowpath through the spool valve to alter a pitch of a plurality of rotor blades of an aircraft. 
     
     
         12 . An aircraft, comprising:
 a piston actuator; and   a spool valve hydraulically coupled to the piston actuator and comprising:
 a body; 
 an outer secondary spool coaxially located within a bore of the body and linearly displaceable relative to the body; 
 an inner primary spool coaxially located within a bore of the secondary spool and linearly displaceable relative to the secondary spool and the body; and 
 a plurality of motor assemblies, each motor assembly comprising:
 a motor configured to provide selective displacement of the primary spool to actuate the piston actuator, and 
 a clutch configured to selectively couple the motor to the primary spool. 
 
   
     
     
         13 . The aircraft of  claim 12 , wherein the piston actuator is coupled to a plurality of rotor blades, and wherein actuation of the piston actuator alters a pitch of the plurality of rotor blades. 
     
     
         14 . The aircraft of  claim 12 , wherein each motor assembly comprises a motor position sensor configured to determine the position of the respective motor. 
     
     
         15 . The aircraft of  claim 14 , wherein each clutch is configured to selectively decouple its associated motor from the primary spool in response to a motor fault of the associated motor. 
     
     
         16 . The aircraft of  claim 12 , wherein each clutch is controlled by a flight control system of the aircraft. 
     
     
         17 . The aircraft of  claim 16 , wherein the aircraft comprises at least one of a rotary-wing aircraft, a tiltrotor, and a fixed-wing aircraft. 
     
     
         18 . A method of operating an aircraft, comprising:
 providing an aircraft comprising a piston actuator and a spool valve comprising a plurality of motor assemblies, each motor assembly comprising a clutch and a motor configured to provide selective displacement of the primary spool to actuate the piston actuator;   detecting a failure of a motor; and   disengaging the clutch associated with the at least one failed motor.   
     
     
         19 . The method of  claim 18 , wherein detecting the failure of a motor is determined by the motor position sensor communicating information to a flight control system regarding the position of at least one of the motors that does not match a commanded operational position of the motor. 
     
     
         20 . The method of  claim 18 , further comprising: simultaneously engaging a clutch associated with another motor configured in a standby mode with the disengaging the clutch associated with the at least one failed motor to maintain redundancy of multiple engaged motor assemblies of the spool valve.