Rocker arm system for engine valve actuation

Abstract

Systems and methods for actuating engine valves are disclosed. The systems may include primary and auxiliary rocker arms disposed adjacent to each other on a rocker arm shaft. A rocker arm coupling assembly may be disposed between the auxiliary rocker arm and the primary rocker arm. The coupling assembly may include a piston having a curved surface disposed in a bore formed in the primary rocker arm, and a slot having a second radius of curvature formed in the auxiliary rocker arm. The piston may be selectively hydraulically locked into an extended position between the primary and auxiliary rocker arms so as to selectively transfer one or more auxiliary valve actuation motions from the auxiliary rocker arm to the primary rocker arm.

1 . A system for actuating an engine valve comprising: 
 a rocker arm shaft;    a means for imparting primary valve actuation motion;    a primary rocker arm disposed on the rocker arm shaft, said primary rocker arm being adapted to actuate an engine valve and receive motion from the means for imparting primary valve actuation motion;    a means for imparting auxiliary valve actuation motion selected from the group consisting of: engine braking motion, exhaust gas recirculation motion, and brake gas recirculation motion;    an auxiliary rocker arm disposed on the rocker arm shaft adjacent to the primary rocker arm, said auxiliary rocker arm being adapted to receive motion from the means for imparting auxiliary valve actuation motion; and    a rocker arm coupling assembly disposed between the auxiliary rocker arm and the primary rocker arm, said coupling assembly being adapted to selectively transfer one or more auxiliary valve actuation motions from the auxiliary rocker arm to the primary rocker arm.    
   
   
       2 . The system of  claim 1 , wherein said coupling assembly comprises: 
 an actuator piston disposed in a bore formed in said primary rocker arm; and    a slot formed in said auxiliary rocker arm for selectively receiving said actuator piston.    
   
   
       3 . The system of  claim 2 , wherein said actuator piston is disposed in said auxiliary rocker arm, and said slot is formed in said primary rocker arm.  
   
   
       4 . The system of  claim 2 , wherein said actuator piston includes a curved surface to facilitate engagement with said slot.  
   
   
       5 . The system of  claim 2 , wherein said slot includes a curved surface to facilitate engagement with said piston.  
   
   
       6 . The system of  claim 1 , wherein said primary rocker arm comprises an exhaust rocker arm, and said auxiliary rocker arm comprises an intake rocker arm.  
   
   
       7 . The system of  claim 1 , further comprising: 
 a control valve; and    a lash piston disposed in a bore formed in said primary rocker arm.    
   
   
       8 . A system for actuating an engine valve comprising: 
 a rocker arm shaft;    a means for imparting primary valve actuation motion;    a primary rocker arm disposed on the rocker arm shaft, said primary rocker arm being adapted to actuate an engine valve and receive motion from the means for imparting primary valve actuation motion;    a means for imparting auxiliary valve actuation motion;    an auxiliary rocker arm disposed on the rocker arm shaft adjacent to the primary rocker arm, said auxiliary rocker arm being adapted to receive motion from the means for imparting auxiliary valve actuation motion; and    a coupling assembly, comprising:    an actuator piston disposed in a bore formed in said primary rocker arm; and    a slot formed in said auxiliary rocker arm for selectively receiving said actuator piston, wherein said actuator piston includes a curved surface to facilitate engagement with said slot.    
   
   
       9 . The system of  claim 8 , said coupling assembly being adapted to selectively transfer one or more auxiliary valve actuation motions from the auxiliary rocker arm to the primary rocker arm.  
   
   
       10 . The system of  claim 8 , wherein said actuator piston includes a curved surface to facilitate engagement with the slot.  
   
   
       11 . The system of  claim 8 , wherein said primary rocker arm comprises an exhaust rocker arm, and said auxiliary rocker arm comprises an intake rocker arm.  
   
   
       12 . The system of  claim 8 , further comprising: 
 a control valve; and    a lash piston disposed in a bore formed in said primary rocker arm.    
   
   
       13 . The system of  claim 8 , the auxiliary valve actuation motion selected from the group consisting of: engine braking motion, exhaust gas recirculation motion, and brake gas recirculation motion.