Energy Recovery System for an Added Motion System

Abstract

A hydraulic circuit is disclosed. The hydraulic circuit includes an actuating mechanism having an engine valve and an engine valve spring, an added motion valve system having a cam system, a valve in fluid communication with the actuator mechanism, and a dump valve and at least one check valve in fluid communication with the valve to allow a recovery of energy stored in an engine valve spring during closing movement of the engine valve associated with the added motion system. A method for controlling a hydraulic circuit is also disclosed.

1 . A hydraulic circuit, comprising:
 an actuating mechanism including an engine valve and an engine valve spring;   an added motion valve system including
 a cam system, and 
 a valve in fluid communication with the actuator mechanism; and 
   a dump valve and at least one check valve in fluid communication with the valve to allow a recovery of energy stored in an engine valve spring during closing movement of the engine valve associated with the added motion system.   
   
   
       2 . The hydraulic circuit according to  claim 1 , wherein the engine valve is an intake engine valve, and wherein the closing movement of the intake engine valve is during an added motion intake stroke of the intake engine valve. 
   
   
       3 . The hydraulic circuit according to  claim 1 , wherein the engine valve is an exhaust engine valve, and wherein the closing movement of the exhaust engine valve is during an added motion exhaust stroke of the exhaust engine valve. 
   
   
       4 . The hydraulic circuit according to  claim 1  further comprising a pressure rail that is in fluid communication with the valve, dump valve, and at least one check valve. 
   
   
       5 . The hydraulic circuit according to  claim 1 , wherein the dump valve momentarily decreases the pressure in the pressure rail. 
   
   
       6 . The hydraulic circuit according to  claim 1 , wherein the at least one check valve increases the pressure in the pressure rail. 
   
   
       7 . The hydraulic circuit according to  claim 1  further comprising an accumulator in fluid communication with the pressure rail to control pressure dynamics of the fluid in the pressure rail. 
   
   
       8 . A method for controlling a hydraulic circuit, comprising the steps of:
 opening an engine valve of an engine valve actuating mechanism during an added motion stroke movement of the engine valve actuating mechanism by way of a cam system;   compressing and storing energy in an engine valve spring during the opening movement of the engine valve;   locking the opening movement of the engine valve and delaying a closing movement of the engine valve;   evacuating fluid from a valve that locks and delays the closing movement of the engine valve;   closing the engine valve; and   recovering the stored energy in the engine valve spring and returning the energy stored in the engine valve spring to the cam system.   
   
   
       9 . The method according to  claim 8 , wherein the added motion stroke movement is during an intake stroke of the intake engine valve. 
   
   
       10 . The method according to  claim 8 , wherein the added motion stroke movement is during an exhaust stroke of the exhaust engine valve.