Crankshaft driven valve actuation

Abstract

A hydraulic valve actuation system ( 30 ) and a method of assembly can include a plurality of hydraulically actuatable valves ( 34 a, 34 b, 34 c, 34 d, 134 a, 134 b, 134 c, 134 d ) operably associated with an internal combustion engine ( 86 ) having a crankshaft ( 50 ) rotatable about a longitudinal axis. The actuation system ( 30 ) can include at least one cam lobe ( 52 ) mounted on or integrally formed with the crankshaft for rotation with the crankshaft ( 50 ). At least one fluid piston pump ( 36, 36 a, 36 b ) connected to the at least one cam lobe ( 52 ) for generating a reciprocating fluid flow in response to rotation of the at least one cam lobe ( 52 ). At least one hydraulically actuated valve ( 34 a, 34 b, 34 c, 34 d, 134 a, 134 b, 134 c, 134 d ) in fluid communication with the reciprocal fluid flow generated by the at least one fluid piston pump ( 36, 36 a, 36 b ) to drive the valve ( 34 a, 34 b, 34 c, 34 d, 134 a, 134 b, 134 c, 134 d ) to be controlled toward an open position.

What is claimed is: 
     
         1 . In a hydraulic valve actuation system ( 30 ) for controlling opening and closing a plurality of hydraulically actuated valves ( 34   a ,  34   b ,  34   c ,  34   d ,  134   a ,  134   b ,  134   c ,  134   d ) associated with an internal combustion engine ( 86 ) having a crankshaft ( 50 ) rotatable about a longitudinal axis, the improvement comprising:
 at least one cam lobe ( 52 ,  52   a ,  52   b ) mounted on the crankshaft ( 50 ) to be driven in rotation with the crankshaft ( 50 );   at least one fluid piston pump ( 36 ,  36   a ,  36   b ,  36   c ,  36   d ) operably connected to the at least one cam lobe ( 52 ,  52   a ,  52   b ) for generating a reciprocating fluid flow in response to rotation of the at least one cam lobe ( 52 ,  52   a ,  52   b ); and   at least one hydraulically actuated valve ( 34   a ,  34   b ,  34   c ,  34   d ,  134   a ,  134   b ,  134   c ,  134   d ) in fluid communication with the reciprocating fluid flow to drive the at least one hydraulically actuated valve ( 34   a ,  34   b ,  34   c ,  34   d ,  134   a ,  134   b ,  134   c ,  134   d ) between a normally closed position and an open position.   
     
     
         2 . The improvement of  claim 1  further comprising:
 at least one accumulator ( 46   a ,  46   b ,  46   c ,  46   d ) for providing lost fluid flow motion to prevent valve actuation in response to the reciprocating fluid flow; and 
 at least one first control valve ( 56 ,  56   a ,  56   b ,  56   c ,  56   d ) for selectively placing the reciprocating fluid flow in fluid communication with the at least one accumulator ( 46   a ,  46   b ,  46   c ,  46   d ). 
 
     
     
         3 . The improvement of  claim 1  further comprising:
 the at least one hydraulically actuated valves including a first hydraulically actuated valve ( 34   a ,  34   c ,  134   a ,  134   c ) and a second hydraulically actuated valve ( 34   b ,  34   d ,  134   b ,  134   d ); and 
 at least one second control valve ( 64 ,  64   a ,  64   b ,  64   c ,  64   d ) for selectively controlling fluid communication between the reciprocating fluid flow and one of the first hydraulically actuated valve ( 34   a ,  34   c ,  134   a ,  134   c ) and the second hydraulically actuated valve ( 34   b ,  34   d ,  134   b ,  134   d ). 
 
     
     
         4 . The improvement of  claim 1  further comprising:
 a slave piston ( 44   a ,  44   b ,  44   c ,  44   d ,  144   a ,  144   b ,  144   c ,  144   d ) connected to each of the at least one hydraulically actuated valves ( 34   a ,  34   b ,  34   c ,  34   d ,  134   a ,  134   b ,  134   c ,  134   d ) to be controlled, each slave piston ( 44   a ,  44   b ,  44   c ,  44   d ,  144   a ,  144   b ,  144   c ,  144   d ) normally biased toward a closed valve position, each slave piston ( 44   a ,  44   b ,  44   c ,  44   d ,  144   a ,  144   b ,  144   c ,  144   d ) driven by reciprocating fluid flow toward an open valve position. 
 
     
     
         5 . The improvement of  claim 1 , wherein the at least one fluid piston pump ( 36 ,  36   a ,  36   b ,  36   c ,  36   d ) further comprises:
 at least one reciprocal master piston ( 38 ,  38   a ,  38   b ,  38   c ,  38   d ), at least one fluid pumping chamber ( 40 ,  40   a ,  40   b ,  40   c ,  40   d ), and at least one biasing spring ( 42 ,  42   a ,  42   b ,  42   c ,  42   d ), the biasing spring ( 42 ,  42   a ,  42   b ,  42   c ,  42   d ) normally biasing the master piston ( 38 ,  38   a ,  38   b ,  38   c ,  38   d ) into engagement with the at least one cam lobe ( 52 ,  52   a ,  52   b ), the master piston ( 38 ,  38   a ,  38   b ,  38   c ,  38   d ) for reciprocally driving fluid in and out with respect to the at least one fluid pumping chamber ( 40 ,  40   a ,  40   b ,  40   c ,  40   d ).   
     
     
         6 . The improvement of  claim 1  further comprising:
 a cam follower ( 54 ,  54   a ,  54   b ,  54   c ,  54   d ) located between the at least one cam lobe ( 52 ,  52   a ,  52   b ) and the at least one fluid piston pump ( 36 ,  36   a ,  36   b ,  36   c ,  36   d ), the cam follower ( 54 ,  54   a ,  54   b ,  54   c ,  54   d ) reciprocally driving the at least one fluid piston pump ( 36 ,  36   a ,  36   b ,  36   c ,  36   d ) in response to rotation of the at least one cam lobe ( 52   a ,  52   b ). 
 
     
     
         7 . A hydraulic valve actuation system ( 30 ) for an internal combustion engine ( 86 ) having a crankshaft ( 50 ) rotatable about a longitudinal axis comprising:
 a cam lobe ( 52 ,  52   a ,  52   b ) mounted on the crankshaft to be driven in rotation with the crankshaft ( 50 );   a fluid piston pump ( 36 ,  36   a ,  35   b ,  36   c ,  36   d ) connected to the cam lobe ( 52 ,  52   a ,  52   b ) for generating a reciprocating fluid flow in response to rotation of the cam lobe ( 52 ,  52   a ,  52   b ); and   a hydraulically actuated valve ( 34   a ,  34   b ,  34   c ,  34   d ,  134   a ,  134   b ,  134   c ,  134   d ) in fluid communication with the reciprocating fluid flow to drive the hydraulically actuated valve ( 34   a ,  34   b ,  34   c ,  34   d ,  134   a ,  134   b ,  134   c ,  134   d ) between a normally closed position and an open position.   
     
     
         8 . The hydraulic valve actuation system ( 30 ) of  claim 7  further comprising:
 an accumulator ( 46   a ,  46   b ,  46   c ,  46   d ) for providing lost fluid flow motion to prevent valve actuation in response to the reciprocating fluid flow; and 
 a first control valve ( 56 ,  56   a ,  56   b ,  56   c ,  56   d ) for selectively placing the reciprocating fluid flow in fluid communication with the accumulator ( 46   a ,  46   b ,  46   c ,  46   d ). 
 
     
     
         9 . The hydraulic valve actuation system ( 30 ) of  claim 7  further comprising:
 the hydraulically actuated valve including a first hydraulically actuated valve ( 34   a ,  34   c ,  134   a ,  134   c ) and a second hydraulically actuated valve ( 34   b ,  34   d ,  134   b ,  134   d ); and 
 a second control valve ( 64 ,  64   a ,  64   b ,  64   c ,  64   d ) for selectively controlling fluid communication between the reciprocating fluid flow and one of the first hydraulically actuated valve ( 34   a ,  34   c ,  134   a ,  134   c ) and the second hydraulically actuated valve ( 34   b ,  34   d ,  134   b ,  134   d ). 
 
     
     
         10 . The hydraulic valve actuation system ( 30 ) of  claim 7  further comprising:
 a slave piston ( 44   a ,  44   b ,  44   c ,  44   d ,  144   a ,  144   b ,  144   c ,  144   d ) connected to the valve ( 34   a ,  34   b ,  34   c ,  34   d ,  134   a ,  134   b ,  134   c ,  134   d ) to be controlled, the slave piston ( 44   a ,  44   b ,  44   c ,  44   d ,  144   a ,  144   b ,  144   c ,  144   d ) normally biased toward a closed valve position and driven by reciprocating fluid flow toward an open valve position. 
 
     
     
         11 . The hydraulic valve actuation system ( 30 ) of  claim 7 , wherein the fluid piston pump ( 36 ) further comprises:
 a reciprocal master piston ( 38 ), a fluid pumping chamber ( 40 ), and a biasing spring ( 42 ), the biasing spring ( 42 ) normally biasing the master piston ( 38 ) into engagement with the cam lobe ( 52 ), the master piston ( 38 ) operable for reciprocally driving fluid in and out with respect to the fluid pumping chamber ( 40 ).   
     
     
         12 . The hydraulic valve actuation system ( 30 ) of  claim 7  further comprising:
 a cam follower ( 54 ) located between the cam lobe ( 52 ) and the fluid piston pump ( 36 ), the cam follower ( 54 ) reciprocally driving the at least one fluid piston pump ( 36 ) in response to rotation of the cam lobe ( 52 ). 
 
     
     
         13 . A method of assembling a hydraulic valve actuation system ( 30 ) for controlling opening and closing a plurality of hydraulically actuated valves ( 34   a ,  34   b ,  34   c ,  34   d ,  134   a ,  134   b ,  134   c ,  134   d ) corresponding to a plurality of cylinders of an internal combustion engine ( 86 ) having a crankshaft ( 50 ) rotatable about a longitudinal axis, the method comprising:
 forming a cam lobe ( 52 ,  52   a ,  52   b ) connected to the crankshaft for rotation with the crankshaft ( 50 );   assembling a fluid pressure piston pump ( 36 ,  36   a ,  36   b ,  3 ) for generating a reciprocating fluid flow in response to rotation of the cam lobe ( 52 ) by the crankshaft ( 50 ); and   connecting at least one hydraulically actuated valve ( 34   a ,  34   b ,  34   c ,  34   d ,  134   a ,  134   b ,  134   c ,  134   d ) to be controlled in fluid communication with the reciprocating fluid flow from the fluid pressure piston pump ( 36 ,  36   a ,  36   b ,  36   c ,  36   d ).   
     
     
         14 . The method of  claim 13  further comprising:
 connecting a first control valve ( 56 ,  56   a ,  56   b ,  56   c ,  56   d ) for selectively directing reciprocal fluid flow between the fluid pressure piston pump ( 36 ,  36   a ,  36   b ,  36   c ,  36   d ) and an accumulator ( 46 ,  46   a ,  46   b ,  46   c ,  46   d ) to prevent actuation of the at least one hydraulically actuated valve ( 34   a ,  34   b ,  34   c ,  34   d ,  134   a ,  134   b ,  134   c ,  134   d ) to be controlled. 
 
     
     
         15 . The method of  claim 13  further comprising:
 assembling the at least one hydraulically actuated valve to include a first hydraulically actuated valve ( 34   a ,  34   c ,  134   a ,  134   c ) and a second hydraulically actuated valve ( 34   b ,  34   d ,  134   b ,  134   d ); and 
 connecting a second control valve ( 64 ,  64   a ,  64   b ,  64   c ,  64   d ) for selectively controlling fluid communication between the reciprocating fluid flow and one of the first hydraulically actuated valve ( 34   a ,  34   c ,  134   a ,  134   c ) and the second hydraulically actuated valve ( 34   b ,  34   d ,  134   b ,  134   d ).