Cam profile summation mechanism

Abstract

A rocker system comprising a summation lever and at least one valve actuating lever for use in a valve train of the type having two cams, a summation lever having followers engaging with both cams and a valve actuating lever pivotally connected to the summation lever for opening and closing an engine valve in dependence upon the sum of the lifts of the two cams, characterised in that the summation lever is assembled from opposed face plates and a separately formed hub.

1 . A rocker system comprising:
 a summation lever and at least one valve actuating lever for use in a valve train of the type having two cams, the summation lever having followers engaging with both cams and the valve actuating lever being pivotally connected to the summation lever for opening and closing an engine valve in dependence upon a sum of lifts of the two cams;   wherein the summation lever is assembled from opposed face plates and a separately formed hub.   
     
     
         2 . The rocker system as claimed in  claim 1 , wherein the faceplates are formed of sheet metal. 
     
     
         3 . The rocker system as claimed in  claim 2 , wherein the faceplates are stamped, pressed or forged. 
     
     
         4 . The rocker system as claimed  claim 2 , wherein the faceplates are formed as one folded sheet metal component. 
     
     
         5 . The rocker system as claimed  claim 1 , wherein the hub is secured to each of the pair of face plates by means of brazing, welding, gluing, heat-shrinking or interference fitting. 
     
     
         6 . The rocker system as claimed in  claim 1 , wherein engaging surfaces between the hub and the face plates are form locking to prevent relative rotation. 
     
     
         7 . The rocker system as claimed in  claim 1  wherein the hub includes a bore for receiving at least one pivot shaft. 
     
     
         8 . The rocker system as claimed in  claim 7 , wherein the bore of the hub is a bearing surface for the pivot shaft. 
     
     
         9 . The rocker system as claimed in  claim 1 , wherein the hub is formed as one piece with an integral pivot shaft. 
     
     
         10 . The rocker system as claimed  claim 1 , wherein the face plates are flanged for at least a portion of their circumference to increase their rigidity. 
     
     
         11 . The rocker system as claimed  claim 1 , wherein the valve actuating lever is rotatably supported and secured on a shaft extending from the hub. 
     
     
         12 . The rocker system as claimed in  claim 11 , wherein a roller element bearing is disposed between the shaft and the valve actuating lever. 
     
     
         13 . The rocker system as claimed in  claim 11 , further comprising another valve actuating lever;
 wherein a respective end cap shaft supporting and retaining a respective one of the valve actuating levers extends from each axial end of the hub.   
     
     
         14 . The rocker system as claimed in  claim 12 , wherein the end cap shaft is retained within an internal bore of the hub by means of an interference fit. 
     
     
         15 . The rocker system as claimed in  claim 14 , wherein formations on the hub are displaced radially outwards upon forced insertion of the end cap shaft into the hub, increasing the engagement between the hub and face plate.