Valve train assembly

Abstract

A cam phasing mechanism (1) for a cam assembly (100) of an internal combustion engine, the cam assembly (100) comprising a camshaft (120) and an actuator (130) for opening a valve (505) at a reference position of rotation of the camshaft (120), the cam phasing mechanism (1) comprising: a force transfer member (2a) for interposition between the camshaft (120) and the actuator (130) of the cam assembly (100) for transferring force between the camshaft (120) and the actuator (130); and an adjuster (2b) for selectively moving the force transfer member (2a) to adjust the reference position of rotation of the camshaft (120).

1 . A cam phasing mechanism ( 1 ) for a cam assembly ( 100 ) of an internal combustion engine, the cam assembly ( 100 ) comprising a camshaft ( 120 ) and an actuator ( 130 ) for opening a valve ( 505 ) at a reference position of rotation of the camshaft ( 120 ), the cam phasing mechanism ( 1 ) comprising:
 a force transfer member ( 2 a) for interposition between the camshaft ( 120 ) and the actuator ( 130 ) of the cam assembly ( 100 ) for transferring force between the camshaft ( 120 ) and the actuator ( 130 ); and   an adjuster ( 2   b ) for selectively moving the force transfer member ( 2   a ) to adjust the reference position of rotation of the camshaft ( 120 ).   
     
     
         2 . The cam phasing mechanism ( 1 ) according to  claim 1  , wherein the adjuster ( 2   b ) comprises a first member ( 4 ) and a second member ( 5 ), wherein the first member ( 4 ) is moveable relative to the second member ( 5 ) for selectively moving the force transfer member ( 2   a ) relative to the second member ( 5 ) to adjust the reference position of rotation of the camshaft ( 110 ). 
     
     
         3 . The cam phasing mechanism ( 1 ) according  claim 2 , wherein the first member ( 4 ) is continuously moveable relative to the second member ( 5 ) for continuously adjusting the reference position of rotation of the camshaft ( 120 ) within a predetermined range. 
     
     
         4 . The cam phasing mechanism ( 1 ) according to  claim 2 , wherein the force transfer member ( 2   a ) is spaced from the first member ( 4 ) by a third member ( 3 ). 
     
     
         5 . The cam phasing mechanism ( 1 ) according to  claim 4 , wherein the third member ( 3 ) is pivotable about the first member ( 4 ). 
     
     
         6 . The cam phasing mechanism ( 1 ) according to  claim 4 , wherein the third member ( 3 ) is Y-shaped such that a distal portion ( 33 ) of the third member ( 3 ) is a bifurcated portion to enclose the force transfer member ( 2   a ). 
     
     
         7 . The cam phasing mechanism ( 1 ) according to  claim 2 , comprising a driving member ( 10 ) for driving the second member ( 5 ) of the adjuster ( 2   b ). 
     
     
         8 . The cam phasing mechanism ( 1 ) according to  claim 7 , wherein an axis of rotation of the driving member ( 10 ) is perpendicular to an axis of rotation of the second member ( 5 ). 
     
     
         9 . The cam phasing mechanism ( 1 ) according to  claim 1 , wherein the first member ( 4 ) is moveable relative to the second member ( 5 ) by translational motion of the first member ( 4 ). 
     
     
         10 . The cam phasing mechanism ( 1 ) according to  claim 1 , wherein the force transfer member ( 2   a ) comprises a first roller ( 21 ) for engagement with the camshaft ( 120 ) of the cam assembly ( 100 ) and a second roller ( 22 ) for engagement with the actuator ( 130 ) of the cam assembly ( 100 ). 
     
     
         11 . The cam phasing mechanism ( 1 ) according to  claim 10 , wherein the first roller ( 21 ) and the second roller ( 22 ) are each independently rotatable about a third roller ( 23 ). 
     
     
         12 . The cam phasing mechanism ( 1 ) according to  claim 10 , wherein the first roller ( 21 ) and the second roller ( 22 ) are coaxial. 
     
     
         13 . The cam phasing mechanism ( 1 ) according to  claim 12 , wherein the first roller ( 21 ) and the second roller ( 22 ) are rotatable about a common axis, and wherein the first roller ( 21 ) is restricted to a central location along the common axis. 
     
     
         14 . The cam phasing mechanism ( 1 ) according to  claim 10 , wherein the second roller ( 22 ) comprises two rollers, wherein one of the two rollers is arranged on one side of the first roller ( 21 ) and the other of the two rollers is arranged on another side of the first roller ( 21 ). 
     
     
         15 . A cam assembly ( 100 ) for an internal combustion engine and for controlling actuation of a valve ( 505 ), the cam assembly ( 100 ) comprising:
 a camshaft ( 120 );   an actuator ( 130 ) moveable by rotation of the camshaft ( 120 ) for opening the valve ( 505 ) at a reference position of rotation of the camshaft ( 120 ); and   a force transfer member ( 2   a ) interposed between the camshaft ( 120 ) and the actuator ( 130 ) for transferring force between the camshaft ( 120 ) and the actuator ( 130 ); wherein the force transfer member ( 2 ) is selectively moveable by an adjuster ( 2   b ) to adjust the reference position of rotation of the camshaft ( 120 ).   
     
     
         16 . The cam assembly ( 100 ) according to  claim 15 , wherein the force transfer member ( 2   a ) is selectively moveable either side (S 1 , S 2 ) of a reference plane (P) between an axis ( 115 ) of the camshaft ( 120 ) and an axis ( 135 ) of the actuator ( 130 ). 
     
     
         17 . The cam assembly ( 100 ) according to  claim 15 , wherein the actuator ( 130 ) comprises a first surface ( 131 ) for avoiding contact with the force transfer member ( 2   a ) and a second surface ( 132 ) for engaging the force transfer member ( 2   a ). 
     
     
         18 . The cam assembly ( 100 ) according to  claim 17 , wherein the force transfer member ( 2   a ) comprises a first roller ( 21 ) for engaging the camshaft ( 120 ) and a second roller ( 22 ) for engaging the second surface ( 132 ) of the actuator ( 130 ). 
     
     
         19 . The cam assembly ( 100 ) according to  claim 18 , wherein the first roller ( 21 ) comprises a diameter that is greater than a diameter of the second roller ( 22 ). 
     
     
         20 . A valve train assembly ( 1000 ) for an internal combustion engine, the valve train assembly ( 1000 ) comprising an exhaust valve and a cam assembly ( 100 ) for actuating the exhaust valve, the cam assembly ( 100 ) comprising:
 a camshaft ( 120 );   an actuator ( 130 ) moveable by rotation of the camshaft ( 120 ) for opening the valve ( 505 ) at a reference position of rotation of the camshaft ( 120 ); and   a force transfer member ( 2   a ) interposed between the camshaft ( 120 ) and the actuator ( 130 ) for transferring force between the camshaft ( 120 ) and the actuator ( 130 ); wherein the force transfer member ( 2 ) is selectively moveable by an adjuster ( 2   b ) to adjust the reference position of rotation of the camshaft ( 120 ).