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US 8,539,920 B2Granted
Valve lash adjustment system for a split-cycle engine
AssigneeScuderi Group, LLC
InventorsRiccardo Meldolesi, Clive Lacy, Anthony Perkins, Ian Gilbert
Life of this patent
Estimating the term…
Abstract
The present invention provides a valve actuation system comprising a valve train for actuating a valve, the valve train including actuating elements and a valve lash, and a valve lash adjustment system for adjusting the valve lash, wherein the valve train and the valve lash adjustment system do not share any common actuating elements.
Claims34
A valve actuation system comprising:
- a valve train for actuating a valve, said valve train including a valve lash and a rocker;
- a valve lash adjustment system for adjusting the lash of the valve train, the valve lash adjustment system including;
- a rocker shaft assembly including a rocker shaft operable to rotatably support the rocker, wherein the rocker shaft includes a pedestal bearing portion that is concentric to a fixed axis, and a rocker bearing portion on which the rocker rotates, the rocker bearing portion being concentric to a movable rocker axis, wherein the movable rocker axis is offset from the fixed axis;
- a rocker shaft lever secured to the rocker shaft so that a rotational position of the rocker shaft is operable to be determined by a rotational position of the rocker shaft lever;
- and
- a lash adjuster assembly, which is operable to exert a force on the rocker shaft lever so as to adjust the rotational position of the rocker shaft lever, thereby controlling the rotational position of the rocker shaft and displacing the rocker, which modifies the lash, wherein a lever ratio defined as a ratio of (1) a shortest distance between a line of action of a force applied to the lash adjuster assembly by the rocker shaft lever and the fixed axis to (2) a shortest distance between a line of action of a force applied to the rocker shaft assembly by the rocker and the fixed axis is 10:1, thereby reducing a force from the rocker onto the lash adjuster assembly and increasing the effective stiffness of the lash adjuster assembly.
3 more elements
A valve lash adjustment system for adjusting a lash of a valve train including a rocker, said valve lash adjustment system comprising:
- a rocker shaft assembly including a rocker shaft operable to rotatably support the rocker, wherein the rocker shaft includes a pedestal bearing portion that is concentric to a fixed axis, and a rocker bearing portion on which the rocker rotates, the rocker bearing portion being concentric to a movable rocker axis, wherein the movable rocker axis is offset from the fixed axis;
- a rocker shaft lever secured to the rocker shaft so that a rotational position of the rocker shaft is operable to be determined by a rotational position of the rocker shaft lever;
- and
- a lash adjuster assembly, which is operable to exert a force on the rocker shaft lever so as to adjust the rotational position of the rocker shaft lever, thereby controlling the rotational position of the rocker shaft and displacing the rocker, which modifies the lash, wherein a lever ratio defined as a ratio of (1) a shortest distance between a line of action of a force applied to the lash adjuster assembly by the rocker shaft lever and the fixed axis to (2) a shortest distance between a line of action of a force applied to the rocker shaft assembly by the rocker and the fixed axis is 10:1, thereby reducing a force from the rocker onto the lash adjuster assembly and increasing the effective stiffness of the lash adjuster assembly.
1 more element
A valve actuation system comprising:
- a valve train for actuating a valve, said valve train including actuating elements and a valve lash;
- and
- a valve lash adjustment system for adjusting the valve lash, said valve lash adjustment system comprising a rocker shaft assembly rotatable about a fixed axis and operatively connected to the valve train, the rocker shaft assembly including a rocker bearing portion which provides a movable axis offset from the fixed axis, a lash adjuster assembly operable to modify the valve lash, the lash adjuster assembly extendable along a centerline axis, and a rocker shaft lever operatively connected between the lash adjuster assembly and the rocker shaft assembly to provide a lever ratio;
- wherein said valve train and said valve lash adjustment system do not share any common actuating elements and wherein the rocker shaft assembly has a stiffness that includes:
- a bending component caused by at least a deflection resulting from deformation of the rocker bearing portion;
- a rotating component caused by at least a deflection resulting from rotation of the rocker shaft assembly, and the lash adjuster assembly has a stiffness that is within 25 percent of the stiffness of the rotating component multiplied by the square of the lever ratio.
3 more elements
A valve lash adjustment system for adjusting a valve lash of a valve train for actuating a valve, said valve lash adjustment system comprising:
- a lash adjuster assembly for adjusting the valve lash, said valve lash adjustment system comprising a rocker shaft assembly rotatable about a fixed axis and operatively connected to the valve train, the rocker shaft assembly including a rocker bearing portion which provides a movable axis offset from the fixed axis, a lash adjuster assembly operable to modify the valve lash, the lash adjuster assembly extendable along a centerline axis, and a rocker shaft lever operatively connected between the lash adjuster assembly and the rocker shaft assembly to provide a lever ratio,
- wherein said valve train and said valve lash adjustment system do not share any common actuating elements and wherein the rocker shaft assembly has a stiffness that includes:
- a bending component caused by at least a deflection resulting from deformation of the rocker bearing portion;
- a rotating component caused by at least a deflection resulting from rotation of the rocker shaft assembly, and the lash adjuster assembly has a stiffness that is within 25 percent of the stiffness of the rotating component multiplied by the square of the lever ratio.
1 more element
A valve actuation system comprising:
- a valve train for actuating a valve, said valve train including actuating elements and a valve lash;
- and
- a valve lash adjustment system for adjusting the valve lash, said valve lash adjustment system comprising a rocker shaft assembly rotatable about a fixed axis and operatively connected to the valve train, the rocker shaft assembly including a rocker bearing portion which provides a movable axis offset from the fixed axis, a lash adjuster assembly operable to modify the valve lash, the lash adjuster assembly extendable along a centerline axis, and a rocker shaft lever operatively connected between the lash adjuster assembly and the rocker shaft assembly to provide a lever ratio;
- wherein said valve train and said valve lash adjustment system do not share any common actuating elements and wherein the rocker shaft assembly has a stiffness that includes:
- a bending component caused by at least a deflection resulting from deformation of the rocker bearing portion;
- a rotating component caused by at least a deflection resulting from rotation of the rocker shaft assembly, and the lash adjuster assembly has a stiffness that is within 10 percent of the stiffness of the rotating component multiplied by the square of the lever ratio.
3 more elements
A valve lash adjustment system for adjusting a valve lash of a valve train for actuating a valve, said valve lash adjustment system comprising:
- a lash adjuster assembly for adjusting the valve lash, said valve lash adjustment system comprising a rocker shaft assembly rotatable about a fixed axis and operatively connected to the valve train, the rocker shaft assembly including a rocker bearing portion which provides a movable axis offset from the fixed axis, a lash adjuster assembly operable to modify the valve lash, the lash adjuster assembly extendable along a centerline axis, and a rocker shaft lever operatively connected between the lash adjuster assembly and the rocker shaft assembly to provide a lever ratio,
- wherein said valve train and said valve lash adjustment system do not share any common actuating elements and wherein the rocker shaft assembly has a stiffness that includes:
- a bending component caused by at least a deflection resulting from deformation of the rocker bearing portion;
- a rotating component caused by at least a deflection resulting from rotation of the rocker shaft assembly, and the lash adjustment system has a stiffness that is within 10 percent of the stiffness of the rotating component multiplied by the square of the lever ratio.
1 more element
Dependencies are inferred from the claim text.