Patent ID: 8539920
Filing Date: 2013-09-24
Classification: F01L,F02B,Y10T

Abstract:
1. 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.