Patent ID: 8544430
Filing Date: 2013-10-01
Classification: F01L,Y10T

Abstract:
1. A valve drive of an internal combustion engine with variable-lift gas exchange valve actuation, comprising: a camshaft having a support shaft and a cam piece, which is arranged on the support shaft for conjoint rotation therewith and so as to be movable between axial positions, the cam piece having two cam groups of directly adjacent cams with different elevations and envelope circle diameters, on an end side, the cam piece having an axial slotted guide, and the cam piece having a bearing journal which has a diameter and runs between the cam groups; a camshaft bearing, which is arranged in a positionally fixed manner in the internal combustion engine and in which the bearing journal is rotatably mounted; and an actuating element, which can be arranged in the axial slotted guide and coupled to the axial slotted guide for moving the cam piece on the support shaft, wherein the diameter of the bearing journal is larger than one of the envelope circle diameters of one of the cams closest to the bearing journal, wherein the one of the cams and the camshaft bearing overlap axially in one of the axial positions of the cam piece, wherein the camshaft bearing forms a hydrodynamic plain bearing with the bearing journal and, the camshaft bearing has a hydraulic medium channel with an outlet that has a narrowed channel portion, such that the outlet is covered by the bearing journal in all axial positions of the cam piece.