Patent ID: 7568459
Filing Date: 2009-08-04
Classification: F01L,Y10T

Abstract:
1. A switchable valvetrain for an internal combustion engine, comprising: a row of rocker arms which extend in a longitudinal direction of a cylinder head, each of the rocker arms having, on an underside at one end, an indirect run-on face for a cam, and at the other end, a valve rest; a rocker arm recess on an upper side of the rocker arm and a head of a bearing journal in the rocker arm recess, with at least a subset of each of the bearing journals being axially moveably arranged in a corresponding bore of an above-situated carrier, a coupling means in the carrier for selectively coupling the bearing journal, at least indirectly to the carrier, so that in a deployed state of the bearing journal, a large valve lift is generated when coupled and a relatively small or zero valve lift is generated when decoupled, and with the bearing journal urged out of the bore by means of a lost motion spring, an annular groove arranged in an outer casing of the bearing journal, an axially lower annular face of the annular groove runs orthogonally with respect to the axial line of the bore, the bore intersected by at least one radially running coupling recess in the carrier, in the decoupled case, at least one piston of the coupling means seated in the coupling recess, the piston having a radially inner face end with a flattening situated underneath the inner face end, and, in the coupled case, the flattening situated on the lower annular face of the annular groove of the bearing journal.