Patent ID: 9021997
Filing Date: 2015-05-05
Classification: F01L,Y10T

Abstract:
1. A cam shaft phase setter comprising a control valve for controlling the feeding and draining of a hydraulic fluid into and out of a pressure chamber which serves to adjust the rotational angular position of a cam shaft relative to a crankshaft of an internal combustion engine, the control valve comprising: a valve housing which comprises a first operating port to the pressure chamber and a first reservoir port to a reservoir for the fluid; a valve piston axially adjustable back and forth in the valve housing between a first position and a second position and comprises an axial hollow space, an axial piston inlet for introducing the fluid into the hollow space, and a piston outlet which leads out of the hollow space and is connected to the first operating port in the first position of the valve piston and separated from the first operating port in the second position of the valve piston; an actuating unit, coupled to the valve piston, for axially adjusting the valve piston; and a coupling member with a cross-sectional area which protrudes through an axially facing closure wall which closes off the valve housing, and couples the actuating unit to the valve piston; wherein the valve piston comprises a radial widening increasing a projection area of the valve piston facing the closure wall, the widening being surrounded by a complementarily widened housing portion of the valve housing and to which the fluid can be applied in an axial direction pointing away from the axially facing closure wall, in order to generate an axial pressure force, and the widening is dimensioned such that the widening at least predominantly compensates for said cross-sectional area of the coupling member and the fluid thus acts on the valve piston with a pressure force of at least substantially equal size in both axial directions, despite the coupling member.