Device for a valve train for switching over the lift of gas-exchange valves of an internal combustion engine

Abstract

A device for a valve train for switching over the lift of gas-exchange valves of an internal combustion engine, the internal combustion engine including a camshaft on which at least one cam carrier with at least three different cam profiles is mounted so as to be torque-proof and axially movable. The device includes an adjustment shaft arranged parallel to the camshaft and on which a first transmission element is mounted so as to be torque-proof and axially movable, the first transmission element having a guide unit, a housing-fixed first guide element operatively connected to the guide unit, a second guide element that, on the one hand, is operatively connected to the guide unit and, on the other hand, to the cam carrier via a second transmission element, whereby the second transmission element is connected to the cam carrier so as to be axially immovable, and a push element.

1 . A device for a valve train for switching over the lift of gas-exchange valves of an internal combustion engine, the internal combustion engine including a camshaft on which at least one cam carrier with at least three different cam profiles is mounted so as to be torque-proof and axially movable, comprising:
 an adjustment shaft arranged parallel to the camshaft and on which a first transmission element is mounted so as to be torque-proof and axially movable, the first transmission element having a guide unit,   a housing-fixed first guide element operatively connected to the guide unit,   a second guide element that, on the one hand, is operatively connected to the guide unit and, on the other hand, to the cam carrier via a second transmission element, whereby the second transmission element is connected to the cam carrier so as to be axially unmovable, and   a push element,   wherein the guide unit has a first guide track and a second guide track arranged axially at a distance from the first guide track, as well as at least two connecting tracks that are between the first guide track and the second guide track and that are at a distance from each other along a circumference of the first transmission unit,   wherein the first guide element and the second guide element run at least one of:
 along the first guide track, 
 along the second guide track, or 
 along one of the connecting tracks, and 
   wherein the push element is operatively connected to the first transmission element in order to effectuate an axial movement of the first transmission element relative to the first guide element and to the second guide element when the first guide element and the second guide element each run along one of the connecting tracks.   
     
     
         2 . The device for a valve train according to  claim 1 , wherein the first guide track is provided for a first switching sequence,
 wherein the second guide track is provided for a second switching sequence between the at least three different cam profiles,   wherein the first switching sequence and the second switching sequence are determined by a sequential switchover between the at least three cam profiles, and   wherein the switching positions of the second switching sequence are shifted relative to the switching positions of the first switching sequence over the circumference of the first transmission element.   
     
     
         3 . The device for a valve train according to  claim 1  wherein the operative connection between the push element and the first transmission element has an axial clearance element.