DE102019131273A1 - Arrangement for adjusting at least one cam on a camshaft for variable valve control of an internal combustion engine - Google Patents

Abstract

The invention relates to an arrangement for adjusting at least one cam (1) on a camshaft (2) for variable valve control of an internal combustion engine, with a camshaft (2) with at least one cam (1) arranged coaxially and rotatably thereon, characterized in that a axially displaceable actuating unit (4) is provided, which interacts with at least one cam track (15, 16) on the cam (1), with an axial displacement of the actuating unit (4) by the cam track (15, 16) in a rotary movement of the cam (1 ) can be transferred for adjustment in the circumferential direction relative to the camshaft (2).

Description

Field of invention

The invention relates to an arrangement for adjusting at least one cam on a camshaft for variable valve control of an internal combustion engine according to the type defined in more detail in the preamble of claim 1.

Hydraulic, mechanical and electrical camshaft adjusters are known for variable valve control of an internal combustion engine. A precise adjustment based on the load, i.e. the accelerator pedal position, and the speed with hydraulic and mechanical camshaft adjustment is problematic, since these depend on the engine speed, the oil pressure and, due to the variable viscosity of the oil, the temperature. The known camshaft adjusters have been developed for multi-cylinder vehicle engines. In smaller engines, the low oil pressure is an obstacle to hydraulic camshaft adjusters, which also require a complex oil supply. Mechanical and electrical camshaft adjusters are expensive and difficult to adapt to the cost-sensitive market for small engines for two-wheelers. Also known are adjustable camshafts with an inner shaft and an outer shaft arranged coaxially therewith with a first cam fixedly arranged on the latter and a second cam which is non-rotatably connected to the inner shaft and rotatable relative to the outer shaft.

Summary of the invention

The invention is therefore based on the object of proposing an arrangement of the aforementioned type which enables precisely variable valve control, in particular for small engines, and which is simple and inexpensive in structure.

The object is achieved by the features of claim 1. Further advantageous configurations emerge from the respective subclaims, the description and the drawings.

An arrangement for adjusting at least one cam on a camshaft for variable valve control of an internal combustion engine is proposed. The arrangement comprises a camshaft with at least one cam arranged on it coaxially and rotatably relative to it. According to the invention, an axially displaceable actuating unit is provided which cooperates with at least one cam track on the cam, such that an axial displacement of the actuating unit through the cam track can be converted into a rotary movement of the cam for adjusting the cam in the circumferential direction relative to the camshaft. This enables precise cam adjustment for variable valve control in a simple and inexpensive manner.

The actuating unit is preferably in rolling contact with at least one roller on the camshaft and is axially guided on this. The roller preferably engages in at least one curved path on the cam at the same time.

In a particularly preferred embodiment of the invention, the camshaft is designed at least in sections as a hollow shaft and the cam with the inner diameter is arranged on this and so as to be rotatable relative to it. Preferably, the axial actuation unit is at least partially arranged coaxially and displaceably in the hollow shaft. In this case, it is preferably in rolling contact with at least one roller projecting radially on the outer diameter in at least one elongated hole on the hollow shaft and is axially guided in the elongated hole. With the roller, it can simultaneously engage in at least one curved path on the inside diameter of the cam. By guiding the roller in the cam track and aligning it with the straight slot on the hollow shaft, the displacement of the actuating unit can be converted in a particularly simple manner into a rotary movement of the cam to move it on the hollow shaft. A precise cam adjustment in the circumferential direction relative to the camshaft can thus be achieved by an axial adjusting movement. At the same time, the actuating unit is connected to the hollow shaft in a rotationally fixed manner via the at least one roller engaging in at least one elongated hole and moves with the roller in the straight elongated hole, guided by rolling, thereby driving the cam.

In a further particularly preferred embodiment of the invention, the actuating unit has an axially longitudinally displaceable sliding pin which is at least partially arranged coaxially in the hollow shaft, at least one roller being arranged on the outer diameter of the sliding pin.

It is also advantageous if the actuation unit has two diametrically arranged rollers on the outer circumference or on the outer diameter, which are in rolling contact at two corresponding elongated holes in the hollow shaft and are axially guided and engage in two corresponding cam tracks on the inner diameter of the cam.

A simple fastening of at least one roller on the outer diameter of the sliding pin can be achieved if at least one pin is provided which is pressed into a radial bore on the sliding pin and protruding radially at the outer diameter of the same, on which the roller is arranged. Preferred are two pins in one radial through hole on the sliding pin each with one end pressed in on the outer diameter of the sliding pin, each pin carrying a roller at the respective protruding end.

In a simple way, at least one cam track can be designed as a groove extending in the axial direction and slightly curved in the circumferential direction on the inside diameter of the cam. This is preferably designed with a rectangular cross-section in such a way that a radially engaging roller is in rolling contact on the opposite inner walls of the groove and is guided. In a further advantageous manner, it is possible to design the curvature of the cam track in such a way that the cam can be fixed in a self-retaining manner in relation to a rotation or adjustment relative to the cam or hollow shaft in any axial position of the actuating unit or the sliding pin.

A further preferred embodiment of the invention comprises a sliding arm for transmitting a sliding movement to the actuating unit, to which the actuating unit is rotatably connected via a bearing and which, on the other hand, interacts with an actuator to pick up a linear movement. This allows an axially parallel arrangement of the actuator and camshaft or actuation unit.

It is also advantageous if the actuator comprises a ball screw drive with a threaded spindle that can be driven in rotation and a spindle nut arranged on this. The latter is preferably held in a rotationally fixed manner by the sliding arm in order to pick up a linear movement. In this way, a precise displacement movement can be transmitted to the actuating unit for adjustment. Due to the fine-grained guidance of the ball screw, the adjustment is achieved smoothly and smoothly without noise and bumps.

The threaded spindle can preferably be driven in rotation by an electric servomotor via a pair of gears. In this way, an axially parallel arrangement of the actuator motor and ball screw drive is possible.

Due to the arrangement according to the invention, precise cam adjustment can be achieved with no or significantly reduced play, whereby the engine performance can be improved.

In a further particularly preferred embodiment, at least one further cam firmly connected to it is arranged coaxially on the camshaft. Preferably, the cam firmly connected to the camshaft is associated with an exhaust valve of the internal combustion engine and the cam arranged adjustably on the camshaft is associated with an intake valve of the internal combustion engine. In this way, only one camshaft is required to control the intake and exhaust valves. The camshaft can be designed as a so-called exhaust camshaft, on which the fixed cam is designed as an exhaust cam in one piece with the camshaft. In particular, due to the simple structure and the space-saving and inexpensive design, the arrangement according to the invention can be used particularly advantageously in the design with an overhead camshaft for variable valve control in smaller engines of the internal combustion engines of two-wheeled and three-wheeled vehicles.

The arrangement according to the invention allows precise cam adjustment for variable valve control based on the load (accelerator pedal) and speed. It has a simple structure, is reliable, cost-effective and also enables simple control. A precise adjustment of either the inlet or outlet cam or of both can be achieved automatically with the arrangement according to the invention as a function of the load and speed.

In a particularly advantageous manner, it enables simple control of at least one inlet valve of the internal combustion engine to ensure a high volumetric efficiency, as a result of which good performance and good driving behavior can be achieved with low emissions. The valve states can be varied with the speed. At higher engine speeds, a delayed or a later controlled closing of the inlet valve in order to effectively use the inertia of the supplied air supports further filling, which determines the volumetric efficiency. In order to achieve high volumetric efficiencies at low engine speeds, the closing of the inlet valve can be controlled early or in the earlier direction so that the return flow to the intake manifold is minimized, which results in a higher so-called trapping efficiency. In this way, the arrangement according to the invention enables variable valve control with optimal valve opening and closing times at any speed and good performance over the entire operating range of the internal combustion engine. A good choice of valve timing also enables a remarkable reduction in pumping losses and can also be used to separate exhaust gas residues to reduce NOx emissions.

Figure list

• 1 eine perspektivische Ansicht einer erfindungsgemäßen Anordnung zur Verstellung eines Nockens auf einer Nockenwelle zur variablen Ventilsteuerung einer Brennkraftmaschine,
• 2 die Anordnung in einer Explosionsdarstellung,
• 3 eine Einzelansicht einer Nockenwelle der Anordnung,
• 4 eine perspektivische Einzelansicht einer Betätigungseinheit der Anordnung,
• 5 eine geschnittene Einzelansicht der Betätigungseinheit,
• 6 eine Einzelansicht eines Schiebestifts der Betätigungseinheit,
• 7 eine Einzelansicht eines verstellbaren Nockens der Anordnung,
• 8 eine geschnittene Einzelansicht des verstellbaren Nockens,
• 9 und 10 verschieden perspektivische Ansichten der Anordnung in einem Ventiltrieb der Brennkraftmaschine,
• 11 eine geschnittene Ansicht der Anordnung in einem Ventiltrieb der Brennkraftmaschine,
• 12 eine geschnittene Ansicht der Anordnung am Zylinderkopf der Brennkraftmaschine,
• 13 eine perspektivische Ansicht der Anordnung am Zylinderkopf der Brennkraftmaschine
• 14 in einem Diagramm den Ventilhub von Ein- und Auslassventil der Brennkraftmaschine in Abhängigkeit von der Kurbelwellenstellung in verschiedenen Betriebszuständen der Brennkraftmaschine,
• 15 die Anordnung im Betriebszustand bei niedriger Drehzahl der Brennkraftmaschine,
• 16 die Anordnung im Betriebszustand bei hoher Drehzahl der Brennkraftmaschine,
• 17 die Anordnung beim vorzeitigen bzw. früheren Schließen des Einlassventils bei niedriger Drehzahl der Brennkraftmaschine,
• 18 die Anordnung beim verzögerten bzw. späteren Schließen des Einlassventils bei hoher Drehzahl der Brennkraftmaschine,

Further features of the invention emerge from the following description and from the drawings, in which an exemplary embodiment of the invention is shown in simplified form. Show it:

• 1 a perspective view of an arrangement according to the invention for adjusting a cam on a camshaft for variable valve control of an internal combustion engine,
• 2 the arrangement in an exploded view,
• 3 an individual view of a camshaft of the arrangement,
• 4th a perspective individual view of an actuating unit of the arrangement,
• 5 a sectional individual view of the actuation unit,
• 6th an individual view of a slide pin of the actuation unit,
• 7th a single view of an adjustable cam of the arrangement,
• 8th a sectional view of the adjustable cam,
• 9 and 10 different perspective views of the arrangement in a valve train of the internal combustion engine,
• 11 a sectional view of the arrangement in a valve train of the internal combustion engine,
• 12 a sectional view of the arrangement on the cylinder head of the internal combustion engine,
• 13 a perspective view of the arrangement on the cylinder head of the internal combustion engine
• 14th in a diagram the valve lift of the inlet and outlet valve of the internal combustion engine as a function of the crankshaft position in different operating states of the internal combustion engine,
• 15th the arrangement in the operating state at low speed of the internal combustion engine,
• 16 the arrangement in the operating state at high speed of the internal combustion engine,
• 17th the arrangement for premature or earlier closing of the inlet valve at a low speed of the internal combustion engine,
• 18th the arrangement for the delayed or later closing of the inlet valve at high engine speed,

Detailed description of the drawings

In the 1 and 2 An arrangement according to the invention for adjusting a cam shown as an example 1 on a camshaft 2 for variable valve control of an internal combustion engine comprises a camshaft 2 at one end section as a hollow shaft 2a is carried out on the relative to this rotatable adjustable cam 1 is arranged coaxially. The adjustable cam 1 is with the inner diameter of a cylindrical hollow portion on the outer diameter of the hollow shaft 2a supported. It is assigned to the actuation of an inlet valve, not shown, of the internal combustion engine. On the camshaft 2 is another cam firmly attached to this one 3 arranged, which is used to actuate an exhaust valve, not shown, of the internal combustion engine.

For adjusting the cam 1 is an operating unit 4th partly in the hollow shaft 2a arranged coaxially, guided axially displaceably on this and from one axially parallel to the camshaft 2 arranged actuator 5 via a push arm 6th displaceably drivable. The actuation unit 4th comprises a longitudinally displaceable sliding pin 7th and two roles 8th , 9 ( 2 and 4th to 6th ). The sliding pin 7th has an end section on the actuation side in the hollow shaft 2a arranged coaxially on which the rollers 8th , 9 are arranged diametrically and radially protruding on the outer diameter. For fastening the rollers 8th , 9 are two pens 10 , 11 into a radial through hole 12 on the sliding pin 7th pressed in and each have one end on the outer diameter of the sliding pin 7th radially in front. The roles 8th , 9 are each on one on the outer diameter of the sliding pin 7th protruding end of the pins 10 , 11 rotatably attached ( 5 and 6th ). They each engage in corresponding ones on the hollow shaft 2a elongated holes formed radially opposite one another 13 , 14th radially, which are designed as radial through holes and each extend in the axial direction. The actuation unit 4th stands with the roles 8th , 9 each in rolling contact with the opposite parallel long sides of the elongated holes 13 , 14th and is guided on these axially displaceable ( 9 to 12 , 15th and 16 ). The actuation unit 4th or the sliding pin 7th is in this way at the same time about the roles 8th , 9 non-rotatably with the hollow shaft 2a connected and driven by rolling at the straight elongated holes 13 , 14th the adjustable cam 1 or the inlet cam.

The adjustable cam 1 is in the area of the elongated holes 13 , 14th on the hollow shaft 2a arranged and has two radially opposite cam tracks on the inner diameter of its cylindrical section 15th , 16 on ( 2 , 7th , 8th , 11 , 12 , 15th and 16 ). These are designed as radial grooves extending in the axial direction and slightly curved in the circumferential direction, each with a rectangular cross section. The curved tracks 15th , 16 correspond to the elongated holes 13 , 14th arranged in such a way that the rollers guided in the latter protrude radially 8th , 9 at the same time in the curved tracks 15th , 16 engage and each with the opposite inner walls of the cam tracks 15th , 16 are in rolling contact and on these are guided. The roles 8th , 9 in this way form cam followers on which the cam tracks 15th , 16 of the cam 1 in the direction of the axial slots 14th , 15th on the hollow shaft 2a depending on the axial displacement position of the slide pin 7th be aligned. In this way there is an axial displacement of the actuating unit 4th or the slide pin 7th on the curved tracks 15th , 16 into a rotary movement of the cam 1 to adjust it in the circumferential direction relative to the cam or hollow shaft ( 2 , 2a ) transferable. This makes the adjustable cam 1 on the hollow shaft 2a relative to this and the fixed cam 3 adjustable in the circumferential direction with a predetermined adjustment angle. In this way, an axial adjusting movement enables precise cam adjustment in the circumferential direction relative to the camshaft 2 , 2a can be achieved.

The curvature of the cam tracks 15th , 16 is preferably designed such that the adjustable cam 1 not through the cam torque acting on it during operation on the hollow shaft 2a can be rotated or adjusted. The adjustment angle of the adjustable cam 1 relative to the hollow shaft 2a or to the fixed cam 3 is only due to the axial displacement of the slide pin 7th changeable. This is used to adjust the adjustable cam 1 or the inlet cam with respect to the fixed cam 3 or the outlet cam in each axial position of the slide pin 7th to fix self-retaining.

The actuator 5 comprises a threaded spindle that can be driven in rotation 17th with a spindle nut 18th ( 1 , 2 , 9 to 12 , 15th and 16 ). The threaded spindle 17th and the spindle nut 18th form a ball screw drive, which is axially parallel to the sliding pin 7th and to the camshaft 2 or to the hollow shaft 2a is arranged. The push arm 6th is transverse to the camshaft axis and the axis of displacement of the slide pin 7th arranged. On the one hand, one end on the drive side is attached to the spindle nut 18th and on the other hand with one end on the actuation side to the slide pin 7th tied up. The push arm forms the end on the drive side 6th a semicircular opening 19th on which the threaded spindle 17th is passed through. At the same time is the spindle nut 18th at the actuator end of the push arm 6th held by this rotationally fixed and axially connected to the latter in such a way that the spindle nut 18th when the threaded spindle rotates 17th limited to a linear movement and this from the sliding arm 6th can be tapped. The linear movement that can be tapped in this way at the drive-side end is transmitted by the sliding arm 6th at its actuation-side end on the slide pin 7th . For this purpose, one free end is removed from the hollow shaft 2a led out and through a warehouse 20th rotatable on the push arm 6th connected. The warehouse 20th is in one at the actuation-side end of the push arm 6th trained socket 21st arranged. The sliding pin 7th has a ring shoulder at the drive end 36 stepped radially inward and forms a bearing seat for the bearing 20th . On the ring heel 36 is the inner ring of the bearing 20th secured axially at the same time. This allows the in operation with the camshaft 2 rotating slide pin 7th through the push arm 6th be guided, while the latter through the spindle nut 18th is precisely positioned axially at different axial positions.

The threaded spindle 17th is on the drive side via a gear pair 22nd , 23 with an electric actuator motor 24 connected to transmit a torque. The pair of gears 22nd , 23 has one on a motor shaft of the electric actuator motor 24 arranged drive wheel 22nd on, the one on the drive-side end of the threaded spindle 17th arranged input wheel 23 combs. Here are the electric actuator motor 24 with the motor shaft, the threaded spindle 17th , and the camshaft 2 arranged axially parallel. The threaded spindle 17th is via a bearing on the input and output sides 25th , 26th supported.

9 to 13 show the arrangement according to the invention in a valve drive for actuating an inlet valve and an outlet valve 27 , 28 on the cylinder head 29 of the internal combustion engine with an overhead camshaft 2 . The one on the hollow shaft 2a arranged adjustable cams 1 as an inlet cam and the one fixed on the camshaft 2 arranged cams 3 as exhaust cams each drive one of the intake valve 27 associated first rocker arm 30th or one of the exhaust valve 28 associated second rocker arm 31 at. The rocker arms 30th , 31 are each mounted pivotably about a pivot axis and engage a cam lift movement on the inlet or outlet cam on a lever end on the camshaft side with a cam roller 1 , 3 at the other end of the lever on the inlet or outlet valve 27 , 28 to operate the same is transferable. The camshaft 2 is at one end on the drive side with a camshaft gear 32 can be driven with a torque by a crankshaft, not shown, of the internal combustion engine. The camshaft sprocket 32 is designed here as a sprocket that can be connected to the crankshaft via a chain drive (not shown). On from the camshaft sprocket 32 remote end section is the camshaft 2 as a hollow shaft 2a formed on which the adjustable cam 1 and on which the actuation unit provided for adjusting the same 4th are arranged.

In 14th is a diagram of the valve control of the inlet and outlet valve 27 , 28 shown by way of example at low and high engine speeds of the internal combustion engine. For this purpose, the valve lift of the inlet and outlet valve is 27 , 28 about the position or the angle of rotation of the crankshaft applied. A first turn 33 shows the valve control of the exhaust valve 28 and a second and third curve 34 or. 35 the valve control of the inlet valve 27 at low or high engine speed. The timing of the intake valve 27 related to the crankshaft position are adapted to different driving conditions, while the valve timing of the exhaust valve 28 related to the crankshaft position for different driving conditions. In this way, different valve control times can be achieved at different speeds. At low speed, the inlet valve is controlled 27 ahead of time or in the direction of early. At high speeds the inlet valve will 27 delayed or controlled in the late direction. A minimal valve overlap, ie the time in which the intake and exhaust valves of the internal combustion engine are open at the same time, contributes to an even idling. A larger valve overlap at higher engine speeds promotes internal exhaust gas recirculation.

15th and 16 show the position of the actuation unit 4th on the camshaft 2 or the hollow shaft 2a and the position of the actuator 5 at low or high engine speed. At low engine speed according to 15th is the spindle nut 18th in the starting position at the drive end of the threaded spindle 17th on the input wheel pressed onto it there 22nd . This is the sliding pin 7th over the push arm 6th in its furthest axially from the hollow shaft 2a pushed out position held. These are located in the elongated holes 13 , 14th the hollow shaft 2a guided roles 8th , 9 in their starting position at the respective drive-side end of the elongated holes 13 , 14th , the one on the hollow shaft 2a adjustable inlet cams 2 is in the starting position and a premature or earlier closing of the inlet valve 27 is achieved. At high engine speed according to 16 becomes the threaded spindle 17th driven by the gear pair 22nd , 23 by the actuator motor 24 twisted until the spindle nut turns 18th in the end position at the other end of the threaded spindle 17th and the slide pin 7th through the push arm 6th in its furthest axially in the hollow shaft 2a shifted position is positioned. This is where the roles 8th , 9 in the elongated holes 13 , 14th axially guided in their end position at the respective actuation-side end thereof. This makes the adjustable intake cam 1 by a predetermined adjustment angle on the hollow shaft 2a adjusted in the circumferential direction, resulting in a delayed or later closing of the inlet valve 27 is achieved.

In 17th and 18th is the phase angle α between the adjustable cam 1 or the inlet cam and the fixed cam 3 or the exhaust cam on the camshaft 2 shown at low and high engine speed. At low speed according to 17th is in the starting position of the actuation unit 4th the arrangement according to the invention a predetermined phase angle α between inlet and outlet cams 1 , 3 and thereby a premature or earlier closing of the inlet valve 27 reached. In the operating state of higher speeds, however, it is possible to adjust the phase angle α by adjusting the inlet cam 1 on the hollow shaft 2a with the help of the actuation unit 4th by an adjustment angle φ to increase to α + φ, resulting in a delayed or later closing of the inlet valve 27 is achieved.

List of reference symbols

1

Cams, inlet cams

2

camshaft

2a

Hollow shaft, hollow shaft section

3

Cams, exhaust cams

4th

Actuation unit

5

Actuator

6th

Sliding arm

7th

Sliding pin

8th

role

9

role

10

pen

11

pen

12

drilling

13

Long hole

14th

Long hole

15th

Curved path

16

Curved path

17th

Threaded spindle

18th

Spindle nut

19th

opening

20th

warehouse

21st

Rifle

22nd

drive wheel

23

Input wheel

24

Actuator motor

25th

warehouse

26th

warehouse

27

Inlet valve

28

outlet valve

29

Cylinder head

30th

rocker arm

31

rocker arm

32

Camshaft gear

33

Curve

34

Curve

35

Curve

36

Ring heel

α

Phase angle

φ

Adjustment angle

Claims (10)

Arrangement for adjusting at least one cam (1) on a camshaft (2) for variable valve control of an internal combustion engine, with a camshaft (2) with at least one cam (1) arranged coaxially and rotatably thereon, characterized in that an axially displaceable actuating unit ( 4) is provided, which interacts with at least one cam (15, 16) on the cam (1), with an axial displacement of the actuating unit (4) by the cam (15, 16) in a rotary movement of the cam (1) for adjustment in Can be transferred circumferentially relative to the camshaft (2). Arrangement according to Claim 1 , characterized in that the actuating unit (4) is in rolling contact with at least one roller (8, 9) on the camshaft (2) and is axially guided and at the same time with the roller (8, 9) in at least one cam track (15, 16) ) engages on the cam (1). Arrangement according to one of the Claims 1 or 2 , characterized in that the camshaft (2) is designed at least in sections as a hollow shaft (2a) and the cam (1) is rotatably arranged with the inner diameter on this, the axial actuating unit (4) at least partially in the hollow shaft (2a) coaxially and is arranged displaceably and is in rolling contact with at least one roller (8, 9) protruding radially on the outer diameter in at least one elongated hole (13, 14) on the hollow shaft (2a) and is axially guided and at the same time in with the roller (8, 9) at least one cam track (15, 16) engages on the inner diameter of the cam (1). Arrangement according to Claim 3 , characterized in that the actuating unit (4) has a sliding pin (7) which is at least partially arranged in the hollow shaft (2a) coaxially and axially longitudinally displaceable and at least one roller (8, 9) is arranged on the outer diameter of the sliding pin (7). Arrangement according to one of the Claims 3 or 4th , characterized in that two diametrically arranged rollers (8, 9) are provided on the outer circumference or on the outer diameter, which are each in rolling contact at two corresponding elongated holes (13, 14) of the hollow shaft (2a) and are axially guided and in two corresponding Engage cam tracks (15, 16) on the inside diameter of the cam (1). Arrangement according to one of the Claims 4 or 5 , characterized in that at least one roller (8, 9) is pressed into at least one radial bore (12) on the sliding pin (7) and arranged on the outer diameter of the same radially protruding pin (10, 11). Arrangement according to one of the Claims 1 to 6th , characterized in that at least one cam track (15, 16) is designed as a groove running slightly curved in the axial direction and in the circumferential direction on the inside diameter of the cam (1). Arrangement according to one of the Claims 1 to 7th , characterized in that a sliding arm (6) is provided to transmit a sliding movement to the actuating unit (4), to which on the one hand the actuating unit (4) is rotatably connected via a bearing (20) and on the other hand to pick up a linear movement with an actuator (5) cooperates. Arrangement according to Claim 8 , characterized in that the actuator (5) comprises a ball screw drive with a rotatably drivable threaded spindle (17) and a spindle nut (18) arranged on this and this is held in a rotationally fixed manner by the sliding arm (6) for picking up a linear movement. Arrangement according to one of the Claims 1 to 9 , characterized in that at least one cam (3) firmly connected to this is arranged coaxially on the camshaft (1), this being an exhaust valve (28) of the internal combustion engine and the cam (1) arranged on the camshaft (2) rotatable relative to this one Inlet valve (27) is assigned to the internal combustion engine.

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