EP1596040B1 - Camshaft phaser - Google Patents

Description

The invention relates to a camshaft adjuster for adjusting and fixing the phase position of a camshaft of an internal combustion engine with respect to a phase angle of the crankshaft with a drive shaft driven by the crankshaft, a camshaft fixed output member which is mounted on a camshaft or an extension of the camshaft and that of the drive wheel via a hydraulic actuator is driven, wherein the actuator consists of at least one pair of mutually working hydraulic pressure chambers and wherein the pressure chambers are supplied via a pressure medium distributor and pressure medium lines with pressure medium.

In internal combustion engines, camshafts are used to actuate the gas exchange valves. The camshaft is mounted in the internal combustion engine such that mounted on her cam to cam followers, for example, bucket tappets, rocker arms or rocker arms abut. When the camshaft is rotated, the cams roll on the cam followers off, in turn, actuate the gas exchange valves. Due to the position and shape of the cam thus both the opening period and amplitude but also the opening and closing time of the gas exchange valves is set.

Modern engine concepts go to design the valve train variable. On the one hand, valve lift and valve opening duration should be variable, up to the complete shutdown of individual cylinders. For this purpose, concepts such as switchable cam followers or electrohydraulic or electric valve actuations are provided. Furthermore, it has been found to be advantageous to be able to influence the opening and closing times of the gas exchange valves during operation of the internal combustion engine. It is also desirable to be able to influence the opening and closing times of the intake or exhaust valves separately in order to be able to set a defined valve overlap, for example, in a targeted manner. By the specific adjustment of the opening and closing times of the gas exchange valves depending on the current map range of the engine, for example, the current speed or the current load, the specific fuel consumption can be reduced, the exhaust behavior positively influenced, the engine efficiency, the maximum torque and the maximum power increases become.

The described variability in the gas exchange valve timing is accomplished by a relative change in the phasing of the camshaft to the crankshaft. The camshaft is usually via a chain, belt, or gear drive in direct drive connection with the crankshaft. Between the driven by the crankshaft chain, belt or gear drive and the camshaft, a camshaft adjuster is mounted, which transmits the torque from the crankshaft to the camshaft. In this case, this device is designed such that during operation of the internal combustion engine, the phase angle between the crankshaft and camshaft securely held and, if desired, the camshaft can be rotated in a certain angular range relative to the crankshaft.

In internal combustion engines, each with a camshaft for the intake and the exhaust valves, these can each be equipped with a camshaft adjuster. As a result, the opening and closing times of the inlet and outlet gas exchange valves can be shifted relative to one another in terms of time and the valve time overlaps can be set in a targeted manner.

The seat of modern camshaft adjuster is generally located at the drive end of the camshaft. It consists of a crankshaft fixed drive wheel, a camshaft fixed output part and a torque transmitting from the drive wheel to the output part adjustment mechanism. The drive wheel may be designed as a chain, belt or gear and is rotatably connected by means of a chain, a belt or a gear drive with the crankshaft. The adjustment mechanism can be operated electrically, hydraulically or pneumatically.

In the case of hydraulically operated camshaft adjusters, a distinction is made between so-called axial piston adjusters and rotary piston adjusters.

In Axialkolbenverstellern the drive wheel is connected to a piston via a helical gear in conjunction. Furthermore, the piston is also connected to the output part via a helical toothing. The piston separates a cavity formed by the driven part and the drive wheel into two pressure chambers arranged axially relative to one another. If now one pressure chamber is acted on by a hydraulic medium, while the other pressure chamber is connected to an oil outlet, the piston shifts in the axial direction. This axial displacement causes by means of the two helical gears a relative rotation of the drive wheel to the output part and thus the camshaft to the crankshaft.

In a Rotationskolbenversteller the drive wheel is rotatably connected to a stator. The stator and the output part are arranged concentrically with each other. The radial gap between these two components takes at least one, but usually several, spaced in the circumferential direction Cavities up. The cavities are limited pressure-tight in the axial direction by side walls. In each of these cavities, a connected to the output part wing extends. This wing divides each cavity into two pressure chambers. By selectively connecting the individual pressure chambers with a hydraulic fluid pump or with a hydraulic fluid outlet, the phase of the camshaft can be adjusted or held relative to the crankshaft.

To control the camshaft adjuster sensors detect the characteristics of the engine such as the load condition and the speed. These data are fed to an electronic control unit, which controls the adjustment motor of the camshaft adjuster or the inflow and outflow of hydraulic fluid to the various pressure chambers after comparing the data with a characteristic field of the internal combustion engine.

The axial position of the camshaft in the cylinder head of an internal combustion engine is determined by a double-acting thrust bearing. Ideally, this is located at the camshaft adjuster end of the camshaft. As a result, displacements of the control drive plane are avoided by thermal elongation of the camshaft under operating conditions.

Such a thrust bearing is for example from the DE 199 58 629 A1 known. In this case, the thrust bearing consists of a one-piece with the camshaft running circumferential radial web, which engages in an annular circumferential groove of a bearing shell. This embodiment of an axial bearing of the camshaft is not suitable when using a camshaft adjuster with a central valve, which is controlled by a central magnet, since large tolerances result from the interplay of different components between the camshaft axial bearing and central magnet. Therefore, a central magnet with a large stroke is required, whereby the axial length of the camshaft adjuster is considerably increased.

In the DE 100 13 877 A1 a device for changing the timing of gas exchange valves of an internal combustion engine is presented, wherein the camshaft thrust bearing is formed on the side facing away from the cam of the camshaft adjuster. A pressure medium adapter is connected by means of a fastening screw with a camshaft fixed component of the camshaft adjuster. At the side facing away from the camshaft adjuster side of the pressure medium adapter, a radially extending collar is formed. Between the pressure medium adapter and the camshaft adjuster a washer is additionally arranged. The collar of the pressure medium adapter and the washer form a ring on the outer circumferential surface of the pressure medium adapter circumferential groove in which engages a cylinder head fixed component, such as the cylinder head itself, a bearing bridge or a housing part. As a result, the camshaft is secured against axial displacement relative to the cylinder head.

This embodiment of an axial bearing of a camshaft by a washer and a pressure medium adapter which is mounted on the side facing away from the cam of the camshaft adjuster, allows the use of a mounted within the camshaft or the rotor of the camshaft adjuster central valve. Due to the small number of components between the camshaft thrust bearing and the central magnet necessary for the adjustment of the central valve, the tolerance chain and thus the stroke and thus the axial length of the central magnet can be reduced in this solution.

The disadvantage of this embodiment is the large number of components required for the axial bearing of the camshaft. This leads to higher costs and weight of the additional components to an increased assembly costs. In addition, assembly errors, such as the accidental omission of the washer, possible.

Summary of the invention

The invention is therefore based on the object to avoid these disadvantages and to provide a camshaft adjuster with a coaxial with the camshaft arranged pressure medium distributor, wherein the tolerance chain between camshaft thrust bearing and pressure distributor is shortened and the number of components of the camshaft bearing is minimized.

According to the invention, this object is achieved in that the pressure medium distributor and the camshaft adjuster together with a cylinder-head-fixed component form a camshaft thrust bearing. In this case, it may be the cylinder head-fixed component, for example, the cylinder head itself, a bearing bridge or a housing part.

In the present invention, a camshaft adjuster is non-rotatably attached to a hollow portion of an at least partially hollow camshaft. The camshaft passes through the central bore of the output part of the camshaft adjuster, wherein it extends in the axial direction over the region of the camshaft adjuster. Of course, it is also conceivable that instead of the camshaft an extension of the camshaft passes through the camshaft adjuster, which is why in the following camshaft either a camshaft or an extension thereof is understood.

The camshaft adjuster consists essentially of a drive wheel, a driven part and various housing parts, wherein at least two mutually acting pressure chambers are formed within these housing parts. The output member is in the present invention form-, friction, force or materially secured to the camshaft. The camshaft is hollow at the front end, which passes through the camshaft adjuster. Inside the camshaft, a pressure medium distributor is arranged. The pressure medium distributor directs the two counteracting pressure chambers to pressure medium. In this case, the pressure medium distributor can be designed either as a pressure medium adapter or as a central valve. Is the pressure medium distributor as Running central valve, this is advantageously operated by a subsequent directly to the central valve electromagnetic actuator.
The pressure medium distributor projects beyond the camshaft on the side facing away from the cam of the camshaft adjuster in the axial direction and is connected with this force, material or positive fit. At the protruding from the camshaft end face of the pressure medium distributor is provided with a radially extending collar, which projects beyond the camshaft in the radial direction.

In the assembled state is thus between the camshaft adjuster and the radial collar of the pressure medium manifold an annular groove encircling the camshaft. In this groove engages a part of the cylinder head, a bearing bridge or a housing. The radial collar of the pressure medium distributor prevents now in interaction with the cylinder head fixed component an axial migration of the camshaft further into the cylinder head inside. Likewise, the camshaft adjuster, in cooperation with the cylinder head-mounted component, prevents the camshaft from wandering in the axially opposite direction. It is also conceivable that a part of the housing as well as that the output part of the camshaft adjuster serves as a contact surface for the cylinder head fixed part of the bearing.

By forming a contact surface of the thrust bearing on the camshaft adjuster and on a centrally located in the camshaft pressure medium manifold, the number of components and thus the cost and assembly cost of the unit is minimized. When using a central valve as a pressure medium distributor, the number of components, compared to a valve disposed outside the camshaft valve, from which the pressure chambers are supplied via a pressure medium adapter with pressure medium, can be further minimized. Since the central valve itself is part of the camshaft thrust bearing, the tolerance chain between the camshaft thrust bearing and central valve is reduced to a minimum, whereby the stroke of the central magnet, which controls the central valve, can be made small. Thereby The axial space of the central magnet and thus the entire unit can be minimized.

In a further embodiment of the invention, the object is achieved in that the pressure medium distributor alone, together with a cylinder head fixed component forms a camshaft thrust bearing. As in the first embodiment, an at least partially hollow camshaft passes through a bore of a camshaft adjuster. The camshaft is hollow at its front end, which passes through the camshaft adjuster. Furthermore, this end of the camshaft projects beyond the camshaft adjuster in the axial direction. The camshaft adjuster consisting essentially of a drive part, an output part and housing parts is attached to the camshaft in a force, friction, form or material fit. At the drive end, a pressure medium distributor is introduced into the hollow portion of the camshaft. This extends in the axial direction of the camshaft adjuster beyond the front end of the camshaft out. The pressure medium distributor can be designed as a pressure medium adapter. In this case, it is provided with at least two pressure medium channels through which the camshaft adjuster is supplied with pressure medium via bores in the camshaft. Likewise, the use of a central valve is conceivable, which consists essentially of a sleeve provided with holes and a control piston disposed within the sleeve. On protruding from the camshaft front end of the pressure medium distributor, this is formed with a radially extending collar, the collar projects beyond the camshaft in the radial direction. The pressure medium distributor is positively, material or positively connected to the camshaft.

In the assembled state, the drive-side end face of the camshaft is in the axial direction within a cylinder head fixed component, such as the cylinder head itself, a bearing bridge or a lid. The cylinder head fixed component is provided with a bore in which the camshaft is arranged. On the inner lateral surface of the bore an annular groove is formed, in which the radially projecting collar of the pressure medium distributor intervenes. The radial collar of the pressure medium distributor forms in this way in cooperation with the cylinder head fixed component, the thrust bearing of the camshaft.

Advantageously, the driven part is pushed over the camshaft or the extension of the camshaft and positively, positively or materially connected thereto. Furthermore, the camshaft or the extension of the camshaft projects beyond the driven part in the axial direction on the side facing away from the cam of the camshaft adjuster. The pressure medium distributor is arranged within the at least partially hollow camshaft and can be designed as a pressure medium adapter or advantageously as a central valve. In the case of a design as a central valve is provided to form the pressure medium distributor as a 4/3-way valve. The pressure medium distributor is positively, positively, materially or by means of a screw fastened in the camshaft and projects beyond the camshaft in the axial direction. The pressure medium distributor has on the side facing away from the camshaft adjuster a radially outwardly extending collar. It is provided that the collar forms a part of the thrust bearing relative to the cylinder head fixed component.

Brief description of the drawings

Figur 1

einen Längsschnitt durch eine Vorrichtung zur Veränderung der Steuerzeiten einer Brennkraftmaschine (Nockenwellenversteller) nach Figur 1 a entlang der Linie I-I, die den prinzipiellen Aufbau eines Nockenwellenverstellers in Rotationskolbenbauart zeigt,

Figur 1 a

einen Querschnitt durch eine Vorrichtung zur Veränderung der Steuerzeiten einer Brennkraftmaschine (Nockenwellenversteller) nach Figur 1 entlang der Linie la-la, ohne Druckmittelverteiler, die den prinzipiellen Aufbau eines Nockenwellenverstellers in Rotationskolbenbauart zeigt,

Figur 2

einen Längsschnitt durch eine erfindungsgemäße Vorrichtung zur Veränderung der Steuerzeiten einer Brennkraftmaschine nach Figur 1 im montierten Zustand,

Figur 3

einen Längsschnitt durch eine erfindungsgemäße Vorrichtung zur Veränderung der Steuerzeiten einer Brennkraftmaschine nach Figur 1 in einem zweiten erfindungsgemäßen Montagezustand.

Further features of the invention will become apparent from the following description and from the drawings, in which embodiments of the invention are shown in simplified form. Show it:

FIG. 1

a longitudinal section through a device for changing the timing of an internal combustion engine (camshaft adjuster) after FIG. 1 a along the line II, which shows the basic structure of a camshaft adjuster in rotary piston type,

FIG. 1 a

a cross section through a device for changing the timing of an internal combustion engine (camshaft adjuster) after FIG. 1 along the line la-la, without pressure medium distributor, which shows the basic structure of a rotary piston type camshaft adjuster,

FIG. 2

a longitudinal section through an inventive device for changing the timing of an internal combustion engine after FIG. 1 in the assembled state,

FIG. 3

a longitudinal section through an inventive device for changing the timing of an internal combustion engine after FIG. 1 in a second mounting state according to the invention.

Detailed description of the drawings

The FIGS. 1a . 1 to 3 show a device for changing the timing of an internal combustion engine (camshaft adjuster 1). It is in the FIGS. 1 and 1 a the basic structure of a camshaft adjuster 1 shown in rotary piston design, while in FIG. 2 and 3 two camshaft adjuster according to the invention are shown in different installation variants. In the illustrated embodiment, the camshaft adjuster 1 is shown as Rotationskolbenversteller. Also conceivable, however, are other embodiments hydraulic powered camshaft adjuster 1 such. B. Axialkolbenversteller. The camshaft adjuster 1 consists essentially of a drive wheel 2, a driven part 3 and two disc-shaped side walls 4 and 5. The drive wheel 2 is designed in the illustrated embodiment as a sprocket, which is connected via a drive chain with a crankshaft, not shown. Also conceivable are embodiments in which the drive wheel 2 is designed as a belt wheel or gear, which is driven by a toothed belt or gear drive of the crankshaft. The drive wheel 2 and the Stripping member 3 are arranged concentrically with each other, wherein the radially inner circumferential surface of the drive wheel 2 is provided with radial recesses 6, engage in the mounted on the driven part 3 bulges 7. The bulges 7 may be extended webs or wings 8. The wings 8 are in axially extending grooves which are formed in the lateral surface of the driven part 3, and are pressed by means of a compression spring 9 sealingly against the radially inner surfaces of the recesses 6 of the drive wheel 2.

In the axial direction of the camshaft adjuster 1 is limited by the first and the second side wall 4, 5. For fastening the side walls 4 and 5 on the drive wheel 2 fastening means such as screws 10 are provided. The drive wheel 2, the driven part 3, the first and the second side wall 4, 5 form a plurality of separate pressure chambers, which are divided by the wings 8 in each case in two oppositely acting pressure chambers 12, 13. To adjust the phase of the camshaft 11 relative to the crankshaft, for example, the first pressure chambers 12 are supplied with pressure medium and the second pressure chambers 13 connected to a pressure medium reservoir, not shown, so the blades attached to the rotor 8 are moved so that the volume of the first pressure chambers 12 larger and that of the second pressure chambers 13 becomes smaller. As a result, the rotor is rotated relative to the camshaft 11 such that the gas exchange valve opening times are shifted, for example, to an earlier point in time. Similarly, the supply of the second pressure chambers 13 with pressure medium and the simultaneous connection of the first pressure chambers 12 with the pressure medium reservoir causes an adjustment of the gas exchange valve opening times to a later date.

In order to prevent the wings 8 of the camshaft adjuster 1 in phases of insufficient pressure medium supply, such as during the starting phase of the internal combustion engine, oscillate uncontrollably between their end positions, the camshaft adjuster 1 is provided with an in FIG. 2 illustrated locking device 14 is provided, the output part 3 in these periods holds in a defined phase to the drive wheel 2. In an axial bore of the driven part 3, a cartridge 15 is arranged, which is supported on the first side wall 4. The cartridge 15 is provided with an axially extending projection about which a coil spring 16 is disposed. The coil spring 16 acts on a cup-shaped piston 17 with a force in the direction of the second side wall 5 in which a link 18 is formed. In phases insufficient pressure medium supply, the piston 17 is held by the spring force in the link 18 and thus held a fixed phase relationship between the camshaft 11 and crankshaft. In order to deactivate the locking mechanism, engaging in the slot 18 end face of the piston 17 is acted upon by pressure medium, whereby the piston 17 is displaced against the spring force of the coil spring 16 in the axial bore of the driven part 3. In order to dissipate the leakage pressure accumulating between the piston 17 and the cartridge 15, radially extending recesses in the cartridge 15 and openings communicating therewith are provided in the first side wall 4.

The camshaft adjuster 1 is positively, positively, frictionally or cohesively mounted on a camshaft 11. The camshaft 11 carries one or more cams 19 and passes through a bore 20 of the driven part 3, wherein it projects beyond the camshaft adjuster 1 on the side facing away from the cam 19 in the axial direction. The camshaft 11 is executed at least at the front end, which passes through the camshaft adjuster 1, hollow. Within this cavity, a pressure medium distributor 21 is introduced. The pressure medium distributor 21 may be a pressure medium adapter which connects the pressure chambers 12, 13, which act against each other, to a pressure medium pump or to the pressure medium reservoir.

In the present example, the pressure medium distributor 21 is designed as a central valve 22. The central valve 22 consists of a sleeve-shaped valve body 23 and a valve piston 24. The valve body 23 extends from the camshaft portion, which is encompassed by the camshaft adjuster 1, in the axial direction to over the drive-side end of the Camshaft 11 addition. In this case, the outer diameter of the valve body 23 is substantially adapted to the inner diameter of the camshaft 11, and non-positively, material or positively connected thereto. By way of example, connection methods such as screw connection, press fit or gluing are specified here. At the protruding from the camshaft 11 front end of the valve body 23, this is provided with a radially extending collar 42 which extends in the radial direction beyond the camshaft 11 also.

The outer circumferential surface of the valve body 23 is provided with a first, a second, a third and a fourth annular channel 25, 26, 27, 28, wherein the annular channels 25 to 28 are arranged axially spaced apart. Each of the annular channels 25 to 28 is designed as a diameter reduction in the outer circumferential surface of the valve body 23 and communicates with each of a group of first to fourth openings 29, 30, 31, 32 which are inserted into the camshaft 11 and each with a group of in the valve body 23 introduced fifth to eighth openings 33, 34, 35, 36 which connect the annular channels 25 to 28 with the interior of the central valve 22. Depending on one of the group of openings 29 to 32, one of the group of openings 33 to 36 and the respective associated annular channel 25 to 28 form a port 37, 38, 39, 40. Furthermore, which is located in the camshaft 11 end face of the valve body 23 provided with a ninth opening 41, which vents the interior of the valve body 23 into the cavity of the at least partially hollow camshaft 11.

Within the valve body 23, a hollow valve piston 24 is arranged axially displaceable. The valve piston 24 can be displaced in the axial direction via an adjusting element 43 of an adjusting device 44 against the restoring force of a spring 45 acting on the valve piston 24 and supporting it on the interior of the valve body 23. The adjusting device 44 may be, for example, an electromagnet in which a permanent magnet connected to the adjusting element 43 is arranged. By varying the current supplied to the electromagnet, the position of the permanent magnet, Thus, the position of the actuating element 43 and thus the position of the valve piston 24 are selectively changed.

The outer circumferential surface of the valve piston 24 is provided with a fifth to seventh annular channel 46, 47, 48, which in turn are designed as a diameter reduction in the outer circumferential surface of the valve piston 24. The fifth annular channel 46 is connected to the interior of the valve piston 24 via a tenth group of openings 49 and the seventh annular channel 48 via an eleventh group of openings 50. The interior of the valve 24 is formed closed except for the tenth and eleventh openings 49, 50. In the illustrated embodiment, the valve piston 24 is cup-shaped. The open end face of the valve piston 24 is pressure-tightly closed by means of a disc-shaped element 51, which bears against both the valve piston 24 and the actuating element 43.

In the following, the operation of the camshaft adjuster 1 will be explained. Via the first port 37, pressure medium is supplied to the fifth annular passage 46. The fifth annular channel 46 communicates via the tenth and eleventh openings 49, 50 with the seventh annular channel 48. The fifth annular channel 46 is designed such that it communicates in each position of the actuator 44 first terminal 37.

In a first switching state of the central valve 22, which corresponds to a de-energized state of the electromagnet of the adjusting device 44, the valve piston 24 is displaced by the spring 45 such that it assumes a position with minimum distance to the adjusting device 44. In this position, the seventh annular channel 48 communicates via the third port 39 with first pressure medium lines 52, which open into the first pressure chambers 12. At the same time the pressure medium from the second pressure chambers 13 via second pressure medium lines 53 and the fourth port 40 into the interior of the valve body 23, which is vented via the ninth opening 41 in the camshaft 11 and from there via vent holes 54 in the crankcase. As a result, the gas exchange valve timing is changed at an earlier time.

In a second, in FIG. 1 illustrated position of the valve piston 24 which is occupied by energizing the electromagnet of the actuator 44 with an average current, the seventh annular channel 48 communicates with neither the third nor with the fourth terminal 40, whereby the pressure fluid flow comes to a standstill and the current phase position between the camshaft 11th and crankshaft is held.

In a third position, a current of maximum current flows through the electromagnet of the adjusting device 44. As a result, the valve piston 24 is brought into a position that is maximally removed from the adjusting device 44. In this switching state of the central valve 22, the pressure medium via the first port 37, the fifth annular channel 46, the tenth and eleventh openings 49, 50 the seventh annular channel 48 and the fourth port 40 to the second pressure medium lines 53, from where they in the second pressure chambers 13 open. At the same time, the first pressure chambers 12 are connected via the first pressure medium lines 52, the third connection 39, the sixth annular channel 47 and the second connection 38 to the pressure medium reservoir. This causes an adjustment of the opening times of the gas exchange valves at a late time.

FIG. 2 shows a first installation situation of a camshaft adjuster 1 according to the invention. The axial position of a camshaft 11 in the cylinder head of an internal combustion engine is determined by a double-acting thrust bearing. Ideally, this is located at the control drive end of the camshaft 11 to avoid displacement of the control drive plane by thermal elongation of the shaft under operating conditions. In the present case, the camshaft thrust bearing is formed by the output part 3 of the camshaft adjuster 1, the radially extending collar 42 of the valve body 23 and a cylinder head fixed component 55. The cylinder head fixed component 55 may be the cylinder head itself, a bearing bridge or a housing part. The cylinder head fixed component 55 engages around the camshaft 11 in the region between the camshaft adjuster 1 and the radially extending collar 42.

It is on the one hand to the radially extending collar 42 at. In the illustrated embodiment, the cylinder head fixed component 55 engages on its side facing away from the collar 42, the first side wall 4 of the camshaft adjuster 1 and is located on the driven part 3 at. An axial displacement of the camshaft 11 is effectively prevented by this arrangement. Advantageously, the cylinder head fixed component 55 is designed so that it does not pass through the first side wall 4 of the camshaft adjuster 1 on the entire circumference of the camshaft 11 in order to ensure effective flow of the pressure medium.

It is equally conceivable, of course, that the second thrust bearing surface is not formed on the output part 3 of the camshaft adjuster 1, but on the first side wall 4.

If a bearing bridge is provided as the cylinder-head-fixed component 55, then it can be designed in one or two parts.
In the case of the one-piece design, the camshaft adjuster 1 is first fixed on the camshaft 11 and inserted into the cylinder head. The bearing bridge is pushed with a bearing bore over a free end of the camshaft 11. Subsequently, the central valve 22 within the camshaft 11 force, substance or positively fixed. This can be done for example by means of a screw, a press fit or by gluing.
In the case of a two-part bearing bridge whose lower shell may already be attached to the cylinder head. In a first step, the camshaft 11 is inserted with fixed camshaft adjuster 1 and fixed central valve 22 in the lower shell. Subsequently, the upper part of the bearing bridge is placed on the lower shell and connected thereto.

FIG. 3 shows a further possibility of the axial bearing of the camshaft 11. The cylinder head fixed component 55 is provided with a bore 56. The inner circumferential surface of the bore 56 is provided with an annular circumferential groove 57. The camshaft 11 is in the bore 56 of the cylinder head fixed Component 55 arranged that the radially extending collar 42 of the valve body 23 engages in the annular circumferential groove 57 of the inner circumferential surface of the bore 56. The cylinder head fixed component 55 is of course designed as a two-part component in this case. During assembly, the camshaft adjuster 1 is joined to the camshaft 11. A lower shell of a bearing bridge is fixed in this case already on the cylinder head. The camshaft 11 with the fixed camshaft adjuster 1 and the pressure medium distributor 21 is inserted into the cylinder head. Subsequently, the upper part of the bearing bridge is placed on the lower part via the free end of the camshaft 11. Finally, the upper and lower part are connected to each other, whereby the radially extending collar 42 together with the annular circumferential groove 57 results in the camshaft thrust bearing.

reference numeral

1

Phaser

2

drive wheel

3

stripping section

4

first sidewall

5

second side wall

6

recesses

7

bulges

8th

wing

9

compression spring

10

screw

11

camshaft

12

first pressure chamber

13

second pressure chamber

14

locking device

15

cartridge

16

spiral spring

17

piston

18

scenery

19

cam

20

drilling

21

Fluid manifold

22

central valve

23

valve body

24

plunger

25

first ring channel

26

second ring channel

27

third ring channel

28

fourth ring channel

29

first opening

30

second opening

31

third opening

32

fourth opening

33

fifth opening

34

sixth opening

35

seventh opening

36

Eighth opening

37

first connection

38

second connection

39

third connection

40

fourth connection

41

ninth opening

42

Federation

43

actuator

44

setting device

45

feather

46

fifth ring channel

47

sixth ring channel

48

seventh ring channel

49

tenth opening

50

eleventh opening

51

element

52

first pressure medium line

53

second pressure medium line

54

ventilation holes

55

cylinder-head-resistant component

56

drilling

57

groove

Claims (10)

1. Camshaft adjuster (1) for adjusting and fixing the phase position of a camshaft (11) of an internal combustion engine in relation to a phase position of its crankshaft, having

   - a timing gear (2) which is driven by the crankshaft,

   - an output part (3) which is secured on the camshaft,

   - is attached to a camshaft (11) or to an extension of the camshaft (11) and

   - is driven by the timing gear (2) via a hydraulic actuating drive,

   - the actuating drive comprising at least one pair of hydraulic pressure chambers (12, 13) operating towards each other, and

   - the pressure chambers (12, 13) being supplied with pressure medium via a pressure medium distributor (21) and pressure medium lines (52, 53), characterized in that

   - the pressure medium distributor (21) and the camshaft adjuster (1) together with a component (55) secured on the cylinder head form a camshaft axial bearing.
2. Camshaft adjuster (1) for adjusting and fixing the phase position of a camshaft (11) of an internal combustion engine in relation to a phase position of its crankshaft, having

   - a timing gear (2) which is driven by the crankshaft,

   - an output part (3) which is secured on the camshaft,

   - is attached to a camshaft (11) or to an extension of the camshaft (11) and

   - is driven by the timing gear (2) via a hydraulic actuating drive,

   - the actuating drive comprising at least one pair of hydraulic pressure chambers (12, 13) operating towards each other, and

   - the pressure chambers (12, 13) being supplied with pressure medium via a pressure medium distributor (21) and pressure medium lines (52, 53), characterized in that

   - the pressure medium distributor (21) on its own, together with a component (55) secured on the cylinder head, forms a camshaft axial bearing.
3. Camshaft adjuster (1) according to either of Claims 1 and 2, characterized in that the output part (3) is pushed over the camshaft (11) or the extension of the camshaft (11) and is connected thereto non-positively, positively or with a cohesive material joint.
4. Camshaft adjuster (1) according to either of Claims 1 and 2, characterized in that the camshaft (11) or the extension of the camshaft (11) protrudes over the output part (3) in the axial direction on the side of the camshaft adjuster (1) which faces away from the cam (19).
5. Camshaft adjuster (1) according to either of Claims 1 and 2, characterized in that the pressure medium distributor (21) is arranged within the camshaft (11) which is of at least partially hollow design.
6. Camshaft adjuster (1) according to either of Claims 1 and 2, characterized in that the pressure medium distributor (21) is designed as a central valve (22).
7. Camshaft adjuster (1) according to either of Claims 1 and 2, characterized in that the pressure medium distributor (21) is designed as a 4/3-way directional control valve.
8. Camshaft adjuster according to either of Claims 1 and 2, characterized in that the pressure medium distributor (21) is fastened in the camshaft (11) non-positively, positively, with a cohesive material joint or by means of a screw connection.
9. Camshaft adjuster (1) according to either of Claims 1 and 2, characterized in that the pressure medium distributor (21), on the side facing away from the camshaft adjuster (1), has a radially outwardly extending shoulder (42).
10. Camshaft adjuster (1) according to either of Claims 1 and 2, characterized in that the shoulder (42) forms part of the axial bearing with respect to the component secured on the cylinder head.

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