Camshaft assembly method and associated camshaft adjustment system

Abstract

The invention relates to a camshaft assembly method and an associated camshaft adjustment system. The camshaft adjustment system comprises a housing (2), wherein a vane-type camshaft adjuster (3) is preassembled in the housing (2), and then a rod (4) of the camshaft (1) is pushed into a cavity (5) at the axial end of a rotor (6) in one working step and mounted on the rotor (6) in a rotationally fixed and axially fixed manner.

Description

Technical Field

[0001] The invention relates to a camshaft assembly method for assembling a camshaft, in particular a camshaft tube in the form of a hollow shaft, of an internal combustion engine of a motor vehicle in a camshaft adjustment system having a housing, in particular an engine housing or a frame member of a valve train, and a preferably vane-type camshaft adjuster. The invention relates to the associated camshaft adjustment system. Background Art

[0002] Approximate prior art is known from documents EP 1 155 770 B1, DE 3 525 186 A1, DE 10 331 089 A1 and DE 10 2009 060 352 B4. In these documents, the camshaft is assembled in the following manner, that is, the cam and, if necessary, the bearing supporting the camshaft are axially positioned in the housing and angularly aligned, and then the cooled and shrunk rod is pushed through the cam and the bearing to form an interference connection or cold expansion connection. Subsequently, the camshaft adjuster can be clamped to the camshaft at the end of the camshaft by a central screw and thus fixed thereto by a screw connection. Alternatively, the welding of the adjuster rotor or the inner rotor to the camshaft can also be provided. Other similar prior art is known, for example, from US 3 621 550 A.

[0003] Alternatively, EP 2 911 826 B1 discloses that the hollow shaft is fixed to the cam by plastic expansion of the hollow shaft by applying internal pressure. Another alternative is that the shaft is connected to the bearing frame, the cam and the camshaft adjuster by a longitudinal interference fit, such as by the subject "Joining process enables the production of ready-to-install valve train systems at room temperature, with low friction and faster assembly (Fügeverfahren The entry "Herstellung von einbaufertigenVentiltriebsystemen bei Raumtemperatur-Weniger Reibung und schnellereMontage)" (https: / / automobilkonstruktion.industrie.de / antrieb / antriebsstrang / wenige r-reibung-und-schnellere-montage / , called on January 21, 2019) is made public.

[0004] Theoretically, the camshaft adjuster can be mounted on the camshaft purely by cooling shrinkage or cold expansion joints, but the disadvantage is that the transmittable torque is too small for transmitting the required working torque of all cams, including safety and inertia torque, in the case of cold expansion joints. The disadvantage of the above-mentioned prior art is that the fixing of the camshaft adjuster on the camshaft is complicated and also requires high-cost reprocessing of the camshaft and the corresponding components of the camshaft adjuster. In addition, it is sometimes impossible to accurately infer the structural design of the relevant components and the accurate assembly process. In principle, the devices of the prior art require more expensive components and / or complex preparation and tools for assembling the camshaft adjuster.

[0005] Furthermore, DE 10 2006 039 371 A1 discloses that a vane-type camshaft adjuster is fixed to the camshaft via a force connection (e.g., by means of a cold expansion joint), a form connection, or a combination thereof. Other similar embodiments of vane-type camshaft adjusters are described in DE 10 2012 202 823 A1, DE 103 34 690 A1, and EP 2 584 158 A1. The exact sequence of the associated assembly sequence cannot be inferred from these documents.

[0006] However, the devices known to date all have camshaft adjuster rotors or camshaft ends which have geometries and / or upper surfaces which are complex in design and / or have post-processing and are expensive to produce, as a result of which the production and assembly of the device is complex and expensive. Summary of the invention

[0007] The object of the present invention is to provide a camshaft assembly method and a camshaft adjustment system which avoid or at least reduce the disadvantages of the prior art. In particular, the object of the present invention is to provide a camshaft assembly method and a camshaft adjustment system which are fast, reliable and simple and which allow the components and component groups to be assembled to be simplified in terms of structure and manufacturing technology.

[0008] In a camshaft assembly method for assembling a camshaft, in particular a camshaft tube in the form of a hollow shaft, of an internal combustion engine of a motor vehicle in a camshaft adjustment system, wherein the camshaft adjustment system has a housing, in particular an engine housing or a frame beam of a valve train, and a preferably vane-type camshaft adjuster, the object of the present invention is achieved as follows, namely, the camshaft adjuster is preassembled in the housing, and then the rod of the camshaft is pushed into a cavity at the axial end of the rotor of the camshaft adjuster in a separate working step and is mounted and / or joined to the rotor in a rotationally fixed manner.

[0009] In other words, the camshaft adjuster is positioned in the housing, in particular without a support (i.e. without being positioned by an additional retaining device to be removed at a later time), and is held only by the housing and, if necessary, by means of a bearing. In this way, retaining devices for positioning the camshaft adjuster can be omitted, which leads to a reduction in the load on the rotor with respect to the clamping force applied by the central screw, and the camshaft can be mounted thereon in a single working step, in particular automatically. In addition, expensive central screws and the expensive reworking of the camshaft and rotor required for this purpose can be omitted.

[0010] For preassembly of the camshaft adjuster, the housing is preferably aligned so that the camshaft installed therein will extend vertically, the camshaft adjuster is then inserted from above with little effort into the base or intermediate plate of the housing and secured from below to prevent it from falling out or slipping out, for example by means of a locking ring. This allows for particularly simple preassembly of the camshaft adjuster.

[0011] Advantageous embodiments are part of the dependent claims and are explained further below.

[0012] Advantageously, in the same working step in which the rod is pushed into the hollow space, the camshaft is pushed by the cam arranged in the housing and aligned and is mounted and / or joined to the cam in a rotationally fixed and axially fixed manner. It has also proven to be effective to pre-assemble bearings, in particular radial bearings, in the housing for the direct support of the rod. The camshaft is also pushed into the bearing in the same working step in which the camshaft is pushed into the hollow space and, if necessary, into the cam and mounted on the cam. This makes it possible to assemble the camshaft and the camshaft adjustment system and to fix all the aforementioned components in one working step. This advantageously makes the assembly method more cost-effective and faster.

[0013] Furthermore, the rod can be cooled and thus contracted before insertion and installation or joining, so that a cold expansion connection or interference connection between the rod and the rotor of the camshaft adjuster is provided after the rod is inserted in the cold state and heated in its inserted end position. This provides a particularly reliable, fast and stable connection between the rod and the rotor. Furthermore, in this way, the cam and the bearing can also be connected to the rod simultaneously, reliably, quickly and stably in a single working step of insertion. Alternatively or additionally, the camshaft can also be pressed into the rotor and, if necessary, into the cam.

[0014] According to one aspect of the invention, the rod and the rotor of the camshaft adjuster are shaped at the joint contact area provided by the two components, preferably by means of a toothing or a torx structure, in order to provide a positive connection. Alternatively or additionally, the rod and / or the rotor of the camshaft adjuster are reprocessed in the corresponding joint contact area to increase friction, preferably by laser structuring or laser ablation. This makes it possible to provide a particularly load-bearing and play-free connection, especially in combination with the above-mentioned cooling expansion method.

[0015] It has proven to be meaningful that the cartridge valve is pushed into the rotor of the camshaft adjuster at the end of the rotor cavity that is remote from the rod, in an angular orientation relative to the rotor, in particular depending on the positioning of the hydraulic medium channels of the two components. That is, the cartridge valve is inserted into the rotor in such a way that it is twisted at a defined angle relative to the rotor, or in other words, the rotor and the cartridge valve have a predetermined angular position relative to each other. This makes it possible to eliminate the central screw that accommodates the valve and accordingly the valve does not have to rotate with the central screw during installation. This eliminates the need to provide distribution grooves or circumferential grooves and associated sealing surfaces on the contact surfaces of the rotor and / or the central screw and / or the cartridge valve. Expensive reworking and leakage losses can therefore be reduced.

[0016] Furthermore, the circumference of the cartridge valve can be enlarged. This increases the volume flow through the valve, in particular in combination with improved leakage behavior, and thus improves the adjustment and reaction speed of the camshaft adjuster. In other words, it is expedient to arrange the cartridge valve in the rotor of the camshaft adjuster in such a way that it lies directly on the inner circumferential surface of the rotor, in particular without central screws or central screw sleeves arranged therebetween.

[0017] The cartridge valve is preferably fixed in the rotor in a force-fitting, in particular friction-fitting manner. This provides a particularly simple, inexpensive fixing method that is well adjustable for angle adjustment. Alternatively, it is conceivable that no separately provided cartridge valve is provided, but that the hydraulic channels and the valve core receptacle (which are otherwise provided by the housing of the cartridge valve) are formed integrally with the rotor material or integrated therein. Since the assembly of the system can be further simplified, leakage losses can be further reduced and a possibly complex angle adjustment between the cartridge valve and the rotor can be omitted.

[0018] According to one design of the present invention, a first adjuster chamber and a second adjuster chamber (also referred to as a vane) that reacts with the first adjuster chamber for phase adjustment of the camshaft are formed between the rotor and the stator of a vane-type camshaft adjuster, and are respectively supplied with hydraulic medium, in particular oil, through first and second hydraulic medium channels, in particular oil channels, that are provided in the cartridge valve and extend radially. Here, the first and second hydraulic medium channels are arranged in the same radial plane. This makes it possible to arrange the cartridge valve in the rotor in an angular orientation, because in this way the distribution groove can be omitted, and the spacing required for reliable sealing between the corresponding outlet openings of the hydraulic medium channels can nevertheless be omitted. As a result, the axial structural space of the valve can be reduced in an advantageous manner.

[0019] According to a preferred aspect of the present invention, the rod can only be partially pushed into the rotor. In particular, the rod is pushed into the rotor in such a way that the end face of the rod is opposite to the end face of the cartridge valve. Or in other words, the cartridge valve is arranged within the rotor and arranged adjacent to the end of the camshaft rod in the axial direction, thereby further increasing the diameter of the cartridge valve and thus increasing its volume flow. This can advantageously further improve the reaction speed of the camshaft adjuster. In addition, the rod can be shortened, which saves weight, rod processing time and the resulting material and manufacturing costs. In addition, in this case, there is a larger radial space for the valve. It is particularly advantageous that the rotor is fixed to the rod by a shape-locking connection or friction enhancement of the joint contact area and by a cold expansion connection, because the torque to be transmitted can also be reliably transmitted through a proportionally reduced joint contact area defined by the rod portion inserted into the rotor when driving and adjusting the camshaft.

[0020] The rotor of the camshaft adjuster is preferably preassembled in the housing by means of a support, preferably by means of a radial bearing and / or a thrust bearing or a combined radial thrust bearing. This is advantageous because the force transmitted to the camshaft adjuster by the drive element during operation of the internal combustion engine can be supported directly on the housing by means of the support, and the connection with the rod will not be overloaded. According to an advantageous manner, the rotor has a shoulder, which preferably extends in the axial direction from the end of the rotor opposite to the rod, on which a support is provided. That is, the camshaft adjuster is preassembled in the housing in such a way that it is radially and / or axially supported on the housing on the side away from the rod. As a result, the camshaft adjustment system can be shortened in the axial direction. In addition, the camshaft adjuster is also arranged in such a way that the camshaft adjuster is protected by the housing, so that the camshaft adjustment system with the housing, the camshaft adjuster and, if necessary, the cartridge valve can be transported particularly safely as a preassembled and shipped component.

[0021] Preferably, an endless transmission element, in particular a driving or driven belt or a driving or driven chain, is mounted on the toothing of the stator of the camshaft adjuster around the rotor before the rod is inserted, preferably before the camshaft adjuster is inserted into the housing. This is provided in particular because, as described above, the camshaft adjuster is preassembled in the housing, i.e., is difficult to access or is not accessible from the outside in the assembled state. An endless transmission element is a simple drive that can be provided in a standardized manner, and the assembly of the endless transmission element before the rod is inserted can provide such a simplified drive and in this case eliminate further, possibly complex, adaptations of the system.

[0022] The object on which the invention is based is also achieved by a camshaft adjustment system for a motor vehicle internal combustion engine, which has a housing, in which a particularly vane-type camshaft adjuster is preassembled, wherein the rotor has a cavity at an axial end, which cavity is ready to be at least partially filled at a later point in time by a camshaft fixed in rotationally fixed relation to the rotor. The camshaft adjustment system can advantageously be provided to the customer as a preassembled component.

[0023] In other words, the camshaft adjustment system is a preassembled assembly with a housing, in which the camshaft adjuster is preassembled. Since the rotor is pushed into the hollow space, the available space in the rotor can also be enlarged without having to provide for additional diameter changes in the rotor geometry, etc. It is particularly advantageous that, according to one aspect of the invention, the camshaft adjustment system or the preassembled assembly also has a cartridge valve, which is preassembled in the rotor of the camshaft adjuster, in particular in such a way that it rests directly on the inner circumferential surface of the rotor. For further explanations of the camshaft adjustment system and the camshaft, see the above description of the camshaft assembly method.

[0024] In other words, the basic idea of ​​the present invention is to reduce costs. Specifically, the central bolt can be eliminated, the camshaft end (tube end) can be simplified, a simple central valve housing can be specified instead of the central bolt when a central valve is used, and a cooling shrink connection can be applied to the connection between the camshaft adjuster and the rotor, wherein a larger torque can be transmitted.

[0025] In summary, the solution of the present invention is to assemble all components for transmitting the camshaft torque from the introduction on the chain to the cam in one working process. Here, according to one aspect of the present invention, the bolt connection between the rotor and the rod is replaced by a gap-free form-locking connection, which is established by the cooling and shrinking of the camshaft tube in the rotor. Alternatively, a circular and non-form-locking connection reinforced by laser structure can be cooled and shrunk. According to another aspect, the connection between the rotor and the rod is relieved from the chain lateral force and axial force by the direct radial support of the camshaft adjuster combined with the axial support on the rotor in the frame beam of the valve transmission mechanism. According to another aspect, in order to gain axial structural space for the connection between the rotor and the rod, oil channels A and B are laid on a plane in the rotor and an area of ​​the rotor is not penetrated by the front tube end of the camshaft, so that the central valve can be placed before the connection.

[0026] More precisely, in order to create a gap-free form fit, the end of the camshaft tube and the inner diameter of the rotor are manufactured in the form of a toothed or hexagonal drive. The assembly play of the connection is eliminated by shrinking, so that the adjusting torque can be transmitted to the camshaft without play. The gap-free form fit allows large adjusting torques to be transmitted. The central valve body and the camshaft end can be omitted.

[0027] The present invention has the following advantages:

[0028] - External support of chain forces on the frame beams rather than through the connection between rotor and rods,

[0029] - The regulator does not need to be assembled with force in the system (especially when the customer is there),

[0030] - the adjuster can be pre-assembled in the frame for automated and force-free pre-assembly in the beam frame (the adjuster is inserted axially and engages the locking ring),

[0031] - cost advantages due to the elimination of the central valve housing as a bolt body,

[0032] - cost advantages due to the elimination of camshaft end pieces,

[0033] - The regulator and cartridge valve can be shipped as a unit and pre-assembled,

[0034] - Eliminate the need for customers to assemble central valves,

[0035] - a valve train with a frame beam as an advantageous embodiment,

[0036] -Relieve the load on the rotor by eliminating the pre-tensioning force generated by the central bolt (can be redesigned),

[0037] - Increased volume flow in the central valve (valve body removed),

[0038] - Reduced leakage in the system by integrating the cartridge valve into the rotor flange, and

[0039] - Higher control speeds within the system (due to improved leakage characteristics and higher volume flows). BRIEF DESCRIPTION OF THE DRAWINGS

[0040] The invention is further described below with the aid of the accompanying drawings, in which preferred embodiments of the invention are shown, wherein the same reference numerals are used for the same features. The accompanying drawings are only schematic and serve for the understanding of the invention. These embodiments can be combined with each other and individual features can be interchanged or omitted without departing from the scope of the invention.

[0041] In the figure:

[0042] Figure 1 shows a longitudinal section of a camshaft which is assembled by means of a camshaft assembly method according to a first embodiment of the present invention,

[0043] Figure 2 A shows a cross-sectional view of a connection point produced by means of a camshaft assembly method according to a first embodiment,

[0044] Figure 2B shows a cross-sectional view of a connection point produced by means of a camshaft assembly method according to a second embodiment, and

[0045] Figure 2 C shows a cross-sectional view of a connection point produced by means of a camshaft assembly method according to a third embodiment. Specific implementation plan

[0046] Figure 1 A camshaft 1 is shown, which is arranged in a housing 2 and is connected axially and radially fixedly to a known vane-type camshaft adjuster 3 at the axial end. The rod 4 of the camshaft 1, which is designed as a hollow shaft, is partially inserted into a cavity 5 at the axial end, which cavity is formed in a rotor 6 of the camshaft adjuster 3. The region of the rod 4 inserted into the cavity 5 is configured as a first engaging contact area 7, while a region of the rotor 6, in particular a part of its inner circumferential surface, is configured as a second engaging contact area 8, which is matched in such a way that, together with the first contact area 7, a fixed connection between the rod 4 and the rotor 6 is provided. A more precise embodiment of these engaging contact areas 7, 8 will be described later. Figure 2 A to 2C are described in more detail.

[0047] The cartridge valve 9 is installed in the hollow chamber 5 of the rotor 6 in such a way that the cartridge valve is adjacent to the end side of the rod 4 and approximately fills the remaining hollow chamber 5 of the rotor 6. The diameter of the cartridge valve 9 corresponds approximately to the inner diameter of the hollow chamber 5. That is, the cartridge valve 9 directly rests on the inner circumferential surface of the hollow chamber 5. In order to be able to place the cartridge valve 9 in the hollow chamber 5, it is particularly short in the axial direction. To achieve this, oil channels A and B are provided in the cartridge valve 9, through which oil pressure is provided during operation to operate the camshaft adjuster 3. These oil channels A and B are configured in such a way that their outlet openings from the cartridge valve 9 are arranged in a common radial plane on the area of ​​the cartridge valve 9 facing the rod 4. In order to selectively control the oil channels A and B, the cartridge valve 9 also has an internal valve core (not shown), through which the oil supply or oil discharge can be selectively connected, closed or switched.

[0048] The cartridge valve 9 is arranged at a certain angle relative to the rotor 6, so that the discharge openings of the oil channels A and B are flush with the associated oil channels (not shown) of the rotor 6, which in turn are connected to the leading vanes or reset vanes or the regulator chambers of the camshaft adjuster 3. The regulating chamber is constructed between the radially outwardly extending vanes of the camshaft adjuster 3 and the stator 10 that accommodates it. Depending on whether the oil leads to the leading vanes or reset vanes or is discharged from the leading vanes or reset vanes, the phase or angle between the stator 10 and the rotor 6 is adjusted to control the valve opening time of the internal combustion engine. A toothed section 11 is provided on the outer circumference of the stator 10, which meshes with the drive chain 12, through which the torque is introduced into the existing system. The engagement contact area and the vanes of the rotor 6 are arranged on the same side of the rotor 6 facing the rod in the axial direction.

[0049] Thus, the bearing shoulder 13 extends from the finned part of the rotor 6 in a single piece in the direction away from the rod 4. The bearing shoulder 13 has a smaller diameter than the finned part of the rotor 6 and serves to support the stator 10 on the rotor 6. Furthermore, a support 14 is provided on the bearing shoulder 13, which provides radial support of the rotor 6 on an adjuster bearing wall 15 of the housing 2 and is axially fixed in the axial direction between the stator 10 and a fixing ring 17 provided at the axial end of the rotor 6 in such a way that axial forces acting on the camshaft 1 or the camshaft adjuster 3 can be transmitted to the adjuster bearing wall 15. Furthermore, the adjuster bearing wall 15 is designed in such a way that the stator 10 is supported on the adjuster bearing wall in the axial direction directly or via a friction-reducing layer or plate additionally arranged therebetween. By arranging the bearing 14 directly on the rotor 6 and directly adjacent to the stator 10, transverse forces transmitted to the camshaft adjuster 3 via the drive chain 12 during operation can provide support on the housing 2 without the connection between the rotor 6 and the rod 4 being unnecessarily loaded. On the side of the adjuster bearing wall 15 facing away from the camshaft adjuster 3 and the camshaft 1, a central magnet is mounted in a sealed manner, which is opposite the valve slide of the cartridge valve 9 for its operation.

[0050] During operation, the torque is transmitted from the drive train 12 via the toothing 11 to the stator 10 of the camshaft adjuster 3. The torque is transmitted to the rotor 6 by the oil pressure existing in the vanes and from there via the engagement contact areas 7, 8 to the rod 4 of the camshaft 1. The camshaft 1 is supported in the axial direction on the intermediate walls 20 of the housing 2 by means of a number (shown here: two) of radial bearings 19. Between the intermediate walls 20, cams 21 are mounted axially and radially fixed on the rod 4, by means of which the intake and exhaust valves of the internal combustion engine are actuated during operation. An oil supply channel 22 is formed in the intermediate wall 20 of the housing 2, through which oil, which serves as a hydraulic and lubricating medium, is introduced from the interior of the housing 2 through the oil supply channel 22, the radial bearing 19 and the associated passage of the rod 4 into the interior of the rod, so as to be fed from there, for example, to the cartridge valve 9 for its actuation. Furthermore, an oil return channel 23 of the internal combustion engine is formed in the adjuster bearing wall 15.

[0051] Within the scope of the camshaft assembly method according to the invention, the cartridge valve 9 is first inserted into the rotor 6 of the assembled camshaft adjuster 3 in an angularly oriented manner and held therein by friction. The camshaft adjuster 3 is then assembled by means of the bearing 14 in the assembly direction M (which is in the direction of the rotor 6). Figure 1The camshaft adjuster 3 (indicated by an arrow in the figure) is inserted into the through-opening of the adjuster bearing wall 15 and fixed there by means of a fixing ring 17. The preassembled subassembly produced in this way is referred to in the disclosure as a camshaft adjustment system. Since the camshaft adjuster 3, in particular the stator 10, is arranged in the housing 2 in this preassembled state and is therefore no longer accessible from the outside, the drive chain 12 is laid around the toothing 11 of the stator 10 immediately before or after the camshaft adjuster 3 is installed. In addition, the radial bearing 19 is installed in the through-opening of the intermediate wall 20 and the cam 21 is positioned and aligned in the housing 2 by means of a retaining device (not shown) provided separately for this purpose.

[0052] If the aforementioned preparations have been completed, in particular if the camshaft adjustment system is preassembled, the rod 4 (which is cooled and thus shrunk or already shrunk) is pushed and engaged into the hollow space 5 of the rotor 6 in a single working step in the assembly direction M through the radial bearing 19, the cam 21. Since the rod 4 is heated to room temperature again and expands, a gap-free interference connection or cold expansion connection is formed between the aforementioned components and the rod. That is, only a single working step is required for the actual fixing of all components on the rod 5, which can be easily set up automatically.

[0053] Figure 2 A, 2B and 2C each show an embodiment of the connection between the rod 4 and the rotor 6, by means of which higher torques can be transmitted than by means of a cold expansion connection alone. Figure 2 In the embodiment shown in A, the engagement contact area 7 of the rod 4 is formed with a toothed or wedge-shaped structure, which engages with the engagement contact area 8 of the rotor 6 with corresponding internal teeth or wedge-shaped recesses and thus provides a positive fit. Figure 2 In the second embodiment shown in B, the engagement contact area 7 of the rod 4 is designed as a torx structure instead of a wedge-shaped structure or a toothed portion, which engages in an inner torx-shaped engagement contact area 8 of the rotor 6 in order to provide a positive fit. Figure 2 C shows a third embodiment between the rod 4 and the rotor 6, according to which the contact zones 7, 8 are of approximately cylindrical design and at least one of the contact zones 7, 8 of the rod 5, preferably the more accessible contact zone 7, is reprocessed to increase friction. For this purpose, the upper surface of the respective contact zone 7, 8 is preferably roughened or a laser structure is introduced, for example by laser ablation.

[0054] Reference numerals list

[0055] 1 Camshaft

[0056] 2 Housing

[0057] 3 Camshaft adjuster

[0058] 4 bars

[0059] 5 empty rooms

[0060] 6 Rotor

[0061] 7 Rod joint contact area

[0062] 8 Rotor joint contact area

[0063] 9 Cartridge valve

[0064] 10 Stator

[0065] 11. Tooth

[0066] 12 Drive chain

[0067] 13 Bearing shoulder

[0068] 14 Supporting part

[0069] 15 Regulator bearing wall

[0070] 17 Fixing ring

[0071] 18 Central magnet

[0072] 19 Radial bearing

[0073] 20 Middle wall

[0074] 21 Cam

[0075] 22 Oil supply channel

[0076] 23 Oil return channel

Claims

1. A camshaft assembly method for assembling a camshaft (1) in a camshaft adjustment system, the camshaft adjustment system having a housing (2), wherein: A vane-type camshaft adjuster (3) is preassembled in the housing (2), and then the rod (4) of the camshaft (1) is pushed into a cavity (5) at the axial end of a rotor (6) of the camshaft adjuster (3) in one working step and mounted on the rotor (6) in a rotationally fixed and axially fixed manner. The rotor (6) of the camshaft adjuster (3) is preassembled in the housing (2) by means of a bearing (14).

2. The camshaft assembly method according to claim 1, characterized in that: In the same working step, the camshaft (1) is pushed over a cam (21) arranged and oriented in the housing (2) and is mounted on the cam in a rotationally fixed and axially fixed manner.

3. The camshaft assembly method according to claim 1, characterized in that: The rod (4) is cooled and thereby shrinks before insertion and joining, so that after insertion a cold expansion connection is provided between the rod (4) and the rotor (6) of the camshaft adjuster (3).

4. The camshaft assembly method according to claim 1, characterized in that: The rod (4) and the rotor (6) of the camshaft adjuster (3) are shaped at the joint contact areas (7, 8) provided by the two components (4, 5) in order to provide a positive connection, and / or the rod (4) and / or the rotor (6) of the camshaft adjuster (3) are reworked at the corresponding joint contact areas (7, 8) to increase friction.

5. The camshaft assembly method according to claim 1, characterized in that: At the end facing away from the rod (4), a cartridge valve (9) is inserted into the rotor (6) of the camshaft adjuster (3) in an angular orientation relative to the rotor (6).

6. The camshaft assembly method according to claim 5, characterized in that: The cartridge valve (9) is arranged in the rotor (6) of the camshaft adjuster (3) in such a way that the cartridge valve bears directly against the inner circumferential surface of the rotor (6).

7. The camshaft assembly method according to claim 5, characterized in that: A first regulator chamber and a second regulator chamber acting in opposition to the first regulator chamber are constructed between the rotor (6) and the stator (10) of the camshaft adjuster (3) for phase adjustment of the camshaft (1), the first regulator chamber and the second regulator chamber being supplied with hydraulic medium respectively via radially extending first and second hydraulic medium channels (A, B) provided in the cartridge valve (9), wherein the first and second hydraulic medium channels (A, B) are arranged in a common radial plane.

8. The camshaft assembly method according to any one of the preceding claims, characterized in that: Before the rod (4) is inserted, the endless transmission element (12) is mounted on a toothing structure (11) of a stator (10) of a camshaft adjuster (3) surrounding a rotor (6).

9. A camshaft adjustment system for a motor vehicle internal combustion engine obtained by the camshaft assembly method according to any one of the preceding claims, the camshaft adjustment system having a housing (2) in which a camshaft adjuster (3) is preassembled, characterized in that: The rotor (6) of the camshaft adjuster (3) has a cavity (5) at an axial end, which cavity is prepared so that a camshaft (1) fixed in a rotationally fixed manner on the rotor (6) can be at least partially filled at a later point in time.

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