Camshaft with oil channel, camshaft adjuster with camshaft and mounting method for camshaft adjuster

Abstract

The invention relates to a camshaft (1) for actuating valves of a valve train for a motor vehicle, the camshaft having a contact surface (2) for transmitting the torque of a rotor (3) of a camshaft adjuster (4) to the camshaft (1), wherein the contact surface (2) is designed as an embossing (5) on the radial outer circumference of the camshaft (1), and the camshaft (1) has at least one oil channel (6) at the free end of the camshaft (1) axially spaced apart from the contact surface (2) for guiding oil to the camshaft adjuster (4). The invention also relates to a camshaft adjuster (4) having a rotor (3) and a camshaft (1). The invention also relates to a method for mounting a camshaft adjuster (4).

Description

Technical Field

[0001] The invention relates to a camshaft for actuating valves of a valve train for a motor vehicle, comprising a contact surface for transmitting the torque of a rotor of a camshaft adjuster to the camshaft, wherein the contact surface is formed as an embossment on the radial outer circumference of the camshaft. The invention also relates to a camshaft adjuster having a rotor and such a camshaft. The invention also relates to an assembly method for such a camshaft adjuster. Background Art

[0002] Camshafts are already known from the prior art which have a camshaft end piece with a toothed, embossed pin for engagement in a camshaft tube.

[0003] However, the prior art still has the disadvantage that the installation of the camshaft adjuster is usually very time-consuming, since individual system components such as rolling bearings, sealing rings, valve filters, non-return valves or sensor wheels must be transported to the installation site through or via the entire camshaft. In addition, in the camshaft adjustment systems known to date, the axial length of the camshaft adjuster, in particular the central valve, is too large for the high demands on compactness. Summary of the invention

[0004] The object of the invention is therefore to avoid or at least reduce the disadvantages of the prior art. In particular, a camshaft, a camshaft adjuster and an assembly method should be provided which allow a simplified assembly of the system. In particular, the individual system components should no longer have to be transported via the camshaft and the axial length of the central valve can be further shortened. At the same time, functionality should be ensured, in particular by pressure-loaded rotor adjustment.

[0005] This object is achieved according to the invention in a camshaft of this type in that the camshaft has an oil duct at the free end of the camshaft, axially spaced apart from the contact surface, for conducting oil to the camshaft adjuster.

[0006] This has the advantage that the oil supply is ensured even if the camshaft is connected to the rotor via a press fit between the contact surface and the inner circumferential surface of the rotor. Thus, the oil can be introduced through the oil channel through the section of the camshaft toward the end face of the camshaft and then into the central valve.

[0007] Advantageous embodiments are claimed in the dependent claims and are explained in detail below.

[0008] It is also advantageous if the oil channel is oriented in the axial direction. That is to say, the oil channel is guided parallel to the axial direction of the oil. For example, the oil channel can be formed between the radially outer circumference of the camshaft and the radially inner circumference of the rotor. As a result, the oil channel can be formed in a particularly simple manner and the guidance of the oil can be ensured.

[0009] It is also preferred that a plurality of oil channels are formed in the camshaft. As a result, the oil delivery rate can be increased. It is particularly advantageous that the oil channels are evenly distributed on the circumference of the camshaft.

[0010] It is also suitable that the camshaft has a centering area on its radial outer circumference, which is axially at least partially arranged at the same height as one or more oil channels. By providing a centering area, for example, which is configured as a centering surface on the outer circumference of the camshaft, the centering orientation of the camshaft relative to the rotor is ensured when the camshaft is installed, so that the concentricity accuracy is improved. It is no longer necessary to grind the cam of the camshaft after installation. By arranging the centering area at the same height as the oil channel, the axial extension of the rotor flange into which the camshaft is inserted and thus the entire camshaft adjuster is reduced. Therefore, a particularly compact camshaft adjuster is provided. The oil is therefore introduced directly into the central valve via the oil channel of the camshaft and is guided from there to the working chamber of the camshaft adjuster in a controlled manner.

[0011] It is also advantageous if the contact surface is arranged distally to the centering region. In other words, the camshaft first contacts the rotor in the region of the centering region when it is inserted into the rotor, before the contact surface engages with the inner circumferential surface of the rotor. The camshaft is thus guided via the centering region when it is inserted into the rotor.

[0012] The object of the present invention is also achieved by a camshaft adjuster for a motor vehicle, for adjusting the phase of the camshaft relative to the crankshaft. Therefore, the camshaft adjuster preferably has a stator and a rotor rotatably arranged relative to it. The camshaft adjuster also has a camshaft, which is arranged in a through-opening extending in the axial direction of the rotor. According to the present invention, the oil channel of the camshaft is connected to the radial opening of the rotor for guiding the oil. When the rotor has a through-opening into which the camshaft is inserted, it is usually difficult to integrate the oil supply device in a way that saves structural space. The configuration according to the present invention has the following advantages, the camshaft is pushed into the rotor, so that the radial opening of the rotor for introducing oil is connected via an oil channel or multiple oil channels in the camshaft. As a result, the oil can be guided from the radial outside of the rotor to the central valve of the camshaft adjuster, which is also arranged in the through-opening of the rotor.

[0013] Furthermore, it is preferred that the contact surface of the camshaft is arranged axially spaced apart from the radial opening, thereby ensuring that the oil introduced via the radial opening does not reach the region of the contact surface, since this would adversely affect the strength of the press fit between the rotor and the embossing.

[0014] It is particularly preferred that the contact surface of the camshaft (in the installed state of the camshaft) is arranged distally from the radial opening. This means that the contact surface is connected to the rotor on the axial side facing the camshaft. This means that the camshaft is only pushed into the rotor so far that the embossing does not push through the radial opening.

[0015] It is also appropriate that the camshaft adjuster has a valve filter, wherein the valve filter is arranged on the radially outer circumference of the rotor flange of the rotor. As a result, the central valve can be further shortened. In addition, the valve filter can thus be pre-installed on the rotor flange in a simple manner.

[0016] It is also advantageous if the valve filter is axially arranged at the same height as the radial opening. As a result, the oil is filtered before it enters the interior of the rotor. Furthermore, the valve filter can be replaced particularly easily. A particularly compact design of the camshaft adjuster is provided.

[0017] The object of the present invention is also achieved by a mounting method for such a camshaft adjuster. Therefore, in a first step, the camshaft adjuster is preassembled from its parts, such as a stator, a rotor and a sealing cover. In a second step, a rolling bearing for supporting the camshaft adjuster in a housing, in particular in a cylinder head, is pushed from a first axial side onto a rotor flange of a rotor of the camshaft adjuster. Thereafter, in a third step, a first sealing ring is pushed from the first axial side onto the rotor flange. The first sealing ring is pushed through a radial opening of the rotor. Subsequently, in a fourth step, a second sealing ring is pushed from the first axial side onto the rotor flange. The second sealing ring is not pushed through the radial opening. The radial opening is therefore sealed toward the housing on both axial sides by the sealing ring. Subsequently, in a fifth step, the camshaft is pressed into the camshaft adjuster so that the contact surface of the camshaft engages with the inner circumferential surface of the rotor flange. The camshaft is only pushed into the rotor so far that the contact surface does not pass through the radial opening.

[0018] It is also advantageous if, in an intermediate step after the third step and before the fourth step, the valve filter is pushed from the first axial side onto the rotor flange. The valve filter can thus be pre-mounted on the rotor flange between the sealing rings.

[0019] It is also advantageous if, in an intermediate step before the fifth step, a radial non-return valve is inserted into the radial opening. This prevents a return flow of oil. If the non-return valve is installed before the camshaft is installed, the non-return valve can be installed particularly easily.

[0020] It is also preferred that the sensor ring is pushed onto the rotor flange in an intermediate step after the fourth step and before the fifth step. Thus, the sensor ring can be pre-installed so that it does not have to be pushed over the installed camshaft.

[0021] In other words, the present invention relates to a camshaft, a camshaft adjuster and an installation method, wherein the connection between the camshaft and the rotor of the camshaft adjuster, in particular the embossed press connection, is configured so that individual system components, such as rolling bearings, sealing rings, valve filters, non-return valves and sensor wheels, can be easily installed and in particular no longer need to be transported through the camshaft. According to the invention, rolling bearings, sealing rings, valve filters, (radial) non-return valves and sensor wheels are pre-installed on the rotor flange, i.e., the axial protrusion of the rotor. Subsequently, the camshaft is joined to the pre-installed assembly in the final assembly line for establishing the embossed press fit, so that other installation of system components can be omitted. The annular filter / valve filter for the central valve can be pre-installed on the rotor flange between the sealing rings. As a result, it is advantageously possible to produce the joint surface for the rolling bearing and the sensor wheel without cutting at the rotor, which is preferably manufactured by sintering. In addition, connecting elements, such as camshaft end pieces and central valve bodies, can be omitted. In addition, stresses and deformations in the rotor are reduced because the connection part is displaced away from the functional area of ​​the rotor. Furthermore, the axial length of the central valve and thus of the rotor flange can be reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The invention is explained below with the aid of the accompanying drawings. The accompanying drawings show:

[0023] Figure 1 A longitudinal section showing a camshaft according to the invention and a camshaft adjuster according to the invention, and

[0024] Figure 2 A detail of a front view of a camshaft is shown.

[0025] The drawings are only schematic and are only useful for understanding the invention. Identical elements are provided with the same reference numerals. DETAILED DESCRIPTION

[0026] Figure 1 A camshaft 1 for actuating valves of a valve train for a motor vehicle is shown. The camshaft 1 has a contact surface 2 for transmitting the torque of a rotor 3 of a camshaft adjuster 4 to the camshaft 1. The contact surface 2 is designed as a toothing / embossing 5 on the radial outer circumference of the camshaft 1. According to the invention, the camshaft 1 has at least one oil channel 6 at the free end of the camshaft 1, axially spaced apart from the contact surface 2, for conducting oil to the camshaft adjuster 4.

[0027] exist Figure 1In the embodiment, the camshaft adjuster 4 is configured as a vane-type camshaft adjuster. The camshaft adjuster 4 has a rotor 3 and a stator 7. The stator 7 is arranged radially outside the rotor 3. The stator 7 is connected to the crankshaft (not shown) in a rotationally fixed manner via its external toothing. The rotor 3 is connected to the contact surface 2 of the camshaft 1 in a rotationally fixed manner via its inner circumferential surface. The rotor 3 is arranged to be limitedly rotatable relative to the stator 7 in order to adjust the phase of the camshaft 1 relative to the crankshaft. The phase is adjusted by applying pressure to the working chamber formed between the stator 7 and the rotor 3. The camshaft adjuster 4 has a central valve 8, which controls the oil guide for the pressure application of the working chamber. The central valve 8 is arranged in a through opening 9 extending in the axial direction of the rotor 3. The central valve 8 is controlled via a central magnet 10.

[0028] In the embodiment shown, the camshaft 1 is inserted, in particular pressed, into the rotor 3. This means that the camshaft 1 or at least a section of the camshaft 1 is arranged radially in a through-opening 9 of the rotor 3. Here, the embossing 5 of the contact surface 2 engages in the inner circumferential surface of the rotor 3, so that an embossed press fit is formed between the rotor 3 and the camshaft 1.

[0029] A radial opening 11 is formed in the rotor 3, which connects the inner circumferential surface to the radial outer circumference of the rotor 3. As a result, oil can be introduced into the rotor 3 from the radial outside and from there to the working chamber through the central valve 8. The radial opening 11 leads to at least one oil channel 6 of the camshaft 1. In the embodiment shown, the camshaft 1 has a plurality of oil channels 6. The oil channels 6 are evenly distributed on the circumference of the camshaft 1. The oil channels 6 extend parallel to the axial direction. As a result, the oil is guided to the free end of the camshaft 1. The oil is therefore guided from the radial outside through the radial opening 11 (or through a plurality of radial openings 11) to the inner circumferential surface of the rotor 3 and from there through the oil channel 6 along the inner circumferential surface of the rotor 3 in the axial direction toward the end side of the camshaft 1. From there, the oil can be guided to the central valve 8 for controlling the oil flow into the working chamber.

[0030] The camshaft 1 is pushed so far in the axial direction into the rotor 3, in particular into the rotor flange 12 of the rotor 3, that the contact surface 2 and the embossing 5 are located distally from the radial opening 11 of the rotor 3 in the installed state of the camshaft 1. This means that the embossing 5 does not pass through the radial opening 11. In other words, the embossing 5 is arranged on the axial side of the radial opening 11 facing the camshaft 1 and axially spaced apart from the radial opening 11.

[0031] The section of the camshaft 1 provided with the oil channel 6 is also used for centering the camshaft 1 relative to the rotor 3. A centering surface 13 is formed on the radial outer circumference in the direction of the rotor 3, spaced apart from the contact surface 2, i.e., at the distal end of the contact surface 2. When the camshaft 1 is pushed into the rotor 3, the centering surface 13 is used for centering and orienting the camshaft 1 relative to the rotor 3. The centering surface 13 is at least partially arranged in the same axial region as the oil channel 6. The centering surface 13 has, for example, a transition fit with the inner circumferential surface of the rotor 3.

[0032] The camshaft adjuster 4 is supported in a housing 14. In particular, the camshaft adjuster 4 is supported in a cylinder head 15. The camshaft adjuster 4 is supported in the housing 14 via a rolling bearing 16, which in the embodiment shown is designed as a ball bearing 17. For installation, the rolling bearing 16 is pushed onto the rotor flange 12 from a first axial side of the rotor 3, i.e., from the axial side facing the camshaft 1. Thereafter, the first sealing ring 18 is pushed onto the rotor flange 12. The first sealing ring 18 is pushed through the radial opening 11. That is to say, the first sealing ring 18 is arranged in the axial direction between the rolling bearing 16 and the radial opening 11.

[0033] Optionally, a valve filter or an annular filter, not shown in the embodiment, can then be pushed onto the rotor flange 12. Optionally, a radial nonreturn valve, not shown in the embodiment, can be inserted into the radial opening 11.

[0034] Afterwards, the second sealing ring 19 is pushed onto the rotor flange 12. The second sealing ring 19 is not pushed through the radial opening 11. That is to say, the second sealing ring 19 is arranged in the axial direction between the radial opening 11 and the axial end of the rotor 3, in particular the end facing the camshaft 1. The radial opening 11 is therefore sealed axially on both sides by the sealing rings 18, 19 toward the housing 14.

[0035] Afterwards, the sensor wheel 19 can optionally be pushed onto the rotor flange 12. In a subsequent step, the camshaft 1 is engaged in the rotor flange 12. This results in a press fit between the rotor 3 and the camshaft 1.

[0036] Description of Reference Numerals

[0037] 1 Camshaft

[0038] 2 Contact surface

[0039] 3 Rotor

[0040] 4 Camshaft adjuster

[0041] 5 Embossing

[0042] 6 Oil channel

[0043] 7 Stator

[0044] 8 Central valve

[0045] 9 Through opening

[0046] 10 Central magnet

[0047] 11 Radial opening

[0048] 12 Rotor flange

[0049] 13 Centering surface

[0050] 14 Housing

[0051] 15 Cylinder head

[0052] 16 Rolling bearings

[0053] 17 Ball bearings

[0054] 18 First sealing ring

[0055] 19 Second sealing ring

[0056] 20 Sensor wheel

Claims

1. A camshaft (1) for actuating valves of a valve train for a motor vehicle, the camshaft having a contact surface (2) for transmitting a torque of a rotor (3) of a camshaft adjuster (4) to the camshaft (1), wherein the contact surface (2) is formed as an embossing (5) on the radial outer circumference of the camshaft (1), It is characterized in that The camshaft (1) has at least one oil channel (6) at its free end, axially spaced apart from the contact surface (2), for guiding oil to the camshaft adjuster (4). The oil can be introduced directly via the oil channel (6) of the camshaft (1) into a central valve (8), which controls the oil guidance for pressure-loading a working chamber of the camshaft adjuster (4). The central valve (8) and the free end of the camshaft (1) having the at least one oil channel (6) are arranged in a through opening (9) of the rotor (3) extending in the axial direction.

2. The camshaft (1) according to claim 1, It is characterized in that The oil channel (6) is oriented in the axial direction.

3. The camshaft (1) according to claim 1 or 2, It is characterized in that The camshaft (1) has a centering region (13) on its radial outer circumference, which is axially arranged at least partially at the same height as the oil channel (6).

4. A camshaft adjuster (4) for a motor vehicle for adjusting the phase position of a camshaft (1) relative to a crankshaft, the camshaft adjuster comprising a rotor (3) and a camshaft (1) according to any one of the preceding claims, the camshaft being arranged in a through opening (9) extending in the axial direction of the rotor (3), wherein the oil channel (6) of the camshaft (1) is connected to a radial opening (11) of the rotor (3) for guiding oil.

5. The camshaft adjuster (4) according to claim 4, It is characterized in that The contact surface (2) of the camshaft (1) is arranged axially spaced apart from the radial opening (11).

6. The camshaft adjuster (4) according to claim 4, It is characterized in that The contact surface (2) of the camshaft (1) is connected to the rotor (3) at the distal end of the radial opening (11).

7. The camshaft adjuster (4) according to any one of claims 4 to 6, It is characterized in that The camshaft adjuster (4) has a valve filter, wherein the valve filter is arranged on the radially outer circumference of a rotor collar (12) of the rotor (3).

8. The camshaft adjuster (4) according to claim 7, It is characterized in that The valve filter is arranged axially at the same height as the radial opening (11).

9. A method for mounting a camshaft adjuster (4) according to any one of claims 4 to 8, wherein in a first step, the camshaft adjuster (4) is preassembled from its parts, wherein in a second step, a rolling bearing (16) for supporting the camshaft adjuster in a housing (14) is pushed from a first axial side onto a rotor flange (12) of a rotor (3) of the camshaft adjuster (4), wherein in a third step, a first sealing ring (18) is pushed from the first axial side onto the rotor flange (12), wherein in a fourth step, a second sealing ring (19) is pushed from the first axial side onto the rotor flange (12), wherein in a fifth step, the camshaft (1) is pressed into the camshaft adjuster (4) so ​​that the contact surface (2) of the camshaft (1) engages with the inner circumferential surface of the rotor flange (12).

10. The installation method according to claim 9, It is characterized in that In an intermediate step after the third step and before the fourth step, a valve filter is pushed onto the rotor flange (12) from the first axial side.

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