CAM PHASER AND MOUNTING METHOD

Abstract

A vane type cam phaser for an internal combustion engine, the vane type cam phaser including a stator and a rotor that is rotatable relative to the stator to adjust a phase angle of a camshaft; a spring element configured to align the rotor with the stator in an idle position; a spring adapter that is arranged between the spring element and the rotor; and an axial fixing device that fixes the spring adapter at the rotor.

Claims

1. A vane type cam phaser for an internal combustion engine, the vane type cam phaser comprising: a stator and a rotor that is rotatable relative to the stator to adjust a phase angle of a camshaft; a spring element configured to align the rotor with the stator in an idle position; a spring adapter that is arranged between the spring element and the rotor; and an axial fixing device that fixes the spring adapter at the rotor.

2. The vane type cam phaser according to claim 1, wherein in the spring element is a torsion spring.

3. The vane type cam phaser according to claim 1, further comprising: a locking disc that is connected with the stator torque proof, wherein the spring element is fixed in the locking disc.

4. The vane type cam phaser according to claim 3, further comprising: a contact ring, wherein the spring element is fixed in the locking disc by the contact ring.

5. The vane type cam phaser according to claim 4, wherein the contact ring is made from hard metal.

6. The vane type cam phaser according to claim 1, wherein the spring adapter includes an inner contour that is configured to transfer a torque.

7. The vane type cam phaser according to claim 1, wherein the axial fixing device includes at least one fixing pin.

8. The vane type cam phaser according to claim 7, wherein the spring adapter includes at least one first fixing opening and the rotor includes at least one second fixing opening configured to receive the at least one fixing pin.

9. The vane type cam phaser according to claim 7, wherein the rotor is configured with a sickle shaped contour which is configured to support the at least one fixing pin.

10. The vane type cam phaser according to claim 1, wherein the rotor includes at least one recess in which the spring adapter is interlockable.

11. A method for assembling the vane type cam phaser according to claims 1, the method comprising: applying the spring adapter to the rotor; engaging the spring element in the spring adapter; torque proof connecting the spring element at the stator; preloading the spring element by rotating the spring adapter; and axially fixing the spring adapter at the rotor.

12. A method according to claim 11, wherein the rotating of the spring adapter is supported in a sickle shaped contour in the rotor.

13. The method according to claim 11, wherein the rotating of the spring adapter (5) includes aligning at least one first fixing opening in the spring adapter and at least one second fixing opening in the rotor with one another.

14. The method according to claim 13, wherein the axially fixing includes inserting a fixing pin into the at least one first fixing opening in the spring adapter and into the at least one second fixing opening in the rotor.

15. The method according to claim 11, wherein the loading of the spring element and the axially fixing of the spring adapter is performed through a mounting opening of a locking disc that is connected with the stator torque proof.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The invention is now described based on embodiments with reference to a drawing figure, wherein:

[0027] FIG. 1 illustrates a perspective view of a first embodiment of a cam phaser according to the invention;

[0028] FIG. 2 illustrates a longitudinal sectional view according to II-II in FIG. 1;

[0029] FIG. 3 illustrates a perspective exploded view of a second embodiment of the cam phaser according to the invention;

[0030] FIG. 4 illustrates a perspective partial view of the cam phaser in FIG. 3;

[0031] FIG. 5 illustrates a perspective exploded partial view of a third embodiment of a cam phaser according to the invention in unloaded condition;

[0032] FIG. 6 illustrates a perspective exploded partial view of the cam phaser in FIG. 5 in a preloaded condition; and

[0033] FIG. 7 illustrates a flow diagram for a method according to the invention for mounting the cam phaser according to the invention.

DETAILED DESCRIPTION OF THE INVENTION

[0034] A vane-type cam phaser 1 that is illustrated FIGS. 1-6 adjusts a phase relationship between a crankshaft and a camshaft in valve trains of internal combustion engines.

[0035] FIG. 1 illustrates a camp phaser 1 in a completely preassembled condition. The cam phaser 1 includes a locking disk 2 which is connected with the cam phaser 1 by plural threaded connections 3. Thus, the locking disk 2 includes a mounting opening 4 in a radial center and a spring adapter 5 is visible through the mounting opening. The spring adapter 5 has a central opening 6 that is configured with an inner contour 7 and an arresting groove 8 that is arranged at an outer edge of the spring adapter. Furthermore, the spring adapter 5 is configured with a first fixing opening 9 and a second fixing opening 10, wherein a first fixing pin 11 is arranged in the first fixing opening 9 and a second fixing pin 12 is arranged in the second fixing opening 10.

[0036] The locking disk 2 includes the mounting opening 4 primarily in order to connect the cam phaser 1 with a cam shaft using a central bolt. Additionally, it is possible in the cam phaser 1 according to the invention to access the spring adapter 5 through the mounting opening 4. Thus, a tool that fits the inner contour 7 of the central opening 6 can be inserted into the spring adapter 5 in order to rotate the spring adapter 5 into a fixing position. When rotating the spring adapter 5, the fixing pins 11, 12 are not yet or at least not yet completely inserted into the fixing openings 9, 10 or recessed therein. Only when the spring adapter 5 is moved into the fixing position the fixing pins 11, 12 are recessed into the fixing openings 9, 10 completely to fix the spring adapter 5. FIG. 1 illustrates the end condition after fixing the spring adapter 5.

[0037] FIG. 2 illustrates the cam phaser 1 of FIG. 1 in a longitudinal sectional view. Out of the components shown in FIG. 1, FIG. 2 shows the locking disk 2 with the mounting opening 4 and the spring adapter 5 with the central opening 6 and the inner contour 7. Additionally, a stator 13 and a rotor 14 are illustrated which form essential components of the cam phaser 1. A spring element 15 and a contact ring 16 are arranged between the locking disk 2 and the spring adapter 5.

[0038] The spring element 15 configured as a coil spring is terminated at the spring adapter 5 and through the contact ring 16 also terminated at the locking disk 2. The spring element 15 is loaded by rotating the spring adapter 5 and retained at the rotor 14 in this condition by fixing the spring adapter 5. A preload of the spring element 15 is necessary to align the stator 13 and the rotor 14 in an idle position of the cam phaser 1.

[0039] In the last assembly step, the spring element 15 is loaded which facilitates unimpaired end of line testing of the cam phaser 1.

[0040] FIG. 3 illustrates an exploded view of a cam phaser 1, e.g. the cam phaser of FIGS. 1 and 2. The cam phaser 1 includes a stator 13 and a rotor 14. Pressure chambers 17 are arranged in intermediary spaces of the stator 13 and the rotor 14. A spring adapter 5, a spring element 15, and a contact ring 16 are illustrated in the exploded view in sequence viewed from the rotor and are put together in the same sequence during assembly.

[0041] The rotor 14 includes a circular recess 18 with a sickle-shaped contour 19 adjoining thereto. A first fixing opening 20 and a second fixing opening 21 are arranged in the recess 18 wherein a first fixing pin 11 is partially inserted into the first fixing opening 20 and a second fixing pin 12 is partially inserted into the second fixing opening 21. The spring adapter 5 includes a central opening 6 (not illustrated) with an inner contour 7, an arresting notch 8 and a first fixing opening 9 and a second fixing opening 10. The fixing openings 9, 10 of the spring adapter 5 and the fixing openings 20, 21 of the rotor 14 form an axial fixing device 22 together with the fixing pins 11, 12. Plural oil bore holes 23 are arranged within the recess 18, wherein the oil bore holes, however, do not form part of the fixing device 22.

[0042] The spring element 15 includes a first arresting spout 24 at an end oriented towards the spring adapter 5 and a second arresting spout 25 at an end oriented towards the contact ring 16. Thus, the first arresting spout 24 is to be arranged in the arresting notch 8 of the spring adapter 5. Accordingly the contact ring 16 has an arresting notch 26 in which the second arresting spout 25 is to be arranged

[0043] FIG. 3 illustrates the components of cam phaser 1 in a final assembly condition in which the spring element 15 is preloaded and the spring adapter 5 is fixed at the rotor 14. Preloading the spring element 15 is performed as illustrated in FIG. 1 by rotating the spring adapter 5 using a tool that precisely fits the central opening 6 or its inner contour 7. Thereafter fixing pins 11, 12 are inserted through the fixing openings 9 10 of the spring adapter 5 into the fixing openings 20, 21 of the rotor 14 so that the spring adapter 5 is fixed at the rotor 14. In order to facilitate the fixing the fixing openings 9, 10 have to be aligned with the fixing openings 20, 21. The manner how this alignment is performed is described infra with reference to FIG. 4.

[0044] FIG. 4 illustrates a perspective partial view of the cam phaser 1 illustrated in FIG. 3 which only shows the stator 13, the rotor 14 and the spring adapter 5. Also here the pressure cavities 17 between the stator 13 and the rotor 14 are visible. Thus, the spring adapter 5 is inserted into the recess 18 of the rotor 14 and fixed by the axial fixing device 22 at the rotor 14. As recited supra the axial fixing device 25 includes the fixing openings 9, 10 of the spring adapter 5, the fixing openings 20, 21 of the rotor 14 and the fixing pins 11, 12. The sickle shaped contour 19 is visible which directly adjoins the recess 18 of the rotor 14. A guide lug 27 is also visible that is configured integrally in one piece with the spring adapter 5 and arranged within the sickle shaped contour 19.

[0045] The illustrated components are arranged in a final assembly condition. Thus, the spring adapter 5 is already fixed at the rotor 14. The required alignment of the fixing openings 9, 10 with the fixing openings 20, 21 is achieved by the guide lug 27 of the spring adapter 5 and the sickle shape contour 19 in the rotor 14. Thus, the guide lug 27 and the sickle shaped contour 19 only facilitate a rotation of the spring adapter 5 by a predetermined rotation angle in a predetermined rotation direction. As soon as the guide lug 27 reaches the end stop of the sickle shaped contour 19 during rotation of the spring adapter 5 the fixing openings 9, 10 are arranged exactly above the fixing openings 20, 21 and are aligned therewith.

[0046] FIG. 5 illustrates a perspective exploded partial view of a cam phaser 1 in unloaded condition. This can also be e.g. the cam phaser 1 of FIGS. 1 and 2. Thus, FIG. 5 only illustrates a rotor 14, a spring adapter 5 and a spring element 15 and an axial fixing device 22. Also in this case, the rotor 14 also includes plural oil bore holes 23. The fixing device 22 includes a first fixing opening 9 and a second fixing opening 10 in the spring adapter 5, a first fixing opening 20 and a second fixing opening 21 in the rotor 14 and a first fixing pin 11 and a second fixing pin 12. Furthermore the fixing device 22 includes a sickle shaped contour 28. It is appreciated that the sickle shaped contour 28 differs from the sickle shaped contour 19 in FIGS. 3 and 4. Thus e.g. the first fixing opening 20 of the rotor 14 is arranged within the sickle shaped contour 28.

[0047] Also in this embodiment the spring adapter 5 includes a central opening 6 with an inner contour 7, an arresting notch 8 and the fixing openings 9, 10 recited supra. By the same token the spring element 15 includes a first arresting spout 24 at an end that is oriented towards the spring adapter 5 and a second arresting spout 25 at an end that is oriented away from the spring adapter 5.

[0048] Thus, the cam phaser 1 of FIG. 5 is in the unloaded condition so that the spring element 15 does not have any preload and the arresting spouts 24, 25 are arranged in a predetermined idled position relative to each other. The position of the arresting spout 25 is provided for fixing with a non-illustrated stator and therefore the position is not adjustable or static. Thus, also the position of the arresting spout 24 is predetermined for the non-preloaded spring element 15. Thus, the arresting spout 24 fixes a rotational position of the spring adapter 5 due to its arrangement in the arresting notch 8 and thus also fixes the position of the fixing openings 9, 10 for the fixing pins 11, 12.

[0049] The sickle shaped contour 28 is arranged in the rotor 14 so that the first fixing pin 11 interlocks in the sickle shaped contour 28 when inserted into the first fixing opening 9. The second fixing pin 12, however, impacts a point on the rotor 14 when inserted into the second fixing opening 10, wherein the point is arranged outside of the sickle shaped contour 28. None of the fixing pins 11, 12 is arranged in the one of the fixing openings 20, 21 arranged in the rotor 14 at this point in time or in this assembly condition.

[0050] Since the first fixing pin 11 impacts the sickle shaped contour 28 when inserted into the first fixing opening 9 this first fixing pin is insertable further through the spring adapter 5 than the second fixing pin 12. The second fixing pin 12 protrudes at a side of the spring adapter 5 that is oriented away from the rotor 14 by approximately 2-5 mm from the second fixing opening 10 after the second fixing pin 12 is inserted into the spring adapter 5. Starting from this assembly condition the cam phaser 1 can be moved into a final assembly condition by rotating and fixing the spring adapter 5. Thus, the interlocked first fixing pin 11 is moved along the sickle shaped contour 28 to an end stop of the sickle shaped contour 28. The fixing openings 9, 10 of the spring adapter 5 and the fixing openings 20, 21 of the rotor are thus brought into alignment so that the fixing pins 11, 12 are move able to their respective end position towards the rotor 15. Additionally the position of the arresting notch 8 and the arresting spout 24 interlocked therein change so that the spring element 15 is moved into a preloaded condition. The final assembly condition of the cam phaser 1 is illustrated in FIG. 6.

[0051] FIG. 6 illustrates a perspective exploded partial view of the cam phaser 1 of FIG. 5 in preloaded condition and thus in final assembly condition. Thus, the first arresting spout 24 of the spring element 15, the spring adapter 5 with its arresting notch 8 and its fixing openings 9, 10 and the fixing pins 11, 12 are rotated and/or moved relative to the illustration of FIG. 5 by an angle and distance that is predetermined by the sickle shaped contour 28. All illustrated components and their functions were already described in detail with respect to FIG. 5 and therefore are not described again with respect to FIG. 6.

[0052] FIG. 7 illustrates a flow chart for a method for mounting a cam phaser 1 according to FIGS. 1-6. The method includes applying 100 the spring adapter 5 to the rotor 14, engaging 110 the spring element 15 in the spring adapter 5, torque proof connecting 120 of the spring element 15 with the stator 13, clamping 130 of the spring element 15 by rotating the spring adapter 5 using an assembly tool and eventually axial fixing 140 of the spring adapter 15 at the rotor 14.

[0053] Another embodiment relates to a vane type cam phaser for an internal combustion engine, the vane type cam phaser comprising a stator, a rotor that is rotatable relative to the stator, wherein the rotor is configured to adjust a phase angle of a cam shaft, a spring element configured to generate a torque between the stator and the rotor, a spring adapter arranged between the spring element and the rotor, wherein the spring adapter is rotated during assembly to preload the spring element and fixated thereafter by a fixing device, wherein a rotation of the spring adapter is limited by a mechanical stop which defines an angular orientation for fixing the spring adapter.

[0054] For example the rotor or a component that is fixed at the rotor during rotation of the spring adapter includes a first contact surface. The spring adapter or a component that is fixed at the spring adapter during the rotation of the spring adapter includes a second contact surface.

[0055] According to another embodiment at least one additional component can be arranged as an intermediary element between the two contact surfaces when rotating the spring adapter so that the two contact surfaces do not have a direct contact. For example the intermediary element is an element of the assembly line. The intermediary element can also be an element of the preassembled fixing device.

[0056] According to an advantageous embodiment the rotor and the stator are positioned relative to each other before loading the spring element, the spring adapter is positioned axially and the spring element is positioned axially without preloading. The spring element is preloaded by rotating the spring adapter and the elements of the fixing device of the spring adapter are not yet assembled or preassembled when the spring adapter is rotated.

[0057] According to another embodiment the spring adapter is freely rotatable between the non-loaded position of the spring element and the loaded position of the spring element. The spring adapter or a component that is fixed at the spring adapter during rotation of the spring adapter for loading the spring element includes a drive contour for a tool. The rotation axis is formed by the contour of the drive of the preloading tool or an inner or outer contour of the spring adapter. For example the spring element is a torsion spring or a coil spring.

[0058] A fixed operating connection is provided between an end portion of the spring element and the rotor or a component that is fixed to the rotor and a second fixed operating connection is provided between the second end portion of the spring element and the stator or a component that is fixed at the stator. A locking disc that is connected to the stator torque proof is e.g. provided, wherein the spring element is interlocked in the locking disc.

[0059] Advantageously the fixing device of the spring adapter is configured with at least one fixing pin, The spring adapter and the rotor are respectively configured with at least one fixing opening, wherein the fixing opening is configured to receive the at least one fixing pin.

[0060] According to an advantageous embodiment the rotor has a sickle shaped contour which provides a movement path for at least one fixing pin when rotating the spring adapter during preloading of the spring element and which provides a stop for the fixing pin for a rotational positioning of the spring adapter relative to the rotor.

[0061] The rotor includes at least one recess wherein the spring adapter is interlock able in the recess.

[0062] A method for mounting the cam phaser includes the steps axial applying of the spring adapter to the rotor with the non-loaded spring element engaged in the spring adapter and the stator or a component fixed at the stator, preloading the spring element by rotating the spring adapter to a mechanical stop and subsequently axial fixing of the spring adapter at the rotor.

[0063] Advantageously at least one fixing opening in the spring adapter and at least one fixing opening in the rotor are aligned with each other during a rotation of the spring adapter. The axial fixing is performed e.g. by inserting a fixing pin into the fixing openings in the spring adapter and in the rotor.

[0064] According to an advantageous embodiment loading the spring element and fixing the spring adapter is performed through a mounting opening of the locking disc that is connected with the stator torque proof.