WO2013182331A1

WO2013182331A1 - Rotor for a hydraulic camshaft adjuster

Info

Publication number: WO2013182331A1
Application number: PCT/EP2013/056330
Authority: WO
Inventors: Olaf Boese; Rainer Ottersbach
Original assignee: Schaeffler Technologies AG & Co. KG
Priority date: 2012-06-06
Filing date: 2013-03-26
Publication date: 2013-12-12
Also published as: DE102012209532A1; CN104334840A; US20150068484A1

Abstract

A rotor (2) is disclosed for a hydraulic camshaft adjuster (1), comprising a hub (5), for receiving a camshaft, and an outer shell (6) with a number of vane elements (7), wherein pressure-medium ducts (24, 26) run from the interior of the hub (5) to the outer shell (6). At least one pressure-medium duct (24, 26) is interrupted by an axial cavity (16), wherein a sleeve (47) which connects the interrupted pressure-medium duct (24, 26) is inserted into the cavity (16). Furthermore, a camshaft adjuster (1) having a rotor (2) of this type is disclosed. The rotor (2) and the camshaft adjuster (1) are particularly light as a result of the disclosed cavity (16).

Description

Designation of the invention Rotor for a hydraulic camshaft adjuster

Description Field of the invention

The invention relates to a rotor for a hydraulic camshaft adjuster, comprising a hub for receiving a camshaft and an outer shell having a number of wing elements, wherein extending from the interior of the hub to the outer jacket pressure medium channels. The invention further relates to a hydraulic camshaft adjuster with such a rotor.

Background of the invention

A rotor and a camshaft adjuster of the aforementioned type are known, for example, from US Pat. No. 7,661,397 B2. In such a phaser, the rotor is rotatably mounted about a rotation axis in a stator. By a relative rotation of the rotor relative to the stator, the phase position of a camshaft relative to a crankshaft of an internal combustion engine can be adjusted. For this purpose, in the installed state of the camshaft vertical distributor, the rotor is non-rotatably connected to the camshaft and the stator is connected in a rotationally fixed manner to the crankshaft of the internal combustion engine.

According to US Pat. No. 7,661,397 B2, the rotor has a hub for receiving the camshaft. On the outer jacket of the rotor, a number of vane elements are arranged, which engage in each case in a sealing manner between separating elements of the stator. Each wing element divides the space between two separating elements of the stator into two pressure chambers, which can be switched over from the interior of the hub to the outer jacket pressure medium channels switchable with a hydraulic pressure medium to be supplied. If pressure medium is applied to one of the pressure chambers while the pressure medium channel of the other pressure chamber is opened to an outlet, the rotor is adjusted relative to the stator. The pressure chamber which, upon application of pressure, leads to a presetting of the rotor relative to the stator is also referred to as an advance chamber. Accordingly, the other pressure chamber is referred to as a retard chamber. For connection to the hydraulic control system, the pressure medium passages in the hub are fluidically connected to externally switchable axial supply chambers in the camshaft or directly to a central valve integrated in the camshaft.

Due to the high use of materials, rotors of this design are disadvantageously quite heavy and, due to the necessary processing steps for introducing the pressure medium channels, for example by drilling, are expensive to manufacture.

Object of the invention

The invention has for its object to provide a rotor of the type mentioned, which is as easy as possible and can be produced as easily as possible. Furthermore, a correspondingly lighter and easily producible camshaft adjuster of the type mentioned in the introduction should be specified.

Solution of the task

The first object is achieved according to the invention for a rotor with a hub for receiving a camshaft and with an outer jacket having a number of wing elements, from the interior of the hub to the outer jacket Druckmittelka- run, that at least one pressure medium channel by an axial material recess is interrupted, wherein in the material recess a the pressure medium channel connecting sleeve is inserted. The invention is based in a first step on the consideration that on a rotor in principle that area can be cut out or released, which has no bearing or sealing function. Surprisingly, however, the invention recognizes in a second step that, in particular, the area of a pressure medium channel can be freed, although in this way the connection of the pressure chambers to the hydraulic system is fundamentally interrupted. The fluidic connection of an interrupted by an exemption or by an introduced Materialausnehmung pressure medium channel is restored in a simple manner by an inserted sleeve.

As a result of a hitherto not considered material recess in the area of a pressure medium channel or in the area of several pressure medium channels, the rotor can be produced with a significantly lower weight in comparison to a previous type. The connection of the interrupted by the material recess pressure fluid channels is done by a simple insertion of a corresponding sleeve in the open material recess. The sleeve may in particular be made of plastic by non-cutting shaping. But also a production of metal, such as aluminum, is possible.

For a secure fluidic coupling and a relatively simple sealing of the inner diameter of the sleeve is chosen to be greater than the diameter of the respective sectioned pressure medium channel. This also facilitates the insertion of the bush into the material recess, since deviations in the alignment of the inserted sleeve with the cut-off pressure medium channel within a certain circumference are tolerated by this measure. Advantageously, the sleeve has form-locking elements, which allow in conjunction with complementary shapes on the rotor only a custom-fit or angle-oriented installation.

The sealing function of the material recess bridging sleeve is ensured according to a preferred embodiment, characterized in that the sleeve under an axial press fit with respect to the pressure medium channel a is set. If the sleeve is made of a suitable, flowable plastic, a permanent sealing functionality sufficient for the camshaft adjuster is achieved. If the sleeve is made of a fiber-reinforced plastic, then such a material is preferably selected which has a thermal expansion coefficient comparable to that of the rotor. For example, for a rotor made of aluminum as a material of the sleeve, a glass fiber reinforced epoxy resin may be used.

The material recess is preferably inserted symmetrically into the rotor in order to avoid an imbalance. In particular, a plurality of ring-segment-shaped material recesses may be provided which each break through a plurality of pressure medium channels. In an advantageous embodiment variant, the material recess is essentially provided as an annular space interrupting a plurality of pressure medium ducts between the hub and the outer casing, a respective sleeve being used for connecting the respectively interrupted pressure medium ducts. By this configuration, a high weight reduction of the rotor can be achieved. For a simple angle-oriented mounting of the sleeves in this case the annular space is advantageously interrupted by at least one radial web. Such a web provides a stop for the sleeve part to be used, whereby the installation can be made only in a defined angular position or exact fit. Alternatively, a projection or a groove in the annular space, in particular on the circumference or on the floor, can be arranged for an angle-oriented mounting of the sleeves. Conveniently, in the case of a ring-segment-shaped or annular-shaped material recess, the or each sleeve is arranged on a ring-segment-shaped or annular insert piece which is inserted into the material recess. In this embodiment, in particular, all sleeves are combined on a single insert, which is then used for assembly, where appropriate, stop at the aforementioned web in the material recess. In particular, the bottom of the rotor forms an axial stop. By form-fitting elements or in particular by a radial web of the angle-oriented installation of the insert is specified. In a further advantageous embodiment, the insert comprises a number of axial extensions, so that the inserted insert terminates in its axial height with the outer shell. In the installed state, this ensures that the sleeves arranged on the insert are arranged on an axial plane with the respective pressure medium channels to be connected. About its axial extensions of the insert between the covers of the camshaft adjuster, in particular between a bottom of the rotor and a locking cover of the stator, held. The axial extensions can be arranged on one side of the insert. However, in the circumferential direction, the axial extensions can also extend alternately on one and on the other axial side.

Advantageously, the or each sleeve is arranged on each of an axial extension. This makes it possible to design a body of the insert piece connecting the sleeves or the axial extensions with as little material as possible and thus particularly light. If the pressure medium channels for the early and late adjustment chambers in the rotor are axially offset from each other, a variant is preferred in which the axial extensions extend alternately in the circumferential direction on one and on the other axial side, wherein the sleeves for supplying the Frühverstellkammern are arranged in the one and the sleeves for the supply of Spätverstellkammern in the other axial extensions. The insert can be made in one or more parts. The insert can in particular be made without cutting from a plastic. Also, non-cutting production from a metal, for example by a sintering process is possible. In an independently inventive embodiment, a weight reduction of a rotor of the type mentioned, which comprises a locking portion with a bore for receiving a movable locking bolt, is provided, the bore except for an axial wall area at the bore Ein- occurs indemnify, wherein in the released area opposite to the bore entrance a locking bar counter-bearing support element is used. This embodiment variant of a rotor is to be carried out independently of the feature of pressure medium channels in the rotor. The invention is based on the consideration that a locking region on the rotor due to the mechanical locking against the stator to be met with a comparatively large mass accumulation by increased use of material is connected. Such a locking region allows for a standstill of the internal combustion engine, the locking of the rotor relative to the stator in a defined angular position to each other. This ensures at a start of the internal combustion engine that the rotor does not move uncontrollably due to a not yet sufficiently generated pressure in the hydraulic system and possibly abuts against the separating elements of the stator, resulting in an undesirable noise inconvenience of the camshaft adjuster.

The independent inventive solution continues from the consideration that the relatively large mass accumulation in the locking area leads to an increased imbalance of the rotor. This imbalance is the greater, the further the locking region is arranged on the rotor away from the axis of rotation. However, an imbalance disadvantageously leads to an undesirable additional load on the bearing and thus to a higher wear of the camshaft adjuster. In addition, it is desirable to reduce the weight of the rotor as a whole.

To solve this problem, the invention surprisingly provides for freeing the bore for receiving a locking bolt, so that only a comparatively thin wall area remains at the bore entry. The support and storage function for a lock-bolt, which was previously taken over by the bottom of the hole, is perceived by a support member opposite the bore entry. This support element can as a be formed separate component and inserted into the released area. However, the support element can also be made as part of the rotor and thus be connected directly to the edge of the released area. In a preferred embodiment, the support element is designed as a support cross, which has an axial spinous process. In particular, a mechanical return means, for example a helical spring or the like, may be placed on this spinous process. The guide and counter bearing of a locking bolt is then ensured by the bore entry and by the spinous process on the support element. Due to the design as a support cross and radial forces of the locking bolt are taken and discharged into the rotor.

In a particularly preferred embodiment, the release of the locking region and the provision of a corresponding support element in a rotor combined with a material recess which interrupts one or more pressure medium channels, wherein in each case a sleeve for connection of the interrupted pressure medium channel is inserted into the material recess.

In a particularly preferred embodiment, the support element is arranged with the or each sleeve on a common insert. This allows a particularly simple installation. In addition, an angle orientation of the sleeves can be achieved via the support element, which is to be used in the freed bore area. The rotor can in particular be produced with a closed annular space between the hub and the outer jacket, which leads to a particularly high weight reduction. During assembly, the corresponding insert piece, on which both the sleeves connecting the pressure medium channels and the support element for a subsequently inserted blocking bolt, are simply inserted into the annular space. Also, the common insert with sleeves and support can be made informal. It can be made of a plastic as well as of a metal. The second object is achieved by a camshaft adjuster comprising a stator and a relative to the stator about a rotation axis rotatable rotor of the type described above. The advantages stated for the rotor and its developments can hereby be transferred analogously to the camshaft adjuster.

BRIEF DESCRIPTION OF THE DRAWING Exemplary embodiments of the invention will be explained in more detail with reference to a drawing. In each case show in perspective view:

FIG. 1 shows the rotor of a hydraulic camshaft adjuster used in a stator, the rotor showing an annular material recess introduced axially, except for the locking region, through which pressure medium channels are interrupted. FIG.

2 shows an insert piece in the material recess of the rotor according to FIG. 1, which comprises a number of sleeves for connecting the interrupted pressure medium channels, FIG.

3 shows the rotor according to FIG. 1 with inserted insert according to FIG. 2, FIG. 4: the underside of the rotor corresponding to FIG. 1 or FIG. 3, FIG.

FIG. 5 shows a further rotor for a hydraulic camshaft adjuster, wherein a circumferential annular material recess, which also comprises a locking region, is introduced axially with the interruption of pressure medium channels, FIG.

6 shows an insert in the annular space of the rotor according to FIG.

5, wherein the insert for connecting the broken Pressure medium channels comprises a number of sleeves and as an abutment for a locking bar a support element,

Fig. 7: the rotor according to FIG. 5 with inserted insert according to Fig. 6, and

Fig. 8: the bottom of the rotor according to FIG. 7 with inserted

Insert.

Detailed description of the drawing

In Fig. 1, a camshaft adjuster 1 with a rotor 2 and a stator 3 is shown. For reasons of clarity, the stator 3 is only partially drawn. The rotor 2 is rotatably mounted relative to the stator 3 about a rotation axis 4. For attachment to a camshaft, the rotor 2 has a hub 5. With attached to the outer casing 6 wing elements 7, the rotor 2 is inserted into the interior of the stator 3. In this case, sealing elements 10 inserted into the grooves 9 on the wing elements 7 seal against the stator 3. The stator 3 is connected via a not shown drive means with the crankshaft of an internal combustion engine.

For locking the rotor 2 relative to the stator 3 in a defined angular position, for example during a starting phase of the internal combustion engine, the rotor 2 further comprises a locking portion 12 with a bore 14 into which a locking bar can be inserted. With a corresponding angular position of the inserted locking bar can engage in a recess of the stator 3, so that rotor 2 and stator 3 are mechanically locked to each other.

The rotor 2 has a substantially annular material recess 16, which is axially introduced except for the locking region 12. The resulting annular space 18 is clearly visible. In the area of the material recess 16, the hub 5 and the outer casing 6 are each reduced to a circumferential collar with the visible wall thickness. In other words, the rotor 2 overall substantially pot-shaped with inclusion of the inner hub 5 is formed. The locking region 12 interrupts the annular material recess 16 in the form of a radial web 19. On the hub 5 and on the outer casing 6, a series of respectively corresponding holes 20 can be seen, which belong respectively to first pressure medium channels 24 and to second pressure medium channels 26. Through the material recess 16, the corresponding pressure medium channels 24, 26 are interrupted. The first pressure medium channels 24 are arranged offset axially relative to the second pressure medium channels 26. The advance chambers 28 formed between the rotor 2 and the stator 3 are connected via the first pressure medium channels 24, and the retard chambers 30 are each connected via the second pressure medium passages 26 to a hydraulic pressure system. The fluidic connection of the respective pressure medium channels 24, 26 takes place in the interior of the hub 5 by coupling to axial supply spaces in the camshaft or by direct coupling to the inlets and outlets of a central valve inserted into the camshaft. To form the early and late adjustment chambers 28 and 30, in each case one wing element 6 engages between two adjacent separating elements 31 of the stator 3.

Due to the approximately annular introduced axial Materialausnehmung 16 of the rotor 2 is compared to known embodiments significantly reduced in weight. To restore the connection of the early and late adjustment chambers 28 and 30, respectively, to the hydraulic pressure system, sleeves 47 (see FIG. 2) are inserted between the respectively corresponding bores 20 in hub 5 and outer jacket 6.

To facilitate assembly, the sleeves 47 are arranged according to FIG. 2 on a common insert 40. The insert 40 has a base body 42 in the form of an open ring. On the main body 42 are alternately in the one and in the other axial direction extending first axial extensions 44 and second axial extensions 45 are arranged. By the axial extensions 44 and 45 are respectively the Sleeves 47 out. At the open ring of the main body 42 of the axial gap 48 is visible. At the same time, a stop 49 on the base body 42 is defined via the axial gap 48. With this stop 49, the insert 40 is in the assembled state of the radial web 19 of the rotor 2 according to FIG. 1 at. As a result, a defined angular position of the insert 40 is set on the rotor 2, so that can be dispensed with during installation on a complex adjustment and control of the installation state.

In Fig. 3, the rotor 2 according to FIG. 1 with the inserted insert 40 corresponding to FIG. 2 is shown. It can be seen how through the inserted insert 40 by means of the respective sleeves 47, the pressure medium channels 24, 26 severed by the material recess 16 are in each case individually fluidically connected again. The axial installation position of the insert 40 results from abutment of the first axial extensions 44 at the bottom of the rotor 2 via the second axial extensions 45, the axial height of the insert 40 closes flush with the axial height of the outer shell 6. In the installed state, a locking cover includes the rotor 2 and thus the insert 40 in the stator 3 axially. The angular position of the insert 40 is defined by abutment of the stop 49 on the locking portion 12.

In an exemplary embodiment, the inner diameter of the sleeves 47 is selected to be greater than the diameter of the holes 20. This ensures safe fluidic coupling even with a non-ideal alignment of the sleeves 47 with respect to the holes 20.

In the installed state according to FIG. 3, it can further be seen that the sleeves 47 of the second axial extensions 45 are axially offset relative to the sleeves 47 of the first axial extensions 44 and thus respectively form the first pressure medium channels 24 and the second pressure medium channels 26 and the corresponding chenden holes 20 connect. The sleeves 47 are in this case inserted by a radial interference fit into the annular space 16 between the hub 5 and the outer casing 6, which corresponds to an axial interference fit in the direction of the bores 20 and the pressure medium channels 24, 26. The resulting sealing functionality meets the required for a hydraulic camshaft adjuster 1 criteria.

In FIG. 4, the rotor 2 according to FIGS. 2 or 3 is shown from another perspective with a view of the floor 50. In the interior of the hub 5 and the outer casing 6, the holes 20 for the first and second pressure medium channels 24, 26 are visible.

FIG. 5 shows a rotor 2 according to an alternative embodiment variant. Compared with the rotor 2 according to FIG. 1, the locking region 12 is additionally exposed in FIG. 5 except for a wall region 52 into which the locking bore 14 is introduced. The introduced between the hub 5 and the outer casing 6 axial Materialausnehmung 16 is so far as a whole annular.

In Fig. 6, a corresponding insert 40 is shown, which is inserted into the annular space 18 of the rotor 2 according to FIG. 5. In addition to the previously described sleeves 47, which in turn are arranged on corresponding axial shoulders 44, 45, the annular base body 42 of the insert 40 according to FIG. 6 now comprises a support element 54 in the form of a support cross 55. This support element 54 takes over in interaction with the Wall portion 52 in the bore portion 2 of the rotor 2, the function of a blind hole in which a locking bar is guided and counteracted. The resulting loss of material results in a further weight reduction of the rotor 2 according to FIG. 5. In particular, an imbalance resulting from the locking region 12 is reduced.

The support member 54 further includes an axial spinous process 57. In the installed state, a coil spring is mounted on this spinous process 57, over which the inserted locking bar is spring-biased against the locking cover. Due to the configuration as a support cross 55, the spinous process 57 is able to generate not only axial forces but also radial forces (be absorbed in the direction of movement of the locking bolt) and dissipate into the rotor 5.

In Fig. 7, the rotor 2 according to FIG. 5 with inserted insert 40 corresponding to FIG. 6 is shown. About the use of the spinous process 57 in the bore 14 on the locking portion 12, the angular orientation of the insert 40 to the rotor 2 is defined defined.

FIG. 8 shows the rotor 2 according to FIG. 7 with a view of the bottom 50. In this perspective, it can be seen how the spinous process 57 is inserted opposite the bore entry 58. The spinous process 57 and the support member 54 takes over the function of a hitherto conventional cartridge in which the locking bar is spring biased.

List of reference numbers

1 camshaft adjuster 57 spinous process

2 Rotor 35 58 Hole entry

3 stators

4 rotation axis

5 hub

6 outer jacket

7 wing element

9 groove

10 sealing element

12 locking area

14 hole

16 material recess

18 annulus

19 footbridge

20 holes

24 first pressure medium channels

26 second pressure medium channels

28 advance chamber

30 retardation chamber

31 separating element

40 insert piece

42 basic body

44 first axial extensions

45 second axial extensions

47 sleeves

48 axial gap

49 stop

50 floor

52 wall area

54 support element

55 support cross

Claims

Patent claims

Rotor (2) for a hydraulic camshaft adjuster (1), comprising a hub (5) for receiving a camshaft and an outer casing (6) with a number of wing elements (7), from the interior of the hub (5) to the outer casing (6) Pressure medium channels (24, 26) run, characterized in that at least one pressure medium channel (24, 26) is interrupted by an axial material recess (16), a sleeve (47) connecting the interrupted pressure medium channel (24, 26) being inserted into the material recess (16). ) is used.

Rotor (2) according to claim 1,

characterized in that the material recess (16) is essentially provided as an annular space (18) between the hub (5) and the outer casing (6) which interrupts several pressure medium channels (24, 26), wherein for connecting the respectively interrupted pressure medium channels (24, 26) one sleeve (47) is inserted.

Rotor (2) according to claim 2,

characterized in that the annular space (18) is interrupted by at least one radial web (19).

Rotor (2) according to one of the preceding claims,

characterized in that the or each sleeve (47) is arranged on an annular segment-shaped or annular insert piece (40) which is inserted into the material recess (16). 2

5. Rotor (2) according to claim 4,

characterized in that the insert piece (40) comprises a number of axial extensions (44, 45), so that the inserted insert piece (40) is flush with the outer jacket (6) in its axial height.

6. Rotor (2) according to claim 5,

characterized in that the or each sleeve (47) is arranged on an axial extension (44, 45).

7. Rotor (2) according to one of the preceding claims,

characterized in that a locking area (12) is included with a bore (14) for receiving a movable locking bolt, which is exposed except for an axial wall area (52) at the bore entry (58), the exposed area being in the A support element (54) opposing the locking bolt is inserted opposite the bore entry (58).

8. Rotor (2) according to claim 7,

characterized in that a support cross (55) with an axial spinous process (57) is used as the support element (54).

9. Rotor (2) according to claim 7 or 8,

characterized in that the support element (54) is arranged with the or each sleeve (47) on the insert (40).

10. Camshaft adjuster (1) with a stator (3) and with a rotor (2) rotatable relative to the stator (3) about an axis of rotation (4) according to one of the preceding claims.