EP2527607B1 - Device for adjusting a rotation angle position of nested camshafts relative to one another - Google Patents

Description

The invention relates to a device for adjusting the relative rotational angular position of nested camshafts of an internal combustion engine and a camshaft phaser, which can be mounted to adjust the relative rotational angular position as a mounting unit at one axial end of the camshaft comprising shaft assembly or is already mounted in the formation of the device according to the invention.

A phaser for adjusting the relative rotational angular position of nested camshafts is already out of the US 1,527,456 known. It is an axial-type phaser, which is an integral part of the shaft assembly. A stator of the phaser serves at the same time also the rotary bearing of the nested camshafts.

From the US 7,469,670 B2 is a nested camshaft mounted vane-type phasor known. The phase adjuster comprises a stator rotatably connected to the outer shaft and a rotor rotatably connected to the inner shaft. The stator is further rotatably connected to a drive wheel of a traction mechanism, via which the stator is driven by the crankshaft of the internal combustion engine. With the rotary drive, the stator takes the rotor with it. However, the rotor is hydraulically pivotable relative to the stator about the common axis of rotation. The rotor is fastened to the inner shaft by means of a central, axially extended screw. For the installation of the phaser multiple steps are required. The stator is screwed onto the outer shaft, and the rotor is fixed non-positively by means of the central screw on the inner shaft. Between these two steps, the drive wheel is adjusted with respect to its rotational angle position relative to the stator and connected in the adjusted rotational angular position by means of several screws fixed to the stator. Only then is the fixation of the rotor on the inner shaft by tightening the central screw. In a variant of the rotor is screwed onto the outer shaft, and the stator is fixed by means of a central connecting screw after adjustment of the rotational angular position of the drive wheel frictionally fixed to the inner shaft.

From the WO 2006/081789 A1 is also an arrangement with nested camshafts known which are rotatable relative to each other by means of a mounted phaser. Stator and rotor of the phaser are fixedly connected to the respective associated camshaft and push the front end while sealing guided by the front ends hydraulic channels against the respective associated camshaft.

The EP 0 686 754 B1 describes nested camshaft with an axial displacement type phaser. The phase adjuster comprises a stator rotatably driven by the crankshaft and a rotor which is rotatable with the stator in a helical tooth engagement and in this tooth engagement relative to the stator. The rotor is secured against rotation with one of the camshafts in a sliding joint, but axially movably connected. The stator is firmly connected together with a drive wheel with the other camshaft in a connecting flange in several places with screws. The stator is provided for adjusting the rotational angular position in the connecting flange with circumferentially extending slot-shaped openings through which the screws extend. The stator forms an end face open to the camshaft pot, in which the rotor in the engagement of the helical gears axially reciprocally movable. For the adjustment, the rotor is acted upon at a side facing away from the camshaft end face with hydraulic pressure. The hydraulic pressure counteracts a return spring, which is supported on one of the camshafts and the rotor. The return spring must be positioned between the rotor and the camshaft during assembly before the rotor is pushed on and the stator fastened, and pre-tensioned during assembly. In order to close the pot formed by the stator in a fluid-tight manner, a flange component is attached to the front end of the associated camshaft.

The DE 10 2009 041 873 A1 relates to a cam phaser for the inner camshaft of a concentric camshaft assembly. The phaser comprises a rotor and a stator. The rotor is connected via a central screw assembly with the inner camshaft. The screw assembly includes a central bore in which a valve assembly is located to control rotation of the rotor relative to the stator. On the stator, a valve pinion is arranged, which is connected via a valve train chain with the crankshaft of the internal combustion engine.

The GB 2 433 974A relates to the attachment of a camshaft with a Nockenphasenverstellers on a machine. The camshaft consists of an inner shaft and a sleeve surrounding the shaft. The inner shaft is connected to a first set of cams, on the outer sleeve a second set of cams is formed. The inner shaft and the outer shell can be rotated relative to each other. The phaser comprises a pinion driven by the crankshaft.

The DE 2008 019 746 A1 relates to a device for variably setting the timing of gas exchange valves of an internal combustion engine, with a drive element that is in driving connection with the crankshaft via a traction or gear drive.

The GB 2 467 333 A relates to a camshaft with a cam phaser. The phaser comprises a stator having external teeth over which a crankshaft drives the phaser.

The GB 2 369 175 A relates to a variable phase clutch to drive off from one crankshaft to two sets of cams. The clutch comprises a drive element which is driven by the crankshaft and two driven elements for connection to one of the cam sets. Each of the driven elements is hydraulically coupled to the drive element so that each of the two driven elements can assume an angular position independently of the other.

It is an object of the invention to facilitate the assembly of a phaser on or on nested camshafts of the type described, in particular for a preferably designed in Flügelzellenbauart phaser.

The invention accordingly starts from a device for adjusting the relative angular position of nested camshafts of an internal combustion engine comprising a shaft arrangement with a first camshaft and a second camshaft, one of which is extended in the other and which are rotatable relative to each other. In particular, one of the camshafts may be an outer shaft and the other may be an inner shaft extending through the outer shaft. Basically, however, it is also conceivable that the a wave sections inside and outside sections and the other wave accordingly sections in the outside and partially inside extends. The device further comprises a phaser, which is mounted as an assembly unit at one axial end of the shaft assembly and a rotatably connected to the first camshaft stator and a rotatably driven by the stator relative to the stator with respect to the rotational angle position adjustable, in this sense rotational angle adjustable rotor. The phase adjuster is fastened to the shaft arrangement by means of a connecting device, preferably axially fixed. The connecting device rotatably connects the rotor with the second camshaft. Part of the device is also a drive wheel which is rotatably connected to the first camshaft and the stator for rotational driving of the first camshaft and the stator. That one component is "non-rotatable" or "rotationally fixed" with another component means that the components that are non-rotatable with respect to a common axis of rotation are rotationally immovable relative to one another. The components can be formed in one piece or separately formed from each other and rotatably joined together, the subsequent joint connection can be positive, non-positive or cohesive. The word "or" is understood here as always by the invention in the usual logical sense of an "inclusive or", ie includes the meaning of "and" and also the meaning of "either ... or", as far as the each concrete context can not only result in one of these two meanings. Related to the form-fitting, non-positive or cohesively rotationally fixed connection, this means, for example, that the respective components can only be positively connected in a first variant, only non-positively in a second variant and only materially connected in a third variant. In further variants, the respective components can be connected to one another by means of one of the three possible combinations of only two of these types of connection, and finally, in a last variant, all three types of connection can be realized.

According to the invention, a rotationally fixed to the first camshaft camshaft-engaging structure and a stator rotatably fixed to the phaser engagement structure are pushed axially into each other and thereby in an anti-rotation, namely a rotation secured axial sliding engagement, which connects the stator by positive engagement against rotation with the first camshaft. By the invention Verdrehsicherungseingriff is obtained in the circumferential direction, the torque form-fitting transmitting connection of the stator and the first camshaft and an axial mountability of the phaser. As far as is spoken of a non-rotating connection or a Verdrehsicherungseingriff, this means that the interconnected components are connected to each other at least by positive locking against rotation. In preferred variants, the respective rotationally secured connection is based only on positive locking, in alternative variants on a combination of positive and non-positive connection. A material bond in addition to a pure form-fitting or in addition to a positive and a force fit should not be excluded, but there is preferably no material connection in Verdrehsicherungseingriff.

The engagement structures may be formed in preferred first embodiments as crown wheels and axially slid into each other. The camshaft engaging structure or the phaser engaging structure may also be one or more axial recesses, such as a hole or a plurality of holes, and the respective other engagement structure adapted shaped one or more axial Abragungen, such as pin or bolt-shaped Abragungen, in a corresponding number have, which are pushed axially into one another during assembly of the phaser and thereby form the Verdrehsicherungseingriff. In preferred second embodiments, one of the engagement structures surrounds the other at least partially, preferably completely, about the axis of rotation of the stator. The engagement structures form during assembly with each other a sliding joint with the common axis of rotation of the stator and the first camshaft as a hinge axis. As such, the engagement structures can be axially movable relative to one another in the rotation-locked engagement even in the mounted state. In particular, in embodiments in which the vane-type or pan-vane type phaser is such mobility must, although advantageous, not necessarily be present. The anti-rotation engagement may, as already mentioned, beyond the form fit also include a frictional connection, so that the engagement structures together form a plug connection in the assembled state of the phaser. The phase adjuster or at least the stator can be axially fixed by the anti-rotation engagement relative to the shaft assembly, but more preferably there is no axial fixation in Verdrehsicherungseingriff Axial fixation is preferably effected by means of the connection means via the rotor of the phaser.

In embodiments in which the engagement structures extend around the axis of rotation, preferably completely around the axis of rotation, d. H. Extending over 360 ° circumferentially and one of the engagement structures the other at least partially, preferably completely surrounds in the circumferential direction, the engagement structures adapted to each other can be shaped as a single or multi-flat or otherwise not rotationally symmetrical, being quite a single or multiple, generally said to have n-fold rotational symmetry. You must also have in such embodiments, no plan, the positive engagement effecting engagement surfaces. The surface which brings about the positive engagement or the several surfaces of the respective engagement structure which jointly effect the positive engagement may or may well be curved, but the cross-sections which form the positive engagement with one another are at least not circular. In preferred embodiments, the engagement structures have teeth in mutual engagement with one another. The teeth can be seen over the circumference have a uniform tooth pitch, but in principle this is not required. The teeth can be pronounced, so have a large tooth depth, but in principle also sufficient flat knurls, as long as only the positive locking causes safe and the required torque can be transmitted without slippage.

The anti-rotation engagement is preferably releasable again, so that the Phasenstellers engagement structure for disassembly of the phaser from the first camshaft can be easily withdrawn axially.

The invention facilitates the assembly of the phase adjuster, since by means of the connecting device, the rotor rotatably connected to the second camshaft and the phase adjuster is thereby secured to the shaft assembly and the positioner at the axial end of the shaft assembly by a simple axial thrust movement the phaser engagement structure in the anti-rotation with the camshaft engaging structure can be pushed. When it is a sliding engagement or it is said that the engagement structures are pushed into each other or during assembly it is not necessary for the engagement structures to slide up or around each other, although this is preferred. If the engagement structures are embodied, for example, as crown toothings, such engagement structures can also be brought into mutual contact for the first time at the very end of the assembly. However, sufficient for the production of Verdrehsicherungseingriffs a relative axial linear motion, in this sense, an axial thrust movement.

In preferred embodiments, the stator is a rotationally fixed component of a phaser actuator housing, which surrounds the rotor at its outer periphery and axially surrounds on both end faces. The phase adjuster housing is preferably fixed axially to the shaft arrangement by means of the connecting device, wherein advantageously the rotor is axially fixed to the second camshaft by means of the connecting device and the phaser housing is axially fixed by fixing the rotor to the shaft arrangement. In order to avoid overdetermination, it is preferable if in the anti-rotation engagement is not additionally axial fixation, but the engagement structures are axially movable at least in principle also in Verdrehsicherungseingriff relative to each other tolerances or thermal expansion differences between the shaft assembly and the phaser can compensate.

The conditions are particularly favorable when the stator is provided in a rotationally fixed component of a phase adjuster housing and the phase adjuster engagement structure is provided on the phaser housing. As already mentioned, the phase adjuster engagement structure accessible from the outside for accessing the camshaft engagement structure may be formed on the phaser housing, for example, as an axial recess or axial projection or a plurality of axial recesses or projections, possibly also realized by a combination of different form elements be. The phasing engagement structure may also be formed separately and subsequently added rotatably to the phaser housing. It may in particular be provided on a front-side cover of the phaser housing. In any case, the shape and arrangement of the phaser engaging structure is such that when the phaser is mounted by an axial movement of the phaser housing relative to the first camshaft and thus can be made relative to the camshaft engaging structure of the anti-rotation engagement.

In embodiments in which the stator is as preferred rotationally fixed component of a phaser case, in the phaser housing advantageously between the stator and the rotor at least one Frühstellkammer, preferably several Frühstellkammern, and the Frühstellkammer or the Frühstellkammern counteracting formed at least one Spätstellkammer or preferably several Spätstellkammern. The Frühstellkammer (s) serves or serve to generate a force acting on the rotor relative to the stator in the direction of advance torque. The late setting chamber (s) serves or serves to generate a torque acting on the rotor in the direction of lag relative to the stator. The Stellkammem can be acted upon to generate the respective torque with a pressurized fluid to adjust the rotational angular position of the rotor relative to the stator can. The pressure prevailing in either the or the Frühstellkammer (s) or the Spätstellkammer (s) or optionally in both Stellkammerarten preferably acts in the circumferential direction of the rotor.

The phaser is in preferred embodiments, a hydraulic phaser. In particular, it may be of the vane-type or swing-wing type, the two terms being understood to be synonymous. In such embodiments, the rotor has at least one rotor blade, to which the at least one early adjustment chamber adjoins the one circumferential direction and the at least one late adjustment chamber in the other direction. The rotor blade shares a circumferentially bounded by the stator pressure chamber in the two adjusting chambers. Preferably, the rotor distributed about its axis of rotation on a plurality of rotor blades, the pressure chambers, which are bounded in the circumferential direction of the stator, each subdivide into an early-adjusting chamber and a respective late-release chamber. Such a phase adjuster can be provided in a particularly simple manner as a prefabricated mounting unit and mounted on the shaft assembly due to the invention.

With regard to the drive wheel, via which the shaft arrangement and the phase adjuster are rotationally driven, it is advantageous if, in first variants, the first camshaft is rotatably drivable via the drive wheel and abrades in the rotation-preventing engagement with the stator or in alternative second variants, the stator is rotatably drivable via the drive wheel and abrades in the rotation-preventing engagement with the first camshaft. In the first variants, the stator-rotation engagement structure which is rotationally fixed with the stator serves as a stator rotational driver; in the second variants, the camshaft engagement structure which is non-rotatable with the first camshaft serves as a camshaft rotary driver.

The drive wheel advantageously has around its axis of rotation circumferentially a toothing for a torque-fixed drive through the crankshaft. Torque-resistant means that the drive wheel is in a predetermined speed relationship to the crankshaft. The drive wheel can, for example, form a spur gear, preferably a spur gear, with a driven gear driving off the drive wheel. The drive wheel may alternatively but for example also be a sprocket or toothed belt wheel of a corresponding traction mechanism drive.

The drive wheel immediately forms the camshaft engagement structure. In such embodiments, it has for rotary driving circumferentially about its axis of rotation said toothing and also on the periphery or on an end face of the engagement structure. The camshaft engagement structure may be provided in addition to the toothing on the drive wheel. It can also be formed by the teeth also equal, in which case the teeth are axially longer than would be necessary for the rotary drive of the camshaft, so that the teeth axially adjacent to each other has a portion for the rotary drive and another portion of the camshafts Meshing structure forms. Although embodiments in which the drive wheel fulfills both the function of torque absorption from outside the device according to the invention and the function as an engagement structure are advantageous, the drive wheel in other embodiments can advantageously also only fulfill the function of the rotary drive for the device. The camshaft engaging structure rotationally fixed to the first camshaft and the phaser rotationally fixed phaser engaging structure are then otherwise formed, for example, the camshaft engaging structure directly on or on the camshaft or other member non-rotatably joined to the first camshaft.

If the phaser is designed as a hydraulic phaser, it has an inlet and an outlet for a pressurized fluid for the hydraulic rotary adjustment of the rotor. The pressurized fluid may in particular be a lubricating oil serving to lubricate the internal combustion engine. The phase adjuster can be supplied with the pressurized fluid via an engine housing of the internal combustion engine, for example a cylinder head or a cylinder head cover, or via the shaft arrangement, preferably via the second camshaft, which is non-rotatable with the rotor. In alternative embodiments, the phase adjuster can be supplied with the pressurized fluid from the outside via a mounting housing attached to the machine housing. The said supply paths can also be combined with one another, for example such that the pressure fluid passes through the engine housing such as a cylinder head or cylinder head cover for shaft arrangement and the shaft assembly to the phaser, or for example such that the pressurized fluid first to said attachment housing and from this directly or indirectly from the mounting housing on the machine housing or the shaft assembly is supplied to the phaser. The attachment housing may have a pressure accumulator arranged upstream of the phaser in the supply circuit for securing a pressure level sufficient for the phaser. Alternatively or preferably, in addition to a pressure accumulator upstream of the phaser a Rückspemnittel such as a check valve may be arranged, preferably in the mounting housing, which prevents the pressurized fluid within the supply to the phaser at an upstream pressure drop back, can flow away from the phaser. If the attachment housing has a pressure accumulator, the optional blocking means is arranged upstream of the pressure accumulator and preferably in the attachment housing. As an alternative or in addition to the functions mentioned, the mounting housing can also be used for mounting the electromagnetic part of an electromagnetically controllable control valve, by means of which the phaser is operated in a controlled manner with the pressurized fluid. As an alternative or in addition to a return blocking means arranged upstream of the pressure accumulator, a return blocking means can be arranged in the fluid supply to the phaser downstream of the pressure accumulator, ie between the pressure accumulator and the phaser, preferably between the pressure accumulator and a control valve of the phaser, the return flow from the phaser in the direction prevented on the accumulator.

In preferred embodiments of a hydraulic phaser, an outlet for the pressurized fluid extends through the region of the anti-rotation engagement and between the engagement structures such that anti-rotation engagement in dual functions is utilized for pressure relief of the phaser. If the fluid is removed from the phaser via the anti-rotation engagement, the discharged fluid can advantageously also provide lubrication in Verdrehsicherungseingriff and counteract the formation of friction. This is particularly advantageous when the engagement structures in the anti-rotation engagement with each other form a sliding joint, so are at least basically axially movable relative to each other.

The engagement structures have, in preferred embodiments, a toothing around each other about a common axis of rotation, and the toothings are in the anti-rotation engagement with each other. The teeth preferably have a uniform tooth pitch, however, one or more teeth may or may be omitted to form, for example, an outlet. The teeth can be advantageously carried out on each of facing end faces of the engagement structures in each case as a crown toothing. Instead, or in principle additionally, one of the engagement structures may have an outer toothing on one outer circumference and the other may have an inner toothing on an inner circumference. Basically it would indeed are sufficient if one of the engagement structures has an engagement groove and the other a cooperating engagement rib, so that the anti-rotation engagement would be performed in the manner of a tongue and groove connection. It could also be provided on each end faces of the engagement structures only one axial recess and cooperating only an axial projection as an engagement element and engagement counter element, wherein the projection in Verdrehsicherungseingriff protrudes into the recess and thereby causes the rotational drive in Verdrehsicherungseingriff. Circumferential gears or at least a plurality of engagement grooves and engagement ribs or a plurality of recesses and projections in preferably uniform distribution about the rotation axis are preferred. In principle, the rotation could also by an axially insertable blocking element, such as a pin, a feather key, a disc spring or the like, are produced, but this would require an additional step in the assembly required. An alternative, which is also advantageous in terms of simple axial Aufschieb-mounting would be engagement structures, one of which surrounds the other about the axis of rotation, wherein the interlocking cross-sections of the engagement structures differ from the circular shape, for example, are polygonal. However, the formation of the anti-rotation engagement with mutually adapted, rotating around the axis of rotation gears is a particularly space-saving variant, which is also suitable for the transmission of high torques. Also conceivable would be a frictional engagement, wherein one of the engagement structures that surrounds the other, could be designed as a clamping sleeve. However, a non-positive anti-rotation engagement may cause undesirable overdetermination, or may require an additional assembly step if such a collet would need to be tensioned, for example, by means of a biasing means after being pushed to establish the anti-rotation engagement. Since in mass production, in particular large-scale production, such as in motor vehicle production, the preferred field of application of the invention, each additional step of the size of the series is repeated thousands or even millions of times, any simplification of assembly means a significant advantage.

If the phase adjuster is designed as a hydraulic phaser as preferred, a control valve controlling the relative rotational angular position of the rotor can advantageously be central be arranged centrally with respect to the rotor and the stator and preferably also with respect to the camshafts. A central control valve can in particular also project into the second camshaft. The second camshaft is provided in such embodiments with a central, open at the phaser front end cavity in which the central control valve projects and in which it can be fixedly connected to the second camshaft, thereby securing the phaser to the shaft assembly.

In embodiments in which the phaser comprises a central control valve with respect to the stator and the rotor for a fluidic adjustment of the rotational angular position of the rotor, the control valve can advantageously form a connecting element of the connecting device, suitably a screw element, and into a cavity of the second camshaft protrude and firmly connected in the cavity with the second camshaft, be suitably screwed. A central, projecting through the rotor and projecting into the second cam shaft connecting member such as a screw is for a rotationally fixed connection of rotor and second camshaft and the attachment of the phaser as a whole but also advantageous if such a link is not part of a control valve.

An advantageous for the purposes of the invention control valve is in the DE 10 2010 002 713 disclosed for advantageous embodiments of the control valve referred to.

In preferred embodiments, the phase adjuster comprises a locking device which mechanically, preferably positively, fixes the rotor in a releasable locking engagement in a specific rotational angle position relative to the stator and changes into an enabling state by applying a pressurized fluid to an adjustment of the rotational angular position of the rotor. When mounting the phaser preferably the locking engagement. Locking devices, as they can be advantageously realized in the context of the invention, are in the DE 10 2011 004 539 and the DE 10 2010 053 685 disclosed with respect to the locking device, with respect to the control valve and also with respect to advantageous features of a pressure accumulator, including the tuning of a Locking device and a pressure accumulator to each other, be referred to.

The phaser may include a torsion spring that biases the rotor relative to the stator toward a rotational angle end position. The torsion spring can advantageously be present in addition or instead of a locking device.

It has already been stated that the engagement structures located in the rotation-preventing engagement when the phaser is mounted can, in particular, be spur toothings adapted to one another or else crown toothings. When it comes to crown gears, the phase adjuster is moved during assembly with its splined engagement structure of a claw or Stirnzahnkupplung correspondingly in the anti-rotation engagement with the adapted splined camshaft engaging structure. As a crown toothing, the invention means any kind of toothing, with a plurality of teeth distributed axially about the axis of rotation of the phaser on one end face, for example a Hirth toothing and also any other type of face toothing. The toothings of the engagement structures can also be inclined to the axis of rotation, that is to say protrude both in the axial and in the radial direction. Thus, the engagement teeth on a conical end face obliquely radially outwardly projecting teeth and the other engagement structure corresponding to a facing conical end face obliquely radially inwardly projecting teeth. However, crown or face gears with at least substantially only axially projecting teeth is preferred. Crown gears in the narrower sense, the teeth protrude accordingly at least substantially only axially on the respective end face, can be produced in a simple manner, ie be shaped. A Verdrehsicherungseingriff with kron- or flat-toothed engagement structures, the teeth protrude at least substantially only axially from end faces, also has the advantage that seen for the anti-rotation engagement radially to the axis of rotation no additional space is needed. In comparison to end-toothed engagement structures, which inevitably require a certain radial space as such due to the shaft bushing arrangement, the sealing of pressure chambers of the phaser can be improved or at least facilitated with otherwise identical dimensions of the phaser.

In terms of an aspired small space requirement in the radial direction are in principle intervention structures of advantage, which are in the mounted state of the phaser in the anti-rotation engaged engagement elements and counter-elements at axially facing end faces at least substantially only axially protrude. In view of the torque load, which must withstand the engagement structures, such engagement elements are preferably the axially projecting teeth of gears, which preferably rotate completely around the axis of rotation, ie over 360 °.

The stator housing comprising the stator can be rotatably mounted on the rotor or in the anti-rotation engagement with the camshaft engagement structure and otherwise have no further pivot bearing, in particular in embodiments in which the first camshaft drifts onto the stator, the phaser engagement structure thus acts as a stator rotary driver , Instead, the stator housing comprising the stator can also be rotatably mounted in an outer rotary bearing, that is to say a rotary bearing which is external with regard to the rotation-preventing engagement and the arrangement of rotor and stator and thus independent of the camshaft arrangement. Thus, the phaser housing in the outer pivot bearing, for example, on the engine case, such as on a cylinder head or a cylinder head cover, be supported. The support in an outer rotary bearing is particularly advantageous for embodiments in which the drive wheel via the stator rotatably drives the first camshaft, that drives the phaser housing on the first camshaft, so that the camshaft Eingriffsstraktur acts as a camshaft rotary driver. In such embodiments, the drive wheel is preferably non-rotatably connected to the stator, for example fixedly joined to the phase adjuster housing or, if appropriate, formed in one piece directly on the stator or a lateral cover of the phaser actuator housing.

The connecting device that secures the phaser to the shaft assembly with respect to the axial direction and rotatably connects the rotor to the second camshaft includes, in preferred embodiments, a camshaft cavity extending at the phaser-facing axial end of the shaft assembly in the second camshaft and is open to the phaser. The connection device further comprises a in this cavity projecting and firmly connected in the cavity with the second camshaft in the assembled state connecting member, so a central link such as a central mounting screw. As already mentioned, the central connecting member can form the housing of a central control valve of the phaser. However, the control valve may instead be located outside the rotor and stator assembly. However, the pressure fluid of the preferred hydraulic phaser is also guided in such embodiments advantageously centrally over the area of the camshaft cavity in the pressure chambers of the phaser, ie by the camshaft cavity and feeds formed in the rotor of the phaser. The central link in such embodiments is not a valve housing, but essentially only fulfills the function of immovably connecting the rotor to the second camshaft.

In the region of the camshaft cavity may be radially extending between the second camshaft and the connecting member axially a first connecting channel for guiding the pressurized fluid, through which the pressurized fluid of the at least one or more preferably Frühstellkammern the phaser or the at least one or preferably a plurality of Spätstellkammern can be supplied. Conveniently, the pressure fluid in the case of reversing the phaser by the first connecting channel of the corresponding type chamber, namely either early or late setting, also be discharged again. The provision of an axially extending connecting channel radially between the connecting member and the camshaft surrounding the connecting member in the region of the cavity is particularly advantageous for embodiments in which the control valve with respect to the phaser or the camshaft not centrally, but outside the arrangement of the rotor and stator is arranged.

At the phaser plate facing the end of the second camshaft, a sleeve structure may be arranged and not rotatable with the second camshaft and preferably also axially non-movably connected. The second camshaft may define with the sleeve structure a second connecting channel through which the pressurized fluid can be supplied to the at least one early adjusting chamber or else to the at least one late setting chamber. If both the axially extending first connecting channel and the axially extending second connecting channel are present, these connecting channels are fluidically separated, ie the one This connection channels is connected only to the or the Frühstellkammer (s) and the other only with the or the Spätstellkammer (s). The sleeve structure may extend partially or wholly within the camshaft cavity to fluidly separate the first and second communication channels in the cavity. The sleeve structure is used in such embodiments as a separating sleeve. Instead, however, the sleeve structure may also be arranged on the outer circumference of the second camshaft so that the second connecting channel is formed on the outer circumference of the second camshaft between the second camshaft and the outer sleeve structure in this case.

The first connection channel or the second connection channel may or may in each case in particular be an annular space which extends completely peripherally around the axis of rotation of the phase adjuster.

In embodiments in which the first connecting channel is formed radially between the central connecting member and a surrounding jacket portion of the second camshaft, the camshaft cavity can advantageously have a variable cavity width, in particular be formed as a stepped bore. The stepped cavity has axially adjacent to each other in such embodiments at its the phaser end facing a greater width and in an axially adjacent thereto, further away from the phaser portion a comparatively smaller width. In the section with the smaller width is in the assembled state of the phaser the fixed connection with the connecting member, such as a screw connection. In contrast, extended cavity portion, the first connection channel extends. In a preferred development of such an arrangement, the already mentioned sleeve structure is then provided as an outer sleeve structure in order to form the second connecting channel on the outer circumference of the second camshaft between the second camshaft and the outer sleeve structure.

The invention relates not only to the shaft assembly with the mounted phaser, but also suitable for mounting on nested camshaft phaser. The phase adjuster comprises a stator and a rotor which is adjustable in angle of rotation relative to the stator within a predetermined angular range about an axis of rotation is arranged. The stator is a non-rotating component of a phaser actuator housing, in which the rotor is received rotatably adjustable. Since the stator rotates in the assembled state of the phaser together with a first of the nested camshafts, the phaser housing is rotationally symmetric with respect to the axis of rotation of the stator. The phaser also includes a link for non-rotatably mounting the rotor to another, second of the nested camshafts. If the phase adjuster has a central control valve as already explained for the device, a valve housing of the control valve can advantageously form the connecting member. According to the invention, the phase adjuster has a phase adjuster engagement structure which is non-rotatable with the phase adjuster housing and has at least one, preferably a plurality of axially extended engagement elements for producing an anti-rotation engagement based on positive locking. The phase adjuster engagement structure forms in the assembled state within the described device, the engagement structure of the phaser in anti-rotation engagement. The phaser engagement structure is provided on the phaser housing in such a manner and adapted to connect in the assembled state in the rotationally locking engagement with an engagement counter-structure of the stator associated with the camshaft, the camshaft engaging structure, the stator with the first camshaft against rotation by positive engagement. The phaser engagement structure is shaped to be axially slidable into or onto a camshaft engagement structure non-rotatable with the first camshaft during assembly of the phaser to establish the anti-rotation engagement. The phaser engagement structure is preferably shaped so that it can be moved by an axial straight motion of the phaser relative to the first camshaft in the anti-rotation engagement.

On the phaser housing, an axially projecting ring can be formed or joined to the phaser housing, which, for example, on one end face or also preferably on an inner or outer ring circumference with a toothing, advantageously provided with a rotating around the axis of rotation of the stator toothing is. The ring preferably extends circumferentially, over 360 °, but in principle can also be formed only as a partial ring. This also applies to the gearing, ie it may be provided partially or preferably completely circumferentially around the axis of rotation. A phaser engagement structure having at least substantially axially projecting Engagement elements, such as in particular a crown toothing, but may advantageously also be formed directly on one of the shaft assembly facing end side of a side cover of the phaser housing. Such a phase adjuster engagement structure can also be formed in a depression formed on the end face of the cover, for example a circumferential groove on the front side or a shoulder radially on the inside of the cover, directly facing the shaft assembly radially, to the space required for Verdrehsicherungseingriff in the axial direction to reduce.

As far as for the components of the phaser, in particular the stator, the phaser housing, the rotor, the connecting member and the phaser engaging structure features in connection with the device, so the phaser in the assembled state, are disclosed, the relevant embodiments also apply with respect to the phaser as such. The phaser is preferably intended for use within the device according to the invention.

Further advantageous features are also disclosed in the subclaims and their combinations.

Figur 1

einen Phasensteller eines ersten Ausführungsbeispiels, der zur Drehwinkelverstellung geschachtelter Nockenwellen an einem axialen Ende der Nockenwellen angeordnet ist, in einem Längsschnitt,

Figur 2

den Phasensteller in einem Querschnitt,

Figur 3

einen Querschnitt, in dem der Phasensteller mit einer der Nockenwellen in einem verdrehgesicherten, axialen Schiebeeingriff ist,

Figur 4

die Nockenwellen und den Phasensteller in einem anderen Längsschnitt,

Figur 5

den Phasensteller mit einer Wellenanordnung, die eine modifizierte Nockenwelle aufweist,

Figur 6

den Phasensteller als solchen,

Figur 7

einen Phasensteller eines zweiten Ausführungsbeispiels in einem Längsschnitt,

Figur 8

das dem Phasensteller zugewandte Ende der Nockenwellenanordnung des zweiten Ausführungsbeispiels,

Figur 9

einen Phasensteller eines dritten Ausführungsbeispiel in einem Längsschnitt,

Figur 10

ein Beispiel einer Eingriffsstruktur mit an einer Stirnseite axial abragenden Zähnen, und

Figur 11

ein weiteres Ausführungsbeispiel einer Eingriffsstruktur mit an einer Stirnseite axial abragenden Zähnen.

Hereinafter, an embodiment of the invention will be explained with reference to figures. The features disclosed in the exemplary embodiment advantageously each individually and in each combination of features form the subject matter of the claims and also the embodiments described above. Show it:

FIG. 1

a phase adjuster of a first embodiment, which is arranged for the rotational angle adjustment of nested camshafts at one axial end of the camshafts, in a longitudinal section,

FIG. 2

the phaser in a cross section,

FIG. 3

a cross section in which the phaser is with one of the camshafts in a rotationally secured, axial sliding engagement,

FIG. 4

the camshafts and the phaser in another longitudinal section,

FIG. 5

the phaser with a shaft assembly having a modified camshaft,

FIG. 6

the phaser as such,

FIG. 7

a phaser of a second embodiment in a longitudinal section,

FIG. 8

the phaser-facing end of the camshaft assembly of the second embodiment,

FIG. 9

a phaser of a third embodiment in a longitudinal section,

FIG. 10

an example of an engagement structure with on one end face axially projecting teeth, and

FIG. 11

a further embodiment of an engagement structure with axially projecting teeth on one end face.

FIG. 1 shows in a first embodiment, a device according to the invention with nested camshafts 1 and 2 and a camshaft phaser S, which is arranged at one axial end of the shaft assembly formed by the camshafts 1 and 2 and the variation of the rotational angle position is used, the camshafts 1 and 2 relative to each other. The first camshaft 1 forms an outer shaft in the shaft arrangement or has an outer shaft section at least at the axial end on which the phaser S is arranged. The second camshaft 2 forms in the shaft assembly an inner shaft which extends at least substantially within the first camshaft 1 or at least at the axial end of the shaft assembly on which the phaser S is arranged, having an outer shaft portion of the camshaft 1 extending inner shaft portion , The camshafts 1 and 2 are rotatable about a common axis of rotation R together and within a predetermined by the phaser S rotation angle range relative to each other in order to vary the timing of cams of the camshaft 1 compared to cams of the camshaft 2 and thereby the associated valves. The device is part of an internal combustion engine, for example a drive motor of a motor vehicle. The shaft arrangement is rotatably mounted in or on a machine housing M of the internal combustion engine, for example in or on a cylinder head.

The phase adjuster S comprises a stator 3, which forms a phase adjuster housing 3, 4, 5 with a stator cover 4 and a stator cover 5, and a rotor 9, which is rotatable relative to the phaser housing 3, 4, 5 about the axis of rotation R back and forth , The stator 3 is with the end-side stator covers 4 and 5 fixed, ie immovably joined relative to the respective stator cover 4 and 5. The stator 3 and the phaser housing 3, 4, 5 is rotatably driven about the axis of rotation R via a transmission of a crankshaft of the internal combustion engine in a predetermined speed relationship to the crankshaft and takes in the rotor 9 during its rotational movement. To vary the relative rotational angular position of the camshafts 1 and 2, however, the rotational angular position of the rotor 9 relative to the stator 3 can be adjusted. The rotor 9 is rotatably connected to the camshaft 2 and as preferred, but only by way of example, with the camshaft 2 axially fixed, ie axially immovable relative to the camshaft 2 connected. The stator 3 is connected against rotation with the camshaft 1 in an anti-rotation engagement, that is, it can not be rotated about the rotation axis R relative to the first camshaft 1.

FIG. 2 shows the phaser in a cross section. The stator 3 is formed as a hollow ring with inwardly projecting in the direction of the axis of rotation R Statorbacken. The rotor 9 accordingly has a rotor hub and rotor blades protruding outward from the rotor hub. The Statorbacken limit circumferentially pressure chambers for a hydraulic pressure fluid. The rotor blades each protrude outwardly between two adjacent stator jaws and each subdivide one of the pressure chambers delimited by the stator jaws into an early setting chamber K ₁ and a late setting chamber K ₂ . If the Frühstellkammern K ₁ is pressurized and relieved the Spätstellkammern K ₂ , the rotor 9 rotates relative to the stator 3 in FIG. 2 clockwise to maximum in the FIG. 2 assumed early position. If the late setting chambers K ₂ are pressurized and the early adjusting chambers K _{1 are} relieved of pressure, the rotor 9 rotates counterclockwise to a maximum of a retarded position. By pressurizing the Frühstellkammern K ₁ , the camshaft 2 is adjusted relative to the camshaft 1 in the direction of advance or "early" because of the rotationally fixed connection with the rotor 9. A relative rotational adjustment in the other direction of rotation corresponds to a delay or adjustment of the camshaft 2 in the direction of lag or "late". The early position and the late position are each specified by a stop contact. In the two end positions, preferably at least one of the rotor blades is in a contact with one of the stator jaws. In preferred embodiments, the rotor 9 can be rotated back and forth not only between these two rotational angle end positions relative to the stator 3, but by corresponding Pressurization of both the Frühstellkammern K ₁ and the Spätstellkammern K _{2 are} hydraulically fixed in any intermediate position.

The phaser S has a with respect to the stator-rotor assembly 3, 9 central control valve 20 with a valve housing 21 and a housing 21 in the valve axially adjustable back and forth arranged valve piston 22. The valve piston 22 is hollow with an axially extending cavity 23. The control valve 20 has a valve inlet P _a at one of the camshaft 2 facing the end and a piston outlet, which passes radially through a cavity 23 surrounding the jacket of the valve piston 22. The valve piston 22 has at its side facing away from the inlet P _a other axial end a coupling member 25 for a coupling with an actuator, which causes the axial displacement of the valve piston 22. The coupling member 25 acts as an actuating plunger of the valve piston 22. The coupling member 25 extends through an end closure wall 26 of the valve housing 21. The end closure wall 26 surrounds the coupling member 25 in close fit and ensures despite the reciprocating coupling member 25 for the fluid-tight closure of the valve housing 21. Das Actuator is exemplified as preferred an electromagnetic actuator, in the embodiment, a Axialhub electromagnet, with a current-carrying coil 27 and an armature 28, which surrounds the coil 27. The coil 27 is rotatably connected to the engine housing M of the internal combustion engine. In the exemplary embodiment, the coil 27 is rotatably connected to a mounting housing 18, which is mounted on the machine housing M and covers the phaser S. The armature 28 is axially movable relative to the coil 27. He is with the coupling member 25 in a coupling engagement, which is formed as an axial pressure contact. When current flows through the coil 27 acts on the armature 28 an axially directed towards the coupling member 25 actuating force acting on the coupling member 25 and thus on the valve piston 20 in the coupling engagement, a pure axial pressure contact.

The control valve 20 comprises a spring member 24 whose spring force counteracts the actuating force of the electromagnetic actuator. The spring member 24 is supported directly on the valve housing 21 and in the direction of the electromagnetic actuator on the valve piston 22. The electromagnetic actuator is controlled by a controller of the internal combustion engine, namely energized. The control is preferably carried out via a stored in a memory of the engine control map, for example, depending on the speed of the crankshaft, the load or other or other relevant for the operation of the internal combustion engine parameters.

Via the inlet P _a is the control valve 20 centrally and in the axial direction of pressurized fluid for controlling the phaser S fed. The pressurized fluid is guided via the shaft arrangement in the central cavity 2a and flows from there axially through the valve inlet P _a into the piston chamber 23. The fluid may in particular be a lubrication of the internal combustion engine serving lubricating oil, which also for lubrication example of a Spurlagers the shaft assembly can serve. The pressurized fluid flows from the piston chamber 23 via passages 23a formed in the jacket of the valve piston 22 as a function of the axial position of the valve piston 22 either via feed channels 9.1 to the early adjusting chambers K ₁ or via feed channels 9.2 to the late setting chambers K ₂ (FIG. FIG. 2 ). The valve housing 21 has through its jacket leading connections for the supply and discharge of the pressurized fluid to and from the adjusting chambers K ₁ and K ₂ . The discharge is used as will be explained an outlet 8. Further details and advantageous features of the control valve 20 are in the aforementioned German patent application DE 10 2010 002 713 and also the other two applications DE 10 2011 004 539 and DE 10 2010 053 685 explained in this regard.

In the exemplary embodiment, the pressurized fluid is supplied via the machine housing M. The mounting housing 18 includes a pressure accumulator 29 for the phaser S, which is connected via a formed in the mounting housing 18 fluid channel 19 to the pressure fluid supply of the machine housing M. If the phase adjuster S does not have its own pressure accumulator, the fluid channel 19 in the attachment housing 18 can be dispensed with. In a modification, the pressure fluid for the phase adjuster S can be supplied to the attachment housing 18, which for this purpose has a pressure fluid connection and preferably also a blocking member upstream of the pressure accumulator. Instead of an external connection to the attachment housing 18, the pressure fluid could also be supplied in a modification via the machine housing M first via the locking member to the accumulator and from this back via the machine housing and the shaft assembly as preferred centrally to the control valve 20.

The phaser S is non-rotatable by means of a connecting member 21 with the second camshaft 2 and, as is preferred, but also axially fixed only by way of example. The connecting member 21 protrudes with a front axial portion in a central cavity 2a of the camshaft 2 and is connected there by means of a screw 14 fixed to the camshaft 2. The connecting member 21 presses the rotor 9 axially fixed against an end wall of the camshaft 2 and thus creates the non-rotatable and axially fixed connection of the rotor 9 and camshaft. 2

The stator 3 is secured against rotation with the first camshaft 1 connected. For the positive connection, a rotationally fixed engagement structure 6 of the phase adjuster S with the stator 3 and an engagement structure 12 which is rotationally fixed with the first camshaft 1 are connected to each other in a rotation-locking engagement based on positive locking. The phaser engaging structure 6 is provided on the phaser housing 3, 4, 5. It runs around the rotation axis R. The camshaft engagement structure 12 also revolves and axially overlaps with the phaser engagement structure 6 in anti-rotation engagement. The engagement structures 6 and 12 can form-lockingly and non-positively engage in the anti-rotation engagement to form a plug connection with each other, but more preferably the Verdrehsicherungseingriff based on positive engagement or at least predominantly on positive engagement, so that the engagement structures 6 and 12 together a sliding joint with the axis of rotation R form as joint axis. The screw connection 14 with the camshaft 2 ensures axial fixing. In the sliding joint of the engagement structures 6 and 12, in such embodiments, possibly required small axial relative movements between the engagement structures 6 and 12 can take place.

The phaser engaging structure 6 is formed on the phaser housing 3, 4, 5 at the end facing the shaft assembly as an axially projecting ring, which is as preferred, but only for example in one piece on the camshaft 1 and 2 facing stator cover 5 is formed. The camshaft engagement structure 12 is formed by the drive wheel 10, in the example on an outer circumference of the drive wheel 10. In reversal of the circumstances, it would also be possible, the engagement peripheral surface as the outer peripheral surface of the phaser engagement structure 6 and the Engagement peripheral counter surface corresponding to form as inner peripheral surface of the drive wheel 10 or a corresponding other, non-rotatable with the camshaft structure 1 structure. The engagement structures 6 and 12 are preferably axially short, stubby, but in principle, other geometries are conceivable. In a modification, the engagement peripheral surface of the engagement structure 6 could also be formed in the axial region of the disk-shaped stator cover 5 instead of on an axially protruding ring. However, the formation of the engagement structure 6 on an externally axially projecting ring or a comparable Abragung has the advantage that in the disc-shaped region of the stator cover 5 pressurized fluid on the axial height of the stator 5 around the shaft assembly resulting cavity in the direction of a pressurized fluid reservoir, for example an oil sump, can be drained. The pressure fluid flowing away from the phase adjuster S is discharged via an outlet 8 which extends in an anti-rotation engagement between the engagement structures 6 and 12, ie the outlet 8 serves to relieve the pressure of the phaser S.

FIG. 3 shows the anti-rotation engagement in a cross section. The engagement structures 6 and 12 are provided at their anti-rotation engagement circumferential surfaces, the engagement peripheral surface and the engagement peripheral counter surface, each with a circumferential about the rotation axis R toothing, the phaser engagement structure 6 with an internal toothing 7 and the camshaft engagement structure 12 with an external toothing thirteenth In one of the teeth 7 and 13, optionally in both teeth 7 and 13, at least one tooth or more preferably a plurality of teeth is flattened, preferably up to the root circle of the respective toothing, so that in the formed as a pure driving engagement Verdrehsicherungseingriff axially through the Verdrehsicherungseingriff extended gaps or at least one gap is formed, which forms or forms the outlet 8. By way of example, to form the outlet 8, as preferred, only the toothing 7 of the phaser engagement structure 6 is provided with one or more flattened teeth or with one or more elongated tooth spaces to form the outlet 8.

The drive wheel 10 forms the camshaft engagement structure 12 in secondary function or dual function. Its primary function is that of a drive shaft for the shaft assembly. The shaft arrangement with the camshafts 1 and 2 is about the with the camshaft. 1 rotatable drive wheel 10 rotationally driven from outside the shaft assembly. In the exemplary embodiment, the conditions are such that a further camshaft 15 or further camshaft arrangement for controlling other valves of the internal combustion engine is mounted parallel to the camshafts 1 and 2 in parallel. The camshaft 15 or shaft assembly 15 is rotationally driven by the crankshaft and drives via a with the camshaft 15 or other shaft assembly rotatably driven gear 16 to the drive wheel 10 from. The wheels 10 and 16 are externally toothed spur gears, which roll with their serrations 11 and 17 in meshing engagement with each other. In modifications of the drive arrangement, it would be conceivable, for example, instead of the rotation prevention engagement according to the invention, to provide the phase adjuster engagement structure 6 with an external toothing in order to drive the stator 3 directly from the output gear 16 in a rolling engagement. For this purpose, only the output gear 16 would have to be extended with its outer teeth 17 in the axial overlap with the engagement structure 6. However, the rotary drive of the phaser S by a non-rolling entrainment, the Verdrehsicherungseingriff invention has significant advantages. There is a pure torque transmission without rolling engagement. The radial tolerance chain is shorter, tolerance problems are thereby reduced. In yet another modification, the output gear 16 could abrade in the rolling engagement only on the phaser S whose engagement structure could also be provided with an external toothing for aborting on the camshaft 1 via the antirotation engagement as in the exemplary embodiment. The disadvantages mentioned, namely the rolling engagement of the phaser S and the extended radial tolerance chain, but also allow such a modification to a drive only on the shaft assembly and the non-rolling, in the driving engagement pure torque transmission to the phaser S inferior appear. Another disadvantage would be the difficult mounting of the phaser S

Namely, according to the invention, the mounting of a phaser at an axial end of a shaft arrangement of nested camshafts 1 and 2 can be simplified and, as a result, the cost can be reduced. The phaser S is largely mounted as a mounting unit on the shaft assembly. The assembly unit comprises the phaser housing 3, 4, 5 with engagement structure 6, the rotor 9 accommodated in the phaser housing 3, 4, 5, and optionally the central control valve 20 with the central connection member 21 forming the same Valve body. This mounting unit will look like FIG. 1 already positioned at the end of the shaft assembly by the phaser engagement structure 6 is pushed into the anti-rotation engagement with the camshaft engagement structure 6. In the positioned state, the connecting member 21 is fixedly connected to the camshaft 2, screwed by way of example. By appropriate shaping of the connecting member 21, the rotor 9 is pressed axially firmly against the camshaft 2 during connection and thereby rotatably and axially fixedly connected to the camshaft 2. Thus, the assembly unit is completely assembled as a whole. All that remains is to attach the attachment housing 18 to the machine housing M. With the attachment of the attachment housing 18 and the electromagnetic part of the control valve 20 is mounted at the same time and the phaser S complete. In order to strengthen the frictional engagement between the camshaft 2 and the rotor 9, a frictional torque increasing friction disc can be arranged between the axial end face located in the frictional engagement. The friction torque can alternatively be increased by filling with a friction mixture containing solid particles, hard particles that dig into the axially facing end faces. Suitable mixtures and Reibverbunde be in the DE 10 2010 003 574.2 described in this regard.

FIG. 4 shows the device in a further longitudinal section. In the longitudinal section is like in FIG. 2 a locking device 30 recognizable. The stator 3 and the rotor 9 are mechanically fixed relative to one another by means of the locking device 30 in a specific rotational angle position in order to prevent oscillations of the rotor 9 relative to the stator 3, in particular in the starting phase of the internal combustion engine. In the exemplary embodiment, the rotor 9 is locked in the early position. The lock in the early position is merely exemplary, although preferred. The locking device 30 comprises a first locking member 31, by way of example in the form of a locking pin, which is axially reciprocally guided axially reciprocally by the rotor 9, and a second locking member 32 which is non-rotatable with the stator 3, for example an engagement opening. The locking member 32 is formed in the phaser housing 3, 4, 5, in the example in the stator cover 5, axially facing on a front side of the locking member 31. In the locking engagement, the locking members 31 and 32 cooperate form-fitting manner. The locking member 31 is biased by a spring member 33 in the locking engagement and can by pressurizing fluid in the Counter direction to be moved from the locking engagement. During the assembly of the phaser S there is expediently the locking engagement.

FIG. 5 shows the device in a modification in which the engagement structure 12 is formed on an end piece 1 a of the camshaft 1. The end piece 1a is a sleeve body, which is rotatably and axially fixedly joined to a pipe section of the camshaft 1, preferably cohesively. The material connection is designated 1b. It is preferably a welded joint, a solder joint would be conceivable. The shaft end piece 1a also forms the drive wheel 10 in one piece with the engagement structure 12.

FIG. 6 shows the phaser housing 3, 4, 5, the rotor 9 and the control valve 20 comprehensive assembly. The assembly unit can be positioned in the illustrated state at the end of the shaft assembly and moved by an axial thrust movement along the axis of rotation R in the direction of the front end of the shaft assembly and thereby the engagement structure 6 are moved in the anti-rotation engagement with the camshaft engagement structure 12. In FIG. 6 extends through the control valve 20 already the stator-rotor assembly, so that the connecting member 21 and valve housing 21 is also moved in the sliding of the engagement structure 6 in the central cavity 2a of the camshaft 2. However, the control valve 20 or the connecting member 21 formed by it can also only be advanced into and through the stator-rotor arrangement 3, 9 into the cavity 2 a, when the anti-rotation engagement is already established. With 21a, a connecting portion of the valve housing or connecting member 21 is designated, which is formed in the embodiment as a threaded portion. The thread is in FIG. 6 but not shown. In FIG. 6 is also the rotational symmetry of the Phasenstellgehäuses 3, 4, 5 recognizable.

FIG. 7 shows a shaft arrangement with a phaser S in a second embodiment. It is again a fluidic phaser of swing vane type with a stator 3 and a rotor 9, which form as described for the first embodiment, early and late adjustment chambers. On average, the FIG. 7 is one of the Frühstellkammern K ₁ and are also one of the feeders 9.1 to the Frühstellkammern K ₁ and one of the feeders 9.2 to the Spätstellkammern recognizable. The Feeds 9.1 and 9.2 lead the pressurized fluid outwardly from a central interior region of the device to the associated early and late staging chambers. The stator 3 forms again with lateral stator lids 4 and 5, the phaser housing 3, 4, 5th

In contrast to the first embodiment, the anti-rotation engagement of the stator 3 and the first camshaft 1 is not formed by serrations, but cooperating crown or face gears 43 and 47. The teeth 43 and 47, as in the first embodiment about the rotation axis R in a uniform pitch completely, d. H. over 360 °, revolve. The toothing 47 is provided on a phase adjuster engagement structure 43 formed on the cover 5, and the toothing 47 is provided on a camshaft engagement structure 41 arranged non-rotatably on the outer circumference of the camshaft 1. During assembly of the phaser S these two engagement structures 41 and 46 act together by means of their teeth 43 and 47 in the manner of a claw or spur gear coupling. The production of the anti-rotation engagement by means of at least substantially axially projecting teeth, or generalized Abragungen, has the advantage that the stator cover 5, which forms the engagement structure 46, with the projecting between the cover 4 and 5 rotor 9 with otherwise the same dimensions in the radial direction can form longer sealing gap 5a than when producing the anti-rotation engagement by means of spur gears, which protrude radially on peripheral surfaces. A radial comparatively long sealing gap could be realized with spur gear teeth only with a complicated producible geometry of the lid 5. Axial projecting engagement elements such as the teeth of the toothing 47 can also be particularly easily formed, for example by compression molding and sintering.

The toothing 47 is in one of the shaft assembly 1, 2 facing, around the rotation axis R circumferential recess of the lid 5 is formed. In the exemplary embodiment, the depression is a shoulder running around the axis of rotation R, which opens axially in the direction of the camshaft engagement structure 41 and radially inwards, ie in the direction of the axis of rotation R. Due to the design of the face gear 46 or a differently shaped engagement surface with axial Abragungen in a recess or an axially recessed portion of the phaser 3, 4, 5, the phaser S can be obtained in an axially short in the field of Verdrehsicherungseingriffs.

The phaser S of the second embodiment has a with respect to the arrangement of the stator 3 and rotor 9 decentralized control valve 35. The control valve 35 is arranged close to the phaser S in the machine housing M, for example a cylinder head or cylinder head cover. The pressurized fluid is controlled by the control valve 35 and supplied in the second embodiment through the region of the central cavity 2a of the camshaft 2 the Frühstell- and Spätstellkammern and discharged from these pressure chambers at pressure relief again.

At the shaft end of the camshafts 1 and 2 supply channels 36 and 37 are formed, which connect the control valve 35 with axially extending connecting channels 48 and 49. The feed channels 36 and 37 are both shown in solid lines. In fact, however, the feed channels 36 and 37 are in the axial direction of the control valve 35, d. H. seen perpendicular to the plane of representation, axially offset from one another. The connecting channel 48 extends in the cavity 2a of the camshaft 2 up to the feeders 9.1, thus connecting them to the control valve 35. The connecting channel 48 extends radially between a central connecting member 45, which due to the decentralized arrangement of the control valve 35 in the second embodiment only The connecting channel 49 extends radially between the outer circumference of the camshaft 2 and an outer circumference immovably joined to the camshaft 2 sleeve structure 42. Both connecting channels 48th and 49 are each formed around the rotation axis R circumferentially as annular spaces.

The cavity 2a is formed in the camshaft 2 as a stepped bore with a phaser S near and open to the phaser S down cavity portion of larger diameter and a distance from the phaser S cavity portion of smaller diameter. In the cavity section of larger diameter, the connecting channel 48 extends. In the exemplary embodiment, the connecting member 45 in the overlapping region with the connecting channel 48 further comprises a shaft portion whose diameter is smaller than the diameter of a adjoining it Shaft portion in the area of the connection with the camshaft 2 consists. However, due to the cavity section widened facing the phase adjuster S, it is not essential that the connecting element 45 additionally has a shank section of smaller diameter in the overlapping area.

44 denotes a shaft seal, which is arranged between the machine housing M and the phaser housing 3, 4, 5 and to seal a space remaining around the anti-rotation engagement between the phaser housing 3, 4, 5 and the machine housing M. In order to dissipate in this space penetrated pressure fluid, so to be able to relieve the pressure in the room, one or more discharge channels can be provided in the machine housing M and open into the room.

The camshaft 1 is rotatably supported on the machine housing M via the engagement structure 41, for which purpose the engagement structure 41 forms a rotary sliding bearing 39 with the machine housing M. Instead of a rotary plain bearing 38, the camshaft 1 could advantageously be supported via the engagement structure 41 in a rolling bearing on the machine housing M. Instead of or in addition to the shaft seal 44, a rotary bearing, for example a roller bearing, could be provided to support the phaser housing 3, 4, 5 of the second embodiment by means of a rotary bearing radially on the machine housing M and thereby relieve the engagement structures 41 and 46 in Verdrehsicherungseingriff.

Another difference to the first embodiment is that in the second embodiment, a drive wheel 40 rotatably connected to the stator 3 and as preferred, but only for example in axial overlap with the stator 3 is arranged so that the shaft assembly 1, 2 via the phaser S is driven in rotation. The stator 3 drives in anti-rotation on the camshaft 1 and also via the rotor 9 to the camshaft 2,

FIG. 8 shows the phaser S facing the end of the shaft assembly 1, 2 without the phaser S, ie before assembly, so that the stepped camshaft cavity 2a is clearly visible. With 2b of the connecting channel 48 surrounding, the sleeve-shaped shell portion of the camshaft 2 is designated after mounting, which extends over the axial length of the cavity portion of larger diameter extends. By means of this jacket section 2b, which is formed in one piece directly by the camshaft 2, the connection channels 48 and 49 in the region of the camshaft 2 are fluidically separated from one another in a structurally particularly simple manner.

Apart from the differences explained, the device of the second embodiment may correspond to that of the first embodiment, so that reference is made to the comments on the first embodiment in this regard.

FIG. 9 shows a shaft assembly 1, 2 with a phaser S of a third embodiment. Comparable with the second exemplary embodiment, a drive wheel 50 drives the camshaft 1 via the stator 3 and the anti-rotation engagement of engagement structures 51 and 56. The engagement structure 51 forms a rotary driver for the camshaft 1. A control valve 35 is arranged according to the second embodiment in the machine housing M. With 54, a shaft seal is referred to, which seals a between the machine housing M and the phaser housing 3, 4, 5 for the rotation-locking engagement remaining space. The phase adjuster housing 3, 4, 5 thus forms, as in the second embodiment, a rotating lid which seals a fluidic part of the device at the axial end of the camshafts 1 and 2. One or more pressure relief passages can be provided in the machine housing M in order to relieve pressure in the space sealed by means of the shaft seal 54.

The camshaft 1 is rotatably supported on the machine housing M in its axial end region close to the phase adjuster S by means of a rotary bearing 39. The rotary bearing 39 is a roller bearing, for example a needle roller bearing. Instead of the rolling bearing 39, however, the camshaft 1 could also, as in the second exemplary embodiment, form a rotary plain bearing with the machine housing M. Instead of or additionally axially adjacent to the shaft seal 54, a rotary bearing could be arranged to support the rotationally driven stator 3 or the phaser housing 3, 4, 5 on the machine housing M. Details of the seal at 54 and the fixed connection of stator 3 and drive wheel 50 are in FIG FIG. 9 recognizable. The Verdrehsicherungseingriff is like also already in the second Embodiment effected by means of crown or face gears 53 and 57, which are formed on mutually facing end sides of the stator 5 and in contrast to the second embodiment directly to the camshaft 1. On the side of the cover 5, the toothing 57 having engagement structure 56 is provided radially inwardly in the form of a ring stub, while the toothing 53 is formed directly on the facing end face of the shell of the camshaft 1. The end of the shell of the camshaft 1 forms the camshaft engagement structure 51.

Also in the third embodiment, the decentralized control valve 35 is connected via in the region of the cavity 2a of the camshaft 2 axially extending connecting channels 58 and 59 with the early and late setting chambers of the phaser S. In contrast to the second embodiment, a sleeve structure 52 is arranged in a diametrically expanded portion of the camshaft cavity 2a, which fluidically separates the connection channels 58 and 59 within the cavity 2a. The connecting channels 58 and 59 can advantageously be formed as circumferentially extending around the rotation axis R annular spaces. The inner connecting channel 58 extends in the third embodiment between the connecting member 55, which corresponds to the connecting member 45 of the second embodiment, and the inner sleeve structure 52. The connecting channel 59 extends between the sleeve structure 52 and the surrounding skirt portion of the camshaft 2. As in FIG. 7 are also in FIG. 9 the supply channels 36 and 37 leading to the connection channels 58 and 59 are shown by solid lines, although the two supply channels 36 and 37 are offset from each other in the axial direction of the control valve 35, ie have a distance from one another perpendicular to the plane of representation.

FIG. 10 shows an example of a preferred embodiment of an engagement structure with axially projecting engagement elements. In the example, it is a crown toothing. In the example, it is assumed that it is the engagement structure 46 or 56 of the phaser S of the second or third embodiment. The toothing as such is denoted by 47 and 57, respectively.

FIG. 11 shows another example of engagement structures with axial Abragungen. In the example of FIG. 11 is Hirth serration in anti-rotation engagement, again using by way of example the reference numerals of the second and third embodiments. Of the phaser engaging structure 46 or 56, only the flat teeth 47 or 57 can be seen, which are in anti-rotation engagement with the corresponding face gears 43 and 53 of the respective camshaft engaging structure 41 and 51 respectively. The teeth 43, 53, 47 and 57 are, as I said by way of example to Hirth gears.

It should be noted that the engagement structures 6 and 12 of the first embodiment can be replaced by engagement structures with axial projections and recesses, in particular by crown or face gears, such as those in Figs FIGS. 10 and 11 illustrated gears. On the other hand, in the second or third embodiment, the remote control valve 35 may be replaced by a centrally located control valve corresponding to the control valve 20 of the first embodiment. The link 45 or 55 would be replaced by the valve housing 21 in such modifications. In particular, with a central arrangement of the control valve, it is advantageous if, as exemplified for the first embodiment, an outlet for the pressurized fluid between the engagement structures 41 and 46 of the second embodiment or the engagement structures 51 and 56 of the third embodiment extends. The connection channels 48, 49, 58 and 59 would be omitted, since the required connections would be made via the central control valve. As in FIG. 9 As can be seen, instead of the stator cover 5, the phase adjuster engagement structure 51 could also be provided on the drive wheel of the phase adjuster S, here by way of example on the drive wheel 50, namely on a support structure of the drive wheel 50.

Reference numerals:

1

first camshaft

1a

shaft end

1b

Retaining compound

2

second camshaft

2a

cavity

2 B

shell section

3

stator

4

Stator

5

Stator

6

Phaser engaging structure

7

gearing

8th

outlet

9

rotor

9.1

feed

9.2

feed

10

drive wheel

11

gearing

12

Camshaft Eingrifisstruktur

13

toothing

14

screw

15

camshaft

16

output gear

17

gearing

18

mounting housing

19

fluid channel

20

control valve

21

valve housing

21a

connecting portion

22

plunger

23

piston chamber

23a

passage

24

spring member

25

coupling member

26

End closure wall

27

Kitchen sink

28

anchor

29

accumulator

30

locking device

31

locking member

32

locking member

33

spring member

34

-

35

control valve

36

feed

37

feed

38

pivot bearing

39

pivot bearing

40

drive wheel

41

Camshaft engagement structure

42

sleeve structure

43

gearing

44

shaft seal

45

link

46

Phaser engaging structure

47

gearing

48

first connection channel

49

second connection channel

50

drive wheel

51

Camshaft engagement structure

52

sleeve structure

53

gearing

54

shaft seal

55

link

56

Phaser engaging structure

57

gearing

58

first connection channel

59

second connection channel

K ₁

Early setting chamber

K ₂

Late parking chambers

M

Engine housing, cylinder head housing, cylinder head

P _a

valve inlet

R

axis of rotation

S

phaser

Claims (15)

1. A device for adjusting the relative rotational angular position of nested cam shafts in a combustion engine, said device comprising:

   (a) a shaft arrangement comprising a first cam shaft (1) and a second cam shaft (2), one of which extends at least in an axial shaft portion in the other, and which can be rotated relative to each other;

   (b) a phase setter (S) which is assembled as an assembly unit on an axial end of the shaft arrangement and comprises a stator (3), which is non-rotationally connected to the first cam shaft (1), and a rotor (9) which can be rotary-driven by the stator (3) and can be adjusted in its rotational angle relative to the stator (3);

   (c) a connecting device (2a, 14, 21; 2a, 14, 45; 2a, 14, 55) which fastens the phase setter (S) to the shaft arrangement in relation to the axial direction and connects the rotor (9) non-rotationally to the second cam shaft (2); and

   (d) a drive wheel (10; 40; 50), which is rotationally fixed to the first cam shaft (1) and the stator (3), for rotary-driving the first cam shaft (1) and the stator (3);

   (e) wherein a cam shaft engaging structure (12; 41; 51), which is rotationally fixed to the first cam shaft (1), and a phase setter engaging structure (6; 46; 56) which is rotationally fixed to the stator (3) are pushed axially into each other in a rotational blocking engagement and connect the stator (3), secured against rotating, to the first cam shaft (1) in a positive fit;
   characterised in that

   (f) the drive wheel (10) forms the cam shaft engaging structure (12).
2. The device according to the preceding claim, characterised in that the stator (3) is a rotationally fixed constituent part of a phase setter housing (3, 4, 5), the phase setter housing (3, 4, 5) is axially fixed on the shaft arrangement by means of the connecting device (2a, 14, 21; 2a, 14, 45; 2a, 14, 55), and the phase setter engaging structure (6) is provided on the phase setter housing (3, 4, 5), wherein in a preferred embodiment, the phase setter engaging structure (6; 46; 56) is arranged on the phase setter housing (3, 4, 5) so as to be accessible from without, such that when the phase setter (S) is assembled, the rotational blocking engagement can be established by an axial movement of the phase setter housing (3, 4, 5) relative to the first cam shaft (1).
3. The device according to any one of the preceding claims, characterised in that:

   - the stator (3) is a rotationally fixed constituent part of a phase setter housing (3, 4, 5);

   - an early setting chamber (K₁) for generating a torque which acts on the rotor (9) relative to the stator (3) in a leading direction, and a late setting chamber (K₂) for generating a torque which acts on the rotor (9) relative to the stator (3) in a trailing direction, are formed in the phase setter housing (3, 4, 5); and

   - in order to generate the respective torque, the early setting chamber (K₁) and the late setting chamber (K₂) can be charged with a pressure fluid in order to be able to adjust the rotational angular position of the rotor (9) relative to the stator (3),

   - wherein the phase setter engaging structure (6; 46; 56) is preferably provided on the phase setter housing (3, 4, 5).
4. The device according to any one of the preceding claims, characterised in that either the first cam shaft (1) can be rotary-driven via the drive wheel (10) and outputs onto the stator (3) in the rotational blocking engagement, such that the phase setter engaging structure (6) forms a rotational slaving means for the stator, or the stator (3) can be rotary-driven via the drive wheel (40; 50) and outputs onto the first cam shaft (1) in the rotational blocking engagement, such that the cam shaft engaging structure (41; 51) forms a rotational slaving means for the cam shaft.
5. The device according to any one of the preceding claims, characterised in that one of the engaging structures (41, 46; 51, 56) comprises a plurality of engaging elements, which project at least substantially axially, in a distribution about the rotational axis (R), and the other of the engaging structures (41, 46; 51, 56) comprises a plurality of engaging counter elements, which are complementary to the engaging elements, in a distribution about the rotational axis (R), and the engaging elements engage at least substantially axially with or between the engaging counter elements in the rotational blocking engagement, wherein the engaging elements and engaging counter elements are preferably teeth or tooth gaps of toothed gearings (43, 47; 53, 57), for example crown or face toothed gearings.
6. The device according to the preceding claim, characterised in that in order to rotary-drive the drive wheel (10; 40; 50), the drive wheel (10; 40; 50) circumferentially comprises a toothed gearing (11), and either the cam shaft engaging structure (12; 41; 51) is provided in addition to said toothed gearing (11), for example on the drive wheel (10), or the toothed gearing (11) comprises an axial portion for rotary-driving and forms the cam shaft engaging structure (12) together with another axial portion.
7. The device according to any one of the preceding claims, characterised in that for hydraulically adjusting the rotational angular position which the rotor (9) assumes relative to the stator (3), the phase setter comprises an inlet (P_a) and an outlet (8) for a pressure fluid and the outlet (8) extends through the region of the rotational blocking engagement between the engaging structures (6, 12).
8. The device according to any one of the preceding claims and at least one of the following features:

   (i) the engaging structures (6, 12; 41, 46; 51, 56) comprise engaging surfaces (7, 13; 43, 47; 53, 57) which extend around a common rotational axis (R) and are in rotational blocking engagement with each other;

   (ii) the engaging structures (6, 12) each comprise an engaging surface (7, 13) about a common rotational axis (R), one of which is formed by a circumferential outer surface (13) and the other of which is formed by a circumferential inner surface (7) which surrounds the circumferential outer surface, wherein the engaging surfaces are not circular as viewed in cross-section and are in rotational blocking engagement with each other;

   (iii) the engaging structures (6, 12; 41, 46; 51, 56) each comprise a toothed gearing (7, 11; 43, 47; 53, 57) about a common rotational axis (R), and the toothed gearings (7, 11; 43, 47; 53, 57), preferably an outer toothed and an inner toothed gearing or crown or face toothed gearings, are in rotational blocking engagement with each other.
9. The device according to any one of the preceding claims, characterised in that the phase setter (S) comprises a control valve (20), which is a central control valve in relation to the stator (3) and the rotor (9), for fluidically adjusting the rotational angular position of the rotor (9), and the control valve (20) is immovably connected to the second cam shaft (2) at the axial end of the shaft arrangement and preferably protrudes into the second cam shaft (2), wherein the control valve (20) is fixedly connected, preferably screwed, to the second cam shaft (2), preferably in a hollow space (2a) of the second cam shaft (2).
10. The device according to any one of the preceding claims, characterised in that:

    - an early setting chamber (K₁) for generating a torque which acts on the rotor (9) relative to the stator (3) in a leading direction, and a late setting chamber (K₂) for generating a torque which acts on the rotor (9) relative to the stator (3) in a trailing direction, are formed in the phase setter housing (3, 4, 5);

    - in order to generate the respective torque, the early setting chamber (K₁) and the late setting chamber (K₂) can be charged with a pressure fluid in order to be able to adjust the rotational angular position of the rotor (9) relative to the stator (3);

    - the connecting device (2a, 14, 45; 2a, 14, 55) comprises a hollow space (2a), which extends in the second cam shaft (2) at one end, and a connecting member (45; 55) which protrudes into the hollow space (2a) and is fixedly connected to the second cam shaft (2) in the hollow space (2a); and

    - a first connecting channel (48; 58) extends axially in the region of the hollow space (2a) radially between the second cam shaft (2) and the connecting member (45; 55), wherein the pressure fluid can be fed to one of the early setting chamber (K₁) and the late setting chamber (K₂) through the first connecting channel (48; 58);

    - wherein the first connecting channel (48; 58) is preferably an annular space which extends circumferentially around the rotational axis (R).
11. The device according to any one of the preceding claims, characterised in that:

    - a sleeve structure (42; 52) is arranged on an end of the second cam shaft (2) facing the phase setter (S) and is non-rotationally connected to the second cam shaft (2);

    - the second cam shaft (2) and the sleeve structure (42; 52) together delineate a second connecting channel (49; 59) through which the pressure fluid can be fed to one of the early setting chamber (K₁) and the late setting chamber (K₂); and

    - the sleeve structure (42) surrounds the second cam shaft (2) and the first connecting channel (48) extends radially between the second cam shaft (2) and the connecting member (45), or the second cam shaft (2) surrounds the sleeve structure (52) and the first connecting channel (58) extends radially between the sleeve structure (52) and the connecting member (55).
12. The device according to any one of the preceding claims, characterised in that the stator (3) is a rotationally fixed constituent part of a phase setter housing (3, 4, 5), and the phase setter housing (3, 4, 5) is supported such that it can be rotated in a rotary bearing (44; 54) on a machine housing (M) of the combustion engine.
13. A phase setter of the device according to any one of the preceding Claims 1 to 12, said phase setter comprising:

    (a) a stator (3) which forms a phase setter housing (3, 4, 5) which is rotationally symmetrical in relation to a rotational axis (R) of the phase setter;

    (b) a rotor (9) which is accommodated in the phase setter housing (3, 4, 5) and can be adjusted in its rotational angle relative to the stator (3) about the rotational axis (R);

    (c) a connecting member (21; 45; 55) for non-rotationally fastening the rotor (9) to the second cam shaft (2);

    (d) and an axially extending phase setter engaging structure (6; 46; 56), which is rotationally fixed to the phase setter housing (3, 4, 5), for establishing a rotational blocking engagement which is based on a positive fit and connects the stator (3), secured against rotating, to the first cam shaft (1) when the phase setter is assembled;

    (e) wherein the phase setter engaging structure (6; 46; 56) is shaped such that when the phase setter (S) is assembled, the phase setter engaging structure (6; 46; 56) can be pushed axially into or onto or against a cam shaft engaging structure (12; 41; 51), which is rotationally fixed to the first cam shaft (1), into the rotational blocking engagement.
14. The phase setter according to the preceding claim, characterised in that the phase setter engaging structure (6; 46; 56) comprises an engaging surface (7; 47; 57) which extends around the rotational axis (R) and is a front-facing surface for an at least substantially axial-only front-facing engagement or is a circumferential surface for a circumferential engagement, wherein the engaging surface (7; 47; 57) is preferably formed by a toothed gearing (47; 57) comprising at least two teeth which project at least substantially axially, at a distance from each other in the circumferential direction, on a front-facing side of the phase setter engaging structure (46; 56) or by a toothed gearing (7) comprising at least two teeth which project radially, at a distance from each other in the circumferential direction, on an inner or outer circumference of the phase setter engaging structure (6).
15. The phase setter according to the preceding claim, characterised in that the rotor (9) comprises at least one rotor vane which projects from a hub of the rotor (9) towards an inner circumferential surface of the stator (3) and sub-divides a chamber, which is delineated in both circumferential directions by the stator (3), into an early setting chamber (K₁) and a late setting chamber (K₂).

Images