WO2007115924A1

WO2007115924A1 - Camshaft drive for an internal combustion engine

Info

Publication number: WO2007115924A1
Application number: PCT/EP2007/052807
Authority: WO
Inventors: Jens Schäfer; Mike Kohrs
Original assignee: Schaeffler Kg
Priority date: 2006-04-08
Filing date: 2007-03-23
Publication date: 2007-10-18
Also published as: DE102006016650B4; DE102006016650A1

Abstract

The invention relates to a camshaft drive for an internal combustion engine. In camshaft drives of this type, a transmitter wheel is usually arranged on that side of the camshaft which faces away from the camshaft adjuster (1), which transmitter wheel communicates with a sensor to detect the rotary angle of the camshaft (6). According to the invention, the sensor is arranged between a wall (8) of the cylinder head and a variable-ratio gear unit (2) of the camshaft adjuster (1), in particular is integrated into an actuator (7). As a result, that end of the camshaft (6) which faces away from the camshaft adjuster (1) can be kept free. Furthermore, simplified mounting of the sensor results together with the actuator (7) or the camshaft adjuster (1), wherein a housing of the actuator (7) or the camshaft adjuster (1) can assume additional protective functions.

Description

Camshaft drive for an internal combustion engine

description

Field of the invention

The invention relates to a camshaft drive for an internal combustion engine, in which a sensor detects a rotational angle of a camshaft (or an angle correlating with the rotational angle), in particular according to the preamble of claim 1.

Background of the invention

Camshaft adjusters can be roughly classified as follows:

A. phase adjuster with an actuator, so a functional unit which engages in the mass flow or energy flow, which is for example formed hydraulically, electrically or mechanically, and rotates with gear elements of the camshaft adjuster.

B. phase adjuster with a separate actuator, ie a functional unit in which from the controller output variable required for the control of the actuator control variable is formed, and a separate

Actuator. Here are the following types:

a. Phase adjuster with a co-rotating actuator and a co-rotating actuator, such as a high-ratio gear, the actuating shaft can be advanced by a co-rotating hydraulic motor or centrifugal motor and can be reset by means of a spring. b. Phase adjuster with a co-rotating actuator and a stationary motor-fixed actuator, such as an electric motor or an electric or mechanical brake, see DE 100 38 354 A1, DE 102 05 034 A1, EP 1 043 482 B1.

c. Phase adjuster with a directional combination of the solutions according to a. and b., For example, a motor-mounted brake, in which a part of the braking power is used, for example, for adjusting to early to tension a spring, which allows the return adjustment after switching off the brake, s. a. DE 102 24 446 A1, WO 03-098010, US 2003 0226534, DE 103 17 607 A1, US 2005 0257761 A1.

For systems according to B. a. to B. c are actuator and actuator connected to each other by means of a control shaft. The connection can be switchable or non-switchable, detachable or non-detachable, free of play or with play and soft or stiff. Also possible is a transmission of torque through an air gap, s. a. US 2005 0257761 A1. Regardless of the design, the adjustment energy can take the form of a provision by a drive and / or a braking power and by utilizing power losses of the shaft system (eg friction) and / or inertias and / or centrifugal forces. A braking, preferably in the adjustment "late" can also be done with full utilization or shared use of the friction of the camshaft. A camshaft adjuster can be equipped with or without a mechanical limitation of the adjustment range. As a gearbox in a camshaft phaser find one or more stages three-shaft gearbox and / or multi-joint or coupling gear use, for example in the form of swashplate gear, eccentric, planetary gear, wave gear, cam gear, Mehrgelenk- or coupling gear or combinations of the individual designs in a multi-level training.

While conventional, hydraulically actuated camshaft phasers or camshaft phasers in the construction with vane, swing or Seg- ment wings have the advantage that

the hydraulic medium can be fed into the camshaft adjuster at any desired point in the camshaft adjuster, the hydraulic medium can be deflected if necessary, and suitable devices for controlling the hydraulic pressure can also be arranged decentrally by the camshaft adjuster can,

is in conventional Nockenwellenverstellem in which the adjusting movement via an electric motor and a superposition gear, three-shaft gear or planetary gear (hereinafter superposition gear) is generated, s. For example, DE 41 10 195 A1, the electric motor usually arranged in alignment with the longitudinal axis of the camshaft and the superposition gearing in front of the superposition gearing. For this reason, build such a camshaft adjuster with an electric actuator and a superposition gear axially larger than corresponding hydraulically actuated camshaft adjuster.

From DE 37 37 602 A1 it is known to use as a superposition gear differential, in which a drive via a standing with the crankshaft in drive connection drive wheel and an output to the camshaft aligned with the longitudinal axis, while the feed of the drive movement of the electric actuator radially the aforementioned longitudinal axis takes place.

From DE 102 60 546 A1 a hydraulic camshaft adjuster is known, to which on the side remote from the camshaft, a vacuum pump can be coupled in alignment with the longitudinal axis.

DE 38 30 382 C1 discloses the drive of a superposition gear axially upstream planetary gear via an electric actuator whose longitudinal axis parallel to the longitudinal axis of the camshaft and the superimposed gearbox is offset.

Known from US 4,747,375 superposition gear is designed as a planetary gear, in which for a first embodiment, the ring gear is driven by a servo motor whose longitudinal axis is arranged parallel to the longitudinal axis of the camshaft, while the sun gear of the planetary gear is in driving connection with the crankshaft of the internal combustion engine and a Output of the planetary gear to the camshaft over the web. For an alternative embodiment, the drive via the servo motor via the sun gear with aligned alignment of the servomotor to the longitudinal axis of the camshaft, while the crankshaft drives the ring gear at output via the web of the planetary gear.

Finally, DE 103 52 255 A1 discloses a coupling of an electric actuator via a flexible shaft, a pneumatic motor, a hydraulic motor, so that the actuator can be arranged at any desired location. Furthermore, the document can be found in the proposal to arrange an electric actuator parallel to the camshaft and to arrange a gear stage between superposition gear and electric actuator.

For the operation of the internal combustion engine, it may be necessary for the rotational or phase angle of the camshaft to be detected by measurement in order to obtain, for example, conclusions about the current setting angle of the camshaft adjuster and the relative angular position of the camshaft with respect to the crankshaft of the internal combustion engine.

DE 602 00 283 T2 relates to a front cover for an internal combustion engine with a camshaft adjuster integrated in the front cover. In the front cover sensors for detecting a rotation angle of the camshaft and additional sensors for detecting the angle of rotation of a crankshaft are present. Furthermore, the front cover carries a control module for the camshaft adjuster, which is in operative connection both with an actuator of the camshaft adjuster and with the aforementioned sensors. According to This document is not to be detected by the sensor of the rotation angle of the camshaft mounted on a cam impulse wheel, but are discharged from a mounted in front of the camshaft adjuster wheel.

From DE 695 18 201 T2 it is known to integrate a sensor for detecting the angle of rotation of a camshaft in a camshaft bearing.

DE 699 02 350 T2 discloses a consideration of an optimal dependency of a setting angle of a camshaft adjuster on an engine speed and a position of an electronic throttle valve. Signals of the camshaft adjuster, a speed sensor associated with the engine and a sensor associated with a throttle valve are supplied to a control device, wherein the control device controls the camshaft adjuster and a fuel injector in accordance with the characteristic map.

From DE 601 02 650 T2 it is known, in addition to a sensor associated with the crankshaft, to use a sensor which has a plurality of sensor elements distributed over the circumference of the camshaft and held by the lateral surface of the camshaft.

According to DE 44 40 656 A1, a camshaft adjuster bears outside its housing a pulse generator wheel, which comes into operative connection with a sensor whose signal is fed to a control device which is responsible for loading the camshaft adjuster and additionally for controlling the fuel supply to the internal combustion engine and a control of the ignition is responsible.

Finally, from DE 101 48 059 A1 a camshaft adjuster is known which has a common carrier unit for the actuators of the camshaft adjuster and two sensors associated with the camshafts. The carrier unit has a flat connection surface to the internal combustion engine, serves as a cover of the internal combustion engine and closes an interior of the internal combustion engine. machine at a passage opening to the outside. The actuators are rotatably connected to the carrier unit, so that the internal combustion engine and the camshaft adjuster in a manner not shown, a rotational movement of the crankshaft must be supplied.

From the not previously published patent application of the applicant with the internal file number of the applicant E 2004 322 and the title "Camshaft adjuster" a camshaft adjuster with a first housing is known, in which an electric servomotor is arranged. A second housing is attached to the outside of the first housing. In the second housing, there is an electronic module, which serves for electrical loading of the control motor. In the electronic module sensors, in particular Hall sensors can be integrated, detect the operating conditions of the servomotor.

Object of the invention

The object of the present invention is to propose a camshaft drive in which a sensor for detecting an angle correlating with a rotational angle of a camshaft is provided

Advantageous integration of the sensor in the camshaft drive, good protection of the sensor against adverse effects and / or contamination and / or

Observe the installation conditions for further components of the internal combustion engine and / or

Consideration of the installation effort and possibly calibration effort.

Summary of the invention

According to the invention the object is solved by the features of independent claim 1. Further embodiments of the invention will become apparent according to the features of the dependent claims 2 to 24 The invention is based initially on the recognition that it is disadvantageous to arrange the sensor for detecting the angle of rotation in the camshaft adjuster opposite end portion of the camshaft. For the separate version of the sensor on the side facing away from the camshaft adjuster side of the camshaft results in a high construction cost with increased mounting requirements including mechanical processing of the resulting interface. Furthermore, an increased effort to protect the sensor to operate, in particular to provide a robust housing which is resistant to spray water and a steam jet. Furthermore, a separate connector for the sensor is required and a supply of the signal of the sensor and a voltage supply for the sensor via separate lines. In most cases, a sensor according to the known embodiments has only a low resolution with approximately 1 to 4 signals per revolution of the camshaft. Tolerances in the distance of transmitter and receiver of the sensor due to manufacturing variations may result in different sensitivities of the sensor.

The aforementioned disadvantages can be avoided according to the invention in that the sensor is arranged in the end region adjacent to the camshaft adjuster. Furthermore, as a result of the arrangement of the sensor in the end region of the camshaft adjacent to the camshaft adjuster, there may be free space in the opposite end region, for example for connecting additional auxiliary devices such as a vacuum pump, which can be driven via the camshaft.

According to the invention, the sensor is arranged inside the housing of the camshaft adjuster. In this context, an "actuator or a housing of the camshaft adjuster" is also subsumed under "the housing of the camshaft adjuster", wherein, for example, the housing of the actuator can be fixedly connected to a further housing part of the camshaft adjuster or the actuator can be supported relative to a cylinder head, while a Connection between a control shaft of the actuator and a transmission ment of the camshaft adjuster is given. The arrangement of the sensor in the housing an automatic position assignment between the housing of the camshaft adjuster and sensor is given, so that for mounting the housing of the camshaft adjuster without further assembly or Justa- steps of the sensor or parts thereof are precisely located at their place of use.

A further simplification can result from the fact that components of the sensor can be fastened to an end region of the camshaft projecting into the housing of the camshaft adjuster. In this case, non-rotatably connected to the camshaft components, such as a frontally screwed via a dowel screw with the camshaft shaft, hub, sleeve, screw or the like, subsumed under the term "end portion of the camshaft". The fact that the components of the sensor are integrated in the Nockenwel- Ie or the end, resulting in a particularly compact design.

Furthermore, according to the invention it is made possible for the sensor to be arranged on the side of the camshaft adjuster facing the cylinder head, which may result in an increase in the possibilities of a structural design and a compact construction space configuration.

In a further embodiment of the camshaft drive according to the invention, the sensor is designed as a Hall sensor, MR sensor or as an induction sensor, in which case a transmitter or a receiver of the sensor is attached to the end region of the camshaft. By "transmitter" in this case, for example, a permanent magnet or a component for generating a variable with the rotation angle of the camshaft magnetic field, for example. A soft magnetic star, or a "standing" behind the receiver arranged permanent magnet understood, while under "receiver" the sensor is understood to mean a component which detects a change in the magnetic field or its orientation and generates a measurement signal in accordance with the change in the magnetic field. Transmitter and receiver are in this case arranged movable relative to each other in dependence on the angle of rotation of the camshaft.

In the event that the transmitter is attached to the end portion of the camshaft, the receiver can be fixed to the housing, which results in particularly good fastening and support options and good supply and removal of the electrical signals is possible.

Otherwise, for attachment of the receiver of the sensor to the end portion of the camshaft, the transmitter can be supported fixed to the housing.

According to a further proposal of the invention, the aforementioned receiver or the transmitter are not supported relative to the housing, but rather against a rotating element of the camshaft adjuster.

A particularly compact embodiment of the camshaft drive according to the invention results when the sensor is integrated in an actuator of the camshaft adjuster.

In the event that the actuator is an electrical system with incoming and outgoing power and / or signal lines, a cable outlet of the sensor can be integrated into the plug connection of the actuator, so that a common supply and / or Discharge of electrical signals from the actuator and the sensor takes place.

In a further alternative or cumulative embodiment, it may be advantageous for reasons of building harnesses or for shortening cable lengths, if the sensor is equipped with a separate plug connection to a housing of the actuator or with a separate cable outlet.

In order not to disturb the signal of the sensor by electromagnetic radiation with an electronically based actuator, in a further embodiment of the invention tion of the sensor to electrical components of the actuator to be shielded. Such shielding can be done for example by sheets, injected films, grids, other screens or shields or by a separate metal housing for the sensor.

Alternatively or cumulatively, it is possible for the measuring signal of the sensor to be fed to a filter, by means of which interference signals due to the electrical components of the actuator are removed from the measuring signal. For this purpose, a filter characteristic of the filter is adapted to the operating characteristics of the actuator. If, for example, an interference frequency of the electric actuator is known, a filtering with the interference frequency can take place in a targeted manner, so that the interference components are filtered out. For example, under certain circumstances, it is possible to find an excitation frequency of the actuator in the measurement signal or an interference frequency which results from a number of pole pairs, a number of windings and / or a rotational speed. Noise signals with the above-explained interference frequencies can be eliminated according to the invention by using the filter.

A particularly good integration of the components of the sensor in the camshaft (or associated, permanently connected to the camshaft components) results when the camshaft (or an associated, fixedly connected to the camshaft component) at least one axial and / or radial recess has, in which a component of the sensor is at least partially integrated. Such recesses can already be produced with the production of the camshaft or be subsequently introduced into the camshaft. A recess can already ensure during manufacture of the camshaft that the component of the sensor is oriented in the desired angular position with respect to the camshaft, without subsequent complicated assembly and / or calibration steps between sensor and camshaft being required. Furthermore, the recess can form a certain protective function for the sensor, for example against mechanical damage, and / or provide a shielding of the component of the sensor. Is the device of the sensor one? Magnetic field generating device or a magnetic field-influencing device such as a soft magnetic sensor wheel, so the camshaft can be exploited for ensuring a particularly good flow.

A multifunctional use of a connector board of the actuator of the camshaft adjuster can then take place when the connector board also serves to supply or discharge the signal line and / or for a voltage supply of the sensor.

In an advantageous embodiment of the camshaft drive according to the invention, a common voltage supply of the sensor and a commutation sensor of the actuator is used, whereby the number of electrical components for a power supply in the camshaft drive for various components can be reduced.

According to a further proposal of the invention, the feed of the drive movement of the actuator in the superposition gear not on the "free end face" of the superposition gear, so on the side facing away from the camshaft, but rather on the camshaft side facing. The invention has in this case recognized that a hydraulically controlled camshaft adjuster usually on the camshaft facing side of the camshaft adjuster existing space for camshaft adjuster with electric actuator and superposition gearbox is unused. This space can thus be used according to the invention. On the one hand, this may be the case if the same internal combustion engine is to be used on the one hand with a hydraulic camshaft adjuster and on the other hand in a variant with a camshaft adjuster with an actuator and a superposition gearbox. On the other hand, such a configuration is also possible for an entire series of an internal combustion engine with actuator. In this case, only the shaft which supplies the superposition gearing can be arranged on the side of the superposition gearing facing the camshaft, or else the entire actuator with an associated control shaft. The free space in hydraulic systems results in particular due to the elimination of transmission elements for a hydraulic medium and suitable control valves.

As a result of the omission of the feed of the drive movement on the camshaft side facing away from the superposition gearing arises on this page free space, which can be used according to a further embodiment of the invention that on this page a shaft is led out, via an auxiliary unit , In particular, a vacuum pump, a gasoline injection pump or an ignition distributor, can be driven. In this case, the shaft can be arranged in alignment or parallel to the longitudinal axis of the camshaft and the camshaft adjuster. The on the side facing away from the camshaft out of the superposition gear shaft can be drivingly coupled with any of the three transmission elements of the superposition gearing, in particular with a sun, a land or a ring gear in the event that the superposition gear is designed as a planetary gear set.

As a result of the configuration according to the invention, in contrast to a series connection of a camshaft, a superposition gear and an electric actuator, axial space can be saved in the above-mentioned sequence, wherein the saving can be up to the axial length of the actuator including an associated control shaft. Furthermore, for the aforementioned series connection of the camshaft, superposition gear and actuator, the support of the actuator - in addition to an already existing wall of the cylinder head, in the region of which the camshaft is mounted and / or a supply of hydraulic fluid for a hydraulic camshaft adjuster takes place - an additional cylinder head fixed Abstützwandung or a corresponding carrier requires, which has nevertheless ensured, for example. Via a suitable opening, the accessibility of the drive wheel of the camshaft adjuster for the traction means of the timing drive. Such an additional wall can be saved according to the invention, so that the camshaft adjuster can be arranged freely accessible on the outer side of the cylinder head. The actuator can be configured as desired, for example as an electric drive unit or as a hydraulic motor, and act as a drive unit and / or as a brake.

According to a further proposal of the invention, the actuator is integrated in an end wall of the cylinder head, resulting in a particularly compact design results in at the same time good support of the actuator.

Preferably, the actuator is arranged adjacent to a first camshaft bearing, where unused space can result from preliminary applications with hydraulic camshaft adjusters.

A particularly compact embodiment of the invention results when the camshaft is passed through the actuator. This can be used radially in the vicinity of the camshaft existing free space for the actuator. Preferably, components, in particular an actuating shaft and an associated rotor of the actuator, designed as a hollow body or hollow shaft through which the camshaft or connecting elements between the camshaft and the camshaft associated with the transmission element are passed.

According to a further proposal of the invention, components of the actuator, in particular the aforementioned control shaft and a rotor associated therewith an actuator, mounted relative to the camshaft. For example, a rolling bearing radially on the inside of the outer surface of the camshaft support and radially outboard on an inner circumferential surface of the rotor or control shaft. UU is supported on such a bearing the entire camshaft adjuster and supported only a stator of the actuator with its housing, for example, with respect to a cylinder head. A bearing of the rotor and actuating shaft of the actuator on the camshaft causes no relative movement is generated in the bearing, as long as no adjustment of the camshaft adjuster takes place. This is advantageous with regard to the thermal and mechanical stress of the bearing.

For a further embodiment of the camshaft adjuster according to the invention, both the rotor of the actuator and the stator of the actuator are supported relative to a front-side cylinder head wall. This can lead to the actuator being designed to be completely sealed, so that no lubricant from the internal combustion engine can enter the actuator. In this case, permanent lubrication of the bearings present in the actuator can be used. The rotor can furthermore be supported via a roller bearing with respect to the stator, which in turn is supported on the front-side cylinder head wall. Such a configuration has the advantage that bearing inaccuracies or manufacturing tolerances, for example between the cylinder head and camshaft or other components, can not affect the function of the actuator. On the other hand, in such a case, the use of bearings with an increased diameter may be required, which may increase the number of rolling elements and the mass of the rotating parts and results in an increased friction radius of the bearings.

According to a development of the camshaft adjuster according to the invention, a longitudinal axis of the actuator, in particular the longitudinal axis of the output shaft of the actuator, is oriented parallel to the camshaft. As a result, the installation space required for the actuator can be displaced further away from the camshaft. It is also possible to interpose between the actuator and the transmission element of the superposition gearing a gear stage, for example, a spur gear, via which the speed ratios and the torque generated in the actuator can be translated appropriately.

Advantageous developments of the invention will become apparent from the claims, the description and the drawings. The advantages of features and combinations mentioned in the introduction to the description a plurality of features are merely exemplary, without these necessarily having to be achieved by embodiments of the invention. Further features are the drawings - in particular the illustrated geometries and the relative dimensions of several components to each other and their relative arrangement and operative connection - refer. The combination of features of different embodiments of the invention or of features of different claims is also possible deviating from the chosen relationships of the claims and is hereby stimulated. This also applies to those features which are shown in separate drawings or are mentioned in their description. These features can also be combined with features of different claims. Likewise, in the claims listed features for further embodiments of the invention can be omitted.

Brief description of the drawings

Further features of the invention will become apparent from the following description and the accompanying drawings in which embodiments of the invention are shown schematically. Show it:

Figure 1 is a schematic representation of a camshaft adjuster according to the prior art, in which an electric actuator on the side facing away from the camshaft of a superposition gear is arranged;

Figure 2 shows an exemplary embodiment of a camshaft adjuster with a swash plate mechanism according to the prior art;

FIG. 3 shows a first embodiment of a camshaft adjuster in which an actuating shaft and an electrical actuator are arranged on the side of the superimposed gearbox facing the camshaft; Figure 4 shows a further embodiment of a camshaft adjuster with arranged on the side facing the camshaft of the superposition gear arranged electric actuator, which is supported via a bearing relative to the camshaft;

Figure 5 shows a further embodiment of a camshaft adjuster, in which a rotor of an electric actuator is mounted relative to a supported in a cylinder head stator;

FIG. 6 shows a further embodiment of a camshaft adjuster in which an electric actuator is arranged eccentrically with respect to a longitudinal axis of the camshaft and a gear stage interposed between the actuator and the superposition gear unit is integrated in the cylinder head;

FIG. 7 shows a camshaft drive according to the prior art, in which a sensor is arranged in the end region of the camshaft facing away from the camshaft adjuster;

FIG. 8 shows a camshaft drive in which a Hall sensor is integrated in an actuator;

9 shows a camshaft drive with an integrated HaII sensor in an actuator, in which a transmitter directly in a radial

Recess of the camshaft is supported;

FIG. 10 shows a camshaft drive in which a component is non-rotatably connected to the camshaft via a fitting screw on the face side and a sensor or receiver of the sensor in a radial direction

Recess of this device is arranged;

Figure 1 1 a arranged in an actuator sensor, the axially sensitive is trained;

Figure 12 shows an integration of a magnetic segment in a recess of a camshaft;

Figure 13 shows an integration of a magnetic ring in a circumferential recess of a camshaft;

FIG. 14 shows an application of a magnet segment in the area of the circumferential surface of a camshaft and of an end face of the camshaft;

Figure 15 shows an application of magnetic rings both in the region of the lateral surface of the camshaft and in the region of the end face of the camshaft;

FIG. 16 shows a longitudinal section of a camshaft with recesses in the area of the lateral surface;

FIG. 17 shows the camshaft according to FIG. 16 in a cross section;

Figure 18 shows a camshaft in longitudinal section with a frontally mounted ring having radial recesses and

19 shows the camshaft according to FIG. 18 in a cross section.

Detailed description of the invention

In the figures, components that correspond in terms of their design and / or function are partially provided with the same reference numerals.

FIG. 1 shows a schematic representation of a camshaft adjuster 1 in which, in a superposition gearbox 2, the movement of two input elements is shown. Menten, here a drive wheel 3 and a control shaft 4 to an output movement of an output element, here a rotatably connected to a camshaft output shaft 5 or directly the camshaft 6, is superimposed. The drive wheel 3 is in driving connection with a crankshaft 56 of the internal combustion engine, for example via a traction means 57 such as a chain or a belt or a suitable toothing, wherein the drive wheel 3 may be formed as a chain or pulley.

The control shaft 4 is driven by an electric control unit or actuator 7, which generates a drive power or acts as a brake. The electric actuator 7 is supported relative to the environment, for example the cylinder head 8 or another motor-fixed part.

Figure 2 shows an exemplary embodiment of a camshaft adjuster 1 with a superposition gear 2 in a swash plate design. A housing 9 is rotatably connected to the drive wheel 3 and sealed in an axial end region via a sealing element 10 relative to the control shaft 4. In the opposite axial end region, the housing 9 is sealed with respect to the cylinder head 8 with a sealing element 11. In an interior formed by the housing 9 and the cylinder head 8, an end portion of the camshaft 6 protrudes. In the interior are also connected via a coupling 12 with the control shaft 4 wobble or eccentric shaft 13, a via a bearing element 14, for example, a roller bearing, mounted swash plate 15 and a hollow shaft 16, via a bearing element 17, for example, a roller bearing, inside is supported in a central recess of the eccentric shaft 13 and a Abtriebskegelrad 18 carries arranged. The driven bevel gear 18 is supported via a bearing 19 relative to the housing 9. Inside, the housing 9 forms a drive bevel wheel 20. The swash plate 15 has on opposite end faces suitable teeth. The eccentric shaft 13 with bearing element 14 rotates about an axis aligned with the longitudinal axis 21-21. The special design of the outer circumferential surface of the eccentric shaft 13 and the bearing element 14 allow the swash plate 15 a rotational movement superimposed on this one rotation of the Longitudinal axis 21 -21 inclined axis. On circumferentially mutually offset portions combing the swash plate 15 meshes on the one hand with the drive bevel gear 20 and on the other hand with the driven bevel gear 18, wherein between the drive bevel gear and driven bevel gear is given over or under-setting. The driven bevel gear 18 is rotatably connected to the camshaft 6.

For the embodiment shown in Figure 2, the hollow shaft 16 is screwed with Abtriebskegelrad 18 via a central screw 22 which extends through the hollow shaft 16, frontally with the camshaft 6. Lubrication with a lubricant, in particular oil, is required in the area of lubrication points 23, 24, which are, for example, at

the contact surfaces between the drive bevel gear 20 and the swash plate 15, - the contact surface between the swash plate 15 and driven bevel gear 18, the bearing 19, bearing element 14 and / or bearing element 17th

can act. For this purpose, a continuous, cyclic, pulsating or intermittent supply and / or forwarding of a lubricant via lubricant channels takes place. Via a Zuführausnehmung 25 of the cylinder head 8, the lubricant is fed to a flow channel 26 of the camshaft 6, which communicates with a flow channel 27, which is hollow cylindrical between an inner circumferential surface 28 of the hollow shaft 16 and an outer circumferential surface 29 of the central screw 22 is formed. Via radial bores 30 of the hollow shaft 16, the lubricant from the flow channel 27 can pass radially outward and are supplied to the lubrication points.

The superposition gearing 2 in the form of a swashplate gear shown in FIG. 2 is merely an exemplary embodiment of such a superposition gearing 2. In FIGS. 3 to 11, the superposition gearing 2 is shown only schematically, with this overlay gearbox 2 about a gear in swash plate design according to Figure 2 or any other superposition gear, s. also the initially classified camshaft adjuster, planetary gear or three-shaft gear, can act. In the case of training as a planetary gear is in the superposition inducing gear elements to

a sun gear, planets mounted opposite a bridge and a ring gear.

For example

the actuator 7 via the control shaft 4 with the web, the ring gear with the drive wheel 3 - and the sun gear with the camshaft. 6

connected.

In an alternative embodiment, the transmission elements producing the superposition are, for example, an axially moved adjusting element, which is acted on by the actuator and cooperates in each case with a drive wheel-fixed thread and a camshaft-fixed thread, cf. For example, EP 1 403 470 A1.

For the embodiment of the invention shown in Figure 3, the control shaft 4 and the actuator 7 are arranged on the camshaft 6 facing side of the superposition gear 2. The electric actuator 7 is supported by a wall 31 of the cylinder head 8. According to Figure 3, the wall 8 has a recess 32 into which the actuator 7 is integrated. Actuator 7 and adjusting shaft 4 are formed concentrically to the camshaft 6, wherein the adjusting shaft 4 is formed as a hollow shaft, which is penetrated by the camshaft 6. The control shaft 4 is on the one hand in drive connection with a rotor of the actuator 7 and on the other hand feeds the drive movement of the actuator 7 over one on the camshaft facing side of the superposition gearing 2 arranged sealed (lubricant closed superposition gearing) or unsealed (lubricant open superposition gearing, eg. Ölschmmierter chain drive) recess, bore or opening in the superposition gear 2 a. The side facing away from the camshaft 6 of the superposition gear 2, as shown in Figure 3, remain free. Alternatively, another unit, in particular a vacuum pump, a petrol injection pump, an ignition distributor or the like, can be driven on this side via a further recess from the housing of the superposition gear 2 and a shaft passing through this recess, the further unit being driven on one side further housing wall 33 or a support may be supported, which is supported or against the cylinder head 8.

For the embodiment shown in Figure 4, the camshaft 6 or a non-rotatably connected thereto connecting element has a cylindrical surface which serves as a bearing surface for a bearing 34, in particular one or more rolling bearings axially one behind the other. On the bearing 34 is supported radially outwardly designed as a hollow shaft actuating shaft 4 from. Preferably, the superposition gear 2 is mounted with the drive wheel 3 via the control shaft 4 by means of the bearing 34. Rotationally connected to the control shaft 4 are two axially limiting the actuator 7 axially outwardly slices 35, 36. The control shaft 4 carries radially outboard a rotor 37 of the Aktua- sector 7, the rotor 37 in a conventional manner by a stator 38, the is supported against the cylinder head 8, driven or braked. In order to enable a rotational movement of the rotor 37 with the adjusting shaft 4, a radial gap 39 is formed between the cylinder head 8 and the radially outer end faces of the discs 35, 36. Undesired lubricant disposed outside the actuator 7 is prevented from entering the interior of the actuator 7 in the axial direction through the gap 39 by the centrifugal force caused by the rotating disks 35, 36.

In the stated storage of the rotor 37 of the actuator 7 on the camshaft 6 occurs no relative movement between the adjusting shaft 4 and the camshaft. 6 on, as long as no adjustment of the camshaft adjuster 1 takes place. This is energetically advantageous in that no electrical energy must be applied to compensate for the friction in the bearing 34 without an adjustment occurs.

In order to make assembly as simple as possible, it is preferable to construct the superposition gear 2 and the electric actuator 7 as a complete unit. This can be done, for example, by means of an elongated hollow-cylindrical actuating shaft 4, on which the rotor 37 is connected in an end region and which extends into the superposition gear 2. Furthermore, unlike the embodiment shown in FIG. 4, it is also possible for the stator 38 to be mounted on the control shaft 4, while an anti-rotation lock is provided between the stator 38 and the cylinder head 8. Due to the arrangement of the bearing 34 directly on the camshaft u. U. a small friction radius can be achieved. Furthermore, u. U. the number of required bearings are reduced, since it is possible that adjusting shaft 4 and rotor 37 are designed without the interposition of additional additional components.

In contrast to the previously described embodiment according to FIG. 4, the setting shaft 4 is not supported by a bearing 34 with respect to the camshaft 6 for the exemplary embodiment shown in FIG. Rather, the control shaft 4 and over this, the superposition gear 2 with drive wheel 3 via two bearings 40, 41 via discs 42, 43 relative to the cylinder head 8 is supported. The discs 42, 43 form in the axial direction terminations of the actuator 7 and are rotatably inserted into the recess 39 of the cylinder head 8. The radially inner holes of the discs 42, 43 receive sealing elements 44, 45 which rest radially inwardly under sealing and ensuring a relative movement of the control shaft 4. The bearings 40, 41 are supported axially outwards in each case on a disc 42, 43 and axially inwardly on the rotor 37. Radially inwardly, the bearings 40, 41 are supported on the outer lateral surface of the control shaft 4, while the bearings 40, 41 radially outwardly on shoulders 46, 47 of the discs 42, 43 are supported. In addition to the illustrated indirect support of the rotor 37 via the discs 42, 43rd can also be a direct support via suitable recordings in the cylinder head. The embodiment illustrated in FIG. 5 represents a completely sealed embodiment, so that no lubricant of the internal combustion engine can penetrate into the interior of the actuator 7. This construction therefore requires u. U. a permanent lubricant supply in the bearings 40, 41 or a seal with Radialwellendichthngen or other sealing elements, eg. Spaltlabyrinthdichtungen. UU are required for a bearing of the rotor 37 in the cylinder head 8 compared to a bearing 34 relative to the camshaft bearing with an enlarged diameter. This increases the number of rolling elements and the mass of the rotating parts. Such a configuration has the advantage that the position of the rotor 37 relative to the stator 38 is influenced only by the manufacturing tolerances of the cylinder head 8 and the games of the bearings 40, 41. However, u. U. the friction radius of the bearings 40, 41, whereby the efficiency of the actuator 7 u. U. is adversely affected. Due to the increased mass of the rotating parts can u. U. also give an increase in the moment of inertia.

For a drive-fixed connection of components of the camshaft adjuster 1 according to the invention, for example a drive connection between the rotor 37 and the actuating shaft 4 and / or a coupling of the control shaft 4 with the associated gear element of the superposition gear 2 are preferably to choose radially small connecting elements. Possibilities for this are, for example, a shaft-hub connection of the type polygon P4C or polygon P3G. It is also conceivable to vulcanize an elastic compensation element in the aforementioned coupling regions. Alternatively or additionally, a magnetic coupling with or without an air gap can be used for a coupling. As a result, a closed design of the engine can be possible. Slippage of the magnetic coupling may be advantageous for a design of an overload protection. UU is a magnetization of the surrounding components, an increase in cost and inertia to accept as well as the fact that metal particles can be attracted to such a magnetization. In solutions according to the invention, the actuators 7 are formed with a hollow output shaft or adjusting shaft 4, so that the camshaft 6 can be passed through the actuator 7. Of particular importance for such a design of the actuator 7, the sealing of the control shaft 4 relative to the environment in the cylinder head 8 or a housing of the superposition gear 2 passing through shaft. For such seals, for example, according to the seals 44, 45, the following configurations may be possible:

Labyrinth seals, helical surface topologies or elements that carry the oil away from the inside of the actuator 7, co-rotating, hurling sheets that spin the lubricant away from critical locations, provide a complete seal of the actuator, e. G. B. in the form of an encapsulation, in which case the mechanical braking or drive power of the actuator 7 can be transmitted by means of a magnetic coupling on the control shaft 4, - a partial sealing functionally sensitive components such as sensors, permanent magnets, winding.

Penetration of lubricant into the actuator may be detrimental if iron particles are present in the lubricant, for example as a result of abrasion. These are attracted by a magnetic field of the actuator 7 and can thus enforce an existing air gap over time or weaken a magnetic field.

While for the embodiments according to Figures 3 to 5, the control shaft 4, which is directly coupled to a transmission element of the superposition gear 2, is designed as the output shaft of the actuator 7 or rotationally fixed or coupled via a suitable coupling with this, is in the illustrated in Figure 6 Embodiment between the adjusting shaft 4 and an output shaft 48th of the actuator 7, a gear stage 49 interposed, which can cause a translation of 1, a transmission or reduction.

For the exemplary embodiment illustrated in FIG. 6, a longitudinal axis 51 - 51 of the actuator 7 is arranged parallel to a longitudinal axis 50 - 50 of the camshaft adjuster 1 and the camshaft 6. According to Figure 6, the gear stage 49 is formed with two meshing spur gears 52, 53, wherein the spur gear 52 rotatably supported on the protruding from the superposition gear 2 end portion of the control shaft 4, while the output shaft 48 of the actuator 7 carries the spur gear 53. The housing of the actuator 7 is arranged in a first recess 54, wherein the output shaft 48 is disposed on the side of the actuator 7 arranged on the superposition gear 2. The first recess 54 opens into a further recess 55 in which the output shaft 48, the associated end region of the control shaft 4, spur gear 52 and spur gear 53 are arranged. The recess 55 may be closed by passage of the actuating shaft 4 and, if necessary, sealing with a cover in the direction of the superposition gear 2.

Further design options for an arrangement and coupling of the camshaft adjuster with its transmission elements, the actuator or electric actuator and the camshaft and u. U. an interposition of other gear stages is the above-mentioned, not previously published prior art of the Applicant.

FIG. 7 shows a camshaft drive 58, in which the crankshaft 56 drives a drive wheel 3 via the traction means 57, which is in driving connection with a camshaft 6 via a camshaft counter 1 with an overlay transmission 2. Detecting the rotational angle of the crankshaft 56 and the camshaft 6 via rotational angle sensors 59, 60, crankshaft 56 and / or camshaft 6 can carry a suitable sender wheel in this end region in the end region remote from the traction means 57. A control unit 61 for the camshaft adjuster 1 is a signal of the electric actuator 7 of the camshaft adjuster 1, the signal of the camshaft 6 zugeordne- th rotational angle sensor 59 and the crankshaft 56 associated with the rotation angle sensor 60 is supplied. In the control unit 61 is a suitable signal for driving the electric actuator 7, for example, a pulse width modulated signal generated. Furthermore, a control unit 62 for the internal combustion engine is present, which is in signal communication with the rotation angle sensors 59, 60 and the control unit 61 and to which an adjuster characteristic field 63 is supplied, in accordance with which the control unit 61 for the camshaft adjuster 1 is suitably influenced. The control units 61, 62 are furthermore connected to a CAN bus system 64 and terminals 65-68, for example "vehicle terminal 15", "vehicle terminal 30", "vehicle terminal 31", "vehicle terminal 50".

The determined angle of rotation is u. U. permanently with the corresponding setpoints, which are stored in a map of the control unit 62 compared. If a deviation between setpoint and actual value is detected, the controlled system of the camshaft adjuster 1 intervenes. However, the two sensors 59, 60 and the determined with these actual camshaft angle can also be used for triggering various other functions in the engine, for example, to determine the injection and ignition timing of selective cylinder. Furthermore, it is possible that existing sensors are used to determine the actual camshaft angle or to increase the resolution and accuracy in the actuator or actuator, for example Hall sensors in a BLDC actuator.

Disadvantages of known embodiments for an arrangement of a sensor are that the sensor head must be made oil-tight, as well as the protruding out of the sensor head part and the connector must be designed splash-proof. Plug connections must be robust and captive. The sensor is usually inserted through a sealed opening in a cylinder head cover and fastened there with a screw. Due to installation tolerances (encapsulated plastic housing, seal between the cylinder head cover and cylinder head), there are differences in the distance to the camshaft fixed encoder wheel and thus in the signal quality, the must be processed by a control unit. For signal processing, an additional line is still required.

Figures 8 to 15 show possibilities for alternative arrangement and integration possibilities of the sensor 59, which can be analogously transferred to the embodiments according to FIGS. 1 to 6.

FIG. 8 shows a part of a camshaft drive 58 with a camshaft 6, in the end face of which a central screw 22 is screwed, by means of which a hinge element 69 of the superposition gear 2 of the camshaft adjuster can be connected in a rotationally fixed manner to the camshaft 6. Radially inwardly of a stator 38 of the electric actuator 7 is at least one sensor 70, in particular a Hall sensor, arranged and supported with a component, in particular the receiver, relative to the stator 38. Another component of the sensor 70, in particular a sensor or signal generator such as a tooth, a tooth gap, a permanent magnet or an electric magnet, is connected to the rotor 37 or non-rotatably connected to the camshaft 6 or the transmission element 69. The electric actuator 7 has a housing 71, which in particular is non-rotatably connected to a housing 72 of the superposition gear 2 or the cylinder head 8.

FIG. 9 shows an arrangement of a magnet segment 73 of a transmitter of a sensor 70 in a radial recess 74 of the camshaft 6, wherein the radial recess 74 is arranged in the area of the end face of the camshaft 6 facing the superposition gearing 2 and opens into the end face. Between the magnetic segment 73 and the receiver 75, a radial distance 80 is formed, which is preferably in the range between 0 mm and 10 mm. The changes in the magnetic field due to the magnetic segment 73 are detected by a receiver 75 and converted into a measurement signal. It is also possible that a simultaneous or staggered detection of multiple relative movements between different transmission elements of the superposition gearing 2 in the electric actuator 7 via a sensor. Support of the sensor 70 can be transmitted via a housing 76 or a carrier, wherein the receiver 75 may be disposed radially outwardly of the carrier or radially inwardly of the carrier. For the embodiment shown in Figure 9, the housing 76 carries radially outboard with the interposition of a rolling bearing 77, the electrical actuator see. 7

For the embodiment shown in Figure 10, the magnetic segment 73 is not arranged in a radial recess of the camshaft 6, but rather in a radial recess of the transmission element 69. In this case, for example, the receiver 75 is radially outwardly supported on an inner circumferential surface of the housing 76 off.

For the embodiment shown in Figure 11, a magnet ring 78 is provided, which is fixed to the superposition gear 2 facing end face of the camshaft and is radially inwardly supported on the outer surface of the transmission element 69. Forming an axial air gap with an axial extent 79, the receiver 75 is arranged adjacent to the magnetic ring 78, which is supported both in the axial direction in the direction of the transitional superposition gear 2 and radially outwardly on the housing or the carrier 76. Preferably, the axial extent 79 of the air gap is in the range between 0 and 10 mm.

FIG. 12 shows the integration of a magnet segment 73 into a radial recess 74 of the camshaft 6. In this way, one or more magnet segments distributed over the circumference can be integrated into the camshaft 6.

FIG. 13 shows the integration of a magnetic ring 78 into an annular groove 81 or a shoulder of the lateral surface of the camshaft 6.

Furthermore, according to FIG. 14, a magnet segment 73 can be fastened radially outward on the front-side lateral surface of the camshaft 6, while a further magnet segment 73a is fastened on the end side of the camshaft 6. For the embodiment shown in Figure 15, a magnetic ring 78 is attached to an outer circumferential surface of the camshaft 6, while a further magnetic ring 78a is attached to the end face of the camshaft 6.

According to FIGS. 16 and 17, evenly or unevenly radial recesses 82 to 85 or grooves can be introduced into the camshaft 6 in the region of which, for example, a magnetic field changes, which can lead to a measurement signal dependent on the angle of rotation and speed. Also possible is the arrangement of a suitable transmitter in at least one of the recesses 82 to 85.

Alternatively, in a frontal collar 86 or paragraph or an annular groove of the camshaft 6, a ring 87 is inserted, in whose outer lateral surface recesses 82 to 85 are introduced. The ring 87 may be formed of a metal or a magnetic material.

The electric control unit or an actuator 7 can act as a brake and / or as a motor, wherein an embodiment of an actuator is fundamentally electrically, mechanically or hydraulically possible.

For the embodiments illustrated in FIGS. 12 to 15, as an alternative to the magnet ring or magnet segment

soft-magnetic elements in the form of rings or segments in the camshaft incorporated gaps or segments ode with the camshaft rotatably connected segment rings, eg. For inductive sensors,

be used.

According to the invention, the sensor 59 is in the actuator 7 or the electric actuator (for example, an electric motor or an electric brake) integrated. This is no longer necessary for the sensor 59, a separate connector. An additional seal and additional attachment of the sensor 59 is not required. Concentric arrangement of the electric actuator 7 about the camshaft 6 usually results in low positioning tolerances than in conventional solutions. The sensor may be integrated such that it is located within a housing of the electric actuator 7 or otherwise secured to this or other parts protruding from the actuator housing. The attachment can also take place outside of the housing in that the sensor 59 is encapsulated with another, protruding from the housing of the electric actuator 7 part with plastic.

It is also possible that the sensor is mounted in separately executed form only on a housing of the actuator in a pre-assembly process. In the case of an arrangement within the actuator, the sensor can be injection-molded together with other components, for example a winding of the stator or an already existing sensor module, together with plastic. In this way, integration of one or more sensors is possible.

Furthermore, it is possible that already used for a commutation sensors of an electric actuator 7 are used to detect the rotational angular position of the camshaft 6. In such a case, a separate sensor 59 for detecting the rotational angle of the camshaft 6 can be omitted entirely.

As a sensor, any sensor can be used, for example, operates on an electrical, optical or mechanical principle, for example, an induction sensor, a Hall sensor or based on a redundancy sensor. The sensor 59 may be radially or axially sensitive.

A signal line for the sensor 59 can be integrated into a connector board for the camshaft adjuster 1. For power supply to the sensor 59, a power supply for a commutation of the electric actuator 7 can be used, so that this power supply is used multifunctionally. The camshaft sensor 59 may be disposed within a housing of the camshaft adjuster 1. It is also possible to use a sensor 59 at the described locations without a housing. Also possible is an embodiment with a soft magnetic "target" on a camshaft-fixed Verstellerbauteil or the camshaft itself. In this case, the sensor 59 and an associated permanent magnet are arranged in the actuator.

The invention relates to the integration of a sensor for detecting the phasing of a camshaft. For this purpose, individual components of a sensor can already be integrated in the actuator or in the control unit of the actuator. Also possible is an integration of a signal processor of a sensor in the control unit of the actuator or on the circuit board of the actuator, so that in a separately executed sensor head only, for example, a Hall probe and a permanent magnet remain. Advantages for this embodiment would be a small space requirement of the sensor as well as lower demands on the signal processor, in particular with regard to the temperature load. Such a signal processor can eg take over a signal conversion analog / digital and / or has various protection mechanisms against overheating, overvoltage, overcurrent or undervoltage.

LIST OF REFERENCE NUMBERS

1 camshaft adjuster 31 wall

2 superposition gear 32 recess

3 drive wheel 33 housing wall

4 control shaft 34 storage

5 output shaft 35 disc

6 camshaft 36 disc

7 actuator 37 rotor

8 cylinder head 38 stator

9 housing 39 game

10 sealing element 40 bearings

11 sealing element 41 bearings

12 clutch 42 disc

13 eccentric shaft 43 disc

14 bearing element 44 sealing element

15 swash plate 45 sealing element

16 hollow shaft 46 paragraph

17 bearing element 47 paragraph

18 output bevel gear 48 output shaft

19 Storage 49 Gear stage

20 pinion gear 50 longitudinal axis

21 longitudinal axis 51 longitudinal axis

22 central screw 52 spur gear

23 lubrication point 53 spur gear

24 lubrication point 54 recess

25 Zuführrausnehmung 55 recess

26 flow channel 56 crankshaft

27 flow channel 57 traction means

28 lateral surface 58 camshaft drive

29 lateral surface 59 rotation angle sensor

30 bore 60 rotation angle sensor 61 control unit

62 control unit

63 Verstellerkennfeld

64 CAN bus system

65 clamp

66 clamp

67 clamp

68 clamp

69 gear element

70 sensor

71 housing

72 housing

73 magnet segment

74 radial recess

75 recipients

76 housing, carrier

77 rolling bearings

78 magnetic ring

79 axial extent

80 distance

81 ring groove

82 recess

83 recess

84 recess

85 recess

86 fret

87 ring

Claims

claims

1. camshaft drive for an internal combustion engine having an actuator (7) and a superposition gear (2) having camshaft adjuster (1) and a sensor (5) for detecting a one with a rotation angle

Camshaft (6) correlating angle, characterized in that the sensor (59) in the region of a superposition gear (2) is arranged and a component (magnetic segment 73, magnetic ring 78) of the sensor (59) on a camshaft adjuster (1) adjacent end of the Camshaft (6) or a camshaft fixed component of the camshaft adjuster (1) is attached.

2. camshaft drive according to claim 1, characterized in that the sensor (59) on the side facing the camshaft of Überlager- tion gear (2) is arranged and a component of the sensor (59) on a camshaft adjuster (1) adjacent end portion of the camshaft (6) is attached.

3. camshaft drive according to claim 2, characterized in that the sensor (59) in the interior of the housing (9; 76) of the camshaft adjuster

(1) or an actuator (7) is arranged and protrudes the component (magnet segment 73, ring magnet 78) of the sensor (59) supporting end portion of the camshaft (6) in the housing (9; 76).

4. camshaft drive according to one of claims 1 to 3, characterized in that the sensor (59) is designed as a Hall sensor, MR sensor or as an induction sensor and a transmitter (magnetic segment 73, magnetic ring 78) or receiver (75) of the sensor (59) is attached to the end portion of the camshaft (6).

5. camshaft drive according to claim 4, characterized in that the non-attached to the camshaft receiver (75) or transmitter (magnet segment 73, magnet ring 78) is supported fixed to the housing.

6. camshaft drive according to claim 4, characterized in that the not fixed to the camshaft (6) receiver (75) or transmitter (magnet segment 73, magnet ring 78) relative to a rotating element of the camshaft adjuster (1) is supported.

7. camshaft drive according to one of the preceding claims, characterized in that the sensor (59) in an actuator (7) of the camshaft adjuster (1) is integrated.

8. camshaft drive according to claim 7, characterized in that signals of the sensor (59) together with electrical signals for the actuator (7) and / or removed.

9. camshaft drive according to claim 7 or 8, characterized in that the sensor (59) with respect to electrical components of the actuator (7) is shielded.

10. Camshaft drive according to one of claims 7 to 9, characterized in that the measuring signal of the sensor (59) is fed to a filter whose filter characteristic is adapted to the operating characteristics of the actuator (7).

11. Camshaft drive according to one of the preceding claims, characterized in that the camshaft (6) has at least one axial and / or radial recess (74) into which a component (magnetic segment 73, magnetic ring 78) of the sensor (59) at least partially integrated is.

12. Camshaft drive according to one of the preceding claims, characterized in that a signal line and / or a voltage supply of the sensor (59) in a connector board of the actuator (7) of the camshaft adjuster (1) is integrated.

13. Camshaft drive according to one of the preceding claims, characterized in that a common voltage supply of the sensor (59) and a commutation sensor of the actuator (7) is used.

14. Camshaft drive according to one of the preceding claims, characterized in that the camshaft adjuster (1) has a superposition gearbox (2) with three gear elements, of which in each case a transmission element of a camshaft (6), a drive wheel (3) and a control unit (7) is assigned, and that an input of the drive movement of the actuator (7) in the superposition gearing (2) on the camshaft (6) facing side of the superposition gearing (2).

15. camshaft adjuster according to claim 14, characterized in that from the superposition gear (2) on the side facing away from the camshaft (6) a shaft is led out, via which an auxiliary unit is driven.

16. Camshaft adjuster according to claim 14 or 15, characterized marked, that the actuator (7) in a wall of the cylinder head (8) is integrated.

17. Camshaft adjuster according to one of claims 14 to 16, characterized in that the camshaft (6) is guided through the actuator (7).

18. Camshaft adjuster according to claim 16, characterized in that components of the actuator (7) relative to the camshaft (6) are mounted.

19. Camshaft adjuster according to claim 18, characterized in that a rotor (37) of the actuator (7) and a stator (38) of the actuator (7) are supported indirectly or directly opposite an end wall of the cylinder head (8).

20. Camshaft adjuster according to one of claims 14 to 19, characterized in that a longitudinal axis (51 -51) of the actuator (7) is oriented parallel to the camshaft (50).

21 camshaft adjuster according to claim 20, characterized in that an output shaft (48) of the actuator (7) via at least one on the camshaft (6) facing side gear stage (49) with a control shaft (4) is drivingly connected.

22. Camshaft adjuster according to one of the preceding claims, characterized in that the sensor (59) generates at least one evaluable for the receiver (75) Lagemerkmal.

23, camshaft adjuster according to one of the preceding claims, characterized in that a computing logic is provided and the logic and logic (59) are configured such that the Lagemerkmal with an accuracy of less than 5 °, preferably less than 1 ° is evaluated.

24. Camshaft adjuster according to one of the preceding claims, characterized in that the calculation logic is integrated in a housing of the receiver (75).