EP1963626A1

EP1963626A1 - Camshaft adjuster

Info

Publication number: EP1963626A1
Application number: EP06830089A
Authority: EP
Inventors: Mike Kohrs; Jens Schäfer
Original assignee: Schaeffler KG
Current assignee: Schaeffler Technologies AG and Co KG
Priority date: 2005-12-15
Filing date: 2006-11-23
Publication date: 2008-09-03
Anticipated expiration: 2026-11-23
Also published as: DE102005059884A1; CN201206482Y; US8141526B2; US20080283009A1; JP2009519401A; WO2007068561A1; DE502006007612D1; EP1963626B1

Abstract

Impurities of a lubricant in traditional camshaft adjusters can cause a problem, leading to impairments of the function and service life of said camshaft adjuster. According to the invention, flow channel areas are provided in the lubricant circuit, which comprise a dead chamber (37) wherein impurities can be deposited as a result of centrifugal force. Alternatively or additionally, a labyrinth is used to deposit impurities.

Description

Name of the invention

Phaser

description

Field of the invention

The invention relates to a camshaft adjuster for an internal combustion engine, in which lubrication takes place via a flow of a lubricant, in particular according to the preamble of claim 1, 3 or 5.

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 gearbox whose adjusting 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.

For systems according to B. a. to B. c are actuator and actuator connected to each other by means of an adjusting shaft. The connection can be switchable or non-switchable, detachable or non-detachable, free of play or with play and soft or stiff. 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 cam phaser may be equipped with or without a mechanical limitation of the adjustment range. As a transmission 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 a swash plate gear, eccentric, planetary gear, wave gear, cam gear, Mehrgelenk- or Koppfelgetriebe or combinations of the individual designs in one multi-level training.

For an operation of the camshaft adjuster, a supply of a lubricant to lubrication points, in particular bearing points and / or rolling toothing, is required, wherein the lubricant lubrication and / or Cooling relative to each other moving components of the camshaft adjuster is used. To this end, camshaft adjusters have a lubricant circuit which can be coupled, for example, to the lubricant circuit of the internal combustion engine.

It is known from DE 696 06 613 T2 that a control fluid for a vane-type camshaft adjuster may contain foreign substances. If such foreign matter is deposited between wings and a wall of a chamber defining an end position of the wing, a change results in the end position of the wing. This has the consequence that a maximum leading or lagging state of the camshaft adjuster can not be achieved exactly, making it impossible to regulate the valve timing as desired. Furthermore, contaminants may get between the upper portion of a wing and an outer peripheral wall of the chamber, thereby increasing the actuating force for actuation of the camshaft phaser and / or degrading fluid tightness between pressure chambers located on opposite sides of the blade. This can lead to a decrease in the response of the camshaft adjuster.

Furthermore, it is known from DE 40 07 981 C2 to interpose a damper in a camshaft adjuster between a pulley and a camshaft, which serves to receive or absorb torque changes of the camshaft. The damper may in this case be designed as a viscosity damper, which comprises annular labyrinth grooves which are filled with a viscous fluid.

Object of the invention

The object of the present invention is to propose a camshaft adjuster, which is also distinguished by a high degree of operational reliability and / or functionality for a contaminated lubricant in the lubricant circuit. Summary of the invention

According to the invention the object is achieved by the features of claim 1. A further solution of the object underlying the invention results according to the features of claim 3. An alternative or cumulative solution of the object underlying the invention is given by the features of claim 5.

The invention is based on the finding that impurities can lead to malfunctions in the adjustment mechanism. The impurities may be, for example, particles or deposits in the lubricant or the combustion and soiling residues contained in the engine oil. The malfunctions or impairments caused by the contaminants may be, for example,

those according to DE 696 06 613 T2, a blockage of a lubricant channel, a change in the flow cross-sections of a lubricant channel, increased wear and / or - a higher power loss due to dirt particles in the functional surfaces during adjustment

act. Furthermore, the impurities in the adjustment mechanism may be quasi centrifuged, so that a transmission according to the prior art may be contaminated or contaminated.

Furthermore, an embodiment of the invention is based on the recognition that flow channel areas are formed in components of the camshaft adjuster, which are set in rotation in the course of the drive movement of the camshaft and / or in the course of the adjustment movement of the camshaft adjuster. As a result, impurities located in the lubricant with a higher density than the density of the lubricant itself move away radially from the axis of rotation of the component containing the flow channel. gene and radially outwardly from the axis of rotation at a boundary of the flow channel area deposit.

On the one hand, this can result in the contaminants permanently depositing in the flow channel region, as a result of which the structurally predetermined and possibly selectively selected cross section of the flow channel region changes. As a result, a function of the camshaft adjuster impairing change in the flow conditions can be caused.

On the other hand, it is also possible that the only temporarily depositing contaminants are entrained by the flow of lubricant and promoted to functional surfaces of the camshaft adjuster, where they lead to adverse effects. In this case, the deposition at the boundary of the flow channel region can also result in "lumping", which results in an amplification of the undesired impairments.

According to the invention, the above-explained knowledge can be exploited in that a dead space is provided which serves specifically for receiving the undesired impurities of the lubricant. The dead space is in this case with an inlet opening, in particular for feeding, and an outlet opening, in particular for forwarding the lubricant to a functional surface, in lubricant connection. Furthermore, the dead space is formed, at least partially, radially outward from the axis of rotation of the component involved with respect to the inlet opening and the outlet opening. Such a configuration has the consequence that, in the case of a flow of a lubricant through the flow channel region from the inlet opening to the outlet opening, the impurities can be accelerated radially outward into the dead space as a result of a centrifugal acceleration and can deposit in the latter. This avoids that the impurities are supplied via the outlet opening further functional surfaces. Preferably, the dead space between the inlet opening and the outlet opening in the flow channel region is a cross-sectional widening of the same, which u. U. the additional consequence that the flow rate of the lubricant is reduced in the dead space and between the inlet opening and the outlet opening, whereby the effect of the centrifugal acceleration and the promotion of the impurities in the dead space can be increased.

The dead space according to the invention may be, for example, a cross-sectional widening of the flow channel, radially outer tare, a circumferential groove, a radially outwardly oriented recess or the like. If a movement of the impurities in the circumferential direction around the axis of rotation is to be prevented, additional radially oriented partitions may be provided for circumferentially circumferential dead spaces.

The dead space may be configured to receive contaminants throughout the life of the camshaft phaser. In an alternative refinement, the dead space has an additional outlet opening radially on the outside of the inlet opening and the outlet opening. This additional outlet opening is used to remove lubricant with an increased concentration of impurities and / or a removal of impurities arranged in the dead space. Accordingly, the radially inner regions of the dead space serve to forward the lubricant to the outlet opening, from which the lubricant reaches the functional surfaces and the actuating unit, while the radially outer region of the dead space serves to collect and remove the lubricant. In this case, the removal can take place to other partial areas of the camshaft adjuster, for which the risk of damage as a result of contaminants is at least reduced, so that branching of the lubricant flow takes place in the region of the dead space. Alternatively, it is also possible that a kind of "bypass" is formed via the additional outlet opening, by means of which centrifuged lubricant, possibly with an increased concentration of impurities, is guided past the functional surfaces of the camshaft adjuster or is promoted to a special facility for the removal of impurities.

For a further solution of the object underlying the invention, a dead space is provided, which is arranged in the installed state of the camshaft adjuster in a geodetically lower height than the inlet opening and the outlet opening. In this case, the conveying effect of the impurities in the dead space is not due to a centrifugal force due to the rotation of the flow channel area, but rather to the gravity of the impurities, which causes the impurities to deposit downwards, ie into the dead space.

To bring about a conveying effect through the additional outlet opening for the lubricant with the impurities, a centrifugal acceleration can be utilized. In this case, it is advisable that the additional outlet opening is assigned a radially outwardly oriented channel. Alternatively or additionally, the conveying effect can be exploited through the outlet opening on a pressure gradient in the dead space with respect to a downstream, the outlet opening associated channel.

For the solution set out above, in the event that the lubricant arranged in the dead space is to be carried away with the contaminants during operation of the camshaft adjuster, the dead space has an additional outlet opening at a lower geodetic height than the inlet opening and the outlet opening, in which case a conveying effect is achieved by the additional outlet opening by the gravity of the lubricant and the impurities.

Another solution of the object underlying the invention is given by the fact that the flow channel area has a labyrinth area. In this case, the flow of lubricant is passed through a labyrinth. This can result in the lubricant braked and accelerated again or diverted several times

becomes. Higher density contaminants than the lubricant may not be accelerated as quickly as the lubricant itself or deflected so rapidly that the contaminants may deposit in the area of the labyrinth. As a result, a reliable possibility for the deposition of impurities is given. Under labyrinth becomes in this context in particular

a reciprocating, meandering, zig-zag course or course with curvatures of different signs

understood with any orientation to the longitudinal axis of the camshaft adjuster, but preferably with radial or axial orientation to this.

Preferably, the outlet opening of the labyrinth region and / or the inlet opening of the labyrinth region is located radially inwardly with respect to the axis of rotation of the flow channel region and / or in a large geodesic height. Furthermore, a further outlet opening can also be arranged in the area of the labyrinth area, preferably at a low geodetic level or at a large radial distance from the axis of rotation, in order to remove lubricant with impurities.

The dead spaces are, in particular, spaces in which the lubricant is more or less, so that the dead spaces form regions which do not directly represent flow zones of the lubricant. Expediently, such dead spaces can also be arranged in the gearbox itself.

The dead space is preferably as a radial recess in the region of a central Frontal bore of the camshaft and / or a front side of the camshaft receiving hollow shaft arranged.

Advantageous developments of the invention will become apparent from the patent claims, the description and the drawings. The advantages of features and of combinations of several features mentioned in the introduction to the description are merely exemplary, without them necessarily having to be achieved by embodiments according to 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 düng are shown schematically. Show it:

Figure 1 is a schematic representation of a camshaft adjuster;

Figure 2 is a schematic representation of a camshaft adjuster with a swash plate transmission;

3 shows a camshaft adjuster in a schematic representation with a lubricant circuit; Figure 4 shows a camshaft adjuster in a schematic representation with a lubricant circuit, in which a filter element is integrated;

FIG. 5 shows a camshaft adjuster in a semi-longitudinal section with a dead space for depositing dirt particles;

Figure 6 shows a camshaft adjuster in a schematic representation with a lubricant circuit which is equipped both on the input side and on the output side with a throttle and a diaphragm;

Figure 7 shows a camshaft adjuster in longitudinal section with the leadership of

Lubricant in a flow channel;

Figure 8 shows a camshaft adjuster in longitudinal section, in which in a

Flow channel two apertures are connected in series;

Figure 9 shows a phaser in longitudinal section with a patch on a central screw flow element which forms an aperture with an inner circumferential surface of the camshaft;

FIG. 10 shows a longitudinal section of a camshaft adjuster with a diaphragm formed between a hollow shaft and a central screw;

11 shows a camshaft adjuster in longitudinal section with the supply of a lubricant via a crossover cross section from an outlet opening of the cylinder head to an inlet cross section of the camshaft;

Figure 12 shows a further embodiment of a supply of a lubricant to a camshaft and a phaser in a longitudinal section; FIG. 13 shows a further embodiment of a supply of a lubricant to a camshaft and to a camshaft adjuster in one embodiment

Longitudinal section;

Figure 14 further embodiment of a supply of a lubricant to a

Camshaft and a camshaft adjuster in one

Longitudinal section;

Figure 15 further embodiment of a supply of a lubricant to a camshaft and a phaser in a longitudinal section;

FIG. 16 shows a longitudinal section of a camshaft adjuster with different examples of an arrangement of orifices or throttles for influencing the flow of a lubricant;

FIG. 17 is a perspective view of a camshaft adjuster with openings of a housing of the transmission for passage of the lubricant in the form of drops, lubricant mist or sprayed lubricant;

FIG. 18 shows a further spatial view of the camshaft adjuster according to FIG. 17 with further possibilities for openings;

19 shows a camshaft adjuster in the installed state with possibilities for lubrication via drops, a lubricant mist and / or sprayed lubricant and

FIG. 20 shows a camshaft adjuster in the installed state in side view with a drip plate, on which drops of an oil mist are deposited and drop in the direction of the interior of the camshaft adjuster. Detailed description of the invention

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

FIG. 1 shows a schematic representation of a camshaft adjuster 1 in which the movement of two input elements, here a drive wheel 3 and an adjusting shaft 4 (also called a wobble shaft) to an output movement of an output element, in this case a rotationally fixed manner to a camshaft, is connected in a gearbox 2 Output shaft 5 or directly the camshaft 6, is superimposed. The drive wheel 3 is in driving connection with a crankshaft of the internal combustion engine, for example via a traction means 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 adjusting shaft 4 is driven by an electric motor 7 or is in operative connection with a brake. The electric motor 7 is supported relative to the surroundings, for example the cylinder head 8 or another part fixed to the engine.

Figure 2 shows an exemplary embodiment of a camshaft adjuster 1 with a gearbox 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 adjusting shaft 4. In the opposite axial end region, the housing 9 is sealed relative to the cylinder head 8 with a sealing element 1 1. In one of the housing 9 and the cylinder head 8 formed interior 36 protrudes an end portion of the camshaft 6 in. In the interior are further connected via a coupling 12 with the adjusting shaft 4 eccentric shaft 13, a mounted on a bearing element 14, such as a rolling bearing, swashplate 15 and a hollow shaft 16, via a bearing element 17, for example, a roller bearing, inside in a central recess of the eccentric shaft 13 is supported 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 and swashplate rotates about an axis inclined relative to a longitudinal axis 21-21 so that the swashplate meshes with the drive bevel gear 20 on the one hand with the drive bevel gear 20 on the other hand with the driven bevel gear 18, wherein between the counter bevel gear wheel and driven bevel gear is given a transmission or reduction. 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. FIG. 3 shows a schematic lubricant circuit. The lubricant is conveyed from a reservoir 31, for example an oil pan or an oil tank, via a pump 32, for example an engine oil pump, through a filter 33, in particular an engine oil filter, to the feed recess 25 and the flow channel 26 of the camshaft 6. The lubricant leaves the camshaft adjuster 1 or the housing 9 thereof via an outlet opening 34 and is returned to the reservoir 31 again.

In contrast to the embodiment according to FIG. 3, the schematic lubricant circuit according to FIG. 4 has an additional filter element 35. The filter element 35 is preferably assigned to the camshaft adjuster 1 and arranged, for example, after a branch of the lubricant circuit to further components to be lubricated and exclusively associated with the branch of the lubricant circuit, which serves to lubricate the camshaft adjuster. In this case, the filter 35 is arranged as close as possible to the installation location of the camshaft adjuster 1 or in the camshaft adjuster itself. The filter element 35 can serve to keep machining residues in flow channels, which are arranged upstream of the filter element 35, away from flow channels of the cylinder head and the camshaft. Furthermore, production residues and dirt particles in the lubricant can be kept away from the transmission 2 of the camshaft adjuster 1. Furthermore, a diaphragm characteristic or a throttle effect of the filter element 35 can be used selectively in order to influence the flow conditions, in particular the pressure, the volume flow and the speed of the lubricant. The filter element 35 is preferably to be implemented in such a way that it can not clog or become clogged due to the flow conditions in the maximum assumed contamination with particles and dirt during the life of the camshaft adjuster. For this purpose, the arrangement in a riser and / or as a bypass filter is advantageous, for example.

The filter element 35 may, for example, as a sieve, a ring filter, a plug-in filter, - a hat filter, filter plates, filter net or sintered filter

be educated.

According to Figure 5 lubricant is conveyed into an interior 36 of the housing 9, for example according to the embodiments described above, wherein in the interior 36, the lubricant comes into contact with the lubrication points. The inner space 36 is in lubricant communication with a dead space 37, which is arranged at a radially farthest point of the inner space 36. A connection of the dead space 37 to the interior 36 can be formed over a large area over crossing cross sections or via separate channels, via which an access of lubricant and an outlet of lubricant to and from the dead space 37 is possible.

For the embodiment shown in Figure 5, the dead space 37 is formed as a circumferential annular channel. A dead space 37 is, in particular, a space in which the lubricant moves or almost rests at low speeds, so that the dead space 37 is not arranged in an immediate, maximum flow zone of the lubricant. In the dead space 37, the lubricant is subjected to a centrifugal force due to the rotation of the housing 9, whereby heavy components and suspended particles are pressed in the lubricant to the outside and can deposit on a radially outer wall 38 and are not performed back to a lubrication point. It is also possible that the annular dead space 37 is separated in the circumferential direction by intermediate walls, so that a plurality of individual chambers are formed in the circumferential direction, through which prevents the lubricant in the dead space 37 from being able to move in the circumferential direction relative to the housing 9. A deposition of dirt is thus analogous to a rotating centrifuge.

Dead spaces according to dead space 37 may be arranged at any point in the transmission and in the region of the camshaft, which can be achieved that important functional surfaces, for example, in the immediate vicinity of the dead, not "silted" by centrifuged dirt in the transmission. The centrifugal action is enhanced by increasing the distance of the dead spaces from the longitudinal axis 21 -21.

According to a first embodiment, the dead space has no additional outflow, so that centrifuged dirt particles are permanently deposited in the dead space 37. According to the preferred embodiment shown in Figure 5, the dead space has at least one additional outlet opening 39, 40, wherein the outlet opening 39 is axially oriented and the outlet opening 40 is radially oriented. As a result of the radial centrifugal force and / or the pressure conditions in the dead space 37 in comparison to the surroundings of the camshaft adjuster 1, the lubricant with deposited dirt particles moves in the radial direction out of the outlet opening 40, the delivery of the dirt particles being assisted by the centrifugal action , Deviating from this, a delivery through the outlet opening 39 takes place exclusively by the pressure difference in the dead space 37 on the one hand and in the surroundings of the camshaft adjuster 1 on the other hand.

For an alternative embodiment, a dirt separation takes place in that the lubricant is guided in a flow channel labyrinth-like or zigzag. Dirt deposition by such a labyrinthine dirt separator is due to the different inertia of the lubricant and interfering particles in the lubricant. In particular, for high flow rates, a strong deflection of the lubricant flow can cause the particles are not deflected, but deposit at the boundaries of the labyrinth. In the event that individual channels are oriented in the radial direction of the labyrinth, can be done in such channels and also in axial channels a deposit in the labyrinth on radially outer surfaces due to the centrifugal action described above. An alternative or cumulative separation effect may occur when the lubricant is decelerated and accelerated, allowing the lighter lubricant to more readily accelerate while leaving debris behind.

In addition to generating the centrifugal effect due to a rotation of the housing 9 or other parts of the camshaft adjuster 1, the centrifugal effect can be at least partially generated by the fact that the lubricant flow channels are circular or spirally oriented, so that solely by the movement of the lubricant through the curved flow channels can form a deposit on outer boundaries of the flow channels.

In contrast to the exemplary embodiments of a lubricant circuit illustrated in FIGS. 3 and 4, the schematic lubricant circuit has an input-side diaphragm 41 and an input-side throttle 42 and an output-side diaphragm 43 and an output-side throttle 44. The diaphragms 41, 43 and throttles 42, 44 form flow elements for influencing the flow conditions in the lubricant circuit. The aforementioned flow elements are associated with a parallel lubricant path, which acts exclusively on the camshaft adjuster 1. Preferably, the flow elements are arranged close to or at least partially in the camshaft adjuster 1, the camshaft or a cylinder head in the region of a bearing for the camshaft.

The orifices 41, 43 and throttles 42, 44 can be used to throttle the volume flow to the camshaft adjuster. An additional throttling can result from the use of the filter element 35. Advantageously, the filter element is arranged in the flow direction upstream of the flow elements, so that the flow elements are not blocked by particles. be added or over time.

In addition to the use of flow elements with constant flow properties, a continuously or step-variable flow element can be used. It is possible to use a flow element whose flow effect

as a function of an engine speed, coupled to a delivery volume of the pump 32 and / or - depending on the temperature of the camshaft adjuster 1 or the lubricant

is variable, said changes can be automatically generated in a mechanical manner or by a suitable control or regulating device which acts on the flow element.

A change of the flow element takes place, for example, such that the volume flow of the lubricant is kept at a constant value, regardless of a temperature of the lubricant. It is also possible that the volume flow is increased or decreased by influencing the flow element in operating areas in which a higher lubricant or cooling demand or a lower such need exists.

For the design of the flow elements in the form of throttles 42, 44 and diaphragms 41, 43 u. U. implement embodiments in which annular gaps or annular cross-sections are used instead of holes with, for example, circular cross-sectional area, as a hole u. U. easier clog than an annular gap.

For the embodiment shown in Figure 7, a supply of lubricant via a plurality of bores 45 of the camshaft 6, wherein the bores 45 are inclined relative to the longitudinal axis 21 -21 and the radial orientation. The camshaft 6 has an end blind bore 46, the merges with a cone-shaped chamfer 47 in a thread for receiving the central screw 22. The holes 45 open into the chamfer 47. In the opposite end of the chamfer 47, the holes 45 are fed by a supply groove of the cylinder head 8 with the lubricant. Approximately centrally in the bore 45, a radial circumferential recess 48 is introduced with rectangular in the longitudinal section shown geometry.

A portion of the bore 48 and bore 46 to the groove 48 supplied lubricant passes through an axial bore 49 of the camshaft 6, which opens into the recess 48, and one with a certain overlap, but radially offset axial bore 50 of the housing 9 in the Interior of the transmission 2 to the lubrication points, for example to the bearing element 17, the bearing element 14, the rolling tooth connections of the swash plate 15 and / or the storage 19th

The other part of the recess 48 supplied lubricant passes through a formed between the inner surface of the hollow shaft 16 and the outer surface of the central screw 22 flow channel 51 with annular cross section to at least one radial bore 52 to a lubrication point, for example, the bearing 17 or in the interior of the transmission 2. The recess 48 is formed with a radial extent, which extends beyond the bore 49, so that radially outwardly a circumferential annular dead space 37 is formed. A transition region 53 in the form of a recess, a radial groove or the like can be formed between the bores 49, 50 in order to allow the passage between the radially offset bores 49, 50. In the form of non-aligned bores 49, 50, a type of aperture can be created for a partial overlap of the bores with a small transitional cross section or aperture cross section, although the bores 49, 50 can be made in themselves with relatively large diameters and thus coarse tools ,

In the case of an otherwise identical embodiment, the extension of the hollow shaft 16 in the longitudinal direction of the embodiment shown in FIG. tion extended such that the hollow shaft protrudes into the recess 48. Between a circumferential edge 54, which is formed by the inner lateral surface of the bore 46 and a recess bounding the transverse surface 55, and an edge 56 which is formed by the outer lateral surface 57 of the hollow shaft 16 and a front face 58 of the hollow shaft 16, a shutter is formed for passage of the lubricant from the bore 46 to the groove 48th

In accordance with FIG. 9, the camshaft 6 according to FIG. 9 has no puncture 48. The bores 49, 50 and the transition region 53 are not provided for the exemplary embodiment according to FIG. 9, so that the lubricant from the bore 46 is completely in the flow channel 51 is supplied. In the annular flow channel, which is formed in the bore 46, which has a rectangular half-section and which is bounded radially inwardly by the lateral surface of the central screw 22 and by an end face 58 of the hollow shaft 16, a flow element 59 is arranged, which is at a striped over the central screw 22 ring, for example, plastic or an elastomer can act. For the embodiment shown in FIG. 9, the flow element 59 has an approximately T-shaped half-longitudinal section, wherein the transverse leg of the T lies radially inward on the lateral surface of the central screw 22 under elastic pressure, while the vertical leg of the T extends radially outward and the front of this leg forms an annular gap 60 with the bore 46, whereby a diaphragm is created.

In a different embodiment, the flow element 59 may, for example, be clamped radially outward against the bore 46, in which case an annular gap 60 is formed between the inner surface of the flow element and the central screw. A positive reception of the flow element 59, for example in a suitable groove of the camshaft or the central screw, is also conceivable. Any configuration of the contour of the flow element 59 in the region of the annular gap 60 for influencing the flow conditions is possible, for example with gradual transition. or continuous transitions.

For the embodiment shown in Figure 10, the hollow shaft 16 in the region of the flow channel 51 has a radial, circumferential recess 61 which is limited on the chamfer 47 side facing by a radially inwardly facing, circumferential radial projection 62. Between the projection 62 and the lateral surface of the central screw 22, an annular gap 63 is formed, which constitutes a diaphragm. The recess 61 forms a dead space 37 radially on the outside, since both the annular gap 63 and the flow channel 51 open radially inward from the dead space 37 into the recess 61.

The camshaft 6 is supplied with lubricant from a lubricant gallery of the cylinder head 8. The transfer of the lubricant from the engine-fixed cylinder head 8 to the rotating camshaft 6 is generally carried out by means of known rotary joints. This is usually an annular groove 64 of the outer surface of the camshaft 6. The annular groove 64 is surrounded by a corresponding cylindrical surface 65 of the cylinder head 8, to which an axially aligned with the annular groove 64 tap hole 66 leads from the lubricant gallery. The stub hole 66 can break the lateral surface 65, as shown in Figure 1 1, radially or break them, for example, tangentially.

A rotary transformer can be arranged in a radial bearing for the camshaft 6 or on a separate shoulder. In the latter, however, because of the usually larger radial gap often sealing rings 67, 68, for example, a steel, cast iron, plastic sealing ring required. In an arrangement of the rotary transformer in a radial bearing of the camshaft 6, it should be noted that the bearing width is reduced by the width of the annular groove.

In a further embodiment, annular grooves can be executed in the form of a cylinder head, for example in the bearing, the bearing bridge or an inserted bearing bush. In the camshaft then no annular grooves 64 are required. The use of a rotary transformer described above causes due to the circumferential annular groove and the radial bores 69 which connect the annular groove 64 with the bore 46, a continuous flow of lubricant from the cylinder head 8 in the camshaft. 6

For a particular embodiment, the tap hole 66 and the annular groove 64 are arranged offset from one another in the axial direction, whereby a kind choke is already created upon passage of the lubricant from the tap hole 66 to the annular groove 64, the opening cross section is smaller, the greater the offset in the axial Direction between tap hole 66 and ring groove 64 is. A throttle effect can be achieved here also for a relatively large diameter of the tap hole 66 and a large width of the annular groove 64, so that no dirt-sensitive and production-sensitive small holes or grooves must be created.

According to a particular further embodiment, the lubricant is supplied via a cyclic lubricant supply. In such a case eliminates the annular groove 64, so that a lubricant connection between the tap hole 66 and the holes 69 is given only for such rotational positions of the camshaft 6, for which the holes 66, 69 are aligned or have an overlap. If enlarged transfer times are desired, the cylinder head 8 or the lateral surface of the camshaft 6 may have a groove running over part of its circumference in the transition region between the tap hole 66 and the bore 69, so that passage from the tap hole 66 to the bore 69 is possible as long as possible these holes 66, 69 are interconnected by the groove. Furthermore, the transfer of the lubricant can be made variable via the design of the width profile of the groove. Thus, a volume flow and mass flow of the lubricant can be specified constructively and cyclically. Further, a pulsating lubricant flow can be effected, which results in pressure fluctuations, which can be used for example for a better mixing and wetting of the lubrication points with the lubricant. Furthermore, can By pulsating lubricant flows, the risk of blockages, for example, of diaphragms or chokes, be reduced. If such lubricant pulsations lead to pulsation oscillations in the lubricant circuit, then a check valve can be arranged in the lubricant circuit, in particular in the region of the cylinder head 8, in the region of the camshaft and / or in the transmission.

FIG. 12 shows an exemplary embodiment in which lubricant 2 is supplied to the transmission 2 via a radial blind hole 70, an axial blind hole 71 of the camshaft opening into the blind bore 70 and a taphole 72 of the housing 9. A simplification of the assembly results when in the transition region between the holes 71 of the camshaft and the bores 72 of the housing 9, a circumferential annular groove 73 is provided, whereby the holes 71, 72 need not be aligned coaxially with each other during assembly.

FIG. 13 shows an exemplary embodiment which essentially corresponds to the exemplary embodiment according to FIG. 9, although no flow element 59 is provided.

Figure 14 shows an embodiment in which the annular groove 64 is connected via a relative to the longitudinal axis 21 -21 and the transverse axis inclined bore 74 directly to the annular channel 73.

For the embodiment shown in Figure 15, the direct connection of the annular channel 73 and the annular groove 64 via a front side introduced into the camshaft, opening into the annular groove 64 and the annular channel 73 pierced bore 75 takes place.

In addition to the design measures for the design of the flow cross sections in the cylinder head and in the camshaft influencing the flow conditions in the lubricant circuit in the transmission is possible. This can be a throttling of the inlet bore through the use of a throttle or aperture. Alternatively or cumulatively, the throttling of the process by a rear closing of the transmission, for example with a sheet metal lid, possible, which forms an annular gap, in particular with a gap height in the range of 0.1 to 2 mm, together with the adjusting.

Moreover, it is possible to use bearings in the gearbox, which are equipped with sealing elements. According to FIG. 16, an annular channel between hollow shaft 16 and central screw 22 has a ring width in the range of 0.2 to 1 mm. The radial connection bores between this flow channel and the interior of the transmission preferably have a diameter between 0.5 and 3 mm. Further influencing or throttling or diaphragms can take place by specification of the axial and / or radial gaps 76, which can be predetermined in terms of design and form flow cross sections or diaphragms or throttles for the lubricant.

According to a further embodiment of a camshaft adjuster 1, the outer circumferential surface of the housing 9 has recesses or windows 77, which may be distributed uniformly or non-uniformly in the circumferential direction, cf. FIG. 17.

Figure 18 shows further possibilities for the arrangement of recesses or openings 78 in the region of an end face of the camshaft adjuster 1. A transmission of the lubricant via the camshaft can be omitted if a lubricant through the openings 78, 77 is supplied to the transmission 2. For example, the lubricant can be conveyed through the openings 77, 78 via a lubricant syringe. Such a lubricant syringe may be arranged on the cylinder head or on a chain case. In the simplest case, a lubricant syringe may simply be a lubricant bore from which a fine jet of lubricant exits and which impinges on a point outside the transmission or within the transmission, for example through the openings 77, 78. In particular, such a point may lie as close as possible to the axis of rotation in the interior of the transmission. Due to the centrifugal force acting on the lubricant in the rotating system the lubricant is distributed to the outside to the lubrication points, for example to a bearing and / or to the toothing.

In addition, the arrangement of the openings 77, 78 of the transmission housing, the lubricant can be sprayed directly onto a toothing or other lubricant sites. It is also conceivable that the spraying with lubricant is combined with the lubricant supply to other engine components, for example a chain or a tensioner. E- it is also conceivable that a point or an area outside the transmission 2m is sprayed with the lubricant. Lubrication is then ensured by the rebounding or reflected lubricant or lubricating mist generated thereby.

According to an alternative embodiment, a supply of lubricant can take place via the lubricant mist which is present in any case in a chain case and can penetrate through the openings 77, 78 into the camshaft adjuster.

In a further embodiment of a lubricant supply according to Figure 20, a drip tray 80 is provided outside of the transmission, on which the lubricant mist condenses and drips. Alternatively or additionally, special drip lubricant nozzles can be provided, which are specifically aligned in the direction of the openings 77, 78.

In order to reliably ensure the function when lubricating with a lubricant mist, with drops of lubricant or with a jet of lubricant even at low temperatures of the lubricant or during a cold start, the lubrication points, such as plain bearings and / or gears, be equipped with emergency running properties. Such emergency running properties can, for example

by a coating of the functional partners or by introducing lubricant reservoirs be guaranteed. In particular, the lubricant reservoirs are provided by microscopic or macroscopic small pockets of lubricant locations in which lubricant may be stored for cold start or at low lubricant temperatures. Better emergency running properties may preferably also be present if rolling bearings are provided at the bearing points as far as possible.

For lubrication, an oil dripping from an oil-lubricated traction means (timing chain) can furthermore be used which passes through an opening in the housing. The traction means u. Lubricated by a dip or Spritzbeölung or by stripping oil from oiled Kettenspanner- or deflecting rails. Part of the oil thus transported by the chain can drip off above the drive wheel (sprocket) of the transmission and so get into underlying openings of the transmission. Furthermore, it is possible to convey oil by capillary action to the gearbox or overlying drip points. It is also possible for oil to be absorbed by air currents, e.g. resulting from the drive movement of Steuertriebs- or adjuster parts, quasi "blown" to the lubrication point. LIST OF REFERENCE NUMBERS

1 camshaft adjuster

2 gear 3 drive wheel

4 adjusting shaft

5 output shaft

6 camshaft

7 electric motor 8 cylinder head

9 housing

10 sealing element

11 sealing element 12 clutch

13 eccentric shaft

14 bearing element

15 swash plate

16 hollow shaft

17 bearing element

18 output bevel gear

19 storage

20 pinion gear

21 longitudinal axis

22 central screw

23 lubrication point

24 lubrication point

25 feed recess

26 flow channel

27 flow channel

28 lateral surface

29 lateral surface

30 hole

31 reservoir

32 pump

33 filters

34 outlet opening

35 filter element

36 interior

37 dead space

38 wall

39 outlet opening

40 outlet opening

41 aperture

42 throttle

43 aperture

44 throttle 45 hole

46 blind hole

47 chamfer

48 puncture

49 bore

50 hole

51 flow channel

52 bore

53 transition area

54 edge

55 transverse surface

56 edge

57 lateral surface

58 front side

59 flow element

60 annular gap

61 puncture

62 advantage

63 annular gap

64 annular gap

65 lateral surface

66 tap hole

67 sealing ring

68 sealing ring

69 bore

70 blind hole

71 blind hole

72 tap hole

73 ring channel

74 bore

75 bore

76 gap

77 opening 78 opening

79 front side

80 drip tray

81 gap 82 partial area

83 subarea

84 flow channel

87 flow channel area

86 outlet opening 85 inlet opening

Claims

claims

First camshaft adjuster (1) for an internal combustion engine for maintaining and adjusting a relative angular position between a drive element (drive wheel 3) and an output element (camshaft 6), wherein the drive element (drive wheel 3) and the output element (camshaft 6) via a transmission (2) are interconnected and lubrication via a flow of a lubricant through a flow channel region (87), characterized in that the flow channel region (87) has an inlet opening (85), an outlet opening (86) for the lubricant and a dead space (37 ), which is formed radially outwardly of the inlet opening (85) and the outlet opening (86) possesses.

2. Camshaft adjuster according to claim 1, characterized in that the dead space (37) radially outboard of the inlet opening (85) and the outlet opening (86) has an additional outlet opening (39, 40).

3. camshaft adjuster (1) for an internal combustion engine for maintaining and adjusting a relative angular position between a drive element (drive wheel 3) and an output element (camshaft 6), wherein the drive element (drive wheel 3) and the output element (camshaft 6) via a transmission (2 ) and a lubrication via a flow of a lubricant through a flow channel region (87), characterized in that the flow channel region (87) an inlet opening, - an outlet opening for the lubricant and a dead space in the installed state of the camshaft adjuster in geodesically lesser Height is arranged as the inlet opening and the outlet opening, has.

4. Camshaft adjuster according to claim 3, characterized in that the dead space in a lower geodetic height than the inlet opening and the outlet opening has an additional outlet opening (area smaller V, radially far outside).

5. Camshaft adjuster (1) for an internal combustion engine for maintaining and adjusting a relative angular position between a drive element (drive wheel 3) and an output element (camshaft 6), wherein the drive element (drive wheel 3) and the output element (camshaft 6) via a transmission (2) are interconnected and lubrication via a stream of lubricant through a flow channel region (87) takes place, in particular camshaft adjuster according to claim 1 and / or claim 3, characterized in that the flow channel region has a labyrinth region.

6. Camshaft adjuster according to claim 5, characterized in that the labyrinth region has an additional outlet opening, which is arranged radially outboard or at a lower geodetic height than an inlet opening and an outlet opening of the flow channel area.

7. Camshaft adjuster according to one of the preceding claims, characterized in that the transmission (2) is designed as a swash plate mechanism.