WO2011157541A1

WO2011157541A1 - Friction disc and camshaft adjustment system

Info

Publication number: WO2011157541A1
Application number: PCT/EP2011/058877
Authority: WO
Inventors: Armin Braun
Original assignee: Schaeffler Technologies Gmbh & Co. Kg
Priority date: 2010-06-17
Filing date: 2011-05-31
Publication date: 2011-12-22
Also published as: DE102010024198A1

Abstract

The invention relates to a friction disc (1, 61, 71) for connecting components in a camshaft adjustment system (91), said disc comprising a substantially annular base body (3, 63, 73) with at least one friction surface for bringing into contact with a friction partner. According to the invention, the base body (3, 63, 73) has a contour (5, 65, 75) extending axially that can be connected to a component of the camshaft adjustment system (91). A friction disc of this type permits a sufficiently secure connection with a simplified assembly process between components of a camshaft adjustment system that are to be joined. The invention also relates to a camshaft adjustment system (91) for an internal combustion engine comprising said friction disc (1, 61, 71 ).

Description

Name of the invention

Friction disc and camshaft adjusting system Description

Field of the invention

The invention relates to a friction disc for connecting components in a camshaft adjusting system, having a substantially annular base body having at least one friction surface for contact with a friction partner. Furthermore, the invention relates to a camshaft adjusting system with such a friction disc.

Background of the invention

A camshaft adjustment system serves for the purposeful adjustment of the phase position between a camshaft and a crankshaft in an internal combustion engine. In the installed state, a rotor is usually rotatably connected to the camshaft. Such a rotationally fixed connection is a prerequisite for the trouble-free operation of a camshaft adjuster.

The connection of the individual components of a camshaft adjuster to a camshaft takes place, for example, via a central screw, which fixes the individual components to one another in a force-fitting manner. The forces transmitted in this case are essentially caused by the friction between the interconnected surfaces of the individual components. To increase the friction and friction between the contact surfaces of the components are used. Since friction discs generally reduce the necessary for coupling normal forces, can be coupled by their use in particular also not normally connectable by frictional material pairings with each other. Friction disks of the abovementioned type are known under the trade name "EKagrip®" from ESK Ceramics GmbH & Co KG and are used, for example, in the automotive industry.These friction disks are designed, for example, as thin steel foils with a friction-increasing nickel-diamond coating, which is to be joined However, this shoring is cumbersome because of the low material thickness of the films and also carries the risk that the slides slip or go unnoticed lost.

Object of the invention

It is therefore a first object of the invention to provide a comparison with the prior art improved friction, which allows for a simplified assembly a sufficiently secure connection between components to be joined a camshaft adjustment system.

A second object of the invention is to provide a camshaft adjustment system with such a friction disk.

The object of the invention is achieved according to the invention by a friction disk for connecting components in a camshaft adjusting system, having a substantially annular basic body which has at least one friction surface for contact with a friction partner. It is provided that the base body has an extending in an axial direction contour for connection to a component of the camshaft adjusting system. In a first step, the invention takes into account that a friction disc for the rotationally fixed connection of a rotor with a camshaft must be mounted securely between the components. Due to an inaccurate positioning, for example during a manual insertion, the friction discs could slip during or after assembly or even be lost completely. However, since the presence of a friction disc for the operational safety of a camshaft adjuster is indispensable, securing of the positioning is accordingly imperative. This considerably impedes the installation of a camshaft adjuster.

Furthermore, the invention takes into account in a second step, that in addition to a possible slippage or the loss of a friction disc and the risk of double assembly of friction plates. Since the friction plates have a low material thickness, in order to allow the connection of the component surfaces with each other without additional space requirements, it may hitherto also occur that two friction plates are mounted in the same place. To prevent this, the installation of several slices must be checked by using additional test stations to query the number of friction plates installed. As a result, the assembly costs and the associated costs are additionally increased.

In view of this, in a third step, the invention recognizes that these problems can be overcome when a friction disc having a contour extending in an axial direction is used to connect components. Due to the contour, the friction plate can be fixed in particular by the formation of a plug connection with a mating contour on a component. The friction disc is secured against slipping both during assembly and in the installed state and can be positioned captive especially at a designated location. Both the production and the assembly here is inexpensive and easy to implement. In addition, the contour prevents undesired double assembly of the friction disks. When installed, the contour of the friction disc takes up space, in particular in a counter contour provided for this purpose, which is finally no longer available for receiving a further contour. Thus, an attachment of additional friction plates is excluded at the same position and a costly check for a possible double assembly can be omitted.

Overall, therefore, the necessary security against multiple rebuilding of friction plates as well as the possibility of a rotational fixation on a component with corresponding mating contour can be ensured only by a modified form of friction.

The use of a friction disk takes account of the requirement for a reduction in the effort involved in the assembly of a camshaft adjusting system. Namely, the torques when assembling the camshaft adjusting system can be reduced because of the increased friction by tightening the central bolt. This reduction in torque during assembly also has a favorable effect on the disassembly, for example in the case of servicing, since a lower torque during fastening makes it easier to release the connection.

The friction disc is essentially formed with an annular base body. This embodiment is due to the use as a connecting element between a camshaft and a camshaft adjuster or a rotor given to allow the penetration of the central screw. The diameter of the friction disc can be selected according to the dimensions of the components to be joined. The main body has at least one friction surface for connection to a component of the camshaft adjusting system. The friction surface provides the necessary contact surface to allow an increase in friction between the components. The friction surface can be sized differently depending on the diameter of the components to be connected.

The friction disc is made in particular as a forming part. Here, the contour can be particularly easily introduced by a plastic deformation. The contour may be formed, for example, as a passage, a knob, a recess, a material recess or as a recess. In an advantageous embodiment of the invention, the contour is formed with an axially extending collar. The collar preferably extends in an axial direction. The collar can engage in the installed state of the friction disc in a mating contour of a component. In this case, an interference fit can be formed, which enables a twist-proof and captive attachment of the friction disc. The axial length of the collar may be different, so that it can be matched to the dimensions of a corresponding mating contour.

In a further advantageous embodiment of the invention, the collar is formed on the inner circumference of the main body as a polygon. The polygon, can thus intervene in a mating contour of another component. The polygon is produced in particular by a forming process and allows a simple and in particular rotationally fixed attachment of the friction disc on a component with the corresponding mating contour. Thus, the position of the friction disc is already fixed after assembly. This embodiment also offers the possibility of providing the friction disk with a friction lining, for example, on one side only. On the side of the friction disc, which can be secured over the collar in a counter contour, it does not necessarily require a friction coating.

In a preferred embodiment, the outer diameter of the contour is slightly larger than the inner diameter of the mating contour. Im installed Condition comes as a press fit, which ensures a secure connection of the components to each other.

In a further advantageous embodiment of the invention, the contour is formed in the base body. The contour may in this case be introduced in particular into the friction surface of the friction disk. This contour is thus in particular off-center. It is realized for example as a passage or as a knob with an axially extending collar. Also embodiments with a plurality of passages or nubs is possible. The collar, which is also preferably made by means of a forming, can engage in a mating contour and held there by a press fit. The friction disc is accordingly secured captive.

Thanks to the axial contour of the friction disc just the use of very thin friction plates without the risk of a double mounting is possible because they are fixed captive to a component in the installed state. The low material thickness allows a secure connection of the components in spite of a friction disc located between them. The contact of the component surfaces to each other is still guaranteed.

Conveniently, the friction disc consists of a hard material containing material, in particular of a diamond-containing material. Such friction plates or friction linings provide the necessary hardness to increase the coefficient of friction and an increase in the transferable forces between two components.

The second object of the invention is achieved according to the invention by a camshaft adjusting system for an internal combustion engine, with a rotor, and with a friction disk in accordance with the abovementioned refinements, wherein the friction disk is positioned between the rotor and the camshaft for axial connection of the rotor to a camshaft is.

Such a camshaft adjusting system offers the possibility of using a friction disk, a rotor and a camshaft with low Mounting effort rotatably attached to each other. Thanks to the contour of the friction disc, a double or double mounting is not possible, since the contour assumes the intended space in the installed state, so that it is no longer available for attachment. The installation of an additional friction disc is no longer possible and a complex test can be dispensed with accordingly.

The attachment of the friction disc can be done on the camshaft or on the rotor. Accordingly, either the camshaft or the rotor could be provided with a mating contour for fastening the contour of the friction disk. Regardless of the contour of the friction disc is connected in the installed state with the mating contour of one of the components.

The rotor may be formed, for example, with a substantially circular base body as a sintered component. The number of blades arranged on the main body can be variable depending on the adjustment angle to be set. In principle, it applies here that the more rotor blades are arranged on the rotor base body, the lower is the adjustable adjustment angle. The rotor blades may be attached to the rotor base body as separate components or may preferably be manufactured in one piece therewith.

In an advantageous embodiment of the invention, the main body of the rotor on a counter contour, via which the contour of the friction disc is connected to form a press fit. An attachment of the friction disc on the rotor is advantageous because the camshaft adjuster so pre-assembled, so in particular can be supplied to the customer with a friction disc already attached to the rotor. Since in the installed state, the contour of the friction disc can engage in particular in a mating contour, in a preferably trained in forming a press fit in the mating contour of another component, attachment of a second friction disc with the same dimensions on dersel- ben place not possible. A complex test can be dispensed with, which shortens the process chain during assembly and reduces the costs or can be implemented at least cost neutral. Preferably, an axial recess for disassembly of the friction disc is formed in the main body of the rotor. The recess can be introduced during manufacture, for example during a sintering process without additional effort. When installed, the friction disc is positioned on the main body of the rotor and is undercut by the axial recess. By engagement of a corresponding Abziehwerkzeugs in the axial recess, the friction disc can be easily removed.

Further advantageous refinements can be found in the subclaims directed to the friction disk, which can be correspondingly transferred to the camshaft adjusting system.

Short description of the drawing

In the following the invention is explained in more detail with reference to a drawing. Show

Fig. 1 is a friction disc in a three-dimensional representation in one

Front, as well as in a rear view,

Fig. 2 shows a rotor in a three-dimensional representation

3 shows a rotor unit with a rotor according to FIG. 2 and a friction disk according to FIG. 1 in the mounted state, FIG.

4 shows a section of a friction disc with a contour designed as a passage, 5 shows a friction disk with a contour formed as a knob and a section of the friction disk,

Fig. 6 shows a further embodiment of a rotor in a three-dimensional

Representation, as well

Fig. 7 shows a camshaft adjusting system in the assembled state in a three-dimensional representation.

Detailed description of the drawing

Fig. 1 shows a friction disc 1 in a three-dimensional representation in a front view and in a rear view. The friction disk 1 consists of a diamond-containing material. The friction disc 1 has a base body 3 with a contour 5, which is formed on the inner periphery 7 of the friction disc 1 as a rounded hexagon with an axially extending collar 9.

The contour 5, or the collar 9 of the friction disc 1 extends axially in one direction and is used in the installed state of fixing to another component. This is shown for example in Fig. 2, where the friction disc 1 is fixed to a rotor. The friction disc 1 provides for a non-positive coupling an increase in the coefficient of friction and thus also the transferable forces between two components. By using a friction disc 1 can be ensured in accordance with a rotationally fixed connection in particular between a camshaft and a rotor.

The friction disc 1 is manufactured in a forming process with a material thickness of 0.15 mm. In this case, the contour 5 can be produced simply by a plastic deformation. The outer circumference of the friction disc 1 is formed substantially circular with introduced Materialausnehmungen 1 1, which simplify disassembly. 2, a rotor 21 can be seen in a three-dimensional representation. The rotor has a rotor main body 23 with four radially outwardly extending rotor blades 25. In the installed state, when the rotor 21 is positioned in a stator, the rotor blades 25 serve to divide a pressure chamber of a camshaft adjuster into two hydraulic regions. This is not shown in detail here.

The rotor base body 23 and the rotor blades 25 are manufactured in one piece by a sintering process from a metallic material. The rotor vanes 25 have winged ends 27 which, when installed, bear against the inner circumference of a stator in a camshaft adjuster. As a result, hydraulic pressure chambers are respectively formed on the right and left in the pressure chambers of a stator. Due to general knowledge, however, a detailed description can be omitted here.

The rotor 21 has in its center a bore 29 for a central screw. Through a central screw, which can be seen in Fig. 7, the individual components of a camshaft adjuster are in the installed state with each other and are mounted together axially on a camshaft.

The rotor 21 is further formed with a mating contour 31, in which the contour of a friction disc according to FIG. 1 can be introduced to form a press fit. This can be seen in FIG. The mating contour 31 is formed as a hexagon socket. The diameter of the hexagon socket is slightly smaller than the outer diameter of the contour 45 of the friction disc 1 of FIG. 1, so that a captive and rotationally fixed connection of the two components to each other is possible

In the wing tips 27 grooves 33 are respectively introduced. These grooves 33 serve to receive sealing elements, not shown, which, when installed, bear against the inner wall of a stator and prevent leakage between the hydraulic areas. In the rotor base body 23, an axial recess 35 for disassembly of a friction disc is formed. By engaging a corresponding Abziehwerkzeugs in the axial recess 35, a mounted on the rotor body friction plate can be easily removed.

Furthermore, 23 oil passages are introduced within the rotor body. The oil passages or the bores 37, 39 shown here each serve to apply pressure medium to the pressure chambers of a camshaft adjuster. In the rotor base body 23, a locking bore 41 is additionally introduced. By the locking hole 41, a piston for locking the rotor 21 and a stator in the installed state engage in a locking link and the rotor and the stator in a mutually fixed position, as they hold in particular for the start or idle of a motor.

FIG. 3 shows a rotor unit 51 with a rotor 21 according to FIG. 2 and a friction disk 1 according to FIG. 1 in the assembled state. The contour of the friction disc 1 engages in the mating contour 31 in the rotor base body 23. The axially extending collar 9 of the friction disc 1 is held by a press fit in the mating contour 31.

The friction disc 1 is secured against slipping both during assembly and when installed. It can be positioned captively by the engagement of the contour 5 in the mating contour 31 at this point. In addition, thanks to the design of the friction disc 1 or by the contour 5, a double assembly of the friction plates 1 can be prevented, since in the installed state after attachment of a first friction disc 1 no space for mounting another friction disc is more available. An expensive test with regard to unwanted double mounting can be dispensed with.

FIG. 4 shows a section of a further friction disk 61. A contour 65 designed as a draft is in the base body 63 of the friction disk 61 an axially extending collar 69 shown. The contour 65 is presently designed for engagement in a mating contour, as can be seen in Fig. 6.

The same applies correspondingly to the friction disk 71 according to FIG. 5. The friction disk 71 shown here is formed with a base body 73 into which a contour 75 is introduced. The contour is formed as a knob 77. Also with this design, the attachment of the friction plate 71 on a rotor as shown in Fig. 6 is possible. Thus, by virtue of the configuration of the friction disks 61, 71, the fixation on a rotor with a corresponding counter contour can be ensured. Both friction disks 61, 71 of FIGS. 4 and 5 are made by forming and consist of a diamond-containing material.

In Fig. 6, a rotor 81 is shown in a three-dimensional representation. The difference from the rotor 21 of FIG. 2 lies in the formation of the mating contour 83. The mating contour is introduced in the form of a depression in the rotor base body 23 and allows the formation of a press fit with the contour of a friction disk. For this purpose, the friction disks 61, 71 shown in FIGS. 4 and 5 are particularly suitable, whose respective contours 65, 75 can be joined into the mating contour 83 of the rotor 81 due to their dimensions.

FIG. 7 shows the camshaft adjusting system 91 in the mounted state in a three-dimensional representation. The camshaft adjuster 93 is in this case attached to the camshaft 95. The individual components are assembled one after the other. Here, the rotor 77 is connected on one side with a sealing cover 99 and positioned in a stator 101. The stator 101 is connected to the camshaft side with a locking cover 103. All components are connected to each other via the central screw 105 and mounted axially on the camshaft 95.

Between the rotor and the camshaft, a friction disc is mounted, which is not visible due to the assembled representation. List of reference numbers

I friction disc

3 basic body

5 contour

7 inner circumference

9 axial collar

I I material recesses

21 rotor

23 rotor body

25 rotor blades

27 wing ends

29 bore

31 counter contour

33 grooves

35 axial recess

37 oil channels

39 oil channels

41 locking hole

51 rotor unit

61 friction disc

63 basic body

65 contour

67 axial collar

71 friction disc

73 basic body

75 contour

77 axial collar

81 rotor unit

83 counter contour

91 Camshaft adjusting system

93 Camshaft adjuster

95 camshaft rotor

sealing cover

stator

Locking cover central screw

Claims

claims

1 . Friction disc (1, 61, 71) for connecting components in a camshaft adjusting system (91), having a substantially annular base body (3, 63, 73) which has at least one friction surface for contact with a friction partner, characterized the base body (3, 63, 73) has a contour (5, 65, 75) extending in an axial direction for connection to a component of the camshaft adjusting system (91).

2. friction disc (1, 61, 71) according to claim 1, characterized in that the contour (5, 65, 75) with an axially extending collar (9, 67, 77) is formed.

3. friction disc (1, 61, 71) according to claim 2, characterized in that the collar (9, 67, 77) on the inner circumference (7) of the base body (3, 63, 73) is designed as a polygon.

4. friction disc (1, 61, 71) according to claim 1 or 2, characterized marked, that the contour (5, 65, 75) in the base body (3, 63, 73) is formed.

5. friction disc (1, 61, 71) according to any one of the preceding claims, characterized in that it consists of a hard material, in particular of a diamond-containing material.

6. camshaft adjusting system (91) for an internal combustion engine, with a rotor (21, 97), and with a friction disc (1, 61, 71) according to one of claims 1 to 5, wherein the friction disc (1, 61, 71) for axial Connection between the rotor (21, 97) and the camshaft (95) is positioned.

7. camshaft adjusting system (91) according to claim 6, wherein the rotor (21, 97) has a mating contour (31, 83) through which the contour (5, 65, 75) of the Friction disc (1, 61, 71) is connected to form a press fit.

8. camshaft adjusting system (91) according to claim 6 or 7, wherein in the rotor (21, 97) an axial recess (35) for disassembly of the friction disc (1, 61, 71) is formed.