WO2018077349A1

WO2018077349A1 - Disc for a wet friction clutch

Info

Publication number: WO2018077349A1
Application number: PCT/DE2017/100915
Authority: WO
Inventors: Pascal Carl; Lucas BRAUN
Original assignee: Schaeffler Technologies AG & Co. KG
Priority date: 2016-10-26
Filing date: 2017-10-25
Publication date: 2018-05-03
Also published as: DE112017005389A5; DE102016221008A1

Abstract

The invention relates to a disc for a wet friction clutch, characterized by a disc body (11) made of aluminum with a radial outer or inner toothing (4), wherein the disc body (11) has on one or both sides a lining (12) made of a material that is harder than aluminum.

Description

Slat for a wet friction clutch

The invention relates to a blade for a wet friction clutch.

Such friction clutches, also called multi-disc clutches, serve to transmit the torque delivered, for example, by an internal combustion engine from the drive side via one or more disc packs to the output side. For this purpose, two radially intermeshing, usually potted components are frictionally connected to each other by means of steel and friction blades. The radially outer component, the outer disk carrier, in this case carries the outer disks, the radially inner component, the inner disk carrier, carries the inner disks. The outer disks are connected to an external toothing positively connected to the outer disk carrier axially movable on this, while the inner disks are positively connected via an internal toothing with the inner disk carrier, also on this axially movable. Depending on the coupling concept, either the outer disks are designed as steel disks and the inner disks as friction disks, or vice versa.

If there is a frictional connection within the disk set comprising a plurality of outer and inner disks, heat is generated, which is why it is necessary to cool the disk set. For this purpose, grooves are usually introduced into the friction linings of the friction disks, usually consisting of an annular carrier with friction linings applied on both sides. Through these grooves, even when the clutch is actuated, that is, when the disk set is compressed, the fluid coolant, usually oil, flow, that is, the oil flows through the disk pack from inside to outside. This can dissipate the heat generated in frictional contact.

The steel blades, on the other hand, are made of steel and have a certain amount of thermal mass to absorb the energy generated by frictional engagement, that is, they heat up. The resulting heat is stored in them and must be used for cooling. be discharged to the oil. Important in this context, therefore, is the heat transfer from the steel plates to the coolant. In addition, to avoid excessive heating of the steel plates, it is possible to increase the fin mass, so the steel mass, so that more heat can be stored, whereby the load on the coupling decreases. However, this increases the mass moment of inertia, which adversely affects the coupling operation.

The invention is therefore based on the problem to provide an improved blade.

To solve this problem, a slat for a wet friction clutch is provided according to the invention, which has a lamella body made of aluminum with a radial outer or inner toothing, wherein the lamellar body on both sides has a coating of a material harder than aluminum.

The blade according to the invention consists in its core of aluminum, so not as usual from steel. The lamellar body made of aluminum is provided with the coupling to the outer or inner disc carrier-making outer or inner toothing, it forms the essential lamellar part. Since aluminum is a relatively soft material, but the blade during operation occurs in frictional engagement with the or adjacent friction plates, according to the invention the aluminum plate body is provided on both sides with a coating which is made of a harder material than aluminum. So there is a sandwich lamella, which has a number of advantages. On the one hand, aluminum is a material that has a low density and a high thermal conductivity, that is, it is much lighter than steel and also has a much better thermal conductivity. The low weight means that the lamella - be it an outer lamella or an inner lamella - has a lower mass, so that the mass moment of inertia of the lamella is significantly reduced compared to an ordinary steel lamella. The better heat conductivity compared to steel is advantageous for a much better heat dissipation into the coolant. On the other hand, the hard coverings applied on both sides ensure that the lamella will withstand the frictional stress in coupling operation without further ado, despite the soft lamella body or core made of aluminum. Overall, the blade of the invention allows better heat dissipation and thus better cooling and thus an improved heat balance within the friction clutch, combined with a very low weight and thus a significantly low moment of inertia, compared with conventional steel blades, at the same time high stability against the given during operation Reibbeanspru- chung.

The disk body may be provided on one side with a coating. This is possible with the lamellae on the outside lamellae, as they reach only on one side in frictional contact with an adjacent friction plate, while the other side is either counteracted to an abutment, or actuated via an actuating element, such as a pressure pot, for compressing the disk set becomes. In any case, arranged inside the disk pack lamellae are provided on both sides with a covering, as they reach both sides in frictional contact with a friction plate. Of course, it is conceivable that the outer slats are equipped on both sides with such a covering.

As regards the one or more provided on the disk body pads, so different configurations are conceivable. Thus, according to a first alternative of the invention, a coating may be a layer applied to the lamella body or produced thereon. That is, the aluminum fin body is coated on one or both side surfaces. Such a layer may be, for example, a ceramic coating, a layer which is characterized by a very high hardness. Such a coating can be applied in a CVD or PVD process. Alternatively, such a layer may also be an anodization layer which is produced via an anodizing bath on the lamellar body. Such an anodization layer is characterized by a sufficiently high hardness. As an alternative to applying or producing a coating forming the coating, it is conceivable to apply to the disk body on one or both sides a covering disk forming the lining. Consequently, the lamella consists of two or a maximum of three individual parts, namely the lamellar body made of aluminum and one or two sealing ring disks, in particular steel ring disks. Here, too, forms a sandwich structure, after - as in the case of coating - the lamellar body forms the core, while this is occupied on one or both sides with lining or steel discs. The pad or steel discs may be connected by gluing, riveting or embossing with the plate body, that is, they are firmly attached to the plate body, so that a torque transmitting frictional engagement with the or the friction plates can be received. An expedient embodiment of this embodiment variant with one or two steel annular disks provides that one or more grooves forming in the joined state from the inner circumference to the outer circumference are provided on the outer surfaces of the disk body and / or the surface of a steel annular disk facing the disk body. The lamellar body and / or the one or both steel annular discs are thus provided with radially extending grooves. If the steel disc or both steel discs are axially placed on the plate body and connected to it, the respective grooves are axially closed, only radial channel openings remain open, so that the total lamella are formed radially continuous channels through which additionally the fluid coolant, ie the oil can flow. Over this an improvement of the lamellar cooling can be achieved. If corresponding grooves are provided both on the lamellar body and on the steel ring disk, these can complement one another in the assembled state to form a common channel, but they can also be closed by the respective surface of the opposite part, so that a correspondingly increased number of channels results ,

To the total mass of the lamella, which is already significantly reduced compared to conventional steel fins, due to the use of the aluminum lamellar body anyway, To further reduce it is expedient if the covering, in particular the or each layer or the or each steel ring disc has a thickness of <1 mm. This means that the layer or steel annular disc thickness is designed to be as thin as possible with a view to maximizing the reduction of the fin mass. Such a thickness is sufficient to easily withstand the frictional load over the life of the clutch.

As already described, in the embodiment of the lamella with steel ring disks arranged on one or both sides, it is possible to form channels in the area of the contact surface between the lamella body and the steel annular disk, through which coolant can flow. In order to be able to form corresponding cooling channels in the embodiment of the lamella with the aluminum lamellar body with the one or both sides applied layer such as the ceramic o- or the anodization, or in the embodiment of the lamella with one or two steel annular discs alternative or additional To be able to realize cooling ducts, provides an expedient development of the invention, that the lamellar body consists of two annular discs, wherein one or both annular discs on the one or more facing surfaces one or more, in abutting state from the inner periphery to the outer circumference extending channels forming grooves , According to this embodiment of the invention, therefore, the fin body is divided axially. One or both of the lamellar body forming annular discs are provided with corresponding grooves extending from the inner periphery to the outer periphery. If now the two annular disks are pushed against one another, then the grooves are closed by the opposite disk surface, so that corresponding channels with radial openings are formed, these channels extending through the disk body itself. That is, the coolant in this case flows directly through the fin body, which provides for even further improvement in the cooling effect.

The two annular discs can be firmly connected to each other, which can be done, for example, by welding, gluing, riveting or embossing. It is also conceivable, however, to mount the two washers as individual parts. Each of the annular disks is provided on an outer surface with the coating, be it the coating such as the ceramic coating or the like, be it with a steel ring disk. The Ring disks are arranged adjacent to each other on the outer or inner disk carrier, but as loose components. During operation of the coupling device, when the formed plate pack is compressed, the two annular discs are pressed against each other. In this case, the grooves formed on or against each other pressed annular disks are closed to form the channels. This means that the channel formation takes place when it is needed, namely when the disk set is closed. In the unloaded, open state, the individual annular discs separate again, so that the channels are opened again. The lamella has on the lamella body a corresponding external or internal toothing, with which it engages positively in corresponding teeth on the outer or inner disc carrier. About this gear engagement, the torque to be transmitted is transmitted via the clutch. The external and internal teeth of the aluminum lamellar body are mechanically loaded. Since, as already described, aluminum is a significantly softer material compared to steel, an expedient development of the invention provides that the edge of the lamellar body which has the external or internal toothing and is not provided with the lining has a greater width than that with the surface Covering provided portion of the lamellar body. This means that the external or internal toothing of the disk body is made axially broadened. Over this, the surface pressure on the outer or inner toothing can be reduced because due to the axial enlargement of the toothing, the contact surface of the outer or inner toothing to the respective toothing of the outer or inner disc carrier is larger and thus distributed the force respectively the pressure over a larger area ,

The invention will be explained below with reference to embodiments with reference to the drawings. The drawings are schematic representations and show: FIG. 1 a schematic representation of a friction clutch, with only the

External disk carrier, the inner disk carrier and the outer and inner disks arranged thereon are shown, a partial perspective view of a Lamel le invention of a first embodiment with applied on an aluminum lamellar body on both sides coatings, an exploded view of two composed of a lamellar body of a blade according to the invention a second embodiment forming annular discs in a perspective partial view of the annular discs of Figure 3 composite lamella, a Friction clutch comprising the blades of Figure 4 in the form of the outer disks, an exploded view of a blade according to the invention a third embodiment with a blade body and both sides arranged thereon steel annular disks, a sectional view through the composite blade of Figure 6, an exploded view of a blade according to the invention a third embodiment, similar from Figure 6, but with a provided with two-sided grooves lamellar body, a sectional view through the composite Slat from Figure 8, and Figure 10 is a schematic representation of a friction clutch comprising lamellae according to Figure 9 in the form of outer plates. FIG. 1 shows a friction clutch 1 according to the invention, comprising an outer disk carrier 2, outer disks 3 guided axially thereon. The outer disks 3 have a radial external toothing 4, with which they engage in corresponding axially extending toothing grooves 5 in a conventional manner.

The friction clutch 1 further comprises an inner disk carrier 6, on which a plurality of inner disks 7 in the form of friction disks, each comprising a carrier 8 with both sides applied thereon friction linings 9, are also guided axially movable. For this purpose, the carriers 8 have a corresponding toothing 10, which engage in a corresponding axially extending toothing groove 22 on the inner disk carrier 6. The structure of such a friction clutch is well known.

According to the invention in the friction clutch 1 of Figure 1 slats are provided, which are designed as sandwich slats. In the exemplary embodiment shown, these are the outer disks 3. These basically consist of a disk body

1 1 made of aluminum, which in the examples shown on both sides with a covering

12 is provided. Both the lamellar body 1 1 of aluminum and the pads 12 may be of different design or type, which will be discussed below. In known per se operation of such a friction clutch, the disk lenpaket consisting of the outer disk 3 and the inner disk 7 via an unspecified shown actuator, usually a pressure pot, against an abutment, also not shown pressed, so that the disk pack compressed and compressed is and it comes to a frictional engagement between the outer disk 3 and the inner disk 7. By way of this, a torque can be transmitted from the outer disk carrier 2 to the inner disk carrier 6.

Figure 2 shows in the form of a perspective view of an inventive outer plate 3 of a first embodiment, wherein the same reference numerals are used for the same components. Already at this point it should be noted that all versions apply equally to an inner plate 7, which can also be carried out according to the embodiments described below, but is provided with a radial internal toothing. In this case, then the outer plates would be the friction plates. FIG. 2 shows an outer disk 3 with the disk body 1 1, which has the radial external toothing 4. The lamellar body 1 1 is made of aluminum, so a relatively soft material, compared with conventional steel plates used previously. In order to reduce the surface pressure in the region of the toothing engagement of the toothing 4 in the toothing groove 5 on the outer disk carrier 6, the aluminum disk body 1 1 in the radial edge region, ie axially widened in the region of its outer teeth 4, so that widened teeth and thus a larger Yielded contact surface.

Otherwise, the soft aluminum lamellar body 1 1 on both sides with a coating 12 forming coating 13 is provided, which is, for example, a ceramic layer or an anodization. This coating 13 is substantially harder than the soft aluminum that binds the lamella core. The coating 13 comes into frictional contact with the inner disks 7 and the friction linings 9, so completes the frictional engagement. However, the coating 13 is so hard that it does not cause any friction-related wear. The thickness of the coating 13 should be <1 mm. If the outer disks 3 shown in FIG. 2 are installed in the friction clutch 1 shown in FIG. 1, then the large-volume aluminum core, which has a very good thermal conductivity, ensures a very rapid heat transfer, so that there is a very fast heat transfer between the outer disks 3 and the inner disks 7 Friction, which leads to a heating of the outer disk 3 respectively of the disk body 1 1, very quickly to the coolant, usually an oil that flows through the disk pack can be discharged. In addition, the respective outer disk 3 is due to the low weight of the aluminum lamellae 1 1 also relatively easy, so that the moment of inertia within the disk pack is significantly reduced. FIG. 3 shows a further embodiment of a blade 3 according to the invention, which here consists of two separate annular disks 14, 15. The two annular discs 14, 15 are axially pushed together at least in the assembly position, so that the mutually facing surfaces 16, 17 touch. As FIG. 3 clearly shows, grooves 18, 19 extending radially from the inside to the outside are provided on these surfaces 16, 17. These grooves open on the inner circumference and on the outer circumference. Now, if the two annular discs 14, 15 pushed together in the context of assembly, so either the grooves 18, 19 can complement each other, so overlapping one another, and form a common channel, which passes through the outer plate 3 radially. Alternatively, the respective surface 16, 17, the respective groove 18, 19 on the opposite annular disc 14, 15 overlap and cover, so that the respective groove 18, 19 forms the respective, the outer plate 3 continuous channel.

As FIG. 3 also shows, each annular disc 14, 15 has one half of the toothing 4, that is to say that the respective toothed sections on the annular discs 14, 15 complement each other with common teeth.

A sectional view through such a composite outer fin 3 is shown in FIG. Since the grooves 18, 19 open at the inner circumference, fluid coolant, ie oil, which flows from the inner disk carrier 6 to the inner circumference of the outer disk 3, can thus flow into the respective groove 18, 19 and flow through the same and exit at the outer circumference. The coolant thus flows through the lamellar body 1 1 itself, about which a very good heat dissipation can be achieved.

In this embodiment too, the annular disks 14, 15 are provided on their outer sides with a respective coating 13 forming the lining 12, which in turn is, for example, a ceramic layer or an anodization layer deposited by means of a CVD or PVD process.

The two annular discs 14, 15 may be firmly connected to each other, which is possible by gluing or riveting or caulking. Alternatively, they can also be set as loose components in the disk set according to FIG. In this case, the annular discs 14, 15 would separate from each other when the friction clutch is relieved, so that the grooves 18, 19 are open. Only when the disk set is compressed, the surfaces 16, 17 are pressed against each other, so that the respective channels form over the grooves 18, 19. Again, of course, each annular disc 14, 15 in turn made of aluminum, so that the outer fin 3 is again very light, but has a very good thermal conductivity. Figure 5 shows the friction clutch 1, in which case the outer plates 3 of the embodiment, as shown in Figures 3 and 4, correspond. Shown are dashed lines the flow arrows A, B, which indicate how the fluid cooling oil coming from the inner disk carrier 6 flows to the outer disk 3 on the inner circumference and leaves through the grooves 18, 19 on the outer periphery of the disk body again and flows through the outer disk carrier 2.

FIG. 6 shows a further exemplary embodiment of an outer disk 3 according to the invention in the form of an exploded view, while FIG. 7 shows the composite disk 3. Shown again is the aluminum lamellar body 1 1, which does not have a groove structure here. In order to form the respective lateral coating 12, steel ring disks 20 are placed on both sides of the lamellar body 1 1 and firmly connected with this, for example, by gluing, riveting, embossing or Verstemm in this embodiment. The steel annular discs 20 are also significantly harder than the aluminum lamella body 1 1, so that in the region of the frictional contact side surfaces a sufficient, the frictional stress resistant surface is given, while the lamellar body made of aluminum is very light and a very good thermal conductivity having. The steel annular discs 20 have the smallest possible thickness, preferably <1 mm. Again, such a small thickness is quite sufficient to wear the wear in operation wear resistant stand. Again, as in the embodiment described above, the axially widened external toothing 4 is provided.

FIG. 8 shows an outer lamella 3 according to the invention which corresponds to the basic construction according to the embodiment according to FIGS. 6 and 7. Again, an aluminum plate carrier 1 1 is provided, which is provided on both sides with the respective lining 12 forming steel annular discs 20. Here, however, the aluminum lamellar body on one or both sides introduced grooves 21 which extend from the inner periphery to the outer periphery. The grooves 21 are also here, similar to the embodiment Example according to Figure 3, bent guided. But you can also be guided in a straight line.

In the assembly position, see Figure 9, so if the steel discs 20 are placed on the lamella body 1 1, close the inner surfaces of the steel discs 20, the grooves 21 so that they form again corresponding, the outer plate 3 radially continuous channels through which flow a coolant can.

Of course, unlike in FIGS. 8 and 9, it is alternatively possible to form the grooves 21 on the steel ring disks 20, which should then be made slightly thicker, or on the grooves 21 in addition to the grooves 21 Steel annular disks 20 form corresponding grooves.

FIG. 10 shows a friction clutch 1 in which the outer disks 3 according to FIGS. 8 and 9 are arranged. It can clearly be seen that the entire disk pack is traversed in the region of the outer disks 3 with a plurality of channels formed over the grooves 21. These channels, in conjunction with the very good thermal conductivity of the aluminum, from which the lamellar body 1 1, ensures a very good and very fast heat dissipation to the coolant and thus cooling of the disk set.

LIST OF REFERENCE NUMBERS

friction clutch

External disk carrier

outer plate

external teeth

spline groove

Inner disk carrier

inner plate

carrier

friction lining

gearing

lamellar bodies

covering

coating

washer

area

groove

Steel washer

groove

spline groove

Claims

claims

1 . Slat for a wet friction clutch, characterized by a lamellar body (1 1) made of aluminum with a radial external or internal toothing

(4), wherein the lamellar body (1 1) on one or both sides of a covering (12) made of a harder aluminum material.

2. lamella according to claim 1, characterized in that the covering (12) on the lamellar body (1 1) applied or generated thereon layer (13).

3. lamella according to claim 2, characterized in that the layer (13) is a ceramic coating or an anodization.

4. lamella according to claim 1, characterized in that on the lamellar body (1 1) one or both sides of a covering (12) forming the steel annular disc (20) is applied.

5. lamination according to claim 4, characterized in that the steel annular discs (20) by gluing, riveting or stamping with the lamellar body (1 1) are connected.

6. lamella according to claim 4 or 5, characterized in that on the outer ßenflächen of the lamellar body (1 1) and / or the lamellar body (1 1) facing surface of a steel annular disc (20) one or more in the joined state from the inner periphery to Outside circumference extending channels forming grooves (21) are provided.

7. lamella according to one of claims 2 to 6, characterized in that the covering (12) has a thickness of <1 mm.

8. lamella according to one of the preceding claims, characterized in that the lamellar body (1 1) consists of two annular discs (14, 15), wherein one or both annular discs (14, 15) on or facing each other Have surfaces (16, 17) one or more in abutting state from the inner periphery to the outer circumference extending channels forming grooves (18, 19).

Slat according to claim 8, characterized in that the two annular discs (14, 15) are connected to each other by welding, gluing, riveting or embossing or axially movable as individual parts in the mounting position against each other, wherein in the adjacent state, the channels are formed.

Slat according to one of the preceding claims, characterized in that the outer or the internal toothing (4) having edge of the lamellar body (1 1) has a greater width than the covering (12) provided with the section of the lamellar body (1 1).