Wet multi-plate clutch

Abstract

The invention relates to a wet multi-plate clutch (1), comprising an inner plate carrier (2) which guides at least one inner plate (12) on a guide section (10), and an outer plate carrier (3) which guides at least one outer plate (8) on a guide section (6). The at least one inner plate (12) and the at least one outer plate (8) are arranged in an axially alternating manner and form a plate pack (14), wherein a control piston (17) is provided which, in the course of its axial displacement into its actuating position, exerts an axial actuating force on the plate pack (14) and thereby brings about a force-fitting connection between the inner plate carrier (2) and the outer plate carrier (3). By partially equipping the inner plate carrier (2) and the outer plate carrier (3) with inner plates (12) and outer plates (8), the plate pack (14) takes up only an axial partial area of the guide sections (6, 10), as a result of which the control piston (17) and the plate pack (14) are permanently separated from one another at an axial distance. A piston extension (30) is fastened to the control piston (17) and bridges the axial distance in the course of the axial displacement of the control piston (17) into its actuating position in that the piston extension (30) brings the control piston (17) indirectly axially into contact with the plate pack (14) and transmits the axial actuating force of the control piston (17) onto the plate pack (14).

Description

[0001] ZF Friedrichshafen AG File 305214 Friedrichshafen 2024-12-16

[0002] Wet multi-plate clutch

[0003] The invention relates to a wet-running multi-plate clutch comprising an inner plate carrier which guides at least one inner plate on a radially outwardly oriented guide section, and an outer plate carrier which guides at least one outer plate on a radially inwardly oriented guide section, wherein the at least one inner plate and the at least one outer plate are arranged axially alternating and form a plate pack, wherein an actuating piston axially displaceable between a home position and an actuating position is provided, which, in the course of its axial displacement from the home position to its actuating position, exerts an axial actuating force on the plate pack and thereby brings about a frictional connection between the inner plate carrier and the outer plate carrier, wherein furthermore at least one supply line is provided.Lubricant and / or coolant can be supplied to a region of the clutch pack at each of its openings, and wherein the actuating piston is coupled to a valve body which, in the actuating piston's home position, is positioned in a closed position and covers each of the openings of the at least one supply line, whereas, during the axial displacement of the actuating piston into the actuating position, the valve body moves out of its closed position and thereby at least partially uncovers each of the openings of the at least one supply line. Furthermore, the invention relates to a transmission with at least one of the aforementioned wet-running multi-plate clutches.

[0004] Multi-plate clutches are used as switchable clutches, particularly in the drive trains of motor vehicles. As friction-based, switchable clutches, they offer the advantage that actuation can be performed even under load and when speed differences still exist at the start of actuation. Furthermore, a compact multi-plate clutch is suitable for transmitting comparatively high torques, especially when the clutch is a wet clutch. In this case, the clutch's multi-plate pack, which transmits torque by friction, is lubricated by a lubricant. (ZF Friedrichshafen AG File 305214 Friedrichshafen 2024-12-16)

[0005] The clutch is lubricated and cooled by coolant, which significantly reduces wear compared to a dry clutch. In some wet clutches, the supply of lubricant and coolant is designed to adapt to the operating conditions, thus meeting the current demand. For example, a clutch in its closed state, and especially during slip operation, requires higher flow rates of lubricant and coolant for adequate lubrication and cooling. Conversely, such high flow rates in an open state would result in increased drag losses.

[0006] A wet-running multi-plate clutch is disclosed in DE 10 2004 027 113 A1, wherein this multi-plate clutch has an inner plate carrier and an outer plate carrier, of which the inner plate carrier guides clutch plates in the form of inner plates on a radially outwardly oriented guide section, and the outer plate carrier guides clutch plates in the form of outer plates on a radially inwardly oriented guide section. In the axial direction, the inner and outer plates are arranged alternately and form a plate pack of the multi-plate clutch. For actuating the multi-plate clutch, it is further equipped with an actuating piston, which can be moved axially from a home position to an actuated position by applying pressure.During this axial displacement, the actuating piston exerts an axial actuating force on the clutch pack through axial contact, thereby creating a frictional connection between the inner and outer plates and thus a positive-locking connection between the inner and outer plate carriers. This results in an actuated state of the wet multi-plate clutch.

[0007] The actuating piston is axially pre-tensioned to its home position by a spring element, with a valve body in the form of a valve ring positioned axially between the actuating piston and the spring element. Due to this intermediate arrangement, the valve ring is coupled to the actuating piston in terms of movement. In the home position of the actuating piston, this valve ring is in a closed position, in which it [ZF Friedrichshafen AG File 305214 Friedrichshafen 2024-12-16]

[0008] The opening of a supply line is concealed, through which lubricant and coolant in the form of oil can be fed into an interior of the multi-plate clutch and thus to a section of the clutch pack. In its closed position, and therefore the initial position of the actuating piston, the valve ring prevents oil from flowing into the interior. However, as the actuating piston moves into its actuated position, the valve ring is moved axially out of its closed position, thereby exposing the opening of the supply line and allowing oil to flow into the interior.

[0009] Based on the prior art described above, the object of the present invention is to provide a wet-running multi-plate clutch in which, firstly, adaptation to a lower nominal torque is achieved with low manufacturing costs by partially populating a multi-plate pack. Secondly, in addition to reliable operation, reliable lubrication and cooling of the multi-plate pack should also be ensured, depending on the operating conditions of the multi-plate clutch.

[0010] This problem is solved starting from the preamble of claim 1 in conjunction with its characterizing features. The subsequent dependent claims each describe advantageous embodiments of the invention. A transmission comprising at least one multi-plate clutch according to the invention is further the subject of claim 13.

[0011] According to the invention, a wet multi-plate clutch comprises an inner plate carrier, which guides at least one inner plate on a radially outwardly oriented guide section, and an outer plate carrier, which guides at least one outer plate on a radially inwardly oriented guide section. The at least one inner plate and the at least one outer plate are arranged axially alternating and form a plate pack. Furthermore, an actuating piston is provided, which is axially displaceable between a home position and an actuated position. During its axial displacement from the home position to its actuated position, the actuating piston exerts an axial actuating force on the plate pack, thereby creating a frictional connection between the ZF Friedrichshafen AG File 305214 Friedrichshafen 2024-12-16

[0012] The inner and outer lamella carriers are brought into contact. Furthermore, at least one supply line is provided, at each of whose openings lubricant and / or coolant can be introduced into a section of the lamella assembly. The actuating piston is coupled to a valve body, which, in the piston's home position, is in a closed position and covers one opening of each of the at least one supply lines. During the axial movement of the actuating piston into the actuating position, the valve body moves out of its closed position, thereby at least partially uncovering one opening of each of the at least one supply lines.

[0013] The multi-plate clutch according to the invention comprises, in a manner known to those skilled in the art, an inner plate carrier and an outer plate carrier. These two plate carriers radially accommodate a plate pack between them, which is formed by at least one inner plate and at least one outer plate. The at least one inner plate is guided on the side of the inner plate carrier, for which purpose the inner plate carrier is equipped with a radially outwardly oriented guide section. A guide section is also provided on the side of the outer plate carrier, which is oriented radially inward and on which the at least one outer plate is guided. The guide sections of the two plate carriers are formed, in particular, by drive teeth, i.e., in the case of the inner plate carrier by external teeth and in the case of the outer plate carrier by internal teeth.The respective lamella is then preferably guided in a rotationally fixed and axially displaceable manner by means of a toothed section designed as a counterpart to this drive toothing.

[0014] Within the multi-plate clutch, the inner plate carrier is specifically assigned to a first coupling side of the multi-plate clutch, and the outer plate carrier to a second coupling side of the multi-plate clutch. Preferably, the inner plate carrier is rotationally fixed to the first coupling side, and the outer plate carrier is rotationally fixed to the second coupling side.

[0015] The at least one inner slat and the at least one outer slat are for

[0016] Formation of the lamellar package arranged axially alternating, i.e., at ZF Friedrichshafen AG file 305214 Friedrichshafen 2024-12-16

[0017] In a multi-plate clutch, an inner plate is followed by an outer plate in the axial direction, and vice versa. Particularly preferred are several inner plates guided in the inner plate carrier, as well as several outer plates guided in the outer plate carrier, with the plate pack then being realized by the axially alternating arrangement of the inner and outer plates.

[0018] Furthermore, the multi-plate clutch is equipped with an actuating piston that can be moved axially between a neutral position and an actuated position. During its axial movement into the actuated position, the actuating piston applies an axial actuating force to the clutch pack. This force causes the plates of the clutch pack to be pressed axially against each other, creating a frictional connection between axially adjacent plates. This results in a positive connection between the inner and outer plate carriers and consequently in torque transmission between them. Thus, the multi-plate clutch achieves torque transmission between the two clutch plates.For applying the actuating force to the lamellar package, the actuating piston is arranged axially on one side of the lamellar package.

[0019] The actuating piston is guided to be axially displaceable between its home position and its actuated position, with the actuating piston being preloaded, particularly in its home position. In this home position, the actuating piston exerts no actuating force on the clutch pack, thus preventing axial pressure on the clutch plates and consequently preventing the formation of a frictional connection between axially adjacent plates. This allows the inner and outer plate carriers, and thus the two clutch surfaces of the multi-plate clutch, to be rotated relative to each other. However, in a manner known in principle to those skilled in the art, a certain amount of torque transmission between the plate carriers, and thus the clutch surfaces, can still occur. This latter phenomenon is commonly referred to as the drag torque of the multi-plate clutch. ZF Friedrichshafen AG File 305214 Friedrichshafen 2024-12-16

[0020] The actuating piston is moved into its actuated position, in particular hydraulically, by pressurizing a pressure chamber associated with the actuating piston with hydraulic fluid. Preferably, this pressure chamber is limited between the actuating piston and at least one other component, particularly on a side of the actuating piston facing away from the lamellar assembly. Most preferably, the actuating piston is also guided axially displaceably on this at least one other component, particularly on a radial inner and a radial outer side of the actuating piston.By pressurizing the pressure chamber, which is axially limited on one side of the actuating piston, an axial actuating force is introduced into the actuating piston, which preferably acts axially in the direction of the lamellar package and causes the axial displacement of the actuating piston from its basic position in the direction of its actuating position.

[0021] The multi-plate clutch according to the invention is designed as a wet-running multi-plate clutch in that lubricant and / or coolant can be supplied to the area of ​​the plate pack, in particular hydraulic fluid, and most preferably hydraulic oil. For this supply, the multi-plate clutch is provided with at least one supply line, at each of which the lubricant and / or coolant can be dispensed. After dispensing, the lubricant and / or coolant can be supplied to an area of ​​the plate pack to provide lubrication and / or cooling. Particularly preferably, several supply lines are provided, at each of which lubricant and / or coolant can be dispensed.

[0022] Furthermore, the multi-plate clutch has a valve body through which the supply of lubricant and / or coolant from the at least one supply line to the area of ​​the multi-plate pack can be controlled depending on the operating situation of the multi-plate clutch. For this purpose, the valve body is coupled to the actuating piston; that is, the axial displacement of the actuating piston is directly or indirectly coupled to a movement of the valve body. In the actuating piston's home position, the valve body is in a closed position, in which the valve body covers one opening of the at least one supply line, thereby preventing the outflow of lubricant and / or coolant from the at least one supply line at each opening.As the actuating piston moves into its actuating position, the valve body is moved out of this closed position, thereby at least partially opening one of the openings of the at least one supply line. Lubricant and / or coolant can then flow out of the at least one supply line, at least in a throttled manner. Preferably, the axial movement of the valve body out of the closed position is proportional to the movement of the actuating piston from its home position to the actuating position, so that as the movement of the actuating piston towards its actuating position increases, so that the valve body also moves out of the closed position increasingly.Particularly preferably, the valve body assumes a release position upon reaching the actuating position of the actuating piston, in which each of the openings of the at least one supply line through the valve body is at least predominantly, preferably completely, released.

[0023] The invention comprises the technical teaching that the lamellar assembly, by partially populating the inner and outer lamellar carriers with inner and outer lamellae, occupies only a portion of the guide sections axially, thereby permanently separating the actuating piston and the lamellar assembly at an axial distance from each other. Furthermore, a piston extension, separate from the actuating piston, is attached to the actuating piston. This piston extension bridges the axial distance during the axial displacement of the actuating piston into its actuating position by indirectly bringing the actuating piston into axial contact with the lamellar assembly during its axial displacement into its actuating position and transmitting the axial actuating force of the actuating piston to the lamellar assembly.

[0024] In other words, in the multi-plate clutch according to the invention, the lamellar pack occupies only an axial portion of the guide sections of the inner and outer plate carriers, by partially fitting both the inner and outer plate carriers with lamellae. Due to this partial fitting, ZF Friedrichshafen AG File 305214 Friedrichshafen 2024-12-16

[0025] The actuating piston does not come into direct contact with the lamellar assembly; an axial gap always remains between the piston and the assembly. To still transmit the actuating force to the lamellar assembly during the axial movement of the piston into its actuated position, a piston extension is attached to the piston. This extension is a separate component. During the axial movement of the piston into its actuated position, this piston extension comes into axial contact with the lamellar assembly, thus indirectly coupling the piston to the assembly. The axial actuating force of the piston is then transmitted to the lamellar assembly via the piston extension.

[0026] This design has the advantage that the multi-plate clutch according to the invention is reliably adapted to a lower nominal torque to be transmitted via the multi-plate clutch by means of the partial assembly of the inner and outer plate carriers. This adaptation can be easily achieved by means of the selected partial assembly, i.e., the selected number of inner and outer plates, and is realized with low manufacturing costs, since largely identical parts can be used. The piston extension ensures that, despite the partial assembly, the axial actuating force of the actuating piston is reliably transmitted into the plate pack formed by the partial assembly.

[0027] Unlike filling the axial gap between the partially assembled clutch pack and the actuating piston with filler plates (either only outer plates or only inner plates), this method allows for more precise clearance adjustment of the clutch pack, thus improving the actuation behavior of the multi-plate clutch compared to a variant with filler plates. Furthermore, compared to a variant with filler plates, the supply of lubricant and / or coolant to the clutch pack is also improved, as this prevents lubricant and / or coolant from escaping the clutch via filler plates. Finally, the valve body, which is motion-coupled to the actuating piston (ZF Friedrichshafen AG File 305214, Friedrichshafen, 2024-12-16), enables simple and reliable, operation-dependent lubrication and cooling of the multi-plate clutch.

[0028] A key aspect of the invention is that, due to the partial assembly of the inner and outer lamella carriers with inner and outer lamellae, an axial gap exists between the actuating piston and the lamella pack, since the latter is located only in a partial axial area, preferably at one axial end, of the guide sections of the outer and inner lamella carriers. To bridge this axial gap and transmit the axial actuating force to the lamella pack, a piston extension is attached to the actuating piston. This extension moves along with the actuating piston and indirectly establishes contact between the actuating piston and the lamella pack.The piston extension artificially lengthens the actuating piston axially in order to exert the axial actuating force on the lamellar package when the actuating piston is axially displaced into the actuating position, despite the partial assembly of the inner and outer lamellar carriers.

[0029] In the context of the invention, "partial assembly" of the inner and outer lamella carriers means that both the inner and outer lamella carriers each carry only a fraction of the number of lamellae that could actually be realized in the respective lamella carrier due to the axial extension of the respective guide section, and which would constitute full assembly of the inner and outer lamella carriers. In particular, the partial assembly deviates significantly from full assembly by being less than 80%, preferably less than 60%, and most preferably less than 50%.

[0030] In accordance with the invention, the piston extension is preferably detachably attached to the actuating piston. This allows the multi-plate clutch to be adapted by replacing the piston extension even when the partial assembly is changed. Generally, the separate nature of the piston extension from the actuating piston (ZF Friedrichshafen AG File 305214, Friedrichshafen, 2024-12-16) allows for simpler adaptability compared to a possible alternative where the actuating piston and the piston extension are manufactured as a single piece.

[0031] In particular, the piston extension is designed as a metal part, preferably made of aluminum. This allows for a low weight and therefore a low moment of inertia during operation.

[0032] In the context of the invention, "axial" refers to an orientation parallel to an axis of rotation of the lamellar coupling according to the invention, wherein the inner lamellar carrier and the outer lamellar carrier are coaxial to this axis of rotation. "Radial," on the other hand, means an orientation in the diameter direction with a center point lying on the axis of rotation.

[0033] According to one embodiment of the invention, the valve body is designed as a valve ring which is guided axially on a cylindrical surface of a component in which the at least one inlet line is formed. In the closed position of the valve ring, the opening of each of the at least one inlet line is located axially at the level of the valve ring and radially adjacent to it. This allows for a multi-plate clutch design in which the valve body is guided in a suitable manner and, in its closed position, reliably covers each opening of the at least one inlet line.

[0034] Preferably, the axially displaceable guide of the valve body, designed as a valve ring, is provided on an outer surface of a component that is positioned radially inside the valve ring. In this configuration, the at least one inlet line opens axially at the same level as and radially inside the valve ring when the valve ring is closed.

[0035] The valve body, designed as a valve ring, preferably has an H-shaped cross-section. In its closed position, the valve ring then covers each of the ZF Friedrichshafen AG File 305214 Friedrichshafen 2024-12-16

[0036] The outlet of the at least one inlet pipe has a cross-section, in particular with a clamp-shaped half of its H-cross-section.

[0037] In a further development of the aforementioned embodiment, the actuating piston is also guided axially on its cylindrical surface between its home position and its actuated position. The valve ring is positioned axially between the actuating piston and a spring element, which biases the actuating piston into its home position and the valve ring into its closed position. Advantageously, this allows for a common bias of the actuating piston and the valve ring into their home and closed positions, respectively. Preferably, the spring element is implemented by a series connection of disc springs; however, within the scope of the invention, an alternative embodiment of the spring element, for example in the form of a helical spring, would also be conceivable.

[0038] In particular, during the axial displacement of the actuating piston into its actuated position and the associated movement of the valve ring from its closed position, each outlet of the at least one supply line comes into contact with a bypass line to which the actuating piston is equipped. This bypass line allows lubricant and / or coolant to flow from the at least one supply line past the actuating piston and valve body to the area of ​​the lamellar pack. This design has the advantage that, despite the axially intermediate arrangement of the valve ring between the actuating piston and the spring element, reliable outflow from the at least one supply line is still ensured when the valve ring moves out of the closed position.

[0039] According to a further embodiment of the invention, the actuating piston and the valve body are provided as separate components. When this embodiment is combined with the variant described above, each bypass line is then formed as a notch on an axial contact surface where the actuating piston is in axial contact with the valve body. This allows for suitable and simple manufacturing of each bypass line. ZF Friedrichshafen AG File 305214 Friedrichshafen 2024-12-16

[0040] Within the scope of the invention, the actuating piston and the valve body could also be designed as a single piece, which is particularly realized when the valve body is designed as a valve ring and arranged axially adjacent to a spring element, by which the actuating piston is biased into its basic position and the valve ring into its closed position.

[0041] In one embodiment of the invention, the piston extension is selected with respect to its axial extent such that no contact is made with the clutch pack in the actuating piston's home position. This allows the drag torque in the multi-plate clutch according to the invention to be kept low.

[0042] According to a further embodiment of the invention, the piston extension is ring-shaped and attached to the actuating piston at an annular contact surface. In a further development of this embodiment, an axially projecting annular guide section is provided on the piston extension, which guides the piston extension to a corresponding annular receiving section of the actuating piston. This provides simple guidance for the piston extension on the actuating piston, and this guidance also simplifies assembly of the piston extension.

[0043] Alternatively or additionally, the piston extension is located radially between the inner and outer vane carriers and has a guide surface on one side facing radially towards the at least one supply line. This guide surface facilitates the flow of lubricant and / or coolant, dispensed from each outlet of the at least one supply line, to the vane pack. This has the advantage of ensuring a reliable supply of lubricant and / or coolant to the vane pack.

[0044] In a further development of the invention, the piston extension is provided with circumferentially spaced receiving bores to which the piston extension is screwed to the adjusting piston. This allows for a simple, detachable fastening of the piston extension to the adjusting piston. In particular, the screw heads of the fastening screws, by means of which the piston extension is screwed to the adjusting piston, are countersunk in the receiving bores. This ensures that the screw heads do not protrude axially on the side of the lamellar pack.

[0045] In a further embodiment of the invention, the piston extension is provided with axially extending openings that are separated from each other in the circumferential direction. These openings allow material to be selectively removed from the piston extension, thereby reducing its weight. In particular, the openings are designed as circular through-holes.

[0046] The invention also relates to a transmission, which may be a motor vehicle transmission. This transmission comprises at least one wet multi-plate clutch according to one or more of the variants described above.

[0047] An advantageous embodiment of the invention, which is explained below, is illustrated in the drawings. It shows:

[0048] Fig. 1 shows a sectional view of a wet multi-plate clutch according to a preferred embodiment of the invention, shown in a first state;

[0049] Fig. 2 is a perspective close-up view of an actuating piston of the multi-plate clutch from Fig. 1;

[0050] Fig. 3 is a perspective close-up view of a piston extension of the multi-plate clutch from Fig. 1; and

[0051] Fig. 4 shows a detailed view of the multi-plate clutch from Fig. 1, shown in a second state. ZF Friedrichshafen AG File 305214 Friedrichshafen 2024-12-16

[0052] Figure 1 shows a sectional view of a multi-plate clutch 1, which is designed according to a preferred embodiment of the invention. The multi-plate clutch comprises an inner plate carrier 2 and an outer plate carrier 3, the latter being formed by a component 4 in the form of a carrier, which is rotationally fixed to a further component 5 in the form of a shaft.

[0053] The outer lamella carrier 3 has a radially inwardly oriented guide section 6 in the form of an internal toothing 7, on which the outer lamella carrier 3 guides several outer lamellae 8 in a rotationally fixed and axially displaceable manner. For this purpose, each outer lamellae 8 is provided with a drive toothing 9, which is designed as a counterpart to the internal toothing 7. The inner lamella carrier 2 also has a guide section 10, which is radially outwardly oriented and designed as an external toothing 11. Several inner lamellae 12 are guided on this external toothing 11, with each inner lamellae 12 being equipped with a drive toothing 13, which is designed as a counterpart to the external toothing 11 and by means of which a rotationally fixed and axially displaceable guide for the respective inner lamellae 12 is achieved.

[0054] The outer lamellae 8 and the inner lamellae 12 are arranged alternately in the axial direction, together forming a lamella assembly 14, which is radially mounted between the outer lamella carrier 3 and the inner lamella carrier 2. A thrust washer 15 is also positioned on one axial side of this lamella assembly 14. This thrust washer is guided by the internal teeth 7 and axially supported on a retaining ring 16 on a side facing away from the lamella assembly 14. This retaining ring 16 is mounted on the outer lamella carrier 3.

[0055] On one side of the clutch pack 14, which is axially opposite the thrust washer 15, the clutch pack 1 is also equipped with an actuating piston 17, which is shown individually in perspective in Fig. 2. As can be seen there, the actuating piston 17 is annular in design, and is guided axially displaceably in the clutch pack 1 radially outside component 4 and radially inside a through-opening 18 on component 5. Furthermore, the actuating piston 17, together with components 4 and 5, defines an intermediate pressure chamber 19, which can be pressurized to actuate the clutch pack 1.

[0056] Fig. 1 shows the multi-plate clutch 1 in a first state, in which the actuating piston 17 is in a home position when the pressure chamber 19 is not pressurized. In this home position, the actuating piston 17 is pre-tensioned by a spring element 20, which is arranged coaxially to the component 5 and is formed by several disc springs connected in series.

[0057] A valve body 22, which is a valve ring 23, is positioned axially between an annular piston base 21, which guides the actuating piston 17 at the through-opening 18 on the component 5, and the spring element 20. As can be seen in Fig. 1, this valve ring 23 has an H-shape in cross-section. Due to the axially intermediate arrangement of the valve ring 23 between the piston base 21 of the actuating piston 17 and the spring element 20, the valve ring 23 is coupled to the actuating piston 17 in terms of movement. In the basic position of the actuating piston 17 shown in Fig. 1, the valve ring 23 is in a closed position, in which the valve ring 23 is axially aligned with and radially surrounding an opening 24 of an inlet line 25. Thus, in its closed position, the valve ring 23 covers the opening 24 of the inlet line 25.The supply line 25 is designed as a radially extending bore in the component 5 and serves to supply lubricant and coolant to the area of ​​the multi-plate clutch 1 in order to lubricate and cool the multi-plate pack 14. The lubricant and coolant is hydraulic fluid, specifically hydraulic oil.

[0058] The valve ring 23 is supported on the piston base 21 by an axial contact surface 26. Several indentations 27 are also provided in the piston base 21 on this contact surface 26, which can be seen in Fig. 1 and also in Fig. 2 and each of which forms a bypass line 28.

[0059] In this case, the inner plate carrier 2 and the outer plate carrier 3 are only partially equipped to achieve a specific nominal torque of the multi-plate clutch 1 (ZF Friedrichshafen AG File 305214 Friedrichshafen 2024-12-16), in that the inner plate carrier 2 guides inner plates 12 only on an axial portion of its guide section 10, and the outer plate carrier 3 also guides outer plates 8 only on an axial portion of its guide section 6. As a result, the resulting plate pack 14 occupies only an axial end region of the guide sections 6 and 10 adjacent to the thrust washer 15. With respect to the actuating piston 17, this creates an axial gap between the plate pack 14 and a piston head 29, through which the actuating piston 17 is intended to actuate the multi-plate clutch 1.

[0060] To enable actuation of the multi-plate clutch 1 despite the partial assembly of the inner and outer plate carriers 2 and 3, a piston extension 30 is attached to the piston head 29 of the actuating piston 17. This extension is shown individually in perspective view in Fig. 3. It can be seen that the piston extension 30 is annular in design, and that it lies axially between the piston head 29 and the plate pack 14, and radially between the inner and outer plate carriers 2 and 3, within the multi-plate clutch 1. Circumferentially, the piston extension 30 is provided with spaced-apart receiving bores 31, each of which accommodates a fastening screw. The piston extension 30 is screwed to the actuating piston 17 via these fastening screws. Furthermore, the piston extension 30 has several circular openings 32 circumferentially between these receiving bores 31.

[0061] The axial extension of the piston extension 30 is selected such that, in the basic position of the actuating piston 17 shown in Fig. 1, the piston extension 30 is not in axial contact with the clutch pack 14. When the pressure chamber 19 is pressurized to actuate the multi-plate clutch 1, this results in an axial displacement of the actuating piston 17 from its basic position towards an actuating position, relative to the spring element 20. During this displacement, the piston extension 30 then comes into axial contact with the clutch pack 14 and consequently transmits an axial actuating force generated by the actuating piston 17 to the clutch pack 14, which then... [ZF Friedrichshafen AG File 305214 Friedrichshafen 2024-12-16]

[0062] The thrust washer 15 is compressed. A frictional connection is established between axially adjacent outer lamellae 8 and inner lamellae 12 by the action of the axial actuating force, resulting in the formation of a force-fit connection between the inner lamella carrier 2 and the outer lamella carrier 3.

[0063] During the axial displacement of the actuating piston 17 into its actuated position, the actuating piston 17 also displaces the valve ring 23 in the opposite direction to the spring element 20, causing the valve ring 23 to leave its closed position and expose the opening 24 of the supply line 25. As a result, lubricant and coolant can flow out of the supply line 25 and bypass the actuating piston 17 and the valve ring 23 via the bypass lines 28. The lubricant and coolant then flow radially outwards through transverse bores 33 in the inner fin carrier 2 and through a radial gap between the piston base 21 and the inner fin carrier 2. A portion of this outflowing lubricant and coolant enters the area of ​​the fin pack 14, providing lubrication and cooling.

[0064] In addition, the ring-shaped piston extension 30 forms a guide surface 34 on a radial inner side, on which the lubricant and coolant flowing radially outwards is additionally redirected axially into the area of ​​the lamellar package 14 in order to achieve the best possible supply of the lamellar package 14.

[0065] Figure 4 shows a detail of the multi-plate clutch 1 in the state in which the actuating piston 17 is axially displaced into its actuating position. As can be seen here, the valve ring 23 has assumed an opening position in this actuating position in which the valve ring 23 almost completely exposes the opening 24 of the supply line 25.

[0066] As can also be seen in Fig. 1, the piston extension 30 is provided axially on a side facing the actuating piston 17 with an axially projecting, annular guide section 35, by which the piston extension 30 is inserted into a receiving section 36. This receiving section 36 is referred to as ZF Friedrichshafen AG File 305214 Friedrichshafen 2024-12-16

[0067] The piston extension 30 is designed as a counterpart to the guide section 35 on the piston head 29, thereby guiding the piston extension 30 on the piston head 29. The piston extension 30 rests against an annular contact surface 37, which is formed by the actuating piston 17 on its piston head 29.

[0068] The inventive design enables the creation of a wet-running multi-plate clutch in which, firstly, adaptation to a lower nominal torque is achieved with low manufacturing costs by partially populating a multi-plate pack. Secondly, in addition to reliable operation, reliable lubrication and cooling of the multi-plate pack is also achieved, depending on the operating conditions of the multi-plate clutch.

[0069] ZF Friedrichshafen AG File 305214 Friedrichshafen 2024-12-16

[0070] Reference mark

[0071] 1 multi-plate clutch

[0072] 2 inner slat carriers

[0073] 3 outer slat carriers

[0074] 4 components

[0075] 5 components

[0076] 6. Guided Section

[0077] 7 Internal teeth

[0078] 8 outer slats

[0079] 9 Drive gear

[0080] 10. Guided tour section

[0081] 11 External teeth

[0082] 12 inner slats

[0083] 13 Drive gear

[0084] 14 slat package

[0085] 15 Thrust washer

[0086] 16 retaining ring

[0087] 17 actuating pistons

[0088] 18 Passage opening

[0089] 19 printing room

[0090] 20 spring element

[0091] 21 Piston base

[0092] 22 Valve bodies

[0093] 23 Valve ring

[0094] 24 Mouth

[0095] 25 Inlet pipe

[0096] 26 Plant area

[0097] 27 notches

[0098] 28 Bypass line

[0099] 29 Piston head

[0100] 30 Piston extension

[0101] 31 drilling operations ZF Friedrichshafen AG File 305214 Friedrichshafen 2024-12-16

[0102] 32 breakthroughs

[0103] 33 cross bores

[0104] 34 Guide surface

[0105] 35 Leadership section

[0106] 36 Recording section

[0107] 37 Plant area

Claims

ZF Friedrichshafen AG File 305214 Friedrichshafen 2024-12-16 Patent claims 1. Wet-running multi-plate clutch (1) comprising an inner plate carrier (2) which guides at least one inner plate (12) on a radially outwardly oriented guide section (10), and an outer plate carrier (3) which guides at least one outer plate (8) on a radially inwardly oriented guide section (6), wherein the at least one inner plate (12) and the at least one outer plate (8) are arranged axially alternating and form a plate pack (14), wherein an actuating piston (17) is provided which is axially displaceable between a home position and an actuating position, which in the course of its axial displacement from the home position to its actuating position exerts an axial actuating force on the plate pack (14) and thereby brings about a force-fit connection between the inner plate carrier (2) and the outer plate carrier (3), wherein at least one supply line (25) is further provided,Lubricant and / or coolant can be guided into a region of the lamellar assembly (14) at each of its openings (24), and wherein the actuating piston (17) is coupled to a valve body (22) which, in the basic position of the actuating piston (17), is positioned in a closed position and there covers each of the openings (24) of the at least one supply line (25), whereas, in the course of the axial displacement of the actuating piston (17) into the actuating position, the valve body (22) moves out of its closed position and thereby at least partially releases each of the openings (24) of the at least one supply line (25), characterized in that the lamellar assembly (14) occupies only an axial partial region of the guide sections (6, 10) by partially equipping the inner lamellar carrier (2) and outer lamellar carrier (3) with inner (12) and outer lamellae (8), whereby the actuating piston (17) and the lamellar assembly (14) are permanently separated from each other at an axial distance,and that a piston extension (30) is attached to the actuating piston (17), which is separate from the actuating piston (17) and bridges the axial distance during the axial displacement of the actuating piston (17) into its actuating position, by the piston extension (30) indirectly bringing the actuating piston (17) into axial contact with the lamellar pack (14) during its axial displacement into its actuating position and transmitting the axial actuating force of the actuating piston (17) to the lamellar pack (14). ZF Friedrichshafen AG File 305214 Friedrichshafen 2024-12-16 2. Multi-plate clutch (1) according to claim 1, characterized in that the valve body (22) is designed as a valve ring (23) which is axially displaceable on a cylindrical surface, in particular an outer surface, of a component (5) in which the at least one inlet line (25) is designed, wherein each opening (24) of the at least one inlet line (25) is located axially at the level of the valve ring (23) and radially, in particular radially inside, adjacent to it in the closed position of the valve ring (23).

3. Multi-plate clutch (1 ) according to claim 2, characterized in that the actuating piston (17) is also guided axially on the cylindrical surface between its home position and its actuating position, wherein the valve ring (23) is placed axially between the actuating piston (17) and a spring element (20) which biases the actuating piston (17) into its home position and the valve ring (23) into its closed position.

4. Multi-plate clutch (1 ) according to claim 3, characterized in that each of the openings (24) of the at least one supply line (25) comes into contact with a bypass line (28) during the axial displacement of the actuating piston (17) into its actuating position and the associated movement of the valve ring (23) from its closed position, with which the actuating piston (17) is provided and which allows lubricant and / or coolant to flow from the at least one supply line (25) past the actuating piston (17) and valve body (22) to the area of ​​the multi-plate pack (14).

5. Multi-plate clutch (1 ) according to at least one of the preceding claims, characterized in that the actuating piston (17) and the valve body (22) are provided as separate components.

6. Multi-plate clutch (1 ) according to claim 4 and claim 5, characterized in that each bypass line (28) is designed as a notch (27) on an axial contact surface (26) on which the actuating piston (17) is in axial contact with the valve body (22). ZF Friedrichshafen AG File 305214 Friedrichshafen 2024-12-16 7. Multi-plate clutch (1 ) according to at least one of the preceding claims, characterized in that the piston extension (30) is selected with respect to its axial extent such that in the basic position of the actuating piston (17) no contact is made with the multi-plate pack (14).

8. Multi-plate clutch (1 ) according to at least one of the preceding claims, characterized in that the piston extension (30) is designed in an annular shape and is attached to the actuating piston (17) on an annular contact surface (37).

9. Multi-plate clutch (1 ) according to claim 8, characterized in that an axially projecting annular guide section (35) is provided on the piston extension (30), with which the piston extension (30) is guided on an annular receiving section (36) of the actuating piston (17) designed as a counterpart thereto.

10. Multi-plate clutch (1 ) according to claim 8 or 9, characterized in that the piston extension (30) lies radially between the inner plate carrier (2) and the outer plate carrier (3) and has a guide surface (34) on one of the radially facing sides of the at least one supply line (25), which at least supports the supply of lubricant and / or coolant dispensed at each of the openings (24) of the at least one supply line (25) to the plate pack (14).

11. Multi-plate clutch (1) according to at least one of the preceding claims, characterized in that the piston extension (30) is provided with receiving bores (31) spaced apart from each other in the circumferential direction, to which the piston extension (30) is screwed with the actuating piston (17).

12. Multi-plate clutch (1 ) according to at least one of the preceding claims, characterized in that the piston extension (30) is provided with axially extending openings (32) which are separated from each other in the circumferential direction. ZF Friedrichshafen AG File 305214 Friedrichshafen 2024-12-16 13. Transmission comprising at least one multi-plate clutch (1 ) according to at least one of the preceding claims.

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