Dual clutch with increased internal cooling fluid flow; and reversing gear

Abstract

A double clutch (1) for a powershift reversing gear (20), comprising a first partial clutch (2), a second partial clutch (3), and an actuating system (4) designed for alternately actuating the partial clutches (2, 3), each partial clutch (2, 3) having a clutch disc (5, 6) and a pressure plate (7, 8) mounted so as to be axially adjustable relative to said clutch disc (5, 6) between an open position and a closed position of the respective partial clutch (2, 3), characterized in that a plurality of blade regions (11) are arranged and designed on mutually facing axial sides (9b, 10a) of the two clutch discs (5, 6) in such a way that they generate a radially outwardly directed cooling fluid flow at least in a closed position of one of the two partial clutches (2, 3).

Description

[0001] The invention relates to a dual clutch for a powershift reversing transmission, comprising a first partial clutch, a second partial clutch, and an actuation system designed for alternately actuating the partial clutches. Each partial clutch has a clutch disc and a pressure plate mounted axially adjustable relative to this clutch disc between an open position and a closed position of the respective partial clutch. These pressure plates thus form movable plates for switching the respective partial clutch back and forth between its closed position and its open position. Furthermore, the invention relates to a reversing transmission per se with this dual clutch.

[0002] Dual clutches of this type are already well known in the art. In particular, the use of dry dual clutches for operating reversing gears is also known. DE 10 2022 114 761 B3, for example, discloses a relevant prior art.

[0003] It should also be noted that clutches used for reversing gears, and thus for power shuttle applications, can experience higher heat input than conventional clutches. Due to the typical arrangement of clutches in a transmission bell housing, heat dissipation occurs through a heat flow across the components and cooling via an air stream. The air used for cooling flows past the surfaces of the heated clutch components, heats up, flows past other surfaces with lower temperatures (e.g., the transmission bell housing), and cools down again. The air flow essentially occurs only within the clutch bell housing.However, previous designs primarily only allow for a sufficiently strong airflow for cooling in the area of ​​the open partial clutch, even though the closed partial clutch immediately after the closing process is actually the area most relevant for cooling. Under certain circumstances, this can lead to local overheating, which can result in consequential damage.

[0004] A single tractor clutch is known from US Pat. No. 2,107,954 A. A double tractor clutch is known from DE 1 294 228 A. DE 26 41 379 A1 and EP 1 892 432 A2 deal with the cooling air distribution within single clutches. DE 10 2010 007 198 A1 deals with the cooling air distribution within a double clutch.

[0005] The object of the present invention is to provide a dual clutch that enables a reliable yet powerful power shuttle clutch arrangement. In particular, the stability of the dual clutch is to be improved with respect to the expected heat input.

[0006] This is achieved according to the invention in that a plurality of blade regions are arranged and designed on mutually facing axial sides of the two clutch discs in such a way that they generate a radially outwardly directed cooling fluid flow at least in a closed position of one of the two partial clutches.

[0007] This creates a pronounced cooling fluid flow, particularly on the opposing sides of the clutch discs, due to their opposing / counter-rotating movement. This flow is also directed radially outward between the pressure plates of the two sub-clutches. The two pressure plates themselves, as well as all other components of the entire dual clutch, are thus cooled by a more intensive and precisely directed cooling fluid flow. This also advantageously allows for an overall increased cooling fluid flow to dissipate heat from the friction discs. The thermal behavior of the entire dual clutch is thus advantageously improved.

[0008] Further advantageous embodiments are claimed in the subclaims and explained in more detail below.

[0009] In this context, it is particularly advantageous if the pressure plates are arranged directly axially adjacent, yet axially spaced from each other. This ensures the most efficient flow of the cooling fluid.

[0010] It is also advantageous if the blade areas are formed as (at least partially) bent sheet metal sections. The sheet metal sections are more preferably formed from a metal sheet, such as a steel sheet. This makes the blade areas as easy to manufacture in large quantities as possible.

[0011] Furthermore, it has been found advantageous if the blade regions arranged on the mutually facing axial sides of the two clutch discs are divided into two groups, with a first group of blade regions being designed such that they generate the cooling fluid flow when the respective clutch disc rotates in a first direction of rotation, and a second group of blade regions being designed such that they are used to act when the respective clutch disc rotates in a second direction of rotation. This results in intensive cooling of the various components, regardless of which partial clutch is currently open or closed.

[0012] Furthermore, it is advantageous if each clutch disc has a spring damper and the blade areas are arranged radially outside the spring elements of the spring damper and / or radially inside the friction linings that can be brought into frictional contact with the respective pressure plate. This allows for a compact design of the clutch discs.

[0013] Furthermore, it is expedient if the sub-clutches are designed and arranged within a housing in such a way that the blade areas each generate a circular cooling fluid circuit (extending axially and radially in sections) during operation. This ensures the most efficient cooling of the entire coupling. In particular, it is further preferred if the two clutch discs of the two sub-clutches each generate a cooling fluid circuit, and the two cooling fluid circuits of the two sub-clutches run axially adjacent and opposite each other. This ensures the most efficient cooling of the entire dual clutch.

[0014] If the two clutch discs each have additional blade areas on opposite axial sides, an even more precisely aligned and stronger cooling fluid flow is generated.

[0015] It is also advantageous if the blade areas on the mutually facing axial sides of the two clutch discs each have an axial extension that exceeds the axial extension of the pressure plate of the associated sub-clutch. This further optimizes coolant delivery.

[0016] If each partial clutch is designed as a dry-running friction clutch, the double clutch can be manufactured easily.

[0017] Furthermore, the invention relates to a reversing transmission with a double clutch according to the invention according to at least one of the previously described embodiments and a transmission device (preferably a manual transmission device), wherein a first input shaft of the transmission device is connected to an output of the first partial clutch and a second input shaft of the transmission device is connected to an output of the second partial clutch.

[0018] The invention will now be explained in more detail below with reference to several figures, in which context different embodiments are also shown.

[0019] They show: Fig. 1 a longitudinal sectional view of a double clutch according to the invention according to a first exemplary embodiment, wherein a cooling fluid circuit generated by a respective clutch disc of two partial clutches of the double clutch is shown, and wherein a first partial clutch is open while a second partial clutch is closed, Fig. 2 a longitudinal section of the entire double clutch according to Fig. 1, which makes their overall structure particularly clear, Fig. 3 a perspective view of a partial assembly of the double clutch according to Fig. 1, wherein several blade areas on one axial side of the clutch disc of the second partial clutches are clearly visible, Fig. 4 a perspective view of the clutch disc of the second partial clutch, Fig. 5 is a schematic longitudinal sectional view of the double clutch of the first embodiment, as it is already coupled to input shafts of a transmission device of a reversing gear, wherein the cooling fluid flows generated during operation are shown and the first partial clutch is closed, while the second partial clutch is open, Fig. 6 a schematic longitudinal section of the double clutch of the first embodiment, similar to Fig. 5, where the cooling fluid flows generated during operation with the first partial clutch open and the second partial clutch closed at the same time can be seen, Fig. 7 is a schematic longitudinal sectional view of a double clutch according to the invention according to a second embodiment, which differs from the first embodiment in particular by the design of the blade areas on the respective clutch disc, and wherein the cooling fluid flows generated during operation are again shown with the first partial clutch closed and the second partial clutch open at the same time, Fig. 8 a schematic longitudinal sectional view of the double clutch of the second embodiment, similar to Fig. 7, where the cooling fluid flows generated during operation with the first partial clutch open and the second partial clutch closed at the same time can be seen, as well as Fig. 9 a schematic longitudinal sectional view of a reversing gear equipped with a double clutch according to the invention.

[0020] The figures are merely schematic in nature and therefore serve solely to clarify the invention. The same elements are designated by the same reference numerals.

[0021] With Fig. 1 illustrates a double clutch 1, which is preferably used in a reversing gear 20 and is thus alternatively also referred to as a reversing clutch.

[0022] The dual clutch 1 is also used as a so-called power shuttle clutch for switching from forward to reverse in motor vehicles, particularly in tractors or other implements, with the switching process preferably being carried out by pressing a button. The dual clutch 1 is thus preferably used in a reversing gear 20, which is used in a commercial vehicle, such as a tractor, i.e., particularly in agricultural machinery.

[0023] The reversing gear 20 is in Fig. 9 is shown schematically. In addition to the dual clutch 1, a transmission device 21 is also illustrated, which transmission device 21 is preferably implemented as a manual transmission. The transmission device 21 is connected to the dual clutch 1 via its input shafts 18, 19. Fig. Figure 9 particularly shows the various gearing stages for the reverse and forward gears realized by the transmission device 21. The dual clutch 1 is coupled to the first input shaft 18 via its first sub-clutch 2 and to the second input shaft 19 via its second sub-clutch 3.

[0024] The dual clutch 1 is designed and operated in such a way that only one of its two sub-clutches 2, 3 is engaged / closed at any one time during operation. The non-engaged / not closed sub-clutch 2, 3 is therefore always disengaged / open.

[0025] In the Fig. 1 and Fig. Figure 2 clearly shows the detailed structure of the dual clutch 1 according to the invention. The dual clutch 1 comprises two sub-clutches 2, 3, each of which is designed as a friction clutch, specifically a dry-running friction clutch. The sub-clutches 2, 3 are also designed as a single-disk friction clutch and thus each have only one clutch disc 5, 6.

[0026] As in the schematic Fig. 5 and Fig. 6, the dual clutch 1 has a single input / torque input, which can be selectively connected to the first input shaft 18 or the second input shaft 19 by means of the respective partial clutch 2, 3.

[0027] The two sub-clutches 2, 3 are designed in the same way and are essentially mirror-symmetrical to one another. The first sub-clutch 2 has a first pressure plate 7 and a first counter-plate 25 axially spaced therefrom. A first clutch disc 5 is arranged axially between the first pressure plate 7 and the first counter-plate 25. The first clutch disc 5 forms an output 22 / torque output of the first sub-clutch 2.

[0028] The second partial clutch 3 is designed analogously to the first partial clutch 2. The second partial clutch 3 thus also has a (second) pressure plate 8 and a (second) counterplate 26, which form an input side / torque input of the second partial clutch 3. An output 23 / torque output of the second partial clutch 3 is formed by a second clutch disc 6, which is arranged axially between the second pressure plate 8 and the second counterplate 26.

[0029] An actuating system 4 is provided for actuating the first partial clutch 2, i.e., for adjusting this first partial clutch 2 from its open position to its closed position and back again. The actuating system 4 naturally also serves to adjust the second partial clutch 3, which in turn serves to adjust the second partial clutch 3 from its open position to its closed position and back again.

[0030] The actuating system 4 has, in the usual way, an actuating lever 29, 30 for each partial clutch 2, 3, which is further coupled during operation to a corresponding return bearing (not shown in detail for the sake of clarity), and an actuating plunger 27, 28 which is axially displaceable by the actuating lever 29, 30 and which in turn directly adjusts the pressure plate 7, 8 of the respective partial clutch 2, 3. In a first position of the first actuating plunger 27, corresponding to a closed position of the first partial clutch 2, the first pressure plate 7 together with the first clutch disc 5 is pressed frictionally against the first counter-plate 25. In a first position of the second actuating plunger 28, corresponding to a closed position of the second partial clutch 3, the second pressure plate 8 together with the second clutch disc 6 is pressed frictionally against the second counter-plate 26.

[0031] Since the actuation of the partial clutches 2, 3 takes place alternately, the second partial clutch 3 is open while the first partial clutch 2 is closed, and vice versa.

[0032] For the sake of completeness, it should be noted that the directions used herein, axial, radial, and circumferential / rotational direction, are to be understood with respect to a central axis of rotation 24 of the dual clutch 1. This axis of rotation 24 is arranged coaxially to a rotational axis of the input shafts 18, 19. The axial / axial direction thus refers to a direction along / parallel to the axis of rotation 24, the radial / radial direction refers to a direction perpendicular to the axis of rotation 24, and the circumferential direction refers to a direction along a circular line concentrically encircling the axis of rotation 24.

[0033] Returning to Fig. Finally, Figure 1 illustrates the inventive design of the clutch discs 5, 6 with different blade regions 11. It can be seen that the two clutch discs 5, 6 have blade regions 11 on mutually facing axial sides, namely a second axial side 9b of the first clutch disc 5 and a first axial side 10a of the second clutch disc 6, which are arranged and designed such that during operation, ie when the first clutch disc 5 or the second clutch disc 6 is rotating, they generate a cooling fluid flow, here an air flow, which runs radially outwards.

[0034] The more precise design of the respective clutch disc 5,6 is in Fig. 4. It is clear that the blade regions 11 are formed by bent / upright sheet metal sections. These sheet metal sections are implemented as arc-segment-shaped sheets that are attached, here riveted, to the clutch disc 5, 6 (in particular, a plate-shaped base body of the clutch disc). In particular, it is clear that the circumferentially aligned sheet metal sections, with their opposing circumferential end regions, directly form two blade regions 11.

[0035] Taking into account the Fig. 1 to 6 also show that the blade regions 11 are divided into two groups 12a, 12b. A first group 12a of the blade regions 11 serves, in particular, to divert / convey cooling fluid during rotation of the clutch disc 5, 6 in a first direction of rotation or a first direction of rotation relative to the other clutch disc 5, 6. The first group 12a is formed, for example, by the first end regions of the sheet metal sections adjoining a first common circumferential direction.

[0036] A second group 12b of the blade regions 11 serves in particular for the corresponding diversion / transport of cooling fluid during a rotation of the clutch disc 5, 6 in a second direction of rotation or a second relative direction of rotation with respect to the other clutch disc 5, 6. The second group 12b is formed, for example, by the second end regions of the sheet metal sections adjoining a second common circumferential direction.

[0037] In other words, the blade regions 11 arranged on mutually facing axial sides 9b, 10a of the two clutch discs 5, 6 are divided into two groups 12a, 12b, wherein a first group 12a of blade regions 11 is designed such that they generate the cooling fluid flow upon rotation of the respective clutch disc 5, 6 in the first direction of rotation and a second group 12b of blade regions 11 are designed such that they are used to act upon rotation of the respective clutch disc 5, 6 in the second direction of rotation.

[0038] With Fig. 3 and Fig. 4 also clearly shows that each clutch disc 5, 6 has a spring damper 13. The blade areas are arranged radially outside of circumferentially distributed spring elements 14 of the spring damper 13 and radially inside of friction linings 15 that can be brought into frictional contact with the respective pressure plate 7, 8.

[0039] With the Fig. 5 and Fig. 6 clearly shows how the blade areas 11 serve to convey the coolant during operation and, in particular, to establish a cooling fluid circuit, as indicated by the corresponding flow arrows. Upon rotation of the input side and thus associated rotation of the first clutch disc 5 according to Fig. 5 or the second clutch disc 6 according to Fig. 6, the blade regions 11 convey the radially inner air both in the axial direction past the respective pressure plate 7, 8, and in the radial direction, through a gap between the pressure plates 7, 8, which are always arranged axially spaced apart, to the outside. Radially outside the pressure plates 7, 8, the fluid flow then splits into two oppositely rotating cooling circuits and is cooled on the inside of a housing 16 that jointly encloses the two partial clutches 2, 3, such as a clutch bell housing or a transmission bell housing, and is then returned radially inward. The clutch bell housing can, in turn, completely enclose the partial clutches 2, 3, but alternatively can also be partially open and allow a certain exchange of air to the outside / environment.

[0040] With these clutch bells, the air flow stimulated by the blade areas would also have a beneficial effect on the internal components of the dual clutch.

[0041] Comparing the Fig. 5 and Fig. 6 on the one hand and the Fig. 7 and Fig. 8, on the other hand, it can be seen that it is also possible to provide several second air vane regions 17, which are then additionally arranged on the opposite axial sides 9a, 10b of the clutch discs 5, 6. These serve in particular to suck in / introduce the fluid flow radially from the outside in the axial direction toward the pressure plates 7, 8.

[0042] While the first blade regions 11 on the mutually facing axial sides 9b, 10a of the two clutch discs 5, 6 each have an axial extent which exceeds an axial extent of the pressure plate 7, 8 of the partial clutch 2, 3 assigned to it, the second blade regions 17 on the mutually facing axial sides 9a, 10b of the two clutch discs 5, 6 are preferably provided with a smaller axial extent than the pressure plate 7, 8.

[0043] Combined with Fig. 6 or Fig. 8 further illustrates that the corresponding cooling fluid supply also functions in the other relative direction of rotation of the two clutch discs 5, 6.

[0044] In other words, the invention proposes equipping the clutch discs 5, 6 with fan surfaces / blades (blade areas 11) at least on the mutually facing sides 9b, 10a. Particularly on the mutually facing sides of the clutch discs 5, 6, the opposing / counter-rotating movement generates a beneficial airflow, which is also directed radially outward between the pressure plates 7, 8 of the two partial clutches 2, 3. However, all components of the overall clutch can also be reached by a more intensive, better oriented / directed airflow. This overall increased airflow can thus be advantageously utilized for heat dissipation from the friction discs. The thermal behavior of the entire Powershuttle clutch can thus be advantageously improved.

[0045] The Fig. 5 and Fig. 6 show a diagram of the air flows in an exemplary power shuttle clutch, with fan surfaces / blades on the mutually oriented sides of the two clutch discs 5, 6. In Fig. 5, the first partial clutch 2 is closed. In Fig. 6 the second partial clutch 3 is closed.

[0046] The fan surfaces / blades achieve an overall stronger airflow. However, an airflow between the rear sides of the two pressure plates 7, 8 is also particularly advantageous (relative movement between the adjacent fan surfaces / blades of the two clutch discs). This results in increased heat dissipation even when the clutch is currently engaged (after the heat has been introduced). This effect is particularly advantageous for the heat balance of the pressure plates 7, 8 in a dry power shuttle clutch.

[0047] Fig. 7 and Fig. 8 also show a diagram of the air flows in an alternative exemplary power shuttle clutch, with fan surfaces / blades on both sides of the two clutch discs 5, 6. In Fig. 7, the first partial clutch 2 is closed. In Fig. 8 the second partial clutch 3 is closed.

[0048] Fig. 1 then shows the more detailed design of an exemplary power shuttle clutch, with fan surfaces / blades on the mutually oriented sides of the two clutch discs 5, 6. It can be seen that even with clutch discs with dampers there is space to place parts (fan surfaces / blades) on the two sides facing each other.

[0049] In Fig. Figure 1 then shows the diagram of the airflow in an exemplary power shuttle clutch, with fan surfaces / blades on the mutually oriented sides of the two clutch discs 5, 6. It can be seen that an overall stronger airflow is to be expected due to the adjacent fan surfaces / blades of the two clutch discs 5, 6. However, a portion of the airflow is particularly stimulated between the rear sides of the two pressure plates 7, 8. Thus, even with the clutch currently engaged (after the heat input), greater heat dissipation occurs.

[0050] Fig. 3 shows an exemplary Powershuttle clutch, with fan surfaces / blades on each of the two clutch discs 5, 6, whereby one clutch disc 5 is hidden.

[0051] Fig.Figure 4 then shows an example clutch disc 5, 6 with fan surfaces / blades. The fan surfaces / blades can be made, for example, from sheet metal parts and attached to suitable components (e.g., the drive plate). Existing rivets can also be used as attachment points. List of reference symbols 1 dual clutch 2 first partial coupling 3 second partial coupling 4 Actuation system 5 first clutch disc 6 second clutch disc 7 first pressure plate 8 second pressure plate 9a first axial side of the first clutch disc 9b second axial side of the first clutch disc 10a first axial side of the second clutch disc 10b second axial side of the second clutch disc 11 first shovel area 12a first group 12b second group 13 spring dampers 14 Spring element 15 Friction lining 16 housings 17 second blade area 18 first input shaft 19 second input shaft 20 reversing gears 21 Gearbox device 22 Output of the first partial coupling 23 Output of the second partial clutch 24 axis of rotation 25 first counter plate 26 second counter plate 27 first actuating plunger 28 second actuating plunger 29 first operating lever 30 second operating lever

Claims

[1] Double clutch (1) for a powershift reversing gear (20), with a first partial clutch (2), a second partial clutch (3) and an actuating system (4) designed for the alternate actuation of the partial clutches (2, 3), each partial clutch (2, 3) having a clutch disc (5, 6) and a pressure plate (7, 8) which is axially adjustable relative to this clutch disc (5, 6) between an open position and a closed position of the respective partial clutch (2, 3), characterized by that on mutually facing axial sides (9b, 10a) of the two clutch discs (5, 6) a plurality of blade regions (11) are arranged and designed in such a way that they generate a radially outwardly directed cooling fluid flow at least in a closed position of one of the two partial clutches (2, 3). [2] Double clutch (1) according to claim 1, characterized bythat the pressure plates (7, 8) are arranged directly axially adjacent, but axially spaced from one another. [3] Double clutch (1) according to claim 1 or 2, characterized by that the blade areas (11) are designed as bent sheet metal sections. [4] Double clutch (1) according to one of claims 1 to 3, characterized by in that the blade regions (11) arranged on mutually facing axial sides (9b, 10a) of the two clutch discs (5, 6) are divided into two groups (12a, 12b), wherein a first group (12a) of blade regions (11) is designed such that they generate the cooling fluid flow when the respective clutch disc (5, 6) rotates in a first direction of rotation and a second group (12b) of blade regions (11) is designed such that they are used to act when the respective clutch disc rotates in a second direction of rotation. [5] Double clutch (1) according to one of claims 1 to 4, characterized bythat each clutch disc (5, 6) has a spring damper (13) and the blade regions (11) are arranged radially outside spring elements (14) of the spring damper (13) and / or radially inside friction linings (15) which can be brought into frictional contact with the respective pressure plate (7, 8). [6] Double clutch (1) according to one of claims 1 to 5, characterized by that the partial couplings (2, 3) are designed and arranged within a housing (16) in such a way that the blade regions (11) each generate a circular cooling fluid circuit during operation. [7] Double clutch (1) according to one of claims 1 to 6, characterized by that the two clutch discs (5, 6) each have additional blade areas (17) on axial sides (9a, 10b) facing away from each other. [8] Double clutch (1) according to one of claims 1 to 7, characterized bythat the blade regions (11) on the mutually facing axial sides (9b, 10a) of the two clutch discs (5, 6) each have an axial extent which exceeds an axial extent of the pressure plate (7, 8) of the partial clutch (2, 3) assigned to it. [9] Double clutch (1) according to one of claims 1 to 8, characterized by that each partial clutch (2, 3) is designed as a dry-running friction clutch. [10] Reversing gear (20) with a double clutch (1) according to one of the preceding claims and a transmission device (21), wherein a first input shaft (18) of the transmission device (21) is connected to an output (22) of the first partial clutch (2) and a second input shaft (19) of the transmission device (21) is connected to an output (23) of the second partial clutch (3).

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