Dual clutch with only one actuator; and reversing gearbox

Abstract

The invention relates to a double clutch (1) for a power-shiftable reversing transmission (20), comprising a first partial clutch (2), a second partial clutch (3) and an actuating system (4) designed for the alternating actuation of the partial clutches (2, 3), wherein a first actuating element (5) for opening or closing the first partial clutch (2) is motionally coupled to a pressure plate (6) of the first partial clutch (2) and a second actuating element (7) for opening or closing the second partial clutch (3) is motionally coupled to a pressure plate (8) of the second partial clutch (3), and wherein an actuating device (9) for adjusting the actuating elements (5, 7) comprises a linear actuator (10) and the linear actuator (10) is motionally coupled to a first actuating lever (11) that specifies the actuating movement of the first actuating element (5) and to a second actuating lever (12) that specifies the actuating movement of the second actuating element (7).Furthermore, the invention relates to a reversing transmission (20) with this double clutch (1).

Description

[0001] The invention relates to a dual clutch for a powershift reversing transmission (preferably of an agricultural utility vehicle, such as a tractor), comprising a first partial clutch, a second partial clutch, and an actuating system designed for alternately actuating the partial clutches. A first actuating element (of the actuating system) for opening or closing the first partial clutch is motion-coupled to a pressure plate of the first partial clutch, and a second actuating element (of the actuating system) for opening or closing the second partial clutch is motion-coupled to a pressure plate of the second partial clutch. These pressure plates thus form displaceable plates for shifting the respective partial clutch back and forth between its closed position and its open position. The invention further relates to a reversing transmission per se having this dual clutch.

[0002] Dual clutches of this type are already well known in the art. In particular, it is also known to minimize the number of actuators required to operate each partial clutch. For example, DE 10 2011 009 807 A1 discloses a dual clutch arrangement with an actuating unit. A dual clutch is also known from DE 10 2022 122 049 B3, which can be read off from the preamble of claim 1.

[0003] In this context, however, it has become apparent that the existing actuation systems are relatively complex. For example, relatively complex overrunning clutches are required to enable the partial clutches to be operated alternately. The drive of the actuation systems is often also relatively complex, in order to integrate the actuation systems into existing installation spaces and implement the necessary actuation movements there.

[0004] It is therefore an object of the present invention to provide a double clutch which has an actuating system which is easy to manufacture and which is also designed with as few components as possible.

[0005] This is achieved according to the invention in that an actuating device which adjusts the actuating elements has one (namely exclusively one (single)) linear actuator and the linear actuator is motion-coupled to a first actuating lever which specifies the actuating movement of the first actuating element and to a second actuating lever which specifies the actuating movement of the second actuating element.

[0006] Such a linear actuator can be cleverly integrated into existing spaces at a suitable circumferential position of the dual clutch / reversing gear, saving installation space. Actuation via the control levers provides a robust actuating mechanism that is arranged in a relatively space-saving manner for coupling with the actuating elements of the pressure plates.

[0007] Further advantageous embodiments are claimed in the subclaims and explained in more detail below.

[0008] In this context, it is particularly advantageous if the linear actuator is coupled to the adjusting levers and the adjusting levers are pivotally mounted in such a way that, starting from a center position (of the linear actuator), during a linear adjusting movement of the linear actuator in a first axial direction, the first adjusting lever is pivoted while engaging the first partial clutch, while the second partial clutch remains open. It has proven particularly expedient if an actuating plunger of the linear actuator, which is connected to the adjusting levers, forms a first stop which, during its movement in the first axial direction, directly entrains the first adjusting lever. This makes the linear actuator connected to the adjusting lever as simple as possible.

[0009] Accordingly, it is also advantageous if the linear actuator is coupled to the adjusting levers and the adjusting levers are pivotably mounted such that, starting from a center position, during a linear adjusting movement of the linear actuator in a second axial direction (i.e., opposite to the first axial direction), the second adjusting lever is pivoted while engaging the second partial clutch, while the first partial clutch remains open. It has also proven advantageous if the actuating plunger forms a second stop, which accordingly drives the second adjusting lever in the second axial direction. This, in turn, simplifies the design of the actuating device.

[0010] According to the invention, the linear actuator is designed such that it automatically locks in a first position in which the first partial clutch is fully engaged, and in a second position in which the second partial clutch is fully engaged, so that a reliable alternating actuation of the partial clutches is implemented.

[0011] Furthermore, it is advantageous if the first adjusting lever is coupled to a first actuating bearing that adjusts the first actuating element, allowing axial adjustment, and / or if the second adjusting lever is coupled to a second actuating bearing that adjusts the second actuating element, allowing axial adjustment. This allows for a radially compact design.

[0012] Furthermore, it is advantageous if the adjusting levers are each coupled to a sliding sleeve that controls the respective actuating element. This allows the further connection to the adjusting levers to be provided at an optimal axial position.

[0013] If the sliding sleeves are arranged concentrically to a rotation axis of the partial couplings / outputs of the partial couplings, a radially compact design is further promoted.

[0014] If the sliding sleeves are guided directly against each other, the adjusting device can be made both compact and durable.

[0015] If the sliding sleeves directly accommodate an actuating bearing in a non-displaceable manner, the structure is kept as simple as possible.

[0016] The actuating bearings, in turn, are preferably arranged on a common axial side of both actuating elements of the actuating system. This allows the dual clutch with the actuating elements to be implemented as compactly as possible. It has proven particularly useful if the actuating elements are designed as levers.

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

[0019] It shows the only Fig. 1 a longitudinal sectional view of a double clutch according to the invention, which is already connected to input shafts of a reversing gear.

[0020] The figure is merely schematic in nature and therefore serves solely to understand the invention.

[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. The double clutch 1 is also used as a so-called power shuttle clutch for changing from forward to reverse in motor vehicles, in particular in tractors, wherein the changeover process is preferably carried out by pressing a button. The double clutch 1 is thus preferably used in a reversing gear 20, which is used in a commercial vehicle, such as a tractor, i.e. in particular in agricultural machinery. The reversing gear 20 with its shift transmission device 21, which is connected to the double clutch 1 on the side of its input shafts 18, 19, is in Fig. 1 is indicated schematically.

[0022] 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 during operation. The non-engaged / closed sub-clutch 2, 3 is therefore always disengaged / open.

[0023] It is in Fig. 1, it can be seen in principle that the partial clutches 2, 3 are each designed as friction clutches, namely as dry-running friction clutches. Furthermore, the partial clutches 2, 3 are each designed as single-disk friction clutches with only one clutch disc 27, 28.

[0024] An input / torque input of the first partial clutch 2 has a first pressure plate 6 and a first counterplate 29 arranged axially spaced therefrom. A first clutch disc 27 is arranged axially between the first pressure plate 6 and the first counterplate 29. The first clutch disc 27 forms an output 22 / torque output of the first partial clutch 2.

[0025] To actuate the first partial clutch 2 (and, as described below, also the second partial clutch 3), an actuating system 4 is adjustably coupled to the first pressure plate 6. The actuating system 4 has a first actuating element 5 in the form of a lever that is movable between at least two positions. In a first position of the first actuating element 5, corresponding to an engaged position of the first partial clutch 2, the first pressure plate 6 together with the first clutch disc 27 is pressed frictionally against the first counter-plate 29. In particular, a first actuating plunger 30 is connected to the first actuating element 5 for axial connection to the pressure plate 6.

[0026] 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) counter-plate 31, 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 28, which is arranged axially between the second pressure plate 8 and the second counter-plate 31. To actuate the second partial clutch 3, at least one second actuating element 7 of the actuating system 4, likewise in the form of a lever, is provided, offset in the circumferential direction from the first actuating element 5. The second actuating element 7 is motion-coupled to the second pressure plate 8 by means of a second actuating plunger 32.In a first position of the second actuating element 7, the pressure plate 8 together with the second clutch disc 28 is pressed frictionally against the second counter plate 31.

[0027] Since the actuation of the partial clutches 2, 3 takes place alternately, the second partial clutch 3 is opened (corresponding to the first position of the second actuating element 7), while the first partial clutch 2 is closed (corresponding to a second position of the first actuating element 5), and vice versa.

[0028] According to the invention, the respective actuating element 5, 7 can now be actuated by an actuating device 9, which also belongs to the actuating system 4. For both partial clutches 2, 3, a single linear actuator 10 is used to move their actuating elements 5, 7, i.e., to engage and disengage the respective partial clutches 2, 3. The linear actuator 10 is preferably designed as a linear electric servomotor, but can alternatively also be hydraulically actuated.

[0029] In Fig. 1 also clearly shows that the linear actuator 10 is arranged at a specific circumferential position of the double clutch 1 / the reversing gear 20. The linear actuator 10 is aligned with its linearly / axially displaceable movement tappet 24 parallel to a rotational axis 17 of the double clutch 1. According to the invention, the movement tappet 24 interacts with two actuating levers 11, 12 (preferably also designed / designated as a fork) or engages them directly, with the actuating levers 11, 12 each controlling / adjusting one of the two actuating elements 5, 7.

[0030] In this regard, it can also be seen that the two adjusting levers 11, 12, like the two actuating elements 5, 7, are adjustable about their own pivot axis fixed to the housing.

[0031] In its entirety, a first actuating lever 11 is mounted / supported and coupled to the linear actuator 10 in such a way that, starting from a center position of the linear actuator 10 / movement plunger 24, as shown in Fig. 1, when the linear actuator 10 / movement tappet 24 moves in a first axial direction (into a first position), the first actuating lever 11 is pivoted while engaging the first partial clutch. However, during this linear actuating movement in the first axial direction, no movement occurs due to pivoting of the second actuating lever 12 (the second actuating lever 12 and the second actuating element 7 coupled thereto with the second partial clutch 3 thus remain unactuated; this means that the second partial clutch 3 remains open). This is shown in Fig. 1 is implemented in that the first adjusting lever 11 rests against a first stop 25 of the movement plunger 24 in the first axial direction, while the movement plunger 24 is displaced forcelessly relative to the second adjusting lever 12.

[0032] Conversely, the actuation of the second actuating lever 12 functions analogously. Thus, the second actuating lever 12 is also mounted and actuated by the linear actuator 10 in such a way that, when the linear actuator / movement plunger 24 moves in a second axial direction opposite to the first axial direction, starting from the center position, the second actuating lever 12 engages the second partial clutch accordingly and thus pivots the second actuating element 7, while the first actuating lever 11 remains in its rest position and thus the first partial clutch 2 remains open. This is achieved by the second actuating lever 12 abutting against a second stop 26 of the movement plunger 24 in the second axial direction, while the movement plunger 24 is displaced forcelessly relative to the first actuating lever 11.

[0033] The two adjusting levers 11, 12 are mounted in a specific manner. It can be seen that the first adjusting lever 11 has a pivot point 33 fixed to the housing, which is positioned radially outside a driving area 34 acted upon by the linear actuator 10. In contrast, a pivot point 35 fixed to the housing, about which the second adjusting lever 12 can pivot, is positioned radially inside a driving area 36 acted upon by the linear actuator 10. For additional security, the second adjusting lever 12 is supported on a housing stop 37 in the center / neutral position (corresponding to an open position of both partial clutches 2, 3).

[0034] It is preferred to guide the driving areas 34, 36 of the adjusting levers 11, 12, which are designed as pins / dowels, in an (axially extending) elongated hole in the movement tappet 24. The elongated hole directly forms the stops 25, 26 with its ends. Preferably, a spring is located between the driving areas 34, 36, preloading them relative to one another.

[0035] With their radially inner end regions 38, 39, the adjusting levers 11, 12 each engage in a groove / counter-contour of a sliding sleeve 15, 16 arranged concentrically to the axis of rotation 17, in particular concentrically and radially outside two input shafts 18, 19 of the reversing gear 20. The sliding sleeves 15, 16 are slidably mounted on a sleeve region 40 fixed to the housing. The sliding sleeves 15, 16 also slide against one another. A first actuating bearing 13 in the form of a rolling bearing is arranged at an end region of the first sliding sleeve 15 closest to the first actuating element 5. A second actuating bearing 14 in the form of a rolling bearing is arranged at an end region of the second sliding sleeve 16 axially closest to the second actuating element 7. It can be seen that the two actuating bearings 13, 14 are arranged towards a common axial side of both actuating elements 5, 7.The respective partial clutches 2, 3 are thus engaged by pressing the respective actuating bearing 13, 14 onto the actuating element 5 or 7 by the respective actuating lever 11 or 12.

[0036] Furthermore, it is pointed out that the linear actuator 10 is preferably designed such that it is self-locking in its position in which the respective partial coupling 2 or 3 is located and / or in the center position.

[0037] In other words, the inventive idea is to have a single linear actuator for the operation of two clutches (power shuttle: forward / reverse). A single linear actuator avoids the simultaneous engagement of both clutches. The actuator can be hydraulic or electric, but an electric actuator is preferred for position control reasons.

[0038] The linear actuator starts from a middle position in which the two clutches (independent / normal) are open. By activating a rod (movement tappet 24) with play, the first clutch (first partial clutch 2) can be released by pressing the right fork (in Fig. 1; corresponding to the first control lever 11). When we return to the neutral position, the fork is retracted thanks to a spring 42 between the two forks (control levers 11, 12) and up to a (mechanical) stop (either the frame (case stop 37) or a mechanical stop in the release system). Then the second clutch (second partial clutch 3) can be released by pulling on the left fork (in Fig.1; corresponding to the second actuating lever 12). By pulling or pushing, the two release bearings (actuating bearings 13, 14) move in the same direction, since the rotational axis of the forks is located either at the top or bottom of the rod position. An electric linear actuator enables precise position control, which can precisely adjust the clutch modulation and the contact point depending on disc wear. To avoid permanent forward current over a long period, with the risk of electronic overheating, a self-locking function can be implemented in the linear actuator.

[0039] Furthermore, it should be noted that the directions used in this context, axial, radial, and circumferential, refer to the central rotational axis 17 of the dual clutch 1. Accordingly, the axial / axial direction refers to a direction along / parallel to the rotational axis 17, the radial / radial direction refers to a direction perpendicular to the rotational axis 17, and the circumferential direction refers to a direction along a circular line concentrically encircling the rotational axis 17. The rotational axis 17 can also be a third shaft of an agricultural vehicle (tractor) used for a rear PTO shaft.

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), wherein a first actuating element (5) for opening or closing the first partial clutch (2) is coupled in motion to a pressure plate (6) of the first partial clutch (2) and a second actuating element (7) for opening or closing the second partial clutch (3) is coupled in motion to a pressure plate (8) of the second partial clutch (3), characterized byin that an actuating device (9) which adjusts the actuating elements (5, 7) has a linear actuator (10), and the linear actuator (10) is movement-coupled to a first actuating lever (11) which specifies the actuating movement of the first actuating element (5), and to a second actuating lever (12) which specifies the actuating movement of the second actuating element (7), the linear actuator (10) being designed in such a way that it locks automatically in a first position in which the first partial clutch (2) is fully engaged, and in a second position in which the second partial clutch (3) is fully engaged. [2] Double clutch (1) according to claim 1, characterized bythat the linear actuator (10) is coupled to the adjusting levers (11, 12) and the adjusting levers (11, 12) are pivotally mounted such that, starting from a center position, during a linear adjusting movement of the linear actuator (10) in a first axial direction, the first adjusting lever (11) is pivoted while engaging the first partial clutch (2), while the second partial clutch (3) remains open. [3] Double clutch (1) according to claim 1 or 2, characterized by that the linear actuator (10) is coupled to the adjusting levers (11, 12) and the adjusting levers (11, 12) are pivotally mounted such that, starting from a center position, during a linear adjusting movement of the linear actuator (10) in a second axial direction, the second adjusting lever (12) is pivoted while engaging the second partial clutch (3), while the first partial clutch (2) remains open. [4] Double clutch (1) according to one of claims 1 to 3, characterized bythat the first adjusting lever (11) is coupled in an axially adjustable manner to a first actuating bearing (13) which adjusts the first actuating element (5) and / or the second adjusting lever (12) is coupled in an axially adjustable manner to a second actuating bearing (14) which adjusts the second actuating element (7). [5] Double clutch (1) according to one of claims 1 to 4, characterized by that the adjusting levers (11, 12) are each coupled in movement to a sliding sleeve (15, 16) controlling the respective actuating element (5, 7). [6] Double clutch (1) according to claim 5, characterized by that the sliding sleeves (15, 16) are arranged concentrically to a rotational axis (17) of the partial couplings (2, 3). [7] Double clutch (1) according to claim 5 or 6, characterized by that the sliding sleeves (15, 16) are guided directly against one another. [8] Double clutch (1) according to one of claims 5 to 7, characterized bythat the sliding sleeves (15, 16) directly accommodate an actuating bearing (13, 14) in a displacement-proof manner. [9] Reversing gear (20) with a double clutch (1) according to one of the preceding claims and a manual transmission device (21), wherein a first input shaft (18) of the manual transmission device (21) is connected to an output (22) of the first partial clutch (2) and a second input shaft (19) of the manual transmission device (21) is connected to an output (23) of the second partial clutch (3).

Images