Coupling device with an intermediate lever and a displacement-based wear adjustment device acting on it, with a locking device acting directly on a ramp ring

Abstract

Coupling device (1) for an agricultural tractor, with a friction clutch (5) comprising a counter plate (2), a pressure plate (3) which is axially displaceable relative to the counter plate (2) and a clutch disc (4) which can be pressed between the counter plate (2) and the pressure plate (3) by frictional force, an actuating device (6) for axially displacing the pressure plate (3), wherein an actuating lever (7) of the actuating device (6) is pivotably arranged on a housing-fixed bearing device (8) and is indirectly coupled axially displaceably to the pressure plate (3) via an intermediate lever (9) of the actuating device (6) pivotably mounted on the actuating lever (7), wherein the actuating lever (7) is coupled at its radially inner end (10a) to an axially displaceable actuating ring (11) and the intermediate lever (9) bears at its radially inner end (12a) against a support surface (13) of an adjustable ramp device (14), while its radially outer end (12b) is axially displaceably coupled to the pressure plate (3), wherein the ramp device (14) is designed to readjust an initial position of the actuating lever (7) which may change as a result of a wear-related displacement of the pressure plate (3) to the counter plate (2), wherein the ramp device (14) has both a ramp ring (15) defining the support surface (13), which can be driven by a drive (16) having a preloading device (17), and a locking device (18) which is designed such that in its locking state it directly blocks the ramp ring (15).

Description

[0001] The invention relates to a clutch device for an agricultural tractor, comprising a counter plate, a pressure plate axially displaceable relative to the counter plate, and a clutch disc pressed between the counter plate and the pressure plate by frictional engagement. Furthermore, the clutch device has an actuating device for axially displacing the pressure plate, wherein an actuating lever of the actuating device is pivotably arranged on a housing-fixed bearing device and is indirectly coupled axially displaceably to the pressure plate via an intermediate lever of the actuating device which is in turn pivotably mounted on the actuating lever.The actuating lever is coupled at its radially inner end to an axially displaceable actuating ring, and the intermediate lever rests at its radially inner end against a bearing surface of an adjustable ramp device, while its radially outer end is axially displaceably coupled to the pressure plate. The ramp device (as part of a wear adjustment device) is designed to readjust the initial position of the actuating lever, which changes as a result of wear-related displacement of the pressure plate relative to the counter plate.

[0002] Basic coupling devices, also simply referred to as tractor couplings, are already well known in the prior art. One such tractor coupling is disclosed, for example, in DE 10 2022 133 281 A1. The individual components of tractor couplings are usually designed to be so robust that, despite a certain amount of wear on the friction surfaces, the couplings can be operated throughout their entire service life.

[0003] Furthermore, a coupling device for an agricultural tractor with an adjustable ramp device is known from CN 112 963 462 A. Likewise, the earlier, but unpublished, DE 10 2023 122 372 A1 discloses a coupling device for an agricultural tractor with an adjustable ramp device.

[0004] However, past developments and the lightweight construction measures implemented in this context, including reduction of installation space, have shown that tractor couplings are often no longer sufficiently wear-resistant.

[0005] It is therefore an object of the present invention to enable a more efficient clutch actuation of a tractor clutch, which also makes clutches with a compact design usable over a long service life.

[0006] This is solved according to the invention by the fact that the ramp device has both a ramp ring that defines the support surface and which can be driven by a drive having a pre-tensioning device, and a locking device which is designed in such a way that it acts directly on the ramp ring in a blocking manner in its locking state.

[0007] This design of the actuating mechanism allows the tractor clutch to be operated efficiently throughout its entire service life, despite its reduced dimensions. At the same time, it enables low-maintenance operation of the clutch system. This implemented wear adjustment mechanism ensures that the actuating lever's cup height is automatically adjusted according to the clutch's wear condition, thus remaining constant. Even with wear, the cup height does not increase. Overall, the clutch system becomes robust and reliable, exhibiting consistent characteristics (such as the wear adjustment threshold) throughout its entire service life.

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

[0009] Accordingly, it is also advantageous if the drive has a preloading device designed such that it is brought into a preloaded state by the actuating ring during axial clutch actuation (preferably opening the friction clutch). This cleverly generates the drive energy required for subsequent readjustment from the axial adjustment that occurs anyway. The design can thus be further simplified.

[0010] In this regard, it is also advantageous if the locking device is designed such that, in the locked state, it acts against a driving force on the ramp ring generated by the pre-tensioning device in its pre-tensioned state. This allows for a simple and compact design of both the locking device and the pre-tensioning device. Preferably, the locking device automatically assumes its locked state upon the pre-tensioned state of the pre-tensioning device being reached once.

[0011] Accordingly, it is also advantageous if the locking device is designed in such a way that it holds the pretensioning device in the pretensioned state when in the locking state.

[0012] If the locking device is designed in such a way that it maintains the locking state of the preloading device up to a certain wear limit of the contacting friction surfaces of the pressure plate, clutch disc and / or counter plate, normal operation can be carried out as efficiently as possible.

[0013] Furthermore, it is advantageous if the locking device is designed such that, upon exceeding a certain wear limit of the contacting friction surfaces of the pressure plate, clutch disc, and / or counter plate, it automatically assumes an unlocked state, thereby releasing a rotation of the ramp ring using the drive force / energy previously stored in the preloading device and thus readjusting the contact surface to the intermediate lever in the direction of the initial position. This ensures a simple final readjustment.

[0014] To ensure the least possible wear on the actuating device, it is advantageous if the radially inner end of the intermediate lever slides against the support surface designed as a ramp rising or falling in the circumferential direction.

[0015] Furthermore, the actuating mechanism is kept as simple as possible if the axial position of the radially inner end of the actuating lever is directly influenced by the position of the intermediate lever. This ensures that any wear-related adjustment / readjustment of the intermediate lever also directly results in a readjustment of the position of the side of the actuating lever that contacts the actuating ring (the radially inner end).

[0016] Furthermore, it is advantageous if the ramp ring has a large number of locking teeth on a first circumferential section, into which a housing-mounted pawl part of the locking device can engage. Preferably, the ramp ring changes its position (stepwise rotation) with each adjustment step and can thus utilize a new section of these locking teeth on the ramp ring with each subsequent locking action. This makes the locking device particularly compact and wear-resistant.

[0017] If the pawl part has an engagement component that can be brought into positive engagement with several locking teeth simultaneously, the toothing is implemented even more robustly.

[0018] Furthermore, it is advantageous if the ramp ring has a large number of preload teeth on a second circumferential area, into which a clamping element of the preloading device can be engaged. This allows the components of the preloading device and the clamping device to be arranged next to each other in the most efficient and space-saving way possible.

[0019] If the friction clutch is designed as a normally closed clutch, the actuating device, including its wear adjustment, can be implemented as simply as possible.

[0020] Furthermore, it is advantageous to have two friction clutches and to have an actuating device designed for independent actuation of these two friction clutches. This allows for the efficient implementation of a compact dual clutch.

[0021] In other words, the invention proposes that the ramp ring is pre-tensioned circumferentially and prevented from rotating by a locking device (acting directly on the ramp ring). When the height of the actuating levers in the engaged state (preferably for the drive clutch / gear-shifting clutch, which is designed as a normally engaged clutch) rises above a certain point, the locking device is released, causing the circumferentially spring-loaded ramp ring to rotate in the adjustment direction. During this process, the tips / ends of the intermediate levers slide down the ramps of the ramp ring to a lower height, thereby also restoring the lower height of the actuating levers, or more precisely, their actuating tips / ends, to their original (initial) position. This is therefore a displacement-based wear adjustment device.

[0022] The invention will now be explained in more detail below with reference to figures, in which context different embodiments are also illustrated.

[0023] They show: Fig. 1 a schematic representation of a coupling device according to the invention according to a preferred embodiment, wherein in particular the structure of an actuating device of the coupling device can be seen and a closed position / a closed state of a friction clutch is implemented, Fig. 2 a schematic representation of the coupling device similar to the Fig. 1, wherein the actuating device in its actuated state has now adjusted the friction clutch to its open position / its open state, wherein at the same time a preloading device of a wear adjustment device is preloaded relative to a ramp ring and a locking device acting against this preloading device already engages the ramp ring, Fig. 3 a schematic representation of the coupling device similar to the Fig. 1, whereby it is clarified that following the state of the Fig. 2, after the friction clutch is closed again, the locking device holds the preloading device in its preloaded state, Fig. 4 a schematic representation of the coupling device similar to the Fig. 1, wherein the friction clutch closes after a certain wear of the components of the friction clutch, so that the locking device is released, Fig. 5 a schematic representation of the coupling device, wherein in comparison to the Fig. 4. An adjustment of the ramp ring has taken place through the pretensioning device which has meanwhile relaxed. Fig. 6 a schematic representation of the coupling device similar to the Fig. 5 in the state after successful readjustment of the actuating device with the locking device reactivated, Fig. 7 a top view of a partial assembly of the coupling device now shown in more detail, comprising a housing and several actuating levers of the actuating device pivotably mounted thereon, Fig. 8 a perspective view of the coupling device according to Fig. 7, additionally with an actuating ring that acts on the actuating levers to adjust them, Fig. 9 a perspective view of a scene in the Fig. 1 to 8 inserted ramp rings illustrating various teeth interacting with the locking device or the preloading device, Fig. 10 a perspective view of a pawl part of the locking device, as well as Fig. Figures 11a to 16b show different views of the coupling device in the area of ​​the pre-tensioning device and the locking device in the individual states before and after wear-related readjustment.

[0024] The figures are purely schematic and serve solely to illustrate the invention. The same elements are identified by the same reference symbols.

[0025] In Fig. Figure 1 schematically depicts the coupling device 1 according to a preferred embodiment of the invention. The coupling device 1 is designed as a double clutch. Furthermore, the coupling device 1 is used as a tractor clutch, that is, as a clutch in a drive train of an agricultural tractor.

[0026] The coupling device 1 therefore has two friction clutches 5, of which, for the sake of clarity, are in Fig. Figure 1 shows only one friction clutch 5. In alternative embodiments, the clutch device 1 can also be implemented as a single clutch and therefore contain only one friction clutch 5. The two friction clutches 5 can be actuated independently of each other.

[0027] To activate the in Fig. The friction clutch 5 shown in the above is actuated by an actuating device 6, which is also part of the clutch assembly 1. For a more detailed description of the design and function of this actuating device 6, reference is made to DE 10 2022 133 281 A1, which is considered incorporated herein for this purpose. The basic design of the actuating device 6 thus corresponds to the actuating device of DE 10 2022 133 281 A1.

[0028] The actuating device 6 therefore serves to actuate the friction clutch 5, that is, to adjust the friction clutch 5 between a closed position and an open position, the closed position representing a normal / start position of the friction clutch 5. The friction clutch 5 is thus implemented as a normally closed friction clutch 5. The actuating device 6 is therefore arranged in its unactuated / inactivated state such that the friction clutch 5 is closed, and in its actuated / activated state such that the friction clutch 5 is open.

[0029] The actuating device 6 has a known design and includes an actuating lever 7, the radially inner / first end 10a of which is axially displaceable by a corresponding actuating bearing, here with an actuating ring 11 interposed. Furthermore, the actuating lever 7 is mounted at its radially outer / second end 10b in a housing-fixed bearing device 8 (pivotably). The actuating device 6 has several (approximately three) actuating levers 7, which are intended for actuating the friction clutch 5.

[0030] Radially between the first end 10a and the second end 10b, each actuating lever 7 is coupled in a displacement-resistant manner to an intermediate lever 9, preferably also via a bearing device 8 / pivot bearing.

[0031] The intermediate lever 9 rests with its radially outer / second end 12b directly against a coupling element 23 which is connected to a pressure plate 3 of the friction clutch 5 in a displacement-resistant manner. With its radially inner / first end 12a, the intermediate lever 9 rests against a support area, preferably further supported by the housing, in the form of a bearing surface 13 of a ramp ring 15. The ramp ring 15 and the previously mentioned actuating ring 11 are part of a wear adjustment device 24, which will be explained in more detail below.

[0032] The wear adjustment device 24 serves to adjust / recalibrate the contact surface 13 and thus indirectly also to adjust the area of ​​the actuating lever 7 in contact with the actuating ring 11 and thus the actuating bearing in the event of wear occurring during operation of the friction surfaces 19 of the pressure plate 3 and the (usually housing-fixed) counter plate 2, and in particular the clutch disc 4 arranged between them. The wear adjustment device 24 thus serves to adjust / axially adjust a contact area between the intermediate lever 9 and the contact surface 13 / the ramp ring 15 ( / a housing-fixed support point of the intermediate lever 9) at a specific wear path / a specific wear limit.

[0033] The ramp ring 15 forming a ramp device 14 of the wear adjustment device 24 is also in conjunction with the Fig. 7 to 16b. The ramp ring 15 has a support surface 13 designed as a ramp for each intermediate lever 9 and thus for each contact area to an intermediate lever 9.

[0034] The ramps fall in relation to the in Fig. The starting position shown (maximum height of the support surface 13) is shown in the circumferential direction. This is in Fig. 1 greatly simplified representation.

[0035] The ramp ring 15 is fixed to the housing, i.e., attached to the housing. Fig. The housing 20, for example, is rotatably mounted in the 7. The ramp ring 15 can be driven by a preloading device 17. The preloading device 17 is thus part of a drive 16 for driving / rotating the ramp ring 15.

[0036] The preload device 17 has a preload spring 25 which serves to, as described below with regard to the Fig. 1 to 6 to recognize, to temporarily store a preload force. Furthermore, the preloading device 17 has a drive ring 21, which in turn can be directly driven by the actuating ring 11. When the drive ring 21 rotates, it directly preloads the preload spring 25.

[0037] The (disc-shaped) actuating ring 11 has an axially inclined contact surface / contact line / contact chamfer 26 with the drive ring 21. This contact chamfer 26 is formed, for example, by a conical bolt 22 and causes the drive ring 21 to rotate in a specific direction when the actuating ring 11 is moved / displaced axially (when the friction clutch 5 is actuated). The drive ring 21 and the preload spring 25 are matched to each other and, in turn, to the contact chamfer 26 of the actuating ring 11, such that axial movement of the actuating ring 11 during actuation of the friction clutch 5 causes the drive ring 21 to preload the preload spring 25.

[0038] In the ultimately achieved pre-tensioned state of the pre-tensioning device 17, a locking device 18 stores the drive energy required for the subsequent wear adjustment by indirectly supporting the pre-tensioning spring 25 in a pre-tensioned manner.

[0039] The locking device 18 is preferably supported / mounted in a housing-fixed manner on one side and designed to provide positive-locking, rotationally fixed support for the ramp ring 15 on the other. In its locked position, the locking device 18 thus acts directly as a blocking element on the ramp ring 15. The locking device 18 can be unlocked by the actuating ring 11.

[0040] For this purpose, the ramp ring 15 has a plurality of locking teeth 34 on a first circumferential region, into which a housing-fixed pawl part 35 of the locking device 18 can engage and is engaged in the locked position. The locking teeth 34 and the pawl part 35 are aligned such that the ramp ring 15 is positively supported by the pawl part 35 in a first direction of rotation against rotation relative to the housing 20.

[0041] Furthermore, the figures show that the pawl part 35 has an engagement component 36 that can be brought into positive engagement with several locking teeth 34 simultaneously. The engagement component 36 is formed by at least two mating teeth that engage with the locking teeth 34.

[0042] The ramp ring 15 further comprises a plurality of preload teeth 37 on a second circumferential region, which is spaced circumferentially apart from the first circumferential region. A clamping element 38 of the preloading device 17 can be engaged into these teeth. The preload teeth 37 and the clamping element 38 engage with each other when the preloading device 17 is preloaded. The preloading device 17 thus preloads the ramp ring 15 in the first direction of rotation via the clamping element 38.

[0043] As finally in the Fig. As can be seen from figures 4 to 6, when a certain wear limit is reached on the friction surfaces 19 of the counter plate 2, pressure plate 3, and clutch disc 4, the actuating ring 11 is displaced by the changed lever height of the intermediate lever 9 and the actuating lever 7 by the actuating bearing (not shown for clarity) to such an extent that the locking device 18 automatically releases from its locked position and thus immediately releases the preloading device 17. It should be noted that the actuating ring 11, which is displaced by the actuating bearing when the clutch is disengaged / actuated, is, conversely, driven by the actuating levers 7 when the clutch is engaged / closed and, in its worn state, reaches an axial height to trigger the adjustment. The actuating bearing may, under certain circumstances, already lift off the actuating ring 11 in the axial direction; thus, it does not actuate it in this case.

[0044] The preloading device 17 thus transfers the drive energy previously stored in the preload spring 25 directly to the drive ring 21, which in turn rotates the ramp ring 15 via the clamping element 38 and the detent mechanism 27 adjoining the ramp ring 15. This returns the preload spring 25 to its relaxed state, while simultaneously rotating the ramp ring 15 relative to the intermediate lever 9 and thus causing the radially inner end 12a of the intermediate lever 9 to slide along the ramped support surface 13. This ultimately returns the contact area between the intermediate lever 9 and the actuating lever 7 axially to its initial position.

[0045] In the Fig. Sections 7 to 16b then provide several details regarding the preferred designs of the individual components.

[0046] In other words, according to the invention, it is proposed that the locking device 18 does not use the same contact areas on the corresponding components for all adjustment steps. For each subsequent clamping operation of the adjustment device, at least a new area on the components is used. For this purpose, it is proposed that the locking device 18 does not act on the drive ring 21, but directly on the ramp ring 15. The ramp ring 15 has, for example, a plurality (pattern) of locking teeth 34 on a circumferential area. With each adjustment step, the ramp ring 15 changes its position (stepwise rotation), and a pawl part 35 fixed to the housing 20 thus uses a new area of ​​this locking toothing / different locking teeth 34 of the ramp ring 15 with each subsequent locking operation. This ensures that the respective geometry of the newly used locking toothing is advantageously not worn and remains functionally unchanged.The locking action on the pawl part 35 always occurs in the same geometric area. Since the pawl / pawl part 35 faces a locking tooth area of ​​the ramp ring 15, several effective locking teeth 34 can be formed on the pawl. This results in lower stress and advantageously reduced wear on this component. However, it would also be possible to provide only (at least) one locking tooth 34.

[0047] The Fig. Figures 1 to 3 show a diagram of the sequence of events during clutch actuation, with the tensioning of the spring accumulator (preloading device 17) and permanently active adjustment lock (locking device 18) on the ramp ring 15.

[0048] The Fig. Figures 3 to 5 show a diagram of the process during an adjustment step: First, the spring accumulator is tensioned and the adjustment lock on the ramp ring is activated ( Fig. 3) Then the adjustment lock is opened / temporarily deactivated and the ramp ring 15 is moved (namely rotated; Fig. 4) Subsequently, the lever tip height (height / axial position of the inner ends 10a of the actuating levers 7) is adjusted / reduced and the spring accumulator relaxes ( Fig. 5) The adjustment lock on ramp ring 15 is immediately active again ( Fig. 6).

[0049] It is therefore evident that the locking device 18 changes the tooth engagement on the ramp ring 15 after each adjustment step. The pawl part 35 can have multiple teeth opposite the ramp locking teeth. Without wear-related opening of the adjustment lock, movement of the ramp ring in the adjustment direction is permanently prevented (no unintentional adjustment, e.g., by torsional vibration impulses, is possible). After each adjustment step, the pawl part 35 engages the teeth of the ramp ring 15 immediately and without any further active drive (adjustment limited to one step size).

[0050] In the schematic representation according to Fig. Figure 1 shows the assembly as follows: an actuating lever 7 with intermediate lever 9 and adjustment ramps. Furthermore, sections with elements for tensioning the adjusting spring accumulator (pre-tensioning device 17) and for wear-dependent locking / unlocking (wear sensing) of the adjustment are shown.

[0051] A component (actuating element / actuating ring 11) is intermediately mounted between the tips / ends of the actuating levers 7 and the actuating bearing (release bearing). The actuation of the levers (actuating levers 7) is effected indirectly by this component / intermediate part.

[0052] When the clutch (friction clutch 5) is actuated / opened, a ramp mechanism 28 engages during the axial disengagement movement, tensioning a spring element or several springs (preload spring 25) to a higher force / torque level. With sufficiently large axial movement (minimum for disengaging the clutch), the locking device 18 activates and prevents the spring accumulator from immediately returning to its initial position when the clutch is subsequently closed. Thus, when the clutch is closed / unactuated, the spring accumulator initially remains in a tensioned position.

[0053] The Fig. Figures 7 to 10 show different representations of the coupling / coupling device 1 and its components.

[0054] The arrangement and function of the actuating lever 7 (e.g. three arranged in a pattern on a coupling) with intermediate lever 9 and contact of the intermediate lever 9 to a ramp ring 15 mounted on the housing 20 is also recognizable here.

[0055] The wear adjustment primarily affects only one friction clutch 5 (driving clutch) of the dual clutch. Therefore, only the relevant parts of the actuation of this clutch are mentioned in the following explanations.

[0056] It is evident that the wear condition can be compensated for by changing the contact height of the intermediate lever 9 on the ramp ring 15. The height of the actuating levers 7 remains largely unchanged. This also means that the axial height or working travel of the actuating ring between the lever tips and the release / actuating bearing remains largely constant.

[0057] It is also evident that the actuating ring 11 rests on the tips of the actuating levers 7 for the self-adjusting clutch. The release / actuating bearing acts on the lever tips via the inner area of ​​the actuating ring.

[0058] When the clutch is engaged / disengaged, the actuating ring 11 is moved axially. With wear, the axial height of the actuating ring 11 changes accordingly when the clutch is engaged / disengaged.

[0059] To prevent axial separation / lifting of the actuating ring 11 from the tips of the actuating levers 7 when the clutch is closed / unactuated (the release bearing lifts off the actuating levers 7), preload springs exert an axial force on the actuating ring 11 and hold it against the lever tips.

[0060] The arrangement of a ramp ring 15, for example mounted in the housing 20, is recognizable. The ramp ring 15 has a toothed section 29 (with several preload teeth 37 of the detent mechanism 27) and can thus be driven stepwise to the adjusting movements, for example, by a drive spring / a clamping element 38. For this purpose, the clamping element 38, which is fixed to the drive ring 21, must be moved stepwise in the circumferential direction.

[0061] During circumferential movement against the adjustment direction, the radially elastic part (arm) of the clamping element 38 first skips one preload tooth 37 of the toothing 29 / ramp ring toothing. For an adjustment step, the clamping element 38 then advances the ramp ring 15 by one tooth width in the direction of adjustment.

[0062] The drive (force / torque) for this adjustment step is to be provided by the spring accumulator. For this purpose, several spring elements (preload springs 25; here designed as torsion springs, acting between the housing 20 and the drive ring 21, which is mounted, for example, on the housing 20, preferably act between the housing 20 and the drive ring 21 and are mounted, for example, on housing-fixed bolts 31). The force / torque level of the spring accumulator is preferably dimensioned such that it is sufficient for the complete execution of a full adjustment step. The extent of each adjustment step is limited by an end stop acting on the drive ring 21 and / or the clamping element 38.

[0063] The tensioning of the spring accumulator to a force / torque level required for readjustment is to be achieved by the axial movement of the actuating ring 11 when the clutch is disengaged / opened.

[0064] The actuating ring 11 is axially displaceable on several guide elements, e.g., guide pins 32 (directly realized by bolts 31), and can thus follow the movements during clutch actuation, but is supported in the direction of rotation (rotationally fixed). The drive ring 21 is axially fixed (not vertically displaceable) in the housing 20, but rotatably mounted (e.g., in recesses / rotation contours of the lever bearing blocks). A ramp arrangement (ramp mechanism 28) acts between the actuating ring 11 and the drive ring 21. For this purpose, conical bolts 22 are fixed to the actuating ring 11, and ramp sections 33 are formed on the drive ring 21 (e.g., arranged three times; other ramp configurations are also possible). During the axial disengagement movement to open the clutch, the ramp contacts act in such a way that the drive ring 21 is rotated. The rotation occurs against the force / torque of the spring storage unit, which is thus (further) tensioned.The force / energy required to tension the spring is thus derived from the release movement. This means that a slightly increased actuation / release force is required for the tensioning process.

[0065] The adjusting lock has the following described function: The locking spring (locking pawl part 35) fixed to the housing 20 acts directly on a toothed area (locking teeth 34) of the ramp ring 15.

[0066] In Fig. Figure 7 clearly shows the arrangement of the spring accumulator for the ramp ring drive and the adjusting lock on the ramp ring 15. The drive ring 21 and the drive spring are visible, engaging with the drive teeth (preload teeth 37) of the ramp ring 15. Furthermore, the locking spring, fixed to the housing, is shown engaging with a separate locking tooth (locking teeth 34) of the ramp ring 15.

[0067] Fig. Figure 9 shows an exemplary embodiment of the ramp ring 15. In addition to the drive teeth (in the second circumferential region), the ramp ring has a further region (first circumferential region) with locking teeth. To achieve a high driving or locking effect, a mirrored shape of the tooth geometry can be selected, for example. With a suitable tooth shape, a combination of the drive and locking teeth in only one tooth region of the ramp ring 15 is also possible.

[0068] Fig. Figure 10 shows an exemplary embodiment of a locking element (pawl part 35) with a contact point (tooth engagement) to the ramp ring 15. The toothing of the pawl, which may engage in several tooth forms of the ramp ring locking toothing, is visible.

[0069] Fig. Figure 8 shows a view of the coupling with the locking device 18 of the ramp ring 15. The locking device 18 acting on the ramp ring 15 is shown. The locking element (pawl part 35; e.g., a spring sheet elastically pre-stressed in the radial direction) is fixed to the housing 20 and is in contact with the toothed area on the circumference of the ramp ring 15. The actuating ring 11 is provided with a release element (e.g., an axially adjustable bolt). It is also possible to integrate the release element into the shape of the actuating ring 11 (e.g., a formed area of ​​the sheet metal part).

[0070] Fig. Figures 11a to 13b show the operation of the locking device 15 when tensioning the spring accumulator. Fig. 11a and Fig. 11b: Initial situation, clutch closed / unactuated, spring brake untensioned; Fig. 12a and Fig. 12b: Clutch open / actuated; spring brake is tensioned; and Fig. 13a and Fig. 13b: Clutch closed / unactuated, spring accumulator tensioned, ramp ring lock remains closed.

[0071] In the initial state (clutch closed / disengaged, spring accumulator not tensioned), the drive ring 21 is initially held in its end position (stop) by the spring accumulator. The locking plate, due to its elastic preload, permanently engages the locking teeth of the ramp ring 15. When the clutch is engaged / disengaged, the drive ring 21 rotates against the force / torque of the spring accumulator. With sufficiently large axial movement (minimum to disengage the clutch), the teeth of the drive pawl can skip one tooth stage of the drive teeth of the ramp ring 15. When the clutch is closed again (disengaged), the ramp and drive rings remain in their positions due to the action of the ramp ring locking pawl, and the spring accumulator remains tensioned (first stage of adjustment).

[0072] Fig. Figures 14a to 16b show the operation of the locking device when performing the adjusting movement. Fig. 14a and Fig. 14b: Clutch closed / unactuated without wear, spring accumulator tensioned, ramp ring lock closed / activated; Fig. 15a and Fig. 15b: Clutch with wear closed / unactuated, height of the actuating lever tips is increased, actuating ring 11 with the release part is axially higher, ramp ring lock open / deactivated; Fig. 16a and Fig. 16b: Clutch closed / unactuated, the spring accumulator can move the drive ring and the ramp ring, adjustment takes place, spring accumulator relaxes, height of the actuating lever tips is reduced / readjusted, lock is closed / activated.

[0073] The prerequisite for the second stage of an adjustment step is that the drive ring 21 is in its tensioned position. The drive spring has skipped one tooth of the ramp ring drive teeth. The drive ring and the ramp ring initially remain in this position due to the activated ramp ring lock, even when the clutch is closed / disengaged. If sufficient wear has already occurred on the clutch, or if further wear occurs during operation, the height of the actuating lever tips increases. The actuating ring 11 follows this change, also rising to a greater axial height. The release element fixed to the actuating ring 11 (e.g., a bolt with an axial stop) elastically deforms / bends the locking plate upwards.If this movement exceeds a certain level, the pawl no longer engages the locking teeth of the ramp ring, the locking effect is deactivated, and the rotational movement of the ramp ring is released. The drive ring, powered by the spring accumulator, can now rotate the ramp ring in the adjustment direction with its drive spring. The contact of the intermediate lever (on the actuating lever) to the ramp ring changes (axially lower), and the actuating lever reduces its crest height. The initial rise of the actuating lever caused by wear is thus compensated for / eliminated. The second stage of adjustment is complete. The drive ring with spring accumulator is now back in its uncompressed position. When the clutch is subsequently engaged / disengaged, the spring accumulator will be tensioned again (first stage of adjustment).By reducing the height of the actuating lever's tip height, the actuating ring 11, with the release element fixed to it, also returns to a lower axial position. As a result, the pawl can re-engage with the locking teeth of the ramp ring, thus immediately reactivating the locking effect. Reference symbol list 1 coupling device 2 Counter plate 3 pressure plate 4 clutch disc 5 friction clutch 6 Actuating device 7 operating levers 8 Storage device 9 intermediate levers 10a first end of the actuating lever 10b second end of the actuating lever 11 Actuating ring 12a first end of the intermediate lever 12b second end of the intermediate lever 13 Contact surface 14 Ramp device 15 Ramp Ring 16 Drive 17 Pre-tensioning device 18 Locking device 19 friction surface 20 cases 21 Drive ring 22 cone bolts 23 coupling element 24 Wear adjustment device 25 Preload spring 26 Contact angle 27 Locking mechanism 28 Ramp mechanism 29 Gearing 31 bolts 32 guide pins 33 Ramp area 34 Locking tooth 35 Locking pawl part 36 Intervention component 37 Preload tooth 38 clamping element

Claims

[1] Coupling device (1) for an agricultural tractor, with a friction clutch (5) comprising a counter plate (2), a pressure plate (3) which is axially displaceable relative to the counter plate (2) and a clutch disc (4) which can be pressed between the counter plate (2) and the pressure plate (3) by frictional force, an actuating device (6) for axially displacing the pressure plate (3), wherein an actuating lever (7) of the actuating device (6) is pivotably arranged on a housing-fixed bearing device (8) and is indirectly coupled axially displaceably to the pressure plate (3) via an intermediate lever (9) of the actuating device (6) pivotably mounted on the actuating lever (7), wherein the actuating lever (7) is coupled at its radially inner end (10a) to an axially displaceable actuating ring (11) and the intermediate lever (9) bears at its radially inner end (12a) against a support surface (13) of an adjustable ramp device (14), while its radially outer end (12b) is axially displaceably coupled to the pressure plate (3), wherein the ramp device (14) is designed to readjust an initial position of the actuating lever (7) which may change as a result of a wear-related displacement of the pressure plate (3) to the counter plate (2), wherein the ramp device (14) has both a ramp ring (15) defining the support surface (13), which can be driven by a drive (16) having a preloading device (17), and a locking device (18) which is designed such that in its locking state it directly blocks the ramp ring (15). [2] Coupling device (1) according to claim 1, wherein the locking device (18) is designed such that in the locking state it acts against a driving force on the ramp ring (15) generated by the preloading device (17) in its preloaded state. [3] Coupling device (1) according to claim 1 or 2, wherein the locking device (18) is designed such that in the locking state it holds the preloading device (17) in the preloaded state. [4] Coupling device (1) according to one of claims 1 to 3, wherein the locking device (18) is designed such that it maintains the locking state of the preloading device (17) up to a certain wear limit of the friction surfaces (19) in contact of the pressure plate (3), clutch disc (4) and / or counter plate (2). [5] Clutch device (1) according to one of claims 1 to 4, wherein the locking device (18) is designed such that when a certain wear limit of the contacting friction surfaces (19) of the pressure plate (3), clutch disc (4) and / or counter plate (2) is exceeded, it automatically assumes an unlocked state, releasing a rotation of the ramp ring (15) by means of the drive force previously stored in the preloading device (17) and thus adjusting the contact surface (13) to the intermediate lever (9) in the direction of the initial position. [6] Coupling device (1) according to one of claims 1 to 5, wherein the ramp ring (15) has a plurality of locking teeth (34) on a first circumferential area into which a housing-fixed locking pawl part (35) of the locking device (18) can be engaged. [7] Coupling device (1) according to claim 6, wherein the pawl part (35) has an engagement component (36) that can be brought into positive engagement with several locking teeth (34) simultaneously. [8] Coupling device (1) according to one of claims 1 to 7, wherein the ramp ring (15) has a plurality of preload teeth (37) on a second circumferential area into which a clamping element (38) of the preloading device (17) can be engaged. [9] Coupling device (1) according to one of claims 1 to 8, wherein an axial position of the radially inner end (10a) of the actuating lever (7) is directly influenced by the position of the intermediate lever (9). [10] Coupling device (1) according to one of claims 1 to 9, wherein the friction coupling (5) is designed as a normally closed coupling.

Images