Shifting device for a motor vehicle transmission

Abstract

Shifting device for a motor vehicle transmission, in particular a fully automatic stepped transmission (10), with a first transmission component (32) and a second transmission component (34) which are rotatable relative to each other about a transmission axis (A), a friction ring (36) which is connected to the first gear component (32) in a rotationally fixed and axially displaceable manner in the circumferential direction and has a conical friction surface (38), several first lamellae (40) which are connected to each other in a rotationally fixed and axially displaceable manner in the circumferential direction, and several second lamellae (42) which are connected to each other and to the second transmission component (34) in a rotationally fixed manner in the circumferential direction and axially displaceable, wherein the first and second plates (40, 42) are arranged alternately one behind the other and form a plate coupling (44), wherein the first lamellae (40) are rotationally fixed to a synchronizing element (48) and the synchronizing element (48) has a conical counter-surface (50) axially adjacent to the conical friction surface (38) of the friction ring (36) for speed synchronization between the first transmission component (32) and the first lamellae (40), characterized in that one of the first lamellae (40) is designed as a synchronization lamella (52) to which the synchronization element (48) is integrally formed and / or that one of the first lamellae (40) is designed as a lamella carrier (76) which couples all first lamellae (40) in a circumferentially positive-locking manner.

Description

[0001] The invention relates to a shifting device for a motor vehicle transmission, in particular a fully automatic multi-step transmission, comprising a first transmission component and a second transmission component which are rotatable relative to one another about a transmission axis, a friction ring which is connected to the first transmission component in a circumferentially fixed and axially displaceable manner and has a conical friction surface, a plurality of first plates which are connected to one another in a circumferentially fixed and axially displaceable manner, and a plurality of second plates which are connected to one another and to the second transmission component in a circumferentially fixed and axially displaceable manner, wherein the first and second plates are arranged alternately one behind the other and form a multi-plate clutch,and wherein the first plates are coupled in a rotationally fixed manner to a synchronization element and the synchronization element has a conical counter-surface axially adjacent to the conical friction surface of the friction ring for speed synchronization between the first transmission component and the first plates,

[0002] In addition to manual gearboxes, automatic gearboxes, in particular stepped fully automatic gearboxes with hydrodynamic torque converters and planetary gears, are used in vehicle technology for power transmission.

[0003] Such fully automatic multi-stage transmissions function as powershift transmissions without interrupted traction, with power flowing through planetary gear sets and gear changes occurring by engaging or disengaging individual planetary gear set elements. Currently, the coupling of individual planetary gear set elements is usually achieved using multi-plate clutches, which must be designed for a maximum torque to be transmitted and accordingly comprise a large number of friction points or plates for torque transmission. Due to the numerous friction points, the undesirable drag torques in the decoupled state are quite high and have a detrimental effect on transmission efficiency.

[0004] For this reason, a vehicle transmission has already been proposed in the generic document DE 102 44 523 A1 in which the inner plate carrier is coupled to a rotatable transmission component, e.g. a transmission shaft, via a synchronizer. The synchronizer enables either decoupling, frictional coupling, or positive coupling of the inner plate carrier to the rotatable transmission component. When the synchronizer is decoupled, drag torques also occur; however, these are significantly lower due to the considerably smaller friction surfaces compared to a multi-plate clutch. When the shift device is decoupled, i.e. when the multi-plate clutch is open and the synchronizer is decoupled, the lower drag torques mean that relative rotation occurs exclusively or at least predominantly in the area of ​​the synchronizer and no longer or hardly at all in the area of ​​the multi-plate clutch, thus increasing the transmission efficiency.

[0005] However, the design of the vehicle transmission disclosed in DE 102 44 523 A1 is relatively complex due to the many individual components and three separate springs for axially loading these individual components and, moreover, has an undesirably high level of shifting force.

[0006] Other multi-plate clutches are known, for example, from US 2002 / 0144563 A1, DE 101 01 407 C1, and DE 103 31 370 A1. DE 101 01 407 C1 discloses a viscous clutch having an annular space filled with a highly viscous fluid and containing first and second clutch plates. DE 103 31 370 A1 shows an automatic transmission with a hydraulically actuated shift element that has an inner and an outer plate carrier, and US 2002 / 0144563 is designed so that the plates can implement a variety of speed ratios.

[0007] From DE 10 2014 117 194 A1 a switching device is known which essentially corresponds to a cone clutch with positive engagement.

[0008] The object of the invention is to keep the number of individual components low and to create a structurally simple switching device for a motor vehicle transmission, which contributes to a high transmission efficiency due to low drag torques.

[0009] According to the invention, this object is achieved by a shifting device of the type mentioned at the outset, in which one of the first plates is designed as a synchronization plate to which the synchronization element is integrally formed and / or in which one of the first plates is designed as a plate carrier which positively couples all of the first plates in the circumferential direction. The integral molding of the synchronization element onto one of the first plates and / or the design of one of the first plates as a plate carrier enables a particularly simple and compact design of the shifting device with a comparatively small number of individual components, in that one of the first plates has a molded-on, angled section on the radial inside which assumes another function, namely forming the friction surface for a synchronization element or serving as a plate carrier for other plates.

[0010] According to one embodiment of the shifting device, the first transmission component forms a transmission shaft rotatable about the transmission axis or is rigidly connected to such a transmission shaft, while the second transmission component forms a further transmission shaft rotatable about the transmission axis or is rigidly connected to such a further transmission shaft. The two separate transmission shafts are, in particular, coaxially arranged transmission shafts of different planetary gear sets, which can be speed-adjusted by the shifting device.

[0011] According to an alternative embodiment of the shifting device, the first transmission component or the second transmission component forms a transmission shaft rotatable about the transmission axis or is rigidly connected to such a transmission shaft, while the other transmission component forms a rotationally fixed transmission housing or is rigidly connected to such a transmission housing. In this case, the shifting device acts as a brake, which can decelerate the rotating transmission shaft and lock it rotationally fixed to the housing. The multi-disk clutch then forms a multi-disk brake in the narrower sense.

[0012] The synchronization plate preferably comprises an annular disk and circumferentially spaced friction projections, each friction projection forming a synchronization element with a conical counter-surface and being integrally formed on a radial edge of the disk. This allows the synchronization plate to be manufactured as a formed sheet metal plate with minimal manufacturing effort.

[0013] Alternatively, it is also conceivable that the synchronization element is a separate synchronization ring which is axially loaded against one of the first plates and bears against it, in particular wherein the synchronization ring has axial coupling projections for the rotationally fixed coupling with the first plate, which engage in corresponding recesses of the first plate.

[0014] Preferably, an actuating body is provided for axially actuating the first and second plates, wherein the actuating body is axially movable from an unactuated initial position via a synchronization position and a positive locking position up to a clutch position, wherein in the unactuated initial position the multi-plate clutch is opened and the first plates are not coupled to the first transmission component in the circumferential direction, wherein in the synchronization position the multi-plate clutch is substantially opened and the first plates are coupled to the first transmission component in the circumferential direction via a friction connection, wherein in the positive locking position the multi-plate clutch is substantially opened and the first plates are coupled to the first transmission component in the circumferential direction via a positive locking connection,and wherein, in the clutch position, the multi-plate clutch is closed, and the first plates are coupled to the first transmission component in the circumferential direction via a positive connection. Consequently, only a single actuating element is required to engage the shifting device, which, with a short shifting travel, first effects synchronization between the first transmission component and the first plates by engaging the multi-plate clutch, and then ensures a frictional connection between the first and second transmission components in the circumferential direction.

[0015] In this case, the synchronization plate is preferably the first plate located axially closest to the actuating body. When the actuating body exerts axial pressure on the multi-plate clutch, it is thus possible to ensure, with minimal effort, that speed synchronization occurs between the first transmission component and the first plates before the multi-plate clutch is engaged.

[0016] According to one embodiment of the shifting device, with the exception of the synchronization plate, each of the first plates has coupling extensions spaced apart in the circumferential direction on a radial plate edge. The coupling extensions extend in the axial direction and each engage in a space between two circumferentially adjacent extensions of the axially adjacent first plate. In this way, two adjacent first plates are connected to one another in a rotationally fixed manner, resulting in an overall series connection through which all first plates are ultimately rotationally fixedly coupled to one another.

[0017] In this embodiment of the switching device, the coupling extensions of the first plate axially furthest away from the actuating body can engage in recesses of the first transmission component in the positive locking position and the coupling position of the actuating body in order to establish a rotationally fixed positive locking connection between the first transmission component and the first plates.

[0018] According to an alternative embodiment of the switching device, the first plate axially furthest away from the actuating body is designed as a plate carrier for the rotationally fixed positive coupling of all first plates.

[0019] In this embodiment, the first plate, designed as a plate carrier, can have an annular plate disc, with axially bent coupling tabs spaced circumferentially apart and connected to one another by a stabilizing ring at an end facing away from the plate disc. The stabilizing ring results in a particularly high load-bearing capacity and torque transmission capacity of the multi-plate clutch.

[0020] Furthermore, the coupling tabs of the first plate designed as a plate carrier can engage in recesses of the first transmission component in the positive locking position and the coupling position of the actuating body in order to establish a rotationally fixed positive locking connection between the first plates and the first transmission component.

[0021] According to a preferred embodiment of the shifting device, a spring element is provided which axially loads the conical friction surface of the friction ring toward the conical counter-surface of the synchronization element. The first transmission component, the friction ring, and the spring element form, in particular, an axially preloaded, preassembled unit.

[0022] The friction ring can, for example, be integrally formed on a first axial end of a sheet metal sleeve, with the sheet metal sleeve having elastic locking elements at an opposite second axial end for forming a locking connection with the first transmission component. This integration of the friction ring into a sheet metal sleeve results in an extremely compact design and a particularly small number of individual components required for the shifting device.

[0023] In this case, the spring element is preferably supported on the first gear component and on bent spring bearing tabs of the sheet metal sleeve.

[0024] Furthermore, it is preferred that the first transmission component is a clutch disc with radially outwardly projecting claws, wherein sheet metal tabs are formed on the second axial end of the sheet metal sleeve, which extend between adjacent claws of the clutch disc and connect the friction ring to the clutch disc in a rotationally fixed manner. The sheet metal sleeve is thus an advantageous multifunctional component, which has a conical friction surface for speed synchronization, sheet metal tabs for a rotationally fixed connection to the first transmission component, and optionally spring bearing tabs for supporting a spring element.

[0025] Further features and advantages of the invention will become apparent from the following description of preferred embodiments with reference to the drawings, in which: -Fig. 1 shows a transmission diagram of a fully automatic multi-step transmission with a switching device according to the invention; - Fig. 2 is an exploded perspective view of a switching device according to the invention according to an embodiment; - Fig. 3 a partially sectioned, perspective exploded view of the switching device according to Fig. 2; - Fig. 4 a longitudinal section through the assembled switching device according to Fig. 2 in an unactuated initial position; - Fig. 5 a further longitudinal section through the assembled switching device according to Fig. 2 the unactuated initial position; - Fig. 6 shows a further longitudinal section through the assembled switching device according to Fig. 2 the unactuated initial position; - Fig. 7 a detailed section through a pre-assembled unit of the switching device according to Fig. 2; - Fig. 8 a perspective view of the pre-assembled unit according to Fig. 7; - Fig. 9 a detailed section through the multi-disk clutch of the switching device according to Fig. 2; - Fig. 10 a perspective view of the multi-disk clutch according to Fig. 9; - Fig. 11 a longitudinal section through the switching device according to Fig. 2 in a coupling position; - Fig. 12 a longitudinal section through a further embodiment of the switching device according to the invention in an unactuated initial position; - Fig. 13 a detail of the switching device according to Fig. 12 in the area of ​​the multi-plate clutch; - Fig. 14 is an exploded perspective view of the switching device according to Fig. 12; - Fig. 15 a longitudinal section through a further embodiment of the switching device according to the invention in an unactuated initial position; - Fig. 16 a further longitudinal section through the switching device according to Fig. 15; - Fig. 17 is a perspective exploded view of a pre-assembled assembly of the switching device according to Fig. 15; - Fig. 18 is an exploded perspective view of a switching device according to the invention according to a further embodiment; - Fig. 19 a longitudinal section through the assembled switching device according to Fig. 18 in an unactuated initial position; - Fig. 20 shows a further longitudinal section through the assembled switching device according to Fig. 18 in an unactuated initial position; - Fig. 21 a perspective view of a multi-disk clutch of the switching device according to Fig. 18; - Fig. 22 a sectional detail of the switching device according to Fig. 19; and - Fig. 23 a longitudinal section through the assembled switching device according to Fig. 19 in a clutch position.

[0026] The Fig. Figure 1 shows an electrohydraulically controlled, fully automatic multi-step transmission 10 of a motor vehicle with a torque converter 12, four planetary gears or planetary gear sets 14, and a schematically indicated transmission housing 16. Furthermore, an input shaft 18, an output shaft 20, and several transmission shafts 24 are provided, whereby the planetary gear carriers, sun gears, and ring gears of the planetary gears are also referred to below as transmission shafts 24. The transmission shafts 24 are assigned to the individual planetary gear sets 14 and are arranged coaxially with one another.

[0027] The multi-step transmission 10 also has switching devices 26, 28 which can be acted upon by hydraulic pressure and which can couple a transmission shaft 24 either to another transmission shaft 24 or to the transmission housing 16 or can decouple the transmission shaft 24 from the other transmission shaft 24 or the transmission housing 16.

[0028] A switching device 26, which couples the transmission shaft 24 to the transmission housing 16, is also referred to as a braking device, and a switching device 28, which couples two transmission shafts 24 to one another, is also referred to as a clutch device. In the present exemplary embodiment, six switching devices 26, 28 are provided, of which three switching devices 26 are designed as braking devices and three switching devices 28 as clutch devices. By way of example, according to Fig. 1 two braking devices and one coupling device in the coupled state (indicated by hatching) as well as one braking device and two coupling devices in the uncoupled state.

[0029] Through various switching combinations of the switching devices 26, 28, the gear ratios corresponding to the individual gear stages of the multi-stage transmission 10 are then obtained between the input shaft 18 and the output shaft 20.

[0030] Since the general design and functioning of fully automatic step transmissions 10 are already generally known from the prior art, this will not be discussed further and only the structural design and function of the switching devices 26, 28 according to the invention will be described in detail below.

[0031] The Fig. 2 to 11 show an embodiment of the switching device 26 of a motor vehicle transmission, specifically a fully automatic multi-step transmission 10, wherein the switching device 26, in particular an actuating body 30 of the switching device 26 can assume different axial positions, specifically an axial starting position ( Fig. 4 to 6), an axial synchronization position, an axial form-locking position and an axial coupling position ( Fig. 11).

[0032] The switching device 26 comprises a first transmission component 32 and a second transmission component 34, which are rotatable relative to one another about a transmission axis A, a friction ring 36 which is connected to the first transmission component 32 in a rotationally fixed and axially displaceable manner in the circumferential direction and has a conical friction surface 38, a plurality of first plates 40 which are connected to one another in a rotationally fixed and axially displaceable manner in the circumferential direction, and a plurality of second plates 42 which are connected to one another and to the second transmission component 34 in a rotationally fixed and axially displaceable manner in the circumferential direction, wherein the first and second plates 40, 42 are arranged alternately one behind the other in the axial direction and form a multi-plate clutch 44.

[0033] In the embodiment according to the Fig. 2 to 11, the first plates 40 are inner plates that are connected to one another on a radial inner side in a rotationally fixed and axially displaceable manner. The coupling of the first plates 40 in the circumferential direction will be discussed in more detail later. Accordingly, the second plates 42 are outer plates that are each connected to the second transmission component 34, designed as an outer plate carrier, in a rotationally fixed and axially displaceable manner.

[0034] The first transmission component 32 is in the embodiment according to the Fig. 2 to 11, a clutch disc 46 is rigidly connected to a transmission shaft 24 of the multi-step transmission 10 or even formed integrally therewith. The second transmission component 34, on the other hand, is designed as a rotationally fixed transmission housing 16 or is rigidly connected to such a transmission housing 16. Accordingly, the switching device 26 acts as a braking device and can lock the transmission shaft 24, which is rigidly connected to the clutch disc 46, to the transmission housing 16.

[0035] Instead of the fixed connection to the transmission housing 16, the second transmission component 34 can alternatively be designed as an additional transmission shaft 24 or be fixedly connected to such an additional transmission shaft 24. This additional transmission shaft 24, which is fixedly connected to the second transmission component 34, and the transmission shaft 24, which is fixedly connected to the first transmission component 32, are explicitly two different, separate transmission shafts 24 of different planetary gear sets 14, which are arranged in particular coaxially. Such a switching device 28 then acts accordingly as a clutch device, which can couple the transmission shaft 24 of one planetary gear set 14 to the transmission shaft 24 of another planetary gear set 14 via a multi-plate clutch 44 and a synchronization in the direction of rotation.In this case, a speed adjustment first takes place between the first plates 40 and the first transmission component 32, before the transmission shafts 24 are essentially connected in a rotationally fixed manner via a frictional connection of the multi-plate clutch 44 and a positive connection of the synchronization.

[0036] The synchronization between the first plates 40 and the clutch disc 46, which is fixedly connected to the transmission shaft 24, is provided in order to reduce the relatively high drag torques in the multi-plate clutch 44 that occur when the multi-plate clutch 44 is open.

[0037] For this purpose, the first plates 40 are coupled in a rotationally fixed manner to a synchronization element 48, wherein the synchronization element 48 has a conical counter-surface 50 axially adjacent to the conical friction surface 38 of the friction ring 36 for speed synchronization between the first transmission component 32 and the first plates 40.

[0038] Based on the Fig. 3, Fig. 4, Fig. 9 and Fig. 11 clearly shows that one of the first plates 40 is designed as a synchronization plate 52, onto which the synchronization element 48 is integrally formed. The synchronization plate 52 comprises an annular plate disc extending in a plane perpendicular to the transmission axis A, as well as circumferentially spaced friction projections 54, each friction projection 54 forming a synchronization element 48 with a conical counter surface 50 and being integrally formed on a radially inner edge of the plate disc.

[0039] In order to ensure reliable synchronization before the multi-plate clutch 44 is closed, the synchronization plate 52 is arranged as close as possible to the actuating body 30 in the axial direction. Particularly preferably, the synchronization plate 52 is even the first plate 40 arranged axially closest to the actuating body 30, as shown in the Fig. 4 and Fig. 11 shown.

[0040] According to the Fig. 9 and Fig. 10, with the exception of the synchronization plate 52, each of the first plates 40 has coupling extensions 56 spaced apart in the circumferential direction on a radially inner plate edge, wherein the coupling extensions 56 extend in the axial direction and each engage in a space between two circumferentially adjacent coupling extensions 56 of the axially adjacent first plate 40. In this way, two adjacent first plates 40 are connected to one another in a rotationally fixed manner, resulting in an overall series connection through which all first plates 40 are ultimately rotationally fixedly coupled to one another.

[0041] Based on the Fig. 10 it becomes clear that the friction projections 54 of the synchronization plate 52 have the same distribution and dimensions in the circumferential direction as the coupling projections 56 of the remaining first plates 40. Consequently, the synchronization plate 52 can also be easily coupled to the remaining first plates 40 in the circumferential direction by means of the coupling projections 56 of the axially adjacent first plate 40 in a substantially rotationally fixed manner by means of a positive fit.

[0042] Due to the described positive coupling of the first plates 40 in the circumferential direction, a separate plate carrier for the first plates 40 can advantageously be dispensed with. This simplifies the design of the switching device 26, and the number of individual components is advantageously reduced.

[0043] The coupling extensions 56 of the first plate 40, which is axially furthest away from the actuating body 30, are also used to establish a rotationally fixed positive connection between the circumferentially coupled first plates 40 and the first transmission component 32. The first transmission component 32 is according to the Fig. 3 and Fig. 8 is designed as a clutch disc 46 with radially outwardly projecting claws 58, wherein the coupling extensions 56 of the first plate 40 axially furthest away from the actuating body 30 in the form-locking position and the coupling position of the actuating body 30 (see Fig. 11) engage in the circumferential direction between the claws 58 and form a rotationally fixed positive connection with the transmission shaft 24 via the clutch disc 46.

[0044] According to the Fig. 4 to 6, the switching device 26 furthermore has a spring element 60 which acts on the conical friction surface 38 of the friction ring 36 axially in the direction of the conical counter-surface 50 of the synchronization element 48.

[0045] In the embodiment according to the Fig. 2 to 11, the friction ring 36 is formed on a first axial end of a sheet metal sleeve 62, wherein the sheet metal sleeve 62 has elastic locking elements 64 at an opposite second axial end for forming a locking connection with the first transmission component 32. The spring element 60 is supported in the axial direction on the one hand on the first transmission component 32 and on the other hand on bent spring bearing tabs 66 of the sheet metal sleeve 62 (see Fig. 5 and Fig. 7), wherein the spring bearing tabs 66 are tongues exposed by punching into the sheet metal sleeve 62, which are angled radially inwards.

[0046] In this way, the first transmission component 32, the spring element 60 and the friction ring 36 or the sheet metal sleeve 62 form an axially pre-stressed, pre-assembled unit 63, as shown in Fig. 8 is shown.

[0047] If the friction ring 36 is now axially acted upon by the actuating body 30 via the synchronization element 48 of the synchronization plate 52, the sheet metal sleeve 62 can move toward the first transmission component 32 against an axial force of the spring element 60. Consequently, the magnitude of the synchronization torque between the friction surface 38 and the counter surface 50 is limited by the axial spring force of the spring element 60.

[0048] Based on the Fig. 8 also shows that sheet metal tabs 68 are formed on the second axial end of the sheet metal sleeve 62, which extend between adjacent claws 58 of the clutch disc 46, so that the friction ring 36 is connected in a rotationally fixed manner to the transmission shaft 24 via the clutch disc 46 in all axial switching positions of the actuating body 30.

[0049] The operation of the switching device 26 is described below starting from the Fig. 4 to 6, the unactuated initial position of the actuating body 30 is described.

[0050] In the illustrated embodiment, the switching device 26 is part of an electro-hydraulically controlled, fully automatic multi-step transmission 10, so that the actuating body 30 can be acted upon by the pressure of a hydraulic fluid in order to influence the rotation of the clutch disc 46 or the transmission shaft 24.

[0051] Instead of a hydraulic actuation, an electric motor actuation of the switching device 26 is of course also conceivable.

[0052] According to the Fig. 4 to 6, the second transmission component 34 has a cylinder section 70. Furthermore, the actuating body 30 is designed as a piston, which is guided axially displaceably within the cylinder section 70. The cylinder section 70 and the actuating body 30, designed as a piston, define a pressurizable, annular chamber 72 for axial displacement of the piston.

[0053] According to the Fig. 4 to 6, the actuating body 30 moves to the left as the hydraulic fluid pressure increases. To return the actuating body 30 to the right, a spring (not shown) can be provided, for example, which urges the actuating body 30 into its axial starting position shown. Alternatively, it is also conceivable for the actuating body 30 to be returned hydraulically.

[0054] In the unactuated, axial initial position of the actuating body 30 according to the Fig. 4 to 6, the friction ring 36 and the synchronization element 48 are in a so-called release position, in which the friction surface 38 is spaced from the counter surface 50. Consequently, the first plates 40 are not coupled to the first transmission component 32 in the circumferential direction.

[0055] Furthermore, in the unactuated initial position of the actuating body 30, the axially adjacent first and second plates 40, 42 are also released, i.e., axially spaced from each other. This means that the multi-plate clutch 44 is open.

[0056] In the release position of the synchronization, a drag torque occurs when there is a speed difference between the first transmission component 32 and the second transmission component 34. However, due to the significantly smaller friction surface, this drag torque is considerably lower than the drag torque of the opened multi-plate clutch 44. Accordingly, in the starting position of the switching device 26, relative rotation takes place exclusively or at least predominantly within the synchronization between the friction ring 36 and the synchronization element 48. Due to the drag torque in the (open) multi-plate clutch 44, the first plates 40 move synchronously or at least largely synchronously with the second plates 42, so that in the starting position of the switching device 26, only the lower drag torque of the synchronization occurs, which has a positive effect on the transmission efficiency.

[0057] As a result of the incipient pressurization of the chamber 72, the actuating body 30 moves to the left into an axial synchronization position and, via the adjacent, axially outer second plate 42, acts on the synchronization plate 52 and thus the conical counter-surface 50 of the synchronization element 48 against the conical friction surface 38 of the friction ring 36. The contact between the two conical surfaces leads to synchronization, i.e. a speed adjustment between the first plates 40 and the friction ring 36 or the first transmission component 32 which is connected in a rotationally fixed manner to the friction ring 36.

[0058] Due to the axial force of the spring element 60, the released multi-plate clutch 44 is not closed. Only a frictional torque acts between the plate disk of the synchronization plate 52 and the second plate 42 arranged axially between the synchronization plate 52 and the actuating body 30. Due to the conical reinforcement between the conical friction surface 38 and the conical counter-surface 50, the frictional torque generated there dominates over the frictional torque in the flat friction surface between the synchronization plate 52 and the second plate 42 axially adjacent to the actuating body 30, whereby the speed of all first plates 40 is synchronized to the speed of the first transmission component 32. The magnitude of the synchronization torque is limited by the axial force of the spring element 60.

[0059] When the hydraulic pressure in the chamber 72 increases, the first plates 40 and the second plates 42 of the multi-plate clutch 44 are displaced axially in the direction of the clutch disc 46 until the coupling extensions 56 of the first plate 40 axially furthest away from the actuating body 30 engage in the spaces between the claws 58 of the clutch disc 46 in order to establish a rotationally fixed positive connection between the first plates 40 and the first transmission component 32.

[0060] When the positive connection is established but the multi-plate clutch 44 is still largely open, the actuating body 30 is in its axial positive locking position.

[0061] If the coupling extensions 56 of the first plate 40 axially furthest from the actuating body 30 cannot be brought into direct engagement with the clutch disc 46 between the claws 58 because the coupling extensions 56 axially border the claws 58, the multi-plate clutch 44 is at least temporarily partially closed due to the hydraulic pressure in the chamber 72, thereby increasing the frictional torque in the multi-plate clutch 44. As a result of this increased frictional torque, a differential speed builds up between the first plates 40 and the first transmission component 32, which enables the coupling extensions 56 to dock between the claws 58.

[0062] If the hydraulic pressure in the chamber 72 is further increased in the positive locking position of the actuating body 30, the first plates 40 and the second plates 42 of the multi-plate clutch 44 are initially moved up to an axial stop ring 74 ( Fig. 11) and then axially compressed. The actuating body 30 then assumes its axial coupling position, in which the multi-plate clutch 44 is closed and the first plates 40 are coupled circumferentially to the first transmission component 32 via a positive connection.

[0063] In this clutch position, the full hydraulic pressure can now be applied in the chamber 72 in order to carry out a speed adjustment between the first transmission component 32 and the second transmission component 34 or to transmit a desired torque.

[0064] When the hydraulic pressure in the chamber 72 drops, the tensioned spring element 60 can axially reset the slats 40, 42, ie according to Fig. 11 to the right, whereby the first plates 40 are decoupled from the clutch disc 46 in the circumferential direction. As soon as the actuating body 30 returns to its unactuated, axial starting position, all friction parts of the switching device 26 can separate from each other or release within the existing axial clearances.

[0065] The Fig. 12 to 14 show a further embodiment of the switching device 26, which differs from the embodiment according to the Fig. 2 to 11 differs only with regard to the coupling of the first lamellae 40 in the circumferential direction.

[0066] According to the Fig. 12 to 14, one of the first lamellae 40 forms a lamella carrier 76, which positively couples all of the first lamellae 40 in the circumferential direction.

[0067] Based on the Fig. 12 and Fig. 13 it becomes clear that in the present case the first slat 40 which is axially furthest away from the actuating body 30 is designed as a slat carrier 76 for the rotationally fixed positive coupling of all first slats 40.

[0068] According to Fig. 14, the first plate 40, designed as a plate carrier 76, has an annular plate disc extending in a plane perpendicular to the transmission axis A. Axial bent coupling tabs 78 are formed on a radially inner edge of the plate disc, spaced apart in the circumferential direction, and are connected to one another at an end facing away from the plate disc by an integrally formed stabilizing ring 80. The first plate 40 is a purely stamped and bent part.

[0069] The coupling extensions 56 of the first lamellae 40, which are arranged axially between the synchronization lamella 52 and the first lamella 40 axially furthest away from the actuating body 30, can thereby be arranged in a manner different from the embodiment according to the Fig. 2 to 11. Thus, the coupling extensions 56 of these first lamellae 40 are Fig. 13 are no longer axially formed, but are merely designed as radially inward-projecting projections.

[0070] By means of the axially interlocked coupling extensions 56 of two adjacent first lamellae 40 according to the Fig. 9 and Fig. 10, the frictional moments that occur are transferred from one first plate 40 to the next first plate 40. As a result, the frictional moments accumulate at the first plate 40 axially furthest from the actuating body 30, so that its freely projecting coupling extensions 56 are subjected to high loads. In contrast, the coupling tabs 78 of the first plate 40, designed as plate carriers 76, do not project freely in the axial direction, but are connected to one another by the stabilizing ring 80. This basket-like, closed shape of the plate carrier 76 results in a particularly high load-bearing capacity of the coupling tabs 78.

[0071] Analogous to the embodiment according to the Fig. 2 to 11, the coupling tabs 78 engage between the claws 58 of the clutch disc 46 in the positive locking position and the coupling position of the actuating body 30 in order to establish a rotationally fixed positive locking connection between the first plates 40 and the first transmission component 32.

[0072] The Fig. 15 to 17 show a further embodiment of the switching device 26, which differs from the embodiment according to the Fig. 2 to 11 differ only with regard to the structural design of the pre-assembled unit 63.

[0073] The complex sheet metal sleeve 62 according to the Fig. 7 and Fig. 8 was replaced by a multi-part assembly comprising a sheet metal sleeve 82, a bearing sleeve 84, a separate friction ring 86 and a snap ring 88.

[0074] The bearing sleeve 84 is firmly connected to the first transmission component 32 in the axial direction, for example, by compression. The sheet metal sleeve 82, the spring element 60 and the friction ring 86 are pushed axially onto the bearing sleeve 84 and locked in an axially preloaded position by the snap ring 88. The friction ring 86 is connected to the bearing sleeve 84 or the first transmission component 32 via a positive connection in a rotationally fixed and axially displaceable manner to a limited extent. Analogous to the sheet metal sleeve 62 according to the Fig. 7 and Fig. 8 also forms the sheet metal sleeve 82 according to the Fig. 15 to 17 form a non-rotatable positive connection with the first transmission component 32 via the sheet metal tabs 68 in all axial positions of the actuating body 30.

[0075] With regard to the functioning of the switching device 26, according to the Fig. 15 to 17 no change compared to the embodiment according to the Fig. 2 to 11.

[0076] The Fig. 18 to 23 show a further embodiment of the switching device 26, wherein the first lamellae 40, in contrast to the previously described embodiments, are designed as outer lamellae and the second lamellae 42 are designed as inner lamellae.

[0077] The first transmission component 32 is a clutch disc 90, which is non-rotatably connected to the transmission housing 16. The second transmission component 34 is designed as an inner disk carrier and is fixedly connected to a transmission shaft 24 of the multi-step transmission 10.

[0078] Analogous to the embodiment according to the Fig. 12 to 14, one of the first slats 40, specifically the first slat 40 axially furthest from the actuating body 30, is designed as a slat carrier 76, which positively couples all the first slats 40 in the circumferential direction ( Fig. 21).

[0079] The rotationally fixed positive coupling between the first slats 40 and the slat carrier 76 is effected by radially outwardly projecting driving cams 94 on the first slats 40, which engage in the circumferential direction with a precise fit in corresponding recesses 96 of the slat carrier 76.

[0080] In the Fig. 18, Fig. 20 and Fig. 21 it is noticeable that the driving cams 94 of the first slat 40 arranged axially closest to the actuating body 30 protrude radially further outwards than the driving cams 94 of the remaining first slats 40. In particular, the driving cams 94 of the first slat 40 arranged axially closest to the actuating body 30 protrude beyond a radial outer side of the coupling tabs 78 of the slat carrier 76.

[0081] The synchronization element 48 of the switching device 26 according to the Fig. 18 to 23 is a separate synchronizer ring 98 which is axially biased against the first plate 40 arranged axially closest to the actuating body 30 and bears against the radially projecting driving cams 94 of this first plate 40.

[0082] According to Fig. 18, the synchronizer ring 98 has axial coupling projections 100 for the rotationally fixed coupling with the first plate 40 arranged axially closest to the actuating body 30, which engage in corresponding recesses 102 between the driving cams 94 of this first plate 40.

[0083] The functioning of the embodiment explained at the beginning can also be applied analogously to the switching device 26 according to the Fig. 18 to 23, whereby explicit reference is made to the corresponding description of the Fig. 2 to 11.

Claims

[1] Shifting device for a motor vehicle transmission, in particular a fully automatic multi-step transmission (10), with a first gear component (32) and a second gear component (34) which are rotatable relative to one another about a gear axis (A), a friction ring (36) which is connected to the first transmission component (32) in a rotationally fixed and axially displaceable manner in the circumferential direction and has a conical friction surface (38), a plurality of first lamellae (40) which are connected to one another in a circumferential direction in a rotationally fixed and axially displaceable manner, and a plurality of second plates (42) which are connected to one another and to the second transmission component (34) in a circumferentially rotationally fixed and axially displaceable manner, wherein the first and second plates (40, 42) are arranged alternately one behind the other and form a multi-plate clutch (44), wherein the first plates (40) are coupled in a rotationally fixed manner to a synchronization element (48) and the synchronization element (48) has a conical counter-surface (50) axially adjacent to the conical friction surface (38) of the friction ring (36) for speed synchronization between the first transmission component (32) and the first plates (40), characterized by that one of the first plates (40) is designed as a synchronization plate (52) onto which the synchronization element (48) is formed in one piece and / or that one of the first plates (40) is designed as a plate carrier (76) which positively couples all of the first plates (40) in the circumferential direction. [2] Switching device according to claim 1, characterized bythat the first transmission component (32) forms a transmission shaft (24) rotatable about the transmission axis (A) or is fixedly connected to such a transmission shaft (24), and that the second transmission component (34) forms a further transmission shaft (24) rotatable about the transmission axis (A) or is fixedly connected to such further transmission shaft (24). [3] Switching device according to claim 1, characterized by that the first transmission component (32) or the second transmission component (34) forms a transmission shaft (24) rotatable about the transmission axis (A) or is fixedly connected to such a transmission shaft (24), and that the other transmission component (34, 32) forms a rotationally fixed transmission housing (16) or is fixedly connected to such a transmission housing (16). [4] Switching device according to one of the preceding claims, characterized bythat the synchronization plate (52) has an annular plate disc and friction projections (54) spaced apart in the circumferential direction, wherein each friction projection (54) forms a synchronization element (48) with a conical counter-surface (50) and is formed on a radial edge of the plate disc. [5] Switching device according to one of claims 1 to 3, characterized by in that the synchronization element (48) is a separate synchronizing ring (98) which is axially acted upon and bears against one of the first plates (40), in particular wherein the synchronizing ring (98) has axial coupling projections (100) for rotationally fixed coupling to the first plate (40), which engage in corresponding recesses (102) of the first plate (40). [6] Switching device according to one of the preceding claims, characterized bythat an actuating body (30) is provided for axially actuating the first and second plates (40, 42), wherein the actuating body (30) is axially movable from an unactuated starting position via a synchronization position and a positive-locking position up to a clutch position, wherein in the unactuated starting position the multi-plate clutch (44) is open and the first plates (40) are not coupled to the first transmission component (32) in the circumferential direction, wherein in the synchronization position the multi-plate clutch (44) is substantially open and the first plates (40) are coupled to the first transmission component (32) in the circumferential direction via a friction connection, wherein in the positive-locking position the multi-plate clutch (44) is substantially open and the first plates (40) are coupled to the first transmission component (32) in the circumferential direction via a positive-locking connection,and wherein in the clutch position the multi-disk clutch (44) is closed and the first disks (40) are coupled in the circumferential direction via a positive connection to the first transmission component (32). [7] Switching device according to claim 6, characterized by that the synchronization plate (52) is the first plate (40) arranged axially closest to the actuating body (30). [8] Switching device according to claim 6 or 7, characterized by that, with the exception of the synchronization plate (52), each of the first plates (40) has coupling extensions (56) spaced apart in the circumferential direction on a radial plate edge, wherein the coupling extensions (56) extend in the axial direction and each engage in a space between two coupling extensions (56) of the axially adjacent first plate (40) that are adjacent in the circumferential direction. [9] Switching device according to claim 8, characterized bythat the coupling extensions (56) of the first lamella (40) axially furthest away from the actuating body (30) engage in recesses of the first transmission component (32) in the positive locking position and the coupling position of the actuating body (30) in order to produce a rotationally fixed positive locking connection between the first lamellae (40) and the first transmission component (32). [10] Switching device according to claim 6 or 7, characterized by that the first slat (40) axially furthest away from the actuating body (30) is designed as a slat carrier (76) for the rotationally fixed positive coupling of all first slats (40). [11] Switching device according to claim 10, characterized bythat the first lamella (40) designed as a lamella carrier (76) has an annular lamella disc, wherein axially bent coupling tabs (78) spaced apart in the circumferential direction are formed on a radial edge of the lamella disc and are connected to one another by a stabilizing ring (80) at an end facing away from the lamella disc. [12] Switching device according to claim 11, characterized by that the coupling tabs (78) engage in recesses of the first transmission component (32) in the positive locking position and the coupling position of the actuating body (30) in order to produce a rotationally fixed positive locking connection between the first plates (40) and the first transmission component (32). [13] Switching device according to one of the preceding claims, characterized bythat a spring element (60) is provided which acts on the conical friction surface (38) of the friction ring (36) axially in the direction of the conical counter-surface (50) of the synchronization element (48). [14] Switching device according to one of the preceding claims, characterized by that the friction ring (36) is formed on a first axial end of a sheet metal sleeve (62), wherein the sheet metal sleeve (62) has elastic locking elements (64) at an opposite second axial end for forming a locking connection with the first transmission component (32). [15] Switching device according to claims 13 and 14, characterized by that the spring element (60) is supported on the first gear component (32) and on bent spring bearing tabs (66) of the sheet metal sleeve (62). [16] Switching device according to claim 14 or 15, characterized bythat the first transmission component (32) is a clutch disc (46) with radially outwardly projecting claws (58), wherein sheet metal tabs (68) are formed on the second axial end of the sheet metal sleeve (62), which extend between adjacent claws (58) of the clutch disc (46) and connect the friction ring (36) to the clutch disc (46) in a rotationally fixed manner.

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