Actuation device comprising a damping device, and hydraulic actuation system comprising the actuation device

Abstract

The invention relates to an actuation device (12) for actuating a coupling device (30), comprising a concentric slave cylinder (13) which has a ring piston (15) and a ring housing (14). The ring piston (15) is received in an annular ring housing (14) chamber (31), which encircles the main axis (100), in an axially movable manner and delimits the annular chamber (31) in the axial direction with respect to the main axis (100) such that a pressure chamber (16) which can be filled with a hydraulic fluid is formed between the ring piston (15) and the ring housing (14). The actuation device also comprises a housing section (18), wherein the ring housing (14) is received in the housing section (18) and forms an intermediate pressure chamber (16), which encircles the rotational axis (100), radially between the ring housing (14) and the housing section (18), said intermediate pressure chamber being fluidically connected to the pressure chamber (16) via at least one fluid opening (17) formed in the ring housing (14) and to a pressure connection (21) via a pressure connection channel (20) formed in the housing section (16). The actuation device (12) has a damping device (44) which is arranged in the pressure connection channel (20), said damping device being designed to damp a hydraulic fluid flow, which pulsates at least temporarily during a movement of the ring piston (15), said hydraulic fluid being displaced by the ring piston (15).

Description

[0001] Actuating device with a tilting device and hydraulic actuating system with the actuating device

[0002] The invention relates to an actuating device for actuating a coupling device having the features of the preamble of claim 1. Furthermore, the invention relates to a hydraulic actuating system having the actuating device.

[0003] Concentric slave cylinders (CSC) are typically used in both hybrid and purely electric vehicle drive systems. These serve, for example, to separate the electric motor from the combustion engine or to change gears. Such slave cylinders essentially consist of an annular housing and an annular piston that can be axially displaced within the housing. The annular piston is operatively connected to a clutch in such a way that the clutch is actuated, in particular, engaged.

[0004] The document DE 10 2020 109 989 A1 discloses a clutch device for a motor vehicle, with a shaft, wherein the shaft extends axially, with a clutch section, wherein the clutch section is arranged coaxially to the shaft and rotates with the shaft, wherein axial and radial forces act on the shaft and / or on the clutch section during rotation of the shaft, wherein at least the radial forces can cause a radial offset of the clutch section and / or a misalignment of the clutch section and / or the shaft, and with a release bearing, wherein the release bearing is axially movable for transmitting an actuating force to the clutch section, wherein the release bearing is guided through the shaft and / or on the shaft in the radial direction to compensate for the axial offset and / or the misalignment.It is an object of the present invention to propose an actuating device which is characterized by a high operational reliability when actuating the coupling device.

[0005] This object is achieved by an actuating device having the features of claim 1, a hydraulic actuating system having the features of claim 9, and a drive train having the features of claim 10. Preferred or advantageous embodiments of the invention emerge from the subclaims, the following description, and the attached figures.

[0006] The subject matter of the invention is an actuating device designed and / or suitable for actuating a clutch device. In particular, the actuating device serves to transmit an actuating force to the clutch device in order to open or close the clutch device. The clutch device is preferably designed as a friction clutch, preferably a friction-disk clutch. Particularly preferably, the actuating device is hydraulically actuated.

[0007] For this purpose, the actuating device has a concentric slave cylinder, also known as a “concentric slave cylinder (CSC),” which essentially comprises an annular piston and an annular housing. In particular, the concentric slave cylinder is designed as a central release cylinder. The annular piston and the annular housing are preferably arranged coaxially and / or concentrically with respect to a main axis. The annular housing preferably has a central through-opening, in particular a bore, through which at least one shaft can be passed when the actuating cylinder is installed. The main axis is preferably defined by a rotational axis of the shaft. The annular piston is preferably rotationally symmetrical with respect to the main axis.

[0008] The annular housing has an annular space surrounding the main axis, wherein the annular piston is accommodated in the annular space of the annular housing so as to be movable axially with respect to the main axis. The annular space is delimited axially with respect to the main axis by the annular piston, so that a pressure chamber that can be filled with a hydraulic fluid is formed between the annular piston and the annular housing. In particular, the annular space is open on one side in the axial direction delimited by the annular piston and closed in an axially opposite direction. When the slave cylinder is actuated, the pressure on the hydraulic fluid is increased, wherein the actuating force is generated due to the rising pressure in the pressure chamber and is transmitted to the annular piston, so that the latter is disengaged axially. In particular, the hydraulic fluid is a hydraulic fluid, more specifically a hydraulic oil.

[0009] The actuating device further comprises a housing section, wherein the annular housing is accommodated in the housing section, and an intermediate pressure chamber is formed radially between the annular housing and the housing section, surrounding the rotational axis. The housing section can be formed by a clutch housing, a transmission housing, or a motor housing. Preferably, the intermediate pressure chamber is bounded in the radial direction by an inner circumference of the housing section and an outer circumference of the annular housing.

[0010] The intermediate pressure chamber is fluidically connected, on the one hand, to the pressure chamber via at least or exactly one fluid opening formed in the annular housing and, on the other hand, to a pressure connection via a pressure connection channel formed in the housing section. In principle, the annular housing can have exactly one fluid opening, which can be arranged at any position viewed in the circumferential direction. Alternatively, however, the annular housing can also have a plurality of fluid openings that are distributed in the circumferential direction and / or evenly spaced from one another. The at least one fluid opening can be arranged on a radial outer side of the annular housing and / or open radially into the pressure chamber or the intermediate pressure chamber. For this purpose, the fluid opening can be formed by a bore or the like made radially in the annular housing. In particular, the pressure connection serves to connect a pressure line.The pressure connection can be arranged on a radial outer side of the housing section. For example, the pressure connection channel can be formed by at least one or exactly one bore or the like introduced into the housing section. In particular, a flow path runs via the pressure connection channel, the intermediate pressure chamber, and the at least one fluid opening into the pressure chamber. In other words, the pressure chamber can be supplied with fluid from the pressure connection via the pressure connection channel, the intermediate pressure chamber, and the at least one fluid opening. Particularly preferably, the pressure line is directly connected to the pressure connection.

[0011] Within the scope of the connection, it is proposed that the actuating device have a damping device arranged in the pressure connection channel, which is designed and / or suitable to dampen and / or dampen a flow of hydraulic fluid displaced by the annular piston that pulsates at least temporarily during a movement of the annular piston, in particular from the intermediate pressure chamber in the direction of the pressure connection. In particular, the damping device serves to reduce or compensate for pressure pulsations during an actuation of the slave cylinder by increasing the flow resistance and generating a counterpressure or counterforce that counteracts the pressure pulsation. The damping device is preferably designed as a so-called "inline damper" which is arranged in the flow path, in particular the pulsating flow, and counteracts the pulsating flow.In principle, the damping device can be fully inserted into the pressure connection channel. Alternatively, however, the damping device can also be arranged only in sections of the pressure connection channel. The damping device is preferably designed as a separate structural unit.

[0012] The invention is based on the finding that during the actuation of the slave cylinder in combination with a misaligned clutch assembly, high vibrations / dynamics occur, which are reflected as a strong wobbling movement in the annular piston. This creates strong fluid dynamics that lead to pressure pulsations. These pressure pulsations negatively impact the entire system and can even lead to failure or the inability to control the actuation assembly under pressure.

[0013] The advantage of the invention is that the pressure pulsations generated by the wobbling movement can be dampened or eliminated by arranging a damping device in the flow path, so that only minimal or no pressure pulsations are present at the outlet of the damping device. A further advantage is that the damping device can be easily installed in the existing pressure connection channel and thus close to the source of the pressure pulsations. The damping device can therefore be easily integrated into or retrofitted to an existing actuating device. Thus, an actuating device is proposed which is characterized by high operational reliability and robust operation, particularly in combination with an oblique coupling device.

[0014] In a specific embodiment, the damping device comprises at least or precisely one piston, which is arranged in a flow path of the pulsating flow and can be excited to oscillate as a function of the pulsating flow in order to dampen the pulsating flow. In particular, as a function of the pulsating flow or in the case of strong pressure pulsations, the piston executes an axial, oscillating movement which has at least one component in the direction of the flow path. In simplified terms, the piston works against the pressure pulsation. Particularly preferably, the piston generates an anti-phase oscillation as a function of the pressure pulsation. Thus, a damping device is proposed which enables load-adaptive damping of the pressure pulsations and increases the damping effect as pressure pulsations increase.

[0015] In a further development, the damping device comprises a spring element designed to apply a restoring force to the piston, counteracting a deflection from an end position. In particular, the piston is set in motion by the pulsating flow, wherein the piston is always returned to its initial position or end position under the action of the restoring force. In simple terms, the piston is set into vibration by a compensation of the spring element, which counteracts the pulsating flow or pressure pulsation. This stabilizes the system and dampens the vibrations. In particular, when there is an incoming flow in a flow direction, the piston can be displaced against the restoring force of the spring element and / or can be subjected to the restoring force counter to the flow direction. A damping device is thus proposed, which is characterized by an oscillatable piston.

[0016] In a further development, the damper device comprises a further piston, wherein the spring element is arranged between the two pistons in order to apply the restoring force to the two pistons against deflection from an end position. In particular, the two pistons are set in motion by the pulsating flow, wherein the pistons are always returned to their initial position or the end position under the action of the restoring force. In simple terms, the pistons are set into oscillation by a compensation of the spring element, which counteracts the pulsating flow or the pressure pulsation both in one flow direction and in a flow direction opposite to the flow. Particularly preferably, the spring element is supported on one side on one piston and on the other side on the other piston.In particular, one piston can be displaced in the direction of flow when flowing in the opposite direction, and the other piston can be displaced against the restoring force of the spring element when flowing in the opposite direction. Alternatively, one piston can be subjected to the restoring force in the opposite direction of flow, and the other piston can be subjected to the restoring force in the opposite direction of flow. This stabilizes the system much more quickly, and vibrations can be damped particularly effectively. In one specific embodiment, the spring element is designed as a helical compression spring. In particular, the helical compression spring is designed to increase the restoring force during compensation. Particularly preferably, the flow path runs through the helical compression spring.Thus, a particularly simple and cost-effective damping device is proposed, whereby the damping effect on the pulsating flow can be easily influenced by changing the spring stiffness.

[0017] In a further specific implementation, it is provided that the damper device has a cylinder housing which is captively mounted in the pressure connection channel, wherein a flow path of the pulsating flow runs via the cylinder housing. In principle, the cylinder housing can be mounted in the pressure connection channel in a force-fitting manner, e.g. via a press fit. Alternatively, however, the cylinder housing can also be mounted in the pressure connection channel in a form-fitting manner, e.g. via a screw connection. In particular, the at least one piston is movably mounted in the cylinder housing. In principle, the spring element can be supported on the one hand on the piston and on the other hand on the cylinder housing. Preferably, however, the spring element is supported within the cylinder housing between the two pistons. In particular, the piston and optionally the further piston are supported in the end position on an end stop of the cylinder housing.The cylinder housing is preferably constructed in two parts, wherein the housing parts of the cylinder housing are connected to one another after assembly of all components, in particular the at least one piston and the spring element. For this purpose, the cylinder housing can be divided either axially or radially. The cylinder housing and / or the at least one piston can be made of a plastic and / or metal, such as a steel or aluminum alloy. Particularly preferably, the at least one piston and optionally the spring element are held together by the cylinder housing to form a common structural unit. For example, the cylinder housing is designed as a cylinder bushing. A damper device is thus proposed which is characterized by a simple structure and particularly simple assembly.In a specific implementation, it is provided that a cylinder chamber of the cylinder housing is divided into at least two working chambers by the at least one piston, wherein the at least one piston can be and / or is excited to oscillate when the pressure conditions between the two working chambers change. In particular, with increasing volume flow at the piston, depending on the flow direction, a back pressure is created in one of the working chambers, wherein, depending on a flow resistance of the piston and / or a spring stiffness of the spring element, a back pressure is created in the other working chamber, which counteracts the back pressure. In other words, the back pressure results from a fluid pressure prevailing in the working chamber and the restoring force of the spring, which act on a side of the piston facing away from the back pressure.If the dynamic pressure acting on the piston exceeds the counterpressure, the piston is moved against the restoring force in the cylinder housing, compressing the spring element. When pressure pulsations occur, at least one piston begins to move or oscillate axially back and forth, with the spring element being alternately relaxed and compressed. Thus, a damping device is proposed that enables the damping of pressure pulsations, particularly high-frequency ones, depending on the volume flow.

[0018] In a further development, it is provided that the cylinder housing protrudes at least partially into the intermediate pressure chamber, wherein the cylinder housing forms an interfering contour and / or a braking gap in the intermediate pressure chamber to increase the flow resistance. In particular, the pulsating flow and / or the flow path from the intermediate pressure chamber in the direction of the pressure connection is braked or diverted by the interfering contour. Alternatively or optionally additionally, the pulsating flow is braked by the braking gap, which is formed radially between the end of the cylinder housing protruding into the intermediate pressure chamber and the annular housing. Preferably, the cylinder housing protrudes so far into the intermediate pressure chamber that a radial distance between the cylinder housing and the annular housing is smaller than a minimum distance between the housing section and the annular housing.Particularly preferably, the cylinder housing extends into the intermediate pressure chamber by more than 40%, preferably more than 60%, and especially more than 80% of the radial distance between the pressure connection channel and the annular housing. This makes it easy to slow down the pulsating flows from the intermediate pressure chamber into the pressure connection channel. This results in a significant reduction in pressure pulsations at the outlet of the damping device.

[0019] In a further specification, it is provided that the at least one piston, preferably the two pistons, and / or the cylinder housing have a central through-opening with an opening cross-section that is reduced compared to the pressure connection channel in order to increase flow resistance. In particular, the back pressure or the counter pressure is determined or co-determined by the opening cross-section of the through-opening. In particular, the hydraulic fluid is pressed through the through-opening with the reduced cross-section, which leads to a damping effect. The back pressure or the counter pressure will arise depending on the size of the through-opening. In simple terms, the cylinder housing and / or the piston(s) form a type of orifice. For example, the reduced opening cross-section can be reduced by at least 10%, preferably more than 30%, in particular more than 50% compared to an opening cross-section of the through-opening.Particularly preferably, the damping device has a reduced opening cross-section, at least on the inlet side, on the side of the intermediate pressure chamber. The invention is based on the idea that pulsating flows or pressure pulsations can be influenced via the flow resistance. The higher the flow resistance, the greater the damping effect. By reducing the opening cross-section, the pulsating flow can thus be easily influenced or pre-damped.

[0020] Another subject of the invention relates to a hydraulic actuation system for a vehicle, comprising the actuation device as described above. In particular, the actuation system serves to hydraulically generate an actuation pressure upon actuation of the slave cylinder, so that an actuation force resulting from the actuation pressure is transmitted to the annular piston, causing it to be axially disengaged.

[0021] For this purpose, the actuation system comprises a pump which is designed and / or suitable for generating an actuation volume flow for the slave cylinder, wherein the pump is connected on a pressure side to the pressure connection of the housing section via a pressure line. In particular, the pump serves to build up and maintain the actuation pressure on the pressure side or in the pressure chamber of the slave cylinder. In particular, the pump is designed as an electrically operated pump. This means that the pump can be driven by a separate electric motor. Preferably, the fluid pump is connected to a fluid source on a suction side via a suction line.

[0022] Furthermore, the actuation system has a pressure control valve connected in parallel to the pump, which is designed and / or suitable for limiting an actuation pressure on the pressure side. In particular, the pressure control valve is designed to control the fluid flow on the pressure side depending on the actuation pressure on the pressure side. Preferably, the pressure control valve is closed until the actuation pressure is reached and maintained, and is opened when it is exceeded and the actuation pressure is reduced. In particular, the pump and the pressure control valve are part of a Smart Hydraulic Actuator (SHA). For this purpose, the pressure control valve can be connected to a branching point of the pressure line on the slave cylinder side.

[0023] Further features, advantages, and effects of the invention will become apparent from the following description of preferred embodiments of the invention. These show:

[0024] Fig. 1 is a schematic representation of a drive train as an embodiment of the invention; Fig. 2 is a schematic representation of a hydraulic actuation system for actuating a clutch device;

[0025] Fig. 3 is a sectional view of a coupling arrangement with a

[0026] actuating device and a coupling device;

[0027] Fig. 4 is a schematic sectional view of a damper device of the

[0028] Actuating device from Fig. 3;

[0029] Fig. 5 shows the damper device in an operating situation in the same representation as shown in Fig. 4.

[0030] Figure 1 shows a highly schematic drive train 1 for a vehicle as an exemplary embodiment of the invention. The drive train 1 comprises a drive module 2 with a clutch assembly 3 and a drive motor 4.

[0031] The drive train 1 further comprises a further drive motor 5, which is drive-technically coupled and / or can be coupled to the drive motor 4 via the clutch assembly 3. The drive motor 4 and the further drive motor 5 can each be designed as an electric machine. Alternatively, however, the further drive motor 5 can also be designed as an internal combustion engine. For example, the drive module 2 can be designed as a so-called hybrid module.

[0032] The clutch arrangement 3 is designed as a separating clutch, also known as a KO clutch, which is designed to interrupt the drive torque between the two drive motors 4, 5. When the clutch arrangement 3 is closed, a shaft 6, e.g. a rotor shaft, of the drive motor 4 and a further shaft 7, e.g. a crankshaft, of the further drive motor 5 are coupled to one another in a rotationally fixed manner and, when open, can be rotated relative to one another. The drive train 1 also has a transmission device 8, which is connected on the input side to the drive motor 4 or the further drive motor 5 and on the output side to a differential 9, wherein a torque generated by the drive motor 4 and / or the further drive motor 5 is transmitted or translated via the transmission device 8 to the differential 9 and thus to the driven wheels 10 of the vehicle.For example, the transmission device 8 can be designed as a dual-clutch transmission.

[0033] Figure 2 shows a hydraulic actuation system 11, which is designed and / or suitable for actuating the clutch assembly 3. For this purpose, the actuation system 11 comprises an actuation device 12 with a concentric slave cylinder 13, abbreviated to CSC, which is arranged or can be arranged coaxially and / or concentrically to the shaft 6 and / or the further shaft 7. The slave cylinder 13 serves to actuate a clutch device 30, as shown in Figures 3 and 4, wherein the slave cylinder 13 is coupled for movement to an actuation element of the clutch device 30.

[0034] The slave cylinder 13 has an annular housing 14 and an annular piston 15 accommodated in the annular housing 14, which is axially movable relative to the annular housing 14 with respect to a main axis 100 of the shaft 6 or the further shaft 7 between an engaged and a disengaged end position 101, 102. The annular housing 14 and the annular piston 15 are arranged coaxially and concentrically with respect to the main axis 100.

[0035] In certain ferry operations in which no drive energy is required, such as sailing operation, the slave cylinder 13 is actuated to open the coupling device 30. The shaft 6 and the further shaft 7 are thus drive-technically separated from one another, so that no energy is transferred to the wheels 10 and the vehicle continues to roll without actively consuming energy from the battery. The annular piston 15 lies radially sealingly within the annular housing 14, so that a pressure chamber 16 is axially delimited or sealed by the annular piston 15. The slave cylinder 13 is hydraulically actuated, wherein the pressure chamber 16 is or is filled with a hydraulic fluid, e.g. hydraulic oil, in an operating state. For this purpose, the annular housing 14 has at least one fluid opening 17 on a radial outer side, via which fluid opening 17 the pressure chamber 16 is supplied with the hydraulic fluid.

[0036] The actuating device 12 has a housing section 18 in which the annular housing 14 is at least partially accommodated. An intermediate pressure chamber 19 is formed radially between the annular housing 14 and the housing section 18, which chamber 19 surrounds the main axis 100 and is fluidly connected to a pressure connection 21 of the housing section 18 via a pressure connection channel 20 formed in the housing section 18. The fluid opening 17 fluidly connects the pressure chamber 16 to the intermediate pressure chamber 19. For example, the housing section 18 is designed as a housing of the drive motor 4, the further drive motor 5, or the transmission 8.

[0037] The hydraulic actuation system 11 has a Smart Hydraulic Actuator (SHA), which essentially comprises a pump 22, a pressure control valve 23, and a check valve 24. The pump 22 is fluidly connected on a pressure side 25 via a pressure line 27 to the pressure port 21 of the housing section 18. The pump 22 generates an actuation volume flow 103, which, during operation, flows from the pump 22 via the pressure line 27 and the intermediate pressure chamber 19 into the pressure chamber 16, thereby increasing the pressure in the pressure chamber 16 and applying an actuation force to the annular piston 15. For this purpose, the pump 22 is connected on a suction side 26 via a suction line 28 to a fluid source 29. For example, the fluid source 29 can be an oil sump.The check valve 24 is connected on the pressure side 25 in series with the pump 22 in the pressure line 27, whereby the check valve 24 permits flow toward the slave cylinder 13 and prevents flow toward the pump 22. The check valve 24 serves to maintain the actuating pressure in the slave cylinder 13 when the pump 22 is at a standstill.

[0038] The pressure control valve 23 is connected in parallel with the pump 22 on the pressure side 25, whereby the pressure control valve 23 limits the actuating pressure. For this purpose, the pressure control valve 23 can be switched at least between a blocking position and an open position depending on the actuating pressure on the pressure side 25, whereby a pressure build-up occurs in the blocking position and a pressure reduction occurs in the open position.

[0039] When the slave cylinder 13 is actuated, the pump 22 pumps hydraulic fluid into the pressure chamber 16 until a specified target pressure is reached, wherein the pressure control valve 23 switches to the open position at least briefly when the target pressure is reached in order to keep the actuating pressure at a constant pressure level. For this purpose, the pressure control valve 23 can be designed as a pressure-controlled directional control valve, e.g. a 2 / 2-way directional control valve. In principle, the excess quantity of hydraulic fluid can be returned via the pressure control valve 23 directly to the fluid source 29, as shown in Fig. 2. Alternatively, however, the excess quantity of hydraulic fluid can also be supplied elsewhere, e.g. for cooling and / or lubricating the drive motor 4 and / or the further drive motor 5 and / or the transmission 8.

[0040] As shown in Figure 3, the clutch assembly 3 is essentially constructed from the clutch device 30 and the actuating device 12, which are arranged coaxially with respect to a main axis 100. The shaft 6 forms an output shaft, and the further shaft 7 forms an input shaft of the clutch assembly 3 or the clutch device 30. The shaft 6 and the further shaft 7 are arranged coaxially and / or concentrically with respect to the main axis 100, with the shaft 6 being designed as a hollow shaft and the shaft 7 as a solid shaft guided through the hollow shaft or as a further hollow shaft.

[0041] The annular housing 14 has an annular chamber 31 which is open on one side axially with respect to the main axis 100 and in which the annular piston 15 is received so as to be axially displaceable with respect to the main axis 100 and delimits the pressure chamber 16. To seal the pressure chamber 16, the slave cylinder 13 has an outer and an inner seal 32, 33, wherein the annular piston 15 bears sealingly against the annular housing 14 in a radial direction via the outer seal 32 in a radial direction with respect to the main axis 100 and via the inner seal 33 in a radially opposite direction with respect to the main axis 100 within the annular chamber 31. The two sealing rings 32, 33 are each designed as an elastomer seal, in particular as grooved sealing rings, which are captively attached to the annular piston 15.For this purpose, the slave cylinder 13 has a retaining ring 34 which is designed to secure the two sealing rings 32, 33 axially with respect to the main axis 100 against loss and / or slipping on the annular piston 15.

[0042] As already described in Figure 2, the intermediate pressure chamber 19 is formed radially between the annular housing 14 and the housing section 18. The slave cylinder 13 has a first and a second sealing ring 35, 36, which seal the intermediate pressure chamber 19 in a fluid-tight manner. For this purpose, the two sealing rings 35, 36 are fixed to the radial outer side of the annular housing 14, wherein the first sealing ring 35 rests circumferentially in the radial direction with respect to the main axis 100 on a radial inner side of the housing section 18 in order to seal the intermediate pressure chamber 19 in an axial direction with respect to the main axis 100, and the second sealing ring 36 rests radially on the housing 16 in order to seal the intermediate pressure chamber 19 in an axial opposite direction with respect to the main axis 100. , wherein the fluid opening 17 is arranged axially between the two sealing rings 35, 36 or opens into the intermediate pressure chamber 19.The actuating device 11 also has a release bearing 37 and a pressure pot 38, which are motion-coupled to the annular piston 15 for transmitting an actuating force of the slave cylinder 12. For example, the release bearing 37 is designed as an angular contact ball bearing, which is designed and / or suitable for absorbing radial and axial forces with respect to the main axis 100.

[0043] The release bearing 37 is arranged radially inside the annular piston 15 or concentrically to the annular piston 15, wherein the release bearing 37 is supported on the one hand, e.g. with an inner ring, axially on the pressure pot 38 and on the other hand, e.g. with an outer ring, axially via an intermediate disk 39, e.g. a shim disk, on the annular piston 15.

[0044] The coupling device 30 has an outer disk carrier 40 and an inner disk carrier 41, wherein the outer disk carrier 40 carries a plurality of outer disks 42 formed as steel disks, and the inner disk carrier 41 carries a plurality of inner disks 43 formed as friction disks, which are arranged alternately one behind the other. The outer disk carrier 40 is rotationally fixedly connected to the shaft 6, and the inner disk carrier 41 is rotationally fixedly connected to the further shaft 7.

[0045] When the master cylinder is actuated, a hydraulic column is displaced toward the slave cylinder 13, with the hydraulic fluid flowing via the pressure connection channel 20 into the intermediate pressure chamber 19 and via the fluid opening 17 into the pressure chamber 16, thereby increasing the fluid pressure in the pressure chamber 16 and applying the actuating force to the annular piston 15. The annular piston 15 is thereby moved axially to transmit the actuating force to the coupling device 30 via the release bearing 37 and the pressure pot 38, whereby the inner and outer plates 42, 43 are frictionally pressed together to close the coupling device 30.

[0046] During actuation of the slave cylinder 12, high vibrations / dynamics can occur with an oblique coupling device 30, which are reflected as a strong wobbling movement in the annular piston 15 and generate strong fluid dynamics that lead to pressure pulsations. These pressure pulsations negatively impact the entire actuation system 11 and can even lead to failure or the pressure control valve 23 no longer being able to regulate pressure-controlled.

[0047] Therefore, a damping device 44, as described in more detail below, is provided in the pressure connection channel 20 between the pressure connection 21 and the pressure chamber 16, which damping device is designed to dampen or dampen a flow that pulsates at least temporarily along a flow path 104 during a movement of the annular piston 15.

[0048] As shown in Figure 4, the damper device 44 comprises a cylinder housing 45 and two pistons 46, 47 arranged within the cylinder housing 45 so as to be movable relative to one another and resiliently supported against one another by a spring element 48. For example, the cylinder housing 45 can be formed in two parts, with the housing parts being connected to one another, e.g., by force-fitting and / or material-fitting, after the assembly of the pistons 46, 47 and the spring element 48. The cylinder housing 45 can, for example, be pressed or screwed into the pressure connection channel 20.

[0049] The cylinder housing 45 has a cylinder chamber 49 through which the flow path 104 runs. The cylinder chamber 49 is divided by the two pistons 46, 47 into an inlet-side and an outlet-side working chamber 50, 51, depending on the flow direction. The inlet-side working chamber 50 is formed between the cylinder housing 45 and one of the two pistons 46, 47, depending on the flow direction, and the outlet-side working chamber 51 is formed between the two pistons 46, 47. For this purpose, the pistons 46, 47 are arranged coaxially to a center axis 105 of the cylinder housing 45.

[0050] Furthermore, the cylinder housing 45 and the two pistons 46, 47 each have a through-opening 52, 53 through which the flow path 104 runs through the damper device 44. The through-opening 52 of the cylinder housing 45 has a reduced opening cross-section compared to the pressure connection channel 20, and the through-opening 53 of the pistons 46, 47 has a reduced opening cross-section compared to the through-opening 52 of the cylinder housing 45. Due to the reduced opening cross-sections, the flow resistance along the flow path 104 is increased by forcing a portion of the displaced hydraulic fluid, or the pulsating flow, through the through-openings 52, 53 upon movement of the annular piston 15. This enables the damping of pressure pulsations, depending on the flow resistance.Furthermore, depending on the flow direction, a back pressure is generated in the inlet-side working chamber 50 at the cross-sectional reduction of the piston 46 or the further piston 47.

[0051] The spring element 48 is clamped axially with respect to the center axis 105 of the cylinder housing 45 between the two pistons 46, 47 in order to apply a restoring force 106 to the two pistons 46, 47 in the direction of an end stop 54, 55 of the cylinder housing 45. For this purpose, the spring element 48 is designed as a helical compression spring, so that the restoring force 106 is increased upon compression. In an end position, the two pistons 46, 47 thus rest against the respective end stop 54, 55 under the action of the restoring force 106. The end stops 54, 55 are each formed by a radial projection extending annularly around the through-opening 52.

[0052] In the case of a pulsating flow, as schematically indicated in Figure 5, of an inlet-side volume flow 107, depending on the flow direction and the pressure conditions between the working chambers 50, 51, either the piston 46 or the additional piston 47 is moved axially with respect to the center axis 105 in the cylinder chamber 49. Depending on the flow direction, a dynamic pressure is generated at the inlet-side working chamber 50, which acts counter to the restoring force 106 and a fluid pressure prevailing in the working chamber 51. In simple terms, the piston 47 or the additional piston 48 is moved axially when the dynamic pressure in the working chamber 50 exceeds a counterpressure resulting from the restoring force 106 and the fluid pressure prevailing in the working chamber 51. The counter pressure depends on the spring stiffness of the spring element 48 and the size of the through opening 54 of the pistons 46, 47.

[0053] As long as the inlet-side volume flow 107 is low, no or only a low back pressure develops at the cross-sectional reduction of the piston 53 or in the working chamber 53, and the spring element 48 is not compressed. When the inlet-side volume flow 107 increases, the back pressure prevailing at the cross-sectional constriction of the piston 53 or in the working chamber 53 increases, and the spring element 48 is compressed. When pressure pulsations or a pulsating flow of the inlet-side volume flow 107 occur, the piston 46 and / or the piston 47 are excited to oscillate in the axial direction due to the fluctuating back pressure, whereby the spring element 48 is alternately relaxed and compressed. This generates a pulsating counterforce or a pulsating counterpressure, which works against the pressure pulsation.This results in the pulsating flow of an output-side volume flow 108 being dampened or cancelled, resulting in less or no pressure pulsations at the output.

[0054] List of reference symbols

[0055] Drivetrain Drive module Clutch device Prime mover Additional prime mover Shaft Additional shaft Gearbox Differential Wheels

[0056] Actuating system Actuating device Slave cylinder Ring housing Ring piston Pressure chamber Fluid opening Housing section Intermediate pressure chamber Pressure connection opening Pressure connection Pump

[0057] Pressure control valve check valve pressure side

[0058] Suction side Pressure line Suction line Fluid source Coupling arrangement

[0059] Annular space outer seal inner seal

[0060] Retaining ring first sealing ring second sealing ring

[0061] release bearing

[0062] pressure cooker

[0063] Intermediate disc

[0064] Outer disc carrier

[0065] inner disc carrier

[0066] Outer slats

[0067] inner slats

[0068] absorber device

[0069] Cylinder housing

[0070] Piston additional piston

[0071] spring element

[0072] Cylinder chamber input-side working chamber output-side working chamber through-hole further through-hole

[0073] End stop further end stop

[0074] Rotary axis engaged end position disengaged end position

[0075] Actuation volume flow

[0076] Flow path Center axis Restoring force Inlet-side volume flow Outlet-side volume flow

Claims

Patent claims 1 . Actuating device (12) for actuating a coupling device (30), - with a concentric slave cylinder (13) which has an annular piston (15) and an annular housing (14), wherein the annular piston (15) is axially movably received in an annular space (31) of the annular housing (14) which surrounds the main axis (100) and delimits the annular space (31) axially with respect to the main axis (100), so that a pressure chamber (16) which can be filled with a hydraulic fluid is formed between the annular piston (15) and the annular housing (14), - with a housing section (18), wherein the annular housing (14) is received in the housing section (18), and an intermediate pressure chamber (16) is formed radially between the annular housing (14) and the housing section (18) which surrounds the axis of rotation (100), which intermediate pressure chamber is fluidically connected, on the one hand, to the pressure chamber (16) via at least one fluid opening (17) formed in the annular housing (14) and, on the other hand, to a pressure connection (21) via a pressure connection channel (20) formed in the housing section (16); characterized by a damping device (44) arranged in the pressure connection channel (20), which is designed to dampen and / or absorb a flow of a hydraulic fluid displaced by the annular piston (15) which pulsates at least temporarily during a movement of the annular piston (15).

2. Actuating device (12) according to claim 1, characterized in that the damping device (44) has at least one piston (46), wherein the piston (46) is arranged in a flow path (104) of the pulsating flow and can be excited to oscillate as a function of the pulsating flow in order to dampen the pulsating flow.

3. Actuating device (12) according to claim 2, characterized in that the damping device (44) has a spring element (48) which is designed to apply a restoring force (106) to the at least one piston (46) against a deflection from an end position.

4. Actuating device (12) according to claim 3, characterized in that the damping device (44) has a further piston (47), wherein the spring element (48) is arranged between the two pistons (46, 47) in order to apply the restoring force (106) to the two pistons (46, 47) against a deflection from a respective end position.

5. Actuating device (12) according to claim 3 or 4, characterized in that the spring element (48) is designed as a helical compression spring.

6. Actuating device (12) according to one of the preceding claims, characterized in that the damping device (44) has a cylinder housing (45) which is mounted captively in the pressure connection channel (20), wherein a flow path (104) of the pulsating flow runs through the cylinder housing (45).

7. Actuating device (12) according to claim 6, characterized in that a cylinder space (49) of the cylinder housing (45) is divided into at least two working chambers (50, 51) by the at least one piston (46), wherein the at least one piston (46) can be excited to oscillate when the pressure conditions between the two working chambers (50, 51) change.

8. Actuating device (12) according to claim 6 or 7, characterized in that the cylinder housing (45) projects at least partially into the intermediate pressure chamber (19), so that the cylinder housing (45) forms an interfering contour and / or a braking gap in the intermediate pressure chamber (19) to increase the flow resistance.

9. Actuating device (12) according to one of claims 2 to 8, characterized in that the at least one piston (46) and / or the cylinder housing (45) have a central through-opening (52, 54) with an opening cross-section reduced compared to the pressure connection channel (20) in order to increase a flow resistance.

10. Hydraulic actuation system (11) for a vehicle, with a pump (22) for generating an actuation volume flow (103) and with a pressure control valve (23) connected in parallel to the pump (22) for limiting an actuation pressure, characterized by an actuation device (12) according to one of the preceding claims, wherein the pump (29) is fluidically connected on a pressure side (32) via a pressure line (33) to the pressure connection (21) of the housing section (18).

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