Actuating device with a damping device and hydraulic actuation system with the actuating device

Abstract

An actuating device 12 for actuating a clutch device 30 is provided, comprising 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 revolves around the main axis 100 and limits 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 which revolves around the axis of rotation 100 is formed radially between the annular housing 14 and the housing section 18.which 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, wherein the actuating device 12 has a damping device 44 arranged in the pressure connection channel 20, which is designed to dampen and / or eliminate a flow of hydraulic fluid displaced by the annular piston 15 that is at least temporarily pulsating during movement of the annular piston 15.

Description

[0001] The invention relates to an actuating device for actuating a clutch device with the features of the preamble of claim 1. The invention further relates to a hydraulic actuating system with the actuating device.

[0002] Concentric slave cylinders (CSCs) are commonly used in hybrid and purely electric vehicle drives. They serve, for example, to disconnect the electric motor from the combustion engine or to shift gears. Such slave cylinders essentially consist of a ring housing and a ring piston that can be axially displaced within the ring housing. The ring piston is operatively connected to a clutch in such a way that the clutch is actuated, in particular, engaged.

[0003] German patent application DE 10 2020 109 989 A1 discloses a clutch device for a motor vehicle, comprising a shaft extending axially, a clutch section arranged coaxially to the shaft and rotating with the shaft, the rotation of which exerts axial and radial forces on the shaft and / or the clutch section, the radial forces being able to cause radial displacement of the clutch section and / or misalignment of the clutch section and / or the shaft, and a release bearing, the release bearing being axially movable to transmit an actuating force to the clutch section, the release bearing being guided through and / or on the shaft to compensate for the axial displacement and / or misalignment in the radial direction. An actuating device according to the preamble of claim 1 is known, for example, from DE 10 2020 105 010 A1.Further state of the art is disclosed in DE 43 38 096 A1 and DE 198 12 254 A1.

[0004] The object of the present invention is to propose an actuating device which is characterized by a high level of operational reliability when actuating the clutch device.

[0005] This problem is solved by an actuating device with the features of claim 1 and a hydraulic actuating system with the features of claim 7. Preferred or advantageous embodiments of the invention will become apparent from the dependent claims, the following description, and the accompanying figures.

[0006] The invention relates to 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. Preferably, the clutch device is designed as a friction clutch, more preferably a multi-plate friction 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 bearing. Preferably, the annular piston and the annular housing are arranged coaxially and / or concentrically to each other with respect to a principal axis. The annular housing preferably has a central through-opening, in particular a bore, through which at least one shaft can pass in an installation position of the actuating cylinder. Preferably, the principal axis is defined by an axis of rotation of the shaft.

[0008] Preferably, the ring piston is rotationally symmetrical with respect to the main axis.

[0009] The annular housing has an annular space surrounding the main axis, with the annular piston being axially movable within the annular space of the housing. The annular space is axially limited by the annular piston, creating a pressure chamber between the annular piston and the annular housing that can be filled with hydraulic fluid. Specifically, the annular space is open on one side in the axial direction limited by the annular piston and closed in the opposite axial direction. When the slave cylinder is actuated, the pressure on the hydraulic fluid increases, generating the actuating force due to the rising pressure in the pressure chamber. This force is then transmitted to the annular piston, causing it to be axially disengaged. The hydraulic fluid is specifically a hydraulic fluid, in particular a hydraulic oil.

[0010] Furthermore, the actuating device comprises a housing section in which the annular housing is received, and an intermediate pressure chamber is formed radially between the annular housing and the housing section, circumferencing the axis of rotation. The housing section can be formed by a clutch housing, a transmission housing, or a motor housing. Preferably, the intermediate pressure chamber is bounded radially on one side by an inner circumference of the housing section and on the other side by an outer circumference of the annular housing.

[0011] The intermediate pressure chamber is fluidically connected to the pressure chamber via at least one fluid opening formed in the annular housing and to a pressure connection via a pressure connection channel formed in the housing section. The annular housing can, in principle, have exactly one fluid opening, which can be located at any position circumferentially. Alternatively, the annular housing can also have several fluid openings, which are distributed circumferentially and / or evenly spaced apart. The at least one fluid opening can be located on a radial outer surface of the annular housing and / or open radially into the pressure chamber or the intermediate pressure chamber. The fluid opening can be formed by a bore or similar feature radially incorporated into the annular housing.

[0012] In particular, the pressure port serves to connect a pressure line. The pressure port can be arranged on a radial outer surface of the housing section. For example, the pressure port channel can be formed by at least one or exactly one bore or the like provided in the housing section. In particular, a flow path runs through the pressure port 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 port via the pressure port channel, the intermediate pressure chamber, and the at least one fluid opening. The pressure line is particularly preferably connected directly to the pressure port.

[0013] Within the scope of this connection, it is proposed that the actuating device includes a damping device arranged in the pressure connection channel, which is designed and / or suitable to dampen and / or eliminate a pulsating flow, particularly from the intermediate pressure chamber towards the pressure connection, of hydraulic fluid displaced by the annular piston, which occurs at least intermittently during movement of the annular piston. Specifically, the damping device serves to reduce or compensate for pressure pulsations during actuation of the slave cylinder by increasing the flow resistance and generating a counter-pressure or counterforce that counteracts the pressure pulsation. Preferably, the damping device is designed as a so-called "inline damper," which is arranged in the flow path, particularly the pulsating flow, and counteracts the pulsating flow.In principle, the damping device can be fully integrated into the pressure connection channel. Alternatively, the damping device can also be arranged only partially within the pressure connection channel. Preferably, the damping device is designed as a separate component.

[0014] The invention is based on the understanding that high vibrations / dynamics occur during the actuation of the slave cylinder in combination with an inclined clutch device, which are reflected as a strong wobbling motion in the annular piston. This results in strong fluid dynamics that lead to pressure pulsations. These pressure pulsations negatively affect the entire system and can even lead to failure or prevent the actuating device from being controlled by pressure.

[0015] The advantage of the invention lies in the fact that the pressure pulsations generated by the wobbling motion can be dampened or eliminated by the arrangement of a damping device in the flow path, so that only reduced 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 inclined coupling device.

[0016] According to the invention, the damping device comprises at least one piston, which is arranged in a flow path of the pulsating flow and can be excited to oscillations depending on the pulsating flow in order to dampen the pulsating flow. In particular, the piston performs an axial, oscillating movement depending on the pulsating flow or in the case of strong pressure pulsations, which has at least one component in the direction of the flow path. In simplified terms, the piston acts in the opposite direction to the pressure pulsation. Particularly preferably, the piston generates an antiphase oscillation depending on the pressure pulsation. Thus, a damping device is proposed which enables load-adaptive damping of the pressure pulsations and increases the damping effect with increasing pressure pulsations.

[0017] According to the invention, the damping device comprises a spring element designed to exert a restoring force on the piston, preventing it from deflecting from an end position. Specifically, the piston is set in motion by the pulsating flow, and under the influence of the restoring force, it is always returned to its initial or end position. In simplified terms, the piston is set into oscillation by the spring element, which counteracts the pulsating flow or pressure pulsation. This stabilizes the system and dampens the oscillations. In particular, when the flow is directed in a direction opposite to the restoring force of the spring element, the piston is displaceable and / or subjected to the restoring force in the opposite direction to the flow. Thus, a damping device characterized by an oscillating piston is proposed.

[0018] According to the invention, the damping device comprises a further piston, with the spring element arranged between the two pistons to exert a restoring force on both pistons to prevent them from deflecting from an end position. In particular, the two pistons are set in motion by the pulsating flow, and under the influence of the restoring force, they are always returned to their initial or end position. In simplified terms, the pistons are set into oscillation by a compensation provided by the spring element, which counteracts the pulsating flow or pressure pulsation in both a flow direction and an opposing flow direction. Preferably, the spring element is supported on one side by one piston and on the other side by the other piston.In particular, one piston can be displaced in the direction of flow when the flow is directed towards it, and the other piston can be displaced against the restoring force of the spring element when the flow is directed against it. Alternatively, one piston can be subjected to the restoring force against the direction of flow and the other piston against the direction of flow. This allows the system to stabilize much faster and the vibrations to be dampened particularly effectively.

[0019] In a more detailed design, the spring element is configured as a helical compression spring. Specifically, the helical compression spring is designed to increase the restoring force during compensation. Preferably, the flow path passes through the helical compression spring. This proposes a particularly simple and cost-effective damping device, where the damping effect on the pulsating flow can be easily influenced by changing the spring stiffness.

[0020] In a further specific implementation, the damping device is designed to have a cylinder housing that is securely mounted in the pressure connection channel, with the pulsating flow path passing through the cylinder housing. In principle, the cylinder housing can be frictionally fitted, e.g., via an interference fit, in the pressure connection channel. Alternatively, the cylinder housing can also be positively fitted, 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 piston on one side and on the cylinder housing on the other. Preferably, however, the spring element is supported within the cylinder housing between the two pistons. Specifically, the piston and, if applicable, the other piston are supported in their end position against an end stop in the cylinder housing.Preferably, the cylinder housing is constructed in two parts, with the housing parts being joined together after the assembly of all components, in particular the at least one piston and the spring element. The cylinder housing can optionally be divided axially or radially for this purpose. 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 single unit. For example, the cylinder housing is designed as a cylinder liner. Thus, a damping device is proposed which is characterized by a simple design and particularly easy assembly.

[0021] In a specific implementation, a cylinder chamber of the cylinder housing is divided into at least two working chambers by at least one piston. This piston is capable of being set into vibration and / or is set into vibration by changes in the pressure conditions between the two working chambers. Specifically, with increasing flow rate at the piston, a dynamic pressure arises in one of the working chambers, depending on the flow direction. Depending on the flow resistance of the piston and / or the spring stiffness of the spring element, a counter-pressure arises in the other working chamber, which opposes the dynamic pressure. In other words, the counter-pressure results from the fluid pressure prevailing in the working chamber and the restoring force of the spring, which acts on the side of the piston facing away from the dynamic pressure.If the dynamic pressure acting on the piston is greater than the counter-pressure, the piston is moved against the restoring force within the cylinder housing, compressing the spring element. When pressure pulsations occur, at least one piston begins to move or oscillate axially, alternately relaxing and compressing the spring element. Thus, a damping device is proposed which, depending on the volume flow rate, enables the damping of pressure pulsations, particularly high-frequency ones.

[0022] In a further development, it is provided that the cylinder housing projects at least partially into the intermediate pressure chamber, with the cylinder housing forming a disruptive contour and / or a braking gap in the intermediate pressure chamber to increase flow resistance. In particular, the pulsating flow and / or the flow path from the intermediate pressure chamber towards the pressure port is slowed or deflected by the disruptive contour. Alternatively or optionally, the pulsating flow is slowed by the braking gap, which is formed radially between the end of the cylinder housing projecting into the intermediate pressure chamber and the annular housing. Preferably, the cylinder housing projects into the intermediate pressure chamber to such an extent that the radial distance between the cylinder housing and the annular housing is smaller than the minimum distance between the housing section and the annular housing.Preferably, the cylinder housing projects more than 40%, preferably more than 60%, and in particular more than 80% of the radial distance between the pressure connection channel and the annular housing into the intermediate pressure chamber. This allows the pulsating flows from the intermediate pressure chamber into the pressure connection channel to be easily dampened. As a result, pressure pulsations at the outlet of the damper device can be significantly reduced.

[0023] In a further specification, it is provided that the at least one piston, preferably both pistons, and / or the cylinder housing have a central through-hole with a reduced opening cross-section compared to the pressure connection channel to increase flow resistance. In particular, the back pressure is determined or partly determined by the opening cross-section of the through-hole. Specifically, the hydraulic fluid is forced through the reduced-cross-section through-hole, resulting in a damping effect. The back pressure will be determined depending on the size of the through-hole. In simplified 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%, and specifically more than 50% compared to the opening cross-section of the through-hole.The damping device preferably 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.

[0024] A further aspect of the invention relates to a hydraulic actuation system for a vehicle, comprising the actuation device as previously described. In particular, the actuation system serves to hydraulically generate an actuation pressure when the slave cylinder is actuated, so that an actuation force resulting from the actuation pressure is transmitted to the annular piston and the piston is axially disengaged.

[0025] The actuation system comprises a pump designed and / or suitable for generating an actuation flow rate for the slave cylinder, the pump being connected on a pressure side to the pressure port 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. Specifically, the pump is designed as an electrically driven pump. This means that the pump can be driven by a separate electric motor. Preferably, the fluid pump is connected on a suction side to a fluid source via a suction line.

[0026] Furthermore, the actuation system includes a pressure control valve connected in parallel to the pump, which is designed and / or suitable for limiting the 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. Preferably, the pressure control valve is closed until the actuation pressure is reached and maintained, and opens when the actuation pressure is exceeded and reduced. Specifically, 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 branch point of the pressure line on the slave cylinder side.

[0027] Further features, advantages, and effects of the invention will become apparent from the following description of preferred embodiments of the invention. These include: Fig. 1 a schematic representation of a drive train as an embodiment of the invention; Fig. 2 a schematic representation of a hydraulic actuation system for actuating a clutch device; Fig. 3 a sectional view of a coupling arrangement with an actuating device and a coupling device; Fig. 4 a schematic sectional view of a damper device of the actuating device made of Fig. 3; Fig. 5. The damping device in an operating situation in the same representation as in Fig. 4 shown.

[0028] Fig. Figure 1 shows a highly schematic drive train 1 for a vehicle as an embodiment of the invention. The drive train 1 comprises a drive module 2 with a coupling arrangement 3 and a drive motor 4.

[0029] The drive train 1 further comprises an additional drive motor 5, which is coupled and / or can be coupled to the drive motor 4 via the coupling arrangement 3. The drive motor 4 and the additional drive motor 5 can each be designed as an electric motor. Alternatively, the additional 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.

[0030] The coupling arrangement 3 is a disconnect coupling, also called a K0 coupling, which is designed to interrupt a drive torque between the two drive machines 4, 5. In a closed state of the coupling arrangement 3, a shaft 6, e.g. a rotor shaft, of drive machine 4 and another shaft 7, e.g. a crankshaft, of the other drive machine 5 are rotationally fixedly coupled to each other and, in an open state, are rotatable relative to each other.

[0031] The drive train 1 also includes a transmission device 8, which is connected on the input side to the drive motor 4 and / or the additional drive motor 5, and on the output side to a differential 9, whereby a torque generated by the drive motor 4 and / or the additional 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.

[0032] Fig. 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 has an actuating device 12 with a concentric slave cylinder 13, abbreviated CSC, which is arranged or can be arranged coaxially and / or concentrically with the shaft 6 and / or the further shaft 7. The slave cylinder 13 serves to actuate a clutch assembly 30, as shown in the Fig. 3 and Fig. 4 shown, wherein the slave cylinder 13 is motionally coupled to an actuating element of the clutch device 30.

[0033] The slave cylinder 13 has a ring housing 14 and a ring piston 15 received in the ring housing 14, which is axially movable relative to the ring 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 ring housing 14 and the ring piston 15 are arranged coaxially and concentrically with respect to the main axis 100.

[0034] In certain driving modes where no drive energy is required, such as sailing, the slave cylinder 13 is actuated to open the clutch device 30. The shaft 6 and the other shaft 7 are thus drive-wise separated from each other, so that no energy is transferred to the wheels 10 and the vehicle continues to roll without actively consuming energy from the battery.

[0035] The annular piston 15 rests radially against the annular housing 14, so that a pressure chamber 16 is axially limited and sealed by the annular piston 15. The slave cylinder 13 is hydraulically actuated, and the pressure chamber 16 is filled with a hydraulic fluid, e.g., hydraulic oil, during operation. The annular housing 14 has at least one fluid opening 17 on a radial outer surface through which 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 received. An intermediate pressure chamber 19, circumferencing the main axis 100, is formed radially between the annular housing 14 and the housing section 18. This intermediate pressure chamber is fluidically connected to a pressure port 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 configured as a housing for the drive motor 4, the additional drive motor 5, or the gearbox 8.

[0037] The hydraulic actuation system 11 features 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 fluidically 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 flow rate 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. This increases the pressure in the pressure chamber 16 and applies an actuating 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.

[0038] The check valve 24 is connected in series with the pump 22 on the pressure side 25 in the pressure line 27, whereby the check valve 24 allows flow towards the slave cylinder 13 and prevents flow towards 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.

[0039] The pressure control valve 23 is connected in parallel to the pump 22 on the pressure side 25, whereby the pressure control valve 23 limits the actuation pressure. For this purpose, the pressure control valve 23 can be switched between at least a closed position and an open position depending on the actuation pressure on the pressure side 25, whereby a pressure build-up takes place in the closed position and a pressure drop takes place in the open position.

[0040] When the slave cylinder 13 is actuated, the pump 22 delivers the hydraulic fluid into the pressure chamber 16 until a defined target pressure is reached. Upon reaching the target pressure, the pressure control valve 23 switches to the open position, at least briefly, to maintain a constant actuation pressure. For this purpose, the pressure control valve 23 can be designed as a pressure-controlled directional control valve, e.g., a 2 / 2-way valve. In principle, the excess hydraulic fluid can be directed via the pressure control valve 23 directly to the fluid source 29, as shown in Fig. 2 shown, can be returned. Alternatively, the excess hydraulic fluid can also be supplied elsewhere, e.g. for cooling and / or lubrication of the drive motor 4 and / or the further drive motor 5 and / or the gearbox 8.

[0041] As in Fig. As shown in Figure 3, the coupling arrangement 3 is essentially composed of the coupling 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 other shaft 7 an input shaft of the coupling arrangement 3 or the coupling device 30, respectively. The shaft 6 and the other 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 or another hollow shaft passing through the hollow shaft.

[0042] The ring housing 14 has an annular space 31 that is open on one side axially with respect to the main axis 100. The annular piston 15 is mounted in this space so as to be axially displaceable with respect to the main axis 100 and defines the pressure chamber 16. To seal the pressure chamber 16, the slave cylinder 13 has an outer and an inner sealing ring 32, 33. The annular piston 15 abuts the ring housing 14 radially in a radial direction with respect to the main axis 100 via the outer sealing ring 32 and radially in the opposite direction with respect to the main axis 100 via the inner sealing ring 33. The two sealing rings 32, 33 are each designed as an elastomer seal, in particular as grooved sealing rings, which are captive and fixed 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 slippage on the ring piston 15.

[0043] As already mentioned in Fig. As described in Figure 2, the intermediate pressure chamber 19 is formed radially between the ring 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 fluid-tight. For this purpose, the two sealing rings 35, 36 are fixed to the radial outer side of the ring housing 14, with the first sealing ring 35 bearing radially against a radial inner side of the housing section 18 with respect to the main axis 100 in a circumferential direction to seal the intermediate pressure chamber 19 with respect to the main axis 100 in an axial direction, and the second sealing ring 36 bearing radially against the housing 16 to seal the intermediate pressure chamber 19 with respect to the main axis 100 in an axial opposite direction. The fluid opening 17 is arranged axially between the two sealing rings 35, 36 or opens into the intermediate pressure chamber 19.

[0044] The actuating device 11 also includes a release bearing 37 and a pressure pot 38, which are kinetically 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.

[0045] 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 annular piston 15 on one side, e.g. with an inner ring, axially on the pressure pot 38 and on the other side, e.g. with an outer ring, axially via an intermediate disk 39, e.g. a shim disk.

[0046] The coupling device 30 has an outer lamella carrier 40 and an inner lamella carrier 41, wherein the outer lamella carrier 40 carries several outer lamellae 42 designed as steel lamellae and the inner lamella carrier 41 carries several inner lamellae 43 designed as friction lamellae, which are arranged alternately one behind the other. The outer lamella carrier 40 is rotationally fixed to the shaft 6 and the inner lamella carrier 41 is fixed to the further shaft 7.

[0047] When the master cylinder is actuated, a hydraulic column is moved towards the slave cylinder 13, whereby the hydraulic fluid flows 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 moved axially to transmit the actuating force via the release bearing 37 and the pressure pot 38 to the clutch assembly 30, thereby pressing the inner and outer plates 42, 43 together frictionally to close the clutch assembly 30.

[0048] During actuation of the slave cylinder 12, high vibrations / dynamics can occur in an inclined clutch device 30, which are reflected as a strong wobbling motion in the annular piston 15 and generate strong fluid dynamics that lead to pressure pulsations. The pressure pulsations negatively affect the entire actuation system 11 and can even lead to failure or cause the pressure control valve 23 to no longer be able to regulate in a pressure-controlled manner.

[0049] Therefore, a damping device 44, as described in more detail below, is provided in the pressure connection channel 20 between the pressure port 21 and the pressure chamber 16, which is designed to dampen or eliminate a flow that pulsates at least temporarily during movement of the ring piston 15 along a flow path 104.

[0050] As in Fig. As shown in Figure 4, the damping device 44 comprises a cylinder housing 45 and two pistons 46, 47 arranged movably relative to each other within the cylinder housing 45, which are resiliently supported against each other by a spring element 48. For example, the cylinder housing 45 can be made of two parts, the housing parts being joined to each other, e.g., by frictional and / or material bonding, after the pistons 46, 47 and the spring element 48 have been installed. The cylinder housing 45 can, for example, be pressed or screwed into the pressure connection channel 20.

[0051] 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. The pistons 46, 47 are arranged coaxially with a central axis 105 of the cylinder housing 45.

[0052] Furthermore, the cylinder housing 45 and the two pistons 46, 47 each have a through-opening 52, 53 through which the flow path 104 passes through the damping 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. These reduced opening cross-sections increase the flow resistance along the flow path 104 because, when the annular piston 15 moves, a portion of the displaced hydraulic fluid, or the pulsating flow, is forced through the through-openings 52, 53. This damping of pressure pulsations is achieved, depending on the flow resistance.Furthermore, depending on the flow direction, a dynamic pressure is generated in the inlet-side working chamber 50 at the cross-sectional reduction of the piston 46 or the further piston 47.

[0053] The spring element 48 is axially clamped between the two pistons 46, 47 with respect to the central axis 105 of the cylinder housing 45 in order to exert a restoring force 106 on each of 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 increases upon compression. In an end position, the two pistons 46, 47 thus rest against their respective end stops 54, 55 under the influence of the restoring force 106. The end stops 54, 55 are each formed by an annular, circumferential radial projection that delimits the through-opening 52.

[0054] In the case of a pulsating flow, as in Fig.As schematically indicated in Figure 5, with an inlet-side volume flow 107, depending on the flow direction and the pressure conditions between the working chambers 50 and 51, either piston 46 or the other piston 47 is moved axially with respect to the central axis 105 in the cylinder chamber 49. Depending on the flow direction, a back pressure is generated at the inlet-side working chamber 50, which acts against the restoring force 106 and the fluid pressure prevailing in the working chamber 51. In simplified terms, piston 47 or the other piston 48 is moved axially when the back pressure in the working chamber 50 exceeds a counter-pressure 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-hole 54 of pistons 46 and 47.

[0055] As long as the inlet volume flow rate 107 is low, no or only a small back pressure is generated 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 volume flow rate 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. In the event of pressure pulsations or a pulsating flow of the inlet volume flow rate 107, the piston 46 and / or the piston 47 are excited to oscillate axially due to the fluctuating back pressure, causing the spring element 48 to alternately relax and compress. This generates a pulsating counterforce or a pulsating back pressure, which acts against the pressure pulsation.This results in the pulsating flow of an output-side volume flow 108 being dampened or eliminated, resulting in lower or no pressure pulsations at the output. Reference symbol list 1 Powertrain 2 Drive module 3 Coupling device 4 drive machine 5 additional drive motors 6 wave 7 more waves 8 gearboxes 9 Differential 10 wheels 11 Actuation system 12 Actuating device 13 slave cylinders 14 ring cases 15 ring pistons 16 printing chamber 17 Fluid opening 18 Housing section 19 Intermediate pressure chamber 20 Pressure connection opening 21 Pressure connection 22 Pump 23 Pressure control valve 24 Check valve 25 printed pages 26 Suction side 27 Pressure line 28 Suction line 29 Fluid source 30 Coupling arrangement 31 Ring space 32 outer sealing ring 33 inner sealing ring 34 retaining ring 35 first sealing ring 36 second sealing ring 37 Release bearing 38 Pressure pot 39 Intermediate disc 40 external slat carriers 41 inner slat carriers 42 outer slats 43 internal slats 44 Tuning device 45 cylinder housing 46 pistons 47 more pistons 48 spring element 49 cylinder room 50 entrance-side work chamber 51 outbound working chamber 52 Passage opening 53 more passageways 54 End stop 55 further end stop 100 rotary axis 101 inset end position 102 extended final position 103 Actuation volume flow 104 Flow path 105 Center axis 106 Restoring force 107 inlet-side volume flow 108 outlet-side volume flow

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 (19) is formed radially between the annular housing (14) and the housing section (18) which surrounds the axis of rotation (100) and which 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 (18); characterized bya 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 at least temporarily pulsates during a movement of the annular piston (15), wherein 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, wherein 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, and wherein 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 (46,47) to be subjected to the restoring force (106) against a deflection from one end position in each case. [2] Actuating device (12) according to claim 1, characterized by that the spring element (48) is designed as a helical compression spring. [3] Actuating device (12) according to one of the preceding claims, characterized by that the damper 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). [4] Actuating device (12) according to claim 3, characterized by that a cylinder chamber (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 upon a change in the pressure conditions between the two working chambers (50, 51). [5] Actuating device (12) according to claim 3 or 4, characterized by 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. [6] Actuating device (12) according to one of claims 1 to 5, characterized by 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 that is reduced compared to the pressure connection channel (20) in order to increase a flow resistance. [7] Hydraulic actuation system (11) for a vehicle, comprising a pump (22) for generating an actuation volume flow (103) and a pressure control valve (23) connected in parallel to the pump (22) for limiting an actuation pressure, characterized byan actuating device (12) according to one of the preceding claims, wherein the pump (29) is fluidly 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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