Slave cylinder with radially supported sealing device, housing arrangement and drive module with the slave cylinder

Abstract

A concentric slave cylinder 3 is proposed, comprising an annular housing 5 which has a pressure chamber 7 rotating around a main axis 100, wherein the annular housing 5 has an axial fluid connection opening 22 fluidically connected to the pressure chamber 7, an annular piston 6 which is axially movably received in the annular housing 5 and limits the pressure chamber 7 in an axial direction 101 with respect to the main axis 100, an outer and an inner piston seal 11, 12 for sealing the pressure chamber 7, wherein the annular piston 6 has an outer sealing receptacle 13 on its outer circumference for receiving the outer piston seal 11 and an inner sealing receptacle 14 on its inner circumference for receiving the inner piston seal 12, and a sealing device 21 for sealing the annular housing 5 against a housing section 2.wherein the sealing device 21 for sealing the fluid connection opening 22 is supported against an environment in the axial direction 101 on an end face of the ring housing 5 and in at least one radial direction 103, 104 on at least one support section 24, 25 of the ring housing 9.

Description

[0001] The invention relates to a concentric slave cylinder with the features of the preamble of claim 1. Furthermore, the invention relates to a housing arrangement and a drive module with the slave cylinder.

[0002] Slave cylinders are known that serve to transmit an actuating force to a hydraulic clutch unit. In a concentric design, such slave cylinders essentially consist of an annular housing and an annular piston that is axially displaceable within the annular housing and can transmit an actuating force to a clutch. In an installation configuration, the slave cylinder can be arranged in a housing of the clutch unit and sealed against it.

[0003] German patent application DE 197 46 538 A1 discloses, for example, a hydraulically actuated release system for a vehicle friction clutch, for selectively disconnecting and connecting two shafts, consisting of a piston-cylinder unit arranged concentrically to a transmission input shaft, the housing of which is attached to the transmission, and the annular piston of which is connected to actuating elements of the friction clutch via a release bearing. A slave cylinder according to the preamble of claim 1 is known from German patent application DE 10 2012 208 750 A1. Further prior art is described in German patent application JP 2004-308 708 A and German patent application DE 10 2017 112 107 A1.

[0004] It is an object of the present invention to create a slave cylinder of the type mentioned at the outset, which is characterized by a particularly high degree of tightness.

[0005] This problem is solved by a slave cylinder with the features of claim 1, a housing arrangement with the features of claim 7, and a drive module with the features of claim 9. 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 a concentric slave cylinder, also known as a "concentric slave cylinder (CSC)." In particular, the slave cylinder serves to transmit a force and / or movement to a clutch device in order to open or close the clutch device. The clutch device can be designed as a friction clutch, preferably a multi-plate clutch, or a positive-lock clutch, preferably a jaw clutch. Alternatively, the slave cylinder can also be designed and / or suitable for actuating a brake device, in particular a friction brake. The slave cylinder is preferably hydraulically actuated.

[0007] The slave cylinder has an annular housing which includes a pressure chamber surrounding a main axis and at least one or exactly one axial fluid connection opening fluid-fluidically connected to the pressure chamber. In particular, the pressure chamber is formed by an annular space surrounding the main axis, which is preferably open in one axial direction and bounded in the opposite axial direction by a wall section of the annular housing. The wall section preferably extends in a radial plane of the main axis. Preferably, the axial fluid connection opening is integrated into the wall section. In principle, the annular housing can have only one fluid connection opening. Alternatively, the annular housing can have several fluid connection openings distributed around the main axis and / or spaced at uniform intervals.The ring housing preferably has a central through-opening, in particular a bore, through which at least or exactly one shaft can pass in an installation position of the slave cylinder. Preferably, the main axis is defined by an axis of rotation of the shaft.

[0008] The slave cylinder has an annular piston which is axially movable within the annular housing and defines the pressure chamber in an axial direction with respect to the main axis. In particular, the annular piston serves to transmit an actuating force to the clutch or brake device. Specifically, the actuating force is to be understood as a compressive force directed axially with respect to the main axis. Preferably, the annular piston is rotationally symmetrical with respect to the main axis. Preferably, the annular piston and the annular housing are arranged coaxially and / or concentrically with respect to the main axis. The pressure chamber can be filled with and / or is filled with an operating medium. When the slave cylinder is actuated, the fluid pressure on the operating medium increases, whereby the actuating force is generated due to the increasing fluid pressure in the pressure chamber and transmitted to the annular piston, so that it is axially disengaged.In particular, the operating medium is a hydraulic fluid, specifically a hydraulic oil.

[0009] The slave cylinder has an inner and an outer piston seal, which are designed and / or suitable for sealing the pressure chamber. The annular piston has an inner seal receptacle on its inner circumference for receiving the inner piston seal and an outer seal receptacle on its outer circumference for receiving the outer piston seal. "Inner" here refers to the radially inner surface and "outer" to the radially outer surface. The piston seals are preferably designed as dynamic seals. Preferably, both piston seals are fixed in their respective seal receptacles and supported against the annular housing in a sealing manner. In particular, the outer and / or inner piston seal is formed by a piston sealing ring, which bears radially against the annular housing during piston movement, preferably permanently and / or fluid-tight. In particular, both piston seals are each designed as an elastomer seal.The sealing receptacles are preferably formed by an annular groove.

[0010] Furthermore, the slave cylinder has a sealing device which is designed and / or suitable for sealing the ring housing against a housing section. The sealing device is preferably designed as a static seal. In particular, the sealing device serves to seal the ring housing against the housing section in the area of ​​the fluid connection opening in a fluid-tight manner, so that fluid leakage between the ring housing and the housing section is prevented. In other words, the sealing device seals the fluid connection opening against the environment.

[0011] Within the scope of the invention, it is proposed that the sealing device for sealing the fluid connection opening against the environment is supported axially on an end face of the ring housing and radially on at least one support section of the ring housing. In particular, the sealing device is positively engaged and / or fixed radially on the at least one support section. Preferably, the support section is formed on the inner diameter of the ring housing, so that the sealing device can be supported at least radially inwards on the support section. The sealing device is preferably annular and / or arranged coaxially to the main axis. Particularly preferably, the ring housing can be supported axially around its circumference by the sealing device in a sealing manner against the housing section.

[0012] The invention is based on the finding that, during testing of special prototype seals, it was discovered that these seals can shift in the direction of the inner diameter. This shift can lead to leakage in the area of ​​the fluid connection. Currently, a special reinforced flat gasket is provided between the ring housing and the housing section, which can therefore leak under certain circumstances and is also characterized by high manufacturing costs. By radially supporting the sealing device on the support section, the sealing device is fixed radially and can therefore no longer move in the radial direction, thus improving the sealing of the slave cylinder. In addition, the radial support eliminates the need for reinforcement or encasing of the sealing device, making the sealing device significantly simpler and more cost-effective.

[0013] According to the invention, the at least one support section is formed by a web oriented axially and circumferentially around the main axis. The term "oriented axially" means, in particular, that the axial extent of the support section is greater than its radial extent. Preferably, the support section is coaxial and / or concentric with the ring housing. Preferably, the web is continuous or ring-shaped. Preferably, the web is formed by a cylindrical extension. For example, the web has an axial extent that is smaller than the axial width of the sealing device. The circumferential web ensures circumferential support of the sealing device.

[0014] In a further development, the ring housing is provided with an inner and an outer support section, wherein the sealing device is supported radially on the outer support section and radially against the inner support section of the ring housing. In particular, the two support sections are each formed by a web oriented axially and circumferentially around the main axis. In other words, the two support sections are formed coaxially and / or concentrically on the ring housing. The sealing device is preferably arranged in a positive-locking and / or play-free and / or precisely fitting manner between the two support sections in the radial direction. This provides a particularly secure seal for the sealing device, which prevents slippage of the sealing device in the radial direction.

[0015] In a more detailed embodiment, the outer support section connects to the ring housing at an outer diameter and / or the inner support section connects to an inner diameter. In particular, the ring housing has an inner and an outer cylindrical section that define the pressure chamber in the radial direction. Preferably, the two cylindrical sections are aligned parallel and / or coaxially with respect to the main axis in the axial direction. The inner support section preferably extends axially from the inner cylindrical section and / or forms a common inner surface with the inner cylindrical section. The outer support section preferably extends axially from the outer cylindrical section and / or forms a common outer surface with the outer cylindrical section.A ring housing is therefore proposed which can be manufactured simply and has no interfering contours on the inner or outer circumference.

[0016] In a preferred embodiment, the sealing device has at least one or exactly one opening through which the at least one fluid connection opening can be fluidically connected to a fluid connection of the housing section. In particular, the opening corresponds at least to the cross-sectional area of ​​the fluid connection opening, so that they are congruent and / or aligned with each other. Preferably, the sealing device can be mounted on the ring housing in only one orientation, in which the opening is aligned with or overlapping the fluid connection opening. For example, the inner and / or the outer support section can have a positive-locking contour and the sealing device a corresponding counter-contour, via which the sealing device can be mounted on the ring housing in the specified orientation or brought into engagement with the positive-locking contour.Preferably, each fluid connection opening is assigned at least one or exactly one opening. This ensures that the fluid connection opening is not obscured by the sealing device or that a flow-related connection can be established via the sealing device.

[0017] In a specific implementation, the sealing device is designed as an elastically deformable flat gasket. Specifically, the flat gasket is elastically deformed or subjected to a contact force during installation. The flat gasket is designed as a flat sealing ring, preferably a flat rubber sealing ring. Optionally, the flat gasket can be reinforced and / or encased. Thus, a sealing device is proposed that is cost-effective and simultaneously ensures a reliable seal.

[0018] In a further embodiment, the sealing device is provided to have an axial sealing thickness of more than 0.3 mm, preferably more than 1 mm, and specifically more than 1.5 mm. In particular, the sealing device has an axial width to radial width ratio of less than 1:10, preferably less than 1:7, and specifically less than 1:5. In other words, the radial width is less than 10 times the axial width of the sealing device. The axial width is to be understood as the sealing thickness, and the radial width as the difference between the inner and outer diameters. Thus, a thicker sealing device is proposed, which can be supported particularly securely in the radial direction by the at least one support section.

[0019] Another aspect of the invention relates to a housing arrangement comprising a housing section and the slave cylinder as previously described.

[0020] The housing section has a receiving area in which the ring housing is received, the ring housing being axially supported by the sealing device and fluidically connected to a fluid connection of the housing section. In particular, the housing section is designed as a coupling housing, e.g., a coupling bell. The receiving area is preferably formed by a cylindrical opening, recess, depression, or the like, in which the ring housing is at least partially or completely received. Specifically, the receiving area has a central through-opening through which the at least one shaft passes. The fluid connection is particularly preferably arranged opposite and / or aligned with the fluid connection opening in the housing section, preferably an intermediate wall.The fluid connection can be configured as an axial bore extending with respect to the main axis, preferably a stepped bore. A sealing device is particularly preferred to create a flow-resistant connection between the fluid connection and the fluid connection opening, sealing it against the environment. In other words, the sealing device seals the annular housing and the housing section in the area of ​​the fluid connection against the environment. Fluid can thus flow into and out of the pressure chamber via the fluid connection to actuate the slave cylinder.

[0021] In a specific embodiment, the housing assembly includes a pressure element that applies an axial pressure force to the ring housing. In particular, the pressure element is connected to the housing section in such a way that it applies the axial pressure force to the ring housing at its outer diameter, preferably at the outer cylindrical section. The pressure element is preferably connected to the housing section by a positive-locking and / or friction-locking connection. For example, the pressure element is designed as an annular pressure disc mounted on an axial end face of the housing section.

[0022] Alternatively, the pressure element can be designed as an annular press-fit disc, which is pressed into the receiving area of ​​the housing section. The pressure force ensures a sealing contact between the sealing device and the housing section and simultaneously secures the ring housing in the receiving area.

[0023] A further aspect of the invention relates to a drive module comprising at least or exactly one drive motor, a clutch assembly, and a slave cylinder, as previously described. In particular, the drive module is connected to a transmission assembly, whereby a torque path between the drive motor and the transmission module is influenced when the clutch assembly is actuated. The drive motor is preferably an electric motor. Optionally, the drive module is connected to another drive motor, e.g., another electric motor or an internal combustion engine, whereby a torque path between the drive motor and the other drive motor is influenced when the clutch assembly is actuated. In simplified terms, the clutch assembly serves selectively to couple the drive motor to the transmission assembly or to the other drive motor.The transmission device can be designed as a stepped automatic transmission, a dual-clutch transmission, or a continuously variable transmission (CVT). The clutch device can therefore be a disconnect clutch (K0) or a dual clutch (K1 / K2) of an electric or hybrid powertrain.

[0024] 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 housing arrangement with a slave cylinder as an embodiment of the invention, Fig. 2 a schematic representation of a drive train with the in Fig. 1 described housing arrangement.

[0025] The Fig. Figure 1 shows a housing arrangement 1 with a housing section 2 and a concentric slave cylinder 3, abbreviated CSC, which is arranged coaxially and / or concentrically to a main axis 100 in a receiving area 4 of the housing section 2.

[0026] The slave cylinder 3 has a ring housing 5 and a ring piston 6 received in the ring housing 5, which is axially movable relative to the ring housing 5 with respect to the main axis 100. The ring housing 5 and the ring piston 6 are arranged coaxially and concentrically with respect to the main axis 100.

[0027] The annular housing 5 and the annular piston 6 define a pressure chamber 7 that rotates around the main axis 100. This pressure chamber is bounded with respect to the main axis 100 in an axial direction 101 by the annular piston 6 and in an axial opposite direction 102 by a wall section 8 of the annular housing 5. It is bounded in a radial direction 103 by an outer cylinder section 9 and in an radial opposite direction 104 by an inner cylinder section 10. To seal the pressure chamber 7, the slave cylinder 3 has an outer and an inner piston seal 11, 12. The annular piston 6 seals against the outer cylinder section 5 in the radial direction 103 via the outer piston seal 11 and against the inner cylinder section 10 in the radial opposite direction 104 via the inner piston seal 12.

[0028] Here, the outer piston seal 11 is securely held in an outer seal receptacle 13, and the inner piston seal 12 is held in an inner seal receptacle 14. For example, the outer seal receptacle 13 is designed as an annular groove arranged on the outer circumference of the annular piston 3, and the inner seal receptacle 14 is designed as an annular groove arranged on the inner circumference of the annular piston 3. Both piston seals 11 and 12 are each designed as a dynamic elastomer seal, in particular as a groove seal ring.

[0029] Housing section 2 and the ring housing 5 each have a central through-opening 16, 17, which are aligned axially with respect to the main axis 100 and / or coaxial to each other. In an installation configuration, a shaft 15 is guided through the two through-openings 16, 17. For example, the main axis 100 is defined by an axis of rotation of the shaft 15. The through-opening 16 of housing section 2 is arranged in an intermediate wall 18, which extends in a radial plane of the main axis 100 and limits the receiving area 4 in the axial opposite direction 102.

[0030] To fill the pressure chamber 7 with a fluid, the ring housing 5 has a fluid connection opening 19 provided in the wall section 8, through which the pressure chamber 7 can be supplied with fluid via a fluid connection 20 arranged in the intermediate wall 18. For example, the fluid is a hydraulic fluid, preferably a hydraulic oil.

[0031] The slave cylinder 3 has a sealing device 21, which is arranged axially between the annular housing 5 and the housing section 2 to seal the fluid connection between the fluid port 20 and the fluid port opening 19 from the environment. The sealing device 21 is designed as a static elastomer seal, in particular as a flat sealing ring, by means of which the annular housing 5 is circumferentially supported against the housing section 2 in the axial opposite direction 102. The sealing device 21 bears against the wall section 8 in the axial direction 101 and against the intermediate wall 18 in the axial opposite direction 102.

[0032] The sealing device 21 has at least one opening 22, which is arranged overlapping or flush with the fluid connection 20 and the fluid connection opening 19 in order to connect them fluidically. For example, the opening 22 corresponds to an opening cross-section of the fluid connection opening 19 and / or the fluid connection 20.

[0033] The slave cylinder 3 also has a clamping element 23, via which the ring housing 5 is subjected to a clamping force 105 in the axial opposite direction 102 towards the intermediate wall 18. The clamping force 105 fixes the ring housing 5 in the receiving area 4 and simultaneously presses the sealing device 21 against the intermediate wall 18. To disengage the ring piston 6 from the ring housing 5 in the axial direction 101, fluid is supplied to the pressure chamber 7 via the fluid connection 20, thereby increasing the fluid pressure in the pressure chamber 7, which acts on the ring piston 6 in the axial direction 101. Due to the increasing fluid pressure, a radial force component acts on the sealing device 21 in the area of ​​the opening 22, causing it to be displaced radially.

[0034] The ring housing 9 has an outer and an inner support section 24, 25, which serve to radially support the sealing device 21. For this purpose, the two support sections 24, 25 are each formed by a web circumferentially around the main axis 100, which is integrally formed on the ring housing 5 in the axial direction. The outer support section 24 is arranged on an outer diameter in axial extension to the outer cylindrical section 9. For example, the outer support section 24 and the outer cylindrical section 9 form a common outer surface. The inner support section 25 is arranged on an inner diameter in axial extension to the inner cylindrical section 10. For example, the inner support section 25 and the inner cylindrical section 10 form a common inner surface.The sealing device 21 can thus be supported in the radial direction 103 on the outer support section 24 and in the radial opposite direction 104 on the inner support section 25. In particular, the sealing device 21 is positively engaged radially between the two support sections 24, 25.

[0035] To ensure axial alignment of the sealing device 21, its axial width 106 in the relaxed or unloaded state is greater than the axial extent of the two support sections 24, 25. For example, the sealing device 21 has an axial width 106 of approximately 1.5 mm. Specifically, the ratio of axial width 106 to radial width 107 is approximately 1:10.

[0036] By arranging the two support sections 24, 25 on the ring housing 5 in combination with a thicker sealing device 21, slippage of the sealing device 21 is prevented and the tightness of the assembly is thus guaranteed.

[0037] The Fig. Figure 2 shows a powertrain 26 for a vehicle, wherein the powertrain 26 comprises a drive module 27 with a clutch unit 28 comprising the housing arrangement 1. For example, the housing section 2 forms part of a clutch housing, not shown, of the clutch unit 28.

[0038] The drive module 27 can be designed as a so-called hybrid module, wherein the drive module 27 comprises a drive machine 29 which is coupled and / or can be coupled to another drive machine 30 via the coupling unit 28. For example, the drive machine 29 can be an electric machine and the other drive machine 30 can be another electric machine or an internal combustion engine.

[0039] The coupling unit 28 has a coupling device 31 designed as a disconnect coupling, also called a K0 coupling, which is configured to interrupt a drive torque between the two drive machines 29, 30. In a closed state of the coupling device 31, the shaft 15, in particular a rotor shaft, of the drive machine 29 and another shaft 32, in particular another rotor shaft or a crankshaft, of the other drive machine 30 are rotationally fixedly coupled to each other and, in an open state, are rotatable relative to each other.

[0040] The slave cylinder 3 serves to actuate the clutch device 31. In certain driving operations where no drive energy is required, such as sailing, the slave cylinder 3 can be actuated to open the clutch device 31, thereby decoupling the drive motor 29 or the other drive motor 30, so that no energy is transferred to the wheels 33 of the vehicle and the vehicle continues to roll without actively consuming energy.

[0041] The drive train 1 also includes a transmission device 34, which is connected on the input side to the drive motor 29 and / or the additional drive motor 30, and on the output side to a differential gear 35, whereby a torque generated by the drive motor 29 and / or the additional drive motor 30 is transmitted or translated via the transmission device 34 to the differential gear 35 and thus to the driven wheels 33 of the vehicle. For example, the transmission device 34 can be designed as a dual-clutch transmission. Reference symbol list 1 Housing arrangement 2 Housing section 3 slave cylinders 4 Recording area 5 ring cases 6 ring pistons 7 Pressure chamber 8 wall section 9 outer cylinder section 10 inner cylinder section 11 outer piston seal 12 inner piston seal 13 outer seal receptacle 14 inner seal receptacle 15 wave 16 Passage opening 17 Passage opening 18 Partition wall 19 Fluid connection opening 20 Fluid connection 21 Sealing device 22 Breakthrough 23 Pressure element 24 outer support section 25 inner support section 26 Powertrain 27 Drive module 28 coupling unit 29 Drive machine 30 additional drive motors 31 Coupling device 32 more waves 33 wheels 34 Gearbox device 35 Differential gear 100 Main axis 101 axial direction 102 axial opposite direction 103 radial direction 104 radial opposite direction 105 contact force 106 axial width 107 radial width

Claims

[1] Concentric slave cylinder (3), - with a ring housing (5) which has a pressure chamber (7) circumferentially around a main axis (100) and an axial fluid connection opening (19) which is fluidically connected to the pressure chamber (7), - with a ring piston (6) which is axially movable in the ring housing (5) and limits the pressure chamber (7) in an axial direction (101) with respect to the main axis (100), - with a sealing device (21) for sealing the ring housing (5) against a housing section (2), wherein the sealing device (21) for sealing the fluid connection opening (19) is supported against an environment in the axial direction (101) on an end face of the ring housing (5) and in at least one radial direction (103, 104) on at least one support section (24, 25) of the ring housing (5). characterized by , that the slave cylinder (3) has an outer and an inner piston seal (11, 12) for sealing the pressure chamber (7), wherein the annular piston (6) has an outer sealing receptacle (13) on its outer circumference for receiving the outer piston seal (11) and an inner sealing receptacle (14) on its inner circumference for receiving the inner piston seal (12), and that the at least one support section (24, 25) is formed by a web oriented in the axial direction and circumferentially around the main axis (100). [2] Slave cylinder (3) according to claim 1, characterized by , that the ring housing (5) has an inner and an outer support section (24, 25), wherein the sealing device (21) is supported in a radial direction (101) on an outer support section (24) and in a radial opposite direction (104) on an inner support section (25) of the ring housing (5). [3] Slave cylinder (3) according to claim 2, characterized by, that the outer support section (24) connects to an outer diameter and / or the inner support section (25) connects to an inner diameter of the ring housing (5). [4] Slave cylinder (3) according to any one of the preceding claims, characterized by , that the sealing device (21) has at least one opening (22) through which the fluid connection opening (19) can be fluidically connected to a fluid connection (20) of the housing section (2). [5] Slave cylinder (3) according to any one of the preceding claims, characterized by , the sealing device (21) is designed as an elastically deformable flat gasket. [6] Slave cylinder (3) according to any one of the preceding claims, characterized by , that the sealing device (21) has an axial width (106) of at least 0.3 millimeters. [7] Housing arrangement (1) with a housing section (2) and with the slave cylinder (3) according to one of the preceding claims, wherein the housing section (2) has a receiving area (4) in which the ring housing (5) is received, wherein the ring housing (5) is axially supported on the housing section (2) via the sealing device (21) and is fluidically connected to a fluid connection (20) of the housing section (2). [8] Housing arrangement (1) according to claim 7 characterized by a pressure element (23) via which the ring housing (5) is subjected to an axial pressure force (105). [9] Drive module (27) for a drive train (26) of a vehicle, comprising a clutch device (31), a drive motor (29) and a slave cylinder (3) according to one of the preceding claims, wherein the slave cylinder (3) is configured to actuate the clutch device (31).

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