Drive assembly with slave cylinder attached to the rear wall of the motor housing

Abstract

Drive arrangement (1) for a motor vehicle drive train, comprising an internal combustion engine (2), which internal combustion engine (2) in turn has an engine housing (3) and a crankshaft (4) rotatably mounted in the engine housing (3), and a slave cylinder (6) arranged concentrically to the crankshaft (4) and designed to actuate a clutch (5) outside the engine housing (3), characterized in that the slave cylinder (6) with its actuator housing (7) is attached to a rear wall (8) of the engine housing (3).

Description

[0001] The invention relates to a drive arrangement for a (preferably hybrid) motor vehicle drive train, i.e. a drive train of a motor vehicle, such as a passenger car, truck, bus or other commercial vehicle, with an internal combustion engine, for example a diesel or gasoline engine, which in turn has an engine housing and a crankshaft rotatably mounted in the engine housing, and with a slave cylinder arranged concentrically to the crankshaft and designed to actuate a clutch outside the engine housing (concentric slave cylinder / “Concentric Slave Cylinder” (CSC)).

[0002] Drive arrangements of this type are already well known from the prior art. For example, DE 10 2017 100 928 A1 discloses a drive train with a hybrid module, which hybrid module has several couplings.

[0003] With regard to the slave cylinders actuating the respective clutch, which are arranged on one side of the internal combustion engine, the prior art has the disadvantage that these are often relatively complex in design and require a relatively large amount of installation space. The slave cylinders, which usually act on a disconnect clutch, are mostly integrated into additional partition walls, which primarily occupy axial installation space. Further prior art is known from DE 100 38 012 A1 and DE 197 46 537 A1.

[0004] It is therefore the object of the present invention to eliminate the disadvantages known from the prior art and in particular to provide a drive arrangement that is implemented in the most space-saving way possible and has a simple design.

[0005] This is solved according to the invention by attaching the slave cylinder with its actuator housing to a rear wall of the motor housing.

[0006] Thus, a clutch actuation device in the form of the slave cylinder is directly integrated into an existing engine housing of an internal combustion engine, so that the further construction of the drive arrangement, including the construction of the clutch, can be significantly simplified.

[0007] Further advantageous embodiments are claimed in the dependent claims and are explained in more detail below.

[0008] The assembly of the slave cylinder is simplified if the ring-shaped slave cylinder is overall larger, i.e., with a smallest inner diameter, than a (maximum radial) outer diameter of a screw-on flange of the crankshaft penetrating the rear wall.

[0009] Further simplification of the assembly is achieved if the actuator housing is attached / fastened to the rear wall in a form-fitting and / or force-fitting manner.

[0010] Regarding the secure attachment of the actuator housing, it is also advantageous if the actuator housing is attached to the rear panel using screws. This ensures a particularly robust mounting of the actuator housing.

[0011] In this context, it is also advantageous if the timing drive of the internal combustion engine is arranged with a continuous drive element facing an interior space within the engine housing and running laterally to the rear wall. In this case, the screw connection and its mounting points are positioned circumferentially around the axis of rotation relative to the continuous drive element.

[0012] In addition to or as an alternative to the force-fit connection, it is advantageous for the actuator housing to be attached to the rear panel via a twist-proof plug connection to ensure a positive-locking connection. This further simplifies the assembly process.

[0013] Furthermore, it is advantageous if the actuator housing has an (axially projecting) centering projection, which centering projection is supported (from the inside) by a radial inner surface of the rear wall that forms an axial opening. This ensures a robust mounting of the actuator housing.

[0014] Regarding the axial actuation forces occurring during operation through the slave cylinder, it is advantageous if these are supported axially via the actuator housing directly against the rear wall of the engine housing. Ideally, the actuation force is transferred, for example, through through-hulls to bearing points behind it, such as on the engine housing, in order to relieve the load on the crankshaft bearings.

[0015] It is also advantageous if a first seal, preferably in the form of a radial shaft seal, sealing an interior of the motor housing to an environment, is arranged radially between the actuator housing and the crankshaft, preferably the mounting flange.

[0016] The sealing of the interior is further improved if a second seal, preferably in the form of an O-ring, is arranged axially between the actuator housing and the rear wall, sealing the interior of the motor housing to the environment.

[0017] It is further advantageous if the slave cylinder has a piston (preferably implemented as a stepped piston) that is slidably mounted in the actuator housing and defines a hydraulic pressure chamber with the actuator housing, wherein a pressure medium supply leading into the pressure chamber has a line extending in a radial direction and connected to the actuator housing.

[0018] The drive arrangement also advantageously features a multiple coupling and / or a hybrid module.

[0019] In this respect, it is also advantageous if the crankshaft is indirectly connected / torsionally coupled to a first clutch component of the clutch, for example via a torsional vibration damper, such as a dual-mass flywheel, or directly.

[0020] In other words, according to the invention, a CSC (concentric slave cylinder) is mounted / attached to the rear of the engine to save space.

[0021] The invention will now be explained in more detail below using figures.

[0022] They show: Fig. 1 a longitudinal sectional view of a part of a drive arrangement according to the invention in the area of ​​a slave cylinder actuating a clutch and of an internal combustion engine illustrated on the side of a rear wall and a crankshaft, Fig. 2 a perspective view of the after Fig. 1 longitudinally cut part of the drive assembly, showing a side of the rear wall facing away from an interior of the internal combustion engine, Fig. 3 a perspective view of part of the drive arrangement in full view from a side of the rear wall facing the interior of the internal combustion engine, showing the course of an endless traction element of a control drive, and Fig. 4 a schematic longitudinal section view of the drive arrangement in the area of ​​a hybrid module.

[0023] The figures are purely schematic and serve solely to illustrate the invention. The same elements are identified by the same reference symbols.

[0024] The basic structure of a drive arrangement 1 according to the invention is described in conjunction with Fig. 4 clearly visible. The drive arrangement 1 includes an internal combustion engine 2. The internal combustion engine 2 is typically designed as a diesel or gasoline engine. For the sake of clarity, the internal combustion engine 2 is only visible with respect to one end of its crankshaft 4 and a rear wall 8 of its engine housing 3. In Fig. Figure 4 shows a highly simplified representation of the motor housing 3. Furthermore, the drive arrangement 1 features a triple-clutch unit, which is implemented as a hybrid module 25. The drive arrangement 1 is therefore part of a hybrid powertrain of a motor vehicle.

[0025] A torsional vibration damping device 26 in the form of a dual-mass flywheel is installed between the crankshaft 4 and the hybrid module 25, specifically a (first) clutch 5 of the hybrid module 25. The crankshaft 4 is therefore indirectly coupled to the first clutch 5 via the torsional vibration damping device 26. A primary side 39 of the torsional vibration damping device 26 is attached to the mounting flange 9 via a screw connection. A secondary side 40 of the torsional vibration damping device 26 is connected to a first clutch component 21a of the first clutch 5 or directly forms part of the first clutch component 21a. In further embodiments, the first clutch 5 / the first clutch component 21a is preferably attached directly to the mounting flange 9.

[0026] The hybrid module 25, in accordance with its design as a multiple-coupling device, specifically a triple-coupling device, comprises, in addition to the first clutch 5, which acts as a disconnecting clutch, a second clutch 27 and a third clutch 28. The second and third clutches 27, 28 together form a double clutch. The second and third clutches 27, 28 thus serve to selectively connect a central rotor carrier 29 of the hybrid module 25 to one of two transmission input shafts of a transmission, which are not shown here for the sake of clarity. A second clutch component 21b of the first clutch 5 is, in turn, rotationally fixed to the rotor carrier 29.

[0027] The rotor carrier 29 is typically used to non-rotatably couple a rotor 30 of an electric machine 31 to the hybrid module 25. In this configuration, the rotor 30 sits directly (concentrically) on the rotor carrier 29. The first coupling 5 is therefore positioned between the crankshaft 4 and the rotor carrier 29 to selectively decouple or couple the rotor carrier 29 to the crankshaft 4 during operation.

[0028] The detailed design of the drive arrangement 1 in the area of ​​the internal combustion engine 2 and a slave cylinder 6 acting on the first clutch 5 is described in conjunction with the Fig. Figures 1 to 3 illustrate the following. According to the invention, the slave cylinder 1 is attached to the rear wall 8 of the engine housing 3. In this embodiment, the rear wall 8 is a cover for a timing drive 22 of the internal combustion engine 2 and is therefore further connected to a base body in the form of an engine block of the engine housing 3, which is not shown for the sake of clarity.

[0029] The slave cylinder 6 is implemented as a hydraulic slave cylinder 6. Furthermore, the slave cylinder 6 is designed as a concentric slave cylinder 6. Consequently, the slave cylinder 6 is entirely ring-shaped and arranged concentrically to a rotational axis 32 of the crankshaft 4. The slave cylinder 6 surrounds the crankshaft 4 radially from the outside towards one end region; that is, the slave cylinder 6 is arranged radially above the crankshaft 4.

[0030] The slave cylinder 6 is attached directly to the rear wall 8 by its actuator housing 7. This is achieved through a positive-locking connection in the form of a plug-in connector 10. The plug-in connector 10 is designed such that the actuator housing 7 is fixed to the rear wall 8 in a rotationally fixed manner. This ensures that the actuator housing 7 is firmly supported on the rear wall 8 with respect to the axis of rotation 32. In addition to or as an alternative to the plug-in connector 10, other embodiments provide a screw connection between the actuator housing 7 and the rear wall 8.

[0031] The actuator housing 7 is always supported on an axial side of the rear wall 8 facing away from an interior space 14 of the internal combustion engine 2, in contact with the rear wall 8 and thus against the rear wall 8. Via an axially extending centering projection 11, the actuator housing 7 is in contact with a radial inner surface 13, which defines a central opening 12 in the rear wall 8. This also supports the actuator housing 7 directly against the rear wall 8 in the radial direction. The opening 12, in turn, serves in a typical manner for the passage of the crankshaft 4. In particular, the crankshaft 4, with its mounting flange 9, protrudes through the opening 12 from the engine housing 3 / the rear wall 8.

[0032] The further construction of the slave cylinder 6 largely corresponds to a typical design of a concentric slave cylinder. Thus, the slave cylinder 6 has a piston 18 which, together with the actuator housing 7, defines a hydraulic pressure chamber 17. Depending on the hydraulic pressure within the pressure chamber 17, the piston 18 is positioned between the cylinder 18 and the cylinder 18. Fig. 1 and Fig. The piston 18 is adjustable between a retracted and an extended position, as illustrated in Figure 2, to engage / disengage the first clutch 5. The piston 18 is connected to an actuating bearing 33 in a displacement-resistant manner. The actuating bearing 33 is also considered part of the slave cylinder 6. As shown in Figure 2, the piston 18 is adjustable between a retracted position and an extended position to engage / disengage the first clutch 5. The piston 18 is connected to an actuating bearing 33 in a displacement-resistant manner. The actuating bearing 33 is also considered part of the slave cylinder 6. Fig. As can be seen in Figure 4, an outer bearing ring 34 of the actuating bearing 33, which is implemented as a rolling bearing, is directly mounted on the piston 18, and an inner bearing ring 35 of the actuating bearing 33 is connected to a sliding element 36 that actuates the first clutch 5 and is in turn non-rotatably connected to the first clutch 5.

[0033] In Fig. Figure 4 also clearly shows that the slave cylinder 6 is overall larger than the maximum outer diameter of the crankshaft 4 in the area of ​​the mounting flange 9. Consequently, the actuator housing 7, the piston 18, and the actuating bearing 33, with their smallest inner diameters, are larger than the outer diameter of the mounting flange 9.

[0034] To seal the interior 14 of the internal combustion engine 2 from the environment, a first seal 15 in the form of a radial shaft seal is inserted radially between the actuator housing 7 and a radial outer surface of the mounting flange 9. The first seal 15 is in direct sealing contact with the mounting flange 9 and the actuator housing 7. To axially secure the first seal 15, i.e., to prevent it from slipping out of its sealing seat, a radially inwardly projecting retaining lug 37 is formed on the actuator housing 7. The first seal 15 also rests against a radial inner surface of that area of ​​the actuator housing 7 which directly forms the centering projection 11. A second seal 16 in the form of an O-ring is inserted axially between the actuator housing 7 and the rear wall 8, on an axial side of the rear wall 8 facing away from the interior 14.The second seal 16 is preferably a component of the slave cylinder 6 and is therefore secured in position on the actuator housing 7.

[0035] As in the Fig. 1 and Fig. As can also be clearly seen in Figure 2, a pressure medium supply 19, which opens into the pressure chamber 17, is provided within a limited circumference of the actuator housing 7. This pressure medium supply 19 has a radially outward-extending line 20. The line 20 is connected to a connection port 38 of the actuator housing 7.

[0036] The axial side of the rear wall 8 facing away from one of the first couplings 5 ​​is, as in Fig. As can be seen in Figure 3, part of the control drive 22 is arranged. An endless cable 23 of the control drive 22 runs along this cable. The endless cable 23, shown schematically, is implemented as a chain and engages with a toothed section 24. The endless cable 23 is thus rotationally fixed to the crankshaft 4 via the toothed section 24. The endless cable 23 extends radially outwards from the crankshaft 4. It should be noted that if, in addition to or as an alternative to the plug connection 10, a screw connection is used between the actuator housing 7 and the rear panel 8, the corresponding screw point is offset circumferentially from the path of the endless cable 23.

[0037] In other words, the embodiment according to the invention relates to a CSC 6 mounted on the rear of the engine (rear wall 8), which surrounds the crankshaft stub (bolt-on flange 9). Furthermore, functions that previously took place internally within the engine can be integrated into the CSC 6 if desired. Ideally, both the CSC 6 and the corresponding bearing (actuating bearing 33) are larger in diameter than the crankshaft stub 9, so that further components can be easily mounted.

[0038] The proposed CSC 6 according to the invention, which is attached to the rear of the engine 8, is preferably supplied with hydraulic fluid via a line 20. Ideally, the CSC 6 is designed to enclose the crankshaft 4; this also means that the release bearing (actuating bearing 33) should be larger than the crankshaft 4. This allows the damper 26 or a clutch flange (first clutch component 21a) to be mounted on the crankshaft stub in the same way as before. The CSC 6 can be centered on a centering diameter in the housing 3. The mounting bosses / mounting points should be located between the points of the timing drive 22 (chain 23). Optionally, the CSC 6 could also be inserted to prevent rotation instead of being screwed in. Ideally, the CSC 6 even performs additional functions. For example, the sealing of engine housing 3 to crankshaft 4 is achieved via an optional O-ring16 and a radial shaft sealing ring 15.If the radial shaft sealing ring 15 is part of the CSC 6, it must be secured, e.g. by a screw connection. Fig. Figure 3 shows the chain drive 22 viewed from the inside and illustrates that screwing is not possible at two positions where the chain 23 is guided radially outwards. The CSC 6 could also be designed with a stepped piston 18 in another version. Lever actuations supported on the rear engine wall 8 are also conceivable. Ideally, the force applied by the CSC 6 is not applied to the crankshaft 4, but rather transferred, for example, via through-passages to bearing points behind it, in order to relieve the load on the crankshaft 4 bearings. If this is not possible, the bearings are reinforced accordingly. Reference symbol list 1 Drive arrangement 2 Internal combustion engine 3 Motor housings 4 Crankshaft 5 Clutch 6 slave cylinders 7 actuator housings 8 Back panel 9 Screw-on flange 10 connectors 11 Centering projection 12 Opening 13 Inside 14 Interior 15 first seal 16 second seal 17 Printing room 18 pistons 19 Pressure medium supply 20 Management 21a first coupling component 21b second coupling component 22 Control drive 23 Endless Traction Units 24 teeth 25 Hybrid module 26 Torsional vibration damping device 27 second clutch 28 third clutch 29 rotor carriers 30 Rotor 31 electric machine 32 Rotary axis 33 Actuating bearings 34 Outer bearing ring 35 Inner bearing ring 36 sliding element 37 Retaining nose 38 connection spigots 39 Primary page 40 Secondary page

Claims

[1] Drive arrangement (1) for a motor vehicle drive train, comprising an internal combustion engine (2), which in turn comprises an engine housing (3) and a crankshaft (4) rotatably mounted in the engine housing (3), and a slave cylinder (6) arranged concentrically to the crankshaft (4) and designed to actuate a clutch (5) outside the engine housing (3), characterized by , that the slave cylinder (6) with its actuator housing (7) is attached to a rear wall (8) of the motor housing (3). [2] Drive arrangement (1) according to claim 1, characterized by , that the ring-shaped slave cylinder (6) is overall larger than the outer diameter of a screw-on flange (9) of the crankshaft (4) penetrating the rear wall (8). [3] Drive arrangement (1) according to claim 1 or 2, characterized by , that the actuator housing (7) is attached to the rear wall (8) in a form-fitting and / or force-fitting manner. [4] Drive arrangement (1) according to claim 3, characterized by , that the actuator housing (7) is attached to the rear wall (8) via a screw connection. [5] Drive arrangement (1) according to claim 3 or 4, characterized by , that the actuator housing (7) is attached to the rear wall (8) via a twist-proof plug connection (10). [6] Drive arrangement (1) according to any one of claims 1 to 5, characterized by , that the actuator housing (7) has a centering projection (11) which centering projection (11) is supported on a radial inner surface (13) of the rear wall (8) forming an axial opening (12). [7] Drive arrangement (1) according to any one of claims 1 to 6, characterized by , that a first seal (15) sealing an interior (14) of the motor housing (3) to an environment is arranged radially between the actuator housing (7) and the crankshaft (4). [8] Drive arrangement (1) according to any one of claims 1 to 7, characterized by, that a second seal (16) sealing the interior (14) of the motor housing (3) to the environment is arranged axially between the actuator housing (7) and the rear wall (8). [9] Drive arrangement (1) according to any one of claims 1 to 8, characterized by , that the slave cylinder (6) further comprises a piston (18) which is slidably received in the actuator housing (7) and which defines a hydraulic pressure chamber (17) together with the actuator housing (7), wherein a pressure medium supply (19) opening into the pressure chamber (17) has a line (20) extending in a radial direction and connected to the actuator housing (7). [10] Drive arrangement (1) according to any one of claims 1 to 9, characterized by , that the crankshaft (4) is indirectly or directly rotationally connected to a first clutch component (21a) of the clutch (5).

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