Clutch module for a powertrain test bench, modular system and powertrain test bench

Abstract

The invention relates to a coupling module (20) for a powertrain test bench for connecting a driveshaft (12) to a drive shaft (11) of a test specimen (10), wherein the coupling module (20) has a first disk (21) and a second disk (22) axially and concentrically opposite the first disk (21), wherein a first interface (21') for coupling to the driveshaft (12) is arranged on an axial outer surface of the first disk (21) and a second interface (22') for coupling to the drive shaft (11) is arranged on an axial outer surface of the second disk (22). The coupling module (20) according to the invention is characterized in that the first disk (21) is elastically connected to the second disk (22) via an elastomer (23) for transmitting torques.The invention further relates to a corresponding modular system for a clutch module and a corresponding powertrain test bench for testing a vehicle powertrain.

Description

[0001] The invention relates to a coupling module for a drive train test bench for connecting a cardan shaft to a drive shaft of a test object according to the preamble of claim 1, a corresponding modular system and a corresponding drive train test bench.

[0002] Powertrain test benches for testing automotive powertrains are well-known in the art. Such powertrain test benches are typically used to detect drivetrain malfunctions at an early stage through a series of stress tests. Typical malfunctions arise, for example, from components subject to play, such as gears, synchronizer rings, synchronizer hubs, multi-plate clutch discs, and shafts, which can be deflected or excited to vibrate.

[0003] In this context, DE 10 2012 018 359 A1 describes a driving cycle for a driving simulation, which is completed by a real motor vehicle on a roller dynamometer. The motor vehicle's drive operates in such a way that the wheel speed of the vehicle corresponds to the respective speed specified in the driving cycle, without the vehicle actually moving. This enables testing of the motor vehicle drive train after installation in the vehicle.

[0004] DE 43 28 537 C2 discloses a transmission test bench with a first servomotor serving as the drive motor and a second servomotor serving as the brake motor. The first drive motor is connected to the drive shaft of a motor vehicle transmission to be tested via a coupling, and its speed is controlled by a PC, whereby any desired speed curves can be simulated. The brake motor is connected to a drive shaft of the motor vehicle transmission to be tested via another coupling. The speed of the second motor is also controlled by the PC. The speed curves simulated by the PC are speed curves measured in real driving tests. Thus, the motor vehicle transmission according to DE 43 28 537 C2 can also be tested before installation in a motor vehicle.

[0005] DE 10 2020 211 025 A1 discloses a coupling module for a powertrain test bench for connecting a propeller shaft to a drive shaft. The coupling module comprises a wheel rim and a wheel housing with a base surface and a sidewall. The wheel rim can be arranged in a rotationally fixed manner on the drive shaft, and the wheel housing can be arranged in a rotationally fixed manner on the propeller shaft. A vehicle tire is arranged on the wheel rim, the tire's tread being in frictional contact with an inner side of the wheel housing's sidewall.

[0006] However, the existing powertrain test benches have the disadvantage that they are only of limited use for realistically testing a powertrain before installation in a vehicle. This is because the torsional stiffness or elasticity of the powertrain measured on the test bench does not correspond to the behavior of the powertrain later installed in the vehicle. The reason for this deviation is primarily that the powertrain is tested on the test bench without wheel shafts and, in particular, without vehicle tires, which leads to comparatively short driveline travel and thus a stiffening of the powertrain compared to real-world operation in the vehicle. The elasticity of the powertrain in real-world operation is, in fact, largely determined by the elasticity of the vehicle tires.However, it has been shown that even the approach known from DE 10 2020 211 025 A1, which uses identical pneumatic tires for damping as those used by the drive train in real operation in the vehicle, still does not allow for optimal simulation of the elasticity occurring in real operation.

[0007] It is an object of the present invention to propose an improved coupling module for a drive train test bench for connecting a cardan shaft to a drive shaft of a test object.

[0008] This object is achieved according to the invention by the coupling module for a drive train test bench for connecting a cardan shaft to a drive shaft of a test specimen according to claim 1. Advantageous embodiments emerge from the subclaims.

[0009] The invention relates to a coupling module for a drive train test bench for connecting a cardan shaft to a drive shaft of a test object, wherein the coupling module has a first disc and a second disc axially and concentrically opposite the first disc, wherein a first interface for coupling to the cardan shaft is arranged on an axial outer side of the first disc and a second interface for coupling to the drive shaft is arranged on an axial outer side of the second disc.

[0010] According to the invention, a clutch module is therefore provided which is suitable for drivingly connecting a drive shaft of a test object, namely a drive train or transmission to be tested, to a cardan shaft of a drive train test bench. The drive shaft represents a shaft which can be driven by a drive motor of a drive train to be tested or by a drive motor of the drive train test bench which is coupled to the drive train to drive the same. The drive motor of the drive train or of the drive train test bench is preferably an electric drive motor. In particular, the drive shaft is not driven directly by the drive motor, but indirectly via a gear stage or a switchable transmission. Alternatively, the drive shaft can also preferably be driven directly by the drive motor, i.e. without an intermediate gear stage or transmission.

[0011] The drive shaft, together with the drive motor that powers it, can advantageously be designed as a drive train intended for installation in a vehicle. This means that the drive train could be, for example, a driven rigid axle, a driven steering axle, or even an independent wheel drive, which would be installed in a corresponding vehicle after the test procedure. Alternatively, the test object could also preferably be a transmission without a drive motor. The vehicle could be, for example, a car, a truck, a commercial vehicle, or even a construction or work machine.

[0012] The clutch module comprises a first disk and a second disk, which are arranged concentrically to one another and axially opposite one another. The disks are advantageously designed as circular disks, each with two flat surfaces, but can also have oppositely identical surface contours. In other words, the first and second disks are arranged relative to one another like the halves of a clutch.

[0013] The first and second discs are preferably made of steel and are suitable for transmitting even high torques.

[0014] The first interface is located on the axial outer side of the first disc, i.e., on the side of the first disc facing away from the second disc. The first interface enables coupling of the first disc to the drive shaft. The first coupling is designed such that the speeds and torques of the drive motor can be transmitted via the first coupling.

[0015] The second interface is located on the axial outer side of the second disk, i.e., on the side of the second disk facing away from the first disk. The second interface enables coupling of the second disk to the drive shaft. The second coupling is designed such that the rotational speeds and torques of the drive motor can be transmitted via the second coupling.

[0016] According to the invention, the first disc is elastically connected to the second disc via an elastomer for transmitting torque. In other words, an elastomer is arranged axially between the first disc and the second disc. This elastomer exhibits the damping and elastic properties typical of an elastomer. Furthermore, the elastomer also exhibits sufficient strength to transmit the speeds and torques of the drive motor.

[0017] This has the advantage that the desired elasticity of the drive train to be tested can be specifically adjusted by suitable selection and dimensioning of the elastomer. As a rule, the desired elasticity corresponds to the elasticity which the drive train has after installation in a vehicle during operation of the vehicle. In the case of an electric drive train in particular, this elasticity is significantly influenced by the tires on the vehicle's driven wheels. However, it has been shown that even when identical pneumatic tires are used for testing and for real vehicle operation, deviations exist between the elasticity of the drive train in test operation and the elasticity of the drive train in real driving operation. This difference in elasticity, which nevertheless exists, can be eliminated by the clutch module according to the invention.

[0018] The elastomer can be, for example, styrene-butadiene rubber (SBR), nitrile rubber (NBR), chloroprene rubber (CR), fluoropolymer rubber (FKM), butadiene rubber (BR), and / or ethylene-propylene-diene rubber (EPDM). Other types of elastomers are also conceivable and preferred.

[0019] The elastomer can preferably be disc-shaped or ring-shaped.

[0020] According to a preferred embodiment of the invention, the second interface is designed as a wheel hub, which can be connected to a wheel rim or a wheel head of the drive shaft via a flange connection. The wheel hub is advantageously designed as a hollow cylinder that engages the wheel rim or the wheel head, in particular, engages a hole ring of the wheel rim or the wheel head, and can thus be connected to the wheel rim or the wheel head via a flange connection. This creates a rotationally fixed, resilient connection.

[0021] According to an alternative preferred embodiment of the invention, the second interface is designed as a wheel pot, which can be connected to a wheel rim or a wheel head of the drive shaft via an elastic friction connection, in that a vehicle tire arranged on the wheel rim or the wheel head is in frictional contact with an inner side of the wheel pot with its tread. In this case too, the wheel pot is preferably designed as a hollow cylinder, which is designed to accommodate a vehicle tire. The vehicle tire advantageously rests with its tread against an inner surface of the wheel pot, so that force is transmitted between the wheel pot and the vehicle tire only via the friction between the tread and the inner surface.Since the vehicle tire already has a certain degree of elasticity, in conjunction with the elastomer, an elasticity can be created that largely corresponds to the elasticity of the drive train in real operation of the vehicle.

[0022] According to a further preferred embodiment of the invention, the elastomer is bonded to the first disc and the second disc. This is a simple and cost-effective, as well as sufficiently force-stable, way of connecting the first disc and the second disc to the elastomer in a torque-transmitting manner.

[0023] According to a further preferred embodiment of the invention, the elastomer is connected to the first disc and the second disc via form-fitting elements. For example, the first disc and the second disc can have corresponding openings, grooves, or projections that interact with openings, grooves, or projections in the elastomer.

[0024] The connection via form-locking elements can be made in addition to or alternatively to gluing.

[0025] According to a further preferred embodiment of the invention, the first interface is designed as a spline. A spline represents an easily removable and installable connection that is suitable for transmitting even high torques.

[0026] According to a further preferred embodiment of the invention, the drive shaft is a driven shaft of an electrically driven axle module. Since electrically driven axle modules, due to their design, exhibit comparatively high torsional rigidity and experience a certain degree of elasticity almost exclusively through the contact of the vehicle tires of the driven vehicle wheels, the use of the coupling module according to the invention—as a replacement or supplementary elasticity for the vehicle tires during the test process—leads to very realistic test behavior.

[0027] The invention further relates to a modular system for a coupling module according to the invention. The modular system is characterized in that it comprises a plurality of first discs and second discs, each connected by an elastomer, wherein the plurality each comprises different elastomers and / or different elastomer diameters and / or different elastomer axial lengths.

[0028] By providing a large number of discs connected by the elastomer, in which the material, diameter and axial length differ, a coupling module with largely optimal damping in terms of elasticity can be provided for each test specimen or for each test procedure.

[0029] Finally, the invention also relates to a drive train test bench for testing a vehicle drive train, comprising at least one clutch module according to the invention.

[0030] According to a further preferred embodiment of the invention, the drivetrain test bench further comprises an electric load motor. The electric load motor generates a load for the electric drive motor of the test object and acts on the drive shaft via the cardan shaft and the clutch module. Since the electric load motor, as an electric motor, also has very high torsional rigidity due to its design, its use is favored by the drivetrain test bench according to the invention with the clutch module according to the invention.

[0031] The invention is explained below by way of example with reference to embodiments shown in the figures.

[0032] It shows: Fig. 1 shows, by way of example and schematically, a possible construction of a coupling module according to the invention for a drive train test bench for connecting a cardan shaft to a drive shaft.

[0033] Identical objects, functional units, and comparable components are designated by the same reference symbols throughout the figures. These objects, functional units, and comparable components are identical in terms of their technical features, unless explicitly or implicitly stated otherwise in the description.

[0034] Fig. 1 shows, by way of example and schematically, a possible structure of a clutch module 20 according to the invention for a drive train test bench (not shown in Fig.1) for connecting a cardan shaft 12 to a drive shaft 11 of a test object 10. The drive shaft 11 is designed, for example, as a wheel head 11 of the test object 10, for example an electrically driven axle module 10.

[0035] The clutch module 20 has a first disc 21 and a second disc 22, wherein the second disc 22 is arranged concentrically to the first disc 21 and axially opposite thereto.

[0036] A first interface 21' for coupling to the drive shaft 12 is arranged on an axial outer side of the first disc 21. The first interface 21' is designed, for example, as a flange connection 21'. A second interface 22' for coupling to the wheel head 11 is arranged on an axial outer side of the second disc 22. The second interface 22' is designed, for example, as a wheel cage 22', which is also connected to the wheel head 11 via a flange connection.

[0037] The first disc 21 is elastically connected to the second disc 22 via an elastomer 23 for torque transmission, for example, by adhesive bonding. This increases the elasticity of the drive train from the test bench to the electrically driven axle module 10 in the torsional direction, so that the elasticity occurring during real driving operation of the electric axle 10 can be largely accurately simulated, resulting in a very realistic test behavior of the electric axle 10. Reference symbol 10 test specimen, electrically driven axle module 11 Drive shaft, wheel head 12 Cardan shaft 20 coupling module 21 first disc 21' first interface, flange connection 22 second disc 22' second interface, wheel basket 23 Elastomer QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] DE 10 2012 018 359 A1

[0003] DE 43 28 537 C2

[0004] DE 10 2020 211 025 A1 [0005, 0006]

Claims

[1] Coupling module (20) for a drive train test bench for connecting a cardan shaft (12) to a drive shaft (11) of a test specimen (10), wherein the coupling module (20) has a first disc (21) and a second disc (22) axially and concentrically opposite the first disc (2), wherein a first interface (21') for coupling to the cardan shaft (12) is arranged on an axial outer side of the first disc (21) and a second interface (22') for coupling to the drive shaft (11) is arranged on an axial outer side of the second disc (22), characterized by that the first disc (21) is elastically connected to the second disc (22) via an elastomer (23) for transmitting torques. [2] Coupling module (20) according to claim 1, characterized bythat the second interface (22') is designed as a wheel pot (22') which can be connected to a wheel rim or a wheel head (11) of the drive shaft (11) via a flange connection (22'). [3] Coupling module (20) according to claim 1, characterized by that the second interface (22') is designed as a wheel basket (22') which can be connected to a wheel rim or a wheel head (11) of the drive shaft (11) via an elastic friction connection, in that a vehicle tire arranged on the wheel rim is in frictional contact with an inner side of the wheel pot (22') with its tread. [4] Coupling module (20) according to at least one of claims 1 to 3, characterized by that the elastomer (23) is glued to the first disc (21) and the second disc (22). [5] Coupling module (20) according to at least one of claims 1 to 4, characterized bythat the elastomer (23) is connected to the first disc (21) and the second disc (22) via form-locking elements. [6] Coupling module (20) according to at least one of claims 1 to 5, characterized by that the first interface (21') is designed as a spline. [7] Coupling module (20) according to at least one of claims 1 to 6, characterized by that the drive shaft (11) is a driven shaft of an electrically driven axle module (10). [8] Modular system for a coupling module (20) according to at least one of claims 1 to 7, characterized by in that the modular system comprises a plurality of first discs (21) and second discs (22), each connected by an elastomer (23), wherein the plurality each comprises different elastomers (23) and / or each different diameters of the elastomer (23) and / or each different axial lengths of the elastomer (23). [9] Drive train test bench for testing a vehicle drive train, comprising at least one clutch module (20) according to at least one of claims 1 to 7. [10] Powertrain test bench according to claim 9, further comprising an electric load motor.

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