Coupling module, output module and drive train test bench for a drive train test bench

Abstract

The invention relates to a coupling module (20) for a drive train test bench for connecting a cardan shaft (22) to a drive shaft (21), wherein the coupling module (20) comprises a rim (23) and a wheel house (24) having a bottom surface (24') and a side wall (24''), wherein the rim (23) is arranged on the drive shaft (21) in a rotationally fixed manner and wherein the wheel house (24) is arranged on the cardan shaft (22) in a rotationally fixed manner. The coupling module (20) according to the invention is characterized in that a vehicle tire (25) is arranged on the rim (23), which vehicle tire is frictionally locked with its active surface (25') against the inner side (24'') of the side wall (24) of the wheel house (24). The invention furthermore relates to a corresponding output module for a drive train test bench and to a corresponding drive train test bench for testing a vehicle drive train.

Description

TECHNICAL FIELD

[0001] The present application relates to a coupling module for a drive train test bench for connecting a cardan shaft with a drive shaft, a corresponding output module for a drive train test bench and a corresponding drive train test bench. BACKGROUND

[0002] Drive train test benches for testing motor vehicle drive trains are known from the prior art. Such drive train test benches are typically used to detect functional faults of a drive train in advance by a series of loadings. Typical functional faults are caused, for example, by components with play, such as gears, synchromeshes, synchronizers, multi-plate clutch plates and shafts, which can shift or excite vibrations.

[0003] In this respect, DE 10 2012 018 359 A1 describes a drive cycle for a drive simulation, which is driven by a real motor vehicle on a roller test bench. The drive of the motor vehicle is operated here in such a way that the wheel rotational speed of the motor vehicle corresponds to the respective speed predefinition of the drive cycle, while the motor vehicle is actually not moving forward. This enables a test of the motor vehicle drive train after installation in the motor vehicle.

[0004] Furthermore, the applicant knows a so-called multi-link drive train test bench, which can be connected in an anti-rotationally fixed manner with the wheel flanges of a motor vehicle and ensures all degrees of freedom of the wheel flanges in their movement possibilities, which can also be the case for the wheels during normal operation of the motor vehicle. The known multi-link drive train test bench for this consists of a plurality of levers and rotational articulations arranged in series, which can each move relative to one another. The drive train of the motor vehicle is driven here directly by the drive unit of the vehicle itself. The cardan shafts of the drive train are axles, which can be loaded with a predetermined brake torque via the wheel flanges by the multi-link motor vehicle transmission test bench.

[0005] DE 43 28 537 C2 discloses a transmission test bench, which has a first servo motor as a drive motor and a second servo motor as a brake motor. The first drive motor is connected via a clutch with the drive shaft of the motor vehicle transmission to be tested and is controlled in its rotational speed via a PC, wherein an arbitrary rotational speed profile can be simulated. The brake motor is connected via a further clutch with the cardan shaft of the vehicle transmission to be tested. The rotational speed of the second motor is also controlled via the PC. The rotational speed profile simulated by the PC is a rotational speed profile measured in a real drive attempt. The motor vehicle transmission according to DE 43 28 537 C2 can thus also be tested before installation in the motor vehicle.

[0006] Figure 1A wheel ball cage module 10 known from the prior art is shown, which couples a drive axle 11 in a detachable manner with a cardan shaft 12. The drive axle 11 is driven by a drive motor not shown and transmits the rotational speed and the torque to the cardan shaft 12 by means of the wheel ball cage module, which can be loaded by a brake motor with a counter force. The wheel ball cage module is made of steel here and is connected to the drive axle via the hole circle of the wheel rim, analogously to a conventional wheel rim.

[0007] However, in this respect, the disadvantage of the known drive train test bench is that it is either not suitable at all for testing motor vehicle drive trains before installation in a vehicle, or it is at least not able to reliably detect, in particular before installation in a vehicle, an electrically driven drive train, since the characteristics of the electrically driven drive train which are measured in the test bench do not correspond to the characteristics of the drive train after its installation in a vehicle. The reason for the deviation of the characteristics measured in the test bench from the characteristics installed in a vehicle in an electrically driven drive train is that the electric drive motor is comparatively stiff compared to an internal combustion engine and is inelastic in terms of its rotational characteristics. Furthermore, the electric drive motor is usually located directly on the axle which it drives, which leads to a relatively short drive path and thus to a further increase in the stiffness of the drive train. However, in the installed state in a vehicle, this lower elasticity of the electrically driven drive train can be largely compensated for by the rubber tires of the vehicle, but not in the drive train test bench. SUMMARY

[0008] It is the task of the present invention to propose an improved coupling module for a drive train test bench for connecting a cardan shaft with a drive shaft.

[0009] According to the invention, this task is solved by a coupling module for a drive train test bench for connecting a cardan shaft with a drive shaft, according to the following.

[0010] The invention relates to a coupling module for a drive train test bench for connecting a cardan shaft with a drive shaft, wherein the coupling module comprises a wheel rim and a wheel cup having a bottom surface and a side wall, wherein the wheel rim is arranged in an anti-rotationally fixed manner on the drive shaft and wherein the wheel cup is arranged in an anti-rotationally fixed manner on the cardan shaft. The coupling module according to the invention is characterized in that an annular damping element is arranged on the wheel rim, which frictionally locks against the inner side of the side wall of the wheel cup.

[0011] According to the application, therefore, a coupling module is provided which is suitable for drivingly connecting a drive shaft of a drive train test bench to a cardan shaft of a drive train test platform. The drive shaft here denotes a shaft which can be driven by a drive motor of the drive train or of the drive train test bench. 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 of the drive motor cannot be driven directly, but rather indirectly via a gear ratio stage or a switchable transmission. From a technical point of view, the drive shaft in the sense of the application can therefore also be a cardan shaft of a gear ratio stage or of a transmission.

[0012] The drive shaft here, together with the drive motor which drives it, can advantageously be configured as a drive train which is provided for installation in a vehicle, that is to say, the drive shaft is, for example, a driven rigid axle, a driven steering axle or a single-wheel drive, which is installed in a corresponding vehicle after the test process. The vehicle can be, for example, a passenger vehicle, a utility vehicle, a commercial vehicle or a construction or work machine.

[0013] The coupling module comprises a wheel rim which can in particular be configured as a conventional wheel rim for a motor vehicle. Furthermore, the coupling module comprises a wheel cover, wherein the wheel cover has a base surface and a lateral wall. The wheel cover is advantageously configured here as a hollow cylinder, wherein the base surface denotes the base surface of the hollow cylinder and the lateral surface denotes the lateral surface of the hollow cylinder. The wheel cover is preferably made of steel.

[0014] The coupling module can be connected to the drive shaft in a rotationally fixed manner via the wheel rim, in particular via the hole circle of the wheel rim. The coupling module can thus be connected to the drive shaft of the drive train like a conventional wheel rim.

[0015] The coupling module can also be connected to the cardan shaft in a rotationally fixed manner via the wheel cover, in particular via the flange connection. The cardan shaft is advantageously driven by an electric load motor which can introduce a braking torque into the drive train which is directed counter to the drive torque of the drive motor. Thereby, dynamic loads of the drive train can be simulated.

[0016] The coupling module according to the application is now characterized in that an annular damping element is arranged on the wheel rim, which damping element in particular rubs frictionally with its radially outer periphery against the inner side of the lateral wall of the wheel cover. Torque can thus be transmitted from the drive shaft via the wheel rim and the damping element to the lateral wall of the wheel cover and thus to the cardan shaft.

[0017] The annular damping element here assumes the torsional damping characteristics of an actual vehicle tire and is in particular fitted on the wheel rim like a vehicle tire.

[0018] The damping element advantageously has a profiled active surface on its radially outer periphery like an actual vehicle tire.

[0019] The damping element can be made, for example, of a damping elastomer or tire rubber. Furthermore, the damping element can be configured as an inflatable hollow body or solid.

[0020] The following advantages are thereby achieved, namely that the coupling module according to the application ensures a flexibility of the drive train in the drive train test bench, which corresponds to the actual flexibility of the drive train in the state of installation in a vehicle. By transmitting the torque of the drive motor via the rim and the damping element, the application makes use of the knowledge that the actual characteristics of the drive train in the state of installation in a vehicle are decisively characterized by the flexibility of the vehicle tires, which are composed of rubber. Thus, by means of the coupling module according to the application, a drive train test can generally be realized which is significantly closer to reality than hitherto in the prior art. The application thus not only attempts to simulate specific drive train characteristics, as is common in the prior art, but also adapts to features which decisively characterize the characteristics of the drive train in the state of actual installation in a vehicle.

[0021] It is preferably provided that the inner side of the side wall of the wheel house has a coating which increases the friction coefficient of the damping element on the inner side. Thus, even in the case of high torques, a slip of the damping element in the wheel house can be avoided.

[0022] It is particularly preferred that the coating is a bitumen coating. This enables a very realistic behavior of the damping element in the wheel house.

[0023] According to a further preferred embodiment of the application, it is provided that the damping element is configured as a vehicle tire, which frictionally engages with its active surface against the inner side of the side wall of the wheel house. By configuring the damping element as a vehicle tire, a realistic behavior of the drive train during the test process can be established.

[0024] It is advantageously provided that the vehicle tire is only filled with compressed air after it has been arranged in the wheel house. If the vehicle tire is only filled with compressed air after it has been arranged in the wheel house, the tire expands radially and thereby engages against the side wall. This also facilitates the easy arrangement of the vehicle tire in the wheel house.

[0025] According to a further preferred embodiment of the application, it is provided that the wheel house has a support ring, which is arranged on the end of the side wall of the wheel house, which is opposite the base surface of the wheel house. Thus, the damping element or the vehicle tire is not only radially enclosed by the inner side of the side wall of the wheel house and by the base surface from the first axial side, but is additionally also enclosed by the support ring from the second axial side. The following advantage is obtained thereby, namely, that the side wall is also stabilized on the axial end, which is opposite the base surface, and both axial ends prevent, in particular, a radial buckling, for example, as a result of a compression air filling of the vehicle tire and the resulting expansion. The support ring thus prevents an undesired deformation of the side wall and thus also ensures a greater possible pressing force of the active surface of the damping element or of the vehicle tire against the side wall, since the side wall does not elastically yield to the pressing force of the vehicle tire.

[0026] The support ring can either only partially enclose or also completely enclose the second axial side of the damping element or of the vehicle tire. In the case of a partial enclosure, the support ring is preferably arranged in a radially outer region of the damping element or of the vehicle tire and is fastened on the side wall of the coupling module.

[0027] According to a particularly preferred embodiment of the application, it is provided that the support ring is arranged on the wheel house in a detachable manner. The following advantage is obtained thereby, namely, that the support ring does not make the installation or removal of the vehicle tire difficult.

[0028] According to a further particularly preferred embodiment of the application, it is provided that the support ring is connected to the wheel rim via a support bearing on its inner circumference. The following advantage is obtained thereby, namely, that the stability of the coupling module, in particular, in the case of high rotational speeds or high dynamic test methods, can be improved via the support bearing.

[0029] If the coupling module has an additional support bearing, a conventional wheel rim is preferably not used, but instead a special wheel rim having a corresponding bearing surface for supporting the support bearing is used.

[0030] According to a further preferred embodiment of the application, it is provided that a centering bearing for centering the wheel house on the wheel rim is arranged in the base surface. For this purpose, the wheel rim can have, for example, a radially central projection, on which the centering bearing can be supported. The centering bearing improves the centering accuracy of the cardan shaft relative to the drive shaft and thus reduces the unbalance of the coupling module, in particular, in the case of high rotational speeds and high dynamic test methods.

[0031] In order to support the centering support on the part of the drive side of the coupling module, it can be preferable to use an adapter, which is configured in particular as a cylinder and has an open and a closed axial end. On the open axial end, a hole ring is preferably provided, which enables an anti-rotation arrangement of the adapter on the hole ring of the rim by means of a screwing. For example, the adapter can be arranged together with the rim on the drive shaft, such that the hole ring of the rim and the hole ring of the adapter are congruently arranged above the hole ring of the drive shaft and such that the rim and the adapter are held by the same screws, which pass through the rim and the adapter and are embedded in the drive shaft. At the closed axial end, a protrusion is preferably provided, which facilitates the arrangement of the centering support.

[0032] According to a further preferred embodiment of the application, the bottom surface is configured as a grid surface or as a section surface with support arms. This means that the bottom surface is not configured as a solid "plate", but rather can be configured with material-free intermediate spaces or intermediate surfaces. Here, the number of support arms can be selected as desired and depending on the material thickness or torque transmission capacity, as can also the grid thickness. The support arms here denote connecting struts, which connect the side wall of the wheel house with the connection point for the universal shaft and thus further conduct the torque transmitted from the tire to the side wall to the universal shaft. The grid surface also further conducts the torque transmitted from the tire to the side wall to the universal shaft. By configuring as a grid surface or as a section surface with support arms, the following advantages are achieved, namely that material can be saved, whereby the coupling module according to the application becomes lighter and cheaper and in particular has a smaller moment of inertia. Furthermore, it is also possible to access the vehicle tire from one side of the bottom surface.

[0033] According to a further preferred embodiment of the application, the side wall is configured as a tensionable side wall. A tensionable side wall is understood to be a side wall whose circumference can be changed mechanically, so that it can be tensioned around the active surface of the vehicle tire. This enables on the one hand a relatively easy assembly of the damping element or of the vehicle tire in the coupling module and on the other hand a reliable clamping of the vehicle tire in the coupling module for a test run. In particular, the vehicle tire does not have to be pressed against the side wall by inflating the vehicle tire, so that a vehicle tire that is already completely inflated can also be assembled. Furthermore, the frictional engagement between the inner surface of the side wall and the active surface of the vehicle tire can be increased in this way, since the pressing force can be greater. Thus, a greater torque can also be transmitted.

[0034] According to a further preferred embodiment of the application, the inner side of the side wall has at least one tire contact patch section. Here, the tire contact patch section is understood to be a deviation from the circular shape in the form of a circular chord section on which the damping element or the vehicle tire rests with its active surface and forms the so-called tire contact patch. Since in the real operation of a vehicle tire on a motor vehicle the force transmission from the vehicle tire to the road only takes place via the tire contact patch, a test method particularly close to reality and a force transmission characteristic of the coupling module can thus be generated by means of the tire contact patch section. If necessary, a plurality of tire contact patch sections can also be provided, whereby, for example, the stiffness in terms of the torque transmission characteristic of the coupling module can be increased. In general, it applies here that the stiffness increases with the provision of more tire contact patch sections.

[0035] According to a further preferred embodiment of the application, the damping element or the active surface of the vehicle tire rests only on at least one tire contact patch section. Thus, a completely realistic torque transmission characteristic of the coupling module can be generated.

[0036] The application also relates to an output module for a drive train test bench, which comprises an electrical load motor and a coupling module according to the application. This leads to the advantages already described in connection with the coupling module according to the application also applying to the output module according to the application.

[0037] Finally, the application also relates to a drive train test bench for testing a vehicle drive train, which comprises at least one output module according to the application. This leads to the advantages already mentioned. BRIEF DESCRIPTION OF DRAWINGS

[0038] Subsequently, the application is illustrated by means of the embodiments shown in the drawings. Therein:

[0039] Figure 1 A wheel ball cage module known from the prior art is shown;

[0040] Figure 2 A possible structure of a coupling module according to the application for connecting a cardan shaft with a drive shaft is shown exemplarily and schematically;

[0041] Figure 3 A cross section through the coupling module is shown; Figure 2

[0042] Figure 4 A cross section through the coupling module with tire contact patch section is shown; Figure 2

[0043] Figure 5 ​​An exemplary and schematic illustration shows another possible structure of the coupling module according to the invention for connecting a universal joint to a drive shaft.

[0044] The same subjects, functional units, and similar parts are indicated by the same reference numerals in the accompanying drawings. These subjects, functional units, and similar parts are implemented identically with respect to their technical features, unless otherwise expressly or implied in the specification. Detailed Implementation

[0045] Figure 1 A wheel ferrule module 10, known in the prior art, is shown, which detachably connects the drive axle 11 to the universal joint 12.

[0046] Figure 2 The possible structure of the coupling module 20 for connecting the universal joint 22 and the drive shaft 21 according to the present invention is illustrated exemplaryly and schematically. According to the example, the drive shaft 21 is connected via (in...) Figure 2 The drive is provided by an electric motor (not shown), which is directly mounted on and fixedly attached to the drive shaft 21. This electric motor also actually drives the drive shaft 21 during actual driving operations in the vehicle. The coupling module 20 includes a rim 23, which is a conventional rim 23, and can also be installed on a vehicle in road traffic, for example. The coupling module 20 also includes a wheel arch 24 having a bottom surface 24' and sidewalls 24'". A damping element 25 configured as a vehicle tire 25 is enclosed by the wheel arch 24. This damping element is arranged on the rim 23 and frictionally engages with the inner side 24'' of the sidewalls 24'' of the wheel arch 24 using its working surface 25'. This results in torque transmission characteristics of the coupling module 20 that are very close to reality, because the elasticity of the vehicle tire 25 is fully utilized, for example, in actual driving operation. Torque is transmitted here first from the drive shaft 21 to the rim 23, and then from the rim 23 to the vehicle tire 24. The vehicle tire 24, according to its elastic characteristics, transmits torque via its working surface 25' to the inner side 24'' of the sidewalls 24'' of the wheel arch 24. The wheel arch 24 then transmits torque to the universal joint 22 via its bottom surface 24'.

[0047] Figure 2 The exemplary coupling module 20 also includes a support ring 30, which is detachably disposed on the end of the sidewall 24" of the wheel cover 24 opposite the bottom surface 24' of the wheel cover 24 by means of a screw connection. The support ring 30 prevents elastic yielding in the sense of radial bending of the sidewall 24" at the axial end of the sidewall 24" facing the support ring 30.

[0048] at last, Figure 2The coupling module 20 also comprises a centering support 26 for centering the wheel house 24 on the wheel rim 23. Here, the coupling module 20 is supported via its bottom face 24' on the protrusion 27 of the adapter means 31, which are connected to the wheel rim 23 via a hole ring with a screw connection. The centering support 26 improves the consistency of the coupling module 20, especially in the case of high rotational speeds and high dynamic test methods.

[0049] Figure 3 A cross section through the coupling module 20 is shown. Here, the side wall 24' and the inner side 24" of the wheel house 24 can be seen. The vehicle tire 25 is arranged in the wheel house 24 with its active face 25', wherein the active face 25' is frictionally locked against the inner side 24", so that a torque can be transmitted. The vehicle tire 25 is arranged on the wheel rim 23. Figure 2

[0050] Figure 4 A cross-sectional view of the coupling module 20 is shown, however, the inner side 24" of the side wall 24' has a tire ground contact section 28 according to the example. The tire ground contact section 28 results in the fact that the vehicle tire 25 in the clamped state in the wheel house 24, as in a real driving operation, configures a tire ground contact on the motor vehicle via which the complete torque is transmitted. According to the example, in the coupling module 20, there is an air gap between the active face 25' of the vehicle tire 25 and the inner side 24" of the side wall 24' away from the tire ground contact section 28. Figure 3 Figure 4

[0051] Figure 5 A further possible configuration of the coupling module 20 for connecting the cardan shaft 22 with the drive shaft 21 according to the application is shown exemplarily and schematically. Figure 5 The coupling module 20 according to Figure 2 The coupling module 20 according to differs only in that a custom wheel rim 23 is used instead of a conventional wheel rim 23, which allows the provision of a support bearing 29. As a result, the following advantage arises, namely that the stability of the coupling module 20, especially in the case of high rotational speeds or high dynamic test methods, can be improved via the support bearing 29. The support ring 30 is correspondingly extended radially inward to the extent that it acts on the support bearing 29.

[0052] List of reference signs

[0053] 10 wheel ball cage module

[0054] 11 drive axle

[0055] 12 cardan shaft

[0056] 20 coupling module

[0057] 21 drive shaft

[0058] ​​​22 universal joint

[0059] 23 rim

[0060] 24 wheel cover

[0061] 24‘bottom surface

[0062] 24“side wall

[0063] 24“‘inner side

[0064] 25 damping element, vehicle tire

[0065] 25‘active surface

[0066] 26 centering support

[0067] 27 protrusion

[0068] 28 tire ground contact surface section

[0069] 29 support bearing

[0070] 30 support ring

[0071] 31 adapter means

Claims

1. Coupling module (20) for a drive train test bench for connecting a cardan shaft (22) to a drive shaft (21), wherein the coupling module (20) comprising a wheel rim (23) and a wheel house (24) having a bottom face (24') and a side wall (24"), wherein the wheel rim (23) is arranged on the drive shaft (21) in a rotationally fixed manner, and wherein the wheel house (24) is arranged on the cardan shaft (22) in a rotationally fixed manner, characterized in that an annular damping element (25) is arranged on the wheel rim (23), which damping element is in frictional engagement with the inner side (24"') of the side wall (24") of the wheel house (24).

2. Coupling module (20) according to claim 1, characterized in that the damping element (25) being configured as a vehicle tire, which vehicle tire is in frictional engagement with the inner side (24"') of the side wall (24") of the wheel house (24) with its active face (25').

3. Coupling module (20) according to claim 1 or 2, characterized in that the wheel house (24) having a support ring (30), which support ring is arranged on the end of the side wall (24") of the wheel house (24) which is opposite the bottom face (24') of the wheel house (24).

4. Coupling module (20) according to claim 3, characterized in that the support ring (30) being arranged on the wheel house (24) in a detachable manner.

5. Coupling module (20) according to claim 3, characterized in that the support ring (30) being connected to the wheel rim (23) on its inner circumference by means of a support bearing (29).

6. Coupling module (20) according to claim 1 or 2, characterized in that a centering bearing (26) for centering the wheel house (24) on the wheel rim (23) is arranged in the bottom face (24').

7. Coupling module (20) according to claim 1 or 2, characterized in that the bottom face (24') being configured as a grid face or as a section face having support arms.

8. Coupling module (20) according to claim 1 or 2, characterized in that the side wall (24") being configured as a tensionable side wall (24").

9. Coupling module (20) according to claim 1 or 2, characterized in that the inner side (24"') of the side wall (24") having at least one tire ground contact section (28).

10. Coupling module (20) according to claim 1, characterized in that the inner side (24"') of the side wall (24") having at least one tire ground contact section (28), wherein the damping element (25) is in frictional engagement only with the at least one tire ground contact section (28).

11. Coupling module (20) according to claim 2, characterized in that the inner side (24"') of the side wall (24") having at least one tire ground contact section (28), wherein the active face (25') of the vehicle tire is in frictional engagement only with the at least one tire ground contact section (28).

12. Output module for a drive train test bench, the output module comprising an electric load motor and a coupling module (20) according to any one of claims 1 to 11.

13. Drive train test bench for testing a drive train of a vehicle, the drive train test bench comprising at least one output module according to claim 12.

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