DE102021203714B3 - Test stand for a drive train of a motor vehicle - Google Patents

Abstract

The invention relates to a test stand (100) for a drive train of a motor vehicle (20), comprising at least one load motor (110) with a motor housing (111) and a motor shaft (112), at least one torque sensor (120) and at least one parking module (130) , wherein the motor shaft (112) is designed to be drivingly connected to a hub (21) of the motor vehicle (20) and wherein the torque sensor (120) is designed to detect a torque generated by the engine. The drive train test bench (1) according to the invention is characterized in that an axial side (115) of the motor housing (11) facing the hub (21) and the at least one parking module (130) are designed to be connected to one another in a rotationally fixed manner and that the torque sensor ( 120) is arranged in the parking module (130) in such a way that it detects a torque acting in the parking module (130) from radially inside to radially outside.

Description

The invention relates to a test stand for a drive train of a motor vehicle according to the preamble of claim 1.

Transmission test benches or drive train test benches for testing motor vehicle transmissions or complete motor vehicle drive trains are known from the prior art. Such test benches are usually used for quality control in order to detect malfunctions in drive trains at an early stage using a series of stress tests. Typical malfunctions are caused, for example, by components that are subject to play, e.g. B. gears, synchronizer rings, synchronizer body, multi-plate clutch discs and shafts that can be deflected and excited to vibrate. As part of such a function test, the acoustic behavior and the shift quality are usually also checked. In addition, such test benches are also used in the development and continuous improvement of motor vehicle drive trains.

In this context, describes the DE 43 28 537 C2 a transmission test stand with a first servomotor serving as a drive motor and a second servomotor serving as a brake motor. The drive motor is connected via a clutch to the drive shaft of a motor vehicle transmission to be tested and its speed is controlled by a PC, among other things, so that any speed curves can be simulated. The brake motor is connected to an output shaft of the motor vehicle transmission to be tested via a further clutch. The speed of the brake motor is also controlled via the PC. The speed curves simulated by the PC are speed curves measured in real driving tests. Thus, the motor vehicle transmission according to the DE 43 28 537 C2 be checked before installation in a motor vehicle.

the DE 103 28 461 A1 discloses a vehicle test stand with a loading machine for each drivable wheel of a motor vehicle. The dynamometers are connected directly, for example via wheel bolts, or indirectly, e.g. via a belt drive, to the rims of the motor vehicle wheels, so that the dynamometers can both drive and brake the drive train. The vehicle test bench DE 103 28 461 A1 further comprises a frame structure over which the motor vehicle and the loading machines can be lifted and aligned with one another. During the testing process, the motor vehicle is completely supported by the frame construction, so that the vehicle wheels do not have any contact with the ground.

From the DE 10 2010 016 587 A1 a wheel set for testing a motor vehicle with stationary tires is known. The wheel set is designed in several parts and has a rim and a hub, the rim being rotatable in the hub and a vehicle tire being able to be arranged on the rim. In this way, during vehicle testing, the tire and rim can be stationary while the hub is rotated to simulate handling characteristics.

the JP 2017 110 956 A shows a vehicle testing device and a simulation wheel for a vehicle testing device. The simulation wheel can be mounted on the axle of a vehicle to be tested so that the vehicle can support itself over the simulation wheel as over an ordinary wheel. The vehicle test device includes a dynamometer which can be connected to the axle of the vehicle via a connection section with a torque sensor. The connection section can rotate together with the axle via a bearing device of the simulation wheel without the tire of the simulation wheel also rotating.

the DE 10 2019 115 902 A1 describes a method for detecting a torque acting on a wheel of a motor vehicle using a torque detection device. The torque detection device has a torque measuring flange, which is arranged between a rim of the wheel and a wheel hub of a wheel suspension for the motor vehicle. A torque acting on the wheel can be detected by means of the torque detection device.

From the DE 101 02 236 A1 an arrangement for detecting physical measured variables, in particular forces, torques, stresses or accelerations on a wheel bearing of a motor vehicle, is known. The arrangement has a radial bearing, a rotatable component connected to the radial bearing, a sensor device with which at least one physical measurement variable that can be transmitted from the rotatable component to the radial bearing can be detected, and a further device connected to the radial bearing, with which the rotational speed of the rotatable component can be influenced. It is further provided that the sensing device and the further device are arranged relative to one another on the radial bearing in such a way that if the rotational speed of the rotatable component is influenced by a force caused by the further device, a direct transfer of part of this force from the further device to the Sensing device at least approximately omitted. This ensures that the physical measurement variable detected by the sensing device is at least close approximately directly caused exclusively by the rotatable component.

However, the known motor vehicle test benches have disadvantages in that they require a comparatively large installation area and, above all, are dependent on a complex and expensive mechanical support structure, especially if they are provided for testing a drive train already installed in the motor vehicle.

It is an object of the present invention to propose an improved test stand for a drive train of a motor vehicle.

According to the invention, this object is achieved by the test stand for a drive train of a motor vehicle according to claim 1 . Advantageous configurations result from the dependent claims.

The invention relates to a test stand for a drive train of a motor vehicle, comprising at least one load motor with a motor housing and a motor shaft, at least one torque sensor and at least one switch-off module, the motor shaft being designed to be drivingly connected to a hub of the motor vehicle and the torque sensor is designed to detect a torque generated by the engine. The test rig according to the invention is characterized in that an axial side of the motor housing facing the hub and the at least one parking module are designed to be connected to one another in a torque-proof manner and that the torque sensor is arranged in the parking module in such a way that it extends in the parking module from radially inwards to radially external torque detected.

The invention thus describes a test stand that is suitable for testing a drive train of a motor vehicle. The motor vehicle can equally be a motor vehicle driven by an electric motor or a conventionally driven motor vehicle.

For this purpose, the test stand comprises at least one load motor with a motor housing and a motor shaft. The load motor is advantageously an electric motor. Electric motors are comparatively compact, have a wide speed range, especially compared to internal combustion engines, and advantageously have the maximum torque over a wide speed range. Only when the so-called "corner point" is reached in the high speed range does the torque decrease indirectly proportional to the further increasing speed due to the increasing field weakening.

Provision is preferably made for the at least one load motor to be designed as a permanently excited synchronous motor. The synchronous motor particularly advantageously includes a comparatively large number of magnetic pole pairs, for example twelve or more magnetic pole pairs. Such synchronous motors are also known as so-called synchro-torque motors. This results in the advantage that the loading motor can be made comparatively compact and short, which consequently leads to the center of gravity of the loading motor being arranged very close to the chassis of the motor vehicle.

Each load motor is advantageously assigned its own inverter. The inverter has a three-phase design, for example.

The at least one loading motor in turn comprises a motor housing, via which the loading motor can be placed, for example, on a base or a device provided for this purpose. Alternatively or additionally, the motor housing is also designed to enable the loading motor to be arranged or supported, for example, via its so-called a-side or b-side.

The motor housing can have water cooling, for example.

Finally, the at least one loading motor also includes a motor shaft, which provides the torque generated by the loading motor and the speed generated by the loading motor. The motor shaft can be drivingly connected to one of the hubs of the wheels of the motor vehicle, so that torque and speed can be introduced from the motor shaft into the hub. The torque and the speed together represent a mechanical power with which the drive train to be tested can be loaded. The torque and the speed therefore represent the load on the drive train occurring during the test.

Within the meaning of the invention, a drive connection is understood to mean a mechanical connection for the transmission of mechanical power, with the torque and the speed being able to be converted as part of the transmission from the load motor to the hub. This means that the load engine provides, for example, a first speed and a first torque, with the first speed and the first torque representing the first power. As part of the transmission of the first power, the first torque ment to be converted to the second torque and the first speed to be converted to the second speed. However, the first performance remains unchanged by the transfer. The definition that the motor shaft is drivingly connected or can be connected to the hub does not specify that there must be a direct mechanical connection, in particular no non-rotatable connection, between the motor shaft and the hub. Rather, the driving connection can also include a gear or an individual transmission stage or other intermediate elements.

Furthermore, the test bench includes at least one torque sensor, the torque sensor being designed to detect a torque generated by the load motor.

The torque sensor preferably includes one or more force-sensitive elements, in particular one or more strain gauges, which initially detect a force acting on the force-sensitive element or forces acting on the multiple force-sensitive elements. The torque acting in each case can then be determined from the detected force or forces via the geometry of the torque sensor.

It is preferably provided that a speed of the load motor is also detected, for example via its control electronics, in particular via its inverter. From the known speed and the known torque, the power or the load can then be determined, for example.

According to the invention, it is also provided that an axial side of the motor housing facing the hub and the at least one storage module are designed to be connected to one another in a rotationally fixed manner via a connection position provided for this purpose. The axial side of the motor housing facing the hub is preferably the so-called a-side of the motor housing. The at least one storage module and the motor housing can be connected to one another in a torque-proof manner via connection means provided for this purpose, for example a flange connection. An axial plug-in connection is also conceivable, which essentially only supports the torque, but is largely movable axially. This results in the advantage that the common center of gravity of the loading motor and the storage module is comparatively close to the contact point of the storage module on a substrate. This in turn leads to the further advantage that only a very small tipping moment acts on the shutdown module, so that the testing of the properties of the drive train is largely unaffected.

Furthermore, there is the advantage that the mechanical connection between the at least one load motor and the hub is designed to be comparatively short and therefore very rigid. Thus, during the operation of the test stand according to the invention, the occurrence of vibrations with an intensity disruptive to the test process can be almost completely avoided.

The storage module is advantageously mounted on the hub of the motor vehicle instead of a vehicle wheel or like a vehicle wheel.

According to the invention, it is further provided that the at least one torque sensor is arranged in the parking module in such a way that it detects a torque acting in the parking module from radially inside to radially outside. For this purpose, the at least one torque sensor can advantageously be arranged radially between an outer circumference of the at least one parking module and the connection position of the at least one loading motor to the parking module. The at least one torque sensor is particularly preferably designed in the form of a ring and is designed in particular as a supporting component of the storage module. As an alternative, the at least one torque sensor can also be designed like spokes. In the latter case, the torque sensor is generally not a load-bearing component of the storage module but can be arranged, for example, on the storage module by means of gluing.

The at least one torque sensor is connected to the storage module in a torque-proof manner via the connection position. Since the at least one load motor introduces a speed and torque into the hub of the motor vehicle, it must support the torque introduced via its connection to the storage module—that is, at the connection position—against the storage module. This connection position is naturally radially inside the outer circumference of the storage module. Since the torque to be supported corresponds to the torque introduced into the drive train, the torque introduced into the drive train can thus be detected in a simple manner via the torque sensor.

Since the at least one torque sensor is also not located in the torque flow from the load motor to the hub, this mechanical connection, which is already short and very stiff, can advantageously be stiffened even further.

At the same time, the load engine—just like the motor vehicle to be tested via its suspension—supports itself via the storage module, which in turn is set up on a base and there supports the weight force acting on it. The substrate can have a particularly high coefficient of friction in relation to the parking module, in order to also enable the transmission of high torques from the load motor to the parking module.

Provision can furthermore be made for the at least one storage module to be able to be connected to a substrate in a non-positive or positive manner. For example, the adhesion of the storage module to the ground can be increased even further by the storage module being clamped over its running surface, for example by means of a tension belt whose ends are firmly connected to the ground. In order to further improve the adhesion of the storage module to the ground, the storage module can also be arranged on the ground, for example by means of a bolt which is arranged in the ground and penetrates the storage module radially from the outside.

The invention thus describes a very compact test stand for testing a drive train of a motor vehicle, in which the load motor can be connected directly to a hub of the motor vehicle without an intermediate shaft. Finally, this also results in the advantage that the required test space is comparatively much smaller and in particular no bulky and expensive test stand or corresponding frame construction is required to hold the motor vehicle and the load motors and to align them with one another.

In particular, complex and time-consuming alignment or adjustment of the drive train or the motor vehicle to the test stand is no longer required. Another significant advantage of the invention is that the testing process using the test stand according to the invention leaves the chassis properties of the motor vehicle to be tested largely unaffected, since the motor vehicle to be tested is supported exclusively by the chassis during the testing process. In this way, chassis-specific properties such as spring deflection behavior, steering behavior and similar properties can be tested very realistically.

Provision is advantageously made for the test stand to include a load motor, a torque sensor and a parking module for each drivable wheel of the motor vehicle. The entire drive train of the motor vehicle can thus be tested in one test run.

According to a preferred embodiment of the invention, it is provided that the at least one storage module has a concentric opening through which the hub is accessible from a side facing the at least one loading motor. The concentric opening is advantageously at least large enough for the hub of the motor vehicle to be completely open. As a result, the motor shaft can be connected directly and non-rotatably to the hub, for example. The parking module with the concentric opening is arranged, for example, in a rotationally fixed manner on the axial side of the loading motor facing the hub of the motor vehicle, so that the motor vehicle is supported via its hub on the loading motor and the loading motor is supported via the connection position on the parking module, which in turn ultimately rests on the ground gets up.

According to an alternative preferred embodiment of the invention, it is provided that the at least one storage module has a radial outer part and a radial inner part, with the inner part being held rotatably in the outer part, with the inner part being designed to be connected to the hub of the motor vehicle in a rotationally fixed manner and wherein the outer part is designed to be non-rotatably connected to the axial side of the motor housing facing the hub. In this case, the at least one storage module is designed in two parts, with the radial inner part of the storage module being rotatable relative to the radial outer part of the storage module, so that in this case, too, the at least one loading motor can be connected to the storage module, namely the outer part, in a torque-proof manner. The at least one loading motor can therefore also be supported on the storage module in this case. At the same time, the storage module can in this case not only be connected to the hub via the loading motor, but also be connected directly to the hub in a rotationally fixed manner via the inner part, which can be rotated relative to the outer part. This results in a simplified assembly of the load motor on the drive train of the motor vehicle, since the parking module can first be mounted on the motor vehicle like a normal vehicle wheel and the motor vehicle can also be pushed with the mounted parking module, for example, and thus positioned and aligned in a simple manner can. However, other configurations or configurations of the at least one storage module and the shaft are also conceivable.

In this embodiment, the at least one torque sensor is advantageously arranged in the radial outer part. Thus, the torque and the speed can be passed on to the hub of the motor vehicle via the inner part, while the supporting torque of the at least one load motor is detected via the torque sensor in the outer part. In this case, too, the torque sensor is radially between the connection position of the loading motor to the storage module and the outer circumference of the storage module.

According to a particularly preferred embodiment of the invention, it is provided that the motor shaft can be connected to the inner part in a rotationally fixed manner. Since the inner part is non-rotatably connected to the hub, a load provided by the loading motor can be transmitted via the motor shaft to the inner part of the storage module and from there can be introduced via the hub into the drive train of the motor vehicle.

According to a particularly preferred embodiment of the invention, it is provided that rotation of the inner part relative to the outer part can be blocked. The blocking can be done, for example, by moving bolts or slides provided for this purpose or by positioning a clamping element, so that a relative movement of the outer part to the inner part is blocked. This results in the advantage that the motor vehicle can even move under its own power and can accordingly be easily positioned and aligned for the test. For example, a correspondingly lockable parking module can be mounted on each wheel to be tested and the motor vehicle can then drive within the test site, for example in a spacious hall, from the location of the parking module assembly to the location of the test.

According to a further preferred embodiment of the invention, it is provided that the at least one storage module has an annular projection which is designed to connect the at least one loading motor to the at least one storage module in a rotationally fixed manner. In this case, the ring-shaped projection thus represents the connection position of the loading motor to the parking module. The ring-shaped projection preferably has connection means provided for connection, such as screw connections, axial bolts or pins, which interact with corresponding connection means of the motor housing.

Since the annular projection leads to a spacing of the loading motor from the hub that is predetermined by the axial length of the projection, a compensating coupling, for example, can be arranged axially between the motor shaft and the hub, with the help of which any existing angular and radial offsets can be compensated. The annular projection then radially encloses the compensating clutch.

According to a further preferred embodiment of the invention, provision is made for a pneumatic tire to be arranged on a radial outer circumference of the at least one storage module. In this case, there is a support behavior of the storage module on the ground, which largely corresponds to the support behavior of a support behavior occurring during normal driving of the motor vehicle. As a result, the quality of the test can be improved since the behavior of the drive train in the test situation is even closer to the behavior of the drive train in normal driving operation of the motor vehicle.

A pneumatic tire is preferably arranged on the parking module, which is also permissible for operation of the motor vehicle when the motor vehicle is being driven on the road.

According to an alternative preferred embodiment of the invention, it is provided that a rubber coating is arranged on a radial outer circumference of the at least one storage module. The rubber coating also enables a comparatively realistic support of the storage module on the ground, but in contrast to the pneumatic tire does not require a separate selection and installation of a suitable pneumatic tire on the storage module. Instead, the rubber coating can be arranged firmly and permanently on the storage module.

According to a further preferred embodiment of the invention, it is provided that the test bench also includes at least one motor support, which is designed to support a tilting moment of the at least one load motor. Since the load motor is only connected to the storage module via one axial side, preferably the a-side, and is held exclusively via the storage module, a tilting moment acts on the load motor, which can have an unfavorable effect on the test. This tilting moment is advantageously intercepted by the motor support. The motor support can be arranged below the motor housing, for example, in the area of the axial side of the motor housing facing away from the hub, preferably the b-side of the motor housing, in order to support the load motor from below. It is also conceivable to attach the motor support in such a way that it holds the loading motor from above, i.e. that the loading motor hangs on the motor support. In the latter case, for example, the motor support can be designed inexpensively and easily as a cable, in particular as a wire cable.

If the motor support holds the loading motor from above, it can in particular comprise a compensation element which is arranged in the power flow and which in turn contains a spring which can be prestressed. An adjustable pretensioning of the spring can advantageously be used to compensate for this rendes tilting moment or a tilting moment that corresponds to a force to be compensated. This can ensure that there is no overcompensation of the tilting moment.

According to a further preferred embodiment of the invention, it is provided that the test stand also comprises at least one support ram, the support ram being adjustable in three spatial directions and/or rotatable about three axes and the support ram being designed to support the storage module or that the test stand further comprises at least one hexapod-like actuator device, wherein the actuator device is designed to adjust the hub in three spatial directions and/or to rotate it about three axes. Appropriate actuation of the supporting plunger, for example along a vertical axis, can thus simulate uneven ground during a journey of the motor vehicle. Likewise, almost all other influences of a possible subsoil can be simulated via the supporting ram, in particular also in connection with steering movements of steerable wheels of the motor vehicle. The hexapod-like actuator device preferably acts on the hub of the motor vehicle and is also able to simulate uneven ground during a journey and almost all other influences of a possible underground. As the name suggests, the hexapod-like actuator device comprises six actuators, which can be designed as hydraulic cylinders, for example. This enables a particularly realistic test of the drive train.

The invention is explained below by way of example using the embodiments shown in the figures.

• 1 beispielhaft und schematisch einen im Stand der Technik bekannten Prüfstand zum Prüfen eines Antriebsstrangs eines Kraftfahrzeugs sowie das zu prüfende Kraftfahrzeug,
• 2 beispielhaft und schematisch eine mögliche Ausführungsform eines erfindungsgemäßen Prüfstands für einen Antriebsstrang eines Kraftfahrzeugs sowie das zu prüfende Kraftfahrzeug,
• 3 beispielhaft und schematisch eine mögliche Ausführungsform eines erfindungsgemäßen Prüfstands im Detail,
• 4 beispielhaft und schematisch eine weitere mögliche Ausführungsform eines erfindungsgemäßen Prüfstands,
• 5 beispielhaft und schematisch eine nochmals weitere mögliche Ausführungsform eines erfindungsgemäßen Prüfstands,
• 6 beispielhaft und schematisch eine nochmals weitere mögliche Ausführungsform eines erfindungsgemäßen Prüfstands,
• 7 beispielhaft und schematisch eine mögliche Ausführungsform eines erfindungsgemäßen Abstellmoduls und
• 8 beispielhaft und schematisch eine nochmals weitere mögliche Ausführungsform eines erfindungsgemäßen Prüfstands.

Show it:

• 1 by way of example and schematically a test bench known in the prior art for testing a drive train of a motor vehicle and the motor vehicle to be tested,
• 2 by way of example and schematically a possible embodiment of a test stand according to the invention for a drive train of a motor vehicle and the motor vehicle to be tested,
• 3 exemplary and schematic of a possible embodiment of a test bench according to the invention in detail,
• 4 exemplary and schematic of another possible embodiment of a test bench according to the invention,
• 5 by way of example and diagrammatically another possible embodiment of a test stand according to the invention,
• 6 by way of example and diagrammatically another possible embodiment of a test stand according to the invention,
• 7 exemplary and schematic of a possible embodiment of a storage module according to the invention and
• 8th by way of example and diagrammatically, another possible embodiment of a test stand according to the invention.

Identical objects, functional units and comparable components are denoted by the same reference symbols across the figures. These objects, functional units and comparable components are designed to be identical in terms of their technical features, unless the description explicitly or implicitly states otherwise.

1 1 shows, by way of example and diagrammatically, a test stand 10 known in the prior art for testing a drive train of a motor vehicle 20 and the motor vehicle 20 to be tested. The drive train is already fully installed in the motor vehicle 20. The known test stand 10 comprises two loading units 11 which are each connected via connecting shafts 12 to hubs 21 of drivable wheels of the motor vehicle 20 . However, test stands 10 of the same generic type are also known, in particular for four-wheel drive vehicles, with four load units 11 . The loading units 11 in turn each comprise a terminal box 14 arranged on the electric drive motor 13 for accommodating the cables which supply the electric drive motor 13 with electric energy. The drive motors 13 are each arranged on a frame 15, the frame 15 being laterally adjustable in order to be able to be adapted to the track width of different vehicle types. The motor vehicle 20 is usually lifted onto the supporting elements 16 by means of a lifting device, for example a crane, and parked there. The support elements 16 each have a receiving bearing for attachment to the hubs of the vehicle wheels. The structure and thus the space requirement of the known test stand 10 are comparatively large. Since no wheels are mounted on the hubs 21 of the motor vehicle 20, the motor vehicle 20 cannot be brought into the test position in the test bench 10 either under its own power or by being pushed.

2 shows an example and schematically a possible embodiment of a test bench 100 according to the invention for a drive train of a Motor vehicle 20 and the motor vehicle 20 to be tested. As can be seen, the test stand 100 according to the invention comprises two load motors 110 which are connected directly to the hubs 21 (not shown in 2 ) of the motor vehicle 20 can be arranged. As a result, the test bench 100 according to the invention is significantly more compact and less expensive than known test benches 10 . In particular, no complex alignment of loading units 11 or loading motors 110 relative to motor vehicle 20 is required. Furthermore, the motor vehicle 20 can be moved under its own power to the required test position by means of the storage modules 130 . It is also of particular advantage that the test stand 100 according to the invention does not require any space-consuming frames 15 due to its construction.

3 shows a possible embodiment of a test bench 100 according to the invention in detail as an example and schematically. The load motor 110 designed as an electric motor 110 can be seen, which has a motor housing 111 and a motor shaft 112 . The electric motor 110 or load motor 110 is, for example, a permanently excited synchro-torque motor 110 with a liquid-cooled motor shaft 112. For example, the motor shaft 112 has a 3 not shown rotary union, in which glycol can be introduced as a coolant. Glycol flows through and cools the motor shaft 112 through bores in the motor shaft 112, which are also not shown. The synchro-torque motor 110 is designed as a synchronous motor and has, for example, 12 permanent-magnetic pole pairs. This comparatively large number of pole pairs gives the load motor 110 a comparatively very high torque, even when subjected to comparatively low current intensities. This embodiment also leads to the advantage that the loading motor 110 has a comparatively large radial width compared to the axial length, as a result of which its center of gravity is close to the contact point of the storage module 130 . Such electric motors 110 are generally known as so-called “torque motors”. An inverter 117 is arranged directly on the motor housing 111 according to the example. Alternatively, however, the inverter 117 can also be arranged at a distance from the motor housing 111 . A torque sensor 120 and a parking module 130 can also be seen. The torque sensor 120 is ring-shaped, for example, and is arranged in the parking module 130 in such a way that it detects a torque acting in the parking module 130 from radially inside to radially outside.

For this purpose, the torque sensor 120 is arranged radially between an outer circumference of the at least one storage module 130 and the connection position of the loading motor 110 to the storage module 130 . The connection position is represented, for example, by a ring-like projection 113 whose outer diameter corresponds exactly to the outer diameter of the motor housing 111 . About an in 3 non-illustrated screw connection, the loading motor 110 is non-rotatably connected with its a-side to the projection 113 .

The torque sensor 120 is ring-shaped and designed as a supporting component of the storage module 120, i.e. the torque sensor bears the weight of the load motor 110 and the motor vehicle 20 to be tested.

Since the loading motor 110 introduces a rotational speed and a torque into the hub 121 of the motor vehicle 20 , it has to support the introduced torque against the parking module 130 via the projection 113 . Since the torque to be supported corresponds to the torque introduced into the drive train, the torque introduced into the drive train can thus be detected in a simple manner via torque sensor 120 .

The load motor 110, the torque sensor 120, the annular body 113 and the storage module 130 together represent a possible embodiment of the test stand 100 according to the invention. The motor vehicle 20, of which FIG 3 For the sake of clarity, only a hub 21, a vibration damper 22 and a wheel linkage 23 can be seen.

The parking module 130 has, for example, a concentric opening 131 through which the hub 21 is accessible from a side facing the loading motor 110 . The hub 21 is drivingly connected to the motor shaft 112 via a compensating clutch 121 which is radially enclosed by the annular projection 113 . Since the hub 21 is an end link of the drive train of the motor vehicle 20, there is also a drive connection to the drive train of the motor vehicle 20, so that the drive train can be loaded and tested. The compensating coupling 121 is intended to compensate for any angular and radial offsets that may exist. As described, the loading motor 110 is non-rotatably connected to a radial outer part 135 of the storage module 130 via the annular projection 113 , a radial inner part 136 being rotatably held in the outer part 135 and the inner part 136 having the concentric opening 131 . As a result of this configuration, the parking module 130 is held on the hub 21 only indirectly via the loading motor 110 . In test mode, the load motor 110 is supported on the outer part 135 of the parking module 130 and can thus Introduce load into the hub 21. According to the example, a rubber coating 139 is also arranged on the parking module 130, which allows a realistic parking behavior of the motor vehicle 20 via the parking module 100 130 on the ground. In contrast to the pneumatic tire 138, the rubber coating 139 advantageously does not require any separate selection and installation on the storage module 130. Instead, the rubber coating 139 can be arranged firmly and permanently on the storage module 130.

According to an alternative, also by 3 In the embodiment illustrated by way of example, the torque sensor 120 is spoke-like, comprising, for example, exactly four force-sensitive elements distributed uniformly over the circumference at an angle of 90° to one another in the form of strain gauges glued to the storage module 130 .

4 shows a further possible embodiment of a test bench 100 according to the invention by way of example and schematically. The test bench 100 of FIG 4 differs from the test bench 100 of the 3 by the formation of the storage module 130. According to the example, a pneumatic tire 138 is arranged on the storage module 130 instead of a rubber coating 139. According to the example, the pneumatic tire 138 is a pneumatic tire 138 which is also approved for road use of the motor vehicle 20 . Since the motor vehicle 20 stands up on the pneumatic tire 138 during a test process, the result is a very realistic test behavior of the drive train of the motor vehicle 20. Another difference to the parking module 130 of FIG 4 to the storage module 130 of 3 lies in the fact that the annular projection 113 has a smaller radial diameter, but instead has a collar 113' which rests against the a-side of the load motor 110 and thus allows a non-rotatable connection, for example via a flange connection. Also, the storage module 130 of 4 no radial inner part 136 which would be rotatable against the radial outer part 135. Instead, the storage module 130 of FIG 4 exclusively a concentric opening 131 through which the motor shaft 112 is directly connected to the hub 21. In addition, the test bench has 100 of the 4 in contrast to the test bench 3 also no compensating clutch 121 on.

5 shows, by way of example and diagrammatically, yet another possible embodiment of a test bench 100 according to the invention. The test bench 100 of FIG 5 differs from the test bench 100 of the 3 again only through the formation of the storage module 130. According to the example, the storage module 130 has no radial inner part 136 which would be rotatably held in the radial outer part 135. Instead, the storage module 130 of 5 exclusively a concentric opening 131 (not shown in the view of 5 ) on. Furthermore, the test bench differs from 100 5 from the test stand 100 of the 3 due to the absence of the annular projection 113. Instead, the storage module 130 is pulled along its axial axis in the shape of a pyramid in the direction of the loading motor 110 and, instead of a pyramid tip, has a connecting surface 114, via which the loading motor 110 is connected to the parking module in a rotationally fixed manner. The connection is made according to the example via a screw connection.

6 shows, by way of example and diagrammatically, yet another possible embodiment of a test bench 100 according to the invention. The test bench 100 of FIG 6 differs from the test bench 100 of the 5 through the formation of the storage module 130. According to the embodiment of 6 the storage module 130 has a radial outer part 135 and a radial inner part 136, the inner part 136 being held via the motor shaft 112 and the loading motor 110. However, the storage module 130 does not have a concentric opening 131 . Instead, the inner part 136 of the storage module 130 is connected in a rotationally fixed manner to the hub 21 on the one hand and is connected in a rotationally fixed manner to the motor shaft 112 on the other hand. In addition, the parking module 130 has a blocking device 132 which, when the loading motor 110 is in the installed state, allows the inner part 136 to rotate relative to the outer part 135 by the outer part 135 being displaced in the direction of the loading motor 110 and thus no longer in a common plane with the inner part 136 is located, so that the blocking device 132 cannot develop a blocking effect between the inner part 136 and the outer part 135. Only when the inner part 136 and the outer part 135 together with the blocking device 132 lie in one plane does the blocking device 132 block the rotatability. This results in the advantage that the motor vehicle 20 can move under its own power and can accordingly be easily positioned and aligned for the test.

7 shows by way of example and schematically a possible embodiment of a storage module 130 according to the invention for a test stand 100. The storage module 130 of FIG 7 differs from the storage module 130 of 6 in that the blocking device 132 can be seen in the blocking state, since the loading motor 110 (not shown in 7 ) is not mounted. In this state, the motor vehicle 20 can move under its own power, since the inner part 136 cannot twist against the outer part 135 .

8th shows, by way of example and diagrammatically, yet another possible embodiment of a test bench 100 according to the invention. The test bench 100 of FIG 8th differs from the test bench 100 of the 6 on the one hand due to the presence of a motor support 118 which, for example, acts on the motor housing 111 from above and absorbs a tilting moment of the loading motor 110 which would otherwise have to be supported on the parking module 130. According to the example, the engine support 118 is a wire rope 118 which is attached to a suitable construction above the test stand 100 . According to the example, the motor support 118 also includes a compensation element 119, which contains a spring that can be preloaded and precisely supports the tilting moment of the load motor 110 by means of a set preload of the spring. On the other hand, the test bench differs from 110 8th also from the test stand 100 of the 6 by the presence of a supporting stamp 133, which can be adjusted in three spatial directions and rotated about three axes (in each case represented by arrows). The storage module 130 can be supported on the support stamp 133 during the testing process. Appropriate actuation of the supporting plunger 133 during the testing process makes it possible, for example, to simulate uneven floors while the motor vehicle 20 is driving. Almost all other influences of a possible subsurface can also be simulated, in particular also in connection with steering movements of steerable wheels of motor vehicle 20.

Reference List

10

test bench

11

loading unit

12

connecting shaft

13

drive motor

14

terminal box

15

frame

16

support element

20

motor vehicle

21

hub

22

vibration damper

23

wheel linkage

100

test bench

110

Load motor, electric motor, permanently excited synchronous motor

111

motor housing

112

motor shaft

113

ring-like projection

113'

collar

114

connection surface

115

axial side facing the hub

116

axial side facing away from the hub

117

inverters

118

Motor support, wire rope

119

compensation element

120

torque sensor

121

compensating clutch

130

storage module

131

concentric opening

132

blocking device

133

support stamp

135

radial outer part

136

radial inner part

137

storage

138

tire

139

rubber coating

Claims (15)

Test stand (100) for a drive train of a motor vehicle (20), comprising at least one load motor (110) with a motor housing (111) and a motor shaft (112), at least one torque sensor (120) and at least one switch-off module (130), the motor shaft (112) is designed to be drivingly connected to a hub (21) of the motor vehicle (20) and wherein the torque sensor (120) is designed to detect a torque generated by the load motor (110), characterized in that one of the The axial side (115) of the motor housing (11) facing the hub (21) and the at least one parking module (130) are designed to be connected to one another in a rotationally fixed manner and that the torque sensor (120) is arranged in the parking module (130) in such a way that it detected in the parking module (130) acting from radially inside to radially outside torque. Test stand (100) according to claim 1 , characterized in that the at least one torque sensor (120) is arranged radially between an outer circumference of the at least one parking module (130) and a connection position of the at least one loading motor (110). Test stand (100) according to one of Claims 1 and 2 , characterized in that the at least one Abstellmodul (130) has a concentric Publ opening (131) via which the hub (21) is accessible from a side facing the at least one load motor (110). Test stand (100) according to one of Claims 1 until 3 , characterized in that the at least one storage module (130) has a radial outer part (135) and a radial inner part (136), the inner part (136) being rotatably held in the outer part (135), the inner part (136) being designed for this purpose is to be connected to the hub (21) of the motor vehicle (20) in a rotationally fixed manner, and the outer part (135) is designed to be connected in a rotationally fixed manner to the axial side (115) of the motor housing (111) facing the hub (21). Test stand (100) according to claim 4 , characterized in that the motor shaft (112) is non-rotatably connected to the inner part (136). Test stand (100) according to one of Claims 4 and 5 , characterized in that a rotation of the inner part (136) against the outer part (135) can be blocked. Test stand (100) according to one of Claims 4 until 6 , characterized in that the at least one torque sensor (120) is arranged in the outer part (135). Test stand (100) according to one of Claims 1 until 7 , characterized in that the at least one storage module (130) has an annular projection (113) which is designed to connect the at least one loading motor (110) to the at least one storage module (130) in a torque-proof manner. Test stand (100) according to one of Claims 1 until 8th , characterized in that a pneumatic tire (138) is arranged on a radial outer circumference of the at least one storage module (130). Test stand (100) according to one of Claims 1 until 8th , characterized in that a rubber coating (139) is arranged on a radial outer circumference of the at least one storage module (130). Test stand (100) according to one of Claims 1 until 10 , characterized in that the at least one storage module (130) is non-positively or positively connected to a substrate. Test stand (100) according to one of Claims 1 until 11 , characterized in that the at least one load motor (110) is designed as a permanently excited synchronous motor (110). Test stand (100) according to one of Claims 1 until 12 , characterized in that the test stand (100) further comprises at least one motor support (118) which is designed to support a tilting moment of the at least one load motor (110). Test stand (100) according to one of Claims 1 until 13 , characterized in that the test stand (100) further comprises at least one support ram (133), the support ram (133) being adjustable in three spatial directions and/or rotatable about three axes and the support ram (133) being designed to support the parking module (130) or that the test stand (100) further comprises at least one hexapod-like actuator device, wherein the actuator device is designed to adjust the hub in three spatial directions and/or to rotate it about three axes. Test stand (100) according to one of Claims 1 until 14 , characterized in that the test stand (100) for each drivable wheel of the motor vehicle (20) comprises a load motor (110), a torque sensor (120) and a parking module (130).

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