Test stand for a drive train of a motor vehicle, and modular system
Patent Information
- Application Number
- EP2023709963
- Authority / Receiving Office
- EP · EP
- Patent Type
- Applications
- Current Assignee / Owner
- Priority Date
- 2022-03-08
- Filing Date
- 2023-03-06
- Publication Date
- 2025-01-15
AI Technical Summary
Existing motor vehicle drive train test benches are large, inefficient in force transmission, and prone to vibrations due to non-ideal design and automatic height adjustment, which complicates quality control and development processes.
A compact, modular test bench with a U-shaped base frame and flange-connected load motors, featuring rigid construction and adjustable components to minimize vibrations and optimize power transmission, allowing for high-speed testing without disruption.
The solution enables efficient, vibration-free testing of motor vehicle drive trains at high speeds, reducing setup time and costs while improving accuracy and adaptability to various test specimens.
Smart Images
Figure 1.1
Abstract
Description
[0001] Test bench for a motor vehicle drive train and modular system
[0002] The invention relates to a test bench for a drive train of a motor vehicle according to the preamble of claim 1 and a corresponding modular system.
[0003] Transmission test benches or drivetrain test benches for testing motor vehicle transmissions or complete motor vehicle drivetrains are well known in the art. Such test benches are typically used for quality control to detect malfunctions in drivetrains 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 bodies, multi-plate clutch discs, and shafts, which can be deflected and excited to vibrate. As part of such quality control, the acoustic behavior and shifting quality are usually also tested. Furthermore, such test benches are also used in the development and continuous improvement of motor vehicle drivetrains.In this context, DE 4328 537 C2 describes a transmission test bench with a first servomotor serving as the drive motor and a second servomotor serving as the brake motor. The drive motor is connected to the drive shaft of a motor vehicle transmission to be tested via a coupling and is controlled, among other things, with regard to its speed via a PC, so that any desired speed curves can be simulated. The brake motor is connected to an output shaft of the motor vehicle transmission to be tested via another coupling. 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 can be tested according to DE 43 28 537 C2 before being installed in a motor vehicle.
[0004] DE 10328 461 A1 discloses a vehicle test bench with a loading machine for each drivable wheel of a motor vehicle. The loading machines are connected to the rims of the motor vehicle wheels directly, for example via wheel bolts, or indirectly, for example via a belt drive, so that the loading machines can both drive and brake the drive train. The vehicle test bench of DE 103 28 461 A1 further comprises a frame structure, via which the motor vehicle and the loading machines can be raised and aligned with each other. During the test procedure, the motor vehicle is held entirely by the frame structure, so that the vehicle wheels have no contact with the ground.
[0005] However, the existing automotive test benches have several disadvantages: First, they are comparatively large and therefore require comparatively large installation areas. Second, they exhibit a less than ideal power flow from the load motors to the test bench foundation. Another disadvantage is that the often provided automatic height adjustment of the test specimen leads to unfavorable vibration behavior, at least in the area of the test specimen.
[0006] It is an object of the present invention to propose an improved test bench for a drive train of a motor vehicle.
[0007] This object is achieved according to the invention by the test bench for a drive train of a motor vehicle according to claim 1. Advantageous embodiments emerge from the subclaims.
[0008] The invention relates to a test bench for a drive train of a motor vehicle, comprising a first load motor, a second load motor and a base frame with a test specimen holder for receiving a test specimen and with a first motor holder for receiving the first load motor and a second motor holder for receiving the second load motor, wherein a first motor shaft of the first load motor and a second motor shaft of the second load motor can be connected to shafts of the test specimen, so that the shafts of the test specimen can be subjected to torques and speeds.The test bench according to the invention is characterized in that the base frame has a U-shaped cross-section, in which a first leg and a second leg extend upwards from a base, wherein the first load motor is connected with one end face to the first leg of the base frame and the second load motor is connected with one end face to the second leg of the base frame.
[0009] The invention therefore describes a test bench suitable for testing a drivetrain of a motor vehicle. The motor vehicle can be either an electric motor-driven motor vehicle or a conventionally powered motor vehicle. Advantageously, however, the test object is an electrically driven axle module for a motor vehicle, which, in addition to the electric drive motor, includes a transmission and two wheel shafts.
[0010] The test bench according to the invention comprises a base frame with a first motor mount and a second motor mount, as well as a first and a second load motor. The first load motor is connected to the base frame via the first motor mount, and the second load motor is connected to the base frame via the second motor mount.
[0011] The base frame advantageously consists at least partially of a particularly rigid material such as a mineral cast, in particular with a metallic skeleton structure.
[0012] Furthermore, the base frame also has a test specimen holder, via which a test specimen to be tested, in particular an axle module, can be connected to the base frame. The test bench can be designed to test an entire drive train of a motor vehicle or just to test a component of the motor vehicle drive train, for example, the transmission.
[0013] The first and second load motors are each advantageously electric motors. Electric motors are comparatively compact, have a broad speed range, especially compared to combustion engines, and advantageously exhibit maximum torque over a wide speed range. Each load motor comprises a motor housing that encloses the load motor. The motor housings are, for example, cylindrical in shape.
[0014] The motor housings can also be water-cooled.
[0015] The first load motor has a first motor shaft, and the second load motor has a second motor shaft, each of which can be drivenly connected to a shaft of the test object. The shaft(s) of the test object can be either input shafts or output shafts of the test object, in particular wheel shafts of an axle module. Thus, the torques and speeds generated by the first and second load motors can be introduced into the test object, meaning the test object can be subjected to these torques and speeds. The torque and speed together represent a mechanical power with which the test object can be loaded.
[0016] For the purposes of the invention, a drive connection is understood to be a mechanical connection for transmitting mechanical power. However, the definition that the motor shafts are or can be drivenly connected to the shafts of the test object does not necessarily stipulate that there must be a direct mechanical connection, in particular a rotationally fixed connection, between the first or second motor shaft and the shafts of the test object. Rather, the drive connection can, in principle, also comprise a gear, for example, a planetary gear, or individual gear stages or other intermediate elements.
[0017] According to the invention, the base frame has a U-shaped cross-section, with a first leg and a second leg extending upward from a base. The base frame is, in particular, a single piece. This results in a comparatively very high rigidity of the base frame, which effectively prevents the occurrence of vibrations.
[0018] Furthermore, according to the invention, the first load motor is connected by one end face to the first leg of the base frame and the second load motor is connected by one end face to the second leg of the base frame. The first motor mount is therefore arranged on the first leg and the second motor mount is correspondingly arranged on the second leg. Preferably, the first and second motor mounts are each a flange connection. A first part of the flange connection is the end face of the respective load motor or the end face of the housing of the respective load motor and a second part is the corresponding motor mount. This results in a comparatively large contact surface for the first load motor and the second load motor on the base frame.This, in turn, also leads to comparatively high rigidity in the area of the electric motor mounts, so that the occurrence of vibrations in the area of the load motors can be effectively prevented. This type of connection of the load motors to the base frame also offers the advantage that generated torques or forces can be directly introduced into the base frame. This creates a clear flow of force. The front end of the first and second load motors, with which the first and second load motors are connected to the base frame, is preferably the so-called a-side of the load motors.
[0019] Furthermore, thanks to the possibility of arranging the first and second load motors on the base frame via a flange connection, the test bench according to the invention can be relatively easily converted for different load intensities by arranging load motors of a higher or lower power class on the base frame. Advantageously, all load motors of the different power classes have a standardized flange interface.
[0020] The test specimen holder is preferably designed to automatically accommodate the test specimen, in particular the axle module, and to lock it in place with particular rigidity using holding means. The holding means can be designed, for example, as automatically actuated clamps that firmly clamp the test specimen into the test specimen holder. The test specimen holder is arranged at the base of the base frame or forms part of the base of the base frame. To ensure the greatest possible rigidity of the test specimen holder, it is advantageously not designed to be height-adjustable, unlike test stands known in the prior art.
[0021] The invention thus describes a highly rigid test bench for testing a motor vehicle drive train, in which the test specimen can be operated even at very high speeds of over 15,000 rpm without vibrations occurring that disrupt the test run. Particularly with an electric axle module as the test specimen, speeds of the axle module's drive motor of over 15,000 rpm are not uncommon, but in known test benches this regularly leads to the occurrence of vibrations that disrupt the test run. The axle module's gearbox typically achieves a speed reduction, so that the wheel shafts of the axle module generally still experience speeds of approximately 2,000 rpm to approximately 2,500 rpm.
[0022] According to a preferred embodiment of the invention, the first load motor and the second load motor are each designed as permanent-magnet synchronous motors with at least twelve magnetic pole pairs. Such synchronous motors are also known as so-called synchro-torque motors. This results in the advantage that the load motor can be comparatively compact and, in particular, axially short and slow-rotating, yet can still provide a high torque. In particular, the first and second load motors can provide speeds of up to 3,000 rpm.
[0023] The described flange connection and the axially compact torque motors also result in the advantage that the entire test bench is comparatively much smaller and more compact than is usual in the state of the art and is therefore also significantly more cost-effective.
[0024] Each load motor is advantageously assigned its own inverter. The inverter is, for example, three-phase. According to a further preferred embodiment of the invention, it is provided that the first motor shaft is designed as a hollow shaft in which a first transfer shaft is arranged in a rotationally fixed manner, and that the second motor shaft is designed as a hollow shaft in which a second transfer shaft is arranged in a rotationally fixed manner. The drive connection between the motor shafts and the shafts of the test object is then preferably established via the first or second transfer shaft, i.e. the transfer shafts can be connected both in a rotationally fixed manner to the shafts of the test object, for example via a spline connection, and in a rotationally fixed manner to the hollow shafts of the load motors, for example also via a spline connection, via a flange connection or via a suitable connecting element.
[0025] According to a particularly preferred embodiment of the invention, it is provided that the first transfer shaft is connected in a rotationally fixed manner to the first motor shaft via a first torque sensor and that the second transfer shaft is connected in a rotationally fixed manner to the second motor shaft via a second torque sensor. The first torque sensor and the second torque sensor each represent a connecting element via which the first motor shaft and the second motor shaft, which are designed as hollow shafts, are rotationally fixedly connected to the first and second transfer shafts inside the respective hollow shaft. As a result, the torque provided by the first load motor is completely guided via the first torque sensor and, correspondingly, the torque provided by the second load motor is completely guided via the second torque sensor.The torque sensors therefore not only represent the drive connection between the respective hollow shaft and the associated transfer shaft, but also fully measure the torque provided. This arrangement of the torque sensors further supports the compact design of the test bench.
[0026] The first and second torque sensors preferably each comprise 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 plurality of force-sensitive elements. The geometry of the torque sensors can then be used to determine the respective acting torque from the detected force or forces.
[0027] According to a particularly preferred embodiment of the invention, the first torque sensor is arranged on a front side of the first load motor facing away from the test object, and / or the second torque sensor is arranged on a front side of the second load motor facing away from the test object. This means that the first torque sensor is arranged on the so-called b-side of the first load motor, and the second torque sensor is arranged correspondingly on the b-side of the second load motor.
[0028] According to an alternative preferred embodiment of the invention, it is provided that the first torque sensor is arranged on an end face of the first load motor facing the test object and / or that the second torque sensor is arranged on an end face of the second load motor facing the test object. In this case, the first and second torque sensors are arranged on the so-called a-side of the first and second load motors, respectively. Thus, the torque sensors, via which the power flow from the motor shafts to the transfer shafts takes place, are arranged comparatively close to the shafts of the test object.
[0029] Preferably, a rotational speed of each of the first load motor and the second load motor is also recorded, for example via their control electronics, in particular via their inverters. From the known rotational speed and the known torque, the mechanical power applied to the test object can then be determined, for example.
[0030] According to a particularly preferred embodiment of the invention, it is provided that the first motor shaft is closed on its end facing away from the test object by means of a first wall, wherein the first wall has a first bearing for the first transfer shaft and / or that the second motor shaft is closed on its end facing away from the test object by means of a second wall, wherein the second wall has a second bearing for the second transfer shaft. The first and second hollow shafts thus have a closed axial end, wherein the wall closing the respective axial end has a bearing. This bearing, in turn, is designed to rotatably mount the first and second transfer shafts with as little force as possible. The transfer shafts are thus reliably mounted in the hollow shafts without impairing the flow of force via the first and second torque sensors.
[0031] According to a further preferred embodiment of the invention, it is provided that the first transfer shaft comprises a first outer hollow shaft in which a first inner transfer shaft is arranged so as to be axially displaceable and non-rotatable, and that the second transfer shaft comprises a second outer hollow shaft in which a second inner transfer shaft is arranged so as to be axially displaceable and non-rotatable. The first or second transfer shaft, consisting of the outer hollow shaft and the inner transfer shaft, is thus a length-adjustable shaft that can be easily adapted to the length required in each case to establish the connection to the docking points of the corresponding shafts, for example the wheel shafts, of the test object. The length is easily adjusted by extending the transfer shaft out of the outer hollow shaft until the connection can be established.This means that the test bench can be quickly and flexibly adapted to different test objects.
[0032] Due to the axial displaceability of the first or second transfer shaft in the first or second outer hollow shaft, the total length of the first or second transfer shaft can be changed in order to establish the connection to the test object for a test procedure and to release the test object again after the test procedure.
[0033] The first or second transfer shaft can be arranged axially displaceably and rotationally fixedly in the first or second outer hollow shaft, for example, via a spline or other positive connection. According to a particularly preferred embodiment of the invention, it is provided that the first transfer shaft is automatically axially displaceable in the first outer hollow shaft by means of a first actuator, and that the second transfer shaft is automatically axially displaceable in the second outer hollow shaft by means of a second actuator.
[0034] This results in the further advantage over known test benches that, according to the invention, the entire first or second load motor does not have to be moved toward the test specimen; instead, only the first or second transfer shaft is extended axially to the test specimen. This simplifies the test bench setup compared to known test benches. In particular, the assembly and alignment of the wiring of the first or second load motor can be carried out comparatively more easily.
[0035] The first or second actuator may, for example, be an electrically, pneumatically or hydraulically actuated actuator, in particular an electrically actuated threaded rod or a pneumatically or hydraulically actuated cylinder-piston unit.
[0036] The first or second actuator can preferably be arranged entirely or partially in the first or second motor shaft, which is designed as a hollow shaft, in particular in the region of the b-side of the first or second load motor. The arrangement of a pneumatically or hydraulically actuated actuator in the motor shaft in the region of the b-side is particularly advantageous if, in addition, the b-side is closed by the first or second wall. The volume within the outer hollow shaft of the first or second transfer shaft and the first or second wall can, with appropriate sealing, advantageously be used as the working chamber of a corresponding cylinder-piston unit.
[0037] Alternatively, the first or second actuator can preferably also comprise a first or second carriage, which is arranged, for example, in the area between the first load motor and the test object or in the area between the second load motor and the test object. The first carriage can then grip the first transfer shaft and axially displace it, and the second carriage can correspondingly grip the second transfer shaft and axially displace it. The first or second carriage can be moved, for example, by actuating a previously described cylinder-piston unit or an electrically actuated threaded rod.
[0038] Particularly preferably, the cylinder-piston unit is also associated with a mechanical return spring, which forces the cylinder-piston unit into an initial position. The cylinder-piston unit can then be actuated against the return force by applying pneumatic or hydraulic pressure.
[0039] This advantageously allows the test specimen not only to be automatically fed to the test specimen holder and positioned there, but also allows the docking points on the test specimen's shafts to be automatically connected to the first and second load motors. This makes the test bench particularly suitable for the automated and rapid testing of a large number of test specimens, such as axle modules, immediately after their production. Advantageously, no operating personnel are required to position the test specimen on the test specimen holder and to establish the connection between the load motors and the docking points on the test specimen's shafts.
[0040] Advantageously, the required length can be fixed after the test specimen-specific adjustment of the length of the first or second transfer shaft, for example by means of a clamping device which clamps the corresponding transfer shaft against the outer hollow shaft.
[0041] At the end of the transfer shaft, a plug connection is preferably arranged, via which the drive connection to the shafts of the test object can be established.
[0042] Particularly advantageously, the first transfer shaft has a first adapter piece on its axial end piece facing the test specimen, and the second transfer shaft has a second adapter piece on its axial end piece facing the test specimen. The drive connection to the test specimen is then advantageously established via the first or second adapter piece. For this purpose, the first or second adapter piece has, for example, a flange connection on its axial end facing the first or second transfer shaft. A rotationally fixed connection to the first or second transfer shaft can then be established via the flange connection. The axial end of the first or second adapter piece facing the test specimen, on the other hand, is designed specifically for the test specimen and is designed, for example, as a spline, so that it can be easily inserted into corresponding counter-spline on the test specimen.This allows the test bench to be easily and quickly adapted to different test specimen types by exchanging adapters. The resulting setup times are comparatively short.
[0043] According to a further preferred embodiment of the invention, the test bench has a first module for vertically adjusting the first load motor and a second module for vertically adjusting the second load motor. The first or second module for vertical adjustment can, for example, be designed to vertically adjust the first or second motor mount electrically or hydraulically. Thus, the first or second module for vertical adjustment can be used to easily and largely automatically align the first or second load motor to the shafts of the test specimen. The first or second module for vertical adjustment is advantageously arranged on the first or second motor mount, respectively, so that the first or second motor mount, together with the first or second load motor, respectively, can be vertically adjusted relative to the base frame.
[0044] According to a further preferred embodiment of the invention, the test bench comprises a first module for horizontally adjusting the first load motor and a second module for horizontally adjusting the second load motor. The first and second horizontal adjustment modules can also advantageously be configured to adjust the first and second motor mounts electrically or hydraulically, but horizontally.
[0045] The first and second horizontal adjustment modules are preferably also arranged on the first and second motor mounts, respectively, in particular adjacent to the first and second horizontal adjustment modules, respectively, so that the first and second motor mounts, respectively, together with the first and second load motors, respectively, are vertically and horizontally adjustable relative to the base frame. In this case, the first and second horizontal adjustment modules can be configured to enable one-dimensional adjustability along a horizontal line perpendicular to a longitudinal axis of the test bench.
[0046] Alternatively, it is preferred that a first and / or second module for horizontal adjustment be arranged between the first and / or second leg and the base of the base frame, so that the first leg and / or the second leg can be adjusted relative to the base frame. In this case, the first and / or second module for horizontal adjustment can be designed to enable two-dimensional adjustability in a horizontal plane.
[0047] Since any height adjustment required to establish a drive connection between the load motors and the test specimen takes place in the area of the load motors, this results in improved conditions for vibration and acoustic investigations compared to the state of the art. Since the test specimen, as mentioned above, can generally have very high motor speeds of over 15,000 rpm, for example in the form of an axle module, it can, in principle, excite the test specimen holder to vibrations across a broad range. However, by making the test specimen holder non-adjustable and thus very rigid, as provided by the invention, and in particular by connecting it very rigidly to the base of the base frame, the occurrence of vibrations can be largely avoided.Instead, the load motors are advantageously adjustable vertically and horizontally for alignment with the test specimen, since here only speeds of no more than 2,500 rpm regularly occur.
[0048] The invention further relates to a modular system for the simple production of a test bench adapted to the test object, comprising at least a first load motor and a second load motor, each from a common power class, and at least a first inverter and a second inverter, each from a common power class, wherein the common power class of the at least first and second inverters corresponds to the power class of the at least first and second electric motors, base frame, and / or a first module for vertical adjustment and a second module for vertical adjustment and / or a first module for horizontal adjustment and a second module for horizontal adjustment, as well as a plurality of different adapter pieces.
[0049] The modular system thus allows the manufacture of a test bench according to the invention and therefore comprises all components of the test bench according to the invention. Furthermore, the modular system optionally comprises a plurality of first and second load motors as well as a plurality of first and second inverters, each paired to a power class. This allows, for example, depending on the test specimen to be tested, more or less powerful load motors to be arranged on the motor mounts of the base frame and controlled via inverters adapted to the power classes of the load motors. The modular system also includes a plurality of test-specimen-specific adapter pieces, so that the test bench can be adapted to a variety of different test specimens, in particular with different shafts or docking points.
[0050] The invention is explained below by way of example using embodiments shown in the figures.
[0051] They show:
[0052] Fig. 1 shows, by way of example and schematically, a possible embodiment of a test bench according to the invention for a drive train of a motor vehicle,
[0053] Fig. 2 the test bench of Fig. 1 , but with two identical load motors,
[0054] Fig. 3 shows, by way of example and schematically, another possible embodiment of a test bench according to the invention for a drive train of a motor vehicle, Fig. 4 shows, by way of example and schematically, another possible embodiment of a test bench according to the invention for a drive train of a motor vehicle,
[0055] Fig. 5 shows an example and schematically another possible embodiment of a test bench according to the invention for a drive train of a motor vehicle,
[0056] Fig. 6 shows a true-to-scale size comparison between a test bench according to the invention and a test bench known and widely used in the prior art and
[0057] Fig. 7 shows, by way of example and schematically, a possible embodiment of a first actuator for the automated displacement of the first transfer shaft axially in the first outer hollow shaft of the first transfer shaft.
[0058] Identical objects, functional units, and comparable components are designated with 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.
[0059] Fig. 1 shows, by way of example and schematically, a possible embodiment of a test bench 100 according to the invention for a drive train of a motor vehicle (in Fig.
[0060] 1 not shown). The test bench 100 comprises a first load motor 110, a second load motor 120, and a base frame 130 with a test specimen holder 131 for holding a test specimen 140.
[0061] The base frame 130 has, as can be seen in Fig. 1, a U-shaped cross-section in which a first leg 135 and a second leg 136 extend upwards from a base 134.
[0062] The test specimen 140 is, for example, an electric axle module that includes an electric drive motor, a gearbox, and two wheel shafts. The test specimen 140 is mounted on the test specimen holder 131. The test specimen holder 131 is firmly and thus very rigidly connected to the base 134 of the base frame 130.
[0063] The first load motor 110 and the second load motor 120 are each designed as electric motors. For example, the first load motor 110 and the second load motor 120 are permanent magnet synchronous motors, each with twelve magnetic pole pairs. Such synchronous motors are also known as synchro-torque motors. As can be seen, the first load motor 110 and the second load motor 120 are therefore comparatively compact and axially short. Nevertheless, they can provide a comparatively high torque.
[0064] The base frame 130 further comprises a first motor mount 132 for accommodating the first load motor 110 and a second motor mount 133 for accommodating the second load motor 120. For example, the first motor mount 132 and the second motor mount 133 are each a flange connection, via which the first load motor 110 is flange-mounted to the base frame 130 with its end face facing the test specimen 140, the so-called a-side. The second motor mount 133 is also, for example, a flange connection, via which the second load motor 110 is flange-mounted to the base frame 130, analogous to the first load motor 110, with its end face facing the test specimen 140, the so-called a-side. The first load motor 110 is arranged on the first leg 135 via the first motor mount 132 and the second load motor 120 is arranged on the second leg 136 via the second motor mount 133.
[0065] A first motor shaft 111 of the first load motor 110 is designed, for example, as a hollow shaft 111 in which a first transfer shaft 112 is arranged, and a second motor shaft 121 of the second load motor 120 is likewise designed, for example, as a hollow shaft 121 in which a corresponding second transfer shaft 122 is arranged. The first transfer shaft 112 is connected in a rotationally and axially fixed manner to the first motor shaft 111 via a first torque sensor 113. Since the torque provided by the first load motor 110 is thus guided via the first torque sensor 113, the torque generated by the first load motor 110 can be reliably detected at any time via the first torque sensor 113.
[0066] The second transfer shaft 122 is similarly connected to the second motor shaft 121 in a rotationally fixed and axially fixed manner via a second torque sensor 123. Since in this case, too, the torque provided by the second load motor 120 is guided via the second torque sensor 123, the torque generated by the second load motor 120 can be detected via the second torque sensor 123.
[0067] In order to illustrate different, but equally suitable designs of the load motors 110, 120 for the test bench 100, the first load motor 110 and the second load motor 120 differ from one another in Fig. 1. As can be seen, the first torque sensor 113 is arranged on an end face of the first load motor 110 facing away from the test specimen 140, the so-called b-side, whereas the second torque sensor 123 is arranged on an end face of the second load motor 120 facing the test specimen 140, the so-called a-side. Accordingly, the second motor mount 133 comprises a collar-like projection 137 to create space for the second torque sensor 123. In this case, the projection has the flange connection by means of which the second load motor is connected to the base frame 130.
[0068] Since the second torque sensor 123 of the second load motor 120 is arranged on the a-side of the second load motor 120, the first motor shaft 121, designed as a hollow shaft, can be closed by a second wall 124 on its end face facing away from the test object 140, the b-side. This provides, for example, the possibility of rotatably supporting the second transfer shaft 122 via a second bearing 125 in the second wall 124. Of course, the second wall can also be provided without simultaneously providing the second bearing.
[0069] The first transfer shaft 112 also comprises a first outer hollow shaft 112', in which a first inner transfer shaft 112" is arranged so as to be axially displaceable and non-rotatable. Likewise, the second transfer shaft 122 comprises a second outer hollow shaft 122', in which a second inner transfer shaft 122" is arranged so as to be axially displaceable and non-rotatable.
[0070] The axial ends of the first inner transfer shaft 112" and of the second inner transfer shaft 122" facing the test specimen 140 can then be drivingly connected to shafts of the test specimen 140 via a first test specimen-specific adapter piece 116 or via a second test specimen-specific adapter piece 126, for example, to two output shafts of the test specimen 140. Thus, the shafts of the test specimen 140 can be subjected to torques and speeds.
[0071] The first and second adapter pieces 116, 126 have, for example, a flange connection at their axial end facing the first and second transfer shafts 112, 122, respectively. A rotationally fixed connection to the first and second transfer shafts 112, 122 can then be established via the flange connection. The axial end of the first and second adapter pieces 116, 126 facing the test piece 140, however, is designed specifically for the test piece and, for example, is configured as a spline, so that it can be easily inserted into a corresponding counter-spline of the test piece 140.
[0072] Since the first transfer shaft 112 and the second transfer shaft 122 each consist of an outer hollow shaft 112', 122' and a first or second transfer shaft 112", 122" arranged axially displaceably in the outer hollow shaft 112', 122', the first transfer shaft 112" and the second transfer shaft 122" can be axially advanced to the test piece 140 or the corresponding docking points of the test piece 140. For example, the first transfer shaft 112" and the second transfer shaft 122" can be axially displaced in the first and second outer hollow shafts 112, 122 in an automated manner by means of a first actuator and a second actuator (both not shown in Fig. ^). The first and second actuators are, for example, pneumatically actuated actuators, each of which has a cylinder-piston unit that can be pressurized with compressed air and a mechanical return spring that counteracts the compressed air.
[0073] Fig. 2 shows the test bench 100 of Fig. 1 , but with two identical load motors 110 and 120, ie the first load motor 110 is identical to the second load motor 120. By way of example, the first and second load motors 110, 120 of Fig. 2 correspond to the first load motor 110 of Fig. 1 .
[0074] In the illustration of Fig. 2, the first load motor 110 is drivingly connected to a shaft of the test specimen 140 via the first test specimen-specific adapter piece 116. Likewise, the second load motor 120 is drivingly connected to a shaft of the test specimen 140 via the second test specimen-specific adapter piece 126.
[0075] As described, the drive connection can be produced comparatively easily and, above all, automatically, since the first inner transfer shaft 112" and the second inner transfer shaft 121" are each arranged in a rotationally fixed but axially movable manner in the first outer hollow shaft 112' and in the second outer hollow shaft 122', respectively, and can be delivered to the test piece 140 by means of the first and second actuators, respectively.
[0076] Fig. 3 shows, by way of example and schematically, another possible embodiment of a test bench 100 according to the invention for a drive train of a motor vehicle (not shown in Fig. 3).
[0077] The test bench 100 of Fig. 3 differs from the test bench 100 of Fig. 2 in that the test bench 100 has a first module 117 for vertical adjustment of the first load motor 110 and a second module 127 for vertical adjustment of the second load motor 120. The first module 117 for vertical adjustment and the second module 127 for vertical adjustment each have, for example, an electric drive (not shown in Fig. 1), via which a vertical adjustment of the first and second load motors 110, 120 relative to the shafts of the test object 140 can be carried out.
[0078] Fig. 4 shows, by way of example and schematically, another possible embodiment of a test bench 100 according to the invention for a drive train of a motor vehicle (not shown in Fig. 4).
[0079] The test bench 100 of Fig. 4 differs from the test bench 100 of Fig. 3 in that the test bench 100, in addition to the first module 117 for vertical adjustment and the second module 127 for vertical adjustment, also has a first module 118 for horizontal adjustment of the first load motor 110 and a second module 128 for horizontal adjustment of the second load motor 120.
[0080] As can be seen, the first module 118 for vertical adjustment is arranged between the first leg 135 and the base 134 of the base frame 130. For example, the first module 118 for vertical adjustment enables two-dimensional adjustability in a horizontal plane. Similarly, the second module 128 for vertical adjustment is arranged between the second leg 136 and the base 134 of the base frame 130. For example, the second module 128 for vertical adjustment also enables two-dimensional adjustability in a horizontal plane. The first and second modules 118, 128 for vertical adjustment each have an electric drive (not shown in Fig. 1), via which a horizontal adjustment of the first and second load motors 110, 120, respectively, relative to the shafts of the test specimen 140 can be effected. Therefore, it is not necessary to adjust the height of the test specimen 140 or the height of the test specimen holder 131.
[0081] Fig. 5 shows, by way of example and schematically, another possible embodiment of a test bench 100 according to the invention for a drive train of a motor vehicle (not shown in Fig. 5).
[0082] The test bench 100 of Fig. 5 differs from the test bench 100 of Fig. 4 by the arrangement of the first module 118 for the horizontal adjustment of the first load motor 110 and the second module 128 for the horizontal adjustment of the second load motor 120. According to the embodiment of Fig. 5, the first and second modules 118, 128 for horizontal adjustment are arranged on the first and second motor mounts 132, 133, respectively, as are the first and second modules 117, 127 for vertical adjustment.
[0083] Fig. 6 shows a true-to-scale size comparison between a test bench 100 according to the invention and a test bench 200 known and widely used in the prior art. As can be seen, the test bench 100 according to the invention is significantly more compact than the known test bench 200. This results in significant cost advantages in addition to the reduced footprint requirements.
[0084] Fig. 7 shows, by way of example and schematically, a possible embodiment of a first actuator 150 for the automated displacement of the first transfer shaft 112" axially in the first outer hollow shaft 112' of the first transfer shaft 112. According to the example, the first actuator 150 comprises a gripper 151 which is fork-shaped in the upper region and can guide the first transfer shaft 112" axially. For this purpose, the first transfer shaft 112" has, for example, two radially circumferential collars between which the fork-shaped end of the gripper 151 is axially captured. The gripper 151, in turn, is arranged on a carriage 152 which, for example, can be displaced by means of a pneumatic actuation in the direction of the test piece 140 (left in Fig. 7) and, when the actuation decreases, is removed from the test piece 140 again by means of a return spring (not shown in Fig. 7) (right in Fig. 7). The gripper 151 shown in Fig.The actuator 150 shown in Fig. 7 is arranged in the area between the first load motor 110 and the test object 140.
[0085] Reference symbol
[0086] 100 test bench
[0087] 110 first load motor
[0088] 111 first motor shaft
[0089] 112 first transfer wave
[0090] 112' first outer hollow shaft
[0091] 112" first inner transfer shaft
[0092] 113 first torque sensor
[0093] 116 first test specimen-specific adapter shaft
[0094] 117 first module for vertical adjustment
[0095] 118 first module for horizontal adjustment
[0096] 120 second load motor
[0097] 122 second transfer wave
[0098] 122' second outer hollow shaft
[0099] 122" second inner transfer shaft
[0100] 123 second torque sensor
[0101] 124 second wall
[0102] 125 second storage
[0103] 126 second test specimen-specific adapter shaft
[0104] 127 second module for vertical adjustment
[0105] 128 second module for horizontal adjustment
[0106] 130 base frame
[0107] 131 Examination of candidates
[0108] 132 first engine mount
[0109] 133 second engine mount
[0110] 134 Base of the base frame
[0111] 135 first leg of the base frame
[0112] 136 second leg of the base frame 137 projection
[0113] 140 candidates
[0114] 150 first actuator
[0115] 151 grippers
[0116] 152 sleds
[0117] 200 test bench
Claims
Patent claims 1. Test stand (100) for a motor vehicle drive train, comprising a first load motor (110), a second load motor (120) and a base frame (130) with a test specimen holder (131) for receiving a test specimen (140) and with a first motor holder (132) for receiving the first load motor (110) and a second motor holder (133) for receiving the second load motor (120), wherein a first motor shaft (111) of the first load motor (110) and a second motor shaft (121) of the second load motor (120) are connectable to shafts of the test specimen (140) so that the shafts of the test specimen (140) can be subjected to torques and rotational speeds, characterized in that the base frame (130) has a U-shaped cross-section, from which a first leg (135) and a Extend the second leg (136) upwards,wherein the first load motor (110) is connected at one end face to the first leg (135) of the base frame (130) and the second load motor (120) is connected at one end face to the second leg (136) of the base frame (130). 2 Test stand (100) according to claim 1 , characterized in that the first load motor (110) and the second load motor (120) are each designed as permanent magnet synchronous motors with at least twelve magnetic pole pairs.
3. Test stand (100) according to at least one of claims 1 and 2, characterized in that the first motor shaft (111 ) is designed as a hollow shaft in which a first transfer shaft (112) is arranged in a rotationally fixed manner and that the second motor shaft (121) is designed as a hollow shaft in which a second transfer shaft (122) is arranged in a rotationally fixed manner 4. Test stand (100) according to claim 3, characterized in that the first transfer shaft (112) is connected to the first motor shaft (111) in a rotationally fixed manner via a first torque sensor (113) and that the second transfer shaft (122) is connected to the second motor shaft (121) in a rotationally fixed manner via a second torque sensor (123).
5. Test rig (100) according to claim 4, characterized in that the first torque sensor (113) is arranged on an end face of the first load motor (110) facing away from the test specimen (140) and / or that the second torque sensor (123) is arranged on an end face of the second load motor (120) facing away from the test specimen (140).
6. Test rig (100) according to claim 4, characterized in that the first torque sensor (113) is arranged on an end face of the first load motor (110) facing the test specimen (140) and / or that the second torque sensor (123) is arranged on an end face of the second load motor (120) facing the test specimen (140).
7. Test stand (100) according to claim 6, characterized in that the first motor shaft (111 ) is closed at its end face facing away from the test specimen by means of a first wall, wherein the first wall has a first bearing for the first transfer shaft (112) and / or that the second motor shaft (121) is closed at its end face facing away from the test specimen (140) by means of a second wall (124), wherein the second wall (124) has a second bearing (125) for the second transfer shaft (122).
8. Test stand (100) according to at least one of claims 1 to 7, characterized in that the first transfer shaft (112) comprises a first outer hollow shaft (112') in which a first inner transfer shaft (112") is arranged axially displaceably and rotationally fixed, and that the second transfer shaft (122) comprises a second outer hollow shaft (122') in which a second inner transfer shaft (122") is arranged axially displaceably and rotationally fixed.
9. Test rig (100) according to claim 8, characterized in that the first transfer shaft in the first outer hollow shaft is automatically axially displaceable by means of a first actuator and that the second transfer shaft in the second outer hollow shaft is automatically axially displaceable by means of a second actuator.
10. Test stand (100) according to at least one of claims 1 to 9, characterized in that the test stand (100) has a first module (117) for vertical adjustment of the first load motor (110) and a second module (127) for vertical adjustment of the second load motor (120).
11. Test stand (100) according to at least one of claims 1 to 10, characterized in that the test stand (100) has a first module (118) for horizontal adjustment of the first load motor (110) and a second module (128) for horizontal adjustment of the second load motor (120).
12. Modular system for the easy production of a test specimen-adapted test stand (100), comprising at least one first load motor (110) and one second load motor (120) each from a common power class, as well as at least one first inverter and one second inverter each from a common power class, wherein the common power class of the at least first and second inverter corresponds to the power class of the at least first and second electric motor (110, 120), a base frame (130), and / or a first module (117) for vertical adjustment as well as a second module (217) for vertical adjustment and / or a first module (118) for horizontal adjustment as well as a second module (218) for horizontal adjustment and a variety of different adapter pieces.