Test stand

Abstract

The disclosure relates to a test stand for a vehicle with wheels, preferably a motor vehicle, comprising: at least one test stand roller (1) and at least one flywheel mass device (2), which is connected to at least one of the at least one test stand roller (1) in such a manner that a torque is transmittable between the flywheel mass device (2) and the at least one test stand roller (1) which is connected to the flywheel mass device (2).

Description

[0001] MAHA Maschinenbau Haldenwang GmbH & Co. KG March 2026

[0002] 221431PC Test bench

[0003] Technical field

[0004] The present subject matter relates to a test bench for a vehicle with wheels, preferably a motor vehicle.

[0005] Background of the invention

[0006] Vehicle test benches are known in the prior art, such as the applicant's MSR 500 / 2 4WD test bench, on which various test programs for motor vehicles can be carried out. Such test benches can be equipped, among other things, with double rollers or pitch rollers for holding the vehicle wheels.

[0007] The driving of the test bench or wheel rollers, such as the crown or double rollers, is carried out in test benches of this type by means of powerful, complex and expensive electric motors, whose power must also be regulated by means of complex control of the electric motors depending on the vehicle weight and other factors.

[0008] It would therefore be desirable to provide a vehicle test bench that is not purely electric or exclusively equipped with an electric motor to drive the test bench rollers. Ideally, a test bench with a less complex and expensive design regarding the drive mechanism for the test bench rollers would be preferable.

[0009] Summary of the invention

[0010] To solve the above problem, reference is made to the attached patent claims, whereby dependent patent claims relate to preferred further developments.

[0011] According to one aspect of the present disclosure, a test rig for a vehicle with wheels, preferably a motor vehicle, comprises the following components:

[0012] At least one test stand roller. The test stand roller can be designed so that at least one wheel of the vehicle to be tested can be placed on it. For example, a test stand roller included here can be designed as a single roller or a double roller. MAHA Maschinenbau Haldenwang GmbH & Co. KG March 2026

[0013] 221431PC. While double rollers typically (though this is not to be interpreted as a limitation) each hold a single wheel of a vehicle, single rollers can also hold one wheel or multiple wheels. For example, single rollers can hold or be positioned on the wheels of one axle of a vehicle. Basically, all these configurations of standard vehicle test stands are intended to be covered here; and this also applies to hybrid configurations where double rollers and single rollers are combined.

[0014] Furthermore, the test bench comprises at least one flywheel assembly. In the present disclosure, the flywheel assembly performs the function of the large electric motor that, in conventional test benches driven / decelerated exclusively by such an electric motor, provides the drive or deceleration of one or more test bench rollers. As already defined terminologically, the flywheel assembly comprises at least one or more flywheels, which may have one or more rotatable (mass) bodies (with a defined mass, hence also "mass bodies") that rotate an axis of rotation of the flywheel assembly; for example, these flywheels or mass bodies may be mounted on a rotating shaft of the flywheel assembly and rotate with the rotating shaft around its axis of rotation, or the flywheels may be mounted on a rotational / rotational axis.

[0015] Furthermore, the at least one flywheel device can be connected to at least one test bench roller; preferably in such a way that a torque can be transmitted between the flywheel device and the connected test bench roller(s).

[0016] It should be clearly stated that, according to the disclosed test rig, no drive systems, in particular no electric motors, are provided for the test rig rollers in addition to the one or more flywheel assemblies. If electric motors are used, they are part of the flywheel assembly and are intended solely as auxiliary units for the subtasks described in more detail below, such as simulating driving resistances or fine-tuning to a vehicle weight in addition to the rotating mass bodies. Rotating mass bodies, or simply mass bodies, are here referred to, unless otherwise described, e.g., with regard to the adjustable ones, preferably (especially MAHA Maschinenbau Haldenwang GmbH & Co. KG March 2026).

[0017] 221431PC preferably rotationally symmetrical (e.g. ring-shaped) masses, which are, for example, simple metal bodies that can be applied to a rotating shaft, whereby the application can be permanent or removable; both via standard means / methods for applying rotationally symmetrical bodies to a shaft.

[0018] The technical advantage of such a test bench design lies particularly in the fact that little or no electrical assistance from an electric motor is required to drive the test bench roller(s). Since the large electric motors of conventionally driven test benches require a lot of space, are expensive and complex to control, and also necessitate large power connections, the test bench described here is more compact, less expensive, and less complex to construct without such an electric motor.

[0019] The flywheel device can be used in such a way that the total mass of the rotating bodies is matched to the weight of the vehicle being tested, e.g. continuously (or variably) or in a fixed ratio such as 1:1, 1:2, 1:3, 1:5, 1:8, 1:10, 2:1, 3:1, 5:1, 8:1, 10:1, or the like. This allows the driving resistance generated by the transmitted torque to be adjusted to suit each type of vehicle being tested.

[0020] According to a further preferred aspect, a connection between at least one flywheel assembly and at least one test bench roller can be implemented by means of at least one transmission unit; preferably such that the transmission unit can transmit a torque between the flywheel assembly(s) and the test bench roller(s) or their axles. The transmission unit can comprise one or more sub-components, which may include belts, chains, cardan shafts, or the like. For example, further sub-components of the transmission unit may include: (customarily arranged) gears that interact with a belt or chain, a torque distribution unit that can interact with the cardan shaft in a customary manner, and / or the like.

[0021] For example, a preferred test rig design may include each test rig roller being mounted on or connected to a rotary axis / shaft, with test rig rollers being particularly preferably connected axially (with respect to the axles of a vehicle) via a rotary shaft, and the MAHA Maschinenbau Haldenwang GmbH & Co. KG March 2026

[0022] 221431PC Transmission unit, e.g., in the form of a belt, is attached to the rotating shaft of a test bench roller axle to transmit torque to or from it. The transmission unit can also be connected to a rotating shaft of the flywheel assembly, thus enabling torque transmission between the shafts of the flywheel assembly and the test roller axle.

[0023] As already mentioned, the flywheel assembly can have at least one (rotatable) mass body, and preferably the mass of this mass or masses is variable or adjustable. For example, it can be provided, in a technically simple manner, that the mass can be adjusted to a vehicle weight by removing or adding rotatable mass bodies (preferably to form a flywheel). For example, a first flywheel assembly can be provided with one or more mass bodies. Further (one or more) second and third flywheel assemblies, each with one or more mass bodies, can also be mounted or removed on the rotating shaft of the flywheel assembly, depending on the target weight.

[0024] Alternatively or additionally, the flywheel(s) or mass body of a flywheel can be adjustable by means of a technical configuration. The latter can be achieved, for example, by making the radial distance of the mass body or a part thereof from the axis of rotation variable. Particularly preferably, this radial distance change can be implemented as follows: The mass can be designed such that its radius can be changed in order to adjust the torque effect. The radius of the rotating mass can be mounted on the shaft / axis by means of a linear displacement unit, which allows the distance to be changed. Alternatively, the radius of the rotating mass can be changed by an adjusting ring that rotates separately on the shaft. The adjustable mass can have the advantage that no assembly or disassembly of mass bodies is necessary.

[0025] According to further preferred aspects: MAHA Maschinenbau Haldenwang GmbH & Co. KG March 2026

[0026] 221431PC Can the flywheel device have at least one first flywheel with a rotatable mass body? The term "first flywheel" shall encompass a body with a defined mass that can be mounted on the axis of the flywheel device, preferably rotationally symmetrical, and which may be composed of one or more sub-bodies / rotatable mass bodies.

[0027] Alternatively or additionally, a variably controllable transmission can be included in the flywheel assembly, preferably arranged between the first flywheel and at least one test bench roller. The transmission can be a continuously variable transmission (CVT) that is part of the flywheel assembly and generates a continuous change in the gear ratio without steps in the driving resistance. For example, the rotating mass of the flywheel assembly's shaft, on which mass elements are mounted in other embodiments, can already be utilized, and the gear ratio can be changed by means of a transmission, either continuously variable or stepped. In this option, with a transmission, continuously variable or not, it is even more advantageous that mass elements are part of the flywheel assembly, which do not necessarily need to be changed, and instead (or additionally) the gear ratio is changed by means of a transmission.

[0028] The gearbox thus allows for a very precise adjustment and control of the flywheel mass and therefore the generable torque with little increase in complexity.

[0029] Alternatively or additionally, at least one clutch can be provided, preferably located between the flywheel assembly and at least one test bench roller. The clutch is particularly preferably configured such that torque transmission is prevented when a torque exceeding a predetermined torque limit is applied. Alternatively or additionally, the clutch can also be designed as a switchable clutch, enabling the switching on or off of weight(s) / mass bodies; up to and including the complete switching off of mass bodies by one or more switchable clutches. The control of the switchable clutch can be implemented electrically / computer-controlled, as is known in the trade. MAHA Maschinenbau Haldenwang GmbH & Co. KG March 2026

[0030] 221431PC

[0031] The clutch thus allows, among other things, that excessively high torques are not transmitted and / or that the weight of a flywheel can be changed by actuating the clutch.

[0032] Alternatively or additionally, the flywheel assembly can include an electric motor positioned between the first flywheel or other rotating bodies / flywheels and at least one test bench roller. Such an electric motor (E-motor) is compact and not as powerful as those used in the conventional test benches described above, as it serves only as a supplement to the flywheels / mass units, allowing the driving resistance to be precisely matched to the vehicle's driving resistance; or more accurately, as a supplement to the rotating masses for fine-tuning and / or control under varying driving conditions or for simulating uphill or downhill driving.

[0033] Another option would be to control the driving resistances (only) via an electric motor, so that, for example, the test bench would still have the flywheel assembly shown here, with the electric motor attached to its (central) axis. The flywheels could be used to adjust the driving resistance in increments. With the electric motor and / or the eddy current brake, as a supplement to the flywheels, the driving resistance could then be precisely matched to the vehicle's driving resistances. Regarding terminology, it should be noted that the flywheels / rotating masses, as part of the flywheel assembly, are intended, for example, for adjusting to the vehicle's weight, while the driving resistances include rolling resistance, friction, air resistance, and road gradients, and could preferably be covered / simulated by a small electric motor.

[0034] The electric motor can also handle parts of the fine-tuning process for adjusting to the vehicle weight, so that in addition to a (fixed) basic flywheel mass, the electric motor enables weight adjustment depending on the vehicle type. MAHA Maschinenbau Haldenwang GmbH & Co. KG March 2026

[0035] 221431PC In short: An electric motor can be provided for both weight adjustment and for the simulation of driving resistances - in each case in addition to the flywheel mass(s) of the flywheel device, whereby the electric motor can also be considered as part of the flywheel device according to the present disclosure.

[0036] - Alternatively or additionally, the flywheel device may have at least a first flywheel and at least a second flywheel, wherein the first flywheel may, for example, include the adjustable mass bodies described above or merely addable or removable mass bodies, so that, based on a fixed second flywheel, a final adjustment to the required weight of a vehicle can be made using the first flywheel.

[0037] - Alternatively or additionally, an eddy current brake can also be provided as an alternative or additional to mass units / mass body(ies) or other options / aspects described above, which can generate driving resistance.

[0038] Alternatively or additionally, the flywheel assembly can include a first flywheel in the form of one or more rotating mass elements, one or more switching clutches, and one or more switching flywheels. The switching clutches then allow mass elements to be added or removed, thus enabling further adjustment to a vehicle weight (and / or driving resistances).

[0039] In summary, a test bench is provided that can apply torque to the test bench roller(s), primarily or exclusively by means of rotating mass elements of a flywheel assembly and without a large electric motor. If such an electric motor is used, it is only in a compact and reduced-power form, for example, to (more accurately) simulate the low driving resistances compared to the vehicle weight or to allow for variable and / or more precise adjustment to the vehicle weight in addition to the rotating mass elements. MAHA Maschinenbau Haldenwang GmbH & Co. KG March 2026

[0040] 221431PC

[0041] Brief description of the characters

[0042] Fig. 1 schematically shows a possible configuration of a test rig according to the disclosure;

[0043] Fig. 2 schematically shows another possible configuration of a test rig according to the disclosure.

[0044] Fig. 3 schematically shows another possible configuration of a test rig according to the disclosure.

[0045] Fig. 4 schematically shows a possible configuration of a flywheel device according to the present disclosure.

[0046] Fig. 5 schematically shows another possible configuration of a flywheel device according to the present disclosure.

[0047] Fig. 6 schematically shows another possible configuration of a flywheel device according to the present disclosure.

[0048] Fig. 7 schematically shows another possible configuration of a flywheel device according to the present disclosure.

[0049] Fig. 8 schematically shows another possible configuration of a flywheel device according to the present disclosure.

[0050] Fig. 9 schematically shows another possible configuration of a flywheel device according to the present disclosure.

[0051] Fig. 10 schematically shows another possible configuration of a flywheel device according to the present disclosure.

[0052] Fig. 11 schematically shows another possible configuration of a flywheel device according to the present disclosure.

[0053] Fig. 12 schematically shows another possible configuration of a flywheel device according to the present disclosure.

[0054] Fig. 13 schematically shows an option for providing mass bodies according to the disclosure whose torque effect is adjustable.

[0055] Fig. 14 schematically shows another option for providing mass bodies according to the disclosure whose torque effect is adjustable.

[0056] Detailed figure description and preferred embodiment examples MAHA Maschinenbau Haldenwang GmbH & Co. KG March 2026

[0057] 221431PC Examples and embodiments of the present invention are described in detail below with reference to the accompanying figures. Identical or similar elements in the figures may be designated by the same reference numerals.

[0058] The following section uses several figures to show how the basic concept of the present disclosure can be flexibly configured and implemented in a test rig.

[0059] Figure 1 shows a variant, configuration, or expansion stage of the test stand with two axes 4 and four test stand rollers 1 (also called "track rollers"), which are shown schematically and can be designed, for example, as double rollers or crown rollers. The test stand rollers 1 are connected to each other axially by means of a rotating shaft / axle 4, and a transmission unit 3, such as a belt, chain, or cardan shaft, connects both axes 4. Furthermore, a rotating shaft / axle 5 of a flywheel assembly 2 is provided, which is rotaryally connected to the two (or, not shown, more than two) axes 4 via the transmission unit 3, so that a torque can be transmitted.

[0060] The flywheel device 2 can be realized / configured in different ways as disclosed, and this will be described in more detail with reference to the following figures.

[0061] Figure 2 then shows a configuration of the test stand, in which an axis 4 and two test stand rollers 1 are provided. It should be noted that in both Figure 2 and Figure 3, the reference numerals "3" and "5" are used twice. This is to indicate that, in particular, the rotating shaft / axis 5 can also be directly connected to the axis 4 (without transmission unit 3).

[0062] Figure 3 shows a configuration of the test rig, where, as in Figure 1, two axes 4 and four test rig rollers 1 are provided. The difference from Figure 1 is that, according to Figure 3, two flywheel assemblies 2 are provided, each acting on one of the two axes 4 via a rotating shaft / axle 5 and / or transmission unit 3 (not explicitly shown). The connection between axis 4 and rotating shaft / axle 5 (if no transmission unit 3 is provided) is made in a manner customary in the industry. MAHA Maschinenbau Haldenwang GmbH & Co. KG March 2026

[0063] 221431PC designed to enable torque transmission between axis 4 and rotation shaft / axis 5.

[0064] Furthermore, in an unshown addition to Figures 1 to 3, configurations of a test rig may also be included in the present disclosure which have more than two axles 4, e.g. for testing trucks.

[0065] Figure 4 then shows a first possible configuration of the flywheel devices 2 described here, which can be used in one of the test bench configurations according to Figures 1 to 3 or other test bench configurations not shown.

[0066] The section of the flywheel assembly 2 shown in Figure 4 features a first flywheel 11 in the form of a rotatable mass body, which is connected by means of an axle / rotation shaft on which the mass body is mounted to an adjustable gearbox 12, shown schematically, and for which any suitable conventional gearbox can be used. The rotation shaft / axle 5 of the flywheel assembly 2 then extends from the gearbox 12 to be connected to the transmission unit 3 or directly to the axle 4, as shown in Figures 1 to 3. It should be noted that the first flywheel 11 can also be formed from several partial mass bodies (not shown), which can be mounted or dismounted as required (or, as shown in further figures, automatically engaged or disengaged).

[0067] Figure 5 shows a section / part of another possible configuration of the flywheel devices 2 described here, which can be used in one of the test bench configurations according to Figures 1 to 3 or other test bench configurations not shown.

[0068] The main difference between the configurations shown in Figures 4 and 5 is that Figure 5 additionally includes a (controllable) clutch 16, which can either open automatically when a maximum torque is exceeded or preset, or which can open electrically. Electrical control lines, etc., are not shown in the schematic figures presented here and are set up in the usual manner. MAHA Maschinenbau Haldenwang GmbH & Co. KG March 2026

[0069] 221431PC. It should also be mentioned that figure 5 shows gear 12, which can also be omitted here to create another possible configuration.

[0070] The coupling 16 thus allows one or more mass bodies / flywheels to be switched off or on.

[0071] Figure 6 shows a section / part of another possible configuration of the flywheel devices 2 described here, which can be used in one of the test bench configurations according to Figures 1 to 3 or other test bench configurations not shown.

[0072] The main difference from the configurations shown in Figures 4 and 5 is that Figure 6 includes an electric motor and / or an eddy current brake (both referenced numeral 13) to more accurately simulate driving resistance, for example, while the first flywheel 11 and the gearbox 12 (which could also be omitted) are used to adjust / simulate the vehicle weight itself. The compact electric motor thus allows for more precise adjustment / control to represent different driving situations. The corresponding control system using a computer / control device is not shown and can be implemented using standard techniques.

[0073] Figure 7 shows a section / part of another possible configuration of the flywheel devices 2 described here, which can be used in one of the test bench configurations according to Figures 1 to 3 or other test bench configurations not shown.

[0074] The configuration is essentially identical to that shown in Figure 6, with the addition of a clutch 16 shown in Figure 5, which enables the basic flywheel 11 to be engaged / disengaged as required.

[0075] Figure 8 shows a section / part of another possible configuration of the flywheel devices 2 described here, which can be used in one of the test bench configurations according to Figures 1 to 3 or other test bench configurations not shown. MAHA Maschinenbau Haldenwang GmbH & Co. KG March 2026

[0076] 221431PC In comparison to Figure 4, a further flywheel is provided here as a second flywheel 10 (also called the basic flywheel), with the gearbox 12 arranged between the first flywheel 11 and the second flywheel 10. Depending on the test bench configuration, the basic flywheel 10 can be selected, for example, to approximately simulate the (predefined) weight of the lightest vehicle to be tested on the respective test bench configuration (optionally minus the weight of the rotating mass of the rollers), while heavier vehicles to be tested can then be simulated on the respective test bench configuration via the additional weight of the first flywheel 11 and its variability by means of the gearbox 12. Examples of test bench configurations could include, among others, that the basic flywheel 10 is selected such that the lightest vehicle to be tested is a motorcycle, a passenger car, or a truck.

[0077] Figure 9 shows a section / part of another possible configuration of the flywheel devices 2 described here, which can be used in one of the test bench configurations according to Figures 1 to 3 or other test bench configurations not shown.

[0078] In this case, a modification is provided compared to Figure 8 such that a coupling 16 is inserted at the position shown.

[0079] Figure 10 shows a section / part of another possible configuration of the flywheel devices 2 described here, which can be used in one of the test bench configurations according to Figures 1 to 3 or other test bench configurations not shown.

[0080] In this version, a modification is provided compared to Figures 8 and 9, such that an electric motor / eddy current brake 13 is inserted at the position shown instead of the clutch 16. It should also be noted that the clutch 16 in the corresponding figures mentioned above can also be configured as a switching clutch 14. In other words, the clutches 14 and 16 described here can each perform either a pure switching / disengaging function and / or have a torque release, as described above, in which disengagement / disengagement occurs when a maximum torque limit is reached. MAHA Maschinenbau Haldenwang GmbH & Co. KG March 2026

[0081] Figure 11 of 221431PC then combines the two configurations according to Figures 9 and 10.

[0082] Figure 12 shows a section / part of another possible configuration of the flywheel devices 2 described here, which can be used in one of the test bench configurations according to Figures 1 to 3 or other test bench configurations not shown.

[0083] Here, a configuration is shown in which a flywheel 10 (or 11 - not shown) is coupled to the rotating shaft / axis 5 with several, preferably smaller, fixed mass elements (switchable flywheels 15). Controllable switching couplings 14 are inserted between the respective mass elements 15 (one mass element, shown; or several mass elements, not shown). These couplings allow, for example, individual mass elements 15 to be switched on or off by means of a computer control system (not shown) that can be implemented using standard methods. This also enables weight adjustment for different vehicle types. The configuration according to Figure 12 can also be combined with the configurations shown above in Figures 4 to 11.

[0084] Figure 13 schematically shows an enlargement of a possible mechanism for providing an adjustable mass of a mass body / flywheel, which can be combined with all the configurations described above, preferably as part of the first flywheel 10 or as the first flywheel 10 itself. The rotating shaft / axis 5 shown can be enclosed by a linear guide 5a, which allows the radial distance of the mass body 10a to the rotating shaft / axis 5 to be changed.

[0085] Figure 14 schematically shows an enlargement of another possible mechanism for providing an adjustable mass of a mass body / flywheel, which can be combined with all the configurations described above, preferably as part of the first flywheel 10 or as the first flywheel 10 itself. Here, the representation is chosen in the direction of the rotating shaft / axis 5, wherein the mass body 10a can be changed in its orientation to the center of the rotating shaft / axis 5 by means of an adjusting ring 5b by rotating the adjusting ring 5b relative to the rotating shaft / axis 5. For this purpose, the adjusting ring 5b has, for example, a spring-and-groove mechanism 5bl, which MAHA Maschinenbau Haldenwang GmbH & Co. KG March 2026

[0086] 221431PC The adjustment range of the adjustment ring 5b is limited / specified by allowing the spring (black dot at position “5bl”) to slide within the groove (oval area at position “5bl”) along a predetermined distance.

[0087] In both options according to Figures 13 and 14, the variable flywheel 10 can be finely adjusted with regard to its torque effect.

[0088] Examples and embodiments of the present disclosure, as well as their advantages, have been described in detail above with reference to the accompanying figures. It should be emphasized again that the present disclosure is in no way limited or restricted to the embodiments / aspects and their features described above, but also includes modifications of these embodiments, in particular those resulting from modifications of the features of the described examples or from combinations of one or more of the features of the described examples within the scope of protection of the independent claims.

Claims

MAHA Maschinenbau Haldenwang GmbH & Co. KG March 2026 221431PC Claims 1. Test stand for a vehicle with wheels, preferably a motor vehicle, comprising: at least one test stand roller (1), wherein the test stand roller (1) is configured to place a wheel of the vehicle to be tested on it; and at least one flywheel device (2) which is connected to at least one of the at least one test bench roller (1) in such a way that a torque can be transmitted between the flywheel device (2) and the at least one test bench roller (1) which is connected to the flywheel device (2).

2. Test stand according to claim 1, wherein the at least one flywheel device (2) is connected to at least one test stand roller (1) by means of at least one transmission unit (3), preferably such that the transmission unit (3) can transmit a torque between flywheel device (2) and test stand roller (1).

3. Test rig according to at least one of the preceding claims, wherein the flywheel device (2) has at least a first or a second flywheel (10, 11) with at least one rotatable mass body.

4. Test rig according to at least one of the preceding claims, wherein the flywheel device (2) has at least one rotatable mass body and the mass of the rotatable mass body is adjustable.

5. Test stand according to at least one of the preceding claims, wherein the flywheel device (2) has at least a first flywheel (11) and a variably controllable transmission (12) arranged between the first flywheel (11) and at least one test stand roller (1).

6. Test stand according to at least one of the preceding claims, wherein at least one coupling (16) is provided which is arranged between the flywheel device (2) and at least one test stand roller (1).

7. Test rig according to at least one of the preceding claims, wherein the flywheel device (2) comprises at least a first flywheel (11) and a MAHA Maschinenbau Haldenwang GmbH & Co. KG March 2026 221431PC electric motor (13) arranged between the first flywheel (11) and at least one test stand roller (1).

8. Test rig according to at least one of the preceding claims, wherein the flywheel device (2) has at least a first flywheel (11) and at least a second flywheel (10), wherein the second flywheel (10) has a predefined base mass.

9. Test rig according to at least one of the preceding claims, wherein the flywheel device (2) comprises a flywheel (10,11), several switching clutches (14) and several switching flywheels (15).

10. Test rig according to at least one of the preceding claims, wherein the mass of a first or second flywheel (10, 11) is designed to be adjustable in such a way that individual rotatable mass bodies can be added or removed, and / or a radial distance of a rotatable mass body to an axis of rotation of the flywheel device (3) is designed to be variable.

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