Test bench and test procedure for rotational dampers of track roller swing arms of heavy tracked vehicles

Abstract

The invention relates to a test bench (1) for rotary dampers (3), in particular lamellar dampers of roller swing arms (2) of heavy tracked vehicles, comprising - a load generating device (6) with an electric motor (7), an electric motor control unit and a crank mechanism (8) driven by the electric motor (7), which generates a push-pull movement of a crank rod (8.3) articulatedly coupled to the crank mechanism (8), - a receiving device (4) for fastening a rotary damper (3) with a roller swing arm (2) relative to the load generating device (6), so that the connecting rod (8.3) can be articulatedly coupled to the roller swing arm (2) for transmitting the generated push-pull movement, and - a measuring device for detecting a measured variable acting on the roller swing arm (2) during a push-pull movement.

Description

[0001] The invention relates to a test bench for rotary dampers, in particular, lamellar dampers of track roller swing arms for heavy tracked vehicles. Furthermore, the invention relates to a test method for rotary dampers, in particular, lamellar dampers of track roller swing arms for heavy tracked vehicles.

[0002] In heavy tracked vehicles, which typically weigh more than 25 tons, track roller systems of the track drive are used to transfer longitudinal forces to the ground and to cushion and dampen the vehicle body. Damping is of great importance here, as good damping stabilizes the tracked vehicle in its movement and helps to minimize stress on the tracked vehicle and its occupants. In some damper systems, the track rollers or wheels over which the tracks run are guided on swing arms or trailing arms. These so-called track roller swing arms are highly stressed components, as they are subjected to bending and torsion loads and, in the case of a version with torsion bar suspension, must support the torsional spring moment. Multi-plate dampers are a special type of rotary damper.Together with torsion bar springs, multi-disk dampers are often used as damping elements for the track roller swing arms of heavy tracked vehicles. Multi-disk dampers are designed to control and reduce vibrations and movements of a torsion bar spring. This dampens vibrations generated when the tracked vehicle travels over uneven surfaces, improving the control and stability of the tracked vehicle. On heavy tracked vehicles, multi-disk dampers are typically mounted in a vehicle side panel concentrically to the torsion bar spring between a track roller swing arm and a vehicle side, such as a vehicle hull. The multi-disk damper is connected to the track roller swing arm in such a way that pivoting movements of the track roller swing arm can be damped.

[0003] Regular inspection, maintenance, and repair of multi-plate dampers is essential for safe vehicle operation and ensures a low failure rate. To check compliance with technical requirements, multi-plate dampers are subjected to a characteristic curve test. This requires special test benches to carry out load tests in the form of vibration generation on the track roller swing arm in accordance with a test specification. To test the functionality of an assembly comprising a track roller swing arm, a multi-plate damper, and a damper housing for the multi-plate damper, the damper housing is first fixed or secured so that the track roller swing arm can move freely around the rotational axis of the multi-plate damper. The track roller swing arm is then set in a pendulum motion against the force of the multi-plate damper, whereby a characteristic curve for the multi-plate damper is created based on a measured variable.The functionality of the lamellar damper or the assembly can be read from the characteristic curve created.

[0004] Test benches for testing the damping force of axial vibration dampers, such as those known from DE 197 26 769 C1, prove to be unsuitable for testing lamellar dampers of roller swing arms.

[0005] JP S62 - 151 738 A describes a test bench for vibration testing of a tracked vehicle's tracked undercarriage. The track rollers are loaded and unloaded by hydraulic lifting drives. Document CN 1 15 046 714 A describes a mobile device for conducting vibration and damping tests on a roller track, with the vibration strokes generated hydraulically.

[0006] It has been shown that generating the vibration frequencies required to test the function of multi-plate dampers on heavy tracked vehicles requires considerable design effort. For example, some test specifications require a vibration frequency of one Hertz (Hz) or more for the pendulum motion of the track roller swing arm, meaning significant forces must be applied to deflect a track roller swing arm against the resistance of the multi-plate damper and the spring. Systems with hydraulically based vibration generation have proven unsuitable due to their high inertia. In addition, hydraulic vibration generation requires complex design and safety measures to cope with the high pressures and resulting temperatures.

[0007] The object of the invention is therefore to propose a test bench for characteristic curve testing of rotary dampers, especially lamellar dampers, of track roller swing arms of tracked vehicles, especially heavy tracked vehicles with a vehicle weight greater than 25 t. The test bench should be suitable for generating push-pull movements with a frequency of at least 1 Hz. Furthermore, it is the object to specify a test method for rotary dampers, especially lamellar dampers of track roller swing arms for heavy tracked vehicles.

[0008] The problem is solved by a test bench having the features according to patent claim 1 and a test method having the features according to patent claim 19. Further developments or embodiments are specified in the respective dependent patent claims.

[0009] The test bench described below is intended for functional testing of rotary dampers, in particular multi-disk dampers, of track roller swing arms for heavy tracked vehicles. Within the meaning of the invention, the term "heavy tracked vehicle" defines tracked vehicles with a vehicle weight of at least 25 t, whereby the test bench is designed for functional testing of rotary dampers, in particular multi-disk dampers, of track roller swing arms of tracked vehicles with a vehicle weight in the range of 60 t to 90 t. Furthermore, within the meaning of the invention, the term "rotary damper" encompasses in particular the special design of multi-disk dampers without being limited to this design. For the sake of simplicity, the term "rotary damper" is used below, which stands for various designs of rotary dampers.

[0010] The essential components of the test bench according to the invention are a load generating device, a mounting device for fastening at least one assembly comprising a roller swing arm, a rotary damper and a damper housing, as well as a measuring device with which a characteristic curve of the rotary damper is recorded.

[0011] The invention is based on the concept of electrical load change generation or vibration generation by using an electric motor as a drive. Thus, the load generation device of the test bench comprises an electric motor, an electric motor control unit, and a crank mechanism driven by the electric motor. The crank mechanism has an articulated connecting rod, with which a push-pull movement is generated as a result of a rotation of the crank of the crank mechanism. In its simplest embodiment, the crank mechanism has a crankshaft, with the connecting rod being articulatedly coupled to a crank pin of the crankshaft. Other variants or embodiments of crank mechanisms can also be provided, provided they are suitable for generating a push-pull movement of the crank rod from a rotational movement. An example of an alternative embodiment of a crank mechanism is a Scotch-yoke crank mechanism.Thus, the crank mechanism of the load generating device can be designed as a Scotch-yoke crank mechanism, with the crank rod having a sliding guide in which a crank pin is guided. To minimize vibrations, the crank mechanism can be equipped with counterweights for mass balancing.

[0012] At least one rotary damper with the roller swing arm can be attached to the mounting device relative to the load generating device in such a way that the connecting rod can be articulated to the roller swing arm for transmitting the generated push-pull movement within a common plane of movement. An assembly comprising a roller swing arm, a rotary damper, and a damper housing is attached in such a way that the rotational axes of the rotary damper, the electric motor, the crank mechanism, and the rotational axis of the coupling between the roller swing arm and the connecting rod are oriented essentially parallel.When coupled, the crank mechanism and the track roller swing arm attached to the mounting device form a coupling mechanism in which a rotation generated by the electric motor is converted into a back and forth movement of the track roller swing arm, allowing the damping properties of the rotary damper to be tested. The track roller swing arm can be attached to the damper housing in such a way that the track roller swing arm can swing freely around a rotation axis of the rotary damper. The positioning of the damper housing attachment should preferably be such that the track roller swing arm is in a zero position, whereby the zero position corresponds to the dead weight position of the track roller swing arm when it is attached to the tracked vehicle. If necessary, the track roller swing arm must be moved to the zero position in order to be coupled to the crank rod.The zero position serves as the starting point for the characteristic curve test in the test procedure.

[0013] The test bench's measuring device is used to record a measured variable acting on the roller swing arm during a push-pull movement. The measured variable is used to determine the force required to deflect the roller swing arm against the resistance of the rotary damper in the respective direction of movement during a push-pull movement. The measuring device is configured to visualize and record a damper characteristic curve of the rotary damper of the roller swing arm, with the recording being based on the recorded measured variable. Preferably, the measuring device is configured to record tensile and / or compressive forces. For this purpose, the measuring device can have a strain sensor arranged on the crank rod. According to one embodiment, the strain sensor for recording the measured variable can be integrated into the crank rod of the crank mechanism.Strain sensors have proven particularly advantageous for measuring compressive forces, as they can measure the deformation of the connecting rod proportional to the applied force. The use of a strain sensor is cost-effective and does not require any additional space. Alternatively or additionally, the measuring device can also have at least one torque sensor to detect the force acting on the roller swing arm. The at least one torque sensor can be arranged on the electric motor or on the crank mechanism to detect the measured variable. However, it can also be provided that two torque sensors are used to detect the measured variable, with a first torque sensor being arranged on the electric motor and a second torque sensor being arranged on the crank mechanism. Furthermore, it is conceivable to determine the measured variable, i.e. a force acting on the roller swing arm, additionally or alternatively based on the power consumption of the electric motor.In any case, appropriate calculations may be necessary to get from the recorded measured value to the actual force acting on the roller swing arm in order to then be able to create a characteristic curve of the rotary damper.

[0014] The measuring device is designed to perform predefined test sequences and to record and visualize a damper characteristic curve of a rotary damper. For this purpose, the measuring device communicates with the electric motor control system. The test sequence defines test parameters such as the number of push-pull movements to be performed and the frequency of the push-pull movements. Typically, a complete push-pull movement in a simple crank mechanism is generated by a complete rotation of the crank, so that the number of rotations of the crank mechanism corresponds to the number of push-pull movements, i.e., the number of oscillations of the roller swing arm. The frequency of the push-pull movements is controlled by the speed of the crank mechanism.

[0015] Alternatively, a push-pull motion can also be achieved by an oscillating change in the direction of rotation of the crank mechanism, but this requires increased effort in terms of electric motor control. Accordingly, large braking resistors must be used to change the direction of the electric motor in order to achieve the high negative accelerations of the electric motor. In this case, the electric motor control unit must be configured accordingly to control a change in the direction of rotation of the electric motor at the required test frequencies.

[0016] In a simple crank drive, the crankshaft is supported by a crankshaft bearing, with the crankshaft bearing being designed to support the weight of the electric motor coupled to the crankshaft. In this case, the crankshaft bearing is designed with at least two spaced-apart axial bearings so that the crankshaft has two support points and can thus bear the forces acting on the crankshaft due to the weight of the electric motor. The axial bearings and the axial bearing mounts must be dimensioned accordingly. The crankshaft is preferably designed as a hollow shaft. A torque support prevents the electric motor from rotating.

[0017] The load generation device is configured and dimensioned to generate push-pull movements of the roller swing arm at a frequency of at least one Hz or higher. These frequencies are made possible by the inventive use of a powerful electric motor, which, as a drive, has a significantly shorter response time compared to hydraulic cylinder drives.

[0018] Preferably, the electric motor has an output of at least 45 kW and a torque of at least 6990 Nm. The electric motor is preferably coupled to the crank mechanism via a transmission gear. This allows for improved power transmission and performance.

[0019] According to a particularly preferred embodiment of the invention, the receiving device is designed as a frame structure with two opposing posts for fastening a left-side roller swing arm to a first post and a right-side roller swing arm to a second post, wherein the load generating device is arranged between the opposing posts such that the crank rod can be pivoted between the two posts for coupling to the left-side roller swing arm or to the right-side roller swing arm. The arrangement of the load generating device between the roller swing arms attached opposite one another to the frame structure enables the crank rod to be pivoted for alternating coupling to the left-side roller swing arm or the right-side roller swing arm, thereby achieving considerable time savings overall.During a test in which the connecting rod is coupled to one of the two roller swing arms mounted on the frame structure, an assembly comprising a roller swing arm, a rotary damper, and a damper housing can be mounted or dismounted on the opposite post of the frame structure. The attachment of a roller swing arm to a post of the supporting structure is preferably carried out using screw connections, by screwing the damper housing that supports the rotary damper to the post of the frame structure in such a way that the roller swing arm can move around the rotational axis of the rotary damper.

[0020] According to a further development of the particularly preferred embodiment of the test bench, the load generating device can be attached to the receiving device, i.e. to the frame structure of the receiving device. The receiving device can have two frames connected to one another via crossbeams, of which a first frame is designed as the front frame and a further frame as the rear frame, wherein the opposite posts are attached to the front frame. Together with the crossbeams, the parallel frames can form a cuboid shape. The frame structures with the crossbeams can be formed, for example, from T-beams or double T-beams. It goes without saying that the frame structures of the receiving device are designed to be particularly torsionally rigid in order to be able to withstand the mechanical loads and the forces acting due to the generated push-pull movements.To improve stability, the frame structures can have cross bracing, gusset plates or reinforcing ribs at sensitive positions.

[0021] The frame structure of the support fixture can be equipped with vibration-damping leveling feet to ensure stability on the ground. Furthermore, the vibration-damping leveling feet help prevent vibration transmission to adjacent machines and minimize the risk of the test stand oscillating when passing through resonant frequencies.

[0022] In the preferred embodiment of the test bench, the load generating device for generating a push-pull movement has a stroke length of at least s = 366 mm. When using a simple crank mechanism, this essentially corresponds to the diameter of the crank. According to the preferred embodiment, the rotational axis of the crank pin, to which the connecting rod is coupled in a simple crank mechanism, is thus spaced 183 mm from the rotational center axis of the crank mechanism.

[0023] The invention further relates to a test method for characteristic curve testing of rotary dampers of track roller swing arms of heavy tracked vehicles using the test bench according to the invention. In the method, a track roller swing arm with a rotary damper, movably mounted on the test bench, is set in a pendulum motion around a rotational axis of the rotary damper. A measured variable acting on the track roller swing arm is recorded, and a characteristic curve of the rotary damper is created based on the measured variable. The pendulum motion of the track roller swing arm is generated by an oscillating push-pull movement of the crank rod, which is articulated to the track roller swing arm.

[0024] The pendulum movement of the roller swing arm can be generated with a frequency in the range of 0.1 Hz to 2 Hz, preferably with a frequency in the range of 0.5 Hz to 1.5 Hz, particularly preferably with a frequency of 1 Hz.

[0025] To create the characteristic curve, several pendulum movements should be performed. According to a preferred procedure, at least two series of at least 50 pendulum movements are performed, with a rest period of a specified duration, for example, 15 minutes, between the series. This rest period is advantageous for cooling the lamellae. Particularly stressed components of the test bench can be actively cooled if necessary.

[0026] According to one embodiment of the method, the pendulum movements are generated by a change in the rotation of the electric motor.

[0027] The invention further relates to a use of the test bench according to the invention for characteristic curve testing of rotational dampers of track roller swing arms of heavy tracked vehicles with a vehicle weight greater than 25 t. Since the test bench according to the invention is designed for functional testing of rotational dampers of track roller swing arms of tracked vehicles with a vehicle weight in the range of 60 t to 90 t, a use of the test bench according to the invention for characteristic curve testing of rotational dampers of track roller swing arms, in particular of tracked vehicles with a vehicle weight in the range of 60 t to 90 t, is provided.

[0028] It has been shown that, taking into account the applicable test specifications for testing rotary dampers, the test bench according to the invention can test four to five rotary dampers with roller-type swing arms within a period of eight hours, resulting in significant time savings. Furthermore, it has been shown that the proposed test bench achieves high efficiency by using an electric motor as the drive, especially when a three-phase geared motor is used.

[0029] Further details, features, and advantages of embodiments of the invention will become apparent from the following description of exemplary embodiments with reference to the accompanying drawings. They show: Fig. 1: a schematic representation of a design of the test bench in a front view, Fig. 2: a schematic representation of the Fig. 1 shown design of the test bench in a plan view, Fig. 3: a schematic representation of the Fig. 1 shown design of the test bench in a side view, Fig. 4: a schematic representation of the Fig. 1 shown design of the test bench in a perspective view and Fig. 5a - 5d: highly schematic representations to explain the functionality of the test bench.

[0030] The Fig. 1 shows a schematic representation of a design of a test bench 1 in a front view.

[0031] The test bench 1 of the Fig. 1 comprises a receiving device 4, a load generating device 6 and a measuring device, which is hidden in the illustration for the sake of simplicity. The receiving device 4 is designed in the form of a frame structure. The frame structure comprises two posts 4.1.1 and 4.1.2, which are connected to one another by an upper cross member 4.2.1 and lower cross members 4.2.2. The upper cross member 4.2.1 and the lower cross members 4.2.2 are each designed as double-T beams. For static stabilization, three spaced-apart cross plates are inserted into the upper cross members 4.2.1 on each side of the double-T beam. The upper cross member 4.2.1 and the lower cross members 4.2.2 have screw-on flanges on their end faces, with which they are screwed to the posts 4.1.1 and 4.1.2. The posts 4.1.1 and 4.1.2 are in turn screwed to a frame structure that extends into the depth of the illustration and has the shape of a cuboid. The design of the cuboid frame structure is shown in the . Fig. 2 to 4 are explained in more detail.

[0032] In the front view, the end faces of the frame structure, designated as posts 4.1.1 and 4.1.2, can be seen. These posts 4.1.1 and 4.1.2 each have mounts 4.5 for attaching a component, comprising a left-hand or right-hand roller swing arm 2, a rotary damper 3, and a damper housing 3.1. In the example shown, the damper housing 3.1 is attached to mount 4.5 of post 4.1.1 with screws 5. The end faces of posts 4.1.1 and 4.1.2, visible to the viewer in the front view of test bench 1, have inward-facing surfaces, as shown in the Fig. 2 and Fig. 4. The obliquely inward-facing surfaces enable the damper housing 3.1 to be mounted in such a way that axial parallelism is achieved between the rotational axis of the rotary damper 3 and the drive axes of the load generating device 6. On the opposite post 4.1.2, the mount 4.5 is free and is thus available for fastening another assembly comprising a roller swing arm 2, a rotary damper 3, and a damper housing 3.1.

[0033] The load generating device 6 comprises an electric motor 7 and a crank mechanism 8 driven by the electric motor 7. The electric motor 7 is a three-phase geared motor with a drive power of 45 kW and a maximum torque of 7840 Nm. The crank mechanism 8, which is coupled to the electric motor 7 via a transmission gear 7.1, comprises a crankshaft 8.1 in the form of a hollow shaft, which is supported by a crankshaft bearing 8.4. The crankshaft bearing 8.4 has two axially spaced axial bearings 8.4.1, which are enclosed in axial bearing receptacles 8.4.2. The crankshaft bearing 8.4 is designed such that it supports the weight of the electric motor 7 coupled to the crankshaft 8.1 and of the transmission gear 7.1. This means that the weight of the electric motor 7 and the weight of the transmission gear 7.1 rest on the crankshaft 8.1, with the electric motor 7 and the transmission gear 7.1 may have a torque support 10, which is attached to the upper cross member 4.2.1. This arrangement simplifies the alignment of the axial coupling between the electric motor 7 and the crankshaft 8.1.

[0034] The crankshaft 8.1 comprises two parallel flywheels 8.1.1 and a crank pin 8.2, to which a crank rod 8.3 is coupled. The crank rod 8.3 is pivotally connected to the roller swing arm 2 at the opposite end. The crank rod 8.3 is attached to a roller mount 12 of the roller swing arm 2 in such a way that a back-and-forth movement of the crank rod 8.3 generated by the rotation of the crankshaft 8.1 is transmitted to the roller swing arm 2, causing the roller swing arm 2 to perform a pendulum motion. In this arrangement, a drive axis of the electric motor 7, the rotation axis of the crankshaft 8.1, and the rotation axis of the rotary damper 3 are oriented parallel.

[0035] In the example shown, the frame structure of the support device 4 serves to accommodate and fasten the components of the load generating device 6. A bearing bed 9, which accommodates the crankshaft bearing 8.4, is bolted to the lower cross members 4.2.2.

[0036] Due to the central arrangement of the load-generating device 6 on the support device 4, the connecting rod 8.3 can be pivoted to both sides of the frame structure, allowing the roller swing arms 2 with rotational dampers 3 on the opposite posts 4.1.1 and 4.1.2 to be checked alternately. Since the support device 4 is mirror-symmetrical, left- and right-side roller swing arms 2 with rotational dampers 3 can be attached and checked.

[0037] The load generating device 6 further comprises an electric motor control unit, which is not shown for the sake of simplicity. The electric motor control unit controls the rotation of the electric motor 7 according to a predetermined test sequence of the measuring device.

[0038] According to a preferred embodiment, the test bench 1 is designed to test rotary dampers 3 with roller swing arms 2 with a length of 500 mm. Preferably, the crank radius of the crank mechanism 8 in this embodiment is r = 183 mm. This results in a stroke length of the crank rod 8.3 of s = 366 mm. A complete push-pull movement thus corresponds to the stroke length s for one complete revolution of the crank mechanism 8. The crank rod 8.3 has a length of 1000 mm. The transmission ratio of the transmission gear 7.1 in the example is i = 25.14. At a speed of the electric motor 7 of n = 1482 rpm, the input speed of the crank mechanism 8 is n A =58.95 rpm

[0039] The measuring device is used to measure the forces acting on the roller swing arm 2 during a push-pull movement of the connecting rod 8.3. The measuring device comprises a strain sensor 11, which is integrated into the connecting rod 8.3. The strain sensor 11 measures the compressive forces required during a push and pull of the connecting rod 8.3 in order to deflect the roller swing arm 2 against the resistance of the rotary damper 3. In this example, the measuring range of the strain sensor 11 covers a range from -45 kN to 45 kN. Based on the compressive force values ​​determined by the strain sensor 11, the measuring device creates a damping characteristic curve for the rotary damper 3.

[0040] According to an alternative embodiment, the test bench 1 has a crank mechanism 8 with a crank radius of 197 mm, wherein the push-pull movement of the crank rod 8.3 is generated by a rotational change of the crankshaft 8.1.

[0041] A stroke position of the crank rod 8.3 can be detected using a rotary encoder of the electric motor 7. If necessary, it may be necessary to release a brake of the electric motor 7 to move the crank rod 8.3 to a zero position for coupling with the roller swing arm 2. The zero position corresponds to the starting point for the test procedure.

[0042] The reference number 15 denotes leveling feet of test stand 1.

[0043] The Fig. 2 shows a schematic representation of the Fig. 1 shown design of the test bench 1 in a top view. Fig. 1 Concealed part of the support structure 4, to which the posts 4.1.1 and 4.1.2 are attached. This rear part of the support structure comprises a front frame 4.3.1 and a rear frame 4.3.2, which are connected by upper cross members 4.4.1 and lower cross members 4.4.2 (see Fig. 3 or Fig. 4) are connected to each other. This rear part of the support device 4 is also essentially formed of cross-plate reinforced double-T beams. The connections between the rear frame 4.3.2 and the upper and lower cross beams 4.4.1 and 4.4.2 are each reinforced with gusset plates.

[0044] The electric motor 7 and the crankshaft 8.1 of the crank mechanism 8 are arranged in a row along a centerline M of the test bench 1, with the crank mechanism 8 mounted on the bearing bed 9. The electric motor 7 is mounted essentially in the center of the frame structure of the mounting device 4, ensuring an even distribution of the masses and the acting forces. Also visible are the axial bearing mounts 8.4.2, which are arranged at a distance along the centerline M. The axial bearing mounts 8.4.2 are screwed to the bearing bed 9 and each accommodate a (hidden) axial bearing 8.4.1, so that the crankshaft 8.1, designed as a hollow shaft, is axially mounted with two support points. This is advantageous because it supports the weight of the electric motor 7 and the transmission gear 7.1, which partially rests on the crankshaft 8.1. The electric motor 7 and the transmission gear 7.1 (hidden in the view) therefore only require a torque support 10, which is attached to the upper cross member 4.2.1, as shown in the illustrations of the . Fig. 1 and Fig. 4 can be removed.

[0045] Furthermore, the top view of test bench 1 shows the parallel flywheels 8.1.1 of crankshaft 8.1. Between the flywheels 8.1.1 is the crankpin 8.2, to which the connecting rod 8.3 is coupled. At its opposite end, the connecting rod 8.3 is coupled to the roller mount 12 with the roller swing arm 2. The flywheels 8.1.1 serve as counterweights for mass balancing to reduce vibrations during rotation.

[0046] As the top view of test bench 1 further shows, the surfaces of the mounts 4.5 on the posts 4.1.1 and 4.1.2 are aligned at an inward angle. In other words, the end faces of the posts 4.1.1 and 4.1.2, on which the mounts 4.5 are located, are chamfered. This is intended to align the screw-on position of the damper housing 3.1 in such a way that an axially parallel alignment of the rotational axis R1 of the rotary damper 3, the rotational axis R2 of the articulated coupling between the track roller swing arm 2 and the connecting rod 8.3, and the rotational axis R3 of the crankshaft 8.1 is ensured. The mounts 4.5 for fastening an assembly comprising a track roller swing arm 2, a rotary damper 3, and a damper housing 3.1 can vary in their design to enable the fastening of corresponding assemblies from different makes of heavy tracked vehicles.The use of adapter elements may also be provided to enable the installation of corresponding assemblies of various makes of heavy tracked vehicles on posts 4.1.1 and 4.1.2.

[0047] The reference number 14 indicates an electrical connection with the electric motor control unit, not shown.

[0048] The Fig. 3 shows a schematic representation of the Fig. 1 shows a side view of the design of the test bench 1. The side view provides a view of the design of the post 4.1.1 and the rear part of the support device 4 with the front frame 4.3.1 and the rear frame 4.3.2, which are connected to one another by the upper cross members 4.4.1 and the lower cross members 4.4.2. The post 4.1.1 is screwed to the front frame 4.3.1 with several screw connections. For static reinforcement, the post 4.1.1 has five horizontally oriented cross plates. Also visible is the rear side of the support 4.5 formed on the post 4.1.1, to which the damper housing 3.1 is screwed. The crank rod 8.3, which is received by the crank pin 8.2 of the crank mechanism 8 between the flywheels 8.1.1, is coupled to the roller holder 12 with the roller swing arm 2. The crankshaft bearing 8.4 is for supporting the crankshaft 8.1 is bolted to the bearing bed 9. The crankshaft 8.1, designed as a hollow shaft, is supported by two axial bearings 8.4.1 (not shown). The axial bearings 8.4.1 are accommodated in the axial bearing mounts 8.4.2. In the illustration shown, one of the two axial bearing mounts 8.4.2 is concealed by the post 4.1.1.

[0049] The Fig. 4 shows a schematic representation of the Fig. 1 shown design of the test bench 1 in a perspective view. In the Fig. 4, the recurring features are identified by the same reference numerals. The perspective view provides a view of the transmission gear 7.1, which couples the electric motor 7 to the crank mechanism 8. The combination of the electric motor 7 and the transmission gear 7.1 has the torque support 10, which is attached to the upper cross member 4.2.1.

[0050] The Fig. 5a to 5d show highly schematic representations to explain the functioning of the test bench 1. The articulated coupling between the roller swing arm 2 and the crank rod 8.3 is shown, whereby the crank rod 8.3 is connected to the roller swing arm 2 at the roller holder 12. At its opposite end, the crank rod 8.3 is attached to a crank pin 8.2 of the crankshaft 8.1. The roller swing arm 2 is rotatable about the rotation axis R1 (see Fig. 2) of the rotary damper 3. The drive is as in Fig. 1 described with an electric motor 7, which is not shown here for reasons of simplified representation.

[0051] The Fig. Figure 5a shows the load generating device 6 in an initial position in a zero position, in which the stroke length s = 0 mm. The stroke length s corresponds to the total maximum deflection of the roller swing arm 2 that can be generated by the load generating device 6.

[0052] The Fig. Figure 5b shows the deflection of the roller swing arm 2 with a stroke length s / 2 after the crankshaft 8.1 has rotated in the direction of arrow 13. The position of the crank pin 8.2 has changed by an angle of slightly more than 90°.

[0053] The Fig. 5c shows the deflection of the roller swing arm 2 with a stroke length s max , which corresponds to the maximum deflection after the crankshaft 8.1 has rotated in the direction of arrow 13. This corresponds to a rotation of the crankshaft 8.1 through an angle of 180°. The stroke length s maxIn the example shown, it is 366 mm, which corresponds to twice the radius r of the crank of the crankshaft 8.1.

[0054] The Fig. Figure 5d shows the deflection of the roller swing arm 2 with a stroke length s / 2 after the crankshaft 8.1 has rotated in the direction of arrow 13. This corresponds to a rotation of the crankshaft 8.1 by an angle of slightly less than 270°. List of reference symbols 1 test bench 2 roller swing arm 3 rotary dampers 3.1 Damper housing 4 Mounting device 4.1.1 Posts 4.1.2 Posts 4.2.1 upper cross member 4.2.2 lower cross member 4.3.1 front frame 4.3.2 rear frame 4.4.1 upper cross member 4.4.2 lower cross member 4.5 Recording 5 screw 6 Load generating device 7 Electric motor 7.1 Transmission gear 8 Crank drive 8.1 Crankshaft 8.1.1 Flywheel 8.2 Crank pin 8.3 Crank rod 8.4 Crankshaft bearings 8.4.1 Thrust bearings 8.4.2 Axial bearing mount 9 camp bed 10 Torque support 11 Strain sensor 12 roller holder 13 Arrow 14 electrical connection 15 leveling feet R1 Rotation axis of the rotary damper 3 R2 Rotation axis of the articulated coupling between the roller swing arm 2 and the crank rod 8.3 R3 Crankshaft rotation axis 8.1 M center line

Claims

[1] Test bench (1) for rotary dampers (3), in particular lamellar dampers of track roller swing arms (2) of heavy tracked vehicles, comprising - a load generating device (6) with an electric motor (7), an electric motor control unit and a crank mechanism (8) driven by the electric motor (7), which generates a push-pull movement of a crank rod (8.3) articulatedly coupled to the crank mechanism (8), - a receiving device (4) for fastening a rotary damper (3) with a roller swing arm (2) relative to the load generating device (6), so that the connecting rod (8.3) can be articulatedly coupled to the roller swing arm (2) for transmitting the generated push-pull movement, and - a measuring device for detecting a measured variable acting on the roller swing arm (2) during a push-pull movement. [2] Test bench (1) according to claim 1, characterized bythat the crank mechanism (8) comprises a crankshaft (8.1), wherein the crank rod (8.3) is articulatedly coupled to a crank pin (8.2) of the crankshaft (8.1). [3] Test bench (1) according to the preceding claim, characterized by that the crankshaft (8.1) has counterweights to balance the mass. [4] Test bench (1) according to claim 1, characterized by that the crank drive (8) is designed as a Scotch-Yoke crank drive. [5] Test bench (1) according to one of the preceding claims, characterized by that the crankshaft (8.1) is mounted by a crankshaft bearing (8.4), wherein the crankshaft bearing (8.4) is designed such that it supports the weight of at least the electric motor (7) coupled to the crankshaft (8.1). [6] Test bench (1) according to claim 5, characterized by that the crankshaft (8.1) is designed as a hollow shaft. [7] Test bench (1) according to one of the preceding claims, characterized bythat the measuring device has a strain sensor (11) which is integrated into the crank rod (8.3) for detecting the measured variable. [8] Test bench (1) according to one of the preceding claims, characterized by that the measuring device has at least one torque sensor, wherein the torque sensor is arranged on the electric motor (7) and / or on the crank drive (8) for detecting the measured variable. [9] Test bench (1) according to one of the preceding claims, characterized by that the measuring device is designed to carry out predetermined test sequences and to record a damper characteristic curve of a rotary damper (3). [10] Test bench (1) according to one of the preceding claims, characterized by that the load generating device (6) is designed to generate push-pull movements of the roller swing arm (2) with a frequency of at least one Hz, preferably greater than one Hz. [11] Test bench (1) according to one of the preceding claims, characterized by that the electric motor (7) has a power of at least 45 kW and a torque of at least 6990 Nm. [12] Test bench (1) according to one of the preceding claims, characterized by that the electric motor (7) is coupled to the crank mechanism (8) via a transmission gear (7.1). [13] Test bench (1) according to one of the preceding claims, characterized by that the electric motor control unit is arranged to control a change in the direction of rotation of the electric motor (7). [14] Test bench (1) according to one of the preceding claims, characterized bythat the receiving device (4) is designed as a frame structure with two opposite posts (4.1.1, 4.1.2) for fastening a left-hand roller swing arm (2) and a right-hand roller swing arm (2), wherein the load generating device (6) is arranged between the opposite posts (4.1.1, 4.1.2) in such a way that the crank rod (8.3) can be pivoted between the two posts (4.1.1, 4.1.2) for coupling to the left-hand roller swing arm (2) or to the right-hand roller swing arm (2). [15] Test bench (1) according to one of the preceding claims, characterized by that the load generating device (6) is attached to the receiving device (4). [16] Test bench (1) according to one of the preceding claims, characterized bythat the receiving device (4) has two frames (4.3.1, 4.3.2) connected to one another via cross members (4.4.1, 4.4.2), wherein the posts (4.1.1, 4.1.2) are fastened to a front frame (4.3.1). [17] Test bench (1) according to one of the preceding claims, characterized by that the frame structure of the receiving device (4) has vibration-damping leveling feet (15). [18] Test bench according to one of the preceding claims, characterized by that the load generating device (6) is designed to generate a pull-push movement with a stroke of at least s = 366 mm. [19] Method for characteristic curve testing of a rotary damper of a track roller swing arm (2) for heavy tracked vehicles with a test bench (1) according to claims 1 to 18, in which a track roller swing arm (2) with rotary damper (3) movably fastened to the test bench (1) is set in a pendulum movement about a rotation axis (R1) of the rotary damper (3), a measured variable acting on the track roller swing arm (2) is recorded and a characteristic curve of the rotary damper (3) is created on the basis of the measured variable. [20] Method according to claim 19, characterized by that the pendulum movement of the roller swing arm (2) is generated with a frequency in the range from 0.1 Hz to 2 Hz, preferably with a frequency in the range from 0.5 Hz to 1.5 Hz, particularly preferably with a frequency of 1 Hz. [21] Method according to claim 19 or 20, characterized bythat to create the characteristic curve, at least two series of at least 50 pendulum movements each are carried out, with a rest phase of a predetermined duration being maintained between the series. [22] Method according to one of claims 19 to 21, characterized by that the pendulum movements are generated by a change in rotation of the electric motor (7). [23] Use of a test bench according to claims 1 to 18 for characteristic curve testing of rotation dampers (3) of track roller swing arms (2) of heavy tracked vehicles having a vehicle weight greater than 25 t, in particular in the range from 60 t to 90 t.

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