This application claims priority under 35 U.S.C. § 119 to German patent application DE 10 2021 122 706.2, filed Sep. 2, 2021, the disclosure of which is incorporated herein by reference.
The present disclosure relates to a torsional vibration damper arrangement having a torsional vibration damper, e.g., for use in a drive train of a motor vehicle. The torsional vibration damper arrangement is useful in situations where a connection to a shaft via an output flange is necessary.
Depending on the installation situation in a motor vehicle, the internal combustion engine and transmission can be directly connected to one another in a common housing, so that a transmission input shaft is usually connected to the crankshaft of the internal combustion engine via a clutch and possibly a torsional vibration damper. Alternatively, the internal combustion engine and the transmission can be designed to be spatially separated from one another and connected to one another by a shaft, in particular a connecting shaft. Here, the shaft is usually connected via an output flange to a torsional vibration damper, which is connected to the clutch. Due to the spatially separate design of the internal combustion engine and transmission, axial and/or angular offsets can occur, which cause a moment at the connection between the shaft and the output flange. This causes additional forces on the connecting elements through which the output flange is connected to other elements of the torsional vibration damper. These connecting elements are thus subjected to a load and can fail, leading to a reduction in transmissible torque and ultimately to component failure.
A torsional vibration damper arrangement according to the disclosure, e.g., for use in a drive train of a motor vehicle, includes a torsional vibration damper having an input flange and at least one first output flange, which can be rotated relative to one another about an axis of rotation against a plurality of spring devices, for example including at least one bow spring. The at least one first output flange is connected via a hub to a second output flange for torque transmission to a further component in a rotationally fixed manner, and the at least one first output flange, the hub and the second output flange are connected in a form-fitting and/or force-fitting manner by at least one first connecting element, which lies on at least one first radius with respect to the axis of rotation. At least one second connecting element connects the hub to the second output flange in a force-fitting and/or form-fitting manner, and the second connecting element is designed to be at least partially radially inside the hub.
Thus, the torsional vibration damper arrangement has an additional second connecting element, which is designed to be radially inside the hub. This installation space is usually free when connecting shafts via an output flange, such as the second output flange in this case, and is used here for the additional second connecting element. If an axial and/or angular offset can be present, this causes a moment which acts on the second output flange via the shaft. This leads to additional forces on the first connecting elements and subjects them to a load, usually in a manner fluctuating over time due to the rotation of the torsional vibration damper arrangement. This can reduce the torque that can be transmitted through the torsional vibration damper and lead to component failure. The second connecting element connects the hub to the second output flange radially on the inside. This applies an additional clamping force which counteracts the adverse bending effect caused by the shaft that can be connected to the second output flange and which at least reduces the additional load on the first connecting elements or even removes it completely.
The second connecting element may be aligned to be flush with the axis of rotation. Second connecting elements may be screws and threads, screws and threaded nuts and/or bolts, which have an axis. This axis may be aligned with the axis of rotation, as the influence on the rotational behavior of the torsional vibration damper arrangement is thus negligible.
The hub may have a largest inner diameter and the second connecting element may extend radially with respect to the axis of rotation within this largest inner diameter. For example, if the second connecting element and the axis of rotation are aligned to be flush, i.e., if the second connecting element is designed to be centrally positioned, the additional clamping force is applied effectively and with low technical expenditure. If the second connecting element extends radially completely inside the hub with respect to the axis of rotation, a compact design of the torsional vibration damper arrangement can be achieved.
Multiple second connecting elements may be designed. This allows for an individual adjustment of the necessary additional clamping force by forming individual combinations of second connecting elements radially inside the hub.
The second connecting element may include a screw and a thread in the second output flange. This allows for a simple structure and mounting of the torsional vibration damper arrangement.
The second connecting element may include a screw and a threaded nut. A design with at least one second connecting element having a threaded nut allows a structure in which the hub and/or two output flanges do not have to be individually adjusted. In this way, a kind of modular kit can be created with individual hubs or hub parts and output flanges that can be adapted to different situations without individual adjustments to the individual components.
The second connecting element may include a spring element for applying an additional clamping force. This can further increase the additional clamping force generated by the second connecting element.
The second connecting element may include a bolt, a locking ring and a spring element for applying an additional clamping force. This allows for easy mounting of the second connecting element.
The spring element may include a disc spring. Such a spring is simple to design and mount.
Furthermore, a motor vehicle is proposed including a connecting shaft and a torsional vibration damper arrangement as proposed herein, wherein the second output flange of the torsional vibration damper arrangement is connected to the connecting shaft in a rotationally fixed manner.
This allows for the construction of drive trains in motor vehicles in which the combustion engine and transmission are designed to be spatially separated from one another. Due to the torsional vibration damper arrangement as proposed here, an axial and/or angular offset does not have a negative effect on the connection between the torsional vibration damper arrangement and the connecting shaft, so that, for example, a cardan shaft can be dispensed with and replaced by a simple connecting shaft.
As a precaution, it should be noted that the numerals used here (“first”, “second”, etc.) serve primarily (only) to distinguish between several similar objects, sizes, or processes, and in particular no necessary dependency and/or sequence of these objects, sizes, or processes to each other is purported. If a dependency and/or sequence is necessary, this is explicitly stated here or results in a manner obvious to the person skilled in the art when studying the specifically described configuration.
Both the disclosure and the technical field are explained in more detail below with reference to the figures. It should be noted that the disclosure is not intended to be limited by the exemplary embodiments shown. For example, unless explicitly stated otherwise, it is also possible to extract partial aspects of the substantive matter outlined in the figures and to combine them with other components and knowledge from the present description and/or figures. It should also be noted that the figures and the proportions shown are only schematic. Identical reference symbols indicate the same objects, so that where applicable, explanations from other figures can also be used. In the figures:
The first output flanges 11 are designed to be rotatable relative to the input flange against the action of a spring device, not shown here, for damping torsional vibrations about an axis of rotation 15. The first output flanges 11 are connected to a hub 12 and a second output flange 13 in a rotationally fixed manner. A shaft, in this case the connecting shaft 4, is connected via the second output flange 13 by connecting means 14. This makes it possible to transmit torque to an output element, such as the connecting shaft 4 in this case, without this being designed to be inside the hub 12.
Where reference is made in this publication to the terms “axial” and “radial”, these are always understood to relate to the axis of rotation 15, unless otherwise specified.
Due to the moment M, which arises as a result of an angular and/or axial offset between the internal combustion engine 2 and the transmission 6, additional forces 16 act on the torsional vibration damper arrangement 9, e.g., on the first connecting elements 17, via which the at least one first output flange 11, the hub 12 and the second output flange 13 are connected to one another in a form-fitting and/or force-fitting manner in order to transmit torque. These additional forces 16 are axial forces in the direction of the axis of rotation 15.
The forces are subject to a certain periodicity due to the rotation of the torsional vibration damper arrangement 9 in operation, so that the amplitude of the additional force 16 acting on a certain first connecting element 17 is variable in time. Depending on the type of connection, this can have different effects. If, as in this example, a riveted connection is provided, the additional force 16 results in an axial load on the riveted connection. If instead a screw connection is designed as the first connecting element 17, the additional force 16 leads to a reduction of the axial clamping force and thus to a reduction of the possible moment transmission in the respective region. If a pin connection or additional toothing is also designed, the additional force 16 results in a bending load due to the elastic deformation of the components such as the second input flange 13 and hub 12, which can possibly lead to a failure of the first connecting element 17, so that the moment transmission via the torsional vibration damper arrangement 9 is at least reduced.
Furthermore, the torsional vibration damper arrangement 9 includes a second connecting element 20. In the present example, the second connecting element 20 is a screw 21, which is arranged radially inside the hub 12 and whose axis is concentric with the axis of rotation 15. The second connecting element 20 is thus aligned to be flush with the axis of rotation. In this example, the second connecting element 20 is designed to be radially completely inside a largest inner radius 38 of the hub 12. The second connecting means 20 is thus designed to be centrally in the hub 12. This facilitates the design and mounting of the torsional vibration damper arrangement 9. In this example, the screw 21 corresponds to a corresponding thread 34 in the second output flange 13 and causes an axially acting additional clamping force 22, which counteracts the moment M applied to the connecting shaft 4.
This can result in a large first radius 19 and thus a large torque to be transmitted via the torsional vibration damper 10 with a reduction in the additional forces 16 acting on the first connecting elements 13. Alternatively, it is also possible to provide a corresponding thread 34 in the hub 12 and to connect the second connecting means 20 or the screw 21 to the thread from the direction of the second output flange 13,
The torsional vibration damper arrangement 9 proposed here includes a torsional vibration damper 10, which can be connected on the output side to a shaft, for example a connecting shaft 4, via a lateral second output flange 13. By means of a second connecting means 20 radially inside the hub 12, an additional clamping force 22 is generated which counteracts an additional force 16 caused by a moment M acting on the second output flange 13 through the connecting shaft 4 due to an axial and/or angular offset and can stress, damage and possibly destroy the first connecting means 17 by which the hub 12 is connected to the second output flange 13 and the at least one first output flange 13 of the torsional vibration damper 10. This eliminates the need for a cardan shaft in installation situations where an internal combustion engine is designed to be spatially separated from a transmission.
Number | Date | Country | Kind |
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10 2021 122706.2 | Sep 2021 | DE | national |