Damping wheel having axis of rotation, drive train for motor vehicle comprising damping wheel, and vehicle comprising drive train

Abstract

The utility model relates to a damping wheel with a rotation axis, a driving system which comprises the damping wheel and is used for a motor vehicle and a vehicle with the driving system. The damping wheel at least comprises a torque input part (7); -a torque output (8); a stop device (9), by means of which a gap angle (10) between the torque input (7) and the torque output (8) is limited to a maximum angle (11) in a predetermined manner, and the torque input (7) and the torque output (8) are connected to one another in a torque-transmitting manner with a second torque stiffness only when the maximum angle (11) is reached by means of the stop device (9); the torque input part (7) and the torque output part (8) are connected to one another in a torque-transmitting manner within the gap angle (10) by means of the torsionally flexible connecting device (12) with a first torque stiffness, and the first torque stiffness is smaller than the second torque stiffness. By means of the damping wheel proposed herein, noise generation due to a zero crossing point can be avoided in a structural space neutral manner.

Description

Field of the Invention

[0001] The present invention relates to a damping wheel having a rotational axis for a drive train with an electric drive motor, a drive train for a motor vehicle having such a damping wheel, and a motor vehicle having such a drive train.

[0002] A damping wheel is proposed here that can be applied in a drive train with at least one electric drive motor. According to one aspect, a drive train for a motor vehicle with at least one electric drive motor is proposed, which drive train has a torsional vibration damping unit (such as a damping wheel). In a drive train for a motor vehicle with at least one electric (drive) motor, i.e., a pure electric motor drive train or a hybrid drive train with an additional internal combustion engine, there are usually two NVH critical phenomena (NVH, English: Noise Vibration Harshness). Background Art

[0003] The periodic lifting and impact of the flank of a gear or a broach caused by the torque zero crossing results in a rattling noise of the gear teeth. The single lifting and impact of the flank of a gear or a broach caused by the torque zero crossing results in a clinking noise.

[0004] The greater the impact mass, the higher the acoustic correlation of the two types of NVH critical phenomena. This is especially true for pure electric motor drive trains and hybrid drive trains because the electric (drive) motor of the integrated transmission has a high mass moment of inertia.

[0005] The following are known measures to prevent rattling noise of the gear teeth:

[0006] (1) Tightening the gear teeth in the force flow of the electric (drive) motor by increasing the torque of the electric (drive) motor (e.g., charging or boosting).

[0007] (2) Shifting the NVH critical operating point to a higher rotational speed.

[0008] (3) Improving the pre-isolation by a torsional vibration damper of higher quality (e.g., replacing a simple dual mass flywheel with a dual mass flywheel having a centrifugal pendulum) or via slip control of a clutch.

[0009] The following are known measures to prevent clinking noise:

[0010] (1) A lower torque gradient of the electric (drive) motor at the torque zero crossing.

[0011] If software measures are used to counter NVH critical phenomena in a cost-effective manner, some undesirable side effects will occur during the operation of the drive train: namely, higher losses, especially the impact on battery aging at low temperatures, and reduced longitudinal dynamics. In contrast, known hardware solutions are associated with significantly higher manufacturing costs. Summary of the Invention

[0012] Therefore, the object of the present invention is to provide a drive train for a motor vehicle having at least one electric motor that is cost-effective both in terms of manufacturing and operation, and in which the NVH characteristics are improved.

[0013] On this basis, the object of the present invention is to at least partially overcome the known disadvantages in the prior art. The features of the present invention are derived from the independent claims, and its advantageous embodiments are shown in the dependent claims. Each feature in the claims can be combined in any technically reasonable way and method. Thus, the descriptions in the following specification and the features in the drawings can also be used for this purpose, which contain supplementary embodiments of the present invention.

[0014] The present invention relates to a damping wheel having a rotational axis, which is used for a drive train with an electric drive motor. The damping wheel at least comprises the following components:

[0015] - A torque input part;

[0016] - A torque output part;

[0017] - A stop device, via which the clearance angle between the torque input part and the torque output part is limited to a maximum angle in a predetermined manner, and only when the maximum angle is reached, the torque input part and the torque output part are connected to each other in a torque transmission manner with a second torque stiffness by means of the stop device; and

[0018] - A torsional flexible connection device, wherein within the clearance angle, the torque input part and the torque output part are connected to each other in a torque transmission manner with a first torque stiffness by means of the torsional flexible connection device,

[0019] wherein the first torque stiffness is less than the second torque stiffness.

[0020] Hereinafter, unless there is a clear contrary indication, if the axial direction, radial direction or circumferential direction and corresponding terms are used, they refer to the said rotational axis. The serial numbers used in the above and following descriptions are only for clear distinction and do not reflect the order or rank of the indicated components, unless there is a clear contrary indication. A serial number greater than one does not necessarily mean the existence of another such component.

[0021] The damping wheel proposed in this text is a component that has not been used in the drive train of motor vehicles so far, whether in terms of function or in terms of its layout or installation space requirements. This is also because a fundamental problem existing in the drive train with at least one electric drive motor - namely the problem of generating a high level of acoustic comfort - was unknown before. In addition, it is also a complex challenge to solve this problem while meeting the technical requirements of such a drive train.

[0022] The damping wheel can be applied at any position in the torque flow in the drive train, preferably radially within a gear or as an integral part of the gear, preferably near the corresponding (preferably electric) drive motor, so that the cause of noise generation (i.e., torque difference and / or speed difference) is decoupled from the drive train as early as possible. Since it is inevitable to use wheels, mostly gears, in the drive train, the damper is provided in the form of a wheel structure. In this way, for a particularly space-saving implementation, the damping wheel can be used as a replacement for a conventional wheel.

[0023] The diameter of a suitable damping wheel is, for example, 80 mm [eighty millimeters] to 150 mm, and can even reach 300 mm in heavy-duty applications.

[0024] In one implementation, the torque input is directly connected to a shaft, preferably connected to the motor shaft (or its motor interface) in a torque-fixed manner, or in another implementation, the torque input is indirectly (e.g., via a spur gear, gear shaping, or disengaging clutch) connected to the motor shaft of the (preferably electric) drive motor (when necessary, with the disengaging clutch closed) in a torque-fixed manner. In the context shown here, the input or output is understood as a mechanical connection (or interface), where this connection is preferably implemented as rigidly as possible, such as an approximately integral implementation, for example, by means of a (star or central) screw connection or gear shaping connection. The term "input" is preferably understood as the torque output of the machine in the direction towards the transmission or the load, i.e., in the direction of what is called the traction torque in the terminology of the motor vehicle field. The term "output" is preferably understood as the torque reception of the machine from the transmission or from the load, i.e., in the direction of what is called the thrust torque in the terminology of the motor vehicle field. However, the opposite definition is also possible. In addition, in many cases (as can be derived from the above description), torque transmission is possible on both sides.

[0025] The torque output is arranged opposite the torque input in the torque flow, i.e., it is connected to the torque input only in a torque-transmitting manner via a torsionally flexible connecting device and a stop device. The torque input is arranged to transmit the torque (from the relevant drive motor) introduced into the torque input to the remaining (couplable) transmission. However, at least it is not excluded here (e.g., for generator operation or eddy current brake and for intermediate operating states), and preferably it is arranged for the opposite torque transmission.

[0026] For a predefined clearance angle, for example, a total of 1° [one degree out of 360 degrees] to ±2°, a maximum angle starting from the neutral angle position (neutral position) is thus defined, and a torque with a first torque stiffness is transmitted by means of the torsional flexible connection device. It should be noted that in one embodiment, the torsional flexible connection device is the only torque-transmitting connection between the torque input part and the torque output part, so the first torque stiffness is only defined by the torsional flexible connection device. In another embodiment, the torsional flexible connection device, for example, is already supported by a stop device (or at least one stop component of the stop device) within the clearance angle from the very beginning (i.e., starting from the neutral position). However, here, under the relative torsion of the torque input part with respect to the torque output part, for example, due to the compression of the relevant stop component, the stiffness will increase. In one embodiment, the torsional flexible connection device is designed for a maximum torque of 20 Nm [twenty Newton meters], preferably 10 Nm, and particularly preferably 5 Nm, and in the design, a vibratory load assumption is preferably used. The service life (or the number of cycles) is designed, for example, according to the target (maintenance-free) service life of the relevant transmission. The maximum torque that can be transmitted via the stop device or by using components related to the second torque stiffness (according to the design) is, for example, at least 80 Nm [eighty Newton meters], preferably above 100 Nm, and particularly preferably above 200 Nm.

[0027] Once the maximum angle is reached, the torque stiffness preferably gradually increases to the second torque stiffness and reaches a sufficient (second) torque stiffness to obtain the desired maximum engine torque. It should be noted that in one embodiment, the second torque stiffness consists of the torque stiffness of the torsional flexible connection device and the torque stiffness of the stop device. Alternatively, the stop device completely takes over the torque transmission when the maximum angle is reached, so the second torque stiffness is equal to the torque stiffness of the stop device. It should also be noted that the second torque stiffness is not necessarily constant under a variable applied torque, and here the maximum angle is not necessarily able to be exceeded, for example, due to further increased (elastic) compression, bending, or torsion.

[0028] In one embodiment, the first torque stiffness is at least one order of magnitude smaller than the second torque stiffness, so it can be neglected compared with the second torque stiffness. In one embodiment, the two torque stiffnesses are of the same order of magnitude. For example, the first torque stiffness is half of the second torque stiffness, where as described above, the second torque stiffness consists at least of the sum of the (first) torque stiffness of the torsional flexible connection device and the torque stiffness of the stop device (when the maximum angle is reached). It should be noted that the stop device is not necessarily limited to one component or structural device, but is, for example, composed of multiple stop components, such as at least one elastic block and at least one flange pair.

[0029] In an advantageous embodiment of the damping wheel, it is further proposed that the torsional flexible connection device includes at least one helical compression spring tangentially aligned with the axis of rotation.

[0030] For embodiments with lower installation space requirements in the axial direction, preferably, at least one helical compression spring is arranged axially overlapping with the member forming the torque input part and / or the member forming the torque output part. For example, the torque input part forms a surrounding outer ring (such as having gear teeth on the preferred outer side) and / or the torque output part forms a surrounding inner ring (such as having pinion teeth on the preferred inner side) or vice versa. The corresponding helical compression spring is preferably supported via the flange of the torque input part and the corresponding flange of the torque output part (preferably pre-tensioned). It should be noted that in one embodiment, multiple helical compression springs are arranged nestedly (such as staggered), preferably coaxially. Optionally or additionally, elastic plastic is arranged at the center of the helical compression spring, and the elastic plastic preferably prevents the block load (Auf-Block-Belastung) of the helical compression spring or at least reduces the energy input and / or also serves as a stop member (of the stop device).

[0031] In the embodiments proposed herein, the torsional flexible connection device is formed by such a helical compression spring, or the helical compression spring is one of the components forming the torsional flexible connection device. Preferably, one pair or two pairs (two in each pair) of helical compression springs radially opposite to each other are provided. In one embodiment, multiple helical compression springs (such as three or five) are distributed around the axis of rotation, and these helical compression springs are preferably evenly spaced. In one embodiment, multiple helical compression springs are arranged tangentially to a common (imaginary) circle, and this circle is concentric with the axis of rotation.

[0032] In one embodiment, a corresponding helical compression spring among multiple helical compression springs is supported at one of its spring ends on the stop member of the torque input part, and at its other spring end on the stop member of the torque output part, and is preferably pre-tensioned at the neutral position therebetween. In one embodiment, at least one component of the stop device is formed by the said stop member (supporting the helical compression spring), specifically indirectly, via the block load of the relevant helical compression spring, or directly, in such a way that these stop members form a force-transmitting contact with each other when the maximum angle is reached. Preferably, in the latter embodiment, the relevant helical compression spring is protected from block load. It should be noted that the said stop member is not necessarily the only component forming the stop device, but only preferred.

[0033] In one embodiment, at least one (preferably all) helical compression springs are implemented as arc springs. Here, before the spring wire bears a bulk load, the bulk load was already the design upper limit of the radial force applied to the spring wire (due to the radial offset movement towards the radial outside). In one embodiment, at least one (preferably all) helical compression springs are implemented as helical compression springs with a straight spring axis.

[0034] In an advantageous embodiment of the damping wheel, it is further proposed that the spur gear is a transmission device for transmitting the torque provided by the drive to the load.

[0035] As described above, a particularly space-saving embodiment is to integrate the (graded) damping function into the gear. Here, it is proposed to integrate this function into the spur gear, particularly preferably into the spur gear pinion. In one embodiment, a helical tooth portion is provided, where preferably (in addition to the radial support), an axial support portion is provided in the relevant components of the torsional flexible connection device and / or the stop device for axial support, for example, by means of a rolling bearing or a sliding bearing having at least an axially supporting component. Alternatively or additionally, the axial support provided by a rolling bearing (preferably already provided for radial support), such as a grooved ball bearing (optionally integrally with the radial support), is sufficient by (axially on one or both sides) supporting the (e.g., centrally arranged) torque output portion on the bearing inner ring or the corresponding shoulder of the shaft, and supporting the (e.g., radially externally arranged) torque input portion on the bearing outer ring or the corresponding shoulder of the shaft (and vice versa). It should be noted that the intermediate element (such as a sleeve and / or a locking ring) provides an indirect force-transmitting contact for axial support. It should be noted that in the straight tooth portion or other structural forms of the spur gear, the above-described embodiments for axial support are also advantageous.

[0036] In an advantageous embodiment of the damping wheel, it is further proposed that the stop device is formed of an elastic plastic and is arranged between the torque input portion and the torque output portion, where preferably, the stop device and the torque input portion or the torque output portion are fixedly connected to each other.

[0037] As described above, elastic plastics (such as traditional elastomers or thermoplastic elastomers [TPE]) are particularly suitable for the purpose of being able to provide a stiffness jump or preferably a progressive increase in stiffness, but at the same time being able to provide sufficient damping to prevent the formation of noise. In one embodiment, heat dissipation can also be used in the elastic plastic to suppress noise. Alternatively or additionally, (approximate) incompressibility can be used, that is, (as described above) deformability for a small (smaller) stiffness and when reaching the (preferably structure space-determined) limit of (slight) deformability, the stiffness rises with a very steep slope and then (at least below the design torque limit) is also almost constant.

[0038] A permanent (fixed) connection between the stop device and the torque input or output is advantageous to avoid any noise and / or uncertainty in the relative position between the components of the stop device and the damping wheel. In one embodiment, the stop device is (at least partially) made of an elastic plastic, and the elastic plastic is fixedly connected to one of the components of the torque input or output by vulcanization. This is preferably combined with the above-described embodiment of grading the stiffness according to the deformation state.

[0039] In a preferred embodiment, corresponding spacings are reserved for the clearance angle on the respectively opposite torque output or torque input, such that the stop device does not form a force-transmitting contact with the (respectively opposite) torque output or torque input before reaching the maximum angle (i.e., only when the maximum angle is reached) under the corresponding torque load.

[0040] In an advantageous embodiment of the damping wheel, it is also proposed that the elastic plastic is arranged radially between the torque input and the torque output.

[0041] For example, in one embodiment, the torque input and the torque output each have elastic plastic arranged between them along the axial end sides, and optionally also have a torsionally flexible connection device, but it is proposed here that for cases with very small axial structural space requirements, the elastic plastic is arranged radially between the torque input and the torque output. For example, in the above-described embodiment having at least one helical compression spring and a coaxially arranged stop member made of elastic plastic, the entire axial extension or most of it is arranged axially within the damping wheel. Thereby (while minimizing the structural space requirements) torsion flexibility is generated in the range of low load torque fluctuations (in this range the considered noise emissions may occur), which reduces or even prevents the lifting and impact of the teeth of the relevant gears. On the other hand, it is still possible to reliably transmit the desired (maximum) torque with the usual response performance, i.e., through a second torque stiffness that occurs at the maximum angle with the help of the stop device.

[0042] According to another aspect, a drive train for a motor vehicle is proposed, the drive train having at least the following components:

[0043] - at least one drive machine, which serves as a torque source for providing torque;

[0044] - at least one load, which is used to convert at least a part of the torque provided by one of the torque sources;

[0045] - a transmission, which is used to transmit at least a part of the torque provided by the torque source to the load,

[0046] Wherein, at least one damping wheel according to the embodiments described above is arranged between the torque source and at least one load,

[0047] Preferably, at least one damping wheel is arranged in the electrical subsystem of the drive train.

[0048] In the case of using multiple drive motors in a respective subsystem, the multiple drive motors must be synchronized with each other or decoupled separately. The latter is mostly not adopted in current application scenarios due to the cost of the separating clutch and the fast controllability of the electric drive motor. In a hybrid drive train, where one of the drive motors is implemented as an internal combustion engine, due to the inherent rotational speed fluctuations in the internal combustion engine caused by the ignition timing, when the preload force on the meshing teeth of the relevant gears is too low, rattling noises in the teeth may occur. The latter is the desired operating state for efficient operation. The second critical state occurs during pure electric driving or in the case of load changes in a (pure) E-axis (a drive train with only one or more electric drive motors), and clanging noises (leaning against switching to the opposite tooth flank) may occur. It should be noted that the low-load operating state exists not only during idling, but also when an electric drive motor is controlled by the rotational speed of another drive motor (especially relevant in the case of an internal combustion engine) through control technology to set the drive train to have no drag torque (at least for the co-running electric drive motors).

[0049] An advantageous solution to the task described herein lies in a torsional vibration damping unit having one or more combinations of the following features:

[0050] - Integrated in one or more gears in the electrical branch of a pure electric motor drive train or a hybrid drive train.

[0051] - Only covering a torque range significantly lower than the maximum torque of the electric (drive) motor.

[0052] - Having low friction and stiffness.

[0053] - Dynamically decoupling the mass inertia (especially the impact mass) of the electric (drive) motor.

[0054] - Capable of being configured as a straight compression spring damper, an arc spring damper, or an elastomer damper.

[0055] - Having a stop downstream for transmitting the full torque of the electric (drive) motor.

[0056] - Arranged in a hybrid transmission, a hybrid module, an electric motor, and an electric axle.

[0057] According to another aspect, a motor vehicle is proposed, which has at least one drive wheel and a drive train according to the above embodiments,

[0058] Wherein, torque can be output from at least one drive machine of the drive system to at least one drive wheel to drive a motor vehicle.

[0059] Wherein, in a low-load operating state, noise emissions in the drive system are reduced or suppressed by means of at least one damping wheel.

[0060] The motor vehicle is, for example, a sedan, a truck or a motorcycle. The motor vehicle has a drive system according to an embodiment as described above. The torque output by at least one drive machine is output to at least one drive wheel (load) via a transmission. In one embodiment, the transmission referred to herein includes a shiftable gear transmission. In one embodiment, the gear transmission includes a differential.

[0061] The motor vehicle proposed herein includes a drive system having at least one damping wheel. By means of the damping wheel, noise emissions caused by tooth lift in a low-load operating state can be effectively and cost-effectively significantly avoided or prevented. At the same time, the damping wheel can be installed in a compact structure and conventional or conventionally designed components can be used substantially unchanged. Compared with a drive system without a damping wheel, the drive system proposed herein can also be designed to operate more efficiently. Description of the Drawings

[0062] The above-mentioned utility model will be described in detail below in the context of the related art with reference to the drawings showing preferred designs. The present utility model is not restricted by any purely schematic drawings. It should be noted here that the drawings are not dimensionally accurate and are not suitable for defining dimensional ratios. In the drawings:

[0063] Figure 1 A transmission for a drive system having three connected drive machines in a first embodiment is shown;

[0064] Figure 2 A transmission for a drive system having three connected drive machines in a second embodiment is shown;

[0065] Figure 3 A transmission for a drive system having one connected drive machine is shown;

[0066] Figure 4 A schematic cross-sectional view of a damping wheel around a rotation axis is shown; and

[0067] Figure 5 A drive system in a motor vehicle is shown. Detailed Description of the Embodiment

[0068] In Figure 1 a first embodiment for (e.g., of motor vehicle 19, see Figure 5)Schematic circuit diagram of a transmission 16 of a drive train 3 with three connected drive motors 4, 5, 6, where the first drive motor is implemented as an internal combustion engine 4 and the other two are implemented as electric drive motors 5, 6. So this is a hybrid drive train. The electric drive motors 5, 6 each include a rotor 23, 24. In the transmission 16, on the spur gear 15 designated as the damping wheel 1, the symbol circle (for example, for the helical compression spring 13, see Figure 4 )identifies the suitable position for mounting the damping wheel 1 (alternatively or additionally) in the transmission 16. Preferably, the (optional) damping wheel 1 in the first electric drive motor 5 and / or the (optional) damping wheel 1 in the second electric drive motor 6 are arranged radially within the respective spur gear 15 (see Figure 4 ). It should be noted that the schematic circuit diagram does not represent the relative geometric positions and / or relative dimensions, but is only interpreted in terms of function. Nor can the preferred transmission ratio be read from the shown dimensional ratios of the gears shown, but only an indication of acceleration or deceleration can be read.

[0069] Here (only optionally) each of the drive motors 4, 5, 6 is provided for providing torque, i.e., a torque source. It should not be excluded that torque (referred to as thrust torque when used in the drive train 3 of a motor vehicle 19) is introduced into the respective torque source. The internal combustion engine 4 is connected or connectable in a torque-transmitting manner to the loads 17, 18 via a first subsystem 20 and the second electric drive motor 6 is connected or connectable in a torque-transmitting manner to the loads 17, 18 via a third subsystem 22. The loads here (only optionally) are the differential 28. The first electric drive motor 5 and the internal combustion engine 4 are (permanently) connected to each other via a second subsystem 21, and the first electric drive motor 5 is connected to the loads 17, 18, here (only optionally) the differential 28, (like the internal combustion engine 4, separable by means of a separating clutch 29) via the second subsystem 21 and the first subsystem 20.

[0070] It is not excluded that a torque source (for example, the first electric drive motor 5 and / or the internal combustion engine 4) is only used for internal purposes, such as for generating current. In the shown embodiment, the (first) subsystem 20 facing the load side differential 28 can be interrupted by means of a separating clutch 29 (preferably the only separating clutch in the drive train 3). The (second) subsystem 21 between the internal combustion engine 4 and the first electric drive motor 5 cannot be interrupted. Therefore, in any operating state in which the internal combustion engine 4 outputs torque, it is possible to generate noise due to gear rattle in a low-load operating state. However, in the (third) subsystem 22 of the second electric drive motor 6, this type of noise emission is generally also possible.

[0071] The first electric drive motor 5 is arranged, for example, for traction of the internal combustion engine 4 and / or for boosting operation to support the internal combustion engine 4, and preferably for generating electric current in generator mode, in particular in a mode for increasing (battery-powered) range, when the internal combustion engine 4 and the first electric drive motor 5 are decoupled from the differential 28 by means of the disconnect clutch 29.

[0072] For some operating points, the second electric drive motor 6 serves as the sole torque source of the drive train 3 to directly provide torque to the loads 17, 18 (for example, for the propulsion operation of the motor vehicle 19), and is (only optionally) inseparably connected to the differential 28 here. For example, for urban driving, the second electric drive motor 6 is sufficient as a torque source and the internal combustion engine 4 does not need to operate.

[0073] Therefore, the (second) torque flow 33 (second subsystem 21) between the internal combustion engine 4 and the first electric drive motor 5 is uninterruptible. Therefore, in any operating state in which the internal combustion engine 4 outputs torque, it is possible to generate noise due to tooth lift in a low-load operating state. This noise emission is caused by the situation described at the beginning, that is, the inherent rotational speed fluctuations in the internal combustion engine 4 due to the ignition time point, that is, if the preload force on the meshing teeth of the relevant gears is too low, then tooth rattling may occur. However, in the (third) torque flow 34 (third subsystem 22) of the second electric drive motor 6, if the first subsystem 20 (first torque flow 32) and the third subsystem 22 (third torque flow 34) are simultaneously connected to the differential 28 (disconnect clutch 29 closed), and at least (or especially alone) the internal combustion engine 4 operates in a torque-outputting manner, this kind of noise emission is usually also possible.

[0074] The second critical state occurs during load changes and may generate a rattling noise (switching to the opposite tooth flank). This is particularly critical in the electric drive motors 5, 6 because there are usually no other torsional vibration damper devices here, such as those commonly found in internal combustion engines 4 (for example, dual-mass flywheels, centrifugal pendulums, multi-flange dampers or rocking lever dampers).

[0075] In Figure 2 a schematic circuit diagram of the transmission 16 for the drive train 3 of the second embodiment with three connected drive motors 4, 5, 6 is shown, where, as in Figure 1 the first drive motor is implemented as an internal combustion engine 4 and the other two are implemented as electric drive motors 5, 6. Only for the sake of clarity and without excluding generality, this circuit diagram is almost the same as the schematic diagram in Figure 1 Reference is made to the description there in this regard. The difference is that here the second electric drive motor 6 or its third subsystem 22 is engaged in the first subsystem 20 of the internal combustion engine 4.

[0076] Figure 3Shown therein is a transmission 16 for a drive train 3 with one (unique) coupled drive machine 6. Such a transmission 16 is also commonly referred to as the E-axis. For the sake of clarity only, the (second) electric drive machine 6 and its (third) sub-system 22 (in the region of the third torque flow 34 of the second electric drive machine 6) up to the differential 28 are shown in the figure. The gear rattle caused by the internal combustion engine 4 (see Figure 1 ) is not necessarily a problem here. However, as described for the transmission 16 shown in reference Figure 1 , the same second critical state is suppressed here, namely the situation during load changes and the possible resulting clatter noise. For other details, also see the above description of Figure 1 .

[0077] In Figure 4 shown is a schematic cross-sectional view of a damping wheel 1 about a rotational axis 2. The damping wheel 1 includes a torque input portion 7 and a torque output portion 8 spaced radially therefrom. In this embodiment, the torque input portion 7 is arranged to be closer to the rotational axis 2 radially. The torque input portion 7 is implemented to have a first torque stiffness and the torque output portion 8 is implemented to have a second torque stiffness, wherein the first torque stiffness is less than the second torque stiffness. The damping wheel 1 is provided for attenuating low torque, such as the torque of the electric drive machines 5, 6.

[0078] The torque input portion 7 and the torque output portion 8 are connected to each other in a torque-transmitting manner by means of a torsional flexible connecting device 12. In one embodiment (shown at the upper part of the schematic here), the torsional flexible connecting device 12 includes at least one helical compression spring 13 having a straight spring axis 14 (tangentially aligned with the rotational axis 2). In one (preferably alternative) embodiment, the torsional flexible connecting device 12 is implemented to have at least one helical compression spring 13 having an arcuate spring axis 14 (at least partially tangentially aligned with the rotational axis 2), wherein the continuously tangentially arranged spring axes 14 depict a circular arc section such that the helical compression spring 13 also depicts a circular arc (preferably formed concentrically with the rotational axis 2) (shown at the lower part of the schematic). Thereby, at low torque (e.g., during zero torque passage), for example, the electric drive machine 5 connected to the internal combustion engine 4 in a torque-transmitting manner is softly damped, and the tooth lift is reduced or suppressed, thereby preventing the generation of undesired noise.

[0079] A stop device 9 is arranged radially between a torque input part 7 and a torque output part 8. Via the stop device, the clearance angle around the neutral position 30 (shown here) between the torque input part 7 and the torque output part 8 is limited in a predefined manner to a maximum angle 11. Once the maximum angle 11 is reached due to the application of a large torque, the torque is transmitted from the torque input part 7 to the torque output part 8 (preferably approximately without damping) by means of the stop device 9. It should be noted that the torque flow can also be from the torque output part 8 to the torque input part 7. In one embodiment, the stop device 9 is implemented using an elastic plastic (only schematically shown here), and this plastic conducts torque transmission by means of a force-transmitting contact between the torque input part 7 and the torque output part 8 in the case where the applied torque is sufficient to reach the maximum angle 11. The elastic plastic is preferably arranged radially between the torque input part 7 and the torque output part 8.

[0080] The damping wheel 1 is implemented as a spur gear 15, and the spur gear 15 preferably has tooth parts 31 of the gear (not shown here) on the radially outer side (i.e., here on the torque input part 7).

[0081] In Figure 5 a top view of the drive train 3 in a motor vehicle 19 is shown, where two drive motors 4, 6 are arranged along the engine axis 26 perpendicular to the longitudinal axis 25. The drive motors 4, 6 are arranged in the driving direction in front of the cab 27 of the motor vehicle 19. The drive train 3 is configured to output torque (preferably dedicated torque) from the drive motors 4, 6 via a transmission 16 to drive the left drive wheel 17 and the right drive wheel 18 (here of the front axle of the motor vehicle 19, which is optional) so as to propel the motor vehicle 19. The transmission 16 is implemented, for example, according to Figure 1 to implement, Figure 1 The first electric drive motor 5 shown here (only optional) is absent or not shown, and is arranged axially, for example, as a (coaxial or axially parallel) hybrid module between the internal combustion engine 4 and the transmission 16. The drive train 3 is implemented, for example, such that the vehicle 19 can be driven in a pure electric mode, i.e., only by means of the electric drive motor 6, or only by means of the internal combustion engine 4, or in a combined manner using the two drive motors 4, 6. By means of the damping wheel 1 arranged within the drive train 3, a reduction in noise emissions can be achieved in a space-compact manner within the drive train 3, for example, in the case of a zero crossing at the electric drive motor 6.

[0082] By means of the damping wheel proposed here, noise emissions caused by zero crossings can be avoided in a space-compact manner.

[0083] List of Reference Signs

[0084] 1 Damping wheel

[0085] 2 Axis of rotation

[0086] 3 Drive train

[0087] 4 Internal combustion engine

[0088] 5 First electric drive motor

[0089] 6 (Second) electric drive motor

[0090] 7 Torque input section

[0091] 8 Torque output section

[0092] 9 Stop device

[0093] 10 Clearance angle

[0094] 11 Maximum angle

[0095] 12 Torsionally flexible coupling device

[0096] 13 Helical compression spring

[0097] 14 Spring axis

[0098] 15 Spur gear

[0099] 16 Transmission

[0100] 17 First drive wheel

[0101] 18 Second drive wheel

[0102] 19 Motor vehicle

[0103] 20 First subsystem

[0104] 21 Second subsystem

[0105] 22 (Third) subsystem

[0106] 23 First rotor

[0107] 24 Second rotor

[0108] 25 Longitudinal axis

[0109] 26 Engine shaft

[0110] 27 Cab

[0111] 28 Differential

[0112] 29 Disengaging clutch

[0113] 30 Neutral position

[0114] 31 Tooth section

[0115] 32 First torque flow

[0116] 33 Second torque flow

[0117] 34 (Third) torque flow

Claims

1. A damping wheel (1) having a rotational axis (2) for a drive train (3) with an electric drive motor (5, 6), the damping wheel having at least the following components: - A torque input part (7); - A torque output part (8); - A stop device (9) via which a clearance angle (10) between the torque input part (7) and the torque output part (8) is limited in a predefined manner to a maximum angle (11), and only when the maximum angle (11) is reached do the torque input part (7) and the torque output part (8) connect to each other in a torque-transmitting manner with a second torque stiffness by means of the stop device (9); and - Torsional flexible connection device (12), wherein, Within the clearance angle (10), the torque input part (7) and the torque output part (8) are connected to each other in a torque-transmitting manner with a first torque stiffness by means of the torsional flexible connection device (12), wherein the first torque stiffness is less than the second torque stiffness.

2. The damping wheel (1) according to claim 1, wherein, The torsional flexible connection device (12) includes at least one helical compression spring (13) tangentially aligned with the rotational axis (2).

3. The damping wheel (1) according to claim 1 or 2, wherein, The damping wheel is a spur gear (15) for a transmission (16) that is used to transmit torque provided by the drive motor (5, 6) to a load (17, 18).

4. The damping wheel (1) according to claim 3, wherein, The stop device (9) is made of an elastic plastic and is arranged between the torque input part (7) and the torque output part (8), wherein the stop device (9) is fixedly connected to the torque input part (7) or the torque output part (8).

5. The damping wheel (1) according to claim 4, wherein, The elastic plastic is arranged radially between the torque input part (7) and the torque output part (8).

6. A drive train (3) for a motor vehicle (19), characterized in that: The drive train includes at least the following components: - At least one drive motor that provides torque as a torque source; - At least one load (17, 18) that is used to convert at least a part of the torque provided by at least one of the torque sources; - A transmission (16) that is used to transmit at least a part of the torque provided by the torque source to the load (17, 18), wherein at least one damping wheel (1) according to any one of the preceding claims is arranged between the torque source and at least one load (17, 18), wherein at least one damping wheel (1) is arranged in the electric sub-system (21, 22) of the drive train (3).

7. A motor vehicle (19), characterized in that: The motor vehicle has: At least one drive wheel and a drive train (3) according to claim 6, wherein torque can be transmitted from at least one drive motor of the drive train (3) to the at least one drive wheel to propel the motor vehicle (19), wherein, in a low-load operating state, noise emissions in the drive train (3) are reduced or suppressed by means of its at least one damping wheel (1).

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