DE102016116069A1 - Device for reducing high-frequency interference currents and vehicle - Google Patents

Abstract

The invention relates to a device (1) for reducing high - frequency interfering currents (100) in a drive train (10) of a vehicle (2) driven by at least one electric machine (20), the device (1) having at least one interference - blocking element (30) and at least one noise propagating element (40), the drive train (10) comprising at least a first shaft portion (11) and a second shaft portion (13), wherein one end (12) of the first shaft portion (11) having one end (14) of the the electric machine (20) further comprising at least a first grounding portion (21) forming a ground potential (70) of the electric machine (20), and the power train (10) further comprising a second ground portion (13) for mechanically transmitting torque second grounding section (15) forming a ground potential (70) of the drive train (10). Furthermore, the invention relates to a vehicle (2) with an electric machine (20) and a drive train (10) driven at least by the electric machine (20), comprising a device (1) for reducing high-frequency interference currents in the drive train (10) of the vehicle (2). ,

Description

The present invention relates to a device for reducing high-frequency interference currents in a driven at least by an electric machine drive train of a vehicle, the device comprising at least one anti-jamming element and / or at least one noise elimination element, the drive train comprising at least a first shaft portion and a second shaft portion, wherein The electric machine is further mechanically operatively connected to one end of the second shaft portion for transmitting torque, the electric machine further comprising at least a first ground portion forming a ground potential of the electric machine, and the powertrain further comprising a second ground portion forming a ground potential of the powertrain. Furthermore, the invention relates to a vehicle having an electric machine and a drive train driven at least by the electric machine, comprising a device for reducing high-frequency interference currents in the drive train of the vehicle.

In modern vehicle technology, it is known to use electric machines for driving a vehicle. Such vehicles may be, for example, pure electric vehicles, but also be designed as hybrid vehicles that have both an internal combustion engine and an electric motor for driving. To store the necessary electrical energy DC high-voltage batteries are often used. For converting the direct current into the alternating current usually required by the electric machines, cyclic inverters are often used, which can be installed in power electronics of the vehicle. Among other causes, it may come in particular in this conversion to generate interference currents, which often have a high frequency. Without appropriate countermeasures, these interference currents in the vehicle, especially in the drive train of the vehicle, spread and lead to disturbances in electrical systems of the vehicle, up to a radiation of interference in the environment, which often disturb even for example even a radio reception, for example, a radio of the vehicle can.

According to the prior art, it is already known to use filter devices for removing, in particular, high-frequency interference currents directly at the source of the interference currents, that is to say, for example, in the converter and / or in the electric machine. However, this is often expensive, since the filter devices are usually large-volume due to the high performance enforced in the vehicle and sometimes even require active cooling. Furthermore, anti-blocking measure such as electrically insulating couplings or, for example, from the DE 10 2015 100 847 A1 It is known to use disturbance measures such as, for example, sliding contacts or conductive bearing devices, in order to mitigate the propagation of interference currents in the drive train or to discharge them from the drive train. In this case, however, such insulating couplings are again large-volume and also often cause a reduction in the transmissible torque in the drive train. Furthermore, it has been found that the effectiveness of a leakage of interference currents is reduced by conductive bearings or sliding contacts, especially for high-frequency interference currents. Also, such conductive bearings or sliding contacts are subject to high wear.

It is therefore an object of the present invention to at least partially overcome the disadvantages described above and to improve a device for reducing high-frequency interference currents and a vehicle. In particular, it is an object of the invention to provide a device for reducing high-frequency interference currents and a vehicle, the most effective prevention of propagation of a high-frequency noise current in a drive train and / or the most effective possible discharge of a high-frequency noise from a drive train in a particularly simple and cost-effective manner enable.

The above object is achieved by a device for reducing high-frequency noise with the features of independent claim 1. Further, the object is achieved by a vehicle having the features of the independent claim 10. Further advantages of the invention will become apparent from the dependent claims, the description and the drawings , In this case, features and details that are described in connection with the device according to the invention, of course, also in connection with the vehicle according to the invention and in each case vice versa, so that with respect to the disclosure of the individual aspects of the invention always reciprocal reference is or may be.

According to a first aspect of the invention, the object is achieved by a device for reducing high-frequency interference currents in a drive train of a vehicle driven at least by an electric machine, the device having at least one interference-blocking element and / or at least one noise-eliminating element, the drive train comprising at least one first shaft section and a second shaft portion, wherein an end of the first shaft portion to an end of the second shaft portion to Transmission of a torque is mechanically operatively connected, the electric machine further comprising at least a first ground portion, which forms a ground potential of the electric machine, and the drive train further comprising a second ground portion, which forms a ground potential of the drive train. A device according to the invention is characterized in that the interference-blocking element comprises a decoupling capacitor electrically connected in series with the first shaft section and the second shaft section for capacitive decoupling of the first shaft section and the second shaft section, and / or in that the noise-removing element is electrically conductive between the second shaft section and the second grounding section arranged coupling capacitor for a capacitive coupling of the second shaft section to the second grounding section, and / or that the disturbance-carrying element comprises a high-frequency electrical conductor, which is arranged at least partially electrically conductive between the second and the first grounding section.

A device according to the invention is intended for use in or on a drive train of a vehicle. In addition, as far as technically possible and / or useful, a device according to the invention can also be used in other places where a reduction of high-frequency interference currents is required. The vehicle has an electric machine, which is designed to drive the drive train. For this purpose, the electric machine is operated as an electric motor. In addition, the electric machine can usually be operated as a generator, in which case a device according to the invention can also be used to reduce high-frequency interference currents. The drive train is formed at least in two parts and has a first shaft portion and a second shaft portion. The shaft sections are usually made of a metal material and thus electrically conductive. To transmit a torque, the two shaft sections are mechanically operatively connected to one another, in which case one end of each of the first and second shaft sections is in particular mechanically operatively connected to one another, for example by splines. In contrast to a clutch can be provided in this way a particularly effective and lossless or at least low-loss transmission of torque between the shaft sections. Furthermore, the electric machine comprises a first grounding section and the drive train comprises a second grounding section, each of which forms a ground potential of the respective element. The safety for a user when using the electric machine or the drive train can be increased and ensured by such a grounding section or a ground potential, since the risk of electric shock can be avoided or at least significantly reduced. In this case, the earthing sections can preferably comprise a housing of the respective component or even be formed by it. Furthermore, a separate potential equalization conductor between the grounding sections is usually required by law.

In particular, when operating the electric machine, but also caused by other sources, high-frequency interference currents can arise, which can propagate especially in the drive train. High-frequency in the sense of the invention means in particular that a frequency of the interference currents is several kilohertz, often even megahertz or gigahertz. This may, for example, lead to disturbances of the electric machine itself or of other electrical or electronic devices of the vehicle. In particular, it can also come to a radiation of the interference currents into the environment, which, for example, a broadcast reception can be disturbed. In order to reduce these interference currents, a device according to the invention has at least one noise-blocking element and / or at least one noise-eliminating element.

It is essential to the invention that the at least one interference-blocking element and / or the at least one element that deflects noise can be configured in different ways or as different measures. Thus, according to a first possibility, it may be provided according to the invention that the interference-blocking element comprises a decoupling capacitor electrically series-connected with the first shaft section and the second shaft section for capacitive decoupling of the first shaft section and the second shaft section. By the electrical series connection can be provided in a particularly simple manner that the two shaft sections are not directly connected to each other electrically conductive. Interference currents, which are designed as direct currents, can be safely avoided. By means of an embodiment of the decoupling capacitor with a low capacitance, a transmission of high-frequency interfering currents through the decoupling capacitor can also be suppressed, the intensity of the suppression increasing as the capacity of the decoupling capacitor decreases. In this case, this capacity, according to a function of the decoupling capacitor as a high-pass filter, preferably also be adapted to the expected frequencies of interference currents. In this case, an overall effect of the measures used depends in particular on further parasitic impedances located in the drive train. Preferably, the capacity may be adapted, for example, to a cutoff frequency above which no or at least no significant high-frequency interfering currents occur or are expected any more. The coupling capacitor can be formed, for example, by an electrically insulating layer between the ends of the shaft sections in the region of the mechanical active connection. In this way, weight and / or required installation space can be saved, in particular with respect to the use of an electrically insulating coupling, wherein furthermore also a transmission of a torque between the shaft sections is not impaired or at least only insignificantly impaired. Due to the low space requirements can also be provided that this coupling capacitor can be used without complex design changes close to a source of interference currents, for example, close to the electric machine. A particularly early and thus effective reduction of high-frequency interference currents can be provided thereby.

A second, alternative or additional possibility provides for the invention that the disturbance-removing element comprises a coupling capacitor which is arranged electrically between the second shaft section and the second ground section for a capacitive coupling of the second shaft section to the second ground section. In other words, the coupling capacitor is electrically connected in parallel with the second shaft portion and the second ground portion. In this way, it can be provided in a particularly simple manner that, on the one hand, the second shaft section and the second ground section remain electrically insulated from one another and, on the other hand, a removal of high-frequency interference currents from the second shaft section to the second ground section can be made possible. This is, as already described above, made possible by the electrical properties of a capacitor that does not forward direct current, but allows a transfer of alternating currents, the forwarding is the more effective, the higher the frequency of the interference current. Thus, high-frequency interference currents are derived by such a coupling capacitor particularly well from the second shaft portion in the second grounding section. In a coupling capacitor, it is advantageous that this has a high capacity, since the coupling-out efficiency also increases with increasing capacity of the coupling capacitor. In particular, it can be made possible by a coupling capacitor according to the invention that the decoupling of the interference currents can be provided without mechanical contact between the second shaft section and the second ground section. In particular, due to the non-contact operation of the proposed capacitive coupling, for example, compared to a sliding contact according to the prior art, a wear-free operation can be provided without maintenance. Likewise, the proposed arrangement in its basic operation is resistant to contamination with liquids or foreign bodies. A particularly good derivation with simultaneous low maintenance susceptibility and long life of a device according to the invention can thus be provided by this possibility. The teaching according to the invention is not abandoned if, analogously, the disturbance-carrying element comprises a coupling capacitor which is arranged electrically between the first shaft section and the first ground section for a capacitive coupling of the first shaft section to the first ground section. Thus, all of the advantages described above can also be provided in this embodiment.

According to a third, likewise alternative or additional possibility, it can furthermore be provided according to the invention that the disturbance-carrying element comprises an electrical high-frequency conductor which is arranged in an electrically conductive manner at least in sections between the second and the first grounding section. In this case, the high-frequency conductor preferably extends over the entire distance between the second and the first grounding section and therefore already constitutes an electrically conductive connection between these grounding sections alone. It is preferable to ensure that the high-frequency conductor does not itself become a radiating element in the derivation of the interference currents becomes. As a result, an identical ground potential forms for these electrically connected grounding sections. A high-frequency conductor according to the invention is a conductor which is particularly well suited for conducting high-frequency currents, for example by its material and / or its construction. In this way, a high-frequency interference current introduced into the second grounding section can be conducted particularly well and effectively into the first grounding section. This is particularly advantageous in that the first grounding section represents a ground potential of the electric machine and the electric machine is often a source of the high-frequency interference currents. A particularly good feedback and thus a particularly effective compensation of the high-frequency interference currents can thus be provided by a high-frequency conductor between the second and the first grounding section.

In summary, each of the possibilities described above can be used to individually prevent the occurrence of high-frequency interference currents in a drive train. The effectiveness of individual measures depends on the electrical properties, in particular, for example, parasitic impedances of the rest of the drive train. By combining at least two of the possibilities described, an effectiveness of the avoidance can be further increased.

Thus, it can be particularly preferred in a device according to the invention that the device has at least one decoupling capacitor and at least one coupling capacitor and at least one high-frequency conductor. In this way, it can be provided that any of the above-mentioned possibilities for avoiding high-frequency interference currents in a drive train driven by an electric machine is used. All the advantages already described above can thus be achieved simultaneously. Thus, a decoupling of the high-frequency interference currents in the drive train can be suppressed by the decoupling capacitor. The coupling capacitor can allow a particularly effective decoupling and dissipating a high-frequency interference current from the drive train in the grounding section and thus in the ground potential, the high-frequency conductor in the connection the decoupled disturbance current particularly effectively and without large losses back to the electric machine and thus usually lead to the source of interference current can. A combination of all possible measures which can be provided by a device according to the invention thus represents a particularly good and effective reduction of high-frequency interference currents in a drive train driven by an electric machine.

Furthermore, it can be provided in a device according to the invention that the decoupling capacitor has a capacity of less than about 10nF, preferably less than about 1nF. As already stated above, the effectiveness of the decoupling capacitor is greater, the smaller its capacitance. However, arbitrarily small capacities are often only available at great expense or even not at all. It can be assumed that with a capacity of less than about 10 nF, preferably less than about 1 nF, for the frequencies occurring most frequently in vehicles the interference currents already present a sufficient prevention of transmission of high-frequency interference currents in the drive train and thus an electrical decoupling of the first shaft section and the second shaft section with respect to the high-frequency interference currents can be achieved. These values thus represent preferred values for a capacity of the decoupling capacitor, since on the one hand they provide the reduction according to the invention of the high-frequency interference currents and on the other hand they can still be produced without too great effort.

In addition, a device according to the invention can be designed such that the coupling capacitor has a capacity of greater than about 10 nF, preferably greater than about 20 nF. As already stated above, the greater the capacity of the coupling capacitor, the greater its effectiveness. However, arbitrarily large capacities are often only available at great expense or even not at all. It has been found that at a capacity greater than about 10nF, preferably greater than about 20nF, for the frequencies occurring in vehicles most frequently occurring interference currents already a mostly sufficient dissipation of high-frequency noise from the second wave section in the second ground section and Thus, an electrical coupling of the high-frequency interference currents from the second shaft section can be achieved. These values thus represent preferred values for a capacitance of the coupling capacitor, since on the one hand they provide the reduction according to the invention of the high-frequency interference currents and on the other hand they can still be produced without too much effort.

Particularly preferably, it can be provided in a device according to the invention that the capacitance of the decoupling capacitor is smaller, in particular at least approximately ten times smaller, preferably at least approximately twenty times smaller, than the capacitance of the coupling capacitor. In one embodiment of a device according to the invention, in which both a decoupling capacitor and a coupling capacitor are present, these form a, in particular complex, voltage divider, by which the interference currents are split, for example, to the second shaft section and the second ground section. The particular double use of capacitors, namely the coupling capacitor and the decoupling capacitor, can thereby make it possible for this voltage divider to have an at least substantially frequency-independent characteristic, in particular if the impedances of the measures taken dominate over the remaining impedances present in the drive train , It is advantageous, in particular, to discharge high-frequency portions of the interference currents through this voltage divider from the drive train and to feed it into the second grounding section. This can be achieved according to the invention in that the capacitance of the decoupling capacitor is smaller, in particular at least approximately ten times smaller, preferably at least approximately twenty times smaller, than the capacitance of the coupling capacitor. For example, it can already be twice as big Capacitance of the coupling capacitor compared to the decoupling capacitor, a voltage potential of the noise current in the drive train after decoupling by the coupling capacitor can be reduced by about a factor of three. With a capacity of the coupling capacitor that is twenty times greater in comparison to the decoupling capacitor, this factor already increases to a value of approximately 21. Overall, it is thus possible to provide a particularly good and effective discharge and thus reduction of the high-frequency interference currents in the drive train.

Furthermore, a device according to the invention can be designed such that the decoupling capacitor is formed by an electrically non-conductive coating of at least one of the ends of the first shaft section or the second shaft section involved in the mechanical operative connection. As already described above, the shaft sections are usually formed of a metal material and in particular electrically conductive. Due to the mechanical operative connection, a transmission of torques between the shaft sections can be made possible. For this, the ends involved in the mechanical active connection shaft sections are usually arranged in a form-fitting manner to each other, for example in a spline. Through this positive fit, the shaft sections touch, so that also forms an electrical conductivity between the shaft sections. By means of an electrically non-conductive coating of at least one of the ends involved in the mechanical operative connection, this direct conduction of electrical charge from the first to the second shaft section or vice versa can be prevented. For this purpose, it can be particularly preferably provided that the electrically non-conductive coating covers an entire section of the end of the corresponding shaft section. In addition to the direct electrical insulation of the two shaft sections against each other, a capacitor is formed by this electrically non-conductive coating together with the two ends of the shaft portions involved in the mechanical operative connection, which is connected in series with the two shaft sections and thus represents a decoupling capacitor in the context of the invention. Additional components for providing the decoupling capacitor can be avoided. A device according to the invention can thus be constructed particularly simply and in particular compactly in this way. Furthermore, corrosion of the ends of the first shaft section or of the second shaft section, which are often formed from a metal material, as explained above, can also be prevented or at least significantly restricted by the electrically non-conductive coating.

According to a further development of a device according to the invention, it can preferably be provided that the at least one end of the first shaft section or of the second shaft section involved in the mechanical operative connection is phosphated to form the electrically non-conductive coating. In such phosphating, a conversion layer of firmly adhering metal phosphates is formed on the treated surface of the end involved in the mechanical active compound. This conversion layer preferably forms directly in the material of the shaft section, so that application of an additional material to form the coating can be avoided. The production of a drive train, which is equipped with a device according to the invention, can be simplified thereby. Also, such phosphatiere surface, in addition to their property of electrical insulation, also particularly wear-resistant. It can thereby be provided that the mechanical operative connection, which is formed by the two ends of the shaft sections, in particular in comparison to a coating with a plastic material, is particularly easy to maintain and durable.

In addition, a device according to the invention can be designed such that the coupling capacitor is formed by a variable capacitor with at least one pair of disks, wherein a first disk of the disk pair electrically and mechanically electrically and mechanically connected to the second shaft portion and a second disc of the disk pair electrically and mechanically connected to the second ground portion is. As a result of this arrangement of the two disks of the disk pair, which in each case are themselves also electrically conductive, a capacitive behavior is provided whereby the coupling capacitor of a device according to the invention can be made particularly simple and compact. The capacity of such a rotary capacitor is determined by the area on which the discs of the disc pair overlap, and by their distance from each other. Moreover, due to the presence of several pairs of disks, it is particularly easy to provide an increase in the capacitance of the rotary condenser formed. In particular, in comparison to the known from the prior art solutions comprising sliding contacts and / or conductive storage devices, by a coupling capacitor according to the invention, which is designed as a variable capacitor, a contactless and thus wear-free dissipation or discharge high-frequency interference currents from the drive train in the grounding section to be provided. Also in this way, an increase in service life and a reduction in maintenance of a powertrain, which is equipped with a device according to the invention, can be made possible.

Furthermore, it can be provided in a device according to the invention that the electrical high-frequency conductor has an HF strand, in particular as an RF strand is formed. By a high-frequency conductor according to the invention, the first and the second grounding section are electrically connected to each other. A continuous, common ground potential can be provided thereby. In this case, the earthing sections can preferably be designed as housing or housing elements of the individual elements of the drive train, which is equipped with a device according to the invention. A high-frequency conductor according to the invention is in particular a conductor which is particularly suitable for conducting high-frequency currents. HF strands consist of a multiplicity of individual strands, which are each electrically insulated from one another and connected in parallel with each other electrically. Furthermore, these individual strands to form the RF strand are usually intertwined with each other such that on average each individual strand occupies as many places as possible in the overall cross section of the HF strand. Adverse effects for conducting high-frequency currents, such as the so-called skin effect, which can occur in a single, massive line can be avoided or at least significantly mitigated. By means of an HF strand, a high-frequency conductor according to the invention can thus be provided in a particularly simple manner.

According to a second aspect of the invention, the object is achieved by a vehicle having an electric machine and a drive train driven at least by the electric machine, comprising a device for reducing high-frequency interference currents in the drive train of the vehicle. An inventive vehicle is characterized in that the device is designed according to the first aspect of the invention. Accordingly, a vehicle according to the invention brings the same advantages as have been explained in detail with reference to a device according to the invention according to the first aspect of the invention.

Further advantages, features and details of the invention will become apparent from the following description in which, with reference to the drawings, embodiments of the invention are described in detail. The features mentioned in the claims and in the description may each be essential to the invention individually or in any desired combination. Elements with the same function and mode of operation are provided with the same reference numerals in the individual figures. They show schematically:

1 a drive train according to the prior art,

2 a simplified equivalent circuit diagram of a drive train,

3 a drive train with a device according to the invention,

4 Shaft sections of a drive train,

5 a first frequency response when using a device according to the invention,

6 a second frequency response when using a device according to the invention, and

7 an inventive vehicle.

1 shows one of at least one electric machine 20 powered drivetrain 10 of a vehicle 2 , here a hybrid vehicle, as it is known in the prior art. The powertrain 10 can as shown many different elements such as couplings 53 , Transmission 54 and / or differentials 55 and serves to supply mechanical energy to the drive wheels 57 of the vehicle 2 which, for example, by a suspension 58 in the vehicle 2 are arranged. storage devices 56 provide a particular low-friction mounting of the drive train 10 in the vehicle 2 for sure. The illustrated powertrain 10 is in a vehicle 2 used, which is designed as a hybrid vehicle and in addition to the electric machine 20 also an internal combustion engine 52 having. The electric machine 20 can be operated as an electric motor or alternatively as a generator. The one for operation as an electric motor 20 required electrical energy is through a battery 50 provided, which is preferably designed as a DC high-voltage battery. Via DC conductor 60 The electrical energy is used as direct current to a power electronics 51 conducted, converted into alternating current in this and subsequently via phase conductors 61 the electric machine 20 fed. In this conversion of the direct current into an alternating current and in particular also during operation of the electric machine 20 it can lead to a generation of high-frequency interference currents 100 come in 1 are shown as curved arrows. About the powertrain 10 and its elements can be as illustrated these interference currents 100 over the entire vehicle 2 spread and disturbances, for example in electrical systems of the vehicle 2 , cause. Also a radiation 103 the interference currents 100 In this case, the environment can occur, as a result of which, for example, interference in a radio reception, for example in a vehicle 2 built-in radio, can come.

In 2 is a simplified equivalent circuit diagram of a powertrain 10 shown. It is shown schematically that the drive train 10 between the electric machine 20 , by phase conductor 61 is supplied with electrical energy, on the one hand, and the suspension 58 on the other hand is arranged and in addition to a mechanical connection also provides an electrical connection of these components. This is in 2 represented by the electrical elements or impedances X_i. These impedances X_i are in particular torque-transmitting elements can, for example, as shaft sections 11 . 12 , as couplings 53 , as gear pairs of gears 54 or differentials 55 be designed as splines or as similar elements. These impedances X_i thus influence the propagation of interference currents 100 (not shown) along the drivetrain 10 , Furthermore, impedances Y_i are depicted, the electrical connections between rotating components of the drive train 10 and fixed elements, in particular grounding sections 15 . 21 or a housing, represent. These compounds may include, for example, storage devices 56 (not shown), sealing elements, cooling devices or the like. The impedances Y_i thus influence the output or discharge of interference currents 100 from the drive train 10 on earthing sections 15 . 21 , In addition, electrical connection elements or connection impedances Z_i are also shown, through which the housings or grounding sections 15 . 21 various elements of the powertrain 10 electrically connected to each other, in particular, a grounding section 21 the electric machine 20 with tied up. These impedances Z_i can be used, for example, as screwed connections in and with the vehicle 2 , be designed as a compensating conductor, as shields or the like, thus ensuring a conduction of interference currents 100 back to their source, which is mostly the power electronics 51 is.

An inventive device 1 In this case, it is possible to bring about improvements at all three impedances X_i, Y_i and Z_i individually, preferably in combination at all three points. For example, here, the impedance X_2 is a noise blocking element 30 , in particular as a decoupling capacitor 31 , educated. As a result, in particular in the case of a decoupling capacitor 31 with a capacity of less than 10nF, already a propagation of high frequency noise in particular 100 in the drive train 10 be avoided or at least significantly suppressed. Further, the impedance Y_3 is a noise canceling element 40 , in particular as a coupling capacitor 41 , educated. As a result, in particular in the case of a coupling capacitor 41 with a capacity of greater than 10nF, a particularly good and effective discharge or discharge, in particular of high-frequency interference currents 100 from the drive train 10 in a grounding section 15 to be provided. As a third measure, a device according to the invention 1 as an additional or alternative fault-guiding element 40 a high-frequency conductor 46 have, which forms the impedance Z_2 in the illustrated embodiment. Through this high-frequency conductor 46 For example, which is preferably designed as an HF strand, a particularly good return of the high-frequency interference currents 100 to power electronics 51 (not shown) of an electric machine 20 , which is usually a source of interference currents 100 be provided. Overall, therefore, by a device according to the invention 1 by each of these measures, in particular by a combination of all measures, a particularly good and effective reduction of interference currents 100 in a drive train 10 to be provided.

3 shows possible mechanical embodiments of a device according to the invention 1 working in a powertrain 10 is used. The powertrain 10 is by storage devices 56 rotatably mounted. High-frequency interference currents 100 are in the powertrain 10 present and effect without further treatment by a device according to the invention 1 in particular a potential difference 101 between the drive train 10 and, for example, a second grounding section 15 , In the illustrated embodiment, the device according to the invention 1 in particular a disturbing blocking element 30 and two troubling elements 40 on. The interference-blocking element 30 is doing as a decoupling capacitor 31 formed, which at the ends involved in the mechanical operative connection 12 . 14 the shaft sections 11 . 13 of the powertrain 10 is arranged electrically in series. This can, for example, in a formed by a spline mechanical operative connection, by an electrically non-conductive coating 32 one of the two ends 12 . 14 to be provided. The first troubling element 40 , an electrical parallel between the second shaft portion 13 and the second grounding section 15 arranged coupling capacitor 41 , is in the illustrated embodiment as a variable capacitor 42 formed, which retains a constant capacity, in particular during a rotational movement. The rotary capacitor 42 has in the illustrated embodiment, three pairs of discs 43 on each of which a first disc 44 with the second shaft section 13 and a second disc 45 with the second earthing section 15 mechanically and electrically conductively connected. Through such use of multiple pairs of discs 43 can be a capacity of the variable capacitor 42 and thus the coupling capacitor 41 especially easy to enlarge. Particularly preferably, the capacitances may be selected such that the capacitance of the coupling capacitor 42 larger, in particular significantly larger, for example twenty times greater than the capacity of the decoupling capacitor 31 , As a result, the decoupling capacitor form 31 and the coupling capacitor 41 a complex voltage divider that is used to remove the high-frequency interference currents 100 from the drive train 10 is particularly suitable. In the above example, where the capacity of the coupling capacitor 42 twenty times larger than the capacity of the decoupling capacitor 31 , can be achieved that a potential difference 102 between the drive train 10 and the second grounding section 15 after the coupling capacitor 41 only less than five percent of the potential difference 101 in front of the coupling capacitor 41 is. Another troubling element 40 , this in 3 is shown is a high frequency conductor 46 which is electrically conductive between the second grounding section 15 on the drive train 10 and the first grounding section 21 a power electronics 51 the electric machine 20 is arranged. A high-frequency conductor 46 is in the context of the invention, in particular a conductor which is particularly well suited for conducting currents at high frequencies, for example an HF-Litze. Through the use of a high-frequency conductor 46 can be a return of the second grounding section 15 discharged high-frequency interference currents 100 be provided with particularly high efficiency. A common ground potential 70 can train in this way very easy. Overall, therefore, by a device according to the invention 1 , especially when using all possible anti-blocking elements 30 or disturbance-leading elements 40 , a particularly good reduction of high-frequency interference currents 100 in one at least by an electric machine 20 powered drivetrain 10 of a vehicle 2 to be provided.

In 4 is a possible mechanical operative connection between two shaft sections 11 . 13 a powertrain 10 shown, being between the shaft sections 11 . 13 a decoupling capacitor 31 a device according to the invention 1 as a disturbing blocking element 30 is arranged. The upper figure shows a side view, the lower figure a sectional view along the line AA. The ends 12 . 14 the two shaft sections 11 . 13 are mechanically operatively connected by a spline for transmitting a torque. In particular, the end 12 of the first wave section 11 an electrically non-conductive coating 32 on. The coating 32 may be preferred, for example, phosphating the end 12 of the first wave section 11 include. A phosphating has the advantage that the electrically non-conductive and therefore insulating coating 32 in the material of the first shaft section 11 itself is formed, whereby additional electrically insulating elements can be avoided. Together with the end 14 of the second shaft section 13 Thus, a decoupling capacitor is formed in a particularly simple and effective manner 31 which, as described above, acts as a noise-blocking element 30 acts.

The 5 and 6 each show frequency characteristics that in a drive train 10 with and without a device according to the invention 1 were measured. The left picture shows an amplitude response 80 . 81 , in the right figure a phase response 90 . 91 shown.

5 was in a powertrain 10 determined in which a device according to the invention 1 (not shown) with a decoupling capacitor 31 as a disturbing blocking element 30 (not shown) was installed. When comparing the amplitude response 80 . 81 a fault current 100 without 80 and with 81 Use of the device according to the invention 1 It is clearly visible that a reduction in the amplitude attenuation for low frequencies can be achieved without simultaneously increasing the amplitude at high frequencies. Also a phase shift, visible when comparing the phase response 90 . 91 without 90 and with 91 built-in device according to the invention 1 , is thereby reduced. Overall, thus, in this way by using a decoupling capacitor 30 a device according to the invention 1 a capacitive coupling in the drive train 10 diminished and a resonance point of a high-frequency interference current 100 be mitigated.

6 was in a powertrain 10 determined in which a device according to the invention 1 (not shown) with a high frequency conductor 46 as a disturbing element 40 (not shown) was installed. When comparing the amplitude response 80 . 81 a fault current 100 without 80 and with 81 Use of the device according to the invention 1 is clearly visible that an increase in the amplitude attenuation can be achieved in particular for high frequencies. Also a phase shift, visible when comparing the phase response 90 . 91 without 90 and with 91 built-in device according to the invention 1 , is at least delayed by it. Overall, thus, in this way by using a high-frequency conductor 46 as a disturbance-leading element 40 a device according to the invention 1 a return of the high-frequency interference currents 100 to their source, mostly the electric machine 20 (not shown) and thus also for high-frequency interference currents 100 a low impedance feedback path can be ensured.

In 7 is a vehicle according to the invention 2 with an electric machine 20 pictured that a powertrain 10 having, with a device according to the invention 1 Is provided. In this case, by a device according to the invention 1 be provided that high-frequency interference currents 100 (not shown) in the drive train 10 can be easily and particularly effectively reduced. Adverse effects due to such high-frequency interference currents 100 , For example, disturbances of electrical components of the vehicle 2 and / or a radiation 103 (not shown) of the high-frequency interference currents 100 in the environment of the vehicle 2 can be avoided.

LIST OF REFERENCE NUMBERS

1

 contraption

2

 vehicle

10

 powertrain

11

 first shaft section

12

 The End

13

 second shaft section

14

 The End

15

 second earthing section

20

 electric machine

21

 first earthing section

30

 interference-blocking element

31

 decoupling

32

 coating

40

 disturbance-leading element

41

 coupling capacitor

42

 variable capacitor

43

 disk pair

44

 first disc

45

 second disc

46

 High frequency circuit

50

 battery

51

 power electronics

52

 internal combustion engine

53

 clutch

54

 transmission

55

 differential

56

 bearing device

57

 drive wheel

58

 Arm

60

 DC conductor

61

 phase conductor

70

 ground

80

 Amplitude response (without device according to the invention)

81

 Amplitude response (with device according to the invention)

90

 Phase response (without device according to the invention)

91

 Phase response (with device according to the invention)

100

 Interference current

101

 Potential difference (before device according to the invention)

102

 Potential difference (according to the device according to the invention)

103

 radiation

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 102015100847 A1 [0003]

Claims (10)

Contraption ( 1 ) for reducing high-frequency interfering currents ( 100 ) in at least one electric machine ( 20 ) Driven drive train ( 10 ) of a vehicle ( 2 ), the device ( 1 ) comprising at least one interference-blocking element ( 30 ) and / or at least one spoofing element ( 40 ), the drive train ( 10 ) comprising at least a first shaft portion ( 11 ) and a second shaft section ( 13 ), one end ( 12 ) of the first shaft section ( 11 ) with one end ( 14 ) of the second shaft section ( 13 ) is mechanically operatively connected to transmit a torque, the electric machine ( 20 ) further comprising at least a first grounding section ( 21 ), which has a ground potential ( 70 ) of the electric machine ( 20 ), and the powertrain ( 10 ) further comprising a second grounding section ( 15 ), which has a ground potential ( 70 ) of the drive train ( 10 ), characterized in that the interference-blocking element ( 30 ) one with the first shaft portion ( 11 ) and the second shaft section ( 13 ) electrically connected in series decoupling capacitor ( 31 ) for the capacitive decoupling of the first shaft section ( 11 ) and the second wave section ( 13 ), and / or that the disturbance-removing element ( 40 ) electrically between the second shaft portion ( 13 ) and the second earthing section ( 15 ) arranged coupling capacitor ( 41 ) for a capacitive coupling of the second wave section ( 13 ) to the second grounding section ( 15 ), and / or that the disturbance-removing element ( 40 ) an electrical high-frequency conductor ( 46 ), the at least partially electrically conductive between the second and the first grounding section ( 21 ) is arranged. Contraption ( 1 ) according to claim 1, characterized in that the device ( 1 ) at least one decoupling capacitor ( 31 ) and at least one coupling capacitor ( 41 ) and at least one high-frequency conductor ( 46 ) having. Contraption ( 1 ) according to claim 1 or 2, characterized in that the decoupling capacitor ( 31 ) has a capacity of less than about 10nF, preferably less than about 1nF. Contraption ( 1 ) according to one of the preceding claims, characterized in that the coupling capacitor ( 41 ) has a capacity of greater than about 10nF, preferably greater than about 20nF. Contraption ( 1 ) according to one of the preceding claims, characterized in that the capacity of the decoupling capacitor ( 31 ) smaller, in particular at least approximately ten times smaller, preferably at least approximately twenty times smaller, than the capacitance of the coupling capacitor ( 41 ). Contraption ( 1 ) according to one of the preceding claims, characterized in that the decoupling capacitor ( 31 ) by an electrically non-conductive coating ( 32 ) at least one of the ends involved in the mechanical active connection ( 12 . 14 ) of the first shaft section ( 11 ) or the second wave section ( 13 ) is formed. Contraption ( 1 ) according to claim 6, characterized in that the at least one participating in the mechanical operative connection end ( 12 . 14 ) of the first shaft section ( 11 ) or the second wave section ( 13 ) to form the electrically non-conductive coating ( 32 ) is phosphated. Contraption ( 1 ) according to one of the preceding claims, characterized in that the coupling capacitor ( 41 ) by a rotary capacitor ( 42 ) with at least one pair of discs ( 43 ) is formed, wherein a first disc ( 44 ) of the disk pair ( 43 ) electrically and mechanically with the second shaft portion ( 13 ) and a second disc ( 45 ) of the disk pair ( 43 ) electrically and mechanically with the second grounding section ( 15 ) connected is. Contraption ( 1 ) according to one of the preceding claims, characterized in that the electrical high-frequency conductor ( 46 ) has an RF strand, in particular as an RF strand is formed. Vehicle ( 2 ) with an electric machine ( 20 ) and one at least by the electric machine ( 20 ) Driven drive train ( 10 ), comprising a device ( 1 ) for reducing high-frequency interference currents in the drive train ( 10 ) of the vehicle ( 2 ), characterized in that the device ( 1 ) is designed according to one of the preceding claims.

Images