CN107800246A - For reducing the device and vehicle of hf interference current - Google Patents

Abstract

The invention relates to a device for reducing high-frequency interference currents in a drive train of a vehicle that is driven at least by an electric machine, the device having at least one blocking element and/or at least one draining element, the drive train comprising at least A first shaft section and a second shaft section, wherein the end of the first shaft section is mechanically operatively connected to the end of the second shaft section for torque transmission, and the motor further comprises at least one first interface The first grounded section forms the ground potential of the electric machine, and the drive train further comprises a second grounded section which forms the ground potential of the drive train. Furthermore, the invention relates to a vehicle with an electric machine and a drive train driven at least by the electric machine, which has a device for reducing high-frequency interference currents in the drive train of the vehicle.

Description

Device and vehicle for reducing high-frequency interference currents

technical field

The invention relates to a device for reducing high-frequency interference currents in a drive train of a vehicle which is driven at least by an electric motor, the device having at least one blocking element and/or at least one draining element, the drive train comprising at least one A first shaft section and a second shaft section, wherein the end of the first shaft section is mechanically operatively connected to the end of the second shaft section for torque transmission, the electric machine furthermore comprises at least one first ground plane The first grounded section forms the ground potential of the electric machine, and the drive train further comprises a second grounded section which forms the ground potential of the drive train. Furthermore, the invention relates to a vehicle with an electric machine and a drive train driven at least by the electric machine, which has a device for reducing high-frequency interference currents in the drive train of the vehicle.

Background technique

In modern vehicle technology it is known to use electric machines for driving the vehicle. Such a vehicle can here be, for example, a purely electric vehicle, but it can also be designed as a hybrid vehicle which has both an internal combustion engine and an electric motor for drive. To store the necessary electrical energy, DC high-voltage batteries are often used here. In order to convert the direct current into the alternating current which is mostly required by the electric motor, a pulse converter (taktender Umrichter, sometimes also referred to as a clock converter) is often used, which can be installed in the power electronics of the vehicle. Interference currents, which often have a relatively high frequency, can be generated especially in the context of this conversion, among other reasons. Without corresponding countermeasures, these interference currents can propagate in the vehicle, in particular in the drive train of the vehicle, and cause disturbances in the electrical system of the vehicle, up to radiation of the interference currents into the surrounding environment, which often for example even May interfere with radio reception, such as a vehicle's radio.

It is known from the prior art to use filter devices for removing especially high-frequency interference currents directly at the source of the interference currents, ie, for example, in converters and/or in electric machines. However, this is often costly since, due to the high performance of the filters installed in the vehicle, most of them are bulky and some even require active cooling. In addition, barrier measures (such as electrically insulating clutches) or barrier measures known, for example, from DE 10 2015 100 847 A1 (such as sliding contacts (Schleifkontakte) or conducting bearings) can be used to damp the disturbance currents in the Propagation in the drive train or conduct the disturbance current out of the drive train. In this case, however, such insulating clutches are again bulky and, moreover, often likewise lead to a reduction in the torque that can be transmitted in the drive train. It has also been found that the propagation efficiency of interference currents through conductive rolling bearings or sliding contacts is reduced especially for high-frequency interference currents. Likewise, such conductive rolling bearings or sliding contacts are subject to high wear.

Contents of the invention

It is therefore the object of the present invention to at least partially eliminate the disadvantages described above and to improve a device and a vehicle for reducing high-frequency interference currents. In particular, the object of the present invention is to provide a device for reducing high-frequency interference currents and a vehicle which make the propagation of high-frequency interference currents in the drive train as effective as possible in a particularly simple and cost-effective manner. and/or make it possible to extract high-frequency interference currents from the drive train as efficiently as possible.

The above object is solved by a device for reducing radio-frequency interference currents with the features of independent claim 1 . Furthermore, the object is achieved by a vehicle with the features of the accompanying claim 10 . Further advantages of the invention emerge from the subclaims, the description and the figures. Here, features and details described in connection with the device according to the invention obviously also apply in connection with the vehicle according to the invention, and correspondingly vice versa, so that cross-references are always made to the disclosure regarding the individual invention aspects.

According to a first aspect of the invention, this object is solved by a device for reducing high-frequency interference currents in a drive train of a vehicle driven at least by an electric machine, which device has at least one blocking element and/or at least A disturbance element, the drive train comprising at least a first shaft section and a second shaft section, wherein the end of the first shaft section and the end of the second shaft section are mechanically active for torque transmission In connection, the electric machine also includes at least one first ground section, which forms the ground potential of the electric machine, and the drive train furthermore includes a second ground section, which forms the ground potential of the drive train. The device according to the invention is characterized in that the blocking element comprises a decoupling device for capacitive decoupling of the first shaft section and the second shaft section, which is electrically connected in series with the first shaft section and the second shaft section. capacitor, and/or the drain element comprises a coupling capacitor for capacitive coupling of the second shaft section relative to the second ground section, arranged conductively between the second shaft section and the second ground section, and/or The noise drain element comprises an electrical high-frequency conductor which is arranged electrically conductively at least in sections between the second ground segment and the first ground segment.

The device according to the invention is intended for use in or at a drive train of a vehicle. Furthermore, as far as technically possible and/or expedient, the device according to the invention can also be used in other locations where a reduction of high-frequency interference currents is required. In this case, the vehicle has an electric machine designed to drive a drive train. For this purpose, the electric machine is operated as an electric motor. Furthermore, the electric machine can also be operated mostly as a generator, wherein in this case the device according to the invention can likewise be used to reduce high-frequency interference currents. In this case, the drive train is designed in at least two parts and has a first shaft section and a second shaft section. In this case, the shaft section is mostly made of metallic material and is therefore electrically conductive. In order to transmit the torque, the two shaft sections are mechanically operatively connected to each other, wherein in particular one end of each of the first and second shaft section is mechanically operatively connected to each other for this purpose, for example by means of a plug toothing. . Compared to clutches, a particularly efficient and loss-free or at least low-loss transmission of torque between the shaft sections can be provided in this way. Furthermore, the electric machine comprises a first grounding section and the drive train comprises a second grounding section, which respectively form the ground potential of the respective component. Through such a grounding path or ground potential, the user's safety when using the electric machine or the drive train can be increased and ensured here, since the risk of electric shock can thus be avoided or at least significantly reduced. Preferably, the ground section can here comprise or even be formed by the housing of the corresponding structural element. Furthermore, special potential-equalizing conductors between the grounding sections are often even legally required.

Especially in the case of operating electric machines (but also caused by other sources) high-frequency interference currents can occur which can propagate in particular in the drive train. High frequency in the sense of the invention here means in particular that the frequency of the disturbance current is here several kilohertz, often even megahertz or gigahertz. This can lead, for example, to disturbances in the electric machine itself or in other electrical or electronic devices of the vehicle. In particular, interference currents can also be emitted into the surroundings, whereby for example radio reception can be disrupted. In order to reduce these interference currents, the device according to the invention has at least one blocking element and/or at least one draining element.

It is essential for the invention that the at least one barrier element and/or the at least one drain element can be embodied in different ways or as different measures. According to a first possibility, it can therefore be provided according to the invention that the blocking element comprises a capacitor for the first shaft section and the second shaft section which is electrically connected in series. decoupling capacitors. The electrical series connection can be provided in a particularly simple manner in that the two shaft sections are not directly electrically conductively connected to one another. Interference currents in the form of direct currents can thus be reliably avoided. Through the embodiment of the decoupling capacitor with low capacitance, the transmission of high-frequency interference currents via the decoupling capacitor can also be suppressed, wherein the strength of this suppression increases with a reduced capacitance of the decoupling capacitor. In this case, the capacitance corresponding to the function of the decoupling capacitor as a high-pass filter can preferably also be adjusted to the expected frequency of the disturbance current. In this case, the overall effect of the measures used depends in particular on other parasitic impedances located in the drive train. Preferably, the capacitance can be adapted, for example, to a limit frequency above which no noteworthy high-frequency interference currents no longer occur or are at least no longer present or expected. In this case, the coupling capacitor can be formed, for example, by an electrically insulating layer between the ends of the shaft section in the region of the mechanically active connection. In this way, weight and/or required installation space can be saved, in particular compared to the use of electrically insulating clutches, wherein the transmission of torque between the shaft sections is likewise not hindered, or at least only not significantly hindered. . The reduced installation space requirement also provides that the coupling capacitor can be used without expensive design changes close to the source of the interference current, for example close to the electric machine. A particularly early and thus effective reduction of the high-frequency current can thus be provided.

An alternative or additional second possibility is essential for the invention to provide that the draining element comprises an electrical connection between the second shaft section and the second ground section for the second shaft area. A coupling capacitor for capacitive coupling of the segment with respect to the second ground segment. In other words, the coupling capacitor is electrically connected in parallel to the second shaft section and to the second ground section. In this way it is particularly easy to provide 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, however, high-frequency interference currents can be passed from the second shaft section to the second The detachment of the ground zone becomes possible. As already described above, this is achieved by the electrical properties of the capacitor, no direct current is transmitted, but the transmission of alternating current is made possible, the transmission being more effective the higher the frequency of the disturbance current. High-frequency interference currents are thus conducted particularly well from the second shaft section into the second ground section via such a coupling capacitor. In the case of a coupling capacitor, it is advantageous that the coupling capacitor has a higher capacitance, since the coupling-out efficiency (Auskoppeleffektivität) likewise increases with an increased capacitance of the coupling capacitor. In particular, the coupling capacitor according to the invention makes it possible to provide a decoupling of interference currents without mechanical contact between the second shaft section and the second ground section. In particular, due to the proposed contactless operating principle of the capacitive coupling, wear-free operation without maintenance costs can be provided, for example, compared to sliding contacts according to the prior art. Likewise, the proposed assembly is resistant to contamination by liquids or foreign objects in its basic operating principle. Particularly good conduction in the case of a longer service life of the device according to the invention and at the same time a lower ease of maintenance can thus be provided by this possibility. If the drain element similarly comprises a coupling capacitor electrically arranged between the first shaft section and the first ground section for the capacitive coupling of the first shaft section relative to the first ground section, it does not leave here According to the teaching of the present invention. Therefore, all the advantages described above can also be provided in the case of this embodiment.

According to a likewise alternative or additional third possibility, it is also essential for the invention that the distracting element comprises an electrical high-frequency conductor which is arranged in an electrically conductive manner at least in sections Between the second grounding zone and the first grounding zone. In this case, the radio-frequency conductor preferably extends over the entire section between the second grounding section and the first grounding section and is therefore already an electrically conductive connection between these grounding sections. In this case, it is preferably ensured that the radio-frequency conductor does not itself become a radiating element in the case of conducting interference currents. The same ground potential is thus formed for the electrically conductively connected ground sections. According to the invention, a high-frequency conductor is a particularly well-suited conductor for conducting high-frequency currents, for example because of its material and/or its configuration. In this way, high-frequency interference currents introduced into the second ground plane can be conducted particularly well and efficiently into the first ground plane. This is especially advantageous since the first ground plane is the ground potential of the electric motor and the electric motor is often a source of high-frequency interference currents. A particularly good return conduction and thus a particularly effective compensation of radio-frequency interference currents can thus be provided by the radio-frequency conductor between the second and the first ground section.

All in all, the avoidance of high-frequency interference currents in the drive train can already be provided individually by each of the possibilities described above. The efficiency of the individual measures here depends on the electrical properties of the remaining drive train, such as in particular parasitic impedances. The effectiveness of the avoidance can be further increased by combining at least two of the described possibilities.

It can therefore be provided particularly preferably in the case of 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 each of the possibilities listed above is used to avoid high-frequency interference currents in the drive train driven by the electric machine. All the advantages already described above can thus be obtained simultaneously. The transmission of radio-frequency interference currents in the drive train can thus be suppressed particularly well by the decoupling capacitor. The coupling capacitor enables a particularly effective decoupling and decoupling of high-frequency interference currents from the drive train into the ground plane and thus into ground potential, wherein the high-frequency conductors can then dissipate the coupled-out interference currents It is conducted particularly efficiently and without major losses back to the electric machine and thus mostly to the source of the disturbance current. The combination of all possible measures that can be provided by the device according to the invention thus results in a particularly good and effective reduction of high-frequency interference currents in a drive train driven by an electric machine.

Furthermore, in the case of a device according to the invention it can be provided that the decoupling capacitor has a capacitance of less than approximately 10 nF, preferably less than approximately 1 nF. As already implemented above, the greater the efficiency of the decoupling capacitor, the lower its capacitance. However, arbitrarily small capacitances are often only available at great expense or are not even available at all. Proceeding from the fact that with a capacitance of less than approximately 10 nF, preferably less than approximately 1 nF, high-frequency disturbance currents in the drive train are already achievable for the frequencies of the occurring disturbance currents which occur most frequently in the vehicle Most of the transmissions are sufficiently prevented and thus an electrical decoupling of the first shaft section and the second shaft section with respect to high-frequency interference currents is achieved. These values are therefore preferred values for the capacitance of the decoupling capacitor, since on the one hand they provide an inventive reduction of high-frequency interference currents and on the other hand they can also be produced without excessive costs.

Furthermore, a device according to the invention can be designed such that the coupling capacitor has a capacitance of greater than approximately 10 nF, preferably greater than approximately 20 nF. As already implemented above, the greater the efficiency of the coupling capacitor, the greater its capacitance. However, arbitrarily large capacitances are often only available at great expense or are not even available at all. It has been shown here that, in the case of capacitances greater than approximately 10 nF, preferably greater than approximately 20 nF, high-frequency disturbance currents are already achievable for frequencies of occurring disturbance currents which occur most frequently in vehicles The majority of the shaft section is sufficiently decoupled from the second ground section and thus an electrically decoupled discharge of radio-frequency interference currents from the second shaft section can be achieved. These values are therefore preferred values for the capacitance of the coupling capacitor, since on the one hand it provides an inventive reduction of high-frequency interference currents and on the other hand it can also be produced without excessive costs.

Particularly preferably, in the case of a device according to the invention it can be provided that the capacitance of the decoupling capacitor is smaller than the capacitance of the coupling capacitor, in particular at most approximately one tenth, preferably at most About one-twentieth. In a further embodiment of the device according to the invention, there are not only decoupling capacitors but also coupling capacitors, which form a particularly complex voltage divider via which the interference current is divided, for example into a second Shaft section and second ground section. Through the in particular dual use of capacitors (ie coupling capacitors and decoupling capacitors), it is possible here to make it possible, in particular if the impedance of the measure taken is dominant relative to the remaining impedances present in the drive train, then the The voltage divider has at least essentially frequency-independent characteristics. It is advantageous here that in particular the high-frequency part of the disturbance current is diverted from the drive train via the voltage divider and fed into the second ground section. According to the invention, this can be achieved in that the capacitance of the decoupling capacitor is lower than that of the coupling capacitor, in particular by at most approximately one-tenth, preferably at most approximately one-twentieth. Thus, for example, if the capacitance of the coupling capacitor is twice as large as that of the decoupling capacitor, the voltage potential of the disturbance current in the drive train can already be reduced by, for example, a factor of three after coupling out via the coupling capacitor. In the case of a coupling capacitor whose capacitance is twenty times greater than that of the decoupling capacitor, this factor can already rise to a value of approximately 21. Overall, a particularly good and efficient conduction and thus a reduction of high-frequency interference currents in the drive train can thus be provided.

Furthermore, a device according to the invention can be designed in that the decoupling capacitor is formed by a non-conductive coating of at least one of the ends of the first shaft section or the second shaft section involved in the mechanically active connection. As already described above, the shaft section is mostly made of metallic material and is especially electrically conductive. The transmission of torque between the shaft sections is made possible by the mechanically active connection. For this purpose, the ends of the shaft sections involved in the mechanically operative connection are mostly arranged in a form-fitting manner with one another, for example in a plug toothing. Through this positive fit, the shaft sections are in contact, so that electrical conductivity between the shaft sections is likewise created. This direct conduction of charges from the first to the second shaft section or vice versa can be prevented by the non-conductive coating of at least one of the ends participating in the mechanically operative connection. For this purpose it can be provided particularly preferably that the non-conductive coating covers the entire section of the end of the respective shaft section. In addition to the direct electrical insulation of the two shaft sections relative to one another, a capacitor is formed by this non-conductive coating together with the two ends of the shaft sections participating in the mechanically active connection, which is connected in series with the two shaft sections and thus is a decoupling capacitor in the sense of the invention. Additional structural elements for providing decoupling capacitors can thus be avoided. A device according to the invention can thus be constructed particularly simply and particularly compactly. Furthermore, the non-conductive coating also prevents or at least significantly limits corrosion of the ends of the first shaft section or of the second shaft section (which, as described above, are often formed from a metallic material) participate in the mechanically active connection. .

Preferably, according to a further development of the device according to the invention it can be provided that at least one end of the first shaft section or of the second shaft section which participates in the mechanically active connection is phosphated in order to form a non-conductive coating. In the case of such phosphating, a conversion layer of firmly adhering metal phosphate forms on the treated surface of the ends involved in the mechanically operative connection. In this case, the conversion layer is preferably formed directly in the material of the shaft section, so that the application of additional material for forming the coating can be avoided. The production of a drive train equipped with the device according to the invention can thus be simplified. Likewise, such a phosphated surface is also particularly wear-resistant in addition to its electrically insulating properties. As a result, it can be provided that the mechanically active connection formed by the two ends of the shaft section is particularly easy to maintain and durable, in particular compared to a covering with plastic material.

Furthermore, a device according to the invention can be constructed in such a way that the coupling capacitor is formed by a variable capacitor with at least one disk pair, wherein the first disk of the disk pair is electrically and mechanically connected to the The second shaft section is connected and the second disk of the pair of disks is electrically and mechanically connected to the second ground section. This arrangement of the two disks of the pair of disks, which is accordingly also electrically conductive in itself, provides a capacitive characteristic, whereby the coupling capacitor of the device according to the invention can be constructed particularly simply and compactly. In this case, the capacitance of such a variable capacitor is determined by the surface on which the disks of the disk pair overlap and by their distance from one another. An increase in the capacitance of the variable capacitor formed can also be provided particularly simply by the presence of a plurality of disc pairs. In particular, compared to solutions known from the prior art with sliding contacts and/or conductive bearings, the coupling capacitor according to the invention configured as a variable capacitor can provide high-frequency interference currents from the drive train to the ground plane Contactless and thus wear-free decoupling or decoupling of segments. Also in this way it is possible to increase the service life and reduce the ease of maintenance of a drive train equipped with the device according to the invention.

Furthermore, in the case of a device according to the invention it can be provided that the electrical high-frequency conductor has a high-frequency strand, in particular is designed as a high-frequency strand. According to the invention, the first and second ground segments are electrically conductively connected to each other via the radio-frequency conductor. A continuous common ground potential can thus be provided. Preferably, the ground section can be configured as a housing or housing element equipped with the individual elements of the drive train of the device according to the invention. A high-frequency conductor within the meaning of the invention is in particular a conductor which is particularly suitable for the conduction of high-frequency currents. High-frequency plied wires are formed from a plurality of individual strands, which are in each case electrically insulated from one another and electrically connected in parallel to one another. Furthermore, the individual strands used to form the high-frequency ply wire are mostly intertwined such that in the middle each individual strand occupies every possible position in the overall cross-section of the high-frequency ply wire with the same frequency. Unfavorable effects for the conduction of high-frequency currents, such as the so-called skin effect which can occur in the case of single solid wires, can thereby be avoided or at least significantly reduced. The high-frequency conductor according to the invention can thus be provided particularly simply by means of high-frequency twisted wires.

According to a second aspect of the invention, the object is solved by a vehicle having an electric machine and a drive train driven at least by the electric machine, which has a device for reducing high-frequency interference currents in the drive train of the vehicle. The vehicle according to the invention is characterized in that it is constructed with the device according to the first aspect of the invention.

Accordingly, the vehicle according to the invention brings about the same advantages as explained in detail with reference to the device according to the invention according to the first aspect of the invention.

Description of drawings

Additional advantages, features and details of the invention emerge from the following description, in which exemplary embodiments of the invention are explained in detail with reference to the drawings. The features mentioned in the claims and in the description can accordingly be essential to the invention individually or in any combination. Elements with the same function and principle of action are provided with the same reference symbols in the various figures. in:

Figure 1 schematically shows a drive train according to the prior art,

Figure 2 schematically shows a simplified alternative diagram of the drive train,

Figure 3 shows schematically a drive train with a device according to the invention,

Figure 4 schematically shows the shaft section of the drive train

Figure 5 schematically shows the first frequency characteristic in the case of using the device according to the invention,

Fig. 6 shows schematically the second frequency characteristic in the case of using the device according to the invention, and

Figure 7 schematically shows a vehicle according to the invention.

List of reference signs

1 device

2 vehicles

10 drive system

11 First axis section

12 ends

13 Second axis section

14 ends

15 Second grounding zone

20 motor

21 First grounding section

30 blocking elements

31 Decoupling capacitor

32 cladding

40 drain element

41 Coupling capacitor

42 variable capacitor

43 disk pairs

44 first disc

45 second disc

46 high frequency conductor

50 batteries

51 Power Electronics

52 Internal combustion engine

53 Clutch

54 transmission mechanism

55 differential

56 support device

57 drive wheel

58 wheel suspension

60 DC conductor

61 phase conductors

70 ground potential

80 Amplitude characteristics (without the device according to the invention)

81 Amplitude characteristic (with device according to the invention)

90 phase characteristics (without the device according to the invention)

91 Phase characteristics (with device according to the invention)

100 Interference current

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

102 potential difference (after the device according to the invention)

103 Radiation.

Detailed ways

FIG. 1 shows a drive train 10 of a vehicle 2 , here a hybrid vehicle, driven by at least one electric machine 20 , as is known from the prior art. Here, the drive train 10 may, as depicted, have a number of different elements, such as a clutch 53 , a transmission 54 and/or a differential 55 and serve to transmit mechanical energy to drive wheels 57 of the vehicle 2 , which drive wheels 57 It is arranged on the vehicle 2 , for example via wheel suspensions 58 . Bearing device 56 ensures a particularly low-friction mounting of drive train 10 in vehicle 2 . The drive train 10 shown here is used in a vehicle 2 which is designed as a hybrid vehicle and which, in addition to the electric machine 20 , also has an internal combustion engine 52 . In this case, electric machine 20 can be operated as an electric motor or, alternatively, as a generator. The electrical energy required for operation as electric motor 20 is provided by battery 50 , which is preferably designed as a DC high-voltage battery. Via the DC conductor 60 , the electrical energy is conducted as a DC current to the power electronics 51 , where it is converted into AC current and then supplied via the phase conductor 61 to the electric machine 20 . During this conversion of direct current into alternating current and especially also during the operation of electric machine 20 , the generation of high-frequency disturbance currents 100 , which are shown as curved arrows in FIG. 1 , can occur. Via the drive train 10 and its components, these disturbance currents 100 , as depicted, can propagate over the entire vehicle 2 and cause disturbances, for example, in the electrical system of the vehicle 2 . Here too, radiation 103 of interference current 100 to the surroundings can occur, whereby for example interference in radio reception, for example a radio installed in vehicle 2 , can arise.

A simplified alternative diagram of drive train 10 is shown in FIG. 2 . It is schematically depicted here that the drive train 10 is arranged between the electric machine 20 , which is supplied with electrical energy via the phase conductor 61 on the one hand, and the wheel suspension 58 on the other hand, and these structural elements are also provided in addition to the mechanical connection. electrical connections. This is shown in FIG. 2 by electrical elements or impedances X_i. This resistance X_i is here in particular a torque-transmitting element, which can be designed, for example, as shaft sections 11 , 12 , as clutch 53 , as a meshing gear of transmission 54 or differential 55 , as Plug-in teeth or similar elements. These impedances X_i thus influence the propagation of disturbance currents 100 (not depicted together) along the drive train 10 . Furthermore, an impedance Y_i is depicted, which is the electrical connection between the rotating component of the drive train 10 and the stationary element, in particular the ground section 15 , 21 or the housing. These connections may eg be bearing means 56 (not depicted together), sealing elements, cooling means or the like. Impedance Y_i thus influences the conduction or conduction of disturbance current 100 from drive train 10 onto grounded sections 15 , 21 . Furthermore, electrical connection elements or connection impedances Z_i are also drawn together, via which the housings or ground sections 15 , 21 of the different elements of the drive train 10 are electrically conductively connected to one another, wherein in particular the ground section 21 of the electric machine 20 is likewise drawn Link together. These impedances Z_i can be formed, for example, as screw connections in and with the vehicle 2 , as balancing conductors, as shields or the like and thus serve to conduct the disturbance current 100 back to its source (most of which is the power electronics 51).

In this case, the device 1 according to the invention can bring about an improvement at all three positions in the case of all three impedances X_i, Y_i and Z_i individually, preferably in combination. Thus, for example, impedance X_2 here is designed as blocking element 30 , in particular as decoupling capacitor 31 . In this way, especially in the case of decoupling capacitors 31 with a capacitance of less than 10 nF, the propagation of high-frequency interference currents 100 , in particular in drive train 10 , can already be avoided or at least significantly suppressed. Furthermore, the impedance Y_3 is formed as a drain element 40 , in particular as a coupling capacitor 41 . In this way, especially in the case of coupling capacitors 41 with a capacitance of greater than 10 nF, a particularly good and effective conduction or conduction of especially high-frequency interference currents 100 from drive train 10 into grounded section 15 can be provided. As a third measure, the device 1 according to the invention can have, as an additional or alternative drain element 40 , a high-frequency conductor 46 which forms an impedance Z_2 in the embodiment shown. A particularly good connection of the high-frequency interference current 100 to the power electronics (not shown together) of the electric machine 20 (mostly the source of the interference current 100 ) can be provided via the high-frequency conductor 46 , which is preferably configured as a high-frequency twisted wire, for example. backticks. Overall, a particularly good and effective reduction of disturbance currents 100 in drive train 10 can therefore be provided by means of device 1 according to the invention by each of these measures, in particular by a combination of all measures.

FIG. 3 shows a possible mechanical configuration of the device 1 according to the invention used in the drive train 10 . The drive train 10 is rotatably mounted via a bearing device 56 . The high-frequency interference current 100 is present in the drive train 10 and, without further operation, in particular causes a potential difference 101 between the drive train 10 and, for example, the second ground section 15 by the device 1 according to the invention. In the embodiment described, the device 1 according to the invention has, in particular, a blocking element 30 and two blocking elements 40 . In this case, the blocking element 30 is designed as a decoupling capacitor 31 which is arranged electrically in series at the ends 12 , 14 of the shaft sections 11 , 13 of the drive train 10 participating in the mechanically active connection. This can be provided, for example, by a non-conductive coating 32 of one of the two ends 12 , 14 in the case of a mechanically active connection via a plug-in toothing. The first distracting element 40 , the coupling capacitor 41 arranged electrically in parallel between the second shaft section 13 and the second ground section 15 are in the form of a variable capacitor 42 , which in particular rotates A constant capacitance is maintained in the event of motion. In this case, the variable capacitor 42 has three pairs of disks 43 in the embodiment shown, wherein respectively the first disk 44 is connected to the second shaft section 13 and the second disk 45 is connected to the second ground section 15 . connected mechanically and electrically. Through such use of a plurality of disc pairs 43 , the capacitance of variable capacitor 42 and thus of coupling capacitor 41 can be increased particularly easily here. Particularly preferably, the capacitance can be selected in such a way that the capacitance of the coupling capacitor 42 is greater, in particular significantly greater, for example twenty times greater than the capacitance of the decoupling capacitor 31 . Decoupling capacitor 31 and coupling capacitor 41 thus form a complex voltage divider which is particularly suitable for diverting high-frequency interference current 100 from drive train 10 . In the case of the above example in which the capacitance of the coupling capacitor 41 is twenty times greater than the capacitance of the decoupling capacitor 31 , it can be achieved that, after the coupling capacitor 41 , between the drive train 10 and the second ground section 15 The potential difference 102 between them is only less than five percent of the potential difference 101 before the coupling capacitor 41 . A further drain element 40 shown in FIG. 3 is a high-frequency conductor 46 which is arranged electrically conductively between the second ground section 15 on the drive train 10 and the first ground section 21 of the power electronics 51 of the electric machine 20 . between. In this case, the high-frequency conductor 46 is particularly well suited within the meaning of the invention for conductors carrying high-frequency currents, for example high-frequency twisted wires. By using the radio-frequency conductor 46 , the return of the radio-frequency interference current 100 conducted here into the second ground section 15 can be provided with particularly high efficiency. Common ground potential 70 can be constructed particularly simply in this way. Overall, therefore, by means of the device 1 according to the invention, especially when all possible blocking elements 30 or 40 are used, it is possible to provide Particularly good reduction of high-frequency interference currents 100 .

FIG. 4 shows a possible mechanically active connection between two shaft sections 11 , 13 of a drive train 10 , wherein a stop element 30 according to the invention is arranged between the shaft sections 11 , 13 . decoupling capacitor 31 of device 1 . Here, the upper image shows a side view and the lower image shows a cross-sectional view along line A-A. The ends 12 , 14 of the two shaft sections 11 , 13 are mechanically operatively connected to one another by means of splines for torque transmission. In particular, the end 12 of the first shaft section 11 has a non-conductive coating 32 . In this case, the coating 32 can preferably comprise, for example, a phosphating of the end 12 of the first shaft section 11 . Phosphating has the advantage here that the non-conductive and thus insulating coating 32 is formed in the material of the first shaft section 11 itself, whereby additional electrically insulating elements can be avoided. Together with the end 14 of the second shaft section 13 , a decoupling capacitor 31 is therefore formed in a particularly simple and efficient manner, which acts as the blocking element 30 as described above.

FIGS. 5 and 6 respectively show the measured frequency curves in the drive train 10 with and without the device 1 according to the invention. In this case, the amplitude characteristics 80 , 81 are correspondingly shown in the image on the left, and the phase characteristics 90 , 91 are shown in the image on the right.

FIG. 5 is taken in a drive train 10 in which a device 1 according to the invention (not depicted together) is installed with a decoupling capacitor 31 as blocking element 30 (not depicted together). In the case of comparing the amplitude characteristics 80, 81 of the interference current 100 used without 80 and with 81 of the device 1 according to the invention, it is evident that a reduction in amplitude attenuation can be achieved for lower frequencies, At the same time, the amplitude does not increase in the case of high frequencies. Likewise, in the case of a comparison of the phase characteristics 90 , 91 of the device 1 according to the invention without 90 and with 91 mounting it can be seen that the phase shift is thereby reduced. Overall, capacitive coupling in drive train 10 can thus be reduced by using decoupling capacitor 30 of device 1 according to the invention and resonance points of high-frequency interference currents 100 can be attenuated in this way.

FIG. 6 is taken in a drive train 10 , in which a device 1 according to the invention (not depicted together) is installed with a high-frequency conductor 46 as a drain element 40 (not depicted together). In the case of comparing the amplitude characteristics 80, 81 of the interference current 100 used without 80 and with 81 of the device 1 according to the invention, it is evident that an increase in amplitude attenuation can be achieved especially for higher frequencies. big. Likewise, it can be seen in the case of a comparison of the phase characteristics 90 , 91 of the device 1 according to the invention without 90 and with 91 mounting that the phase shift is at least delayed thereby. Overall, in this way by using the high-frequency conductor 46 as the drain element 40 of the device 1 according to the invention, the connection of the high-frequency interference current 100 to its source, mostly the electric machine 20 (not depicted together), can be improved. Returning and thus likewise ensuring a low-resistance return path for high-frequency interference currents 100 .

FIG. 7 depicts a vehicle 2 according to the invention with an electric machine 20 having a drive train 10 equipped with a device 1 according to the invention. In this case, the device 1 according to the invention provides that the radio-frequency interference currents 100 (not shown together) in the drive train 10 can be reduced in a simple and particularly effective manner. The adverse effects of such high-frequency interference currents 100 , such as disturbances of electrical components of the vehicle 2 and/or likewise the radiation 103 (not shown together) of the high-frequency interference current 100 into the surroundings of the vehicle 2 can thus be prevented avoid.

Claims (10)

1. one kind is used to reduce in vehicle (2) at least through the High-frequency Interference electricity in motor (20) powered drivetrain (10) Flow the device (1) of (100), described device (1), which has, at least one obstructs element (30) and/or at least one row disturbs element (40), the drivetrain (10) includes at least one first axle section (11) and the second axle section (13), wherein, the first axle The end (12) of section (11) is mechanically effectively connected with the end (14) of the second axle section (13) in order to transmit torque, The motor (20) includes at least one first ground connection section (21) in addition, and the first ground connection section (21) forms the motor (20) earth potential (70), and the drivetrain (10) includes the second ground connection section (15) in addition, the second ground connection section (15) The earth potential (70) of the drivetrain (10) is formed,

Characterized in that,

The use for obstructing element (30) and including being electrically coupled with the first axle section (11) and the second axle section (13) In the first axle section (11) and the decoupling capacitors (31) of the capacitor-decoupling of the second axle section (13), and/or

The row, which disturbs element (40), to be included electrically being arranged in the second axle section (13) and the described second ground connection section (15) Between be used for the second axle section (13) relatively it is described second ground connection section (15) capacity coupled coupled capacitor device (41), and/or

The row, which disturbs element (40), includes electric high-frequency conductors (46), the electric high-frequency conductors (46) conductively at least part section Ground is arranged between the second ground connection section and the first ground connection section (21).

2. device (1) according to claim 1, it is characterised in that described device (1) has at least one decoupling capacitors And at least one coupled capacitor device (41) and at least one high-frequency conductors (46) (31).

3. device (1) according to claim 1 or 2, it is characterised in that the decoupling capacitors (31), which have, to be less than about 10nF, desirably less than about 1nF electric capacity.

4. device (1) according to any one of the preceding claims, it is characterised in that the coupled capacitor device (41) has More than about 10nF, preferably more than about 20nF electric capacity.

5. device (1) according to any one of the preceding claims, it is characterised in that the electricity of the decoupling capacitors (31) Hold it is smaller compared to the electric capacity of the coupled capacitor device (41), be especially up to its about 1/10th, preferably at most its is big About 1/20th.

6. device (1) according to any one of the preceding claims, it is characterised in that the decoupling capacitors (31) pass through The end that at least one participation machinery of the first axle section (11) or the second axle section (13) effectively connects (12,14) nonconducting coating (32) formation.

7. device (1) according to claim 6, it is characterised in that the first axle section (11) or the second axle area The end (12,14) that effectively connects of at least one participation machinery of section (13) is in order to form nonconducting coating (32) By phosphatization.

8. device (1) according to any one of the preceding claims, it is characterised in that the coupled capacitor device (41) passes through Variable condenser (42) formation with least one disk to (43), wherein, first disk (44) of the disk to (43) Electrically and mechanically be connected with the second axle section (13) and the disk to second disk (45) of (43) electrically And mechanically it is connected with the described second ground connection section (15).

9. device (1) according to any one of the preceding claims, it is characterised in that electrically high-frequency conductors (46) tool There is high frequency twine, be especially configured to high frequency twine.

10. one kind carries motor (20) and the vehicle (2) at least through the motor (20) powered drivetrain (10), it has There is the device (1) for reducing the hf interference current in the drivetrain (10) of the vehicle (2), it is characterised in that described Device (1) constructs according to any one of preceding claims.