Electrical connection device and electric drive machine

Abstract

The invention relates to an electrical connection device and to an electric drive machine comprising at least one electrical connection device. The electrical connection device (1) is used to electrically connect at least one winding of a phase of an electric drive machine and comprises at least one bus bar (21, 22, 23) and, connected to the bus bar (21, 22, 23), at least two line elements (31, 32) designed for electrical connection to a winding of a phase of an electric rotating machine, the line elements (31, 32) being fixed to one another by means of a clamping element (50). Using the electrical connection device proposed here and the electric drive machine equipped therewith, devices are provided which ensure, in a simple and economical way, a long service life despite oscillations that occur.

Description

[0001] Electrical connection device and electric drive machine

[0002] The invention relates to an electrical connection device and an electrical drive machine comprising at least one electrical connection device. In electrical drive machines such as electrical rotating machines, high vibration loads can occur on the connected contacts. During operation of electrical rotating machines, a stator rotates in relation to a rotor. Vibrations occurring during this process can be transmitted to the stator. The stator typically comprises windings assigned to individual phases of the stator's electrical connections. Connected to the windings are line elements which connect the windings to phase circuits. The phase circuits are often implemented on or by busbars. Such busbars can be arranged on a fixed structure, so that relative vibrational movements can occur between the stator and the busbars.Accordingly, the line elements are exposed to vibration loads. Over their lifetime, these vibration loads can lead to failures in the high-voltage contact between the stator of the electric rotating machine and the power electronics in the so-called high-voltage terminal.

[0003] There are various approaches to reducing vibration in electrical rotating machines.

[0004] US 2019 356 193 A1 discloses a decoupling element for connecting power electronics to an electrical machine, comprising at least one holder made of insulating material and at least one busbar arranged on the holder. The decoupling element has a first region, a second region arranged substantially parallel to the first region and spaced therefrom, and a curved third region serving as a spring element, which connects the first region to the second region. The at least one busbar is connected at its second region to the holder via at least one holding element. The decoupling element basically operates according to the principle of a curved spiral spring, which is only loaded in the elastic, third curved region, which results, among other things, in a long service life.Furthermore, the spring action ensures a large tolerance compensation between the individual components while maintaining high stability. Furthermore, vibrations can be decoupled, which improves vibration resistance.

[0005] DE 10 2020212 117 A1 teaches an electric machine system for a motor vehicle, comprising an electric machine for driving the motor vehicle and power electronics for operating the electric machine. The electric machine has winding wires that extend out of the electric machine for electrically coupling the electric machine to the power electronics. A coupling sleeve for electrically coupling to a busbar of the power electronics is arranged at a wire end region of a winding wire. The coupling sleeve has a coupling region facing away from the winding wire for mechanically and electrically coupling to the busbar. The coupling region has two coupling legs, a receiving region being formed between the coupling legs, and a busbar section of the busbar being arranged and held in the receiving region.

[0006] Based on this, the present invention is based on the object of providing an electrical connection device and an electric drive motor equipped therewith, which ensure a long service life in a simple and cost-effective manner despite the occurrence of vibrations. This object is achieved by the electrical connection device according to claim 1 and by the electric drive motor according to claim 10. Advantageous embodiments of the electrical connection device are specified in subclaims 2 to 9.

[0007] The features of the claims can be combined in any technically reasonable manner, whereby the explanations from the following description as well as features from the figures can also be used to comprise additional embodiments of the invention.

[0008] The invention relates to an electrical connection device for electrically connecting at least one winding of a phase of an electric drive machine, comprising at least one busbar and at least two conductor elements connected to the busbar, which are configured for electrical connection to a winding of a phase of an electric rotary machine. The conductor elements are fixed to one another by means of a clamping means.

[0009] The electrical connection device can also be referred to as a terminal. The electrical connection device can, for example, be a high-voltage terminal and be configured accordingly to implement the electrical connection in a high-voltage area.

[0010] The power rail can also be called a busbar.

[0011] The conducting elements oscillate relative to the busbar. The conducting elements can be designed as wires, for example.

[0012] The clamping means fixes the line elements to one another by clamping a respective line element at a respective clamping point and a rigid mechanical connection between the clamping points.

[0013] If necessary, line elements arranged in pairs, which are assigned to respective phases of an electric drive device, can be clamped with a clamping means described.

[0014] A special embodiment provides for line elements assigned to different phases to be clamped in pairs using the clamping device. This only requires sufficient electrical insulation from the clamping device.

[0015] By using the clamping device, the natural frequency of the line elements fixed to each other can be significantly influenced.

[0016] Accordingly, the line elements can be made to vibrate with a significantly lower amplitude than in a situation without the use of the clamping device, and / or to have a natural frequency that is far removed from the vibrations induced during operation of a connected electrical rotating machine. This ensures that the line elements, as well as elements electrically coupled to the line elements, such as the windings and / or busbars, are subjected to significantly lower mechanical loads while still having a long service life. Furthermore, the eigenform of the natural frequency can be modified in such a way that the point of occurrence of the maximum mechanical stress is shifted. This can prevent cracking at points with excessive stress due to notch effects.

[0017] The line elements can be indirectly connected to one another by means of the busbar in respective connection areas and can be mechanically fixed in relation to one another in such a way that the clamping means fixes the line elements at a distance D of the clamping points to the connection areas.

[0018] The ratio of a distance D between the clamping point and the connection area to a length L of the conductor elements from the connection area to the electrical connection of the conductor element to a winding can be D / L <0.2. The length L of the conductor elements from the connection area to the electrical connection of the conductor element to a winding can also be referred to as the free vibration length if the conductor element is considered without clamping. The length of the conductor elements is determined by the average of the lengths of the two conductor elements connected per phase, and not by the sum of the lengths of the two conductor elements.

[0019] The conductor elements can extend at least partially in one plane, and sections of the conductor elements running in this plane can be fixed in this plane by means of the clamping means through its clamping action. Conductor sections running in one plane can directly adjoin the connecting regions, although the invention is not limited thereto. An alternative embodiment provides that the conductor elements extend at least partially in one plane, and sections of the conductor elements running in this plane are fixed outside this plane by means of the clamping means through its clamping action.

[0020] The clamping means can be in contact with the busbar, at least in part. This positively locking mechanism at least partially deprives the conductor elements of the ability to move in a translational degree of freedom perpendicular to the plane, since the clamping means can be supported on the busbar, and the clamps thus fix the conductor elements perpendicular to the busbar or to the arrangement plane in which the conductor elements and the busbar are arranged.

[0021] However, the present invention is not limited to this embodiment, but can also be designed such that there is a distance between the clamping means and the busbar, so that the line elements mechanically fixed to one another by means of the clamping means are given more freedom of movement along the aforementioned translational degree of freedom.

[0022] The electrical connection device can be designed such that the clamping means clamps a respective line element at only one clamping point. A clamping point comprises at least two opposing regions of the respective line element, which are subjected to compressive forces generated by the clamping means.

[0023] An alternative embodiment provides that the clamping means clamps a respective line element at several clamping points.

[0024] At least one of the conductor elements can be welded to the busbar in a respective connection area. This means that the connection areas are formed by welding. The welding is carried out along the longitudinal direction of a respective conductor element on the busbar, thereby achieving a mechanically secure clamping of the attached section of the conductor element to the busbar.

[0025] The clamping element can be made of plastic. An advantageous embodiment of the clamping element provides that the plastic is temperature-resistant.

[0026] Furthermore, it cannot be ruled out that the mass of the clamping device has an influence on the changed natural frequency of the line elements, since the clamping device together with sections of the line elements forms an oscillating system.

[0027] The described electrical connection device enables the reduction of vibrations of the line elements when subjected to vibration, such as in the case of an electric drive motor, to whose windings the electrical line elements are connected. A further aspect of the present invention is an electric drive machine comprising at least one described electrical connection device.

[0028] The invention described above will be explained in detail below against the relevant technical background with reference to the accompanying drawings, which show preferred embodiments. The invention is in no way limited by the purely schematic drawings, and it should be noted that the embodiments shown in the drawings are not limited to the dimensions shown. It is shown in

[0029] Figure 1 : an electrical connection device in a first perspective view,

[0030] Figure 2: the electrical connection device in view from below, and

[0031] Figure 3: Detail A from Figure 2 in an enlarged view.

[0032] Figure 1 shows an electrical connection device 1 according to the present invention in a perspective view.

[0033] The electrical connection device 1 comprises three connections for electrical contact with phases, namely with a first phase 11, a second phase 12 and a third phase 13.

[0034] The respective phases are connected to corresponding busbars, namely to a first busbar 21, a second busbar 22 and a third busbar 23. A respective busbar 21, 220, 23 forms a so-called respective busbar.

[0035] The electrical connection device 1 further comprises a housing 14, such as made of plastic, for receiving the connections of the phases 11, 12, 13 and the busbars 21, 22, 23.

[0036] Each of the busbars 21, 22, 23 is contacted by two conducting elements, namely a first conducting element 31 and a second conducting element 32. These conducting elements 31, 32 are designed to be electrically conductively connected to windings of the relevant phase of a stator (not shown here) of an electrical rotary machine.

[0037] Figure 2 shows electrical connection device 1 from below, wherein a respective clamping means 50 can be seen assigned to each busbar 21, 22, 23, which is arranged in the region of the mechanical connection of the two line elements 31, 32 to a respective busbar 21, 22, 23.

[0038] Such a clamping means 50 and its effect are explained below with reference to the enlarged view of detail A in Figure 3 marked in Figure 2. Here, the end region of the first busbar 21 is shown, as well as a first line element 31 connected thereto and a second line element 32 connected to the busbar 21. It can be seen that both line elements 31, 32 are aligned parallel to one another and run in a plane that corresponds to the plane of representation in Figure 3.

[0039] Both line elements 31, 32 are connected to the first busbar 21 in respective connection areas 40 by means of parallel welds 41, namely in the area of ​​a respective wire 33 exposed from insulation material 34. Furthermore, a clamping means 50 is provided in the form of a plastic part, which is connected to each of the two line elements 31, 32 by means of two clamping points, namely a first clamping point 51 and a second clamping point 52. The respective first clamping point 51 in the embodiment shown here merely helps to fix the clamping means 50 to the two line elements 31, 32. Accordingly, the first clamping point 51 merely serves to stabilize the clamping means 50 itself in order to ensure a more stable mechanical fixation of the two line elements 31, 32 outside the connection area 40.

[0040] The respective second clamping point 52 is spaced apart from the respective connecting region 40 along the longitudinal direction of the two line elements 32 by a distance D. Here, in the plane shown, the two line elements 31, 32 are clamped at respective second clamping points 52 on each of the two line elements. For this purpose, the clamping means in the embodiment shown here has a central part 54 which acts on both line elements 31, 32. With the respective second clamping points 52, a respective line element 31, 32 is thus clamped on both sides in the plane shown, so that, as shown by way of example with the first line element 31 at the second clamping point 52, compressive forces 60 act on both sides of the first line element 31. These compressive forces 60 are therefore also applied at the distance D between the second clamping point 52 and the connecting region 40.Without the described clamping means 50, the line elements 31, 32 would oscillate around the support point 42. This would allow the line elements 31, 32 to exhibit a significantly higher amplitude during the oscillation.

[0041] Due to the arrangement of the clamping means 50, the support point of the oscillating movement 53 is now located at the point where the compressive forces 60 are introduced, or at the second clamping point 52. The distance D of the second clamping point 52 to the connecting region 40 is significantly less than the length L of the line elements, which is indicated graphically in Figure 2. Nevertheless, the distance D of the second clamping point 52 to the connecting region 40 is sufficiently large to prevent the amplitude of a pivoting movement of the line elements from being very large. In addition, this influences the natural frequency of the oscillating system, which comprises the busbar, the line elements 31, 32, and the clamping means 50, so that the natural frequency range of this oscillating system can be shifted in such a way that resonant behavior of this oscillating system is excluded during normal operation of an electrical rotating machine having the electrical connection device.

[0042] It is further obvious that the clamping means 50 can be displaced along the longitudinal direction of the line elements 31, 32 in order to be able to set different amplitudes and their own natural frequency ranges.

[0043] A further effect of the clamping means 50 used is that the maximum mechanical bending stress now occurs at the second clamping points 52, and no longer at the connection area 40, where there is a higher risk of breakage for the line elements 31, 32 due to the higher stress concentration. The electrical connection device proposed here, as well as the electric drive motor equipped with it, provide devices that ensure a long service life in a simple and cost-effective manner despite vibrations occurring.

[0044] I Electrical connection device

[0045] II First Phase

[0046] 12 Second Phase

[0047] 13 Third Phase

[0048] 14 housings

[0049] 21 First busbar

[0050] 22 Second busbar

[0051] 23 Third busbar

[0052] 31 First line element

[0053] 32 Second line element

[0054] 33 wire

[0055] 34 Insulation material

[0056] 40 connection area

[0057] 41 Welding

[0058] 42 Support point of the swinging movement without clamping means

[0059] 50 clamping devices

[0060] 51 First terminal point

[0061] 52 Second terminal point

[0062] 53 Support point of the swinging movement with clamping device

[0063] 54 Middle section

[0064] 60 pressure force

[0065] D Distance of the clamping point to the connection area

[0066] L Length of the line elements

Claims

Patent claims 1. Electrical connection device (1) for the electrical connection of at least one winding of a phase of an electrical drive machine, comprising at least one busbar (21, 22, 23) and at least two line elements (31, 32) connected to the busbar (21, 22, 23) which are designed for electrical connection to a winding of a phase of an electrical rotary machine, characterized in that the line elements (31, 32) are fixed to one another by means of a clamping means (50).

2. Electrical connection device according to claim 1, characterized in that the line elements (31, 32) are indirectly connected to one another by means of the busbar (21, 22, 23) in respective connection areas (40) and are mechanically fixed in relation to one another in such a way that the clamping means (50) fixes the line elements (31, 32) at a distance D of the clamping points (51, 52) to the connection areas (40).

3. Electrical connection device according to claim 2, characterized in that the ratio of a distance D of the clamping point (51, 52) to the connecting region (40) in relation to a length L of the line elements (31, 32) from the connecting region (40) to the electrical connection of the line element (31, 32) to a winding is: D / L <0.

2.

4. Electrical connection device according to one of the preceding claims, characterized in that the line elements (31, 32) extend at least in sections in one plane, and sections of the line elements (31, 32) running in this plane are fixed in this plane by means of the clamping means (50) by its clamping action.

5. Electrical connection device according to one of the preceding claims, characterized in that the clamping means (50) rests at least partially on the busbar (21, 22, 23).

6. Electrical connection device according to one of the preceding claims, characterized in that the clamping means (50) clamps a respective line element (31, 32) at only one clamping point (51, 52).

7. Electrical connection device according to one of claims 1 to 5, characterized in that the clamping means (50) clamps a respective line element (31, 32) at a plurality of clamping points (51, 52).

8. Electrical connection device according to one of the preceding claims, characterized in that at least one of the line elements (31, 32) is welded to the busbar (21, 22, 23) in a respective connection area (40).

9. Electrical connection device according to one of the preceding claims, characterized in that the material of the clamping means (50) is a plastic.

10. Electric drive machine, comprising at least one electrical connection device (1) according to one of claims 1 to 9.

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