Fastening device for the elastic suspension of a vehicle component on a vehicle

Abstract

The invention relates to a fastening device (20) for the elastic suspension of a vehicle component (31) on a vehicle (30), the fastening device (20) comprising an outer housing (1) that can be attached to the vehicle (30) and a receiving component (2) arranged in the housing (1), which is mounted relative to the housing (1) by means of elastic elements (5) and has a bearing (8) for a fastening element of the vehicle component (31), wherein the housing (1) has a central, annular section (3) with the receiving opening (4) for receiving the receiving component (2), and wherein the receiving component (2) is inserted into the receiving opening (4) of the housing (1) with the elastic elements (5) interposed, and at least part of the elastic elements (5) is formed from compression springs (5a). The invention further comprises a vehicle.

Description

The invention relates to a fastening device for the elastic suspension of a vehicle component on a vehicle and to a vehicle with at least one such fastening device. Mounting a vehicle component to a vehicle can be problematic, especially if it is a large component, for example, one weighing 4 to 8 tons, attached to the vehicle structure of a rail vehicle. Two main issues can arise here: the large component and the vehicle body may be made of different materials with different coefficients of thermal expansion, and the large component may be subjected to vibration during operation, for example, by transformer coils (transformer hum), motors, or compressors. Known fastening devices comprise an outer housing that can be attached to the vehicle's body shell, and a receiving component arranged within the housing. This receiving component is mounted relative to the housing by means of elastic elements and provides a bearing for a fastening element of the vehicle component. Such fastening devices are used in particular for suspending large components (underfloor, such as a main transformer with cooling system, a line filter choke, a power supply unit, a container unit for electrical equipment, a brake container, batteries, power converters, a line choke, or on the roof, such as a braking resistor) from the supporting structure of a rail vehicle. In the event that the main component and the supporting structure ("body shell") of the rail vehicle are made of different materials whose coefficients of thermal expansion also differ, the fastening device should be suitable to compensate for different thermal expansions of the component and the body shell of the rail vehicle, such as occur when the temperature at the fastening device increases during operation of the rail vehicle, starting from an installation temperature of 20°C, to an operating temperature of, for example, 60°C, and the body shell of the rail vehicle is made of aluminum, but the vehicle component is made of steel or a composite material. The mounting device should also allow for the decoupling of vibrations from the vehicle component it supports. This requires elastic mounting of the component relative to the vehicle. Transmitting the component's vibrations to the vehicle would result in increased noise emissions and reduced ride comfort. Furthermore, without vibration decoupling, the connection points between the component and the vehicle body would be subjected to greater dynamic stress and would therefore need to be dimensioned accordingly. Up to now, these requirements for the fastening device have primarily been met through the use of rubber-metal elements. For example, a wedge bearing can be used, in which vibration decoupling (=vibration isolation) of the component from the vehicle's body shell is achieved via vulcanized rubber elements. However, the use of these rubber elements has the significant disadvantage that the rubber is subject to considerable aging and exhibits undefined aging behavior. This means that the rubber elements must be replaced regularly, resulting in high vehicle maintenance costs because the maintenance effort required to loosen, especially the large components, is very significant. Furthermore, the insulating properties of rubber are temperature-dependent, and its stiffness cannot be influenced after manufacturing (vulcanization). Recently, all-metal bearings have become available, using cushions made of woven metal wire instead of rubber elements. These metal cushions offer good mechanical vibration isolation (decoupling), but noise can still penetrate the car body and reduce comfort. Furthermore, direct adjustment of stiffness is not possible, except to a limited extent by using multiple metal cushions in parallel or series configurations. Optimal adaptation of a mounting device to the weight of a vehicle component is therefore not feasible. It is an object of the present invention to provide a fastening device for the elastic suspension of a vehicle component on a vehicle and a vehicle with which the disadvantages described above are avoided. This problem is solved by a fastening device according to claim 1 and a vehicle according to claim 10. A fastening device according to the invention serves for the elastic suspension of a vehicle component to a vehicle, in particular to the load-bearing structure (the body shell) of the vehicle. It comprises an outer housing that can be attached to the vehicle and a receiving component arranged in the housing, which is mounted relative to the housing by means of elastic elements and has a bearing for a fastening element of the vehicle component. The housing has an annular section, in particular a central one, with a receiving opening for receiving the receiving component. Furthermore, the receiving component is inserted into the receiving opening of the housing with the elastic elements interposed, and at least part of the elastic elements are formed from compression springs. The mounting device therefore consists of several components which together enable a largely maintenance-free, elastic suspension of a vehicle component to a vehicle. The vehicle is preferably a rail vehicle such as a locomotive or a so-called "multiple unit" such as a modern high-speed train with driving components in individual train sections. This mounting device features a housing that serves as a fixed anchor point on the vehicle. It is designed for easy, secure, and firm attachment to the vehicle. The housing preferably has holes for screws, allowing it to be mounted to the vehicle. While the housing could theoretically be welded or glued to the vehicle, a screw connection is preferred. The housing provides a stable base for the mounting component. An example of such a housing would be a steel or aluminum body that accommodates a mounting component in its center and has projections on its sides containing holes for screwing it to the vehicle. The receiving component is arranged within the housing and is supported relative to the housing by means of elastic elements. It includes a special bearing for the vehicle component's fastening element. This bearing can be, for example, a hole into which a bolt can be inserted as the fastening element for the vehicle component, or a screw can be inserted to fasten the vehicle component to the receiving component. Alternatively, the bearing can be a bolt that can be inserted into a corresponding hole in the vehicle component. However, how a vehicle component can be held on a receiving component is not part of the invention and is well known to those skilled in the art. Due to its support by means of elastic elements, the receiving component provides the necessary elasticity to dampen shocks and vibrations, while simultaneously offering a secure connection for the vehicle component.An example would be a cuboid element made of steel or aluminum with a central hole. The receiving component is housed in a central, ring-shaped section of the casing; this section has a receiving opening for receiving the receiving component. The term "ring-shaped" here does not necessarily mean "circular," but rather means that the receiving component is completely enclosed in one plane by the housing material. Looking at this plane, one is looking at the receiving component. It should be noted here that while it can be advantageous for the receiving opening in the housing to be designed so that the receiving component can be inserted from the front or rear, this is not always absolutely necessary. It is only required that the vehicle component can be mounted elastically, meaning that there must be an opening in the housing wall with sufficient clearance to prevent the mounted component from colliding with the housing. However, the housing must always have a receiving opening inside. For example, the housing could be a single piece with a receiving opening extending to the edge; a two-piece design consisting of two half-shells with the receiving opening in the center (where they are joined) and openings at their edges to accommodate the movement of the vehicle component; or a two-piece or multi-piece design made of, for example, [materials / components].the first part, which, however, is provided with an edge covering to prevent the receiving component from being pushed out laterally. Regarding the coordinates and position of the mounting device, "top" refers to the side on which it is attached to the vehicle (as it is typically mounted in a suspended position), "bottom" to the opposite side, and "sides" to the other two sides where the mounting component is enclosed by the housing. "Front" refers to the side where the vehicle component can later be positioned, and "rear" to the corresponding opposite side. The elastic elements form the core of the mounting device. These elements serve to decouple (dampe) movements and impacts and dampen vibrations between the mounting component and the outer housing. As mentioned above, it is already known to use rubber buffers or metal cushions. While these can certainly be used in addition, with metal cushions being preferred because rubber buffers wear out over time, a very important aspect of the invention is that compression springs are used as the elastic elements. At least some of these elements consist of compression springs, preferably at least some of which are arranged under the mounting component. These not only enable the elastic mounting of the mounting component within the housing, but also increase vibration isolation (reduce vibrations) and thus improve comfort.Furthermore, they are largely maintenance-free and offer the additional advantage that their spring force, and thus the stiffness of the bearing, can be adjusted. A preferred example of compression springs are cylindrical helical compression springs (e.g., made of stainless steel) with defined spring constants. Their spring force should be adapted to the specific requirements of the suspension, in particular to known parameters of the vehicle component, such as weight and excitation frequency. Although leaf springs, for example, can be used, coil springs are preferred. A single elastic element can be formed from a compression spring, or several such elements can be used. The elastic elements are preferably pre-stressed in their installed state. This pre-stressing allows the bearing's stiffness to be adapted to the specific application. Less pre-stress results in a softer bearing and thus higher vibration isolation, while more pre-stress leads to a stiffer bearing and therefore lower isolation. The use of compression springs for fastening devices involves elements whose spring force is defined and can also be adjusted, for example, by adding tension through the attachment of a preload element, such as a metal plate above or below the spring. The resulting advantage is explained in more detail below. Preload elements primarily serve to hold and guide the helical compression spring. Furthermore, these two components can act as a stop against each other in the direction of movement of the compression spring to prevent over-compression. The dimensions of the preload elements also determine the preload of the compression spring and, when using bearings for different vehicles or vehicle components, allow for the identical use of the mounting component and housing. Therefore, creating different bearing variants can be achieved simply by varying the preload elements and the springs. To achieve mechanical decoupling, a vehicle component should be mounted as elastically and softly as possible. To protect the vehicle from the transmission of vibrations from the vehicle component, active isolation or source isolation is advantageous. This is achieved by minimizing the transmittance (VD < 1). The transmittance is the ratio of the force on the surroundings to the excitation force (VD = Ff / Fe), where Ff acts on the vehicle and Fe is the excitation force caused by the vehicle component. Explanation of decoupling using the example of a spring-mounted single-mass oscillator: The level of the transmittance VD in an oscillating system is related to the frequency ratio η. The frequency ratio η is calculated from the excitation frequency ω of the mounted large component, e.g., the operating frequency of the transformer (16.7, 50, or 60 Hz), and the natural frequency ω0 of the system (η = ω / ω0). The value of the transmittance VD of a single-mass oscillator is at its maximum when the excitation frequency equals the natural frequency, which is sometimes also referred to as a "resonance catastrophe". If one considers a diagram that shows the relationship between transmittance VD and frequency ratio η, then one sees, starting from the value 1, with increasing frequency ratio η, initially a steep increase in the transmittance VD up to a very large value η = 1 (the aforementioned resonance catastrophe), followed by a similarly strong drop back to the value 1 at approximately η = √2.For larger η, the transmittance value VD falls below 1, which is the desired range. In this range, the system then operates as a vibration isolator. Therefore, this range represents the ideal operating point for an isolating bearing for the mounting devices. The natural frequency ω0 of the system consisting of the vehicle component and its mounting device(s) is calculated from the (resulting) spring constant k of the mounting device(s) and the mass m of the vehicle component (ω0² = k / m). Since the mass m of the vehicle component is essentially predetermined, the (resulting) spring constant k remains as a freely adjustable parameter. Because preloading a system of springs changes its resulting spring constant, a specific permeability VD can be set below 1 by selecting appropriate compression springs and adjusting the preload. Metal cushions can then, for example, provide the desired damping. Since a compression spring has a clearly defined (and calculable) spring constant, and a system of compression springs also has a defined spring constant, the use of compression springs is ideal for designing mounting devices for a known vehicle component with a known mass and excitation frequency, enabling a suspension with a permeability VD < 1. Furthermore, the permeability VD can be adjusted by subsequently changing the preload of the compression springs. This can be achieved, for example, by replacing individual springs or by adding or removing preload elements. A vehicle according to the invention is, in particular, a rail vehicle. It comprises a plurality of fastening devices according to the invention, which are attached to the vehicle, in particular to the vehicle frame (the supporting structure of the vehicle, the "body"). The vehicle also preferably comprises a vehicle component held in these fastening devices, in particular comprising a transformer, e.g., a main transformer, optionally with a cooling system, a line filter choke, a power supply unit, a container unit for electrical equipment, a brake container, batteries, power converters, a line choke, or a braking resistor. However, the vehicle can also be equipped only with fastening devices, e.g., for transporting loads from one place to another. The invention solves several problems, namely the decoupling of the vehicle component (expansion decoupling and vibration decoupling / isolation), maintenance-free connection, at least when elastic metal elements are used, and the ability to absorb high loads. In addition to the solutions offered by a (known) all-metal bearing made of metal cushions, the all-metal spring bearing presented here offers the following properties: 1. The bearing becomes softer at the operating point (lower stiffness at the operating point). This results in a higher frequency ratio and reliable vibration isolation. Continuous supercritical operation is therefore possible. 2. By varying the installation dimensions, the preload of a compression spring-metal cushion spring assembly can be continuously adjusted during bearing design and easily adapted to specific conditions. 3.By varying the compression springs used and the arrangement and number of metal cushions, different masses can be mounted with insulation. 4. By selecting the spring constants of the compression springs and varying the preload using preload elements (e.g., shims), a single type of mounting device can be used for different requirements (e.g., transformer mass and frequencies). Maintenance-free operation can be achieved by eliminating the use of elastomers in the elastic elements. For example, stainless steel metal cushions and stainless steel helical compression springs can be designed to be completely maintenance-free and extremely durable. The housing components for mounting these cushions and helical compression springs can also be designed to be maintenance-free. However, buffer cushions made of elastomers could represent a cost-effective alternative. High load capacities can be achieved by arranging multiple compression springs and, if necessary, other elastic elements, such as metal cushions, in parallel. A corrosion-protected steel is the preferred material for the compression springs due to its very high fatigue strength. A simple and robust embodiment for practical use can be formed from a housing and a receiving component (particularly made of stainless steel or aluminum), both advantageously formed in one piece. A number of compression springs are arranged between the components, preferably with at least one compression spring positioned below the receiving component. A number of additional elastic elements should be arranged above the receiving component to elastically decouple upward movements. Metal cushions are suitable for this purpose, but compression springs can also be used. To elastically decouple movements to other sides of the housing, elastic elements are preferably also arranged there, most preferably metal cushions. Generally speaking, all movement possibilities of the receiving component within the annular opening of the housing should be elastically decoupled, with downward elastic decoupling provided by the compression springs.A completely elastic support in all directions of movement can only be achieved through a support system consisting of two opposing or mutually aligned supports. In practice, the mounting to the vehicle can be achieved using screws that are inserted through holes in the housing and screwed into corresponding threaded holes on the vehicle. These threaded holes should be present in or on the vehicle's load-bearing structure. The dimensions of the components (at least the housing, mounting bracket, and compression springs) depend on the vehicle component being supported. However, subsequent adjustment of the spring assembly's preload is possible using preload elements, such as ring-shaped inserts placed under or over the compression springs. In a practical design, the housing and / or the mounting component could be made from a milled aluminum part. This contributes to weight reduction. However, electrical voltages could build up here due to the different materials. Generally, it is preferable for the mounting component to be galvanically isolated from the housing, at least if the housing and mounting component are made of different materials. The same applies to the elastic elements. If an elastic element is made of a different metal than the housing or the mounting component, then it should be galvanically isolated from it. This isolation serves to protect the components from corrosion. Galvanic isolation can be achieved, for example, by a sheet metal plate, particularly an electrically insulating one, which is placed between the respective parts and electrically isolates them from each other.In general, it is therefore preferred that an electrically insulating separating plate is arranged between two components of the fastening device, especially if these are made of different metals or metal mixtures. To protect the elastic elements, the fastening device can have stop elements on the housing and the mounting component that strike each other before an elastic element reaches a critical point. These stop elements (stops) can be implemented via a profile contour of the housing and the mounting component, e.g., on the rear side (the side facing away from the vehicle component). They prevent, in particular, the compression springs and metal cushions from being over-compressed. Further, particularly advantageous embodiments and developments of the invention result from the dependent claims and the following description, wherein the claims of one claim category may also be further developed analogously to the claims and description parts of another claim category and, in particular, individual features of different embodiments or variants may be combined to form new embodiments or variants. A preferred fastening device is characterized by the fact that part of the elastic elements are formed by elastomer and / or metal cushions, preferably by all-metal cushions. Various arrangements of the compression springs and metal cushions around the receiving component are conceivable. The compression springs and metal cushions can complement each other and can be positioned at different angles and orientations around the center of the bearing. An exemplary fastening device can be formed from just two stainless steel components, several stainless steel metal cushions, and two compression springs. The component to be supported is mounted in the receiving bore of the receiving component. A preferred fastening device is characterized by the fact that the housing is formed in one piece, preferably from steel or aluminum. Milled parts are particularly preferred in this respect. The housing preferably has mounting sections projecting outwards from the central section for attaching the housing to the vehicle's body shell. Attachment to the vehicle's load-bearing structure is preferably achieved via screws that are inserted through these holes in the housing and screwed into the vehicle. Preferably, the receiving component and the central, annular section of the housing are each generally designed with a right-angled cross-section, and the fastening sections of the housing extend in extension of one side of the central, annular section. A preferred fastening device is characterized by the fact that the compression springs are arranged so that they are pre-tensioned, i.e., exert a force against the receiving component. It is preferred that a number of pre-tensioning elements are arranged on at least one of the end faces (the force-exerting sides) of the compression springs. The pre-tension can be adjusted by varying the pre-tensioning elements. To ensure that all metal cushions and compression springs are always in contact with the inner receptacle and the housing when the bearing is loaded, they are preferably pre-tensioned. The compression springs, as well as the other elastic elements, should be installed with such pre-tension that neither the compression springs nor the other elastic elements (e.g., metal cushions) can completely lose their pre-tension during operation.A pre-stressed state can be maintained by additional components during assembly for further transport and storage until attachment to the vehicle, wherein these components preferably introduce a pre-stress axially to the ring-shaped arrangement and can be removed and reused after alignment and fastening of the vehicle component to the vehicle. For assembly, the housing should be placed in a holder, the cushions and compression springs pre-tensioned, inserted into the mounting component, and pressed into place. The mounting component is then guided through the bore and pressed into the housing. A preferred fastening device is characterized by the fact that the receiving component has recesses (e.g., cutouts) on its circumferential sections facing the housing for receiving the elastic elements. Alternatively or additionally, the housing includes recesses on its circumferential sections facing the receiving component for receiving the elastic elements. These recesses serve to securely receive the elastic elements and can vary from section to section. A preferred fastening device is characterized by the fact that the receiving component and the (or some of the) elastic elements are pre-assembled, and this pre-assembled unit is pressed into the receiving opening of the housing. For example, a receiving component could already be connected to compression springs, e.g., because these have been attached to precisely fitting recesses on the receiving component. The receiving component can then be inserted into the housing, pressed downwards, and, while pressed down, metal cushions are placed between the receiving component and the housing. When the compression springs are released, the receiving component presses against the metal cushions, creating a preload. A preferred fastening device comprises stop elements on the housing and / or the receiving component. These stop elements are designed to prevent compression springs and, in particular, metal cushions from being over-compressed, and / or to limit movement of the receiving component along the receiving opening. Such stop elements can be provided by structural features on the relevant parts or formed by additional components. For example, a plunger (in particular cylindrical or prismatic) can be inserted into a compression spring to prevent the spring from being fully compressed. A preferred fastening device is characterized by the fact that the receiving component, the housing, and the compression springs are made of metal. It is preferred that the housing and receiving component are formed from different metals and that a separating plate is arranged between the elastic elements and the housing and / or the receiving component, wherein the separating plate is designed to electrically isolate the housing and receiving component from each other. It is particularly preferred that an electrically insulating separating plate is present between two components of the fastening device that are formed from different metals. This separating plate provides galvanic isolation for corrosion protection of the components. The separating plates can also serve as preload elements.It is preferred that a galvanically isolating separating plate is present between any two components of the fastening device which are made of different metals, which prevents electrochemical corrosion of the components by electrolytes that may be present. A preferred fastening device is characterized by the fact that the housing and the receiving component are made from sheet / bar semi-finished products and / or are manufactured by investment casting or by 3D printing. The invention is explained in more detail below with reference to the accompanying figures and exemplary embodiments. The same components are designated with identical reference numerals in the various figures. The figures are generally not to scale. They show: Fig. 1 a rail vehicle with a vehicle component suspended from fastening devices. Fig. 2 a fastening device according to the prior art, Fig. 3 the fastening device of Fig. 2 from the front, Fig. 4 a fastening device according to the invention, Fig. 5 a receiving component with recesses, Fig. 6 another fastening device according to the invention with an aluminum housing. Fig. 7 another fastening device according to the invention with a single compression spring. Fig. 8 a mounting unit for axially pre-tensioning a fastening device according to the invention with respect to the annular cutout.9 an axially prestressed fastening device according to the invention with mounting unit, Fig. 10 a diagram to illustrate the relationship between transmittance VD and frequency ratio η for different damping ϑ using the example of an elastically mounted single-mass oscillator. Fig. 1 shows a rail vehicle 30 with a vehicle component 31 suspended from fastening devices 20. The rail vehicle 30 is shown here as a locomotive, but could also be a wagon or a multiple unit, e.g., a train set. The vehicle component 31 is mounted under the vehicle 30, but could also be attached to its roof. It is elastically held on both sides by two fastening devices 20. Fig. 2 shows a fastening device 20 for the elastic suspension of a vehicle component 31 on a vehicle 30 according to the prior art. It comprises an outer housing 1, which can be attached to the vehicle 30, and a receiving element 2 arranged in the housing 1, which is mounted relative to the housing 1 by means of elastic elements 5 (here made of metal cushions) and has a bearing 8 for a fastening element of the vehicle component 30. The housing 1 has a central, annular section 3 with the receiving opening 4 for receiving the receiving element 2, and the receiving element 2 is inserted into the receiving opening 4 of the housing 1 with the elastic elements 5 (above, below, and laterally) interposed. More elastic elements 5 are arranged below the receiving element 2, since the greatest force from the vehicle component 31 acts downwards. Fig. 3 shows the fastening device 20 according to Fig. 2 from the front. This serves to better illustrate the difference between the invention according to Fig. 3 and the prior art. Fig. 4 shows a fastening device 20 according to the invention. It is basically constructed like the fastening device according to Figs. 2 and 3, with the significant difference that part of the elastic elements 5 are formed from compression springs 5a. These are arranged here below the receiving component 2, since the greatest force acts downwards through the vehicle component 31 in its rest position. Fig. 5 shows a receiving component 2 with recesses 10. This is the receiving component 2 shown in Fig. 4. The metal cushions 5 and the compression springs 5a are partially arranged in the recesses 10 to restrict the movement of the metal cushions 5 and compression springs 5a, in particular to prevent slippage and / or to allow sliding only in certain directions. Fig. 6 shows another fastening device 20 according to the invention with a housing 1 made of aluminum. It is constructed according to the same principle as Fig. 4, with the difference that the housing 1 is designed to be somewhat more robust. In addition, the receiving component 2 is supported downwards by four compression springs 5a and upwards by three metal cushions 5. In this example, it is also assumed that the receiving component 2 and the elastic elements 5 are made of stainless steel. To prevent corrosion, the parts are therefore galvanically isolated from the housing by electrically insulating separating plates 11. The housing could also be made of steel, but even then, the separating plates 11 would be preferred in order to galvanically isolate the housing 1 from the stainless steel cushions 5. Fig. 7 shows another fastening device 20 according to the invention with a single compression spring 5a. Here, too, the principle of Figs. 4 and 6 is applied, whereby it can be assumed that the housing 1 is made of aluminum or steel and the receiving component 2 and the elastic elements 5 are made of stainless steel. The compression spring 5a is comparatively robust and is pre-tensioned by means of pre-tensioning elements 12 above and below the compression spring 5a. The thickness and number of the pre-tensioning elements 12 influence the degree of pre-tension. A spacer 13 can be seen in the compression spring 5a. Fig. 8 shows an assembly unit 21 for mounting a vehicle component 31 with a fastening device 20 according to the invention onto a vehicle 30 (see Fig. 1). This assembly unit 21 is a right-angle bent sheet metal, which is provided here with four screws 21a that engage in holes of the receiving component 2 of a fastening device 20 and can be fastened there. By means of sliding discs 21b, the assembly unit 21 can slide along the housing 1 of the fastening device 20. These sliding discs 21b can be made, for example, of plastic or self-lubricating metals such as bronze. Fig. 9 shows the preloading of a fastening device 20 according to the invention with a mounting unit 21 from Fig. 8. The mounting unit 21 is mounted here on a receiving component 2 of a fastening device 20 (whose screws 21a were inserted through bores 7, not visible here, and screwed in place) and can slide along the housing 1 of the fastening device 20 with its sliding discs 21b. After mounting the fastening device 20, the mounting unit 21 is screwed firmly to the receiving component 2 (on its rear side), thus preventing uncontrolled sliding apart of the bearing itself and setting the preload or clearance axially to the annular arrangement of the elastic elements 5. It is also possible to set a defined clearance, i.e., a preload of less than or equal to zero. For mounting on the vehicle, the mounting device 20 is first attached to the vehicle component 31 (see Fig. 1) with the bearing 8 in the mounting component 2. This is followed by mounting the vehicle component 31 with the mounting device 20 to the supporting structure of the vehicle 30. During this process, the mounting component 2 moves downwards due to the weight of the vehicle component 31, and the compression spring 5a is compressed. The mounting unit 21 allows this movement by sliding along the housing on the sliding discs 21b. After the vehicle component 31 has been completely mounted on the vehicle 30, the mounting unit 21 should be removed. Fig. 10 shows a diagram illustrating the relationship between transmittance VD and frequency ratio η for different damping ϑ using the example of the elastically mounted single-mass oscillator. To achieve mechanical decoupling, a vehicle component 31 (see Fig. 1) should be mounted on a soft, elastic bearing. To protect the vehicle 30 from the transmission of vibrations from the vehicle component 31, active isolation or source isolation is advantageous. This is achieved by minimizing the transmittance, VD < 1. The transmittance is the ratio of the force on the surroundings to the excitation force (VD = Ff / Fe) with respect to the force F acting on the vehicle and the excitation force Fe caused by the vehicle component. The transmittance VD in an oscillating system is related to the frequency ratio η. The frequency ratio η is calculated from the excitation frequency ω of the supported large component, e.g., the operating frequency of the transformer (16.7, 50, or 60 Hz), and the natural frequency ω0 of the system (η = ω / ω0). The value of η is therefore at its maximum when the excitation frequency equals the natural frequency. If one considers a diagram showing the relationship between transmittance VD and frequency ratio η for different damping values ​​ϑ (different curves), then, starting from a value of 1 in the subcritical range, one sees a steep increase in transmittance VD with increasing frequency ratio η, reaching a very high value at η = 1 (at low damping values, the aforementioned resonance catastrophe = "critical range"), followed by the supercritical range, with a similarly steep drop back to the value 1 at approximately η = √2. For larger η, the value of transmittance VD falls below 1, which is the desired range. In this range, the system then operates as a vibration isolator. Therefore, this range represents the ideal operating point for an isolating bearing for the mounting devices. The diagram shows that for frequency ratios in the range 0 < η < √2, the excitation force on the surroundings is amplified. For frequency ratios η > √2, the transmittance VD < 1 is independent of the damping; however, the damping influences how much VD is less than 1. The system operates as a vibration isolator in this range, therefore this is the ideal operating point for an isolating bearing. The natural frequency ω0 of the system vehicle component & fastening device(s) is calculated from the (resulting) spring constant k of the fastening device(s) and the mass m of the vehicle component (ω02= k / m). For a large frequency ratio, the stiffness at the operating point must be as low or as flexible as possible, and the mass m as high as possible. An additional increase in the mass m is ruled out due to the resulting higher vehicle weight, and the mass of the component being supported is assumed to be constant. Thus, the spring constant k (or stiffness of the support at the operating point) remains the only factor influencing the vibration behavior. Since the preload of a system consisting of helical compression springs and metal cushions alters its resulting spring constant, a specific damping coefficient (VD) can be set below 1 by selecting appropriate springs and adjusting the preload. Due to the internal friction of the wire mesh, the metal cushions exhibit a high damping factor of approximately 0.4. Helical compression springs, on the other hand, exhibit virtually no damping. The combination of helical compression springs and metal cushions, with the damping provided by the metal cushions, effectively prevents resonance from occurring even during short-term excitations in the subcritical frequency range.These vibrations, while amplified by the bearing, do not correspond to the long-term operating conditions. Examples of vehicle-side vibrations include slow travel through a switch or slowly traversing rail defects such as squats, indentations, or slip waves. An example of component-side vibration is the start-up of a motor (since it rotates slowly for a short time, the vibration is also very low-frequency and passes through the range in which it is amplified). The use of the spring ensures that the component's operating frequency is always in the system's supercritical range, thus decoupling it from the car body. This reduces structure-borne noise transmitted to the car body and increases ride comfort.Using only metal cushions is not effective, especially for low-frequency excited components. Therefore, these bearing types are often operated in the subcritical or even critical frequency range, leading to an amplification of unwanted noise. In these cases, the bearings primarily serve to compensate for thermal expansion, not to decouple the vibrations. The amplification of structure-borne noise reduces ride comfort. Finally, it should be noted once again that the invention described in detail above merely represents exemplary embodiments, which can be modified in various ways by a person skilled in the art without departing from the scope of the invention. Furthermore, the use of the indefinite articles "a" or "an" does not preclude the possibility that the features in question may be present multiple times. Likewise, terms such as "unit" do not preclude the possibility that the components in question consist of several interacting sub-components, which may also be spatially distributed. The term "a number" should be read as "at least one." Regardless of the grammatical gender of a particular term, persons of male, female, or other gender identities are included.

Claims

Fastening device (20) for the elastic suspension of a vehicle component (31) on a vehicle (30), the fastening device (20) comprising an outer housing (1) that can be attached to the vehicle (30) and a receiving component (2) arranged in the housing (1), which is supported relative to the housing (1) by means of elastic elements (5) and has a bearing (8) for a fastening element of the component of the vehicle (30), wherein the housing (1) has an annular section (3) with the receiving opening (4) for receiving the receiving component (2), and wherein the receiving component (2) is inserted into the receiving opening (4) of the housing (1) with the elastic elements (5) interposed, and at least part of the elastic elements (5) is formed from compression springs (5a). Fastening device (20) according to claim 1, wherein part of the elastic elements (5) is formed by elastomer and / or metal cushions (5), preferably by all-metal cushions made of a wire mesh. Fastening device (20) according to one of claims 1 or 2, wherein the housing (1) is formed in one piece, preferably made of steel or aluminium, in particular as a milled part, and preferably has fastening sections (6) projecting outwards from the central section (3) for fastening the housing (1) to the body shell of the vehicle (30). Fastening device (20) according to one of claims 1 to 3, wherein the compression springs (5a) are arranged such that they are preloaded, wherein a number of preloading elements (12) are arranged on at least one of the end faces of the compression springs (5a). Fastening device (20) according to one of claims 1 to 4, wherein the receiving component (2) has recesses (10) on its circumferential sections facing the housing (1) for receiving the elastic elements (5) and / or the housing (1) has recesses (10) on its circumferential sections facing the receiving component (2) for receiving the elastic elements (5). Fastening device (20) according to one of the preceding claims, wherein the receiving component (2) and the elastic elements (5) are pre-assembled and this pre-assembled unit is pressed into the receiving opening (4) of the housing (1). Fastening device (20) according to one of the preceding claims, comprising stop elements (9) on the housing (1) and / or on the receiving component (2) designed to prevent compression springs (5a) and in particular also metal cushions (5) from being over-pressed, and / or to limit movement of the receiving component (2) along the receiving opening (4). Fastening device (20) according to one of the preceding claims, wherein the receiving component (2), the housing (1) and the compression springs (5a) are made of metal, preferably wherein the housing (1) and receiving component (2) are formed from different metals and a separating plate (11) is arranged between the elastic elements (5) and the housing (1) and / or the receiving component (2), wherein the separating plate (11) is designed to electrically insulate the housing (1) and receiving component (2) from each other, preferably wherein an electrically insulating separating plate (11) is provided between any two components of the fastening device (20) that are formed from different metals. Fastening device (20) according to one of the preceding claims, wherein the housing (1) and the receiving component (2) are made from sheet / bar semi-finished products and / or are manufactured by investment casting or by 3D printing. Vehicle (30), in particular rail vehicle, comprising a plurality of fastening devices (20) according to one of the preceding claims, which are attached to the vehicle (30), in particular to the vehicle frame (30), and preferably a vehicle component (31) held in these fastening devices (20), in particular comprising a transformer.

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