Damper system and muffler bushing for a vehicle

Abstract

The invention relates to a damper system of a vehicle and to a sound deadening bush, the damper system comprising one or more primary dampers (8) and one or more sound deadening bushes (10). The respective primary damper (8) is tuned to vibrations in a low frequency range. The respective sound deadening bush (10) is tuned to vibrations in a high frequency range, the high frequency range being higher and non-coincident with the low frequency range.

Description

Technical Field

[0001] This invention relates to reducing vibration-related noise in vehicles. In particular, it relates to a damper system for damping the vibration of a vehicle unit and a sound-absorbing bushing for coupling the unit in a vibration-damping manner to a carrier structure that is an integral part of the vehicle, either already present in the vehicle or provided as an additional assembly structure. Background Technology

[0002] The vehicle unit has one or more rotating or reciprocating components that vibrate due to the motion of the corresponding components. Such vibrations are absorbed at the support points of the vehicle unit. To dampen the vibrations and associated noise, the vehicle unit is supported at the relevant support points on the vehicle's carrier structure by elastomeric dampers, such as on the outer shell of another unit or on the vehicle's body structure.

[0003] Auxiliary units such as pumps, compressors, and fans often generate high-frequency vibrations exceeding 400Hz or 800Hz, typically with very small amplitudes of less than 0.01mm. These vibrations can be transmitted to adjacent components, potentially causing mechanical and acoustic vibrations in different locations throughout the vehicle. To decouple these high frequencies, soft-adjustable dampers are used to achieve as much isolation as possible. However, these dampers require significant installation space and are susceptible to excitation by external disturbances, such as those caused by rough road surfaces traversed by the vehicle itself. Summary of the Invention

[0004] The purpose of this invention is to improve the support of vehicle units in terms of vibration damping.

[0005] The subject of this invention is a damper system for damping vibrations in vehicle units. Vehicles can refer particularly to motor vehicles, such as road passenger or freight vehicles, or rail vehicles. Units can refer particularly to auxiliary units, such as pumps, compressors, fans, alternators, or servo motors.

[0006] The damper system includes one or more primary dampers for supporting the unit in a vibration-damped manner within the vehicle. The respective primary dampers are tuned to vibrations in the low-frequency range. The damper system also includes one or more anechoic bushings for coupling the unit to the vehicle's carrier structure in a vibration-damped manner. The respective anechoic bushings are tuned to vibrations in the high-frequency range, which is higher than and does not overlap with the low-frequency range. One or more anechoic bushings should have a higher tuning stiffness than one or more primary dampers. Preferably, low-frequency vibrations are damped primarily by the respective primary dampers, and / or preferably, high-frequency vibrations are damped primarily by the respective anechoic bushings. The respective anechoic bushings can be designed to transmit low-frequency vibrations in the low-frequency range substantially undamped.

[0007] Low-frequency excitation may be transmitted to the unit from the outside via support points; for example, rough road surfaces can cause low-frequency excitation. High-frequency excitation may be introduced into the unit specifically from its support points, and insufficient damping can lead to undesirable noise. This invention improves damping across the frequency range by creating a damper system with at least two different dampers, wherein at least one primary damper and at least one silencing bushing are tuned differently to the desired vibration with respect to the vibration spectrum, so that their damping characteristics are suited to their respective primary vibration frequencies to be damped.

[0008] If the following text refers to only one or the main damper or only one or the anechoic bushing without further distinction, the corresponding statements also apply to each optional additional main damper and / or each optional additional anechoic bushing of the damper system. The repeated use of the terms "corresponding main damper" and "corresponding anechoic bushing" should be avoided only.

[0009] The tuning should be such that the main damper has a first natural frequency in the low-frequency range, and the silencing bushing has a first natural frequency in the high-frequency range. This is possible if the main damper and / or the silencing bushing, in fulfilling their function, can each absorb and dampen multiple different vibration modes, such as one or more translational vibrations in mutually orthogonal planes and / or one or more rotational vibrations about mutually orthogonal axes; or if the main damper and / or the silencing bushing can have different first natural frequencies for each of the different vibration modes. Of the multiple different first natural frequencies of the main damper, the smallest first natural frequency can be in the low-frequency range. Of the multiple different first natural frequencies of the silencing bushing, the smallest first natural frequency can be in the high-frequency range.

[0010] In some improvements, the main damper has a first natural frequency in the low-frequency range for at least two different vibration modes. In an advantageous embodiment, the anechoic bushing has a first natural frequency in the high-frequency range for at least two different vibration modes.

[0011] For one or more different translational vibration modes, the anechoic bushing can have a first natural frequency in the high-frequency range. The anechoic bushing can have a first natural frequency for axial vibration (i.e., vibration parallel to the longitudinal axis of the anechoic bushing) and a first natural frequency for radial vibration (i.e., vibration radial to the longitudinal axis of the anechoic bushing), both in the high-frequency range. Advantageously, the ratio of the first natural frequency for axial vibration to the first natural frequency for radial vibration is 1:2 to 2:1. In such embodiments, the first natural frequency for axial vibration is at least half and at most twice the first natural frequency for radial vibration. In an advantageous embodiment, the anechoic bushing is designed and tuned to absorb both translational vibration modes.

[0012] The main damper can be tuned for one or more translational vibration modes. Suitablely, these are mutually orthogonal translational vibration modes. If the main damper is also in the form of a bushing, for example, it can be designed to absorb axial vibration. In an improved embodiment, the main damper can also be designed to absorb radial vibration, i.e., vibration radial to its longitudinal axis. In such embodiments, the first natural frequency, particularly for axial vibration, can be in the low-frequency range. In an improved embodiment, the first natural frequency of radial vibration can also be in the low-frequency range.

[0013] The damping effect of the two different types of vibration dampers is based on the dissipation of vibration energy. By plotting the relationship between the dissipated energy and the vibration frequency in the corresponding damper, the main damper can be effectively tuned so that the global maximum value of the dissipated vibration energy is in the low-frequency range. The sound-absorbing bushing can be designed in a way that ensures its global maximum value of dissipated vibration energy is in the high-frequency range.

[0014] The low-frequency range can reach 50Hz or even 75Hz. The main damper is tuned accordingly to dissipate vibrational energy within this frequency range. In most cases, the main damper is designed to dampen vibrations in the 5Hz to 30Hz or 10Hz to 30Hz range. In advantageous embodiments, the anechoic bushing is tuned to a high-frequency range above 100Hz or above 200Hz. The anechoic bushing can also be tuned to dampen vibrations in the range above 400Hz.

[0015] In such advantageous embodiments of the damper system, one or more of the first natural frequencies of the main damper with respect to the translational vibration of the damper and / or one or more of the first natural frequencies of the damper with respect to the rotational vibration of the damper are at most 75 Hz or at most 50 Hz, while the first natural frequencies of the silencing bushing with respect to axial vibration and / or with respect to radial vibration and / or with respect to torsional vibration are higher than 100 Hz or higher than 200 Hz or higher than 400 Hz.

[0016] In typical applications, the vehicle unit to be decoupled has a housing and one or more rotating components, such as an electric motor and / or a feed wheel for conveying fluid, or a reciprocating lifting assembly, rotatably supported within or on the housing. The purpose of the damper system is to support the housing and decouple it from the vehicle's surrounding environment in terms of vibration. If the rotating components vibrate during operation due to imbalance and / or changes in speed, or if the lifting assembly vibrates due to reciprocating motion, the vibration of the rotating or lifting components causes the housing to vibrate through the supports of the rotating or lifting components, which in turn causes the housing to resonate. In a preferred embodiment, the anechoic bushing is tuned to one or more resonant frequencies of the housing that occur during operation at speeds above 500 rpm or above 1000 rpm, or at stroke commutations above 500 or 1000 times per minute. However, in typical applications, the unit's resonant frequencies are higher than one or more natural frequencies to which the anechoic bushing is tuned.

[0017] If the damper system comprises multiple silencing bushings, the number of silencing bushings can be identical. Two identical silencing bushings are tuned identically in terms of dissipating vibrational energy. In an advantageous embodiment, they are structurally identical. In a modification, the damper system has silencing bushings that are different from each other. Thus, it can have a first silencing bushing and a second silencing bushing, which differ from each other in spring stiffness. This may be advantageous when the silencing bushings, due to limited available structural space, can only be arranged asymmetrically with respect to the vehicle assembly mass, i.e., fewer silencing bushings are arranged on one side of the vehicle assembly's center of mass than on the other side. For example, if only one silencing bushing can be arranged on one side of the center of mass, while two or more can be installed on the opposite side, it is advantageous that the spring stiffness of one silencing bushing is equal to the sum of the spring stiffnesses of the silencing bushings arranged on the other side.

[0018] One or more main dampers can be tuned to be equivalent in tuning to dampers commonly found in vehicle structures for auxiliary units such as coolant compressors, coolant pumps, and oil pumps. On the other hand, the silencing bushing is tuned to be stiffer, and correspondingly, for one or more different vibration modes, the silencing bushing can have a higher spring stiffness than the main damper.

[0019] In an advantageous embodiment, the anechoic bushing includes an inner core, an outer sheath, and an elastomeric structure, the elastomeric structure surrounding the inner core and the outer sheath surrounding the elastomeric structure. The outer peripheral surface of the inner core extends about the longitudinal axis of the anechoic bushing. The elastomeric structure is in surface contact with the outer peripheral surface of the inner core. The inner peripheral surface of the outer sheath is in surface contact with the outer peripheral surface of the elastomeric structure and also surrounds the outer peripheral surface of the inner core in the region of surface contact. The elastomeric structure couples the inner core and outer sheath in a shear-resistant and / or torsional-resistant manner about the longitudinal axis. Relative translational and / or rotational movements between the inner core and outer sheath can only occur within the elastic range of the elastomeric structure. Advantageously, the inner peripheral surface of the outer sheath in surface contact with the elastomeric structure and the outer peripheral surface of the inner core in surface contact with the elastomeric structure are axially coincident at least for a substantial portion of their respective lengths, for example, axially coincident for at least 70% of their lengths.

[0020] The elastomeric structure can advantageously extend around the entire circumference of the inner core, i.e., form a closed loop. The elastomeric structure advantageously closes around the entire circumference and can fill the annular volume left between the inner core and the outer sheath. In an advantageous embodiment, the inner core and / or outer sheath extend around the longitudinal axis of the sound-absorbing bushing, thus closing or having at least one closed axial ring segment.

[0021] The outer peripheral surface of the inner core and / or the inner peripheral surface of the outer sheath in contact with the elastomer structural surface can both be circular, for example, cylindrical. More advantageously, the outer peripheral surface of the inner core or the inner peripheral surface of the outer sheath is non-circular, i.e., deviates from a circular shape. Even more preferably, both outer peripheral surfaces are non-circular, and advantageously, the non-circular outer peripheral surfaces match each other such that they follow each other at at least substantially equal distances. In an advantageous embodiment, the outer peripheral surface of the inner core and / or the inner peripheral surface of the outer sheath in contact with the elastomer structural surface are polygonal. Even more preferably, both outer peripheral surfaces are polygonal and match each other. In such embodiments, the elastomer structure is also non-circular, preferably polygonal. The corresponding polygon is preferably a regular polygon. A preferred polygon is hexagonal.

[0022] If the outer circumferential surface of the inner core and the inner circumferential surface of the outer sheath are non-circular and match each other, then in the unloaded state of the anechoic bushing, the inner core and the outer sheath can be twisted relative to each other by a certain amount, i.e., a lead angle, about the longitudinal axis of the anechoic bushing. This allows them to disengage from the initial unloaded state and rotate relative to each other about the longitudinal axis against the elastic restoring force of the elastomer structure, with the outer circumferential surface of the inner core and the inner circumferential surface of the outer sheath being parallel to each other and / or concentric about the longitudinal axis at least on most of the circumference (preferably on the entire circumference). The anechoic bushing can then be pre-tensioned by relative rotation (i.e., by the torsion of the elastomer structure), wherein the circumferential surfaces are at least partially, preferably circumferentially parallel, in the pre-tensioned state. If the cross-sections of the two circumferential surfaces are polygonal, then in a preferred embodiment, at least the long sides of the polygons are parallel to each other. If coupling with the vehicle unit is achieved, for example, by screwing, where the longitudinal axis of the anechoic bushing is also the screwing axis, then the tightening torque acting on the anechoic bushing due to the establishment of the screwing can be compensated. Advantageously, the torsional stiffness of the noise-absorbing bushing corresponds to a predetermined or anticipated tightening torque. In this embodiment of the noise-absorbing bushing, no resistance is required to support the tightening torque when establishing the bolted connection.

[0023] Compared to the main damper, the silencing bushing needs to resist vibration frequencies at higher frequencies, thus requiring high torsional stiffness. Advantageously, in the unloaded state of the silencing bushing, the outer circumferential surface of the non-circular inner core and the inner circumferential surface of the non-circular outer sheath rotate relative to each other only about the longitudinal axis by a very small lead angle, for example, at least 1° or at least 1.5°, starting from parallel. The lead angle is preferably at most 6° or at most 5°. For high spring stiffness, such as torsional resistance, it is advantageous that a preload corresponding to the tightening torque is achieved at a very small lead angle.

[0024] The outer sheath can be shear-resistantly joined to the vehicle assembly, or more preferably to the carrier structure, and / or torsionally joined around the longitudinal axis of the anechoic bushing. The inner core can be shear-resistantly joined to the carrier structure, or more preferably to the vehicle assembly, and / or torsionally joined around the longitudinal axis. In an improved embodiment, for the purpose of joining, the outer peripheral surface of the outer sheath is non-circular, preferably polygonal. The non-circular outer peripheral surface can extend along the entire length of the outer sheath, but the outer sheath more preferably has a joining section with the non-circular outer peripheral surface. In an advantageous embodiment of the anechoic bushing, the joining section extends over a large portion of the length of the outer sheath. Preferably, the non-circular outer peripheral surface of the outer sheath, the outer peripheral surface of the inner core, and the elastomer structure coincide over at least a large portion of their respective lengths, for example, over 70% of their respective lengths.

[0025] For engagement with a carrier structure, or more preferably with a vehicle assembly, the inner core may have a longitudinally extending cavity around which the outer peripheral surface of the inner core extends. The cavity is open at at least one of the two end sides of the inner core, preferably at the end tip, allowing fasteners to be introduced into the cavity to engage the assembly with the muffler bushing and thereby support the assembly through the muffler bushing. Preferably, the cavity is a channel extending axially through the inner core from one end side to the other. The cavity or channel preferably extends from the center to the outer peripheral surface of the inner core. In a preferred embodiment, the cavity has an engagement structure for engagement with the vehicle assembly. The engagement structure may particularly refer to internal threads for fastening the vehicle assembly. Fastening can be achieved, for example, by means of a bolt as a fastener, which extends through the fastening section of the vehicle assembly until it achieves threaded engagement with the internal threads of the inner core, such that the vehicle assembly is axially pressed against the facing end tip of the muffler bushing by means of the bolt. The cavity need not have an engagement structure for direct engagement with fasteners; for example, it can be simple and smooth. For example, the bolt forming the fastener can be long enough to extend through the channel and its threaded section can protrude beyond the axial rear end of the inner core facing away from the vehicle unit. In such embodiments, a tightening torque is applied by means of a nut to create an axial press-fit with the vehicle unit, the nut being tightened into a threaded engagement with the bolt and pressed against the rear end side of the inner core.

[0026] In one improved embodiment, the inner core protrudes axially beyond the outer sheath at its tip, and the protruding tip has an end face for axially pressing against the carrier structure or, more preferably, the vehicle assembly, to achieve an axial press fit. As described above, this technical solution is particularly advantageous when the sound-absorbing bushing has an axially extending cavity or channel having internal threads for forming a threaded engagement with a fastening threaded member.

[0027] The carrier structure, or more preferably the vehicle unit, only contacts the inner core in a coupled state, and the vibration of the unit is transmitted to the carrier structure under damping through the elastomer structure in a transmission path obtained by means of the sound-absorbing bushing.

[0028] The outer sheath of the silencing bushing may have a joint section for engagement with a unit or preferably a carrier structure, and a radially outwardly projecting flange on the joint section, such that the silencing bushing can be axially pressed against the engagement couple, preferably the carrier structure, by means of the flange. The flange may form an axial stop for axially fixing the outer sheath. The inner circumferential surface of the outer sheath may extend in surface contact with the elastomer structure, with at least a majority of its length within the joint section and preferably also within the flange region.

[0029] The inner core, outer sheath, and elastomer structure can each have a flange, and the flange of the elastomer structure protrudes radially outward between the flanges of the inner core and the outer sheath, allowing the flange of the elastomer structure to be axially elastically compressed between the flanges of the inner core and the outer sheath. By distributing the elastomer material of the elastomer structure circumferentially between the inner core and the outer sheath, and distributing it end-side between the flanges of the inner core and the outer sheath, the adjustability of the spring stiffness is improved. High spring stiffness can be flexibly adjusted to precisely adapt to corresponding application conditions. Axial and radial spring stiffness can be specifically tuned. In particular, the ratio of axial to radial spring stiffness can be adjusted by adaptively varying the thickness of the elastomer structure flange measured longitudinally.

[0030] In the axial tip, advantageously in the axial tip of the joint section described for the outer sheath, the outer sheath may have a radially outwardly projecting locking protrusion or a plurality of radially outwardly projecting locking protrusions distributed around the longitudinal axis, so that the silencing bushing is axially fixed relative to the coupling couple in the engaged state, preferably axially fixed relative to the carrier structure. In the event of damage to the silencing bushing (e.g., breakage), the corresponding locking protrusion can serve as a protection against loss. If the outer sheath has the aforementioned flange, the flange and one or more locking protrusions may be axially spaced apart from each other via the joint section.

[0031] The damper system may further include a carrier structure. The damping bushings and optionally one or more additional damping bushings of the damper system, as well as the main dampers and optionally one or more additional main dampers of the damper system, can be coupled to the carrier structure. The unit is attached to or has been attached to the damping bushings. In a preferred embodiment, the respective main dampers remain independent of the unit, allowing the carrier structure to be supported in the motor vehicle, for example, on the body structure or other units of the vehicle. The carrier structure can then serve as a decoupling structure because the unit is assembled on the carrier structure with higher elasticity via one or more damping bushings, while the carrier structure, together with the unit, is supported on another structure via one or more main dampers with lower elasticity.

[0032] The carrier structure can be integrally molded. Alternatively, the carrier structure may include multiple separately formed substructures that are joined together, such as a carrier base structure and an adapter structure joined thereto, for accommodating one or more sound-absorbing bushings.

[0033] In addition to the aforementioned damper system, the present invention also relates to a sound-absorbing bushing for coupling a vehicle assembly to a carrier structure in a vibration-damping manner, the carrier structure of which may already exist in the vehicle or be provided as an additional assembly structure. With regard to the sound-absorbing bushing as the subject of the invention, the sound-absorbing bushing has an inner core, an outer sheath, and a radially elastic structure between the two structures, the elastic structure coupling the inner core and the outer sheath in a shear-resistant and / or torsional-resistant manner within its elastic range, wherein the coupling surface of the inner core (i.e., its outer circumferential surface) and the coupling surface of the outer sheath (i.e., its inner circumferential surface) are each non-circular, preferably polygonal. The sound-absorbing bushing can be advantageously further improved by incorporating one or more features disclosed in the sound-absorbing bushing of the damper system. As long as this disclosure relates to features concerning the sound-absorbing bushing of the damper system, these features are equally applicable to such improvements to the sound-absorbing bushing.

[0034] If the anechoic bushing has the inner core, outer sheath, and elastomer structure of any of the configurations disclosed herein, the inner core and outer sheath vibrate relative to each other in an axial vibration mode, parallel to the longitudinal axis of the anechoic bushing. In a radial vibration mode, the inner core and outer sheath vibrate relative to each other radially to the longitudinal axis of the anechoic bushing. In a torsional vibration mode, the inner core and outer sheath vibrate relative to each other about the longitudinal axis of the anechoic bushing. Attached Figure Description

[0035] The embodiments of the present invention are described below with reference to the accompanying drawings. The features disclosed in the embodiments are used individually or in combination to improve the above technical solution. In the figures:

[0036] Figure 1 The damper system is shown to have multiple dampers and a carrier structure for supporting the vehicle unit in a damping manner;

[0037] Figure 2 The vehicle unit is supported by a damper system.

[0038] Figure 3 A longitudinal sectional view of the sound-absorbing bushing of the damper system is shown;

[0039] Figure 4 A front view of the sound-absorbing bushing is shown;

[0040] Figure 5 A perspective view of the front face of the sound-absorbing bushing is shown;

[0041] Figure 6 A perspective view of the rear end face of the sound-absorbing bushing is shown;

[0042] Figure 7 A detailed front view of the carrier structure assembled with the sound-absorbing bushing is shown;

[0043] Figure 8 A longitudinal sectional view of the sound-absorbing bushing in its assembled state is shown;

[0044] Figure 9 The sound level pressure of a vehicle unit supported by the damper system is shown compared to that of a conventionally supported unit.

[0045] Explanation of reference numerals in the attached figures

[0046] 1. Carrier Structure

[0047] 2 channels

[0048] 3 end faces

[0049] 4 units

[0050] 5. Outer shell

[0051] 6 rotating components

[0052] 7 channels

[0053] 8 main vibration dampers

[0054] 9 end faces

[0055] 10 silencer bushing

[0056] 11 inner core

[0057] 12 outer perimeter

[0058] 13 cavities, channels

[0059] 14. Joint structure, internal thread

[0060] 15 end face

[0061] 16 flanges

[0062] 17 weeks

[0063] 18 Elastomer Structure

[0064] 19 flanges

[0065] 20-

[0066] 21 outer sheath

[0067] 22 inner circumferential surface

[0068] 23 joint segment

[0069] 24 outer perimeter

[0070] 25 flange

[0071] 26 Locking Protrusions

[0072] K body structure

[0073] L longitudinal axis

[0074] α lead angle

[0075] Sound level pressure when E is equipped with a sound-absorbing bushing

[0076] The sound level pressure R without a silencing bushing. Detailed Implementation

[0077] Figure 1 A bearing arrangement for vibration-damping support of a vehicle unit (e.g., a coolant compressor) is illustrated. The bearing arrangement includes a carrier structure 1 and a damper system with multiple dampers via which the vehicle unit can be supported within the vehicle. The damper system includes multiple main dampers 8 and multiple sound-absorbing bushings 10; in this embodiment, three main dampers 8 and three sound-absorbing bushings 10 are included. Each of the main dampers 8 and the sound-absorbing bushings 10 is respectively engaged with the carrier structure 1.

[0078] The main dampers 8 are coupled to the carrier structure 1 such that they each have a free end face 9 for press-fitting with the housing of other vehicle structures (e.g., body structure) or other vehicle units. The anechoic bushings 10 each have a free end face 15 for press-fitting with vehicle units. The dampers 8 and 10 can be arranged, as in this embodiment, such that the end face 9 of each main damper 8 points in a direction orthogonal to the end face 15 of the anechoic bushing 10. In this embodiment, the end faces 9 of the main dampers 8 are parallel to each other. Similarly, the end faces 15 of the anechoic bushings 10 are parallel to each other. This arrangement is merely exemplary. The main dampers 8 can also be oriented differently. This also applies to the anechoic bushings 10. For example, one of the anechoic bushings 10 can have the same orientation as one of the main dampers 8. In extreme cases, all the dampers 8 and 10 of the damper system can also be arranged in parallel orientation at their press-fitting end faces 9 and 15.

[0079] Figure 2 A schematic diagram of a bearing arrangement including unit 4 is shown, which is supported on carrier structure 1 via a sound-absorbing bushing 10. Carrier structure 1 is supported on, for example, vehicle body structure K via main dampers 8 in a motor vehicle. Each main damper 8 has a damper structure coupled to carrier structure 1, a damper structure coupled to vehicle body structure K, and an elastomer structure coupled to both damper structures in a shear-resistant and / or torsional-resistant manner, which allows the two damper structures to perform the necessary vibration-damping movements relative to each other within their elastic range. Figure 2 The sound-absorbing bushing 10 is not shown in the diagram.

[0080] Unit 4 has a housing 5 and at least one rotating component 6, which is rotatably supported within the housing 5. During operation of unit 5, imbalance and speed variations in the rotating component 6 can cause vibrations, which are transmitted to the housing 5 via the rotating bearing of the rotating component 6, causing the housing 5 to vibrate, or possibly resonate. Typical high-frequency housing vibrations are absorbed by the sound-absorbing bushing 10. In the opposite direction, vibrations of the vehicle body structure K, for example, due to rough roads, are absorbed by the main vibration damper 8. Vibration excitation is damped by the vibration dampers 8 and 10 and the carrier structure 1 inserted in the vibration, and unit 4 is decoupled from its surrounding environment (e.g., the vehicle body structure K) in terms of vibration.

[0081] For attachment to the sound-absorbing bushing 10, the unit 4 (in this embodiment, the housing 5) is provided with channels 7 along the sound-absorbing bushing 10. The sound-absorbing bushings 10 are arranged according to the arrangement of the channels 7 so that when the unit 4 is positioned relative to the carrier structure 1 for assembly, the corresponding sound-absorbing bushing 10 is axially aligned with the associated channel 7. In the positioned state, screws such as bolts pass through each channel 7 in the direction of downward direction towards the sound-absorbing bushing 10 (in Figure 2 In the middle, the sound-absorbing bushing 10 is covered by the unit 4 and screwed to the corresponding sound-absorbing bushing 10 so that the unit 4 is axially pressed against the sound-absorbing bushing 10, thereby creating a press fit.

[0082] For the purpose of decoupling, the main task of the main vibration damper 8 is to decouple the housing 5 and the unit 4 as a whole from the low-frequency vibrations in the surrounding environment (in this embodiment, the vehicle body structure K), while the sound-absorbing bushing 10 absorbs the relatively high-frequency vibrations of the housing 5, thereby decoupling the carrier structure 1 from the unit 4. Accordingly, the main vibration dampers 8 are each tuned to vibrations in the low-frequency range, while the sound-absorbing bushings 10 are each tuned to vibrations in the high-frequency range, which is higher than and does not overlap with the low-frequency range. The sound-absorbing bushing 10 is tuned to be stiffer than the main vibration dampers 8.

[0083] Figures 3 to 6 The image shows the situation before the sound-absorbing bushing is joined to the carrier structure 1. Figure 3 A longitudinal sectional view of the sound-absorbing bushing 10 is shown. The longitudinal section includes the central longitudinal axis L of the sound-absorbing bushing 10. Figure 4 This is a rear end view of the sound-absorbing bushing 10. Figure 5 This is a perspective view of the front face of the sound-absorbing bushing 10, against which the unit 4 can abut during engagement. Figure 6 This is the back-end view.

[0084] The sound-absorbing bushing 10 includes an inner core 11 and an outer sheath 21. The outer peripheral surface 12 of the inner core 11 extends around a longitudinal axis L, and the inner peripheral surface 22 of the outer sheath 21 extends around the longitudinal axis L, with the inner peripheral surface 22 surrounding the outer peripheral surface 12 at a certain radial distance. The sound-absorbing bushing 10 also includes an elastomer structure 18, which is arranged in an annular volume defined radially inside and outside by the peripheral surfaces 12 and 22. The elastomer material of the elastomer structure 18 preferably fills the annular volume. The elastomer structure 18 is in surface contact with the outer peripheral surface 12 and the inner peripheral surface 22 around the longitudinal axis L, and the inner core 11 and the outer sheath 21 are connected in a shear-resistant and torsional-resistant surface contact within their elastic range, such that the radial movement, axial movement, and rotational movement of the inner core 11 and the outer sheath 21 relative to each other can only occur within the elastic range of the elastomer structure 18.

[0085] The silencing bushing 10 has a central cavity 13 extending axially in the inner core 11, the cavity 13 having a design for engagement with the unit 4 ( Figure 2 The engagement structure 14. The inner core can be sleeve-shaped as in this embodiment, and the cavity 13 can also extend through the inner core 11 as in this embodiment, particularly as a straight channel, hence hereinafter also referred to as channel 13. Channel 13 can be cylindrical, particularly cylindrical. Engagement structure 14 can especially refer to an internal thread for threaded engagement with a threaded component.

[0086] The outer sheath 21 has an axially extending sleeve-shaped engagement section 23 having an outer peripheral surface 24 that is free before the sound-absorbing bushing 10 is assembled. The elastomer structure 18 extends in face contact with the inner peripheral surface 22 in the engagement section 23 and can extend in face contact along the entire length of the engagement section 23 and preferably along the entire length of the outer sheath 21.

[0087] At the axial rear end of the outer sheath 21, a flange 25 projects radially outward from the joining section 23. The flange 25 may extend around the entire longitudinal axis L as in this embodiment, but in principle, the flange 25 may also be interrupted at one or more points. A closed, surrounding flange 25 is preferred.

[0088] The inner core 11 has an axial sleeve section surrounded by an outer sheath 21 and having a joining structure 14, and a flange 16 projecting radially outward from its sleeve section at the axial rear end of the inner core 11. The flange 16 preferably extends in a closed loop around the longitudinal axis 11, but in principle it may be interrupted at one or more points. The flange 16 projects radially outward beyond the inner circumferential surface 22 of the outer sheath 21 and is opposed to the flange 25 of the outer sheath 21 at a certain axial distance, such that a similarly annular flange volume is left between flanges 16 and 15 around the longitudinal axis L, into which the elastomeric structure 18 extends. Accordingly, the elastomeric structure 18 itself has a flange 19 made of elastomeric material between flanges 16 and 25. Advantageously, the elastomeric structure 18 fills the flange volume axially. As a result, radial and axial layered structures are obtained in the regions of flanges 16, 19 and 25, wherein the elastomer structure 18 is arranged between the inner core 11 and the outer sheath 21 in both radial and axial layered structures and they are respectively in surface contact coupling, but direct contact between the inner core 11 and the outer sheath 21 should be avoided, thereby separating the inner core 11 and the outer sheath 21 from each other.

[0089] Because the flange 16 of the inner core 11 protrudes radially beyond the inner circumferential surface 22 of the outer sheath 21, it plays a role in preventing loss.

[0090] The axial front tip of the inner core 11 protrudes beyond the outer sheath 21, so that the front end face 15 of the inner core 11 simultaneously forms the front tip of the sound-absorbing bushing 10. The end face 15 forms a mating surface. In the engaged state of the unit 4, the unit 4 presses against the mating surface with axial pressure to form an axial press fit between the inner core 11 and the unit 4.

[0091] The outer sheath 21 is used to engage the sound-absorbing bushing 10 to the carrier structure 1. The outer peripheral surface 24 of the outer sheath 21 is non-circular to resist torsional engagement, allowing it to be received in a corresponding non-circular channel of the carrier structure 1 by form fit and preferably by press fit. The outer peripheral surface 24 may be polygonal, as in this embodiment, preferably hexagonal.

[0092] The channel 13 of the inner core 11 widens radially at its axial rear end. At the widened end, the channel 13 has a non-circular, preferably polygonal, inner perimeter 17, which can be, for example, hexagonal. Figure 4 The view and Figure 5As shown in the perspective view, a tip with a non-circular inner circumference 17 is used to engage the silencing bushing 10 to the carrier structure 1. Before being inserted into the channel of the carrier structure 1, the silencing bushing 10 can be positioned at a rotation angle by a non-circular engagement tool that matches the inner circumference 17, where the non-circular outer circumferential surface 24 of the silencing bushing 10 is correctly positioned relative to the correspondingly shaped channel of the carrier structure 1, so that the silencing bushing 10 can be pushed into a position in the channel of the carrier structure 1 by pressure, where the silencing bushing 10 abuts against the end face of the carrier structure 1 with its flange 25. The silencing bushing 10 then axially protrudes beyond the carrier structure 1 with its front end face 15.

[0093] The outer sheath 21 has a plurality of locking protrusions 26 distributed around the longitudinal axis L at its axial anterior end. These locking protrusions 26 protrude radially outward from the outer peripheral surface 24 and face the flange 25 axially with their rear end faces. The outer peripheral surface 24, which serves as the mating surface, extends axially from the flange 25 into the region of the remaining protrusions 26.

[0094] Figure 7 and Figure 8 The sound-absorbing bushing 10 is shown in its assembled state, wherein the outer sheath 21 is press-fitted immovably to the carrier structure 1. Figure 7 This is an axial view of the front end face of the sound-absorbing bushing 10. Figure 8 With Figure 3 The same longitudinal section shows the sound-absorbing bushing 10, as well as the carrier structure 1 in the assembly area.

[0095] During assembly, the silencing bushing 10 is pushed into the channel 2 of the carrier structure 1 until the flange 25 of the outer sheath 21 abuts against the rear end face 3 of the carrier structure 1. The stop contact of the flange 25 on the end face 3 defines the axial position of the silencing bushing 10 relative to the carrier structure 1. In the fully assembled state, the silencing bushing 10 protrudes through the channel 2, such that the inner core 11, with its front end face 15, protrudes freely beyond the carrier structure 1, at least within the region of the channel 2. The outer sheath 21 also protrudes through the channel 2, with locking protrusions 26 protruding radially beyond the channel 2. In the assembled state, each of the locking protrusions 26 is a small axial distance from the front end face of the carrier structure 1 at its rear end face. The locking protrusions 26 are not used for fixation but only as a safety measure in case of damage to the silencing bushing 10. The flange 25 and the locking protrusions 26 also securely hold the silencing bushing 10 to the carrier structure 1.

[0096] As described above, the outer peripheral surface 24 of the outer sheath 21 is non-circular to match the cross-section of the channel 2 of the carrier structure 1 (hexagonal in this embodiment). The carrier structure 1 then defines its channel 2 with its non-circular (hexagonal in this embodiment) inner peripheral surface. In the assembled state, the outer sheath 21 is press-fitted into the channel 2 with its outer peripheral surface 24, and rotation relative to the carrier structure 1 is further prevented by the shape fit of the two non-circular peripheral surfaces 2 and 24.

[0097] from Figure 7 The view and Figure 5 As can be seen from the perspective view, the outer peripheral surface 12 of the inner core 11 and the inner peripheral surface 22 of the outer sheath 21 are non-circular and match each other. In this embodiment, both outer peripheral surfaces 12 and 22 are hexagonal. While the outer peripheral surfaces 12 and 22 could theoretically be non-circular and match each other in other ways, polygons, especially hexagons, with rounded corners are particularly advantageous. The outer peripheral surfaces 12 and 22 follow each other circumferentially at a certain radial distance. Their flat sides are parallel to each other.

[0098] If we consider the silencing bushing 10, i.e., in the initial unloaded state, the non-circular outer circumferential surfaces 12 and 22 are twisted relative to each other by a certain lead angle around the longitudinal axis L. At this relative rotation angle, the inner core 11 and outer sheath 21 are still in an assembled state, but before being press-fitted with the unit 4. Therefore, as... Figure 7 As shown, the lead angle is marked as "α".

[0099] During the assembly of unit 4, due to the tightening torque from the threaded engagement of the engagement structure 14, the inner core 11 overcomes the elastic restoring force of the elastomeric structure 18 and rotates about the longitudinal axis L relative to the outer sheath 21, which prevents rotation, towards a concentric position. The spring stiffness of the elastomeric structure 18 is matched with the tightening torque (appropriately specified) required to produce the press fit, so that once the inner core 11 reaches a concentric position relative to the outer sheath 21, the relative rotation of the inner core 11 is terminated by the increase in axial pressure between the inner core 11 and unit 4. The spring stiffness and lead angle α are matched accordingly.

[0100] Given the desired high spring stiffness, at least higher than that of the main damper 8, it is advantageous that the lead angle α is at most 6° or at most 5°. To ensure that the peripheral surfaces 12 and 22 are as precisely parallel as possible after the press fit is established, it is advantageous that the lead angle α is at least 0.5°, at least 1°, or at least 1.5°. The aim of striving for parallelism is to make the elastomer structure 18 exhibit multiple rotational symmetries in the preloaded state. The outer peripheral surfaces 12 and 22, and the corresponding preloaded elastomer structure 18, should each preferably exhibit at least threefold rotational symmetry, more preferably sixfold rotational symmetry, in the preloaded state. This achieves the greatest possible invariance to changes in the radial vibration direction of the unit 4.

[0101] The silencing bushing 10 dampes the vibrations of the unit 4 about its longitudinal axis L in both the radial and axial directions. It also dampes the torsional vibrations of the unit 4, i.e., tilting oscillations. Radial vibrations are primarily compensated by the elastomeric material located between circumferential surfaces 12 and 22. Axial vibrations are damped by the same elastomeric material, and also to a large extent by the elastomeric material of flange 19 located between flanges 16 and 25. By varying the ratio of the axially measured thickness of the elastomeric flange 19 to the length and / or radial thickness of the elastomeric material located between the non-circular outer circumferential surfaces 12 and 22, the axial and radial spring stiffnesses can be precisely and specifically matched to each other.

[0102] Regarding the elastomer structure 18 and the outer sheath 21, it should also be noted that the elastomer structure 18 is not limited by the outer sheath 21 at its axial tip. This makes it easier to match the axial and radial spring stiffnesses.

[0103] In terms of materials, the inner core can be made of metal or metal alloy. The outer sheath 21 is advantageously molded from plastic, especially from thermoplastic materials. Suitable elastomeric materials for the elastomeric structure 18 are, for example, ethylene propylene diene monomer (EPDM) rubber and / or silicone resin, especially vinyl methyl silicone resin (VMQ) and / or natural rubber (NR). Thermoplastic elastomers (TPE) are also particularly suitable.

[0104] Figure 9 The sound level pressure, in dB(A), of the vibrations occurring during the operation of the coolant compressor is shown, measured in Unit 4. Curve E represents the sound level pressure during coolant compressor support. Figure 1 The damper system of the present invention shown is used as the first series of measurements to measure the sound level pressure. For example... Figure 2 Schematic illustration shows that the carrier structure 1 is supported on the vehicle body structure K by the main vibration damper 8. During measurement, the coolant compressor is coupled to the carrier structure 1 via the silencing bushing 10. Curve R represents the sound level pressure from a series of reference measurements recorded for comparison, using the same carrier structure 1 and with the support of the main vibration damper 8 remaining unchanged. To record the series of reference measurements, the silencing bushing 10 is replaced with a simple screw insert, and the coolant compressor is securely fixed to the carrier structure 1 by screws. To record both series of measurements, the coolant compressor is operated throughout its operating range according to a specified measurement procedure.

[0105] In the range from below 100 Hz to up to approximately 300 Hz, the noise reduction effects of the two measurement arrangements or bearing arrangements are comparable. In the high-frequency range, particularly across the entire range above approximately 800 Hz, when supported by the damper system of this invention, the measured sound level pressure E is significantly lower than the reference measured sound level pressure R. The small anomaly at approximately 400 Hz is not noticeable in vehicles and can be tolerated or eliminated through optimized arrangement.

Claims

1. A damper system for damping the vibration of a vehicle unit (4), the damper system comprising: One or more main dampers (8), tuned or individually tuned to vibrations in the low-frequency range, so that the unit (4) is supported in the vehicle in a damping manner; as well as One or more sound-absorbing bushings (10), tuned or individually tuned to vibrations in a high-frequency range that is higher than and does not overlap with the low-frequency range, so that the unit (4) is coupled to the vehicle's carrier structure (1) in a vibration-damping manner.

2. The damper system according to claim 1, wherein, The corresponding main damper (8) has a first natural frequency in the low frequency range, and the corresponding silencing bushing (10) has a first natural frequency in the high frequency range.

3. The damper system according to claim 2, wherein, The first natural frequency of the corresponding main damper (8) is the first natural frequency of the translational vibration mode of the corresponding main damper (8), and / or the first natural frequency of the corresponding sound-absorbing bushing (10) is the first natural frequency of the translational vibration mode of the corresponding sound-absorbing bushing (10).

4. The damper system according to any one of claims 1 to 3, wherein, The corresponding main damper (8) has a global maximum value of dissipated vibration energy in the low frequency range, and the corresponding sound-absorbing bushing (10) has a global maximum value of dissipated vibration energy in the high frequency range.

5. The damper system according to any one of claims 1 to 3, wherein, The low-frequency range is at most 75 Hz, and / or the high-frequency range is higher than 100 Hz.

6. The damper system according to any one of claims 1 to 3, wherein, The low-frequency range is at most 50 Hz, and / or the high-frequency range is higher than 100 Hz.

7. The damper system according to claim 5, wherein, The low frequency range is 10Hz to 30Hz, and / or the high frequency range is higher than 400Hz.

8. The damper system according to claim 6, wherein, The low frequency range is 10Hz to 30Hz, and / or the high frequency range is higher than 400Hz.

9. The damper system according to any one of claims 1 to 3, wherein the sound-absorbing bushing (10) comprises: The inner core (11) has an outer peripheral surface (12) that extends around the longitudinal axis (L) of the sound-absorbing bushing (10); The outer sheath (21), the inner circumferential surface (22) of which surrounds the outer circumferential surface (12); and An elastomer structure (18) is provided that is in surface contact with the outer peripheral surface (12) of the inner core (11) and in surface contact with the inner peripheral surface (22) of the outer sheath (21), and the inner core (11) and the outer sheath (21) are in surface contact and shear-resistantly and / or torsional-resistantly coupled about the longitudinal axis (L).

10. The damper system according to claim 9, wherein, The outer peripheral surface (12) of the inner core (11) and the inner peripheral surface (22) of the outer sheath (21) are in surface contact with the elastomer structure (18), and both are non-circular.

11. The damper system according to claim 10, wherein, The outer peripheral surface (12) of the inner core (11) and the inner peripheral surface (22) of the outer sheath (21) are both polygonal.

12. The damper system according to claim 9, wherein, Starting from the unloaded initial state of the silencing bushing (10), the outer sheath (21) is able to rotate about the longitudinal axis (L) relative to the inner core (11) by a lead angle (α) to a rotation angle position against the elastic restoring force of the elastomer structure (18), where the outer peripheral surface (12) of the inner core (11) is at least partially parallel to and / or concentric about the longitudinal axis (L) with respect to the inner peripheral surface (22) of the outer sheath (21).

13. The damper system according to claim 12, wherein, Starting from the unloaded initial state of the silencing bushing (10), the outer sheath (21) is able to rotate about the longitudinal axis (L) relative to the inner core (11) by a lead angle (α) to a rotation angle position against the elastic restoring force of the elastomer structure (18), where the outer circumferential surface (12) of the inner core (11) is circumferentially parallel to and / or concentric about the longitudinal axis (L) with respect to the inner circumferential surface (22) of the outer sheath (21).

14. The damper system according to claim 9, wherein, The outer sheath (21) has a non-circular outer peripheral surface (24) so ​​as to be torsionally engaged with the carrier structure (1) around the longitudinal axis (L).

15. The damper system according to claim 14, wherein, The outer sheath (21) has a polygonal outer peripheral surface (24) so ​​as to be torsionally engaged with the carrier structure (1) around the longitudinal axis (L).

16. The damper system according to claim 9, wherein, The inner core (11) has an axially extending cavity (13), and the outer peripheral surface (12) of the inner core (11) extends around the cavity (13), wherein the cavity (13) extends to at least one end of the sound-absorbing bushing (10).

17. The damper system according to claim 16, wherein, The cavity (13) is an axial straight channel (13) that allows fasteners to be inserted into the cavity (13) to engage with the unit (4).

18. The damper system according to claim 9, wherein, The inner core (11) protrudes axially beyond the outer sheath (21) at its tip, and the protruding tip has an end face (15) for axial pressing to create an axial press fit with the unit (4).

19. The damper system according to claim 9, wherein, The inner core (11), the outer sheath (21), and the elastomer structure (18) each have a flange, and the flange (19) of the elastomer structure (18) is axially located between the flange (16) of the inner core (11) and the flange (25) of the outer sheath (21) and protrudes radially outward, so that the flange (19) of the elastomer structure (18) can be axially elastically compressed between the flange (16) of the inner core (11) and the flange (25) of the outer sheath (21).

20. The damper system according to claim 9, wherein, The outer sheath (21) has a radially outwardly projecting locking protrusion (26) at its axial tip to axially retain the corresponding sound-absorbing bushing (10) in the mounting position when engaged with the carrier structure (1).

21. The damper system according to any one of claims 1 to 3, wherein, The damper system includes a carrier structure (1); The corresponding main vibration damper (8) and the corresponding sound-absorbing bushing (10) are joined to the carrier structure (1); and The unit (4) is connected to the corresponding silencing bushing (10).

22. The damper system according to claim 21, wherein, The corresponding main damper (8) is independent of the unit (4) so ​​that the carrier structure (1) is coupled to the other structure (K) of the vehicle in a damping manner through the corresponding main damper (8).

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