Shaft vibration damper

Abstract

The present disclosure relates to a shaft vibration damper, and in particular proposes a shaft vibration damper for absorbing vibrations of a shaft (4, 6), comprising an elastomer (8) passed through by a central longitudinal center axis (A), wherein the elastomer (8) has a retaining geometry protruding in a radial direction (R) and extending in a longitudinal direction (L), for pressing the shaft vibration damper together with the shaft (4, 6), wherein the retaining geometry is respectively arranged in two first angle windows (W1) with a width of at most 90°, which are opposite to each other with respect to the longitudinal center axis (A), so that the shaft vibration damper (2) can form a radial pressure with the shaft (4, 6) along a first tuning axis (A1) extending in the radial direction (R), and the radial pressure is greater than the pressure in a different spatial direction extending in the radial direction (R).

Description

Technical Field

[0001] The present invention relates to axle vibration dampers and assemblies. Background Art

[0002] In all-wheel-drive rear-wheel-drive vehicles, the force from the engine, located in the front of the vehicle, is transmitted to the rear wheels via a longitudinal shaft and axle shafts. The longitudinal shaft connects the engine or transmission unit to the differential and can be designed as a multi-piece structure. The differential is connected to the rear wheel hubs via axle shafts. The inherent shape of the shaft can cause vibrations when the shaft accelerates. This vibration results in unbalanced forces acting on the shaft's bearings, which in turn causes noise within the vehicle.

[0003] In order to reduce noise, it is known from practice that Figure 1 The shock absorber shown can be fixed to the corresponding shaft as a rotating shock absorber. The shock absorber is tuned radially to the corresponding frequency of the inherent shape of the shaft to reduce the reinforcement of the inherent shape. This can reduce the noise in the vehicle caused by the excitation of the inherent shape. The shock absorber can be, for example, an internal tube shock absorber, which can be fixed in the inner cavity of a hollow shaft, or alternatively a half-shaft shock absorber, which can be fixed to the outer circumference of the shaft. For fixing, the shock absorber can be pressed against the shaft by an elastomer part, which exerts radial pressure on the shaft. This pressure determines the axial force used to mount the shock absorber on the shaft through friction.

[0004] In tuning the damper to the inherent shape of the shaft, the damper's radial inherent shape is tuned to coincide with the shaft's natural bending frequency in all axial directions. This type of damper is also referred to as a radial damper. This applies to both conventional tubular dampers and conventional half-shaft dampers, which is why they are designed to be rotationally symmetrical about the longitudinal center axis, sometimes with a multiplicity of 8 or higher. If the compressive force is applied by an elastomeric element without an additional clamping sleeve, this affects the axial pressure or pressing force used to install the damper into or onto the shaft. The elastomeric element also contributes to the damper's radial inherent shape. The axial force used to mount the damper on the shaft should not fall below a lower threshold to prevent the damper from slipping axially along the shaft and becoming less effective or even losing its effectiveness due to positional changes during its service life. Especially at low tuning frequencies below 120 Hz, tubular dampers typically require a support clamping sleeve, while half-shaft dampers typically require fasteners, such as a support hose clamp, to maintain the damper's position. This results in additional costs and an undesirable increase in the installation outlay. Summary of the Invention

[0005] The object of the present invention is therefore to provide a shaft vibration damper for absorbing vibrations of a shaft, which has a reduced installation outlay and reduced costs.

[0006] According to the present invention, a shaft vibration damper for absorbing vibrations of a shaft is proposed, comprising an elastomer body through which a central longitudinal center axis passes, wherein the elastomer body has retaining geometries protruding in the radial direction and extending in the longitudinal direction for pressing the shaft vibration damper against the shaft, wherein the retaining geometries are respectively arranged in two first angular windows, each having a width of at most 90°, located opposite each other with respect to the longitudinal center axis, so that the shaft vibration damper can generate a radial pressure force against the shaft on a first tuning axis extending in the radial direction, which is greater than a pressure force in a spatial direction extending in a different radial direction. The radial pressure force that can be generated can be, for example, at least 400 N, preferably at least 450 N, and more preferably at least 500 N, so as to be greater than an axial compressive force that would cause the shaft vibration damper to move axially and / or radially out of its installed state.

[0007] The shaft vibration damper according to the present invention is therefore distinguished by the fact that it is not tuned identically in all radial directions or has different tuning in radial directions. Instead, it can achieve different damping frequencies in radial directions. This basic concept is structurally implemented by opposing corner windows with a constant geometry, preferably a unique constant geometry. The shaft vibration damper thus has at least two tuning axes that differ in their function and tuning.

[0008] The tuning axes extend in radial directions. They can intersect the longitudinal center axis of the shaft vibration damper. Opposite tuning directions can extend along each tuning axis. Tuning directions on a tuning axis can be assigned the same tuning frequency. The first tuning axis can pass centrally through the two first corner windows.

[0009] The shaft damper is highly tuned or tunable along a first tuning axis by means of a retaining geometry. It is rigid in this direction. The first tuning axis can also be called a sacrificial axis, since the damping capacity in this direction is sacrificed to the ease of compaction. However, it has been shown that the negative impact of the height tuning along the first tuning axis on the ability of the shaft damper to tune to the inherent curved shape of the shaft is relatively low. A sufficiently high axial pressure can be achieved by height tuning along the first tuning axis. The clamping sleeve used by the prior art to ensure sufficient pressure can be omitted. The retaining geometry contained in the first corner window ensures a pressure sufficient for permanently fixing the shaft damper to the shaft.

[0010] The shaft vibration damper is tuned or can be tuned to a tuning frequency corresponding to the natural bending shape of the shaft along a spatial direction different from the first tuning axis or along a second tuning axis different from the first tuning axis. It is soft in this direction. The primary function of the shaft vibration damper or its structure is frequency tuning.

[0011] The shaft damper according to the present invention is therefore no longer a radial damper, but rather a uniaxial damper, which is fixed along a defined tuning axis and damps vibrations along a different tuning axis. The shaft damper according to the present invention is stiffer along the first tuning axis than along a different spatial direction and / or than along the second tuning axis. The difference in stiffness can be at least 20%, preferably at least 30%, more preferably at least 40%, and even more preferably at least 50%. Designing the shaft damper to be stiffer in the radial direction along the first tuning axis than in any other spatial direction means that the first tuning axis specifies the defined vibration direction. The shaft damper can thus vibrate in two vibration directions along the defined vibration axis during use. Preferably, this vibration axis corresponds to the second tuning axis. It has been found that different vibration frequencies can be achieved in the radial direction by correspondingly contouring the elastomer with retaining geometries. In the shaft damper according to the present invention, these retaining geometries can therefore be spaced unevenly from one another in the circumferential direction.

[0012] In principle, the two first corner windows can be of the same or different sizes. It is conceivable that the width of the first corner window is determined by an outer geometry, such as an edge, a side edge of the retaining surface in the circumferential direction, an edge at the side wall or the bottom of the side wall, or at least one retaining geometry arranged in the corner window.

[0013] The elastic body may comprise a main body which surrounds the vibration-damping body, and the retaining geometry may protrude therefrom.

[0014] The axle vibration damper according to the present invention can be an inner tube type vibration damper, in which case these retaining geometries extend radially outwards, but it can also be a half-axle vibration damper, in which case these retaining geometries extend radially inwards.

[0015] The pre-installed state is intended to refer to the condition in which the shaft vibration damper is not pressed against the shaft and no external forces are acting. The installed state is intended to refer to the condition in which the shaft vibration damper is pressed against the shaft. Retaining geometry is intended to refer to the structure or structural arrangement that primarily, and preferably exclusively, serves to retain or compress the shaft vibration damper. Primarily means that the retaining geometry primarily serves a function. With respect to retaining geometries, it cannot be absolutely ruled out that they unintentionally or unavoidably perform other functions in addition to their primary retaining function, such as vibration damping. However, secondary functions that lag behind the primary function are significantly less important than the primary function in terms of the effect caused by the retaining geometry. Therefore, other structures of the shaft vibration damper that are not primarily used to retain the shaft vibration damper differ from the retaining geometry. For example, radial stops primarily serve to limit radial deflection, although they, like retaining geometries, can protrude radially. Structures that merely abut the shaft without exerting any significant retaining pressure on the shaft vibration damper are also conceivable; in this context, such structures are not to be considered retaining geometries. The operational state is intended to refer to the condition in which the shaft vibration damper rotates with the shaft in the installed state. The corner window may have a sector shape, wherein two circle radii intersect at the longitudinal center axis of the shaft damper.

[0016] According to one conceivable development of the shaft vibration damper according to the invention, the shaft vibration damper is designed so that, in the installed state, at least 60%, preferably at least 70%, more preferably at least 80%, even more preferably at least 90%, and even particularly preferably at least 95% of the pressure force holding the shaft vibration damper is applied by the retaining geometry within the two first corner windows. The higher the proportion of the pressure force due to the retaining geometry within the first corner windows, the stiffer the shaft vibration damper is designed along the first tuning axis.

[0017] According to one conceivable refinement of the shaft vibration damper according to the invention, the retaining geometries include contact surfaces, via which they rest against the shaft in the installed state. These contact surfaces are preferably arranged on the distal radial inner and outer circumferences of the retaining geometries. It is conceivable that, in the pre-installed state, the contact surfaces rest on the surface of an imaginary cylinder, whose longitudinal center axis is coaxial with the longitudinal center axis of the shaft vibration damper. This ensures a uniform stress distribution in the retaining geometries in the installed state.

[0018] According to one conceivable development of the shaft vibration damper according to the invention, it comprises only two tuning axes, wherein the first tuning axis is preferably arranged orthogonally to the second tuning axis. This allows the formation of a shaft vibration damper that is stable in multiple spatial directions along the first tuning axis and vibrates in a spatial direction extending perpendicular thereto along the second tuning axis.

[0019] According to a conceivable improvement of the shaft vibration damper according to the invention, the elastomer is designed to be integral with the retaining geometry. It is conceivable that the elastomer has no material connection to the stabilizing element, in particular the clamping sleeve.

[0020] According to a conceivable improvement of the shaft vibration damper according to the invention, at least one of the retaining geometries has at least one retaining longitudinal web. It is conceivable that exactly one retaining longitudinal web is provided for each retaining geometry and that this retaining longitudinal web is surrounded by the retaining geometry. However, it is also conceivable that each retaining geometry has two, three or more retaining longitudinal webs. It is also conceivable that adjacent retaining longitudinal webs of a retaining geometry are arranged equidistantly in the circumferential direction. It is also conceivable that the two retaining geometries within the two first corner windows are designed to be identical or different. The advantage of the space formed by the slots between adjacent retaining longitudinal webs or by the slots within the first corner windows is that the retaining geometries or the retaining longitudinal webs can be better spread out during installation.

[0021] According to a conceivable improvement of the shaft vibration damper according to the present invention, the side walls of at least one retaining longitudinal connector, preferably all retaining longitudinal connectors, extend parallel to or obliquely relative to the first tuning axis. This inclination can be achieved in a positive direction, thereby forming a retaining longitudinal connector with a trapezoidal cross section, whose short side faces away from the shaft vibration damper. However, this inclination can also be achieved in a negative direction, thereby forming a retaining longitudinal connector with a trapezoidal cross section, whose long side faces away from the shaft vibration damper. The opposite side can contain the retaining surface. In the case of a positive inclination, the angle in the transition between the retaining longitudinal connector and the adjacent section of the elastomer can be increased, which leads to a reduction in stress in the installed and operating state, thereby resulting in a longer service life. The transition section can also have a radius. The retaining longitudinal connector can be designed to have a ring segment cross section.

[0022] According to a conceivable improvement of the shaft vibration damper according to the invention, two first corner windows enclose at least two second corner windows in the circumferential direction, wherein the second corner windows are preferably designed as intermediate gaps, or they contain intermediate gaps and / or do not have retaining geometries that are primarily used for pressing together with the shaft. The second corner windows can therefore be used advantageously to ensure that the bearing is as free to vibrate as possible during use. The second corner windows can be directly enclosed by the first corner windows. It is conceivable that the bearing includes exactly two second corner windows. The second corner windows can be designed to be open or closed on one or both sides in the longitudinal direction. It is also conceivable that the retaining geometries of the two first corner windows enclose at least two intermediate gaps in the circumferential direction.

[0023] According to one conceivable refinement of the shaft vibration damper according to the present invention, the second corner windows each comprise a space with a ring segment-shaped cross section. The ring segment-shaped space can extend circumferentially between two first corner windows or adjacent retaining geometries of two first corner windows and / or be bounded radially on one side by an elastomer, a vibration damping body, or an elastomer segment directly surrounding the vibration damping body, and can also be open. The radial opening can be radially outward in the case of an inner tube vibration damper and radially inward in the case of a half-shaft vibration damper.

[0024] According to a conceivable development of the shaft vibration damper according to the invention, the retaining geometries are arranged only in the first corner window. As a result, the shaft vibration damper can be tuned very hard along a first tuning axis and very softly along another tuning axis.

[0025] According to one refinement of the shaft vibration damper according to the invention, the retaining geometries are arranged rotationally symmetrically about the longitudinal center axis, preferably with a multiplicity of 2. Additionally or alternatively, the retaining geometries can be arranged mirror-symmetrically about a central longitudinal center plane. The longitudinal center axis of the shaft vibration damper lies within this central longitudinal center plane. This allows the two first corner windows to have an identical design.

[0026] According to a conceivable development of the shaft vibration damper according to the invention, the retaining geometries of the first corner windows are radially diametrically opposed with respect to the longitudinal center axis. Thus, the first tuning axis can intersect the longitudinal center axis of the shaft vibration damper.

[0027] According to a refinement of the shaft vibration damper according to the present invention, the sum of the angles of the second angled windows relative to the longitudinal center axis in the cross section of the shaft vibration damper is at least 180°, preferably at least 220°, and more preferably at least 240°. This allows the large inner or outer circumference of the shaft vibration damper to be utilized to form a radial deflection distance.

[0028] According to one conceivable development of the shaft vibration damper according to the present invention, the sum of the angles of the first angled windows relative to the longitudinal center axis in the cross section of the shaft vibration damper is at most 140°, preferably at most 120°, and more preferably at most 90°. This allows for a small window and a small overlap width between the retaining geometry and the shaft, which in turn increases the space available for vibrations of the shaft vibration damper. A large inner or outer circumference of the shaft vibration damper can be utilized to create a radial deflection distance.

[0029] According to one refinement of the axle vibration damper according to the present invention, the sum of the angles of the circumferential retaining surfaces of the retaining geometry relative to the longitudinal center axis in cross section is at most 180°, preferably at most 160°, more preferably at most 140°, and even more preferably at most 120°. An angle of at most 100° is also conceivable. The retaining surfaces can be inner or outer retaining surfaces, depending on the type of axle vibration damper. Preferably, the retaining surfaces arranged in the first corner window are of equal size on both sides relative to the longitudinal center axis.

[0030] According to one conceivable refinement of the shaft vibration damper according to the present invention, the shaft vibration damper includes a damping body at least partially, preferably completely, surrounded by an elastomer and made of a different material. The damping body can be made of metal. This allows for radial stopping without metallic noise and corrosion protection of the damping body.

[0031] According to a refinement of the shaft vibration damper according to the present invention, it eliminates the need for stabilizers, particularly clamping sleeves or clips. The retaining geometry preferably extends between the damping body and its respective retaining surface and / or along its radial extent, but without the need for stabilizers, particularly clamping sleeves. The stabilizer is characterized by its cylindrical design and, in the installed state, ensures a radial pressure force that is greater than the axial pressure force for permanent securing of the vibration damper. Due to the design of the longitudinal retaining web and its explicit placement within the two first corner windows, such stabilizers are unnecessary. This significantly reduces production costs and installation expenditure.

[0032] According to one conceivable refinement of the shaft vibration damper according to the invention, at least one retaining geometry is installed radially behind the longitudinal recess in the damping body. The same applies analogously to the retaining longitudinal webs. This allows for the formation of an elastic body geometry with a greater radial extent than without the longitudinal recess. This also allows for the influence of the stiffness in the direction of the first tuning axis and the vibration or deflection capacity transversely thereto.

[0033] According to a conceivable improvement of the shaft vibration damper according to the invention, at least one of the retaining geometries has at least one slot extending in the longitudinal direction. The slot separates the multiple sections of the retaining geometry in the circumferential direction. It can be arranged, for example, between the longitudinal retaining webs. The slot can have a radial extension that is equal to the radial extension of the retaining geometry or the adjacent longitudinal retaining webs. However, it can also be designed to be shorter, for example with a radial extension that is half or one-third of the radial extension of the retaining geometry or the adjacent longitudinal retaining webs. The space formed by the slots between adjacent longitudinal retaining webs or by the slots within the first corner window allows the retaining geometry or the longitudinal retaining web to be better spread out during installation.

[0034] According to a conceivable improvement of the shaft vibration damper according to the invention, the cross section of the slot is designed to be V-shaped, U-shaped, semi-elliptical or semi-circular. It is conceivable that the slot extends parallel to the longitudinal center axis of the shaft vibration damper.

[0035] According to a refinement of the shaft vibration damper according to the present invention, in the pre-installed state of the shaft vibration damper, which is free of stress, the retaining surface lies on the surface of a first imaginary cylinder having a first cylindrical diameter. In the installed state, when the shaft vibration damper is pressed against the shaft, the retaining surface can lie on the surface of a second imaginary cylinder having a second cylindrical diameter. The second diameter is at most 0.95 times, preferably at most 0.9 times, and more preferably at most 0.85 times, the magnitude of the first diameter, or the first diameter is at most 0.95 times, preferably at most 0.9 times, and more preferably at most 0.85 times the magnitude of the second diameter. The imaginary cylinders can be arranged coaxially with one another, i.e., share a common axis. These values ​​represent the diameter reduction of the shaft vibration damper after installation. In principle, a larger diameter change can result in higher pressures, without producing any technical effects that differ from those within the required range near each desired value. The effects differ only in their molding.

[0036] According to a refinement of the shaft vibration damper according to the present invention, the elastomer body has at least one radial stop protruding radially within the second corner window, preferably a stop link designed so that, in the installed state, it has a smaller radial extent than the retaining geometry. However, a smaller radial extent is also present in the pre-installed state. It is conceivable that the radial stops are diametrically opposed to one another with respect to the longitudinal center axis of the shaft vibration damper and are arranged mirror-symmetrically with respect to a central longitudinal plane, in which the longitudinal center axis of the shaft vibration damper and / or the first tuning axis lie. By appropriately contouring the elastomer body in a spatial direction different from the first tuning axis or in the direction of the second tuning axis, a characteristic curve with a linear or gradual profile can be adjusted, thereby extending the service life.

[0037] According to a conceivable development of the shaft vibration damper according to the invention, the cross section of the radial stop is designed as an elongated rectangle, a triangle, a semi-ellipse or a semi-circle.

[0038] According to a conceivable development of the shaft vibration damper according to the invention, in the installed state of the shaft vibration damper, the radial distance between the circumferential surface of the damping body and at least one of the retaining surfaces is at most 0.25 times, preferably at most 0.125 times, more preferably at most 0.1 times the diameter of the damping body.

[0039] The present invention also provides an assembly comprising a shaft and a shaft damper according to the present disclosure, which is pressed against the shaft via retaining surfaces with a retaining geometry. The shaft damper can be, for example, an internal tube damper, which can be fixed in the interior of a hollow shaft, or a half-shaft damper, which can be fixed to the outer circumference of the shaft. The shaft can be a longitudinal shaft or a half-shaft. Multiple shafts with multiple identical or different shaft dampers are also conceivable. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Further features, details and advantages of the invention are derived from the wording of the claims and from the following description of embodiments in conjunction with the accompanying drawings, in which:

[0041] Figure 1 A vibration damper known from practice is shown;

[0042] Figure 2 shows a schematic cross-sectional view of a vehicle having an axle damper;

[0043] Figure 3 A perspective view shows a shaft vibration damper according to the invention according to a first embodiment;

[0044] Figure 4 The end view shows the Figure 3 Axle vibration damper;

[0045] Figure 5 Based on Figure 4 The cross-sectional view along line VV shows the Figure 3 Axle vibration damper;

[0046] Figure 6 Based on Figure 4 The cross-sectional view along line VI-VI shows the Figure 3 Axle vibration damper;

[0047] Figure 7 A perspective view shows a shaft vibration damper according to the invention according to a second embodiment;

[0048] Figure 8 The end view shows the Figure 7 Axle vibration damper;

[0049] Figure 9 Based on Figure 8 The cross-sectional view along line IX-IX shows the Figure 7 Axle vibration damper;

[0050] Figure 10 Based on Figure 8 The cross-sectional view along line XX shows the Figure 3 Shaft vibration damper 3.

[0051] In the drawings, identical or corresponding parts are respectively indicated by the same reference numerals and will not be described again unless it is inappropriate. Features that have already been described will not be described again to avoid repetition and can be applied to all parts with identical or corresponding reference numerals, unless expressly excluded. The disclosure contained in the entire specification applies to the same parts with the same reference numerals or the same component names in accordance with the meaning. Position descriptions selected in the description, such as top, bottom, sideways, etc., also relate to the drawings just described and shown and are transferred to the new positions in accordance with the meaning when the position changes. In addition, individual features or combinations of features from the different embodiments shown and described can also be independent, creative or solutions according to the invention.

[0052] Reference Signs List

[0053] 2-axis shock absorber

[0054] 4-axis

[0055] 6-axis

[0056] 8 Elastomer

[0057] 10 Main Body

[0058] 12 Vibration damper

[0059] 14. Keep the vertical strips connected

[0060] 16 Intermediate space

[0061] 18 Keep Surface

[0062] 26 sidewall

[0063] 28 sides

[0064] 30 Side wall bottom

[0065] 102 shock absorber

[0066] 108 Elastomer

[0067] 112 vibration damper

[0068] 114 Keep vertical strips

[0069] 118 Keep Surface

[0070] 140 Fastening sleeve

[0071] 202 vehicles

[0072] 204 Transmission

[0073] 206 differential

[0074] 208 engine

[0075] 210 rear wheel

[0076] A longitudinal center axis

[0077] A1 First tuning axis

[0078] A2 Second tuning axis

[0079] E longitudinal center plane

[0080] L Longitudinal direction

[0081] R radial direction

[0082] U Circumferential direction

[0083] W1 first corner window

[0084] W2 Second corner window

[0085] αW1 Width of the first corner window

[0086] αW2 Width of the second corner window DETAILED DESCRIPTION

[0087] exist Figure 1 , a vibration damper 102 in the form of an inner tube vibration damper known from practice is shown in a pre-installed position. The vibration damper 102 is centered by a longitudinal center axis A and has a longitudinal direction L, a radial direction R, and a circumferential direction U. The vibration damper 102 can be fixed in the shaft 4 for absorbing vibrations and comprises an elastomer 108. The elastomer 108 surrounds a central, completely cylindrical vibration damper body 112. Figure 1 In the figure, a portion of the elastomer 108 is omitted for illustrative purposes only, so that the vibration damping body 112 is visible. A clamping sleeve 140 is provided as a fastening element within the elastomer 108 and on the circumferential side of the vibration damping body 112. The elastomer 108 has retaining geometries that protrude from the clamping sleeve 140 on the circumferential side of the clamping sleeve 140 in the radial direction R and extend in the longitudinal direction L. These retaining geometries are each designed to retain longitudinal links 114 and serve to press the vibration damper 102 against the shaft. To this end, the retaining longitudinal links 114 each have a retaining surface 118 on the circumferential side. It can now be seen that the retaining longitudinal links 114 are all designed to be identical and are arranged equidistantly from one another in the circumferential direction U. The vibration damper 102 is therefore tuned identically in all radial directions R and can therefore be referred to as a radial vibration damper. The clamping sleeve 140 serves, on the one hand, to be mounted behind the retaining longitudinal web 114 and thereby to achieve a sufficiently large radial pressure, and, on the other hand, to mount the damping body 112 in a manner that allows for free vibration in all radial directions R.

[0088] exist Figure 2, a vehicle 202 is shown with a transmission 204 at the front and a differential 206 at the rear. Transmission 204 transmits the force of an engine 208 to differential 206 via the vehicle's longitudinal shaft, which can be shaft 4. Differential 206 is in turn coupled to rear wheels 210 via axle shafts, which can also be referred to as shaft 6. The longitudinal shaft is hollow and includes an axle damper 2 in the form of an internal tubular damper according to the present invention for absorbing vibrations of shaft 4. The axle shafts also each include an axle damper 2 as axle damper for absorbing vibrations of their respective shaft 6. Although vehicle 202 is shown here as having an internal combustion engine, the present invention can also be directly applied to hybrid vehicles or purely electric vehicles.

[0089] The present invention also provides an assembly comprising a shaft and a shaft vibration damper according to the present disclosure, which is pressed against the shaft via retaining surfaces with a retaining geometry. The shaft vibration damper can be, for example, an internal tube vibration damper, which can be fixed in the interior of a hollow shaft, or a half-shaft vibration damper, which can be fixed to the outer circumference of the shaft. The shaft can be a longitudinal shaft or a half-shaft. Multiple shafts with multiple identical or different shaft vibration dampers are also conceivable.

[0090] exist Figures 3 to 6 , a shaft vibration damper 2 according to the invention is shown in a pre-installed position in an embodiment designed as an inner tube vibration damper. The shaft vibration damper 2 is centered by a longitudinal center axis A and has a longitudinal direction L, a radial direction R and a circumferential direction U. The shaft vibration damper 2 can be fixed in the shaft 4 for absorbing vibrations and comprises a one-piece elastomer 8. The elastomer 8 has no material connection to a stabilizing element, in particular to a clamping sleeve 140. The shaft vibration damper 2 comprises a completely cylindrical vibration damping body 12, which is completely surrounded by the elastomer 8. For illustrative purposes only, the shaft vibration damper 2 is shown in FIG. Figure 3 A portion of the elastic body 8 is hidden in the figure to reveal the vibration damping body 12 .

[0091] Different from using Figure 1 While the vibration damper 102 shown in FIG. 1 is an example of a known vibration damper, the shaft vibration damper 2 according to the present invention does not have a retaining geometry that is equidistant from one another in the circumferential direction. To this end, the shaft vibration damper 2 includes two first corner windows W1 diametrically opposed with respect to the longitudinal center axis A and having an identical width αW1. These first corner windows W1 directly enclose two second corner windows W2 having an identical width αW2 in the circumferential direction U.

[0092] The elastomer 8 comprises a hollow cylindrical body 10 and retaining geometries protruding from the body in the radial direction R and extending in the longitudinal direction L. Each retaining geometry is designed as a retaining longitudinal link 14 and serves to press the shaft damper 2 against the shaft 4. To this end, the retaining longitudinal links 14 each have a retaining surface 18 on the outer circumference, against which the shaft 4 rests when installed. The retaining longitudinal links 14 extend over the entire longitudinal extent of the shaft damper. The retaining longitudinal links 14 extend between the damping body 12 and its respective retaining surface 18, but without any intermediate stabilizing elements, particularly clamping sleeves. The retaining longitudinal links 14 are arranged only in the first corner window W1; the two second corner windows W2 do not have retaining geometries for pressing the shaft 4 together. This results in the formation of two different tuning axes A1 and A2 in the radial direction R, which intersect the longitudinal center axis A.

[0093] The first tuning axis A1 extends centrally through the first corner window W1, while the second tuning axis extends perpendicularly thereto centrally through the two second corner windows W2. The shaft damper 2 is highly tuned or tunable along the first tuning axis A1 by means of a retaining geometry. It is rigid in this direction. Due to the high degree of tuning along the first tuning axis A1, a sufficiently high axial pressure can be achieved. The shaft damper 2 is tuned or tunable to a tuning frequency corresponding to the natural bending shape of the shaft 4 in a spatial direction different from the first tuning axis A1, or along a second tuning axis A2 different from the first tuning axis A1. It is flexible in this direction. The primary function of the shaft damper 2 or its structure is frequency tuning. Consequently, the shaft damper 2 exerts a radial pressure on the shaft 4 along the first tuning axis A1 that is greater than the pressure along the second tuning axis A2.

[0094] In the embodiment shown, the retaining geometry is arranged only in the first corner window A1 . Therefore, in the installed state, 100% of the pressure holding the axle vibration damper 2 is exerted by the retaining geometry in the two first corner windows W1 .

[0095] The shaft damper 2 is arranged rotationally symmetrically about the longitudinal center axis A, having a multiplicity of 2. Furthermore, these retaining geometries can be arranged mirror-symmetrically about the central longitudinal neutral plane E. The longitudinal center axis of the shaft damper lies in this central longitudinal center plane.

[0096] The cross-section of the longitudinal retaining web 14 shown is designed to be annular in shape, with the respective side walls 26 pointing in the circumferential direction U extending parallel to the first tuning axis A1 when viewed in cross-section. Consequently, each of the side walls 26 forms an angle greater than 90° with the main body 10. Between each side wall 26 and the main body 10, the edge 28 of the side wall base 30 has a radius. The two longitudinal retaining webs 14 are designed so that their two retaining surfaces 18 form an angle of 120° in cross-section with respect to the longitudinal center axis. The retaining surfaces 18 arranged within the two first corner windows W1 are of equal size on both sides of the longitudinal center axis A. Consequently, the shaft damper 2 utilizes only one-third of its entire circumference for securing it to the shaft 4.

[0097] The portion of the main body 10 of the elastomer 8 arranged within the two corner windows W2 serves as a radial stop. The two second corner windows W2 are designed as intermediate gaps 16 and do not have a retaining geometry primarily for pressing together with the shaft 4 and are therefore advantageously used to ensure that the bearing 2 is as free as possible from vibration when in use. The cross-section of the second corner window W2 is designed to be ring segment-shaped and the second corner window is designed to be open on both sides in the longitudinal direction L. Its ring segment-shaped space extends between the two first corner windows W1 in the circumferential direction U. In the radial direction, the ring segment-shaped space is delimited on the inside by the elastomer 8 or the elastomer segment that directly surrounds the vibration damping body 12. On the opposite side, the ring segment-shaped space is open, so that it is delimited by the inner circumference of the shaft 4 in the installed state.

[0098] The shaft vibration damper 2 according to the invention is therefore not tuned to the radial natural frequency in all radial directions R. Instead, the frequency in only one direction (and the opposite direction) is tuned to the natural curvature of the shaft 4. The frequency in the second radial direction (and the opposite direction) is tuned much higher, and the required axial pressure force is achieved in the installed and operating state, which permanently secures the shaft vibration damper 2 to the shaft 4.

[0099] exist Figures 7 to 10 1 shows an axle vibration damper 2 according to the invention in the installed position in an embodiment designed as a half-axle vibration damper. Only the differences from the first embodiment will be described below to avoid repetition.

[0100] The shaft vibration damper 2 is fixed to the circumference of the shaft 6 for absorbing vibrations. The shaft vibration damper 2 comprises a hollow cylindrical damping body 12 which is completely surrounded by the elastic body 8. Figure 7 1 , a portion of the shaft vibration damper 2 is hidden only for illustrative purposes in order to illustrate the vibration damping body 12. The shaft vibration damper does not have any stabilizing elements, in particular hose clamps.

[0101] The longitudinal retaining webs 14 each have an inner circumferential retaining surface 18 , against which the shaft 6 rests in the installed state.

[0102] The illustrated retaining longitudinal webs 14 are designed in a trapezoidal cross-section, with their respective side walls 26, indicated in the circumferential direction U, extending in a raised manner relative to the first tuning axis A1, as seen in cross-section. Each side wall 26 is designed as a radius and transitions into the main body 10 at its base. The two retaining longitudinal webs 14 are designed so that their two retaining surfaces 18, in cross-section, have an angle of 100° with respect to the longitudinal center axis. Consequently, only approximately 28% of the total circumference of the shaft vibration damper 2 is used for its attachment to the shaft 6.

[0103] The second corner window W2 has a ring-segment cross-section and is open on both sides in the longitudinal direction L. Its ring-segment-shaped space extends between the two first corner windows W1 in the circumferential direction U. In the radial direction, the ring-segment-shaped space is bounded on the outside by the elastomer 8 or elastomer segment directly surrounding the damping body 12. This ring-segment-shaped space is open on the opposite side and, in the installed state, is bounded by the outer circumference of the shaft 6.

[0104] The invention is not limited to any of the above-described embodiments but can be varied in many ways. All features and advantages arising from the claims, the description, and the drawings, including structural details, spatial arrangements, and method steps, can be essential to the invention both individually and in various combinations.

[0105] All combinations of at least two of the features disclosed in the description, the claims and / or the drawings fall within the scope of the invention.

[0106] To avoid repetition, features disclosed with respect to the apparatus should also be considered as disclosed and claimable with respect to the method. Likewise, features disclosed with respect to the method should also be considered as disclosed and claimable with respect to the apparatus.

Claims

1. A shaft damper for absorbing vibrations of a shaft (4, 6), comprising an elastic body (8) through which a central longitudinal center axis (A) passes, wherein: The elastic body (8) has a retaining geometry protruding in the radial direction (R) and extending in the longitudinal direction (L) for pressing the shaft damper and the shaft (4, 6) together, characterized in that the retaining geometry is respectively arranged in two first angle windows (W1) with a width of at most 90° with respect to the longitudinal center axis (A), so that the shaft damper (2) can form a radial pressure with the shaft (4, 6) along a first tuning axis (A1) extending in the radial direction (R), and the radial pressure is greater than that in a different A pressure in a spatial direction extending in a radial direction (R), wherein the retaining geometry extends between the damping body (12) and its respective circumferential retaining surfaces (18) and / or within its radial extension without an intervening stabilizing element, wherein the retaining geometry comprises a contact surface, via which the retaining geometry rests against the shaft (4, 6) in the installed state and is pressed against the shaft (4, 6), and wherein at least 60% of the pressure holding the shaft damper in the installed state is exerted by the retaining geometry in the two first corner windows.

2. The shaft vibration damper according to claim 1, characterized in that At least one of the retaining geometries has at least one retaining longitudinal web (14).

3. The shaft vibration damper according to claim 1 or 2, characterized in that: The two first corner windows (W1) mutually enclose at least two second corner windows (W2) in the circumferential direction (U).

4. The shaft vibration damper according to claim 1, characterized in that The retaining geometry is arranged rotationally symmetrically about the longitudinal center axis (A) and / or the retaining geometry is arranged mirror-symmetrically about a central longitudinal center plane (E).

5. The shaft vibration damper according to claim 3, characterized in that The sum of the angles of the second corner window (W2) with respect to the longitudinal center axis (A) in a cross section of the shaft damper (2) is at least 180°.

6. The shaft vibration damper according to claim 1, characterized in that The angular sum of the circumferential retaining surfaces (18) of the retaining geometry in cross section with respect to the longitudinal center axis (A) is at most 180°.

7. The shaft vibration damper according to claim 1, characterized in that In the stress-free pre-installed state of the shaft vibration damper, the circumferential retaining surface (18) can be located on a first imaginary cylindrical surface having a first cylindrical diameter, and in the installed state of the shaft vibration damper in which it can be pressed together with the shaft (4, 6), the circumferential retaining surface (18) can be located on a second imaginary cylindrical surface having a second cylindrical diameter, wherein the second cylindrical diameter is at most 0.95 times the size of the first cylindrical diameter, or the first cylindrical diameter is at most 0.95 times the size of the second cylindrical diameter.

8. The shaft vibration damper according to claim 3, characterized in that The elastic body (8) has at least one radial stop protruding in the radial direction (R) within the second corner window (W2), and the radial stop is designed so that in the installed state it has a smaller extension in the radial direction (R) than the retaining geometry.

9. The shaft vibration damper according to claim 3, characterized in that The second corner windows (W2) are designed as intermediate spaces (16) or they comprise the intermediate spaces and / or have no retaining geometry primarily for pressing together with the shafts (4, 6).

10. An assembly comprising a shaft (4, 6) and a shaft vibration damper (2) according to any one of claims 1 to 9, the shaft vibration damper being pressed against the shaft (4, 6) via a circumferential retaining surface (18) of the retaining geometry.

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