DE 199 07 216 CI discloses a rotary vibration absorber which has a base part which is rotatable about an axis of rotation and which is in the form of a carrier plate. On the base part there is arranged an inertial mass part which is rotatable relative to the base part counter to the restoring force of a restoring apparatus. The restoring apparatus has a bending spring which extends in a radial direction and which is fastened at one side to the base part and at the other side to the inertial mass part. Furthermore, the restoring apparatus has a sliding block which is guided in a radial direction on the base part and which serves for supporting the bending spring on the base part in the mutually opposite directions of rotation. In this case, the sliding block can, in the direction of extent of the bending spring, be displaced inward or outward relative to the bending spring in the radial direction in order to vary the effective length of the bending spring. Consequently, in this way, a restoring apparatus is created which can be adjusted so as to vary a restoring force characteristic curve of the restoring force acting on the inertial mass part. An increase in the rotational speed of the base part causes the sliding block to move radially outward in the restoring apparatus under centrifugal force action, thus leading to an increased gradient of the restoring force characteristic curve of the restoring force acting on the inertial mass part, whereas a spring element effects a restoring movement of the sliding block with decreasing rotational speed.

The known rotary vibration absorber thus has the disadvantage of requiring a bending spring, which is relatively large and thus takes up a large amount of structural space, of the restoring apparatus, especially as said bending spring must be fixed or supported at one side on the inertial mass part and at the other side on the base part. The latter requirement for support of the bending spring at one side on the base part and at the other side on the inertial mass part also has the consequence that the arrangement of the bending spring on the rotary vibration absorber is substantially predefined. Consequently, a flexible arrangement of the bending spring is not possible in the case of rotary vibration absorbers of the described type.

It is therefore an object of the present invention to provide a rotary vibration absorber of the generic type which has a simplified and structural space- saving construction, wherein a particularly flexible arrangement of the spring device should be possible.

Said object is achieved by means of the features specified in patent claim 1. The subclaims relate to advantageous embodiments of the invention.

The rotary vibration absorber according to the invention has a base part which is rotatable about an axis of rotation and which can be fastened rotationally conjointly for example to an output side of a driven shaft, wherein in this case, the base part is preferably, in the region of the axis of rotation, connected rotationally conjointly to the output side of a driven shaft. The base part may for example be formed by a base or carrier plate extending substantially in a radial direction. The rotary vibration absorber furthermore has an inertial mass part which is arranged on the base part. In this case, the inertial mass part may be arranged either directly or indirectly on the base part, for example indirectly via the restoring apparatus described below. Accordingly, the rotary vibration absorber also has a restoring apparatus, wherein the inertial mass part can be rotated relative to the base part counter to the restoring force of said restoring apparatus. The restoring apparatus has a spring device for generating an actuating force, wherein the spring device may for example have one or more spring elements. Furthermore, the restoring apparatus has a lever element which is pivotable about an articulation point. Accordingly, the pivotable lever element may for example be articulated on the base part indirectly via the articulation point or directly. It is preferable here for the lever element to be pivotable in a plane spanned by the radial directions of the rotary vibration absorber and consequently about an axis which extends in the axial directions of the rotary vibration absorber and through the articulation point. Moreover, the pivotable lever element is preferably a flexurally rigid or stiff lever element. The lever element is arranged between the spring device, at one side, and the inertial mass part, at the other side, such that the actuating force generated by the spring device can be transmitted to the inertial mass part so as to generate the restoring force which acts on the inertial mass part. This firstly has the advantage that the spring device, which generates the actuating force, of the restoring apparatus does not need to act directly on the inertial mass part, and can instead be arranged at some other location on the base part of the rotary vibration absorber, permitting a space-saving and flexible arrangement of the spring device on the rotary vibration absorber. Secondly, owing to the lever element, it is possible for a lever ratio to be set or predefined, based on which the restoring force acting on the inertial mass part is greater or smaller than the actuating force generated by the spring device of the restoring apparatus. It is accordingly possible for the stiffness of the restoring apparatus to be increased in targeted fashion through presetting of the lever ratio, without the need for a particularly rigid spring device for generating the actuating force. It can thus be stated firstly that the spring device need merely have a low spring stiffness and can consequently be of particularly space-saving form, wherein moreover, a flexible arrangement of the spring device on the base part of the rotary vibration absorber is possible.

In a preferred embodiment of the rotary vibration absorber according to the invention, it is furthermore the case that an adjustment apparatus is provided by means of which the restoring apparatus can be adjusted with variation of a restoring force characteristic curve of the restoring force acting on the inertial mass part. Accordingly, it is for example possible for the gradient of the restoring force characteristic curve of the restoring force acting on the inertial mass part to be increased or reduced through adjustment of the restoring apparatus, such that the stiffness of the restoring apparatus is increased or reduced accordingly. Consequently, a restoring apparatus is provided which can react in flexible fashion to operating states within a drivetrain. In a particularly preferred embodiment of the rotary vibration absorber according to the invention, the restoring apparatus is designed such that the lever ratio of the lever element of the restoring apparatus can be varied by means of the adjustment apparatus. A particularly simple restoring apparatus which is insusceptible to faults is created in this way. In this embodiment, it is furthermore preferable if the above-mentioned articulation point of the lever element is adjustable and/or displaceable, that is to say variable in terms of its position, so as to vary the lever ratio of the lever element. Accordingly, the articulation point may for example be arranged in movable fashion on the base part, wherein a movement of the articulation point in the radial direction relative to the base part is preferable. Moreover, the articulation point is preferably formed by a projection which is arranged in adjustable or displaceable fashion on the base part.

In an advantageous embodiment of the rotary vibration absorber according to the invention, the lever element has a first lever section between an actuating force action point and the articulation point and has a second lever section between the articulation point and a restoring force action point, wherein the length of the first and second lever section can be varied by rotation of the inertial mass part relative to the base part, with the lever ratio being substantially maintained. The variation, that is to say elongation or shortening, of the first and second lever sections may in this case be realized in any desired manner; for example, the stated lever sections may for example be of telescopic form. Regardless of the respective design variant, the elongation or shortening of the lever sections makes it possible for the inertial mass part to be rotated relative to the base part while maintaining a predetermined radial spacing to the axis of rotation of the base part. This embodiment also encompasses design variants in which, owing to the design configuration, in particular in the region of articulation point, actuating force action point and/or restoring force action point, rotation of the inertial mass part relative to the base part can result in slight changes in the lever ratio. Such a slight change may arise for example owing to the fact that, during the rotation of the inertial mass part relative to the base part, the actuating force action point is moved along a straight line, possibly a straight line parallel to a radial line, whereas the restoring force action point is moved along a circular path around the axis of rotation. In this case, and in other cases, the design should however preferably be configured such that the lever ratio is varied by at most 5%, particularly preferably by at most 3% or at most 1%, as a result of rotation of the inertial mass part relative to the base part.

In a further preferred embodiment of the rotary vibration absorber according to the invention, two of the abovementioned points, that is to say two points out of articulation point, actuating force action point and restoring force action point, are displaceable relative to the lever element with variation of the length of the lever sections. Here, it is preferable if the articulation point on the one hand and the actuating force action point or the restoring force action point on the other hand are displaceable relative to the lever element with variation of the length of the lever sections, whereas the remaining point is particularly preferably arranged immovably on the lever element.

In a particularly advantageous embodiment of the rotary vibration absorber according to the invention, the restoring apparatus can be adjusted into a blocking state in which the restoring apparatus interacts with the inertial mass part so as to hinder, preferably by frictional contact, or prevent, preferably by positive locking, a rotation of the inertial mass part relative to the base part. Consequently, the rotation of the inertial mass part relative to the base part is in this embodiment hindered or prevented by the restoring apparatus in the blocking state thereof, which is an advantage in particular during starting processes. Consequently, in this embodiment, the rotary vibration absorber is highly suited to a drivetrain which has a so-called automatic start-stop facility. In this embodiment, it is furthermore preferable if the above-mentioned adjustable or displaceable projection, which forms the articulation point, of the restoring apparatus interacts with the inertial mass part. Accordingly, it is for example possible for said adjustable or displaceable projection, in the corresponding state, to realize frictional contact with the inertial mass part or interact in positively locking fashion with the inertial mass part, such that a rotation of the inertial mass part relative to the base part is hindered or prevented. In this case, the displaceable or adjustable projection may for example interact with the inertial mass part indirectly, possibly via the support part described in more detail further below, or directly.

In a further advantageous embodiment of the rotary vibration absorber according to the invention, the spring device for generating the actuating force has a first spring element and a second spring element, which act on the lever element oppositely to one another. In this embodiment, it is preferable for the two spring elements that act on the lever element oppositely to one another to be in the form of compression springs, possibly helical compression springs.

In a further advantageous embodiment of the rotary vibration absorber according to the invention, the lever element is arranged in an initial state under preload of the first and second spring elements of the spring device. This has the advantage that a particularly high stiffness of the spring device is attained in a rotational angle range of the lever element around the initial state. In this embodiment, it is moreover preferable for the first and second spring element to be preloaded such that they both exert a respective actuating force on the lever element over the maximum rotational angle range of the inertial mass part relative to the base part. In this way, increased stiffness of the spring device is ensured over the maximum rotational angle range of the inertial mass part.

In a further preferred embodiment of the rotary vibration absorber according to the invention, the first spring element and the second spring element each have a longitudinal axis which is offset radially outward in relation to the axis of rotation. It is ensured in this way that the base part of the rotary vibration absorber can be securely rotationally conjointly connected, in the region of the axis of rotation, to an outlet side of a component, for example the output side of a flywheel mass, the output side of a drive unit or the output side of a torsional vibration damper, without the spring elements of the spring device posing a hindrance or restriction. In this context, it has proven to be advantageous for the spring elements, and not only the longitudinal axes thereof, to be spaced apart in the radial direction from the axis of rotation of the base part. In a further preferred embodiment of the rotary vibration absorber according to the invention, the adjustment apparatus has an actuation part arranged on the base part. The actuation part can be moved relative to the base part with adjustment of the restoring apparatus.

In a further particularly preferred embodiment of the rotary vibration absorber according to the invention, the actuation part is displaceable in translational fashion relative to the base part with adjustment of the restoring apparatus. It is preferable here if the actuation part is displaceable in translational fashion relative to the base part such that said actuation part moves along a straight line, which is possibly arranged parallel to a radial line of the rotary vibration absorber.

In a further particularly advantageous embodiment of the rotary vibration absorber according to the invention, the actuation part is rotatable about the axis of rotation with adjustment of the restoring apparatus relative to the base part.

It would basically be possible for the above-mentioned actuation part, regardless of its respective design, to interact directly with the restoring apparatus in order to adjust the latter. However, to obtain a more flexible arrangement of the actuation part on the base part, it is particularly preferable for the actuation part to interact by way of an actuation lever, possibly two actuation levers articulatedly connected to one another, with the restoring apparatus, preferably with the articulation point thereof, possibly with a projection that forms the articulation point. In the case of two actuation levers articulatedly connected to one another, it is preferable for a first actuation lever to be articulated at one side on the actuation part and at the other side on a first end of the second actuation lever, whereas the second actuation lever is articulated on the base part, wherein that end of the second actuation lever which is remote from the first actuation lever interacts with the restoring apparatus, possibly with the articulation point or with a projection which forms the articulation point. If the second actuation lever interacts with the articulation point or with the projection which forms the articulation point, it is furthermore preferable if the articulation point or the projection which forms the articulation point is displaceable relative to the second actuation lever in the direction of extent thereof. This may be realized for example by virtue of the articulation point or the projection which forms the articulation point being guided in displaceable fashion in a guide in the second actuation lever.

In a further preferred embodiment of the rotary vibration absorber according to the invention, the actuation part can be or is hydraulically driven. Whereas, in the case of the rotary vibration absorber according to DE 199 07 216 CI , only an adjustment of the restoring apparatus is realized under the action of centrifugal and spring force, it is thus the case in this embodiment that a hydraulic drive is used for the actuation part, which can be provided in a significantly more space-saving and flexible manner on the rotary vibration absorber than is the case if the actuation part is driven only by a spring force. Nevertheless, an actuation part that can be or is driven hydraulically may additionally be driven by a spring force. Accordingly, this also encompasses embodiments in which the actuation part is driven hydraulically in one movement direction and is driven by a spring force in the opposite movement direction.

In a preferred embodiment of the rotary vibration absorber according to the invention, the actuation part which can be or is driven hydraulically has a slave piston or a slave cylinder, whereas a corresponding slave cylinder or slave piston is arranged on the base part. In this embodiment, it is preferable if the slave piston is provided on the actuation part, whereas the slave cylinder, in which the slave piston of the actuation part is arranged, is arranged on the base part. Here, the expressions "slave piston" and "slave cylinder" are to be understood in the broadest sense and do not constitute a restriction with regard to their geometric design; rather, it is crucial that the slave piston and slave cylinder delimit a hydraulic functional space, such as for example the first and/or second slave chamber described in more detail further below, and, in interaction, have the function of a hydraulic piston-cylinder arrangement.

In a further particularly preferred embodiment of the rotary vibration absorber according to the invention, there is arranged on the base part a master cylinder which is arranged radially further inward than the slave cylinder and which serves for pressurizing the slave cylinder and in which there is arranged a driveable master piston. In this embodiment, it is moreover preferable for the slave cylinder to be in the form of an annular cylinder and for the master piston to be in the form of an annular piston, wherein the annular piston is preferably arranged in the annular cylinder so as to be displaceable in an axial direction of the rotary vibration absorber.

As already indicated above, the master piston can be driven, with a drive apparatus being provided for this purpose. The drive apparatus, which can also be referred to as force action apparatus, is decoupled in terms of rotational drive from the master piston, wherein this is realized preferably by means of an engagement bearing. In this embodiment, it is furthermore preferable for the drive apparatus to be of static form or to be formed by a static piston-cylinder arrangement. Accordingly, the master piston can interact, for example in a manner decoupled in terms of rotational drive, with a piston of the static piston-cylinder arrangement, wherein a displacement of the piston of the static piston-cylinder arrangement in the axial directions effects a corresponding displacement of the master piston within the master cylinder.

In a further advantageous embodiment of the rotary vibration absorber according to the invention, the actuation part, the slave piston or the master piston is movable counter to the spring force of a restoring spring in at least one direction of movement. Consequently - as has already been indicated above - the actuation part, the slave piston or the master piston can be driven hydraulically in a first movement direction and by the spring force of the restoring spring in the opposite, second movement direction.

In a further particularly preferred embodiment of the rotary vibration absorber according to the invention, the slave cylinder and the master cylinder are in the form of double-acting cylinders. Accordingly, in this embodiment, it is preferable if a first slave chamber of the slave cylinder is connected in terms of flow to a first master chamber of the master cylinder and a second slave chamber of the slave cylinder is connected in terms of flow to a second master chamber of the master cylinder, and it is particularly preferable if a closed hydraulic system is formed between the master cylinder and the slave cylinder. In a further preferred embodiment of the rotary vibration absorber according to the invention, to permit targeted and precise adjustment of the restoring apparatus, at least one sensor for the indirect or direct detection of the state of the restoring apparatus is provided. Direct detection of the state of the restoring apparatus is to be understood to mean detection by means of a sensor which is assigned directly to a component of the restoring apparatus, whereas an indirect detection of the state of the restoring apparatus is to be understood to mean a detection by means of a sensor which is assigned to a component, for example the actuation part, which interacts with the restoring apparatus. By virtue of the fact that the state of the restoring apparatus can be detected by means of the at least one sensor, precise adjustment into a predetermined state of the restoring apparatus is possible, and any deviation from the predetermined state of the restoring apparatus can be detected, such that appropriate control countermeasures can be taken.

In a further advantageous embodiment of the rotary vibration absorber according to the invention, the sensor is in the form of a co-rotating sensor for detecting the position of the actuation part or of the articulation point, possibly of the projection which forms the articulation point, relative to the base part. Accordingly, in this variant, use may for example be made of a sensor which is fastened to the actuation part, to the articulation point, possibly to the projection which forms the articulation point or to the base part, and which thus co-rotates with the respective part. Alternatively, however, the at least one sensor may also be in the form of a static sensor for detecting the position of the actuation part relative to the base part, wherein said sensor is then not of co-rotating form. Accordingly, the at least one static sensor may for example be fastened to a static housing of the rotary vibration absorber.

In a further preferred embodiment of the rotary vibration absorber according to the invention, the static sensor is designed for detecting the rotational position of the actuation part and for detecting the rotational position of the base part. Consequently, only one static sensor is used for detecting both the rotational position of the actuation part and the rotational position of the base part. Alternatively, a first static sensor may be provided for detecting the rotational position of the actuation part and a second static sensor may be provided for detecting the rotational position of the base part. Regardless of whether only one static sensor or two static sensors are used, it is possible from the rotational positions of the actuation part and of the base part to determine the rotational offset between the actuation part and base part, which is representative of the position of the actuation part relative to the base part, wherein for this purpose, the rotary vibration absorber or the at least one sensor may be assigned a corresponding evaluation device. On the basis of the rotational offset between the actuation part and base part, it is thus possible to infer the position of the actuation part relative to the base part, and thus the state of the restoring apparatus.

In a further advantageous embodiment of the rotary vibration absorber according to the invention, the at least one static sensor is in the form of a contactless, preferably optical, photoelectric or magnetic sensor. Alternatively, the at least one static sensor may however also be in the form of a contact-type, preferably sliding-contact sensor. Regardless of the respective design variant of the at least one static sensor, the at least one static sensor is particularly preferably in the form of an incremental encoder, possibly gearwheel encoder.

In a further particularly advantageous embodiment of the rotary vibration absorber according to the invention, the inertial mass part is rotatable relative to the base part while maintaining a predetermined radial spacing to the axis of rotation. Consequently, in this embodiment, it is possible for vibrations or movements of the inertial mass part in the radial direction to be prevented, such that compensation of such vibrations or movements of the inertial mass part in the radial direction can be disregarded from a design aspect, which leads to a simplified construction of the rotary vibration absorber.

In a further advantageous embodiment of the rotary vibration absorber according to the invention, the inertial mass part is of annular form. In this way, only one inertial mass part has to be provided, wherein owing to the annular form, imbalances are avoided and targeted balancing is rendered superfluous. The inertial mass part may for example be supportable or supported at the inside in the radial direction directly or indirectly on the base part, on the greatest outer diameter of the base part, or on the greatest outer diameter of that side of the base part which faces toward the inertial mass part. In a further particularly preferred embodiment of the rotary vibration absorber according to the invention, at least one support part is provided which is connected rotationally conjointly to the inertial mass part and which, supporting the inertial mass part at the inside in the radial direction, is or can be supported in the region of a diameter which is smaller than the greatest outer diameter of the base part or smaller than the greatest outer diameter of that side of the base part which faces toward the inertial mass part. Owing to the relatively small diameter in the region of which the inertial mass part can be or is supported by means of the support part, the support or bearing surface area is reduced considerably, resulting in lower friction forces as the inertial mass part rotates relative to the base part. Moreover, the support in the region of a relatively small diameter simplifies the manufacture of the rotary vibration absorber.

In a further advantageous embodiment of the rotary vibration absorber according to the invention, the support part is or can be supported at the inside in the radial direction substantially in the region of the same diameter as the base part. Here, the support part does not imperatively have to be supported or supportable at the inside in the radial direction at the same diameter as the base part, and instead, the diameter at which the support part is or can be supported at the inside in the radial direction may deviate by up to 10% from the diameter at which the base part is or can be supported at the inside in the radial direction, that is to say may be as much as 10% greater or smaller than the diameter at which the base part is or can be supported at the inside in the radial direction.

In a further preferred embodiment of the rotary vibration absorber according to the invention, the support part is of disk-shaped form, in order to firstly ensure reliable support at the inside in the radial direction and secondly ensure a small axial structural length of the support part. It is preferable here for the disk-shaped support part to have cutouts or windows, which may for example be provided so as to form interposed spokes or struts in the support part. The cutouts or windows may for example also serve for the leadthrough of other components of the rotary vibration absorber, for example of the spring device or of the projection which forms the articulation point.

In a further advantageous embodiment of the rotary vibration absorber according to the invention, the support part at least partially, preferably over its entire radial extent, has a smaller extent in an axial direction than the inertial mass part itself.

In a further advantageous embodiment of the rotary vibration absorber according to the invention, the support part is arranged between two disks of the base part as viewed in the axial direction. It is preferable here for the disks to have cutouts or windows, which may for example be provided so as to form interposed spokes or struts in the disks.

In a further particularly advantageous embodiment of the rotary vibration absorber according to the invention, the support by the support part is realized with a spacing between that side of the inertial mass part which points inward in the radial direction and that side of the base part which faces outward in the radial direction toward the inertial mass part. Consequently, in this embodiment, there is no need for that side of the inertial mass part which faces inward in the radial direction to be supported on that side of the base part which faces outward in the radial direction toward the inertial mass part, such that here, no friction is generated and there is no need for increased manufacturing outlay. In this embodiment, it is moreover preferable if the inertial mass part can be or is supported toward the inside in the radial direction exclusively via the support part, so as to eliminate any points of friction with the base part and simplify the manufacture of the rotary vibration absorber.

The invention will be explained in more detail below on the basis of exemplary embodiments and with reference to the appended drawings. In the drawings:

Figure 1 shows a schematic side view of an embodiment of the rotary vibration absorber according to the invention, Figure 2 shows a partial front view of the rotary vibration absorber from Figure 1 in a first design variant,

Figure 3 shows a partial front view of the rotary vibration absorber from Figure 1 in a second design variant,

Figure 4 shows a partial front view of the rotary vibration absorber from the preceding figures in the region of the articulation point.

Figure 1 shows a schematic side view of an embodiment of the rotary vibration absorber 2 according to the invention. The mutually opposite axial directions 4, 6, the mutually opposite radial directions 8, 10 and the mutually opposite circumferential directions 12, 14 of the rotary vibration absorber 2 are indicated on the basis of corresponding arrows, wherein the circumferential directions 12, 14 may also be referred to as rotational directions 12, 14. The rotary vibration absorber 2 has an axis of rotation 16 extending in an axial direction 4, 6.

The rotary vibration absorber 2 has a base part 18 which is rotatable about the axis of rotation 16. The base part 18 is formed substantially by two disks 20, 22 which are situated opposite one another in the axial direction 4, 6, wherein the two disks 20, 22 are spaced apart from one another in the axial direction 4, 6 but are connected rotationally conjointly to one another. Here, the two disks 20, 22 of the base part 18 each extend substantially in a plane spanned by the radial directions 8, 10. The base part 18 is, to the inside in the radial direction 10, connected rotationally conjointly via the disk 20 to an output hub 24, wherein the output hub 24 is for example the output hub of a flywheel mass (not illustrated in any more detail) or of a drive unit (not illustrated in any more detail), for example of an internal combustion engine. The output hub 24 may likewise be the output hub of a torsional vibration damper or the like, that is to say a unit arranged in the torque transmission path of a drivetrain. Furthermore, the base part 18 is, to the inside in the radial direction 10, connected rotationally conjointly, in this case via the disk 22, to an input hub 26. The input hub 26 may for example be the input hub of a clutch device, preferably of a multiple clutch device, or of a transmission. For weight-saving purposes, cutouts or windows may be provided in the disks 20, 22 of the base part 18 so as to form interposed struts or spokes. On the base part 18 of the rotary vibration absorber 2 there is arranged an inertial mass part 30, which is rotatable relative to the base part 18 in the circumferential directions 12, 14 about the axis of rotation 16 counter to the restoring force of a restoring apparatus 28. The inertial mass part 30 is of annular form, that is to say is of encircling form in the circumferential direction 12, 14, and is in a nested arrangement with the base part 18 substantially in the radial direction 8, 10. The inertial mass part 30 is connected rotationally conjointly to a disk-shaped support part 32. The disk-shaped support part 32, which in turn may have a multiplicity of windows or cutouts, has a smaller extent in the axial direction 4, 6 than the inertial mass part 30 and extends inward in the radial direction 10 from the inertial mass part 30, wherein the disk-shaped support part 32 is arranged or runs between the disks 20, 22 of the base part 18 as viewed in the axial direction 4, 6.

The support part 32 serves for the indirect support of the inertial mass part 30 at the inside in the radial direction 8, 10. Accordingly, the support part 32 can be or is supported at the inside in the radial direction 8, 10 in the region of a diameter di in order to indirectly support the inertial mass part 30 at the inside in the radial direction 8, 10, wherein in the embodiment illustrated, the support is realized on the input hub 26. Alternatively, the support at the inside in the radial direction 8, 10 may also be realized on a section of the base part 18 or on a section of the disks 20, 22 of the base part 18. Moreover, it is likewise conceivable for the support at the inside in the radial direction 8, 10 to be realized on the output hub 24.

The diameter di is smaller than the greatest outer diameter d ₂ of the base part 18. Moreover, the diameter di corresponds substantially to the diameter d3 on which the base part 18 is supported at the inside in the radial direction 8, 10 on the input hub 26. In other words, the support part 32 is or can be supported at the inside in the radial direction 8, 10 substantially in the region of the same diameter d3 as the base part 18. In this case, it is preferable for a plain bearing to be formed between that side of the support part 32 which points inward in the radial direction 10 and the input hub 26, alternatively the output hub 24 or a section of the base part 18. Owing to the relocation of the diameter di to the inside in the radial direction 10 proceeding from the diameter d ₂ , the friction forces occurring here are low, wherein the manufacture of the plain bearing or of an alternative radial bearing is also simplified. As an alternative to the plain bearing, a rolling bearing could for example be used as a radial bearing.

As can also be seen from Figure 1, the support of the inertial mass part 30 on the support part 32 is realized with a spacing between that side 34 of the inertial mass part 30 which faces inward in the radial direction 10 and that side 36 of the base part 18 which faces outward in the radial direction 8 toward the inertial mass part 30, such that no support and/or friction are generated here. Moreover, the inertial mass part 30 can be or is supported toward the inside in the radial direction 10 exclusively via the support part 32.

Below, a design variant of the restoring apparatus 28 from Figure 1 will be described in more detail with reference to Figure 2. The restoring apparatus 28 is composed substantially of a spring device 38 for generating an actuating force and of at least one lever element 42 which is pivotable about an articulation point 40. The lever element 42, which is in the form of a flexurally rigid or stiff lever element 42, extends substantially in the radial direction 8, 10 in the initial state shown in Figure 2, wherein the lever element 42 is articulated on the base part 18 so as to be pivotable about the articulation point 40. Consequently, the lever element 42 is pivotable about an axis extending in the axial direction 4, 6 through the articulation point 40. A first lever section 44 extends between an actuating force action point 46, at which the actuating force of the spring device 38 acts and about which the lever element 42 is pivotable, and the articulation point 40, wherein the first lever section 44 extends substantially inward in the radial direction 10 proceeding from the articulation point 40. Furthermore, the lever element 42 has a second lever section 48 which extends substantially outward in the radial direction 8 proceeding from the articulation point 40 to a restoring force action point 50.

The first lever section 44 has a length , whereas the second lever section

48 has a length 1 ₂ . At the restoring force action point 50, the lever element 42 is pivotably connected to the inertial mass part 30 such that the restoring force can be transmitted to the inertial mass part 30 via the restoring force action point 50. The lever ratio of the lever element 42 is thus h/b, meaning divided by b. An actuating force exerted on the actuating force action point 46 by the spring device 38 can therefore be transmitted to the inertial mass part 30 via the lever element 42 so as to generate the restoring force, acting via the restoring force action point 50, on the inertial mass part 30.

The lever ratio h/b may however be varied by adjustment and/or displacement of the articulation point 40 in the radial direction 8 or 10. For this purpose, a projection 52 protruding in the axial direction 4, 6 is provided on the base part 18, which projection extends, so as to form the articulation point 40, into an elongate guide 54 within the lever element 42, wherein the projection 52 is arranged on the base part 18 so as to be adjustable or displaceable, and consequently variable in terms of position, in the radial direction 8, 10 for the purposes of varying the lever ratio h/b. It is consequently possible for the restoring apparatus 28 to be adjusted - in this case in continuously variable fashion - with variation of a restoring force characteristic curve of the restoring force acting on the inertial mass part 30 at the restoring force action point 50.

The inertial mass part 30 can be rotated relative to the base part 18 while maintaining a predetermined radial spacing π to the axis of rotation 16 of the rotary vibration absorber 2. To permit this in the embodiment illustrated, the lengths li and b of the lever sections 44, 48 can be varied, that is to say shortened or lengthened, by rotating the inertial mass part 30 in the circumferential directions 12, 14 relative to the base part 18, with the lever ratio li / b substantially being maintained. For this purpose, it is possible - as already indicated above - for the articulation point 40, or the projection 52 which forms the articulation point 40, to be displaced relative to the lever element 42 by virtue of the projection 52 being guided in the guide 54 in the lever element 42 so as to be displaceable in the direction of extent of said lever element. Furthermore, at least one of the two remaining points, that is to say either the restoring force action point 50 or the actuating force action point 46, is also displaceable relative to the lever element 42. In the example illustrated, the restoring force action point 50 is formed immovably on the lever element 42, whereas the actuating force action point 46 can be displaced relative to the lever element 42. To form the actuating force action point 46, there is in turn provided a projection 56 which protrudes in the axial direction 4, 6 and which is guided displaceably in a guide 58 in the lever element 42.

The spring device 38 has a first spring element 60 and a second spring element 62. The two spring elements 60, 62 are each in the form of compression springs - in this case helical compression springs - and act on the lever element 42 oppositely to one another via the actuating force action point 46 or via the projection 56 which forms the actuating force action point 46. In this case, it is however not necessary for the two spring elements 60, 62 to act directly on the projection 56, it rather being preferable - in a manner which is however not illustrated - for the spring elements 60, 62 to act on both sides of a displaceable load-bearing part on which the protruding projection 56 is arranged, said projection extending into the guide 58 so as to form the actuating force action point 46.

The lever element 42 is arranged in the initial state shown in the figures under preload of the first spring element 60 and of the second spring element 62. Accordingly, the two spring elements 60, 62 are each preloaded in the initial state, in which the spring elements 60, 62 are supported at one side on the base part 18 and at the other side on the lever element 42 via the projection 56. The two spring elements 60, 62 extend in each case along a longitudinal axis 64, 66 which is offset outward in the radial direction 8 in relation to the axis of rotation 16 and is arranged in a plane spanned by the radial directions 8, 10. In this case, the longitudinal axes 64, 66 extend parallel to a radial line, extending in the radial directions 8, 10, of the rotary vibration absorber 2. The longitudinal axes 64, 66 are furthermore offset outward in the radial direction 8 in relation to the axis of rotation 16, such that the spring elements 60, 62 are themselves spaced apart from the axis of rotation 16 in the radial direction 8, as indicated by the radial spacing r ₂ . Also, the longitudinal axes 64, 66 of the two spring elements 60, 62 are arranged along a common straight line, that is to say the two longitudinal axes 64, 66 are arranged in alignment with one another.

The first and second spring elements 60, 62 are preloaded in the initial state such that the two spring elements 60, 62 exert a respective actuating force on the lever element 42 over the maximum rotational angle range of the inertial mass part 30 relative to the base part 18. Owing to the preload of the two spring elements 60, 62, the spring device 28 has an actuating force characteristic curve which has an increased gradient in a rotational angle range around the initial state of the lever element 42, such that the stiffness of the spring device 28 is increased in said rotational angle range. As already mentioned above, said rotational angle range should fully encompass the maximum rotational angle range of the inertial mass part 30 in order to realize an increased stiffness of the spring device 28 over the maximum rotational angle range of the inertial mass part 30 relative to the base part 18.

The result is a correspondingly configured restoring force characteristic curve for the restoring force acting on the inertial mass part 30 in the region of the restoring force action point 50. To increase the stiffness of the restoring apparatus 28, the articulation point 40 can be adjusted or displaced outward in the radial direction 8 with an enlargement of the lever ratio li/b, such that the restoring force characteristic curve is varied. By means of said measure, the gradient of the restoring force characteristic curve is increased. By contrast, if it is sought to decrease the stiffness of the restoring apparatus 28, then the articulation point 40 is adjusted or displaced inward in the radial direction 10, such that the lever ratio li/b is reduced and the restoring force characteristic curve has a reduced gradient.

To be able to adjust the restoring apparatus 28 with variation of the restoring force characteristic curve of the restoring force acting on the inertial mass part 30, the rotational vibration absorber 2 also has an adjustment apparatus 68, with a first design variant of the adjustment apparatus 68 being illustrated in Figure 2. As can be seen from Figure 2, the rotary vibration absorber 2 has two restoring apparatuses 28 which are arranged opposite one another on the base part 18, wherein the adjustment apparatus 68 effects an equal adjustment of both restoring apparatuses 28, 28. Consequently, one adjustment apparatus 68 is provided for two or more restoring apparatuses 28.

The adjustment apparatus 68 has an actuation part 70 arranged on the base part 18. In the design variant of Figure 2, the actuation part 70 is in the form of an element which is elongate in the radial direction 8, 10 and which extends across the axis of rotation 16 in the radial directions 8, 10 and which can rotate about the axis of rotation 16 with adjustment of the restoring apparatus 28 relative to the base part 18. In this case, the actuation part 70 interacts, via at least one actuation lever, with the articulation point 40 or with the projection 52 which forms the articulation point 40. In the embodiment illustrated, a first actuation lever 72 and a second actuation lever 74 are provided for this purpose. The first actuation lever 72 is articulated on the actuation part 70 at a point 76, such that the first actuation lever 72 is fastened to the actuation part 70 so as to be pivotable about an axis extending in the axial direction 4, 6 through the point 76. By contrast, at its end remote from the actuation part 70, the first actuation lever 72 is articulatedly connected to the second actuation lever 74. Accordingly, the first actuation lever 72 is fastened to the second actuation lever 74 at the point 78 so as to be pivotable about an axis extending in the axial directions 4, 6 through the point 78. By contrast, the second actuation lever 74 is arranged on the base part 18 so as to be pivotable about an articulation point 80 which is fixed on the base part 18. By contrast, by way of its end section remote from the first actuation lever 72 or from the point 78, the second actuation lever 74 interacts with the articulation point 40 or with the projection 52 which forms the articulation point 40 of the restoring apparatus 28. Accordingly, in the embodiment illustrated, there is provided in the second actuation lever 74 a receptacle 81 into which the projection 52 extends, such that the projection 52 is engaged behind by the second actuation lever 74 in both radial directions 8, 10, wherein the receptacle 81 is designed such that the projection 52, and thus the articulation point 40 of the restoring apparatus 28, can be displaced relative to the second actuation lever 74 in the direction of extent of the second actuation lever 74 when the articulation point 40 is displaced or adjusted by means of the adjustment apparatus 68. If the actuation part 70 is rotated relative to the base part 18 in the circumferential direction 12 about the axis of rotation 16, the actuation levers 72, 74 have the effect that the articulation point 40 or the projection 52 which forms the articulation point 40 is displaced in the radial direction 10 relative to the base part 18, whereas a rotation of the actuation part 70 in the circumferential direction 14 relative to the base part 18 results in a displacement or adjustment of the articulation point 40 or of the projection which forms the articulation point 40, toward the outside in the radial direction 8. In this case, each of the two articulation points 40 of the two restoring apparatuses 28 is assigned both a first and a second actuation lever 72, 74 of the above-described type, as can be seen from Figures 1 and 2.

The actuation part 70 may be actively driven in order to adjust the restoring apparatus 28. Accordingly, the actuation part 70 is in the form of a hydraulically driveable or driven actuation part 70. For this purpose, there is arranged on the actuation part 70 a slave piston 82 which is guided displaceably in a slave cylinder 84 arranged on the base part 18. In this case, a slave chamber 86 is formed within the slave cylinder 84, wherein the slave cylinder 84 is in the form of a single-acting cylinder in the embodiment illustrated. Furthermore - as can be seen from Figure 1 - a master cylinder 88 for pressurizing the slave cylinder 84 is arranged on the base part 18. The master cylinder 88 is arranged further toward the inside in the radial direction 10 than the slave cylinder 84, and accommodates a master piston 92 which can be driven by a drive apparatus 90. The master cylinder 88 is in the form of an annular cylinder, whereas the driveable master piston 92 is in the form of an annular piston. The master cylinder 88 and master piston 92 are accordingly of encircling form in the circumferential direction 12, 14 around the axis of rotation 16, wherein the master piston 92 is arranged within the master cylinder 88 so as to be displaceable in the axial direction 4, 6. In this case, there is formed within the master cylinder 88 a master chamber 94 which is connected in terms of flow to the slave chamber 86 of the slave cylinder 84 via a line 96, which is merely indicated in Figure 2. The above-mentioned drive apparatus 90 by means of which the master piston 92 can be driven or displaced in the axial directions 4, 6 is decoupled in terms of rotational drive from the master piston 92, which co-rotates with the base part 18 during the operation of the rotary vibration absorber 2. In the embodiment illustrated, this is effected by means of an engagement bearing 98, which is merely schematically illustrated in Figure 1. Consequently, the drive apparatus 90 can be designed to be static, as is the case in the embodiments illustrated. A static drive apparatus 90 is to be understood to mean a drive apparatus which is designed so as not to co-rotate with the rotary vibration absorber 2, wherein, in the embodiments illustrated, the drive apparatus 90 is for this purpose fastened in static fashion to a housing (not illustrated in any more detail) which does not co- rotate or which is static. Even though any drive apparatus 90 may be used here for the displacement of the master piston 92 within the master cylinder 88, the drive apparatus 90 is, in the embodiment illustrated, in the form of a static piston- cylinder arrangement. In this case, the piston-cylinder arrangement has a cylinder 100 and a piston 102 which is arranged in displaceable fashion in the cylinder 100 and which interacts via the engagement bearing 98 with the master piston 92 within the master cylinder 88.

If the master piston 92 is displaced in the axial direction 4 by means of the drive apparatus 90, the hydraulic medium is displaced out of the master chamber 94 into the slave chamber 86 of the slave cylinder 84 via the line 96, such that the actuation part 70 - as already explained above - is rotated relative to the base part 18 in the circumferential direction 12 about the axis of rotation 16. The movement of the actuation part 70 in said movement direction or circumferential direction 12 takes place counter to the spring force of a restoring spring 104. The restoring spring 104, which in this case is again in the form of a compression spring, preferably helical compression spring, is supported at one side on the base part 18 and at the other side on the actuation part 70. It would however alternatively also be possible for the restoring spring 104 to be supported at the other side on the slave piston 82. In a further alternative embodiment, the restoring spring 104 could interact at one side with the base part 18 and at the other side with the master piston 92, and, in this context, be arranged for example in the master chamber 94, as indicated by the dashed illustration in Figure 1. The restoring spring 104 effects a restoring movement of the actuation part 70 relative to the base part 18 in the opposite circumferential direction 14 when the master piston 92 is no longer displaced in the axial direction 4, or blocked, by the drive apparatus 90.

To adjust the restoring apparatus 28 in targeted fashion into a predetermined state and possibly be able to correct the state of the restoring apparatus 28 in targeted fashion, the rotary vibration absorber 2 is assigned at least one sensor for the indirect or direct detection of the state of the restoring apparatus 28. In the design variant in Figure 2, at least one static sensor is provided for detecting the position of the actuation part 70 relative to the base part 18, especially as the state of the restoring apparatus 28 can be inferred from the position of the actuation part 70 relative to the base part 18. In the design variant in Figure 2, a first static sensor 106 is provided for detecting the rotational position of the actuation part 70 and a second static sensor 108 is provided for detecting the rotational position of the base part 18. As an alternative to this, however, it is also possible for a single static sensor to be provided which serves both for detecting the rotational position of the actuation part 70 and for detecting the rotational position of the base part 18. Regardless of the respective design variant, it is possible from the rotational positions of the actuation part 70 and of the base part 18 to determine the rotational offset between the actuation part 70 and the base part 18, which is representative of the position of the actuation part 70 relative to the base part 18, wherein the sensors 106, 108 or the single sensor may for this purpose interact with a corresponding evaluation device.

The single static sensor or the two static sensors 106, 108 is/are in the form of incremental encoder(s). Accordingly, the first static sensor 106 is assigned a first structure 110, which is of encircling form in the circumferential direction 12, 14 and exhibits a regularly repeating pattern, on the actuation part 70, whereas the second static sensor 108 is assigned a second structure 112, which is of encircling form and exhibits a regularly repeating pattern, on the base part 18. The first structure 110 is in this case provided on an annular part 114, wherein the annular part 114 is connected rotationally conjointly to the actuation part 70. By contrast, the second structure 112 is provided on an annular part 116 which is connected rotationally conjointly to the base part 18.

In the embodiment illustrated, the static sensors 106, 108 are thus designed so as not to co-rotate with the rotary vibration absorber 2; rather, only the first and second structures 110, 112 which interact with the sensors 106, 108 are designed to co-rotate. Accordingly, the static sensors 106, 108 may be fastened for example to a housing which does not co-rotate, for example to a housing of the rotary vibration absorber 2. The static sensors 106, 108 also operate in contactless fashion, wherein optical, photoelectric or magnetic or inductive sensors 106, 108, for example, may be used as contactless sensors 106, 108. Although not illustrated, the sensors could however likewise be in the form of contact-type, for example sliding-contact sensors, wherein, as a contact-type incremental encoder, a gearwheel encoder, for example, may also be used as a first and/or second sensor 106, 108.

Figure 3 shows a further design variant of the rotary vibration damper 2 of Figure 1 which corresponds substantially to the design variant as per Figure 2, such that only the differences will be discussed below, the same reference signs are used for identical or similar parts, and the above description otherwise applies correspondingly.

It is also the case in the second design variant as per Figure 3 that the actuation part 70 can be moved relative to the base part 18 so as to adjust the restoring apparatus 28, wherein, in the second design variant, the actuation part 70 is displaceable in translational fashion relative to the base part 18. More precisely, the actuation part 70 is in this case displaceable rectilinearly relative to the base part 18, wherein the actuation part 70 is formed substantially by a tension/thrust rod. The actuation part 70 is also displaceable along a straight line which extends parallel to a radial line of the rotary vibration absorber 2 and spaced apart in the radial direction 8, 10 from the axis of rotation 16. The slave piston 82, which is fastened to the actuation part 70, is arranged in the slave cylinder 84 so as to divide the interior of the slave cylinder 84 into the above- mentioned slave chamber, or first slave chamber 86, and a second slave chamber 118. The slave cylinder 84 is consequently a double-acting cylinder in this case. The master cylinder 88 is also in the form of a double-acting cylinder, such that the above-mentioned master chamber, or first master chamber 94, and a second master chamber 120 are formed therein, whereas, in the first design variant as per Figure 2, basically only the master chamber 94 is required, such that the first design variant as per Figure 2 can also be said to involve a single-acting master cylinder 88. Whereas the first slave chamber 86 is connected in terms of flow to the first master chamber 94 via the line 96, the second slave chamber 118 is connected in terms of flow to the second master chamber 120 via a further line 122. As is already the case in the first design variant as per Figure 2, a closed hydraulic system is created in this way.

It is also the case in the design variant of the rotary vibration absorber 2 as per Figure 3 that a restoring spring 104 within the meaning of the restoring spring described above is provided, wherein the restoring spring may again be assigned to the actuation part 70, to the slave piston 82 or, as indicated by dashed lines in Figure 1, to the master piston 92, such that the actuation part 70, the slave piston 82 or the master piston 92 is movable in at least one direction of movement counter to the spring force of the restoring spring.

Similarly to the first design variant as per Figure 2, it is also possible for the rotary vibration absorber 2 as per Figure 3 to be assigned at least one or two static sensors. Since, however, the actuation part 70 is an actuation part 70 which is displaceable in translational fashion relative to the base part 18, and is not for example an actuation part which is rotatable relative to the base part 18 about the axis of rotation 16, the at least one static sensor should be designed so as to detect for example the position of the piston 102 of the drive apparatus 90 or - in general terms - the state of the drive apparatus 90. Alternatively, however, it is also possible in this case - as in the design variant as per Figure 2 - for one or more co-rotating sensors to be provided for the indirect or direct detection of the state of the restoring apparatus 28, wherein a co-rotating sensor is to be understood to mean a sensor which co-rotates with the rotary vibration absorber 2, that is to say is for example fastened to the base part 18, to the adjustment apparatus 68 or to the restoring apparatus 28. Accordingly, a correspondingly co-rotating sensor should preferably be designed such that it can detect the position of the actuation part 70 or of the articulation point 40, or of the projection 52 which forms the articulation point, relative to the base part 18. Here, too, the above-mentioned types of sensors can again be used.

Below, a further feature of the rotary vibration absorbers 2 described above with reference to Figures 1 to 3 will be discussed with reference to Figure 4.

Accordingly, the restoring apparatus 28 can be adjusted into a blocking state in which the restoring apparatus 28 interacts with the inertial mass part 30 so as to prevent a rotation of the inertial mass part 30 relative to the base part 18. In this case, the restoring apparatus 28 may interact with the inertial mass part 30 either indirectly or directly. In the specific embodiment, the projection 52 which forms the articulation point 40 can be adjusted or displaced into an outer position as viewed in the radial direction 8, in which the projection 52 interacts with the inertial mass part 30 such that the latter, by positive locking, prevents a rotation relative to the base part 18. In the design variant illustrated in Figure 4, the positive locking is achieved in that the projection 52, in the outer position as viewed in the radial direction 8, is introduced into a receptacle 124 on the inertial mass part 30 or on the support part 32, such that the projection 52 is engaged behind by the inertial mass part 30 or by the support part 32 both in one circumferential direction 12 and in the other circumferential direction 14.

Alternatively, the restoring apparatus 28 can, in the blocking state, interact with the inertial mass part 30 so as to hinder, preferably by frictional contact, a rotation of the inertial mass part 30 relative to the base part 18, as indicated by dashed lines in Figure 4. In this case, the projection 52 which forms the articulation point 40, in its outer position as viewed in the radial direction 8, is not engaged behind in the circumferential directions 12, 14 by the inertial mass part 30 or by the support part 32; rather, the projection 52 is merely pressed with frictional contact against a surface, facing the projection 52, of the inertial mass part 30 or of the support part 32, whereupon corresponding frictional contact is generated. Consequently, the rotary vibration absorbers 2 as per Figures 1 to 4 are suitable in particular for a drivetrain with an automatic start-stop facility and during starting processes.

LIST OF REFERENCE SIGNS

2 Rotary vibration absorber

4 Axial direction

6 Axial direction

8 Radial direction

10 Radial direction

12 Circumferential direction

14 Circumferential direction

16 Axis of rotation

18 Base part

20 Disk

22 Disk

24 Output hub

26 Input hub

28 Restoring apparatus

30 Inertial mass part

32 Support part

34 Side

36 Side

38 Spring device

40 Articulation point

42 Lever element

44 First lever section

46 Actuating force action point

48 Second lever section

50 Restoring force action point

52 Projection

54 Guide

56 Projection

58 Guide

60 First spring element 62 Second spring element

64 Longitudinal axis

66 Longitudinal axis

68 Adjustment apparatus

70 Actuation part

72 First actuation lever

74 Second actuation lever

76 Point

78 Point

80 Articulation point

81 Receptacle

82 Slave piston

84 Slave cylinder

86 First slave chamber

88 Master cylinder

90 Drive apparatus

92 Master piston

94 First master chamber

96 Line

98 Engagement bearing

100 Cylinder

102 Piston

104 Restoring spring

106 First static sensor

108 Second static sensor

110 First structure

112 Second structure

114 Annular part

116 Annular part

118 Second slave chamber

120 Second master chamber 122 Line

124 Receptacle di Diameter d ₂ Outer diameter d3 Diameter li Length b Length ri Radial spacing r ₂ Radial spacing