Asymmetric centrifugal pendulum device

Abstract

Centrifugal pendulum device (1) for arrangement in the drive train of a motor vehicle, with at least two pendulum masses (4a, 4b) arranged on a carrier disk (2) and able to perform a relative movement to the carrier disk (2) along a predetermined pendulum path in order to assume a variable distance to the axis of rotation (R) of the carrier disk (2), characterized in that the carrier disk (2) has an imbalance which, in a basic position of the pendulum masses (4a, 4b), is compensated by a corresponding imbalance of the pendulum masses (4a, 4b), wherein the cam guides of the respective pendulum paths are arranged such that the distance of the pendulum masses (4a, 4b) to the axis of rotation (R) is different, whereby the pendulum masses (4a, 4b) have different pendulum paths and radii, so that different orders can be damped or eliminated.

Description

The invention relates to a centrifugal pendulum device for arrangement in the drive train of a motor vehicle, having at least two pendulum masses which are arranged on a carrier plate and can execute a relative movement with respect to the carrier plate along a predefined pendulum path in order to assume a variable distance from the axis of rotation of the carrier plate, and to a carrier plate for use in a centrifugal pendulum device.In order to reduce torsional vibrations, for example in a drive train of a motor vehicle, additional masses are attached as what is known as pendulum masses on a rotating part of the torsional vibration system. The drive train usually comprises an internal combustion engine, a vehicle clutch, a shift transmission, a differential gear and drive wheels as well as torque transmission means such as shafts and clutches, each arranged between the mentioned elements. In a transmission automatic machine, instead of the vehicle clutch and the transmission, a torque converter and a transmission automatic machine are arranged in the drive train. In operation, the pendulum masses perform oscillations on predetermined paths due to the rotation of the rotating part in the field of centrifugal acceleration when they are excited by speed irregularities. These oscillations draw energy from the exciter oscillation at suitable times and feed it back at other suitable times, so that the exciter oscillation is calmed down, i.e., the pendulum mass acts as an absorber. Since both the natural frequency of the centrifugal pendulum oscillation and the excitation frequency are proportional to the rotational speed, an absorption effect of a centrifugal pendulum can be achieved over the entire frequency range of the oscillations excited by rotational speed irregularities. A centrifugal pendulum device of the relevant type serves to reduce vibrations and noises in the drive train of a motor vehicle. Such a centrifugal pendulum device comprises at least one pendulum mass, which is suspended on a rotating carrier disk, for example, by means of carrier rollers or the like and can execute a relative movement with respect to the carrier disk along predefined pendulum paths, in order to assume a variable distance from the axis of rotation of the carrier disk. The structure and function of such a centrifugal pendulum device is described, for example, in DE 10 2006 028 552 A1.Centrifugal pendulum masses are known from the prior art, which are designed in pairs such that the center of gravity, which results from two pendulum masses, is located on the axis of rotation of the centrifugal pendulum device. This means that the two pendulum masses do not cause a static geometric imbalance.In the case of an odd number of pendulum masses, 3 or 5 pendulum masses, for example, are designed such that the center of gravity, which results from 3 or 5 pendulum masses, is located on the axis of rotation of the centrifugal pendulum device. This means that the 3 or 5 pendulum masses do not cause any static geometric imbalance.A special form of this embodiment consists of identical pendulum masses with the same mass and the same center of gravity spacing. The carrier disk or flange on which the pendulum masses are accommodated then does not have any geometric imbalance. As a result of both measures, the entire centrifugal pendulum device has no imbalance.Drive trains in motor vehicles become increasingly sensitive, so that it is necessary or at least desirable to cancel out several orders of oscillations. The damper effect that can be achieved is different depending on the excitation amplitude, so that different pendulum masses are advantageous.The design of the pendulum masses according to the prior art, however, permits only a slight deviation between two opposite pendulum masses. The above-mentioned imbalance criterion, the avoidance of a static imbalance, represents here the limit to greater deviations between the pendulum masses.It is therefore an object of the invention to specify a centrifugal pendulum device and a carrier disk for use in a centrifugal pendulum device which permits greater imbalance between pendulum masses than in the prior art.This problem is solved by a centrifugal pendulum device according to claim 1 and a carrier disc for use in a centrifugal pendulum device according to claim 9. Preferred embodiments or refinements of the invention are specified in the dependent claims.The above-mentioned problem is solved in particular by a centrifugal pendulum device for arrangement in the drive train of a motor vehicle, having at least two pendulum masses which are arranged on a carrier plate and can execute a relative movement with respect to the carrier plate along a predefined pendulum path in order to assume a variable distance from the axis of rotation of the carrier plate in this case, wherein the carrier plate has an imbalance which is compensated in a basic position of the pendulum masses by a corresponding imbalance of the pendulum masses. The basic position of the pendulum masses is understood to mean a position that they assume in the event of a uniform rotational movement, i.e. without torque fluctuations in the drive train of the motor vehicle. The center of gravity of the carrier disk is thus not located on the axis of rotation of the centrifugal pendulum device, but rather is at a distance from it. Accordingly, the overall center of gravity of the pendulum masses is likewise not on the axis of rotation, but rather has a distance from it. The axis of rotation of the centrifugal pendulum device lies on a straight line through the center of gravity of the pendulum masses and the center of gravity of the carrier disk. The masses of the carrier disk and of the pendulum masses and the distances of the centers of gravity from the axis of rotation are dimensioned such that an overall center of gravity of the centrifugal pendulum device results, which lies on the axis of rotation of the centrifugal pendulum device. The system is thus completely free of imbalance. Because the imbalance of the two pendulum masses is compensated by a corresponding imbalance of the carrier disk, the mass difference of the two pendulum masses can be greater. This makes it possible to cancel different orders of oscillations.In one embodiment of the invention, the carrier disk has a geometric imbalance. This means that even the geometric shape of the carrier disk, with the same material and thus the same density over the entire carrier disk, produces an imbalance. Alternatively or additionally, it can be provided that the carrier disk comprises imbalance masses. The imbalance masses can be, for example, rivets which are arranged in corresponding bores of the carrier disk. The rivets can be made of a material of a lower or a higher density than the carrier disc. Alternatively or additionally, individual bores or recesses can also introduce further imbalance into the system.In one embodiment of the invention, the pendulum masses have different shapes and / or different masses. Both by the different shapes and by the different masses, the position of the center of gravity of each individual pendulum mass and thus the position of the total center of gravity of the multiple pendulum masses can be controlled.In one embodiment of the invention, it is provided that the pendulum masses have different pendulum paths. The pendulum tracks are predetermined, similar to a link guide, by elongated holes in the carrier disc and elongated holes in the pendulum part masses, wherein the elongated holes of carrier disc and pendulum part masses are connected to one another by bolts with rollers. The bolts project from the elongated hole in one pendulum mass through the elongated hole of the carrier disk into the elongated hole of the other pendulum part mass.In one embodiment of the invention, the pendulum masses have different distances between the center of gravity and an axis of rotation of the centrifugal pendulum device. This measure ensures that the total center of gravity of the plurality of pendulum masses is at a distance from the axis of rotation of the centrifugal pendulum device.In one embodiment of the invention, the centrifugal pendulum device has an even number of pendulum masses. These can be, for example, two or four pendulum masses. In this case, the pendulum masses can each be provided with imbalance in pairs, wherein the carrier disk is accordingly provided with imbalance for compensating these imbalance in pairs.In an alternative embodiment of the invention, it is provided that the centrifugal pendulum device has an odd number of pendulum masses. In this case, three or five or more pendulum masses must each together form an imbalance which is compensated by a corresponding imbalance of the carrier disk.In one embodiment of the invention, the pendulum masses have different geometric shapes and in a further embodiment of the invention also different masses and thus different centers of gravity and optionally different center of gravity masses. In the case of an even number of pendulum masses, identical or different pairs of pendulum masses can be provided. Pairs of pendulum masses are understood to mean two opposite pendulum masses.Exemplary embodiments of the invention are explained in more detail below with reference to the attached drawings. The following are shown: FIG. 1 shows a first exemplary embodiment of a centrifugal pendulum device according to the invention in plan view; FIG. 2 shows the pendulum masses of FIG. 1 in an individual illustration; FIG. 3 shows the carrier disc of FIG. 1 in an individual illustration; FIG. 4 shows a second exemplary embodiment of a centrifugal pendulum device according to the invention in plan view; FIG. 5 shows a section G-G in FIG. 4.FIG. 1 shows a first exemplary embodiment of a centrifugal pendulum device according to the invention in plan view. The centrifugal pendulum device 1 comprises a carrier disk 2 which can be connected to the hub of a clutch disk, not shown in detail, by a caulking connection 3, not shown in detail. The centrifugal pendulum device 1 rotates in the installed position about an axis of rotation R. The circumferential direction is understood here to mean a rotation about the axis of rotation R, the axial direction is understood to mean the direction parallel to the axis of rotation R and the radial direction is understood to mean a direction perpendicular to the axis of rotation R. In the installed position, the centrifugal pendulum device 1 is arranged between a drive unit, in particular an internal combustion engine with a crankshaft as the drive shaft, and a transmission, wherein a clutch, which can be actuated by a disengagement device, is arranged between the two. The centrifugal pendulum device 1 is usually arranged on the transmission side of the clutch and thus on the clutch plate.In the exemplary embodiments of the centrifugal pendulum device 1 according to FIG. 1, two pendulum masses 4 are arranged on the outer circumference of the carrier disk 2. The pendulum masses 4 have different geometries and are therefore differentiated here into pendulum mass 4 aand pendulum mass 4 b. The pendulum masses 4 acomprise in each case two pendulum partial masses 5 aand 5 b, which are arranged in each case on both sides of the carrier disc 2. In the illustration of FIG. 1, the pendulum part mass 5 ais arranged in the plane of the drawing in front of the carrier disc 2, and in the illustration of FIG. 1 the pendulum part mass 5 bis arranged in the plane of the drawing behind the carrier disc 2 and is therefore not visible. The pendulum masses 4b each comprise two pendulum partial masses 5c and 5d, which are arranged on both sides of the carrier disk 2. In the illustration of FIG. 1, the pendulum part mass 5 cis arranged in the plane of the drawing in front of the carrier disc 2, and in the illustration of FIG. 1 the pendulum part mass 5 dis arranged in the plane of the drawing behind the carrier disc 2 and is therefore not visible. The pendulum part masses 5 aand 5 bof the pendulum mass 4 aand the pendulum part masses 5 cand 5 dof the pendulum mass 4 bare each firmly connected to one another and are mounted on predetermined tracks by means of link guides so as to be displaceable (movable) with respect to the carrier disc 2.The two pendulum partial masses 5 aand 5 band 5 cand 5 dof each centrifugal pendulum 4 aand 4 bare connected to one another by a plurality of connecting bolts 6. The connecting bolts 6 are arranged in a central, central region of the pendulum masses 5 and are connected to the pendulum partial masses 5 aand 5 bor 5 cand 5 din the manner of rivets. For this purpose, the region of the connecting bolts arranged between the respective pendulum part masses has, for example, a larger diameter than the outer outer regions which project through bores of the pendulum part masses 5 aand 5 bor 5 cand 5 d, the heads of which are provided with setting heads during assembly.Since the pendulum masses 4 a, 4 bare arranged displaceably relative to the carrier disk 2 both in the circumferential direction and in the radial direction along a slotted guide, cut-outs 7 aand 7 bare formed in the carrier disk 2, in each of which the connecting bolts 6 are arranged with play with respect to the carrier disk 2. At the same time, a spacer made of metal, which is not shown, arranged between the pendulum part masses, and a stop element 11 made of rubber, which can be connected to one another, are fixed between the pendulum part masses 5 a, 5 b, by the rivet 6.Rollers 10 are arranged in elongated holes 8 in the pendulum part masses 5 a, 5 b, 5 cand 5 dand also in elongated holes 9 in the carrier disc 2. The rollers 10, in conjunction with the elongated holes 8 in the pendulum partial masses 5 a, 5 b, 5 cand 5 dand the elongated holes 9 in the carrier disk 2, form a slotted guide for the respective pendulum mass 4, which guide allow a movement of the pendulum masses 4 a, 4 balong predefined paths relative to the carrier disk 2. The pendulum masses 4 a, 4 bare suspended in a bi-filar manner with respect to the carrier disk 2, that is to say, the suspension of the pendulum masses 4 a, 4 bon the carrier disk 2 results in both the radial movement of the pendulum masses 4 a, 4 bwith respect to the carrier disk 2 and at the same time the movement in the circumferential direction being predefined, so that effectively only one degree of freedom of each pendulum mass 4 a, 4 bis given with respect to the carrier disk 2. The raceways of the rollers 10 with respect to the carrier disk 2 or the pendulum masses 4 a, 4 bare designed such that the center of gravity of the respective pendulum mass 4 a, 4 bcoulises at a respective instantaneous radius about the distance from a center point which is given by the axis of rotation R. However, other non-circular tracks are also possible here. This movement creates a variable distance of the center of gravity from the center point. The ratio of radius to distance is a measure of the order with which the respective pendulum mass 4 is excited to oscillate. When tuning is carried out close to or directly to the main exciter arrangement of the drive train, the oscillation amplitude is reduced over the entire rotational speed range.The pendulum masses 4 aand 4 bin the exemplary embodiment according to the invention of FIG. 1 have, on the one hand, different geometries, i.e. different spatial shapes, and also different masses. In addition, the arrangement of the link guides of the respective pendulum tracks is designed such that the distance of the pendulum masses from the axis of rotation R is different. As a result, the pendulum paths and radii are also different, as explained above, so that different orders can be attenuated or cancelled.To clarify the geometric relationships, the pendulum masses 4 aand 4 btogether with the rollers 10 are shown individually in FIG. 2. The axis of rotation of the centrifugal pendulum device 1 is marked with the reference symbol R in FIG. 2. The center of mass or center of gravity of the centrifugal pendulum 4 ais denoted in FIG. 2 by the reference symbol SP 1. The center of mass or center of gravity is the mass-weighted average of the positions of the mass points of the respective body. Accordingly, the center of mass of the pendulum mass 4 bis provided with the reference symbol SP 2. The common center of mass of the two pendulum masses 4 aand 4 bresulting from the center of mass SP 1 and SP 2 is denoted by SPGin FIG. 2. The common center of mass SPG of the pendulum masses 4 aand 4 bis not located on the axis of rotation R of the device, but is arranged at a distance A 1 from it. The pendulum masses 4 aand 4 btogether are therefore not balanced, but rather have a static imbalance.FIG. 3 shows the carrier disc 2 of the centrifugal pendulum device 1 according to FIG. 1 in an individual illustration in plan view. The carrier disk 2 is constructed symmetrically to an axis of symmetry B which runs through the axis of rotation R. A region 13 serves to receive the centrifugal pendulum 4 a, and correspondingly a region 14 of the carrier disk 2 serves to receive the centrifugal pendulum 4 b. Bores 15a and 15b and recesses 16a, 16b and 17 are arranged in the carrier disc 2. The bores 15 a, 15 band the recesses 16 a, 16 b, 17 serve on the one hand to reduce the weight of the carrier disc 2, and on the other hand the position of the center of gravity of the carrier disc 2 can be influenced with its shape, position and size. The center of mass or center of gravity of the carrier disk 2 is denoted in FIG. 3 by the reference symbol ST. The center of mass ST of the carrier disk 2 does not coincide with the axis of rotation R of the centrifugal pendulum device 1, but is spaced apart from it by a distance A 2. That of the carrier disc 2 is therefore not balanced by itself, but rather has a static imbalance.The total center of gravity of the centrifugal pendulum device 1, i.e. of the carrier disk 2 with the centrifugal pendulums 4 aand 4 barranged thereon, is determined by the mass of the carrier disk 2 and the masses of the centrifugal pendulums 4 a, 4 band the distances A 1 and A 2 of the previously described center of mass SPG 1 of the centrifugal pendulums 4 aand 4 band of the center of mass ST of the carrier disk 2. For the position of the center of mass SG of the centrifugal pendulum device, it holds true that the distances of the respective partial center of mass multiplied by the associated masses balance each other. According to the invention, the centrifugal pendulum device 1, i.e. the carrier disk 2 with the centrifugal pendulums 4 aand 4 barranged thereon, is designed such that the center of mass SGof the centrifugal pendulum device coincides with the axis of rotation R, i.e. here A1× MF=A2× MT applies, wherein MFis the mass of the two centrifugal pendulums 4 a, 4 bis combined, MTis the mass of the carrier disk 2, A1is the distance of the center of mass SPG1of the centrifugal pendulums 4 aand 4 bfrom the axis of rotation R, and A2is the distance of the center of mass STof the carrier disk 2 from the axis of rotation R. The overall system centrifugal pendulum device 1 therefore has no imbalance, wherein the two subsystems, namely the two centrifugal pendulums 4 a, In the embodiment shown in FIG. 4 b, the carrier disk 2 per se each have an imbalance, which, however, balance out in the overall system of the centrifugal pendulum device.FIGS. 4 and 5 show an alternative exemplary embodiment of a centrifugal pendulum device 1 according to the invention. FIG. 4 shows a plan view, FIG. 5 shows a section G-G in FIG. 4. In the exemplary embodiment of FIG. 4, the carrier disk 2 is provided with two rivets 18 a, 18 bwhich are arranged in corresponding bores of the carrier disk 2. The rivets 18 a, 18 bare each solid rivet and have a rivet shank which projects through the bore in the carrier disc 2 and is provided on one side with a prefabricated rivet head 19 and on the other side with a setting head 20 by the riveting process. The rivets 18 a, 18 bare arranged symmetrically to the axis B. The rivets 18 a, 18 bmay be made of a material having a higher or lower density than the carrier disc 2.List of reference characters1 Centrifugal pendulum device 2 Carrier disk 3 Caulked connection 4 a, 4 b Fliehkraft pendulum 5 a, 5 b Pendel part masses 6 Connecting bolt 7 Cut-outs 8 Elongated hole in the pendulum part mass 9 Elongated hole in the carrier disk 10 Caster 11 Stop element 13 Part of the carrier disk for receiving the centrifugal pendulum 4 a 14 Part of the carrier disk for receiving the centrifugal pendulum 4 b 15 a, 15 b Bohrungen 16 a, 16 b Aussparungen 17 Aussparung 18 a, 18 b Niet 19 Rivet head 20 Setting head R Axis of rotation SP 1 Center of mass of centrifugal pendulum 4 a SP 2 Center of mass of centrifugal pendulum 4 b SPG Center of mass of centrifugal pendulum 4 aand 4 b ST Center of mass of carrier disk 2 SG Center of mass of centrifugal pendulum device B Axis of symmetry

Claims

Centrifugal pendulum device (1) for arrangement in the drive train of a motor vehicle, having at least two pendulum masses (4a, 4b) which are arranged on a carrier disc (2) and can execute a relative movement with respect to the carrier disc (2) along a predetermined pendulum path in order to assume a variable distance from the axis of rotation (R) of the carrier disc (2), characterized in that the carrier disc (2) has an imbalance which, in a basic position of the pendulum masses (4a, 4b), is compensated by a corresponding imbalance of the pendulum masses (4a, 4b), wherein the link guides of the respective pendulum paths are arranged such that the distance of the pendulum masses (4a, 4b) from the axis of rotation (R) is different, as a result of which the pendulum masses (4a, 4b) have different pendulum paths and radii, so that different orders can be attenuated or cancelled.Centrifugal pendulum device according to claim 1, wherein the carrier disc (2) has a geometric imbalance.Centrifugal pendulum device according to claim 1 or 2, wherein the carrier disc (2) comprises imbalance masses (18a, 18b).Centrifugal pendulum device according to one of the preceding claims, wherein the pendulum masses (4a, 4b) have different shapes.Centrifugal pendulum device according to one of the preceding claims, wherein the pendulum masses (4a, 4b) have different masses.Centrifugal pendulum device according to one of the preceding claims, wherein the pendulum masses (4a, 4b) have different centre of gravity distances from an axis of rotation (R) of the centrifugal pendulum device (1).Centrifugal pendulum device according to one of the preceding claims, wherein it has an even number of pendulum masses (4a, 4b).Centrifugal pendulum device according to one of Claims 1 to 6, wherein said device has an odd number of pendulum masses (4).Carrier disc (2) for use in a centrifugal pendulum device according to one of the preceding claims, wherein the centre of mass (ST) of the carrier disc (2) is spaced apart from the axis of rotation (R) of the carrier disc (2).

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