centrifugal pendulum

Abstract

Centrifugal pendulum (1) with a pendulum flange (2) rotating about an axis of rotation (24) and several pendulum masses (4) distributed around the circumference and displaceable within stops (12, 13, 14, 15) relative to the pendulum flange (2), characterized in that the stops (12, 13, 14, 15) of the pendulum masses (4) on the pendulum flange (2) are hydraulically damped, wherein the pendulum masses (4) are received by means of rolling elements (11) which roll on raceways (9, 10) formed by cutouts (7, 8) in the pendulum flange (2) and the pendulum masses (4), and the cutouts (7, 8) are each limited in the circumferential direction by a stop (12, 13, 14, 15) and at least one stop (12, 13, 14, 15) with the associated rolling element (11) forms a gap-filled chamber (18, 19) at least partially filled with a hydraulic fluid and a sack-shaped extension (16) formed from the cutout (7, 8) in the area of ​​the stop (12, 13, 14, 15).17) is partially closed by the circumference of the rolling element (11) forming two gaps, and wherein a chamber (18) provided in the cutout (7) of the pendulum flange (2) is at least partially closed at the end faces of the pendulum flange (2) by a ring flange (23) arranged on the rolling element (11).

Description

[0001] The invention relates to a centrifugal pendulum, in particular in a torsional vibration damper of a drive train of a motor vehicle.

[0002] Such centrifugal pendulum absorbers are known, for example, from German patent applications DE 10 2006 028 556 A1, DE 10 2007 024 115 A1, DE 102 24 874 A1, DE 100 59 101 A1, and DE 199 11 561 A1. For example, a pendulum flange, which may be part of a torsional vibration damper and may have corresponding functional elements such as window cutouts for energy storage devices, is provided with cutouts along whose raceways rolling elements roll, which in turn roll in cutouts with raceways of pendulum masses, which are preferably arranged on both sides of the side surfaces of the pendulum flange, with two opposing pendulum masses connected to each other. The shape of the cutouts in the pendulum flange and in the pendulum masses determines the displacement of the pendulum masses relative to the pendulum flange.When torsional vibrations occur, the pendulum masses shift relative to the pendulum flange and, as a result of their pendulum movement, act as torsional vibration dampers with increasing displacement in the circumferential direction and radially outwards.

[0003] If the oscillation angle transmitted to the pendulum flange increases, for example, due to an internal combustion engine installed in a motor vehicle's drivetrain, the pendulum masses can be deflected to such an extent that they strike the pendulum flange. This can reduce the centrifugal pendulum's damping effect or even lead to resonance, so that the impaired insulation behavior of the centrifugal pendulum can worsen the overall vibration behavior of the vehicle. Furthermore, the centrifugal pendulum can be damaged.

[0004] The task therefore arises to propose a centrifugal pendulum with improved oscillation behavior.

[0005] The object is achieved by a centrifugal pendulum having the features of claim 1, by a torsional vibration damper having the features of claim 4 and by a hydrodynamic torque converter having the features of claim 5.

[0006] This object is achieved by a centrifugal pendulum absorber, particularly in a torsional vibration damper of a motor vehicle drivetrain, comprising a pendulum flange rotating about a rotational axis and a plurality of pendulum masses distributed around the circumference and displaceable relative to the pendulum flange within stops. The stops of the pendulum masses on the pendulum flange are hydraulically damped. The hydraulic damping prevents a hard impact of the pendulum masses. According to the invention, the pendulum masses run onto a buffer of hydraulic fluid before a hard metallic impact on the pendulum flange or intermediate components. This buffer can be displaced with increasing impact pressure.

[0007] Hydraulic damping can be particularly advantageously provided in arrangements in which the pendulum masses are supported by rolling elements that roll along raceways formed by cutouts in the pendulum flange and the pendulum masses. In this case, the pivoting paths are generally limited by stops in the cutouts, against which the rolling elements run during the pivoting of the pendulum masses relative to the pendulum flange. The rolling elements can run against the corresponding stops in the circumferential direction on both sides of the cutouts in the pendulum flange and in the pendulum masses.It is therefore proposed for such embodiments to form a gap-like chamber, at least partially filled with a hydraulic fluid, in the area of ​​at least one stop, but preferably at all stops, in conjunction with the associated rolling element. This chamber is formed when the rolling element approaches the stop, and as the rolling element approaches the stop further, the hydraulic fluid enclosed in the chamber is displaced through the gap formed between the rolling element and the cutout. In this way, a resistance builds up over the remaining pivoting path up to the hard stop, which prevents the pendulum masses from striking the pendulum flange hard or, if necessary, from striking at all.

[0008] According to an advantageous embodiment, a sack-shaped recess can be made from the cutout in the region of the deflection, which is partially closed by the circumference of the rolling body to form two gaps when a predetermined approach of the rolling body to the stop is reached.

[0009] In order to further at least partially seal the preferably disc-shaped components, namely the pendulum flange and pendulum masses, on their sides and thus prevent the hydraulic fluid from escaping without resistance, a chamber provided in the cutout of the pendulum flange can be at least partially closed on the end faces of the pendulum flange by an annular rim arranged on the rolling element. For example, two axially spaced annular rims of a barrel-shaped rolling element slide along the side surfaces of the pendulum flange, wherein these rims are radially expanded such that they cover the chamber completely as the rolling element approaches it. The annular rim can simultaneously serve to axially stabilize the rolling element in the cutout.

[0010] Similarly, the annular flange, a chamber provided in the cutout of a pendulum mass, can at least partially close the side of the pendulum mass facing the pendulum flange, while the side of the pendulum mass facing away from the pendulum flange can preferably be at least partially closed by a baffle. The distances between the annular flanges and the side surfaces of the pendulum masses or the pendulum flange, and / or the baffle, can also have clearance relative to the side surfaces, so that hydraulic fluid can also escape from them under pressure.

[0011] To provide the hydraulic fluid contained in the chambers formed in this way, the centrifugal pendulum absorber is preferably operated in a wet environment. For this purpose, the centrifugal pendulum absorber can be encapsulated in otherwise dry environments. It has proven particularly advantageous if the centrifugal pendulum absorber is installed in a housing of a torque converter or a wet clutch, so that the hydraulic fluid can be the converter fluid or clutch fluid.

[0012] The invention also encompasses a torsional vibration damper with a centrifugal pendulum of the described form, wherein the damper is formed from an input part and an output part that can be rotated relative to the input part, counteracting the effect of energy storage devices, and can have multiple damper stages. The centrifugal pendulum can be integrated into a disc part of a damper stage, for example, into the input or output part.

[0013] In the same way, the inventive concept encompasses a hydrodynamic torque converter with a housing at least partially filled with a hydraulic fluid, which contains a centrifugal pendulum designed according to the inventive concept or a torsional vibration damper with the latter.

[0014] The invention is based on the Fig. 1 and Fig. 2 are explained in more detail. They show: Fig. 1 a section of a centrifugal pendulum in view and Fig. 2 a section through the centrifugal pendulum of the Fig. 1 along section line AA.

[0015] Fig. Figure 1 shows a section of a centrifugal pendulum absorber 1. The basic structure of centrifugal pendulum absorbers and torsional vibration dampers can be found, for example, in DE 10 2006 028 556 A1. The centrifugal pendulum absorber 1 is formed from the pendulum flange 2, which, as a functional component of a torsional vibration damper, contains window-shaped recesses 3 for accommodating or loading energy storage devices acting in the circumferential direction and can serve as a disc part for the torsional vibration damper.

[0016] Radially outside the recesses 3, the pendulum flange 2 accommodates pendulum masses 4 distributed around the circumference, pivotably mounted on the pendulum flange 2. One of the pendulum masses 4 is firmly connected to each other on each side of the pendulum flange 2 by means of connecting means 5, such as bolts or rivets. Accordingly, the pendulum flange 2 has cutouts 6 through which the connecting means are guided, and whose shape is designed according to the pivoting range of the pendulum masses 4.

[0017] The shape of the pivoting range of the pendulum masses 4 relative to the pendulum flange 2 is predetermined by cutouts 7, 8 in both the pendulum flange 2 and the pendulum masses 4, in which the rolling elements 11 roll on raceways 9, 10. To limit the pivoting range, the design of the centrifugal pendulum can ideally be selected, for example, via the pitch of the raceways 9, 10, the mass of the pendulum masses 4, their arrangement diameter, and the like, such that, within the occurring oscillation angle entered in the centrifugal pendulum 1, impact of the rolling elements on the circumferential stops 12, 13 of the cutouts 7 of the pendulum flange 2 or on the stops 14, 15 of the cutouts 8 of the pendulum masses is unlikely.

[0018] If, for example, at high oscillation angles, a hard impact of the rolling elements 11 on the stops 12, 13, 14, 15 is imminent, this is dampened by a hydraulic damping of the pendulum masses 4 relative to the pendulum flange. For this purpose, the cutouts 7, 8 have bag-like extensions 16, 17 on both sides in the circumferential direction, which, when the rolling elements 11 approach the stops 12, 13, 14, 15, form a gap-filled chamber 18, 19 with the rolling elements 11, in each of which a hydraulic fluid is located, which is displaced via the gaps formed between the rolling elements 11 and the extensions 16, 17 when the rolling elements 11 reduce the volume of the chambers 18, 19 due to their approach to the stops 12, 14 in one pivoting direction or to the stops 13, 15 in the other pivoting direction. When the rolling elements 11 approach the stops 12, 13, 14, 15, the hydraulic fluid is displaced in the direction of the arrows 20, 21.To form a suitable gap between the rolling elements 11 and the extensions 16, 17, the cutouts 7, 8 can have corresponding noses 22.

[0019] Refilling of the chambers 18, 19 with hydraulic fluid can occur, for example, through the centrifugal force of the hydraulic fluid surrounding the centrifugal pendulum 1, for example, in an application in a hydraulic torque converter, a wet clutch, or through appropriate encapsulation of the centrifugal pendulum. It is understood that this device for hydraulic damping can alternatively also be provided exclusively at the cutouts 7 of the pendulum flange 2 or at the cutouts 8 on the pendulum masses 4. Furthermore, such a damping device cannot be provided at all cutouts 7, 8.

[0020] In order to seal the chambers 18, 19 on the side surfaces of the pendulum flange 2 at least to the extent that hydraulic damping can be achieved when the rolling elements 11 approach the stops 12, 13, 14, 15, an annular rim 23 is provided on the rolling elements 11 on both side surfaces of the pendulum flange 2. This annular rim 23 is radially expanded relative to the rolling diameter of the rolling elements 11 such that it radially overlaps the radial extent of the chambers 18, 19. This annular rim 23 also seals the side surface of the chamber 19 of the pendulum masses 4 facing the pendulum flange 2 in the same way. The side surface of the chamber 19 facing away from the pendulum flange 2 is sealed by a cover (not shown).

[0021] The Fig. 2 shows that in Fig. 1 along the section line AA. From this illustration, the hatched chambers 18, 19 of the pendulum flange 2 and the pendulum masses 4 emerge. To achieve hydraulic damping, the chambers 18, 19 are adequately sealed against the axial side surfaces of the pendulum flange 2 and the pendulum masses 4 relative to the rotational axis 24 of the centrifugal pendulum 1 by means of the annular rims 23 of the rolling element 11 and the orifices 25. The orifices 25 can tightly close the chambers 19, while the annular rims 23 form gaps 26 to the chambers 18, 19, through which the rolling elements 11 approach the stops 12, 13, 14, 15 ( Fig. 1) in addition to the columns in the direction of arrows 20, 21 ( Fig. 1) can escape in the direction of arrows 27, 28. List of reference symbols 1 centrifugal pendulum 2 pendulum flange 3 recess 4 pendulum mass 5 connecting devices 6 free cut 7 Excerpt 8 Excerpt 9 Career 10 Career 11 rolling elements 12 stops 13 stop 14 stop 15 stops 16 Expansion 17 Expansion 18 Chamber 19th Chamber 20 Arrow 21 Arrow 22 Nose 23 Ringbord 24 axis of rotation 25 aperture 26 gap 27 Arrow 28 Arrow

Claims

[1] Centrifugal pendulum (1) with a pendulum flange (2) rotating about a rotation axis (24) and several pendulum masses (4) distributed over the circumference and displaceable to a limited extent relative to the pendulum flange (2) within stops (12, 13, 14, 15), characterized bythat the stops (12, 13, 14, 15) of the pendulum masses (4) on the pendulum flange (2) are hydraulically damped, wherein the pendulum masses (4) are received by means of rolling elements (11) which roll along raceways (9, 10) formed by cutouts (7, 8) in the pendulum flange (2) and the pendulum masses (4), and the cutouts (7, 8) are each delimited in the circumferential direction by a stop (12, 13, 14, 15), and at least one stop (12, 13, 14, 15) forms, with the associated rolling element (11), a gap-filled chamber (18, 19) which is at least partially filled with a hydraulic fluid, and a chamber (18, 19) which emerges from the cutout (7, 8) in the region of the stop (12, 13, 14, 15) formed sack-shaped extension (16, 17) is partially closed by the circumference of the rolling body (11) to form two gaps,and wherein a chamber (18) provided in the cutout (7) of the pendulum flange (2) is at least partially closed on the end faces of the pendulum flange (2) by a respective annular rim (23) arranged on the rolling element (11). [2] Centrifugal pendulum (1) according to claim 1, characterized by that a chamber (19) provided in the cutout (8) of a pendulum mass (4) is at least partially closed on the side of the pendulum mass (4) facing away from the pendulum flange (2) by means of a diaphragm (25) and on the side facing the pendulum flange (2) by an annular rim (23) of the rolling body (11). [3] Torsional vibration damper with a centrifugal pendulum (1) according to one of claims 1 to 2. [4] Hydrodynamic torque converter with a housing at least partially filled with a hydraulic fluid and a centrifugal pendulum (1) according to one of claims 1 to 2 or a torsional vibration damper according to claim 3 accommodated therein.

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