Torsional vibration damper

Abstract

A torsional vibration damper for transferring torque between a first and a second rotatable element, having a rotatable pressure plate to transfer the torque from the first element, a rotatable output element to transfer the torque to the second element, and a vibration damper element to transfer the torque between the pressure plate and the output element, where the vibration damper element includes an energy-storing spring system. A driving element is formed in a single piece on the pressure plate to fit against the spring system.

Claims

1. A torsional vibration damper, comprising: a rotatable pressure plate having a strap extending from the pressure plate in an axial direction; a rotatable hub flange arranged to connect to an output shaft; a holding plate arranged to transfer torque to the rotatable hub flange; a spring circumferentially aligned with the strap to transfer the torque between the pressure plate and the holding plate; a pendulum flange located axially between the pressure plate and the spring, the pendulum flange connected to the holding plate and having a cutout; a plurality of centrifugal force pendulums distributed around a circumference of the pendulum flange, wherein the strap extends axially through the cutout in the pendulum flange.

2. The torsional vibration damper as recited in claim 1, wherein the pressure plate has an axial frictional surface in order to transfer the torque.

3. The torsional vibration damper as recited in claim 2, wherein the spring is situated in a radially outer region of the pressure plate.

4. The torsional vibration damper as recited in claim 1, wherein the strap extends inward in a radial direction.

5. The torsional vibration damper as recited in claim 1, wherein: the pressure plate has a plurality of straps extending from the pressure plate in the axial direction.

6. The torsional vibration damper as recited in claim 1, wherein the pressure plate is made from a metal sheet.

7. The torsional vibration damper as recited in claim 1, wherein the pressure plate has an encircling rim which extends in the axial direction.

8. The torsional vibration damper as recited in claim 1, wherein the hub flange is set up to be moved axially on the output shaft while ending torque.

9. A torsional vibration damper, comprising: a pressure plate having a strap extending from the pressure plate in an axial direction; a hub flange arranged to connect to an output shaft; a holding plate arranged to transfer torque to the rotatable hub flange; a spring circumferentially aligned with the strap to transfer the torque between the pressure plate and the holding plate; a pendulum flange: connected to the holding plate; located axially between the pressure plate and the holding plate; and, having a cutout; and, a plurality of centrifugal force pendulums distributed around a circumference of the pendulum flange, wherein the strap extends axially through the cutout.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The nature and mode of operation of the present invention will now be more fully described in the following detailed description of the invention taken with the accompanying drawing figures, in which:

(2) FIG. 1 is a sectional view through part of a torsional vibration damper;

(3) FIG. 2 is a another sectional view through part of a torsional vibration damper; and,

(4) FIG. 3 is an exploded view of part of a torsional vibration damper.

DETAILED DESCRIPTION OF THE INVENTION

(5) At the outset, it should be appreciated that like drawing numbers on different drawing views identify identical, or functionally similar, structural elements of the invention. While the present invention is described with respect to what is presently considered to be the preferred aspects, it is to be understood that the invention as claimed is not limited to the disclosed aspects.

(6) Furthermore, it is understood that this invention is not limited to the particular methodology, materials and modifications described and, as such, may, of course, vary. It is also understood that the terminology used herein is for the purpose of describing particular aspects only, and is not intended to limit the scope of the present invention, which is limited only by the appended claims.

(7) Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood to one of ordinary skill in the art to which this invention belongs. Although any methods, devices or materials similar or equivalent to those described herein can be used in the practice or testing of the invention, the preferred methods, devices, and materials are now described.

(8) FIG. 1 shows the upper half of a longitudinal section through torsional vibration damper 100. Essentially, only the cross sections are shown; encircling edges beyond the sectional plane are not visible.

(9) Torsional vibration damper 100 is set up to rotate around axis of rotation 105. Torque is transferred along axis of rotation 105 generally in both directions. A preferred direction of transmission runs from left to right, for example, from a drive motor of a motor vehicle to a transmission of the motor vehicle.

(10) Pressure plate 110 carries friction lining 115 on its left face in a radially outer region. The torque to be transferred can be introduced into torsional vibration damper 100, for example, by means of a flywheel (not shown) that can rotate around axis of rotation 105. The flywheel is pressed axially against friction lining 115. In other embodiments, friction lining 115 can also be fastened to the flywheel, in which case the frictional engagement can be produced by means of axial pressure between friction lining 115 and pressure plate 110. The friction-disk clutch set up by the flywheel, friction lining 115 and pressure plate 110 may be a dry clutch or a wet clutch running in an oil bath. There may also be a plurality of plates with friction linings 115 and/or a plurality of steel plates contained in the clutch.

(11) In yet another embodiment, instead of friction lining 115 the torque may also be coupled and uncoupled by means of a plate carrier, which is placed on the left face of pressure plate 110. The plate carrier is part of a clutch, for example, a multi-plate lamellar clutch, which optionally runs dry or in a fluid bath. In this constellation, an outer zone of pressure plate 110 is subjected to weaker forces, so that pressure plate 110 can be more thinly dimensioned. This enables a total mass, and, for example, a rotating mass of pressure plate 110 or of torsional vibration damper 100 to be reduced.

(12) In the region of pressure plate 110 that is the furthest away from axis of rotation 105, pressure plate 110 extends in the axial direction to the right and forms encircling collar 120. Strap 125 extends out from collar 120 in a first section axially to the right and radially inward, and then runs out in a second section that runs parallel to axis of rotation 105. Strap 125 is limited in its width to a small part around a circumference of pressure plate 110 and axis of rotation 105, and does not extend around the entire circumference.

(13) Strap 125 fits against one end of outer bow spring 130, perpendicular to the drawing direction. Bow spring 130 extends along another circumference around axis of rotation 105. In other embodiments, instead of outer bow spring 130 a compression spring may also be used, which extends in a straight direction tangential to the circumference around axis of rotation 105. Outer bow spring 130 can be varied in a usual manner, for example, through parallel or serial arrangement of a plurality of spring elements, which, for example, have different spring properties.

(14) In an embodiment, outer bow spring 130 is supported in the axial direction toward the right, and, for example, in the radial direction toward the outside, by holding plate 135 (retainer).

(15) The opposite end of outer bow spring 130 fits against meshing element 140, which is fastened rigidly to holding plate 135 by means of riveted connection 145. This causes holding plate 135 to be rotatable counter to pressure plate 110 around axis of rotation 105, while outer bow spring 130 is compressed. During the transfer of torque by torsional vibration damper 100, torsional vibrations are isolated or canceled by this compression and a corresponding decompression.

(16) By means of another riveted connection 145, holding plate 135 is connected in an axial direction to pendulum flange 150. Pendulum flange 150 extends radially outward from riveted connection 145, where centrifugal force pendulum 155 is attached movably to pendulum flange 155. Centrifugal force pendulum 155 is usually installed rotatably and/or slidably on pendulum flange 150 by means of a sliding block guide in such a way that it is slidable or swingable around axis of rotation 105 in and contrary to the direction of rotation of pendulum flange 150. This enables torque fluctuations that are transferred by torsional vibration damper 100 to be canceled or isolated.

(17) Sections of holding plate 135 and of pendulum flange 150 which extend radially inward from riveted connection 145 fit against one end of inner bow spring 160. In the depicted embodiment, inner bow spring 160 includes an outer spring element and an inner spring element concentric thereto, which operate parallel to each other. The inner bow spring can be varied in a manner corresponding to outer bow spring 130, for example, also as a straight compression spring. In the radially outer region of inner bow spring 160, sections of holding plate 135 and of pendulum flange 150 are shaped so that they support inner bow spring 160 radially toward the outside. Such a support is necessary in order to counteract centrifugal forces, which drive inner bow spring 160 radially outward at high rotational speeds of torsional vibration damper 100.

(18) Holding plate 135 continues inward in a radial direction and is fastened to flange 165 and turbine 170 by means of yet another riveted connection 145, where only a lower fastening section of turbine 170 is depicted. Depicted torsional vibration damper 100 is set up to be employed in a torque converter, in which an impeller that is connected to the flywheel acts hydrodynamically on turbine 170 as long as there is a sufficient difference in speed between the impeller and turbine 170. By engaging the friction-disk clutch that is constructed in the region of friction lining 115, the impeller can be coupled mechanically with turbine 170.

(19) Inner flange 175 fits against a second end of inner bow spring 160. Inner bow spring 160 causes a vibration-damping transfer of force from holding plate 135 to inner flange 175. Inner flange 175 is connected to hub flange 180, for example, by means of gearing or splining. Hub flange 180 has internal toothing to transfer torque to output shaft S. For example, hub flange 180 and output shaft S are connected to each other, for example, by means of a splined. connection in such a way that a torsional connection is guaranteed, while hub flange 180 is movable in an axial direction on output shaft S. By sliding hub flange 180 on output shaft S, the frictional engagement in the area of frictional element 115 can be established or severed selectively.

(20) The introduction of force into outer bow spring 130 by means of strap 125, which is formed in a single piece on base plate 110, results on the one hand in sufficient construction space to situate outer bow spring 130 with a large diameter and radially far outside. On the other hand, there is sufficient construction space in an area axially between outer bow spring 130 and friction lining 115 for centrifugal force pendulum 155 and pendulum flange 150.

(21) Contrary to known torsional vibration dampers, the depicted embodiment of torsional vibration damper 100 allows inner flange 175 to be designed in a plane. Offset inner flange 175 or hub flange 180 can thus be avoided, which enables the life expectancy of inner leaf spring 160 to be increased. The torque transferred by means of outer bow spring 130 can be removed at holding plate 135, and does not have to be rerouted in a complex way as in the case of known torsional vibration dampers.

(22) FIG. 2 shows another sectional view through part of torsional vibration damper 100 in a different embodiment. Depicted torsional vibration damper 100 corresponds in most of its design features to torsional vibration damper 100 from FIG. 1.

(23) In torsional vibration damper 100 shown in FIG. 2 also, strap 125 of pressure plate 110 is directly engaged with outer bow spring 130. in this embodiment, the distance of outer bow spring 130 from axis of rotation 105 is somewhat smaller than in FIG. 1, so that holding plate 135 does not protrude in a radial direction over collar 120 of pressure plate 110.

(24) In contrast to the embodiment depicted in FIG. 1, pendulum flange 150 is attached to holding plate 135 by means of only one riveted connection which is situated radially further inside. At the same time, riveted connection 145 fastens turbine 170 to holding plate 135. As an additional difference from the embodiment in FIG. 1, both pendulum flange 150 and inner flange 175 are offset in a region radially outside of riveted connection 145. Furthermore, inner flange 175 is made in a single piece with hub flange 180.

(25) FIG. 3 shows an exploded view of part of torsional vibration damper 100 corresponding to torsional vibration dampers 100 from FIGS. 1 and 2.

(26) It can be seen in the depiction in FIG. 3 that pendulum flange 150 carries a total of four centrifugal force pendulums 155, which are distributed around a circumference of pendulum flange 150. Between adjacent pendulum flanges 155 in each case radial cutout 305 is provided in an outer region of pendulum flange 105. Cutouts 305 correspond to straps 125 of pressure plate 110, which extend radially inward from collar 120. By virtue of cutouts 305, pendulum flange 150 can be brought past straps 125 close to the right side of pressure plate 110 in the axial direction, until pendulum flange 150 with centrifugal force pendulums 155 is located radially inside the collar, Cutouts 305 thus enable pendulum flange 150 with centrifugal force pendulums 155 to be mounted past the end sections of straps 125 on pressure plate 110. The remaining elements of torsional vibration damper 100, described above in reference to the tracks 1 and 2, are installed in a known manner.

(27) Thus, it is seen that the objects of the present invention are efficiently obtained, although modifications and changes to the invention should be readily apparent to those having ordinary skill in the art, which modifications are intended to be within the spirit and scope of the invention as claimed. It also is understood that the foregoing description is illustrative of the present invention and should not be considered as limiting. Therefore, other embodiments of the present invention are possible without departing from the spirit and scope of the present invention.

LIST OF REFERENCE NUMBERS

(28) 100 torsional vibration damper 105 axis of rotation 110 pressure plate 115 friction lining 120 collar 125 strap 130 outer bow spring 135 holding plate (retainer) 140 meshing element 145 riveted connection 150 pendulum flange 155 centrifugal force pendulum 160 inner bow spring 165 flange 170 turbine 175 inner flange 180 hub flange 305 cutout