DE102014210489A1 - centrifugal pendulum - Google Patents

Abstract

A centrifugal pendulum comprises a pendulum flange, at least one pendulum mass which is attached to the pendulum flange so as to be displaceable along a pendulum track, and a spring element for braking the pendulum mass at an end region of the pendulum track. Furthermore, the spring element is designed in the form of a coiled torsion spring.

Description

The invention relates to a centrifugal pendulum. In particular, the invention relates to a centrifugal pendulum for the eradication of rotational irregularities in a drive train, such as a motor vehicle.

A centrifugal pendulum is adapted to eliminate rotational irregularities or torsional vibrations in a drive train. The rotational irregularities can originate in particular from a reciprocating internal combustion engine. If the rotation of the shaft is accelerated, the centrifugal pendulum energy stores energy between, the wave is delayed again, so the centrifugal pendulum, the cached energy from again. For this purpose, the centrifugal pendulum comprises a pendulum for connection to the shaft and one or more pendulum masses, which are each slidably mounted along a pendulum in the plane of rotation of the pendulum. A simple centrifugal pendulum uses pendulum tracks, which allow only a displacement of the pendulum masses. In a trapezoidal centrifugal pendulum, the pendulum masses are also rotated around their own axes in addition to their displacement movement, so that the rotational momentum of the pendulum masses can be used for improved energy storage.

The pendulum masses can strike each other or on the pendulum when the drive train is in a specific operating condition, for example, when it is in an automatic transmission is changed to idle, when driving very slowly, when the engine is started or stopped or when the motor vehicle runs to a stop , In order to prevent premature wear of the pendulum masses and the pendulum flange and to minimize interference by rattling noises, it is known to use spring elements that decelerate the pendulum masses at end portions of their pendulum tracks.

DE 10 2011 087 693 shows a centrifugal pendulum with pendulum masses whose movements are limited by means of stop dampers.

It is known to carry out such a stop damper as a rubber buffer. Rubber has a high internal damping, so that the moving pendulum masses not only cushioned, but their movement is also damped. However, a rubber buffer is often unable to absorb enough energy or to return the absorbed energy to an environment. The deceleration of the pendulum masses may therefore either be insufficiently strong or the rubber buffers may tend to show cracks, breakouts or other phenomena of disintegration during operation.

It is an object of the present invention to provide an improved centrifugal pendulum. The invention solves this problem by means of a centrifugal pendulum with the features of the independent claim. Subclaims give preferred embodiments again.

A centrifugal pendulum according to the invention comprises a pendulum, at least one pendulum mass, which is mounted displaceably along a pendulum track on the pendulum, and a spring element for braking the spring mass, wherein the spring element is in the form of a tortuous torsion spring. The tortuous torsion spring provides a very stable design of the spring element. In addition, the torsion spring is reliably stable even with a long service life. A change in the spring function and / or damage to the torsion spring hardly or not occur even with long periods of operation of the centrifugal pendulum. Thus, a centrifugal pendulum is provided by means of the torsion spring, which reliably performs its function even over a long service life.

According to the invention, a known rubber buffer can be replaced by an example metallic spring element, which has a higher stability even at high load and can improve a recorded energy in the form of heat to give an environment. The pendulum mass can be braked sufficiently strong in this way in order to avoid premature wear and rattling noise, while at the same time a load capacity and a service life of the spring element can be increased. Preferably, the torsion spring is designed in such a way to decelerate the pendulum mass at an end region of the pendulum track.

In one embodiment, a friction element is provided for engagement with the spring element. Preferably, the spring element is shaped so that the spring element only comes into contact with the friction element at a predetermined spring travel. In this way, a further improvement of the function of the spring element can be achieved.

In one embodiment, the spring element comprises a tortuous torsion spring which is adapted to engage the friction element on a radial outer side. The engagement of the friction element can be controlled, for example, by the fact that the spring deforms under load in its length or in its diameter. The friction between the spring element and the friction element can be precisely controlled in terms of their strength as a function of the spring travel. This can be purposeful the part of the pendulum is damped in a predetermined manner, which is at the end of the range of motion of the pendulum mass.

In one variant, the spring element has an increasing diameter with increasing distance from one of its ends. For this purpose, the tortuous torsion spring, for example, be barrel-shaped, which can provide the additional advantage that a natural frequency of the torsion spring is less pronounced. By means of differently shaped spring elements different degrees of damping can be effected. As a result, the centrifugal pendulum can be tuned to different load requirements or purposes.

In another embodiment, however, which can be combined with the aforementioned embodiment, the friction element is designed integrally with the spring element. One section of the spring element rubs against another section, so that a heat input and a closure can take place exclusively on the part of the spring element. The spring element can be arranged in an improved way to withstand these loads. Larger elements of the centrifugal pendulum, such as the pendulum flange or pendulum mass, need not be complicated to be modified for use as a friction partner.

The spring element may comprise a radially outer first and a radially inner second wound torsion spring whose turns are arranged alternately in the axial direction and dimensioned in the radial direction so that they abut each other when the torsion springs are compressed, in particular beyond a predetermined level , Thus, the friction effect can be controlled easily and reliably. In addition, the natural frequency of the arrangement can again be less pronounced by the parallel connection of two torsion springs. To produce the spring element, for example, a cylindrical helical spring can be screwed into another cylindrical helical spring.

The torsion springs can also be designed to be integrated with one another, in that a torsion spring has turns which have alternating large and small diameters. Thereby, the spring element may be integrally formed so that it can be easier to handle during assembly of the centrifugal pendulum.

Alternatively, the spring element may also comprise a plurality of parallel wound torsion springs, which are arranged side by side and their turns mesh in the axial direction when the torsion springs are compressed, in particular beyond a predetermined amount. This arrangement can be space-saving feasible and allow greater freedom of design in the dimensioning of both torsion springs.

In one embodiment, the torsion spring is attached to at least one first end both pressure-resistant and tensile strength. The first end may be attached to the pendulum mass or the pendulum flange. By attaching also tensile strength a risk of axial detachment of the torsion spring can be reduced from their investment. The release can be effected in particular by a centrifugal force when the centrifugal pendulum swings at high speed and deforms the torsion spring radially outward. In addition, it can be prevented by acting in both axial directions of the spring element attachment that results between the spring bearing surface and the fastener a game that can affect the vibration behavior of the centrifugal pendulum.

The torsion spring may have at a first end a conical winding for a form-fitting tension-proof contact on a boundary of a fastening element. The fastener may carry a recess whose boundary abuts an axial end of the torsion spring to transmit compressive forces. Furthermore, a limit of the recess may rest against the conical winding in order to transmit tensile forces. Thus, the torsion spring can be attached form-fitting tension and pressure resistant with little effort. The fastening element may in particular comprise the pendulum mass or the pendulum flange.

In a further embodiment, the torsion spring is also attached to a second end both pressure-resistant and tensile strength, wherein the second end may also be mounted on the pendulum or on a pendulum mass.

All mentioned embodiments can be installed on a centrifugal pendulum on which the spring element acts between the pendulum mass and the pendulum flange. Due to the individual braking of the individual pendulum mass their pendulum can be determined with improved accuracy.

However, each of the described embodiments may alternatively be installed on a centrifugal pendulum in which the spring element between the pendulum mass and another pendulum mass acts, which is adjacent in the circumferential direction of the pendulum. By supporting adjacent pendulum masses together, a more homogeneous response of the entire Centrifugal pendulum supported. In addition, a spring element can be used economically to support several pendulum masses. In normal operation, the maximum deflections of the pendulum masses are preferably not limited by the spring element, a deceleration of both pendulum masses takes place only at mutual approach below a predetermined minimum distance. Such an approximation can be done, for example, at particularly low speeds, such as when stopping a drive motor.

The invention will now be described in more detail with reference to the attached figures, in which: 1 to 2 two views of a centrifugal pendulum;

3 to 5 three views of a spring element on the centrifugal pendulum of 1 to 2 in a first embodiment;

6 to 7 a spring element for the centrifugal pendulum of 1 to 2 in a second embodiment;

8th to 10 three views of the spring element of 6 to 7 at the centrifugal pendulum of the 1 or 2 , and

11 represents a further embodiment of a spring element on a centrifugal pendulum.

1 and 2 show two views of a centrifugal pendulum 100 , In 1 is the centrifugal pendulum 100 shown in a middle position, in 2 with complete deflection of its pendulum masses clockwise. The following description refers to both illustrations, unless stated otherwise.

A centrifugal pendulum 100 includes a pendulum flange 105 that is about a rotation axis 110 rotatably mounted and adapted for connection to a shaft of a drive train. Furthermore, the centrifugal pendulum includes 100 one or more pendulum masses 115 , each along pendulum tracks 120 in the plane of rotation of the pendulum flange 105 are slidably mounted. In the illustrated preferred embodiment, there are three pendulum masses 115 provided on a circumference about the axis of rotation 110 evenly distributed, but it can also more or less pendulum masses 115 be provided. Every pendulum mass 115 is preferably by two pendulum elements 125 formed on opposite axial sides of the pendulum flange 105 attached and rigidly connected in pairs. The aerial tramways 120 are usually through slide guides 130 determined, in each case a bolt 135 through recesses 140 in the pendulum element 125 and the pendulum flange 105 runs.

In the 1 upper pendulum mass 115 is in the middle of her aerial tramway 120 shown in 2 she takes the extreme right position. For braking the pendulum masses 115 are spring elements 145 provided in the illustrated embodiment, in each case between adjacent pendulum masses 115 Act. In another embodiment, the spring elements 145 but also between the pendulum mass 115 and the pendulum flange 105 Act.

In the illustrated embodiment, a friction element 150 provided to be in lateral engagement with the spring element 145 to get. The friction element 150 can always or only from a predetermined spring travel of the spring element 145 in lateral contact with the spring element 145 reach. The friction preferably takes place via a predetermined end section of the pendulum track 120 , wherein the friction force in dependence of the spring travel remain the same or can change, in particular may increase.

In the present embodiment, the spring elements are 145 around tortuous torsion springs, in particular cylindrical coil springs. Ends of the spring elements 145 lie in designated recesses 155 the pendulum masses 115 , The recesses 155 are preferably shaped so that they are the spring element 145 lead in its radial direction along its travel. The friction element 150 is formed in the illustrated embodiment by a lateral boundary of the pendulum mass 115 in the area of the recess 155 , Will the spring element 145 compressed, as in 2 is shown, so its diameter or its direction of force can change in the contact area, so that the friction element 150 in engagement with a radial surface of the spring element 145 arrives. By appropriate design of the spring element 145 and the friction element 150 are different degrees of friction at different spring travel adjustable. Preferably, the frictional engagement begins at a predetermined distance of the pendulum mass 115 from the end of his aerial tramway 120 and stays until the end of the aerial tramway 120 receive. This can be the end of the aerial tramway 120 by the position of the pendulum mass 115 with respect to the pendulum flange 105 or with respect to the adjacent pendulum mass 115 be specified.

Depending on the chosen embodiment may be on the friction element 150 be waived. In this embodiment, the ends of the spring element lie 145 at contact surfaces of the recesses 155 on, without z. B. a lateral boundary of the recesses 155 to touch. That's it Spring element arranged with the ends between the contact surfaces of the recesses, in particular clamped without a friction element acts, in particular without a lateral boundary acts as a friction element. Instead of recesses, other means for attachment and / or for the installation of the ends of the spring element 145 be provided.

3 to 5 show views of a spring element 145 at the centrifugal pendulum 100 of the 1 to 2 in a first embodiment. It corresponds 3 a detailed representation 1 4 shows a variant in which the spring element 145 one-sided on the pendulum flange 105 is supported. It can be on the pendulum flange 105 only one contact surface or a recess for the spring element 145 be provided. In addition, a friction element analogous to the 1 and 2 be provided on the pendulum. 5 adds to the presentation of 4 the highlighted outline of the pendulum flange 105 added.

The spring element 145 of the 3 to 5 may, as shown, comprise a cylindrical, torsion coil spring. The extent of the engagement between the spring element 145 and the friction element 150 may be determined by how many turns of the spring element 145 inside the recess 155 the pendulum mass 115 lie. The spring element 145 may also be configured to compress its diameter in the area of the recess 155 to increase, so that the friction to the friction element 150 is reinforced. Furthermore, the spring element 145 for controlling the engagement with the friction element 150 have a different than a cylindrical silhouette, for example a barrel-shaped, wherein the outer diameter of the spring element 145 with increasing distance from one of the ends of the spring element 145 increases. Other shapes are also possible. The friction force can also be influenced by the fact that the recesses 155 change their relative positions to each other during compression, that is, for example, that they are the spring element 145 during compression in the middle of bending stress, so that a frictional force between outer regions of the spring element 145 and the friction element 150 is enlarged.

In other embodiments, the spring element 145 instead of by boundaries of the recess 155 be guided by an additional component, for example, a riveted sheet metal with a wing. The spring element 145 can be performed by the additional component radially outside and / or radially inside.

The spring element 145 can also include several individual springs, for example, with respect to the axis of rotation 110 can be offset radially or axially. Each spring element 145 can, as in the 3 to 5 is shown, substantially on a circumference about the axis of rotation 110 lie, be arranged radially or occupy any angle between these two extreme positions. In addition, the spring element 145 as shown partially within the geometry of the pendulum masses 115 be included, or completely within or completely outside of this geometry.

The spring element 145 preferably comprises a compression spring, but it is also possible embodiments with a bow spring. In all cases, the spring element 145 optionally wear end caps at the ends. A spring characteristic of the spring element 145 may be one or more stages and linear or non-linear, in particular progressive. The mass ratio of the spring element 145 to the pendulum mass 115 is preferably in a range between 0.015 and 1.5.

6 and 7 show sectional views of a spring element 145 according to a second embodiment for use in the centrifugal pendulum 100 of the 1 to 2 , 6 shows an expanded and 7 a compressed spring element 145 , The embodiment of the spring element shown here 145 Integrates the friction element 150 so that a predetermined portion of the spring travel of the spring element 145 damped by friction. A the spring element 145 actuating pendulum mass 115 can be damped in their movement by the friction. This allows the spring element 145 already be sufficient to both suspension and damping of a pendulum mass 115 on an end section of a tramway 120 to ensure. Nevertheless, the spring element 145 of the 6 to 7 also be used in conjunction with one of the embodiments in which the friction element 150 is not integrated.

The spring element 145 includes a first, radially outer portion 605 and a second radially inner portion 610 , In one embodiment, the outer portion is 605 wound from a first wire and the second section 610 from a second wire, so the two sections 605 and 610 actually comprise separate spring elements, which are for example screwed concentrically into each other to form the illustrated constellation. Alternatively, the two sections 605 and 610 be made integral with each other by alternately one turn of the first section 605 and the second section 610 is wound from the same wire.

The turns of the sections 605 and 610 lie along the extension direction of the spring element 145 alternately next to each other. It is the outer diameter of the turns of the second section 610 greater than the inner diameter of the turns of the first section 605 , Will the spring element 145 axially compressed, as in 7 is shown, so get the turns of the sections 605 and 610 from a predetermined travel in mutual contact. Will the spring element 145 compressed even further, so are the turns of the first section 605 radially outward and that of the second section 610 pushed radially inwards, rubbing against each other. In this sense, the turns of the sections can 605 and 610 the friction element 150 of the 1 to 5 replace or supplement.

8th to 10 show three views of the spring element 145 of the 6 to 7 at the centrifugal pendulum 100 of the 1 to 2 , In 8th is from the spring element 145 only the first section 605 shown. Here it becomes clear that by inserting the second section 610 a friction damping can be achieved, which readily with the embodiment of 3 can be combined. 9 and 10 show the complete spring element 145 of the 6 and 7 in the variant of the centrifugal pendulum 100 in which ends of the spring element 145 on neighboring pendulum masses 115 are supported. The spring element 145 of the 6 to 7 However, it can be readily used on an embodiment in which one of its ends on the pendulum flange 105 supported, as in the in 5 illustrated embodiment.

Depending on the selected embodiments may be provided in the examples described at one end of the spring element or at both ends of the spring element or at no end of the spring element, a friction element.

11 shows a variant of the attachment of a spring element 145 at the centrifugal pendulum 100 of the 1 or 2 , The features of the illustrated embodiment can be combined with those of all the aforementioned embodiments.

The spring element 145 is with a first, in 11 left end 905 on the pendulum mass 115 attached. The opposite second end 910 of the spring element 145 (not shown) may alternatively on an adjacent pendulum mass 115 or the pendulum flange 105 be fixed, as has already been explained in more detail above. The pendulum mass 115 includes a recess 915 into which the first end of the spring element 145 is introduced. This is the spring element 145 such a positive fit in the recess 915 that between the pendulum mass 115 and the spring element 145 both tensile and compressive forces can be transmitted.

In the axial direction is the spring element 145 at a first boundary 920 the recess 915 at. About this system can compressive forces between the spring element 145 and the pendulum mass 115 be transmitted. For transmission of tensile forces is an outer diameter of the spring element 145 to its first end 905 running upward, so that in the area of the end 905 a conical outer contour of the spring element 145 results. A second limit 925 the recess 915 follows this conical contour and lies on the conical portion of the spring element 145 on, whereby a tensile force between the spring element 145 and the pendulum mass 115 can be transferred.

It is particularly preferred that the conically extending end portion of the spring element 145 comprises a plurality of windings and that these windings are wound on block, that touch each other in the axial direction. Such turns are also called dead turns. This allows the portion of the spring element 145 , which is responsible for guiding or transmitting tensile forces to the pendulum flange 115 is provided, are kept relatively short, while the remaining area of the spring element 145 is available for providing the suspension travel. In addition, the mass loss that occurs in the pendulum mass 115 through the recess 915 arises, by the compact arrangement of several turns of the spring element 145 be at least partially compensated.

The recess 915 For example, by punching and embossing in the pendulum mass 115 be introduced. As already described above, sections of the pendulum mass 115 that radially inward or radially outward of the spring element 145 lie, for radial guidance or frictional engagement with the spring element 145 be used. Will the spring element 145 on both sides in the manner shown positive pressure and tensile strength held, only a small portion of the spring element 145 remain, which is not guided radially. The spring and damping behavior of the spring element 145 can be precisely controlled by the improved guidance.

The attachment of the second end 910 can as shown at the first end 905 pressure and tensile strength or the spring element 145 lies at its second end 910 only pressure-resistant to the respective fastener 105 . 115 at.

LIST OF REFERENCE NUMBERS

100

 centrifugal pendulum

105

 pendulum

110

 axis of rotation

115

 pendulum mass

120

 aerial tramway

125

 shuttle

130

 link guide

135

 bolt

140

 recess

145

 spring element

150

 friction

155

 recess

605

 first section (radially outward)

610

 second section (radially inside)

905

 first end

910

 second end

915

 recess

920

 first limit

925

 second boundary

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 102011087693 [0004]

Claims (12)

Centrifugal pendulum ( 100 ), comprising: - a pendulum flange ( 105 ); - at least one pendulum mass ( 115 ) along a reversing track ( 120 ) displaceable on the pendulum flange ( 105 ) is attached; A spring element ( 145 ) for braking a movement of the pendulum mass ( 115 ) along the aerial tramway ( 120 ), characterized in that - the spring element ( 145 ) in the form of a tortuous torsion spring ( 145 ) is trained. Centrifugal pendulum ( 100 ) according to claim 1, wherein a friction element ( 150 ) for engagement with the spring element ( 145 ) is provided. Centrifugal pendulum ( 100 ) according to claim 2, wherein the spring element ( 145 ) is shaped so that the spring element ( 145 ) only at a predetermined spring travel in contact with the friction element ( 150 ). Centrifugal pendulum ( 100 ) according to one of claims 2 or 3, wherein the tortuous torsion spring ( 145 ) is arranged, on a radial outer side in the friction element ( 150 ) intervene. Centrifugal pendulum ( 100 ) according to one of the preceding claims, wherein the spring element ( 145 ) has an increasing diameter with increasing distance from one of its ends. Centrifugal pendulum ( 100 ) according to one of claims 2 to 5, wherein the friction element ( 150 ) integrated with the spring element ( 145 ) is executed. Centrifugal pendulum ( 100 ) according to one of the preceding claims, wherein the spring element ( 145 ) a radially outer first ( 605 ) and a radially inner second ( 610 ) torsion coil wound whose windings are arranged alternately in the axial direction and are dimensioned in the radial direction so that they abut each other when the torsion springs ( 605 . 610 ) are compressed. Centrifugal pendulum ( 100 ) according to one of the preceding claims, wherein the torsion spring ( 145 ) at least at a first end ( 905 ) is both pressure-resistant and tensile strength attached. Centrifugal pendulum ( 100 ) according to claim 8, wherein the torsion spring ( 145 ) also at a second end ( 910 ) is both pressure-resistant and tensile strength attached. Centrifugal pendulum ( 100 ) according to one of the preceding claims, wherein the spring element ( 145 ) a plurality of parallel wound torsion springs ( 145 ), which are arranged side by side and whose turns mesh in the axial direction with each other, when the torsion springs ( 145 ) are compressed. Centrifugal pendulum ( 100 ) according to one of the preceding claims, wherein the spring element ( 145 ) between the pendulum mass ( 115 ) and the pendulum flange ( 105 ) acts. Centrifugal pendulum ( 100 ) according to one of the preceding claims, wherein the spring element ( 145 ) between the pendulum mass ( 115 ) and another pendulum mass ( 115 ) acting in the circumferential direction of the pendulum flange ( 105 ) is adjacent.

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