CN114761703A

CN114761703A - Torsional vibration damper with torque limiting device

Info

Publication number: CN114761703A
Application number: CN202080083787.6A
Authority: CN
Inventors: 罗马·魏森伯恩; 帕斯卡尔·施特拉塞尔
Original assignee: Schaeffler Technologies AG and Co KG
Current assignee: Schaeffler Technologies AG and Co KG
Priority date: 2020-01-20
Filing date: 2020-11-24
Publication date: 2022-07-15
Also published as: EP4093990A1; DE102020101129A1; WO2021148067A1; DE112020006571A5

Abstract

The invention relates to a torsional vibration damper (1) having an input part (2) which is rotatably received about a rotational axis (d) at an internal combustion engine by means of a fastening screw (14) and an output part (3) which is arranged rotatably about the rotational axis (d) relative to the input part against the action of a spring device (4) and has a passage opening (46) for screwing the fastening screw (14) arranged at an output hub (7) and a torque limiting device (5) which is connected downstream of the spring device (4) on the output side. In order to be able to remove the torsional vibration damper from the crankshaft without additional tools, an engagement section (40) which can be axially released and axially pretensioned by means of a pretensioning means (41) is provided between the torque limiting device (5) and the output hub (7), despite the presence of a torque limiting device (5) which is activated if necessary.

Description

Torsional vibration damper with torque limiting device

Technical Field

The invention relates to a torsional vibration damper having an input part which is accommodated in an internal combustion engine rotatably about a rotational axis by means of a fastening screw, and an output part which is arranged rotatably about the rotational axis relative to the input part against the action of a spring device and has a through-opening for screwing the fastening screw, which is arranged at an output hub, and a torque limiting device which is connected downstream of the spring device on the output side.

Background

Such torsional vibration dampers are widely known and are used for torsional vibration damping of internal combustion engines with rotational speed in the drive train of a motor vehicle and are screwed to the crankshaft of the internal combustion engine by means of the fastening screws of the input part thereof. In order to be able to screw the torsional vibration damper with the crankshaft in the completely installed state, a through-opening for a screwing tool, which is aligned with the fastening screw, can be provided in its output part, for example in the output hub.

In addition, such torsional vibration dampers have so-called torque limiting devices which are connected downstream of the spring devices acting in the circumferential direction between the input part and the output part and which are triggered at a predetermined limit torque in order to protect the torsional vibration damper and the components of the drive train following it from overload.

A torsional vibration damper with a spring device arranged in an annular chamber is known, for example, from the publication DE 102018119505 a1, wherein a torque limiting device is arranged radially inside the spring device and in the annular chamber with grease.

In the unpublished publication DE 102019118504.1, which hereby fully incorporates the present disclosure, a torsional vibration damper is described, the torque limiting device of which comprises a dry running friction lining which is arranged outside the annular chamber.

When the torque limiting device is activated, the output hub of the torsional vibration damper is rotated relative to its input part, so that the fastening opening and the through-opening may no longer be aligned with one another. In order to be able to remove the torsional vibration damper from the crankshaft again, for example in the case of maintenance, a realignment of the fastening screw and the through-opening is necessary.

For this purpose, the output part must be rotated relative to the input part against the action of the spring device or the torque limiting device must be released by means of a corresponding tool in order to rotate the output hub.

Disclosure of Invention

The object of the invention is to improve such a torsional vibration damper. In particular, the object of the invention is to provide a torsional vibration damper having a torque limiting device which enables a rotation of the output hub with low forces and without additional tools, if the through-openings may not be aligned with the fastening screws.

This object is achieved by the subject matter of claim 1. Claims dependent on claim 1 depict advantageous embodiments of the subject matter of claim 1.

The proposed torsional vibration damper serves to isolate torsional vibrations, in particular in a drive train having an internal combustion engine with torsional vibrations. The torsional vibration damper is accommodated by means of a fastening screw on a crankshaft of the internal combustion engine so as to be rotatably arranged about a rotational axis, in particular the rotational axis of the crankshaft.

The torsional vibration damper comprises an input part with fastening openings and, if appropriate, reinforcing rings for fastening screws, which are produced, for example, as a modification from a disk part and can form the primary flywheel mass. For this purpose, further radially outer mass elements may be provided. For controlling the internal combustion engine, a sensor ring can be provided and for starting the internal combustion engine a starter ring gear can be provided. The disk elements can form an annular chamber in which spring devices acting in the circumferential direction are accommodated.

An output part is arranged in a manner that the output part can rotate in a limited manner around a rotation axis relative to the input part against the action of a spring device, and the output part is provided with a through opening which is used for a screwing tool for screwing the torsional vibration damper and the crankshaft and is aligned with a fastening opening or a fastening screw. The output part has an output hub, in which a through-opening is preferably introduced.

The spring device may comprise circumferentially distributed bow springs or circumferentially distributed bow spring groups of bow springs nested one inside the other. The arc springs are loaded in the circumferential direction on the input side and on the output side on their end sides. For this purpose, a corresponding punch can be provided on the disk part of the input part forming the annular cavity. The output part may comprise a flange part with radially widened limbs, which is joined between the end sides adjacent in the circumferential direction.

In order to limit the peak torque transmitted via the torsional vibration damper, a torque limiting device is provided. The torque limiting device can be formed, for example, as a friction device having a friction disk which is prestressed between two side parts and has friction linings arranged on both sides, which are prestressed axially between the side parts by means of disk springs to a predetermined slip torque. If the predetermined permissible limit torque exceeds the friction torque, the torque limiting device slides in a limited manner as a result of the transmittable torque of the torsional vibration damper, in order to protect its components and the components of the drive train downstream of the torsional vibration damper. The torque limiting device is preferably arranged radially inside the spring device and outside the annular chamber, which is preferably grease-lubricated, in order to prevent contamination of the torque limiting device by the lubricant of the annular chamber.

The lateral part of the torque limiting device can be connected to the output hub and the friction lining can form a flange part for loading the spring device on the output side.

Upon activation of the torque limiting device, the input member and the output member rotate relative to each other. In order to be able to rotate the output hub into the aligned state of the fastening screw and the through-opening, possibly with reduced force and without tools, for example, in the case of maintenance and repair, in order to be able to easily remove the torsional vibration damper from the crankshaft, an engagement section is provided between the torque limiting device and the output hub, which engagement section is axially releasable and axially pretensioned by means of a pretensioning mechanism. This means that the component of the torque limiting device and the output hub engage with one another in a form-fitting manner in the circumferential direction and that the engagement is axially pretensioned and fixed in the normal operation of the torsional vibration damper. If maintenance is to take place, the engagement can be released if necessary in that: against the action of the pretensioning, the engagement section is released by an axial displacement of the output hub, and the output hub is rotated, for example, in the aligned state of the through-opening and the fastening opening and the engagement is established again. The axial pretensioning is thus used to secure the engagement section and is not as important here as the rotation of the spring device and can be performed manually in a simple manner and without an auxiliary mechanism.

The output hub can be designed to be rotatable to a limited extent relative to the torque limiting device after releasing the pretensioning against the action of the pretensioning means. The angle of rotation of the output hub can be configured in relation to the pitch angle of the clamping screw. For example, in the case of six fastening screws arranged distributed over the circumference with a division angle of 60 °, the angle of rotation can be limited to 30 °. The prestressing means can be formed by leaf springs arranged distributed over the circumference, at least one side having an annular segment-shaped slot. The leaf spring axially pretensions the engagement section and is axially elastically deformed when the engagement section is manually released. The leaf springs are fastened to the torque limiting device and to the output hub, respectively, wherein at least on one side the circumferential clamping at the elongated hole is provided in a circumferentially limited manner. For example, the leaf spring is fastened at the end face between the side parts to be accommodated at the rivet of the rivet device of the friction lining of the torque limiting device or at a separate rivet of the rivet device of the side part. The other lateral part can have a corresponding recess for forming the riveting device. The leaf spring can be fixed firmly on the end side to the output hub and by means of the slot to the torque limiting device, so that when the engagement is released, a partial circumferential rotation of the output hub relative to the torque limiting device in the region of the slot can be achieved.

Preferably, the output member is associated with a centrifugal pendulum. The centrifugal force pendulum is preferably arranged outside the annular chamber and its pendulum mass carrier is connected to the output hub. Opposite the pendulum mass carrier, the pendulum masses are accommodated in a pivotable manner, for example by means of pivot bearings, in a centrifugal force field of a pendulum mass carrier which is rotatable about a rotational axis and is distributed over the circumference. The pendulum mass carrier can be formed from a plurality of carrier parts in which the pendulum mass is accommodated in an encapsulated manner, so that burst protection is formed to the outside for the pendulum mass and the components of the pendulum bearing and at least a large part of the contamination is blocked for the pendulum mass.

In the sense of the invention, the pendulum mass carrier is suitable as part of the output hub, so that the leaf spring is fixed at the end on the torque limiting device and is also rotatable to a limited extent at the pendulum mass carrier by means of the slot in order to be able to be received at the output hub.

The centrifugal force pendulum, the output hub and the leaf spring can form a subassembly which is connected to the torque limiting device at the leaf spring after the torsional vibration damper is completed. The riveting of the rivets of the lateral parts can be performed by corresponding through-openings provided in the centrifugal pendulum and in the input part.

Drawings

The invention is explained in detail with reference to the exemplary embodiments shown in fig. 1 to 5. The figures show:

figure 1 shows a sectional view of an upper part of a torsional vibration damper with a torque limiting device arranged rotatably about a rotational axis,

figure 2 shows a detail of the torsional vibration damper of figure 1 in the region in which the leaf spring is accommodated at the torque limiting device,

figure 3 shows a detail of the torsional vibration damper of figure 1 in the region of the riveting of the leaf springs to the output hub,

FIG. 4 shows a view of the leaf spring of the torsional vibration damper of FIG. 1, and

fig. 5 shows a detail of the axial pretensioning of the engagement section of the torsional vibration damper from the radial outside in fig. 1.

Detailed Description

Fig. 1 shows a sectional view of an upper part of a torsional vibration damper 1 which is arranged rotatably about a rotational axis d and has an input part 2 and an output part 3 which is arranged rotatably about the rotational axis d relative to the input part against a spring device 4 and has a torque limiting device 5, a centrifugal pendulum 6 and an output hub 7.

The input part 2 is formed by disk parts 8, 9, which are connected to one another sealingly in the radial direction on the outside and form an annular chamber 10. The projection 11, which axially overlaps the disk element 8 on the radially outer side, can contain a sensor marking for controlling the internal combustion engine accommodating the torsional vibration damper 1. The input part 2 has a primary flywheel mass which, together with a secondary flywheel mass, for example the rotor of the electric machine of the hybrid drive, a double clutch or the like, connected downstream of the output hub 7, forms a double-mass flywheel action. Radially on the inside, the disk part 8 and the reinforcing ring 12 have fastening openings 13 for fastening screws 14 for fastening the torsional vibration damper 1 to a crankshaft of an internal combustion engine.

The spring devices 4 accommodated in the annular chamber 10 are formed by arc springs 15 arranged distributed over the circumference, which are acted upon in the circumferential direction on the input side by the stamped-out

parts

16, 17 of the disk elements 8, 9. The output-side application of the bow spring 15 takes place by means of a flange part 19 which is formed as a friction disk 18 of the torque limiting device 5. The flange part has an arm 20 which engages from the radially inside into the annular chamber and between the end sides of the arcuate spring 15. The annular chamber 10 is sealed between the flange part 19 and the disk parts 8, 9 by means of friction rings 21, 22 which form a friction device and are axially prestressed by means of disk springs 47.

The torque limiting device 5 comprises two

lateral parts

23, 24 which are connected to one another in a radially inner manner by means of rivets of a riveting device 49, which is only indicated in a schematic manner, and are spaced apart axially on the radially outer side in order to accommodate the friction linings 18 together with the

friction linings

27, 28 connected to one another. The lateral parts 23 here directly form a mating friction surface for the friction linings 27, while the support disk 29 forms a mating friction surface for the friction linings 28. Between the support disk 29 and the lateral part 24, the disk spring 30 is axially prestressed to generate a friction torque between the

friction linings

27, 28 and the corresponding mating friction surfaces. The support disk 29 and the disk spring 30 are fixedly suspended in the lateral part 24. The lateral part 23 together with the reinforcing ring 12 forms a predetermined core means 31 for simplifying the assembly of the subassembly 32 formed by the input part 2, the spring means 4 and the torque limiting means 5 with the subassembly 33 formed by the output hub 7 and the centrifugal force pendulum 6.

The centrifugal force pendulum 6 has a pendulum mass carrier 34, which is firmly connected to the output hub 7. The pendulum mass carrier 34 has two

lateral parts

35, 36 which form an enclosure for the pendulum mass 37 and serve radially outside as a burst protection element 38. The pendulum masses 37 are accommodated in a circumferentially distributed manner on the pendulum mass carrier 34 in a pivotable manner by means of pendulum bearings 39. The lateral part 24 forms, at its inner circumference, a mesh 40 with the outer circumference of the output hub, which mesh is prestressed by means of an axial prestressing mechanism 41 acting between the torque-limiting device 5 and the output hub 7. The prestressing mechanism 41 tensions the output hub 7 against the lateral part 23 of the torque limiting device 5, so that during operation of the torsional vibration damper 1, a torque transmission from the torque limiting device 5 to the output hub is ensured.

In the exemplary embodiment shown, leaf springs 42 distributed over the circumference serve as prestressing means 41. The leaf spring 42 is designed in a ring-shaped section and is connected fixedly at one end thereof in an invisible manner to the lateral part 35 of the pendulum mass carrier 34 and thus operatively connected to the output hub 7. At its other end, the leaf spring 42 is suspended by means of the elongated hole in a sleeve 43 of each rivet 25 of the riveting device 26 in an axially fixed and circumferentially displaceable manner. The riveting device 26 is in this case formed separately from the riveting devices of the

lateral parts

23, 24, so that the lateral part 23 has a corresponding recess 48 at the location of the rivet 25. In a further embodiment of the torsional vibration damper 1, the rivet arrangement 49 of the

lateral parts

23, 24 and the leaf spring 42 can be combined with the rivet arrangement 26 of the lateral part 24.

The final assembly of the torsional vibration damper 1 is carried out by forming the riveting device 26 so that the subassembly 32 is connected to the subassembly 33 at the leaf spring 42 provided at the subassembly 33 by means of the torque limiting device 5. The riveting device 26 is realized on the one hand between the pendulum masses 37 in the circumferential direction via the through-openings 44 in the

lateral parts

35, 36 of the pendulum mass carrier 34 and on the other hand at the through-opening 45 at the input part 2.

The mounted torsional vibration damper 1 is screwed to the crankshaft of the internal combustion engine by means of the fastening screw 14. For threading the screwing tool onto the screw head of the fastening screw 14, a through-opening 46 is provided in the output hub 7. If, during operation of the torsional vibration damper 1, the torque limiting device 5 is actuated due to a limit torque exceeding the friction torque of the torque limiting device, the output hub 7 is rotated relative to the input part 2 such that the through-openings 46 are no longer aligned with the fastening screws 14, if necessary. This is important if the torsional vibration damper 1 is to be removed for maintenance or repair purposes. In this case, the output hub 7 can be disengaged from the engagement portion 40 in a simple manner, for example, by pulling or the like at the outer periphery of the pendulum mass carrier 34 axially against the action of the biasing mechanism 41 such as the leaf spring 42. As a result, the output hub 7 can be rotated relative to the torque limiting device 5 and in the course of the movement relative to the input part 2 within the circumference of the elongated hole of the leaf spring 42 and the alignment between the fastening screw 14 and the through-opening 46 is reestablished. The maximum angle of rotation is at most half of the graduation angle of the fastening screw 14, since the complete coverage of the arcuate arc between two adjacent through openings 46 is in each case half of the graduation angle of the fastening screw 14. If, for example, six fastening screws are provided on the reference circle, the reference angle is 60 °. The rotation of the entire cover up to the alignment of the through-openings 46 is 30 ° in this case. If alignment is achieved, the engagement 40 can be reestablished and the torsional vibration damper 1 can be removed.

The sectional detail of the torsional vibration damper 1 of fig. 1 shown in fig. 2 shows the engagement 40 between the lateral part 24 and the output hub 7. The engagement 40 is secured during operation of the torsional vibration damper 1 by means of the leaf springs 42 arranged distributed over the circumference in such a way that: the output hub 7 is prestressed by a leaf spring 42 onto the lateral part 23 of the torque limiting device 5. The leaf spring 42 is axially supported here between the lateral part 35 of the pendulum mass carrier, which is firmly connected to the output hub 7, and the lateral part 24 of the torque limiting device 5. In this case, the elongated hole of the leaf spring 42 is riveted to the lateral part 24 by means of the sleeve 43 and the rivet 25. The lateral parts 23 have corresponding recesses 48 in order to form the rivet device 26 without interference.

Fig. 3 shows a sectional detail of the torsional vibration damper 1 from fig. 1, a view of the leaf spring 42 with the engagement 40 of the lateral part 35 of the pendulum mass carrier 34 by means of a rivet 51. The lateral part 35 and thus the pendulum mass carrier 34 are connected to the output hub 7 by means of rivets 52 arranged circumferentially between the through-openings 46, so that the pretensioning of the engagement 40 is effected between the output hub 7 and the lateral part 24. As shown in fig. 2, the leaf spring 42 is supported at its opposite ends on the lateral parts 24.

Fig. 4 shows the arrangement of the ring-segment-shaped leaf spring 42 on the circumference. The end-side openings 53 are each firmly connected to the lateral part 35 (fig. 3) by means of a rivet 51, while the elongated holes 54 are connected to the lateral part 24 (fig. 2) by means of the sleeve 43 and the rivet 25. The angle of rotation of the output hub 7 relative to the torque limiting device 5 (fig. 1) which is predetermined by the length of the elongated hole 54 is 30 °.

Fig. 5 shows the representation in fig. 1 from the radially outside in a sectional view a pretensioned connection between the

lateral parts

23, 24 of the torque limiting device 5 and the pendulum mass carrier 34 with the

lateral parts

35, 36 between the two pendulum masses 37. The sleeve 43 is riveted to the lateral part 24 by means of a rivet 25 and receives the elongated hole 54 of the leaf spring 42 in an axially fixed manner. The opposite end of the leaf spring 42 is firmly connected to the lateral part 35 of the pendulum mass carrier 34 by means of a rivet 51. The leaf spring 42 is axially preloaded between the lateral part 35 and the lateral part 24 in the mounted state of the torsional vibration damper 1. The rivet 25 is riveted during the final assembly by the through-openings 44 and the recesses 48 of the

lateral parts

35, 36.

Description of the reference numerals

1 torsion damper 2 input part 3 output part 4 spring means 5 torsion limiting means 6 centrifugal pendulum 7 output hub 8 disk part 9 disk part 10 annular cavity 11 fastening opening 14 fastening screw 15 arc spring 16 punch 17 punch 18 friction plate 19 flange part 20 arm 21 friction ring 22 friction ring 23 side part 24 side part 25 rivet 26 rivet means 27 friction lining 28 friction lining 29 support disk 30 disc spring 31 prearranged core means 32 sub-assembly 34 pendulum block carrier 35 side part 36 side part 37 pendulum block 38 anti burst means 39 pendulum bearing 40 engagement 41 pretensioning means 42 leaf spring 43 sleeve 44 through opening 45 through opening 47 disc spring 48 notch 49 rivet means 51 52 rivet 53 opening 54 slotted hole d rotary slotted d A movable axis.

Claims

1. A torsional vibration damper (1) having an input part (2) which is accommodated rotatably about a rotational axis (d) at an internal combustion engine by means of a fastening screw (14) and an output part (3) which is arranged rotatably to a limited extent about the rotational axis (d) relative to the input part against the action of a spring device (4), the output part having a through-opening (46) which is provided at an output hub (7) for screwing the fastening screw (14) and a torque limiting device (5) which is connected downstream of the spring device (4) on the output side,

it is characterized in that the preparation method is characterized in that,

an engagement section (40) which can be axially released and which is axially pretensioned by means of a pretensioning mechanism (41) is provided between the torque limiting device (5) and the output hub (7).

2. Torsional vibration damper (1) according to claim 1,

the output hub (7) is configured to be rotatable in a limited manner relative to the torque limiting device (5) after releasing the pretension against the action of the pretensioning means (41).

3. Torsional vibration damper (1) according to claim 2,

the angle of rotation of the output hub (7) is designed in relation to the pitch angle of the fastening screw (14).

4. Torsional vibration damper (1) according to claim 2 or 3,

the prestressing mechanism (41) is formed by leaf springs (42) arranged distributed over the circumference, at least one side of which has an annular segment-shaped slot (54).

5. Torsional vibration damper (1) according to claim 4,

the leaf spring (42) is fastened at the end face by means of rivets (25) of a riveting device (26) to a lateral component (24) of the torque limiting device (5).

6. Torsional vibration damper (1) according to claim 4,

the leaf spring (42) is firmly fixed axially on the end face at the output hub (7) and axially at the torque limiting device (5) by means of an elongated hole (54).

7. Torsional vibration damper (1) according to any of claims 1 to 6,

the output part (3) is associated with a centrifugal pendulum (6).

8. Torsional vibration damper (1) according to claim 6,

the pendulum mass carrier (34) of the centrifugal pendulum (6) is firmly connected to the output hub (7).

9. Torsional vibration damper (1) according to claim 5 or 6,

the leaf spring (42) is axially fixed and can rotate to a limited extent at the torque limiting device (5) at the end by means of an elongated hole and is firmly received at the pendulum mass carrier (34).

10. The torsional vibration damper (1) according to any of the claims 7 to 9,

the centrifugal force pendulum (6), the output hub (7) and the leaf spring (42) form a subassembly (33) which is connected to the torque limiting device (5) at the leaf spring (42).