CN114076175A

CN114076175A - Torsional vibration damper with secondary side sealing structure

Info

Publication number: CN114076175A
Application number: CN202110929559.2A
Authority: CN
Inventors: 帕斯卡·斯特拉瑟; 菲利普·施韦德勒
Original assignee: Schaeffler Technologies AG and Co KG
Current assignee: Schaeffler Technologies AG and Co KG
Priority date: 2020-08-17
Filing date: 2021-08-13
Publication date: 2022-02-22
Also published as: DE102021110024A1

Abstract

The invention relates to a torsional vibration damper, which is designed as a dual mass flywheel (1) and can be used in a drive train of a vehicle driven by an internal combustion engine, comprising a primary part (2) and a secondary part (3), which are connected by means of a spring damping device (6) and can rotate in a limited manner relative to one another about an axis of rotation (4), the secondary part comprising a support flange (7) and a driven hub (9) connected by means of a rivet (8), the dual mass flywheel being fixable at a crankshaft flange of the internal combustion engine by means of a fastening bolt (11) which can be passed through an opening (12) of the secondary part and a bore (13) of the primary part and screwed into a threaded bore of the crankshaft flange, wherein disk-shaped sealing elements (14a to 14h) are provided for closing the opening (12) in the secondary part, which can be locked in a clamping manner automatically by means of elastic fastening elements directly or indirectly in a secondary manner At the component of the stage.

Description

Torsional vibration damper with secondary side sealing structure

Technical Field

The present application relates to a torsional vibration damper according to the preamble of claim 1, which is designed as a dual mass flywheel and can be used in the drive train of a vehicle driven by an internal combustion engine.

Background

Dual mass flywheels are used to damp torsional vibrations in the drive train of a motor vehicle. The torsional vibrations are triggered by the periodic combustion process of the reciprocating internal combustion engine, which, in conjunction with the ignition sequence, leads to rotational irregularities which are introduced into the drive train by the crankshaft.

DE 19608271 a1 shows a dual mass flywheel which forms a structural unit together with the clutch system. The dual mass flywheel is fixed by a screw connection at a crankshaft flange of the internal combustion engine. For this purpose, the fastening bolts are passed through openings in the secondary part and through bores in the primary part of the dual mass flywheel and screwed into complementary threaded bores in the crankshaft flange.

According to FR 2765293 a, the fastening bolts for fastening the dual mass flywheel to the internal combustion engine are secured against loss by means of a cap-shaped plastic part. For this purpose, after the insertion of the fastening bolt into the corresponding hole of the primary part, a plastic cap is pressed onto each bolt head, which is then fixed to the primary part by means of clips.

A torsional vibration damper, which is arranged in the drive train between the internal combustion engine and the transmission and is designed as a dual-mass flywheel, is exposed to environmental factors or sources of pollution in a substantially unprotected manner. Therefore, dust, salt, water spray, and the like may enter the inside of the dual mass flywheel during the driving of the vehicle, and water may enter the inside of the dual mass flywheel when the vehicle is cleaned, for example, by a high pressure cleaning apparatus.

A torque transmission device is known from DE 10002259 a1, the torsional vibration damper of which comprises two axially flexible parts designed as sealing diaphragms, which axially limit the spring damper. Both sealing diaphragms are riveted to the disk-shaped secondary part and each sealing diaphragm is axially supported relative to the disk-shaped primary part or flange part. Due to this arrangement, the spring damper device is sealed against the ingress of dust and grease losses from the spring damper device at high temperatures during operation of the torsional vibration damper.

Disclosure of Invention

The object of the present application is to provide a sealing structure by which water and dust can be effectively prevented from entering the interior of a dual mass flywheel.

This object is achieved by a torsional vibration damper designed according to the features of claim 1. Advantageous embodiments are given in the dependent claims.

According to the disclosure, after the assembly of the dual mass flywheel has been completed, a disk-shaped sealing element is provided to close the opening in the secondary part, which sealing element can be automatically clamped directly or indirectly by means of an elastic fastening element or retaining element to a component of the secondary part.

After the dual mass flywheel has been screwed to the internal combustion engine, the sealing element is fitted directly to the secondary flywheel of the secondary part or indirectly to a component of the secondary part. As fastening element, the sealing element comprises a releasable latching connection with a preferably axially pre-held or axially pre-tensioned spring function. Starting from the released state of the sealing element, the fastening element is permanently pretensioned in the axial and/or radial direction in the installed state and is automatically and self-locking locked in the component of the secondary part in a force-locking and/or form-locking manner. Due to this latching connection, the sealing element is permanently and reliably secured in position, while undesired automatic loosening is effectively prevented. The removal of the sealing element is effected in that the locking connection of the sealing element is first released against the locking direction and then the sealing element is pulled apart in the axial direction.

The latching connection (which may also be referred to as a snap connection or a snap fastening) of the sealing element forms an effective anchoring and at the same time a centering of the sealing element at the component of the secondary part. Furthermore, the sealing element serves to reliably seal all openings of the secondary part for the installation of the fastening bolts and, if appropriate, the ventilation windows. The sealing element prevents dirt and/or water from entering the dual mass flywheel and also prevents the grease filling from escaping from the spring damping device, so that the operational reliability or reliability is increased and the service life of the torsional vibration damper is prolonged.

With regard to the specific design of the individual sealing elements, there are various solutions for fixing the sealing elements at the component of the secondary part by means of self-acting fastening elements or holding elements.

In a preferred embodiment, the sealing element is provided with latching tongues (also referred to as fingers) as fastening elements, which are angled radially on the inside and/or radially on the outside, are spaced apart from one another and are distributed circumferentially. In the installed state, the sealing element is fixed to the secondary part in a force-fitting and form-fitting manner by means of locking tongues, which are preferably formed with a toothed profile and act like a spring clip, wherein the respective locking tongue is, for example, formed in a C-shape. The spring elasticity of the locking tongue forms an elastic clamping element which ensures a secure clamping and fixing of the sealing element. The elastic locking tongues attached radially outside or radially inside the sealing element are used to exert an axial and/or radial force.

When the sealing element is inserted axially, the elastic locking tongues can be deflected radially inward or radially outward against the influence of a pretensioning force. When the sealing element reaches the end position, the locking tongue returns to the end position and locks, for example, in an annular groove of the secondary part, thereby causing a radial overlap or undercut (Hinterschnitt) with respect to the retaining edge, so that a robust, process-safe fixing of the sealing element is formed. Furthermore, separate locking tongues for dismounting the sealing element can be used, wherein these locking tongues are preferably provided with holes for engagement by a tool for simplified assembly.

A preferred embodiment provides that the locking disk (also referred to as a retaining disk) which is fastened to the secondary part by means of a rivet connection forms an obliquely bent circumferential edge on the radial inside or on the radial outside, at which the locking tongues of the sealing element are locked by radial overlapping. For this purpose, a sealing element can be used, which is supported via a radially inner region on the driven disk hub of the secondary part. By applying an axial force (manually or mechanically), the radially outer region of the sealing element is locked at the edge of the locking disk by the locking tongue and generates a permanent axial and radial force. With this variant, both the opening for the fastening bolt and the ventilation window in the secondary part are closed and sealed by the sealing element, while the rivet of the secondary part is covered. Alternatively, the locking disk can be provided for riveting with a radially inwardly offset edge, to which the sealing element is fixed by means of a bent locking tongue.

According to a further embodiment, the locking tongues of the sealing element are directly locked in a circumferential recess on the end face of the driven disk hub. The recess, also referred to as the rotary contour, is preferably positioned radially below the rivet of the secondary part, thereby covering the opening in the secondary part for fastening the bolt.

Furthermore, it is advantageously provided that the sealing element is centered, directly or indirectly, on the secondary part offset relative to the locking bolt. For this purpose, the sealing element is formed, for example, radially on the inside with a rounded-end section angled at an angle, which directly engages in an end-side annular groove of the driven disk hub.

In a further embodiment, a sealing element is provided which is locked on the radial inside by a section bent at an angle and including a locking tongue directly at a circumferential shoulder of a radially encircling annular groove in the cylindrical section of the driven disk hub. Alternatively thereto, the disclosure includes a sealing element which additionally extends radially beyond the rivet and surrounds the driven disk hub to a limited extent on the outside and is additionally secured thereto by means of an outer latching tongue.

The sealing element is preferably made of a steel sheet material, for example spring steel, is suitable. Alternatively, it is also possible to use sealing elements made of plastic, which fulfill all requirements with regard to strength and heat resistance. A suitable plastic is, for example, polypropylene (PP).

According to a further embodiment, a sealing material is used between the sealing element and the contact surface at the secondary part in order to optimize the sealing quality. For example, it is advisable for the latching connection of the sealing element to be supported by means of an elastic sealing mass or sealing disk at the corresponding contact surface of the secondary part, preferably of the driven hub.

Advantageously, the sealing element can be assigned to a pre-assembled dual mass flywheel in order to meet the requirements of the vehicle manufacturer with regard to the provision or delivery of the finished assembled supplier part. Before the final assembly of the dual mass flywheel, the sealing element can be easily removed in order to be able to introduce the fastening bolt into the opening or bore of the secondary part. The sealing element is then installed, which is firmly locked in a clamping manner at the secondary part by means of the fastening element. Furthermore, it is proposed to equip the torsional vibration damper with fastening bolts, which are fastened to the components of the dual mass flywheel by means of a loss prevention mechanism. In this manner, with the sub-assembly, a dual mass flywheel including all components can be provided as a supplier part to an automotive manufacturer for its assembly line. In this way, assembly time can be reduced and sources of error, for example in the selection of fastening bolts, can be avoided.

Drawings

The subject matter is described in more detail below in connection with various embodiments in eleven diagrams. However, the present application is not limited to the embodiments shown in the drawings. The attached drawings are as follows:

FIG. 1: a half-sectional view of a dual mass flywheel having a secondary part sealed according to a first variant;

FIG. 2: a half-sectional view of a dual mass flywheel having a secondary part sealed according to a second variant;

FIG. 3: a half sectional view of a dual mass flywheel having a secondary part sealed according to a third variant;

FIG. 4: a half sectional view of a dual mass flywheel having a secondary part sealed according to a fourth variant;

FIG. 5: a half sectional view of a dual mass flywheel having a secondary part sealed according to a fifth variant;

FIG. 6: a half sectional view of a dual mass flywheel having a secondary part sealed according to a sixth variation;

FIG. 7: a half sectional view of a dual mass flywheel having a secondary part sealed according to a seventh variation;

FIG. 8: a half sectional view of a dual mass flywheel having a secondary part sealed according to an eighth variation;

FIG. 9: a partial enlargement of a sealing element for the secondary part, the sealing element having a radially inwardly arranged locking tongue;

FIG. 10: a partial enlargement of a sealing element for the secondary part, which sealing element has a tooth lock tongue arranged radially on the outside;

FIG. 11: a partial enlargement of a sealing element for a secondary part, which sealing element has a radially outwardly arranged individual locking tongue.

Detailed Description

Fig. 1 shows the structure of a dual mass flywheel 1 in a half-section, the dual mass flywheel 1 also being referred to as a torsional vibration damper, having a known structure and a known mode of action, which can be arranged in the drive train of a motor vehicle between a crankshaft flange (not shown) of an internal combustion engine and the output side of, for example, a vehicle clutch (not shown). The torque of the internal combustion engine is transmitted from the vehicle clutch, for example via a transmission and a differential connected to a universal shaft, to the drive wheels of the motor vehicle. The dual-mass flywheel 1 has a primary part 2, also referred to as primary mass, and a secondary part 3, also referred to as secondary mass, which is composed of a plurality of components, the primary part 2 and the secondary part 3 being arranged so as to be jointly rotatable about an axis of rotation 4 and rotatable relative to one another. The primary part 2 is connected to the secondary part 3 by a spring damping device 6, which comprises an arc spring 5. The secondary part 3 comprises a support flange 7 which is connected to the arcuate springs 5 of a spring absorber device (centrifugal pendulum device) 6 and is connected radially on the inside to a driven disk hub 9 via a rivet 8, for example a drive shaft (not shown) being insertable into a spline toothing 10 of the driven disk hub 9. The dual mass flywheel 1 is fastened to the crankshaft flange by means of fastening screws 11, which fastening screws 11 pass axially in the direction of the arrow through openings 12 in the driven disk hub 9 and through holes 13 in the primary part 2 and are screwed into threaded holes in the crankshaft flange.

In order to seal and shield all openings 12, which are distributed in the circumferential direction and are formed at the driven disk hub 9, sealing elements 14a are provided. The substantially disk-shaped sealing element 14a is locked by means of radially outer, angularly bent elastic fastening elements or retaining elements in the form of locking tongues 15 on the locking disk 16, the locking disk 16 being fixed to the secondary part 3 by means of a rivet 8. The locking disk 16 has, radially above the rivet 8, an inclined edge 17 in the direction of the axis of rotation 4, which forms an undercut, at which edge 17 the locking tongue 15 automatically and permanently locks in a clamping manner when the sealing element 14a is installed. In order to center the sealing element 14a, which is designed in the form of a pot and simultaneously blocks the rivet 8, the sealing element 14a engages with a radially inner curved section 18 in an annular groove 19 on the end side of the driven disk hub 9.

Fig. 2 to 8 show the dual mass flywheel 1 in conjunction with differently designed sealing elements 14b to 14h of the secondary part 3 in terms of construction. Identical or functionally identical components have the same reference numerals in fig. 2 to 8 and are only mentioned or described several times where necessary for understanding.

In contrast to the sealing element 14a according to fig. 1, the sealing element 14b depicted in fig. 2 is not configured in a pot-like manner. The locking disk 16 is shown in fig. 3 to 5 in conjunction with the sealing

elements

14c, 14d, 14e, wherein the edges 27 of the locking disk 26 are each arranged radially on the underside of the rivet 8, so that the rivet 8 is not covered by the sealing

elements

14c, 14d, 14 e. The locking tongues 15 of the sealing element 14c face the driven hub 9 here. In contrast, the sealing

elements

14d, 14e have latching tongues 15 facing away from the driven disk hub 9. The sealing element 14e is disk-shaped and is supported over a large surface area at the end face on the driven disk hub 9. In order to achieve an improved seal, a sealing material 28, for example in the form of a sealing ring, is inserted between the sealing element 14e and the driven disk hub 9.

The sealing element 14f shown in fig. 6 is bent radially outward, wherein the locking tongue 15 of the sealing element 14f latches into a recess 29, which is configured as a rotational contour, located on the underside of the rivet 8. The opening 12 and the ventilation window (not shown) of the secondary part 3 are thus effectively closed and sealed.

Fig. 7 and 8

show sealing elements

14g, 14h, which are each locked with locking tongues 15 on shoulders forming undercuts in a radially encircling annular groove 30 of driven hub 9. The sealing element 14f extends radially below the rivet 8. In contrast, the sealing element 14g covers the rivet 8 and surrounds the driven disk hub 9 on the outside.

Fig. 9 to 11 each show a partial enlargement of a sealing element for the secondary part 3. According to fig. 9, the disc-shaped sealing element 14g comprises on the radial inside a locking tongue 15 forming a toothed profile. Fig. 10 and 11 show a sealing element 14f with a radially outwardly arranged locking tongue 15 which forms a toothed profile, is substantially C-shaped in design and forms a spring clip. In fig. 10, the locking tongues 15 are closely spaced; in fig. 11, the locking tongues 15 are offset from one another by a greater distance. Fig. 10 also shows the locking bolt 15 with a hole 31, which hole 31 is intended to receive a tool in order to release the locking bolt 15 against the locking direction and then to separate the locking bolt 15 from the secondary part 3 by means of an axial pull.

List of reference numerals

1 dual mass flywheel

2 Primary part

3 Secondary part

4 axis of rotation

5 arc spring

6 spring damper unit

7 support flange

8 riveting part

9 driven disc hub

10 spline tooth part

11 fastening bolt

12 opening

13 holes

14a sealing element

14b sealing element

14c sealing element

14d sealing element

14e sealing element

14f sealing element

14g sealing element

14h sealing element

15 lock tongue

16 locking disk

17 edge

18 section(s)

19 annular groove

26 locking disk

27 edge of

28 sealing Material

29 recess

30 ring groove

31 holes

Claims

1. Torsional vibration damper, which is designed as a dual-mass flywheel (1) and can be used in the drive train of a vehicle driven by an internal combustion engine, comprising a primary part (2) and a secondary part (3), which primary part (2) and secondary part (3) are connected by means of a spring damping device (6) and can rotate relative to one another in a limited manner about an axis of rotation (4), wherein the secondary part (3) comprises a carrier flange (7) and a driven hub (9) which are connected by means of a rivet (8), wherein the dual-mass flywheel (1) can be fastened to a crankshaft flange of the internal combustion engine by means of fastening bolts (11) which can be passed through openings (12) of the secondary part (3) and through holes (13) of the primary part (2) and screwed into threaded holes of the crankshaft flange, characterized in that a disk-shaped sealing element (14a to 14h) is provided for closing the opening (12) in the secondary part (3), which sealing element can be automatically locked at a component of the secondary part (3) directly or indirectly in a clamping manner by means of an elastic fastening element.

2. The torsional vibration damper as claimed in claim 1, characterized in that the sealing elements (14a to 14h) have, as fastening elements, circumferentially distributed latching tongues (15) which are angled radially on the inside and/or radially on the outside and are spaced apart from one another and which can be deflected radially inwardly or outwardly against the influence of a preload when the sealing elements (14a to 14h) are pushed in axially.

3. The torsional vibration damper as claimed in any of the preceding claims, characterized in that the locking disk (16, 26) which is fixed at the secondary part (3) by means of the rivet (8) has an obliquely bent edge (17, 27) on the radial inside or on the radial outside, at which the locking tongues (15) of the sealing elements (14a to 14h) can be locked.

4. The torsional vibration damper as claimed in any of the preceding claims, characterized in that the latching tongues (15) of the sealing element (14f) can directly engage and latch into a circumferential recess (29) at the end side of the driven hub (9).

5. The torsional vibration damper as claimed in any of the preceding claims, characterized in that the sealing elements (14g, 14h) can be directly latched by means of radially inner latching tongues (15) at the shoulder of a radially encircling annular groove (30) of the driven hub (9).

6. The torsional vibration damper as claimed in any of the preceding claims, characterized in that the sealing elements (14a to 14f) are centered at the driven hub (9) radially offset with respect to the latching tongues (15).

7. The torsional vibration damper as claimed in any of the preceding claims, characterized in that the sealing elements (14g, 14h) can be fixed in position at the driven hub (9) by means of locking tongues (15) located radially inside and/or radially outside.

8. The torsional vibration damper as claimed in any of the preceding claims, characterized in that sealing elements (14g to 14h) made of sheet metal or plastic are used.

9. The torsional vibration damper as claimed in any of the preceding claims, characterized in that a sealing material (28) is provided between the sealing element (14e) and a component of the secondary part (3).

10. The torsional vibration damper as claimed in any of the preceding claims, characterized in that the sealing elements (14g to 14h) are assigned to a preassembled dual mass flywheel (1) as a supplier part.