DE102022129454A1 - Dual mass flywheel - Google Patents

Abstract

Dual-mass flywheel (1) with a primary side (2) and a secondary side (3) which can be rotated relative to one another against the force of an energy store (7), the primary side (2) comprising a primary mass cover (5) and a primary flywheel (6) which have a tongue and groove arrangement (22, 23) for mutual centering and which are welded to one another by means of a weld seam (21), the primary mass cover (5) and primary flywheel (6) forming an arc spring receptacle (8) for receiving the arc spring (7), the primary mass cover (5) and/or the primary flywheel (6) having a circumferential groove (24, 25) on a surface facing the other component.

Description

The invention relates to a dual-mass flywheel with a primary side and a secondary side that can be rotated relative to one another against the force of an energy storage device, the primary side comprising a primary mass cover and a primary flywheel that have a tongue and groove arrangement for mutual centering and that are welded together by means of a weld seam, the primary mass cover and primary flywheel forming an arc spring holder for receiving the arc spring. The invention further relates to a primary mass cover and a primary flywheel for use in such a dual-mass flywheel and a method for changing a component, in particular an arc spring, in such a dual-mass flywheel.

Dual mass flywheels are state of the art, for example from the DE 41 17 582 A1 , known. Such dual-mass flywheels are used as vibration absorbers for torsional vibrations in the drive trains of motor vehicles, whereby the dual-mass flywheel is usually arranged between the crankshaft of an internal combustion engine driving the motor vehicle and a vehicle clutch upstream of the manual transmission. The primary side with a primary flywheel and the secondary side with a secondary flywheel, which can be rotated relative to one another against the spring force of one or more arc springs as energy storage and possibly also against dry friction, cancel out torsional vibrations caused by the non-uniform drive torque of the internal combustion engine, which is usually designed as a piston engine.

The reconditioning of grease-filled dual-mass flywheels in the form of arc spring dampers is problematic in that replacing the internal components, in particular the arc spring or flange, requires exposing the circumferential laser weld. After replacing the components, repeating the laser weld is difficult due to the previously removed component areas and also requires complex equipment.

An object of the invention is therefore to provide a dual-mass flywheel which enables a component exchange with less effort, in particular when producing the previously separated weld seam.

This problem is solved by a dual-mass flywheel according to claim 1, a primary flywheel according to claim 5, a primary mass cover according to claim 6 and a method according to claim 7. Preferred embodiments, refinements or developments of the invention are specified in the dependent claims.

The above-mentioned problem is solved in particular by a dual-mass flywheel with a primary side and a secondary side, which can be rotated relative to one another against the force of an energy storage device, wherein the primary side comprises a primary mass cover and a primary flywheel, which have a tongue and groove arrangement for mutual centering and which are welded together by means of a weld seam, wherein the primary mass cover and primary flywheel form an arc spring holder for receiving the arc spring, wherein the primary mass cover and/or the primary flywheel have a circumferential groove on a surface facing the other component. The energy storage device comprises at least one arc spring. If the arc spring is compressed, this causes a restoring moment between the primary and secondary sides. The weld seam is preferably produced by means of laser welding, since the dual-mass flywheel is sealed by a circumferential laser seam.

In one embodiment of the invention, both the primary mass cover and the primary flywheel each have a circumferential groove, which together form a receiving space that is suitable for receiving an O-ring as a seal. During disassembly by separating the laser weld seam between the primary mass cover and the primary flywheel and then re-welding after repairing or replacing components, an O-ring can be inserted as a seal between the primary mass cover and the primary flywheel, which creates a seal between the two, so that the weld seam then produced no longer has to be tight and can be produced using the MSG process.

In one embodiment of the invention, the two circumferential grooves are arranged radially within a tongue and groove arrangement, since this position has the greatest possible distance from the weld seam and the risk of thermal damage to the O-ring during welding is reduced.

In one embodiment of the invention, the primary mass cover and the primary flywheel lie flat against each other in the area of the circumferential groove. This means that the O-ring cannot move into a gap between the two, even under pressure.

The problem mentioned at the outset is also solved by a primary flywheel for use in a dual-mass flywheel according to the invention, which has a circumferential groove on a side facing the primary mass cover in the installed position.

The problem mentioned at the outset is also solved by a primary mass cover for use in a dual-mass flywheel according to the invention, which has a circumferential groove on a side facing the primary flywheel in the installed position.

• - Trennen der Schweißnaht;
• - Trennen von Primärmassendeckel und Primärschwungrad;
• - Wechsel des Bauteils bzw. der Bogenfeder;
• - Einlegen eines O-Rings in eine der Nuten von Primärmassendeckel oder Primärschwungrad;
• - Positionieren und Zentrieren von Primärmassendeckel und Primärschwungrad;
• - Verschweißen von Primärmassendeckel und Primärschwungrad.

The problem mentioned at the outset is also solved by a method for changing a component, in particular a bow spring in a dual-mass flywheel according to the invention, comprising the steps

• - Separating the weld seam;
• - Separating the primary mass cover and primary flywheel;
• - Replacement of the component or the arc spring;
• - Inserting an O-ring into one of the grooves of the primary mass cover or primary flywheel;
• - Positioning and centering of primary mass cover and primary flywheel;
• - Welding of primary mass cover and primary flywheel.

In one embodiment of the invention, welding is carried out using metal inert gas welding (MIG). The weld seam is welded from the radial outside or in a fillet position.

• 1 ein Ausführungsbeispiel eines erfindungsgemäßen Zweimassenschwungrades in einer Schnittdarstellung,
• 2 das Ausführungsbeispiel der 1 nach Komponententausch bei Verwendung des alten Primärmassendeckels,
• 3 das Ausführungsbeispiel der 1 nach Komponententausch bei Verwendung eines neuen Primärmassendeckels.

Embodiments of the invention are explained in more detail below with reference to the accompanying drawings.

• 1 an embodiment of a dual-mass flywheel according to the invention in a sectional view,
• 2 the embodiment of the 1 after replacing components when using the old primary mass cover,
• 3 the embodiment of the 1 after component replacement when using a new primary mass cover.

1 shows an embodiment of a dual-mass flywheel 1 according to the invention. Such a dual-mass flywheel 1 is arranged in the drive train of a motor vehicle, in particular between the crankshaft of an internal combustion engine and the vehicle clutch. The internal combustion engine is usually a petrol or diesel engine. The torque of the vehicle clutch is usually transmitted to the drive wheels via a manual transmission, which can be a dual-clutch transmission, as well as via a differential gear and cardan shafts.

The rotation axis of the dual mass flywheel is in 1 designated by R. The rotation axis R is the rotation axis of the dual-mass flywheel 1 and at the same time the rotation axis of a crankshaft of an internal combustion engine (not shown) and also the rotation axis of a vehicle clutch arranged downstream of the dual-mass flywheel 1, which is also not shown. In the following, unless otherwise stated, the axial direction is understood to mean the direction parallel to the rotation axis R, the radial direction is understood to mean a direction perpendicular to the rotation axis R and the circumferential direction is understood to mean a rotation about the rotation axis R.

The dual-mass flywheel 1 comprises an input side or primary side 2 and an output side or secondary side 3, which can be rotated relative to one another about the rotation axis R against the force of a bow spring arrangement 4. The bow spring arrangement 4 comprises one or two bow springs 7 arranged in the circumferential direction, wherein each bow spring 7 can comprise coaxially arranged inner and outer springs. The primary side 2 comprises an engine-side primary flywheel 6 and a clutch-side primary mass cover 5. The primary flywheel 6 and the primary mass cover 5 enclose a bow spring holder 8 in which the bow spring 7 is arranged.

During operation, the arc spring 7 is pressed outwards against the primary flywheel 6 by the centrifugal force acting on it. Therefore, a sliding shell 9 is arranged on the radially inner side of the essentially hollow cylindrical region of the primary flywheel 6, which reduces the wear between the arc springs 7 and the primary flywheel 6.

The arc spring 7 is supported with the outer areas of the spring ends on the primary side 2, for example on lugs (not shown here) that protrude into the arc spring holder 8 enclosed by the primary flywheel 6 and the primary mass cover 5. The inner area of the spring ends of the arc spring 7 is supported on a flange wing 11 of an arc spring flange 10. With two arc springs 7, there are two flange wings. The flange wing 11 extends radially outwards and is touched on both sides by the spring ends of the arc spring 7. The arc spring flange 10 is connected to an output hub 12 by means of rivets 13 of a main rivet. The output hub 12 can be coupled to components arranged downstream of the dual-mass flywheel 1 in the torque flow of the drive train, such as a clutch, by means of a spline 14 on the inner circumference of the output hub.

In the installed position, the primary side 2 is screwed to the crankshaft of the internal combustion engine (not shown) with crankshaft screws that protrude through crankshaft screw holes 15 in the primary flywheel in order to transmit torque to the crankshaft of the internal combustion engine.

A cover plate 16 is attached to the primary side 2 with the crankshaft screws. The cover plate 16 has a friction ring 17 on its outside, which is arranged between the primary flywheel 6 and the arc spring flange 9 and forms a clutch-side seal for the arc spring mount 8. A starter ring gear 18 is welded or shrunk onto the outer circumference of the primary flywheel 6.

A centrifugal pendulum device (not shown here) can be arranged on the secondary flange. To reduce torsional vibrations, additional moving masses are attached to a rotating part of the torsional vibration system as so-called pendulum masses. These masses execute vibrations on predetermined paths in the field of centrifugal acceleration when they are excited by speed irregularities. These vibrations remove energy from the excitation vibration at the right times and then add it back, so that the excitation vibration is dampened, so that the pendulum mass acts as a vibration absorber. Since both the natural frequency of the centrifugal pendulum vibration and the excitation frequency are proportional to the speed, a centrifugal pendulum can have an absorbing effect over the entire frequency range of the vibrations excited by speed irregularities.

A starter ring gear 18 is arranged on the outer circumference of the primary flywheel 6, for example shrunk on. A disc spring membrane 19 is arranged on the arc spring flange 10. This is clamped between the arc spring flange 10 and the output hub 12 and riveted together with them by means of the rivet 13 of the main riveting. A contact surface of the disc spring membrane 19 is in sliding contact with a membrane ring 20 that is arranged on the primary mass cover 5. The disc spring membrane 19 is pre-tensioned in the axial direction so that the contact surface is pressed onto the membrane ring 20. The disc spring membrane 19 forms with the membrane ring 20 on the one hand a clutch-side seal of the arc spring holder 8 and on the other hand a friction element for dry and/or viscous friction between the primary side 2 and the secondary side 3.

The primary mass cover 5 is welded to the primary flywheel 6. For this purpose, a circumferential laser weld seam 21, usually a laser weld seam, is introduced from the radial outside into the joint where the primary mass cover 5 and the primary flywheel 6 touch. The dual-mass flywheel 1 is welded tightly by the circumferential laser seam. Fitting elements located radially inside the seam ensure the correct position of the primary-side cover in relation to the primary disk. The fitting elements here are a tongue and groove arrangement comprising a groove 22 and a tongue 23. In the embodiment shown here, the groove 22 is arranged in the primary flywheel 6, the tongue 23 in the primary mass cover 5. The groove 22 and tongue 23 are preferably circumferential with respect to the axis of rotation R and are pressed into the primary flywheel 6 and the primary mass cover 5, for example.

During assembly, the tongue and groove arrangement as a fitting element ensures centering of the primary flywheel 6 and primary mass cover 5 after pre-assembly of the components and assemblies arranged in the arc spring holder 8. These are then welded together in a next production step.

A circumferential groove 24, 25 is arranged within the tongue and groove arrangement in both the primary flywheel 6 and the primary mass cover 5. A groove 24 is arranged in the primary mass cover 5 and a groove 25 is arranged in the primary flywheel 6. The grooves 24, 25 are formed off-tool during the punching and forming of the primary flywheel 6 and the primary mass cover 5.

The grooves 24, 25 form a toroidal receiving space 26 with a minimum inner diameter D.

When the dual-mass flywheel 1 is dismantled, for example to replace the arc spring(s) or other parts, the weld seam 21 is opened, for example by machining. If the weld seam is then restored to connect the primary flywheel 6 and the primary mass cover 5, this is generally not possible with a tight laser weld seam. Instead, as in 2 shown a circumferential weld seam 27 is produced, which is placed radially on the outside and is produced by means of a MSG welding process (metal protection gas welding MSG). Metal protection Gas welding is an arc welding process in which an endless wire electrode melts under a protective gas cover. Since such a weld seam is not always tight, an O-ring 28 is inserted into the receiving space 26 before the primary flywheel 6 and primary mass cover 5 are assembled. The O-ring 28 has a cross-sectional diameter that corresponds to the inner diameter, i.e. is usually somewhat larger, so that the O-ring 28 is pressed firmly and sealingly into the receiving space 26. The circumferential length of the O-ring 28 corresponds to that of the receiving space 26, so that the O-ring 28 can be placed in one of the two circumferential grooves 24, 25 for assembly without stress.

If a new primary mass cover 5 is used instead of the separated original primary mass cover 5, then as in 3 As shown, a fillet weld must be welded because the primary mass cover 5 projects radially outward beyond the primary flywheel 6.

List of reference symbols

1

Dual mass flywheel

2

Primary page

3

Secondary side

4

Bow spring arrangement

5

Primary mass cover

6

Primary flywheel

7

Bow spring

8th

Bow spring mount

9

Sliding shell

10

Bow spring flange

11

Flange wings

12

Output hub

13

Rivet of the main riveting

14

Spline connection

15

Crankshaft bolt bore

16

Cover plate

17

Friction ring

18

Starter ring gear

19

Disc spring diaphragm

20

Membrane ring

21

Laser welding seam

22

Groove

23

Feather

24

circumferential groove primary mass cover

25

circumferential groove primary flywheel

26

Recording room

27

Weld

28

O-ring

QUOTES INCLUDED IN THE DESCRIPTION

This list of documents listed by the applicant was 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 accepts no liability for any errors or omissions.

Cited patent literature

• DE 4117582 A1 [0002]

Claims (10)

Dual-mass flywheel (1) with a primary side (2) and a secondary side (3), which can be rotated relative to one another against the force of an energy store (7), the primary side (2) comprising a primary mass cover (5) and a primary flywheel (6), which have a tongue and groove arrangement (22, 23) for mutual centering and which are welded to one another by means of a weld seam (21), the primary mass cover (5) and primary flywheel (6) forming an arc spring receptacle (8) for receiving the arc spring (7), characterized in that the primary mass cover (5) and/or the primary flywheel (6) have a circumferential groove (24, 25) on a surface facing the other component. Dual mass flywheel according to Claim 1 , characterized in that both the primary mass cover (5) and the primary flywheel (6) each have a circumferential groove (24, 25) which together form a receiving space (26) which is suitable for receiving an O-ring as a seal. Dual mass flywheel according to Claim 2 , characterized in that the two circumferential grooves (24, 25) are arranged radially within a tongue and groove arrangement (22, 23). Dual mass flywheel according to one of the Claims 1 until 3 , characterized in that the primary mass cover (5) and the primary flywheel (6) lie flat against one another in the region of the circumferential groove (24, 25). Primary flywheel (6) for use in a dual-mass flywheel (1) according to one of the Claims 1 until 4 , characterized in that it has a circumferential groove (25) on a side facing the primary mass cover (5) in the installed position. Primary mass cover (5) for use in a dual mass flywheel (1) according to one of the Claims 1 until 5 , characterized in that it has a circumferential groove (24) on a side facing the primary flywheel (6) in the installed position Method for replacing a component, in particular a bow spring (7) in a dual-mass flywheel (1) according to one of the Claims 1 until 6 , comprising the steps of - separating the weld seam (21); - separating the primary mass cover (5) and primary flywheel (6); - changing the component; - inserting an O-ring into one of the grooves (24, 25) of the primary mass cover (5) or primary flywheel (6); - positioning and centering the primary mass cover (5) and primary flywheel (6); - welding the primary mass cover (5) and primary flywheel (6). Procedure according to Claim 7 , characterized in that the welding is carried out by means of metal inert gas welding -MSG-. Procedure according to Claim 7 or 8th , characterized in that the weld seam (27) is welded from the radial outside for welding. Procedure according to Claim 7 or 8th , characterized in that the weld seam (27) is welded in a throat position.

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