Dual-mass flywheel with releasable torque limiter

Description

[0001] The invention relates to a dual-mass flywheel having a primary side and a secondary side which are rotatable relative to one another against a restoring torque of an energy storage device, comprising a secondary-side torque limiter comprising two counter-disks riveted to one another which are in frictional contact with a secondary flange, and an output hub which is coupled to the counter-disks for transmitting a torque.

[0002] Dual-mass flywheels (DMF) are used to dampen vibrations in the drivetrain of motor vehicles between an internal combustion engine and a vehicle clutch. In a dual-mass flywheel of this type, a friction device on the secondary side serves as a torque limiter (TLM).

[0003] DE 10 2016 207708 A1 discloses a torsional vibration damper whose primary input part is screwed directly to a crankshaft and between whose primary part and secondary part a slip clutch is arranged.

[0004] A dual-mass flywheel of this type is disclosed in DE 10 2016 204261 A1. This discloses a dual-mass flywheel with a primary side and a secondary side. The primary side and the secondary side can be rotated relative to each other against a restoring torque of an energy storage device. A slip clutch serves as a torque limiter on the secondary side. Two counter plates are riveted together with a secondary mass and are frictionally connected to the secondary flange to form the slip clutch. An output hub is coupled to the secondary mass via a toothing to transmit torque and is riveted to the counter plates. The primary mass has a primary mass plate, which can be connected to the crankshaft on the engine side by means of crankshaft bolts via holes in the primary mass plate.The output hub has holes through which the crankshaft bolts are accessible when the dual-mass flywheel is installed. A disc spring is axially clamped between the output hub and one of the counter discs, which applies a pressure force to the disc spring axially against a stop formed by the secondary mass.

[0005] One object of the invention is to provide a simple and cost-effective measure by which, in the event of an angular misalignment between the bores of the output hub and the screw connections of the dual-mass flywheel on the crankshaft, the output flange can be rotated by releasing the clutch until the bores are aligned with the heads of the screws.

[0006] The problem is solved by a dual-mass flywheel according to claim 1 and a method according to claim 8. Preferred embodiments, refinements or developments of the invention are specified in the dependent claims.

[0007] The invention provides a dual-mass flywheel with a primary side and a secondary side, which are rotatable relative to each other against a restoring torque of an energy storage device, comprising a secondary-side torque limiter comprising two riveted counter-disks that are in frictional contact with a secondary flange, and an output hub that is coupled to the counter-disks for transmitting torque. The output hub has a toothing that engages with a toothing of one of the counter-disks, wherein the output hub is axially loaded by a disc spring with a pressure force acting against a stop in the direction of the primary side.

[0008] The disc spring rests on a retaining plate attached to the counter discs. The retaining plate is preferably riveted to the counter discs. Riveting of the counter discs is preferred for this purpose. The retaining plate prevents deformation of the disc spring during assembly of the rivets that connect the counter disc and the retaining plate. Without the retaining plate, the disc springs would have to rest directly on the rivet heads, and the riveting would have to be carried out in the presence of the disc spring. Unintentional deformation of the disc spring can change the slipping torque of the torque limiter or even lead to premature failure due to a breakage of the disc spring or similar.

[0009] The retaining plate comprises a mounting ring and a support ring arranged axially offset from the mounting ring. The outer circumference of the disc spring preferably rests against the support ring and its inner circumference rests against a shoulder of the output hub. This defines the radial position of the disc spring and simultaneously contributes to the centering of the assemblies.

[0010] The inner diameter of the friction disc facing the primary mass plate is preferably smaller, at least in some areas, than the outer diameter of the gearing of an output hub. Thus, the friction disc forms an axial stop for the output hub.

[0011] The output hub has holes through which the crankshaft bolts are accessible when the dual-mass flywheel is installed.

[0012] The problem mentioned at the outset is also solved by a drive train of a motor vehicle comprising a dual-mass flywheel according to the invention.

[0013] The problem mentioned at the outset is also solved by a method for disassembling a dual-mass flywheel according to the invention from a crankshaft, comprising the method steps: Loosen the toothing between the output hub and the counter-disk by lifting the output hub against the force of the disc spring, turn the output hub so that the holes (20) in the output hub (18) are congruent with the crankshaft screws, create the toothing between the output hub and the counter-disk by moving the output hub in the direction of force of the disc spring, loosen the crankshaft screw connection.

[0014] An embodiment of the invention is explained in more detail below with reference to the accompanying drawings. Figure 1a first embodiment of a dual-mass flywheel according to the invention in a sectional view in a first radial section through a rivet of the riveting of the counter discs, Figure 2 the embodiment of the Figure 1 in a second radial cut outside the riveting, Figure 3 a radial section through the embodiment of the Figure 1 in a spatial representation.

[0015] The Figures 1 and 2 show a dual-mass flywheel according to the invention in sectional views in two radial planes. The dual-mass flywheel 1 comprises a primary mass or primary side 2 and a secondary mass or secondary side 3, which can be rotated relative to each other about the rotational axis R against the force of a bow spring 4. The rotational axis of the dual-mass flywheel is in Fig. 1designated by R. In the following, unless otherwise stated, the axial direction is understood to be the direction parallel to the axis of rotation R, the radial direction a direction perpendicular to the axis of rotation R and the circumferential direction a rotation about the axis of rotation R. The primary mass 2 comprises a primary mass plate 6 on the engine side and a primary mass cover 5 on the clutch side. The primary mass plate 6 and the primary mass cover 5 enclose a bow spring receptacle 7 in which the bow spring 4, or possibly also a plurality of bow springs 4, is or are arranged. The bow spring 4 is supported with one spring end on the primary mass 2, for example on lugs not shown here, which protrude into the bow spring receptacle 7 enclosed by the primary mass plate 6 and the primary mass cover 5. The other spring end of the bow spring 4 is supported on flange wings of a secondary flange 8.The flange wings extend radially outward and enclose the spring ends of the arc springs 4. The primary mass plate 6 can be connected to a crankshaft via bores 10 using crankshaft bolts (not shown). A sliding shell 11 is arranged on the primary mass plate 6 on the outer circumference of the arc spring 4.

[0016] The secondary flange 8 forms a slip clutch 14 with two counter discs, a left counter disc 12 and a right counter disc 13. The counter discs 12, 13 are riveted together with a disc spring membrane 9 and a retaining plate 15 by means of rivets 16. The slip clutch 14 serves as a torque limiter. If a slip torque MR defined by the static friction between the counter discs 12, 13 and the secondary flange 8 is exceeded, the slip clutch 14 slips and thus limits the transmitted torque MMax. The rivets are, as shown in Figure 3As can be seen, they are arranged around the circumference and firmly connect the riveted parts together.

[0017] The right counter-disk 13 has a toothing 17 on its inner circumference, into which a corresponding toothing 19 of an output hub 18 engages. This has bores 20 through which the crankshaft screw connection is accessible, as well as a plug-in toothing 21 for connecting the secondary side 3 to downstream components in the drive train.

[0018] The retaining plate has a mounting ring 22 and a support ring 23, which are connected by an axially extending cylindrical part 24, which, as in Figure 3 can also be seen as individual webs, are connected to each other.

[0019] A disc spring 25 is arranged between the support ring 23 and the output hub 18. Its outer circumference is centered on the cylindrical portion 24 of the retaining plate, and its inner circumference is centered on a shoulder 26 of the output hub 18. The left counter disc 12 has an inner circumference that is smaller than the outer circumference of the toothing 19 of the output hub 18. This forms an axial stop for the output hub 18 in the direction of the primary mass plate 6.

[0020] The outer region of the diaphragm spring 9 is in sliding contact near the outer circumference with a diaphragm ring 27 arranged on the primary mass cover 5. A disk 28 with a collar 29 is fastened to the primary mass plate 6 by the crankshaft screw connection. A friction ring 30 is clamped between the collar 29 and the output hub 18 and creates additional friction during a relative rotation of the primary side 2 with respect to the secondary side 3. Grease caps 31 cover mounting holes 32 in the primary mass plate 6, through which the rivets 16 are accessible during assembly of the dual-mass flywheel 1. A starter ring gear 33 is arranged on the outer circumference of the primary mass plate 6. List of reference symbols

[0021] 1 Dual-mass flywheel 2 Primary side 3 Secondary side 4 Arc spring 5 Primary mass cover 6 Primary mass plate 7 Arc spring mount 8 Secondary flange 9 Diaphragm spring 10 Bore 11 Sliding shell 12 Left counter plate 13 Right counter plate 14 Slip clutch 15 Retaining plate 16 Rivet 17 Toothing 18 Output hub 19 Toothing 20 Bore 21 Spline 22 Mounting ring 23 Support ring 24 Cylindrical part 25 Diaphragm spring 26 Shoulder 27 Diaphragm ring 28 Disc 29 Collar 30 Friction ring 31 Grease caps 32 Mounting hole 33 Starter ring gear

Claims

1. A dual-mass flywheel (1) having a primary side (2) and a secondary side (3), which are rotatable relative to one another against a restoring torque of an energy storage device (4), comprising a slip clutch (14) which serves as a secondary-side torque limiter (14), comprising two counter disks (12, 13) riveted to one another, which are in frictional contact with a secondary flange (8), and an output hub (18), which is coupled to the counter disks (12, 13) for transmitting a torque, and wherein the secondary flange (8) forms the slip clutch (14) with the two counter disks (12, 13), wherein the primary mass (2) comprises a motor-side primary mass plate (6), which is connectable to a crankshaft by means of crankshaft screws via drilled holes (10), wherein the output hub (18) has drilled holes (20) through which the crankshaft screws are accessible in an installation situation of the dual-mass flywheel (1), wherein the output hub (18) has a toothing (19), via which the output hub is coupled to the counter disks (12, 13) for transmitting the torque, and wherein the output hub (18) is axially acted upon by a plate spring (25) with a pressure force acting against a stop (12), characterized in that the toothing (19) is in engagement with a toothing (17) of one of the counter disks (13), wherein the output hub (18) is axially acted upon by the plate spring (25) with a pressure force acting in the direction of the primary side (2) and in that the plate spring (25) is supported on a retaining plate (15), wherein the retaining plate (15) is fastened to the counter disks (12, 13).

2. The dual-mass flywheel according to claim 1, characterized in that the retaining plate (15) is riveted (16) to the counter disks (12, 13).

3. The dual-mass flywheel according to claim 2, characterized in that the retaining plate (15) comprises a mounting ring (22) and a support ring (23) arranged axially offset relative thereto.

4. The dual-mass flywheel according to claim 3, characterized in that the plate spring (25) is supported with its outer circumference on the support ring (23).

5. The dual-mass flywheel according to claim 4, characterized in that the plate spring (25) is supported with its inner circumference on a shoulder (26) of the output hub (18).

6. The dual-mass flywheel according to one of the preceding claims, characterized in that the inner diameter of the counter disk (12) facing the primary mass plate (6) is smaller at least in sections than the outer diameter of the toothing (19) of the output hub (18).

7. A drive train of a motor vehicle comprising a dual-mass flywheel according to one of the preceding claims.

8. A method for dismantling a dual-mass flywheel according to one of claims 1 to 7 from a crankshaft, comprising the method steps: - Loosening the toothing between the output hub and the counter disk by lifting the output hub against the force of the plate spring, - Rotating the output hub so that the drilled holes (20) in the output hub (18) are congruent with the crankshaft screws, - Establishing the toothing between the output hub and the counter disk by moving the output hub in the direction of force of the plate spring, - Loosening the crankshaft screw connection.