Torsional vibration damper

Abstract

A torsional vibration damper comprising a primary mass (2) to be coupled to an input element, a secondary mass (6) to be coupled to an output element, and a spring damper arrangement (10) coupled to the disk-shaped primary mass (2) and the secondary mass (6), comprising several arc springs (11) against which the primary mass (2) and the secondary mass (6) are rotatable relative to each other, wherein the secondary mass (6) has an annular spring channel (9) in which the arc springs (11) are received, and wherein at least one elastic vibration damper device (22, 26) is provided on the primary mass (2). The arrangement is characterized in that the secondary mass (6) has a disk-shaped flange section (7) which transitions into the spring channel (9) at its outer circumference and to which a hub flange (17), via which the connection to the output element is made, is attached.

Description

[0001] The invention relates to a torsional vibration damper comprising a disk-shaped primary mass to be coupled to an input element, a secondary mass to be coupled to an output element, and a spring damper arrangement coupled to the primary mass and the secondary mass, comprising several arc springs against which the primary mass and the secondary mass are rotatable relative to each other, wherein the secondary mass has an annular spring channel in which the arc springs are received.

[0002] A torsional vibration damper, sometimes also called a dual-mass flywheel or torsional vibration damper, is primarily used to dampen torsional vibrations in the drivetrains of motor vehicles. The torsional vibration damper is typically positioned between the crankshaft of an internal combustion engine powering the vehicle and a clutch located upstream of the transmission. It features a primary mass, which forms the input component of the torsional vibration damper and is coupled to an input element, such as the crankshaft. A secondary mass is also provided, forming the output component of the torsional vibration damper and being coupled to an output element, such as a transmission input shaft.The primary and secondary masses are coupled to each other and relative to each other in a known manner via a spring-damper arrangement, which comprises several arc springs serving as energy storage devices against which the rotation of the two masses occurs. This makes it possible to dampen any torsional or rotational vibrations that arise during the operation of the internal combustion engine, so that these are not transmitted to the output element, or are transmitted only in a damped form. These torsional or rotational vibrations result from the uneven torque or drive torque of the internal combustion engine, which is generally a piston engine. They are inherent to the design and operation of the engine and are transmitted to the primary mass coupled to it via the input element, i.e., the crankshaft.The vibrations are transmitted from the primary mass to the spring damper assembly, specifically the arc springs, which dampen the vibrations and transmit them to the secondary mass only in a damped state. The basic function of such a torsional vibration damper is known. A torsional vibration damper of this type, designed as a pulley, is based on... Fig. 1 of DE 41 03 213 A1. The pulley is mounted on the crankshaft of an internal combustion engine in a rotationally fixed manner and is divided into two mass parts. A torsionally elastic damper formed by springs is arranged between these two mass parts. One mass part is located on the primary side of the torsional vibration damper and consists of a hub that is rotationally fixed on the crankshaft, two housing parts that define an annular spring chamber for the springs, and a vibration damping device. The other mass part, located on the output side (secondary side), consists of a flange and a belt race of the pulley that is rigidly connected to the flange.

[0003] Besides the conventional design of such a torsional vibration damper, as described, for example, in DE 10 2016 223 413 A1, in which the primary mass has an annular spring channel in which the arc springs are housed, while the secondary mass is designed as a simple disc-shaped flange that engages between the arc springs, a design known as a "reversed damper" is also known. In this design, the primary mass is a simple disc-shaped flange, while the secondary mass has the annular spring channel in which the arc springs are housed. An example of such a torsional vibration damper can be found in DE 10 2017 127 525 A1. Accordingly, the housing enclosing the arc springs with the annular channel is not connected to the crankshaft, as is usually the case, but to the transmission input shaft. The flange disk interacting with the arc springs, i.e., the primary mass, is attached to the crankshaft.This makes it possible to implement a functionally improved torque transmission device using simple and cost-effective means, characterized by a vibration damper that is optimized for installation space, at least in the axial direction.

[0004] Another example of a torsional vibration damper designed as a "reversed damper" and configured as a pulley is disclosed in DE 42 25 314 B4. Disclosed is a torsional vibration damper whose secondary mass (6) comprises the housing with an annular spring channel containing the arc springs and whose primary mass is provided with an elastic vibration damping device.

[0005] Such torsional vibration dampers are characterized by an integrated vibration damping device, i.e., a torsional vibration damper, which is provided directly on the primary mass and thus forms part of it. The installation of a separate torsional vibration damper on the crankshaft is therefore unnecessary, as this functionality is additionally provided by the torsional vibration damper according to the invention or by the primary mass. The torsional vibration damper according to the invention is therefore not only able to dampen torsional vibrations, but also to eliminate resonances in the higher engine orders in order to counteract any potential strength or NVH (noise, vibration, harshness) problems. The invention is based on the problem of providing such a torsional vibration damper with improved damping properties.

[0006] It is provided that the secondary mass has a disc-shaped flange section that transitions into the spring channel at its outer circumference and to which a hub flange, via which the connection to the output member is made, is attached. In the damper device according to the invention, as described above, the secondary mass has the annular spring channel for the arc springs. In a specific embodiment, the secondary mass can have a disc-shaped flange section that transitions into the spring channel at its outer circumference and to which a hub flange, via which the connection to the output member is made, is attached. The flange section is thus designed in an annular disc shape and transitions radially outwards into the spring channel, for which purpose a correspondingly designed cover component is attached to the flange component, so that the corresponding annular channel is formed over both components.A corresponding hub flange is attached to the inner circumference of the flange component, preferably via appropriate rivet connections, so that the secondary mass can be coupled to the output member, for example a transmission input shaft, via a toothed connection or similar, via the hub flange, which is ultimately also part of the secondary mass.

[0007] In the damper device according to the invention, the secondary mass has an annular spring channel for the arc springs. The secondary mass also has a disc-shaped flange section that transitions into the spring channel at its outer circumference and to which a hub flange, via which the connection to the output member is made, is attached. The flange section is thus annular and transitions radially outwards into the spring channel, for which purpose a correspondingly designed cover component is attached to the flange component, so that the corresponding annular channel is formed over both components. A hub flange is attached to the inner circumference of the flange component, preferably by means of rivet connections, so that the secondary mass can be coupled to the output member, for example a transmission input shaft, via a splined connection or similar means, via the hub flange, which is ultimately also part of the secondary mass.

[0008] According to a practical embodiment of the invention, an additional damper mass can be arranged via an elastic connecting element to integrate the vibration damping device onto the primary mass. The elastic connecting element is preferably a plastic component, preferably made of an elastomer, which, in addition to its connecting function, also provides a damping function. The connection of the connecting element to the damper mass on one side and to the disc-like flange component of the primary mass on the other is preferably achieved by bonding.

[0009] Preferably, the damping mass is a mass ring that is attached to an axial disk surface of the primary mass via the connecting element. Due to the annular design of the damping mass, the connecting element is also annular, i.e., a corresponding plastic or elastomer ring. Like the disk-shaped flange component of the primary mass, the mass ring is also disk-shaped, which allows for simple arrangement on the axial disk surface of the primary mass or the flange component of the primary mass.

[0010] As an alternative to this axial arrangement, it is also conceivable that the damping mass is a mass ring that is attached via the connecting element to a radial outer circumferential surface of the primary mass or the disc-shaped flange component of the primary mass. In this configuration, the mass ring of the damping mass connects radially to the primary mass or the flange component of the primary mass, with this connection also being elastic, as it is made via an annular elastic connecting element, which in turn can be bonded accordingly. The mass ring could, for example, be a sensor ring for a sensor system.

[0011] If the damper mass or mass ring is arranged on the radial outer circumferential surface, the coupling of the primary mass to the spring damper assembly cannot be achieved via corresponding coupling elements provided on the outer circumference, as is the case with an axial arrangement. Instead, in this embodiment of the invention, it is preferably provided that several axially bent, radially extending drivers are provided on the primary mass, via which the primary mass is coupled to the spring damper assembly. Corresponding drivers are bent onto the primary mass or the disc-like flange component of the primary mass, on which the mass ring is arranged radially outside, via which the coupling to the spring damper assembly is achieved, i.e., which engage between the curved springs. These drivers can be easily formed during the manufacturing process of the primary mass component, for example, by simple stamping and bending.

[0012] In the embodiment described above, an additional damping mass is arranged on the primary mass or the disc-shaped flange component of the primary mass, with the damping mass, together with the connecting element, contributing to the total mass of the primary mass. According to an alternative embodiment of the invention, it is conceivable that the primary mass has a disc-shaped flange section in which several openings, separated circumferentially by spokes, are provided to form a spoke damper. In this embodiment, the vibration damping device is integrated directly into the flange component or the flange section of the primary component. Corresponding openings, i.e., windows, are provided in the flange section, spaced apart from one another circumferentially by corresponding webs.These webs form spokes, so that this design creates a spoke damper that provides the elasticity required for vibration damping.

[0013] It is conceivable that the primary mass has only one such integrated spoke damper. However, it is also conceivable that, in addition to the spoke damper, a separate damper mass is arranged on the primary mass or the flange component, for example in the form of the radially outer mass ring described above. In this case, two different damper elements are provided on the primary mass.

[0014] The secondary mass can be centered via the flange section on a centering section provided on the primary mass. This centering section can, for example, be formed by a ring of several mounting bolts that attach the primary mass to the crankshaft, with the bolt heads providing the centering function. It is also conceivable that the centering section could be formed by washers that support the mounting bolts towards the primary mass, or similar configurations.

[0015] The invention is explained below with reference to exemplary embodiments and the drawings. The drawings are schematic representations and show: Fig. 1 a schematic representation of a torsional vibration damper according to the invention of a first embodiment, Fig. 2 a schematic representation of a torsional vibration damper of a second embodiment according to the invention, and Fig. 3 a top view of the primary mass of the torsional vibration damper from Fig. 2.

[0016] Fig. Figure 1 shows a schematic representation of a torsional vibration damper 1 according to the invention, designed as a “reversed damper”, comprising a primary mass 2 with an annular flange component 3, which has several openings 4 through which fastening screws 5 engage, via which the primary mass 2 is screwed to a crankshaft, i.e. an input element, which is not shown in detail.

[0017] Furthermore, a secondary mass 6 is provided, comprising an annular flange section 7, which is radially connected, in particular welded, to a cover-shaped component 8 on the outside, so that an annular spring channel 9 is formed in which a spring damper arrangement 10 comprising at least two arc springs 11 is received. The arc springs 11 are supported at one end on the secondary mass 6. In the region of the other end, corresponding coupling elements 12, which are formed on the outer circumference of the flange component 3 of the primary mass 2, engage between the arc springs, so that the arc springs 11 contact these coupling elements 12, i.e., corresponding drivers, at their other end.The spring channel 9, which is filled with grease, is sealed by means of suitable friction rings 13, 14, of which the friction ring 14 is axially spring-loaded by a spring element 15, wherein the friction ring 13 is arranged between the flange component 3 of the primary mass 2 and the flange section 7, while the friction ring 14 is arranged between the flange component 3 of the primary mass 2 and the cover-shaped component 8.

[0018] A hub flange 17 is attached to the inner circumference of the flange section 7 by means of suitable connecting elements 16, in this example rivets. The hub flange 17 is connected to an output member 19, here a transmission input shaft, via a toothed section 18.

[0019] Furthermore, the flange section 7 serves to center the secondary mass 2, for which purpose an axially bent section 20 is provided on the inner circumference of the flange section 7, via which the centering is carried out on a ring of several washers 21, over which the fastening screws 7 with their screw heads are supported on the flange component 3.

[0020] The primary mass 2 is equipped with a vibration damping device 22, which here comprises an additional damping mass in the form of a mass ring 23, for example, in the form of a sensor ring as part of a sensor system, and an elastic connecting element 24, for example, an elastomer ring. The connecting element 24 is connected, in particular bonded, to the mass ring 23 on one side and to the flange component 3 on the other, so that the vibration damping device 22 is attached to the axial end face 25 of the flange component 3, i.e., the primary mass 2. Corresponding vibrations can be dampened via this vibration damping device 22, or rather the elasticity of the connecting element 24, with this damping function being provided by the primary mass 2, since the vibration damping device 22 is provided on the primary mass 2 or is part of it.In addition, the damping of the rotational irregularities introduced by the crankshaft is carried out via the spring damper arrangement 10, as is usual with such a torsional vibration damper.

[0021] Fig. Figure 2 shows a further embodiment of a torsional vibration damper 1 according to the invention, wherein the same reference numerals are used for identical components. The torsional vibration damper 1 again comprises a primary mass 2 with a flange section 3 and corresponding openings 4 for receiving the fastening screws (not shown here). A secondary mass 6 is also provided, to which, as in the already mentioned above, Fig. As described in Figure 1, a spring channel 9 is formed in which a spring damper arrangement 10 comprising at least two arc springs 11 is received. A hub flange 17 is also provided, which is welded on in the example shown.

[0022] Unlike the design according to Fig.1. Several axially bent, radially extending drivers 12 are provided on the flange component 3, which engage between the arc springs 11. This is necessary here because a first vibration damper 22 in the form of a mass ring 23 is arranged on the outer circumference of the flange component 3 via an elastic connecting element 24. This means that the outer circumference cannot serve for coupling to the arc springs 11, since a first damper is provided on it.

[0023] Furthermore, a second vibration damper 26 is provided, which is directly integrated into the flange component 3 and is designed as a spoke damper 27. This second vibration damper 26 has a plurality of openings 28, which are window-like, and between which corresponding spoke-like sections 29 are positioned circumferentially, as can be seen from the top view of the axial end face 25 of the flange section 3. The openings 28 can be arranged equidistantly around the circumference, or they can be spaced at different intervals. The length of all openings 25 can also be the same or different. That is, there are corresponding variations available, which allow the properties of the vibration damper 27 to be adjusted. A certain degree of elasticity is introduced via these openings 28 in conjunction with the webs 29, which serves to dampen the vibrations.

[0024] While in this embodiment two separate vibration damping devices 22, 26 are provided, it is conceivable that only the first vibration damping device 22 or only the second vibration damping device 26 is provided. Reference symbol list 1 torsional vibration damper 2 Primary mass 3 Flange component 4 breaches 5 mounting screws 6 Secondary mass 7 Flange section 8 components 9 spring channel 10 Spring damper arrangement 11 bow feathers 12 coupling elements 13 Friction ring 14 friction ring 15 spring element 16 Connecting element 17 Hub flange 18 Gear section 19 Starting element Section 20 21 Washer 22 Vibration damper device 23 Mass ring 24 Connecting element 25 Front surface 26 Vibration damper device 27 spoke dampers 28 breaches 29 Bridge

Claims

[1] Torsional vibration damper comprising a primary mass (2) to be coupled to an input element, a secondary mass (6) to be coupled to an output element and a spring damper arrangement (10) coupled to the disk-shaped primary mass (2) and the secondary mass (6), comprising several arc springs (11) against which the primary mass (2) and the secondary mass (6) are rotatable relative to each other, wherein the secondary mass (6) has an annular spring channel (9) in which the arc springs (11) are received, and wherein at least one elastic vibration damper device (22, 26) is provided on the primary mass (2). characterized by , that the secondary mass (6) has a disk-shaped flange section (7) which transitions into the spring channel (9) at the outer circumference and to which a hub flange (17) is attached, via which the connection to the output member is made. [2] Torsional vibration damper according to claim 1, characterized by, that an additional damping mass (23) is arranged on the primary mass (2) via an elastic connecting element (24). [3] Torsional vibration damper according to claim 2, characterized by , that the damper mass is a mass ring (23) which is attached via the connecting element (24) to an axial disk surface (25) of the primary mass (2). [4] Torsional vibration damper according to claim 2, characterized by , that the damper mass is a mass ring (23) which is attached via the connecting element (24) to a radial outer circumferential surface of the primary mass (2). [5] Torsional vibration damper according to claim 4, characterized by , that several axially bent, radially extending drivers (17) are provided on the primary mass (2), via which the primary mass (2) is coupled to the spring damper arrangement (10). [6] Torsional vibration damper according to any one of claims 3 to 5, characterized by , that the mass ring (23) is a sensor ring. [7] Torsional vibration damper according to any of the preceding claims, characterized by , that the primary mass (2) has a disk-shaped flange section (3) on which several openings (28) separated in the circumferential direction by spokes (29) are provided to form a spoke damper (27). [8] Torsional vibration damper according to claim 1, characterized by , that the secondary mass (6) is centered via the flange section (7) on a centering section provided on the primary mass (2).

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