spoke damper

Abstract

Spoke damper comprising a first axial cover section (8) and a second axial cover section (11), between which a spoke element assembly (2) comprising several spoke elements (3), each of which has an externally circumferential ring section and several of them radially inwardly extending spokes, and two disc springs (4, 5), one of which is supported on the first cover section (8) and the other on the second cover section (11), characterized in that an overload disc spring (12) is provided, which is attached via several rivet connections (13) to the side of the first cover section (8) facing the spoke element assembly (2) and which clamps the spoke element assembly (2) against the second cover section (11), wherein the spoke element assembly (2) is in frictional contact with the overload disc spring (12) and with the second cover section (11).

Description

The invention relates to a spoke damper comprising a first axial cover section and a second axial cover section, between which a spoke element package comprising several spoke elements, each of which has an externally circumferential ring section and several of which have radially inwardly extending spokes, as well as two disc springs, one of which is supported on the first cover section and the other on the second cover section. German patent DE 10 2008 022 767 A1 discloses a torsional vibration damper with a torque limiter, forming a dual-mass flywheel. The torsional vibration damper consists of input plates and an output plate. The input plates are rigidly connected to an output shaft of a drive motor, and the output plate also serves as the clutch plate of a vehicle clutch. A spoke element assembly is arranged between the input and output plates, acting as a torque transmitter and damping energy storage device. This spoke element assembly comprises several spoked wheels with elastic spokes. US Patent 3,387,505A describes a damper consisting of several plates and designed to limit torque. The plates are slotted, which makes them elastically flexible in the direction of rotation. A spoke damper is known, for example, from CN 2 19 795 972 U. The spoke damper serves to dampen rotational irregularities in a rotating system, such as an internal combustion engine. It is attached to a rotating shaft, such as the crankshaft of an internal combustion engine, by means of an inner ring or hub, and thus rotates with the shaft. In the case of rotational irregularities, the circumferential spacing of an annular outer mass from the hub via the spokes, and the moment of inertia of the outer mass, cause a slight rotation of the outer mass relative to the inner ring, which dampens the vibration. To prevent excessively large vibration angles from occurring, it is necessary to dampen the spoke damper. In the spoke damper from CN 219795972 U, axially mounted, annular friction discs are provided for this purpose, which must be fixed using corresponding retaining rings.Spoke dampers are also described in DE 10 2016 207 130 A1 and US 2023 / 0 265 908 A1. The spoke damper considered here is a ring-shaped structure with two outer, annular cover sections and a spoke element assembly consisting of several annular spoke elements, each typically comprising an inner and an outer ring section with spokes extending between them. Several such spoke elements are arranged axially as a assembly. Friction planes are formed by two disc springs, whereby the friction occurring during relative movement of the cover sections to the disc springs provides additional damping, in addition to the damping provided by the spoke element assembly. The invention is based on the problem of providing an improved spoke damper. To solve the problem, according to the invention, an overload disc spring is provided in a spoke damper of the type mentioned at the outset, which is attached to the side of the first cover section facing the spoke element package via several rivet connections and which tensions the spoke element package against the second cover section, wherein the spoke element package is in frictional contact with the overload disc spring and with the second cover section. The spoke damper according to the invention is characterized, according to this first embodiment, by an additionally integrated overload disc spring, which is arranged between the first cover section and the spoke element assembly. It is fixed to the inside of the first cover section by several rivet connections and therefore cannot rotate circumferentially relative to the cover section. The overload disc spring axially clamps the spoke element assembly against the opposite second cover section, causing it to bear against it. The design is such that the spoke element assembly is in frictional contact with both the overload disc spring and the second cover section. One disc spring, which forms one friction plane, is axially supported on the first cover section. The other disc spring, which forms the second friction plane, is supported on the second cover section; both disc springs are in frictional contact with the overload disc spring and the second cover section, respectively.the second lid section. The spoke assembly, or the spokes themselves, can deform to dampen loads within the normal load range. This deformation is achieved through damping, while the friction generated by the two disc springs and the resulting relative movement of the disc springs (which are fixed to the hub) against the overload disc spring and the second cover section is dampened by the two disc springs. However, if a high load is applied, i.e., an overload situation occurs, the spoke assembly, or the spokes themselves, can move circumferentially, resulting in relative movement of the spoke assembly against both the overload disc spring and the second cover section. As described, the spoke assembly is in frictional contact with the overload disc spring and the second cover section.This frictional contact, i.e., the axial tension, is designed such that a correspondingly high breakaway torque must be present, resulting from the applied high load, in order to move the spoke element assembly relative to both the overload disc spring and the second cover section. This means that, in the event of an overload, the spoke element assembly can slip relative to the overload disc spring and the second cover section, thus preventing damage or even breakage. As soon as the load is released, the frictional contact between the spoke element assembly, the overload disc spring, and the second cover section re-engages, restoring the usual damping function. This provides overload protection, safeguarding the spoke damper from damage in the event of an overload.In this way, a tolerance-limited, defined frictional force can be set via the spring properties of the overload disc spring, in particular its disc spring characteristic curve, which is given in the friction system between the spoke element package as well as the overload disc spring and the second cover section. In a further specification of the invention, the cover can consist of two cover components, one comprising the first cover section and the other the second cover section, the two cover components being connected to each other via multiple rivet connections, which also secure the overload plate spring. One cover component can, for example, be designed as an annular disc produced from a metal sheet by stamping. The other cover component can, for example, be an L-shaped component in cross-section, with a section radially circumferential around the spoke element assembly, to which the second cover section adjoins radially inwards. The two cover components can abut each other axially and are connected via the common rivet connections together with the overload plate spring. The rivet connections can be formed using stepped rivets, each featuring a step formed by an increasing rivet diameter, against which the overload disc spring is axially supported. The overload disc spring rests directly against the first cover section. To prevent axial movement of the spring relative to this cover section, stepped rivets are used. The steps formed by the increased rivet diameter press the overload disc spring axially against the first cover section, thus preventing any axial movement. Naturally, numerous such rivet connections are provided around the circumference in an equidistant arrangement. These rivet connections are only installed once the spoke damper is completely assembled.For this purpose, starting from the above-described component with cross-section L, all components are first inserted into it, i.e. first the one disc spring, then the spoke element package, then the overload disc spring and the second disc spring, after which the other cover component is placed on top and the rivet connections are made. A further development of this variant involves connecting the spoke elements to each other via several additional rivet connections in the area of ​​the ring section. The individual spoke elements are thus also axially fixed via these additional rivet connections, so that the spoke element assembly is held together on the outer circumference by these additional rivet connections, which are also expediently placed at equidistant intervals. According to a second variant, to solve the problem in a spoke damper of the type mentioned at the outset, an overload disc spring can be provided which is axially attached to the spoke element package via several rivet connections and is supported on the side of the first cover section facing the spoke element package and which tensions the spoke element package against the second cover section, wherein the overload disc spring is in frictional contact with the first cover section and the spoke element package is in frictional contact with the second cover section. The spoke damper of this second variant according to the invention is also characterized by an additionally integrated overload disc spring, which is arranged between the first cover section and the spoke element assembly. In contrast to the first variant, however, the overload disc spring in this variant is fixed to the spoke element assembly itself by several rivet connections; it is therefore an integral part of the assembly and moves with it relative to the cover sections in the event of an overload. The overload disc spring cannot therefore rotate circumferentially relative to the spoke element assembly, but it can rotate relative to the first cover section. Via the overload disc spring, which is preloaded against the first cover section, the spoke element assembly is axially preloaded against the opposite second cover section, thus bearing against it.The design is such that the overload disc spring is in frictional contact with the first cover section, while the spoke element assembly is in frictional contact with the second cover section. The two disc springs, which form the additional friction surfaces, are axially supported on the first and second cover sections. In the event of an overload, the combination of the spoke element assembly and the attached overload disc spring slips, causing the overload disc spring to move relative to the first cover section and the spoke element assembly relative to the second cover section. Here, too, the frictional force between the overload disc spring and the first cover section, as well as between the spoke element assembly and the second cover section, can be adjusted by modifying the design of the overload disc spring and its spring characteristic curve, thus defining the breakaway torque accordingly. In this specific variant, the cover can consist of two cover components, one comprising the first cover section and the other the second cover section, with the two cover sections connected to each other by several additional rivet connections. Here too, two separate cover components can be provided, similar to the variant described above, which are connected to each other by the multiple rivet connections distributed equidistantly around the circumference, so that here as well, the cover provides a corresponding enclosure for the spoke element assembly, including the overload plate spring fixed to it via the rivet connections. Similarly, stepped rivets can also be used here as further rivet connections, each having a step formed over an increasing rivet diameter, on which the first or second cover section is supported. 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 in the form of a sectional view of a spoke damper of a first embodiment according to the invention, Fig. 2 a schematic representation in the form of a sectional view of a spoke damper of a second embodiment according to the invention, and Fig. 3 a schematic representation in the form of a sectional view of a spoke damper of a third embodiment according to the invention. Fig. 1 shows a partial view of a spoke damper 1 according to the invention, comprising a spoke element assembly 2 consisting of a plurality of individual, axially stacked spoke elements 3, which are arranged in a rotationally fixed manner on a hub (not shown in detail), via which the spoke damper 1 is connected to a rotating component to be damped, such as a crankshaft. Two disc springs 4, 5 are also provided, which are likewise arranged in a positionally fixed manner on the hub side and on which two corresponding friction surfaces, which also serve to dampen rotational irregularities, are formed relative to a cover 6. The cover 6 itself encompasses the spoke element assembly 2 externally and axially on both sides, thus enclosing it. It consists of two cover components 7 and 9, with cover component 7 being designed in the form of an annular disc. A first cover section 8 is defined by the first cover component 7, which axially overlaps the spoke element assembly 2. The second cover component 9 has an L-shaped cross-section with a radially outer section 10 and an adjoining, radially inward-facing section that forms a second axial cover section 11, which axially overlaps the spoke element assembly 2 on the other side. The spoke element assembly 2 thus projects into the annular, U-shaped cover 6, and the two disc springs 4 and 5 also engage within it, their outer edges bearing in frictional contact with the inner surfaces of the cover sections 8 and 11. Furthermore, an overload disc spring 12 is provided, which is attached to the first cover section 8 by means of rivet connections 13, which also connect the two cover components 7, 9 to each other. The rivet connections 13, placed equidistantly around the circumference, extend through the cover components 7, 9 and the overload disc spring 12 in corresponding openings and are riveted to the cover components 7, 9. The rivet connections 13 are stepped rivets, i.e., a step 14 is formed over an increased diameter, over which the overload disc spring 12 is pressed axially against the first cover section 8. The overload disc spring 12, for example, is designed with corresponding, radially inwardly projecting spring tabs 15, which are cranked or bent and bear against the outer ring section of the spoke element assembly 2 in a frictional connection with a corresponding contact surface. The spoke element assembly 2 is axially clamped within the cover 6 by means of these spring tabs 15; it is clamped against the second cover section 11, where it bears against the cover in a frictional contact. This means that, in this configuration, the spoke element assembly 2 bears against both the overload disc spring 12 and its spring tabs 15, as well as the second cover section 11, in an axial friction arrangement. In the event of an overload resulting from, for example, a rotational irregularity of the crankshaft, exceeding the load present during normal operation, the spoke element assembly 2 can slip relative to the cover 6. This means that a relative movement of the spoke element assembly 2 occurs with respect to both the overload disc spring 12 and its friction surfaces, as well as the second cover section 11. This relative movement prevents excessive deformation of the spoke element assembly 2 and / or the spoke elements 3, which could lead to breakage.The frictional force between the spoke element assembly 2 and the overload disc spring 12, as well as the second cover section 11, is designed such that a relatively high release torque resulting from the overload must be present before slippage occurs. This frictional force, and the release torque defined by it, can be adjusted by appropriately designing the overload disc spring 12, its spring characteristic, and the corresponding mounting geometry. Fig. 2 shows an embodiment of a spoke damper 1 according to the invention, which is structurally identical to the spoke damper 1 from Fig. 1. In addition, however, the spoke element assembly 2 is axially riveted in the region of its outer ring section by means of further rivet connections 16, i.e., the ring section of the spoke element assembly is fixed accordingly by means of these further rivet connections 16. For this purpose, corresponding, aligned openings are provided in the individual storage elements 3, which are penetrated by the further rivet connections 16. The basic function of this embodiment is identical to that described above with reference to Fig. 1. Another embodiment of a spoke damper 1 according to the invention is shown in Fig. 3. The spoke damper 1 also has a spoke element assembly 2 consisting of several axially stacked spoke elements 3 and the two disc springs 4, 5. A cover 6 is also provided, which consists of the two cover components 7 and 9, wherein a first cover section 8 is provided on the cover component 7, which is again designed, for example, as an annular disc, while a radially outer circumferential section 10 and the second cover section 11 are formed on the L-shaped cover component 9. This variant also incorporates an overload disc spring 12, which, however, is axially riveted to the outer ring section of the spoke element assembly 2 via rivet connections 17. It is thus rigidly connected to the spoke element assembly 2 and consequently moves with it in the event of a load, or particularly in the event of an overload. The overload disc spring 2 can also have corresponding spring tabs 15, which in this case bear against the first cover section 8 in a frictional contact, meaning that the preferably planar friction plane between the overload disc spring 12 or its spring tabs 15 and the first cover section 8 is present. Due to the spring properties of the overload disc spring 12 or the spring tab 15, the spoke element assembly 2 is also axially deflected against the second cover section 11, where the second friction plane is formed. In the event of an overload, the spoke element assembly 2, together with the overload disc spring 12, can slip relative to the cover 6, thus preventing damage. Here, too, the breakaway torque or the magnitude of the frictional force between the overload disc spring 12 and the first cover section 8 on the one hand, and between the spoke element assembly 2 and the second cover section 11 on the other, can be adjusted by appropriately designing the overload disc spring 12 or its spring characteristic. The two cover components 7, 9 are also axially riveted together here via corresponding additional rivet connections 18, whereby the rivet connections 18 can also be designed as stepped rivets. However, it is also conceivable in this variant to weld the two cover components 7, 9 together, in particular by laser welding. This would eliminate the need for riveting. Reference symbol list 1 Spoke damper 2 Spoke element package 3 Storage element 4 Disc spring 5 Disc spring 6 Cover 7 Cover component 8 Cover section 9 Cover component 10 Section 11 Cover section 12 Overload disc spring 13 Rivet connection 14 Step 15 Spring tab 16 Rivet connection 17 Rivet connection 18 Rivet connection

Claims

Spoke damper comprising a first axial cover section (8) and a second axial cover section (11), between which a spoke element assembly (2) comprising several spoke elements (3), each of which has an externally circumferential ring section and several of them radially inwardly extending spokes, and two disc springs (4, 5), one of which is supported on the first cover section (8) and the other on the second cover section (11), characterized in that an overload disc spring (12) is provided, which is attached via several rivet connections (13) to the side of the first cover section (8) facing the spoke element assembly (2) and which clamps the spoke element assembly (2) against the second cover section (11), wherein the spoke element assembly (2) is in frictional contact with the overload disc spring (12) and with the second cover section (11). Spoke damper according to claim 1, characterized in that a cover (6) is provided which consists of two cover components (7, 9), one of which has the first cover section (8) and the other the second cover section (11), wherein the two cover components (7, 9) are connected to each other via the multiple rivet connections (13), via which the overload disc spring (12) is also attached. Spoke damper according to claim 2, characterized in that the rivet connections (13) are formed by means of stepped rivets, each having a step (14) formed over an increasing rivet diameter, on which the overload disc spring (12) is axially supported. Spoke damper according to one of the preceding claims 1, 2 or 3, characterized in that the spoke elements (3) are connected to each other via several further rivet connections (16) in the area of ​​the ring section. Spoke damper comprising a first axial cover section (8) and a second axial cover section (11), between which a spoke element assembly (2) comprising several spoke elements (3), each of which has an externally circumferential ring section and several of them radially inwardly extending spokes, and two disc springs (4, 5), one of which is supported on the first cover section (8) and the other on the second cover section (11), characterized in that an overload disc spring (12) is provided, which is axially attached to the spoke element assembly (2) via several rivet connections (17) and is supported on the side of the first cover section (8) facing the spoke element assembly (2) and which tensions the spoke element assembly (2) against the second cover section (11), wherein the overload disc spring (12) is in frictional contact with the first cover section (8) and the spoke element assembly (2) is in frictional contact with the second cover section (11). Spoke damper according to claim 5, characterized in that the cover (6) consists of a first cover component (7) and a second cover component (9), wherein the first cover component (7) has the first cover section (8) and the second cover component (9) has the second cover section (11), wherein the first cover component (7) and the second cover component (9) are connected to each other via several further rivet connections (18). Spoke damper according to claim 5 or 6, characterized in that the further rivet connections (18) are formed by means of stepped rivets, each having a step formed over an increasing rivet diameter, on which the first cover section (8) or the second cover section (11) is axially supported.

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