Gear with integrated torsional vibration damper

Abstract

The present invention relates to a gear (1) with an integrated torsional vibration damper (2), comprising a gear ring (3) rotatably arranged about an axis of rotation (D) with at least one input flange section (12) for receiving a torque, at least one output flange section (13) for transmitting a torque to a shaft, and several rocker elements (4) distributed in the circumferential direction (U) of the gear (1) in a torque-transmitting connection between the input flange section (12) and the output flange section (13), wherein each rocker element (4) has at least one first rolling element (5) and at least one second rolling element (6), wherein each rocker element (4) has a first cam track (7) for rolling the first rolling element (5) and a second cam track (8) for rolling the second rolling element (6).wherein the inlet flange section (12) has a first counter-track (9) complementary to the first cam track (7) and the outlet flange section (13) has a second counter-track (10) complementary to the second cam track (8), wherein the first rolling element (5) is guided to roll between the first cam track (7) and the first counter-track (9) and the second rolling element (6) is guided to roll between the second cam track (8) and the second counter-track (10), and wherein at least one energy storage element (11) is arranged between two rocker elements (4) adjacent in the circumferential direction (U) and supports them oscillatively against each other.

Description

[0001] The present invention relates to a gear with an integrated torsional vibration damper, for example for a gearbox in a drive train of a motor vehicle.

[0002] Periodic or impulsive torque zero crossings in internal combustion engines, combined with play in the drivetrain (e.g., in shaft connections or gears), can lead to disturbing noises such as rattling or knocking. Torsional vibration dampers with specific stiffness and friction characteristics are used to reduce these noises.

[0003] These noise phenomena pose a particular challenge in hybrid or fully electric powertrains. For example, the combustion engine produces periodic noises (rattling) when electric motors (generator or traction motor) that are not coupled without backlash or via gear stages are operated without load or at low load.

[0004] In the case of an unfired or mechanically decoupled combustion engine in conjunction with an electric drive or in the case of a fully electric drive - such as an electrically driven axle - even single zero torque crossings of the electric drive motor (load change) can lead to clicking or knocking noises.

[0005] In this context, for example, a gear with an integrated torsional vibration damper is known from DE 10 2013 221 361 A1.

[0006] The object of the present invention is to provide a gear by which torsional vibrations can be effectively reduced, in particular to prevent disturbing noises during the operation of a motor vehicle.

[0007] According to the invention, this problem is solved by a gear with an integrated torsional vibration damper according to claim 1, comprising a gear ring rotatably arranged about an axis of rotation with at least one input flange section for receiving a torque, at least one output flange section for transmitting a torque to a shaft, and several rocker elements arranged circumferentially of the gear in a torque-transmitting connection between the input flange section and the output flange section, wherein at least one first rolling element and at least one second rolling element are provided for each rocker element, wherein the respective rocker element has a first cam track for rolling the first rolling element and a second cam track for rolling the second rolling element.wherein the input flange section has a first counter-track complementary to the first cam track and the output flange section has a second counter-track complementary to the second cam track, wherein the first rolling element is guided to roll between the first cam track and the first counter-track and the second rolling element is guided to roll between the second cam track and the second counter-track.

[0008] Since at least one energy storage element is arranged between two circumferentially adjacent rocker elements and supports them against each other in a way that allows oscillation, torsional vibrations can be effectively reduced.

[0009] Preferably, exactly one first rolling element and exactly one second rolling element are provided per rocker element. This allows torsional vibrations to be effectively reduced.

[0010] Furthermore, preferably a hub is formed in the radial direction of the gear within the output flange section, thereby improving the connection of the gear to other components.

[0011] Furthermore, preferably two output flange sections are spaced apart from each other in the axial direction of the gear and formed in one piece with the hub, thereby improving the design of the gear.

[0012] It is advantageous if a splined connection is formed within the hub, which further improves the connection of the gear to other components.

[0013] Furthermore, it is advantageous if the gear ring has two input flange sections that are spaced apart in the axial direction, and between which the rocker elements are arranged in the circumferential direction, thereby further improving the design of the gear.

[0014] It is also advantageous if one of the output flange sections is arranged between the rocker elements arranged centrally in the axial direction and the respective input flange section arranged on the outside in the axial direction, which further improves the design of the gear.

[0015] Preferably, the output flange section is annular and has radially projecting support sections in which the second mating tracks are formed. This further improves the design of the gear.

[0016] It is advantageous if the end faces of the support sections can come into contact with stop sections projecting radially inwards from the toothed ring in order to limit relative rotation in a clockwise and / or counterclockwise direction. This effectively reduces torsional vibrations.

[0017] Furthermore, it is advantageous if at least one friction device is integrated into the torsional vibration damper of the gear, which can effectively reduce torsional vibrations.

[0018] Preferably, the rocker elements and the energy storage elements arranged circumferentially between them are formed in one piece. This further improves the design of the gear.

[0019] The present invention is explained in more detail below with reference to preferred embodiments in conjunction with the accompanying figures. These show: Fig. 1: A first embodiment of a gear with a torsional vibration damper comprising rocker elements and separate energy storage elements, in a perspective view, Fig. 2: the gear made of Fig. 1 in a top view, Fig. 3: the gear from Fig. 1 in a sectional view, Fig. 4: a second embodiment of a gear with a torsional vibration damper and a friction device in a half sectional view, and Fig. 5: a one-piece assembly comprising rocker elements and energy storage elements in a top view for a third embodiment of a gear with a torsional vibration damper.

[0020] The following description relates to various embodiments of a gear 1 with an integrated torsional vibration damper 2, which has rocker elements 3 and energy storage elements 11. Features not identified as essential to the invention in the following description are to be understood as optional.

[0021] In the Fig. Figures 1 to 3 show a first embodiment of a gear 1 with an integrated torsional vibration damper 2, which has rocker elements 3 and separate energy storage elements 11. The gear 1 has a toothed rim 3 which is rotatably arranged about an axis of rotation D. In the illustrated embodiment, the toothed rim has helical teeth, but could, for example, also have spur teeth.

[0022] The gear ring 3 is rotationally fixed to at least one input flange section 12 of the torsional vibration damper 2 for absorbing a torque, for example by welding. The input flange section 12 is essentially ring-shaped and arranged radially R of the gear 1 within the gear ring. The input flange section 12 can be formed integrally with the gear ring 3, but can also be – as in the Fig. 1 to 3 shown - to be designed as a separate component.

[0023] In particular, the gear ring 3 has two input flange sections 12 on its inner radial direction R, which are spaced apart from each other in the axial direction A of the gear 1 and which define the interior of the gear 1. It is possible that one of the two input flange sections 12 is formed integrally with the gear ring 3, and the other of the two input flange sections 12 is formed as a separate component, or that both input flange sections 12 are formed as separate components.

[0024] The torsional vibration damper 2 integrated into the gear 1 further comprises at least one output flange section 13 for transmitting a torque to a shaft (not shown). In the illustrated embodiment, a hub 14 is formed radially R within the output flange section 13, which defines the interior of the gear 1. A splined connection 15 is formed within the hub 14 for the rotationally fixed attachment of the shaft (not shown).

[0025] In the illustrated embodiment, two outlet flange sections 13 are arranged spaced apart from each other in the axial direction A. Both outlet flange sections 13 are formed integrally with the hub 14 and the splined connection 15 contained therein, for example in the form of a sintered component or a forged component. In the axial direction A, the two outlet flange sections 13 extend within the two inlet flange sections 12.

[0026] The input flange sections 12 are rotatably supported on the output flange sections 13 or on the hub 14 by means of rolling bearings 22, which are preferably designed as cage-guided ball bearings. More precisely, with reference to Fig. 3 the left input flange section 12 is rotatably supported via the left rolling bearing 22 in a transition area between the left output flange section 13 and the hub 14, while the right input flange section 12 is rotatably supported via the right rolling bearing 22 in a transition area between the right output flange section 13 and the hub 14.

[0027] Although not shown, it is also possible to connect the output flange sections 13 to a separate hub 14, for example by welding or riveting. It is also possible that the hub 14 does not have a splined connection 15, but instead is, for example, shrink-fitted onto a shaft in a rotationally fixed manner.

[0028] Furthermore, the torsional vibration damper 2 integrated into the gear 1 has several rocker elements 4 – two in the illustrated embodiment – ​​distributed around the circumference U of the gear 1. The rocker elements 4 are arranged in a torque-transmitting connection between the input flange section 12 and the output flange section 13. Each rocker element 4 has at least one first rolling element 5 and at least one second rolling element 6.

[0029] Each of the rocker elements 4 has a first cam track 7 for rolling the first rolling element 5 and a second cam track 8 for rolling the second rolling element 6. The input flange section 12 has a first counter-track 9 complementary to the first cam track 7. The output flange section 13 has a second counter-track 10 complementary to the second cam track 8. The first rolling element 5 is guided to roll between the first cam track 7 and the first counter-track 9. The second rolling element 6 is guided to roll between the second cam track 8 and the second counter-track 10. The cam tracks 7, 8 and the counter-tracks 9, 10 are designed, for example, with an oval or kidney-shaped basic form, to allow a pendulum motion of the rocker elements 4.

[0030] Furthermore, the torsional vibration damper 2 integrated into the gear 1 has at least one energy storage element 11. The illustrated embodiment has two energy storage elements 11, each of which is arranged between two rocker elements 4 adjacent in the circumferential direction U, more precisely between their ends, and supports them oscillatively against each other. The energy storage elements 11 are preferably designed as compressible helical springs.

[0031] In the illustrated embodiment, the energy storage elements 11 are not located in the torque flow from the input flange section 12 to the output flange section 13, or from the gear ring 3 to the hub 14. However, it is also possible to arrange the energy storage elements 11 in the torque flow from the input flange section 12 to the output flange section 13, or from the gear ring 3 to the hub 14.

[0032] Furthermore, in the illustrated embodiment, exactly one first rolling element 5 and exactly one second rolling element 6 are provided per rocker element 4. However, it is also possible that more than one first rolling element 5 and / or more than one second rolling element 6 are provided per rocker element 4.

[0033] The rocker elements 4, distributed circumferentially U, are arranged axially A between the inlet flange sections 12. Furthermore, the rocker elements 4, distributed circumferentially U, are arranged axially A between the outlet flange sections 13, such that the outlet flange sections 13 are arranged axially A between the outer inlet flange sections 12 and the centrally arranged rocker elements 4, distributed circumferentially U. Thus, with reference to the Fig. 3. Sectional view shown, the sequence of components viewed from left to right: left inlet flange section 12, left outlet flange section 13, rocker element 4, right outlet flange section 13, right inlet flange section 12.

[0034] The output flange sections 13 are annular in shape. Each output flange section 13 has radially outwardly projecting support sections 16, which terminate shortly before the inner edge of the toothed ring 3 and in which the second mating tracks 10 are formed. The radially outwardly projecting support sections 16 have end faces 17 when viewed in the circumferential direction U. Furthermore, radially inwardly projecting stop sections 18 are formed within the toothed ring 3, with which the end faces 17 can come into contact with the input flange sections 12 during the relative rotation of the output flange sections 13 clockwise and / or counterclockwise in order to limit the relative rotation.

[0035] In Fig. Figure 4 shows a second embodiment of a gear 1 with an integrated torsional vibration damper 2, which has rocker elements 3 and separate energy storage elements 11. Only the differences from the first embodiment are discussed, where the same reference numerals denote the same features.

[0036] In contrast to the first embodiment, the one in Fig. Figure 4 shows a gear 1 additionally featuring a friction device 19, which is integrated into the torsional vibration damper 2. In the axial direction A, on both sides of the gear 1, between the input flange section 12 and the output flange section 13, preferably in an annular recess, a friction ring 20 and a disc spring 21 acting on this ring in the axial direction A are provided. The friction device 19 can generate hysteresis during the damping of torsional vibrations or during the relative rotation of the input flange section 12 to the output flange section 13.

[0037] Fig. 5 relates to a third embodiment of a gear 1 with an integrated torsional vibration damper 2, wherein only the assembly differing from the first or second embodiment is shown.

[0038] Specifically, the rocker elements 4 and the energy storage elements 11 arranged between them are formed as a single piece. The energy storage elements 11 are not designed as helical springs, but rather as wave springs or serpentine bending springs, the ends of which transition into the ends of the rocker elements 4 in the circumferential direction U. The entire assembly is preferably stamped or cut from sheet metal, for example using a laser beam.

[0039] The preceding embodiments relate to a gear 1 with an integrated torsional vibration damper 2, comprising a gear ring 3 rotatably arranged about an axis of rotation D, with at least one input flange section 12 for receiving a torque, at least one output flange section 13 for transmitting a torque to a shaft, and several rocker elements 4 distributed in the circumferential direction U of the gear 1 in a torque-transmitting connection between the input flange section 12 and the output flange section 13, wherein each rocker element 4 has at least one first rolling element 5 and at least one second rolling element 6, and wherein each rocker element 4 has a first cam track 7 for rolling the first rolling element 5 and a second cam track 8 for rolling the second rolling element 6.wherein the input flange section 12 has a first counter-track 9 complementary to the first cam track 7 and the output flange section 13 has a second counter-track 10 complementary to the second cam track 8, wherein the first rolling element 5 is guided to roll between the first cam track 7 and the first counter-track 9 and the second rolling element 6 is guided to roll between the second cam track 8 and the second counter-track 10, and wherein at least one energy storage element 11 is arranged between two rocker elements 4 adjacent in the circumferential direction U and supports them oscillatively against each other. Reference symbol list 1 gear 2 torsional vibration dampers 3 sprocket 4 rocker elements 5 first rolling element 6 second rolling element 7 first scenery track 8 second scenery track 9 first opposite lane 10 second opposite lane 11 Energy storage element 12 Inlet flange section 13 Outlet flange section 14 hub 15 Splined connection 16 Support section 17 Front surface 18 Stop section 19 Friction device 20 friction ring 21 Belleville spring 22 rolling bearings A axial direction D axis of rotation R radial direction U circumferential direction QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. 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

[0000] DE 10 2013 221 361 A1

[0005]

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