Pulley decoupler

Abstract

A pulley decoupler (1) having an input side (2) and an output side (3) and a common axis of rotation (4) and at least one spring element (5) acting between the input side (2) and the output side (3), the input side (2) and the output side (3) being rotatable relative to one another in a circumferential direction (6) counter to the spring action of the at least one spring element, wherein the output side (3) is rotatably supported relative to the input side (2) via a bearing (7) arranged at the input side (2), wherein the output side (3) extends from the bearing (7) on a first side (8) of the at least one spring element (5) in a radial direction (9) outwardly to a belt section (10), wherein a cover (14) extends from the belt section (10) and inwardly in a radial direction (9) on a second side (11) opposite the first side (8).

Description

Technical Field

[0001] The invention relates to a pulley decoupler having an input side and an output side and a common axis of rotation and at least one spring element acting between the input side and the output side, the input side and the output side being twistable relative to one another in the circumferential direction against the spring force of the at least one spring element. In particular, in addition to the at least one spring element, the pulley decoupler comprises at least one vibration damping device (torsional vibration damper—TSD). Background Art

[0002] The pulley decoupler is designed in particular for attaching a pulley to a drive machine, such as a crankshaft of a motor vehicle. This should at least reduce or prevent the transmission of torsional vibrations, such as torsional vibrations of the drive machine, to a belt driven by the pulley. However, the pulley decoupler can also form a dual mass flywheel.

[0003] Such pulley decouplers or drive wheels are known from DE 10 2017 111 664.8 and DE 10 2017 113 043.8 as well as DE 10 2013 206 444 A1, respectively, in which a gap / volume (a spring receiving space there) (which is at least partially filled with lubricant, for example) is sealed against the external environment via a sealing and positioning device on the one hand, and the drive wheel is positioned in the axial direction on the other hand. For this purpose, a spring element (disc spring) is arranged between the traction device attachment area (output side) and the shaft attachment area (input side), which spring element tensions the areas against each other in the axial direction. In this case, the spring element is held via a friction ring (without an elastic sealing lip), which likewise ensures a sealing effect.

[0004] The sealing requirements for the gap are very high. Therefore, due to the higher requirements, various pollution tests are carried out, such as water splashing test, mud salt water test, dust test, salt spray test, and wading test.

[0005] There is a continuing desire to simplify components for motor vehicles, such as pulley decouplers, and to reduce manufacturing costs. Summary of the invention

[0006] Based on this, the object of the present invention is to provide a belt pulley decoupler which is of the simplest possible construction and, in particular, comprises as few components as possible.

[0007] The object is achieved by means of a pulley decoupler. Other advantageous embodiments of the invention are described herein. The features listed individually herein can be combined with one another in a technically meaningful manner and can define other embodiments of the invention. In addition, the features of the invention are described and explained in detail in the description, wherein other preferred embodiments of the invention are shown.

[0008] A pulley decoupler is proposed, which has an input side and an output side and a common rotation axis and at least one first spring element acting between the input side and the output side, and the input side and the output side can be rotated relative to each other in the circumferential direction against the spring action of the at least one first spring element. The output side is rotatably supported relative to the input side via a (sliding) bearing arranged at the input side. The output side extends outwardly in the radial direction from the (sliding) bearing on the first side of the at least one first spring element to a belt section (a belt can be arranged at the belt section, and the belt can be driven via the belt section or via the pulley decoupler). A cover extends from the belt section and inwardly in the radial direction on a second side opposite to the first side in the axial direction extending along the rotation axis. A second spring element is arranged on the first side and between the input side and the output side, and the second spring element generates a spring force acting in the axial direction between the input side and the output side.

[0009] The input side (also referred to as the shaft attachment area, since the input side can be connected or is connected to a shaft, for example to a crankshaft, in a rotationally fixed manner) can be twisted relative to the output area (also referred to as the belt attachment area, since the output side can be connected or is connected to the belt in a rotationally fixed manner via a belt section) by at most an angle range extending in the circumferential direction (for example, by an angle of at most 30 degrees), in particular against the spring force of at least one spring element and in particular against the damping effect of at least one torsional vibration damper. The twisting is limited, for example, by a stop (for example, formed on the one hand by the input side and on the other hand by a cover or the output side). The stop on the output side is in particular formed at least by an angle element attached to the output side (for example, by riveting or welding, etc.).

[0010] The torque is transmitted via the output side to the belt connected to the belt section, in particular via at least one first spring element and stops on the input side and the output side.

[0011] Torsional vibrations can at least be reduced by a relative rotation of the input side relative to the output side, which takes place counter to a spring force and, if appropriate, counter to a damping effect.

[0012] In particular, the second spring element is designed to be annular and to extend around the circumference.

[0013] The second spring element is, in particular, a disc spring.

[0014] The cover is supported on the input side, in particular, via a first friction ring. The first friction ring is in particular annular and circumferential in shape.

[0015] The cover is connected to the output side in a rotationally fixed manner, in particular via an interference fit.

[0016] The first friction ring is attached in particular to the cover, wherein the first friction ring together with the cover and the output side can be rotated relative to the input side in the circumferential direction.

[0017] Alternatively, the first friction ring is attached to the input side, wherein the first friction ring together with the input side can be rotated relative to the cover and the output side in the circumferential direction.

[0018] The cover can be extended further in the radial direction toward the rotation axis by the displacement of the second spring element away from the cover and toward the first side. Thereby, in particular, only a (first) friction ring is required between the cover and the input side.

[0019] The (sliding) bearing is particularly arranged on a (largest) first diameter, and the first friction ring together with the input side forms a sealing surface on a (largest) second diameter, wherein the (largest) second diameter is smaller than or equal to the (largest) first diameter or is at most 15 percent, in particular at most 5 percent, preferably at most 2 percent larger than the (largest) first diameter. The sealing surface is preferably arranged on the smallest possible diameter in order to achieve the best possible sealing effect.

[0020] The first diameter extends in particular in radial direction via the rotation axis to the inner circumferential surface of the output side that is in contact with the (sliding) bearing. The second diameter extends in particular in radial direction via the rotation axis to the maximum diameter of the sealing surface between the first friction ring and the input side or between the first friction ring and the output side or the cover.

[0021] In particular, a second friction ring is arranged on the first side and between the input side and the output side. The second friction ring enables low-friction relative rotation between the input side and the output side on the first side. The second friction ring is particularly annular and circumferentially configured. The second friction ring extends in particular at least in the radial direction. The second friction ring is particularly arranged in the axial direction between the output side and the input side.

[0022] The second friction ring is arranged in particular in the axial direction between the output side and the second spring element. The second spring element in particular contacts the second friction ring on the one hand and the input side on the other hand.

[0023] The second spring element is arranged in particular in a space which is separated from the environment (of the pulley decoupler) by the second friction ring and the input side. Corrosion can thus be reduced in particular, since the second spring element is arranged in a protected manner against environmental influences.

[0024] In particular, between the input side and the output side, only the first friction ring is arranged on the second side and only the second friction ring is arranged on the first side.

[0025] In particular, the cover together with the belt section forms a sealing surface which seals the volume against the environment.

[0026] At least one first spring element is in particular arranged in a volume formed at least by the output side (on the first side) and the cover (on the second side), wherein the volume is at least partially filled with a fluid (lubricant, such as grease) and is sealed on the second side from the environment of the pulley decoupler by the cover and the first friction ring.

[0027] The cover is supported via a first friction ring on the input side or on a torsional vibration damper (TSD).

[0028] In particular, a buckling of the at least one first spring element can be prevented by the cover. In particular, the rigidly designed cover itself absorbs the forces acting in the axial direction.

[0029] In particular, a number of advantages result from the embodiment of the pulley decoupler. On the one hand, the filling of the volume with fluid, in which at least one spring element is arranged, can be improved by the cover extending further inward in the radial direction. In addition, the tightness of the volume during operation of the pulley decoupler is improved, since there are fewer sealing surfaces (only the first friction ring is still required for sealing the volume). In addition, the sealing surface is arranged on a small second diameter, so that the sealing surface is relatively small, so that the tightness can be further improved. In addition, the complexity of the pulley decoupler is now less than that of the known designs, since only the first friction ring on the second side is required.

[0030] It is to be noted in advance that the numerals used here ("first", "second", ...) are preferably (only) used to distinguish between a plurality of similar objects, quantities or processes, i.e., in particular, a correlation and / or sequence of the objects, quantities or processes with one another is not mandatory. If a correlation and / or sequence is required, this is explicitly stated here or is obvious to a person skilled in the art when studying the specifically described embodiments. As long as a component can occur multiple times ("at least one"), the description of one of the components can also apply to all or some of the multiple components, but this is not mandatory. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] The present invention and the technical field are explained in detail below with reference to the drawings. It should be noted that the present invention should not be limited by the listed embodiments. In particular, if not explicitly stated otherwise, some aspects of the facts described in the figures can also be extracted and combined with other components and knowledge of the present description. It should be noted in particular that the drawings and in particular the dimensional relationships shown are only schematic. The drawings show:

[0032] Figure 1 A cross section of a first embodiment variant of a known pulley decoupler is shown in a side view;

[0033] Figure 2A section through a second variant embodiment of a known belt pulley decoupler is shown in a side view; and

[0034] Figure 3 The pulley decoupler is shown in section in a side view. DETAILED DESCRIPTION

[0035] Figure 1 The side view shows a cross section of a first embodiment variant of the known pulley decoupler 1. The pulley decoupler 1 comprises an input side 2 and an output side 3 and a common axis of rotation 4 and at least one first spring element 5 acting between the input side 2 and the output side 3, by means of which the input side 2 and the output side 3 can be rotated relative to each other in the circumferential direction 6. The output side 3 is rotatably supported relative to the input side 2 via a (sliding) bearing 7 arranged at the input side 2. The output side 3 extends from the (sliding) bearing 7 on a first side 8 of the at least one first spring element 5 outwardly in a radial direction 9 to a belt section 10, on which a belt can be arranged, which can be driven via the belt section 10 or via the pulley decoupler 1. A cover 14 extends from the belt section 10 and inwardly in a radial direction 9 on a second side 11 opposite the first side 8. The cover 14 is connected via a first friction ring 15 to a disk spring 23, by means of which the output side 3 and the input side 2 are arranged in a tensioned manner relative to each other in the axial direction 13. The disc spring 23 is arranged in a clamped manner by two elements of the input side 2, on the one hand by a stop of the input side 2 for forming part of the first spring element 5, and on the other hand by a torsional vibration damper 24. The cover 14 and the output side 3 together form a volume 21, in which the spring element 5 is arranged. The volume 21 is at least partially filled with a fluid 22. On the first side 8, the volume 21 is sealed by a second friction ring 18, which bridges the gap between the input side 2 and the output side 3.

[0036] The (sliding) bearing 7 is arranged on the (largest) first diameter 16 and the first friction ring 15 (on the second side 11 ) together with the cover 14 or the disc spring 23 forms a sealing surface on the (largest) second diameter 17 , wherein the (largest) second diameter 17 is significantly larger than the (largest) first diameter 16 .

[0037] Figure 2 A second embodiment variant of the known belt pulley decoupler 1 is shown in cross section in a side view. Figure 1 implementation plan.

[0038] Unlike the first embodiment, in the second embodiment, two friction rings 15, 25 (a first friction ring 15 and a third friction ring 25) are arranged on the second side 11 of the first spring element 5. The disc spring 23 is arranged between the friction rings 15, 25. The first friction ring 15 is arranged on the cover 14. The third friction ring 25 is arranged between the disc spring 23 and the torsional vibration damper 24.

[0039] The two friction rings 15, 25 (on the second side 11) form sealing surfaces together with the cover 14 or the disk spring 23 on the one hand and the torsional vibration damper 24 on the other hand at the respective second diameter 17. The largest second diameter 17 is significantly larger than the largest first diameter 16.

[0040] Figure 3 The pulley decoupler 1 is shown in cross section in a side view. The pulley decoupler 1 comprises an input side 2 and an output side 3 and a common axis of rotation 4 and at least one first spring element 5 acting between the input side 2 and the output side 3, against the spring action of which the input side 2 and the output side 3 can be rotated relative to each other in a circumferential direction 6. The output side 3 is supported rotatably relative to the input side 2 via a (sliding) bearing 7 arranged at the input side 2. The output side 3 extends outwardly from the (sliding) bearing 7 on a first side 8 of the at least one spring element 5 in a radial direction 9 to a belt section 10, on which a belt can be arranged, which can be driven via the belt section 10 or via the pulley decoupler 1. A cover 14 extends from the belt section 10 and inwardly along the radial direction 9 on a second side 11 opposite the first side 8. A second spring element 12 is arranged on the first side 8 and between the input side 2 and the output side 3, which generates a spring force acting in an axial direction 13 between the input side 2 and the output side 3.

[0041] The second spring element 12 is designed to be annular and to circumferentially extend in the circumferential direction 6. The second spring element 12 is a disk spring.

[0042] The cover 14 is supported on the input side 2 via a first friction ring 15 . The first friction ring 15 is annular and circumferential in the circumferential direction 6 .

[0043] The first friction ring 15 is attached to the cover 14 , wherein the first friction ring 15 together with the cover 14 and the output side 3 can be rotated relative to the input side 2 in the circumferential direction 6 .

[0044] By eliminating the second spring element 12 on the second side 11 of the first spring element 5 , the cover 14 can be extended further in the radial direction 9 toward the rotation axis 4 . As a result, only the first friction ring 15 is required between the cover 14 and the input side 2 on the second side 11 .

[0045] The (sliding) bearing 7 is arranged on a first, largest diameter 16 and the first friction ring 15 together with the input side 2 or the torsional vibration damper 24 forms a sealing surface on a second, largest diameter 17 , wherein the second, largest diameter 17 is approximately 110% of the first diameter 16 .

[0046] A second friction ring 18 is arranged on the first side 8 and between the input side 2 and the output side 3. The second friction ring 18 enables a low-friction relative rotation between the input side 2 and the output side 3 on the first side 8. The second friction ring 18 is annular and circumferential in the circumferential direction 6. The second friction ring 18 extends at least in the radial direction 9. The second friction ring 18 is arranged between the output side 3 and the input side 2 in the axial direction 13.

[0047] The second friction ring 18 is arranged in the axial direction 13 between the output side 3 and the second spring element 12. The second spring element 12 contacts the second friction ring 18 on the one hand and contacts the input side 2 on the other hand.

[0048] The second spring element 12 is arranged in a space 19 which is separated from an environment 20 of the pulley isolator 1 by the second friction ring 18 and the input side 2 .

[0049] Between the input side 2 and the output side 3 , only the first friction ring 15 is arranged on the second side 11 and only the second friction ring 18 is arranged on the first side 8 .

[0050] The cover 14 forms, together with the belt section 10 , a sealing surface which seals the volume 21 against the environment 20 .

[0051] The first spring element 5 is arranged in a volume 21 formed by the output side 3 (on the first side 8) and the cover 14 (on the second side 11), wherein the volume 21 is at least partially filled with a fluid 22 (lubricant, such as grease) and is sealed on the second side 11 from the environment 20 of the pulley decoupler 1 by the cover 14 and the first friction ring 15.

[0052] The cover 14 is supported via a first friction ring 15 on the input side 2 or on a torsional vibration damper (TSD) 24 .

[0053] Reference numerals list

[0054] 1 Pulley decoupler

[0055] 2 Input side

[0056] 3 Output side

[0057] 4 Axis of rotation

[0058] 5 First spring element

[0059] 6 Circumferential direction

[0060] 7 Bearings

[0061] 8 First side

[0062] 9 Radial direction

[0063] 10 belt sections

[0064] 11 Second side

[0065] 12 Second spring element

[0066] 13 Axial direction

[0067] 14 Cover

[0068] 15 First friction ring

[0069] 16 First diameter

[0070] 17 Second diameter

[0071] 18 Second friction ring

[0072] 19 Space

[0073] 20 Environment

[0074] 21 Volume

[0075] 22 Fluid

[0076] 23 Disc spring

[0077] 24 Torsional vibration damper

[0078] 25 Third friction ring

Claims

1. A pulley decoupler (1), comprising an input side (2) and an output side (3) and a common axis of rotation (4) and at least one first spring element (5) acting between the input side (2) and the output side (3), the input side (2) and the output side (3) being able to rotate relative to each other in a circumferential direction (6) against the spring action of the at least one first spring element, wherein the output side (3) is rotatably supported relative to the input side (2) via a bearing (7) arranged at the input side (2), wherein the output side (3) extends from the bearing (7) on a first side (8) of the at least one first spring element (5) outwardly in a radial direction (9) to a belt section (10), wherein starting from the belt section (10) and along the belt section (10) A cover (14) extends inwardly from the radial direction (9) on a second side (11) opposite the first side (8) in an axial direction (13) extending along the rotation axis (4), wherein a second spring element (12) is arranged on the first side (8) and between the input side (2) and the output side (3), the second spring element generating a spring force acting in the axial direction (13) between the input side (2) and the output side (3), and wherein a second friction ring (18) is arranged on the first side (8) and between the input side (2) and the output side (3), the second spring element (12) being arranged in a space (19) separated from an environment (20) of the pulley decoupler (1) by the second friction ring (18) and the input side (2).

2. The pulley decoupler (1) according to claim 1, wherein the second spring element (12) is a disc spring.

3. The pulley decoupler (1) according to claim 1, wherein the cover (14) is supported on the input side (2) via a first friction ring (15).

4. The pulley decoupler (1) according to claim 3, wherein the first friction ring (15) is attached to the cover (14), wherein the first friction ring (15) can be twisted together with the cover (14) and the output side (3) relative to the input side (2) along the circumferential direction (6).

5. A pulley decoupler (1) according to any one of claims 3 and 4, wherein the bearing (7) is arranged on a first diameter (16) and the first friction ring (15) together with the input side (2) forms a sealing surface on a second diameter (17), wherein the second diameter (17) is smaller than or equal to the first diameter (16) or is at most fifteen percent larger than the first diameter.

6. The pulley decoupler (1) according to claim 1, wherein the second friction ring (18) is arranged between the output side (3) and the second spring element (12) along the axial direction (13).

7. The pulley decoupler (1) according to claim 1, wherein only a first friction ring (15) is arranged on the second side (11) between the input side (2) and the output side (3).

8. A pulley decoupler (1) according to any one of claims 1 to 4, wherein the at least one first spring element (5) is arranged in a volume (21) formed at least by the output side (3) and the cover (14), wherein the volume (21) is at least partially filled with a fluid (22) and is sealed on the second side (11) relative to the environment (20) of the pulley decoupler (1) by the cover (14).

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