Damping device

Abstract

The present invention relates to a vibration damper. The sound generated when the vibration damper operates in the positive and negative torsion regions is suppressed. The vibration damper (1) comprises an input side plate (30), a hub flange (40), and an elastic link (50). The elastic link (50) has four coil springs (51) that are pre-compressed and arranged in a neutral state in which no relative rotation between the input side plate (30) and the hub flange (40) occurs. When the input side plate (30) is twisted relative to the hub flange (40) from the neutral state to one side (R1), two coil springs (51) are further compressed from the compressed state via a free state. In addition, the other two coil springs (51) are further compressed from the compressed state via the free state when the input side plate (30) is twisted relative to the hub flange (40) from the neutral state to the other side (R2).

Description

Technical Field

[0001] This invention relates to vibration damping devices. Background Technology

[0002] For example, in hybrid vehicles equipped with an engine and an electric motor, a damping device with torque limiting function, as shown in Patent Document 1, is used to prevent excessive torque from being transmitted from the output side to the engine side when the engine starts.

[0003] The vibration damping device in Patent Document 1 has a damping section with a pair of plates and a plurality of torsion springs, and a torque limiter is provided on the outer periphery of the damping section. The torque limiter is connected to the damping section by rivets. Furthermore, the plates of the torque limiter are fixed to the flywheel by bolts.

[0004] Here, the torque transmitted between the damping unit and the flywheel is limited by a torque limiter to prevent excessive torque from being transmitted between the two.

[0005] Patent Document 1: Japanese Patent Application Publication No. 2011-226572

[0006] In hybrid vehicles, the drive motor is sometimes used to preheat the engine. In this case, a vibration damping device located between the motor and the engine operates in two torsional working areas, positive and negative, depending on the engine's rotational variation. Thus, the relative rotational directions of the input and output rotating parts in the damping device alternate, resulting in a power exchange between the components constituting these rotating parts, which produces a knocking sound. Furthermore, when a gear train is provided to change the speed of the motor, noise is generated in the gear pairs constituting the gear train for the same reason. Summary of the Invention

[0007] The objective of this invention is to suppress the sound generated when the vibration damping device operates in the torsional regions on both the positive and negative sides.

[0008] (1) The vibration damping device according to the present invention includes: a first rotating body and a second rotating body that rotate about a rotation axis respectively; and an elastic connecting part. The second rotating body is configured to rotate relative to the first rotating body. The elastic connecting part has a first elastic member and a second elastic member that are pre-compressed in a neutral state where there is no torsion caused by the relative rotation between the first rotating body and the second rotating body, and elastically connects the first rotating body and the second rotating body in the rotation direction.

[0009] When the first rotating body twists relative to the second rotating body from a neutral state to a first side in the direction of rotation, the first elastic member is further compressed from a compressed state to a free state. Similarly, when the first rotating body twists relative to the second rotating body from a neutral state to a second side in the direction of rotation, the second elastic member is further compressed from a compressed state to a free state.

[0010] Furthermore, the "free state" here refers to the state in which each elastic member is at its free length without compression or elongation.

[0011] In this vibration damping device, in the neutral state, due to the first elastic member and the second elastic part being configured in a compressed state, the first rotating body and the second rotating body are subjected to torsional torque in either the first side or the second side of the rotation direction. Therefore, even if a torque variation less than the torsional torque generated by the compressed elastic member is input, the torsional angle (relative rotation) between the first and second rotating bodies can be suppressed to a small extent. Thus, collision noise between the components caused by torque variation can be suppressed within a specified torsional angle range.

[0012] (2) Preferably, the first elastic member is further compressed from the compressed state when the first rotating body is twisted from the neutral state to the second side of the rotation direction relative to the second rotating body. In addition, the second elastic member is further compressed from the compressed state when the first rotating body is twisted from the neutral state to the first side of the rotation direction relative to the second rotating body.

[0013] (3) Preferably, the first elastic member and the second elastic member have the same rigidity.

[0014] (4) Preferably, the first rotating body has a first support portion and a second support portion. The second rotating body also has a first receiving portion and a second receiving portion. The first receiving portion is offset to a first side in the rotational direction such that it partially overlaps with the first support portion when viewed axially. The second receiving portion is offset to a second side in the rotational direction such that it partially overlaps with the second support portion when viewed axially. Furthermore, in this case, a first elastic member is disposed on the first support portion and the first receiving portion. Additionally, a second elastic member is disposed on the second support portion and the second receiving portion, and operates in parallel with the first elastic member.

[0015] (5) Preferably, the first support portion and the second support portion each have a first support surface at their ends on a first side of the rotation direction and a second support surface at their ends on a second side of the rotation direction. Furthermore, the first receiving portion and the second receiving portion each have a first receiving surface at their ends on the first side of the rotation direction and a second receiving surface at their ends on the second side of the rotation direction. Moreover, in this case, the first elastic member is compressed between the first support surface and the second receiving surface, and the second elastic member is compressed between the first receiving surface and the second support surface.

[0016] (6) Preferably, the elastic connecting portion further comprises a third elastic member and a fourth elastic member. The third elastic member and the fourth elastic member are pre-compressed and configured in a neutral state. Furthermore, when the first rotating body twists relative to the second rotating body from a neutral state to a first side in the rotational direction, the third elastic member is further compressed from a compressed state to a free state. When the first rotating body twists relative to the second rotating body from a neutral state to a second side in the rotational direction, the fourth elastic member is further compressed from a compressed state to a free state.

[0017] (7) Preferably, the first rotating body further includes a third support portion and a fourth support portion. The third support portion is disposed opposite to the first support portion across the rotation axis. The fourth support portion is disposed opposite to the second support portion across the rotation axis. Furthermore, preferably, the second rotating body also includes a third receiving portion and a fourth receiving portion. The third receiving portion is disposed opposite to the first receiving portion across the rotation axis. The fourth receiving portion is disposed opposite to the second receiving portion across the rotation axis. Moreover, the third receiving portion is offset towards a first side in the rotational direction such that it partially overlaps with the third support portion when viewed axially. The fourth receiving portion is offset towards a second side in the rotational direction such that it partially overlaps with the fourth support portion when viewed axially.

[0018] Furthermore, in this configuration, the third elastic member is disposed in the third support portion and the third receiving portion. Additionally, the fourth elastic member is disposed in the fourth support portion and the fourth receiving portion, and operates in parallel with the third elastic member.

[0019] In the present invention as described above, it is possible to suppress the sound generated when the vibration damping device operates in the torsional region on both the positive and negative sides. Attached Figure Description

[0020] Figure 1 This is a cross-sectional view of a vibration damping device according to an embodiment of the present invention.

[0021] Figure 2 yes Figure 1 Front view of the vibration damping device.

[0022] Figure 3 This is a schematic diagram showing the relationship between the input side plate and the hub flange.

[0023] Figure 4 This is a schematic diagram showing the relative rotation angle between the input side plate and the hub flange as θ1.

[0024] Figure 5 This is a schematic diagram showing the relative rotation angle between the input side plate and the hub flange as θ2.

[0025] Figures 6A to 6C This is a diagram showing the torsional characteristics of the vibration damping unit. Detailed Implementation

[0026] [Overall Structure]

[0027] Figure 1 This is a cross-sectional view of a vibration damping device 1 with a torque limiter according to an embodiment of the present invention (hereinafter referred to simply as "vibration damping device"). Additionally, Figure 2 This is a front view of the vibration damping device 1, showing a portion of it with its constituent components removed. Figure 1 In the middle, an engine (not shown) is arranged on the left side of the vibration damping device 1, and a drive unit (not shown) including an electric motor, a transmission device, etc. is arranged on the right side.

[0028] Furthermore, in the following description, the axial direction is the direction in which the rotation axis O of the vibration damping device 1 extends. Additionally, the circumferential direction is the circumferential direction of the circle centered on the rotation axis O, and the radial direction is the radial direction of the circle centered on the rotation axis O. Furthermore, the circumferential direction does not need to be perfectly aligned with the circumferential direction of the circle centered on the rotation axis O. Additionally, the radial direction does not need to be perfectly aligned with the diametrical direction of the circle centered on the rotation axis O.

[0029] The vibration damping device 1 is disposed between the flywheel (not shown) and the input shaft of the drive unit, and is used to limit the torque transmitted between the engine and the drive unit, and to attenuate rotational fluctuations. The vibration damping device 1 has a torque limiting unit 10 and a vibration damping unit 20.

[0030] [Torque Limiting Unit 10]

[0031] The torque limiting unit 10 is disposed on the outer periphery of the vibration damping unit 20. The torque limiting unit 10 limits the torque transmitted between the flywheel and the vibration damping unit 20. The torque limiting unit 10 has a cover plate 11, a support plate 12, a friction disc 13, a pressure plate 14, and a conical spring 15.

[0032] The cover plate 11 and the support plate 12 are arranged axially at a predetermined interval, and the outer periphery of the two plates 11 and 12 is fixed to the flywheel by a plurality of bolts 16.

[0033] The friction disc 13, pressure plate 14, and conical spring 15 are axially positioned between the cover plate 11 and the support plate 12.

[0034] The friction disc 13 has a core plate and a pair of friction members fixed to both sides of the core plate. Furthermore, the inner periphery of the friction disc 13 is fixed to the vibration damping unit 20 by a plurality of rivets 17. A pressure plate 14 and a conical spring 15 are disposed between the friction disc 13 and the support plate 12.

[0035] The pressure plate 14 is formed in a ring shape and is disposed on the support plate 12 side of the friction disc 13. In addition, a plurality of claws 14a are formed on the outer periphery of the pressure plate 14, which engage with a plurality of engagement holes 12a formed on the support plate 12.

[0036] A conical spring 15 is disposed between the pressure plate 14 and the support plate 12. The conical spring 15 presses the friction disc 13 against the cover plate 11 via the pressure plate 14.

[0037] [Vibration Damping Unit 20]

[0038] The vibration damping unit 20 has an input side plate 30 (an example of a first rotating body), a hub flange 40 (an example of a second rotating body), an elastic connection 50, and a hysteresis generation mechanism 60.

[0039] <Input Side Panel 30>

[0040] The input side plate 30 has a first plate 31 and a second plate 32. The first plate 31 and the second plate 32 are formed as circular plates with a hole in the center, and are spaced apart from each other axially. The first plate 31 has four stop portions 31a and four fixing portions 31b on its outer periphery. Additionally, the first plate 31 and the second plate 32 each have a pair of first support portions 301 and a pair of second support portions 302. The first support portions 301 and the second support portions 302 are formed at the same positions in both the first plate 31 and the second plate 32. Furthermore, an assembly hole 32a is formed in the first plate 31 at a position corresponding to the rivet 17.

[0041] The stop portion 31a is formed by bending the outer periphery of the first plate 31 toward the second plate 32 and extends axially. The fixing portion 31b is formed by bending the front end of the stop portion 31a radially outward. The fixing portion 31b is fixed to the outer periphery of the second plate 32 by a plurality of rivets 33. Therefore, the first plate 31 and the second plate 32 cannot rotate relative to each other and cannot move axially relative to each other.

[0042] A pair of first support portions 301 are arranged opposite each other across a rotation axis O. Additionally, a pair of second support portions 302 are arranged opposite each other across a 90° gap from the first support portions and also across the rotation axis O. Each support portion 301, 302 has an axially penetrating hole and raised edges cut out from the inner and outer peripheries of the hole.

[0043] like Figure 3As schematically shown, each support portion 301, 302 has an R1 support surface 301a, 302a at its end on the first rotation direction side (hereinafter referred to as "R1 side"), and an R2 support surface 301b, 302b at its end on the second rotation direction side (hereinafter referred to as "R2 side"). The width of the hole in each support portion 301, 302 (the distance between the R1 support surface and the R2 support surface) is L. Furthermore, the end face of the helical spring 51, described later, can abut against each support surface 301a, 301b, 302a, 302b.

[0044] In addition, Figure 3 In the diagram, the first support portion 301 and the second support portion 302 are shown by solid lines, and the first receiving portion 401 and the second receiving portion 402 of the hub flange 40 (described later) are shown by dashed lines. Additionally, Figure 3 This is a schematic diagram, and... Figure 2 The actual shape shown is different.

[0045] <Hub flange 40>

[0046] like Figure 1 as well as Figure 2 As shown, the hub flange 40 has a hub 41 and a flange 42. The hub flange 40 is rotatable relative to the input side plate 30 within a specified angular range. The hub 41 is formed in a cylindrical shape and has a spline hole 41a formed in its center. In addition, the hub 41 has a hole that passes through the center of the first plate 31 and the second plate 32. The flange 42 is formed as a circular plate with a hole in its center and is disposed radially outward of the hub 41. The flange 42 is axially disposed between the first plate 31 and the second plate 32.

[0047] like Figure 2 As shown, a plurality of external teeth 41b are formed on the outer peripheral surface of the hub 41, and a plurality of internal teeth 42a are formed on the inner peripheral surface of the flange 42, which mesh with the external teeth 41b of the hub 41. Therefore, the hub 41 and the flange 42 rotate integrally. Furthermore, in this embodiment, the hub 41 and the flange 42 are constructed independently, but they can also be constructed from a single component.

[0048] The flange 42 has four stop protrusions 42b, a pair of first storage portions 401 and second storage portions 402, and four cutouts 403.

[0049] Four stop protrusions 42b are formed by protruding radially outward from the outer periphery of the flange 42. The position where each stop protrusion 42b is formed is radially outward from the center of the circumferential direction of each receiving portion 401, 402. Moreover, when the input side plate 30 and the hub flange 40 rotate relative to each other, the stop protrusions 42b abut against the stop portion 31a of the first plate 31, thereby preventing the relative rotation of the input side plate 30 and the hub flange 40.

[0050] like Figure 3 As shown, a pair of first storage portions 401 are positioned corresponding to a pair of first support portions 301. Additionally, a pair of second storage portions 402 are positioned corresponding to a pair of second support portions 302. More specifically, in a neutral state (torsion angle 0°) where the relative rotation angle between the input side plate 30 and the hub flange 40 is 0° and there is no twisting between them, the pair of first storage portions 401 are offset by an angle θ1 towards the R1 side, partially overlapping the first support portions 301 when viewed axially. Furthermore, the second storage portions 402 are offset by an angle θ1 towards the R2 side, partially overlapping the second support portions 302 when viewed axially.

[0051] Each storage section 401 and 402 is an almost rectangular hole with an arc-shaped outer perimeter. For example... Figure 3 As shown, each storage portion 401, 402 has an R1 storage surface 401a, 402a at its R1 side end and an R2 storage surface 401b, 402b at its R2 side end. The width of the hole in each storage portion 401, 402 (the distance between the R1 storage surfaces 401a, 402a and the R2 storage surfaces 401b, 402b) is set to L, the same as the width of the hole in each support portion 301, 302. Furthermore, the end face of the coil spring 51 (described later) can abut against each storage surface 401a, 401b, 402a, 402b.

[0052] Four cutouts 403 are formed radially inward from the outer periphery of the flange 42 to a predetermined depth between adjacent circumferentially adjacent receiving portions 401 and 402. The positions of each cutout 403 correspond to the positions of the rivets 17 that connect the friction disc 13 of the torque limiting unit 10 and the first plate 31. Therefore, the torque limiting unit 10 and the vibration damping unit 20, which are assembled in different processes, can be fixed by using the assembly hole 32a of the second plate 32 and the cutouts 403 of the flange 42 and by using the rivets 17.

[0053] <Elastic Connector 50>

[0054] The elastic connection 50 has four helical springs 51 (an example of a first elastic member and a second elastic member) and four resin members 52. Each helical spring 51 has an outer spring and an inner spring. The four helical springs 51 are housed in the respective housing portions 401, 402 of the flange 42 and are supported radially and axially by the respective support portions 301, 302 of the input side plate 30. These helical springs 51 operate in parallel.

[0055] Furthermore, the free length Sf of all four helical springs 51 is the same. The free length Sf of the helical spring 51 is the same as the width L of each support portion 301, 302 and each storage portion 401, 402. In addition, the four helical springs 51 have the same rigidity, and the four resin components 52 have the same rigidity.

[0056] <Storage state of coil spring 51>

[0057] Here, the arrangement of each support portion 301, 302 and each storage portion 401, 402 in the neutral state, as well as the storage state of each coil spring 51, will be described in detail below. Furthermore, in the following description, the first support portion 301 and the first storage portion 401 will sometimes be referred to as "first window group w1", and the second support portion 302 and the second storage portion 402 will sometimes be referred to as "second window group w2".

[0058] As mentioned above, in a neutral state, such as Figure 3 As shown, a pair of first storage portions 401 are offset by an angle θ1 relative to the corresponding first support portion 301 towards the R1 side. On the other hand, a pair of second storage portions 402 are offset by an angle θ1 relative to the second support portion 302 towards the R2 side. Furthermore, a coil spring 51 is fitted in a compressed state at the opening (a hole extending through the axis) of the axially overlapping portion of each storage portion 401, 402 corresponding to each support portion 301, 302.

[0059] Specifically, such as Figure 3 As shown, in the neutral state, in a pair of first window groups w1, the R1 side end face of the coil spring 51 abuts against the R1 support surface 301a, and the R2 side end face abuts against the R2 receiving surface 401b. On the other hand, in a pair of second window groups w2, the R1 side end face of the coil spring 51 abuts against the R1 receiving surface 402a, and the R2 side end face abuts against the R2 support surface 302b.

[0060] <Hysteresis Generating Mechanism 60>

[0061] like Figure 1 As shown, the hysteresis generating mechanism 60 includes a first bushing 61, a second bushing 62, and a conical spring 63. The first bushing 61 is axially disposed between a first plate 31 and a flange 42. A friction member is fixed to the friction surface between the first bushing 61 and the first plate 31. The second bushing 62 is axially disposed between a second plate 32 and a flange 42. A friction member is fixed to the friction surface between the second bushing 62 and the flange 42. Furthermore, a plurality of axially protruding engaging protrusions 62a are formed on the second plate 32 side surface of the second bushing 62, which engage with engaging holes 32b in the second plate 32. The conical spring 63 is axially compressed and disposed between the second bushing 62 and the second plate 32.

[0062] Based on the above structure, the first bushing 61 is pressed by the first plate 31, and the second bushing 62 is pressed by the flange 42. Therefore, when relative rotation occurs between the input side plate 30 and the hub flange 40, a hysteresis torque is generated between them.

[0063] [action]

[0064] In addition, in the following action instructions and Figures 6A to 6C In the torsional characteristics, the hysteresis torque is omitted.

[0065] <First window group w1>

[0066] In a neutral state where the input side plate 30 and the hub flange 40 do not rotate relative to each other, such as Figure 3 As shown, the coil spring 51 of the first window group w1 is compressed between the R1 support surface 301a and the R2 receiving surface 401b. The gap G0 between the R1 support surface 301a and the R2 receiving surface 401b is narrower than the width L (equal to the free length Sf of the coil spring) of each support portion 301, 302 and each receiving portion 401, 402. Therefore, as Figure 6B As shown, in the first window group w1, a torsional torque -t is generated due to the compression of the helical spring 51.

[0067] Figure 4 This illustrates the state where there is a torque variation at the input of the damping unit 20 and the hub flange 40 is twisted by an angle θ1 relative to the input side plate 30 from a neutral state towards the R2 side. Here, in the first window group w1, the gap G1 between the R1 support surface 301a abutted by the end face of the coil spring 51 on the R1 side and the R2 receiving surface 401b abutted by the end face of the coil spring 51 on the R2 side is greater than the gap G0. This gap G1 is the same as the free length Sf of the coil spring. That is, when the twist angle between the input side plate 30 and the hub flange 40 is +θ1, in the first window group w1, the coil spring 51 becomes the free length Sf, as shown. Figure 6B As shown, the torsional torque becomes "0".

[0068] Additionally, if the hub flange 40 is twisted relative to the input side plate 30 by more than an angle θ1, then as Figure 5 As shown ( Figure 5 The diagram shows the case where the torsion angle is θ2 (>θ1). The end face of the coil spring 51 on the R1 side of the first window group w1 abuts against the R1 receiving surface 401a, and the end face on the R2 side abuts against the R2 supporting surface 301b. Here, the gap G2 between the R1 receiving surface 401a and the R2 supporting surface 301b is narrower than the free length Sf of the coil spring 51. That is, if the torsion angle between the input side plate 30 and the hub flange 40 exceeds θ1, the coil spring 51 is compressed from its free length Sf, as shown... Figure 6BAs shown, the torsional torque gradually increases.

[0069] On the other hand, when the hub flange 40 twists relative to the input side plate 30 from a neutral state toward the R1 side, the coil spring 51 is always compressed between the R1 support surface 301a and the R2 receiving surface 401b. That is, in the first window group w1, as... Figure 6B As shown, in the torsional region on the negative side, as the torsional angle increases, the torsional torque also increases towards the negative side.

[0070] <Second window group w2>

[0071] In the neutral state, the helical spring 51 of the second window group w2 is compressed between the R1 receiving surface 402a and the R2 support surface 302b. The interval between the R1 receiving surface 402a and the R2 support surface 302b is G0, which is narrower than the width L (equal to the free length Sf of the helical spring) of each support portion 301, 302 and each receiving portion 401, 402. Therefore, as Figure 6C As shown, in the second window group w2, a torsional torque +t is generated due to the compression of the helical spring 51.

[0072] When the hub flange 40 twists relative to the input side plate 30 from a neutral state toward the R2 side, the coil spring 51 is always compressed between the R1 receiving surface 402a and the R2 supporting surface 302b. That is, in the second window group w2, as Figure 6C As shown, in the torsion region on the positive side, the torsional torque increases as the torsion angle increases.

[0073] On the other hand, when the hub flange 40 is twisted by an angle θ1 relative to the input side plate 30 from the neutral state towards the R1 side, the distance between the R1 receiving surface 402a abutted by the end face of the coil spring 51 on the R1 side and the R2 support surface 302b abutted by the end face of the coil spring 51 on the R2 side is greater than the distance G0. This distance is the same as the free length Sf of the coil spring 51. That is, when the twist angle between the input side plate 30 and the hub flange 40 is -θ1, in the second window group w2, as... Figure 6C As shown, the torsional torque becomes "0".

[0074] Furthermore, if the hub flange 40 twists relative to the input side plate 30 by more than an angle θ1 toward the R1 side, the end face of the coil spring 51 of the second window assembly w2 on the R1 side abuts against the R1 support surface 302a, and the end face on the R2 side abuts against the R2 receiving surface 402b. Moreover, if the twist angle exceeds -θ1, the coil spring 51 is compressed from its free length Sf, such as... Figure 6C As shown, the torsional torque gradually increases towards the negative side.

[0075] <Synthetic Torsional Properties>

[0076] As a whole vibration damping unit, the composite Figure 6B The characteristics shown and Figure 6C The characteristics shown become Figure 6A The torsional characteristics are shown. That is, in the neutral state, the torsional torque is "0", and as the torsional angle increases towards the positive and negative sides, the torsional torque also increases towards the positive and negative sides.

[0077] Here, regarding the overall torsional characteristics of the damping unit, the apparent torsional torque is "0" in the neutral state. However, as mentioned above, the components on the input and output sides experience both positive and negative torsional torques. Therefore, when the torque variation is within the range of +t to -t, the torsional angle between the input side plate 30 and the hub flange 40 is reduced to the range of -θ1 to +θ1, and the end faces of the coil springs 51 of the first window group w1 do not contact the R1 receiving surface 401a and the R2 support surface 301b, respectively. Furthermore, the end faces of the coil springs 51 of the second window group w2 do not contact the R2 receiving surface 402b and the R1 support surface 302a, respectively. Therefore, it is possible to suppress the collision noise between the components caused by torque variation within the range of +t to -t.

[0078] In addition, when the torsion angle exceeds ±θ1, the helical springs 51 of the first window group w1 or the second window group w2 become free length, but compared with the structure in which all helical springs 51 are set to free length, it is able to suppress the collision noise between components.

[0079] In addition, such as Figure 6A As shown, if the torsion angle becomes ±θ3, the resin components 52 of each window group w1 and w2 are compressed. Therefore, the overall torsion characteristic becomes a level 2 characteristic. Moreover, if the torsion angle further becomes ±θ4, the stop protrusion 42b of the flange 42 abuts against the stop portion 31a of the first plate 31, and the relative rotation between the input side plate 30 and the hub flange 40 is prohibited.

[0080] [Other Implementation Methods]

[0081] The present invention is not limited to the embodiments described above, and various modifications or variations can be made without departing from the scope of the present invention.

[0082] (a) The relationship between the width of each support portion 301, 302 and each storage portion 401, 402 and the free length of the helical spring 51 is not limited to the above embodiment.

[0083] (b) In the above embodiments, all helical springs are made to have the same stiffness, but helical springs with different stiffnesses can also be used.

[0084] (c) The number of storage parts, support parts and helical springs is an example and is not limited to the above embodiment.

[0085] Explanation of reference numerals in the attached figures

[0086] 1... Vibration damping device; 30... Input side plate (first rotating body); 301... First support part; 302... Second support part; 301a, 302a... R1 support surface; 301b, 302b... R2 support surface; 40... Hub flange (second rotating body); 401... First storage part; 402... Second storage part; 401a, 402a... R1 storage surface; 401b, 402b... R2 storage surface; 50... Elastic connection part; 51... Helical spring (first elastic member, second elastic member).

Claims

1. A vibration damping device, comprising: The first rotating body rotates about its axis of rotation; A second rotating body, rotating about the rotation axis, and configured to rotate relative to the first rotating body; and The elastic connecting part has a first elastic member and a second elastic member pre-compressed and configured in a neutral state. The elastic connecting part elastically connects the first rotating body and the second rotating body in the rotational direction. The neutral state is a state in which there is no torsion caused by the relative rotation between the first rotating body and the second rotating body. When the first elastic member twists relative to the second rotating body from the neutral state to a first side in the rotational direction, it transitions from a pre-compressed state to a free state, and is then re-compressed. When the first rotating body twists relative to the second rotating body from the neutral state to a second side in the direction of rotation, the second elastic member transitions from a pre-compressed state to a free state, and is then re-compressed. The first rotating body has a first support portion and a second support portion. The second rotating body has: a first storage portion, which is offset to a first side in the rotation direction in the neutral state such that it partially overlaps with the first support portion when viewed axially; and a second storage portion, which is offset to a second side in the rotation direction in the neutral state such that it partially overlaps with the second support portion when viewed axially. The first elastic member is disposed in the first support portion and the first receiving portion. The second elastic member is disposed on the second support portion and the second receiving portion, and the second elastic member operates in parallel with the first elastic member.

2. The vibration damping device according to claim 1, wherein, The first elastic member is further compressed from a pre-compressed state when the first rotating body twists relative to the second rotating body from the neutral state to a second side in the direction of rotation. The second elastic member is further compressed from the pre-compressed state when the first rotating body twists relative to the second rotating body from the neutral state to the first side of the rotation direction.

3. The vibration damping device according to claim 1 or 2, wherein, The first elastic member and the second elastic member have the same rigidity.

4. The vibration damping device according to claim 1, wherein, The first support portion and the second support portion each have a first support surface at their ends on a first side of the rotation direction and a second support surface at their ends on a second side of the rotation direction. The first storage portion and the second storage portion have a first storage surface at their ends on the first side of the rotation direction, and a second storage surface at their ends on the second side of the rotation direction. In the neutral state, the first elastic member is pre-compressed and positioned between the first support surface and the second receiving surface. The second elastic member is pre-compressed and configured between the first receiving surface and the second supporting surface in the neutral state.

5. The vibration damping device according to claim 1, wherein, The elastic connecting part also has a third elastic member and a fourth elastic member that are pre-compressed in the neutral state. The third elastic member transitions from a pre-compressed state to a free state when the first rotating body twists relative to the second rotating body from the neutral state to a first side in the rotational direction, and is then re-compressed. The fourth elastic member transitions from a pre-compressed state to a free state when the first rotating body twists relative to the second rotating body from the neutral state to the second side of the rotation direction, and is then re-compressed.

6. The vibration damping device according to claim 5, wherein, The first rotating body further comprises: a third support portion disposed opposite to the first support portion across the rotation axis; and a fourth support portion disposed opposite to the second support portion across the rotation axis. The second rotating body further comprises: a third storage portion disposed opposite to the first storage portion across the rotation axis; and a fourth storage portion disposed opposite to the second storage portion across the rotation axis. The third storage portion is offset toward a first side in the direction of rotation in the neutral state, such that it partially overlaps with the third support portion when viewed in the axial direction. The fourth storage portion is offset to a second side in the direction of rotation in the neutral state, such that it partially overlaps with the fourth support portion when viewed in the axial direction. The third elastic member is disposed in the third support portion and the third receiving portion. The fourth elastic member is disposed on the fourth support portion and the fourth storage portion, and the fourth elastic member operates in parallel with the third elastic member.

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