Rotating device

Abstract

To provide a rotary device capable of improving attenuation performance.SOLUTION: A rotary device rotates to a first side in a rotating direction during traveling. The rotary device is equipped with an input member, an output member, a damper portion, and a viscous fluid. The damper portion elastically couples the input member and the output member in the rotating direction. The viscous fluid is disposed between the input member and the damper portion. The damper portion has a first seat member, and a second seat member. The first seat member is disposed at an interval from the input member. The first seat member is disposed so as to relatively rotate to the input member. The second seat member is disposed on a second side in the rotating direction with respect to the first seat member. The second seat member is disposed at an interval from the input member. The first seat member has a shearing torque reducing portion. The shearing torque reducing portion reduces shearing torque generated between the input member and the first seat member.SELECTED DRAWING: Figure 7A

Description

Technical Field

[0001] The present invention relates to a rotating device.

Background Art

[0002] Conventionally, in vehicles such as automobiles, a rotating device such as a dual mass flywheel (DMF) is installed to attenuate the rotational fluctuations of an engine. This rotating device attenuates the rotational fluctuations of the engine by a damper portion that elastically connects an input member and an output member.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the rotating device as described above, it is desired to improve the attenuation performance during running. Therefore, an object of the present invention is to provide a rotating device capable of improving the attenuation performance.

Means for Solving the Problems

[0005] (1) The rotating device according to the present invention rotates in a first direction of rotation while traveling. The rotating device comprises an input member, an output member, a damper section, and a viscous fluid. The input member is rotatably arranged. The output member is rotatably arranged relative to the input member. The damper section elastically connects the input member and the output member in the direction of rotation. The viscous fluid is disposed between the input member and the damper section. The damper section has a first sheet member and a second sheet member. The first sheet member is disposed with a gap between it and the input member. The first sheet member is rotatably arranged relative to the input member. The second sheet member is disposed in a second direction of rotation relative to the first sheet member. The second sheet member is disposed with a gap between it and the input member. The first sheet member has a shear torque reduction section. The shear torque reduction section reduces the shear torque generated between the input member and the first sheet member.

[0006] The inventors have found that when the input member and the sheet member rotate relative to each other, a shear torque is generated in the viscous fluid placed between them, and this shear torque reduces the damping performance of rotational fluctuations.

[0007] Therefore, in the present invention, a shear torque reduction portion is formed in the first sheet member to prevent a decrease in the damping performance of rotational fluctuations and to improve the damping performance. The details are as follows.

[0008] During operation, the input member rotates in the first direction of rotation, and the power from the input member is transmitted to the output member via the second and first seat members. At the start of torque input from the engine, the second seat member rotates integrally with the input member, while the first seat member rotates relative to the input member without rotating integrally with it. After the second seat member comes into contact with the first seat member, both the second and first seat members rotate relative to the input member. In other words, during normal operation, the first seat member mainly rotates relative to the input member. This generates a shear torque between the first seat member and the input member.

[0009] Here, the first sheet member has a shear torque reduction section for reducing the shear torque described above. Therefore, the first sheet member can reduce the shear torque generated during normal operation. As a result, the rotating device can prevent a decrease in the damping performance of rotational fluctuations and improve damping performance.

[0010] (2) Preferably, the damper portion has a third seat member. The third seat member is positioned on the second side in the rotational direction relative to the second seat member. The input member has a first contact portion and a second contact portion. The first contact portion contacts the first seat member. The first contact portion is positioned on the first side in the rotational direction relative to the first seat member. The second contact portion contacts the third seat member. The second contact portion is positioned on the second side in the rotational direction relative to the third seat member. The output member has a first power transmission portion and a second power transmission portion. The first power transmission portion contacts the first seat member. The first power transmission portion is positioned on the first side in the rotational direction relative to the first seat member. The second power transmission portion contacts the third seat member. The second power transmission portion is positioned on the second side in the rotational direction relative to the third seat member. The area of ​​the surface of the first seat member facing the input member is smaller than the area of ​​the surface of the third seat member facing the input member.

[0011] The inventors have further discovered that the magnitude of the shear torque is proportional to the area of ​​contact with the viscous fluid on the surface of the sheet member facing the input member. In the present invention, the area of ​​the surface of the first sheet member facing the input member is smaller than the area of ​​the surface of the third sheet member facing the input member. Therefore, the shear torque generated between the second sheet member and the input member can be reduced. In other words, the first sheet member can reduce the shear torque generated during normal driving.

[0012] (3) Preferably, the shear torque reduction section includes a through hole. The through hole is located on the surface facing the input member.

[0013] (4) Preferably, the shear torque reduction section includes a groove. The groove is located on the surface facing the input member.

[0014] (5) Preferably, the shear torque reduction part includes a tapered surface. The tapered surface connects a surface facing the axial direction of the first sheet member and a surface facing the radially outer side of the first sheet member. The tapered surface is inclined so as to move away from the input member in the radial direction.

[0015] (6) Preferably, the rotating device further includes a first elastic member and a second elastic member. The first elastic member is disposed between the first sheet member and the second sheet member. The second elastic member is disposed on the second side in the rotational direction with respect to the two sheet members. The second elastic member has a spring constant larger than that of the first elastic member.

Advantages of the Invention

[0016] In the present invention as described above, it is possible to provide a rotating device capable of improving damping performance.

Brief Description of the Drawings

[0017] [Figure 1] Cross-sectional view of a rotating device according to an embodiment of the present invention. [Figure 2] Front view of the rotating device of FIG. 1. [Figure 3] Front view of the input part. [Figure 4] Partial cross-sectional perspective view from the radially outer side of the rotating device. [Figure 5] Schematic diagram for explaining the position of the grease. [Figure 6] Partial enlarged view of FIG. 1. [Figure 7A] Side view of the end spring sheet. [Figure 7B] Front view of the end spring sheet. [Figure 8A] Side view of an end spring sheet different from that in FIG. 7A. [Figure 8B] Front view of an end spring sheet different from that in FIG. 7B. [Figure 9] Side view of the intermediate spring sheet. [Figure 10] Front view of the end spring sheet in the modification. [Figure 11] A diagram showing the relationship between the viscosity index and the shear torque increase rate.

Mode for Carrying Out the Invention

[0018] [Overall Configuration] FIG. 1 is a cross-sectional view of a dual mass flywheel 100 (an example of a rotating device, hereinafter simply referred to as "DMF100") according to an embodiment of the present invention. Further, FIG. 2 is a front view of the DMF100, showing a part of the member (for example, the left half of the secondary flywheel 5, etc.) removed. In FIG. 1, the line O-O is the rotation axis O. In FIG. 1, an engine is arranged on the left side of the DMF100, and a drive unit including an electric motor, a transmission, etc. is arranged on the right side.

[0019] In the following description, the axial direction is the direction in which the rotation axis O of the DMF100 extends. The left side of FIG. 1 is the "first axial side", and the right side of FIG. 1 is the "second axial side". Also, the rotation direction is the rotation direction of a circle centered on the rotation axis O. The radial direction is the radial direction of a circle centered on the rotation axis O. The arrow D1 in FIG. 2 is the first rotation direction side, and the arrow D2 is the second rotation direction side on the opposite side (the same in the following figures). The DMF100 rotates in the first rotation direction side during running by the torque input from the engine.

[0020] This DMF100 is provided between the crankshaft of an engine (an example of a member on the drive source side) not shown and the input shaft of the drive unit, and is a device for attenuating rotational fluctuations. The DMF100 has a primary flywheel 2 (an example of an input member), a secondary flywheel 5, grease 4 (an example of a viscous fluid), and a plurality of damper portions 40.

[0021] [Primary Flywheel 2] As shown in FIG. 1, power from the engine is input to the primary flywheel 2. The primary flywheel 2 is fixed to a member on the engine side, for example, a crankshaft (not shown).

[0022] The primary flywheel 2 is rotatably positioned around the rotation axis O. The primary flywheel 2 includes an input plate 21, a seal plate 22, and a support member 23.

[0023] The input plate 21 is held between the crankshaft and the support member 23 and fixed to the crankshaft by bolts.

[0024] As shown in Figures 1 and 2, the input plate 21 has a first main body portion 21a and a cylindrical portion 21b. The first main body portion 21a is configured to be rotatable about the rotation axis O. The first main body portion 21a is substantially formed in the shape of a disc.

[0025] As shown in Figure 3, the first main body portion 21a has an inner circumference portion 21h and an outer circumference portion 21e. The outer circumference portion 21e is positioned on the first axial side relative to the inner circumference portion 21h of the first main body portion 21a (see Figure 1).

[0026] Furthermore, the first main body portion 21a has a first contact portion 21f and a second contact portion 21g. The first contact portion 21f and the second contact portion 21g are portions that contact the damper portion 40 in the rotational direction. The first contact portion 21f and the second contact portion 21g are provided on the outer circumference 21e of the first main body portion 21a. The first contact portion 21f and the second contact portion 21g extend radially along the outer circumference 21e. The first contact portion 21f and the second contact portion 21g protrude to the second side in the axial direction (see Figure 1).

[0027] As shown in Figures 1 and 2, the cylindrical portion 21b is cylindrical in shape and extends in the axial direction. The cylindrical portion 21b extends from the outer peripheral end of the first main body portion 21a to the second side in the axial direction. The cylindrical portion 21b is formed integrally with the first main body portion 21a.

[0028] The seal plate 22 is configured to rotate integrally with the input plate 21. For example, the seal plate 22 is fixed to the cylindrical portion 21b by fixing means, such as welding.

[0029] The seal plate 22 is rotatably positioned around the axis of rotation O. The seal plate 22 is substantially annular in shape.

[0030] The seal plate 22 is positioned at a distance from the first main body 21a in the axial direction. A spring seat 3 is positioned between the seal plate 22 and the first main body 21a in the axial direction.

[0031] The seal plate 22 has a third contact portion 22d and a fourth contact portion 22e. The third contact portion 22d and the fourth contact portion 22e are portions that contact the damper portion 40 in the rotational direction. The third contact portion 22d and the fourth contact portion 22e are each positioned opposite the first contact portion 21f and the second contact portion 21g in the axial direction, with a gap between them.

[0032] As shown in Figure 4, the seal plate 22 has an aperture portion 22j. The aperture portion 22j is formed on the axially second side surface of the third contact portion 22d and the fourth contact portion 22e. The aperture portion 22j is a recess that opens to the axially second side. The bottom of the aperture portion 22j may protrude to the axially first side at the third contact portion 22d and the fourth contact portion 22e. The aperture portion 22j may also be formed on the axially first side surface of the first contact portion 21f and the second contact portion 21g. In this case, the aperture portion 22j is a recess that opens to the axially first side.

[0033] The support member 23 is a member that supports the input plate 21 and the seal plate 22. The support member 23 supports the input plate 21 so that it can rotate integrally with the input plate 21. The support member 23 also supports the seal plate 22 so that it can rotate integrally with the seal plate 22.

[0034] The support member 23 is configured to be rotatable around the rotation axis O. The support member 23 is substantially cylindrical in shape.

[0035] [Secondary flywheel 5] The secondary flywheel 5 transmits the power transmitted from the primary flywheel 2 to the damper section 40 to the output-side component.

[0036] The secondary flywheel 5 is rotatably positioned around the rotation axis O of the primary flywheel 2. The secondary flywheel 5 is rotatable relative to the primary flywheel 2. In detail, the secondary flywheel 5 is rotatably supported on the support member 23 of the primary flywheel 2 via a bearing 39.

[0037] The secondary flywheel 5 includes a first output member 51 (an example of an output member) and a second output member 52. The first output member 51 is configured to rotate integrally with the second output member 52. The first output member 51 is fixed to the second output member 52.

[0038] The first output member 51 includes a second main body 51a, a first power transmission unit 51b, and a second power transmission unit 51c.

[0039] The second main body portion 51a is substantially annular in shape. The second main body portion 51a is fixed to the inner circumference of the second output member 52 by rivets.

[0040] The power transmitted from the engine to the primary flywheel 2 is transmitted to the first power transmission section 51b and the second power transmission section 51c via the damper section 40. The first power transmission section 51b and the second power transmission section 51c extend radially outward from the second main body section 51a. The first power transmission section 51b and the second power transmission section 51c are spaced apart from each other in the rotational direction.

[0041] The first power transmission unit 51b and the second power transmission unit 51c are positioned axially between the first main body 21a and the seal plate 22 of the primary flywheel 2, respectively. More specifically, as shown in Figure 4, the first power transmission unit 51b is positioned axially with a gap 84 between it and the first contact portion 21f of the primary flywheel 2. The second power transmission unit 51c is positioned axially with a gap between it and the second contact portion 21g.

[0042] The first power transmission unit 51b is rotatable relative to the first contact portion 21f and the third contact portion 22d in the axial direction between the first contact portion 21f and the third contact portion 22d. The second power transmission unit 51c is rotatable relative to the second contact portion 21g and the fourth contact portion 22e at the second contact portion 21g and the fourth contact portion 22e.

[0043] The second output member 52 is positioned in the axial direction between the transmission and the damper portion 40. More specifically, the second output member 52 is positioned in the axial direction between the transmission and the seal plate 22.

[0044] [Damper Section 40] As shown in Figures 1 and 2, the damper section 40 includes a plurality of spring seats 3 (an example of a first seat member and a second seat member) and a plurality of coil springs 41 (an example of a first elastic member and a second elastic member). The damper section 40 elastically connects the primary flywheel 2 and the secondary flywheel 5. More specifically, the damper section 40 elastically connects the primary flywheel 2 and the secondary flywheel 5 in the rotational direction.

[0045] In this embodiment, there is a pair of damper sections 40. In Figure 2, only one of the pair of damper sections 40 is shown.

[0046] Each damper section 40 is positioned radially inward of the cylindrical section 21b. Each damper section 40 is positioned between the first main body section 21a of the input plate 21 and the secondary flywheel 5 in the axial direction.

[0047] Each damper section 40 has a plurality (for example, 5) spring seats 3 and a plurality (for example, 4) coil springs 41.

[0048] [Spring Seat 3] The spring seat 3 is positioned to be rotatable relative to the primary flywheel 2. The spring seat 3 is positioned with a gap between it and the primary flywheel 2. More specifically, the spring seat 3 is positioned axially between the input plate 21 and the seal plate 22. The spring seat 3 is positioned with a gap between it and the axially second side surface of the first body portion 21a, the inner circumferential surface of the cylindrical portion 21b, and the axially first side surface of the seal plate 22. The spring seat 3 is movable by receiving circumferential pressure when the primary flywheel 2 or the secondary flywheel 5 rotates.

[0049] As shown in Figures 5 and 6, there is a first gap 81 between the input plate 21 and the spring seat 3. There is a second gap 82 between the seal plate 22 and the spring seat 3. More specifically, there is a first gap 81 in the axial direction between the first axial side surface of the spring seat 3 and the second side surface of the first main body portion 21a. There is a second gap 82 in the axial direction between the second axial side surface of the spring seat 3 and the first axial side surface of the seal plate 22. There is a third gap 83 in the radial direction between the outer circumferential surface of the spring seat 3 and the inner circumferential surface of the cylindrical portion 21b.

[0050] The spring seat 3 is positioned to be rotatable relative to the primary flywheel 2.

[0051] As shown in Figure 2, the spring seat 3 includes a first end spring seat 3a (an example of a first seat member), a second end spring seat 3e (an example of a third seat member), a first intermediate spring seat 3b (an example of a second seat member), a second intermediate spring seat 3c, and a third intermediate spring seat 3d. Since the second intermediate spring seat 3c and the third intermediate spring seat 3d have the same shape as the first intermediate spring seat 3b, a detailed description of them is omitted.

[0052] The first end spring seat 3a abuts against the primary flywheel 2 and the secondary flywheel 5 on the first side in the rotational direction. More specifically, the first end spring seat 3a abuts against the first contact portion 21f, the third contact portion 22d, and the first power transmission portion 51b on the first side in the rotational direction.

[0053] As shown in Figures 7A and 7B, the first end spring seat 3a has an inner circumference 34a, an outer circumference 34c, two side portions 34d, a bottom portion 34e, and a through hole 37. The inner circumference 34a, outer circumference 34c, and side portions 34d extend from the bottom portion 34e to one side in the direction of rotation. The inner circumference 34a, outer circumference 34c, two side portions 34d, and bottom portion 34e define a housing portion 36. The housing portion 36 is positioned on the rotation direction surface 34W of the first end spring seat 3a facing the direction of rotation. The housing portion 36 extends in the direction of rotation and opens to one side in the direction of rotation.

[0054] The first end spring seat 3a has a first surface F1 and a second surface F2. The first surface F1 is the surface facing the primary flywheel 2. That is, the first surface F1 includes the outer surface 34X and two side surfaces 34Y of the first end spring seat 3a. The second surface F2 is the surface not facing the primary flywheel 2. That is, the second surface F2 includes the rotation direction surface 34W and the inner surface 34Z.

[0055] The through-hole 37 penetrates the first surface F1 in the axial direction. More specifically, the through-hole 37 is located on the axially facing side surface 34Y of the first end spring seat 3a. The through-hole 37 may be defined on all four sides by the inner circumference 34a, the outer circumference 34c, and the side surface 34d, or it may be defined on three sides by the inner circumference 34a, the outer circumference 34c, and the side surface 34d.

[0056] The second end spring seat 3e is positioned on the second side in the rotational direction relative to the first end spring seat 3a. The second end spring seat 3e contacts the primary flywheel 2 and the secondary flywheel 5 on the second side in the rotational direction. More specifically, the second end spring seat 3e contacts the second contact portion 21g, the fourth contact portion 22e, and the second power transmission portion 51c on the second side in the rotational direction.

[0057] As shown in Figures 8A and 8B, the second end spring seat 3e has an inner circumference 34a, an outer circumference 34c, two side portions 34d, and a bottom portion 34e. The inner circumference 34a, outer circumference 34c, and side portions 34d extend from the bottom portion 34e to one side in the direction of rotation. The inner circumference 34a, outer circumference 34c, two side portions 34d, and bottom portion 34e define a housing portion 36. The housing portion 36 is positioned on the rotation direction surface 34W of the first end spring seat 3a facing the direction of rotation. The housing portion 36 extends in the direction of rotation and opens to one side in the direction of rotation.

[0058] The second end spring seat 3e has a first surface F1 and a second surface F2. The first surface F1 is the surface facing the primary flywheel 2. That is, the first surface F1 includes the outer surface 34X and two side surfaces 34Y of the second end spring seat 3e. The second surface F2 is the surface not facing the primary flywheel 2. That is, the second surface F2 includes the rotation direction surface 34W and the inner surface 34Z.

[0059] The area of ​​the outer surface 34X of the first end spring seat 3a is smaller than the area of ​​the outer surface 34X of the second end spring seat 3e.

[0060] The first intermediate spring seat 3b is positioned on the second rotational side relative to the first end spring seat 3a. As shown in Figure 9, the first intermediate spring seat 3b has a shape in which the bottoms 34e of the two second end spring seats 3e are abutted together and aligned in the rotational direction. Therefore, a detailed explanation of the first intermediate spring seat 3b is omitted.

[0061] As shown in Figure 2, the multiple coil springs 41 (for example, four) included in each damper section 40 are arranged so that each is adjacent to the spring seat 3 in the rotational direction. Each of the multiple coil springs 41 is arranged to act in series with each other between the primary flywheel 2 and the secondary flywheel 5. Each of the multiple coil springs 41 is located in the region defined by the axial second side surface of the first main body section 21a, the inner circumferential surface of the cylindrical section 21b, and the axial first side surface of the seal plate 22.

[0062] Multiple coil springs 41 contained in each damper section 40 are pressed by the first and second power transmission sections 51b and 51c, and the first and second contact sections 21f and 21g, and the third and fourth contact sections 22d and 22e in the rotational direction, via the spring seat 3. In this way, the multiple coil springs 41 expand and contract between the first and second power transmission sections 51b and 51c and the first and second contact sections 21f and 21g, and the third and fourth contact sections 22d and 22e.

[0063] Each of the multiple (e.g., five) spring seats 3 included in each damper section 40 is positioned at the end of each coil spring 41 and supports the end of each coil spring 41. In detail, the end of each coil spring 41 is housed in a housing section 36.

[0064] The coil springs 41 include first to fourth coil springs 41a, 41b, 41c, and 41d. The first coil spring 41a corresponds to the first elastic member of the present invention. The second coil spring 41b corresponds to the second elastic member of the present invention. The third and fourth coil springs 41c and 41d have the same configuration as the second coil spring 41b, so a detailed description of their shapes is omitted.

[0065] The first coil spring 41a is adjacent to the power transmission section 51b in the rotational direction. The first coil spring 41a is positioned between the first end spring seat 3a and the first intermediate spring seat 3b. The first end of the first coil spring 41a in the rotational direction is supported by the first end spring seat 3a. The second end of the first coil spring 41a in the rotational direction is supported by the first intermediate spring seat 3b.

[0066] The second coil spring 41b is positioned on the second side in the rotational direction of the first intermediate spring seat 3b. The end of the second coil spring 41b on the first side in the rotational direction is supported by the first intermediate spring seat 3b. The end of the second coil spring 41b on the second side in the rotational direction is supported by the second intermediate spring seat 3c.

[0067] The second coil spring 41b has a higher spring constant than the first coil spring 41a. The spring constant of the first coil spring 41a is set to the extent that it mainly expands and contracts during the relative rotation of the primary flywheel 2 and the secondary flywheel 5. As a result, the second coil spring 41b does not contract in the initial stages of travel, and the first intermediate spring seat 3b can slide integrally with the primary flywheel 2. On the other hand, the first coil spring 41a mainly contracts, and only the first end spring seat 3a rotates relative to the primary flywheel 2.

[0068] The first end spring seat 3a is in circumferential contact with the first power transmission section 51b, the first contact section 21f, and the third contact section 22d, respectively. The second end spring seat 3e is in circumferential contact with the second power transmission section 51c, the second contact section 21g, and the fourth contact section 22e. When the DMF 100 is activated, one of the first and second end spring seats 3a, 3e is pressed by the primary flywheel 2. The other of the first and second end spring seats 3a, 3e is pressed in the rotational direction by the first output member 51b or the second output section 51c. In this way, the first to fourth coil springs 41a, 41b, 41c, and 41d expand and contract between the first and second output members 51b, 51c and the first and second contact parts 21f, 21g and the third and fourth contact parts 22d, 22e via the spring seat 3.

[0069] The following explanation applies to all spring seats 3, and therefore the first end spring seat 3a will be described as spring seat 3. However, the structure for reducing shear torque does not apply to the second end spring seat 3e, or the first to third intermediate spring seats 3b, 3c, and 3d.

[0070] [Grease 4] As shown in Figures 5 and 6, the grease 4 is placed between the primary flywheel 2 and the damper portion 40. More specifically, the grease 4 is placed in the gap between the primary flywheel 2 and the spring seat 3. More specifically, the grease 4 is placed in the first gap 81 between the input plate 21 and the spring seat 3, and in the second gap 82 between the seal plate 22 and the spring seat 3. The grease 4 is also placed in the third gap 83 between the inner circumferential surface of the cylindrical portion 21b and the outer circumferential surface of the spring seat 3.

[0071] In detail, the grease 4 is filled into the area defined by the second axial side surface of the first main body 21a, the inner circumferential surface of the cylindrical portion 21b, and the first axial side surface of the seal plate 22. When the DMF 100 is in operation, the grease 4 is received by the inner circumferential surface of the cylindrical portion 21b and spreads around the entire circumference of the cylindrical portion 21b by centrifugal force. When the DMF 100 is in operation, the grease 4 is filled to fill the first axial gap 81 between the spring seat 3 and the seal plate 22, the second axial gap 82 between the first main body 21a and the spring seat 3, and the third radial gap 83 between the spring seat 3 and the cylindrical portion 21b. When the DMF 100 is in operation, the inner circumferential portions of the first gap 81 and the second gap 82 do not need to be filled with grease 4. When the DMF 100 is in operation, the third gap 83 is completely filled with grease 4.

[0072] The grease 4 further contacts the first surface F1 of the spring seat 3. More specifically, the grease 4 is filled so as to cover the entire outer surface 34X of the spring seat 3. The grease 4 may also be filled so as to cover the entire or partially cover two sides 34Y of the spring seat 3.

[0073] The grease 4 does not come into contact with the second surface F2 of the spring seat 3. More specifically, it is filled so as not to come into contact with the inner surface 34Z of the spring seat 3.

[0074] The grease 4 is filled so that it may cover the entire surface of the spring seat 3 that comes into contact with the coil spring 41, or it may cover only a portion of it.

[0075] Grease 4 is also filled in the fourth axial gap 84 between the first contact portion 21f and the first power transmission portion 51b, and the fifth axial gap 85 between the first power transmission portion 51b and the third contact portion 22d. Grease 4 is also filled in the axial gap between the second contact portion 21g and the second power transmission portion 51c, and the axial gap between the second power transmission portion 51c and the fourth contact portion 22e.

[0076] The grease 4 generates a shear torque T. Specifically, when the DMF100 is in operation, the spring seat 3 rotates relative to the primary flywheel 2. This relative rotation shears the grease 4, generating a shear torque in the grease 4. This shear torque of the grease 4 is used as the shear torque T.

[0077] Shear torque T occurs in the first gap 81, the second gap 82, and the third gap 83. The shear torque T occurring in the first gap 81 will be described below. The total shear torque obtained in each spring seat 3 is the sum of the shear torques T calculated for the first gap 81, the second gap 82, and the third gap 83, respectively.

[0078] The shear torque T is proportional to the characteristic radius R of the grease 4, the area A of the grease 4 in contact with the spring seat 3, the apparent viscosity η of the grease 4, and the relative angular velocity ω between the primary flywheel 2 and the spring seat 3. Furthermore, the shear torque T is inversely proportional to the axial dimension H of the gap between the primary flywheel 2 and the spring seat 3. In other words, the shear torque T is defined by the following equation (1). Equation (1) allows us to define the shear torque T generated by the grease 4 in contact with one spring seat 3.

[0079]

number

[0080] The representative radius R is the representative radius of the grease 4 when the DMF100 is in operation. Specifically, when the DMF100 is in operation, the grease 4 is subjected to centrifugal force and spreads radially outward within the region defined by the axial second side surface of the first main body 21a, the inner circumferential surface of the cylindrical part 21b, and the axial first side surface of the seal plate 22. In other words, when the DMF100 is in operation, the grease 4 is in contact with the axial second side surface of the first main body 21a, the inner circumferential surface of the cylindrical part 21b, the axial first side surface of the seal plate 22, the axial first side surface of the spring seat 3, the outer circumferential surface of the spring seat 3, and the axial second side surface of the spring seat 3. The representative radius of the grease 4 at this time is R. The representative radius R is defined by the following equation (2) using the minimum grease radius R1 and the maximum grease radius R2 during operation. The maximum grease radius R2 is the distance from the rotation axis O to the outer surface 34X.

[0081]

number

[0082] Area A is the area of ​​grease 4 in contact with each surface of the spring seat 3 when the DMF 100 is in operation in the first gap 81.

[0083] The relative angular velocity ω is the relative angular velocity between the primary flywheel 2 and the spring seat 3 when the DMF100 is in operation.

[0084] Dimension H is the axial dimension of the gap between the primary flywheel 2 and the spring seat 3 when the DMF100 is in operation. In other words, for the first gap 81, dimension H is the axial dimension H1 of the first gap 81.

[0085] The shear torques T generated in the second gap 82 and the third gap 83 can be calculated in the same way as the shear torque T generated in the first gap 81. The differences between the shear torque T obtained in the third gap 83 and the shear torque T obtained in the first gap 81 are explained below.

[0086] In the third gap 83, the representative radius R is the distance from the axis of rotation O to the outer surface 34X, i.e., the maximum grease radius R2. Also, in the third gap 83, the area A is the area of ​​the grease 4 that is in contact with the outer surface 34X of the spring seat 3 when the DMF100 is in operation. In the third gap 83, the dimension H is the radial dimension H3 of the third gap 83.

[0087] The apparent viscosity η is the apparent viscosity of grease 4 when the DMF100 is in operation. The apparent viscosity η is defined by the following equation (3).

[0088]

number

[0089] In equation (3), μ is the well-known viscosity coefficient of grease 4.

[0090] n is the viscosity index of grease 4. The viscosity index n is a physical property that represents the velocity dependence of grease 4; a larger value indicates a smaller change in viscosity with velocity. The viscosity index n is calculated by the following method. The viscosity index n is calculated from the relationship between the shear rate of grease 4 and the apparent viscosity of grease 4. Specifically, the viscosity index n is calculated by changing the shear rate conditions of grease 4 at 24°C and measuring the apparent viscosity η of grease 4 using a capillary rheometer. The logarithm of the shear rate of grease 4 is plotted on the x-axis and the logarithm of the apparent viscosity of grease 4 is plotted on the y-axis, and the obtained results are plotted on a graph. A regression line is found for multiple plots. The regression line can be found using a well-known method. The regression line may be found, for example, by the least squares method or by other methods. The value obtained by adding 1 to the slope of the obtained line is taken as the viscosity index n of grease 4.

[0091] The viscosity index n is 0.4 or higher. If the viscosity index n is 0.4 or higher, resonance that occurs during engine startup can be sufficiently suppressed. The reason for this is as follows: From equations (1) and (3), the shear torque T can be defined by the following equation (4).

number

[0092] Generally, the relative angular velocity ω (hereinafter simply referred to as relative angular velocity ω) between the primary flywheel 2 and the secondary flywheel 5 when resonance occurs during engine startup is considered to be approximately 40 times the relative angular velocity ω during normal operation. Normal operation refers to the time when the DMF100 is rotating due to torque input from the engine. On the other hand, the fluctuation range of the damper input torque when resonance occurs during engine startup is approximately 5 times the fluctuation range of the damper input torque during normal operation. The rate of increase in the relative angular velocity and damper input torque fluctuation range between engine startup and normal operation remains similar even if the size of the DMF100 changes. The shear torque T can be used as hysteresis torque. Therefore, if a shear torque T of 5 times or more than the shear torque T required during normal driving is generated when the relative angular velocity ω changes 40 times, the resonance that occurs during engine startup can be sufficiently suppressed.

[0093] According to equation (4), the rate of increase of shear torque T with respect to relative angular velocity is greatly influenced by the viscosity index n. Therefore, as shown in the embodiment described below, the relationship between the viscosity index n and the shear torque fluctuation rate was investigated. As a result, it was found that if the viscosity index n is 0.4 or higher, the shear torque increase rate can be increased by 5 times or more. Therefore, the viscosity index n is 0.4 or higher. Conventional DMFs generally used have a viscosity index n of around 0.2. In this embodiment, since the viscosity index n is significantly higher than that of conventional greases, for example, to 0.4 or higher, resonance that occurs when the engine starts can be sufficiently suppressed.

[0094] Although the spring seat 3 and the coil spring 41 rotate relative to each other, the relative speed of the two members and the area in contact with the grease 4 are significantly smaller compared to the other first gap 81, second gap 82, and third gap 83. Therefore, the surface of the spring seat 3 that contacts the coil spring 41 does not contribute to the generation of shear torque T.

[0095] The total shear torque obtained for the entire DMF100 is the sum of the shear torques T calculated for each of the first and second end spring seats 3a and 3e, and the first to third intermediate spring seats 3b, 3c, and 3d.

[0096] Furthermore, the shear torque of the grease 4 can also be generated by the relative rotation between the primary flywheel 2 and the secondary flywheel 5. In this case, the shear torque of the grease 4 generated in the fourth gap 84 between the first contact portion 21f and the first power transmission portion 51b, and the fifth gap 85 between the first power transmission portion 51b and the third contact portion 22d can also be used as the shear torque T. The shear torque of the grease 4 generated in the gap between the second contact portion 21g and the second power transmission portion 51c, and the gap between the second power transmission portion 51c and the fourth contact portion 22e can also be used as the shear torque T.

[0097] [Shear Torque Reduction Unit P] The first end spring seat 3a has a shear torque reduction section P. The shear torque reduction section P reduces the shear torque T generated between the primary flywheel 2 and the first end spring seat 3a.

[0098] As described above, the shear torque T is proportional to the characteristic radius R of the grease 4, the area A of the grease 4 in contact with the spring seat 3, the apparent viscosity η of the grease 4, and the relative angular velocity ω between the primary flywheel 2 and the spring seat 3. Furthermore, the shear torque T is inversely proportional to the axial dimension H of the gap between the primary flywheel 2 and the spring seat 3. Therefore, in order to reduce the shear torque T, these elements should be reduced or increased.

[0099] In this embodiment, the shear torque T generated between the first end spring seat 3a and the primary flywheel 2 is reduced. On the other hand, the shear torque T generated between the second end spring seat 3e, the first to third intermediate spring seats 3b, 3c, and 3d and the printer is kept large. Therefore, in order to reduce the shear torque T, the area A of the grease 4 in contact with the first end spring seat 3a is reduced, or the axial dimension H1 of the first gap 81 between the first end spring seat 3a and the primary flywheel 2 is increased, etc.

[0100] In this embodiment, the area of ​​the outer surface 34X of the first end spring seat 3a is smaller than the area of ​​the outer surface 34X of the second end spring seat 3e. Therefore, the area A of the grease 4 in contact with the first end spring seat 3a in equation (1) is reduced. As a result, the shear torque T can be reduced.

[0101] Furthermore, in this embodiment, a through hole 37 located on the first surface F1 of the first end spring seat 3a is used as the shear torque reduction section P. As described above, the through hole 37 is located on the first surface F1 of the first end spring seat 3a facing the primary flywheel 2. Therefore, the area A of the grease 4 in contact with the first end spring seat 3a in equation (1) is reduced. As a result, the shear torque T can be reduced.

[0102] [Action / Effect] The torque transmitted from the engine to the primary flywheel 2 is input to the damper section 40. In the damper section 40, torque is input to the input plate 21, and this torque is transmitted to the secondary flywheel 5 via the coil spring 41, and then to the output side electric motor, generator, transmission, etc. During normal operation, that is, when the DMF 100 is rotating due to the torque input from the engine, it is necessary to dampen the rotational fluctuations caused by the transmitted torque. The shear torque T of the grease 4 generated between the primary flywheel 2 and the first end spring seat 3a reduces the damping performance of rotational fluctuations.

[0103] In this embodiment, the first end spring seat 3a, which mainly rotates relative to the primary flywheel 2 during normal operation, has a shear torque reduction section P. The shear torque reduction section P reduces the shear torque T of the grease 4 generated between the primary flywheel 2 and the first end spring seat 3a. This prevents a decrease in the damping performance of rotational fluctuations and improves the damping performance. The details are as follows.

[0104] During normal operation, the primary flywheel 2 rotates in the first direction of rotation, and power from the primary flywheel 2 is transmitted to the secondary flywheel 5 via the first intermediate spring seat 3b and the first end spring seat 3a. Here, when torque input from the engine begins, the first intermediate spring seat 3b rotates integrally with the primary flywheel 2, while the first end spring seat 3a rotates relative to the primary flywheel 2 without rotating integrally with it. After the first intermediate spring seat 3b comes into contact with the first end spring seat 3a, the first intermediate spring seat 3b and the first end spring seat 3a rotate relative to the primary flywheel 2. In other words, during normal operation, the first end spring seat 3a mainly rotates relative to the primary flywheel 2. As a result, a shear torque is generated between the first end spring seat 3a and the primary flywheel 2.

[0105] Here, the first end spring seat 3a has a shear torque reduction section P for reducing the shear torque described above. Therefore, the first end spring seat 3a can reduce the shear torque generated during normal operation. As a result, the rotating device can prevent a decrease in the damping performance of rotational fluctuations and improve damping performance.

[0106] [Other embodiments] The present invention is not limited to the embodiments described above, and various modifications or alterations are possible without departing from the scope of the present invention.

[0107] (a) In the above embodiment, the shear torque reduction portion P was a through hole 37 located on the axially facing side surface 34Y of the first end spring seat 3a. However, it is not limited to this. For example, the shear torque reduction portion P may include a groove located on the first surface F1. Grease 4 does not enter the groove. Therefore, the groove reduces the area of ​​the first surface F1 of the first end spring seat 3a.

[0108] (b) The shear torque reduction section P may be located on the outer surface 34X of the first end spring seat 3a.

[0109] (c) As shown in Figure 10, the shear torque reduction section P may include a tapered surface 34V. The tapered surface 34V connects the side surface 34Y of the first end spring seat 3a to the outer surface 34X of the first end spring seat 3a. The tapered surface 34V is inclined to move away from the primary flywheel 2 as it extends radially. In this case, the axial dimension H1 of the first gap 81 between the first end spring seat 3a and the primary flywheel 2 increases. As a result, the shear torque T generated between the first end spring seat 3a and the primary flywheel 2 is reduced.

[0110] (d) In the above embodiment, the third and fourth coil springs 41c and 41d have the same configuration as the second coil spring 41b, but are not limited thereto. The second to fourth coil springs 41b, 41c and 41d may have different spring constants, as long as the seat member on the second side in the rotational direction can slide integrally with the primary flywheel 2.

[0111] (e) In the above embodiment, DMF100 was described as an example of a rotating device, but the rotating device is not limited to DMF100. For example, the rotating device does not have to include a secondary flywheel 5. The rotating device may also be a clutch device or a damper device, etc.

[0112] (f) In the above embodiment, the first elastic member and the second elastic member were coil springs 41, but are not particularly limited thereto. The first elastic member and the second elastic member may be made of materials other than coil springs. For example, the first elastic member and the second elastic member may be made of rubber. [Examples]

[0113] The following describes embodiments of the present invention. The following embodiments were obtained by numerical simulation analysis. However, the present invention is not limited to the embodiments described below.

[0114] [Preparation of DMF100] DMF100 was manufactured such that the representative radius R of the grease 4 in formula (1), the area A of the grease 4 in contact with the first end spring seat 3a, and the axial dimension H between the primary flywheel 2 and the first end spring seat 3a were as follows: In the first gap 81 and the second gap 82, the representative radius R was 115 mm, and the area A was 15.4 cm² (total of the first gap 81 and the second gap 82). 2 The dimensions H1: 0.5 mm and H2: 0.5 mm were used. The third gap 83 was omitted. The total hysteresis torque, which is the sum of the hysteresis torques T calculated for the first gap 81 and the second gap 82, was used as the hysteresis torque obtained for each test number.

[0115] In this simulation, the relative angular velocity ω during normal operation (not at engine startup, but during stable driving) was 50 deg / s. The relative angular velocity ω when resonance occurred at engine startup was 2000 deg / s. In other words, the relative angle when resonance occurred at engine startup was 40 times the relative angular velocity ω during normal operation.

[0116] Furthermore, in this simulation, the fluctuation range of the damper input torque during normal operation was ±20 Nm. When resonance occurred during engine startup, the fluctuation range of the damper input torque was ±100 Nm. In other words, the fluctuation range of the damper input torque when resonance occurred during engine startup was five times that of the damper input torque during normal operation.

[0117] As shown in Table 1, various greases with different viscosity indices n were prepared. The greases used in Test No. 1 and Test No. 2 are greases commonly used in conventional DMFs. Using the prepared greases, the increase ratio of the shear torque T at engine startup compared to the shear torque T during normal operation (hereinafter referred to as the shear torque increase ratio) when the relative angular velocity ω between the primary flywheel 2 and the secondary flywheel 5 in the DMF100 is 40 times was simulated by numerical analysis using equation (1). The results are shown in Table 1 and Figure 11.

[0118] [Table 1]

[0119] [Evaluation Results] As described above, the fluctuation range of the damper input torque when resonance occurred during engine startup was five times that of the damper input torque during normal operation. Therefore, if the hysteresis torque increase rate is increased by five times or more, resonance occurring during engine startup can be sufficiently suppressed. As shown in Table 1 and Figure 11, when the viscosity index n was 0.43 or higher, the shear torque increase rate was five times or more. Thus, it was confirmed that resonance occurring during engine startup can be sufficiently suppressed if the viscosity index n is 0.4 or higher. [Explanation of Symbols]

[0120] 2. Primary flywheel (an example of an input component) 3 Spring Seat 3a Spring seat for the first end (an example of the first seat member) 3b First intermediate spring seat (an example of a second seat member) 3e Spring seat for the second end (an example of a third seat member) 4. Grease (an example of a viscous fluid) 21 Input section 21a Main body 21b Cylindrical part 40 Damper section 41 Coil springs 41a First coil spring (an example of a first elastic member) 41b Second coil spring (an example of a second elastic member) 51 First output member 51b First power transmission section (an example of an output component) 100 DMF (Example of a rotating device) O Rotation axis P Shear Torque Reduction Section

Claims

1. In a rotating device that rotates in the first direction of rotation while in motion, Rotatably positioned input member, An output member arranged to be rotatable relative to the input member, A damper portion elastically connects the input member and the output member in the rotational direction, A viscous fluid is disposed between the input member and the damper portion, Equipped with, The damper section is, A first sheet member is positioned with a gap between it and the input member, and is rotatable relative to the input member. A second sheet member is positioned on the second rotational side relative to the first sheet member, with a gap between it and the input member, It has, The first sheet member has a shear torque reduction section that reduces the shear torque generated between the input member and the first sheet member, The damper portion has a third sheet member that is positioned on the second side in the rotational direction relative to the second sheet member. The input member has a first contact portion that abuts the first sheet member and is positioned on the first side in the rotational direction relative to the first sheet member, and a second contact portion that abuts the third sheet member and is positioned on the second side in the rotational direction relative to the third sheet member. The output member has a first power transmission unit that contacts the first sheet member and is positioned on the first rotational side relative to the first sheet member, and a second power transmission unit that contacts the third sheet member and is positioned on the second rotational side relative to the third sheet member. The area of ​​the surface of the first sheet member facing the input member is smaller than the area of ​​the surface of the third sheet member facing the input member. Rotating device.

2. The shear torque reduction section includes a through hole located on the surface facing the input member. The rotating device according to claim 1.

3. The shear torque reduction section includes a groove positioned on the surface facing the input member. The rotating device according to claim 1 or claim 2.

4. The shear torque reduction portion includes a tapered surface, The tapered surface connects the axially oriented surface of the first sheet member with the radially outward oriented surface of the first sheet member, and is inclined to move away from the input member as it extends radially. The rotating device according to any one of claims 1 to 3.

5. A first elastic member is disposed between the first sheet member and the second sheet member, A second elastic member is positioned on the second side in the rotational direction relative to the second sheet member, and has a larger spring constant than the first elastic member. Furthermore, The rotating device according to any one of claims 1 to 4.

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