Rotating device

Abstract

To provide a rotary device capable of damping a rotational fluctuation.SOLUTION: The rotary device includes a first rotary body, a second rotary body, and a hysteresis torque generation mechanism. The first rotary body has a housing part. The second rotary body is arranged at a space from an inner wall surface of the housing part. The second rotary body is arranged rotatably relatively to the first rotary body. The second rotary body is arranged in the housing part, The hysteresis torque generation mechanism comprises a viscous fluid. The viscous fluid is filled in the housing part. The hysteresis torque generation mechanism is configured to generate hysteresis torque T. The hysteresis torque T is proportional to a representative radius R of the viscous fluid, an area A of the viscous fluid contacting the second rotary body, apparent viscosity η of the viscous fluid, and a relative angle speed ω between the first rotary body and the second rotary body. The hysteresis torque T is inversely proportional to an axial space H between the first rotary body and the second rotary body.SELECTED DRAWING: Figure 5

Description

Technical Field

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

Background Art

[0002] Conventionally, in vehicles such as automobiles, as a rotating device that is attached to an engine and effectively attenuates rotational fluctuations of the engine, for example, a dual mass flywheel (DMF) is known. The DMF has a hysteresis torque generation mechanism in order to prevent resonance from occurring at engine startup (for example, Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the DMF of Patent Document 1, rotational fluctuations may not be sufficiently attenuated during running. Therefore, an object of the present invention is to provide a rotating device capable of attenuating rotational fluctuations.

Means for Solving the Problems

[0005] (1) The rotating device according to the present invention comprises a first rotating body, a second rotating body, and a hysteresis torque generating mechanism. The first rotating body has a housing. The second rotating body is arranged at a distance from the inner wall surface of the housing. The second rotating body is arranged to be rotatable relative to the first rotating body. The second rotating body is arranged inside the housing. The hysteresis torque generating mechanism is composed of a viscous fluid. The viscous fluid is filled inside the housing. The hysteresis torque generating mechanism generates a hysteresis torque T. The hysteresis torque T is proportional to the representative radius of the viscous fluid, the area of ​​the grease in contact with the second rotating body, the apparent viscosity of the viscous fluid, and the relative angular velocity between the first and second rotating bodies. The hysteresis torque T is inversely proportional to the axial gap between the first and second rotating bodies.

[0006] In this hysteresis torque generation mechanism, the shear torque of a viscous fluid can be determined based on the relative angular velocity ω. As described above, the shear torque can be used as hysteresis torque. Therefore, the rotating device of the present invention can change the hysteresis torque based on the relative angular velocity ω. As a result, the rotating device of the present invention can generate hysteresis torque when resonance occurs during engine startup. On the other hand, the rotating device of the present invention can reduce the hysteresis torque during driving. As a result, the rotating device of the present invention can dampen rotational fluctuations while suppressing resonance.

[0007] (2) Preferably, the viscosity index n of the viscous fluid is 0.43 or higher.

[0008] (3) Preferably, the first rotating body has a first input section and a second input section. The second input section is positioned axially apart from the first input section. The second rotating body is positioned axially between the first input section and the second input section. The viscous fluid is positioned in the first gap between the first input section and the second rotating body, and in the second gap between the second input section and the second rotating body. The axial dimension of the second gap is configured to be smaller than the axial dimension of the first gap.

[0009] (4) Preferably, the rotating device further comprises a third rotating body. The third rotating body is positioned axially between the first input and the second input. The third rotating body is rotatable relative to the first and second inputs. The axial dimension of the fourth gap between the first input and the third rotating body is different from the axial dimension of the fifth gap between the second input and the third rotating body.

[0010] (5) Preferably, the second rotating body has a first surface and a second surface. The first surface faces the first rotating body. The second surface does not face the first rotating body. The second rotating body has a weight-reducing portion on the second surface.

[0011] (6) Preferably, the rotating device further comprises an elastic member. The elastic member is arranged adjacent to the second rotating body in the circumferential direction. The second rotating body has an elastic member housing portion that accommodates the elastic member on a surface facing the circumferential direction. The opening area of ​​the weight-reducing portion is smaller than the opening area of ​​the elastic member housing portion.

[0012] (7) Preferably, the second rotating body has a circumferential surface facing the circumferential direction. The weight-reducing portion is located on the circumferential surface of the second rotating body.

[0013] (8) Preferably, the weight-reducing portion is a recess that opens in the circumferential direction.

[0014] (9) Preferably, the weight-reducing portion is positioned radially outward or radially inward with respect to the elastic member housing portion.

[0015] (10) Preferably, the weight-reducing portion has a first weight-reducing portion and a second weight-reducing portion. The first weight-reducing portion is located radially outward with respect to the elastic member housing portion. The second weight-reducing portion is located radially inward with respect to the elastic member housing portion. The first weight-reducing portion is larger than the second weight-reducing portion.

[0016] (11) Preferably, the viscous fluid is placed in the first hollowed-out section but not in the second hollowed-out section. [Effects of the Invention]

[0017] In the present invention as described above, a rotating device capable of attenuating rotational fluctuations can be provided.

Brief Description of the Drawings

[0018] [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 member. [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 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 8] Side view of the intermediate spring sheet. [Figure 9A] Side view of the end spring sheet according to a modified example. [Figure 9B] Front view of the end spring sheet according to a modified example. [Figure 10A] Side view of the end spring sheet according to a modified example different from FIG. 9A. [Figure 10B] Front view of the end spring sheet according to a modified example different from FIG. 9A. [Figure 11A] Side view of the end spring sheet according to a modified example different from FIGS. 9A and 10A. [Figure 11B] Front view of the end spring sheet according to a modified example different from FIGS. 9B and 10B. [Figure 12] Partial cross-sectional view from the outer peripheral side of the rotating device in a modified example. [Figure 13] Partial cross-sectional view from the outer peripheral side of the rotating device in a modified example different from FIG. 12. [Figure 14] Diagram showing the relationship between the spring sheet and the power transmission part. [Figure 15]A diagram showing the relationship between viscosity index and the rate of increase in hysteresis torque. [Modes for carrying out the invention]

[0019] [Overall structure] Figure 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 one embodiment of the present invention. Figure 2 is a front view of the DMF100, with some components (for example, the left half of the secondary flywheel 5) removed. In Figure 1, line OO represents the rotation axis O. In Figure 1, the engine is located on the left side of the DMF100, and the drive unit, including the electric motor and transmission, is located on the right side.

[0020] In the following explanation, "axial direction" refers to the direction in which the rotation axis O of the DMF100 extends. The left side of Figure 1 is referred to as the "first axial direction," and the right side of Figure 1 is referred to as the "second axial direction." Furthermore, "circumferential direction" refers to the circumferential direction of a circle centered on the rotation axis O. "Radial direction" refers to the radial direction of a circle centered on the rotation axis O.

[0021] The DMF100 is a device installed between the crankshaft of an engine (an example of a component on the drive source side) and the input shaft of a drive unit, and is used to dampen rotational fluctuations. The DMF100 includes a primary flywheel 2 (an example of a first rotating body), a plurality of spring seats 3 (an example of a second rotating body), and a plurality of damper sections 40 including a hysteresis torque generating mechanism 4. The DMF100 further includes a secondary flywheel 5.

[0022] [Primary Flywheel 2] As shown in Figure 1, the primary flywheel 2 receives power from the engine. The primary flywheel 2 is fixed to an engine component, such as the crankshaft (not shown).

[0023] The primary flywheel 2 is rotatably positioned around the rotation axis O. The primary flywheel 2 includes an input plate 21 (an example of a first input section), a seal plate 22 (an example of a second input section), a support member 23, and a housing section S.

[0024] The input plate 21 is held between the crankshaft and the support member 23 and fixed to the crankshaft by bolts.

[0025] 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.

[0026] 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).

[0027] Furthermore, the first main body portion 21a has a plurality (for example, two) of first contact portions 21f. Each first contact portion 21f is a portion that contacts the damper portion 40 in the circumferential direction. Each first contact portion 21f is provided on the outer periphery portion 21e of the first main body portion 21a. Each first contact portion 21f extends radially along the outer periphery portion 21e. Each first contact portion 21f protrudes to the second side in the axial direction (see Figure 1).

[0028] 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.

[0029] 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.

[0030] The seal plate 22 is rotatably positioned around the axis of rotation O. The seal plate 22 is substantially annular in shape.

[0031] 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. More specifically, the spring seat 3 is positioned in the housing S.

[0032] The housing section S is 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.

[0033] The seal plate 22 has a plurality (for example, two) second contact portions 22d. Each second contact portion 22d is a portion that contacts the damper portion 40 in the rotational direction. Each second contact portion 22d is positioned opposite each first contact portion 21f in the axial direction, with a gap between them.

[0034] 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 second contact portion 22d. 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 on the second contact portion 22d. The aperture portion 22j may be formed on the axially first side surface of the first contact portion 21f. In this case, the aperture portion 22j is a recess that opens to the axially first side.

[0035] 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.

[0036] The support member 23 is configured to be rotatable around the rotation axis O. The support member 23 is substantially cylindrical in shape.

[0037] [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.

[0038] 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.

[0039] The secondary flywheel 5 includes a first output member 51 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 partially positioned in the housing S described above. The first output member 51 is fixed to the second output member 52.

[0040] The first output member 51 has a second main body 51a and a plurality (for example, two) power transmission units 51b.

[0041] 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.

[0042] The power transmitted from the engine to the primary flywheel 2 is transmitted to the multiple power transmission units 51b via the damper units 40. Each power transmission unit 51b extends radially outward from the second main body 51a. The power transmission units 51b are spaced apart from each other in the circumferential direction.

[0043] Each power transmission unit 51b is positioned between the first main body 21a and the seal plate 22 of the primary flywheel 2 in the axial direction. More specifically, as shown in Figure 4, each power transmission unit 51b is positioned with a fourth gap 84 between it and the first contact portion 21f of the primary flywheel 2 in the axial direction.

[0044] Each power transmission section 51b is rotatable relative to each first contact section 21f and each second contact section 22d in the axial direction between each first contact section 21f and each second contact section 22d.

[0045] 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.

[0046] [Damper Section 40] As shown in Figures 1 and 2, 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 circumferential direction.

[0047] 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.

[0048] 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. In other words, each damper section 40 is positioned in the housing section S.

[0049] Each damper section 40 has a plurality (for example, 5) spring seats 3 and a plurality (for example, 4) coil springs 41.

[0050] [Spring Seat 3] The spring seat 3 is positioned within the housing S. The spring seat 3 is positioned at a distance from the inner wall surface of the housing S. The spring seat 3 is positioned so as 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. In detail, the spring seat 3 is positioned axially between the input plate 21 and the seal plate 22. The spring seat 3 is positioned at a distance from the axial second side surface of the first main body portion 21a, the inner circumferential surface of the cylindrical portion 21b, and the axial first side surface of the seal plate 22.

[0051] 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.

[0052] The spring seat 3 is positioned to be rotatable relative to the primary flywheel 2.

[0053] As shown in Figure 2, the spring seat 3 includes first and second end spring seats 3a and 3e, and first to third intermediate spring seats 3b, 3c, and 3d. The first end spring seat 3a corresponds to the second rotating body of the present invention. Since the second end spring seat 3e has the same shape as the first end spring seat 3a, and the second intermediate spring seat 3c and third intermediate spring seat 3d have the same shape as the first intermediate spring seat 3b, a detailed explanation of these will be omitted.

[0054] As shown in Figures 7A and 7B, the first end spring seat 3a has an inner circumference 34a, an outer circumference 34c, two side surfaces 34d, a bottom 34e, and a weight-reducing section 35. The inner circumference 34a, outer circumference 34c, and side surfaces 34d extend from the bottom 34e to one side in the circumferential direction. The inner circumference 34a, outer circumference 34c, two side surfaces 34d, and bottom 34e define an elastic member housing section 36. The elastic member housing section 36 is positioned on the circumferential surface 34W of the first end spring seat 3a facing the circumferential direction. The elastic member housing section 36 extends in the circumferential direction and opens to one side in the circumferential direction.

[0055] 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 circumferential surface 34W and the inner surface 34Z.

[0056] The weight-reducing portion 35 is located on the second surface F2. More specifically, the weight-reducing portion 35 is located on the circumferential surface 34W. The weight-reducing portion 35 is a recess that opens in the circumferential direction. The weight-reducing portion 35 opens in a circular shape. The depth of the weight-reducing portion 35 is set to a depth that provides the amount necessary for weight reduction. For example, the depth of the weight-reducing portion 35 can be the same as the depth of the elastic member housing portion 36. The weight-reducing portion 35 extends circumferentially parallel to the elastic member housing portion 36. The weight-reducing portion 35 may also be a through hole that penetrates in the circumferential direction. The weight-reducing portion 35 is located radially outward from the elastic member housing portion 36. Two weight-reducing portions 35 are provided.

[0057] The opening area of ​​the weight-reducing section 35 is smaller than the opening area of ​​the elastic member housing section 36. Here, the opening area refers to the area of ​​the opening of the weight-reducing section 35 or the elastic member housing section 36.

[0058] As shown in Figure 8, the first intermediate spring seat 3b has a shape in which the bottoms 34e of the two first end spring seats 3a are butted together and arranged in the circumferential direction. Therefore, a detailed explanation of the first intermediate spring seat 3b is omitted.

[0059] Each damper section 40 contains a plurality of coil springs 41 (for example, four), each arranged so as to be adjacent to the spring seat 3 in the circumferential direction. Each of the plurality of coil springs 41 is arranged so as to act in series with each other between the primary flywheel 2 and the secondary flywheel 5. Each of the plurality of 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. Each of the plurality of coil springs 41 (for example, four) contained in each damper section 40 is arranged in the housing section S so as to act in series with each other between the primary flywheel 2 and the secondary flywheel 5.

[0060] Multiple coil springs 41 contained in each damper section 40 are pressed against the power transmission section 51b and the first contact section 21f and second contact section 22d in the circumferential direction via the spring seat 3. In this way, the multiple coil springs 41 expand and contract between the power transmission section 51b and the first contact section 21f and second contact section 22d.

[0061] 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 an elastic member housing section 36. The opening area of ​​the elastic member housing section 36 is larger than the opening area of ​​the weight-reducing section 35. Therefore, the weight-reducing section 35 cannot accommodate the end of the coil spring 41, but the elastic member housing section 36 can accommodate the end of the coil spring 41.

[0062] Here, the first to third intermediate spring seats 3b, 3c, and 3d included in each damper section 40 are positioned between adjacent coil springs 41 in the circumferential direction and support the ends of each coil spring 41. In addition, the first and second end spring seats 3a and 3e support the ends of the coil springs 41 adjacent to the power transmission section 51b in the circumferential direction.

[0063] Each of these two first and second end spring seats 3a and 3e is in circumferential contact with the power transmission section 51b, the first contact section 21f, and the second contact section 22d, respectively. When the DMF 100 is activated, one of the first and second end spring seats 3a and 3e is pressed by the primary flywheel 2. The other of the first and second end spring seats 3a and 3e is pressed in the circumferential direction by the first output member 51. In this way, the multiple coil springs 41 expand and contract between the first output member 51 and the primary flywheel 2 via the spring seats 3.

[0064] [Hysteresis Torque Generation Mechanism 4] As shown in Figures 5 and 6, the hysteresis torque generating mechanism 4 is composed of grease (an example of a viscous fluid). The grease is placed in the gap between the primary flywheel 2 and the spring seat 3. More specifically, the grease 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 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.

[0065] In detail, the grease 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. The grease is filled into the housing S. When the DMF 100 is in operation, the grease 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 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. When the DMF 100 is in operation, the third gap 83 is completely filled with grease.

[0066] The grease further contacts the first surface F1 of the spring seat 3. More specifically, the grease is filled so as to cover the entire outer surface 34X of the spring seat 3. The grease may also be filled so as to cover the entire or partially cover two sides 34Y of the spring seat 3.

[0067] The grease 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.

[0068] The grease 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 only partially cover it.

[0069] The grease is also filled into the fourth axial gap 84 between the first contact portion 21f and the power transmission portion 51b, and the fifth axial gap 85 between the power transmission portion 51b and the second contact portion 22d.

[0070] The hysteresis torque generating mechanism 4 generates a hysteresis 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, generating a shear torque for the grease. This shear torque for the grease is used as the hysteresis torque T.

[0071] Hysteresis torque T occurs in the first gap 81, the second gap 82, and the third gap 83. The hysteresis torque T that occurs in the first gap 81 will be described below. The total hysteresis torque obtained from the first end spring seat 3a is the sum of the hysteresis torques T calculated for each of the first gap 81, the second gap 82, and the third gap 83.

[0072] The hysteresis torque T is proportional to the characteristic radius R of the grease, the area A of the grease in contact with the spring seat 3, the apparent viscosity η of the grease, and the relative angular velocity ω between the primary flywheel 2 and the spring seat 3. Furthermore, the hysteresis 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 hysteresis torque T is defined by the following equation (1). Equation (1) allows us to define the hysteresis torque T generated by the grease in contact with one spring seat 3.

[0073]

number

[0074] The representative radius R is the representative radius of the grease when the DMF100 is in operation. Specifically, when the DMF100 is in operation, the grease is subjected to centrifugal force and spreads radially outward within the housing S defined by the second axial side surface of the first main body 21a, the inner circumferential surface of the cylindrical part 21b, and the first axial side surface of the seal plate 22. In other words, when the DMF100 is in operation, the grease is in contact with the second axial side surface of the first main body 21a, the inner circumferential surface of the cylindrical part 21b, the first axial side surface of the seal plate 22, the first axial side surface of the spring seat 3, the outer circumferential surface of the spring seat 3, and the second axial side surface of the spring seat 3. The representative radius of the grease 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. Note that the maximum grease radius R2 is the distance from the rotation axis O to the outer surface 34X.

[0075]

number

[0076] Area A is the area of ​​grease in contact with each surface of the spring seat 3 when the DMF100 is operating in the first gap 81.

[0077] 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.

[0078] 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.

[0079] The hysteresis torque T generated in the second gap 82 and the third gap 83 can be calculated in the same way as the hysteresis torque T generated in the first gap 81. The differences between the hysteresis torque T obtained in the third gap 83 and the hysteresis torque T obtained in the first gap 81 are explained below.

[0080] 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 ​​grease 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.

[0081] Apparent viscosity η is the apparent viscosity of the grease during operation. Apparent viscosity η is defined by the following equation (3).

[0082]

number

[0083] In equation (3), μ is the well-known viscosity coefficient of the grease.

[0084] n is the viscosity index of the grease. The viscosity index n is calculated from the relationship between the shear rate of the grease and the apparent viscosity of the grease. Specifically, the viscosity index n is calculated by varying the shear rate conditions of the grease at 24°C and measuring the apparent viscosity η of the grease using a capillary rheometer. The logarithm of the shear rate of the grease is plotted on the x-axis and the logarithm of the apparent viscosity of the grease 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. For example, the regression line may be found using the least squares method or by other methods. The value obtained by adding 1 to the slope of the line is taken as the viscosity index n of the grease.

[0085] The viscosity index n is 0.4 or greater. The reason for this is as follows: From equations (1) and (3), the hysteresis torque T can be defined by the following equation (4).

number

[0086] Generally, the relative angular velocity (hereinafter simply referred to as relative angular velocity) 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 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 the fluctuation range of the damper input torque between engine startup and normal operation remains similar even if the size of the DMF100 changes. Therefore, if a hysteresis torque T of 5 times or more than the hysteresis torque T required during normal operation is generated when the relative angular velocity changes 40 times, the resonance that occurs during engine startup can be sufficiently suppressed.

[0087] According to equation (4), the rate of increase of hysteresis 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 rate of hysteresis torque fluctuation was investigated. As a result, it was found that if the viscosity index n is 0.4 or higher, the rate of increase of hysteresis torque 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.

[0088] 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 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 hysteresis torque T.

[0089] The total hysteresis torque obtained for the entire DMF is the sum of the hysteresis torques T calculated for each of the first and second end spring seats 3a and 3e, and the first to third intermediate spring seats b to d.

[0090] Furthermore, the shear torque of the grease 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 generated in the fourth gap 84 between the first contact portion 21f and the power transmission portion 51b, and the fifth gap 85 between the power transmission portion 51b and the second contact portion 22d can also be used as the hysteresis torque T. In this case, preferably, the fourth gap 84 between the first contact portion 21f and the power transmission portion 51b is smaller than the fifth gap 85 between the power transmission portion 51b and the second contact portion 22d.

[0091] [Action / Effect] The torque transmitted from the engine to the primary flywheel 2 is input to the damper section 40 via the hysteresis torque generation mechanism 4. In the damper section 40, torque is input to the input plate 21, and this torque is transmitted to the output side electric motor, generator, transmission, etc. via the coil spring 41.

[0092] Furthermore, for example, during engine startup, resonance may occur due to the large inertia of the output side, resulting in excessive torque being input to the damper section 40. In such cases, it is necessary to generate hysteresis torque T. On the other hand, during driving, it is necessary to reduce the hysteresis torque.

[0093] The hysteresis torque generation mechanism 4 can change the hysteresis torque T according to the relative angular velocity ω. As a result, it is possible to dampen rotational fluctuations from the engine while suppressing resonance.

[0094] In this embodiment, the weight-reducing portion 35 is located on the second surface F2 of the spring seat 3, which does not face the primary flywheel 2, and the first surface F1 that faces the primary flywheel 2. As shown in equation (1), the magnitude of the hysteresis torque T is proportional to the area in contact with the grease on the surface of the spring seat 3 that faces the primary flywheel 2. Since the weight-reducing portion 35 is not located on the first surface F1 where the hysteresis torque T is generated, the hysteresis torque T is not reduced. Therefore, the second rotating body can be made lighter without reducing the hysteresis torque T on the first surface F1. On the other hand, by arranging the weight-reducing portion 35 on the second surface F2, the spring seat 3 can be made lighter.

[0095] Furthermore, in the first end spring seat 3a, the axial dimension H2 of the second gap 82 is smaller than the axial dimension H1 of the first gap 81. Therefore, a larger hysteresis torque T can be generated compared to the case where the axial dimension H1 of the first gap 81 and the axial dimension H2 of the second gap 82 are the same, as in the first to third intermediate spring seats 3b, 3c, 3d and the second end spring seat 3e.

[0096] [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.

[0097] (a) In the above embodiment, DMF100 was described as an example of a rotating device, but the rotating device is not limited to DMF. 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.

[0098] (b) In the above embodiment, the first end spring seat 3a and the second end spring seat 3e had the same shape, and the first intermediate spring seat 3b, the second intermediate spring seat 3c, and the third intermediate spring seat 3d had the same shape, but the embodiment is not limited to this. For example, the first end spring seat 3a and the second end spring seat 3e may have different shapes, and the first intermediate spring seat 3b, the second intermediate spring seat 3c, and the third intermediate spring seat 3d may have different shapes.

[0099] (c) In the above embodiment, the weight-reducing portion 35 is positioned radially outward relative to the elastic member housing portion 36, but is not limited thereto. As shown in Figures 9A and 9B, the weight-reducing portion 35 may be positioned radially inward relative to the elastic member housing portion 36.

[0100] (d) In the above embodiment, the weight-reducing portion 35 is positioned radially outward relative to the elastic member housing portion 36, but is not limited thereto. As shown in Figures 10A and 10B, the weight-reducing portion 35 may have both a first weight-reducing portion 35a positioned radially outward relative to the elastic member housing portion 36 and a second weight-reducing portion 35b positioned radially inward relative to the elastic member housing portion 36.

[0101] In this modified example, the first cutout portion 35a is larger than the second cutout portion 35b. That is, the opening area of ​​the first cutout portion 35a is larger than the opening area of ​​the second cutout portion 35b. Also, in this modified example, grease is placed in the first cutout portion 35a but not in the second cutout portion 35b.

[0102] (e) In the above embodiment, the weight-reducing portion 35 had a circular opening, but is not limited to this. As shown in Figures 11A and 11B, the weight-reducing portion 35 may have an opening that extends in the axial direction.

[0103] (f) In the above embodiment, the weight-reducing portions 35 were arranged in pairs on the radially inward and / or radially outward sides of the elastic member housing portion 36, but the invention is not limited thereto. As shown in Figures 11A and 11B, the weight-reducing portions 35 may be arranged with one on the radially inward side and one on the radially outward side of the elastic member housing portion 36.

[0104] (g) In the above embodiment, the input plate 21 was exemplified as the first input section and the seal plate 22 as the second input section, but the configuration of the primary flywheel 2 is not limited thereto. For example, the seal plate 22 may be the first input section and the input plate 21 may be the second input section. That is, the gap between the first main body portion 21a of the input plate 21 and the spring seat 3 may be the second gap, and the gap between the seal plate 22 and the spring seat 3 may be the first gap, and the axial dimension of the second gap may be smaller than the axial dimension of the first gap.

[0105] (h) In the above embodiment, in the stationary state, the axial dimension H2 of the second gap 82 was smaller than the axial dimension H1 of the first gap 81. However, the relationship between the first gap 81 and the second gap 82 in the stationary state is not particularly limited to this. For example, when the DMF 100 is in operation, if the axial dimension H2 of the second gap 82 is smaller than the axial dimension H1 of the first gap 81, then in the stationary state, the axial dimension H1 of the first gap 81 and the axial dimension H2 of the second gap 82 may be the same.

[0106] Furthermore, as shown in Figure 5, the radius of curvature of the first corner C1 connecting the first main body 21a and the cylindrical portion 21b is greater than the radius of curvature of the second corner C2 of the spring seat 3 facing the first corner C1. Therefore, when the DMF 100 is in operation and the spring seat 3 moves radially outward due to the radially outward stress caused by the coil spring 41, the first corner C1 can move the spring seat 3 axially. This makes the axial dimension H2 of the second gap 82 smaller than the axial dimension H1 of the first gap 81.

[0107] (i) In the above embodiment, the axial dimension H2 of the second gap 82 was smaller than the axial dimension H1 of the first gap 81 only in the first end spring seat 3a, but is not limited to this. In one or more of the spring seats 3 other than the first end spring seat 3a, for example, the first to third intermediate spring seats 3b, 3c, 3d, and the second end spring seat 3e, the axial dimension H2 of the second gap 82 may be smaller than the axial dimension H1 of the first gap 81. Also, in one or more of the spring seats 3 other than the first end spring seat 3a, for example, the first to third intermediate spring seats 3b, 3c, 3d, and the second end spring seat 3e, the axial dimension H1 of the first gap 81 may be smaller than the axial dimension H2 of the second gap 82.

[0108] (j) In the above embodiment, the first end spring seat 3a was described as an example of the second rotating body, but the second rotating body may be any other spring seat 3. That is, in at least one of the multiple spring seats 3, the axial dimension H2 of the second gap 82 is smaller than the axial dimension H1 of the first gap 81. In the other spring seats 3, the axial dimension H1 of the first gap 81 and the axial dimension H2 of the second gap 82 may be the same.

[0109] (k) In the above embodiment, the axial dimension H4 of the fourth gap 84 and the axial dimension H5 of the fifth gap 85 were the same, but the embodiment is not limited to this. For example, the power transmission unit 51b is further arranged with a gap between the second contact portion 22d of the seal plate 22 and the fifth gap 85 in the axial direction. The axial dimension H4 of the fourth gap 84 may be smaller than the axial dimension H5 of the fifth gap 85. Or, the axial dimension H5 of the fifth gap 85 may be smaller than the axial dimension H4 of the fourth gap 84. This makes it possible to obtain a greater hysteresis torque than when the axial dimensions H4 of the fourth gap 84 and the axial dimensions H5 of the fifth gap 85 are the same.

[0110] (l) In the above embodiment, the axial dimension G of the gap between the input plate 21 and the seal plate 22 was the same except between the first contact portion 21f and the second contact portion 22d, but is not limited to this. As shown in Figure 12, the stationary position of the spring seat 3 is defined as the first position, and the position to which the spring seat 3 moves during operation is defined as the second position. The axial dimension G1 of the gap 71 between the input plate 21 and the seal plate 22 at the first position is different from the axial dimension G2 of the gap 72 between the input plate 21 and the seal plate 22 at the second position. Dimension G1 may be larger or smaller than dimension G2.

[0111] Specifically, when the torsional angle between the primary flywheel 2 and the spring seat 3 exceeds a predetermined value, the dimension G1 in the region where the first end spring seat 3a is located can be made smaller than the dimension G2. Therefore, a larger hysteresis torque can be generated when the torsional angle between the primary flywheel 2 and the spring seat 3 is large.

[0112] (m) In the above embodiment, the spring seat 3 was positioned parallel to the primary flywheel 2, but is not limited thereto. The side surface 34Y of the spring seat 3 may be inclined circumferentially with respect to the side surface of the primary flywheel 2. In particular, as shown in Figure 13, the axial dimension H1 of the first gap 81 on the first circumferential side is different from the axial dimension H1 of the first gap 81 on the second circumferential side. That is, the spring seat 3 is inclined with respect to the seal plate 22. In the first gap 81, the axial dimension H1 of the first gap 81 on the first circumferential side may be smaller or larger than the axial dimension H1 of the first gap 81 on the second circumferential side.

[0113] (n) The DMF100 may further include a cam mechanism 9. As shown in Figure 14, the cam mechanism 9 is positioned between the spring seat 3 and the power transmission unit 51b. The cam mechanism 9 is configured to convert the circumferential movement of the spring seat 3 into axial movement when the spring seat 3 and the secondary flywheel 5 come into contact. At this time, the third rotating body does not move in the axial direction.

[0114] The cam mechanism 9 is composed of a first cam surface 91 and a second cam surface 92. The first cam surface 91 is formed on the spring seat 3. More specifically, the first cam surface 91 is formed on the inner wall surface defining the engagement recess 91a of the spring seat 3. The first cam surface 91 is oriented axially and circumferentially. This allows the spring seat 3 and the secondary flywheel 5 to come into contact during the operation of the DMF 100, and the cam mechanism 9 to convert the circumferential movement of the spring seat 3 into axial movement. The second cam surface 92 is formed on the secondary flywheel 5. The second cam surface 92 faces the first cam surface 91.

[0115] (o) In the above embodiment, the input plate 21 and the seal plate 22 are formed from separate components, but the invention is not limited to this. For example, the input plate 21 and the seal plate 22 may be made from a single component.

[0116] (p) In the above modified example, the DMF100 had a first cam surface 91 and a second cam surface 92, but is not limited thereto. The DMF100 may have only the first cam surface 91. [Examples]

[0117] 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.

[0118] [Preparation of DMF100] DMF100 was manufactured such that the representative radius R of the grease in formula (1), the area A of the grease 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.

[0119] In this simulation, the relative angular velocity ω during normal operation was 50 deg / s. The relative angular velocity ω when resonance occurred during engine startup was 2000 deg / s. In other words, the relative angle when resonance occurred during engine startup was 40 times the relative angular velocity ω during normal operation.

[0120] 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.

[0121] 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 hysteresis torque at engine startup relative to the hysteresis torque during normal operation (hereinafter referred to as the hysteresis torque increase ratio) when the relative angular velocity 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 15.

[0122] [Table 1]

[0123] [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 15, the hysteresis torque increase rate was five times or more when the viscosity index n was 0.43 or higher. 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]

[0124] 2. Primary flywheel (an example of a first rotating body) 3. Spring seat (an example of a second rotating body) 4. Hysteresis Torque Generation Mechanism 21 Input section 21a Main body 21b Cylindrical part 35. Weight reduction section 40 Damper section 41 Coil springs 51 First output member 100 DMF (Example of a rotating device) O Rotation axis S Storage Unit

Claims

1. A first rotating body having a housing section, A second rotating body is disposed within the housing so as to be rotatable relative to the first rotating body, with a gap between it and the inner wall surface of the housing, A hysteresis torque generation mechanism, which is composed of a viscous fluid filled in the aforementioned housing, Equipped with, The hysteresis torque generating mechanism generates a hysteresis torque that is proportional to the representative radius of the viscous fluid, the area of ​​the viscous fluid in contact with the second rotating body, the apparent viscosity of the viscous fluid, and the relative angular velocity between the first and second rotating bodies, and inversely proportional to the axial gap between the first and second rotating bodies. The viscosity index n of the viscous fluid is 0.43 or greater. Rotating device.

2. The first rotating body is First input unit and A second input unit is arranged at an axial distance from the first input unit, It has, The second rotating body is positioned between the first input unit and the second input unit in the axial direction. The viscous fluid is disposed in the first gap between the first input section and the second rotating body, and in the second gap between the second input section and the second rotating body. The axial dimension of the second gap is configured to be smaller than the axial dimension of the first gap. The rotating device according to claim 1.

3. The system further comprises a third rotating body positioned axially between the first input section and the second input section, and capable of relative rotation with respect to the first input section and the second input section. The axial dimension of the fourth gap between the first input section and the third rotating body is different from the axial dimension of the fifth gap between the second input section and the third rotating body. The rotating device according to claim 2.

4. The second rotating body has a first surface facing the first rotating body and a second surface not facing the first rotating body. The second rotating body has a weight-reducing portion on the second surface. The rotating device according to any one of claims 1 to 3.

5. The system further comprises an elastic member positioned adjacent to the second rotating body in the circumferential direction, The second rotating body has an elastic member housing portion that houses the elastic member on a surface facing the circumferential direction, The opening area of ​​the weight-reducing portion is smaller than the opening area of ​​the elastic member housing portion. The rotating device according to claim 4.

6. The second rotating body has a circumferential surface facing the circumferential direction, The weight-reducing portion is arranged on the circumferential surface of the second rotating body, The rotating device according to claim 4 or claim 5.

7. The aforementioned weight-reducing portion is a recess that opens in the circumferential direction. The rotating device according to claim 6.

8. The weight-reducing portion is positioned radially outward or radially inward relative to the elastic member housing portion. The rotating device according to claim 5.

9. The aforementioned weight-reducing portion is, A first weight-reducing portion is provided, which is located radially outward from the elastic member housing portion. A second weight-reducing portion is positioned radially inward from the elastic member housing portion, It has, The first weight-reducing portion is larger than the second weight-reducing portion. The rotating device according to claim 8.

10. The viscous fluid is placed in the first hollowed-out section, but not in the second hollowed-out section. The rotating device according to claim 9.

11. A first rotating body having a housing section, A second rotating body is disposed within the housing so as to be rotatable relative to the first rotating body, with a gap between it and the inner wall surface of the housing, A hysteresis torque generation mechanism, which is composed of a viscous fluid filled in the aforementioned housing, Equipped with, The hysteresis torque generating mechanism generates a hysteresis torque that is proportional to the representative radius of the viscous fluid, the area of ​​the viscous fluid in contact with the second rotating body, the apparent viscosity of the viscous fluid, and the relative angular velocity between the first and second rotating bodies, and inversely proportional to the axial gap between the first and second rotating bodies. The first rotating body is First input unit and A second input unit is arranged at an axial distance from the first input unit, It has, The second rotating body is positioned between the first input unit and the second input unit in the axial direction. The viscous fluid is disposed in the first gap between the first input section and the second rotating body, and in the second gap between the second input section and the second rotating body. The axial dimension of the second gap is configured to be smaller than the axial dimension of the first gap. Rotating device.

12. A first rotating body having a housing section, A second rotating body is disposed within the housing so as to be rotatable relative to the first rotating body, with a gap between it and the inner wall surface of the housing, A hysteresis torque generation mechanism, which is composed of a viscous fluid filled in the aforementioned housing, Equipped with, The hysteresis torque generating mechanism generates a hysteresis torque that is proportional to the representative radius of the viscous fluid, the area of ​​the viscous fluid in contact with the second rotating body, the apparent viscosity of the viscous fluid, and the relative angular velocity between the first and second rotating bodies, and inversely proportional to the axial gap between the first and second rotating bodies. The second rotating body has a first surface facing the first rotating body and a second surface not facing the first rotating body. The second rotating body has a weight-reducing portion on the second surface, The second rotating body has a circumferential surface facing the circumferential direction, The weight-reducing portion is arranged on the circumferential surface of the second rotating body, The aforementioned weight-reducing portion is a recess that opens in the circumferential direction. Rotating device.

13. A first rotating body having a housing section, A second rotating body is disposed within the housing so as to be rotatable relative to the first rotating body, with a gap between it and the inner wall surface of the housing, A hysteresis torque generation mechanism, which is composed of a viscous fluid filled in the aforementioned housing, Equipped with, The hysteresis torque generating mechanism generates a hysteresis torque that is proportional to the representative radius of the viscous fluid, the area of ​​the viscous fluid in contact with the second rotating body, the apparent viscosity of the viscous fluid, and the relative angular velocity between the first and second rotating bodies, and inversely proportional to the axial gap between the first and second rotating bodies. The second rotating body has a first surface facing the first rotating body and a second surface not facing the first rotating body. The second rotating body has a weight-reducing portion on the second surface, The system further comprises an elastic member positioned adjacent to the second rotating body in the circumferential direction, The second rotating body has an elastic member housing portion that houses the elastic member on a surface facing the circumferential direction, The opening area of ​​the weight-reducing portion is smaller than the opening area of ​​the elastic member housing portion. The weight-reducing portion is positioned radially outward or radially inward relative to the elastic member housing portion. Rotating device.

Images