Patent Publication Number: US-2019178333-A1

Title: Damper device

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     This application is based upon and claims the benefit of priority from Japanese Patent Application No. 2017-235553, filed Dec. 7, 2017, the entire contents of which are incorporated herein by reference. 
     FIELD 
     Embodiments described herein relate generally to a damper device. 
     BACKGROUND 
     Conventionally known are damper devices provided on a rotation transmission path between a rotation output side, such as an engine, and a rotation input side, such as a transmission. Damper devices damp rotational fluctuations generated in rotation on the output side and transmit the rotation to the input side. 
     Various structures usable for damper devices are known, including a structure in which an inertia ring and weights are provided to a rotator. The inertia ring can relatively rotate with respect to the rotator. The weights can be moved in a radial direction by centrifugal force generated by rotation of the rotator. Rollers provided to the inertia ring come into contact with respective cam-like curved surfaces of the weights. When a rotational phase difference is generated between the rotator and the inertia ring, the centrifugal force acting on the weights is converted into force in a circumferential direction for reducing the rotational phase difference (Japanese Patent Application Laid-open No. 2017-53467). 
     In the conventional structure, however, the weights may each possibly rotate around the contact point of the roller and the curved surface, thereby generating rotational inertia and friction. If movement of the weights is prevented by the rotational inertia and/or the friction, the damping performance of the damper device is degraded. 
     In view of the disadvantage described above, the present invention aims to provide a damper device that can suppress degraded performance in damping rotational fluctuations of a rotator. 
     SUMMARY 
     For example, a damper device according to an embodiment of the present invention includes: a rotator capable of rotating about a first center of rotation and provided with at least one first opening; a first oscillator capable of oscillating about the first center of rotation with respect to the rotator; at least one second oscillator including two guide surfaces recessed in a direction closer to the first center of rotation and at least one transmitting part capable of being supported by an edge of the first opening in a circumferential direction of the first center of rotation and capable of moving along the first opening, the second oscillator capable of oscillating in a radial direction of the first center of rotation with respect to the rotator; and two rollers that extend along a second center of rotation and at least part of which is supported by the first oscillator rotatably about the second center of rotation, the rollers being configured to come into contact with the respective two guide surfaces of the second oscillator pushed outward in the radial direction of the first center of rotation by centrifugal force generated by rotation of the rotator, and configured to roll along the respective two guide surfaces by oscillation of the first oscillator with respect to the rotator and to be pushed by the respective two guide surfaces in the circumferential direction of the first center of rotation. The second oscillator is capable of translation (moving without rotation) in the radial direction of the first center of rotation with the two guide surfaces supported by the respective two rollers. This structure, for example, suppresses rotational inertia generated in the second oscillator about a rotational axis passing therethrough by rotation of the second oscillator about the rotational axis and undesired friction generated between the second oscillator and the rotator or the first oscillator. Consequently, the second oscillator can smoothly oscillate in the radial direction of the first center of rotation, and the rollers can smoothly roll along the respective guide surfaces. The rollers supported by the first oscillator are pushed by the respective guide surfaces in the circumferential direction of the first center of rotation. As a result, restoring force acts on the rotator via the second oscillator, thereby damping the rotational fluctuations of the rotator. As described above, the rollers can smoothly roll along the respective guide surfaces, thereby suppressing degraded performance of the damper device in damping the rotational fluctuations of the rotator. 
     For example, in the damper device, the two guide surfaces are formed mirror-symmetrically with respect to a first virtual line extending in the radial direction of the first center of rotation. This structure, for example, suppresses arrangement of the center of gravity of the second oscillator in a manner deviating in the circumferential direction of the first center of rotation. Consequently, the second oscillator can be translated in the radial direction of the first center of rotation more reliably. 
     For example, in the damper device, the rotator is provided with two of the first openings, and the second oscillator includes two of the transmitting parts and is capable of translation in the radial direction of the first center of rotation with the two guide surfaces supported by the respective two rollers and with at least one of the two transmitting parts supported by the edge of at least one of the two first openings. Consequently, for example, the second oscillator is supported at at least three points and can be translated in the radial direction of the first center of rotation more reliably. 
     For example, in the damper device, the two first openings are formed mirror-symmetrically with respect to a second virtual line extending in the radial direction of the first center of rotation, and the two transmitting parts are provided mirror-symmetrically with respect to the second virtual line. This structure, for example, suppresses arrangement of the center of gravity of the second oscillator in a manner deviating in the circumferential direction of the first center of rotation. Consequently, the second oscillator can be translated in the radial direction of the first center of rotation more reliably. 
     For example, in the damper device, the second oscillator is capable of translation in the radial direction of the first center of rotation with the two guide surfaces supported by the respective two rollers and with the transmitting part supported by the edge of the first opening. Consequently, for example, the second oscillator is supported at at least three points and can be translated in the radial direction of the first center of rotation more reliably. 
     For example, in the damper device, the at least one transmitting part is positioned between the two guide surfaces in the circumferential direction of the first center of rotation. Consequently, for example, the second oscillator can be translated in the radial direction of the first center of rotation more reliably. 
     For example, in the damper device, the second oscillator is provided with two second openings, and the two guide surfaces include part of closed edges of the respective two second openings. Consequently, for example, part of the second oscillator can be provided on the outer side than the second openings in the radial direction of the first center of rotation, thereby increasing the centrifugal force acting on the second oscillator. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a front view of an example of a damper device according to a first embodiment; 
         FIG. 2  is a sectional view of part of an example of the damper device according to the first embodiment along line F 2 -F 2  of  FIG. 1 ; 
         FIG. 3  is a sectional view of part of an example of the damper device according to the first embodiment along line F 3 -F 3  of  FIG. 1 ; 
         FIG. 4  is a sectional view of part of an example of the damper device according to the first embodiment along line F 4 -F 4  of  FIG. 1 ; 
         FIG. 5  is a sectional view of part of an example of the damper device according to the first embodiment along line F 5 -F 5  of  FIG. 1 ; 
         FIG. 6  is a sectional view of part of an example of the damper device according to the first embodiment along line F 6 -F 6  of  FIG. 2 ; 
         FIG. 7  is a front view of an example of the damper device in which an inertia ring and mass members oscillate according to the first embodiment; 
         FIG. 8  is a sectional view of part of an example of the damper device according to a modification of the first embodiment; 
         FIG. 9  is a sectional view of part of an example of the damper device according to a second embodiment; 
         FIG. 10  is a front view of part of an example of the damper device according to a third embodiment; 
         FIG. 11  is a sectional view of part of an example of the damper device according to the third embodiment along line F 11 -F 11  of  FIG. 10 ; 
         FIG. 12  is a sectional view of part of an example of the damper device according to the third embodiment along line F 12 -F 12  of  FIG. 11 ; 
         FIG. 13  is a front view of part of an example of the damper device according to a fourth embodiment; 
         FIG. 14  is a sectional view of part of an example of the damper device according to the fourth embodiment along line F 14 -F 14  of  FIG. 13 ; and 
         FIG. 15  is a sectional view of part of an example of the damper device according to the fourth embodiment along line F 15 -F 15  of  FIG. 13 . 
     
    
    
     DETAILED DESCRIPTION 
     First embodiment 
     A first embodiment is described below with reference to  FIGS. 1 to 8 . In the present specification, components according to embodiments and explanation of the components may be described in a plurality of expressions. The components and the explanation described in a plurality of expressions may be described in other expressions not described herein. Components and explanation not described in a plurality of expressions may be described in other expressions not described herein. 
       FIG. 1  is a front view of an example of a damper device  1  according to the first embodiment.  FIG. 2  is a sectional view of part of an example of the damper device  1  according to the first embodiment along line F 2 -F 2  of  FIG. 1 .  FIG. 3  is a sectional view of part of an example of the damper device  1  according to the first embodiment along line F 3 -F 3  of  FIG. 1 .  FIG. 4  is a sectional view of part of an example of the damper device  1  according to the first embodiment along line F 4 -F 4  of  FIG. 1 .  FIG. 5  is a sectional view of part of an example of the damper device  1  according to the first embodiment along line F 5 -F 5  of  FIG. 1 . 
     The damper device  1  is mounted on a vehicle and connected to an input shaft of a transmission, for example. The damper device  1  may be connected to other rotators. When an engine rotates an output shaft, the rotation is transmitted from the output shaft to the input shaft. The damper device  1  damps rotational fluctuations generated in the rotation transmitted from the output shaft to the input shaft. The rotational fluctuations include at least one of fluctuations in torque and fluctuations in rotational speed. 
     As illustrated in  FIGS. 1 to 5 , the damper device  1  includes a disk plate  2 , an inertia ring  3 , six mass members  4 , six rollers  5 , six transmitting parts  6 , a plurality of first spacers  7 , a plurality of second spacers  8 , and a plurality of third spacers  9 . The disk plate  2  is an example of a rotator. The inertia ring  3  is an example of a first oscillator. The mass member  4  is an example of a second oscillator. 
     The disk plate  2  can rotate about a central axis Ax 1  illustrated in  FIG. 1 . The central axis Ax 1  is an example of a first center of rotation. In the following description, a direction orthogonal to the central axis Ax 1  is referred to as a radial direction of the central axis Ax 1 . A direction along the central axis Ax 1  is referred to as an axial direction of the central axis Ax 1 . A direction rotating about the central axis Ax 1  is referred to as a circumferential direction of the central axis Ax 1 . 
     The disk plate  2  is made of metal, such as iron, and has a disk shape expanding in the radial direction of the central axis Ax 1 . The disk plate  2  may be made of other materials. The disk plate  2  is connected to the input shaft of the transmission. Consequently, rotation generated by the engine is transmitted to the disk plate  2 . 
     As illustrated in  FIG. 4 , the disk plate  2  has two side surfaces  21  and an outer peripheral surface  22 . As illustrated in  FIG. 1 , the disk plate  2  is provided with a connecting part  25  and six first recesses  26 . The first recess  26  is an example of a first opening. 
     As illustrated in  FIG. 4 , the two side surfaces  21  face the axial direction of the central axis Ax 1 . The side surfaces  21  have a substantially flat shape and are orthogonal to the central axis Ax 1 . The side surfaces  21  may have a protrusion and a recess and a part inclined with respect to the radial direction of the central axis Ax 1 . The outer peripheral surface  22  faces outward in the radial direction of the central axis Ax 1 . 
     As illustrated in  FIG. 1 , the connecting part  25  is provided at substantially the center of the disk plate  2 . To the connecting part  25 , the input shaft of the transmission is connected. The six first recesses  26  are cut-outs penetrating the disk plate  2  in the axial direction of the central axis Ax 1  and opening in the two side surfaces  21  and the outer peripheral surface  22 . The first opening is not limited to a cut-out and may be a hole having a closed edge. 
     In the following description, three virtual lines L illustrated in  FIG. 1  are defined. The virtual line L is an example of a first virtual line and a second virtual line. The first virtual line and the second virtual line may be different from each other. The virtual lines L extend from the central axis Ax 1  in the radial direction of the central axis Ax 1 . The three virtual lines L are provided at every 120° about the central axis Ax 1 . In other words, the virtual lines L extend radially from the central axis Ax 1 . 
     The virtual lines L are provided based on the disk plate  2 . If the disk plate  2  rotates about the central axis Ax 1 , the virtual lines L also rotate about the central axis Ax 1 . By contrast, if the other members, such as the inertia ring  3  and the mass members  4 , move with respect to the disk plate  2 , the virtual lines L do not move with respect to the disk plate  2 . 
     Two first recesses  26  are formed mirror-symmetrically with respect to one virtual line L. Consequently, the distances between the respective two first recesses  26  and the virtual line L are equal to each other. The two first recesses  26  according to the present embodiment extend from the outer peripheral surface  22  in substantially parallel with the virtual line L. Consequently, the two first recesses  26  extend in substantially parallel with each other. 
       FIG. 6  is a sectional view of part of an example of the damper device  1  according to the first embodiment along line F 6 -F 6  of  FIG. 2 . As illustrated in  FIG. 6 , the disk plate  2  has first edges  26   a  and second edges  26   b  sectioning (defining) the respective first recesses  26 . The first edge  26   a  and the second edge  26   b  are an example of an edge of the first opening. 
     The first edge  26   a  and the second edge  26   b  are part of the edge of the first recess  26  and substantially flat surfaces formed on the disk plate  2 . The first edge  26   a  and the second edge  26   b  may include a curved surface. 
     The first edge  26   a  and the second edge  26   b  extend in substantially parallel with the virtual line L and face each other. The first edge  26   a  is closer to the virtual line L than the second edge  26   b  is. The first edge  26   a  is longer than the second edge  26   b.    
     As illustrated in  FIG. 1 , the inertia ring  3  is made of metal, such as iron, and has an annular shape extending in the circumferential direction of the central axis Ax 1 . The inertia ring  3  may be made of other materials. 
     As illustrated in  FIG. 4 , the inertia ring  3  has two side surfaces  31  and an inner peripheral surface  32 . The two side surfaces  31  face the axial direction of the central axis Ax 1 . The side surfaces  31  have a substantially flat shape and are orthogonal to the central axis Ax 1 . The side surfaces  31  may have a protrusion and a recess and a part inclined with respect to the radial direction of the central axis Ax 1 . The inner peripheral surface  32  faces inward in the radial direction of the central axis Ax 1 . 
     The inside diameter of the inertia ring  3  is larger than the outside diameter of the disk plate  2 . The inertia ring  3  surrounds the disk plate  2  with a space interposed therebetween. As a result, the inner peripheral surface  32  of the inertia ring  3  and the outer peripheral surface  22  of the disk plate  2  face each other with a space interposed therebetween. 
     The inertia ring  3  can oscillate about the central axis Ax 1  with respect to the disk plate  2 . In other words, the inertia ring  3  can rotate about the central axis Ax 1  with respect to the disk plate  2  within at least a predetermined angular range. 
     If the damper device  1  rotates without rotational fluctuations, for example, the disk plate  2  and the inertia ring  3  rotate about the central axis Ax 1  at a substantially equal speed. At this time, the disk plate  2 , the inertia ring  3 , and the mass members  4  are present at the positions illustrated in  FIG. 1  and rotate about the central axis Ax 1 . 
       FIG. 7  is a front view of an example of the damper device  1  in which the inertia ring  3  and the mass members  4  oscillate according to the first embodiment. As illustrated in  FIG. 7 , when rotational fluctuations are input to the damper device  1 , a difference is generated between the rotational speed of the disk plate  2  and that of the inertia ring  3 . As a result, the inertia ring  3  oscillates about the central axis Ax 1  with respect to the disk plate  2 . 
     Because the inertia ring  3  oscillates about the central axis Ax 1  with respect to the disk plate  2 , a rotational phase difference is generated between the disk plate  2  and the inertia ring  3 . The rotational phase difference is a relative rotational angle about the central axis Ax 1  between the disk plate  2  and the inertia ring  3 . In the present specification, the rotational phase difference between the disk plate  2  and the inertia ring  3  illustrated in  FIG. 1  is defined as 0°. 
     As illustrated in  FIG. 1 , the inertia ring  3  is provided with six support holes  35 . The support hole  35  penetrates the inertia ring  3  in the axial direction of the central axis Ax 1  and opens in the two side surfaces  31 . The support hole  35  has a substantially circular section. The support hole  35  may have other shapes. 
     When the rotational phase difference between the disk plate  2  and the inertia ring  3  is 0°, two support holes  35  are positioned mirror-symmetrically with respect to one virtual line L. Consequently, the distances between the respective two support holes  35  and the virtual line L are equal to each other. 
     The six mass members  4  are weights having the mass substantially equal to one another. As illustrated in  FIG. 2 , the disk plate  2  and the inertia ring  3  are disposed between two mass members  4  in the axial direction of the central axis Ax 1 . 
     As illustrated in  FIG. 1 , a pair of the mass members  4  overlapping in the axial direction of the central axis Ax 1  is disposed such that one virtual line L passes through the center of the pair of the mass members  4  in the circumferential direction of the central axis Ax 1 . Consequently, three pairs of the mass members  4  are disposed at every certain angle in the circumferential direction of the central axis Ax 1 . 
     As illustrated in  FIG. 2 , the six mass members  4  each include an oscillating member  41  and a cover  42 . The oscillating member  41  and the cover  42  according to the present embodiment are made of metal, such as iron. The oscillating member  41  and the cover  42  may be made of other materials. 
     The oscillating member  41  has an inside surface  41   a  and an outside surface  41   b.  The inside surface  41   a  faces one side in the axial direction of the central axis Ax 1 . The inside surface  41   a  faces the side surface  31  of the inertia ring  3  with a space interposed therebetween. The outside surface  41   b  faces the other side in the axial direction of the central axis Ax 1 . 
     As illustrated in  FIG. 1 , the oscillating member  41  also has an arc part  45  and two protrusions  46 . The arc part  45  and the protrusions  46  are part of the oscillating member  41  and formed integrally with each other. The arc part  45  and the protrusions  46  each have the inside surface  41   a  and the outside surface  41   b  of the oscillating member  41 . 
     The arc part  45  has a substantially circular arc shape extending in the circumferential direction of the central axis Ax 1 . The inside surface  41   a  of the arc part  45  faces the side surface  31  of the inertia ring  3  with a space interposed therebetween. The two protrusions  46  extend in a direction closer to the central axis Ax 1  from the arc part  45 . The two protrusions  46  face the respective two first recesses  26  of the disk plate  2 . 
     The two protrusions  46  are formed mirror-symmetrically with respect to one virtual line L. Consequently, the distances between the respective two protrusions  46  and the virtual line L are equal to each other. The two protrusions  46  according to the present embodiment extend in substantially parallel with the virtual line L. Consequently, the two protrusions  46  extend in substantially parallel with each other. 
     The arc part  45  is provided with two guide holes  48 . The guide hole  48  is an example of a second opening. The guide hole  48  penetrates the arc part  45  in the axial direction of the central axis Ax 1  and opens in the inside surface  41   a  and the outside surface  41   b.    
     The oscillating member  41  has inside edges  48   a  and outside edges  48   b  sectioning (defining) the respective guide holes  48 . The inside edge  48   a  is an example of a guide surface. The inside edge  48   a  and the outside edge  48   b  are part of the edge of the guide hole  48  and curved surfaces formed in the oscillating member  41 . In other words, the inside edge  48   a  and the outside edge  48   b  each include part of the edge of the guide hole  48 . The edge of the guide hole  48  has a closed shape and serves as a closed path the start point and the end point of which are identical. The inside edge  48   a  and the outside edge  48   b  may have a flat surface. 
     The inside edge  48   a  is a part recessed in a direction closer to the central axis Ax 1  in the edge of the guide hole  48  formed in the oscillating member  41 . Consequently, the inside edge  48   a  faces outward in the radial direction of the central axis Ax 1 . 
     The outside edge  48   b  is a part recessed in a direction away from the central axis Ax 1  in the edge of the guide hole  48  formed in the oscillating member  41 . Consequently, the outside edge  48   b  faces inward in the radial direction of the central axis Ax 1 . The inside edge  48   a  and the outside edge  48   b  according to the present embodiment have asymmetric shapes. 
     The two guide holes  48  are formed mirror-symmetrically with respect to one virtual line L. Consequently, the inside edges  48   a  and the outside edges  48   b  of the two guide holes  48  are formed mirror-symmetrically with respect to the virtual line L. The shape of the two guide holes  48  is not limited to the example described above. 
     As illustrated in  FIG. 3 , the cover  42  has an inside surface  42   a  and an outside surface  42   b.  The inside surface  42   a  faces one side in the axial direction of the central axis Ax 1 . The inside surface  42   a  faces the outside surface  41   b  of the oscillating member  41 . The outside surface  42   b  faces the other side in the axial direction of the central axis Ax 1 . 
     The cover  42  covers the guide holes  48  of the oscillating member  41  from one side in the axial direction of the central axis Ax 1 . The cover  42  is fixed to the oscillating member  41  by bolts, rivets, welding, or other methods, for example. With this structure, the cover  42  can move integrally with the oscillating member  41 . 
     The six rollers  5  each include a bearing  51  and a rolling shaft  52 . The six rollers  5  are fitted into the respective six support holes  35  of the inertia ring  3 . When the rotational phase difference between the disk plate  2  and the inertia ring  3  is 0°, two rollers  5  are positioned mirror-symmetrically with respect to one virtual line L. 
     The bearing  51  is a ball bearing, for example. Alternatively, the bearing  51  may be other rolling bearings, such as a roller bearing, or sliding bearings, such as a bush. The bearing  51  is hold in the inner peripheral surface of the support hole  35  and supported by the inertia ring  3 . The bearing  51  is interposed between the rolling shaft  52  and the inertia ring  3 . 
     The rolling shaft  52  is made of metal, such as iron. The rolling shaft  52  may be made of other materials. The rolling shaft  52  has a substantially columnar shape extending along a first rotational axis Ax 2  inside the bearing  51 . The first rotational axis Ax 2  is an example of a second center of rotation. The first rotational axes Ax 2  are central axes of the respective six rolling shafts  52  and extend in substantially parallel with the central axis Ax 1 . 
     The rolling shaft  52  has a peripheral surface  52   a  and two end surfaces  52   b.  The peripheral surface  52   a  faces in a direction orthogonal to the first rotational axis Ax 2  and is supported by an inner ring  51   a  of the bearing  51 . As a result, the rolling shaft  52  is supported by the bearing  51  and the inertia ring  3  rotatably about the first rotational axis Ax 2  with respect to the inertia ring  3 . The end surfaces  52   b  face the axial direction of the first rotational axis Ax 2 . In other words, the end surfaces  52   b  face a direction along the first rotational axis Ax 2 . 
     The diameter of the peripheral surface  52   a  according to the present embodiment is substantially uniform. Consequently, the diameter of the peripheral surface  52   a,  which is the largest outside diameter of the rolling shaft  52 , is smaller than the outside diameter of an outer ring  51   b,  which is the largest outside diameter of the bearing  51 . The diameter of the peripheral surface  52   a  may differ depending on the positions in the axial direction of the first rotational axis Ax 2 . 
     Parts of the rolling shaft  52  protrude in the axial direction of the central axis Ax 1  from the side surfaces  31  of the inertia ring  3 . The parts of the rolling shaft  52  are accommodated in the guide holes  48  of the two mass members  4 . As a result, the peripheral surface  52   a  of the rolling shaft  52  faces the inside edge  48   a  and the outside edge  48   b  of the guide hole  48 . The rolling shaft  52  can come into contact with at least one of the inside edge  48   a  and the outside edge  48   b.    
     The cover  42  of the mass member  4  covers the rolling shaft  52  accommodated in the guide hole  48  from one side in the axial direction of the central axis Ax 1 . The end surface  52   b  of the rolling shaft  52  faces the inside surface  42   a  of the cover  42  in the axial direction of the first rotational axis Ax 2  with a gap interposed therebetween. 
     As illustrated in  FIG. 1 , two transmitting parts  6  are attached to the respective protrusions  46  of the mass member  4 . Consequently, the two transmitting parts  6  are provided mirror-symmetrically with respect to one virtual line L. The distance between the virtual line L and the transmitting part  6  is substantially equal to the distance between the virtual line L and the first recess  26 . The transmitting parts  6  and the first recesses  26  are positioned between the two guide holes  48  in the circumferential direction of the central axis Ax 1 . In other words, the transmitting parts  6  and the first recesses  26  are positioned between the two inside edges  48   a  in the circumferential direction of the central axis Ax 1 . The transmitting parts  6  and the first recesses  26  are positioned between at least part of one of the two inside edges  48   a  and at least part of the other thereof in the circumferential direction of the central axis Ax 1 . 
     As illustrated in  FIG. 2 , the two transmitting parts  6  are inserted into the respective two first recesses  26  and connect the two mass members  4  overlapping in the axial direction of the central axis Ax 1 . With this stricture, the two mass members  4  can integrally move with respect to the disk plate  2  and the inertia ring  3 . The six transmitting parts  6  each include a support shaft  61  and a roller  62 . The support shaft  61  is an example of a shaft. 
     The support shaft  61  has a substantially columnar shape extending along a second rotational axis Ax 3 . The second rotational axes Ax 3  pass through the centers of the respective six transmitting parts  6  and extend in substantially parallel with the central axis Ax 1 . The support shaft  61  according to the present embodiment is made of metal, such as iron. The support shaft  61  may be made of other materials. 
     Both ends of the support shaft  61  in the axial direction of the second rotational axis Ax 3  are fixed to the two mass members  4 . As a result, the support shaft  61  connects the two mass members  4  and is supported by the mass members  4 . The support shaft  61  restricts relative movement of the two mass members  4 . The support shaft  61  holds the mass members  4  at the positions separated from the disk plate  2  and the inertia ring  3  in the axial direction of the central axis Ax 1 . 
     The roller  62  has a substantially cylindrical shape extending along the second rotational axis Ax 3 . The roller  62  according to the present embodiment is made of resin, such as synthetic resin. In other words, the support shaft  61  and the roller  62  are made of different materials. The roller  62  may be made of other materials. 
     As illustrated in  FIG. 6 , the support shaft  61  is inserted into the roller  62 . As a result, the roller  62  is supported by the support shaft  61  and the mass members  4  rotatably about the second rotational axis Ax 3 . 
     One part of the roller  62  is interposed between the support shaft  61  and the first edge  26   a  of the first recess  26 . Another part of the roller  62  is interposed between the support shaft  61  and the second edge  26   b  of the first recess  26 . 
     The roller  62  comes into contact with one of the first edge  26   a  and the second edge  26   b.  As a result, the roller  62  is supported by the first edge  26   a  or the second edge  26   b  in the circumferential direction of the central axis Ax 1 . The roller  62  may be temporarily separated from the first edge  26   a  and the second edge  26   b.    
     The two mass members  4  fixed to each other by the transmitting parts  6  can integrally oscillate with respect to the disk plate  2  in the radial direction of the central axis Ax 1 . In other words, the two mass members  4  can integrally oscillate with respect to the disk plate  2  in the radial direction of the central axis Ax 1  within at least a predetermined range. 
     The mass member  4  can oscillate along the virtual line L. The oscillation direction of the mass member  4  is substantially parallel to the extending direction of the virtual line L and the extending direction of the first recess  26 . The mass member  4  oscillates, whereby the transmitting part  6  moves along the first recess  26 , and the roller  62  rolls along the first edge  26   a  or the second edge  26   b.  When the mass member  4  oscillates, the roller  62  may be separated from the first edge  26   a  and the second edge  26   b.    
     The first spacers  7 , the second spacers  8 , and the third spacers  9  illustrated in  FIG. 1  are made of resin, such as synthetic resin. The first spacers  7 , the second spacers  8 , and the third spacers  9  are made of a material different from that of the disk plate  2 , the inertia ring  3 , and the mass members  4 . The first spacers  7 , the second spacers  8 , and the third spacers  9  may be made of other materials. 
     As illustrated in  FIG. 4 , the first spacer  7  is attached to the oscillating member  41  of the mass member  4 . The first spacer  7  protrudes from the oscillating member  41  toward the disk plate  2  and faces the disk plate  2  with a gap interposed therebetween. The first spacer  7  restricts movement of the mass member  4  with respect to the disk plate  2  in the axial direction of the central axis Ax 1  and suppresses contact of the mass member  4  with the disk plate  2 . 
     As illustrated in  FIG. 5 , the second spacer  8  is attached to the oscillating member  41  of the mass member  4 . The second spacer  8  protrudes from the oscillating member  41  toward the inertia ring  3  and faces the inertia ring  3  with a gap interposed therebetween. The second spacer  8  restricts movement of the mass member  4  with respect to the inertia ring  3  in the axial direction of the central axis Ax 1  and suppresses contact of the mass member  4  with the inertia ring  3 . 
     As illustrated in  FIG. 1 , the third spacer  9  is attached to the disk plate  2 . Part of the third spacer  9  is positioned between the outer peripheral surface  22  of the disk plate  2  and the inner peripheral surface  32  of the inertia ring  3 . The third spacer  9  restricts movement of the inertia ring  3  with respect to the disk plate  2  in the radial direction of the central axis Ax 1  and suppresses contact of the disk plate  2  with the inertia ring  3 . 
     As illustrated in  FIG. 7 , when a rotational phase difference is generated between the disk plate  2  and the inertia ring  3 , the inertia ring  3  relatively oscillates (reciprocates) about the central axis Ax 1  with respect to the disk plate  2 . In addition, the mass members  4  relatively oscillate (reciprocate) in the radial direction of the central axis Ax 1  with respect to the disk plate  2 . The following describes oscillation of the inertia ring  3  and the mass members  4 . 
     As illustrated in  FIG. 1 , while the disk plate  2  rotates about the central axis Ax 1 , torque is transmitted from the first edge  26   a  or the second edge  26   b  of the first recess  26  of the disk plate  2  to the mass member  4  via the transmitting part  6 . As a result, the mass member  4  rotates about the central axis Ax 1  integrally with the disk plate  2 , and centrifugal force acts on the mass member  4 . By the centrifugal force generated by rotation of the disk plate  2 , the mass member  4  is pushed outward in the radial direction of the central axis Ax 1  and moves outward in the radial direction of the central axis Ax 1 . 
     Movement of the mass member  4  brings the inside edge  48   a  of the guide hole  48  into contact with the rolling shaft  52  of the roller  5 . In other words, the rolling shaft  52  supports the mass member  4  pushed outward in the radial direction of the central axis Ax 1  by the centrifugal force. 
     One mass member  4  is supported by the two rolling shafts  52  in contact with the inside edges  48   a  of the respective two guide holes  48 . The two guide holes  48  and the two rolling shafts  52  are separated from each other in the circumferential direction of the central axis Ax 1 . As described above, one mass member  4  is supported by the rolling shafts  52  at a plurality of different positions in the circumferential direction of the central axis Ax 1 . 
     The rolling shaft  52  comes into contact with the inside edge  48   a  recessed in the direction closer to the central axis Ax 1 , whereby the torque is transmitted to the inertia ring  3  from the inside edge  48   a  of the mass member  4  via the roller  5 . As a result, the inertia ring  3  rotates about the central axis Ax 1  together with the disk plate  2  and the mass members  4 . 
     When the rotational phase difference between the disk plate  2  and the inertia ring  3  is 0°, the mass members  4  are each positioned at a first position P 1  illustrated in  FIG. 1 . The mass member  4  at the first position P 1  is positioned outermost in the radial direction of the central axis Ax 1  in the oscillation range of the mass member  4  with respect to the disk plate  2 . At this time, the rolling shaft  52  comes into contact with, but not necessarily, a part of the inside edge  48   a  closest to the central axis Ax 1 , for example. 
     When the rotational phase difference between the disk plate  2  and the inertia ring  3  is the largest, the mass members  4  are each positioned at a second position P 2  illustrated in  FIG. 7 . The mass member  4  at the second position P 2  is positioned innermost in the radial direction of the central axis Ax 1  in the oscillation range of the mass member  4  with respect to the disk plate  2 . 
     The mass member  4  is pushed by the centrifugal force, whereby the inside edge  48   a  is pressed against the rolling shaft  52 . When the inertia ring  3  oscillates about the central axis Ax 1  with respect to the disk plate  2 , the inside edge  48   a  and the rolling shaft  52  are kept in contact with each other. 
     The rolling shaft  52  in contact with the inside edge  48   a  rolls along the inside edge  48   a  with oscillation of the inertia ring  3  with respect to the disk plate  2 . In one mass member  4 , the two rolling shafts  52  roll along the respective two inside edges  48   a  while being in contact with the respective inside edges  48   a.  The rolling shafts  52  rolling along the respective inside edges  48   a  are separated from the respective outside edges  48   b.  Rolling of the rolling shafts  52  along the inside edges  48   a  may be facilitated by increasing the coefficient of friction on the peripheral surfaces  52   a  of the rolling shafts  52  by surface finishing, for example. 
     The rolling shaft  52  rolls along the inside edge  48   a  recessed in the direction closer to the central axis Ax 1 . When the inertia ring  3  oscillates with respect to the disk plate  2  in a direction in which the rotational phase difference between the disk plate  2  and the inertia ring  3  increases, the rolling shaft  52  pushes the mass member  4  in the direction closer to the central axis Ax 1 . As a result, the mass member  4  moves inward in the radial direction of the central axis Ax 1 . 
     By contrast, when the inertia ring  3  oscillates with respect to the disk plate  2  in a direction in which the rotational phase difference between the disk plate  2  and the inertia ring  3  decreases, the mass member  4  pushes the rolling shaft  52  in the direction away from the central axis Ax 1  by the centrifugal force. As a result, the mass member  4  moves outward in the radial direction of the central axis Ax 1 . 
     The mass member  4  oscillates in the radial direction of the central axis Ax 1  with the two inside edges  48   a  supported by the respective two rolling shafts  52  by the centrifugal force. As a result, the mass member  4  can be translated (move without rotation) in the radial direction of the central axis Ax 1  without rolling. The mass member  4  may slightly roll. 
     Force causing the mass member  4  to roll may possibly act on the oscillating mass member  4 . In other words, the force about a rotational axis passing through the mass member  4  and substantially parallel to the central axis Ax 1  may possibly act on the mass member  4 . In this case, the roller  62  of the transmitting part  6  is supported by the first edge  26   a  or the second edge  26   b  of the first recess  26 , thereby suppressing rotation of the mass member  4 . In other words, the mass member  4  can be translated in the radial direction of the central axis Ax 1  with the two inside edges  48   a  supported by the respective two rolling shafts  52  and with at least one of the two transmitting parts  6  supported by the first edge  26   a  or the second edge  26   b  of at least one of the two first recesses  26 . 
     The force of the inside edge  48   a  of the mass member  4  pushing the rolling shaft  52  by the centrifugal force can be resolved into a component force (radial direction component force) in the radial direction of the central axis Ax 1  and a component force (circumferential direction component force) in the circumferential direction of the central axis Ax 1 . The ratio between the radial direction component force and the circumferential direction component force varies depending on the position of the contact part of the inside edge  48   a  with the rolling shaft  52 . 
     When a rotational phase difference is generated between the disk plate  2  and the inertia ring  3  by oscillation of the inertia ring  3 , the inside edge  48   a  pushes the rolling shaft  52  in the direction for reducing the rotational phase difference about the central axis Ax 1  by the circumferential direction component force. In other words, the rolling shaft  52  is pushed in the circumferential direction of the central axis Ax 1  by the inside edge  48   a  of the mass member  4  pushed outward in the radial direction of the central axis Ax 1  by the centrifugal force. 
     The rolling shaft  52  pushes the inside edge  48   a  in the direction for reducing the rotational phase difference about the central axis Ax 1  by reaction force of the circumferential direction component force. The reaction force of the circumferential direction component force acts on the inside edge  48   a  of the mass member  4  as restoring force for reducing the rotational phase difference. The restoring force acts on the disk plate  2  via the transmitting parts  6 . 
     In one mass member  4 , the two inside edges  48   a  receive the reaction force of the circumferential direction component force in the direction for reducing the rotational phase difference by the two rolling shafts  52 . As a result, the rotational phase difference between the disk plate  2  and the inertia ring  3  is damped. Consequently, the rotational fluctuations between the disk plate  2  and the input shaft of the transmission connected to the disk plate  2  are damped. 
     When the rotational phase difference between the disk plate  2  and the inertia ring  3  is 0°, the circumferential direction component force is minimized. As a result, the disk plate  2  and the inertia ring  3  are kept at substantially the same position in the circumferential direction of the central axis Ax 1 . 
     When the rotational phase difference between the disk plate  2  and the inertia ring  3  is 0°, the inside edge  48   a  may push the rolling shaft  52  by the circumferential direction component force. In this case, in one mass member  4 , the circumferential direction component force of one inside edge  48   a  pushing the corresponding rolling shaft  52  and that of the other inside edge  48   a  pushing the corresponding rolling shaft  52  cancel out each other. As a result, the disk plate  2  and the inertia ring  3  are kept at substantially the same position in the circumferential direction of the central axis Ax 1 . 
     The damper device  1  damps the rotational fluctuations in both of the cases where the inertia ring  3  oscillates clockwise about the central axis Ax 1  with respect to the disk plate  2  as illustrated in  FIG. 7  and where the inertia ring  3  oscillates counterclockwise about the central axis Ax 1  with respect to the disk plate  2 . 
     The damper device  1  is a dry damper disposed near a clutch and configured to operate without oil, for example. With this structure, the damper device  1  may possibly be exposed to dust generated by abrasion of the clutch, for example. The dust may possibly move outward in the radial direction of the central axis Ax 1  by the centrifugal force of the damper device  1  and adhere to the outside edges  48   b  of the guide holes  48 . The rolling shafts  52 , however, roll along the respective inside edges  48   a  of the guide holes  48  and are separated from the respective outside edges  48   b.  As a result, the dust is less likely to prevent rolling of the rolling shafts  52 . The damper device  1  may be disposed at other positions and may be a wet damper. 
     When the engine stops, rotation of the damper device  1  stops. As a result, oscillation of the inertia ring  3  and the mass members  4  also stops. The mass members  4  that stop oscillating may be moved in the radial direction of the central axis Ax 1  by the force of gravity, for example. 
     Force for causing the mass member  4  to rotate may possibly act on the mass member  4  moved by the force of gravity. The two transmitting parts  6  supported by the mass member  4  are each supported by the first edge  26   a  or the second edge  26   b  of the first recess  26 . As a result, the mass member  4  moved by the force of gravity can be translated in the radial direction of the central axis Ax 1  without rolling. 
     In the damper device  1  according to the first embodiment, the mass member  4  can be translated in the radial direction of the central axis Ax 1  with the two inside edges  48   a  supported by the respective two rollers  5 . This structure suppresses rotational inertia generated in the mass member  4  by rotation of the mass member  4  and undesired friction generated between the mass member  4  and the disk plate  2  or the inertia ring  3 . Consequently, the mass member  4  can smoothly oscillate in the radial direction of the central axis Ax 1 , and the rollers  5  can smoothly roll along the respective inside edges  48   a.  The rollers  5  supported by the inertia ring  3  are pushed by the respective inside edges  48   a  in the circumferential direction of the central axis Ax 1 . As a result, restoring force acts on the disk plate  2  via the mass member  4 , thereby damping the rotational fluctuations of the disk plate  2 . As described above, the rollers  5  can smoothly roll along the respective inside edges  48   a,  thereby suppressing degraded performance of the damper device  1  in damping the rotational fluctuations of the disk plate  2 . 
     The rollers  5  roll along the respective inside edges  48   a  recessed in the direction closer to the central axis Ax 1 . This structure suppresses accumulation, on the inside edges  48   a,  of dust moved in the direction away from the central axis Ax 1  by the centrifugal force. Consequently, the rollers  5  can smoothly roll along the respective inside edges  48   a,  thereby suppressing degraded performance of the damper device  1  in damping the rotational fluctuations of the disk plate  2 . 
     In addition, the inside edges  48   a  are formed in the mass member  4  smaller than the disk plate  2  and the inertia ring  3 . Consequently, the inside edges  48   a  can be accurately formed, and the mass member  4  can be translated in the radial direction of the central axis Ax 1  more reliably. 
     The inside edges  48   a  are formed mirror-symmetrically with respect to the virtual line L extending in the radial direction of the central axis Ax 1 . This structure suppresses arrangement of the center of gravity of the mass member  4  in a manner deviating in the circumferential direction of the central axis Ax 1 . Consequently, the mass member  4  can be translated in the radial direction of the central axis Ax 1  more reliably. 
     The disk plate  2  has the two first recesses  26 , and the mass member  4  includes the two transmitting parts  6 . The mass member  4  can be translated in the radial direction of the central axis Ax 1  with the two inside edges  48   a  supported by the respective two rollers  5  and with at least one of the two transmitting parts  6  supported by the first edge  26   a  or the second edge  26   b  of at least one of the two first recesses  26 . With this structure, the mass member  4  is supported at at least three points and can be translated in the radial direction of the central axis Ax 1  more reliably. 
     The two transmitting parts  6  are supported by the first edge  26   a  or the second edge  26   b  of the respective first recesses  26 . This structure suppresses rotation of the mass member  4  by the force of gravity, for example, when rotation of the disk plate  2  stops. 
     The two transmitting parts  6  are provided mirror-symmetrically with respect to the virtual line L extending in the radial direction of the central axis Ax 1 . This structure suppresses arrangement of the center of gravity of the mass member  4  in a manner deviating in the circumferential direction of the central axis Ax 1 . Consequently, the mass member  4  can be translated in the radial direction of the central axis Ax 1  more reliably. 
     The transmitting parts  6  are positioned between the two inside edges  48   a  in the circumferential direction of the central axis Ax 1 . Consequently, the mass member  4  can be translated in the radial direction of the central axis Ax 1  more reliably. 
     The mass member  4  is provided with the two guide holes  48 , and the two inside edges  48   a  include part of the closed edges of the respective two guide holes  48 . With this structure, part of the mass member  4  can be provided on the outer side than the guide holes  48  in the radial direction of the central axis Ax 1 , thereby increasing the centrifugal force acting on the mass member  4 . 
     The rolling shaft  52  extends along the first rotational axis Ax 2  inside the bearing  51  supported by the inertia ring  3  and rolls along the inside edge  48   a.  This structure can reduce the friction between the rolling shaft  52  and the bearing  51  that relatively rotate and can reduce the rotational inertia of the rolling shaft  52  about the first rotational axis Ax 2  by downsizing the rolling shaft  52  serving as a rotating part. This structure thus suppresses the rotational inertia of the rolling shaft  52  preventing oscillation of the inertia ring  3  when the oscillation direction of the inertia ring  3  reverses, for example. Consequently, the rolling shaft  52  can smoothly roll along the inside edge  48   a.  The rolling shaft  52  supported by the inertia ring  3  with the bearing  51  interposed therebetween is pushed by the inside edge  48   a  in the circumferential direction of the central axis Ax 1 . As a result, restoring force acts on the disk plate  2  via the mass member  4 , thereby damping the rotational fluctuations of the disk plate  2 . As described above, the rolling shaft  52  can smoothly roll along the inside edge  48   a,  thereby suppressing degraded performance of the damper device  1  in damping the rotational fluctuations of the disk plate  2 . 
     The guide hole  48  can be downsized by downsizing the rolling shaft  52 . Downsizing the guide hole  48  can increase the mass of the mass member  4 , thereby increasing the centrifugal force acting on the mass member  4 . 
     The largest outside diameter of the rolling shaft  52  is smaller than that of the bearing  51 . This structure can reduce the rotational inertia of the rolling shaft  52  serving as a rotating part about the first rotational axis Ax 2 , thereby enabling the rolling shaft  52  to smoothly roll along the inside edge  48   a.    
     Two mass members  4  have the respective inside surfaces  42   a  facing the two end surfaces  52   b  of the rolling shaft  52  in the axial direction of the first rotational axis Ax 2 . In other words, the rolling shaft  52  is positioned between the inside surfaces  42   a  of the respective two mass members  4 . With this structure, the inside surfaces  42   a  prevent the rolling shaft  52  from coming out of the bearing  51  in the axial direction of the first rotational axis Ax 2 . As a result, the rolling shaft  52  does not require any step for preventing it from coming off, thereby suppressing an increase in the mass and the rotational inertia of the rolling shaft  52  caused by adding a step. 
     The transmitting part  6  extends along the second rotational axis Ax 3  and is supported by the mass member  4  rotatably about the second rotational axis Ax 3 . The transmitting part  6  can be supported by the first edge  26   a  or the second edge  26   b  of the first recess  26  in the circumferential direction of the central axis Ax 1  and roll along the first edge  26   a  or the second edge  26   b  of the first recess  26 . This structure suppresses abrasion at the contact part of the transmitting part  6  with the first edge  26   a  or the second edge  26   b  of the first recess  26  and a change in the distance between the transmitting part  6  and the first edge  26   a  or the second edge  26   b  of the first recess  26 . This structure suppresses a backlash in the mass member  4  and the transmitting part  6 , thereby enabling the mass member  4  to smoothly oscillate in the radial direction of the central axis Ax 1 . Consequently, the roller  5  can smoothly roll along the inside edge  48   a,  thereby suppressing degraded performance of the damper device  1  in damping the rotational fluctuations of the disk plate  2 . 
     The transmitting part  6  includes the support shaft  61  and the roller  62 . The support shaft  61  is supported by the mass members  4 . The roller  62  is supported by the support shaft  61  rotatably about the second rotational axis Ax 3  and can roll along the first edge  26   a  or the second edge  26   b  of the first recess  26 . In other words, not the whole transmitting part  6  but the roller  62  in the transmitting part  6  can rotate. This structure can reduce the rotational inertia of the transmitting part  6  about the second rotational axis Ax 3  and suppress the rotational inertia of the transmitting part  6  preventing oscillation of the mass members  4  when the oscillation direction of the mass members  4  reverses, for example. As a result, the transmitting part  6  can smoothly roll along the first edge  26   a  or the second edge  26   b  of the first recess  26 . 
     One of the support shaft  61  and the roller  62  is made of metal, and the other thereof is made of resin. This structure can suppress contact of metal members and reduce the friction and abrasion between the support shaft  61  and the roller  62  that relatively rotate. 
     In the first embodiment, the inside surfaces  42   a  of the covers  42  face the end surfaces  52   b  of the rolling shaft  52 , thereby preventing the rolling shaft  52  from coming out of the bearing  51 . Alternatively, a step or a protrusion formed on the rolling shaft  52  may prevent the rolling shaft  52  from coming out of the bearing  51 . Steps formed on the rolling shaft  52  in a manner facing the inside surfaces  41   a  of the oscillating members  41  or protrusions formed on the rolling shaft  52  in a manner facing the outside surfaces  42   b  of the covers  42 , for example, may prevent the rolling shaft  52  from coming out of the bearing  51 . 
     In the first embodiment, the inside edge  48   a  along which the rolling shaft  52  rolls is part of the closed edge of the guide hole  48 . Alternatively, the mass member  4  may be provided with a cut-out opening in the direction away from the central axis Ax 1 , for example. The inside edge  48   a  may be part of the edge of the cut-out. 
       FIG. 8  is a sectional view of part of an example of the damper device  1  according to a modification of the first embodiment. As illustrated in  FIG. 8 , the transmitting part  6  may further include an intervening part  63 . The intervening part  63  is made of resin, such as synthetic resin, and has a substantially cylindrical shape. The intervening part  63  is interposed between the support shaft  61  and the roller  62 . 
     In the modification of the first embodiment, the support shaft  61  and the roller  62  are made of metal. Consequently, the support shaft  61  and the intervening part  63  coming into contact with each other are made of different materials. In addition, the roller  62  and the intervening part  63  coming into contact with each other are made of different materials. This structure can suppress contact of the metal members and reduce the friction and abrasion between the support shaft  61 , the roller  62 , and the intervening part  63  that relatively rotate. 
     Second Embodiment 
     The following describes a second embodiment with reference to  FIG. 9 . In the following description of a plurality of embodiments, components having functions similar to those of the components already described above are denoted by like reference numerals, and explanation thereof may be omitted. No all the functions and properties of the components denoted by like reference numerals are the same, and the components may have different functions and properties corresponding to the embodiments. 
       FIG. 9  is a sectional view of part of an example of the damper device  1  according to the second embodiment. As illustrated in  FIG. 9 , the oscillating members  41  according to the second embodiment each are provided with a fitting hole  41   c.  The fitting hole  41   c  is a substantially circular hole penetrating the oscillating member  41  in the axial direction of the central axis Ax 1  and opening in the inside surface  41   a  and the outside surface  41   b,  for example. 
     The covers  42  according to the second embodiment are made of resin, such as synthetic resin. The covers  42  each have a protrusion  42   c.  The protrusion  42   c  protrudes from the inside surface  42   a  and is fitted into the fitting hole  41   c  of the oscillating member  41 . 
     The protrusion  42   c  has a claw  42   d  formed at a position separated from the inside surface  42   a.  The protrusion  42   c  can be elastically deformed to increase and decrease the outside diameter. The protrusion  42   c  is fitted into the fitting hole  41   c  while being elastically deformed to decrease the outside diameter. When the elastic deformation of the protrusion  42   c  is finished, the outside diameter of the protrusion  42   c  is restored, and the claw  42   d  is caught on the oscillating member  41 . As a result, the cover  42  is fixed to the oscillating member  41 . In other words, the protrusion  42   c  is fitted into the fitting hole  41   c  by a snap-fit mechanism. 
     The fitting hole  41   c  may be formed in the cover  42  made of metal, and the protrusion  42   c  may be formed on the oscillating member  41  made of resin. Alternatively, the oscillating member  41  and the cover  42  may be made of resin. 
     In the damper device  1  according to the second embodiment, one of the oscillating member  41  and the cover  42  is provided with the fitting hole  41   c,  and the other thereof has the protrusion  42   c  fitted into the fitting hole  41   c  while being elastically deformed. With this structure, the inside surface  42   a  that prevents the rolling shaft  52  from coming out of the bearing  51  can be provided to the mass member  4  in a simpler manner. 
     Third Embodiment 
     The following describes a third embodiment with reference to  FIGS. 10 to 12 .  FIG. 10  is a front view of part of an example of the damper device  1  according to the third embodiment. As illustrated in  FIG. 10 , the damper device  1  according to the third embodiment further includes a plurality of springs  10 , a plurality of coupling members  11 , and a plurality of sheets  12 . The spring  10  is a coil spring, for example. 
       FIG. 11  is a sectional view of part of an example of the damper device  1  according to the third embodiment along line F 11 -F 11  of  FIG. 10 . As illustrated in  FIG. 11 , the coupling member  11  has a substantially columnar shape extending in the axial direction of the central axis Ax 1 . Both ends of the coupling member  11  in the axial direction of the central axis Ax 1  are fixed to the two mass members  4 . As a result, the coupling member  11  connects the two mass members  4 , thereby enabling the two mass members  4  to integrally move with respect to the disk plate  2  and the inertia ring  3 . 
       FIG. 12  is a sectional view of part of an example of the damper device  1  according to the third embodiment along line F 12 -F 12  of  FIG. 11 . As illustrated in  FIG. 12 , the disk plate  2  according to the third embodiment is provided with a plurality of second recesses  28 . The second recesses  28  are cut-outs penetrating the disk plate  2  in the axial direction of the central axis Ax 1  and opening in the two side surfaces  21  and the outer peripheral surface  22 . 
     The second recess  28  extends in one virtual line L from the outer peripheral surface  22 . Consequently, the second recess  28  extends in substantially parallel with the two first recesses  26  formed mirror-symmetrically with respect to the virtual line L. The second recess  28  is positioned between the two first recesses  26  in the circumferential direction of the central axis Ax 1 . 
     The coupling member  11  is accommodated in the second recess  28 . The mass members  4  oscillate in the radial direction of the central axis Ax 1  with respect to the disk plate  2 , thereby causing the coupling member  11  to move in the second recess  28 . 
     As illustrated in  FIG. 10 , the two protrusions  46  of the oscillating member  41  according to the third embodiment are provided with two holes  41   d.  The holes  41   d  penetrate the oscillating member  41  in the axial direction of the central axis Ax 1  and open in the inside surface  41   a  and the outside surface  41   b.  The hole  41   d  is an oval hole extending in a direction closer to the virtual line L, for example. The hole  41   d  may have other shapes, such as an elliptical or rectangular shape. 
     As illustrated in  FIG. 11 , the support shaft  61  is fitted into the hole  41   d  movably along the hole  41   d.  As a result, the support shaft  61  is supported by the mass members  4  but can move in a direction along the hole  41   d  with respect to the mass members  4 . 
     The support shaft  61  includes first receiving parts  61   a  protruding from the respective oscillating members  41 . The first receiving part  61   a  supports one end of the spring  10  with the sheet  12  interposed therebetween. The first receiving part  61   a  restricts movement of the spring  10  and the sheet  12  in the radial direction and the axial direction of the central axis Ax 1 . 
     The oscillating member  41  according to the third embodiment further includes two second receiving parts  41   e.  The second receiving parts  41   e  protrude from the outside surface  41   b.  The hole  41   d  is positioned between the two second receiving parts  41   e  in the circumferential direction of the central axis Ax 1 . 
     The second receiving part  41   e  supports the other end of the spring  10  with the sheet  12  interposed therebetween. The second receiving part  41   e  restricts movement of the spring  10  and the sheet  12  in the radial direction and the axial direction of the central axis Ax 1 . 
     The spring  10  supported by the first receiving part  61   a  and the second receiving part  41   e  extends in substantially parallel with the hole  41   d.  As a result, the spring  10  pushes the transmitting part  6  in the extending direction of the hole  41   d,  that is, the direction closer to the virtual line L. 
     As illustrated in  FIG. 12 , the roller  62  of the transmitting part  6  is pushed by the spring  10 , thereby coming into contact with the first edge  26   a  of the first recess  26 . In other words, the spring  10  elastically thrusts the transmitting part  6  against the first edge  26   a  of the first recess  26 . 
     In the damper device  1  according to the third embodiment, the springs  10  elastically thrust the two transmitting parts  6  against the respective first edges  26   a  of the two first recesses  26 . This structure suppresses a change in the distance between the transmitting part  6  and the first edge  26   a  of the first recess  26  caused by abrasion and a backlash in the mass member  4  and the transmitting part  6 . Consequently, the mass member  4  can smoothly oscillate in the radial direction of the central axis Ax 1 . 
     The mass member  4  is provided with the two holes  41   d  extending in a direction in which the springs  10  push the two transmitting parts  6 . The two transmitting parts  6  are fitted into the respective two holes  41   d  movably along the two holes  41   d.  As a result, the transmitting part  6  can be moved by the elastic force of the spring  10 . This structure suppresses a change in the distance between the transmitting part  6  and the first edge  26   a  of the first recess  26  caused by abrasion and a backlash in the mass member  4  and the transmitting part  6 . Consequently, the mass member  4  can smoothly oscillate in the radial direction of the central axis Ax 1 . 
     The two transmitting parts  6  are thrusted against the respective first edges  26   a  to hold the disk plate  2 . This structure suppresses rotational inertia generated in the mass member  4  by rotation of the mass member  4 . Consequently, the mass member  4  can smoothly oscillate in the radial direction of the central axis Ax 1 , and the roller  5  can smoothly roll along the inside edge  48   a.    
     Fourth Embodiment 
     The following describes a fourth embodiment with reference to  FIGS. 13 to 15 .  FIG. 13  is a front view of part of an example of the damper device  1  according to the fourth embodiment. As illustrated in  FIG. 13 , the damper device  1  according to the fourth embodiment includes a plurality of springs  10  and a plurality of coupling members  11 . 
       FIG. 14  is a sectional view of part of an example of the damper device  1  according to the fourth embodiment along line F 14 -F 14  of  FIG. 13 . As illustrated in  FIG. 14 , the support shaft  61  according to the fourth embodiment includes first engaging parts  61   b  protruding from the respective oscillating members  41 . One end of the spring  10  engages with the corresponding first engaging part  61   b.  The first engaging part  61   b  restricts movement of the spring  10  in the radial direction and the axial direction of the central axis Ax 1 . 
       FIG. 15  is a sectional view of part of an example of the damper device  1  according to the fourth embodiment along line F 15 -F 15  of  FIG. 13 . As illustrated in  FIG. 15 , the oscillating members  41  according to the fourth embodiment each further include a second engaging part  41   f.    
     The second engaging part  41   f  protrudes from the outside surfaces  41   b.  The second engaging part  41   f  is positioned between the two holes  41   d  in the circumferential direction of the central axis Ax 1 . The other ends of the two springs  10  engage with the second engaging part  41   f.  The second engaging part  41   f  restricts movement of the springs  10  in the radial direction and the axial direction of the central axis Ax 1 . 
     The spring  10  engaging with the first engaging part  61   b  and the second engaging part  41   f  extends in substantially parallel with the hole  41   d.  As a result, the spring  10  pulls the transmitting part  6  in the extending direction of the hole  41   d,  that is, the direction closer to the virtual line L. 
     The roller  62  of the transmitting part  6  is pulled by the spring  10 , thereby coming into contact with the first edge  26   a  of the first recess  26 . In other words, the spring  10  elastically thrusts the transmitting part  6  against the first edge  26   a  of the first recess  26 . 
     In the damper device  1  according to the fourth embodiment, the spring  10  engages with the first engaging part  61   b  of the transmitting part  6  and the second engaging part  41   f  of the mass member  4 . The spring  10  pulls the transmitting part  6  toward the first edge  26   a  of the first recess  26 . This structure does not require any member like the sheet  12 , whereby the damper device  1  requires a smaller number of parts. 
     While certain embodiments have been described, these embodiments have been presented by way of example only, and are not intended to limit the scope of the inventions. Indeed, the novel methods and systems described herein may be embodied in a variety of other forms; furthermore, various omissions, substitutions and changes in the form of the methods and systems described herein may be made without departing from the spirit of the inventions. The accompanying claims and their equivalents are intended to cover such forms or modifications as would fall within the scope and spirit of the inventions.