JP2018179229A - Rotary damper - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rotary damper that can preferably exert damping force without using working fluid.SOLUTION: A rotary damper 1 includes a cylinder 10, a rotor 40 and elastomer particulates 90. The rotor 40 freely rotatable about a rotation center axis is disposed in the cylinder 10. A plurality of elastomer particulates 90 having elasticity is filled in the cylinder 10.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a rotary damper.

Non-Patent Document 1 discloses a conventional rotary damper. In this rotary damper, a steel ball, which is a granular body, is filled in a space surrounded by a cylinder and a pair of caps, and the rotor is configured to rotate therein.
In this rotary damper, when the rotor is rotated relative to the cylinder, the particles flow with the movement of the rotor, and a torque is generated in the direction opposite to the direction in which the rotor rotates. That is, since this rotary damper does not use the working fluid, it can generate torque without the working fluid flowing out. Also, the torque thus generated is a damping force acting in the direction of suppressing the rotation of the rotor.

Koichi Hayashi, Koji Imon "The Influence of Rotor Position of Rotating Granular Damper on Damping Force Characteristics," Proceedings of the 65th Annual Meeting of the Japan Society for the Opportunity, Proceedings of the Annual Conference, March 17-18, 2004. No. 163-1

  In the rotary damper of Non-Patent Document 1, steel balls, which are granular bodies, are filled in a cylinder. Steel balls are not flexible. For this reason, when the rotor rotates in the cylinder, the particles are pushed by the rotor, and adjacent particles may be burned. As a result, the rotary damper can not rotate the rotor, and there is a possibility that the movement of the rotor is impeded and torque (damping force) can not be generated well. In addition, this rotary damper needs to add lubricating oil together with the particles in the cylinder in order to prevent the particles from burning together.

  The present invention has been made in view of the above-described conventional circumstances, and an object of the present invention is to provide a rotary damper capable of generating a damping force well without using a working fluid.

  The rotary damper of the present invention comprises a case, a rotor and particles. In the case, a rotatable rotor is disposed around a rotation center axis. The particles have elasticity and are packed in the case.

  In this rotary damper, when the rotor rotates around the central axis of rotation, the particles filled in the case are elastically deformed. The rotary damper generates a damping force due to the frictional force between the particles, the frictional force between the particles and the case or the rotor, and the elastic repulsive force of the particles.

  Therefore, the rotary damper of the present invention can generate damping force well without using a working fluid.

  The rotor of the rotary damper of the present invention may be circular, elliptical or polygonal in cross section perpendicular to the central axis of rotation. In this case, the area of the surface in contact with the particles is changed by changing the cross-sectional shape of the rotor to a circular shape, an elliptical shape or a polygonal shape, and the degree of elastic deformation of the particles filled in the case is variously changed. be able to. Thereby, the frictional force between particles, and the frictional force between particles and the case or the rotor can be changed, and the characteristics of the damping force generated by the rotary damper can be variously changed.

  The rotor of the rotary damper of the present invention may be formed with grooves or at least one of the protrusions in the axial direction on the surface. In this case, the area of the surface in contact with the particles is variously changed by forming grooves, protrusions, etc. on the surface of the rotor, and the degree of elastic deformation of the particles filled in the case is variously changed. Can. As a result, it is possible to change the frictional force between particles, and the frictional force between particles and the case or the rotor, and it is possible to more variously change the characteristics of the damping force generated by the rotary damper.

BRIEF DESCRIPTION OF THE DRAWINGS It is sectional drawing which shows the rotary damper of Embodiment 1, Comprising: (A) is sectional drawing of the rotation-center axial direction of a rotor, (B) is AA sectional drawing in FIG. 1 (A). (A) is AA sectional drawing in FIG. 1 (A), Comprising: (B) is the elements on larger scale which expand and show a part of (A). In the case where the cylinder of the rotary damper of Embodiment 1 is filled with the elastomer particles which are particles of hardness 40 and the elastomer particles of hardness 60, the filling ratio of the elastomer particles is 50, 60, 70%. FIG. 6A is a graph showing the relationship between the rotational speed of the rod and the rotor and the torque (damping force) at the time of (A) shows the case where the hardness of the elastomer particle is 40, and (B) shows that of the elastomer particle. The case where the hardness is 60 is shown. The relationship between the damping force with respect to the rotational speed and the torque (damping force) with respect to the filling rate in the case where the rotary damper of Embodiment 1 is filled with the elastomer particles of hardness 60 at filling rates 40, 50, 60, 70, 75%. It is a graph, and (A) shows the relationship between the rotational speed and torque (damping force) of a rod and a rotor, (B) is a filling rate of the elastomer particle in 60 (rpm) of rotational speeds of a rod and a rotor. It is a graph which shows the relationship between and torque (damping force). It is sectional drawing of the rotary damper of Embodiment 2-4, Comprising: (A) shows the cross-sectional shape of the center part orthogonal to the rotation central axis of the rotor of Embodiment 2, (B) is a rotor of Embodiment 3 4C shows the cross-sectional shape of the central portion orthogonal to the central axis of rotation, and FIG. 5C shows the cross-sectional shape of the central portion orthogonal to the central axis of rotation of the rotor of the fourth embodiment. In each of the cases where the cylinder is filled with elastomer particles having a hardness of 40 at a filling rate of 50, 60, 70%, the rotational speed and torque (damping force) of the rod and rotor of the rotary damper in each of Embodiments 1 to 4 (A) shows the case where the filling rate is 50%, (B) shows the case where the filling rate is 60%, (C) shows the case where the filling rate is 70% Indicates the case of FIG. 13 is a partially enlarged view of the cross-sectional shape of the central portion orthogonal to the central axis of rotation of the rotor of the rotary damper according to Embodiment 2. It is sectional drawing of the rotary damper of Embodiment 5-8, Comprising: (A) shows the cross-sectional shape of the center part orthogonal to the rotation central axis of the rotor of Embodiment 5, (B) is a rotor of Embodiment 6 Shows the cross-sectional shape of the central portion orthogonal to the central axis of rotation of the rotor, (C) shows the cross-sectional shape of the central portion orthogonal to the central axis of rotation of the rotor of Embodiment 7; (D) is the rotor of Embodiment 8 The cross-sectional shape of the center part orthogonal to the central axis of rotation of is shown.

  Embodiments embodying the rotary damper of the present invention will be described with reference to the drawings.

First Embodiment
As shown in FIG. 1A, the rotary damper 1 according to the first embodiment includes a cylinder 10 as a case, a first rod guide 75, a second rod guide 72, a third rod guide 73, a fourth rod guide 74, and a rotation. The element 40, the rod 50, and the elastomer particle 90 which is a particle are provided. The cylinder 10 is in the form of a cylinder open at both ends.

  The first rod guide 75 is disk-shaped, and is connected to the cylinder 10 so that one end face of the cylinder 10 abuts on the other side to close one side of the cylinder 10. A first through hole 75A is provided at the disc-like center of the first rod guide 75 in the thickness direction. Further, in the first through hole 75A on the other surface side of the first rod guide 75, a first attaching portion 75B extending in a flat plate shape inward from the inner peripheral surface of the first through hole 75A is formed. The inner diameter of the first abutment portion 75B is slightly larger than the outer diameter of the rod 50 described later. The shield bearing 60 is fitted in the first through hole 75A, and one surface of the shield bearing 60 is in contact with one surface of the first attaching portion 75B.

  The second rod guide 72 is disc-shaped, and is connected to the cylinder 10 so that one surface is in contact with the other end surface of the cylinder 10 to close the other side of the cylinder 10. A second through hole 72A is provided at the disk-shaped center of the second rod guide 72 in the thickness direction. Further, a second attaching portion 72B extending in a flat plate shape inward from the inner peripheral surface of the second through hole 72A is formed in the middle portion of the second through hole 72A penetrating in the thickness direction. The inner diameter of the second abutment portion 72B is slightly larger than the outer diameter of the rod 50 described later. Further, the inner diameter of the second through hole 72A is compared with the distance from one surface of the second attaching portion 72B to one surface of the second rod guide 72 (hereinafter referred to as one side of the second through hole 72A). The distance between the other surface of the second abutment portion 72B and the other surface of the second rod guide 72 (hereinafter referred to as the other side of the second through hole 72A) is smaller. The shield bearing 60 is fitted on the other side of the second through hole 72A, and one surface of the shield bearing 60 is in contact with the other surface of the second attachment portion 72B.

  The third rod guide 73 has a disk shape thicker than the first rod guide 75 and the second rod guide 72. The third rod guide 73 has a disk-like outer diameter substantially the same as the inner diameter of the cylinder 10. The third rod guide 73 is engaged with one open end 10A of the cylinder 10 with the disk-like one surface abutting on the other surface of the first rod guide 75 and connected to the first rod guide 75 There is. A third through hole 73A is provided at the disk-shaped center of the third rod guide 73 so as to penetrate in the thickness direction. Further, in the third through hole 73A on the other surface side of the third rod guide 73, a third attaching portion 73B extending in a flat plate shape inward from the inner peripheral surface of the third through hole 73A is formed. The inner diameter of the third abutment portion 73B is slightly larger than the outer diameter of the first end 40B of the rotor 40 described later.

  The fourth rod guide 74 has a disk shape that is thicker than the first rod guide 75 and the second rod guide 72 and thinner than the third rod guide 73. Further, the fourth rod guide 74 has a disk-like outer diameter substantially the same as the inner diameter of the cylinder 10. The fourth rod guide 74 is engaged with the other open end portion 10A of the cylinder 10 with the other surface of the disk shape being in contact with one surface of the second rod guide 72 and connected to the second rod guide 72. There is. A fourth through hole 74A is provided at the disc-like center of the fourth rod guide 74 in the thickness direction. Further, in the fourth through hole 74A on one surface side of the fourth rod guide 74, a fourth attaching portion 74B extending in a flat plate shape inward from the inner peripheral surface of the fourth through hole 74A is formed. The inner diameter of the fourth abutment portion 74B is slightly larger than the outer diameter of the second end 40C of the rotor 40.

  The rotor 40 has a central portion 40A, a first end 40B, and a second end 40C. The central portion 40A is disposed between the other surface of the third rod guide 73 and one surface of the fourth rod guide 74, as shown in FIGS. 1 (A) and 1 (B). The cross-sectional shape (hereinafter referred to as the cross-sectional shape) of the central portion 40A orthogonal to the central axis of rotation of the fulcrum is a square shape having a polygonal shape (see FIG. 1B). Further, a weir (hereinafter referred to as a weir) is formed between two adjacent ones of the four faces forming the square shape.

  Further, at each of both ends of the central portion 40A in the rotational center axis direction of the rotor 40, a first plane 40D orthogonal to the rotational center axis of the rotor 40 is formed.

  Each of the first end 40B and the second end 40C has a cylindrical shape and extends in the opposite direction from the center of each of two first flat surfaces 40D of the center 40A. In addition, on the side away from the central portion 40A of the first end 40B and the second end 40C, a second plane 40E orthogonal to the rotation center axis of the rotor 40 is formed.

  The rod 50 extends from each of the centers of the first end 40B and the second flat surface 40E of the second end 40C. The rod 50 and the first end 40B and the second end 40C are coaxial with each other. The rotor 40 is disposed in the cylinder 10.

  The rod 50 is rotatably connected to the first rod guide 75 and the second rod guide 72 via shield bearings 60 fitted in the first rod guide 75 and the second rod guide 72, respectively. Further, each of the first end 40B and the second end 40C corresponds to the third abutment portion 73B of the third through hole 73A of the third rod guide 73 and the fourth of the fourth through hole 74A of the fourth rod guide 74. It is rotatably inserted into the abutment portion 74B.

  In addition, the thrust bearing 80 is disposed inside the third through hole 73A of the third rod guide 73, and the second flat surface 40E of the first end 40B and the first rod inserted in the third attachment portion 73B. The thrust bearing 80 is sandwiched by the other surface of the guide 75. Further, the thrust bearing 80 is disposed also inside the fourth through hole 74A of the fourth rod guide 74, and the second flat surface 40E of the second end 40C and the second rod which are inserted into the fourth attachment portion 74B. The thrust bearing 80 is sandwiched by one surface of the guide 72. Thus, the rod 50 and the rotor 40 are both rotatable around the central axis of rotation.

The plurality of elastomeric particles 90 are spherical in shape. These elastomer particles 90 are elastic bodies made of silicone rubber having a predetermined size of durometer type A hardness (hereinafter referred to as hardness). That is, these elastomeric particles 90 have elasticity. The elastomer particles 90 are filled in a space surrounded by the cylinder 10, the third rod guide 73, and the fourth rod guide 74 at a filling rate of a predetermined size.
Here, the filling rate is expressed by the following equation (1). The filling volume is the volume of the space in which the elastomer particles 90 are filled.

Here, a mechanism in which the rotary damper 1 generates torque (damping force) will be described. As shown in FIGS. 2A and 2B, when the rotor 40 rotates in the cylinder 10, the elastomeric particles 90 filled in the cylinder 10 flow. At this time, between the inner circumferential surface of the cylinder 10 and the elastomeric particles 90 in contact with the inner circumferential surface of the cylinder 10, between the adjacent elastomeric particles 90, and the surface of the central portion 40A of the rotor 40 and the rotor 40. A frictional force F is generated between the center of the central portion 40A and the elastomeric particle 90 which abuts on the surface. In addition, the elastomer particles 90 that contact the surface of the central portion 40A of the rotor 40 are crushed by the central portion 40A of the rotating rotor 40. At this time, the central portion 40A of the rotor 40 is pushed back by the elastic repulsive force R generated by the elastomer particles 90 crushed by the central portion 40A of the rotor 40. That is, the rotary damper 1 generates torque (damping force) in the direction opposite to the direction in which the rotor 40 rotates based on the frictional force F thus generated and the elastic repulsive force R. The torque (damping force) thus generated acts in the direction to suppress the rotation of the rotor 40.
Moreover, when using the steel ball which has no flexibility and is described in the nonpatent literature 1 as a granular material, a steel ball contacts with the adjacent partner and carries out point contact. On the other hand, when elastic elastomer particles 90 are used as particles, the elastomer particles 90 are crushed and elastically deformed to form the inner peripheral surface of the cylinder 10, the adjacent elastomer particles 90, and the central portion of the rotor 40. Since surface contact is made with a partner such as the surface of 40A, a larger torque (damping force) is generated as compared with the case of using a steel ball. Further, since the magnitude of the frictional force F changes depending on the degree of elastic deformation of the elastomer particles 90, the magnitude of the generated torque (damping force) can be widely varied.
In addition, the elastomer particles 90 have a smaller mass than the steel balls described in Non-Patent Document 1. Therefore, when the elastomer particles 90 are used as particles, they are less susceptible to the influence of gravity than steel balls, so the magnitude of the generated torque (damping force) is the angle of the central axis of rotation of the rotor 40 (ie, the rotary It can be made hard to depend on the angle at which the damper is installed.

  Next, the rotation of the rod 50 and the rotor 40 of the rotary damper 1 in each case of filling the cylinder 10 with elastomeric particles 90 having hardness 40 and hardness 60 so that the filling factor is 50, 60, 70%. The relationship between the speed (hereinafter referred to as rotational speed) and the torque (damping force) is shown in FIGS. 3 (A) and 3 (B). Specifically, the rotational speeds of the rod 50 and the rotor 40 are changed to 1, 2, 3, 5, 10, 15, 30, 45, 60, 90, 120 (rpm) and measured.

  As shown in FIGS. 3A and 3B, the torque (damping force) generated increases as the rotational speed increases. Also, as the rotational speed increases, the degree to which the generated torque (damping force) increases increases. Also, the magnitude of the torque (damping force) generated becomes larger as the filling rate becomes larger. When the filling rate is the same, the torque (damping force) generated by using the elastomer particles 90 having hardness 60 is larger than that of the elastomer particles 90 having hardness 40.

  Next, the elastomer particles 90 of hardness 60 are filled in the cylinder 10 so that the filling factor is 40, 50, 60, 70, 75%, and the rod 50 and the rotor 40 of the rotary damper 1 at each filling factor The relationship between the rotational speed and the torque (damping force) is shown in FIG. 4 (A). Further, FIG. 4B shows the relationship between the filling factor of the elastomer particles 90 and the damping force when the rotational speed of the rod 50 and the rotor 40 is 60 (rpm).

  As shown in FIG. 4A, at any filling rate, the torque (damping force) generated increases as the rotational speed increases. Also, as the rotational speed increases, the degree to which the generated torque (damping force) increases increases. In addition, when the rotational speed is the same, the magnitude of the torque (damping force) generated is larger as the filling rate is larger. Further, as shown in FIG. 4 (B), the degree to which the generated torque (damping force) increases as the filling rate increases is increasing.

  As described above, in the rotary damper 1, when the rod 50 and the rotor 40 rotate around the central axis of rotation of the rotor 40, the plurality of elastomeric particles 90 filled in the cylinder 10 elastically deform. The rotary damper 1 generates torque (damping force) by the frictional force F of the elastomer particles 90 and the elastic repulsive force R of the elastomeric particles 90 which are generated at this time.

  Therefore, the rotary damper 1 of the present invention can generate torque (damping force) well without using a working fluid.

<Embodiments 2 to 4>
Next, as shown in FIGS. 5A to 5C, in order to compare the relationship between the rotational speed of the rod and the rotor and the torque (damping force) when the cross-sectional shapes of the rotors are different. The rotary dampers 11, 21, and 31 of Embodiments 2 to 4 provided with a rotor having a cross-sectional shape different from that of the rotor 40 of Embodiment 1 were produced. The other configuration is the same as that of the first embodiment, and the same configuration as the first embodiment is denoted by the same reference numeral, and the detailed description is omitted.

  As shown to FIG. 5 (A), the cross-sectional shape of center part 140A of the rotor 140 of the rotary damper 11 of Embodiment 2 is circular shape.

  As shown to FIG. 5 (B), the cross-sectional shape of center part 240A of the rotor 240 of the rotary damper 21 of Embodiment 3 is a rectangular shape.

  As shown in FIG. 5C, the cross-sectional shape of the central portion 340A of the rotor 340 of the rotary damper 21 according to the fourth embodiment is along the inner circumferential surface of the cylinder 10 and opposite to each other with the central axis of rotation of the rotor 340 It has a shape in which two arc-shaped surfaces located at are connected by two planes parallel to each other.

  Next, elastomeric particles 90 with hardness 40 are filled in the cylinders 10 of the rotary dampers 1, 11, 21 and 31 of the first to fourth embodiments so that the filling factor is 50, 60 and 70%, respectively. 6A to 6 (A) show the results of measuring the relationship between the rotational speed and the torque (damping force) of the rods 50 and the rotors 40, 140, 240 and 340 of the rotary dampers 1, 11 and 21 and 31 at the filling rate. C).

  As shown in FIGS. 6A to 6C, at any filling rate, the torque (damping force) generated increases as the rotation speed increases. Also, as the rotational speed increases, the degree to which the generated torque (damping force) increases increases. In the same embodiment, the magnitude of the torque (damping force) generated is larger as the filling rate is larger. In addition, since it exceeds the measurement allowable range of the measuring device which measures torque (damping force), the rotary damper 31 of Embodiment 4 has a filling rate of 120 (rpm) at 50%, and torque at 60 and 70% filling rate. (Damping force) was not measured.

  Here, a mechanism for generating torque (damping force) in the rotary damper 11 of the second embodiment will be described. As shown in FIG. 7, when the rotor 140 rotates in the cylinder 10, friction is generated between the outer peripheral surface of the central portion 140A of the rotor 140 and the elastomeric particles 90 abutting on the outer peripheral surface of the central portion 140A of the rotor 140. Force F is generated. Then, the elastomeric particles 90 in contact with the outer peripheral surface of the central portion 140A of the rotor 140 move in the rotating direction of the rotor 140 while rotating. Further, when the elastomeric particle 90 in contact with the outer peripheral surface of the central portion 140A of the rotor 140 rotates, a frictional force F is also generated between the rotating elastomeric particle 90 and the elastomeric particle 90 adjacent to the elastomeric particle 90. . Further, in the rotary damper 11 of the second embodiment, even if the central portion 140A of the rotor 140 rotates, the elastomer particles 90 are not crushed. Therefore, in the rotary damper 11 of the second embodiment, the elastomeric particle 90 does not generate an elastic repulsive force. That is, the rotary damper 11 of Embodiment 2 generates torque (damping force) in the direction opposite to the direction in which the rotor 140 rotates based on the frictional force F thus generated. The torque (damping force) thus generated acts in the direction of suppressing the rotation of the rotor 140.

  Thus, in the rotary dampers 11, 21, and 31, when the rod and the rotors 140, 240, and 340 rotate around the rotation center axes of the respective rotors, the plurality of elastomeric particles 90 filled in the cylinder 10 Elastically deform. The rotary dampers 11, 21 and 31 generate torque (damping force) by the frictional force F of the elastomer particles 90 and the elastic repulsive force of the elastomer particles 90 generated at this time.

  Therefore, the rotary dampers 11, 21 and 31 of the present invention can also generate torque (damping force) well without using a working fluid.

  Further, the rotors 140, 240, 340 of the rotary dampers 11, 21, 31 have a rectangular shape whose cross-sectional shape orthogonal to the rotation center axis is circular or polygonal. Therefore, by changing the cross-sectional shape of the rotor to a circular shape or a polygonal shape like the rotors 140, 240, and 340, the area of the surface that abuts the elastomer particles is changed, and the elastomer filled in the cylinder 10 The degree of elastic deformation of the particles can be varied in many ways. Thereby, the characteristics of the torque (damping force) generated by the rotary damper can be variously changed.

<Embodiments 5 to 8>
As shown to FIG. 8 (A)-(C), Embodiment 5-8 differs in the cross-sectional shape of the center part of each rotor of rotary damper 41, 51, 61, 71 from Embodiment 1-4. . In addition, the other structure is the same as that of Embodiment 1-4, the structure same as Embodiment 1-4 attaches | subjects the same code | symbol, and detailed description is abbreviate | omitted.
As shown in FIG. 8A, the cross-sectional shape of the central portion 440A of the rotor 440 of the rotary damper 41 of the fifth embodiment is provided with a plurality of grooves 440C in the axial direction on the outer peripheral surface which is a circular surface. ing.
As shown in FIG. 8B, the cross-sectional shape of the central portion 540A of the rotor 540 of the rotary damper 51 of the sixth embodiment is provided with a plurality of protrusions 540C in the axial direction on the outer peripheral surface which is a circular surface. ing.
As shown in FIG. 8 (C), the cross-sectional shape of the central portion 640A of the rotor 640 of the rotary damper 61 of the seventh embodiment is elliptical.
As shown in FIG. 8D, the cross-sectional shape of the central portion 740A of the rotor 740 of the rotary damper 71 of the eighth embodiment is a pentagonal shape having a polygonal shape.

  In this manner, the rotary dampers 41, 51, 61, 71 have a plurality of cylinders 10 filled in the cylinder 10 when the rod and the rotors 440, 540, 640, 740 rotate around the rotation center axes of the respective rotors. The elastomeric particles are elastically deformed. The rotary dampers 41, 51, 61, 71 generate torque (damping force) by the frictional force between the elastomeric particles and the elastic repulsive force of the elastomeric particles.

  Therefore, the rotary dampers 41, 51, 61, 71 of the present invention can also generate torque (damping force) satisfactorily without using a working fluid.

  Further, the rotors 640 and 740 of the rotary dampers 61 and 71 have elliptical and polygonal cross-sectional shapes orthogonal to the rotation center axis. Therefore, by changing the cross-sectional shape of the rotor to an elliptical shape or a polygonal shape like the rotors 640 and 740, the area of the surface in contact with the elastomer particles is changed to change the area of the elastomer particles filled in the cylinder 10. The degree of elastic deformation can be changed variously. Thereby, the characteristics of the torque (damping force) generated by the rotary damper can be variously changed.

  Further, grooves 440C and protrusions 540C are formed in the axial direction on the outer peripheral surface which is the surface of the rotors 440 and 540 of the rotary dampers 41 and 51, respectively. For this reason, by forming grooves 440C or protrusions 540C on the surface of the rotor, the area of the surface that abuts the elastomer particles can be changed more variously, and the elastic deformation degree of the elastomer particles filled in the cylinder 10 can be further improved. It can be changed variously. Thereby, the characteristics of the torque (damping force) generated by the rotary damper can be changed in various ways.

The present invention is not limited to the first to eighth embodiments described above with reference to the drawings. For example, the following embodiments are also included in the technical scope of the present invention.
(1) In the first to eighth embodiments, the elastomer particles are silicone rubber elastic bodies having a durometer type A hardness of 40 and 60, but any other material may be used as long as it can be elastically deformed. In addition, these materials may be used in combination. In addition, the durometer type A hardness may be approximately 40 to 90.
(2) In the first to eighth embodiments, the particle diameter of the elastomer particles filled in the cylinder is uniform, but elastomer particles of plural kinds of particle diameters may be filled in the cylinder.
(3) In the first to eighth embodiments, the rod protrudes from the open end of the cylinder to the outside of the cylinder, but the rod protrudes from one of the rotors and the rod is the cylinder from one open end of the cylinder It may protrude to the outside of the
(4) In the fifth and sixth embodiments, the grooves and the protrusions are formed on the outer peripheral surface of each of the rotors, but the grooves and the protrusions may be provided. In addition, these grooves and projections may be formed on the surface of an elliptical or polygonal rotor. Further, the number of the grooves and the projections formed is not limited to the number disclosed in the embodiment.
(5) In the first embodiment, the ridges are formed between two adjacent surfaces of the four surfaces forming the square shape, but the ridges are not limited to the exact corners, but may be chamfered, The two surfaces may be formed as a curved surface so as to be continuous.

  DESCRIPTION OF SYMBOLS 10 ... Cylinder (case), 40, 140, 240, 340, 440, 540, 640, 740 ... Rotor, 440C ... Groove | channel, 540C ... Protrusion, 90 ... Elastomer particle (particle)

Claims (3)

With the case,
A rotor disposed in the case and rotatable about a central axis of rotation;
A plurality of elastic particles filled in the case;
The rotary damper characterized by having.   The rotary damper according to claim 1, wherein the rotor has a circular, elliptical or polygonal cross-sectional shape perpendicular to the central axis of rotation.   The rotary damper according to claim 1 or 2, wherein at least one of a groove or a protrusion is formed in the surface of the rotor in the axial direction.