JP2010270915A - Rotary damper - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a rotary damper used in a cold district capable of preventing a trouble by reducing torque fluctuation to a temperature change caused by a seal material. <P>SOLUTION: The rotary damper D includes: a housing 11; silicone oil 21 filled in the housing 11; a rotary shaft 32 projecting from the housing 11 in a part thereof; a rotor 31 continuously provided at a lower end of the rotary shaft 32 and having a rotor braking plate 35 rotatably housed in the housing 11; and an O-ring 41 arranged between the housing 11 and the rotary shaft 32 to prevent the leakage of the silicone oil 21 out of the housing 11. The O-ring 41 is formed of ethylene-propylene-diene rubber having a non-swelling property relative to the silicon oil 21 to reduce the torque fluctuation caused by the O-ring 41. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a rotary damper that brakes the rotation of a driven gear that meshes with a gear or a rack, for example.

  The rotary damper described above is housed in a housing, a viscous fluid filled in the housing, a rotary shaft partially protruding from the housing, and a lower end portion of the rotary shaft that is rotatably provided in the housing. A rotor having a rotor braking plate, and a seal member that is disposed between the housing and the rotating shaft and prevents the viscous fluid from leaking out of the housing. Then, the driven gear is attached to the portion of the rotating shaft protruding from the housing so as to rotate integrally.

  In this rotary damper, silicone oil used as a viscous fluid has a small change in viscosity (viscosity) due to a change in temperature, and is excellent as a material that gives a braking torque to the rotor braking plate. However, when a sealing material formed of silicon rubber or the like, for example, an O-ring is used, the silicone oil penetrates into the sealing material and the sealing material swells, thereby generating a frictional resistance between the housing and the rotating shaft. Affects braking torque. Therefore, by forming the sealing material with self-lubricating silicon rubber, the change in dimensions is reduced, and the influence on the braking torque due to the frictional resistance between the housing and the rotating shaft is eliminated.

Japanese Patent No. 2808118

  However, even if the sealing material is formed of self-lubricating silicone rubber, the silicone oil penetrates the sealing material, and the sealing material comes into contact with the housing, the rotating shaft, and the sealing material. Resistance due to the permeated silicon oil is generated, and particularly at a low temperature, there is a case where a large influence is exerted on the braking torque, for example, the braking torque becomes large and the rotating shaft may not rotate.

  The present invention has been made to solve the above-described inconveniences, and it is possible to reduce a torque fluctuation caused by a sealing material with respect to a temperature change, and to provide a rotary damper that can be used without any trouble even in a cold region. It is to provide.

  The present invention includes a housing, a viscous fluid filled in the housing, a rotating shaft partially protruding from the housing, and a lower end portion of the rotating shaft, and is rotatably accommodated in the housing. In a rotary damper comprising a rotor having a rotor braking plate and a sealing material disposed between the housing and the rotating shaft to prevent the viscous fluid from leaking out of the housing, the sealing material is not It is formed of a material having swelling property, and torque fluctuation caused by the sealing material is reduced. The viscous fluid is made of silicon oil, and the sealing material is made of one of ethylene propylene rubber, isobutylene isoprene rubber, chloroprene rubber, fluorine rubber, urethane rubber, or the viscous fluid is made of silicon oil and the sealing material Is preferably made of ethylene propylene diene rubber, and further, a surface finish is applied to the surface of the sealing material.

  According to the present invention, since the sealing material is formed of a material having non-swelling property with respect to the viscous fluid, the torque fluctuation caused by the sealing material with respect to the temperature change can be reduced, and it can be used without any trouble even in a cold region. It can be set as the rotation damper which can. In addition, the seal material is made of a material that does not swell with viscous fluid, and the surface of the seal material is finished with a ground finish, so torque fluctuations caused by the seal material with respect to temperature changes can be reduced. Therefore, it is possible to provide a rotary damper that can be used without problems even in cold regions.

It is a top view of the rotation damper which is one embodiment of this invention. It is sectional drawing by the AA line of FIG. It is a torque characteristic figure when the rotation damper of this invention and the conventional rotation damper are used at 23 degreeC and -30 degreeC. It is a torque change rate characteristic figure which shows the change rate of the torque when using it at -30 degreeC with respect to the torque when using the rotational damper of this invention and the conventional rotation damper at 23 degreeC. When the surface is polished as an O-ring in the rotary damper of the present invention and the amount of crushing is 10%, 15%, and 20%, the abrasive of particle size # 320 is sprayed on the surface as the O-ring in the rotary damper of the present invention. It is a torque characteristic diagram of only an O-ring when it is used at 23 ° C. when the finish is finished and the crushing amount is 10%, 15%, and 20%. When the surface is polished as an O-ring in the rotary damper of the present invention and the amount of crushing is 10%, 15%, and 20%, the abrasive of particle size # 320 is sprayed on the surface as the O-ring in the rotary damper of the present invention. It is a torque characteristic diagram of only an O-ring when it is used at −30 ° C. when it is used with a finish finish and its crushed amount is 10%, 15%, and 20%. The torque when the crushing amount of the O-ring shown in FIG. 6 is 10%, 15% and 20% with respect to the torque when the crushing amount of the O-ring shown in FIG. 5 is 10%, 15% and 20%. It is a torque change rate characteristic figure which shows a change rate. Polishing the surface as an O-ring in a conventional rotary damper and setting the crushing amount to 10%, 15%, and 20%, and spraying abrasive with a particle size of # 320 on the surface as an O-ring in a conventional rotary damper It is a torque characteristic diagram of only an O-ring when it is used at 23 ° C. when ground finish is applied and the crushed amount is 10%, 15%, and 20%. Polishing the surface as an O-ring in a conventional rotary damper and setting the crushing amount to 10%, 15%, and 20%, and spraying abrasive with a particle size of # 320 on the surface as an O-ring in a conventional rotary damper It is a torque characteristic diagram of only an O-ring when it is used at −30 ° C. when ground finishing is performed and the crushed amount is 10%, 15%, and 20%. The torque when the crushing amount of the O-ring shown in FIG. 9 is 10%, 15% and 20% with respect to the torque when the crushing amount of the O-ring shown in FIG. 8 is 10%, 15% and 20%. It is a torque change rate characteristic figure which shows a change rate. The surface is polished as an O-ring in the rotary damper of the present invention, and the particle size # 400 or # 240 is applied to the surface as the O-ring in the rotary damper of the present invention with respect to the torque when the crushing amount is 10%, 15%, and 20%. It is a torque change rate characteristic figure which shows the change rate of the torque of only an O-ring when the ground material finish is performed by spraying abrasives and the crushed amount is 10%, 15% and 20%.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a plan view of a rotary damper according to an embodiment of the present invention, and FIG. 2 is a sectional view taken along line AA of FIG.
In these drawings, the rotary damper D includes a housing 11, silicon oil 21 as a viscous fluid filled in the housing 11, a rotating shaft 32 partially protruding from the housing 11, and the rotating shaft 32. A rotor 31 having a rotor braking plate 35 connected to the lower end portion and rotatably accommodated in the housing 11 is disposed between the housing 11 and the rotating shaft 32, and the silicon oil 21 is moved out of the housing 11. An O-ring 41 serving as a sealing material for preventing leakage and a driven gear 51 attached to a portion of the rotary shaft 32 protruding from the housing 11 are configured.

  The housing 11 described above includes a housing body 12 molded from a synthetic resin and a cap 16 molded from a synthetic resin. The housing body 12 has a cylindrical portion 13 having a bottom, a support shaft 14 having a circular cross section that is connected to the center of the cylindrical portion 13 and protrudes upward from the cylindrical portion 13, and the cylindrical portion 13 is opposed to the cylindrical body 13. It is comprised by the attachment pieces 15A and 15B provided so that it might extend in the radial direction outer side at the outer side position. The attachment piece 15A is provided with an attachment hole 15a, and the attachment piece 15B is provided with an attachment recess 15b. The cap 16 is provided with a circular through hole 17a through which the rotary shaft 32 passes, and has a stepped shape that is concentric with the through hole 17a and is larger in diameter than the through hole 17a. The circular top plate 17 provided with the O-ring accommodating portion 17b, and the peripheral wall 18 which is continuously provided around the periphery of the top plate 17 and the cylindrical portion 13 is fitted inside.

  The rotor 31 described above is formed of a synthetic resin and has a rotating shaft 32 partially protruding from the housing 11 and a rotor braking plate that is connected to the lower end portion of the rotating shaft 32 and is rotatably accommodated in the housing 11. 35. The rotating shaft 32 is concentrically connected to the large-diameter shaft portion 33 having a bearing portion 33a formed of a cylindrical recess into which the support shaft 14 is rotatably inserted from the lower side, and the upper side of the large-diameter shaft portion 33. The driven gear 51 is configured with an attachment shaft portion 34 attached so as to rotate integrally. The attachment shaft portion 34 is formed in an I-cut shape so as to rotate the driven gear 51 integrally, and is provided with a locking recess 34a in the lower portion of the parallel surface. The rotor braking plate 35 is provided on the outer periphery of the lower end of the large-diameter shaft portion 33 in a disk shape concentric with the large-diameter shaft portion 33.

  The O-ring 41 as the sealing material described above is formed of a material that does not swell with respect to the silicon oil 21, for example, ethylene propylene diene rubber included in the category of ethylene propylene rubber. The driven gear 51 is provided with a mounting hole 52 having an engaging portion 53 corresponding to the locking recess 34a on the inner peripheral surface.

  Next, an example of assembly of the rotary damper will be described. First, after the housing body 12 is installed on a work table, for example, with the open side of the cylindrical portion 13 facing upward, the support shaft 14 is inserted into the bearing portion 33a of the large-diameter shaft portion 33 constituting the rotating shaft 32. And the rotor braking plate 35 is rotatably accommodated in the cylindrical portion 13. Next, an appropriate amount of silicon oil 21 is injected (filled) into the cylindrical portion 13.

  Then, after mounting the O-ring 41 in the O-ring accommodating portion 17b of the top plate 17, the large-diameter shaft portion 33 is press-fitted into the O-ring 41 from the mounting shaft portion 34 side with the peripheral wall 18 facing down, and the mounting shaft The part 34 penetrates the through hole 17 a and protrudes from the top plate 17, and the cylindrical part 13 is fitted inside the peripheral wall 18. By attaching the cap 16 to the housing main body 12 in this way, the O-ring 41 is pushed by the top plate 17 and the large-diameter shaft portion 33 and deformed, thereby deforming the space between the housing 11 (cap 16) and the rotor 31. And the silicon oil 21 is prevented from leaking out of the housing 11 from between the housing 11 and the rotor 31.

  Next, the peripheral wall 18 is circumferentially welded to the cylindrical portion 13 by, for example, ultrasonic welding, thereby preventing the silicon oil 21 from leaking out of the housing 11 from between the cylindrical portion 13 and the peripheral wall 18. At the same time, the cap 16 is attached and fixed to the housing body 12. When the engagement portion 53 side is set to the lower side and the engagement shaft 53 is press-fitted into the attachment hole 52 with the engagement portion 53 corresponding to the engagement recess 34a, the engagement portion 53 is inserted into the engagement recess 34a. By engaging, the driven gear 51 does not come off from the rotary shaft 32 and rotates integrally with the rotary shaft 32.

  The rotary damper D assembled in this way can be mounted at a desired position by using the mounting holes 15a and the mounting recesses 15b of the mounting pieces 15A and 15B, and a gear that applies braking by the driven gear 51, Can be engaged with a rack or the like.

  Next, the operation will be described. First, when a force to rotate is applied to the driven gear 51 of the rotary damper D assembled and attached as shown in FIGS. 1 and 2, the rotor braking plate in the housing 11 filled with silicon oil 21. 35 will rotate. When the rotor brake plate 35 rotates in the silicon oil 21, the rotation of the driven gear 51 is braked by the viscous resistance and shear resistance of the silicon oil 21 acting on the rotor brake plate 35. Therefore, the rotation damper D brakes the rotation or movement of the gear, rack, etc. with which the driven gear 51 is engaged, and makes the rotation or movement slow.

  FIG. 3 is a torque characteristic diagram when the rotary damper of the present invention and the conventional rotary damper are used at 23 ° C. and −30 ° C. In FIG. 3, the vertical axis represents torque (mN · m), and the horizontal axis represents rotation speed (rmp). Here, the rotary damper according to the present invention uses an O-ring formed of ethylene propylene diene rubber as a seal member (the same applies to FIG. 4). An O-ring formed of a lubricious silicone rubber is used as a seal member (the same applies to FIG. 4). The portions other than the O-ring are the same for the rotary damper of the present invention and the conventional rotary damper (the same applies in the following description).

In FIG. 3, N ₃₁ is a torque characteristic curve when the rotary damper of the present invention is used at 23 ° C., and N ₃₂ is a torque characteristic curve when the rotary damper of the present invention is used at −30 ° C. O ₃₁ is a torque characteristic curve when a conventional rotary damper is used at 23 ° C., and O ₃₂ is a torque characteristic curve when a conventional rotary damper is used at −30 ° C.

  FIG. 4 is a torque change rate characteristic diagram showing the change rate of torque when used at −30 ° C. with respect to the torque when used at 23 ° C. of the rotary damper of the present invention and the conventional rotary damper. In FIG. 4, the vertical axis represents the torque change rate (%), and the horizontal axis represents the rotational speed (rmp).

In FIG. 4, N ₄₁ is a torque change rate characteristic curve showing the rate of change of torque when used at −30 ° C. with respect to torque when used at 23 ° C., and O ₄₁ is a conventional rotary damper. It is a torque change rate characteristic curve which shows the change rate of the torque when used at -30 degreeC with respect to the torque when used at 23 degreeC.

The torque change rates of the torque characteristic curves N ₃₂ and O ₃₂ of FIG. 3 with respect to the torque characteristic curves N ₃₁ and O ₃₁ of FIG. 3 are the torque change rate characteristic curves N ₄₁ and O _{41 of} FIG. It can be seen that the torque change rate is smaller than that of the conventional rotary damper.

  As described above, according to one embodiment of the present invention, since the O-ring is formed of ethylene propylene diene rubber having non-swelling property with respect to silicone oil, torque fluctuation caused by the O-ring with respect to temperature change is reduced. Therefore, the rotary damper can be used without any problem even in a cold region.

  FIG. 5 shows a case where the surface is polished as an O-ring in the rotary damper of the present invention, and the amount of crushing is 10%, 15%, and 20%. It is a torque characteristic diagram of only an O-ring when it is used at 23 ° C. when the material is sprayed and the finish is applied and the crushed amount is 10%, 15%, and 20%. In FIG. 5, the vertical axis represents torque (mN · m), and the horizontal axis represents rotation speed (rmp).

In FIG. 5, N ₅₁ is a torque characteristic curve when the surface of the O-ring is polished and used at 23 ° C. with a crushing amount of 10%. N ₅₂ is an abrasive of particle size # 320 sprayed on the surface of the O-ring. Torque characteristics curve when N23 is used at 23 ° C with a crushed finish and the crushing amount is 10%, N ₅₃ is the torque when the surface of the O-ring is polished and the crushing amount is 15% and used at 23 ° C Characteristic curve, N ₅₄ is the torque characteristic curve when N-type abrasive is sprayed on the surface of the O-ring to give a ground finish, and the crushed amount is 15%, and it is used at 23 ° C. N ₅₅ is the surface of the O-ring The temperature characteristic curve when polishing is applied at 23 ° C with a crushing amount of 20%, N ₅₆ is a surface finish by spraying an abrasive of grain size # 320 on the surface of the O-ring, and the crushing amount is 20% When used at 23 ℃ Which is the temperature characteristic curve.

FIG. 6 shows a case where the surface is polished as an O-ring in the rotary damper of the present invention, and the amount of crushing is 10%, 15%, and 20%. It is a torque characteristic diagram of only an O-ring when it is used at −30 ° C. when the material is sprayed to give a finish and the crushed amount is 10%, 15%, and 20%.
In FIG. 6, the vertical axis represents torque (mN · m), and the horizontal axis represents rotation speed (rmp).

In FIG. 6, N ₆₁ is polished on the surface of the O-ring and a torque characteristic curve when used at −30 ° C. with a crushing amount of 10%. N ₆₂ is sprayed with abrasive of particle size # 320 on the surface of the O-ring. Torque characteristic curve when used at -30 ° C with 10% crushed finish, N ₆₃ is polished on the O-ring surface and used at -30 ° C with 15% crushed amount N ₆₄ is a torque characteristic curve when N ₆₄ is used at −30 ° C. with 15% crushing amount by spraying abrasive of grain size # 320 on the surface of the O-ring, N ₆₅ is O Torque characteristic curve when the surface of the ring is polished and crushed 20% and used at -30 ° C. N ₆₆ is a surface finish by spraying abrasive of grain size # 320 on the surface of the O-ring. -30 ° C with 20% amount It is the torque characteristic curve when used.

  FIG. 7 shows the case where the crushed amount of the O-ring shown in FIG. 6 is 10%, 15% and 20% with respect to the torque when the crushed amount of the O-ring shown in FIG. 5 is 10%, 15% and 20%. It is a torque change rate characteristic figure which shows the change rate of the torque of. In FIG. 7, the vertical axis represents the torque change rate (%), and the horizontal axis represents the rotational speed (rmp).

7, N ₇₁ polishes the surface of the O-ring shown in FIG. 5, and the surface of the O-ring shown in FIG. 6 with respect to the torque characteristic curve N ₅₁ when used at 23 ° C. with a crushing amount of 10%. Torque change rate characteristic curve showing the change rate of torque characteristic curve N ₆₁ when polished and used at −30 ° C. with a crushing amount of 10%, N ₇₂ is the particle size # 320 on the surface of the O-ring shown in FIG. Abrasive finish is applied to the surface of the O-ring shown in FIG. 6 with respect to the torque characteristic curve N ₅₂ when the crushing amount is 10% and used at 23 ° C. subjected to pear finish, the torque change rate characteristic curve showing the change rate of the torque characteristic curve N62 when used at -30 ° C. the collapse amount as 10%, N ₇₃ is the polished surface of the O-ring shown in FIG. 5 2 and crushed 15% ° C. surface of the O-ring shown in FIG. 6 with respect to the torque characteristic curve N ₅₃ when used in refining, the rate of a change in the torque characteristic curve N ₆₃ when used at -30 ° C. the collapse amount as 15% Torque change rate characteristic curve, N ₇₄ is a torque characteristic curve when the surface of O-ring shown in FIG. The change rate of the torque characteristic curve N ₆₄ when N ₅₄ is applied to the surface of the O-ring shown in FIG. N ₇₅ is a torque change rate characteristic curve indicating the torque characteristic curve N ₅₅ when the surface of the O-ring illustrated in FIG. 5 is polished and used at 23 ° C. with a crushing amount of 20%. Polish the surface of the ring Torque change rate characteristic curve showing the change rate of torque characteristic curve N ₆₅ when used at -30 ° C. with a crushing amount of 20%, N ₇₆ is an abrasive of particle size # 320 on the surface of the O-ring shown in FIG. To the surface of the O-ring shown in FIG. 6 for the torque characteristic curve N ₅₆ when used at 23 ° C. with a crushed amount of 20%. alms, the torque change rate characteristic curve showing the change rate of the torque characteristic curve N ₆₆ when used at -30 ° C. the collapse amount as 20%.

As can be seen from the torque characteristic curves N _{51 to} N ₅₆ and N _{61 to} N _{66 in} FIGS. 5 and 6, when the amount of crushing of the O-ring in the rotary damper of the present invention is small, the torque is small and the surface of the O-ring is polished. Even if it is applied, the torque is almost the same even if a surface finish is applied by spraying an abrasive of grain size # 320 on the surface of the O-ring. However, when the amount of crushing of the O-ring is large, the torque is large, and the surface finish of the O-ring surface is sprayed with abrasive material of grain size # 320 rather than the torque applied to the surface of the O-ring. Torque is small. Further, as can be seen from the torque change rate characteristic curves N _{71 to} N ₇₆ in FIG. 7, the torque change rate increases as the crushing amount of the O-ring increases when the rotational speed is small, and the particle size # 320 of the surface of the O-ring increases. It is smaller for those who have applied abrasive finish to the finish. Therefore, it can be seen that the rate of change in torque is reduced by applying a finish to the surface of the O-ring in the rotary damper of the present invention.

  FIG. 8 shows a case where the surface is polished as an O-ring in a conventional rotary damper, and the amount of crushing is 10%, 15%, and 20%. It is a torque characteristic diagram of only an O-ring when it is used at 23 ° C. when it is sprayed and finished with a finish, and the amount of crushing is 10%, 15%, and 20%. In FIG. 8, the vertical axis represents torque (mN · m), and the horizontal axis represents rotation speed (rmp).

In FIG. 8, O ₈₁ is a torque characteristic curve when the surface of the O-ring is polished and used at 23 ° C. with a crushing amount of 10%, and O ₈₂ is an abrasive of particle size # 320 sprayed on the surface of the O-ring. Torque characteristics curve when used at 23 ° C with a finish on the ground, with a crushing amount of 10%, O ₈₃ is a torque characteristic when the surface of the O-ring is polished and used at 23 ° C with a crushing amount of 15% Curve, O ₈₄ is the surface of the O-ring surface with a grain size # 320 abrasive, and the surface finish is applied. Torque characteristic curve when used at 23 ° C with 15% crushing amount. O ₈₅ is the surface of the O-ring. Polished, temperature characteristic curve when used at 23 ° C with 20% crushed amount, O ₈₆ sprayed abrasive material of grain size # 320 on the surface of O-ring to give a ground finish, 20% crushed amount When used at 23 ° C A temperature characteristic curve.

  FIG. 9 shows a case where the surface is polished as an O-ring in a conventional rotary damper, and the amount of crushing is 10%, 15%, and 20%. It is a torque characteristic diagram of only an O-ring when it is used at −30 ° C. when it is sprayed and finished with a finish, and the amount of crushing is 10%, 15%, and 20%. In FIG. 9, the vertical axis represents torque (mN · m), and the horizontal axis represents rotation speed (rmp).

In FIG. 9, O ₉₁ is a torque characteristic curve when the surface of the O-ring is polished and the amount of crushing is 10% and used at −30 ° C., and O ₉₂ is sprayed with an abrasive of particle size # 320 on the surface of the O-ring. Torque characteristic curve when used at -30 ° C with 10% crushed finish, O ₉₃ is polished on the surface of the O-ring and used at -30 ° C with 15% crushed amount Torque characteristic curve, O ₉₄ is a torque characteristic curve when O-ring surface is sprayed with abrasive material of grain size # 320 to give a ground finish and the crushed amount is 15%, and used at −30 ° C., O ₉₅ is O Torque characteristic curve when the surface of the ring is polished and crushed 20% and used at -30 ° C. O ₉₆ is a surface finish by spraying abrasive material of grain size # 320 on the surface of the O-ring. -30 ° C with 20% amount It is the torque characteristic curve when used.

  FIG. 10 shows the case where the crushed amount of the O-ring shown in FIG. 9 is 10%, 15% and 20% with respect to the torque when the crushed amount of the O-ring shown in FIG. 8 is 10%, 15% and 20%. It is a torque change rate characteristic figure which shows the change rate of the torque of. In FIG. 10, the vertical axis represents the torque change rate (%), and the horizontal axis represents the rotational speed (rmp).

10, O ₁₀₁ is polished on the surface of the O-ring shown in FIG. 8, and the surface of the O-ring shown in FIG. 9 with respect to the torque characteristic curve O ₈₁ when used at 23 ° C. with a crushing amount of 10%. A torque change rate characteristic curve showing the change rate of the torque characteristic curve O ₉₁ when polished and used at −30 ° C. with a crushing amount of 10%, O ₁₀₂ is the particle size # 320 on the surface of the O-ring shown in FIG. Abrasive finish is applied by spraying a polishing material of No. 320, and a polishing material of particle size # 320 is sprayed on the surface of the O-ring shown in FIG. 9 for a torque characteristic curve O ₈₂ when the crushing amount is 10% and used at 23 ° C. Torque change rate characteristic curve showing the change rate of torque characteristic curve O ₉₂ when used at -30 ° C with 10% crushing amount, O ₁₀₃ is polished on the surface of the O-ring shown in FIG. And set the crushing amount to 15% Honed surface of the O-ring shown in FIG. 9 with respect to the torque characteristic curve O ₈₃ when used at 23 ° C., the rate of change of the torque characteristic curve O ₉₃ when used at -30 ° C. the collapse amount as 15% The torque change rate characteristic curve shown, O ₁₀₄ is the torque characteristic when the surface of the O-ring shown in FIG. subjected to pear finish by blowing abrasive grain size of # 320 to O-ring surface as shown in FIG. 9 with respect to the curve O _84, the change in the torque characteristic curve O ₉₄ when used at -30 ° C. the collapse amount as 15% A torque change rate characteristic curve showing the rate, O ₁₀₅ is shown in FIG. 9 with respect to the torque characteristic curve O ₈₅ when the surface of the O-ring shown in FIG. 8 is polished and used at 23 ° C. with a crushing amount of 20%. Polish the surface of the O-ring The torque change rate characteristic curve showing the change rate of the torque characteristic curve O ₉₅ when used at −30 ° C. with a crushing amount of 20%, O ₁₀₆ is the particle size # 320 on the surface of the O-ring shown in FIG. No abrasive is sprayed on the surface of the O-ring shown in FIG. 9 with respect to the torque characteristic curve O ₈₆ when used at 23 ° C. with a crushing amount of 20%. subjecting the earth finishing, the torque change rate characteristic curve showing the change rate of the torque characteristic curve O ₉₆ when used at -30 ° C. the collapse amount as 20%.

As can be seen from the torque characteristic curves O _{81 to} O ₈₆ and O _{91 to} O _{96 in} FIGS. 8 and 9, the particle size on the surface of the O-ring is higher than that in the case of polishing the surface of the O-ring in the conventional rotary damper. Torque is smaller in the case where the finish is applied by spraying # 320 abrasive.
However, as can be seen from the torque change rate characteristic curves O _{101 to} O ₁₀₆ in FIG. 10, the torque change rate improves as the overall rotational speed increases, but the corresponding torque change rate characteristic curve N in FIG. 7. ₇₁ to N can not be found what is improved than _76.

  As described above, according to another embodiment of the present invention, an O-ring is formed of ethylene propylene diene rubber having non-swelling property with respect to silicon oil, and a surface finish is applied to the surface of the O-ring. Therefore, the torque fluctuation caused by the O-ring with respect to the temperature change can be reduced, and the rotary damper can be used without any trouble even in a cold region.

  FIG. 11 shows that the surface is polished as an O-ring in the rotary damper of the present invention, and the particle size # 400 on the surface as an O-ring in the rotary damper of the present invention with respect to torque when the amount of crushing is 10%, 15%, and 20%. It is a torque change rate characteristic figure which shows the change rate of the torque of only an O-ring when the finishing material is given by spraying # 240 abrasive and the crushing amount is 10%, 15% and 20%. In FIG. 11, the vertical axis represents the torque change rate (%), and the horizontal axis represents the rotational speed (rmp).

In FIG. 11, N ₁₁₁ polishes the surface of the O-ring and sprays an abrasive having a particle size of # 400 on the surface of the O-ring with respect to the torque characteristic curve when the crushing amount is 10% and used at 23 ° C. Torque change rate characteristic curve showing the rate of change of torque characteristic curve when used at -30 ° C with crushed finish and 10% crushed amount, N ₁₁₂ is polished O-ring surface and crushed amount is 10% As a result, the surface of the O-ring is sprayed with a polishing material having a particle size of # 240 on the surface of the O-ring to give a torque finish. torque change rate characteristic curve showing the change rate of the curve, N ₁₁₃ is the particle size on the surface of the O-ring with respect to the torque characteristic curve when the honed surface of the O-ring was used at 23 ° C. the crushing weight of 15% # Spraying an abrasive grain size of 00 subjected to a pear finish, the torque change rate characteristic curve showing the change rate of the torque characteristic curve when used at -30 ° C. the collapse amount as 15%, N ₁₁₄ is the surface of the O-ring The surface of the O-ring is sprayed with an abrasive with a particle size of # 240 on the surface of the O-ring against the torque characteristic curve when the crushing amount is 15%, and the crushing amount is 15%. Torque change rate characteristic curve showing the rate of change of the torque characteristic curve when used at −30 ° C., N ₁₁₅ is a torque characteristic curve when the surface of the O-ring is polished and used at 23 ° C. with a crushing amount of 20% Torque change rate characteristic showing the change rate of torque characteristic curve when used with -30 ° C with 20% crushing amount by spraying abrasive material of particle size # 400 on the surface of O-ring against The curve, _N116, is the surface of the O-ring that is polished by spraying abrasive with a particle size of # 240 on the surface of the O-ring against the torque characteristic curve when the crushing amount is 20% and used at 23 ° C. It is a torque change rate characteristic curve which shows the change rate of a torque characteristic curve when it finishes and it uses at -30 degreeC by making 20% of crushing amounts.

  As can be seen from a comparison between FIG. 11 and FIG. 10, the abrasive of grain size # 320 is applied to the O-ring even if the abrasive is finished by spraying the abrasive of grain size # 400 or # 240 on the surface of the O-ring. The same effect can be obtained as when a surface finish is applied by spraying on the surface.

In the above-described embodiment, an example in which the viscous fluid is silicone oil, the sealing material is an O-ring, and the O-ring is formed of ethylene propylene diene rubber having non-swelling property to the silicone oil has been described. Even if the sealing material is formed of any of ethylene propylene rubber other than ethylene propylene diene rubber, isobutylene isoprene rubber, chloroprene rubber, fluorine rubber, and urethane rubber, the same effect can be obtained. In addition, an example in which an abrasive having a grain size of # 400, # 320, or # 240 is applied to the surface of the sealing material to perform a finish finish has been shown. However, viscous fluid may flow between the housing (cap) and the rotating shaft from the housing. If it can be prevented from leaking to the outside, the same effect can be obtained even if the surface finish is applied with an abrasive of another particle size.

D Rotating damper 11 Housing 12 Housing body 13 Cylindrical portion 14 Support shaft 15A Mounting piece 15a Mounting hole 15B Mounting piece 15b Mounting recess 16 Cap 17 Top plate 17a Through hole 17b O-ring housing portion 18 Peripheral wall 21 Silicon oil (viscous fluid)
31 Rotor 32 Rotating shaft 33 Large diameter shaft portion 33a Bearing portion 34 Mounting shaft portion 34a Locking recess 35 Rotor braking plate 41 O-ring (seal material)
51 Driven Gear 52 Mounted Hole 53 Engagement Section

Claims (4)

A housing, a viscous fluid filled in the housing, a rotating shaft partially protruding from the housing, and a rotor brake connected to the lower end of the rotating shaft and rotatably accommodated in the housing In a rotary damper comprising a rotor having a plate, and a seal member that is disposed between the housing and the rotating shaft and prevents the viscous fluid from leaking out of the housing,
The sealing material is formed of a material having non-swelling property with respect to the viscous fluid, and torque fluctuation caused by the sealing material is reduced.
It is a rotating damper. The rotary damper according to claim 1, wherein
The viscous fluid is silicone oil,
The sealing material was formed of one of ethylene propylene rubber, isobutylene isoprene rubber, chloroprene rubber, fluorine rubber, and urethane rubber.
Rotating damper characterized by that. The rotary damper according to claim 1, wherein
The viscous fluid is silicone oil,
The sealing material was formed of ethylene propylene diene rubber.
Rotating damper characterized by that. The rotary damper according to any one of claims 1 to 3,
A surface finish was applied to the surface of the sealing material,
Rotating damper characterized by that.

Images