JP2013167318A - Rotational vibration suppression device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rotational vibration suppression device capable of suppressing rotational vibration with a simple structure without requiring power.SOLUTION: A rotational vibration suppression device includes: a disc 11 rotating integrally with a rotary shaft 60 around the same axis N; a casing 20 having opposite surfaces 21, 22 facing both surfaces 11a, 11b of the disc 11 through predetermined spaces, respectively, and arranged relatively rotatably with respect to the disc 11 and the rotary shaft 60; magnetic viscous fluid 30 interposed in the predetermined spaces; and magnetic field generation means to generate a magnetic field penetrating the predetermined spaces where the magnetic viscous fluid 30 is interposed and the disc 11. The magnetic field generation means are a pair of permanent magnets 40 arranged on both sides in a plate thickness direction of the disc 11 outside the casing 20.

Description

  The present invention relates to an apparatus for suppressing rotational vibration in a power transmission system, and relates to a rotational vibration suppressing apparatus using a magnetorheological fluid.

  Conventionally, a rotating device in which a magnetorheological fluid is sealed has been proposed. For example, a rotating device (rotary damper) disclosed in Patent Document 1 includes a casing, a rotor provided in the casing so as to be relatively rotatable, and an electromagnet, and encloses a magnetorheological fluid in a gap between the casing and the rotor. It is a thing. The electromagnet includes a coil that generates a magnetic field, a bobbin around which the coil is wound, and a magnetic yoke that induces a magnetic path. This rotating device changes the viscosity (shear stress) of the magnetorheological fluid by changing the strength of the magnetic field applied to the magnetorheological fluid, thereby adjusting the damping force against the rotation of the rotor. ing.

JP 2008-202744 A

  By the way, in a power transmission system that transmits rotational power via a gear mechanism, continuous vibration due to meshing of gears and temporary vibration due to backlash clogging with the reversal of the rotation direction of the gears occur. It is known.

  Such rotational vibration can be suppressed by arranging the rotating device of Patent Document 1 on the output side of the gear mechanism. That is, if the shaft that rotates integrally with the rotor of the rotating device is connected to the output side of the gear mechanism, the casing of the rotating device is fixed outside the rotating power transmission system, and the viscosity of the magnetorheological fluid is adjusted appropriately, the shaft The transmitted rotational vibration is absorbed and suppressed by the magnetorheological fluid.

  However, such a conventional rotating device gives a magnetic field to the magnetorheological fluid by an electromagnet, so that it is necessary to supply power to the apparatus, and there is a problem in that the structure of the apparatus becomes complicated.

  The present invention has been made in view of such a problem, and an object of the present invention is to provide a rotational vibration suppressing device capable of suppressing rotational vibration with a simple structure without requiring electric power.

  The rotational vibration suppressing device of the present invention has a disk that rotates around the same axis integrally with a rotation shaft, and opposing surfaces that face each other with a predetermined gap on both surfaces of the disk, and the disk and the disk A casing provided so as to be rotatable relative to a rotating shaft, a magnetic viscous fluid interposed in the predetermined gap, and a magnetic field that generates a magnetic field penetrating the predetermined gap and the disc in which the magnetic viscous fluid is interposed. Generating means, wherein the magnetic field generating means is a pair of permanent magnets disposed on both sides of the disk in the plate thickness direction outside the casing.

  In the rotational vibration suppressing device having such a configuration, when the rotational shaft is rotationally oscillated, the rotational vibration is transmitted to the disk. Since a magnetorheological fluid to which a magnetic field is applied is interposed in a predetermined gap between the disc and the casing, the rotational vibration transmitted to the disc can be reduced by fixing the casing outside the rotating system. Damped by viscous resistance due to fluid. Thereby, the rotational vibration in the rotational power transmission system in which the rotating shaft is installed is suppressed.

  In the rotational vibration suppressing device having the above-described configuration, it is desirable that the casing and the disc are partly or entirely made of a magnetic material interposed between the pair of permanent magnets.

  According to the rotational vibration suppressing device having such a configuration, the magnetic field that can be applied to the magnetorheological fluid can be strengthened, and the damping force against the rotational vibration can be increased.

  In the rotational vibration suppressing device having the above-described configuration, the casing and the disk are partly or entirely made of a magnetic material between the pair of permanent magnets, and parts other than the magnetic material are non-conductive. More preferably, it is made of a magnetic material.

  According to the rotational vibration suppressing device having such a configuration, the magnetic path is not diffused except between the pair of permanent magnets, and the magnetic field applied to the magnetorheological fluid is further increased by forming the magnetic path only between the permanent magnets. It becomes possible to strengthen.

  In the rotational vibration suppressing device having the above-described configuration, it is desirable to include a separation distance adjusting means for adjusting a separation distance in the plate thickness direction of the disk between the permanent magnet and the casing.

  According to the rotational vibration suppressing device having such a configuration, the magnetorheological fluid interposed in the gap between the both surfaces of the disk and the facing surface of the casing by adjusting the separation distance between the casing and the permanent magnet by the separation distance adjusting means. It is possible to adjust the strength of the magnetic field penetrating through. As a result, the viscosity of the magnetorheological fluid can be adjusted, and the degree of attenuation of the rotational vibration of the rotating shaft can be adjusted appropriately.

  The separation distance adjusting means includes, for example, a magnet support member provided integrally with the permanent magnet, and is screwed to the magnet support member, and a tip portion extends from the magnet support member side toward the casing side. And a bolt that adjusts the separation distance by degenerating.

  According to the rotational vibration suppressing device of the present invention, it is possible to suppress rotational vibration in a rotational power transmission system in which a rotating shaft is installed with a simple structure. And since a magnetic field is provided to a magnetorheological fluid with a permanent magnet, supply of electric power is not required.

It is the front view which looked at the rotational vibration suppression device which concerns on embodiment of this invention from the axial direction of the rotating shaft. It is ABC sectional drawing of FIG. In order to show the magnetic poles in the cross section of the permanent magnet, hatching is omitted (the same applies to other drawings). FIG. 2 is a cross-sectional view taken along the line A-B-D in FIG. 1. FIG. 2 is a cross-sectional view taken along the line A-B-D in FIG. 1. It is sectional drawing of the rotational vibration suppression apparatus which concerns on other embodiment, Comprising: It is a figure which shows the cross-sectional site | part similar to FIG.

  Hereinafter, a rotational vibration suppressing device according to an embodiment of the present invention will be described with reference to FIGS. The rotational vibration suppressing device 100 includes a rotor 10, a casing 20, a magnetic viscous fluid 30, a magnetic field generating unit 40, a separation distance adjusting unit 50, and the like. The rotary shaft 60 is adapted to receive rotational power from a drive source such as an electric motor (not shown) via a gear mechanism or the like. It is assumed that the gear mechanism can reverse the rotational direction of the rotational power from the drive source.

  The rotor 10 includes a disk 11 and a rotor hub 12 that are integrally formed with each other. The rotor hub 12 has a shaft hole 13 into which the rotary shaft 60 is fitted at the center thereof, and the disc 11 is integrally formed on the outer diameter side. The rotor hub 12 is formed with a female screw penetrating from the outer periphery to the shaft hole 13, and a set screw 14 is screwed to the female screw. The rotor 10 and the rotating shaft 60 are fixed to each other so as to rotate integrally around the axis N by fitting the rotating shaft 60 into the shaft hole 13 and tightening the set screw 14.

  The disc 11 is provided so as to rotate around the same axis N as the rotation shaft 60. Both surfaces 11 a and 11 b of the disk 11 are flat surfaces orthogonal to the axis N. Further, a portion (a portion interposed between a pair of permanent magnets 40 to be described later) that falls within a range of a predetermined first radius R1 to a second radius R2 in the disk 11 is made of a magnetic material, and other than the magnetic material. The portion and the rotor hub 12 are made of a nonmagnetic material.

  The casing 20 has a two-divided structure having a joint surface on a plane including the axis N, and the members that can be divided into two are fastened to each other by bolts or the like (not shown). Both members constituting the casing 20 are respectively formed with semicircular cavities, and by joining the two members, a disk-like shape slightly larger than the diameter and thickness of the disk 11 is formed in the casing 20. A cavity 23 is formed. As shown in FIGS. 2 and 3, the casing 20 covers both surfaces 11 a and 11 b and the outer peripheral surface of the disk 11, and faces the both surfaces 11 a and 11 b of the disk 11 with a predetermined gap therebetween. 21 and 22. The opposing surfaces 21 and 22 are flat surfaces orthogonal to the axis N, like the both surfaces 11 a and 11 b of the disk 11.

  The casing 20 is provided to be rotatable relative to the rotor 10 (disk 11) and the rotation shaft 60. For example, as shown in FIGS. 2 and 3, a shaft hole 24 is formed in the casing 20, and the rotor hub 12 is fitted into the shaft hole 24 via a radial gap. A bearing 25 is interposed between the outer peripheral portion of the rotor hub 12 and the inner peripheral portion of the casing 20. As a result, the casing 20 is rotatable relative to the rotor 10 (disk 11) and the rotating shaft 60. In the present embodiment, the casing 20 is fixed to an object (wall surface or the like) (not shown) outside the rotational power transmission system (not shown). The rotor hub 12 and the casing 20 are respectively formed with housings 12a and 20a of the bearing 25. The bearing 25 is held by an annular holding plate 26 bolted to the casing 20 so as not to be removed from the housings 12a and 20a. Yes.

  Further, of the wall body including the opposing surfaces 21 and 22 of the casing 20, a portion (a portion interposed between a pair of permanent magnets 40 described later) that falls within a range of a predetermined first radius R1 to a second radius R2 is: The other parts are made of a non-magnetic material, and the other parts are made of a non-magnetic material.

  The magnetorheological fluid 30 is sealed in the gap between the disk 11 and the casing 20, thereby being interposed in the gap between the both surfaces 11 a and 11 b of the disk 11 and the opposing surfaces 21 and 22 of the casing 20. The magnetorheological fluid 30 is a liquid in which magnetic particles are dispersed in a dispersion medium, and in particular, a liquid in which the magnetic particles are composed of nano-sized metal particles (metal nanoparticles) can be used. The magnetic particles are made of a magnetizable metal material, and the metal material is not particularly limited, but a soft magnetic material is preferable. Examples of the soft magnetic material include alloys such as iron, cobalt, nickel, and permalloy.

  The metal nanoparticles preferably have an average particle diameter of 20 to 500 nm, and more preferably 70 to 200 nm. In addition, the magnetic particles may include an aggregate in which metal nanoparticles are aggregated, and in particular, may include an aggregate in which metal nanoparticles are aggregated in a lump. Agglomerated aggregates, for example, lower the base viscosity as compared with the case where rod-like or chain-like aggregates are contained in the magnetorheological fluid. The size of the aggregate is preferably 10 μm or less, more preferably 5 μm or less, as an average particle size by a laser diffraction scattering method.

  The dispersion medium is not particularly limited, and a hydrophobic silicone oil can be given as an example. Depending on the type of the dispersion medium to be used, the magnetic particles may be subjected to surface modification having high affinity with the dispersion medium. By doing so, the dispersion stability of the magnetic particles is increased. For example, when hydrophobic silicone oil is used as the dispersion medium, it is preferable to subject the magnetic particles to surface modification with a coupling agent.

  The blending amount of the magnetic particles in the magnetorheological fluid may be, for example, 3 to 40 vol%. Various additives can also be added to the magnetorheological fluid in order to obtain various desired properties.

  The magnetic field generating means 40 includes a pair of permanent magnets 40 that generate a magnetic field penetrating the disk 11 and the magnetorheological fluid 30 in the thickness direction of the disk 11. The pair of permanent magnets 40 are disposed on both sides in the plate thickness direction of the disk 11 outside the casing 20 and are opposed to different magnetic poles. In the present embodiment, an annular one having an axis N as the center is adopted as the permanent magnet 40, and a magnet support member 41 made of a nonmagnetic material is integrally formed on the outer diameter side of the permanent magnet 40. ing.

  Of the disc 11 and the casing 20, a portion that falls within the range of the predetermined first radius R <b> 1 to the second radius R <b> 2, that is, a portion that is interposed between the pair of permanent magnets 40 is made of a magnetic material. Parts other than the part which consists of a magnetic body of the casing 20 are comprised with the nonmagnetic body. For this reason, the magnetic path is not diffused except between the pair of permanent magnets 40, and the magnetic path is formed only between the permanent magnets 40, whereby the magnetic field applied to the magnetorheological fluid 30 is strengthened.

  The separation distance adjusting means 50 is for adjusting a separation distance between the permanent magnet 40 and the casing 20 (a separation distance in the plate thickness direction of the disk). 3 and FIG. 4 includes a magnet support member 41 and a bolt 42 screwed to the magnet support member 41. That is, a female screw is formed through the magnet support member 41 in a direction parallel to the axis N, and the bolt 42 is screwed to the female screw. The screw 42 has a screw length longer than that of the female screw, and the tip of the bolt 42 can be exposed from the surface 41 a of the magnet support member 41 on the casing 20 side. Therefore, when the bolt 42 is turned to one side (for example, right), the tip end portion of the bolt 42 extends from the magnet support member 41 side toward the casing 20 side, and the permanent magnet 40 is attracted to the portion of the casing 20 made of a magnetic body. The separation distance is increased against the force of On the other hand, when the bolt 42 is turned to the opposite side (for example, to the left), the tip of the bolt 42 is retracted toward the magnet support member 41, and the permanent magnet 40 is attracted to the portion made of the magnetic body of the casing 20. These separation distances are reduced.

  As the separation distance between the casing 20 and the permanent magnet 40 is increased by the separation distance adjusting means 50, the magnetorheological fluid 30 interposed in the gap between the both surfaces 11 a and 11 b of the disk 11 and the opposing surfaces 21 and 22 of the casing 20. The magnetic field penetrating through is weakened. As a result, the viscosity of the magnetorheological fluid 30 is lowered, and the rotational energy and rotational vibration energy absorption rate of the rotor 10 are also lowered. On the other hand, as the separation distance between the casing 20 and the permanent magnet 40 is reduced, the magnetic field penetrating the magnetorheological fluid 30 interposed in the gap becomes stronger. As a result, the viscosity of the magnetorheological fluid increases and the absorption rate of the rotational energy and rotational vibration energy of the rotor 10 also increases.

  In the rotational vibration suppressing device 100 configured as described above, when rotational power is transmitted to the rotary shaft 60 from a drive source (not shown) via the gear mechanism, the rotary shaft 60 rotates about the axis N. At this time, the continuous rotation vibration generated by the gear mechanism and the temporary rotation vibration generated when the rotation direction is reversed by the gear mechanism and the backlash is clogged are transmitted through the rotating shaft 60 to the disc 11 of the rotor 10. Is transmitted to. A magnetorheological fluid 30 to which a magnetic field is applied is interposed in the gap between the disk 11 and the casing 20, and the casing 20 is fixed outside the rotating system, so that it is applied to the magnetorheological fluid 30. If the strength of the magnetic field is an appropriate value, the rotational vibration of the disk 11 is attenuated by the viscous resistance due to the magnetorheological fluid 30, and the rotational vibration in the rotational power transmission system is suppressed.

  The strength of the magnetic field applied to the magnetorheological fluid 30, that is, the viscosity resistance by the magnetorheological fluid 30 can be adjusted by the separation distance adjusting means 50, and is in an optimum state as appropriate according to the specific characteristics of the gear mechanism and the like. It is desirable to adjust to. That is, the distance between the casing 20 and the permanent magnet 40 may be adjusted so that the most effective rotational vibration suppression effect can be obtained.

<Other embodiments>
In the above-described embodiment, the rotor hub 12 is interposed between the rotating shaft 60 and the disk 11. However, if the disk 11 and the rotating shaft 60 rotate about the same axis as a single unit, the rotating shaft A thing other than the rotor hub 12 may intervene between 60 and the disk 11. Alternatively, the disk may be directly attached to the rotating shaft 60 by, for example, spline fitting.

  As described in the above-described embodiment, the permanent magnet 40 is preferably an annular one, but any permanent magnet 40 that generates a magnetic field penetrating the disk 11 and the magnetorheological fluid 30 in the thickness direction of the disk 11 can be used. It is not limited to an annular permanent magnet. For example, a plurality of permanent magnets arranged at intervals in the circumferential direction may be used.

  According to the above-described embodiment, the strength of the magnetic field applied to the magnetorheological fluid 30 can be easily adjusted at any time by the separation distance adjusting means 50, but the separation distance adjusting means 50 is not provided, and other measures are taken. Thus, a magnetic field having an appropriate strength may be applied to the magnetorheological fluid 30. For example, as in the rotational vibration suppressing device 100A shown in FIG. 5, an annular permanent magnet 40 is detachably provided directly on the outer surface of the casing 20 (back side surfaces of the facing surfaces 21 and 22), and the permanent magnet 40 has different magnetic forces. A plurality of annular permanent magnets 40 may be prepared, and these may be sequentially attached, and a permanent magnet that can most effectively reduce rotational vibration may be employed. In FIG. 5, the same reference numerals as those in FIGS. 1 to 4 are assigned to the same configurations as those in the above-described embodiment.

  In the embodiment described above, all of the portions interposed between the pair of permanent magnets 40 of the disk 11 and the casing 20 are made of a magnetic material, and the portions other than the portions made of the magnetic material are made of a non-magnetic material. However, of the disc 11 and the casing 20, a part of a portion interposed between the pair of permanent magnets 40 is made of a magnetic material, and a portion other than the portion made of the magnetic material is made of a non-magnetic material. However, it is possible to apply a magnetic field to the magnetorheological fluid 30.

  The present invention can be applied to, for example, an apparatus for suppressing rotational vibration in a power transmission system that transmits rotational power via a gear mechanism.

DESCRIPTION OF SYMBOLS 11 Disc 11a, 11b Both surfaces of a disk 20 Casing 21,22 Opposite surface 30 Magnetorheological fluid 40 Permanent magnet (magnetic field generation means)
41 Magnet support member 42 Bolt 50 Separation distance adjusting means 60 Rotating shaft 100 Rotational vibration suppressing device 100A Rotational vibration suppressing device

Claims (5)

A disk that rotates around the same axis as the rotation axis;
A casing provided on both sides of the disc with opposing surfaces facing each other with a predetermined gap, and provided so as to be relatively rotatable with respect to the disc and the rotation shaft;
A magnetorheological fluid interposed in the predetermined gap;
Magnetic field generating means for generating a magnetic field penetrating the predetermined gap and the disc, wherein the magnetorheological fluid is interposed;
A rotational vibration suppressing device comprising:
The rotational vibration suppressing device according to claim 1, wherein the magnetic field generating means is a pair of permanent magnets disposed on both sides of the disk in the plate thickness direction outside the casing. The rotational vibration suppressing device according to claim 1,
The casing and the disk are partly or entirely made of a magnetic material between portions of the pair of permanent magnets. The rotational vibration suppressing device according to claim 1,
The casing and the disk are rotational vibrations characterized in that a part or the whole of a portion interposed between the pair of permanent magnets is made of a magnetic material, and a portion other than the magnetic material is made of a non-magnetic material. Suppression device. The rotational vibration suppression device according to any one of claims 1 to 3,
A rotational vibration suppressing device comprising a separation distance adjusting means for adjusting a separation distance in the plate thickness direction of the disk between the permanent magnet and the casing. The rotational vibration suppressing device according to claim 4,
The separation distance adjusting means is
A magnet support member provided integrally with the permanent magnet;
A bolt that is screwed onto the magnet support member, and that adjusts the separation distance by extending and retracting a tip portion from the magnet support member side toward the casing side;
A rotational vibration suppressing device characterized by comprising: