JP7611733B2 - Coupling - Google Patents

Description

The present invention relates to a coupling using a magnetorheological fluid.

Couplings that connect shafts and transmit rotational power from the driving side to the driven side are known (see, for example, Patent Documents 1 to 4). The couplings disclosed in these documents include a driving side joint portion that is fixed to the driving side shaft, a driven side joint portion that is fixed to the driven side shaft, and an intermediate portion that is connected between these joint portions. In the couplings disclosed in Patent Documents 1 to 3, a leaf spring is included in the intermediate portion, and in the coupling disclosed in Patent Document 4, a rubber material is included in the intermediate portion.

The general roles of a coupling are (1) to transmit power from the driving side to the driven side, (2) to absorb installation errors between the driving and driven shafts, (3) to absorb vibrations on the driving side, and (4) to prevent heat from the driving motor or the like from being transmitted to the driven side. In the couplings disclosed in Patent Documents 1 to 4, with regard to the role of (3) above, vibrations on the driving side are absorbed in the middle section.

JP 2012-167743 A JP 2002-372068 A Japanese Unexamined Patent Publication No. 155335/1983 JP 2014-092168 A

By the way, the torsional vibration absorbed by the coupling can be suppressed by changing the torsional rigidity of the coupling, and the resonance point of the torsional vibration can also be changed.

However, in the couplings disclosed in Patent Documents 1 to 4, in order to change the torsional rigidity, it is necessary to replace the leaf spring or rubber material used in the middle part of the coupling with one having a different rigidity, or to replace the entire coupling with another coupling having a different torsional rigidity.

The present invention was devised in light of the above situation, and aims to provide a coupling whose torsional rigidity can be easily changed.

The coupling according to the first aspect of the present invention comprises a first joint part attached to one shaft so as to be non-rotatable relative to the other shaft, a second joint part attached to the other shaft so as to be non-rotatable relative to the other shaft, and an intermediate part connected between the first joint part and the second joint part to absorb torsional vibrations, and further comprises a magnetic field generating part that generates a magnetic field. The intermediate part has a plurality of first blade parts connected to the first joint part, extending radially outward, arranged in a circumferential direction, and rotating with the one shaft, and a plurality of second blade parts connected to the second joint part, extending radially inward, arranged in a circumferential direction, and rotating with the other shaft. Between the adjacent second blade parts, a storage space having a volume necessary for the first blade part to enter is formed, and the first blade part is arranged so as to enter the storage space, and the first blade part and the second blade part are arranged alternately in the circumferential direction. A magnetorheological fluid is filled between the first blade part and the second blade part in the storage space. The storage space has a one-side space formed on one circumferential side of the first blade portion and an other-side space formed on the other circumferential side of the first blade portion. A communication flow path is formed in the middle portion to connect the one-side space and the other-side space, and the magnetic field generating unit is provided so as to apply a magnetic field to the magnetorheological fluid in the communication flow path.

A coupling with this configuration allows the torsional rigidity to be easily changed.

The coupling according to the second aspect of the present invention is the coupling according to the first aspect, in which the angle by which the first blade portion can rotate relative to the second blade portion in the circumferential direction within the storage space is a predetermined angle of 5 degrees or less.

The coupling according to the third aspect of the present invention is the coupling according to the first or second aspect, in which the communication passage includes an annular passage formed in an annular shape when viewed in the axial direction.

The coupling according to the fourth aspect of the present invention is the coupling according to the third aspect, wherein the communication flow passage further includes a one-side orifice that opens into the one-side space and the annular flow passage, respectively, and a second-side orifice that opens into the other-side space and the annular flow passage, respectively.

The coupling according to the fifth aspect of the present invention is the coupling according to the third or fourth aspect, in which the magnetic field generating unit has a yoke formed in a shape that axially sandwiches the annular flow path, and a coil wound so as to form a magnetic path within the yoke, and when a current is applied to the coil, a magnetic path is formed that penetrates the magnetorheological fluid within the annular flow path.

The present invention provides a coupling whose torsional rigidity can be easily changed.

FIG. 2 is a cross-sectional view taken along a radial direction, showing a characteristic portion of a coupling according to an embodiment of the present invention. 2 is a cross-sectional view taken along line AOA in FIG. 1. 2 is a cross-sectional view taken along line BB in FIG. 1.

The following describes a coupling according to an embodiment of the present invention with reference to the drawings.

As shown in FIG. 2, the coupling 1 according to this embodiment is connected between the driving side rotating shaft 2 and the driven side rotating shaft 3, and includes a first joint section 5, a second joint section 6, an intermediate section 7, a magnetorheological fluid 8, and a magnetic field generating section 9. In this specification, the driving side rotating shaft may be referred to as the "driving shaft" and the driven side rotating shaft as the "driven shaft". In this specification, directions may be referred to with the driving shaft side as the top and the driven shaft side as the bottom.

The first joint part 5 is attached to the drive side rotating shaft 2 so that it cannot rotate relative to the drive side rotating shaft 2, and rotates integrally with the drive side rotating shaft 2. It is preferable that the first joint part 5 is made of a non-magnetic material.

The second joint part 6 is attached to the driven rotating shaft 3 so as not to rotate relative to the driven rotating shaft 3, and rotates integrally with the driven rotating shaft 3. It is preferable that the second joint part 6 is made of a non-magnetic material.

The intermediate section 7 is connected between the first joint section 5 and the second joint section 6. In this embodiment, the intermediate section 7 has a plurality of first blade sections 10, a first blade section rotating shaft 11, bearing housing members 12, 14, bearings 13, 15, a plurality of second blade sections 20, a first cylindrical section 21, a second cylindrical section 22, and a third cylindrical section 23.

The first blade section rotating shaft 11 is a rotating shaft that is integrally connected to the first joint section 5 on the axis N and extends in the direction of the axis N from the first joint section 5 toward the second joint section 6. The first blade section rotating shaft 11 rotates in conjunction with the rotation of the drive side rotating shaft 2. It is desirable that the first blade section rotating shaft 11 is made of a non-magnetic material.

As shown in FIG. 2, the first blade portion 10 is a blade-shaped portion extending radially outward from an approximately axially intermediate position of the first blade portion rotating shaft 11. As shown in FIG. 1, the first blade portions 10 are arranged in the circumferential direction at equal angles and extend radially from the first blade portion rotating shaft 11 around the axis N. The first blade portions 10 rotate together with the rotation of the drive side rotating shaft 2 via the first joint portion 5 and the first blade portion rotating shaft 11. As shown in FIG. 1, the first blade portion 10 is formed in a rectangular shape when viewed in the axial direction. Also, as shown in FIG. 2, the first blade portion 10 is formed in a rectangular shape when viewed in the radial direction. It is preferable that the first blade portion 10 is made of a non-magnetic material.

As shown in Figs. 1 to 3, the first cylindrical portion 21 is formed in a cylindrical shape extending in the direction of the axis N, and is disposed radially outward of the first blade portions 10. As shown in Figs. 2 and 3, the drive shaft 2 side end face of the first cylindrical portion 21 is in relatively rotatable contact with the driven shaft 3 side end face of the first joint portion 5. The first cylindrical portion 21 is a component of the intermediate portion 7, and also serves as a component of the magnetic field generating portion 9 (first inner yoke 21) as described below. Therefore, the first cylindrical portion 21 is constructed using a magnetic material.

As shown in Figs. 2 and 3, the second cylindrical portion 22 is composed of an inner cylindrical portion 22a and an outer cylindrical portion 22b, and the inner diameter of the first cylindrical portion 21 and the inner diameter of the inner cylindrical portion 22a are the same, and the outer diameter of the first cylindrical portion 21 and the outer diameter of the outer cylindrical portion 22b are the same. The end face of the second cylindrical portion 22 on the drive shaft 2 side is connected to the end face of the first cylindrical portion 21 on the driven shaft 3 side so as not to rotate relative to each other. As described below, the second cylindrical portion 22 forms an annular flow passage kp between its outer cylindrical portion 22b and inner cylindrical portion 22a. The second cylindrical portion 22 is composed of a non-magnetic material.

2 and 3, the third cylindrical portion 23 is formed in a cylindrical shape with the same diameter as the third cylindrical portion 23 and the second cylindrical portion 22. The drive shaft 2 side end surface of the third cylindrical portion 23 is connected to the driven shaft 3 side end surface of the second cylindrical portion 22 so as not to rotate relative to the second cylindrical portion 22. Furthermore, the driven shaft 3 side end surface of the third cylindrical portion 23 is connected to the drive shaft 2 side end surface of the second joint portion 6 so as not to rotate relative to the second cylindrical portion 22. As a result, the first cylindrical portion 21, the second cylindrical portion 22, and the third cylindrical portion 23, which are connected to each other so as not to rotate relative to each other, rotate together with the driven shaft 3 via the second joint portion 6. The third cylindrical portion 23 is a component of the intermediate portion 7, and also serves as a component of the magnetic field generating portion 9 (second inner yoke 23) as described later. Therefore, the third cylindrical portion 23 is made of a magnetic material.

As shown in FIG. 3, the second blade portion 20 is a blade-shaped portion extending radially inward from the first cylindrical portion 21 at a position approximately on the driven shaft 3 side of the first cylindrical portion 21 and at the same height position in the axial direction as the first blade portion 10. As shown in FIG. 1, the multiple second blade portions 20 are arranged in the circumferential direction at equal angles and extend radially from the first cylindrical portion 21 around the axis N. The multiple second blade portions 20 rotate together with the driven side rotating shaft 3 via the first cylindrical portion 21, the second cylindrical portion 22, the third cylindrical portion 23, and the second joint portion 6. As shown in FIG. 1, the second blade portion 20 is formed in a fan shape when viewed in the axial direction. It is preferable that the second blade portion 20 is made of a non-magnetic material.

As shown in FIG. 1, between the second blades 20 adjacent to each other in the circumferential direction, a storage space cs having a volume necessary for the first blade 10 to enter is formed. That is, in the intermediate portion 7, a plurality of storage spaces cs are formed in a line in the circumferential direction. One storage space cs is formed corresponding to one first blade 10, and the first blade 10 is arranged so that it enters the storage space cs, and the first blade 10 and the second blade 20 are alternately arranged in the circumferential direction. In the storage space cs, the first blade 10 can rotate relative to the second blade 20. Therefore, the storage space cs has a small play (angular interval) corresponding to a predetermined angle between the first blade 10 and the adjacent second blade 20 in the circumferential direction. Specifically, the angle at which the first blade 10 can rotate relative to the second blade 20 in the circumferential direction in the storage space cs is a predetermined angle of 5 degrees or less. That is, the storage space cs has a small space (one-side space s1) formed on one side of the first blade portion 10 in the circumferential direction, and a small space (other-side space s2) formed on the other side of the first blade portion 10 in the circumferential direction.

The storage space cs is filled with magnetorheological fluid 8 between the first blade portion 10 and the second blade portion 20. That is, in the storage space cs, one side space s1 and the other side space s2 are each filled with magnetorheological fluid 8. In this embodiment, the portions filled in gray in Figures 1 to 3 are filled with magnetorheological fluid 8.

The magnetorheological fluid 8 is a liquid in which magnetic particles are dispersed in a dispersion medium. For example, nano-sized metal particles (metal nanoparticles) can be used as the magnetic particles. The magnetic particles are made of a magnetizable metal material, and although there is no particular restriction on the metal material, soft magnetic materials are preferred. Examples of soft magnetic materials include alloys such as iron, cobalt, nickel, and permalloy. Although there is no particular restriction on the dispersion medium, hydrophobic silicone oil can be given as an example. The amount of magnetic particles in the magnetorheological fluid can be, for example, 3 to 40 vol.%. Various additives can also be added to the magnetorheological fluid in order to obtain various desired characteristics.

As shown in FIG. 1, the shape of the storage space cs is preferably a substantially sector shape expanding in the circumferential direction. In other words, the storage space cs is preferably formed in a shape in which the circumferential distance increases from the radially inner side to the radially outer side. This makes it easier to push out the magnetorheological fluid 8 filled in the one-side space s1 or the other-side space s2 toward the first orifice or1 or the second orifice or2 described below when the first blade portion 10 rotates relative to the second blade portion 20 in the storage space cs. The radially outer wall surface of the storage space cs is formed by the inner surface of the first cylindrical portion 21, and the radially inner wall surface of the storage space cs is formed by the first blade portion rotation shaft 11.

As shown in Figures 2 and 3, a bearing housing member 12 is fixed to the drive shaft 2 side of the second blade portion 20, radially inside the first cylindrical portion 21. A bearing 13 is interposed between the bearing housing member 12 and the first blade portion rotating shaft 11. The bearing 13 supports the first blade portion rotating shaft 11 at the intermediate portion 7 so that it can rotate on the axis N. A part of the end face of the bearing housing member 12 on the driven shaft 3 side forms a wall surface (top surface of the accommodation space cs) on the drive shaft 2 side of the accommodation space cs. It is preferable that the bearing housing member 12 is made of a non-magnetic material.

Similarly, as shown in Figs. 2 and 3, a bearing housing member 14 is fixed to the driven shaft 3 side of the second blade section 20, radially inward of the first cylindrical section 21, the second cylindrical section 22, and the third cylindrical section 23. A bearing 15 is interposed between the bearing housing member 14 and the first blade section rotating shaft 11. The bearing 15 supports the first blade section rotating shaft 11 at the intermediate section 7 so that it can rotate on the axis N. A part of the end surface of the bearing housing member 14 on the drive shaft 2 side forms the wall surface (bottom surface of the accommodation space cs) on the driven shaft 3 side of the accommodation space cs. It is preferable that the bearing housing member 14 is made of a non-magnetic material.

In the intermediate portion 7, a communication flow path cp is formed that connects the one-side space s1 and the other-side space s2. The communication flow path cp includes a first orifice or1, a second orifice or2, and an annular flow path kp.

As shown in Figures 2 and 3, the second cylindrical portion 22 is formed with an annular flow passage kp, which is an annular flow passage when viewed in the axial direction, so that the magnetorheological fluid 8 flows circumferentially inside the second cylindrical portion 22. The annular flow passage kp is open to the drive shaft 2 side end face and the driven shaft 3 side end face of the second cylindrical portion 22, and is a flow passage formed to go around the inside of the second cylindrical portion 22 in the circumferential direction. The driven shaft 3 side end face of the first cylindrical portion 21 forms the top surface of the annular flow passage kp, and the drive shaft 2 side end face of the third cylindrical portion 23 forms the bottom surface of the annular flow passage kp.

As shown in Figs. 1 and 2, the first cylindrical portion 21 is formed with a first orifice OR1 that opens into the one-side space s1, and a second orifice OR2 that opens into the other-side space s2. That is, the first orifice OR1 and the second orifice OR2 each open into the inner surface of the first cylindrical portion 21 that forms the radially outer wall surface of the storage space cs.

Furthermore, the first orifice OR1 and the second orifice OR2 each extend axially through the first cylindrical portion 21 from the opening on the side of the storage space cs, and each also opens to the top surface of the annular flow passage kp (the end surface of the first cylindrical portion 21 on the driven shaft 3 side). As a result, the first orifice OR1 communicates the one-side space s1 with the annular flow passage kp, and the second orifice OR2 communicates the other-side space s2 with the annular flow passage kp. In this embodiment, as shown in FIG. 2, the flow passage cross-sectional area of each of the first orifice OR1 and the second orifice OR2 is smaller than the flow passage cross-sectional area of the annular flow passage kp, but is not limited to this.

That is, the one-side space s1 and the other-side space s2 are connected to each other through the first orifice or1, the second orifice or2, and the annular flow path kp. Therefore, the first orifice or1, the second orifice or2, and the annular flow path kp constitute a communication flow path cp that connects the one-side space s1 and the other-side space s2 to each other.

The magnetorheological fluid 8 can flow from the one-side space s1 to the other-side space s2, or from the other-side space s2 to the one-side space s1 by flowing through the communicating flow path cp. That is, when the first blade portion 10 rotates relative to the second blade portion 20 to one side in the circumferential direction, the volume of the one-side space s1 decreases and the volume of the other-side space s2 increases. Accordingly, the magnetorheological fluid 8 filled in the one-side space s1 can flow through the communicating flow path cp and into the other-side space s2. When the first blade portion 10 rotates relative to the second blade portion 20 to the other side in the circumferential direction, the volume of the other-side space s2 decreases and the volume of the one-side space s1 increases. Accordingly, the magnetorheological fluid 8 filled in the other-side space s2 can flow through the communicating flow path cp and into the one-side space s1.

In other words, the energy of the relative rotation (including relative oscillation) of the first blade portion 10 with respect to the second blade portion 20 in the storage space cs is converted into the flow energy of the magnetorheological fluid 8.

In order to seal the one-side space s1 and the other-side space s2 from each other within the accommodation space cs, a seal member se2 is interposed between the first blade portion 10 and a member surrounding the first blade portion 10 in the axial or radial direction to fill the gap.

Specifically, as shown in FIG. 1, a seal member se2 is interposed between the inner surface of the first cylindrical portion 21 and the radially outer surface of the first blade portion 10. A groove extending in the axial direction and recessed radially outward is formed on the inner surface of the first cylindrical portion 21, and the seal member se2 is fitted into the groove. The seal member se2 is in slidable contact with the radially outer surface of the first blade portion 10. It is preferable that the seal member se2 is made of a non-magnetic material.

Furthermore, although not shown, it is preferable that the seal member se2 is interposed between the axial side of the drive shaft 2 of the first blade portion 10 and the bottom surface of the bearing housing member 12. Similarly, it is preferable that the seal member se2 is interposed between the axial side of the driven shaft 3 of the first blade portion 10 and the top surface of the bearing housing member 14.

As shown in Figs. 1 and 2, in order to seal adjacent storage spaces cs from each other, a seal member se1 is interposed between the second blade portion 20 and a member surrounding the second blade portion 20 in the axial or radial direction to fill the gap.

Specifically, as shown in FIG. 1, a groove extending in the axial direction and recessed radially outward is formed on the radial inner side surface of the second blade portion 20, and a seal member se1 is fitted into the groove. The seal member se1 in this portion is in sliding contact with the first blade portion rotating shaft 11. Furthermore, as shown in FIG. 3, a groove extending in the radial direction and recessed toward the drive shaft 2 side is formed on the bottom surface (driven shaft 3 side) of the second blade portion 20, and the seal member se1 is fitted into the groove. The seal member se1 in this portion is in contact with the top surface of the bearing housing member 14. Similarly, a groove extending in the radial direction and recessed toward the driven shaft 3 side is formed on the top surface (drive shaft 2 side) of the second blade portion 20, and the seal member se1 is fitted into the groove. The seal member se1 in this portion is in contact with the bottom surface of the bearing housing member 12. It is preferable that the seal member se1 is made of a non-magnetic material.

The magnetic field generating unit 9 generates a magnetic field to be applied to the magnetorheological fluid 8. In this embodiment, the magnetic field generating unit 9 includes a yoke and a coil 25.

As shown in Figures 2 and 3, in this embodiment, the yoke is composed of a first inner yoke 21, a second inner yoke 23, and an outer yoke 24. Naturally, all of the components that make up the yoke are made of magnetic material.

The first inner yoke 21 is the first cylindrical portion 21. The second inner yoke 23 is the third cylindrical portion 23. These form a magnetic path that extends in the axial direction at a position radially outside the intermediate portion 7.

The first inner yoke 21 and the second inner yoke 23 axially sandwich the second cylindrical portion 22, which has an annular flow passage kp therein.

One end face of the outer yoke 24 faces the radially outer surface of the first inner yoke 21 via a small gap, and the other end face faces the radially outer surface of the second inner yoke 23 via a small gap. In this embodiment, the outer yoke 24 is formed in an overall ring shape and has a cross section that is approximately C-shaped.

As shown in FIG. 3, bearing housing members 16 and 18 are fixed to both axial sides of the outer yoke 24. A bearing 17 is interposed between the bearing housing member 16 and the first joint part 5, and a bearing 19 is interposed between the bearing housing member 18 and the second joint part 6. Therefore, the first joint part 5, the second joint part 6, and the intermediate part 7 are rotatable relative to the outer yoke 24 and the coil 25. It is preferable that the bearing housing members 16 and 18 are made of a non-magnetic material.

As shown in Figures 2 and 3, the coil 25 is wound around the inside of the outer yoke 24. A current of a desired value can be supplied to the coil 25 from the power supply unit 31. When a current is supplied to the coil 25, it can form a magnetic path within the yoke. When a magnetic path is formed within the yoke, a magnetic field is applied to the magnetorheological fluid 8 within the annular flow path kp that is sandwiched between the first inner yoke 21 and the second inner yoke 23.

In the coupling 1 having the above-mentioned configuration, when a current is applied to the coil 25 by the power supply unit 31, a magnetic path is formed in the yoke, for example along the direction of the arrow P in Figures 2 and 3. In particular, a magnetic path is formed that penetrates the magnetorheological fluid 8 flowing in the annular flow path kp, and the magnetorheological fluid 8 exhibits a viscosity that corresponds to the strength of the applied magnetic field. And, by changing the value of the current applied to the coil 25, the viscosity of the magnetorheological fluid 8 can be changed, and therefore the torsional rigidity of the coupling 1 can also be changed.

In detail, when a magnetic field is applied to the magnetorheological fluid 8 filling the annular flow passage kp, viscosity is generated in the magnetorheological fluid 8 in the annular flow passage kp. At this time, when a torsional vibration is input from the drive side rotating shaft 2 to the coupling 1, the first blade portion 10 rotates (sways) in the circumferential direction in the accommodation space cs via the first joint portion 5 and the first blade portion rotating shaft 11. In response to the rotation of the first blade portion 10, the respective volumes of the one-side space s1 and the other-side space s2 change, and the magnetorheological fluid 8 tries to move between the one-side space s1 and the other-side space s2 through the communicating flow passage cp. The magnetorheological fluid 8 flows through the annular flow passage kp of the communicating flow passage cp, but since a magnetic field is applied in the annular flow passage kp, resistance according to viscosity is generated in the flow between the one-side space s1 and the other-side space s2. Therefore, the energy associated with the rotational vibration (swing) of the first blade portion 10 is dissipated by the resistance of the magnetorheological fluid 8 as it flows through the communication flow path cp. In other words, the torsional rigidity of the entire coupling 1 can be changed by the magnetic field generated by the magnetic field generating unit 9, so that the torsional vibration input from the drive side rotating shaft 2 can be suppressed.

In this way, with the coupling 1 according to this embodiment, the torsional rigidity of the coupling 1 can be changed simply by changing the current value applied to the coil 25, so the torsional vibration input to the coupling 1 can be easily suppressed, and the resonance point of the torsional vibration can also be easily changed.

In addition, in the coupling 1 having the above-mentioned configuration, the angle at which the first blade portion 10 can rotate relative to the second blade portion 20 in the circumferential direction within the accommodation space cs is a predetermined angle of 5 degrees or less, so that large rotations (rotations exceeding the predetermined angle) input from the driving side rotating shaft 2 are transmitted to the driven side rotating shaft 3, while minute rotational vibrations (oscillations) input from the driving side rotating shaft 2 that are less than the predetermined angle are absorbed as fluid resistance of the magnetorheological fluid 8 and are suppressed.

In addition, in the coupling 1 having the above-mentioned configuration, the communication flow path cp includes an annular flow path kp formed in an annular shape when viewed in the axial direction, so that the magnetorheological fluid 8 can be easily caused to flow between the one-side space s1 and the other-side space s2 formed side by side in the circumferential direction. Of course, even in this case, the magnetorheological fluid 8 can generate fluid resistance in response to the magnetic field applied to the magnetorheological fluid 8 by the magnetic field generating unit 9.

In addition, in the coupling 1 having the above-mentioned configuration, the communication flow passage cp further includes a one-side orifice or1 that opens into the one-side space s1 and the annular flow passage kp, respectively, and an other-side orifice or2 that opens into the other-side space s2 and the annular flow passage kp, respectively, so that it becomes easy to flow the magnetorheological fluid 8 between the one-side space s1 and the annular flow passage kp, and also easy to flow the magnetorheological fluid 8 between the other-side space s2 and the annular flow passage kp.

In addition, in the coupling 1 having the above-mentioned configuration, the magnetic field generating unit 9 has a yoke formed in a shape that axially sandwiches the annular flow path kp, and a coil 25 wound so as to form a magnetic path within the yoke. When a current is applied to the coil 25, a magnetic path is formed that penetrates the magnetorheological fluid 8 within the annular flow path kp, so that a concentrated magnetic field can be applied to the magnetorheological fluid 8 flowing within the annular flow path kp, and the viscosity of the magnetorheological fluid 8 can be easily changed.

<Modification>
In the above-mentioned embodiment of the present invention, the communication flow path cp is composed of the first orifice or1, the second orifice or2, and the annular flow path kp, but the openings of the first orifice or1 and the second orifice or2 on the side away from the accommodation space may be directly connected to each other to be composed of orifices (not shown) opening into the one-side space s1 and the other-side space s2, respectively. Even in this case, the magnetic field generating unit 9 can form a magnetic path penetrating the magnetorheological fluid 8 flowing through the orifice, so that the torsional rigidity of the coupling 1 can be changed simply by changing the current value applied to the coil 25, so that the torsional vibration input to the coupling 1 can be easily suppressed, and the resonance point of the torsional vibration can also be easily changed.

The present invention can be applied, for example, to a coupling for connecting shafts.

1 Coupling 2 Drive side rotating shaft (drive shaft)
3 Driven rotating shaft (driven shaft)
5 First joint portion 6 Second joint portion 7 Intermediate portion 8 Magnetorheological fluid 9 Magnetic field generating portion 10 First blade portion 11 First blade portion rotating shaft 20 Second blade portion 21 First cylindrical portion (first inner yoke)
22 Second cylindrical portion 23 Third cylindrical portion (second inner yoke)
24 Outer yoke 25 Coil 31 Power supply part cs Storage space s1 One side space s2 Other side space cp Communication flow passage kp Annular flow passage or1 First orifice or2 Second orifice N Axis

Claims (3)

A first joint portion that is attached to one of the shafts so as not to rotate relative to the one of the shafts;
A second joint portion that is attached to the other shaft so as not to rotate relative to the other shaft;
an intermediate portion connected between the first joint portion and the second joint portion and configured to absorb torsional vibration;
A coupling comprising:
Further comprising a magnetic field generating unit that generates a magnetic field,
The intermediate portion is
a plurality of first blade portions connected to the first joint portion, extending radially outward, arranged in a circumferential direction, and rotating together with the one shaft;
A plurality of second blade portions that are connected to the second joint portion, extend radially inward, are arranged in a circumferential direction, and rotate together with the other shaft;
having
Between the adjacent second blade portions, an accommodation space having a volume necessary for the first blade portion to enter is formed,
The first blade portion is disposed so as to enter the accommodation space, and the first blade portion and the second blade portion are alternately arranged in a circumferential direction,
A magnetorheological fluid is filled between the first blade portion and the second blade portion in the accommodation space,
The accommodation space has a one-side space formed on one circumferential side of the first blade portion and a second-side space formed on the other circumferential side of the first blade portion,
A communication flow path is formed in the intermediate portion, the communication flow path connecting the one-side space and the other-side space to each other,
the magnetic field generating unit is provided so as to be able to apply a magnetic field to the magnetorheological fluid in the communicating flow path,
The communication passage includes an annular passage formed in an annular shape when viewed in the axial direction,
The magnetic field generating unit is
a yoke formed in a shape that sandwiches the annular flow passage in the axial direction;
A coil wound so as to form a magnetic path within the yoke;
having
When a current is applied to the coil, a magnetic path is formed through the magnetorheological fluid in the annular flow channel.
A coupling characterized by: 2. The coupling according to claim 1,
The angle at which the first blade portion can rotate relative to the second blade portion in the circumferential direction within the accommodation space is a predetermined angle of 5 degrees or less.
A coupling characterized by: 3. The coupling according to claim 1 or 2 ,
the communication flow passage further includes a first-side orifice that opens into the first-side space and the annular flow passage, respectively, and a second-side orifice that opens into the second-side space and the annular flow passage, respectively.
A coupling characterized by: