TWI612235B - Coupling - Google Patents

Abstract

A coupling (10) comprising: a pair of hub members formed by a first hub member (111) and a second hub member (112), wherein the first hub member (111) and the second hub member (112) The inner end surface (11a) and the plurality of claw portions (12a, 12b) are disposed at the inner end surface (11a) with a space therebetween at intervals, and protrude from the hub In the axis (x) direction of the member (111, 112), the inner end surface (11a) of the first hub member (111) and the inner end surface (11a) of the second hub member (112) are disposed to face each other and respectively The plurality of claw portions (12a) of the first hub member (11) are disposed in a gap between the two claw portions (12b) adjacent to the second hub member (112), and the plurality of claws of the second hub member (112) are respectively The portion (12b) is disposed between the two claw portions (12a) adjacent to the first hub member (111); and the rubber spacer (13) is disposed between the opposite inner end faces (11a).

The attenuation ratio (ζ) of the coupler (10) and the square root of the dynamic torsion spring constant (K) (K^1/2The product of ) is 1.3~12.0.

Description

Coupling

The present invention relates to a coupler for use in a servo motor that improves speed gain control, improves responsiveness, and at the same time reduces settling time.

In the servo motor, torque transmission from the driving side rotation shaft to the passive side rotation shaft is performed via the coupling. Such a coupling is composed of a pair of hub members and a rubber spacer interposed between the two hub members. As the rubber spacer, for example, urethane rubber, hydrogen butadiene rubber, styrene-butadiene copolymer rubber (SBR) or the like is used. Such rubber spacers are required to have a certain rigidity, suppress the amplitude caused by vibration, and improve the torque transmission performance.

Non-Patent Document 1 discloses the problem of such a servo motor. That is, in order to avoid resonance, it is necessary to increase the resonance angular frequency and away from the input angular frequency. In this case, however, it is necessary to at least increase the torsional rigidity of the shaft coupling which is representative of the mechanical system. In the case of a resonant relationship due to low torsional stiffness, the gain control of the control system, particularly the servo motor, must be reduced to a level that does not cause resonance, or a selective pass filter must be used in order to remove resonance.

For example, when the coupling is formed to be highly rigid in order to increase the natural frequency, the coupling is increased in size, and the moment of inertia is increased. However, in high-speed, high-response precision positioning mechanisms, the use of couplings with large moments of inertia will accelerate the acceleration and deceleration. The influence of time and stopping accuracy is difficult to control the positioning mechanism. In addition, the capacity of the motor must also be increased for the coupling to be larger than the size required for the operation originally handled by the motor. Because of this, the size of the coupling that can be used has an upper limit.

[Previous Technical Literature]

[Non-Patent Document 1] "Second Generation Precision Positioning Technology", pages 359 to 361, April 25, 2000, issued by Fuji Technology Co., Ltd.

As described in Non-Patent Document 1, there is an upper limit to increasing the torsional rigidity of the coupling as a coupling, and increasing the speed gain control of the servo motor and improving the responsiveness. However, in addition to the torsional rigidity of the coupler, characteristics associated with speed gain control or responsiveness are not disclosed.

It is an object of the present invention to provide a coupler that can improve speed gain control and that can shorten the settling time.

In order to achieve the above object, an aspect of the present invention provides a coupler including a pair of hub members formed of a first hub member and a second hub member, wherein the first hub member has a first inner portion The end surface and the plurality of first claw portions, wherein the plurality of first claw portions are disposed on the first inner end surface at intervals in the circumferential direction, and have a plurality of first claws protruding in the axial direction of the first hub member a first gap is provided between the adjacent two first claw portions, the second hub member has a second inner end surface and a plurality of second claw portions, and the plurality of second claw portions are spaced apart in the circumferential direction Arranging on the second inner end surface at intervals, and having a plurality of second claw portions protruding in the axial direction of the second hub member, and providing a second gap between the adjacent two second claw portions, the first inner end surface And the second inner end faces are disposed to face each other, and the plurality of first claw portions are respectively disposed in the second gap, and the plurality of second claw portions are respectively disposed in the first gap; and are disposed in the first inner end surface and the second inner portion The rubber spacer between the end faces; the product of the attenuation ratio ζ and the square root of the dynamic torsion spring constant K ^1/2 is 1 .3~12.0.

In the above coupling, the loss tangent tan δ of the rubber material forming the rubber spacer is preferably 0.2 to 1.3.

In the above coupling, in the cross section orthogonal to the axis of the pair of hub members, the cross-sectional area of the rubber spacer between the inner circumference and the outer circumference of the plurality of first claw portions and the plurality of second claw portions is preferably The rubber spacer is formed between the inner circumference and the outer circumference of the plurality of first claw portions and the plurality of second claw portions and the plurality of first claw portions and the plurality of second claw portions in the cross section The total area of the break is 20~50%.

In the above coupling, the attenuation ratio ζ is preferably from 0.07 to 0.27.

In the above coupling, the square root K ^1/2 of the dynamic torsion spring constant K is preferably set at 12.2 to 58.3.

The relationship between the aforementioned attenuation ratio ζ and the square root K ^1/2 of the dynamic torsion spring constant K is represented by an attenuation curve. When the square root K ^{1/2 of the} dynamic torsion spring constant K is formed smaller, the attenuation ratio ζ is formed larger. When the square root K ^{1/2 of the} dynamic torsional spring constant K is formed to be larger, the attenuation is smaller than the ζ formation. The speed gain control indicating responsiveness in the coupler is such that the square root K ^{1/2 of the} dynamic torsion spring constant K and the larger the attenuation ratio ζ are formed. In the coupler of the present invention, the product of the square root K ^{1/2 of the} dynamic torsion spring constant K and the attenuation ratio ζ is 1.3 to 12.0. Thereby, the square root K ^{1/2 of the} dynamic torsion spring constant K and the attenuation ratio ζ can be increased together, which can contribute to the improvement of the gain.

In addition, since the attenuation can be improved by increasing the attenuation ratio 联 of the coupling, and the square root K ^{1/2 of the} dynamic torsional spring constant K is increased, the rigidity can be increased, so that the delay of the torque transmission can be suppressed.

Accordingly, with the coupler of the present invention, in addition to improving the speed gain control, the effect of shortening the stabilization time can be achieved.

10‧‧‧Connector

111‧‧‧1st hub

112‧‧‧2nd hub

11a‧‧‧ inside end

12,12a,12b‧‧‧ claws

13‧‧‧Rubber spacers

20‧‧‧ gap

21‧‧‧ Space Department

X‧‧‧ axis

Fig. 1 is a perspective view showing a coupler according to a first embodiment of the present invention.

Fig. 2 is a cross-sectional view showing a rubber spacer portion of the coupler in the first embodiment.

The exploded perspective view shown in Fig. 3 is a coupler shown in the first embodiment.

The graph shown in Fig. 4 is a graph showing the relationship between the square root K ^{1/2 of the} dynamic torsional spring constant K and the attenuation ratio ζ.

The exploded perspective view shown in Fig. 5 is a coupler shown in the second embodiment.

Fig. 6 is a cross-sectional view showing a rubber spacer portion of the coupler in the second embodiment.

(First embodiment)

Hereinafter, a first embodiment in which the present invention is embodied will be described in detail with reference to Figs. 1 to 4 .

As shown in FIG. 3, the components of the coupler 10 of the first embodiment include a cylindrical one-piece hub member formed by the first hub member 111 and the second hub member 112. Each of the first hub member 111 and the second hub member 112 has an inner end surface 11a, and the inner end surfaces 11a are disposed to face each other. Three claw portions 12 for connection are disposed on the inner end faces 11a at equal intervals in the circumferential direction. Each of the claw portions 12 protrudes in the direction of the axis x of the first hub member 111 and the second hub member 112. A rubber spacer 13 as a constituent element of the coupler 10 is disposed between the first hub member 111 and the second hub member 112. In the center portion of the first hub member 111 and the second hub member 112, an insertion hole 14 penetrating through the axis x direction is formed. The through hole 15 formed in the rubber spacer 13 is a insertion hole 14 that connects the first hub member 111 and the second hub member 112.

As shown in FIG. 1, the coupler 10 is configured such that a rotary shaft 16 on the drive side such as a servo motor is inserted into one of the insertion holes 14 of the first hub member 111 and the second hub member 112, and the other is configured. The insertion hole 14 is inserted into the rotating shaft 17 on the passive side and connected to the rotating shaft 16.

As the metal forming the first hub member 111 and the second hub member 112, aluminum (aluminum alloy), cast iron, steel (stainless steel), copper alloy or the like is used. As the rubber material forming the rubber spacer, a fluorine-based rubber, an acrylonitrile-butadiene-copolymer rubber hydride (HNBR), a natural rubber (NR), and a styrene-butadiene copolymer rubber (SBR) are used. Hydrogen butadiene rubber (CR), urethane rubber (U), ruthenium rubber (Q), and the like. Among these rubber materials, it is preferable to use a fluorine-based rubber from the viewpoints of hardness, attenuation, and the like. As a fluorine rubber, A vinylidene fluoride rubber (FKM) or the like is listed.

The loss tangent tan δ of the rubber material is preferably 0.2 to 1.3, more preferably 0.2 to 0.7. The loss tangent tan δ is a ratio indicating a loss shear elastic modulus for a storage shear modulus, and an energy level absorbed by the rubber material when the rubber material is deformed, that is, a level at which heat is converted. When such a loss tangent tan δ is within the above range, the attenuation ratio ζ and rigidity of the coupler 10 can be more easily improved.

The attenuation ratio 联 of the coupler 10 is preferably from 0.07 to 0.27. The attenuation ratio ζ is a coefficient indicating the attenuation characteristic, and the calculation is such that the amplitude of the attenuation free vibration waveform is exponentially functionally attenuated, and when the logarithmic decay rate of the logarithm of the adjacent amplitude ratio is often formed to a certain value, The logarithmic decay rate is calculated. When the attenuation ratio ζ is within the above range, the amplitude magnitude and rigidity of the coupler 10 can be set to a preferred value.

The outer end faces of the first hub member 111 and the second hub member 112 are provided with a notched portion 11c having a semi-cylindrical shape cut away. A fastening member 18 is attached to the notch portion 11c. A pair of through holes 11b extending in a direction orthogonal to the axis x are formed in the first hub member 111 and the second hub member 112. The fastening member 18 forms a pair of screw holes 18a.

As shown in FIG. 1 and FIG. 3, the rotating shaft 16 on the driving side is inserted into the insertion hole 14 of the first hub member 111, and the rotating shaft 17 on the passive side is inserted into the insertion hole 14 of the second hub member 112. In this state, the pair of hexagon socket bolts 19 pass through the through holes 11b of the first hub member 111 and the second hub member 112, and are screwed and locked by a hexagonal wrench (not shown). The screw hole 18a of the 18 is such that the rotating shaft 16 on the driving side and the rotating shaft 17 on the driven side are coupled by the coupler 10. In this state, the torque is transmitted to the rotating shaft 17 on the passive side via the coupling 10 from the rotating shaft 16 on the driving side.

The coupler 10 is produced by a method described later. First, the first hub member 111 and the second hub member 112 are disposed to face each other in the molding die. At this time, in order to arrange the first claw portion 12a of the first hub member 111 and the second claw portion 12b of the second hub member 112 at equal intervals in the circumferential direction, the respective first claw portions 12a are positioned adjacent to each other. The gap 20 between the two second claw portions 12b. Further, an insert is disposed in a portion of the insertion hole 14 of the first hub member 111 and the second hub member 112 and the through hole 15 corresponding to the rubber spacer 13. The molding die is clamped in this state. Next, the molten rubber material is injected into the space portion 21 formed between the inner end surface 11a of the first hub member 111 and the second hub member 112 to be molded. Thereafter, the molding die is cooled, the mold is opened, and the molded product is taken out, whereby the coupler 10 in which the rubber spacer 13 is interposed between the first hub member 111 and the second hub member 112 is produced.

As shown in FIG. 2, when the first claw portion 12a of the first hub member 111 and the second claw portion 12b of the second hub member 112 are arranged at equal intervals in the circumferential direction, the rubber spacer 13 is disposed. The space portion 21 formed between the opposing inner end faces 11a of the first hub member 111 and the second hub member 112 is interposed. In the cross section orthogonal to the axis x of the first hub member 111 and the second hub member 112, the sectional area of the rubber spacer 13 between the inner circumference and the outer circumference of the claw portion 12 is set to be in relation to the section thereof. The total sectional area of the rubber spacers 13 between the inner and outer circumferences of the claw portion 12 and the claw portion 12 is preferably 20 to 50%. When the sectional area of the rubber spacer 13 falls within the above range, the vibration can be suppressed by the rubber spacer 13, and the square root K ^{1/2 of the} spring constant K of the dynamic torsion is more easily increased.

For example, when the outer diameter of the coupling 10 (rubber spacer 13) is 25 mm and the diameter of the through hole 15 of the rubber spacer 13 is 5 mm, the claw portion 12 can be used. The ratio of the sectional area is set to 53%, in other words, the ratio of the sectional area of the rubber spacer 13 can be set to 47%. Further, when the outer diameter of the coupling 10 is 25 mm and the diameter of the through hole 15 of the rubber spacer 13 is 12 mm, the ratio of the sectional area of the claw portion 12 can be set to 61%, in other words, the rubber interval can be set. The ratio of the sectional area of the piece 13 was set to 39%.

In order to increase the resonance frequency of the coupler 10, the square root K ^1/2 of the dynamic torsion spring constant K of the coupler 10 is preferably set to 12.2 to 58.3. When the aforementioned K ^1/2 value falls within the above range, a sufficient gain can be easily obtained.

As shown in FIG. 4, for the rubber spacer 13, the relationship between the square root K ^1/2 of the dynamic torsion spring constant K and the attenuation ratio ζ is represented by an attenuation curve, and when the K ^1/2 value is small, the ζ value is large. As the K ^1/2 value becomes larger, the ζ value becomes smaller. In the rubber spacer 13 of the first embodiment, the product of ζ and K ^1/2 is set to be 1.3 to 12.0, preferably set to 2.5 to 12.0.

In other words, as shown by the single-dot chain line in Fig. 4, the attenuation curve (1) is a case where the product of ζ and K ^1/2 is 1.3. Further, as shown by the dot lock line in Fig. 4, the attenuation curve (2) is a case where the product of ζ and K ^1/2 is 12.0. Therefore, the product of the attenuation ratio ζ and the square root K ^1/2 of the dynamic torsion spring constant K is in the range of 1.3 to 12.0, and the attenuation curve (1) and the attenuation curve shown by the hatching of FIG. 4 are used. (2) Indicated between the areas R.

When the product of ζ and K ^1/2 is less than 1.3, the amplitude due to vibration is suppressed, although the stabilization time can be shortened, but a satisfactory gain cannot be obtained, and for the driving side, the passive side The responsiveness will also be worse. On the other hand, when it exceeds 12.0, although the gain can be increased, the outer diameter of the coupler 10 is formed to be larger than 40 mm, so that the use range of the coupler 10 is limited, which is not appropriate.

The aforementioned product value of ζ and K ^1/2 is affected by the outer diameter of the coupler 10. The outer diameter of the coupler 10 is preferably set in the range of 15 to 40 mm. When the outer diameter value of the coupler 10 falls within the above range, the range of use of the coupler 10 can be maintained over a wide range, and sufficient gain can be obtained.

Next, the action of the coupler 10 constituting the above will be described.

When the rotating shaft 16 on the driving side and the rotating shaft 17 on the driven side are connected to the coupler 10, the torque of the rotating shaft 16 on the driving side such as the servo motor is transmitted to the rotating shaft 17 on the passive side via the coupler 10. The product of the attenuation ratio ζ of the coupler 10 and the square root K ^1/2 of the dynamic torsion spring constant K is set in the range of 1.3 to 12.0. The relationship between the ζ and K ^1/2 is the attenuation curve shown in Fig. 4. When the K ^1/2 value is small, the ζ value is large, and when the K ^1/2 value is large, the ζ value is small. Therefore, by setting the product of ζ and K ^1/2 in the range of the region R shown in Fig. 4, the values of ζ and K ^1/2 can be set to be higher than in the past. In this way, speed gain control can be improved and responsiveness can be improved.

Hereinafter, the effects exerted by the first embodiment described above in detail will be explained and explained.

(1) The gain indicating the responsiveness in the coupler 10 is formed such that the larger the square root K ^{1/2 of the} dynamic torsional spring constant K and the larger the attenuation ratio 、, the higher. Therefore, by setting the product of K ^1/2 and ζ to form 1.3 to 12.0, it is possible to simultaneously increase the values of K ^1/2 and ζ. This is because the hunting phenomenon is suppressed, which in turn increases the gain.

Furthermore, the rubber spacer 13 can uniformly exhibit torsional rigidity and attenuation. Therefore, the torque transmission can be improved.

Thereby, the coupler 10 of the first embodiment can achieve the so-called shortening stabilization time in addition to the speed gain control.

(2) The loss tangent tan δ of the rubber material forming the rubber spacer 13 is 0.2 to 1.3. Therefore, the rubber material can easily absorb vibration energy and the like, and can reduce the amplitude caused by the vibration.

(3) In the cross section orthogonal to the axis x of the first hub member 111 and the second hub member 112, the sectional area of the rubber spacer 13 between the inner circumference and the outer circumference of the claw portion 12 is set to be The rubber spacer 13 between the inner circumference and the outer circumference of the claw portion 12 and the claw portion 12 in this cross section is 20 to 50% of the total sectional area. Therefore, while maintaining the torsional rigidity of the coupler 10, an increase in gain can be obtained.

(4) The attenuation ratio ζ of the aforementioned coupling 10 is 0.07 to 0.27. Thereby, the amplitude in the resonance frequency of the coupler 10 can be effectively suppressed.

(5) The square root K ^1/2 of the dynamic torsion spring constant K of the aforementioned coupling 10 is 12.2 to 58.3. Therefore, the coupler 10 has sufficient torsional rigidity, and the stabilizing time can be shortened while suppressing the chasing phenomenon and achieving an increase in gain.

(Second embodiment)

Next, a second embodiment in which the present invention has been embodied will be described with reference to Figs. 5 and 6 . In the second embodiment, the differences from the first embodiment will be mainly described, and the same portions as those in the first embodiment will not be described.

As shown in FIG. 5, five first claw portions 12a for connection are disposed at equal intervals in the circumferential direction on the inner end surface 11a of the first hub member 111 and the second hub member 112. And five second claw portions 12b. The first claw portion 12a and the second claw portion 12b protrude in the direction of the axis x of the first hub member 111 and the second hub member 112. In order to arrange the five first claw portions 12a of the first hub member 111 and the five second claw portions 12b of the second hub member 112 at equal intervals in the circumferential direction, the first claw portions 12a are respectively positioned adjacent to each other. The gap 20 between the second claw portions 12b. A rubber spacer 13 is interposed in the space portion 21 between the inner end surface 11a of the first hub member 111 and the second hub member 112.

As shown in FIG. 6, when the outer diameter of the first hub member 111 and the second hub member 112 is 25 mm, and the diameter of the insertion hole 14 of the first hub member 111 and the second hub member 112 is 5 mm, The ratio of the sectional area of the claw portion 12 was set to 69%, in other words, the ratio of the sectional area of the rubber spacer 13 was set to 31%. Further, when the outer diameters of the first hub member 111 and the second hub member 112 are 25 mm and the diameters of the insertion holes 14 of the first hub member 111 and the second hub member 112 are 12 mm, the claw portion 12 can be provided. The ratio of the sectional area is set to 79%, in other words, the ratio of the sectional area of the rubber spacer 13 can be made 21%.

In the coupler 10 of the second embodiment, the first claw portion 12a of the first hub member 111 and the second claw portion 12b of the second hub member 112 are five. Therefore, the ratio of the sectional area of the rubber spacer 13 is smaller than that in the first embodiment. Therefore, compared with the coupler 10 of the first embodiment, the coupler 10 of the second embodiment has high torsional rigidity and can more effectively suppress the amplitude due to vibration. Therefore, when the torque is transmitted from the rotation axis of the drive side to the rotation axis 17 of the passive side via the coupler 10, the gain can be further increased and the stabilization time can be shortened as compared with the case of the first embodiment.

[Examples]

Hereinafter, the above embodiments will be described more specifically by way of examples and comparative examples.

(Examples 1 to 12 and Comparative Examples 1 to 7)

In Examples 1 to 10 and Comparative Examples 1 to 7, the outer diameter of the coupler 10 was 25 mm, and the rubber spacer 13 was formed using a rubber material as shown below. In Examples 11 and 12, the outer diameter of the coupler 10 was 39 mm, and the rubber spacer 13 was formed using a rubber material as shown below.

Example 1: NBR-based rubber (loss tangent tan δ was 0.20, curve (1) of Fig. 4).

Example 2: NR-based rubber (tan δ was 0.28, curve (2) of Fig. 4).

Example 3: SBR-based rubber (tan δ was 0.26, curve (3) of Fig. 4).

Example 4: BR-based rubber (tan δ was 0.21, curve (4) of Fig. 4).

Example 5: CR-based rubber (tan δ was 0.28, curve (5) of Fig. 4).

Example 6: Fluorine-based rubber (tan δ was 0.50, curve (6) of Fig. 4).

Example 7: Fluorine rubber (tan δ was 0.48, curve (7) of Fig. 4).

Example 8: HANENITE (registered trademark) rubber manufactured by Inner and Outer Rubber Co., Ltd. (tan δ was 1.30, curve (8) of Fig. 4).

Example 9: Fluorine-based rubber (tan δ was 0.50, curve (9) of Fig. 4).

Example 10: Fluorocarbon rubber (tan δ is 0.50, curve of Fig. 4 (10)).

Example 11: Hydrogenated NBR rubber (tan δ was 0.20, curve (21) of Fig. 4).

Example 12: Fluorine-based rubber (tan δ was 0.50, curve (22) of Fig. 4).

Comparative Example 1: NR-based rubber (tan δ was 0.21, curve (11) of Fig. 4).

Comparative Example 2: SBR rubber (tan δ was 0.22, curve (12) of Fig. 4).

Comparative Example 3: BR rubber (tan δ was 0.12, curve (13) of Fig. 4).

Comparative Example 4: CR-based rubber (tan δ was 0.17, curve (14) of Fig. 4).

Comparative Example 5: urethane rubber (tan δ was 0.08, curve (15) of Fig. 4).

Comparative Example 6: fluorene-based rubber (tan δ was 0.07, curve (16) of Fig. 4).

Comparative Example 7: fluorene-based rubber (tan δ was 0.18, curve (17) of Fig. 4).

In the embodiments 9, 10 and 12, the hub member having the five claw portions is used as the first hub member 111 and the second hub member 112. In addition, the hub member having three claw portions is used as the first hub member 111 and the second hub member 112. Various rubber materials The loss tangent tan δ is a value obtained by a dynamic viscoelasticity test at a temperature of 20 ° C and a frequency (vibration frequency) of 10 Hz.

The loss tangent (tan δ) of the rubber materials, the attenuation ratio ζ of the coupler 10, the square root K ^{1/2 of the} dynamic torsion spring constant K, and the product of the attenuation ratio ζ and the square root K ^1/2 of the dynamic torsional spring constant K Revealed in Table 1.

In the first to twelfth and the comparative examples 1 to 7, the drive side rotation shaft 16 and the passive side rotation shaft 17 are coupled to the coupler 10 to which the rubber spacer 13 is attached. Thereafter, the torque is transmitted from the rotating shaft 16 connected to the driving side of the motor to the rotating shaft 17 on the passive side. The operating conditions were set as follows, and the speed gain control (rad/s) and the settling time (ms) obtained under the operating conditions were measured in accordance with a conventional method.

Motor revolutions: 3000 (min ^-1 ).

The acceleration time from 0 to 3000 (min ^-1 ) of the motor revolution number: 50 (ms).

Deceleration time from 3000 to 0 (min ^-1 ) for motor revolutions: 50 (ms).

Workpiece stroke on the ball screw on the passive side: 100 (mm).

The ratio of the load moment of inertia of the moment of inertia ratio on the passive side of the drive side is 3.5 (times).

Further, the impact point was applied to the shock point on the driving side by an impact hammer, and analyzed by an FFT analyzer to measure the attenuation ratio ζ and the dynamic torsion spring constant K (Nm/rad). These results are disclosed in Table 1. Further, a graph showing the relationship between the square root K ^{1/2 of the} dynamic torsional spring constant K and the attenuation ratio ζ is shown in Fig. 4 .

As shown in Table 1, in the examples 1 to 12, since the product of ζ and K ^1/2 is in the range of 1.3 to 12.0, the gain control speed can be as high as 1636 to 3688 (rad/s). And can achieve a very short stabilization time of 2~9 (ms). On the other hand, in Comparative Examples 1 to 7, since either ζ×K ^{1/2 did} not reach 1.3, sufficient gain could not be obtained, and the tendency for the stabilization time to increase was exhibited.

In addition, as shown in FIG. 4, the attenuation curves of Examples 1 to 12 ((1) of FIG. 4 ~(10), (21), and (22)] are all located in the region R between the attenuation curve (1) and the attenuation curve (2). On the other hand, the attenuation curves of Comparative Examples 1 to 7 ((11) to (17) of Fig. 4) are all outside the range of the region R between the attenuation curve (1) and the attenuation curve (2).

The above embodiment can also be modified as follows.

. Each of the first hub member 111 and the second hub member 112 may have two, four, or six or more claw portions 12, respectively.

. In the foregoing embodiments 1 to 12, the outer diameter of the coupler 10 (the outer diameter of the rubber spacer 13) may be formed to be less than 25 mm or may be formed to be larger than 39 mm.

. The length of the rubber spacer 13 in the direction of the axis x can be appropriately changed by adjusting the lengths of the claw portions 12 of the first hub member 111 and the second hub member 112.

10‧‧‧Connector

111‧‧‧1st hub

112‧‧‧2nd hub

11a‧‧‧ inside end

12a, 12b‧‧‧ claws

Claims (4)

A coupling device comprising: a pair of hub members formed by a first hub member and a second hub member, wherein the first hub member has a first inner end surface and a plurality of first claw portions, the plural The first claw portions are disposed on the first inner end surface at intervals in the circumferential direction, and protrude from the axial direction of the first hub member to provide a first gap between the adjacent two first claw portions; The second hub has a second inner end surface and a plurality of second claw portions, and the plurality of second claw portions are disposed on the second inner end surface at intervals in the circumferential direction, and protrude from the second hub member. a second gap is provided between the adjacent two second claw portions in the axial direction; the first inner end surface and the second inner end surface are disposed to face each other, and the plurality of first claw portions are respectively disposed in the second gap a gap, wherein the plurality of second claw portions are respectively disposed in the first gap; and the rubber spacer is disposed between the first inner end surface and the second inner end surface; and orthogonal to an axis of the pair of hub members In the cross section, the inner circumference and the outer circumference of the plurality of first claw portions and the plurality of second claw portions The sectional area of the rubber spacer between the plurality of first claw portions and the plurality of second claw portions and the plurality of first claw portions and the plurality of second portions in the cross section The total cross-sectional area of the rubber spacer between the inner circumference and the outer circumference of the claw is 20 to 50%, and the product of the attenuation ratio (ζ) and the square root of the dynamic torsion spring constant (K) (K ^1/2 ) is 1. 3~12.0. The coupler according to claim 1, wherein the rubber material forming the rubber spacer has a loss tangent (tan δ) of 0.2 to 1.3. The coupler according to claim 1 or 2, wherein the aforementioned attenuation ratio (ζ) is 0.07~0. 27. The coupler according to claim 1 or 2, wherein the square root (K ^1/2 ) of the dynamic torsion spring constant (K) is 12.2 to 58.3.