JP2552598B2 - Rotary joint - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotary joint capable of increasing the tolerance for the alignment of the shaft centers when connecting an input shaft and an output shaft and accurately transmitting rotation.

[0002]

2. Description of the Related Art Conventionally, various flexible joints have been proposed as those capable of increasing the tolerance for the alignment of shaft centers in rotary joints. In these flexible joints, the input shaft and output shaft are inserted into the cylindrical parts at both ends, and fixed with screws, pins, keys, etc., and the middle part is
In order to have flexibility, it is formed of a metal coil or a flexible synthetic resin cylinder.

In many of such rotating mechanisms, it is necessary to control the rotation angle by a control motor such as a pulse motor or a servo motor. These control motors are provided with a rotating function in proportion to the control signal, that is, a holding function using a magnetic force that does not cause positional deviation. For example, in the case of a pulse motor, tooth shapes for reducing the rotation angle are formed on the circumference of the stator and the rotor, and the stator has a plurality of coils of 2, 4, 5, etc. An electric current is sequentially switched to a coil by a pulse signal to generate a magnetic field that rotates according to the pulse signal, and a rotor having a permanent magnet is rotated by a predetermined angle.

[0004]

However, since the conventional flexible joint has flexibility,
The intermediate part is formed of a metal coil or a flexible synthetic resin, etc., but when a strong rotating torque is applied to these, twisting etc. occurs, and accurate transmission of the rotating force cannot be performed. There was a problem such as damage. Therefore, it is not suitable when the rotation torque is large or when accurate control of the rotation angle is required.

Further, when controlling the rotation angle, the control motor is required to accurately stop rotation at a predetermined rotation angle, but as a matter of course, inertial force remains in the rotating body, A stopping force is required to overcome this inertial force. However, in the case of the pulse motor, there is a gap between the stator and the rotor, and the stopping force depends only on the magnetic force. Therefore, when the inertial force becomes larger than the magnetic force, such as when rotating at a high speed, positional deviation easily occurs, and satisfactory accuracy cannot be obtained. In addition, a motor that also uses an electromagnetic brake is known to increase the stopping force, but in order to immediately stop high-speed rotation,
A considerable braking force is required, the brake mechanism becomes large, and the energy consumption required for braking increases.

Therefore, an object of the present invention is to provide a flexible joint which can accurately transmit a rotational force even if a relatively large rotational torque is applied and is not damaged. Especially. Another object of the present invention is to provide a rotary joint in which even if the rotation stopping force of the input shaft is small, the inertial force of the output shaft is attenuated so that the rotary joint can be stopped at a predetermined rotation angle.

[0007]

In order to achieve the above object, the present invention provides a rotary joint for coaxially buttingly connecting an input shaft and an output shaft, the rotary joint being mounted on the outer periphery of the input shaft, Of the input side sleeve, the outer diameter of which is reduced in multiple steps toward the tip of the output shaft, and the output which is attached to the outer circumference of the output shaft and whose outer diameter is reduced in multiple steps toward the tip direction of the output shaft. A side sleeve, a plurality of coil springs that are concentrically mounted on the corresponding outer peripheries of the input side sleeve and the output side sleeve, respectively, and have their winding directions alternately changed from the center toward the outer radial direction; and the input shaft. When the rotation angle of the input shaft is larger than that of the output shaft when rotating and stopping in a certain direction, a winding tightening force is generated in one winding direction of the coil spring to rotate the output shaft. The angle is above the input shaft The case is large, characterized in that it comprises a one-way clutch mechanism for generating a tightening force to one of the other winding direction of the coil spring.

In one of the preferred embodiments of the present invention,
The plurality of coil springs are mounted such that the inner circumferences of their intermediate portions have a predetermined gap with respect to the members located inside thereof, and when the tightening force is generated, the coil springs are rotated by a predetermined angle, and then the coil springs are rotated. The rotational force is closely transmitted to the member located inside.

In another preferred aspect of the present invention, the plurality of coil springs are mounted so that their inner circumferences are in close contact with a member located inside thereof, so that the winding tightening force is generated. When it does, the rotational force is immediately transmitted.

In a further preferred aspect of the present invention, the input-side sleeve and the output-side sleeve are each composed of a plurality of cylindrical members separated by a stepped portion whose outer diameter changes, and each cylindrical member has a meshing direction. It is attached to the input shaft or the output shaft via one-way clutches that are alternately changed.

In still another preferred aspect of the present invention, the input side sleeve and the output side sleeve are integrally formed, and the plurality of coil springs are
It is attached to the input side sleeve and the output side sleeve with a spring clutch action.

In still another preferred aspect of the present invention, a first gear is mounted at a specific position of the input side sleeve, and a second gear is provided at a position of the output side sleeve corresponding to a specific position of the input side sleeve. Fitted, these first
Corresponding to the gear and the second gear, a first sensor and a second sensor for detecting the number of feed teeth of them are attached.

[0013]

In the rotary joint of the present invention, first, the operation will be described with respect to a mode in which a plurality of coil springs are mounted with intermediate portions thereof having a predetermined clearance with respect to a member located inside thereof. Then, it is now assumed that when the input shaft rotates in a certain direction, the coil spring in one winding direction (hereinafter, referred to as the first coil spring) is tightened through the input side sleeve attached to the input shaft. In this case, when the first coil spring is tightened up to a point where the diameter cannot be further reduced, the input side sleeve attached to the input shaft and the output side sleeve attached to the output shaft are integrated into a rigid body. Rotates together with the input shaft. At this time, the input shaft idles with respect to the coil spring in the other winding direction (hereinafter referred to as the second coil spring) due to the action of the one-way clutch mechanism, and the second coil spring performs both the tightening action and the unwinding action. I do not receive it.

When the rotation of the input shaft is stopped in this state, the output shaft tends to continue rotating due to the moment of inertia. As a result, the action of the one-way clutch mechanism causes the second coil spring to be wound tightly and the first coil spring to be unwound. The output shaft further rotates due to the inertia moment even if it exceeds the rotation stop angle of the input shaft, but it rotates to the point where the second coil spring cannot be reduced in diameter any more, and the input side sleeve mounted on the input shaft,
When the output side sleeve attached to the output shaft is integrated into a rigid body, or when the repulsive force of the coil spring in the other winding direction becomes larger than the moment of inertia remaining on the output shaft, the rotation is stopped. , The second coil spring rotates in the opposite direction this time by the repulsive force.

As a result, the first coil spring is rewound and the second coil spring is unwound. Then, if the rotation of the output shaft exceeds the rotation stop angle of the input shaft and returns too much, the output shaft rotates again in the opposite direction due to the repulsive force of the first coil spring. In this way, the moment of inertia remaining on the output shaft side when the input shaft is stopped is gradually damped as repetitive vibration due to the alternating winding action of the first coil spring and the second coil spring, and finally damped. Stop at the correct rotation position according to the rotation angle of the input shaft. In this case, the damping effect of the inertia moment can be further enhanced by making the spring constant of the first coil spring different from the spring constant of the second coil spring.

As described above, according to one aspect of the rotary joint of the present invention, the moment of inertia remaining on the output shaft side when the input shaft is stopped is changed between the first coil spring and the second coil spring. Since it can be dampened by tightening the winding, the rotation can be stopped at an accurate position without displacement even if the stopping force on the input shaft side is relatively small. Therefore, for example, by connecting the output shaft to the drive shaft of the pulse motor through the rotary joint of the present invention, it becomes possible to stop the rotation at an accurate position even if the rotation speed is increased, and the normal brake By connecting the output shaft to the drive shaft of the attached motor via the rotary joint of the present invention, it becomes possible to stop the rotation at an accurate position even if the braking force is small.

Next, the operation of the rotary joint of the present invention in which a plurality of coil springs are closely attached to the members located inside thereof will be described. First, there will be an input shaft. When rotated in the direction, the first coil spring is wound and tightened via the input sleeve. However, since the first coil spring is already mounted in close contact with the member located inside thereof, its rotational force is immediately transmitted to the output side sleeve, and the input shaft and the output shaft rotate integrally. To do.

When the rotation of the input shaft is stopped, the output shaft tries to continue rotating due to the moment of inertia. As a result, the action of the one-way clutch mechanism in turn causes the second coil spring to be wound and tightened. However, as described above, the second coil spring is closely attached to the member located inside the second coil spring and cannot be further tightened. Therefore, the moment of inertia of the second coil spring is immediately applied to the input shaft side. It is transmitted and the output shaft stops due to the stopping force of the input shaft. Whichever the input shaft rotates, the same result is obtained. That is, the input shaft and the output shaft are completely integrated and rotate and stop.

In the rotary joint of the present invention, as described above, by providing a gap in the inner circumference of each coil spring,
It can also have a function to damp the moment of inertia when the rotation is stopped, or the inner circumference of each coil spring can be brought into close contact with the inner member so that the rotational force of the input shaft and It is also possible for the stopping force to be immediately transmitted to the output shaft. In either case, since the rotation force and the stopping force are transmitted by tightening one of the first coil spring and the second coil spring, the rotation force is not increased even if a relatively large rotation torque is applied. Accurate transmission is possible and damage to the joint is also prevented.

Further, since the rotary joint of the present invention has a structure in which the input side sleeve and the output side sleeve are connected by a plurality of coil springs, the axes of the input shaft and the output shaft are accurately aligned. Even if it is not necessary, some deviation is absorbed by the coil spring, so that it is possible to increase the tolerance for the alignment of the shaft centers and facilitate the alignment at the time of assembling the device.

In the present invention, the first coil spring and the second coil spring
As a one-way clutch mechanism that generates a winding tightening force on a coil spring, the input side sleeve and the output side sleeve are each composed of a plurality of cylindrical members separated by a stepped portion whose outer diameter changes. When adopting a structure that is mounted on the input shaft or output shaft through the one-way clutch that has been changed alternately, it is possible to transmit rotation without backlash by the one-way clutch.
The advantage is that the shafts can be joined simply by inserting the input shaft and the output shaft into the one-way clutch.

In the present invention, the first coil spring and the second coil spring
When the structure in which the first coil spring and the second coil spring are mounted so as to have the spring clutch action, respectively, is adopted as the one-way clutch mechanism for generating the winding tightening force on the coil spring, the structure of the joint is said to be simplified. Benefits are obtained. However, since the spring clutch is liable to slip with respect to a large rotational torque, the structure using the one-way clutch is preferable when rotational accuracy is particularly required.

In a preferred embodiment of the present invention, a first gear is mounted on a specific portion of the input side sleeve, and a second gear is mounted on a portion of the output side sleeve corresponding to the above, and these first gear and second gear are mounted. Corresponding to, when the first sensor and the second sensor for detecting the number of feed teeth are attached,
The number of feed teeth of the corresponding gear can be detected by the first sensor and the second sensor to obtain the respective rotation angles of the input shaft and the output shaft, and the deviation of the rotation angle between the input shaft and the output shaft can be confirmed. it can. In this case, the gear may be any gear as long as it has a protrusion that can be detected by a sensor on the outer periphery, and is not limited to the shape of a normal gear, and may be, for example, a large number of triangular teeth having sharper angles. It may be provided on the outer circumference.

[0024]

1 shows an embodiment of a rotary joint according to the present invention.

The rotary joint 11 includes a pair of support plates 12,
It has a frame in which 13 are opposed to each other in parallel and a plurality of columns 14 connect them. A motor 15 with a brake is mounted on the support plate 12, and its drive shaft constitutes an input shaft 16 of the present invention, and the input shaft 16 penetrates the support plate 12 and projects into the frame. Further, a bearing sleeve 18 having a bearing 17 on the inner circumference is attached to penetrate through the other support plate 13, and the bearing sleeve 18
The output shaft 19 is inserted through. The input shaft 16 and the output shaft 19 are coaxially arranged so that their tip ends abut.

A one-way clutch 20 is attached to the input shaft 16.
The diameter-expanding cylinder 21 is mounted on the base side via the one-way clutch 22, and the diameter-reducing cylinder 23 is mounted on the tip side via the one-way clutch 22. The sleeve 24 is configured. The one-way clutch 20 meshes only when the input shaft 16 rotates in the direction of the arrow A in the drawing relative to the expanded diameter cylinder 21, and the one-way clutch 22 has the reduced diameter cylinder 23 relative to the input shaft 16. Only meshes when rotating in the direction of arrow A. That is, the one-way clutches 20, 22 are
The directions of meshing with each other are opposite.

A one-way clutch 25 is attached to the output shaft 19.
The diameter-expanding cylinder 26 is mounted on the base side via the one-way clutch 27, and the diameter-reducing cylinder 28 is mounted on the tip side via the one-way clutch 27. A sleeve 29 is configured. The one-way clutch 25 meshes only when the expanded cylinder 26 rotates relative to the output shaft 19 in the direction of the arrow A in the figure, and the one-way clutch 27 includes the one-way clutch 27 in which the output shaft 19 relatively moves to the contracted cylinder 28. Only meshes when rotating in the direction of arrow A. That is, the one-way clutches 25 and 27 are
The directions of meshing with each other are opposite. As a result, the four one-way clutches 20, 22, 25, 27 are arranged such that the meshing directions are alternately opposite.

A first coil spring 30 is mounted between the expanding cylinder 21 of the input sleeve 24 and the expanding cylinder 26 of the output sleeve 29. This first coil spring 30
Is a diameter-expanding cylinder 21 when viewed from the output shaft 19 side (upper side in the figure).
Is tightened when the clockwise and the expanded cylinder 26 relatively rotates in the counterclockwise direction. A cylindrical spacer 31 is arranged on the inner circumference of the first coil spring 30, and a predetermined amount of gap is formed between the inner circumference of the first coil spring 30 and the outer circumference of the cylindrical spacer 31. It has become. The tubular spacer 31 is composed of two tubular bodies separated from each other in order to prevent the flexibility of the joint from being impaired. Further on the inner circumference of the tubular spacer 31, the reduced diameter cylinder 23 of the input side sleeve 24
The second coil spring 32 is mounted between the output side sleeve 29 and the reduced diameter cylinder 28. The second coil spring 32 is wound in a direction opposite to that of the first coil spring 30, and is tightened when the diameter-reducing cylinder 23 rotates counterclockwise and the diameter-reducing cylinder 28 rotates clockwise relative to the output shaft 19 side. It is designed to be used. The diameter-reduced cylinders 23 and 28 are formed with further reduced diameter portions 23a and 28a, and a predetermined amount of gap is formed between the outer circumference of this portion and the inner circumference of the second coil spring 32. It is supposed to be done. Further, in the case of this embodiment, the respective coil springs 30 and 32 are fixed to the corresponding cylinders at both ends thereof.

Next, the rotating operation when this rotary joint is used will be described.

When the input shaft 16 starts to rotate in the direction of arrow A in the figure by the operation of the motor 15, the one-way clutch 20
Transmits the rotational force to the expanded diameter cylinder 21 of the input side sleeve 24, and one end of the first coil spring 30 fixed to the expanded diameter cylinder 21 rotates in the arrow A direction. The other end of the first coil spring 30 is connected to the expanded diameter cylinder 26 of the output side sleeve 29.
However, since the one-way clutch 25 engages the output shaft 19, the expanded diameter cylinder 26 is fixed to the output shaft 19
You cannot rotate unless you rotate. As a result, the first coil spring 30 is twisted and tightly wound, and the tubular spacer 31
If it cannot be tightened any further, it will stick to the outer periphery of
The input shaft 16, the input-side expanded cylinder 21, the output-side expanded cylinder 26, and the output shaft 19 rotate integrally. Since the one-way clutch 22 idles with respect to the rotation of the input shaft 16 and does not transmit the rotational force to the reduced diameter cylinder 23 on the input side,
No winding tightening or unwinding force is generated on the second coil spring 32.

When the input shaft 16 is stopped by the brake after the input shaft 16 is rotated by the motor 15 by a predetermined angle in this way, the output shaft 19 tries to continue to rotate due to the moment of inertia. When the input shaft 16 stops,
The one-way clutch 20 idles to allow the expanded cylinder 21 to rotate in the direction of arrow A. Further, when the output shaft 19 rotates faster than the diameter-expanding cylinder 26, the one-way clutch 25 idles and does not transmit the rotational force to the diameter-expanding cylinder 26. As a result, the first coil spring 30 is rewound in proportion to the rotation angle of the output shaft 19.

On the other hand, when the output shaft 19 continues to rotate due to the moment of inertia, the output-side reduced diameter cylinder 28 that meshes via the one-way clutch 27 rotates, causing one end of the second coil spring 32 to rotate in the same direction. However, the second
Input-side reduced diameter cylinder 2 to which the other end of the coil spring 32 is fixed
Since 3 meshes with the input shaft 16 by the one-way clutch 22, it cannot rotate in the direction of arrow A when the input shaft 16 stops. As a result, a torsional force acts on the second coil spring 32, and the second coil spring 32 is wound and tightened. Second
When the coil spring 32 comes into close contact with the further reduced diameter portions 23a and 28a of the reduced diameter cylinders 23 and 28, further tightening cannot be performed, and the output shaft 19, the reduced diameter cylinders 28 and 23, and the input shaft 16 are integrated. Therefore, the rotation of the output shaft 19 in the arrow A direction in the figure is stopped. At this time, the output shaft 19 is in a position where it has excessively rotated beyond the rotation angle of the input shaft 16,
Since the second coil spring 32 is wound tightly as described above, its repulsive force acts to start rotating in the opposite direction this time. When the repulsive force of the second coil spring 32 is strong, the rotation of the output shaft 19 stops when the repulsive force becomes larger than the moment of inertia remaining on the output shaft 19,
This time it starts rotating in the opposite direction.

When the output shaft 19 rotates in the opposite direction, the one-way clutch 25 meshes with each other to rotate the expanded diameter cylinder 26 on the output side in the same direction. On the other hand, the expanded cylinder 21 on the input side is
Since the one-way clutch 20 meshes with the input shaft 16, it cannot rotate. As a result, the torsional force acts on the first coil spring 30 again, and the first coil spring 3
0 is wound up. Then, when the repulsive force due to the tightening of the first coil spring 30 exceeds the rotational moment of the output shaft 19 in the opposite direction, the output shaft 19 reverses again and rotates in the direction of arrow A in the figure, and again this time. The two-coil spring 32 will be wound tightly. In this way, when the input shaft 16 is stopped, the inertia moment remaining on the output shaft 19 side is caused by the alternating tightening action of the second coil spring 32 and the first coil spring 30 and the gradual amplitude of the output shaft 19. Of the output shaft 19
Finally stops at a rotation angle according to the input shaft 16.
In this case, the effect of damping the moment of inertia can be enhanced by making the spring constants of the first coil spring 30 and the second coil spring 32 different.

Therefore, even if the braking force attached to the motor 15 is small, the moment of inertia remaining on the output shaft 19 side when the input shaft 16 is stopped is reduced by the second coil spring 32 and the first coil spring 30. The output shaft 19 can be stopped at an accurate position by dampening. Also,
According to this rotary joint 11, the input shaft 16 and the output shaft 19
Can be connected simply by inserting them into the respective one-way clutches 20, 22, 25, 27 of the corresponding sleeves 24, 29. Further, even if the axes of the input shaft 16 and the output shaft 19 do not exactly coincide with each other, some deviation of the axes is absorbed by the deformation of the first coil spring 30 and the second coil spring 32. Therefore, the connection work is relatively easy.

FIG. 2 shows another embodiment of the rotary joint according to the present invention. Note that, hereinafter, substantially the same parts will be denoted by the same reference numerals and the description thereof will be omitted.

The rotary joint 41 includes a pair of support plates 12,
13 parallel to each other, their side walls 42, 43
It has a frame connected by. A motor 15 is attached to the support plate 12, and its drive shaft, that is, the input shaft 16
Penetrates through the support plate 12 and projects into the frame.
An input side sleeve 46 is attached to the input shaft 16 via two one-way clutches 44 and 45 whose meshing directions are opposite to each other. The input-side sleeve 46 includes a tubular portion 47 in which the one-way clutches 44 and 45 are installed on the inner circumference, a first gear 48 that projects most outwardly, and a diametrical expansion portion 49 that projects outwardly. Reduced diameter portion 5 reduced in diameter from expanded diameter portion 49
0 and 0 have a structure in which they are sequentially connected from the lower side in the drawing. The input side sleeve 46 is the one-way clutch 4 described above.
By 4, 45, it rotates substantially integrally with the input shaft 16.

An output shaft 19 is inserted through and supported by the other support plate 13 via a bearing sleeve 18 as in the above embodiment. The output shaft 19 has two opposite meshing directions.
An output sleeve 53 having a reduced diameter in multiple stages is mounted via one one-way clutch 51, 52. The output-side sleeve 53 has a second gear 54 that projects most outwardly.
Then, the enlarged diameter portion 55 that protrudes outward and the reduced diameter portion 56 that has the smallest diameter are connected in order from the upper side in the drawing. Further, a tapered spacer ring 57 is mounted between the input sleeve 46 and the output sleeve 53.

The first coil spring 30 is mounted between the expanded diameter portion 49 of the input side sleeve 46 and the expanded diameter portion 55 of the output side sleeve 53. A cylindrical spacer 31 is arranged on the inner circumference of the first coil spring 30 as in the above-described embodiment. Further, the second coil spring 32 is mounted between the reduced diameter portion 50 of the input side sleeve 46 and the reduced diameter portion 56 of the output side sleeve 53. The second coil spring 32 is configured to come into close contact with the outer periphery of the tapered spacer ring 57 when wound. As in the case of the first embodiment, the first coil spring 30 is twisted and tightened when the enlarged diameter portion 49 rotates clockwise and the enlarged diameter portion 55 rotates counterclockwise relative to the output shaft 19 side. , Second coil spring 3
Similarly, when viewed from the output shaft 19 side, the reduced diameter portion 2 is twisted and tightened when the reduced diameter portion 50 rotates counterclockwise and the reduced diameter portion 56 relatively rotates clockwise. The coil springs 30 and 32 are attached to the sleeves 46 and 53 so as to have a so-called spring clutch function. When the sleeves 46 and 47 rotate in the winding direction, they are tightened, but in the unwinding direction. When it rotates, it slips and spins.

On one side wall 43, a first sensor 61 is installed at a position corresponding to the first gear 48, and a second sensor 62 is installed at a position corresponding to the second gear 54. These sensors 61 and 62 count the number of teeth of the gears 48 and 54 sent with rotation.

Next, the rotating operation when this rotary joint is used will be described.

When the motor 15 operates and the input shaft 16 starts to rotate in the direction of arrow A in the figure, the one-way clutch 44,
The engagement of 45 causes the input side sleeve 46 to rotate integrally. As a result, a torsional force acts on the first coil spring 30, and the first coil spring 30 is wound and tightened. When the first coil spring 30 comes into close contact with the outer periphery of the tubular spacer 31 and is no longer tightened, the input side sleeve 46 and the output side sleeve 53 are integrated, and the output shaft 19 rotates at the same speed as the input shaft 16. To do. Since the second coil spring 32 is twisted in the unwinding direction at the initial stage of rotation, it slips between the second coil spring 32 and the input-side sleeve 46 to rotate idly and is not subjected to a twisting action.

The first sensor 61 detects the number of feed teeth of the first gear 48, and the second sensor 62 detects the number of feed teeth of the second gear 54. Then, the rotation angles of the input shaft 16 and the output shaft 19 are respectively obtained, and the deviation of the rotation angle can be confirmed. Thus, when the rotation angle detected by the first sensor 61 and the second sensor 62 reaches a predetermined angle, a stop signal is sent to the motor 15. Then, the motor 15 stops and the input shaft 16 stops at a predetermined rotation angle.

When the input shaft 16 is stopped, the input side sleeve 46, which is substantially integrated with the input shaft 16 by the one-way clutches 44 and 45, is also stopped. However, output shaft 1
9 and the output sleeve 53 continue to rotate due to the remaining moment of inertia. At this time, the first coil spring 30 is rewound, slips between the first coil spring 30 and the sleeves 46 and 53, and idles. On the other hand, the second coil spring 32 is twisted between the input side sleeve 46 and the output side sleeve 53 by being twisted. When the second coil spring 32 comes into close contact with the outer periphery of the tapered spacer ring 57 and is no longer tightened, and the input side sleeve 46 and the output side sleeve 53 are integrated, or the repulsive force of the second coil spring 32. Is greater than the moment of inertia of the output shaft 19, the stopping force of the input shaft 16 acts and the output shaft 19
Stops rotating.

However, since the second coil spring 32 is wound tightly, the repulsive force causes the output shaft 19 to reverse and rotate in the opposite direction. As a result, the second coil spring 32
Is unwound and slips between the sleeves 46 and 53 to run idle. In addition, the first coil spring 30 receives the twisting action again and is wound and tightened. Then, when the repulsive force of the first coil spring 30 exceeds the rotational moment of the output shaft 19 in the opposite direction, the output shaft 19 is inverted again and rotated in the direction of arrow A in the figure, and this time again the second coil spring. 32 will be wound up. In this way, when the input shaft 16 is stopped, the inertia moment remaining on the output shaft 19 side is caused by the alternating tightening action of the second coil spring 32 and the first coil spring 30 and the gradual amplitude of the output shaft 19. Is gradually reduced and the output shaft 19 finally stops at a rotation angle corresponding to the input shaft 16. When the second coil spring 32 is wound tightly, the second coil spring 32 comes into close contact with the tapered spacer ring 57, so that a characteristic that the repulsive force becomes stronger as the winding is tightened is given.
The inversion of 9 is made effective.

In each of the above embodiments and the embodiments described below, the first coil spring 30 and the second coil spring 32 are used.
May be mounted in a state in which it is wound to some extent in advance. Thereby, the first coil spring 30 and the second coil spring 32
The output shaft 19 is stopped when the spring force is balanced, and the stop position of the output shaft 19 can be more reliably determined.

FIG. 3 shows another embodiment of the rotary joint according to the present invention.

This rotary joint 71 is obtained by changing the clutch mechanism of the rotary joint shown in FIG. 2 into one having the structure shown in FIG.

That is, the input side sleeve 74 is divided into the expanded diameter cylinder 73 and the reduced diameter cylinder 72, and the output side sleeve 84 is divided into the expanded diameter cylinder 83 and the reduced diameter cylinder 82. The expanded cylinder 73 includes a tubular portion 76 and a first gear 77.
And the enlarged diameter portion 78 are connected to each other, and the one-way clutch 20 is attached to the inner periphery thereof. The one-way clutch 20 engages only when the input shaft 16 rotates in the direction of arrow A in the figure relative to the expanded diameter cylinder 73.
Further, the reduced diameter cylinder 72 disposed adjacent to the enlarged diameter cylinder 73.
The one-way clutch 22 is attached to the inner circumference of the one-way clutch 22, and the one-way clutch 22 meshes only when the reduced diameter cylinder 72 rotates in the direction of arrow A in the figure relative to the input shaft 16.

Similarly, the enlarged diameter cylinder 83 of the output side sleeve 84 has a shape in which the second gear 87 and the enlarged diameter portion 88 are connected to each other, and the one-way clutch 25 is attached to the inner periphery thereof. The one-way clutch 25 is an expanded cylinder 8
3 meshes only when 3 rotates in the direction of arrow A relative to the output shaft 19. Further, the one-way clutch 2 is provided on the inner circumference of the diameter-reduced cylinder 82 arranged adjacent to the diameter-expanded cylinder 83.
7, the one-way clutch 27 engages only when the output shaft 19 rotates in the direction of arrow A relative to the reduced diameter cylinder 82. Therefore, the one-way clutches 20, 22, 27, 25 sequentially arranged in the axial direction
Are alternately arranged so that the meshing directions are opposite.

Input side sleeve 74 and output side sleeve 84
A tapered spacer ring 57 is interposed between and. Further, the end portion of the first coil spring 30 is fixed between the expanded diameter portion 78 of the expanded diameter cylinder 73 of the input side sleeve 74 and the expanded diameter portion 88 of the expanded diameter cylinder 83 of the output side sleeve 84. The cylindrical spacer 31 is arranged on the inner peripheral side of the first coil spring 30. Further, the reduced diameter cylinder 72 of the input side sleeve 74 and the output side sleeve 84
The second coil spring 32 is attached to the diameter-reduced cylinder 82 with its end portion fixed, and is tightly attached to the outer periphery of the tapered spacer ring 57 when tightened.

The rotation operation using this rotary joint is as follows.
Since it is basically the same as the rotary joint shown in FIG. 1, its outline will be described.

When the input shaft 16 is rotated in the direction of arrow A in the figure by the operation of the motor 15, the one-way clutches 20, 2
0 transmits the rotational force to the expanding cylinder 73, and the expanding cylinder 7
When the first coil spring 30 whose one end is fixed to 3 is twisted and wound tightly and comes into close contact with the outer periphery of the cylindrical spacer 31 and further tightening cannot be performed, the input shaft 16, the diameter expansion cylinder 73, the diameter expansion The cylinder 83 and the output shaft 19 rotate integrally.

When the input shaft 16 is rotated by a predetermined angle and then stopped by a brake, the output shaft 19 tries to continue to rotate due to the moment of inertia. When the output shaft 19 rotates, the diameter-reducing cylinder 82 of the output-side sleeve 84 that meshes with the one-way clutch 27 rotates, and a torsional force acts on the second coil spring 32, so that the second coil spring 32 is tightened.

The second coil spring 32 is attached to the spacer ring 57.
Close to the outer circumference of the
The output shaft 19 stops rotating, and the repulsive force of the second coil spring 32 causes the output shaft 19 to start rotating in the opposite direction. Since the spacer ring 57 has a tapered shape, the second coil spring 32 has a characteristic that the repulsive force becomes stronger as the second coil spring 32 is wound and tightened, thereby effectively reversing the output shaft 19.

Thereafter, similarly to the embodiment shown in FIG. 1, the output shaft 19 makes a swinging motion whose amplitude gradually decreases, and then stops at a predetermined rotation angle. In this way, the input shaft 1
When 6 stops, the inertia moment remaining on the output shaft 19 can be gradually attenuated, and the output shaft 19 can be stopped at a rotation angle corresponding to the input shaft 16.

FIG. 4 shows a further embodiment of the rotary joint according to the present invention.

This rotary joint 91 basically has a structure similar to that of the rotary joint shown in FIG. 1, but the first coil spring 30 and the second coil spring 32 are provided on the inner peripheral surface side thereof. The difference is that it was mounted in close contact with the inner member without providing a gap.

That is, the input side sleeve 94 is composed of two cylindrical members, the expanded diameter cylinder 92 and the contracted diameter cylinder 93, and the output side sleeve 104 is the two expanded cylinders 102 and 103. It is composed of members. One-way clutches 20, 22, 27, 25 having meshing directions changed alternately are attached to the inner circumferences of the cylinders 92, 93, 103, 102, as in the embodiment shown in FIG. The first coil spring 30 is mounted between the enlarged diameter cylinder 92 of the input side sleeve 94 and the enlarged diameter cylinder 102 of the output side sleeve 104. Also, the input side sleeve 9
The second coil spring 32 is mounted between the reduced diameter cylinder 93 of No. 4 and the reduced diameter cylinder 103 of the output side sleeve 104. Then, the second coil spring 32 and the first coil spring 30
Cylindrical spacers 108 and 109 are arranged side by side in the axial direction between and, and the first coil spring 30 is closely attached to the outer peripheries of these cylindrical spacers 108 and 109. In addition, the second coil spring 32 includes the input side sleeve 94.
Diameter reducing cylinder 93 and output side sleeve 104 diameter reducing cylinder 9
It is attached in close contact with the outer circumference of No. 3. The other structures such as the frame are similar to those of the embodiment shown in FIG.

Next, the rotating operation when the rotary joint 91 is used will be described.

The input shaft 1 is driven by the operation of a motor (not shown).
When 6 rotates in the direction of arrow A in the figure, the one-way clutch 20 meshes with each other and the expanded diameter cylinder 92 of the input side sleeve 94,
Also, the first coil spring 30 whose one end is fixed to the expanded cylinder 92 rotates in the same direction. At this time, since the inner peripheral surface of the first coil spring 30 is in close contact with the outer peripheral surfaces of the cylindrical spacers 108 and 109 in advance, the first coil spring 30
Cannot be further tightened, and its rotational force is immediately transmitted to the expanded diameter cylinder 102 of the output side sleeve 104, and the output shaft 19 is integrally rotated via the one-way clutch 25.

When the input shaft 16 stops in this state, the output shaft 19 tries to continue to rotate due to the moment of inertia, but at this time, the diameter-reducing cylinder 103 of the output side sleeve 104 becomes the same through the one-way clutch 27. Try to rotate in the direction. Therefore, the tightening force acts on the second coil spring 32, but the second coil spring 32 includes the reduced diameter cylinder 93 of the input side sleeve 94 and the output side sleeve 10.
Since it is in close contact with the outer circumference of the diameter-reduced cylinder 103 of No. 4, it cannot be further tightened, and its moment of inertia is transmitted to the input shaft 16 via the one-way clutch 22. That is, when the input shaft 16 is stopped, a stop force is immediately applied to the output shaft 19, and the output shaft 19 is
Stop at the same time as 6.

On the other hand, when the input shaft 16 rotates in the opposite direction to the above, the diameter-reducing cylinder 93 of the input side sleeve 94 rotates in the same direction via the one-way clutch 22, and one end of the diameter-reducing cylinder 93 is attached. The winding tightening force acts on the fixed second coil spring 32. However, since the second coil spring 32 is mounted in a state in which it cannot be further tightened as described above, its rotational force is immediately transmitted to the reduced diameter cylinder 103 of the output side sleeve 104, and the one-way clutch 27 is closed. The output shaft 19 rotates through the output shaft 19.

When the input shaft 16 stops, the inertia moment remaining on the output shaft 19 causes the one-way clutch 25 and the expanded cylinder 102 of the output sleeve 104 to expand.
Although a winding tightening force is generated in the first coil spring 30 via the, the first coil spring 30 is mounted in a state in which it cannot be further tightened as described above, and therefore, the diameter expansion cylinder of the input side sleeve 94 is 92 and one-way clutch 20
The moment of inertia is received by the input shaft 16 via, and the output shaft 19 stops.

As described above, in the rotary joint of FIG.
Like a normal joint, the input shaft and the output shaft rotate together and stop. However, in this rotary joint, since the transmission of the rotational force is performed by winding and tightening the coil springs 30 or 32, it can be applied to the transmission of a large rotational torque, and the rotation can be accurately performed without causing a positional deviation. Can be transmitted to. Further, since the shafts can be joined simply by inserting the input shaft 16 into the one-way clutches 20 and 22, and inserting the output shaft 19 into the one-way clutches 25 and 27, the assembling work can be performed quickly.

FIG. 5 shows still another embodiment of the rotary joint of the present invention.

In this rotary joint 111, the input side sleeve 120 mounted on the outer periphery of the input shaft 16 is mounted via the one-way clutch 114 and the first sleeve 113 having the largest diameter mounted via the one-way clutch 112. The second sleeve 115 having the next largest diameter, the third sleeve 117 having the next largest diameter mounted via the one-way clutch 116, and the fourth sleeve 119 having the smallest diameter mounted via the one-way clutch 118. It consists of and.

The output side sleeve 130 mounted on the outer periphery of the output shaft 19 is mounted via the one-way clutch 122 and the first sleeve 123 having the largest diameter. Second sleeve 125 having a large diameter and one-way clutch 126
3rd sleeve 127 with the next largest diameter attached through
And a fourth sleeve 129 with the smallest diameter mounted via the one-way clutch 128.

The one-way clutches 112, 114, 1 sequentially arranged from the input shaft 16 side toward the output shaft 19 side.
16, 118, 128, 126, 124, 122 have their meshing directions alternately reversed in this order. That is, the input shaft 16 and the output shaft 19 are inside, and each sleeve 11
3, 115, 117, 119, 129, 127, 12
One-way clutch 11 when 5, 123 is outside
2, 116, 128, and 124 mesh when the inner side rotates relative to the outer side in the direction of arrow B, and the one-way clutches 114, 118, 126, and 122 engage the inner side in the opposite direction to arrow B with respect to the outer side. It meshes when rotating relatively.

A first coil spring 131 is mounted between the first sleeves 113 and 123, and the second sleeve 115 and
The second coil spring 132 is mounted between 125 and the third coil spring 1 between the third sleeves 117 and 127.
33 is mounted, and the fourth coil spring 134 is mounted between the fourth sleeves 119 and 129. Of these coil springs arranged concentrically, the first coil spring 131 and the third coil spring 133 have the input sleeve 120 in the counterclockwise direction and the output sleeve 130 in the clockwise direction when viewed from the output shaft 19 side. The second coil spring 132 and the fourth coil spring 134 are
When viewed from the output shaft 19 side, the input side sleeve 120 is wound and tightened when the output side sleeve 130 relatively rotates in the clockwise direction and the output side sleeve 130 rotates in the counterclockwise direction. That is, the coil springs 131 to 134 are arranged such that the winding directions thereof are alternately reversed from the inner side to the outer side.

A cylindrical spacer 135 is arranged inside the first coil spring 131 with a predetermined gap, and a cylindrical spacer 136 is arranged inside the second coil spring 132 with a predetermined gap. A cylindrical spacer 137 is arranged inside the three-coil spring 133 with a predetermined gap, and inside the fourth coil spring 134, the fourth sleeves 119 and 129.
The reduced diameter portions of are also arranged with a predetermined gap. The tubular spacers 135, 136, 137 are separated into two at the intermediate portion so as to be divided into an input side and an output side.

Therefore, in the rotary joint 111, when the input shaft 16 starts rotating in the direction of arrow B in the drawing, the first sleeve 113 and the third sleeve 117 of the input side sleeve 120 are passed through the one-way clutches 112 and 116.
Rotate in the same direction, and the first coil spring 131 and the third coil spring 133 are tightened. When the first coil spring 131 and the third coil spring 133 come into close contact with the corresponding inner cylindrical spacers 135 and 137, the first coil spring 131 and the third coil spring 133 cannot be further tightened, and the first sleeve 123 and the first sleeve 123 of the output side sleeve 130, The output shaft 19 rotates integrally with the three sleeves 127.

In this state, when the input shaft 16 stops, the output shaft 19 tries to continue rotating due to the moment of inertia, but at this time, the one-way clutches 124, 128.
Output side second sleeve 125, fourth sleeve 1
29 rotates in the same direction, and this time, the second coil spring 13
The second and fourth coil springs 134 are tightly wound. And
The spring force of the second coil spring 132 and the fourth coil spring 134 overcomes the moment of inertia, or the second coil spring 132 and the fourth coil spring 134 are located inside the tubular spacer 136 and the fourth sleeve. 11
When it comes into close contact with the reduced diameter portions of 9, 129, the stopping force of the input shaft 16 acts and the rotation of the output shaft 19 in the B direction stops, but due to the repulsive force of the second coil spring 132 and the fourth coil spring 134, This time, it returns in the opposite direction of arrow B and rotates.

Then, the one-way clutches 122, 12
Since the first sleeve 123 and the third sleeve 127 rotate in the same direction via 6, the winding tightening force acts on the first coil spring 131 and the third coil spring 133. Due to such an action, the inertia moment remaining on the output shaft 19 side when the input shaft 16 is stopped is the second coil spring 132 and the fourth coil spring 134, and the first coil spring 131 and the third coil spring 133. The output shaft 19 is gradually damped by being converted into a swinging motion of which the amplitude is gradually reduced by the alternate tightening action of the output shaft 19, and the output shaft 19 is finally stopped at a predetermined position according to the rotation angle of the input shaft 16. To do. In this embodiment, as described above, two winding directions are different (a total of four winding directions).
By using the coil spring of (1), it can be applied to a rotary connection having a high rotary torque.

[0074]

As described above, according to the present invention,
The input shaft and output shaft are connected by a plurality of coil springs with different winding directions, and any one of the coil springs is wound by the one-way clutch mechanism to transmit the rotational force regardless of the rotating direction. Since this is done, the shaft alignment can be facilitated by the flexibility of the joint, and it can be applied even when a relatively large rotational torque is applied, and sufficient strength and durability can be obtained. Also, when a one-way clutch is provided on the inner circumference of the input side sleeve and the output side sleeve,
There is also an advantage that the shaft can be connected only by inserting the input shaft and the output shaft.

When the coil spring is mounted so as to have a predetermined gap between the coil spring and the member arranged inside,
When the input shaft is stopped, the moment of inertia remaining on the output shaft side is converted into a oscillating motion of gradually decreasing amplitude of the output shaft due to the alternate tightening action of the coil springs, and the output shaft is damped. It can be stopped accurately at a rotation angle according to. Therefore, even if the stopping force of the input shaft is small, it is possible to stop the output shaft at an accurate position, improve the stopping accuracy of the rotating mechanism that needs to control the rotation angle, and simplify the stopping mechanism. It is possible to save energy for stoppages.

[Brief description of drawings]

FIG. 1 is a longitudinal sectional view showing an embodiment of a rotary joint of the present invention.

FIG. 2 is a vertical sectional view showing another embodiment of the rotary joint of the present invention.

FIG. 3 is a vertical sectional view showing still another embodiment of the rotary joint of the present invention.

FIG. 4 is a vertical sectional view showing still another embodiment of the rotary joint of the present invention.

FIG. 5 is a vertical sectional view showing still another embodiment of the rotary joint of the present invention.

[Explanation of symbols]

11, 41, 71, 91, 111 Rotary joint 15 Motor 16 Input shaft 19 Output shaft 24, 46, 74, 94, 120 Input side sleeve 29, 53, 84, 104, 130 Output side sleeve 21, 26, 73, 83 , 92, 102 diameter-expanded cylinder 23, 28, 72, 82, 93, 103 diameter-decreased cylinder 20, 22, 25, 27, 44, 45, 51, 52 one-way clutch 30 first coil spring 32 second coil spring 48, 77 1st gear 54, 87 2nd gear 61 1st sensor 62 2nd sensor 108, 109, 135, 136, 137 Cylindrical spacer 131 1st coil spring 132 2nd coil spring 133 3rd coil spring 134 4th coil spring

Claims (6)

(57) [Claims] 1. A rotary joint in which an input shaft and an output shaft are coaxially butted and connected to each other, the rotary joint being mounted on the outer periphery of the input shaft, and having an outer diameter reduced in a plurality of steps toward a tip direction of the input shaft. An input side sleeve, an output side sleeve mounted on the outer circumference of the output shaft and having an outer diameter reduced in multiple steps toward the tip end direction of the output shaft, and correspondence between the input side sleeve and the output side sleeve A plurality of coil springs, each of which is concentrically attached to the outer circumference of the coil and whose winding direction is alternately changed from the center toward the outer diameter, and the input shaft rotates when the input shaft rotates in a certain direction and stops. When the angle is larger than the output shaft, a tightening force is generated in one winding direction of the coil spring, and when the rotation angle of the output shaft is larger than the input shaft, the coil spring is The other winding method Rotary joint, characterized in that it comprises a one-way clutch mechanism for generating a clamping force around the thing. 2. The plurality of coil springs are mounted such that the inner circumferences of their intermediate portions have a predetermined gap with respect to the members located inside thereof, and when the winding tightening force is generated, the coil springs have a predetermined angle. 2. The rotating force is closely contacted with the member located inside after the rotation so as to transmit the rotating force.
The rotary joint described. 3. The plurality of coil springs are mounted so that their inner circumferences are in close contact with a member located inside thereof, and when the winding tightening force is generated, the rotational force is immediately transmitted. The rotary joint according to claim 1, wherein 4. The input-side sleeve and the output-side sleeve each include a plurality of cylindrical members separated by a stepped portion whose outer diameter changes, and each cylindrical member is a one-way clutch in which meshing directions are alternately changed. The rotary joint according to any one of claims 1 to 3, which is attached to the input shaft or the output shaft via the rotary shaft. 5. The input-side sleeve and the output-side sleeve are integrally formed respectively, and the plurality of coil springs are attached to the input-side sleeve and the output-side sleeve with a spring clutch action. The rotary joint according to any one of claims 1 to 3. 6. A first gear is attached to a specific location of the input sleeve, and a second gear is attached to a location of the output sleeve corresponding to a specific location of the input sleeve. The rotary joint according to any one of claims 1 to 5, wherein a first sensor and a second sensor that detect the number of feed teeth of the second gear are attached corresponding to the second gear.