JPH06123389A - Rotary joint - Google Patents

Abstract

PURPOSE:To prevent the severe wear and heating of seal rings by bringing a static seal ring into sliding contact with a rotary seal ring only when a rotating member requiring the supply of fluid is stopping, and insuring the sealing property between the both. CONSTITUTION:A fluid is guided to a pressurizing chamber 9 through the fluid inlet port 4e of a retainer 4 in the state where the rotation of a rotating shaft 1 is stopped, a static seal ring 3 is pushed onto a rotary seal ring 2 by the fluid pressure to seal the space between seal end surfaces 2a, 3a. O-rings 7, 8 are twisted as being rolled according to the seal ring 3, the seal ring 3 is energized by its reaction in the direction of separating from the seal ring 2 against the pressure of the fluid guided to the pressurizing chamber 9, and the fluid in the pressurizing chamber 9 is supplied to the fluid passage 1b of the rotating shaft 1 through a communicating passage 10. The fluid to the pressurizing chamber 9 is stopped according to the rotation of the rotating shaft 1, whereby the sealed ring 3 is separated from the seal ring 2 by the reaction accompanying the twisting of the O-rings 7, 8 to release the sealed state. Thus, the severe wear and heating of the seal end surfaces 2a, 3a can be prevented.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a rotary joint for supplying a fluid to a rotating member.

[0002]

2. Description of the Related Art Conventionally, in a winder for continuously winding a long wire such as an electric wire, a strip-shaped sheet, or a thread, a fluid formed inside the rotary shaft in a state where the rotation of the rotary shaft is stopped. The take-up holder attached to the rotary shaft is removed by supplying compressed air through the passage. The supply of compressed air to the fluid passage of the rotary shaft is performed through a rotary joint connected to the rotary shaft.

The rotary joint is, for example, as shown in FIG. 5, a hollow rotary member 10 connected to a rotary shaft 100.
1 is rotatably attached to a closed casing 102, and the gap between the casing 102 and the hollow rotating body 101 is usually a mechanical seal 10.
It is sealed by 3. This mechanical seal 10
3 is a rotary seal ring 10 that rotates integrally with the hollow rotary body 101.
5, one sealing end surface 105a and the other sealing end surface 105b
And the stationary seal rings 106 and 107 are brought into sliding contact with each other.
The coil spring 108 is always urged toward the rotary seal ring 105 by the coil spring 108 while being fitted in the shaft 02 so as to be movable in the axial direction.

[0004]

In the above winding machine, the rotating shaft 10 is stopped with the rotating shaft 100 stopped rotating.
Since compressed air is supplied to the fluid passage 100a of 0, as for the rotary joint, if the sealability between the rotary seal ring 105 and the stationary seal rings 106 and 107 can be secured only when the rotation of the rotary shaft 100 is stopped. Good.

However, in the conventional rotary joint, the rotary seal ring 105 and the stationary seal rings 106, 107 are used.
Since they are always in sliding contact with each other and the sealing property between them is always ensured, there is a problem that the sliding contact surface is heavily worn and the sealing performance is deteriorated at an early stage. Further, heat generated by friction of the sliding contact surface is intense, and a separate cooling device may be required in some cases.

The present invention has been made in view of the above problems, and it is possible to secure the sealing performance only when necessary.
An object of the present invention is to provide a rotary joint with less wear and heat generation on the sliding contact surface.

[0007]

As a rotary joint of the present invention for achieving the above object, there is provided a rotary seal ring provided on the outer periphery of a rotary member and rotating integrally with the rotary member, and a sealed end face of the rotary seal ring. A stationary seal ring that slides on the
A retainer that movably supports the stationary sealing ring in the axial direction in a state where the stationary sealing ring is introduced into the annular groove, a first seal member that seals between the groove of the retainer and the inner circumference of the stationary sealing ring, and a retainer of the retainer. A second seal member for sealing between the groove and the outer circumference of the stationary seal ring, a pressure chamber for introducing a fluid to press the stationary seal ring against the sealing end face of the rotary seal ring, a rotary seal ring and a stationary seal ring. And a fluid passage provided inside the rotary member for communicating the pressure chamber with the fluid passage, a retainer provided with a fluid inlet for introducing a fluid into the pressure chamber, and a stationary seal ring. And a biasing member for separating the rotary seal ring from the sealing end face.

However, as the rotary joint, at least one of the first seal member and the second seal member may also serve as the urging member. The biasing member may be a permanent magnet or a spring.

[0009]

According to the rotary joint having the above-described structure, the stationary seal ring can be connected to the rotary seal ring by introducing the fluid into the pressure chamber through the fluid introduction port of the retainer while the rotation of the rotary member is stopped. It is possible to press against the sealed end face to seal between the two, and in this sealed state, the fluid introduced into the pressurizing chamber can be supplied to the fluid passage of the rotating member through the communication passage.

Further, by stopping the supply of the fluid to the pressurizing chamber during the rotation of the rotary member, the urging member separates the stationary seal ring from the sealing end face of the rotary seal ring, and the sealed state is maintained. Can be canceled. As described above, according to the rotary joint, the static sealing ring can be slidably contacted with the sealing end surface of the rotary sealing ring only when the rotary member that needs to supply the fluid is stopped to ensure the sealing performance.

On the other hand, when at least one of the first seal member and the second seal member also serves as the urging member, when the stationary seal ring is pressed against the seal end face of the rotary seal ring, the seal is sealed. When the member is rolled up following the stationary seal ring to be twisted and deformed and the fluid pressure is released, the stationary seal ring can be separated from the sealing end surface of the rotary seal ring by the reaction force caused by the twisted deformation.

When the biasing member is a permanent magnet, the static sealing ring can be easily separated from the sealing end surface of the rotary sealing ring by the magnetic force. Further, when the biasing member is a spring, the stationary seal ring can be mechanically biased to be reliably separated from the sealing end surface of the rotary seal ring.

[0013]

Embodiments of the present invention will be described in detail below with reference to the accompanying drawings. FIG. 1 is a sectional view showing an embodiment of the rotary joint of the present invention. This rotary joint supports a rotary seal ring 2 fitted on the outer periphery of a rotary shaft 1 as a rotary member, a static seal ring 3 that is in sliding contact with a seal end surface 2 a of the rotary seal ring 2, and a static seal ring 3. The main part is constituted by the retainer 4.

The rotary seal ring 2 is an annular ring made of ceramics, cemented carbide, carbon or the like, and a seal member 5 such as an O-ring for sealing between the inner circumference of the rotary seal ring 2 and the rotary shaft 1.
Due to the frictional resistance of 1, it is possible to rotate integrally with the rotary shaft 1. A fluid passage 1b for supplying fluid to the shaft end side is formed inside the rotary shaft 1. The upstream open end of the fluid passage 1b is provided at a position corresponding to the rotary seal ring 2 on the outer circumference of the rotary shaft 1.

The stationary seal ring 3 is a ring made of ceramics, cemented carbide, carbon or the like, and a sealing end face 3a formed on one end face of the stationary seal ring 3 is brought into sliding contact with the sealing end face 2a of the rotary seal ring 2. As a result, it is possible to ensure the sealing performance with the rotary sealing ring 2. This stationary seal ring 3
The inner peripheral surface and the outer peripheral surface are formed parallel to each other.
Further, an annular step portion 3b which is recessed in the axial direction is formed on the outer peripheral side of the other end surface of the stationary seal ring 3.

The retainer 4 has an annular groove 4a on one end surface side.
Is formed into an annular shape, and a flange portion 4b formed on the outer periphery thereof is bolted to the end surface of the casing 6. The retainer 4 is supported concentrically with the rotary shaft 1 by introducing the stationary seal ring 3 into the groove 4a so as to be movable in the axial direction. A space between the inner circumference of the stationary seal ring 3 and the side wall 4c on the inner circumference side of the concave groove 4a is sealed by a first O-ring 7 as a first seal member, and the static seal is formed. Between the outer circumference of the ring 3 and the side wall 4d on the outer circumference side of the groove 4a, a second seal member is provided.
It is sealed by an O-ring 8. The gap between the inner circumference of the stationary seal ring 3 and the side wall 4c on the inner circumference side of the concave groove 4a and the gap between the outer circumference of the stationary seal ring 3 and the side wall 4d on the outer circumference side of the concave groove 4a are equal to each other. When the stationary seal ring 3 is pressed against the sealing end surface 2a of the rotary seal ring 2, the first O-ring 7 and the second O-ring 8 are wound along the stationary seal ring 3 in the direction indicated by the arrow. It is set in a range where twisting can occur.

A pressurizing chamber 9 into which a fluid is introduced is formed between the annular step portion 3b on the end surface of the stationary seal ring 3 and the bottom portion of the concave groove 4a of the retainer 4, and the retainer 4 has A fluid introduction port 4e for introducing a fluid into the pressure chamber 9 is formed on the outer periphery. Further, the pressurizing chamber 9
Is communicated with the fluid passage 1b of the rotary shaft 1 through a communication passage 10 formed in the rotary seal ring 2 and the stationary seal ring 3. An annular groove 10c for communicating the communication passage 10a on the rotary seal ring 2 side and the communication passage 10b on the stationary seal ring 3 side is formed in the middle of the communication passage 10. The annular groove 10c is formed by recessing at least one of the sealing end faces 2a, 3a of the respective sealing rings 2, 3, and the communicating groove 10c on the rotary sealing ring 2 side and the communication channel on the stationary sealing ring 3 side. Passage 1
0b can be always communicated with regardless of the rotational position of the rotary seal ring 2. The opening area of the communication passage 10 in the pressurizing chamber 9 is sufficiently smaller than the cross-sectional area of the pressurizing chamber 9.

With the above structure, the stationary seal ring 3 is rotated by the fluid pressure by introducing the fluid into the pressurizing chamber 9 through the fluid introducing port 4e of the retainer 4 while the rotation of the rotating shaft 1 is stopped. The sealing end faces 2a of the sealing rings 2 can be pressed to seal between the sealing end faces 2a, 3a of the respective sealing rings 2, 3. At this time, the first O-ring 7 and the second O-ring 7
The O-ring 8 is twisted so as to be wound up following the stationary seal ring 3, and its reaction force resists the pressure of the fluid introduced into the pressurizing chamber 9 to cause the stationary seal ring 3 to rotate. Is urged in a direction away from the sealed end surface 2a. In the sealed state, the fluid introduced into the pressurizing chamber 9 can be supplied to the fluid passage 1b of the rotary shaft 1 through the communication passage 10.

Further, by stopping the supply of the fluid to the pressurizing chamber 9 with the rotation of the rotary shaft 1, the reaction force caused by the twisting of the first O-ring 7 and the second O-ring 8 is generated. The stationary sealing ring 3 can be separated from the sealing end surface 2a of the rotary sealing ring 2 to release the sealed state. As described above, according to the rotary joint, the static sealing ring 3 is slidably contacted with the sealing end surface 2a of the rotary sealing ring 2 only when the rotary shaft 1 is stopped to ensure the sealing performance. It is possible to prevent the sealed end faces 2a, 3a of the plate 3 from being severely worn or generating heat.

Further, since the stationary seal ring 3 is separated from the sealing end surface 2a of the rotary seal ring 2 by utilizing the twist of the first O ring 7 and the second O ring 8, the stationary seal ring 3 is separated. There is no need to separately configure a biasing member for
Therefore, the structure can be simplified. In addition, the first
At least one of the O-ring 7 and the second O-ring 8 may be configured to be twisted. Examples of the fluid supplied from the fluid inlet 4e to the pressurizing chamber 9 include gases such as air and liquids such as cutting oil, lubricating oil and cooling water.

FIG. 2 is a sectional view showing another embodiment. In this embodiment, the permanent magnet 1 is used as a biasing member that separates the stationary seal ring 3 from the sealing end surface 2a of the rotary seal ring 2.
1 is used. A plurality of the permanent magnets 11 are embedded in the stationary seal ring 3, and each of the permanent magnets 11 is arranged concentrically with the rotating shaft 1 while facing the pressurizing chamber 9. In addition, at least the portion of the retainer 4 facing the permanent magnet 11 is formed of a magnetic material.

According to this embodiment, the static sealing ring 3 can be easily separated from the sealing end surface 2a of the rotary sealing ring 2 by the magnetic force of the permanent magnet 11. In the above embodiment, the entire rotary joint is arranged in the casing 6, and the fluid passage 6a formed in the casing 6 is communicated with the fluid introduction port 4e of the retainer 4.

FIG. 3 is a sectional view showing still another embodiment. In this embodiment, the spring 12 is used as a biasing member that separates the stationary seal ring 3 from the sealing end surface 2a of the rotary seal ring 2. More specifically, on the outer peripheral portion of the retainer 4, there is provided a short cylindrical portion 4f protruding to the outer peripheral position of the stationary sealing ring 3, and the short cylindrical portion 4f.
A snap ring 4g is fitted to the inner circumference of the. Also,
On the outer circumference of the stationary seal ring 3, an annular spring bearing portion 3c is provided so as to face the snap ring 4g, and the spring 12 is provided between the snap ring 4g and the spring bearing portion 3c. Intervened. As the spring 12, a wave spring in which a corrugated thin thin plate 12a is spirally wound (see FIG. 4) is used, and a predetermined amount of compressive deformation is applied between the snap ring 4g and the spring receiving portion 3c. It is intervened in the state of being.

According to this embodiment, the stationary sealing ring 3 can be reliably separated from the sealing end surface 2a of the rotary sealing ring 2 by the biasing force of the spring 12. That is, when the rolling bearing 13 that supports the rotating shaft 1 is provided adjacent to the stationary seal ring 3, the movement of the stationary seal ring 3 in the axial direction is restricted by the viscosity of the grease that has exuded from the rolling bearing 13. However, even in this case, the stationary seal ring 3 can be strongly pressed by the spring 12 to be reliably separated from the rotary seal ring 2. However, when the spring 12 is used, a large pressing force is required to press the stationary seal ring 3 against the rotary seal ring 2 due to its elastic resistance. Therefore, it is preferable to increase the area of the stationary seal ring 3 facing the pressurizing chamber 9 by reducing the diameter of the communication passage 10b.

It is preferable to use the above-mentioned wave spring as the spring 12 because it requires a small installation space, but other springs such as a disc spring and a coil spring can also be used. The rotary joint of the present invention is not limited to the above embodiment, and for example, the pressurizing chamber 9 is formed by recessing the bottom of the recessed groove 4a of the retainer 4, and a shaft seal or oil is used as a seal member. Various design changes can be made such as using a seal and integrally forming the rotary seal ring 3 and the rotary shaft 1.

[0026]

As described above, according to the rotary joint of the first aspect, the stationary seal ring and the rotary seal ring are slidably contacted with each other only while the rotary member requiring the supply of fluid is stopped. Therefore, it is possible to prevent the respective sealing rings from being severely worn or generating heat. Therefore, it is possible to secure a good sealing property for a long period of time, and it becomes extremely excellent in durability.

Particularly, according to the rotary joint of the second aspect, since the stationary seal ring can be separated from the rotary seal ring by at least one of the first seal member and the second seal member, the separation is prevented. There is a unique effect that the structure can be simplified without the need to separately configure a biasing member for performing the operation. Further, according to the rotary joint of the third aspect, it is possible to easily separate the stationary seal ring from the seal end surface of the rotary seal ring by the magnetic force, which is a unique effect.

Further, according to the rotary joint of the fourth aspect, there is a unique effect that the stationary sealing ring can be reliably separated from the sealing end surface of the rotary sealing ring by the mechanical biasing force of the spring.

[Brief description of drawings]

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

FIG. 2 is a cross-sectional view showing another embodiment.

FIG. 3 is a sectional view showing still another embodiment.

FIG. 4 is a perspective view showing an example of a spring used in the embodiment of the previous figure.

FIG. 5 is a cross-sectional view showing a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 rotating shaft (rotating member) 2 rotating sealing ring 3 stationary sealing ring 4 retainer 4a concave groove 4e fluid inlet 7 first O-ring (first sealing member) 8 second O-ring (second sealing member) 9 Pressurizing Chamber 10 Communication Passage 11 Permanent Magnet (Biasing Member) 12 Spring (Biasing Member)

Claims (4)

[Claims] 1. A rotary seal ring, which is provided on the outer periphery of a rotary member and rotates integrally with the rotary member, a static seal ring slidably in contact with a sealed end face of the rotary seal ring, and a static seal ring introduced into an annular groove. A retainer that movably supports in the axial direction in a state, and a first groove that seals between the recessed groove of the retainer and the inner circumference of the stationary seal ring.
A seal member, a second seal member for sealing between the concave groove of the retainer and the outer circumference of the stationary seal ring, and a pressure chamber for introducing a fluid to press the stationary seal ring against the sealed end face of the rotary seal ring, A fluid passage that is formed in the rotary seal ring and the stationary seal ring and that communicates the fluid passage provided inside the rotating member with the pressure chamber, and the fluid introduction provided in the retainer to introduce the fluid into the pressure chamber. A rotary joint comprising a mouth and a biasing member for separating the stationary seal ring from the sealing end face of the rotary seal ring. 2. The rotary joint according to claim 1, wherein at least one of the first seal member and the second seal member also serves as the biasing member. 3. The rotary joint according to claim 1, wherein the biasing member is a permanent magnet. 4. The rotary joint according to claim 1, wherein the biasing member is a spring.