JP4474041B2 - Open / close rotary joint with liquid leakage prevention structure - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an open / close rotary joint disposed at a connection portion between a fluid supply system and a rotary shaft when supplying a fluid such as a coolant liquid through a rotary shaft of a machine tool or the like, and more particularly to an open / close rotary joint. TECHNICAL FIELD OF THE INVENTION
[0002]
[Prior art]
For example, as shown in FIG. 7, the conventional open / close rotary joint includes a floating sheet 1 supported on the end of the mounting base 10 so as to be slidable in the axial direction, and a floating sheet 1 on the end of the rotating shaft 20. The floating sheet 1 is provided with a rotor 2 disposed so as to face the first flow path 1a communicating with the fluid path 11 of the mounting base 10 and a first mechanical seal 12 is attached to the tip. The rotor 2 has a structure in which a second flow path 2 a communicating with the fluid path 21 of the rotary shaft 20 is formed inside, and a second mechanical seal 22 is attached to the tip.
[0003]
When fluid is supplied from the fluid path 11 of the mounting base 10 to the first flow path 1a when supplying the fluid to the fluid path 21 of the rotating shaft 20, the floating pressure of the floating sheet 1 is reduced as shown in FIG. ), The first flow path 1a and the second flow path 2a communicate with each other in a state where the first mechanical seal 12 and the second mechanical seal 22 are abutted, and the joint is closed.
Further, when the supply of fluid is stopped, the fluid pressure to the floating sheet 1 is released, so that the floating sheet 1 moves backward as shown in FIG. 7 (a), and the first mechanical seal 12 and the second mechanical seal 22 are retreated. In a state where the two are separated from each other, the communication between the first flow path 1a and the second flow path 2a is cut off, and the joint is opened.
[0004]
[Problems to be solved by the invention]
As described above, since the first flow path and the second flow path are communicated with each other or released by sliding of the floating sheet due to the fluid pressure of the fluid, the joint is opened and closed. Fluid leaked from the tip of the flow path.
In recent years, the sliding stroke of the floating sheet tends to be lengthened. In such a case, the amount of fluid leakage increases, and this leakage has become a problem.
[0005]
The present invention has been made in order to solve the conventional problems as described above, and has a liquid leakage prevention structure that can reduce fluid leakage when opening and closing the joint with a simple structure . An object is to provide an open / close rotary joint .
[0006]
[Means for Solving the Problems]
In order to solve the above problems, an open / close rotary joint (Claim 1) having the liquid leakage prevention structure of the present invention is provided as follows .
A floating sheet supported so as to be slidable in the axial direction and a rotor disposed opposite to the floating sheet are provided. The floating sheet has a first flow path formed therein and a first seal surface (first The rotor is provided with a second flow path formed therein and a second seal surface (second mechanical seal) is provided at the tip, and the floating sheet advances and the first seal surface and the second seal The first flow path and the second flow path communicate with each other in a state in which the seal surface is abutted, and the first flow path is in a state in which the floating sheet is retracted and the first seal surface and the second seal surface are separated from each other. In the open / close rotary joint formed so that the communication of the second flow path is divided,
A liquid leakage prevention pipe is provided so as to extend from the floating sheet so as to be inserted into the second flow path of the rotor, and this liquid leakage prevention pipe is inserted into the second flow path within the sliding stroke range of the floating sheet. Formed to a length that maintains the
A first seal lubrication flow path is formed between the outer periphery of the liquid leakage prevention pipe and the inner periphery of the floating sheet, and a fluid induction hole opened in the first seal lubrication flow path is formed in the middle of the liquid leakage prevention pipe. Forming,
In addition, in a state where the first flow path and the second flow path are communicated with each other with the first seal surface and the second seal surface in contact, a seal portion is provided between the outer periphery of the liquid leakage prevention pipe and the inner periphery of the rotor. As a boundary, a second seal lubrication flow channel communicating with the first seal lubrication flow channel is formed.
[0007]
In this liquid leakage prevention structure, the sliding of the floating sheet due to the fluid pressure of the fluid causes the first flow path and the second flow path to communicate with each other or to be released, thereby opening and closing the joint.
The liquid leakage prevention pipe is extended from the floating sheet so as to be inserted into the second flow path of the rotor, and the liquid leakage prevention pipe is within the sliding stroke range of the floating sheet when the joint is opened and closed. , The insertion state is always maintained. Therefore, when the joint is opened and closed, the fluid that is about to leak from the first flow path is introduced into the second flow path through the liquid leakage prevention pipe, so that liquid leakage can be prevented.
[0008]
In addition, the flow of the fluid when the joint is closed causes a negative pressure in the second seal lubrication flow path, and the suction of the negative pressure attracts the fluid in the liquid leakage prevention pipe from the fluid induction hole into the first seal lubrication flow path. Is done. Since a bypass channel is formed in which the fluid attracted into the first seal lubrication channel flows out from the second seal lubrication channel to the second channel, the middle of the bypass channel, i.e., the first A fluid can be introduced into the seal portion at the boundary between the seal lubrication flow channel and the second seal lubrication flow channel, and lubrication of the seal portion can be ensured. This is particularly effective when the fluid is a gas-liquid mixed fluid such as oil mist.
[0009]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, reference techniques and embodiments of the present invention will be described with reference to the drawings. The specific configuration of the present invention is not limited to the following embodiment.
FIG. 1 is a cross-sectional view showing a first embodiment of the present invention, which is an open / close rotary joint provided with a liquid leakage prevention structure, and FIG. 2 is a cross-sectional view showing a main part of the liquid leakage prevention structure.
[0010]
The open / close rotary joint includes a floating sheet 1 supported on the end of the mounting base 10 so as to be slidable in the axial direction, and a rotor 2 disposed on the end of the rotating shaft 20 so as to face the floating sheet 1. I have.
A first flow path 1 a communicating with the fluid path 11 of the mounting base 10 is formed inside the floating sheet 1, and a first mechanical seal 12 is attached to the tip.
The rotor 2 has a structure in which a second flow path 2 a communicating with the fluid path 21 of the rotary shaft 20 is formed inside, and a second mechanical seal 22 is attached to the tip.
The first mechanical seal 12 has a front end surface serving as a first seal surface 1b, and the second mechanical seal 22 has a front end surface serving as a second seal surface 2b. In some cases, the front end surface is formed of ceramic or the like, and the sealing surface is used. In such a case, it is not necessary to attach a mechanical seal.
[0011]
When supplying the fluid to the fluid passage 21 of the rotating shaft 20, when the fluid flows into the first passage 1 a from the fluid passage 11 of the mounting base 10, the floating sheet 1 receives the fluid pressure and the floating sheet 1 is shown in FIG. 1. As shown in (b), the first flow path 1a and the second flow path 2a communicate with each other with the first mechanical seal 12 and the second mechanical seal 22 butted, and the joint is closed. Become.
Further, when the supply of fluid is stopped, the fluid pressure to the floating sheet 1 is released, so that the floating sheet 1 moves backward as shown in FIG. 1 (a), and the first mechanical seal 12 and the second mechanical seal 22 are retreated. In a state where the two are separated from each other, the communication between the first flow path 1a and the second flow path 2a is cut off, and the joint is opened.
[0012]
Next, the liquid leakage prevention structure will be described. The liquid leakage prevention structure is extended from the floating sheet 1 so as to be inserted into the second flow path 2a of the rotor 2, and a liquid leakage prevention pipe 3 is provided.
This liquid leakage prevention pipe 3 is formed in a length that maintains the state of being inserted into the second flow path 2a within the sliding stroke range of the floating sheet 1, and is therefore always in the second flow path 2a. The state inserted in is maintained.
In this case, the liquid leakage prevention pipe 3 is formed as a separate part from the floating sheet 1, its base end is fitted into the first flow path 1 a, and its distal end is sealed within the second flow path 2 a. It is inserted while holding the path T. The seal lubrication channel T is formed between the outer periphery of the liquid leakage prevention pipe 3 and the inner periphery of the rotor 2 when the joint is closed. Can be introduced into the seal portion S by both seal surfaces 1b and 2b, and the seal portion S can be lubricated.
[0013]
In this liquid leakage prevention structure, the sliding of the floating sheet 1 by the fluid pressure of the fluid causes the first flow path 1a and the second flow path 2a to communicate with each other or to be released, thereby opening and closing the joint.
The liquid leakage prevention pipe 3 extended from the floating sheet 1 so as to be inserted into the second flow path 2a of the rotor 2 always maintains its insertion state when the joint is opened and closed. When opening and closing, the fluid that is about to leak from the first flow path 1 a is introduced into the second flow path 2 a through the liquid leakage prevention pipe 3. Accordingly, liquid leakage can be prevented.
Further, by forming the liquid leakage prevention pipe 3 as a separate part from the floating sheet 1, a liquid leakage prevention structure can be added by simply modifying the existing floating sheet 1 as a part.
[0014]
Next, FIG. 3 is an embodiment of the present invention and is a cross-sectional view showing the main part of the liquid leakage prevention structure.
In this liquid leakage prevention structure, a first seal lubrication flow channel T1 is formed between the outer periphery of the liquid leakage prevention pipe 3 and the inner periphery of the floating sheet 1, and opens into the first seal lubrication flow channel T1. A fluid induction hole 30 is formed in the middle of the liquid leakage prevention pipe 3.
Further, when the joint is closed, a second seal lubrication channel T2 communicating with the first seal lubrication channel T1 with the seal portion S as a boundary is provided between the outer periphery of the liquid leakage prevention pipe 3 and the inner periphery of the rotor 2. Is formed.
[0015]
As a result, the flow of the fluid when the joint is closed causes a negative pressure in the second seal lubrication flow path T2, and the fluid in the liquid leakage prevention pipe 3 is sucked from the fluid induction hole 30 by the suction due to the negative pressure. Invited into the road T1.
Therefore, a bypass channel is formed in which the fluid attracted into the first seal lubrication channel T1 flows out from the second seal lubrication channel T2 to the second channel 2a. That is, the fluid can be introduced into the seal portion S at the boundary between the first seal lubrication flow channel T1 and the second seal lubrication flow channel T2, and the lubrication of the seal portion S can be ensured. This is particularly effective when the fluid is a gas-liquid mixed fluid such as oil mist.
[0016]
Next, FIG. 4 is a sectional view showing an open / close type rotary joint provided with a liquid leakage prevention structure, which is a second reference technique of the present invention.
In this case, the liquid leakage prevention structure is extended from the rotor 2 so as to be inserted into the first flow path 1a of the floating sheet 1, and a liquid leakage prevention pipe 4 is provided.
The liquid leakage prevention pipe 4 is formed in a length that maintains the state of being inserted into the first flow path 1a within the sliding stroke range of the floating sheet 1, and is therefore always in the first flow path 1a. The state inserted in is maintained.
Other configurations and operations are the same as those in the first reference technique .
[0017]
Next, FIG. 5 is a sectional view showing a third embodiment of the present invention, which is an open / close rotary joint having a liquid leakage prevention structure.
In this case, the liquid leakage prevention structure is extended from the floating sheet 1 so as to cover the tip of the rotor 2, and a liquid leakage prevention cover 5 is provided.
The liquid leakage prevention cover 5 is formed in such a length as to maintain the state of covering the front end portion of the rotor 2 within the sliding stroke range of the floating sheet 1, and therefore always covers the front end portion of the rotor 2. Is maintained.
In this case, the liquid leakage prevention cover 5 is formed as a separate part from the floating sheet 1, its base end is fitted to the outer periphery of the front end of the floating sheet 1, and the front end slides on the outer periphery of the front end of the rotor 2. It can be fitted.
[0018]
In this liquid leakage prevention structure, the liquid leakage prevention cover 5 provided so as to extend from the floating sheet 1 so as to cover the front end portion of the rotor 2 maintains a state where the front end portion of the rotor 2 is always covered when the joint is opened and closed. Therefore, even if a fluid leaks from the first flow path 1a when the joint is opened and closed, the fluid is received by the liquid leakage prevention cover 5, so that the liquid leakage can be prevented.
In addition, by forming the liquid leakage prevention cover 5 as a separate part from the floating sheet 1, a liquid leakage prevention structure can be added by simply modifying the existing floating sheet 1 as a part.
[0019]
Next, FIG. 6 is a sectional view showing an open / close type rotary joint having a liquid leakage preventing structure as a fourth reference technique of the present invention.
In this case, the liquid leakage prevention structure is extended from the rotor 2 so as to cover the tip of the floating sheet 1 and is provided with a liquid leakage prevention cover 6.
The liquid leakage prevention cover 6 is formed in a length that maintains the state of covering the front end portion of the floating sheet 1 within the sliding stroke range of the floating sheet 1. The covering state is maintained.
Other configurations and operations are the same as those of the third reference technique .
[0020]
The liquid leakage prevention structure of the present invention uses a liquid leakage prevention pipe . The liquid leakage prevention pipe shown in the third reference technique (FIG. 5) and the fourth reference technique (FIG. 6) is used for this liquid leakage prevention pipe. A liquid leakage prevention structure combining a cover can also be provided.
[0021]
【The invention's effect】
As described above, the open / close rotary joint (Claim 1) provided with the liquid leakage prevention structure of the present invention has a configuration in which a liquid leakage prevention pipe is provided. Fluid leakage can be reduced.
[0022]
In addition, since the first seal lubrication flow channel having the fluid induction hole opened communicates with the second seal lubrication flow channel with the seal portion as a boundary, the fluid is introduced into the seal portion by the seal surface when the joint is closed. Thus, lubrication of the seal portion can be ensured.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view showing an open / close rotary joint having a liquid leakage prevention structure as a first reference technique of the present invention.
FIG. 2 is a cross-sectional view showing the main part of the liquid leakage preventing structure of the first reference technique .
FIG. 3 is a cross-sectional view showing the main part of the liquid leakage prevention structure according to the embodiment of the present invention.
FIG. 4 is a cross-sectional view showing an open / close type rotary joint provided with a liquid leakage prevention structure according to a second reference technique of the present invention.
FIG. 5 is a cross-sectional view showing an open / close type rotary joint provided with a liquid leakage prevention structure according to a third reference technique of the present invention.
FIG. 6 is a cross-sectional view showing an open / close type rotary joint having a liquid leakage prevention structure according to a fourth reference technique of the present invention.
FIG. 7 is a cross-sectional view showing a conventional open / close rotary joint.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Floating sheet 1a 1st flow path 1b 1st seal surface 12 1st mechanical seal 10 Mounting base 11 Fluid path 2 Rotor 2a 2nd flow path 2b 2nd seal surface 22 2nd mechanical seal 20 Rotating shaft 21 Fluid path 3 Liquid leakage Prevention Pipe 30 Fluid Induction Hole 4 Liquid Leakage Prevention Pipe 5 Liquid Leakage Prevention Cover 6 Liquid Leakage Prevention Cover T Seal Lubrication Channel T1 First Seal Lubrication Channel T2 Second Seal Lubrication Channel S Seal Part

Claims (1)

A floating sheet supported so as to be slidable in the axial direction and a rotor disposed opposite to the floating sheet are provided. The floating sheet has a first flow path formed therein and a first seal surface provided at the tip. The rotor has a second flow path formed therein and a second seal surface provided at the tip thereof, and the floating sheet advances and the first seal surface and the second seal surface are in contact with each other. Formed so that the communication between the first flow path and the second flow path is cut off in a state where the flow path and the second flow path communicate with each other, and the floating sheet moves backward and the first seal surface and the second seal surface are separated from each other. In the open / close rotary joint,
A liquid leakage prevention pipe is provided so as to extend from the floating sheet so as to be inserted into the second flow path of the rotor, and this liquid leakage prevention pipe is inserted into the second flow path within the sliding stroke range of the floating sheet. Formed to a length that maintains the
A first seal lubrication flow path is formed between the outer periphery of the liquid leakage prevention pipe and the inner periphery of the floating sheet, and a fluid induction hole opened in the first seal lubrication flow path is formed in the middle of the liquid leakage prevention pipe. Forming,
In addition, in a state where the first flow path and the second flow path are communicated with each other with the first seal surface and the second seal surface in contact, a seal portion is provided between the outer periphery of the liquid leakage prevention pipe and the inner periphery of the rotor. An open / close rotary joint having a liquid leakage prevention structure, characterized in that a second seal lubrication channel communicating with the first seal lubrication channel is formed as a boundary.

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