JPH1089572A - Swivel joint - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve drag of a heavy load in a swivel joint arranged in a piping for transporting mud and the like drained by tunnel work and the like by rotatably engaging a rotary shaft part with a barrel part, and interposing multiple needle valves between the rotary shaft part and the barrel part, and constituting the swivel joint as a roller bearing. SOLUTION: In a swivel joint 1 arranged in a transport piping for mud and the like, a rotary shaft part 3 is rotatably engaged with a barrel part 2, and multiple needles 6 are interposed as a bearing part 5 of the rotary shaft part 3 and the barrel part 2 so as to form the swivel joint 1 as a roller bearing. One end part of the barrel part 2 is formed as an engaging part 7, a screw engaging part 8 is formed on the other end thereof, and an annular groove 9 is formed on the engaging part 7. The outside surface part of the rotary shaft 3 is formed as an engaging part 10, a screw engaging part 11 is formed inside an outer end part, and an annular groove 12 is formed on the engaging part 10. A needle inserting port 13 is formed on the outer wall of the barrel part 2, and a retainer cap 14 for closing the inserting port 13 is fixed to the barrel part 2 by a vis.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a swivel joint suitable for placing in a pipe for transporting concrete, muddy water or the like in a shield construction method such as tunnel construction.

[0002]

2. Description of the Related Art A swivel joint is interposed in a pipe when rotating a pipe or moving it up and down, left and right, and back and forth when transporting a fluid subject to hydraulic pressure, water pressure, air pressure, or the like. Is used.

Conventionally, as a swivel joint of this type, a cylindrical rotary shaft is rotatably fitted to a cylindrical body, and a large number of bearings are mounted on the bearing between the rotary shaft and the body. Generally, steel balls are interposed, and a smooth rolling motion is performed while maintaining a constant interval by a retainer so that the steel balls do not contact each other.

[0004]

By the way, the conventional swivel joint is a ball bearing, so that the shaft runout during rotation of frictional resistance is small, and therefore, the application requiring high speed, high precision, low torque and low vibration. Suitable for. Therefore, it is suitable for the transportation of pressurized oil and fluid, but it is used for fluid piping of muddy water or viscous fluid under heavy load or impact load or concrete pumping because of its small contact surface and small allowable load. In this case, it is impossible to withstand the applied load, and the life is shortened due to breakage.

[0005] In order to solve the above-mentioned difficulties, a deep groove is formed in a fitting portion of a body portion and a rotary bearing portion corresponding to an outer ring and an inner ring, or a ball diameter is increased so as to increase the entire contact surface. However, when forming a deep groove, not only the processing becomes complicated, but also the thickness of the fitting portion must be increased. In addition, when the ball diameter is increased, there is a problem that the fitting portion itself becomes large due to the ball diameter.

Accordingly, an object of the present invention is to provide a swivel joint suitable for fluid piping such as muddy water which can solve the conventional problems at once.

[0007]

Means for Solving the Problems In order to achieve the above object, the present inventor has conducted intensive studies. As a result, if a needle (needle roller) is used instead of a conventional steel ball, a body corresponding to an outer ring and an inner ring is obtained. Since there are many contact surfaces with the shaft and the rotating shaft, and they can be integrated with them, they can withstand heavy loads or impact loads sufficiently, and the outer and inner rings can be reduced in thickness, reducing the overall weight. It has been found that it is possible to provide a bearing part that is possible and easy to process.

Therefore, in the present invention, a cylindrical rotary shaft is rotatably fitted to a cylindrical body, and a bearing between the rotary shaft and the body is provided with a large number of needles. A swivel joint which is a roller bearing is provided.

When this needle is used, the contact with the body and the rotating shaft corresponding to the outer ring and the inner ring becomes linear contact as compared with the point contact in the case of a ball, so that the allowable load in the radial direction increases. Even if it is installed in a pipeline for feeding muddy water, concrete, or a viscous fluid, it can be sufficiently used.

[0010] Further, if the needle is installed so as to be interposed in the annular groove formed in the body and the rotary shaft, the thrust load applied in the axial direction of the rotary shaft in the cross section of the needle can be reduced. And the axial length is large, so that the allowable thrust load can be greatly improved as compared with the ball bearing. Therefore, a needle having a small cross-sectional area can be used for these loads, and the outer ring and the inner ring can be made smaller in thickness than the ball bearing, and a small swivel joint can be provided.

Further, since the needle is long in the axial direction, it is easier to align the needle than the ball bearing. In order to perform the same alignment, the ball bearing needs to be arranged in multiple rows. There is an advantage that the needle can cope sufficiently. Needless to say, arranging the needles in double rows not only facilitates the centering of the piping path, but also increases the thrust allowable load.

[0012] The insertion of the needle into the fitting portion is performed by inserting a needle into a member located outside of the fitting portion of the body portion and the rotating shaft portion so that the needle can be inserted into the bearing portion; If a retainer cap that closes is provided, it is possible to easily insert a large number of needles simply by sequentially feeding them from the insertion port. At this time, if the grease is simultaneously injected from the insertion port, the operation of injecting the grease can be easily performed.

The swivel joint having the above structure can be used for concrete feeding, tunnel press-fitting inside a tunnel, muddy water drainage, piping of industrial machinery, water treatment sites, etc., as well as fluid handling, food industry and the like. . In particular, there is an advantage that when used in a transportation pipeline for concrete or muddy water, it can sufficiently cope with the heavy load or impact load.

[0014]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a side view of a swivel joint according to a first embodiment, and FIG. 2 is a cross-sectional view taken along line AA of FIG. As shown in the figure, a swivel joint 1 in this embodiment is installed in a pipeline for conveying concrete or muddy water, and a cylindrical rotating shaft 3 is rotatable with respect to a cylindrical body 2. And the rotating shaft 3
And a bearing part 5 between the body part 2 and the body part 2 is a roller bearing in which a large number of needles 6 are interposed.

The body part 2 is a steel elbow joint curved at 90 degrees, one end of which is slightly overlaid to form a fitting part 7 into which the rotary shaft part 3 is fitted. A screw fitting portion 8 for connecting a hose or a pipe is formed.
An annular groove 9 into which the needle 6 is rotatably fitted is formed in the fitting portion 7 of the body 2.

On the other hand, the rotary shaft portion 3 is formed in a cylindrical shape, and its inner end is formed as a fitting portion 10 with the body portion 2, and a screw for connecting a hose or pipe is provided inside the outer end portion. The fitting portion 11 is provided. The fitting portion 10 of the rotating shaft portion 3
Is formed with an annular groove 12 into which the needle 6 is rotatably fitted.

The annular grooves 9 and 1 between the body 2 and the rotating shaft 3
The gap 2 is formed to have the same size as the diameter of the cylindrical needle 6. The needle 6 is a steel roller, and the bearing 6 is formed by the needle 6 and the annular grooves 9 and 12 of the body and the rotating shaft 3.

A needle insertion opening 13 large enough to insert the needle 6 into the bearing portion 5 is formed on the outer wall of the body 2, and a retainer cap 14 for closing the insertion opening 13 is formed with a screw by a screw. It is fixed to the section 2. The needles 6 are inserted one by one from the insertion port 13 and grease is inserted into the bearing portion 5. Of course,
Of course, grease may be injected from a grease injection port formed separately from the insertion port.

A dust seal 15 for preventing dust from entering the bearing 5 is disposed between the fitting portions 7 and 10 outside the needle 6 in the axial direction of the bearing 5. Furthermore, between the fitting portions 7 and 10 axially inside the needle 6, a wear-resistant plastic for preventing leakage of high-pressure fluid passing through the inside of the cylinder of the body 2 and the rotating shaft 3. A packing 16 made of tetrafluoroethylene (Teflon: a trademark of DuPont) is arranged. The materials of the body 2, the rotating shaft 3, the needle 6, the seal 15, and the packing 16 can be appropriately selected according to the use conditions.

The trunk 2 of the swivel joint 1 having the above configuration
If a pipe (not shown) is screwed and connected to the fitting portions 8 and 11 of the rotating shaft portion 3, the rotating shaft portion 3 can be rotated 360 degrees around the center of the shaft. Can rotate freely.

When the swivel joint 1 is used, the needle 6 is connected to the annular grooves 9, 1, 2 of the body 2 and the rotating shaft 3.
Since it comes into contact with 2 in a line contact state, it can withstand a heavy load or an impact load as compared with the case where a ball bearing is used.

The needle 6 is connected to the body 2 and the rotating shaft 3.
Even if a thrust load is applied in the axial direction of the rotary shaft 3, the thrust is received by the cross section of the needle 6 and the side wall of the annular groove, and the thrust tolerance of the ball bearing is increased. This is a much larger allowable load than the load. Therefore, the needle 6 having a small sectional area with respect to these loads is used.
Can be used, and the small swivel joint 1 can be used sufficiently.

Further, since the needle 6 is long in the axial direction,
Centering is easier than ball bearings, and ball bearings need to be arranged in multiple rows to achieve the same centering, whereas a single row of needles has the advantage that they can be adequately accommodated.

FIG. 3 is a side view showing the swivel joint 1 of the second embodiment, and FIG. 4 is a sectional view taken along the line BB of FIG.
As shown in the figure, the swivel joint 1 has the needles 6 arranged in multiple rows (two rows), and
a, 9b, 12a, and 12b are formed in two rows. Thereby, there is an advantage that the centering of the piping path can be easily performed, the pressure receiving area in the thrust direction increases, and the allowable thrust load increases. The other configuration is the same as that of the first embodiment, and the description is omitted.

FIG. 5 is a side view of a swivel joint according to a third embodiment. As shown in the figure, in this embodiment, the rotating shaft portions 3 are provided at both ends of the elbow joint which is the body portion 2.
The configuration of the bearing 5 of each rotating shaft 3 is the same as that of the first embodiment shown in FIGS. 1 and 2.

FIG. 6 is a side view of a swivel joint according to a fourth embodiment. As shown in the figure, in this embodiment, an intermediate straight pipe joint is used as the body 2 instead of the elbow joint of each of the above embodiments.
Is similar to that of the first embodiment.

In each of the above embodiments, the steel 2 is used as the material of the body 2 and the rotating shaft 3. However, the material is not limited to this, and the material of the synthetic resin may be used. Of course. Further, in each of the above-described embodiments, the rotation shaft portion 3 is shown as being fitted inside the body portion 2. However, the same function can be obtained even when the rotation shaft portion 3 is fitted outside the body portion 2. Can be demonstrated.

Further, in this embodiment, an example has been shown in which the swivel joint is disposed in the piping for concrete feeding or muddy water transport. However, it is needless to say that the present invention may be applied to a hydraulic circuit for fluid handling and the like. Further, in each of the above embodiments, the structure in which the needles 6 are fitted into the annular grooves 9 and 12 has been described, but a configuration in which a number of grooves corresponding to the diameters are formed in each needle may be used.

[0029]

As is clear from the above description, according to the present invention, since the bearing of the swivel joint is a roller bearing using a needle, the allowable load can be greatly improved with respect to the ball bearing. Further, there is an effect that the centering of the rotating shaft can be easily performed.

Further, if the needles are arranged in a double row in the axial direction of the rotary shaft portion, the centering of the piping path can be more easily performed, and there is an advantage that the thrust allowable load is increased.

Further, if a member located outside of the fitting portion of the body portion and the rotating shaft portion is provided with a needle insertion opening for inserting a needle into the bearing portion and a retainer cap for closing the insertion opening. It is easy to insert a large number of needles simply by sequentially feeding them from the insertion port. At this time, if grease is simultaneously injected from the insertion port, there is an advantage that the grease injection operation can be easily performed. Further, when used in a transportation pipeline for concrete or muddy water, there is an advantage that it can sufficiently cope with the heavy load or the impact load.

[Brief description of the drawings]

FIG. 1 is a side view of a swivel joint according to a first embodiment.

FIG. 2 is a sectional view taken along line AA of FIG. 1;

FIG. 3 is a side view showing a swivel joint according to a second embodiment.

FIG. 4 is a sectional view taken along line BB of FIG. 3;

FIG. 5 is a side view of a swivel joint according to a third embodiment.

FIG. 6 is a side view of a swivel joint according to a fourth embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Swivel joint 2 Trunk part 3 Rotation shaft part 5 Bearing part 6 Needle 7 Fitting part 9,12 Annular groove 10 Fitting part

Claims (4)

[Claims] A cylindrical rotating shaft is rotatably fitted to a cylindrical body, and a bearing between the rotating shaft and the body is a roller bearing having a number of needles interposed therebetween. A swivel joint. 2. The swivel joint according to claim 1, wherein said needles are arranged in a plurality of rows in an axial direction of a rotating shaft portion. 3. A needle insertion opening for allowing the needle to be inserted into the bearing portion in a member located outside of the fitting portion between the body and the rotating shaft, and a retainer cap for closing the insertion opening. The swivel joint according to claim 1, wherein the swivel joint is provided. 4. A swivel joint according to claim 1, which is interposed in a muddy water transport path.