JP2018021571A - Rotary joint and use method of rotary joint - Google Patents

Abstract

PROBLEM TO BE SOLVED: To solve a problem in a rotary joint in which a pair of upper and lower packings are disposed to a flow channel of a housing, that a sliding mark generates between the packings and a shaft, and the sliding mark is deepened with a lapse of working time, which causes leakage of a fluid.SOLUTION: A rotary joint 10 is composed of a rotary shaft having a vertical shaft center to drive and rotate an apparatus 7, and a housing 13 having packings 30 disposed in a fixed state to a case 11 and being slide-contact with an outer periphery of the rotary shaft. A pipe 17 for supplying a fluid to the apparatus 7 is connected to the case 11, the housing 13 is provided with a housing-side flow channel 21 communicated with both of a case-side flow channel 20 of the case 11 connected with the pipe 17 and a shaft-side flow channel 23 of he rotary shaft, and the housing 13 is further provided with the pair of upper and lower packings 30 at different distances in a shaft center direction from a prescribed reference position of the housing 13, and is constituted to be vertically inverted to the case 11.SELECTED DRAWING: Figure 6

Description

  The present invention relates to a rotary joint that supplies a fluid to equipment of a device that is driven and rotated in the ground, and a method of using the rotary joint.

  2. Description of the Related Art Conventionally, a configuration including a non-rotating case with respect to a shaft for driving and rotating a device of an apparatus and a housing fixed to the case in the case is known (Patent Document 1).

Japanese Patent Publication No. 61-52315

Although the details are not described in the above-mentioned known example, conventionally, a pair of upper and lower packings are provided with respect to the flow path of the housing, and a sliding streak is generated between the packing and the shaft. There is a problem that the sliding muscles become deeper with the passage of time and fluid leaks.
Moreover, in the known example, the maintenance of the shaft in which the sliding stripes are generated is not easy, and there is a problem that a great expense is generated when the shaft is replaced.
In the present application, the maintenance of the sliding muscle of the rotating shaft body is not required, and the fluid is prevented from leaking.

The invention according to claim 1 is the rotary joint 10 for supplying fluid to the device 7 of the device 5 that is driven and rotated in the ground. The rotary joint 10 is a rotary shaft whose vertical axis is driven to rotate the device 7. A case 11 that does not rotate with respect to the rotating shaft, and a housing 13 that has a packing 30 that is slidably in contact with the outer periphery of the rotating shaft that is fixed to the case 11 in the case 11. A pipe 17 for supplying fluid to the device 7 is connected, and a housing-side flow path 21 communicating with the case-side flow path 20 of the case 11 connected to the pipe 17 and the shaft-side flow path 23 of the rotating shaft is provided. The housing 13 is provided with a pair of upper and lower packings 30 at different distances in the axial direction from a predetermined reference position of the housing 13. It is obtained by a rotary joint in which a vertically inverted freely configured for the case 11.
The invention according to claim 2 is configured such that the housing-side flow path 21 is formed at an upper and lower intermediate position of the housing 13, and the packing 30 is provided in a pair of upper and lower positions at different distances in the vertical direction from the center of the housing-side flow path 21. The rotary joint 10 is provided with a flange-shaped receiving portion 35 on one of the upper and lower sides of the case 11 and a lid member 36 on the other side of the upper and lower sides. The case 11 is a fluid supplied to the rotating shaft. A pair of upper and lower pipes 17 are connected to each other, and the housing 13 formed separately in each case-side flow path 20 to which the pipes 17 are connected is formed as a rotary joint that is attached upside down.
The invention according to claim 3 is configured such that the housing-side flow path 21 is formed at an upper and lower intermediate position of the housing 13, and the packing 30 is provided in a pair of upper and lower positions at different distances in the vertical direction from the center of the housing-side flow path 21. This is a rotary joint.
The invention of claim 4 is a rotary joint in which the rotary joint 10 is provided with a flange-shaped receiving portion 35 on one of the upper and lower sides of the case 11 and a lid member 36 on either the upper or lower side. is there.
According to a fifth aspect of the present invention, the case 11 includes a housing 13 formed by separately connecting a pair of upper and lower pipes 17 of fluid to be supplied to the rotating shaft, and separately forming each case-side flow path 20 to which the pipe 17 is connected. It is a rotary joint that can be turned upside down.
The invention of claim 6 is a rotary joint in which a plurality of cases 11 in which housings 13 formed separately are attached in a vertically reversible manner are detachably arranged in a vertical direction.
The invention of claim 7 is a rotary joint 10 for supplying a fluid to the device 7 of the device 5 that is driven and rotated in the ground, wherein the rotary joint 10 is driven with respect to a rotation axis and a rotation axis for driving and rotating the device 7. The case 11 is constituted by a non-rotating case 11 and a housing 13 fixed to the case 11 in the case 11. A pipe 17 for supplying a fluid to the device 7 is connected to the case 11, and a pipe 17 is connected to the case 11. The housing 13 is provided with a housing-side channel 21 that communicates with each of the 11 case-side channels 20 and the shaft-side channel 23 of the rotating shaft, and a pair of upper and lower packings 30 are provided in the housing 13. And a rotary joint configured to be positioned at a position different from the packing 30 before the upside down in the up and down direction. Those were.
The invention according to claim 8 is the housing side flow path 21 of the housing 13 to the case side flow path 20 of the case 11 of the rotary joint 10 connected to the pipe 17 for supplying fluid to the device 7 of the device 5 that is driven and rotated in the ground. The housing side flow path 21 is formed at an intermediate position between the upper and lower sides of the housing 13, and in the initial start state of the rotary joint 10, a sliding line at a position where the upper packing 30 is located with respect to the housing side flow path 21. The distance T1 between L1 and the center of the housing side flow path 21 and the distance T2 between the sliding line L2 at the position where the lower packing 30 is located and the center of the housing side flow path 21 are: Work in the ground is performed at a distance different from T1> T2, and when the predetermined time has elapsed from the start of the work, the housing 13 is turned upside down with respect to the case 11 to The distance t 1 between the sliding line L 3 at the position where the packing 30 is located and the center of the housing side flow path 21, and the sliding line L 4 at the position where the lower packing 30 is located and the center of the housing side flow path 21 The distance t2 between them is t1 <t2, and the usage method of the rotary joint is set such that all of the sliding lines L1 to L4 do not overlap.

In the first aspect of the present invention, a pair of upper and lower packings 30 are provided at different distances from the predetermined reference position of the housing 13 in the axial direction, and are vertically reversible with respect to the case 11. By doing so, the packing 30 of the housing 13 can be slidably contacted with the outer peripheral surface of the rotating shaft without the sliding streak without maintenance of the sliding streak of the rotating shaft or replacement of the rotating shaft, thereby preventing fluid leakage. .
According to the second aspect of the present invention, the housing-side flow path 21 is formed at the upper and lower intermediate positions of the housing 13 and the packing 30 is provided at different distances from the center of the housing-side flow path 21 in the vertical direction. Since the housing 13 is sandwiched between the upper and lower receiving portions 35 and the lid member 36 of the case 11, the housing 13 can be stably supported and fluid can be leaked. In addition, several types of fluids can be supplied.
According to the third aspect of the present invention, the housing-side flow path 21 is formed at the upper and lower intermediate positions of the housing 13 and the packing 30 is provided at different distances from the center of the housing-side flow path 21 in the vertical direction. It is possible to easily set the mounting position.
In the invention of claim 4, since the housing 13 is sandwiched between the upper and lower receiving portions 35 and the lid member 36 of the case 11, the housing 13 can be stably supported and fluid leakage can be prevented.
In the invention of claim 5, two kinds of fluids can be supplied.
In the invention of claim 6, a plurality of types of fluids can be supplied.
In the invention of claim 7, when the pair of upper and lower packings 30 are turned upside down in the housing 13, they are positioned at different positions in the up and down direction from the packing 30 before the upside down. Therefore, when the housing 13 is turned upside down. The packing 30 of the housing 13 can be slidably contacted with the outer peripheral surface of the rotating shaft without the sliding streak without maintenance of the sliding streak of the rotating shaft or replacement of the rotating shaft, thereby preventing fluid leakage.
According to the eighth aspect of the present invention, the packing 30 of the housing 13 can be easily brought into sliding contact with the outer peripheral surface of the rotating shaft without sliding stripes, and fluid leakage can be prevented.

The side view of a drilling rig. The side view of a rotary joint. The assembly state perspective view of a rotary joint. FIG. Sectional drawing of the virtual state which reverses a housing. Sectional drawing which reversed the housing. Sectional drawing of the rotary joint of other embodiment. Sectional drawing of the rotary joint of other embodiment.

An embodiment of the present invention will be described with reference to the drawings. Reference numeral 1 is a base machine, and 2 is a leader provided in the base machine 1. A rotary drive unit 3 of a device 5 such as a ground improvement device or an excavating device is attached to the leader 2 so as to be movable up and down. Install the top of 4 (FIG. 1).
An upper part of the rotating shaft 6 of the device 5 is attached to the rotating shaft 4 via a rotary joint 10. A device 7 of the device 5 is attached to the rotary shaft 6 (FIG. 1).
That is, the device 5 is configured by providing a rotary joint 10 between the lower part of the rotary shaft 4 below the rotary drive unit 3 and the upper part of the rotary shaft 6, and the rotary joint 10 supplies fluid to the device 7 of the device 5. To supply. This fluid may be any of liquids such as water and solidified liquid (cement milk), hydraulic oil for operating hydraulic equipment, and air (air) used for stirring the liquid. Supplied in various combinations.

The rotary joint 10 has a cylindrical case 11. A cylindrical housing 13 is closely fitted in the case 11, and a rotary shaft (shaft) 14 is rotatable and detachable on the inner periphery of the housing 13. Insert and attach to (Fig. 3).
The upper part of the rotating shaft 14 is detachably attached to the lower part of the rotating shaft 4, and the upper part of the rotating shaft 6 is detachably attached to the lower part of the rotating shaft 14.
In this case, the rotary joint 10 is configured so that the mounting arm 12 is interposed between the case 11 and the leader 2 so that the case 11 is in a non-rotating state, and is movable up and down with respect to the leader 2. . (FIG. 1).

The housing 13 and the case 11 are in a non-rotating state with respect to the leader 2, the rotating shaft 14 rotates with respect to the housing 13, and fluid is supplied to the rotating rotating shaft 14 from the non-rotating case 11 and the housing 13. .
The case 11 is formed with an inlet 15 for the fluid to be supplied to the rotary shaft 14 (FIG. 4). The inlet 15 is provided with a connection nozzle 16, and the tip of a pipe 17 for transferring the fluid is connected to the connection nozzle 16. To do.

The inlet 15 is formed on the outer end side of the case side channel 20 formed in the case 11, and the outer end of the housing side channel 21 of the housing 13 is communicated with the inner end of the case side channel 20. A communication groove 22 formed in a ring-shaped recess is provided on the inner periphery of the housing 13 at the inner end of the housing-side flow path 21, and the outer end of the shaft-side flow path 23 formed in the rotating shaft 14 is provided in the communication groove 22. Let them communicate.
Therefore, the outer end of the shaft-side flow path 23 is always open to the communication groove 22, and the fluid flows into the shaft-side flow path 23 from the communication groove 22.

In addition, in order to understand easily, illustration of the communication groove | channel 22 is abbreviate | omitted in FIG.
Although not shown, the lower part of the shaft-side flow path 23 is integrally connected to the rotation-side flow path formed on the rotation shaft 6 and connected to the device 7 of the apparatus 5.
Therefore, for example, when the fluid is “water”, the fluid is discharged into the ground from the discharge port (not shown) of the device 7 of the device 5 through the shaft-side flow path 23. For example, the fluid is “liquid such as solidified liquid”. ”Improves the ground by discharging from the discharge port (not shown) of the device 7 of the device 5 into the ground. For example, when the fluid is“ hydraulic oil ”, the expansion wing 24 of the device 7 is Sent to hydraulic equipment such as a cylinder to be expanded or contracted.
The rotary shaft 14 mounted on the housing 13 of the rotary joint 10 only needs to be able to supply a fluid to the device 7 of the device 5, and has a configuration that is shared with the rotary shaft 4 below the rotary drive unit 3 or the rotary shaft 6 of the device 5. There may be.

Thus, a pair of upper and lower packings 30 are provided on the upper and lower sides of the housing-side channel 21. The pair of packings 30 are arranged at different distances in the vertical direction (axial direction) from the center of the housing-side flow path 21 on the inner surface side of the housing 13, and the housing 13 can be mounted upside down with respect to the case 11. Configure.
Since the packing 30 is in sliding contact with the outer peripheral surface of the rotating shaft 14, sliding streaks are generated due to wear on the outer peripheral surface of the rotating shaft 14 at the sliding portion with the packing 30, and the sliding streaks become deeper when used for a long time. In addition, the sealing performance may deteriorate due to deterioration of the packing 30 and fluid may leak from the rotary joint 10. However, in the present application, the pair of packings 30 are pivoted from a predetermined reference position (center of the housing side flow path 21). Since the housing 13 is configured to be mounted upside down with respect to the case 11 while being arranged at different distances in the center direction, the rotary joint 10 is disassembled and the housing 13 is installed upside down. Change the position of the sliding line.

  In other words, the housing-side channel 21 is formed at an intermediate position between the upper and lower sides of the housing 13, and in an initial state, as shown in FIG. 4, the sliding at a position where one (upper) packing 30A is located with respect to the housing-side channel 21. Line L1 (in order to facilitate understanding, shows a place where a sliding stripe may be formed, whether or not there is an actual sliding stripe) and a predetermined reference position (center of the housing-side flow path 21) ) Is T1, and the distance between the sliding line L2 at the position where the other (lower) packing 30B is located and the predetermined reference position (center of the housing-side flow path 21) is T2, T1 And T2 are set such that T1> T2 and different distances.

Next, when there is an indication that fluid has leaked from the packing 30 after a predetermined working time has elapsed, the rotary joint 10 is removed from the rotary shaft 4 and the rotary shaft 6, the rotary shaft 14 is removed from the rotary joint 10, and the rotary joint 10 After removing the housing 13 from the case 11 and replacing the packing 30 of the housing 13, the housing 13 is turned upside down and attached to the case 11 as shown in FIG. 5, and the rotary shaft 14 is attached to the rotary joint 10.
Then, as shown in FIG. 6, the distance between the sliding line L3 at the position where the one (upper) packing 30a (original packing 30B) is located and the predetermined reference position (center of the housing side flow path 21) is t1 ( The distance between the sliding line L4 at the position where the other (lower) packing 30b (original packing 30A) is located and the predetermined reference position (center of the housing-side flow path 21) is t2 (original T1). Thus, t1 <t2 is reversed and all of the sliding lines L1 to L4 do not overlap.

Therefore, the position of the upper and lower packings 30 does not overlap with the position before the upper and lower inversion only by turning the housing 13 upside down, and fluid leakage from the packing 30 due to wear of the rotating shaft 14 without replacing the rotating shaft 14. Can be prevented at low cost.
Thus, the configuration of the rotary joint 10 is arbitrary including the configuration for turning the housing 13 upside down. However, as an example, a flange-shaped receiving portion 35 is provided on one of the upper and lower sides of the case 11. The lid member 36 is provided on either the upper or lower side, and the housing 13 is sandwiched between the receiving portion 35 and the lid member 36. Reference numeral 37 denotes a fastening device to which the lid member 36 is attached.

Note that a plurality of fluid inlets 15 to be supplied to the rotating shaft 14 are formed in the case 11 in the vertical direction so that different types of fluids can be supplied from the respective inlets 15. A housing 13 having a pair of packings 30 arranged at different distances in the axial direction from a predetermined reference position is attached to the inflow port 15, the case side flow path 20, and the housing side flow path 21 so as to be vertically inverted. (FIG. 7).
In the rotary joint 10, as shown in FIG. 8, the case 11 is divided into a plurality of upper and lower parts according to the number of the pipes 17, the flange parts 38 are respectively provided on the divided cases 11, and the upper and lower flange parts 38 are bolts 39. It is set as the structure fixed by.

That is, when supplying fluid such as “liquid such as solidified liquid”, “water”, “air”, and “hydraulic oil” to the device 7 of the apparatus 5, four pipes 17 are necessary, and four pipes 17 Four housings 13 having housing-side flow paths 21 corresponding to the above are required, and the four housings 13 are attached to the case 11 so as to be reversible (FIG. 8). Further, when several kinds of “liquid such as solidified liquid” are used, the number of pipes 17 and housings 13 may be further increased.
Reference numeral 40 denotes an O-ring.
As shown in FIG. 2, case covers 41 are respectively attached to the upper and lower surfaces of the uppermost case 11 and the lowermost case 11 with bolts 42, and the case 11, the rotary shaft 14, and the housing 13 are integrally formed by the case cover 41. Assembled.

(Operation of the embodiment)
The present invention is configured as described above, the upper part of the rotary shaft 14 of the rotary joint 10 is connected to the lower part of the rotary shaft 4 of the rotary drive unit 3, and the upper part of the rotary shaft 6 having the device 7 is attached to the lower part of the rotary shaft 14. The installation of the device 5 is completed.
Next, the rotary drive unit 3 rotates the rotary shaft 4, the rotary shaft 14, and the rotary shaft 6 to operate the device 7 of the device 5 to perform work.
The device 5 is configured by a ground improvement device, a drilling device, or the like, and is provided by a fluid supply device (not shown) configured by a base machine 1 or a pump or compressor installed on the ground, and a hose or the like that connects these to the rotary joint 10. The fluid is supplied to the rotary joint 10, and the rotary joint 10 supplies the fluid to the rotating shaft 6 that rotates the device 7 of the device 5.

  A rotary joint 10 that supplies fluid to a shaft-side flow path 23 of a rotating shaft 14 that is connected to a rotating shaft 6 that rotates the device 7 of the device 5 is attached to the case 11 and a non-rotating case 11 with respect to the reader 2 side. The housing 13 includes a housing-side channel 21 communicating with the shaft-side channel 23 of the rotating shaft 14 and a pair of packings 30 at different distances in the axial direction from a predetermined reference position of the housing 13. Since the apparatus 5 is operated and the operation is continued, when the sliding portion between the packing 30 and the rotating shaft 14 wears out and signs of fluid leakage occur, the apparatus 5 is stopped and rotated. The rotary joint 10 is removed from the rotary shaft 4 of the drive unit 3 and the rotary shaft 6 of the device 5, and then the housing 13 is removed from the rotary joint 10, and the housing is removed. 13 upside down against the case 11 is mounted, the respective rotation axis 6 of the rotating shaft 4 and the device 5 of the rotary drive portion 3 to the rotary joint 10 and attached to resume the work.

That is, since a pair of packings 30 are arranged in the housing 13 at different distances from the predetermined reference position in the axial direction, when the housing 13 is turned upside down with respect to the case 11, the upper and lower packings 30 respectively. It contacts the rotating shaft 14 at a position different from the original position.
Therefore, it is possible to prevent fluid from leaking from the packing 30 of the rotary joint 10 due to wear of the rotary shaft 14 without replacing the rotary shaft 14.

  In other words, the housing-side channel 21 is formed at an intermediate position between the upper and lower sides of the housing 13, and in an initial state, as shown in FIG. 4, the sliding at a position where one (upper) packing 30A is located with respect to the housing-side channel 21. The distance between the line L1 and the predetermined reference position (center of the housing-side flow path 21) is T1, and the sliding line L2 at the position where the other (lower) packing 30B is located and the predetermined reference position (housing-side flow path 21). Since the distance from the center T2 is different from T1> T2, when the housing 13 is turned upside down as shown in FIG. 6, one (upper) packing 30a (original) The distance t1 (original T2) between the sliding line L3 at the position where the packing 30B is located and a predetermined reference position (center of the housing-side flow path 21), and the other (lower) packing 30b (original packing 30A) of The distance t2 (original T1) between the sliding line L4 at the position and the predetermined reference position (center of the housing side flow path 21) is reversed to t1 <t2, and the sliding line L1 to the sliding line L4 All of the will not overlap.

Therefore, the position of the upper and lower packings 30 (sliding lines) does not overlap with the position before the upside down just by turning the housing 13 upside down, and the packing caused by the wear of the rotating shaft 14 without replacing the rotating shaft 14. The fluid leakage from 30 can be prevented at low cost.
Thus, the rotary joint 10 is provided with a flange-shaped receiving portion 35 on either one of the upper and lower sides of the case 11 and a lid member 36 on either the upper or lower side, so that the housing 13 has the receiving portion 35 and the lid. It is clamped by the member 36.
Accordingly, when the rotary shaft 14 is removed from the rotary joint 10 and the cover member 36 is removed, the housing 13 can be removed from the case 11, and then the housing 13 is fitted into the case 11 by turning it upside down. When the lid member 36 is attached to the case 11, the housing 13 is sandwiched between the receiving portion 35 of the case 11 and the lid member 36.

  A plurality of fluid inlets 15 to be supplied to the rotating shaft 14 are formed in the case 11 so that different types of fluids can be supplied from the inlets 15. A plurality of housings 13 are prepared in which a pair of packings 30 are arranged at different distances from the predetermined reference position in the axial direction so as to correspond to each of the inlet 15 and the case side flow path 20. Each housing 13 is attached to the case 11 so as to be turned upside down in correspondence with each of the paths 20.

That is, when supplying fluid such as “liquid such as solidified liquid”, “water”, “air”, and “hydraulic oil” to the device 7 of the apparatus 5, four pipes 17 are necessary, and four pipes 17 Four housings 13 having housing-side flow paths 21 corresponding to the above are required, and the four housings 13 are attached to the case 11 so as to be reversible. In addition, when several types of “liquid such as solidified liquid” are used, the number of pipes 17 and housings 13 is further increased.
Therefore, the rotary joint 10 of the present application can supply a plurality of types of fluids to the device 7 of the apparatus 5 by arranging a plurality of cases 11 having the inflow ports 15 in a detachable manner in the axial direction.

  DESCRIPTION OF SYMBOLS 1 ... Base machine, 2 ... Leader, 3 ... Rotation drive part, 4 ... Drive rotation shaft, 5 ... Apparatus, 6 ... Rotation shaft, 7 ... Apparatus, 10 ... Rotary joint, 11 ... Case, 12 ... Mounting arm, 13 ... Housing, 14 ... Rotating shaft, 15 ... Inlet, 16 ... Connecting nozzle, 17 ... Piping, 20 ... Case side channel, 21 ... Housing side channel, 22 ... Communication groove, 23 ... Shaft side channel, 30 ... Packing 35 ... receiving part, 36 ... lid member, 37 ... fastening device, 38 ... flange part, 39 ... bolt, 40 ... O-ring.

Claims (8)

  In the rotary joint 10 that supplies fluid to the device 7 of the device 5 that is driven and rotated in the ground, the rotary joint 10 is configured such that the axis that drives and rotates the device 7 has a vertical rotation axis and a rotation axis. A non-rotating case 11 and a housing 13 having a packing 30 in sliding contact with the outer periphery of a rotating shaft fixed to the case 11 in the case 11. A pipe 17 to be supplied is connected, and a housing side flow path 21 communicating with each of the case side flow path 20 of the case 11 to which the pipe 17 is connected and the shaft side flow path 23 of the rotating shaft is provided in the housing 13. The housing 13 is provided with a pair of upper and lower packings 30 at different distances in the axial direction from a predetermined reference position of the housing 13, and the case 11 Rotary joint was upside down freely configured.   In claim 1, the housing-side flow path 21 is formed at an upper and lower intermediate position of the housing 13, and the packing 30 is provided with a pair of upper and lower portions at different distances from the center of the housing-side flow path 21 in the vertical direction. The rotary joint 10 is provided with a flange-shaped receiving portion 35 on one of the upper and lower sides of the case 11 and a lid member 36 on the other side of the upper and lower sides. The case 11 is a pipe for fluid supplied to the rotating shaft. A rotary joint in which a housing 13 formed separately in each case-side flow path 20 to which a pipe 17 is connected is attached to each case side flow path 20 to be vertically inverted.   In Claim 1, the said housing side flow path 21 was formed in the up-and-down intermediate position of the housing 13, and the said packing 30 set it as the structure provided in the upper and lower direction at a different distance from the center of the said housing side flow path 21 at an up-down direction. Rotary joint.   4. The rotary joint according to claim 1, wherein the rotary joint 10 is provided with a flange-shaped receiving portion 35 on one of the upper and lower sides of the case 11 and a lid member 36 on the other side of the upper and lower sides.   5. The case 11 according to claim 1, wherein the case 11 is formed as a separate body in each case-side flow path 20 to which a pair of pipes 17 of fluid to be supplied to the rotating shaft are connected. Rotary joints with the housings 13 mounted upside down.   6. The rotary joint according to claim 5, wherein a plurality of cases 11 in which the housings 13 formed separately in the inside thereof are respectively attached upside down are detachably arranged in the vertical direction.   In a rotary joint 10 that supplies fluid to the device 7 of the device 5 that rotates in the ground, the rotary joint 10 includes a rotating shaft that drives and rotates the device 7, a case 11 that does not rotate with respect to the rotating shaft, and the case 11. The case 11 is constituted by a housing 13 fixed to the case 11, and a pipe 17 for supplying a fluid to the device 7 is connected to the case 11, and a case-side flow path 20 of the case 11 to which the pipe 17 is connected. The housing 13 is provided with a housing-side channel 21 that communicates with the shaft-side channel 23 of the rotary shaft. When the housing 13 is turned upside down, a pair of upper and lower packings 30 are provided in the housing 13. A rotary joint configured to be located at a different position in the vertical direction from the packing 30 before inversion.   The housing-side flow path 21 of the housing 13 is communicated with the case-side flow path 20 of the case 11 of the rotary joint 10 connected to the pipe 17 for supplying fluid to the device 7 of the device 5 that rotates in the ground. The flow path 21 is formed at an upper and lower intermediate position of the housing 13, and in the initial start state of the rotary joint 10, the sliding line L1 at a position where the upper packing 30 is located with respect to the housing side flow path 21 and the housing side flow path. The distance T1 between the center 21 and the distance T2 between the sliding line L2 at the position where the lower packing 30 is located and the center of the housing-side flow path 21 is different from T1> T2. When the ground work is performed as a distance and a predetermined time has elapsed from the start of the work, the housing 13 is turned upside down with respect to the case 11, and the upper packing 30 is closed. The distance t1 between the sliding line L3 at the position and the center of the housing side flow path 21 and the distance between the sliding line L4 at the position where the lower packing 30 is located and the center of the housing side flow path 21 A method of using a rotary joint in which t2 is such that t1 <t2 and all of the sliding lines L1 to L4 do not overlap.

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