JP3247574B2 - Excavator direction control unit pressure equalizer - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention is to prevent leakage of lubricating oil sealed in a drilling direction control unit housed in a cylindrical housing of a drilling rig such as an oil well or gas well drilling machine, and to improve lubrication. The present invention relates to an excavating direction control unit pressure equalizing device for preventing intrusion of muddy water into an oil filling unit.

[0002]

2. Description of the Related Art Drilling rigs for drilling holes underground for the purpose of collecting underground resources or civil engineering work, especially for collecting underground fluid resources such as oil, natural gas, geothermal steam, etc. A rotary drilling rig, a typical drilling rig that efficiently drills a well, requires a drilling direction control device that changes the direction of drilling in order to continue drilling work by bypassing hard rock. is there. In addition, when the excavation direction is misaligned for some reason during excavation, an excavation direction control device is required to correct the excavation direction to a target direction.

Conventionally, as an excavation direction control device for a rotary excavator, Japanese Patent Application Laid-Open Nos. 57-21695, 57-100290, and 58-21030 have been disclosed.
No. 0 publication proposes various excavation direction control mechanisms. However, Japanese Patent Application Laid-Open Nos.
The excavation direction control mechanism disclosed in Japanese Patent Application Laid-Open No. 7-100290 and Japanese Patent Application Laid-Open No. 58-210300 not only cannot control the excavation direction in all directions but also has a problem that the mechanism is complicated. And was not fully satisfactory.

Recently, a plurality of hollow harmonic gear reducers and an eccentric hollow portion connected to each output element of the hollow harmonic gear reducer and eccentrically rotating with respect to each corresponding reducer rotating shaft. A plurality of eccentric rotating members comprising: a hollow shaft of the excavator drill mounted so as to penetrate through the hollow portion of the hollow type harmonic gear reducer and the eccentric hollow portion of the eccentric rotating member. A device in which a portion of the rotating shaft is displaced in a direction substantially perpendicular to a shaft central axis by an inner peripheral surface of the rotating eccentric hollow portion (Japanese Patent Laid-Open No. 4-76183), A first and a second hollow-type harmonic gear reducer arranged at a first annular member arranged coaxially with the first hollow-type harmonic gear reducer and rotated by the reducer; A second annular member arranged coaxially with the second hollow-type harmonic transmission and rotated by the transmission, wherein the first and second annular members are relatively rotatable. The annular end faces are superimposed on each other in a state, and the superposed end faces are set as inclined surfaces inclined by a fixed angle with respect to the center axis direction, and the first and second circles are set. A rotating shaft of a drilling drill is arranged in a state penetrating the hollow portion of the annular member, and the first and second annular members are relatively rotated to bend the rotating shaft in a predetermined direction. As shown in FIG. 5, a cylindrical housing 101 and a cylindrical housing 101 are rotatably supported on a circular inner peripheral surface of the cylindrical housing 101 and are opposed to the cylindrical housing 101. A first annular member 102 having an eccentric circular inner peripheral surface; and a first annular member 102 rotatably supported on the circular inner peripheral surface of the first annular member 102 and having a circular inner peripheral surface. A second annular member 103 having a circular inner peripheral surface eccentric with respect to the first annular member 103;
And a hollow harmonic gear reducer 104, 105 for relatively rotating the second annular members 102, 103 around their centers.
1 and the amount of eccentricity of the circular inner peripheral surface of the first annular member 102 with respect to the first annular member 102 is equal to the amount of eccentricity of the circular inner peripheral surface of the second annular member 103 with respect to the first annular member 102. And the second annular member 10
3 and a rotary shaft 107 having a drill bit 106 at the tip thereof so as to move integrally with the center of the circular inner peripheral surface of the third annular member 103 and the first and second annular members 103 By rotating the first and second annular members 102, 103 relatively,
A device for positioning the rotary shaft 107 with a fulcrum bearing 108 above the fulcrum 3 as a fulcrum (Japanese Patent Laid-Open No. Hei 5-2026)
No. 89) has been proposed.

Since the excavation direction control device of the excavator is used at the bottom of a pit, it needs to be protected from high temperature and high pressure of muddy water. The digging direction control device is disposed in an annular gap between the digging direction control device and a cylindrical housing provided on the outer periphery of the rotary shaft, and it is necessary to seal the lubricating oil in a watertight state with seals at both ends of the cylindrical housing. The lubricating oil that protects the excavation direction control device is sealed on the ground at atmospheric pressure and normal temperature, and then exposed to high temperature and high pressure at the bottom of the pit. If the pressure difference exceeds the limit pressure difference between the seals at both ends of the cylindrical housing, leakage will occur, or muddy water will enter the lubricating oil filling portion, making it impossible to operate the excavation direction control device. Conventionally, as a seal device between a cylindrical housing and a rotary shaft, a double ring seal as shown in FIGS. 4a and 4f of Japanese Patent Application Laid-Open No. 57-21695 has been adopted.

[0006]

Problems to be Solved by the Invention
In the double ring seal as shown in FIGS. 4a and 4f of Japanese Patent No. 695, it is impossible to follow the pressure fluctuation of the lubricating oil enclosed in the excavation direction control unit between the cylindrical housing and the rotating shaft. However, it is not possible to cope with displacement of the rotating shaft in the direction perpendicular to the axis when changing the excavation direction, and it is impossible to prevent leakage of lubricating oil and intrusion of muddy water.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems of the prior art, and to excavate an excavator capable of preventing leakage of lubricating oil or muddy water sealed in an excavation direction control unit of an excavator for a long period of time. An object of the present invention is to provide a direction control unit pressure equalizing device.

[0008]

The present inventors have conducted various tests and studies to achieve the above object, and found that the displacement of the rotary shaft in the direction perpendicular to the axis at the time of changing the excavation direction by the excavation direction control unit of the excavator. Can be absorbed by interposing a universal joint as part of the rotating shaft, and the upper rotating shaft above the universal joint is
It does not move in the axial direction, and the displacement in the direction perpendicular to the axis of the lower rotary shaft below the universal joint can be absorbed by connecting the seal box and the cylindrical housing flexibly, and the upper rotary shaft above the universal joint can be absorbed. By providing a seal device with a pressure equalizing mechanism between lubricating oil and mud near the bearing, it is possible to prevent the leakage of lubricating oil and the intrusion of mud filled in the excavation direction control unit of the excavator for a long period of time. And reached the present invention.

That is, according to the present invention , a sealing device is provided at the upper and lower ends.
Is rotatably supported in a cylindrical housing with
Universal between the rotating shaft and the lower rotating shaft
Joint eccentrically in the direction perpendicular to the axis
Made of hollow center shaft with muddy water inside
Through the fluid of
In the drilling direction control device to which urchin arrangement, the upper rotary Shah
Top directly above the upper bearing supporting the shift via a bearing
An outer fitting annular spacer section rotating shaft, a seal mechanism which allowed interposed between said annular spacer and the upper rotary shaft, via the annular gap between the annular spacer and the cylindrical housing
And sliding due to the pressure difference between the lubricating oil below the annular gap and the muddy water above the annular gap enclosed in the excavation direction control mechanism ,
It is the plurality of the piston which is disposed a slit, drilling direction control unit a pressure equalization device for an excavator comprising a window hole in a cylindrical housing in opposition to the slit in the axial direction movement amount for confirmation on the outer peripheral surface .

[0010]

According to the pressure equalizing device of the present invention, an annular spacer externally fitted to an upper rotary shaft via a bearing directly above an upper bearing, a sealing mechanism interposed between the annular spacer and the upper rotary shaft, an annular spacer, Interposed in the annular gap with the cylindrical housing and sealed in the excavation direction control mechanism
Slides by a pressure difference between the mud of the lubricating oil and the annular gap above the annular gap lower, a piston disposed slit in the axial direction movement amount for confirmation on the outer peripheral surface, the cylindrical housing opposite the said slit It is provided with a window opening, when the lubricating oil sealed between the pressure equalizing device and the lower sealing unit by the hot at the bottom hole pressure expands rises, the piston lubricating oil pressure is outside along the annular spacer mud Slide upward until pressure equalizes. Furthermore, when the external mud pressure becomes high,
Conversely, the piston slides down along the annular spacer until the internal lubricating oil pressure equalizes the external mud pressure. Therefore, the internal pressure of the lubricating oil sealed between the pressure equalizing device and the lower seal device is equalized with the external muddy water pressure, and the differential pressure becomes almost zero. Can be prevented from entering.

Further, in the pressure equalizing device according to the present invention, a plurality of slits for confirming the amount of movement in the axial direction are provided on the outer peripheral surface of the piston, so that the position of the piston can be known from the window hole provided in the cylindrical housing. By setting the piston position when lubricating oil is filled between the pressure equalizer and the lower seal device, the capacity of the piston on the muddy water side and the capacity on the lubricating oil side can be arbitrarily changed according to changes in temperature and pressure. In addition, the capacity of the piston on the muddy water side and the capacity on the lubricating oil side can be calculated according to the environmental conditions of the pit bottom, and the piston can be set at a predetermined position. Further, as a seal mechanism interposed between the pressure equalizing device and the lower seal device, a combination of a mechanical seal and an O-ring can be used.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The details of the present invention will be described below with reference to FIGS. 1 is a schematic overall configuration diagram of the excavation direction control device of the present invention, FIG. 2 is a schematic overall configuration diagram of the excavation direction control device of the present invention in a state where the rotary shaft is eccentric, and FIG. , FIG.
1 is an overall sectional view of a pressure equalizing device. 1 and 2, reference numeral 1 denotes an upper rotating shaft of a rotary drilling rig,
Is a lower rotating shaft, which is connected to the upper rotating shaft 1 by a universal joint 3. Reference numeral 4 denotes a drill collar coaxially connected to the tip of the lower rotary shaft 2;
Is a drill bit fixed to the tip of the drill collar 4, and the upper rotary shaft 1 is connected to a rotary drive mechanism (not shown) at the upper part. Reference numeral 6 denotes a cylindrical housing arranged so as to surround the outer periphery of the upper and lower rotary shafts 1 and 2 above the drill collar 4, and a lower seal device 7 is provided between the tip of the cylindrical housing 6 and the lower rotary shaft 2. Have been.

Reference numeral 8 denotes a fulcrum bearing for receiving the load of the drill bit 5 provided between the cylindrical housing 6 above the lower sealing device 7 and the lower rotary shaft 2, and 9 denotes a cylindrical housing 6 above the fulcrum bearing 8 and the lower rotating shaft. A first circle having a circular inner peripheral surface eccentric with respect to the cylindrical housing 6 rotatably mounted on the inner peripheral surface of the cylindrical housing 6 by a double eccentric mechanism provided between the shaft and the shaft 2. An annular member 11 and a second annular member 12 rotatably mounted on a circular inner peripheral surface of the first annular member 11 and having a circular inner peripheral surface eccentric to the circular inner peripheral surface. Have been. 13 is a first harmonic gear reducer for rotating the first annular member 11 provided immediately above the double eccentric mechanism 9, and 14 is a double eccentric mechanism 9
A second harmonic reduction gear for rotating the second annular member 12 provided immediately below the second annular member 12. Reference numeral 15 denotes an upper bearing that supports the lower portion of the upper rotary shaft 1, and 16 denotes a pressure equalizing device between the upper portion of the cylindrical housing 6 and the upper rotary shaft 1.

In FIG. 3, reference numeral 21 denotes the lower rotating shaft 2.
, A seal box attached to the seal box 21 via a bearing 22, a mechanical seal 23 incorporated in an annular gap between the seal box 21 and the lower rotary shaft 2, a bellows holding member 24 attached to the seal box 21, and a cylindrical type 25. A bellows holding member attached to the lower inner periphery of the housing 6, a bellows 26 for connecting the bellows holding member 24 and the bellows holding member 25, and a seal box 21 through which the lower rotary shaft 2 screwed to the lower end of the cylindrical housing 6 passes. And a protective cover for the bellows 26. Double eccentric mechanism 9
The first and second annular members 11 and 12 are rotated by the first and second harmonic gear reducers 13 and 14, and the lower rotary shaft 2 is bent with respect to the cylindrical housing 6 around the fulcrum bearing 8. Then, the seal box 21 and the mechanical seal 23 are eccentric with respect to the cylindrical housing 6, but the bellows 26 is deformed to absorb this eccentric amount, so that the sealing function is not affected. Also,
The bellows 26 has a bellows holding member 24, 25 in which the connection between the cylindrical housing 6 and the seal box 21 is hermetically sealed, so that the lubricating oil sealed inside the excavation direction control device does not leak out. I have.

[0015] In FIG. 4, 41 top directly above the upper bearing 15
A tubular spacer externally fitted to the upper rotating shaft 1 via a pair of lower bearings 42; 43, a mechanical seal interposed between the annular spacer 41 and the upper rotating shaft 1; 44, an annular shape of the annular spacer 41 and the cylindrical housing 6 Pistons having seal packing seals 45 and 46 at both ends slidably installed in the gap and slits 47 for confirming the amount of axial movement provided at equal intervals on the outer peripheral surface are provided in the cylindrical housing 6. The position of the piston 44 can be known by checking the position of the slit 47 in the window hole for checking the slit 47. When the pressure of the lubricating oil 49 sealed inside the excavation direction control device becomes higher than the pressure of the muddy water 50 due to the high temperature at the pit bottom, the piston 44 is moved toward the muddy water 50 until the pressure of the lubricating oil 49 becomes equal to the pressure of the muddy water 50. The piston 44 is stopped when the pressure of the lubricating oil 49 and the pressure of the muddy water 50 are equalized.

Conversely, when the pressure of the mud 50 becomes higher than the pressure of the lubricating oil 49 sealed inside the excavation direction control device, the piston 44 moves the lubricating oil 49 until the pressure of the mud 50 becomes equal to the pressure of the lubricating oil 49. Pushed down to the side, muddy 5
When the pressure of 0 and the pressure of the lubricating oil 49 become equal, the piston 44 stops, and the pressure of the lubricating oil 49 sealed inside the excavation direction control device and the pressure of the muddy water 50 are balanced. Further, while confirming the position of the piston 44 through the window hole 48, the lubricating oil 49 is sealed and the piston 44 is
By changing the position of the lubricating oil 4 of the piston 44,
The capacity on the 9th side and the capacity on the muddy water 50 side can be changed arbitrarily, and the capacity on the lubricating oil 49 side and the capacity on the muddy water 50 side of the piston 44 are calculated in accordance with the environmental conditions of the pit bottom, and the piston 44 is moved to a predetermined position. It is configured to be set. Reference numeral 51 denotes a packing for dust seal.

With the above configuration, FIG.
The lubricating oil 49 tightly sealed on the ground in the annular gap between the lower seal device 7 shown in FIG.
When the pipe goes down to the bottom of the pit, it becomes high temperature and expands to generate a high pressure. It is pushed up to the muddy water 50 side and lubricating oil 4
When the pressure of 9 and the pressure of mud 50 become equal, the piston 44 stops. Also, when the pressure of the external mud 50 becomes higher than the pressure of the lubricating oil 49, the piston 44 moves toward the lubricating oil 49 until the pressure of the mud 50 becomes equal to the pressure of the lubricating oil 49. When the pressure of the mud 50 and the pressure of the lubricating oil 49 become equal, the piston 44 stops, and the pressure of the lubricating oil 49 sealed inside the excavation direction control device and the pressure of the mud 50 are balanced. Therefore, the lower sealing device 7 shown in FIG.
The pressure of the lubricating oil 49 densely sealed on the ground in the annular gap between the pressure equalizer 16 and the pressure equalizer 16 shown in FIG.
The leakage of the lubricating oil 49 from the lubricating oil 6 can be prevented, and the intrusion of the muddy water 50 into the lubricating oil 49 enclosure can be prevented.

Further, the first and second annular members 11 and 12 of the double eccentric mechanism 9 are rotated by the first and second harmonic reduction gears 13 and 14, and as shown in FIG.
When the lower rotary shaft 2 is bent with respect to the cylindrical housing 6 about the fulcrum bearing 8, the lower seal device 7 causes the seal box 21 and the mechanical seal 23 to be eccentric with respect to the cylindrical housing 6, but the bellows 26 is deformed. As a result, the eccentric amount is absorbed, and the sealing function of the mechanical seal 23 is not impaired, and the relative inclination between the lower rotary shaft 2 and the cylindrical housing 6 is absorbed by the bellows 26 of the lower seal device 7. be able to.

[0019]

As described above, the excavating direction control unit pressure equalizing device of the present invention can be used even when the excavating direction is changed by inclining the lower rotating shaft, so that the lower sealing device is provided between the lower rotating shaft and the cylindrical housing. The sealing function is not impaired, and the relative inclination can be absorbed by the bellows of the lower seal device, and the pressure of the lubricating oil sealed in the annular gap including the excavation direction control unit is evenly maintained with the muddy water pressure by the piston of the pressure equalizer It is possible to prevent the leakage of the lubricating oil from the lower seal device and the pressure equalizing device, prevent the intrusion of the muddy water into the lubricating oil sealing portion, and prevent the excavation direction control portion from being damaged.

[Brief description of the drawings]

FIG. 1 is a schematic overall configuration diagram of an excavation direction control device of the present invention.

FIG. 2 is a schematic overall configuration diagram showing a state in which a rotary shaft is decentered by the excavation direction control device of the present invention.

FIG. 3 is an overall sectional view of a lower sealing device.

FIG. 4 is an overall sectional view of the pressure equalizing device.

FIG. 5 is a schematic explanatory view of a drilling direction control device for an oil well drilling machine disclosed in Japanese Patent Application Laid-Open No. 5-202689.

[Explanation of symbols]

1 Upper rotary shaft 2 Lower rotary shaft 3 Universal joint 4 Drill collar 5, 106 Drill bit 6, 101 Cylindrical housing 7 Lower seal device 8, 108 Support point bearing 9 Double eccentric mechanism 11, 102 First annular member 12 , 103 Second annular member 13 First harmonic gear reducer 14 Second harmonic gear reducer 15 Upper bearing 16 Equalizing device 21 Seal box 22 Bearing 23, 43 Mechanical seal 24, 25 Bellows holding member 26 Bellows 27 protective cover 41 tubular spacer 42 bearing 44 piston 45 Pas Kkinshiru 47 slit 48 window hole 49 lubricating oil 50 mud 51 dust seal packing 104, 105 conditioner gear reducer

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int. Cl. ⁷ , DB name) E21B 44/00 E21B 17/04

Claims (1)

(57) [Claims] 1. A cylindrical housing having sealing devices at upper and lower ends.
Upper rotating shaft rotatably supported in jing and lower
Universal joint interposed between the rotating shaft
Center shaft that is eccentrically joined in the direction perpendicular to the axis
And the inside of it is dug through fluid such as muddy water.
In the drilling direction control device configured to discharge the excavated crushing that occurs when cutting the outer fitting the annular spacer in the upper rotating shaft through a bearing directly above the upper bearing supporting the upper rotating shaft, the annular spacer and the upper The seal mechanism interposed between the rotating shafts, the lubricating oil below the annular gap, and the upper part of the annular gap sealed in the digging direction control mechanism , interposed in the annular gap between the annular spacer and the cylindrical housing.
Slides by the pressure difference between the mud, a piston disposed a plurality of slits in the axial direction movement amount for confirmation on the outer peripheral surface, the
I and a window hole provided in the cylindrical housing opposite the slit
Drilling direction control unit a pressure equalization device that excavator.