JP3124701B2 - Hollow universal joint for excavator - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an excavator for controlling the excavation direction of an excavator such as an oil well or gas well excavator for preventing deflection due to a displacement in a direction perpendicular to an axis applied to a rotary shaft. The present invention relates to a hollow universal joint for a machine.

[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 in 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 harmonic transmission and rotated by the transmission, wherein the first and second annular members are rotatable relative to each other. The annular end faces are superimposed on each other, and these superimposed end faces are set as inclined surfaces inclined by a certain angle with respect to the center axis direction, and the first and second annular members have the same end faces. Place the rotating shaft of the drilling drill in a state penetrating the hollow part,
By relatively rotating these first and second annular members,
A device for bending the rotating shaft in a predetermined direction (Japanese Patent Application Laid-Open
As shown in FIG. 8, a cylindrical housing 101, and a circular housing 101 rotatably supported on a circular inner peripheral surface of the cylindrical housing 101 and eccentric with respect to the cylindrical housing 101. A first annular member 102 having an inner peripheral surface, and the first annular member 1
02, a second annular member 103 rotatably supported on the circular inner peripheral surface and having a circular inner peripheral surface eccentric with respect to the circular inner peripheral surface; Of the hollow type harmonic gear reducers 104, 1 for relatively rotating the annular members 102, 103 around the center of those members.
05, the amount of eccentricity of the circular inner peripheral surface of the first annular member 102 with respect to the cylindrical housing 101, and the amount of eccentricity of the second annular member 103 with respect to the first annular member 102. The rotary shaft 107 having a drill bit 106 at the tip so as to move integrally with the center of the circular inner peripheral surface of the second annular member 103 is set so that the amount of eccentricity of the peripheral surface is equal. A fulcrum above the first and second annular members 102, 103 by being connected to the second annular member 103 and relatively rotating the first and second annular members 102, 103. Apparatus for positioning the rotary shaft 107 with a bearing 108 as a fulcrum (Japanese Patent Laid-Open No. 5-202689).
Proposals such as have been made.

The above-mentioned JP-A-4-76183, JP-A-5-149079 and JP-A-5-202689
In the excavation direction control device disclosed in Japanese Patent Laid-Open Publication No. H10-210, the fulcrum of the bending of the rotary shaft is a shaft holding mechanism on the upper portion of the excavation direction control device, and there is a concern that the bending given to the rotation shaft may cause breakage due to excessive bending stress. . The deflection imparted to the rotating shaft when changing the excavation direction of the excavator,
If a universal joint is interposed in the maximum bending stress generating portion of the rotating shaft and absorbed, the breakage of the rotating shaft due to excessive bending stress can be prevented.

[0006]

However, the conventional universal joint connects two eccentric drive shafts used for a drive shaft of a rotary machine or the like and only transmits rotational power. There is no known structure such as a drill pipe used in a place where a fluid flows inside.

[0007] An object of the present invention is to provide a hollow universal joint for an excavator capable of eliminating the deflection imparted to the rotary shaft by the above-described excavation direction control device and preventing the muddy water flowing inside the rotary shaft from flowing out of the rotary shaft. It is in.

[0008]

Means for Solving the Problems The present inventors have conducted extensive trial production tests in order to achieve the above object. As a result, a through hole is provided at the center of the cross pin that connects the hollow yoke and the hollow center shaft having a hollow yoke at both ends, and a connection portion between the hollow yoke and the hollow yoke at both ends of the hollow center shaft and the cross pin is provided. By inserting and sealing the seal tube inside, it is possible to absorb the deflection given to the rotating shaft and to prevent the muddy water flowing inside the rotating shaft from flowing out to the outside,
The invention has been reached.

[0009] That is, the present invention includes an upper rotating shaft
Hollow sensor that is eccentrically joined to the lower rotating shaft
Made of fluid, such as muddy water.
It is configured to discharge drilling debris generated during drilling.
In the excavation direction control device, an upper rotating shaft having a lower yoke connected to a hollow yoke, a hollow center shaft having an upper and lower hollow yoke connected, and a lower rotating shaft having a hollow yoke connected to the upper end. the hollow center between and between the lower rotating shaft and the hollow center shaft of the shaft has a through hole in its central portion, and a hollow connecting portions inside drilling linked watertight with cross pin inserted and fitted seal tube cutting machine and It is a universal joint.

[0010]

The hollow universal joint for an excavator according to the present invention is provided with a through hole in the center of the cross pin, and between the hollow yoke of the upper rotary shaft and the hollow yoke at the upper end of the hollow center shaft and the hollow of the lower rotary shaft. Between the yoke and the hollow yoke at the lower end of the hollow center shaft, by inserting a seal tube inside the connection portion and connecting it in a watertight manner, even if the axes of the vertical rotating shaft and the hollow center shaft are shifted, It is possible to prevent the fluid flowing through each hollow from flowing out of the hollow yoke of the vertically rotating shaft and the connecting portions of the hollow yoke and the cross pin at both ends of the hollow center shaft to the outside.

In the present invention, the seal tube is made of an elastic material such as synthetic rubber, and the synthetic rubber is made of urethane rubber, nitrile rubber or the like. In mounting the seal tube according to the present invention, both ends of the seal tube are caulked to a vertical rotating shaft and a hollow center shaft and fixed with an adhesive or the like. Attach to absorb by the elasticity of the tube.

[0012]

【Example】

Embodiment 1 Hereinafter, details of the present invention will be described with reference to FIGS. 1 to 6 showing an embodiment. FIG. 1 is a schematic overall configuration diagram of an excavation direction control device having a hollow universal joint according to the present invention, FIG. 2 is a schematic overall configuration diagram of a state in which a rotary shaft is eccentric with the excavation direction control device having a hollow universal joint according to the invention, 3 is a side view of a connecting portion of the hollow universal joint of the present invention, FIG. 4 is an enlarged sectional view of a seal tube attaching portion, and FIG. 5 is a schematic diagram in which the hollow universal joint of the present invention is applied to a drilling direction control device of an oil well drilling machine. FIG. 6 is a schematic explanatory view when the connection angle of the hollow universal joint is changed. 1 and 2, reference numeral 1 denotes an upper rotary shaft of a rotary excavator, 2 denotes a lower rotary shaft, and an upper rotary shaft 1.
And a cross pin having a through hole in the center through a hollow center shaft 3 by a hollow universal joint,
A seal tube is inserted and fitted for hermetic connection. Reference numeral 4 denotes a drill collar coaxially connected to the tip of the lower rotary shaft 2, and reference numeral 5 denotes 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 7 is provided between the lower end of the cylindrical housing 6 and the lower rotary shaft 2. An upper seal 8 and a bearing 9 are provided between the upper part of the cylindrical housing 6 and the upper rotary shaft 1. Reference numeral 10 denotes a fulcrum bearing for receiving the load of the drill bit 5 provided between the cylindrical housing 6 above the lower seal 7 and the lower rotary shaft 2, and 11 denotes a cylindrical housing 6 above the fulcrum bearing 10.
A double eccentric mechanism provided between the lower rotary shaft 2 and the lower rotary shaft 2 is provided by two eccentric plates 12 and 13 rotatably supported on the inner peripheral surface of the cylindrical housing 6.
Is displaced in the direction perpendicular to the axis about the fulcrum bearing 10.

3 to 6, reference numeral 21 denotes a first hollow yoke connected to the lower end of the upper rotary shaft 1, reference numeral 22 denotes a first cross pin, and a through hole 23 is provided in the center. 24 are bolts 25 above and below the first hollow yoke 21.
A thrust needle 26 and a roller 27 are provided between the bearing case and the first cross pin 22.
Is provided. Reference numeral 28 denotes a bearing case fixed by bolts 29 to the left and right sleeves of the hollow center shaft 3 which will be described later. A thrust needle and rollers (not shown) are provided between the bearing case 28 and the first cross pin 22 as described above.

Reference numeral 30 denotes a flexible first fitting which is inserted into a through hole 23 of the cross pin 22 at a connection portion between the first hollow yoke 21, the hollow center shaft 3 and the first cross pin 22.
One end of which is fixed to an inner peripheral groove 31 provided on the inner surface of the first hollow yoke 21 by an adhesive. The other end of the first seal tube 30 is fixed and sealed by an adhesive in an inner peripheral groove 32 provided at an end of the hollow center shaft 3. Reference numeral 33 denotes a sleeve that has a ridge 35 that engages with the axial outer circumferential groove 34 of the hollow center shaft 3, and is slidable in the axial direction of the hollow center shaft 3. The bearing case 28 is fixed to the left and right by bolts 29. ing. Muddy water flowing from the upper rotating shaft 1 to the inner surfaces of the hollow yoke 21 and the hollow center shaft 3 is fitted into the through hole 23 of the first cross pin 22 at the connection between the first hollow yoke 21 and the hollow center shaft 3. First
And the first seal tube 30
Even if the connection angle between the hollow yoke 21 and the hollow center shaft 3 is changed, the hermetic force is absorbed by the elasticity of the first seal tube 30 and the hermetic seal is maintained, and the connection between the first hollow yoke 21 and the hollow center shaft 3 is maintained. The expansion and contraction due to the change of the connection angle is configured to be absorbed by the sliding of the sleeve 33.

Reference numeral 36 denotes a second hollow yoke connected to the upper end of the lower rotary shaft 2, and reference numeral 37 denotes a second cross pin, which has a through hole 38 at the center similarly to the first cross pin 22. Reference numeral 39 denotes a bearing case fixed by bolts 40 above and below the second hollow yoke 36.
A thrust needle 41 and a roller 42 are provided between the thrust needle 41 and the roller 42. Reference numeral 43 denotes a bearing case fixed to the left and right sides of the hollow center shaft 3 by bolts 44. A thrust needle and rollers (not shown) are provided between the bearing case 43 and the second cross pin 37 as described above. Reference numeral 45 denotes a second seal tube which is inserted into the through hole 38 of the cross pin 37 at the connection between the second hollow yoke 36, the hollow center shaft 3 and the second cross pin 37, and is provided on the inner surface of the hollow center shaft 3. Inner circumferential groove 46
Is fixed by an adhesive. The other end of the second seal tube 45 is fixedly adhered to an inner peripheral groove 47 provided at an end of the second hollow yoke 36 with an adhesive, and a connection angle between the second hollow yoke 36 and the hollow center shaft 3 is formed. Even if is changed, it is configured to be absorbed by the elasticity of the second seal tube 45 and to maintain the hermeticity.

With the above configuration, the upper rotary shaft 1, the through hole 23 of the first cross pin 22,
Muddy water flowing through the hollow center shaft 3, the through hole 38 of the second cross pin 37, and the lower rotating shaft 2
The first and second seal tubes 30 and 45 inserted into the through holes 23 and 38 of the first and second cross pins 22 and 37 of the universal joint are hermetically sealed, and the cylindrical housing 6 and the vertically rotating shafts 1 and 2 are sealed. Does not leak into the gap. When the excavation direction is changed, as shown in FIG. 2, the two eccentric plates 1 of the double eccentric mechanism 11 are used.
The lower rotary shaft 2 is displaced in the direction perpendicular to the axis about the fulcrum bearing 10 by the two and 13, but the deflection of the lower rotary shaft 2 imparted by the double eccentric mechanism 11 is interposed at both ends of the hollow center shaft 3. Since it is absorbed by the first and second cross pins 22 and 37 of the universal joint, no bending stress is applied to the upper lower rotary shaft 2 from the double eccentric mechanism 11 and the hollow center shaft 3 and the upper rotary shaft are rotated. The fatigue life of the shaft 1 is dramatically improved.

Further, the first and second hollow yokes 2
1, 36 and the through holes 23 of the first and second cross pins 22, 37 interposed at both ends of the hollow center shaft 3;
38, the first and second seal tubes 30,
45 is fixedly sealed in the inner circumferential grooves 31, 47 of the first and second hollow yokes 21, 36 and the inner circumferential grooves 32, 46 at both ends of the hollow center shaft 3, so that muddy water flowing inside the shafts is cylindrical. There is no leakage to the gap between the mold housing 6 and the lower rotary shaft 2 and the hollow center shaft 3. Also, the first and second hollow yokes 21, 36
When the connection angle between the first and second cross pins 22 and 37 is changed, the connection angle between the first and second cross pins 22 and 37 is changed.
First and second seal tubes 3 inserted into the third and third 38
Nos. 0 and 45 are deformed by elasticity but maintain the seal.

Furthermore, the thrust force of the rotor of the rotary shaft driving mud motor connected above the cylindrical housing 6 acts downward during excavation. The deflection of the rotating shaft when displaced in the
First and second cross pins 22 interposed at both ends,
Since it is absorbed by 37 parts, the upper rotating shaft 1 connected to the upper part of the hollow center shaft 3 does not move in the axial direction. Therefore, since the bearing 9 can use a thrust bearing that receives the thrust force of the rotor of the mud motor, the thrust force of the rotor of the mud motor is not transmitted to the lower rotary shaft 2 below the hollow center shaft 3 but is higher than the fulcrum bearing 10. A large thrust force does not act on the small diameter portion of the lower rotating shaft 2, which is advantageous for the fatigue strength of the shaft.

Embodiment 2 As shown in FIG. 7A, the upper rotating shaft 7 of the excavator
1 and the lower rotary shaft 72, the hollow center shaft 7
3, the upper rotating shaft 71 and the lower rotating shaft 72 are connected by a universal joint.
The finite element method (Finite
Element Method Analysis Model
The stress analysis of each part shown in (a) was performed. The result is shown in FIG.
(B). In FIG. 7A, 74 is a drill collar, 75 is a drill bit, 76 is a cylindrical housing,
Reference numeral 7 denotes a lower seal, 78 denotes a bearing, 79 denotes a fulcrum bearing, and 80 denotes a double eccentric mechanism unit including two eccentric plates 81 and 82. The upper rotating shaft 71 and the lower rotating shaft 72 are
When connected by a universal joint via the hollow center shaft 73, the bending of the rotary shaft imparted by the double eccentric mechanism 80 is limited to the hollow center shaft 7
7 is absorbed by the universal joints at both ends, so that the rotating shaft at the upper part
As indicated by A in (b), no bending stress is generated, and the fatigue life of the hollow center shaft 73 and the upper rotating shaft 71 is significantly improved. On the other hand, when the upper rotary shaft 71 and the lower rotary shaft 72 are connected by a screw-connected hollow flexible joint, a maximum stress of 58 kgf / mm ² is generated at the hollow flexible joint as shown by B in FIG. 7B. are doing.

[0020]

As described above, the hollow universal joint for an excavator according to the present invention can prevent the fluid flowing through the hollow portion from leaking to the outside. In addition, the bending stress of the rotating shaft is greatly reduced, and the fatigue life of the rotating shaft is dramatically improved.

[Brief description of the drawings]

FIG. 1 is a schematic overall configuration diagram of an excavation direction control device having a hollow universal joint according to the present invention.

FIG. 2 is a schematic overall configuration diagram of a state in which a rotary shaft is eccentric in a digging direction control device having a hollow universal joint according to the present invention.

FIG. 3 is a side view of a connection portion of the hollow universal joint according to the present invention.

FIG. 4 is an enlarged sectional view of a seal tube mounting portion.

FIG. 5 is a schematic explanatory view in which the hollow universal joint of the present invention is applied to a drilling direction control device of an oil well drilling machine.

FIG. 6 is a schematic explanatory view when the connection angle of the hollow universal joint is changed.

FIG. 7 is a stress diagram based on a finite element method analysis model,
(A) is an explanatory view of the stress analysis position of the drilling direction control device of the oil well drilling machine, and (b) is a graph showing the relationship between the distance from the upper bearing and the stress.

FIG. 8 is a schematic explanatory view of an excavation direction control device for an oil well excavator disclosed in Japanese Patent Application Laid-Open No. 5-202689.

[Explanation of symbols]

 1, 71 Upper rotating shaft 2, 72 Lower rotating shaft 3, 73 Hollow center shaft 4, 74 Drill collar 5, 75, 106 Drill bit 6, 76, 101 Cylindrical housing 7, 77 Lower seal 8 Upper seal 9, 78 Bearing 10, 79, 108 Support point bearing 11, 80 Double eccentric mechanism 12, 13, 81, 82 Eccentric plate 21 First hollow yoke 22 First cross pin 23, 38 Through hole 24, 28, 39, 43 Bearing case 25 , 29, 40, 44 Bolt 26, 41 Thrust needle 27, 42 Roller 30 First seal tube 31, 32, 46, 47 Inner circumferential groove 33 Sleeve 34 Outer circumferential groove 35 Protrusion 36 Second hollow yoke 37 Second Cross pin 45 Second seal tube 102 First annular member 103 Second annular member 104, 105 Harmonic gear reducer 107 Rotary shaft A Hollow universal joint B Hollow flexible joint

Continuation of the front page (58) Field surveyed (Int.Cl. ⁷ , DB name) E21B 17/04 E21B 7/08

Claims (1)

(57) [Claims] 1. An upper rotating shaft and a lower rotating shaft.
From a hollow center shaft that is eccentrically joined between
Generated during excavation by passing fluid such as mud
Excavation direction control device configured to discharge excavating crushing
In the upper rotating shaft connecting a hollow yoke at the lower end, a hollow center shaft connecting a hollow yoke up and down, and a lower rotating shaft connecting a hollow yoke to the upper end, the upper rotating shaft and the hollow center shaft between and between the lower rotating shaft and the hollow center shaft has a through hole in its central portion, and a hollow universal joint for connecting the drilling machine watertight with cross pin inserted and fitted to seal the tube within the connection portion.