Anti-reverse screw drill

Abstract

The invention relates to an anti-reversion screw drill which comprises a stator and rotor motor assembly, a universal shaft assembly, an anti-reversion pup joint and a transmission shaft assembly which are connected in sequence. The two ends of the anti-reverse short circuit are fixedly connected with shells of the universal shaft assembly and the transmission shaft assembly respectively; the device further comprises a one-way clutch. An outer ring of the one-way clutch is connected with the anti-reversion pup joint in an eccentric mode, and an inner ring of the one-way clutch is connected with a transmission shaft in the transmission shaft assembly through a key; the one-way clutch is sealed between the anti-reversion pup joint and the transmission shaft by a sealing structure, so that the one-way clutch is positioned in an oil bath of the sealed cavity; according to the anti-reverse-rotation screw drill, the anti-reverse-rotation function of the rotor can be achieved, the purpose that after the stator is abraded, the drill can continue to work without being pulled out of the drill is achieved, and due to the specific anti-reverse-rotation structure, the anti-reverse-rotation screw drill has the advantages of being large in non-return torque, high in adaptive rotating speed and long in service life.

Description

Technical Field

[0001] The invention belongs to the technical field of oil and natural gas exploitation, and in particular relates to an anti-reversal screw drill. Background Art

[0002] As a downhole power tool, screw drill is widely used in the field of oil drilling engineering, providing downhole power and wellbore trajectory control for drilling directional wells and horizontal wells. The size and durability of its power output directly affect the efficiency of drilling. The screw drill provides downhole power by compressing the drilling fluid or gas to the rotor of the downhole drive motor to rotate in the stator. The stator and rotor of the motor are the core components of power conversion; the rotor is a multi-head multi-stage spiral steel rotating body, and the stator is a rubber spiral cavity with one more head than the rotor. The stator and rotor teeth are both left-handed, and the two are meshed with each other. Under pressure, the rotor rotates clockwise (from top to bottom). The rotational motion is transmitted to the output end of the lower drive shaft through the universal shaft assembly and the drive shaft assembly, driving the drill bit connected to it to perform rock breaking drilling operations.

[0003] Under the condition of composite drilling, the drilling rig drives the drill pipe to rotate clockwise, and drives the stator housing of the screw drill to rotate clockwise. Driven by drilling fluid or gas, the motor's rotor rotates clockwise relative to the stator; in this way, the rotor relative to the drill pipe is the superposition of the two, that is, the rotor speed is equal to the drill pipe speed plus the motor speed, and the rotor then transmits the speed to the output end of the drive shaft through the universal shaft assembly and the drive shaft assembly to drive the drill bit to break the rock. After a period of use, the stator rubber wears, the sealing effect of the rotor and the stator gradually weakens, the motor mud or air medium leaks, the motor speed gradually decreases, and the output speed of the drive shaft also decreases accordingly; gradually, the motor leakage increases further, and the motor output speed will change from positive to negative, that is, the motor reverses from clockwise to counterclockwise; until finally, the motor reversal speed is equal to the driving speed provided by the drill pipe, but in the opposite direction, and the final output speed of the drive shaft is zero, and the power output is completely lost, causing the drilling operation to stagnate. Therefore, in order to solve the above problems, it is necessary to study a drilling tool that can prevent the rotor from reversing so that the output end of the transmission shaft can still rotate under the drive of the drill pipe even when the motor is not working, so that the drilling operation can proceed smoothly. Summary of the invention

[0004] The present invention solves the technical problem by adopting the following technical solutions:

[0005] An anti-reverse screw drill comprises a stator-rotor motor assembly, a universal shaft assembly, an anti-reverse short circuit, and a transmission shaft assembly which are connected in sequence; the two ends of the anti-reverse short circuit are fixedly connected to the outer shells of the universal shaft assembly and the transmission shaft assembly respectively;

[0006] It also includes a one-way clutch; the outer ring of the one-way clutch is eccentrically connected to the anti-reverse short circuit, and the inner ring of the one-way clutch is connected to the transmission shaft in the transmission shaft assembly through a key;

[0007] The one-way clutch is sealed between the anti-reverse short circuit and the transmission shaft by a sealing structure, so that the one-way clutch is in an oil bath in the sealing cavity.

[0008] Furthermore, the sealing structure includes an upper sealing body, a lower sealing body, and a lower short section; one end of the lower short section is fixedly connected to the housing of the transmission shaft assembly, the upper sealing body is arranged between the anti-reverse short circuit and the transmission shaft, and the lower sealing body is arranged between the transmission shaft and the lower short section, so that a sealed cavity is formed between the transmission shaft, the housing of the transmission shaft assembly, the anti-reverse short circuit, and the lower short section through the upper sealing body and the lower sealing body.

[0009] Furthermore, the sealing cavity is filled with lubricating oil.

[0010] Furthermore, one end of the anti-reverse short circuit is connected to the universal shaft housing in a threaded manner, and the universal shaft housing is sequentially connected to the stator housing of the stator-rotor motor assembly, the anti-drop short circuit, and the bypass valve assembly, and finally connected to the drill pipe.

[0011] Furthermore, the transmission shaft is connected to the universal shaft assembly and the rotor of the stator-rotor motor assembly in sequence upward through threads, and the transmission shaft is directly connected to the drill bit downward.

[0012] Furthermore, the TC radial bearing and the multi-row angular contact ball bearing of the transmission shaft assembly are both in an oil bath in the sealed cavity.

[0013] Furthermore, the rotational power is transmitted from the drill pipe to the stator through a threaded connection, in sequence through the bypass valve assembly, the anti-drop short circuit, and the stator-rotor motor assembly. The rotor generates a rotational motion relative to the housing of the stator-rotor motor assembly under the pressure of the driving medium, and is transmitted to the output end of the transmission shaft through the universal joint assembly and the transmission shaft assembly, outputting rock-breaking power to the connected drill bit.

[0014] The advantages and positive effects of the present invention are:

[0015] The anti-reverse screw drill of the present invention can realize the anti-reverse function of the rotor, so as to achieve the purpose of being able to continue working without drilling after the stator is worn. Its unique anti-reverse structure enables it to have the advantages of large reverse torque, high adaptability to speed and long service life. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] The technical solution of the present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments, but it should be understood that these drawings are designed only for explanation purposes and are not intended to limit the scope of the present invention. In addition, unless otherwise specified, these drawings are intended only to conceptually illustrate the structural configurations described herein and are not necessarily drawn to scale.

[0017] Figure 1 A structural cross-sectional view of an anti-reversal screw drill provided by an embodiment of the present invention;

[0018] Figure 2 A schematic diagram of the rotation direction of the stator and rotor of the screw drill motor of the anti-reverse screw drill provided in an embodiment of the present invention;

[0019] FIG. 3 is a structural diagram of a roller-type one-way clutch provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0020] First of all, it should be noted that the specific structure, features and advantages of the present invention will be specifically described below by way of example, but all descriptions are only for illustration and should not be understood as limiting the present invention in any way. In addition, any single technical feature described or implied in the embodiments mentioned herein, or any single technical feature displayed or implied in the drawings, can still be combined or deleted between these technical features (or their equivalents) to obtain more other embodiments of the present invention that may not be directly mentioned in this document. In addition, in order to simplify the drawings, the same or similar technical features may be marked only in one place in the same drawing.

[0021] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application may be combined with each other.

[0022] like Figure 1 As shown, an anti-reverse screw drill provided in this embodiment includes a stator-rotor motor assembly, a universal shaft assembly 6, an anti-reverse short circuit 7, and a transmission shaft assembly 11 connected in sequence; the two ends of the anti-reverse short circuit are fixedly connected to the outer shells of the universal shaft assembly and the transmission shaft assembly respectively;

[0023] It also includes a one-way clutch 9; the outer ring of the one-way clutch 9 is connected to the anti-reverse short circuit 7 in an eccentric manner, and the inner ring of the one-way clutch 9 is connected to the transmission shaft 15 in the transmission shaft assembly through a key;

[0024] The one-way clutch in the present invention adopts a roller-type single-phase clutch. The one-way clutch 9 is sealed between the anti-reverse short circuit 7 and the transmission shaft 15 by a sealing structure, so that the one-way clutch 9 is in an oil bath in the sealed cavity, which makes the one-way clutch always work in the sealed oil, with a good operating environment and a long service life.

[0025] Specifically, Figure 1 As shown, the sealing structure includes an upper sealing body 8, a lower sealing body 14, and a lower short section 13; one end of the lower short section is fixedly connected to the housing of the transmission shaft assembly 11, the upper sealing body is arranged between the anti-reverse short circuit and the transmission shaft, and the lower sealing body is arranged between the transmission shaft and the lower short section 13, so that a sealing cavity is formed between the transmission shaft, the housing of the transmission shaft assembly, the anti-reverse short circuit, and the lower short section through the upper sealing body 8 and the lower sealing body 14; the sealing cavity is filled with lubricating oil.

[0026] One end of the anti-reverse short circuit 7 is connected to the universal shaft housing in a threaded manner, and the universal shaft housing is sequentially connected to the stator housing of the stator-rotor motor assembly, the anti-drop short circuit 3, the bypass valve assembly 2, and finally connected to the drill pipe 1.

[0027] The transmission shaft 15 is connected to the universal shaft assembly 6 and the rotor 5 of the stator-rotor motor assembly in sequence upward through threads, and the transmission shaft 15 is directly connected to the drill bit downward.

[0028] In addition, the TC radial bearing 10 and the multi-row angular contact ball bearing 12 of the transmission shaft assembly 11 are both in an oil bath in the sealed cavity, so that they are not eroded by the mud medium, thereby increasing the service life of each component.

[0029] The rotational power is transmitted from the drill pipe to the motor stator 4 through a threaded connection, through the bypass valve assembly, the anti-drop short circuit, and the stator-rotor motor assembly in sequence. The rotor generates a rotational motion relative to the stator-rotor motor assembly housing under the pressure of the driving medium, and is transmitted to the output end of the transmission shaft through the universal joint assembly and the transmission shaft assembly, outputting rock breaking power to the connected drill bit.

[0030] During compound drilling, the drilling rig drives the drill pipe to rotate in a clockwise direction (from top to bottom, the same as the rest), and the drill pipe 1 drives the bypass valve assembly 2, the anti-drop short circuit 3 and the motor stator 4 of the screw drilling tool to rotate clockwise; the screw drilling tool rotor 5 rotates clockwise around the stator 4 under the pressure of the drilling fluid or gas, and the speed of the rotor 5 is the superposition of the two (such as Figure 2 ); the rotational motion of the rotor 5 is transmitted to the transmission shaft assembly 11 through the universal joint assembly 6, and then output to the bottom end through the transmission shaft 15 to drive the drill bit to rotate and break the rock; when the rubber of the screw drill stator 4 is worn too much, the drilling fluid or gas is not enough to drive the rotor 5 to rotate, and even a reverse trend (counterclockwise) is generated under the resistance of the drill bit cutting the rock. At this time, the one-way clutch installed in the anti-reverse short-circuit 7 works to prevent the transmission shaft 15 connected to the inner ring and the anti-reverse short-circuit connected to the outer ring from rotating relative to each other, that is, to prevent the transmission shaft 15 from reversing, and the transmission shaft 15 and the rotor 5 are threadedly connected through the universal joint assembly, which also prevents the rotor from reversing.

[0031] like Figure 3(a) ,3(b) As shown, the outer ring of the roller-type one-way clutch 9 is connected to the anti-reverse short-circuit 7 in an eccentric manner, and the anti-reverse short-circuit 7 is then connected to the universal shaft housing, the motor stator housing, the anti-drop short-circuit, and the bypass valve assembly housing in a threaded manner, and finally connected to the drill pipe; the inner ring of the roller-type one-way clutch 9 is connected to the transmission shaft 15 through a key, and the transmission shaft 15 is connected to the universal shaft assembly 6 and the rotor 5 in sequence upward through threads; and is directly connected to the drill bit downward.

[0032] The anti-reverse screw drill of the present invention adds a roller-type one-way clutch between the transmission shaft assembly and the universal shaft assembly to ensure that the speed of the rotor is always positive with respect to the stator, that is, the rotor always rotates clockwise relative to the stator; when the stator rubber is seriously worn, the one-way clutch takes effect to ensure that the relative speed between the rotor and the stator is zero, and the output of the final transmission shaft is the drill pipe driving speed, ensuring that the drilling operation can continue; the roller-type one-way clutch needs to work in an environment with good lubrication conditions. The sealing structure designed by the present invention adopts a split layout, which increases the radial design space of the one-way clutch and also increases the volume of the lubricating oil cavity, making lubrication more reliable. The anti-reverse structure has a long service life. While providing a wider design space for the roller-type one-way clutch, it also ensures that the TC radial bearing and the multi-row radial angular contact ball bearing in the transmission shaft assembly are located in a large lubricating liquid cavity;

[0033] In more detail, the outer ring of the roller type one-way clutch is connected to the anti-rotation short section through an eccentric connection, that is, the eccentricity of the outer ring of the one-way clutch corresponds to the deflection on the inner wall of the anti-reverse short section, and the two do not rotate relatively after being assembled together, which plays the role of a fixing key; the inner ring of the roller type one-way clutch and the transmission shaft are connected by a key, that is, the inner ring and the transmission shaft are guaranteed to rotate as a whole, and the upper end of the transmission shaft is connected to the universal joint and the rotor through a thread, so that a one-way locking mechanism is formed between the rotor of the motor and the drill pipe; in addition, a support bearing is placed next to the roller type one-way clutch to support and fix the one-way clutch.

[0034] The above embodiments describe the present invention in detail, but the contents are only preferred embodiments of the present invention and cannot be considered to limit the scope of the present invention. All equivalent changes and improvements made within the scope of the present invention should still fall within the scope of the present invention.

Claims

1. An anti-reverse screw drill, characterized in that: It includes a stator-rotor motor assembly, a universal shaft assembly, an anti-reverse short circuit, and a transmission shaft assembly which are connected in sequence; the two ends of the anti-reverse short circuit are fixedly connected to the outer shells of the universal shaft assembly and the transmission shaft assembly respectively; It also includes a one-way clutch; the outer ring of the one-way clutch is eccentrically connected to the anti-reverse short circuit, and the inner ring of the one-way clutch is connected to the transmission shaft in the transmission shaft assembly through a key; The one-way clutch is sealed between the anti-reverse short circuit and the transmission shaft by a sealing structure, so that the one-way clutch is in an oil bath in the sealing cavity.

2. The anti-reverse screw drill according to claim 1, characterized in that: The sealing structure includes an upper sealing body, a lower sealing body, and a lower short section; one end of the lower short section is fixedly connected to the housing of the transmission shaft assembly, the upper sealing body is arranged between the anti-reverse short circuit and the transmission shaft, and the lower sealing body is arranged between the transmission shaft and the lower short section, so that a sealed cavity is formed between the transmission shaft, the housing of the transmission shaft assembly, the anti-reverse short circuit, and the lower short section through the upper sealing body and the lower sealing body.

3. The anti-reverse screw drill according to claim 1, characterized in that: One end of the anti-reverse short circuit is connected to the universal shaft housing in a threaded manner, and the universal shaft housing is sequentially connected to the stator housing of the stator-rotor motor assembly, the anti-drop short circuit, the bypass valve assembly, and finally connected to the drill pipe.

4. The anti-reverse screw drill according to claim 1, characterized in that: The transmission shaft is connected to the universal shaft assembly and the rotor of the stator-rotor motor assembly in sequence upward through threads, and the transmission shaft is directly connected to the drill bit downward.

5. The anti-reverse screw drill according to claim 3, characterized in that: The rotational power is transmitted to the stator by the drill pipe through a threaded connection, the bypass valve assembly, the anti-drop short circuit, and the stator-rotor motor assembly in sequence. The rotor generates a rotational motion relative to the housing of the stator-rotor motor assembly under the pressure of the driving medium, and is transmitted to the output end of the transmission shaft through the universal joint assembly and the transmission shaft assembly, outputting rock-breaking power to the connected drill bit.

6. The anti-reverse screw drill according to claim 2, characterized in that: The sealing cavity is filled with lubricating oil.

7. The anti-reverse screw drill according to claim 6, characterized in that: The TC radial bearings and multi-row angular contact ball bearings of the transmission shaft assembly are both in an oil bath in the sealed cavity.

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