A screw motor connection anti-tipping device

Abstract

This invention discloses an anti-backlash device for the connection of a screw motor, relating to the field of oil drilling technology. It includes a drive shaft, a connector, a stator, and a nut. One end of the drive shaft is threaded with a nut, and a connector is located outside the nut. A stator is located outside the drive shaft. An anti-backlash assembly is provided at the connection between the drive shaft and the nut. This assembly prevents the nut from loosening and backlashing. Several torque transmission components are located at one end of the anti-backlash assembly, arranged in a ring array outside the assembly. These components transmit the torque from the drive shaft to the anti-backlash assembly. Sealing and buffering components are located at both ends of the anti-backlash assembly. When sudden situations such as well slippage or stuck drill occur downhole, the device can convert the impact torque into rotational kinetic energy, greatly blocking the transmission of reverse torque and solving the problem of nut backlash and disengagement.

Description

Technical Field

[0001] This invention relates to the field of oil drilling technology, specifically to an anti-backlash device for the connection part of a screw motor. Background Technology

[0002] Screw motors are a type of positive displacement hydraulic motor. Their core working logic is to utilize the energy conversion of high-pressure fluid downhole to achieve mechanical energy output, providing power for downhole drilling, well workover, and other operations.

[0003] The existing screw motor assembly adopts an integrated anti-drop structure with a nut. This structure has obvious design flaws and safety hazards under complex downhole operating conditions. The specific problems are as follows: During downhole operations, the motor operation will generate continuous vibration and impact loads. At the same time, due to the scouring effect of high-pressure fluid, a continuous force will be exerted on the integrated anti-drop nut. When the motor falls into the well or other emergencies occur, the rotor torque and external impact force will directly act on the integrated nut, which is prone to back-threading or disengagement of the nut. This will cause the connection between the motor assembly and related downhole components to fail, and the components will fall into the well. This will not only damage the equipment and affect the progress of the operation, but may also cause serious safety accidents such as stuck drill bit and well wall collapse. The overall reliability is low and cannot meet the safety protection requirements of complex downhole operations. Summary of the Invention

[0004] This invention overcomes the shortcomings of the prior art and proposes an anti-backlash device for the connection part of a screw motor to solve the problem of backlash or disengagement of the nut caused by sudden external events that cause the rotor torque and external impact force to act directly on the integrated nut.

[0005] This invention is achieved through the following technical solution: A screw motor connection anti-backlash device includes a drive shaft, a connector, a stator, and a nut. One end of the drive shaft is threaded with a nut, and a connector is located outside the nut. A stator is located outside the drive shaft. An anti-backlash assembly is provided at the connection between the drive shaft and the nut to prevent the nut from loosening and backlashing. One end of the anti-backlash assembly has several torque transmission components arranged in a ring array outside the anti-backlash assembly to transmit torque from the drive shaft to the anti-backlash assembly. Both ends of the anti-backlash assembly have sealing buffer components to buffer and seal the pressure borne by the anti-backlash assembly. The anti-backlash assembly includes a bearing mounted on the outside of one end of the drive shaft, and a washer is fitted onto the outside of the bearing.

[0006] Furthermore, the anti-tipping assembly also includes several arc-shaped flow channels, which are used to guide the liquid flow. The several arc-shaped flow channels are formed in a ring array on the outer sidewall of the gasket.

[0007] Furthermore, the torque transmission component includes a connecting seat, which is fixedly connected to the bottom outer wall of the gasket, and the connecting seat and the gasket are an integral structure; the torque transmission component also includes an inclined guide groove, which is opened on the outside of the connecting seat. The inclined guide groove is used to deflect the high-speed liquid outward. The inclined guide groove is connected to the arc-shaped guide groove, and the number of inclined guide grooves and arc-shaped guide grooves is the same and they correspond one-to-one.

[0008] Furthermore, the torque transmission component also includes several first dovetail grooves, which are opened through the inner side of the connector, and the inner wall of each first dovetail groove is engaged with a first soft pad.

[0009] Furthermore, the torque transmission assembly also includes a transmission seat located inside the connecting seat. A number of second dovetail grooves are provided through one outer wall of the transmission seat, and each second dovetail groove is engaged with the first soft pad.

[0010] Furthermore, the torque transmission assembly also includes an arc-shaped fitting groove, which is opened on the inner wall of the other side of the transmission seat. The arc-shaped fitting groove fits against the outer wall of the drive shaft, and a collection groove is opened at the bottom of the transmission seat.

[0011] Furthermore, the torque transmission component also includes several corrugated pads, which are fixedly connected to the inner side of the arc-shaped bonding groove, and the corrugated pads are vertically and equidistantly distributed on the inner wall of the arc-shaped bonding groove.

[0012] Furthermore, the sealing and buffering assembly includes two third soft pads, which are fixedly connected to the inner surfaces of both ends of the washer, and the two third soft pads are respectively in contact with the drive shaft and the nut.

[0013] Furthermore, annular pressure relief grooves are provided on one side surface of both third pads.

[0014] Furthermore, the sealing buffer assembly also includes two sealing rings, which are respectively embedded in the outer surfaces of both ends of the gasket. The two sealing rings are respectively matched with the drive shaft and the nut, and are used to seal the contact surfaces of the gasket and the nut.

[0015] The beneficial effects of this invention compared to the prior art are as follows: 1. When sudden situations such as well slippage or stuck drill occur downhole, a huge reverse impact torque is generated externally. The corrugated soft pad in the torque transmission component will automatically slip, and in conjunction with the bearing in the anti-backlash component, the washer and the drive shaft will rotate independently, converting the impact torque into rotational kinetic energy. This greatly blocks the transmission of reverse torque to the nut and threaded pair. The nut only bears axial pressure and has no circumferential torsional load, fundamentally preventing loosening, backlash, and disengagement. At the same time, it effectively prevents the motor assembly from failing to connect with downhole components and prevents components from falling into the well. It also prevents serious safety accidents such as stuck drill, wellbore collapse, and equipment damage caused by component detachment. It meets the safety protection requirements of high temperature, high pressure, and high impact complex working conditions in oil drilling. When there is no reverse torque impact or vibration damage, the threaded connection between the drive shaft and the nut always maintains the initial pre-tightened state and will not experience thread wear or stripping due to repeated impacts, thus extending the service life of the threaded pair.

[0016] 2. When the screw motor is running normally in the forward direction, the outer wall of the drive shaft is tightly fitted with the corrugated soft pad. This invention reliably transmits forward torque through flexible friction. The torque is smoothly transmitted to the pad through the transmission seat and connecting seat. The pad rotates lightly synchronously with the drive shaft, without losing power or interfering with fluid circulation, ensuring the efficiency of motor drilling and well repair operations. At the same time, the floating engagement structure of the first dovetail groove, the second dovetail groove and the first soft pad can realize the radial position fine adjustment of the transmission seat. Combined with the arc-shaped fitting groove design, the corrugated soft pad and the outer wall of the drive shaft are fitted without gaps and in full circumference. The torque transmission is uniform and stable, without local stress concentration. In addition, a debris collection groove is set at the bottom of the transmission seat, which can automatically collect the debris generated by the wear of the corrugated soft pad, prevent debris from jamming the transmission structure, and ensure long-term reliable torque transmission.

[0017] 3. This invention forms a continuous and smooth high-pressure fluid guiding channel through the arc-shaped guide groove and the inclined guide groove on the connecting seat, guiding the fluid to flow in an orderly manner without eddies, stagnation, or blockage. At the same time, the inclined guide design changes the fluid flow direction, preventing the high-pressure fluid from directly scouring the inner wall of the component, reducing the erosion and wear of the device by the fluid, reducing fluid energy loss, improving the hydraulic energy conversion efficiency of the motor, avoiding motor stalling, operation jamming and other malfunctions, and ensuring continuous and stable downhole operations.

[0018] 4. This invention uses a third soft pad to attach to the drive shaft and the nut respectively. Through elastic compression, it actively absorbs downhole vibration and axial impact load, isolates the impact source from the nut, and avoids the impact force acting directly on the threaded pair. At the same time, an annular pressure relief groove is opened on the surface of the third soft pad to provide directional accommodation space for the soft pad to be squeezed and deformed, avoid stress concentration, prevent the soft pad from being over-compressed and causing permanent deformation, maintain the buffering and shock absorption effect, and significantly reduce vibration and impact, improve the fatigue strength of the overall structure, and extend the service life of the screw motor.

[0019] 5. This invention uses embedded sealing rings on both outer sides of the gasket to tightly fit the drive shaft and nut, effectively preventing mud, rock cuttings, and impurities from entering the bearing. This prevents the bearing from jamming, wearing, or seizing due to impurities, ensuring flexible bearing rotation. It also achieves dual functions of sealing protection and buffering shock absorption. No additional sealing components are needed, resulting in a compact structure, simplified assembly, and more comprehensive protection. This significantly reduces the overall failure rate of the device, decreases the frequency of downhole maintenance and replacement, and lowers operating costs. Attached Figure Description

[0020] Figure 1 A three-dimensional structural diagram of the anti-tipping device at the connection point of the screw motor; Figure 2 A three-dimensional cross-sectional schematic diagram of the anti-backlash device at the screw motor connection point; Figure 3 A schematic diagram of the three-dimensional structure of the anti-overturning component; Figure 4 A three-dimensional structural diagram of the anti-overlapping assembly and the torque transmission assembly; Figure 5 A three-dimensional structural diagram of the anti-overturning assembly and the sealing buffer assembly; Figure 6 This is a schematic diagram of the three-dimensional structure of the torque transmission component; Figure 7 A three-dimensional structural diagram of the torque transmission component; Figure 8 for Figure 4 A magnified schematic diagram of the structure at point A in the diagram.

[0021] Figure label: 1. Drive shaft; 2. Connector; 3. Stator; 4. Nut; 5. Anti-backlash assembly; 501. Washer; 502. Bearing; 503. Arc-shaped guide groove; 6. Torque transmission assembly; 601. Connecting seat; 602. Inclined guide groove; 603. First dovetail groove; 604. First soft pad; 605. Second dovetail groove; 606. Transmission seat; 607. Arc-shaped fitting groove; 608. Corrugated soft pad; 7. Sealing buffer assembly; 701. Third soft pad; 702. Annular pressure relief groove; 703. Sealing ring. Detailed Implementation

[0022] To make the technical problems to be solved, the technical solutions, and the beneficial effects of this invention clearer, the invention will be further described in detail with reference to the embodiments and accompanying drawings. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention. The technical solutions of this invention are described in detail below with reference to the embodiments and accompanying drawings, but the scope of protection is not limited thereto.

[0023] Please see Figures 1 to 8This embodiment proposes an anti-backlash device for the connection part of a screw motor, including a drive shaft 1, a connector 2, a stator 3, and a nut 4. One end of the drive shaft 1 is threadedly connected to the nut 4, which axially locks and fixes the drive shaft 1 and the connector 2, forming a stable overall assembly structure. This structure can withstand the axial tensile force, compressive force, and impact load generated during drilling operations, maintaining the connection rigidity between the drive shaft 1 and the connector 2, and preventing the overall connection from loosening. The connector 2 is located outside the nut 4, and the stator 3 is located outside the drive shaft 1. The drive shaft 1, connector 2, stator 3, and nut 4 are all... In the existing structure, to help the motor drive the screw to rotate, an anti-backlash component 5 is provided at the connection between the drive shaft 1 and the nut 4. The anti-backlash component 5 is used to prevent the nut 4 from loosening and backlashing. One end of the anti-backlash component 5 is provided with several torque transmission components 6. The several torque transmission components 6 are arranged in a ring array on the outside of the anti-backlash component 5. The torque transmission components 6 are used to transmit the torque of the drive shaft 1 to the anti-backlash component 5. Both ends of the anti-backlash component 5 are provided with sealing buffer components 7. The sealing buffer components 7 are used to buffer and seal the pressure borne by the anti-backlash component 5.

[0024] The anti-tipping assembly 5 includes a bearing 502, which is installed on the outer side of one end of the drive shaft 1. A washer 501 is fitted on the outer side of the bearing 502. The bearing 502 provides rotational freedom. When transmitting positive torque, it allows the washer 501 to rotate freely without being constrained by the drive shaft 1. At the same time, it provides radial limiting and centering, so that the washer 501 always remains coaxial with the drive shaft 1. The anti-tipping assembly 5 also includes several arc-shaped flow guide grooves 503. The arc-shaped flow guide grooves 503 are used to guide the liquid to ensure smooth liquid flow under normal working conditions. Several arc-shaped flow guide grooves 503 are arranged in a ring array on the outer sidewall of the washer 501.

[0025] The torque transmission component 6 includes a connecting seat 601, which is fixedly connected to the bottom outer wall of the washer 501. The connecting seat 601 and the washer 501 are an integral structure. The torque transmission component 6 also includes an inclined guide groove 602, which is opened on the outside of the connecting seat 601. The inclined guide groove 602 is used to deflect the high-speed liquid outward to avoid eddy currents caused by straight guidance and reduce energy loss. The inclined guide groove 602 is connected to the arc-shaped guide groove 503. The number of inclined guide grooves 602 and arc-shaped guide grooves 503 is the same and they correspond one-to-one.

[0026] The torque transmission assembly 6 also includes a plurality of first dovetail grooves 603, which are formed through the inner side of the connecting seat 601. Each first dovetail groove 603 has a first soft pad 604 engaged with its inner wall. The torque transmission assembly 6 also includes a transmission seat 606, which is located inside the connecting seat 601. A plurality of second dovetail grooves 605 are formed through one outer wall of the transmission seat 606. Each second dovetail groove 605 is engaged with the first soft pad 604. The torque transmission assembly 6 also includes an arc-shaped fitting groove 607, which is formed on the inner wall of the other side of the transmission seat 606. The arc-shaped fitting groove 607 fits against the outer wall of the drive shaft 1. A collection groove is formed at the bottom of the transmission seat 606 for collecting worn soft pad debris. The first dovetail groove 603 and the second dovetail groove 605 are used to limit the first soft pad 604 to prevent the first soft pad 604 from falling off during normal operation. The first soft pad 604, as a floating structure, is used to finely adjust the radial position of the transmission seat 606 so that the transmission seat 606 can get closer to the drive shaft 1, and at the same time, it can make the arc-shaped fitting groove 607 fit better with the drive shaft 1.

[0027] The torque transmission component 6 also includes several corrugated pads 608. The corrugated pads 608 can reliably transmit torque through the high-pressure contact points formed by the crests and troughs, and the troughs can accommodate the discharged wear debris. At the same time, the elasticity of the corrugated structure is used to achieve buffering and adaptively fit the drive shaft 1. Several corrugated pads 608 are fixedly connected to the inner side of the arc-shaped fitting groove 607. Several corrugated pads 608 are vertically and equidistantly distributed on the inner wall of the arc-shaped fitting groove 607.

[0028] The sealing buffer assembly 7 includes two third soft pads 701, which are fixedly connected to the inner surfaces of both ends of the washer 501. The two third soft pads 701 are respectively in contact with the drive shaft 1 and the nut 4. The third soft pads 701 absorb axial impact load through elastic compression and isolate the impact source of the nut 4, so that the impact force is absorbed by the third soft pads 701 and then transmitted to the nut 4 in a gentle manner, maintaining the pre-tightness stability of the threaded pair and fundamentally reducing the cause of backlash.

[0029] An annular pressure relief groove 702 is provided on one side surface of each of the two third soft pads 701. The annular pressure relief groove 702 provides directional accommodation space for the deformation of the third soft pad 701, avoids stress concentration, and reduces the risk of permanent deformation caused by excessive compression of the third soft pad 701. The sealing buffer assembly 7 also includes two sealing rings 703. The two sealing rings 703 are respectively embedded in the outer surfaces of both ends of the washer 501. The two sealing rings 703 are respectively matched with the drive shaft 1 and the nut 4. The sealing rings 703 are used to seal the contact surface between the washer 501 and the nut 4 to prevent the bearing 502 from being damaged due to the entry of external mud and sand into the bearing 502.

[0030] The working principle of the technical solution provided by this invention is as follows: During operation, when the screw motor is running normally, the drive shaft 1 continuously outputs power in the positive direction. The outer circumference of the drive shaft 1 generates uniform friction with the corrugated soft pad 608. This friction transmits the positive torque through the corrugated soft pad 608 to the transmission seat 606, then through the transmission seat 606 to the connecting seat 601, and finally through the connecting seat 601 to the washer 501. At this time, the washer 501, through the arc-shaped fitting groove 607 of the bottom transmission seat 606 and the flexible contact between the corrugated soft pad 608 and the surface of the drive shaft 1, rotates slightly synchronously with the drive shaft 1, without affecting the normal power transmission and fluid circulation of the motor. However, in the event of a sudden situation such as a fall into a well, the external resistance increases instantaneously. When the external impact force acts directly on the washer 501, the force reverses... The torque far exceeds the limit of static friction bearing capacity of the corrugated soft pad 608, causing the contact surface of the corrugated soft pad 608 to slip. The corrugated soft pad 608 and the outer surface of the drive shaft 1 slide in a circumferential direction. The transmission seat 606 loses friction drive and is no longer driven by the drive shaft 1. The washer 501, with the help of the inner built-in bearing 502, simultaneously breaks away from the flexible contact with the drive shaft 1 and achieves independent rotation, converting the external impact torque into its own rotational kinetic energy, blocking the transmission of reverse torque to the nut 4 and the drive shaft 1. At the same time, the third soft pad 701 isolated at the top of the washer 501 further blocks the upward transmission of residual torque, completely isolating the reverse torque from contacting the nut 4. The nut 4 always only bears axial pressure and has no circumferential torsional load, preventing the nut 4 from loosening, buckling, or coming off.

[0031] In addition, when the equipment is operating normally, the arc-shaped guide groove 503 structure around the gasket 501 forms a smooth fluid channel, guiding the liquid flowing through the arc-shaped guide groove 503 to the inclined guide groove 602, and then the inclined guide groove 602 continues to guide the liquid to flow downward, thereby ensuring the normal flow of high-pressure fluid, while avoiding fluid blockage of the motor and causing operational failure, further ensuring safe operation downhole.

[0032] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. A screw motor connection anti-reverse buckling device, comprising a drive shaft (1), a connector (2), a stator (3), and a nut (4); one end of the drive shaft (1) is threadedly connected to the nut (4), the connector (2) is provided on the outside of the nut (4), and the stator (3) is provided on the outside of the drive shaft (1); characterized in that, An anti-backlash assembly (5) is provided at the connection between the drive shaft (1) and the nut (4). The anti-backlash assembly (5) is used to prevent the nut (4) from loosening and backlashing. A number of torque transmission assemblies (6) are provided at one end of the anti-backlash assembly (5). The number of torque transmission assemblies (6) are arranged in a ring array on the outside of the anti-backlash assembly (5). The torque transmission assemblies (6) are used to transmit the torque of the drive shaft (1) to the anti-backlash assembly (5). Both ends of the anti-backlash assembly (5) are provided with sealing buffer assemblies (7). The sealing buffer assemblies (7) are used to buffer and seal the pressure borne by the anti-backlash assembly (5). The anti-backlash assembly (5) includes a bearing (502). The bearing (502) is installed on the outside of one end of the drive shaft (1). A washer (501) is sleeved on the outside of the bearing (502).

2. The anti-reverse buckling device for the connection part of a screw motor according to claim 1, characterized in that, The anti-tipping assembly (5) also includes several arc-shaped flow guide grooves (503), which are used to guide the liquid. The several arc-shaped flow guide grooves (503) are arranged in a ring array on the outer sidewall of the gasket (501).

3. The anti-reverse buckling device for the connection part of a screw motor according to claim 2, characterized in that, The torque transmission component (6) includes a connecting seat (601), which is fixedly connected to the bottom outer wall of the washer (501). The connecting seat (601) and the washer (501) are an integral structure. The torque transmission component (6) also includes an inclined guide groove (602), which is opened on the outside of the connecting seat (601). The inclined guide groove (602) is used to deflect the high-speed liquid outward. The inclined guide groove (602) is connected to the arc-shaped guide groove (503). The number of inclined guide grooves (602) and arc-shaped guide grooves (503) is the same and they correspond one-to-one.

4. The anti-reverse buckling device for the connection part of a screw motor according to claim 3, characterized in that, The torque transmission assembly (6) also includes a plurality of first dovetail grooves (603), which are opened through the inner side of the connecting seat (601), and a first soft pad (604) is engaged with the inner wall of each first dovetail groove (603).

5. The anti-reverse buckling device for the connection part of a screw motor according to claim 4, characterized in that, The torque transmission assembly (6) also includes a transmission seat (606), which is located inside the connecting seat (601). A number of second dovetail grooves (605) are provided through one side of the outer wall of the transmission seat (606), and each second dovetail groove (605) is engaged with the first soft pad (604).

6. The anti-reverse buckling device for the connection part of a screw motor according to claim 5, characterized in that, The torque transmission assembly (6) also includes an arc-shaped fitting groove (607), which is opened on the inner wall of the other side of the transmission seat (606). The arc-shaped fitting groove (607) fits against the outer wall of the transmission shaft (1), and a collection groove is opened at the bottom of the transmission seat (606).

7. The anti-reverse buckling device for the connection part of a screw motor according to claim 6, characterized in that, The torque transmission assembly (6) also includes several corrugated pads (608), which are fixedly connected to the inner side of the arc-shaped bonding groove (607). The corrugated pads (608) are vertically and equidistantly distributed on the inner wall of the arc-shaped bonding groove (607).

8. The anti-reverse buckling device for the connection part of a screw motor according to claim 1, characterized in that, The sealing buffer assembly (7) includes two third soft pads (701), which are fixedly connected to the inner surfaces of both ends of the washer (501) and respectively fit against the drive shaft (1) and the nut (4).

9. The anti-reverse buckling device for the connection part of a screw motor according to claim 8, characterized in that, An annular pressure relief groove (702) is provided on one side surface of each of the two third pads (701).

10. The anti-reverse buckling device for the connection part of a screw motor according to claim 9, characterized in that, The sealing buffer assembly (7) also includes two sealing rings (703). The two sealing rings (703) are respectively embedded in the outer surfaces of both ends of the gasket (501). The two sealing rings (703) are respectively fitted with the drive shaft (1) and the nut (4). The sealing rings (703) are used to seal the contact surfaces of the gasket (501) and the nut (4).

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