A long-life high-temperature resistant rotary guide screw

Abstract

The present invention relates to the technical field of positive displacement motors, and particularly relates to a long-life high-temperature-resistant rotary steering positive displacement motor, which comprises a motor assembly, a universal shaft assembly and a transmission shaft assembly connected in sequence from top to bottom. The motor assembly includes a stator and a rotor rotatably disposed within the stator. The universal shaft assembly includes a straight housing and a universal shaft body movably disposed within the straight housing. The transmission shaft assembly includes an upper transmission housing and a transmission shaft rotatably disposed within the upper transmission housing. A first threaded hole is recessed at the lower end of the rotor. A first threaded post threadedly connected to the first threaded hole is provided at the upper end of the universal shaft body. A water cap is installed at the upper end of the transmission shaft, and the upper end of the water cap is hingedly connected to the lower end of the universal shaft body. The connection between the lower end of the universal shaft body and the upper end of the water cap is covered and sealed by a metal bellows. The universal shaft part adopts a structure form of a flexible shaft plus hinge, which greatly improves the fatigue life. The metal bellows seal is adopted, which has the advantages of high temperature resistance, erosion resistance and long life.

Description

Technical Field

[0001] The present invention relates to the technical field of positive displacement downhole motors, and particularly to a long-life high-temperature-resistant rotary steerable positive displacement downhole motor. Background Art

[0002] A positive displacement downhole motor is a downhole power drill that uses drilling fluid as power to convert the liquid pressure energy into mechanical energy. When the mud pumped out by the mud pump flows through the bypass valve and enters the motor, a certain pressure difference is formed at the inlet and outlet of the motor, pushing the rotor to rotate around the axis of the stator, and transmitting the rotational speed and torque to the drill bit through the universal joint shaft and the transmission shaft, thereby realizing the drilling operation.

[0003] In the existing oil and gas exploitation, positive displacement downhole motors are widely used. A screw is used as the power output, and a rotary steering tool is used to improve the drilling speed and accuracy. Since the oil and gas layers are buried relatively deep and the bottom hole temperature is relatively high. Currently, the screw for cooperating with the rotary steering is usually connected to the transmission shaft by a flexible shaft universal joint structure with direct rigid connection at the upper and lower ends. After long-term use, metal fatigue is likely to occur, resulting in fracture or other failures, and it cannot meet the long-term use requirements. The failure at the bottom hole greatly affects the drilling and exploitation cycle. Summary of the Invention

[0004] The purpose of the present invention is to provide a long-life high-temperature-resistant rotary steerable positive displacement downhole motor, which solves the problem that the screw for cooperating with the rotary steering is usually connected to the transmission shaft by a flexible shaft universal joint structure with direct rigid connection at the upper and lower ends. After long-term use, metal fatigue is likely to occur, resulting in fracture or other failures.

[0005] To solve the above technical problems, the present invention adopts the following technical solutions:

[0006] A long-life high-temperature-resistant rotary steerable positive displacement downhole motor includes a motor assembly, a universal joint shaft assembly, and a transmission shaft assembly connected in sequence from top to bottom. The motor assembly includes a stator and a rotor rotatably arranged in the stator. The universal joint shaft assembly includes a straight housing and a universal joint shaft body movably arranged in the straight housing. The transmission shaft assembly includes a transmission upper housing and a transmission shaft rotatably arranged in the transmission upper housing. The upper and lower ends of the straight housing are respectively connected to the lower end of the stator and the upper end of the transmission upper housing. A first threaded hole is recessed at the lower end of the rotor. A first threaded post threadedly connected to the first threaded hole is arranged at the upper end of the universal joint shaft body. A water cap is installed at the upper end of the transmission shaft, and the upper end of the water cap is hinged to the lower end of the universal joint shaft body; the connection between the lower end of the universal joint shaft body and the upper end of the water cap is covered and sealed by a metal bellows.

[0007] A further technical solution is that a first connection groove is recessed at the lower end of the universal shaft body. A driving groove is recessed on the groove wall of the first connection groove. The lower groove wall of the driving groove communicates with the lower end of the universal shaft body. An outer wall of the upper end of the water cap is provided with a driving block matching the driving groove. When the upper end of the water cap is placed in the first connection groove, the driving block is fitted into the driving groove, and a gap is left between the driving block and the driving groove. A first semi-circular groove is recessed on the groove wall of the driving groove. A second semi-circular groove is recessed at a position of the driving block aligned with the first semi-circular groove. An arc roller is movably arranged between the first semi-circular groove and the second semi-circular groove. Opposite sides of the arc roller are respectively movably arranged in the first semi-circular groove and the second semi-circular groove. An upper groove wall of the second semi-circular groove communicates with the upper end of the driving block to form a placing port. An installation ring groove is arranged around a position of the first connection groove close to the groove opening. An elastic retaining ring is clamped in the installation ring groove. An inner wall of the elastic retaining ring protrudes from the installation ring groove and is placed below the driving block.

[0008] A further technical solution is that the upper end of the metal bellows is installed on the outer wall of the lower end of the universal shaft body through an upper pressing semi-ring, and the lower end of the metal bellows is installed on the outer wall of the water cap through a lower pressing semi-ring. An upper clamping ring is protruded on the outer wall of the lower end of the universal shaft body. An upper clamping groove matching the upper clamping ring is recessed on the inner side of the upper pressing semi-ring. The upper pressing semi-ring is provided with two, and the two upper pressing semi-rings are symmetrically installed on the upper clamping ring to form an upper pressing ring. The upper end of the metal bellows is fixed between the upper pressing ring and the outer wall of the universal shaft body. An upper clamping hoop groove is recessed on the outer wall around the upper pressing ring. An upper clamping hoop is installed in the upper clamping hoop groove. A lower clamping ring is protruded on the outer wall of the water cap below the universal shaft body. A lower clamping groove matching the lower clamping ring is recessed on the inner side of the lower pressing semi-ring. The lower pressing semi-ring is provided with two, and the two lower pressing semi-rings are symmetrically installed on the lower clamping ring to form a lower pressing ring. The lower end of the metal bellows is fixed between the lower pressing ring and the outer wall of the water cap. A lower clamping hoop groove is recessed on the outer wall around the lower pressing ring. A lower clamping hoop is installed in the lower clamping hoop groove.

[0009] A further technical solution is that a second connection groove is arranged at the lower end of the water cap. The upper end of the transmission shaft is threadedly installed in the second connection groove. A through hole penetrating the upper and lower ends is arranged at the center of the transmission shaft. A first water hole communicating with the through hole is arranged at the groove bottom of the second connection groove. A second water hole communicating with the first water hole is arranged on the outer wall of the water cap. A first alloy sleeve and a second alloy sleeve are respectively arranged on the hole walls of the first water hole and the second water hole. A third alloy sleeve is arranged on the inner wall of the upper end of the through hole.

[0010] A further technical solution is that an upper anti-falling ring is installed on the inner wall of the upper end of the stator. An anti-falling rod is connected to the upper end of the rotor. The upper end of the anti-falling rod passes through the central hole of the upper anti-falling ring, and an anti-falling ring is connected above the upper anti-falling ring. The outer diameter of the anti-falling ring is larger than the aperture of the central hole of the upper anti-falling ring.

[0011] A further technical solution is that the hole wall of the upper anti-drop ring central hole is recessed with a through groove, and the upper groove wall and the lower groove wall of the through groove are respectively communicated with the upper side and the lower side of the upper anti-drop ring; a plurality of through grooves are arranged around the hole wall of the central hole; the outer wall of the upper end of the upper anti-drop ring is convexly provided with a limiting mounting ring, and the inner wall of the stator is provided with a stepped bevel near the upper end, the inner diameter of the upper side of the stepped bevel is larger than the inner diameter of the lower side of the stepped bevel, the mounting ring is clamped on the upper side of the stepped bevel, and the outer diameter of the mounting ring is larger than the inner diameter of the stator at the lower side of the stepped bevel.

[0012] A further technical solution is that the upper end of the anti-drop rod is provided with a threaded rod, and a nut is threadedly connected to the threaded rod, and the anti-drop ring is sleeved on the threaded rod between the nut and the anti-drop rod; the upper end of the rotor is recessed with a second threaded hole, and the lower end of the anti-drop rod is provided with a second threaded post threadedly connected to the second threaded hole.

[0013] A further technical solution is that the inner wall of the lower end of the transmission upper housing is threadedly connected with a transmission lower housing, the inner wall of the lower end of the transmission lower housing protrudes inward to form an anti-drop limiting ring, and a lower anti-drop ring is installed on the outer wall of the transmission shaft above the anti-drop limiting ring, and the outer diameter of the lower anti-drop ring is larger than the inner diameter of the anti-drop limiting ring.

[0014] A further technical solution is that the lower anti-drop ring is formed by splicing two anti-drop half rings, a first toothed ring is arranged on the outer wall of the transmission shaft above the anti-drop limiting ring, and a second toothed ring meshing with the first toothed ring is arranged on the inner wall of the anti-drop half ring. When the two anti-drop half rings are spliced to form the lower anti-drop ring and installed on the outer wall of the transmission shaft, a lower washer is sleeved on the outer wall of the anti-drop ring.

[0015] A further technical solution is that the outer wall of the transmission shaft and the inner wall of the transmission upper housing are rotationally connected by a series bearing. The series bearing includes an inner ring and an outer ring. A plurality of first roller ring cavities and second roller ring cavities are arranged at intervals from top to bottom between the inner ring and the outer ring. First rollers are arranged in the first roller ring cavities in a rolling manner, and second rollers are arranged in the second roller ring cavities in a rolling manner. The diameter of the first rollers is smaller than the diameter of the second rollers, and the height of the first rollers is greater than the height of the second rollers.

[0016] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. The universal shaft part adopts a structure form of a flexible shaft plus a hinge. Compared with a flexible shaft with direct rigid connection at the upper and lower ends, the fatigue life is greatly improved. 2. The hinge part at the lower end of the universal shaft adopts the form of spherical arc-shaped balls to transmit torque. Compared with a shear-force-bearing universal shaft, the arc-shaped balls can bear higher pressure loads and greatly extend the service life. 3. The seal at the connection between the lower end of the universal shaft body and the upper end of the water cap adopts a metal bellows seal, which has the advantages of high temperature resistance, erosion resistance, and long service life. At the same time, the seal is installed at the lower part, which can greatly reduce erosion. Description of the Drawings

[0017] Figure 1 Overall schematic diagram of a long - life high - temperature resistant rotary guiding screw of the present invention.

[0018] Figure 2 For Figure 1 Partial enlarged schematic diagram at marked position A in [diagram not specified].

[0019] Figure 3 Upper anti - dropping ring schematic diagram of a long - life high - temperature resistant rotary guiding screw of the present invention.

[0020] Figure 4 Side cross - sectional schematic diagram of the upper anti - dropping ring of a long - life high - temperature resistant rotary guiding screw of the present invention.

[0021] Figure 5 For Figure 1 Partial enlarged schematic diagram at marked position B in [diagram not specified].

[0022] Figure 6 For Figure 1 Partial enlarged schematic diagram at marked position C in [diagram not specified].

[0023] Figure 7 Cross - sectional schematic diagram of the connection between the universal shaft body and the water cap of a long - life high - temperature resistant rotary guiding screw of the present invention.

[0024] Figure 8 Schematic diagram of the transmission assembly of a long - life high - temperature resistant rotary guiding screw of the present invention.

[0025] Figure 9 For Figure 8 Partial enlarged schematic diagram at marked position D in [diagram not specified].

[0026] Icons: 1 - conversion short circuit, 2 - motor assembly, 3 - universal shaft assembly, 4 - transmission shaft assembly, 5 - stator, 6 - rotor, 7 - straight housing, 8 - universal shaft body, 9 - upper transmission housing, 10 - transmission shaft, 11 - first threaded hole, 12 - first threaded post, 13 - water cap, 14 - metal bellows, 15 - first connection groove, 16 - drive groove, 17 - drive block, 18 - first semi-circular groove, 19 - second semi-circular groove, 20 - arc roller, 21 - mounting ring groove, 22 - circlip, 23 - universal ball seat, 24 - ball head support, 25 - upper pressure semi-ring, 26 - lower pressure semi-ring, 27 - upper snap ring, 28 - upper snap groove, 29 - upper hoop, 30 - lower snap ring, 31 - lower snap groove, 32 - lower hoop, 33 - second sealing ring, 34 - third sealing ring, 35 - second connection groove, 36 - through hole, 37 - first water hole, 38 - second water hole, 39 - first alloy sleeve, 40 - second alloy sleeve, 41 - third alloy sleeve, 42 - upper anti-falling ring, 43 - anti-falling rod, 44 - anti-falling ring, 45 - through slot, 46 - mounting ring, 47 - stepped slope, 48 - first sealing ring, 49 - threaded rod, 50 - nut, 51 - second threaded hole, 52 - second threaded post, 53 - lower transmission housing, 54 - anti-falling limit ring, 55 - lower anti-falling ring, 56 - lower dynamic TC bearing, 57 - fourth sealing ring, 58 - first gear ring, 59 - second gear ring, 60 - lower washer, 61 - series bearing, 62 - inner ring, 63 - outer ring, 64 - first roller, 65 - second roller, 66 - upper static spacer. Detailed implementation mode

[0027] In order to make the objectives, technical solutions and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0028] Figures 1 to 9 The following shows an embodiment of the present invention.

[0029] Embodiment 1:

[0030] A long-life high-temperature-resistant rotary guide screw, comprising a motor assembly 2, a universal shaft assembly 3 and a transmission shaft assembly 4 connected in sequence from top to bottom. The motor assembly 2 includes a stator 5 and a rotor 6 rotatably arranged within the stator 5. The universal shaft assembly 3 includes a straight housing 7 and a universal shaft body 8 movably arranged within the straight housing 7. The transmission shaft assembly 4 includes a transmission upper housing 9 and a transmission shaft 10 rotatably arranged within the transmission upper housing 9. The upper and lower ends of the straight housing 7 are respectively connected to the lower end of the stator 5 and the upper end of the transmission upper housing 9. A first threaded hole 11 is recessed at the lower end of the rotor 6. A first threaded post 12 threadedly connected to the first threaded hole 11 is arranged at the upper end of the universal shaft body 8. A water cap 13 is installed at the upper end of the transmission shaft 10, and the upper end of the water cap 13 is hingedly connected to the lower end of the universal shaft body 8; the connection between the lower end of the universal shaft body 8 and the upper end of the water cap 13 is hermetically covered by a metal bellows 14. A conversion short circuit 1 is installed at the upper end of the stator 5. The universal shaft part adopts a structure form of a flexible shaft plus hinge. Compared with the flexible shaft with direct rigid connection at the upper and lower ends, the fatigue life is greatly improved. The connection between the lower end of the universal shaft body 8 and the upper end of the water cap 13 is sealed by a metal bellows 14, which has the advantages of high temperature resistance, erosion resistance and long life. At the same time, the seal is installed at the lower part, which can greatly reduce erosion.

[0031] A first connection groove 15 is recessed at the lower end of the universal shaft body 8. A drive groove 16 is recessed in the groove wall of the first connection groove 15. The lower groove wall of the drive groove 16 communicates with the lower end of the universal shaft body 8. A drive block 17 matching the drive groove 16 is protruded on the outer wall of the upper end of the water cap 13. When the upper end of the water cap 13 is placed in the first connection groove 15, the drive block 17 is fitted in the drive groove 16, and there is a gap between the drive block 17 and the drive groove 16. A first semi-circular groove 18 is recessed in the groove wall of the drive groove 16. A second semi-circular groove 19 is recessed at the position of the drive block 17 aligned with the first semi-circular groove 18. An arc-shaped roller 20 is movably arranged between the first semi-circular groove 18 and the second semi-circular groove 19. The opposite sides of the arc-shaped roller 20 are respectively movably arranged in the first semi-circular groove 18 and the second semi-circular groove 19. The upper groove wall of the second semi-circular groove 19 communicates with the upper end of the drive block 17 to form a placement opening; An installation ring groove 21 is arranged around the position of the first connection groove 15 close to the groove opening. An elastic retaining ring 22 is clamped in the installation ring groove 21. The inner wall of the elastic retaining ring 22 protrudes from the installation ring groove 21 and is placed below the drive block 17. A universal ball seat 23 is installed at the bottom of the first connection groove 15. A ball head support 24 matching the universal ball seat 23 is installed at the upper end of the water cap 13. The articulated part at the lower end of the universal shaft body 8 uses the form of an arc-shaped roller 20 to transmit torque. Compared with a shear-force-bearing universal shaft, the arc-shaped roller 20 can withstand higher pressure loads and greatly extend the service life. Generally, four sets of the drive groove 16, the drive block 17 and the arc-shaped roller 20 are provided. In this way, the transmission can be more uniform. When the universal shaft body 8 rotates, the universal shaft body 8 drives the drive groove 16 to rotate together. By means of the first semi-circular groove 18 on the drive groove 16, the arc-shaped roller 20 is pushed to drive the drive block 17. By moving the drive block 17 together with the drive groove 16, the water cap 13 can be driven to rotate. By setting the elastic retaining ring 22, the separation of the water cap 13 from the universal shaft body 8 can be avoided and the anti-falling function can be achieved.

[0032] The upper end of the metal bellows 14 is installed on the outer wall of the lower end of the universal shaft body 8 through the upper pressing half-ring 25, and the lower end of the metal bellows 14 is installed on the outer wall of the water cap 13 through the lower pressing half-ring 26; an upper snap ring 27 is formed by the convexity on the outer wall of the lower end of the universal shaft body 8, and an upper clamping groove 28 matching the upper snap ring 27 is recessed on the inner side of the upper pressing half-ring 25. The upper pressing half-ring 25 is provided in two, and the two upper pressing half-rings 25 are symmetrically installed on the upper snap ring 27 to form an upper pressing ring. The upper end of the metal bellows 14 is fixed between the upper pressing ring and the outer wall of the universal shaft body 8; an upper hoop 29 groove is recessed on the outer wall surrounding the upper pressing ring, and an upper hoop 29 is installed in the upper hoop 29 groove; a lower snap ring 30 is formed by the convexity on the outer wall of the water cap 13 below the universal shaft body 8, and a lower clamping groove 31 matching the lower snap ring 30 is recessed on the inner side of the lower pressing half-ring 26. The lower pressing half-ring 26 is provided in two, and the two lower pressing half-rings 26 are symmetrically installed on the lower snap ring 30 to form a lower pressing ring. The lower end of the metal bellows 14 is fixed between the lower pressing ring and the outer wall of the water cap 13; a lower hoop 32 groove is recessed on the outer wall surrounding the lower pressing ring, and a lower hoop 32 is installed in the lower hoop 32 groove. The inner wall of the upper end of the metal bellows 14 is hermetically attached to the outer wall of the universal shaft body 8 through the second sealing ring 33. The inner wall of the lower end of the metal bellows 14 is hermetically attached to the outer wall of the water cap 13 through the third sealing ring 34. Through the upper hoop 29, the upper pressing ring composed of two upper pressing half-rings 25 can be tightly clamped on the upper snap ring 27, so as to press and fix the upper end of the metal bellows 14 by means of the inner wall of the upper pressing ring and the outer wall of the lower end of the transmission shaft 10. Similarly, through the lower hoop 32, the lower pressing ring composed of two lower pressing half-rings 26 can be tightly clamped on the west snap ring, so as to press and fix the lower end of the metal bellows 14 by means of the inner wall of the lower pressing ring and the outer wall of the water cap 13. Through the second sealing ring 33, the gap between the metal bellows 14 and the outer wall of the universal shaft body 8 can be sealed. By providing the third sealing ring 34, the gap between the metal bellows 14 and the outer wall of the water cap 13 can be sealed.

[0033] Embodiment 2:

[0034] On the basis of Embodiment 1, a second connection groove 35 is provided at the lower end of the water cap 13, the upper end of the transmission shaft 10 is threadedly installed in the second connection groove 35, a through hole 36 penetrating through the upper and lower ends is provided at the center of the transmission shaft 10, a first water hole 37 communicating with the through hole 36 is provided at the bottom of the second connection groove 35, a second water hole 38 communicating with the first water hole 37 is provided on the outer wall of the water cap 13, first alloy sleeves 39 and second alloy sleeves 40 are respectively provided on the hole walls of the first water hole 37 and the second water hole 38, and a third alloy sleeve 41 is provided on the inner wall of the upper end of the through hole 36. Erosion-resistant alloy sleeves are installed for the water pressure of the mud flow in both the water cap 13 and the transmission shaft 10, greatly extending the service life without being eroded and damaged. The mud enters the first water hole 37 through the second water hole 38, and then enters the through hole 36 through the first water hole 37.

[0035] Example 3:

[0036] On the basis of the foregoing embodiments, an upper anti-falling ring 42 is installed on the inner wall of the upper end of the stator 5, an anti-falling rod 43 is connected to the upper end of the rotor 6, the upper end of the anti-falling rod 43 passes through the central hole of the upper anti-falling ring 42, and an anti-falling ring 44 is connected above the upper anti-falling ring 42. The outer diameter of the anti-falling ring 44 is larger than the aperture of the central hole of the upper anti-falling ring 42. When the lower part of the stator 5 breaks and the rotor 6 falls along with the broken part, the anti-falling rod 43 will be driven. Since the outer diameter of the anti-falling ring 44 is larger than the central hole of the upper anti-falling ring 42, it cannot pass through and is stuck. At the same time, it will completely cover the central hole of the anti-falling ring, causing the mud to be unable to flow through and resulting in pressure build-up, reminding the operator of abnormal conditions underground.

[0037] A through groove 45 is recessed on the hole wall of the central hole of the upper anti-falling ring 42. The upper groove wall and the lower groove wall of the through groove 45 are respectively communicated with the upper side and the lower side of the upper anti-falling ring 42; several through grooves 45 are arranged around the hole wall of the central hole; an outer wall of the upper end of the upper anti-falling ring 42 is convexly provided with a limiting installation ring 46, and a variable-diameter inclined surface 47 is arranged at a position near the upper end of the inner wall of the stator 5. The inner diameter of the upper side of the variable-diameter inclined surface 47 is larger than the inner diameter of the lower side of the variable-diameter inclined surface 47. The installation ring 46 is clamped on the upper side of the variable-diameter inclined surface 47, and the outer diameter of the installation ring 46 is larger than the inner diameter of the stator 5 at the lower side of the variable-diameter inclined surface 47. The outer wall of the upper anti-falling ring 42 is hermetically connected to the inner wall of the stator 5 through a first sealing ring 48. The present invention combines the anti-falling function with the motor stator 5 for the first time. Compared with the split structure of the two, for example, the currently common solution is to add an anti-falling short joint between the stator and the conversion stub. The overall design of the present invention is more compact and more convenient for disassembly and assembly. At the same time, when the thread type at the upper part of the screw rod is changed, the connection joint can be quickly replaced without disassembling the rest. Through the cooperation of the installation ring 46 and the variable-diameter inclined surface 47, the upper anti-falling ring 42 can be installed on the inner wall of the stator 5 by an interference fit method, which is convenient for disassembly, and at the same time, it can ensure that the position of the upper anti-falling ring 42 will not move down during use.

[0038] A threaded rod 49 is provided at the upper end of the anti-falling rod 43, and a nut 50 is threadedly connected to the threaded rod 49. The anti-falling ring 44 is sleeved on the threaded rod 49 between the nut 50 and the anti-falling rod 43; a second threaded hole 51 is recessed at the upper end of the rotor 6, and a second threaded post 52 threadedly matched with the second threaded hole 51 is provided at the lower end of the anti-falling rod 43. By providing the threaded rod 49 and the nut 50, the anti-falling ring 44 can be stably installed at the upper end of the anti-falling rod 43. By providing the second threaded hole 51 and the second threaded post 52, the anti-falling rod 43 and the rotor 6 can be stably installed together.

[0039] Example 4:

[0040] On the basis of the foregoing embodiments, the inner wall of the lower end of the transmission upper housing 9 is threadedly and matingly connected to the transmission lower housing 53. An anti-falling limit ring 54 is formed by inward protrusion of the inner wall of the lower end of the transmission lower housing 53. A lower anti-falling ring 55 is installed on the outer wall of the transmission shaft 10 above the anti-falling limit ring 54, and the outer diameter of the lower anti-falling ring 55 is greater than the inner diameter of the anti-falling limit ring 54. The inner wall of the anti-falling limit ring 54 is rotationally connected to the outer wall of the transmission shaft 10 through a lower moving TC bearing 56, and the inner wall of the anti-falling limit ring 54 is hermetically fitted to the outer wall of the lower moving TC bearing 56 through a fourth sealing ring 57.

[0041] The lower anti-falling ring 55 is formed by splicing two anti-falling half rings. A first toothed ring 58 is provided on the outer wall of the transmission shaft 10 above the anti-falling limit ring 54. A second toothed ring 59 meshing with the first toothed ring 58 is provided on the inner wall of the anti-falling half ring. When the two anti-falling half rings are spliced to form the lower anti-falling ring 55 and installed on the outer wall of the transmission shaft 10, a lower washer 60 is sleeved on the outer wall of the anti-falling ring. The lower anti-falling structure is to design a toothed ring structure on the transmission shaft 10, sleeved with two anti-falling half rings on the outside, and then pressed tightly with the lower washer 60 to achieve the lower anti-falling function. In the prior art, there is no good anti-falling structure for the transmission shaft 10. When the upper part of the transmission shaft 10 breaks, the lower part of the transmission shaft 10 and the drill bit installed at the lower part of the transmission shaft 10 will fall into the drilling well, which delays the project progress on the one hand and causes economic losses on the other hand. Through the cooperation of the anti-falling limit ring 54 and the lower anti-falling ring 55, the present invention can prevent the lower part of the transmission shaft 10 from continuing to fall when the upper part of the transmission shaft 10 breaks.

[0042] Embodiment 5:

[0043] On the basis of the foregoing embodiments, the outer wall of the transmission shaft 10 and the inner wall of the transmission upper housing 9 are rotationally connected through a series bearing 61. The series bearing 61 includes an inner ring 62 and an outer ring 63. A plurality of first roller 64 ring cavities and second roller 65 ring cavities are arranged at intervals from top to bottom between the inner ring 62 and the outer ring 63. First rollers 64 are rollingly arranged in the first roller 64 ring cavities, and second rollers 65 are rollingly arranged in the second roller 65 ring cavities. The diameter of the first rollers 64 is smaller than that of the second rollers 65, and the height of the first rollers 64 is greater than that of the second rollers 65. The series bearing 61 replaces the traditional steel balls with cylindrical first rollers 64 and second rollers 65, improving the load-bearing capacity. At the same time, a horizontal and vertical cross arrangement is adopted, which can bear both the radial force and the axial pressure during the drilling process. This method cancels the upper and lower TC bearings in the traditional design, making the structure more compact. An upper static spacer 66 is sleeved on the upper end of the transmission shaft 10, and the upper static spacer 66 is rotationally fitted to the inner wall of the transmission upper housing 9.

[0044] Although the present invention has been described herein with reference to a number of illustrative embodiments of the present invention, it should be understood that those skilled in the art can design many other modifications and embodiments that will fall within the scope of the principles and spirit disclosed in this application. More specifically, within the scope of the disclosure, the drawings and the claims of this application, various variations and improvements can be made to the components and / or the layout of the subject combination layout. In addition to the variations and improvements made to the components and / or the layout, other uses will also be apparent to those skilled in the art.

Claims

1. A long-life high-temperature resistant rotary guide screw, comprising a motor assembly (2), a universal shaft assembly (3) and a transmission shaft assembly (4) connected in sequence from top to bottom. The motor assembly (2) includes a stator (5) and a rotor (6) rotatably arranged in the stator (5). The universal shaft assembly (3) includes a straight housing (7) and a universal shaft body (8) movably arranged in the straight housing (7). The transmission shaft assembly (4) includes a transmission upper housing (9) and a transmission shaft (10) rotatably arranged in the transmission upper housing (9). The upper and lower ends of the straight housing (7) are respectively connected to the lower end of the stator (5) and the upper end of the transmission upper housing (9), and it is characterized in that, The lower end of the rotor (6) is recessed with a first threaded hole (11). The upper end of the universal shaft body (8) is provided with a first threaded post (12) threadedly connected to the first threaded hole (11). The upper end of the transmission shaft (10) is installed with a water cap (13), and the upper end of the water cap (13) is hinged to the lower end of the universal shaft body (8). The connection between the lower end of the universal shaft body (8) and the upper end of the water cap (13) is hermetically covered by a metal bellows (14). The lower end of the universal shaft body (8) is recessed with a first connection groove (15). The groove wall of the first connection groove (15) is recessed with a driving groove (16). The lower groove wall of the driving groove (16) communicates with the lower end of the universal shaft body (8). The outer wall of the upper end of the water cap (13) is protruded with a driving block (17) matching the driving groove (16). When the upper end of the water cap (13) is placed in the first connection groove (15), the driving block (17) is fitted in the driving groove (16), and there is a gap between the driving block (17) and the driving groove (16). The groove wall of the driving groove (16) is recessed with a first semi-circular groove (18). The position of the driving block (17) aligned with the first semi-circular groove (18) is recessed with a second semi-circular groove (19). An arc-shaped roller (20) is movably arranged between the first semi-circular groove (18) and the second semi-circular groove (19). The opposite sides of the arc-shaped roller (20) are respectively movably arranged in the first semi-circular groove (18) and the second semi-circular groove (19). The upper groove wall of the second semi-circular groove (19) communicates with the upper end of the driving block (17) to form a placing port. An installation ring groove (21) is arranged around the position of the first connection groove (15) close to the groove opening. An elastic retaining ring (22) is clamped in the installation ring groove (21). The inner wall of the elastic retaining ring (22) protrudes from the installation ring groove (21) and is placed below the driving block (17).

2. The long-life high-temperature-resistant rotating guide screw according to claim 1, characterized in that: The upper end of the metal bellows (14) is installed on the outer wall of the lower end of the universal shaft body (8) through the upper pressing half-ring (25), and the lower end of the metal bellows (14) is installed on the outer wall of the water cap (13) through the lower pressing half-ring (26); a upper snap ring (27) is formed by a convex on the outer wall of the lower end of the universal shaft body (8), an upper clamping groove (28) matching with the upper snap ring (27) is recessed on the inner side of the upper pressing half-ring (25), the upper pressing half-ring (25) is provided with two, and the two upper pressing half-rings (25) are symmetrically installed on the upper snap ring (27) to form an upper pressing ring, and the upper end of the metal bellows (14) is fixed between the upper pressing ring and the outer wall of the universal shaft body (8); an upper hoop (29) groove is recessed on the outer wall surrounding the upper pressing ring, and an upper hoop (29) is installed in the upper hoop (29) groove; a lower snap ring (30) is formed by a convex on the outer wall of the water cap (13) below the universal shaft body (8), a lower clamping groove (31) matching with the lower snap ring (30) is recessed on the inner side of the lower pressing half-ring (26), the lower pressing half-ring (26) is provided with two, and the two lower pressing half-rings (26) are symmetrically installed on the lower snap ring (30) to form a lower pressing ring, and the lower end of the metal bellows (14) is fixed between the lower pressing ring and the outer wall of the water cap (13); a lower hoop (32) groove is recessed on the outer wall surrounding the lower pressing ring, and a lower hoop (32) is installed in the lower hoop (32) groove.

3. A long-life high-temperature resistant rotary guiding screw according to claim 1, characterized in that: A second connection groove (35) is provided at the lower end of the water cap (13), the upper end of the transmission shaft (10) is threadedly installed in the second connection groove (35), a through hole (36) penetrating through the upper and lower ends is provided at the center of the transmission shaft (10), a first water hole (37) communicating with the through hole (36) is provided at the bottom of the second connection groove (35), a second water hole (38) communicating with the first water hole (37) is provided on the outer wall of the water cap (13), a first alloy sleeve (39) and a second alloy sleeve (40) are respectively provided on the pore walls of the first water hole (37) and the second water hole (38), and a third alloy sleeve (41) is provided on the inner wall of the upper end of the through hole (36).

4. A long-life high-temperature resistant rotary guide screw according to claim 1, characterized in that: An upper anti-falling ring (42) is installed on the inner wall of the upper end of the stator (5), an anti-falling rod (43) is connected to the upper end of the rotor (6), the upper end of the anti-falling rod (43) passes through the central hole of the upper anti-falling ring (42), and an anti-falling ring (44) is connected above the upper anti-falling ring (42), and the outer diameter of the anti-falling ring (44) is larger than the aperture of the central hole of the upper anti-falling ring (42).

5. The long-life high-temperature resistant rotary guide screw according to claim 4, characterized in that: The hole wall of the central hole of the upper anti-falling ring (42) is recessed with a through groove (45). The upper groove wall and the lower groove wall of the through groove (45) are respectively communicated with the upper side and the lower side of the upper anti-falling ring (42). A plurality of the through grooves (45) are arranged around the hole wall of the central hole. The outer wall of the upper end of the upper anti-falling ring (42) is convexly provided with a limit mounting ring (46). The inner wall of the stator (5) is provided with a variable diameter inclined surface (47) near the upper end. The inner diameter of the upper side of the variable diameter inclined surface (47) is larger than the inner diameter of the lower side of the variable diameter inclined surface (47). The mounting ring (46) is clamped on the upper side of the variable diameter inclined surface (47), and the outer diameter of the mounting ring (46) is larger than the inner diameter of the stator (5) at the lower side of the variable diameter inclined surface (47).

6. The long-life high-temperature-resistant rotating guide screw according to claim 5, wherein: The upper end of the anti-falling rod (43) is provided with a threaded rod (49). A nut (50) is threadedly connected to the threaded rod (49). The anti-falling ring (44) is sleeved on the threaded rod (49) between the nut (50) and the anti-falling rod (43). The upper end of the rotor (6) is recessed with a second threaded hole (51). The lower end of the anti-falling rod (43) is provided with a second threaded post (52) threadedly connected to the second threaded hole (51).

7. A long-life high-temperature resistant rotary guide screw according to claim 1, characterized in that: The inner wall of the lower end of the transmission upper housing (9) is threadedly connected to a transmission lower housing (53). The inner wall of the lower end of the transmission lower housing (53) protrudes inward to form an anti-falling limit ring (54). A lower anti-falling ring (55) is installed on the outer wall of the transmission shaft (10) above the anti-falling limit ring (54). The outer diameter of the lower anti-falling ring (55) is larger than the inner diameter of the anti-falling limit ring (54).

8. A long-life high-temperature resistant rotary guiding screw according to claim 7, characterized in that: The lower anti-falling ring (55) is formed by splicing two anti-falling half rings. The outer wall of the transmission shaft (10) is provided with a first gear ring (58) above the anti-falling limit ring (54). The inner wall of the anti-falling half ring is provided with a second gear ring (59) meshing with the first gear ring (58). When the two anti-falling half rings are spliced to form the lower anti-falling ring (55) and installed on the outer wall of the transmission shaft (10), a lower washer (60) is sleeved on the outer wall of the anti-falling ring.

9. A long-life high-temperature resistant rotary guide screw according to claim 1, characterized in that: The outer wall of the transmission shaft (10) and the inner wall of the transmission upper housing (9) are rotationally connected by a series bearing (61). The series bearing (61) includes an inner ring (62) and an outer ring (63). A plurality of first roller (64) ring cavities and second roller (65) ring cavities are arranged at intervals from top to bottom between the inner ring (62) and the outer ring (63). First rollers (64) are rollingly arranged in the first roller (64) ring cavities, and second rollers (65) are rollingly arranged in the second roller (65) ring cavities. The diameter of the first rollers (64) is smaller than the diameter of the second rollers (65), and the height of the first rollers (64) is greater than the height of the second rollers (65).

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