A downhole positive displacement motor with self - adaptive adjustable centralizer orientation

Abstract

The present invention relates to the technical field of screw drilling tools, and specifically to a screw drilling tool capable of adaptively adjusting the position of a straightening bar in a well, wherein a straightening device is provided on the outer rotating sleeve of a transmission shaft housing, a sliding hole is provided at the lower end of the straightening device at the position corresponding to the straightening bar, a reversing lock tongue is slidably provided in the sliding hole, a pop-up member for controlling the downward movement of a toggle block is provided at the bottom of the sliding hole, a trigger hole connected to the surface of the straightening bar is provided on the wall of the sliding hole, a wear-resistant layer is provided on the surface of the straightening bar, a trigger and an elastic member are movably provided in the trigger hole, and the elastic member is used to push the trigger to separate from the surface of the reversing lock tongue after the wear-resistant layer is completely worn; a toggle block is provided on the outer wall of the transmission shaft below the reversing lock tongue to drive the straightening device to rotate, and a second top block for driving the reversing lock tongue to retract to the sliding hole is provided on the surface of the transmission shaft housing below the straightening device. The invention solves the problem that the straightening bar of the straightening device of the screw drilling tool has no adaptive adjustment capability in the well.

Description

Technical Field

[0001] The present invention relates to the technical field of positive displacement motors, and particularly relates to a positive displacement motor with an underground self - adaptive adjustable centralizer strip orientation. Background Art

[0002] A positive displacement motor mainly consists of five parts: a drive shaft assembly, a universal shaft assembly, a bent housing assembly, a motor assembly, and a falling prevention assembly. According to different drilling conditions, different drill string combinations need to be matched, and some positive displacement motors require a centralizer. The centralizer of a positive displacement motor is generally located on the outer housing of the drive shaft assembly, and centralizers with different structures and sizes are selected according to the size of the wellbore.

[0003] The centralizers of positive displacement motors are divided into integral centralizers and replaceable centralizers. The replaceable centralizer is thread - connected to the drive shaft assembly. The centralizer strip of the centralizer is a key component of the centralizer, which has the functions of controlling the wellbore trajectory, reaming, and trimming the wellbore wall. By adjusting the position and size of the centralizer, the drill string structure can be changed, and its build - up, holding, and dropping inclination performances can be changed, so as to reduce the footage of sliding directional drilling and use more drilling parameters that are more conducive to saving time. The centralizer strips are classified according to different wear - resistant layers, mainly including wear - resistant surfacing layers, hard alloy wear - resistant blocks, and thermally stable polycrystalline wear - resistant blocks, etc. Regardless of the wear - resistance of the centralizer strip, uneven wear will occur due to contact with the wellbore wall during use, which will affect the control of the wellbore trajectory and lead to the situation of pulling out the drill string to replace the positive displacement motor.

[0004] For the existing centralizer structures, whether integral centralizers or replaceable centralizers, once uneven wear occurs, they can only be returned to the factory for disassembly, repair, or replacement.

[0005] The existing centralizers of the drive shaft assembly of positive displacement motors all have obvious deficiencies, which are mainly manifested as follows:

[0006] 1. The centralizer strip of the centralizer has no self - adaptive adjustment ability underground;

[0007] 2. The wear - resistant performance of the centralizer has a cask - effect compared with the service life of the positive displacement motor itself, which will affect the drilling cycle and efficiency. During the actual use of the centralizer, due to the bent housing assembly having a certain curvature, during the use of the drive shaft assembly, the centralizer strip corresponding to the outermost side of the bent housing assembly on the drive shaft assembly wears most severely, and the wear - resistant layer on the centralizer strip will be worn out first. Although the centralizer strip without the wear - resistant layer can still work normally, if the wear - resistant layer is not repaired or replaced after wear, the centralizer strip without the wear - resistant layer will wear rapidly, resulting in the entire centralizer losing its function. Summary of the Invention

[0008] The purpose of the present invention is to provide a screw drill with an adaptively adjustable position of a stabilizing bar in the well, so as to solve the problem in the prior art that the stabilizing bar of the screw drill has no adaptive adjustment capability in the well.

[0009] In order to solve the above technical problems, the present invention adopts the following technical solutions:

[0010] A screw drill tool capable of adaptively adjusting the position of a straightening bar in a well comprises an anti-drop assembly, a motor assembly, a bent housing assembly, a universal shaft assembly and a transmission shaft assembly which are sequentially arranged from top to bottom. The transmission shaft assembly comprises a transmission shaft housing and a transmission shaft rotatably arranged in the transmission shaft housing. A straightening device is rotatably sleeved on the outer side of the transmission shaft housing. A plurality of straightening bars are vertically arranged around the outer side of the straightening device. A sliding hole is arranged at the lower end of the straightening device at a position corresponding to the straightening bar. A reversing locking tongue is slidably arranged in the sliding hole. A pop-up member for controlling the downward movement of a toggle block is arranged at the bottom of the sliding hole. The hole wall of the sliding hole is provided with and A trigger hole is connected to the surface of the straightening bar, and a wear-resistant layer is provided on the surface of the straightening bar, which blocks the trigger hole. A trigger and an elastic member are movably provided in the trigger hole, and the outer end of the trigger abuts against the inner side of the wear-resistant layer, and the other end is clamped with the surface of the reversing lock tongue. The elastic member is used to push the trigger to separate from the surface of the reversing lock tongue after the wear-resistant layer is completely worn out; a toggle block is provided on the outer wall of the transmission shaft below the reversing lock tongue, and the lower end of the reversing lock tongue contacts the toggle block when it moves downward, so as to drive the straightener to rotate, and a second top block for driving the reversing lock tongue to retract to the sliding hole is provided on the surface of the transmission shaft housing below the straightener.

[0011] A further technical solution is that the pop-up part includes a telescopic rod and a first spring, an elastic hole is recessed in the bottom of the sliding hole, one end of the telescopic rod is connected to the bottom of the elastic hole, and the other end is connected to the upper end of the reversing lock tongue, the first spring is sleeved on the outer wall of the telescopic rod, and the upper end of the first spring is connected to the bottom of the elastic hole, and the lower end is connected to the upper end of the reversing lock tongue.

[0012] A further technical solution is that the elastic member is a second spring, a limiting nut is provided on the inner wall of the inner end of the trigger hole, a limiting ring is provided on the outer wall of the trigger on the outside of the limiting nut, the second spring is sleeved on the outer wall of the trigger between the limiting ring and the limiting nut, and the two ends of the second spring are respectively connected to the limiting ring and the limiting nut; the reversing lock tongue is provided with a clamping hole at the position aligned with the trigger hole, and the inner end of the trigger is clamped in the clamping hole through the limiting nut; one end of the trigger that fits the wear-resistant layer is set to a wear-prone material.

[0013] A further technical solution is that the lower end of the reversing lock tongue is connected with a driving block below the sliding hole, and a rotating groove is arranged in a side depression surrounding the lower end of the transmission shaft housing, the lower groove wall of the rotating groove is connected to the lower end of the transmission shaft housing, and a first top block is arranged on the inner side protrusion of the driving block, the inner side of the first top block is slidably fitted with the groove bottom of the rotating groove, the side of the first top block facing the rotation direction of the stabilizer is arranged as a first arc surface, the first arc surface gradually inclines along the rotation direction of the stabilizer from bottom to top, the second top block protrudes and is arranged at the groove bottom of the rotating groove, the spacing between the second top block and the upper groove wall of the rotating groove is greater than the height of the first top block, and the side of the second top block facing away from the rotation direction of the stabilizer is arranged as a second arc surface slidably fitted with the first arc surface; the hole wall of the sliding hole is provided with a first accommodating hole and a second accommodating hole at intervals below the trigger hole, and the reversing A locking hole is provided on the surface of the lock tongue, and a locking column is provided in the first accommodating hole. The locking column is connected to the bottom of the first accommodating hole by a third spring, and a nylon ball is provided in the locking hole, and the nylon ball is connected to the bottom of the locking hole by a fourth spring; when the inner end of the trigger is clamped in the clamping hole, the first accommodating hole and the locking hole are aligned, and the locking column and the nylon ball are in contact and fit, so that the nylon ball is placed in the locking hole, and the locking column is placed in the first accommodating hole; after the reversing lock tongue is moved downward, the second accommodating hole and the locking hole are aligned, and the fourth spring pushes the nylon ball into the second accommodating hole, and the depth of the second accommodating hole is the same as the diameter of the nylon ball; after the first top block and the second top block cooperate to push the reversing lock tongue to move upward, the first accommodating hole and the locking hole are aligned again, and the third spring pushes the inner end of the locking column to enter the locking hole.

[0014] A further technical solution is that a bearing movable sleeve is provided on the outer wall of the transmission shaft near the lower end, and the shifting block is arranged on the bearing movable sleeve.

[0015] A further technical solution is that a stopper is provided at the bottom of the rotating groove on the side of the reversing lock tongue at the outermost position of the corresponding bent shell assembly toward the rotation direction of the stabilizer, and the stopper is arranged in contact with the upper groove wall of the rotating groove, the height of the stopper is smaller than the spacing between the first accommodating hole and the second accommodating hole, and the thickness of the stopper is lower than the depth of the rotating groove.

[0016] A further technical solution is that a cross roller bearing is installed on the upper side of the centralizer of the transmission shaft housing, the inner ring of the cross roller bearing is connected to the outer wall of the transmission shaft housing, and the upper end of the centralizer is fixedly connected to the outer ring of the cross roller bearing by fixing bolts.

[0017] A further technical solution is that a cross roller bearing is installed at the connection between the transmission shaft housing and the bent housing assembly, a ratchet is arranged around the upper side of the outer ring of the cross roller bearing, a ratchet is arranged around the upper side of the ratchet, and a pawl matching the ratchet is arranged at the lower end of the bent housing assembly, and the pawl is used to limit the one-way rotation of the ratchet.

[0018] A further technical solution is that a stop ring is provided at the lower end of the surround bending shell assembly, a pawl is provided on the lower side of the stop ring, a telescopic groove is provided in the recessed portion of the surround bending shell assembly, an adjustment ring is provided at the upper end of the surround stopping ring, the adjustment ring is slid up and down in the telescopic groove, a fifth spring is installed in the telescopic groove, the upper end of the fifth spring is connected to the bottom of the telescopic groove, and the lower end is connected to the upper side of the stop ring; a limiting slide groove is provided at the lower end of the bending shell assembly, a limiting block matching the limiting slide groove is provided at the upper end of the stop ring, and the limiting block is slid up and down in the limiting slide groove.

[0019] A further technical solution is that the inner wall of the transmission shaft housing is rotatably connected to the outer wall of the transmission shaft through a composite sheet bearing.

[0020] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. Before the wear-resistant layer on the straightening strip is worn away, the wear-resistant layer is used to support the trigger, so that the inner end of the trigger is engaged with the surface of the reversing lock tongue, thereby fixing the reversing lock tongue. At this time, the toggle block always moves with the transmission shaft, but the toggle block is located at the lower end of the reversing lock tongue and is in contact, so that the straightening device cannot be driven to rotate. When the wear-resistant layer is worn away, the outer end of the commutator loses the obstruction of the wear-resistant layer. Under the push of the elastic member, the outer end of the trigger passes through the trigger hole, so that the inner end of the trigger is separated from the surface of the reversing lock tongue. At this time, the reversing lock tongue is pushed downward by the pop-up member until the lower end of the reversing lock tongue contacts the toggle block, so that the commutator is rotated under the push of the toggle block, so that the straightening strip with the worn-away wear-resistant layer moves away from the original direction, that is, moves away from the outermost position of the corresponding bent shell assembly, and the straightening strip without the worn-away wear-resistant layer moves to this position. After rotating into place, the lower end of the reversing lock tongue is supported by the second top block, and the reversing lock tongue is retracted into the sliding hole with the help of the second top block, so that the toggle block is separated from the reversing lock tongue, and the commutator cannot be driven to rotate. And when the wear-resistant layer on the straightening bar at the outermost position of the bent shell assembly is worn out, the above movement will be automatically repeated to rotate the next straightening bar to this position, thereby realizing automatic adjustment of the straightening bar. The present invention allows the straightening bar of the stabilizer to have downhole adaptive ability and realize automatic reversing after eccentric wear of the straightening bar. Improve the service life of the entire screw, solve the short board effect of the barrel caused by eccentric wear of the straightening bar, and improve drilling efficiency; 2. Greatly improve the drilling efficiency of the screw drilling tool and the utilization rate of the wear-resistant material of the straightening bar of the stabilizer. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 The overall schematic diagram of a screw drill tool capable of adaptively adjusting the orientation of a straightening bar in a well according to the present invention.

[0022] Figure 2 The present invention is a schematic diagram of a transmission shaft assembly of a screw drill capable of adaptively adjusting the position of a straightening bar in a well.

[0023] Figure 3 The present invention is a schematic diagram of a transmission shaft housing and a rotating groove of a screw drill tool capable of adaptively adjusting the orientation of a straightening bar in a well.

[0024] Figure 4 The present invention is a schematic diagram of a reversing locking tongue of a screw drill tool capable of adaptively adjusting the orientation of a straightening bar in a well.

[0025] Figure 5 The present invention is a cross-sectional schematic diagram of a transmission shaft assembly of a screw drill tool capable of adaptively adjusting the orientation of a straightening bar in a well.

[0026] Figure 6 for Figure 5 A partial enlargement of the mark A in the middle Figure 1 .

[0027] Figure 7 for Figure 5 A partial enlargement of the mark A in the middle Figure 2 .

[0028] Figure 8 for Figure 5 A partial enlargement of the mark A in the middle Figure 3 .

[0029] Figure 9 for Figure 5 A partial enlarged schematic diagram of the area marked B in the middle.

[0030] Icons: 1-anti-drop assembly, 2-motor assembly, 3-bend housing assembly, 4-universal shaft assembly, 5-drive shaft assembly, 6-drive shaft housing, 7-drive shaft, 8-centralizer, 9-centralizer bar, 10-sliding hole, 11-reversing lock tongue, 12-trigger hole, 13-wear-resistant layer, 14-trigger, 15-sliding block, 16-second top block, 17-telescopic rod, 18-first spring, 19-elastic hole, 20-second spring, 21-limiting nut, 22-limiting ring, 23-card hole, 24-drive block, 25 -rotation groove, 26-first top block, 27-first arc surface, 28-second arc surface, 29-first accommodating hole, 30-second accommodating hole, 31-locking hole, 32-locking column, 33-third spring, 34-nylon ball, 35-fourth spring, 36-bearing sleeve, 37-stopper, 38-cross roller bearing, 39-fixing bolt, 40-ratchet, 41-ratchet, 42-pawl, 43-stop ring, 44-telescopic groove, 45-adjusting ring, 46-fifth spring, 47-composite sheet bearing, 48-limiting block. DETAILED DESCRIPTION

[0031] In order to make the objectives, technical solutions and advantages of the present invention more clear and understandable, 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.

[0032] Figures 1 to 9 The following shows an embodiment of the present invention. In the embodiment, the upper end is Figure 1 , Figure 2 , Figure 3 , Figure 5 the right end shown in the following, and the lower end is the left end in the above figure.

[0033] Embodiment 1:

[0034] A downhole screw drill with an adaptively adjustable centralizer strip orientation includes a drop prevention assembly 1, a motor assembly 2, a bent housing assembly 3, a universal shaft assembly 4, and a drive shaft assembly 5 arranged in sequence from top to bottom. The drive shaft assembly 5 includes a drive shaft housing 6 and a drive shaft 7 rotatably arranged within the drive shaft housing 6. An outer side of the drive shaft housing 6 is rotatably sleeved with a centralizer 8. A plurality of centralizer strips 9 are vertically arranged around an outer side of the centralizer 8. A sliding hole 10 is provided at a position of the lower end of the centralizer 8 corresponding to the centralizer strip 9. A reversing lock tongue 11 is slidably arranged within the sliding hole 10. A pop-up member for controlling the downward movement of a toggle block 15 is provided at a bottom of the sliding hole 10. A trigger hole 12 communicating with a surface of the centralizer strip 9 is provided in a wall of the sliding hole 10. A wear-resistant layer 13 is provided on the surface of the centralizer strip 9, and the wear-resistant layer 13 seals the trigger hole 12. A trigger 14 and an elastic member are movably arranged within the trigger hole 12. An outer end of the trigger 14 abuts against an inner side of the wear-resistant layer 13, and the other end is engaged with a surface of the reversing lock tongue 11. The elastic member is used to push the trigger 14 to separate from the surface of the reversing lock tongue 11 after the wear-resistant layer 13 is worn out; a toggle block 15 is provided on an outer wall of the drive shaft 7 below the reversing lock tongue 11. When the lower end of the reversing lock tongue 11 moves downward, it contacts the toggle block 15 to drive the centralizer 8 to rotate. A second top block 16 for driving the reversing lock tongue 11 to retract into the sliding hole 10 is provided on a surface of the drive shaft housing 6 below the centralizer 8. Before the wear-resistant layer 13 on the centralizer strip 9 is worn out, the wear-resistant layer 13 is used to hold the trigger 14, so that an inner end of the trigger 14 is engaged with a surface of the reversing lock tongue 11, thereby fixing the reversing lock tongue 11. At this time, the toggle block 15 always moves together with the drive shaft 7, but the toggle block 15 is located in contact with the lower end of the reversing lock tongue 11, so that the centralizer 8 cannot be driven to rotate. After the wear-resistant layer 13 is worn out, the outer end of the centralizer 8 loses the block of the wear-resistant layer 13. Under the push of the elastic member, the outer end of the trigger 14 penetrates out of the trigger hole 12, so that the inner end of the trigger 14 is separated from the surface of the reversing lock tongue 11. At this time, the pop-up member is used to push the reversing lock tongue 11 downward until the lower end of the reversing lock tongue 11 contacts the toggle block 15, so that under the push of the toggle block 15, the centralizer 8 rotates, and the centralizer strip 9 with the worn-out wear-resistant layer 13 is moved away from its original orientation, that is, moved away from the position corresponding to the outermost side of the bent housing assembly 3, and the centralizer strip 9 without the worn-out wear-resistant layer 13 moves to this position. After rotating in place, the lower end of the reversing lock tongue 11 contacts the second top block 16, and the reversing lock tongue 11 is retracted into the sliding hole 10 by means of the second top block 16, so that the toggle block 15 is separated from the reversing lock tongue 11, and the centralizer 8 cannot be driven to rotate. And when the wear-resistant layer 13 on the centralizer strip 9 at the outermost side position of the bent housing assembly 3 is worn out at this time, the above movement will be automatically repeated, so that the next centralizer strip 9 rotates to this position, thereby realizing the automatic adjustment of the centralizer strip 9. The present invention enables the centralizer strip 9 of the centralizer 8 to have downhole adaptability and realizes the automatic commutation of the centralizer strip 9 after eccentric wear.Improve the service life of the entire positive displacement motor, solve the "barrel short board effect" caused by the eccentric wear of the centralizer 9, and improve the drilling efficiency. Greatly improve the drilling efficiency of the positive displacement motor and the utilization rate of the wear-resistant material of the centralizer 9.

[0035] The ejecting member includes a telescopic rod 17 and a first spring 18. An elastic hole 19 is recessed at the bottom of the sliding hole 10. One end of the telescopic rod 17 is connected to the bottom of the elastic hole 19, and the other end is connected to the upper end of the reversing lock tongue 11. The first spring 18 is sleeved on the outer wall of the telescopic rod 17, and the upper end of the first spring 18 is connected to the bottom of the elastic hole 19, and the lower end is connected to the upper end of the reversing lock tongue 11. By providing the first spring 18, when the trigger 14 is separated from the reversing lock tongue 11, the elastic force of the first spring 18 is used to push the reversing lock tongue 11 to move downward quickly. By providing the telescopic rod 17, it can support the first spring 18 and prevent the first spring 18 from being bent during compression and extension, resulting in the reversing lock tongue 11 not being able to pop out quickly smoothly.

[0036] The elastic member is a second spring 20. A limit nut 21 is provided on the inner wall of the inner end of the trigger hole 12. A limit ring 22 is provided on the outer wall of the trigger 14 outside the limit nut 21. The second spring 20 is sleeved on the outer wall of the trigger 14 between the limit ring 22 and the limit nut 21, and both ends of the second spring 20 are in contact with and abutted against the limit ring 22 and the limit nut 21 respectively; a clamping hole 23 is provided at the position where the reversing lock tongue 11 aligns with the trigger hole 12, and the inner end of the trigger 14 passes through the limit nut 21 and is clamped in the clamping hole 23; the end of the trigger 14 that fits the wear-resistant layer 13 is made of a material that is easily worn. Through the clamping hole 23, when the wear-resistant layer 13 has not been worn off, the reversing lock tongue 11 can be fixed in the sliding hole 10 by means of the clamping hole 23 and the trigger 14. The material that is easily worn is selected from plastics, low-density metals, or other materials that can be worn off in a short time. In this way, when the second spring 20 pushes the trigger 14 to move outward toward the trigger hole 12, the inner end of the trigger 14 can be quickly separated from the reversing lock tongue 11 by quickly wearing off the easily worn material. After the wear-resistant layer 13 is worn, the second spring 20 pushes the trigger 14 to move toward the outer end of the trigger hole 12 so that the outer end of the trigger 14 contacts and rubs against the hole wall of the drilling hole, thereby quickly consuming the easily worn material and separating the trigger 14 from the clamping hole 23.

[0037] The lower end of the reversing locking tongue 11 is connected with a driving block 24 below the sliding hole 10. A rotating groove 25 is recessed on the side surface around the lower end of the transmission shaft housing 6. The lower groove wall of the rotating groove 25 is communicated with the lower end of the transmission shaft housing 6. A first top block 26 is protruded on the inner side of the driving block 24. The inner side of the first top block 26 is slidably attached to the bottom of the rotating groove 25. One side of the first top block 26 facing the rotating direction of the aligner 8 is provided with a first arc surface 27. The first arc surface 27 is gradually inclined along the rotating direction of the aligner 8 from bottom to top. A second top block 16 is protruded on the bottom of the rotating groove 25. The distance between the second top block 16 and the upper groove wall of the rotating groove 25 is greater than the height of the first top block 26. One side of the second top block 16 facing away from the rotating direction of the aligner 8 is provided with a second arc surface 28 that is slidably attached to the first arc surface 27. The hole wall of the sliding hole 10 is provided with a first accommodation hole 29 and a second accommodation hole 30 at intervals below the trigger hole 12. A locking hole 31 is provided on the surface of the reversing locking tongue 11. A locking column 32 is arranged in the first accommodation hole 29. The locking column 32 is in contact with the bottom of the first accommodation hole 29 through a third spring 33. A nylon ball 34 is arranged in the locking hole 31. The nylon ball 34 is in contact with the bottom of the locking hole 31 through a fourth spring 35. When the inner end of the trigger 14 is clamped in the clamping hole 23, the first accommodation hole 29 and the locking hole 31 are aligned, and the locking column 32 and the nylon ball 34 are in contact and fit, so that the nylon ball 34 is placed in the locking hole 31 and the locking column 32 is placed in the first accommodation hole 29. After the reversing locking tongue 11 moves downward to complete, the second accommodation hole 30 and the locking hole 31 are aligned, and the fourth spring 35 pushes the nylon ball 34 into the second accommodation hole 30. The depth of the second accommodation hole 30 is the same as the diameter of the nylon ball 34. After the first top block 26 and the second top block 16 cooperate to push the reversing locking tongue 11 upward to complete, the first accommodation hole 29 and the locking hole 31 are aligned again, and the third spring 33 pushes the inner end of the locking column 32 into the locking hole 31. With such a setting, as Figure 6 shown, when the wear-resistant layer 13 is not worn off, the inner end of the trigger 14 is inserted into the clamping hole 23 to fix the reversing locking tongue 11. At this time, the first accommodation hole 29 and the locking hole 31 are aligned, and the locking column 32 and the nylon ball 34 are in contact and fit. By selecting different elastic third springs 33 and fourth springs 35, the nylon ball 34 and the locking column 32 are in a balanced state. The nylon ball 34 is placed in the locking hole 31 and the locking column 32 is placed in the first accommodation hole 29. As Figure 7As shown, after the friction wears off, the trigger 14 gradually separates from the locking hole 23. When the trigger 14 moves away from the locking hole 23, the reversing lock tongue 11 is quickly pushed downward by the thrust of the first spring 18, so that the lower end of the reversing lock tongue 11 can contact the toggle block 15. At this time, the locking hole 31 moves downward with the reversing lock tongue 11, from being aligned with the first accommodating hole 29 to being aligned with the second accommodating hole 30, and the nylon ball 34 is pushed into the second accommodating hole 30 by the fourth spring 35. When the toggle block 15 moves to the position of the reversing lock tongue 11 that pops out, the centralizer 8 is rotated under the drive of the toggle block 15. When the reversing lock tongue 11 that pops out moves to the position of the second top block 16, the reversing lock tongue 11 is pushed upward by the contact between the first arc surface 27 and the second arc surface 28, and retracted into the sliding hole 10 again, as shown in FIG. Figure 8 As shown, at this time, the locking hole 31 of the reversing lock tongue 11 moves from the position aligned with the second receiving hole 30 to the position aligned with the first receiving hole 29, so that the locking column 32 in the first receiving hole 29 enters the locking hole 31 under the push of the third spring 33 and compresses the fourth spring 35. At this time, the reversing lock tongue 11 is re-locked in the sliding hole 10. For example, when there are five straightening bars 9 distributed on the surface of a straightener 8, it pops out from the reversing lock tongue 11, contacts the second top block 16 under the push of the toggle block 15, and retracts into the sliding hole 10. In this process, the straightener 8 rotates 72 degrees, that is, the angle of one-fifth of a circle. And each subsequent reversing lock tongue 11 rotates this angle after it pops out until all five straightening bars 9 rotate to this position to work.

[0038] The outer wall of the transmission shaft 7 near the lower end is sleeved with a bearing sleeve 36, and the toggle block 15 is arranged on the bearing sleeve 36. The bearing sleeve 36 serves as a friction member between the transmission shaft housing 6 and the transmission shaft 7 to avoid direct friction contact between the transmission shaft 7 and the transmission shaft housing 6.

[0039] A stopper 37 is provided at the bottom of the rotation groove 25 on the side of the reversing lock tongue 11 at the outermost position of the curved shell assembly 3 facing the rotation direction of the centralizer 8. The stopper 37 is arranged in contact with the upper groove wall of the rotation groove 25. The height of the stopper 37 is less than the spacing between the first receiving hole 29 and the second receiving hole 30, and the thickness of the stopper 37 is less than the depth of the rotation groove 25. By providing the stopper 37, when the centralizer 8 is working, the part of the reversing lock tongue 11 protruding from the sliding hole 10, that is, the first top block 26 is in contact with the stopper 37, so that the centralizer 8 is restricted from rotating in the same direction as the transmission shaft 7 when working. When the reversing lock tongue 11 pops out, the first top block 26 moves downward to bypass the stopper 37 and then drives the centralizer 8 to rotate under the drive of the toggle block 15.

[0040] Embodiment 2:

[0041] On the basis of Embodiment 1, a crossed roller bearing 38 is installed on the upper side of the centralizer 8 on the transmission shaft housing 6. The inner ring of the crossed roller bearing 38 is connected to the outer wall of the transmission shaft housing 6, and the upper end of the centralizer 8 is fixedly connected to the outer ring of the crossed roller bearing 38 through a fixing bolt 39. By providing the crossed roller bearing 38, the centralizer 8 can rotate smoothly on the surface of the transmission shaft housing 6, and at the same time, the centralizer 8 can work stably.

[0042] The crossed roller bearing 38 is installed at the connection between the transmission shaft housing 6 and the bent housing assembly 3. A ratchet wheel 40 is provided on the upper side of the outer ring surrounding the crossed roller bearing 38, a ratchet tooth 41 is provided on the upper side of the ratchet wheel 40, and a ratchet pawl 42 matching the ratchet tooth 41 is provided at the lower end of the bent housing assembly 3. The ratchet pawl 42 is used to limit the one-way rotation of the ratchet wheel 40. Through the cooperation of the ratchet wheel 40 and the ratchet pawl 42, the rotation direction of the centralizer 8 can be restricted, and the centralizer 8 can be prevented from rotating in the direction opposite to the transmission shaft 7.

[0043] A stop ring 43 is provided around the lower end of the bent housing assembly 3. The ratchet pawl 42 is provided on the lower side of the stop ring 43. A telescopic groove 44 is recessed around the lower end of the bent housing assembly 3. An adjusting ring 45 is provided around the upper end of the stop ring 43. The adjusting ring 45 is slidably arranged up and down in the telescopic groove 44. A fifth spring 46 is installed in the telescopic groove 44. The upper end of the fifth spring 46 is in contact with the bottom of the telescopic groove 44, and the lower end is in contact with the upper side of the stop ring 43. A limiting sliding groove is provided at the lower end of the bent housing assembly 3, and a limiting block 48 matching the limiting sliding groove is provided at the upper end of the stop ring 43. The limiting block 48 is slidably arranged up and down in the limiting sliding groove. When the centralizer 8 rotates, the ratchet tooth 41 on the ratchet wheel 40 rotates with the ratchet wheel 40, thereby pushing the ratchet pawl 42 engaged with the ratchet tooth 41 to move upward, thereby pushing the stop ring 43 to move upward. During the upward movement of the stop ring 43, the adjusting ring 45 is driven to compress the fifth spring 46. Every time the ratchet tooth 41 and the ratchet pawl 42 move a tooth pitch distance, the fifth spring 46 will push the stop ring 43 to move downward to make the ratchet tooth 41 and the ratchet pawl 42 engage. With the cooperation of the limiting sliding groove and the limiting block 48, the rotation of the stop ring 43 can be restricted, and thus the rotation of the centralizer 8 can be restricted by the stop ring 43.

[0044] The inner wall of the transmission shaft housing 6 is rotatably connected to the outer wall of the transmission shaft 7 through a composite sheet bearing 47.

[0045] Although the present invention has been described herein with reference to various illustrative embodiments of the invention, it should be understood that those skilled in the art can devise many other modifications and embodiments that will fall within the scope and spirit of the principles 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 layout of the subject combination layout. In addition to the variations and improvements to the components and / or layout, other uses will also be apparent to those skilled in the art.

Claims

1. A downhole positive displacement motor with an adaptively adjustable centralizer orientation, comprising, from top to bottom, a falling prevention assembly (1), a motor assembly (2), a bent housing assembly (3), a universal shaft assembly (4) and a drive shaft assembly (5). The drive shaft assembly (5) includes a drive shaft housing (6) and a drive shaft (7) rotatably disposed within the drive shaft housing (6), characterized in that, The outer rotating sleeve of the transmission shaft housing (6) is provided with a centralizer (8), and a plurality of centralizer bars (9) are vertically arranged around the outer side of the centralizer (8). The lower end of the centralizer (8) is provided with a sliding hole (10) at a position corresponding to the centralizer bar (9), and a reversing lock tongue (11) is slidably arranged in the sliding hole (10). A pop-up member for controlling the downward movement of the toggle block (15) is provided at the bottom of the sliding hole (10). A trigger hole (12) connected to the surface of the centralizer bar (9) is provided on the wall of the sliding hole (10), and a wear-resistant layer (13) is provided on the surface of the centralizer bar (9). The wear-resistant layer (13) blocks the trigger hole (12), and the trigger hole (12) A trigger (14) and an elastic member are movably provided inside, the outer end of the trigger (14) abuts against the inner side of the wear-resistant layer (13), and the other end is clamped with the surface of the reversing lock tongue (11), and the elastic member is used to push the trigger (14) to separate from the surface of the reversing lock tongue (11) after the wear-resistant layer (13) is completely worn; the outer wall of the transmission shaft (7) is provided with a toggle block (15) below the reversing lock tongue (11), and the lower end of the reversing lock tongue (11) contacts the toggle block (15) when moving downward, so as to drive the centralizer (8) to rotate, and the surface of the transmission shaft housing (6) is provided with a second top block below the centralizer (8) for driving the reversing lock tongue (11) to retract to the sliding hole (10) The reversing lock tongue (11) is connected to a driving block (24) at the lower end of the sliding hole (10), and a rotation groove (25) is arranged in a side depression around the lower end of the transmission shaft housing (6); a first top block (26) is arranged on the inner side protrusion of the driving block (24); a first arc surface (27) is arranged on the side of the first top block (26) facing the rotation direction of the centralizer (8), and the first arc surface (27) is gradually inclined from bottom to top along the rotation direction of the centralizer (8), and the second top block (16) is protruded and arranged at the bottom of the rotation groove (25); a side of the second top block (16) facing away from the rotation direction of the centralizer (8) is arranged to be slidably fitted with the first arc surface (27). a second curved surface (28) of the first receiving hole (29) and the second receiving hole (30) are arranged at intervals on the wall of the sliding hole (10) below the trigger hole (12); a locking hole (31) is arranged on the surface of the reversing lock tongue (11); a locking column (32) is arranged in the first receiving hole (29); the locking column (32) is connected to the bottom of the first receiving hole (29) by a third spring (33); a nylon ball (34) is arranged in the locking hole (31); the nylon ball (34) is connected to the bottom of the locking hole (31) by a fourth spring (35); a cross roller bearing (38) is installed on the upper side of the centralizer (8) of the transmission shaft housing (6);A ratchet wheel (40) is provided on the upper side of the outer ring of the crossed roller bearing (38), and ratchet teeth (41) are provided on the upper side of the ratchet wheel (40). A pawl (42) matching the ratchet teeth (41) is provided at the lower end of the bent housing assembly (3). A stop ring (43) is provided around the lower end of the bent housing assembly (3), a telescopic groove (44) is recessed around the lower end of the bent housing assembly (3), and an adjusting ring (45) is provided around the upper end of the stop ring (43).; 2. The positive displacement motor with an underground self-adaptive adjustable centralizer orientation according to claim 1, wherein: The pop-up member comprises a telescopic rod (17) and a first spring (18); the bottom of the sliding hole (10) is recessed to form an elastic hole (19); one end of the telescopic rod (17) is connected to the bottom of the elastic hole (19), and the other end is connected to the upper end of the reversing lock tongue (11); the first spring (18) is sleeved on the outer wall of the telescopic rod (17), and the upper end of the first spring (18) is connected to the bottom of the elastic hole (19), and the lower end is connected to the upper end of the reversing lock tongue (11).

3. The positive displacement motor with an underground self-adaptive adjustable centralizer orientation according to claim 1, wherein: The elastic member is a second spring (20); a limiting nut (21) is arranged on the inner wall of the inner end of the trigger hole (12); a limiting ring (22) is arranged on the outer side of the limiting nut (21) on the outer wall of the trigger (14); the second spring (20) is sleeved on the outer wall of the trigger (14) between the limiting ring (22) and the limiting nut (21); and the two ends of the second spring (20) are respectively connected to the limiting ring (22) and the limiting nut (21); the reversing lock tongue (11) is provided with a clamping hole (23) at a position aligned with the trigger hole (12); the inner end of the trigger (14) passes through the limiting nut (21) and is clamped in the clamping hole (23); and one end of the trigger (14) that contacts the wear-resistant layer (13) is provided with an easily-worn material.

4. A positive displacement downhole motor with an axially adjustable centralizer according to claim 3, wherein: The lower groove wall of the rotating groove (25) is connected to the lower end of the transmission shaft housing (6), the inner side of the first top block (26) is slidably fitted with the groove bottom of the rotating groove (25), and the distance between the second top block (16) and the upper groove wall of the rotating groove (25) is greater than the height of the first top block (26); when the inner end of the trigger (14) is clamped in the clamping hole (23), the first receiving hole (29) and the locking hole (31) are aligned, and the locking column (32) and the nylon ball (34) are in contact with each other, so that the nylon ball (34) is placed in the locking hole (31), and the locking column (32) is placed in the first receiving hole (29). After the reversing lock tongue (11) has moved downward, the second receiving hole (30) and the locking hole (31) are aligned, and the fourth spring (35) pushes the nylon ball (34) into the second receiving hole (30), and the depth of the second receiving hole (30) is the same as the diameter of the nylon ball (34); after the first top block (26) and the second top block (16) cooperate to push the reversing lock tongue (11) to move upward, the first receiving hole (29) and the locking hole (31) are aligned again, and the third spring (33) pushes the inner end of the locking column (32) into the locking hole (31).

5. The positive displacement motor with an underground self - adaptive adjustable centralizer orientation according to claim 1, characterized in that: A bearing movable sleeve (36) is sleeved on the outer wall of the transmission shaft (7) near the lower end, and the shifting block (15) is arranged on the bearing movable sleeve (36).

6. The positive displacement motor with an axially adjustable centralizer according to claim 1, wherein: The bottom of the rotating groove (25) is provided with a stop block (37) on the side where the reversing locking tongue (11) corresponding to the outermost position of the bent housing assembly (3) faces the rotation direction of the aligner (8). The stop block (37) is arranged in contact with the upper groove wall of the rotating groove (25). The height of the stop block (37) is less than the distance between the first receiving hole (29) and the second receiving hole (30), and the thickness of the stop block (37) is lower than the depth of the rotating groove (25).

7. A positive displacement motor with an underground self - adaptive adjustable centralizer orientation according to claim 1, characterized in that: The inner ring of the crossed roller bearing (38) is connected to the outer wall of the transmission shaft housing (6), and the upper end of the aligner (8) is fixedly connected to the outer ring of the crossed roller bearing (38) through a fixing bolt (39).

8. The positive displacement motor with an underground self-adaptive adjustable centralizer orientation according to claim 7, characterized in that: The crossed roller bearing (38) is installed at the connection between the transmission shaft housing (6) and the bent housing assembly (3), and the pawl (42) is used to limit the one-way rotation of the ratchet wheel (40).

9. A positive displacement motor for downhole use with an axially adjustable centralizer strip according to claim 8, characterized in that: The pawl (42) is arranged on the lower side of the stop ring (43). The adjusting ring (45) is slidably arranged up and down in the telescopic groove (44). A fifth spring (46) is installed in the telescopic groove (44). The upper end of the fifth spring (46) is in contact with the bottom of the telescopic groove (44), and the lower end is in contact with the upper side of the stop ring (43). A limit sliding groove is provided at the lower end of the bent housing assembly (3), and a limit block (48) matching the limit sliding groove is provided at the upper end of the stop ring (43). The limit block (48) is slidably arranged up and down in the limit sliding groove.

10. A positive displacement motor with an axially adjustable centralizer according to claim 1, characterized in that: The inner wall of the transmission shaft housing (6) is rotationally connected to the outer wall of the transmission shaft (7) through a composite film bearing (47).

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