Wellhead blowout preventer

Abstract

The present invention relates to the technical field of oil production engineering, and is a wellhead blowout prevention device, comprising a blowout prevention housing, a left valve core, a right valve core and a driving assembly, wherein the upper end of the blowout prevention housing is provided with an installation through hole for inserting a light rod. The present invention has a reasonable and compact structure, and when the light rod in the installation through hole is not in the center, the right valve core moves to the left, so that the eccentric light rod can move along the inner wall of the guide groove to the right sealing groove, which can play a straightening effect on the eccentric light rod, and then the guide part moves to the right again to seal and contact with the guide groove, and finally the left sealing groove, the guide part and the right sealing groove are close to each other to form a cylindrical sealing hole that passes through from top to bottom, and the outer side of the light rod is in sealing contact with the inner wall of the sealing hole, thereby playing the effect of closing the installation through hole, and when the light rod leaks or a steam blowout occurs, the installation through hole can be quickly and timely closed by the driving assembly, thereby ensuring the safe operation of the wellhead blowout preventer of the pumping unit and reducing the occurrence of wellhead pollution incidents.

Description

Technical Field

[0001] The invention relates to the technical field of oil production engineering and relates to a wellhead blowout prevention device. Background Art

[0002] During the heavy oil production process, the oil well polished rod seal relies on the wellhead polished rod sealer for sealing. When the seal packing in the packing cavity wears and leaks or there is a risk of blowout due to steam interference between wells, inspection personnel are required to go to the site for maintenance in time to prevent wellhead pollution. Due to the large number of points and wide coverage, manual inspections cannot achieve full coverage (especially at night), and oil well seal leakage cannot be discovered in time, resulting in large-scale leakage and pollution of oil wells.

[0003] A Chinese patent document with publication number CN115653530A records a blowout prevention sealing device for an oil wellhead, including a main body of the blowout prevention sealing device, a through-shaped central pipe for accommodating a light rod is opened in the middle of the main body, sliding chambers are arranged on the left and right sides of the main body, and sealing mechanisms are slidably connected in the two sliding chambers. A hydraulic push rod is arranged on the sealing mechanism to drive it to slide. The sealing mechanism includes: a mounting frame, which is slidably connected in the sliding chamber, and the hydraulic push rod is connected to the side of the mounting frame away from the central pipe; an elastic sealing body, which is fixedly connected to the side of the mounting frame close to the central pipe, an upper mounting block is fixedly connected above the elastic sealing body, and a lower mounting block is installed below the elastic sealing body, and the upper mounting block, the lower mounting block and the mounting frame are fixedly connected and separated by the elastic sealing body, and the upper mounting block, the lower mounting block and the elastic sealing body are A groove adapted to the light rod is provided at the corresponding position, and when the sealing mechanisms on the left and right sides move toward the center and contact and close, the elastic sealing body seals the central pipe; a scraper is provided on the upper mounting block and the lower mounting block, and a slidable and resettable scraper is provided on the upper mounting block and the lower mounting block in the direction close to the central pipe, and the scraper is adapted to the light rod, and in the initial state, the scraper extends outward, and when the scraper slides and retracts into the upper mounting block or the lower mounting block, the impurities on it are blocked and removed, and a pulling mechanism driving it to retract inward is provided on the inner side of the scraper. The elastic sealing body used to seal the outer side of the light rod in the anti-blowout sealing device for the oil wellhead is relatively complex in structure, which is not easy to process and manufacture, and will lead to a substantial increase in the subsequent maintenance cost, and it cannot return the eccentric light rod to the center, making the sealing operation more difficult.

[0004] The Chinese patent document with the publication number CN118167234A discloses a gate packing type polished rod sealer, comprising a fixed tube, a first fixed ring is arranged on the fixed tube, a connecting shell is arranged on the side of the first fixed ring away from the fixed tube, a sealing shell is threadedly connected to the connecting shell, a sealing cover is threadedly connected to the sealing shell, a fixed plate with a mirror image distribution is fixedly connected in the sealing shell, a sliding ring is slidably connected in the sealing shell, a spring is arranged between the sliding ring and the adjacent fixed plate, a second fixed ring is fixedly connected in the sealing shell, the sliding ring and the second fixed ring are both located between the fixed plates with a mirror image distribution, and the sliding ring and the second fixed ring are connected to the fixed plates with a mirror image distribution. The second fixed rings are rotatably connected to a rotating plate, the opposite sides of the fixed plates in mirror distribution are rotatably connected to rotating blocks, the opposite sides of the rotating blocks in mirror distribution are fixedly connected to force storage plates through mounting rods, torsion springs are arranged between the force storage plates and adjacent rotating plates, packings are arranged between the rotating plates in mirror distribution, and gate plates in mirror distribution are commonly arranged between the fixed tube and the connecting shell, a pre-tightening mechanism for providing a tightening force for the packing is arranged on the fixed plate near the second fixed ring, and the sealing of the light rod by the gate plate packing type light rod sealer requires inspection personnel to operate on site, which not only has certain safety hazards, but also increases maintenance costs.

[0005] Faced with the current situation of a continuous decrease in team staff and an increasing number of oil wells under management, there is an urgent need for technology that can automatically seal the source of leakage when the wellhead sealer leaks or there is a risk of blowout. Summary of the invention

[0006] The present invention provides a wellhead blowout prevention device, which overcomes the deficiencies of the above-mentioned prior art and can effectively solve the problems of the existing polished rod sealer, such as high labor intensity in manual inspection of oil wells, difficulty in closing the oil well seal when it leaks, and easy to cause large-scale leakage and pollution of the oil well.

[0007] The technical scheme of the present invention is realized by the following measures: a wellhead blowout prevention device, comprising a blowout prevention housing, a left valve core, a right valve core and a driving assembly, the upper end of the blowout prevention housing is provided with a mounting through hole for penetrating a polished rod, the left end of the blowout prevention housing is provided with a left sealing hole, the right end of the left sealing hole is communicated with the mounting through hole, a left valve core is installed in the left sealing hole, a left sealing groove opening to the right and passing through up and down is provided at the right end of the left valve core, a right sealing hole is provided at the right end of the blowout prevention housing, the left end of the right sealing hole is communicated with the mounting through hole, a right valve core is installed in the right sealing hole, and a left portion of the right valve core is provided with a left sealing groove opening to the right and passing through up and down A right sealing groove passes through downward, a guide groove opening to the left and gradually narrowing from left to right is provided at the left end of the right valve core, the right part of the guide groove is communicated with the left part of the right sealing groove, and the front right end and the rear right end of the left valve core corresponding to the position of the left sealing groove are fixed with guide parts matching the guide groove, and a driving assembly capable of making the left valve core and the right valve core approach each other or move away from each other is provided on the outside of the blowout prevention shell, when the left valve core and the right valve core approach each other, the left sealing groove, the guide part and the right sealing groove can form a light rod sealing hole passing through from top to bottom, and the inner wall of the light rod sealing hole can be in sealing contact with the outside of the light rod.

[0008] The following are further optimizations and / or improvements to the above technical solutions:

[0009] The guide groove may be in an arc shape opening to the left, and the width of the left end of the guide groove is smaller than the diameter of the right valve core.

[0010] The above-mentioned driving assembly may include a left end cover, a left valve stem, a right end cover, a right valve stem and a driving mechanism, the left end cover is fixedly installed on the left end of the blowout prevention shell, a left threaded hole extending left and right is provided in the center of the left end cover, a left valve stem whose right end is fixedly installed with the left end of the left valve core is threaded in the left threaded hole, the right end cover is fixedly installed on the right end of the blowout prevention shell, a right threaded hole extending left and right is provided in the center of the right end cover, a right valve stem whose left end is fixedly installed with the right end of the right valve core is threaded in the right threaded hole, the driving mechanism can drive the left valve stem and the right valve stem to rotate, and when the left valve stem and the right valve stem rotate, the left valve core and the right valve core are close to or away from each other.

[0011] The above-mentioned left valve stem may include a push rod, a push plate and a push rod. The left end of the left valve core is provided with a mounting groove opening to the left. The outer side of the right part of the push rod is inserted into the mounting groove. The left end of the push rod is fixed with a top plate fixedly installed together with the left part of the left valve core. The outer side of the right part of the push rod is provided with a feed thread matching with the left threaded hole. The outer side of the right part of the push rod is screwed into the left threaded hole. The left end of the top plate is provided with a clamping groove opening to the left. The clamping groove includes a removal section and a limiting section. The removal section is in an arc shape opening downward, and the limiting section is in a U shape opening upward. The lower part of the segment is connected with the upper part of the limit segment, and a right limit plate is fixedly installed on the right end of the push rod and is rotatably installed on the inner side of the lower part of the limit segment. A U-shaped limit boss with an opening upward is fixedly installed on the inner side of the left part of the limit segment corresponding to the left side of the right limit plate, and an annular left limit plate is fixedly installed on the outer side of the right part of the push rod between the left side of the limit boss and the right side of the left end cover. The right valve stem has the same structure as the left valve stem and is symmetrically arranged, and the driving mechanism is respectively installed with the left part of the push rod and the right middle part of the right valve stem corresponding to the left part of the push rod.

[0012] A left sealing assembly may be provided between the push rod and the left end cover, the left sealing assembly comprising a sealing sleeve, a sealing packing, a compression sleeve and a pressure cap, the left end of the left end cover is fixedly installed together with the right end of the sealing sleeve which is sleeved on the outside of the push rod, a rotating ring platform is fixed to the inner side of the left end of the left end cover, a sealing packing is installed between the inner side of the sealing sleeve corresponding to the left end of the rotating ring platform and the outer side of the push rod, a compression sleeve is sleeved on the inner side of the left part of the sealing sleeve corresponding to the left end of the sealing packing, a supporting outer ring platform is fixedly installed on the outer side of the left end of the compression sleeve, a pressure cap is screwed on the outer side of the sealing sleeve, a compression inner ring platform which is sleeved on the outside of the push rod is fixed to the inner side of the left end of the pressure cap corresponding to the left end of the supporting outer ring platform, and a right sealing assembly which has the same structure as the left sealing assembly and is symmetrically arranged is provided between the right valve stem and the right end cover.

[0013] As a preferred embodiment, the above-mentioned driving mechanism may include a support seat, a reduction box, a speed reducer, a first motor, a left driving gear and a right driving gear. The left driven gear is detachably fixedly installed on the outer side of the left part of the push rod corresponding to the left position of the gland, and the right driven gear is fixedly installed on the position corresponding to the outer side of the left part of the push rod in the right valve stem corresponding to the right position of the right sealing assembly. The support seat is fixedly installed on the outer side of the blowout prevention shell, and the speed reducer is fixedly installed in the support seat. The speed reducer is fixedly installed on the front side of the speed reducer, and the front side of the speed reducer is fixedly installed with the rear side of the first motor. The front end of the input shaft of the speed reducer is drivingly connected with the rear end of the output shaft of the first motor, and the rear end of the output shaft of the speed reducer passes through the rear end of the front side of the speed reducer Located in the reduction box, the rear end of the output shaft of the reducer is fixedly installed with an active bevel gear, the left and right parts of the reduction box are respectively a left rotating hole and a right rotating hole, the left output shaft is rotatably installed in the left rotating hole, the outer side of the right end of the left output shaft is fixedly installed with a left driven bevel gear meshing with the left part of the active bevel gear, the outer side of the left end of the left output shaft is fixedly installed with a left driving gear, the left driven gear is meshed with the left part of the left main gear, the right output shaft is rotatably installed in the right rotating hole, the outer side of the left end of the right output shaft is fixedly installed with a right driven bevel gear meshing with the right part of the active bevel gear, the outer side of the right end of the right output shaft is fixedly installed with a right driving gear, the right driven gear is meshed with the right part of the right driving gear.

[0014] The difference between the tooth width of the left driving gear and the left driven gear is not less than 15mm, the difference between the tooth width of the right driving gear and the right driven gear is not less than 15mm, and the inner wall of the guide groove can contact the outer side of the polished rod before the guide part.

[0015] The above-mentioned driving mechanism may also include a first control module, a left connecting frame is fixedly installed on the left end of the left end cover, and a first proximity switch and a second proximity switch are fixedly installed in the left connecting frame corresponding to the left and right positions of the left driving gear, respectively. The first proximity switch and the second proximity switch are both connected to the first control module, and the first control module is connected to the first motor.

[0016] As another preferred embodiment, the above-mentioned driving mechanism may include a left mounting frame, a right mounting frame, a second motor and a third motor. The left mounting frame is fixedly mounted on the left end of the left end cover, the second motor is fixedly mounted on the left end of the left mounting frame, the right end of the output shaft of the second motor is transmission-connected to the left end of the push rod, the right mounting frame is fixedly mounted on the right end of the right end cover, the third motor is fixedly mounted on the right end of the right mounting frame, the left end of the output shaft of the third motor is transmission-connected to the right end of the right valve stem, and when the second motor and the third motor respectively drive the push rod and the right valve stem to rotate, the left valve core and the right valve core approach or move away from each other.

[0017] The driving mechanism may further include a second control module, and the second control module is connected to the second motor and the third motor respectively.

[0018] The present invention has a reasonable and compact structure, and the blowout prevention shell can utilize the shell of the existing well-known single-gate blowout preventer, which can improve the versatility of the wellhead blowout prevention device installation, and can quickly install the blowout prevention shell and the wellhead equipment together. The guide groove opens to the left and gradually narrows from left to right, and the right part of the guide groove is connected with the left part of the right sealing groove. In this way, when the light rod in the installation through hole is not in the center, the right valve core moves to the left, so that the eccentric light rod can move along the inner wall of the guide groove into the right sealing groove, which can have a straightening effect on the eccentric light rod, and then the guide part moves to the right again to contact with the guide groove sealing, and finally the left sealing groove, the guide part and the right sealing groove are close to each other to form a cylindrical sealing hole that passes through from top to bottom, and the outer side of the light rod is in sealing contact with the inner wall of the sealing hole, thereby playing the effect of closing the installation through hole, and when the light rod leaks or steam blowout occurs, the installation through hole can be quickly and timely closed by the driving component, thereby ensuring the safe operation of the wellhead blowout preventer of the pumping unit and reducing the occurrence of wellhead pollution incidents. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Attached Figure 1 It is a schematic diagram of the main structure when using embodiments 1 to 8 of the present invention.

[0020] Attached Figure 2 It is a schematic diagram of the front cross-sectional structure when using embodiments 1 to 8 of the present invention.

[0021] Attached Figure 3 It is a schematic diagram of the right side cross-sectional structure when using embodiments 1 to 8 of the present invention.

[0022] Attached Figure 4 It is a schematic diagram of the left side cross-sectional structure when using embodiments 1 to 8 of the present invention.

[0023] Attached Figure 5 It is a schematic diagram of the three-dimensional structure when using embodiments 1 to 8 of the present invention.

[0024] Attached Figure 6 It is a schematic diagram of the three-dimensional structure when the left valve core and the right valve core are close to each other in embodiments 1 to 10 of the present invention.

[0025] Attached Figure 7 It is a schematic diagram of the three-dimensional structure of the left valve core in embodiments 1 to 10 of the present invention.

[0026] Attached Figure 8 For attachment Figure 2 Schematic diagram of the enlarged cross-sectional view of the valve core on the left side of the middle.

[0027] Attached Fig. 9 It is a schematic diagram of the three-dimensional structure of the right valve core in embodiments one to ten of the present invention.

[0028] Attached Fig.10 For attachment Figure 2 Schematic diagram of the top view and enlarged cross-section of the valve core on the middle right.

[0029] Attached Fig.11 It is a schematic diagram of the left side cross-sectional structure of the top plate in Examples 1 to 10 of the present invention.

[0030] Attached Fig.12 It is a schematic diagram of the right side cross-sectional structure of the top plate in Examples 1 to 10 of the present invention.

[0031] Attached Fig.13 It is a schematic diagram of the left side cross-sectional structure of the left valve stem in embodiments one to ten of the present invention.

[0032] Attached Fig.14 Schematic diagram of the circuit structure of embodiments 1 to 8 of the present invention.

[0033] Attached Fig.15 This is a schematic diagram of the front cross-sectional structure of the ninth embodiment of the present invention when in use.

[0034] Attached Fig.16 It is a schematic diagram of the three-dimensional structure of the ninth embodiment of the present invention when in use.

[0035] Attached Fig.17 This is a schematic diagram of the circuit structure of the tenth embodiment of the present invention.

[0036] The codes in the accompanying drawings are: 1 is the blowout prevention housing, 2 is the installation through hole, 3 is the left valve core, 4 is the right valve core, 5 is the guide groove, 6 is the guide part, 7 is the polished rod sealing hole, 8 is the polished rod, 9 is the left end cover, 10 is the right end cover, 11 is the right valve stem, 12 is the push rod, 13 is the top plate, 14 is the push rod, 15 is the removal section, 16 is the limiting section, 17 is the right limiting plate, 18 is the left limiting plate, 19 is the limiting boss, 20 is the sealing sleeve, 21 is the sealing packing, 22 is the pressing sleeve, 23 is the pressure cover, 24 is the rotating ring table, 25 is the supporting outer ring table, 26 is the pressing inner ring table, 27 is the right Sealing assembly, 28 is a support seat, 29 is a reduction box, 30 is a reducer, 31 is a first motor, 32 is a left driving gear, 33 is a right driving gear, 34 is an active bevel gear, 35 is a left driven bevel gear, 36 is a right driven bevel gear, 37 is a left output shaft, 38 is a right output shaft, 39 is a left driven gear, 40 is a right driven gear, 41 is a first control module, 42 is a left connecting frame, 43 is a first proximity switch, 44 is a second proximity switch, 45 is a left mounting frame, 46 is a right mounting frame, 47 is a second motor, 48 is a third motor, and 49 is a second control module. DETAILED DESCRIPTION

[0037] The present invention is not limited by the following embodiments, and specific implementation methods can be determined based on the technical solution of the present invention and actual conditions.

[0038] In the present invention, for the convenience of description, the relative position relationship of each component is described according to the attached Figure 1The layout is described in detail, such as the positional relationship of front, back, top, bottom, left, right, etc., which is based on the attached manual. Figure 1 The layout direction is determined by the

[0039] The present invention will be further described below in conjunction with embodiments and drawings:

[0040] Embodiment 1: As shown in the attached Figures 1 to 10 As shown, the wellhead blowout prevention device comprises a blowout prevention housing 1, a left valve core 3, a right valve core 4 and a driving assembly. The upper end of the blowout prevention housing 1 is provided with a mounting through hole 2 for penetrating a polished rod 8. The left end of the blowout prevention housing 1 is provided with a left sealing hole, the right end of the left sealing hole is communicated with the mounting through hole 2, a left valve core 3 is installed in the left sealing hole, a left sealing groove opening to the right and passing through from top to bottom is provided at the right end of the left valve core 3, a right sealing hole is provided at the right end of the blowout prevention housing 1, the left end of the right sealing hole is communicated with the mounting through hole 2, a right valve core 4 is installed in the right sealing hole, a right sealing groove opening to the left and passing through from top to bottom is provided at the left part of the right valve core 4, and a right A guide groove 5 which opens to the left and gradually narrows from left to right is provided at the left end of the valve core 4, and the right part of the guide groove 5 is communicated with the left part of the right sealing groove. A guide part 6 which matches the guide groove 5 is fixed to the front right end and the rear right end of the left valve core 3 corresponding to the position of the left sealing groove. A driving component which can make the left valve core 3 and the right valve core 4 approach each other or move away from each other is provided on the outside of the blowout prevention housing 1. When the left valve core 3 and the right valve core 4 approach each other, the left sealing groove, the guide part 6 and the right sealing groove can form a polished rod sealing hole 7 which runs through from top to bottom, and the inner wall of the polished rod sealing hole 7 can be in sealing contact with the outer side of the polished rod 8.

[0041] According to the requirements, a vent hole connected inside and outside is provided on the rear side of the middle part of the blowout preventer housing 1, and a hollow vent nozzle is fixedly installed in the vent hole, and a vent plug is screwed on the inner side of the rear of the vent nozzle. During use, the blowout preventer housing 1 can utilize the housing of the existing well-known single-gate blowout preventer, which can improve the versatility of the installation of the wellhead blowout preventer, and can quickly install the blowout preventer housing 1 and the wellhead equipment together. The guide groove 5 opens to the left and gradually narrows from left to right, and the right part of the guide groove 5 is connected to the left part of the right sealing groove. In this way, when the light rod 8 in the installation through hole 2 is not in the center, the right valve core 4 moves to the left, so that the eccentric light rod 8 can move along the inner wall of the guide groove 5 into the right sealing groove, which can have a straightening effect on the eccentric light rod 8, and then the guide part 6 moves to the right again to seal and contact with the guide groove 5. Finally, the left sealing groove, the guide part 6 and the right sealing groove are close to each other to form a cylindrical light rod sealing hole 7 that runs through from top to bottom, and the outer side of the light rod 8 is connected to the inner wall of the sealing hole. The wall sealing contact plays the effect of closing the installation through hole 2. When the light rod 8 leaks or the steam blowout occurs, the installation through hole 2 can be closed in time and quickly by the driving component, so as to ensure the safe operation of the wellhead blowout preventer of the pumping unit and reduce the occurrence of wellhead pollution incidents. The driving component can be an existing well-known hydraulic cylinder or air cylinder. The two hydraulic cylinders or cylinders are respectively installed at the left end and the right end of the blowout prevention housing 1. The piston rod ends of the two hydraulic cylinders or the two air cylinders are respectively installed with the left valve core 3 and the right valve core 4. The driving component can also be an existing well-known trapezoidal lead screw and a matching lead screw nut. The first ends of the two trapezoidal lead screws are respectively installed with the left valve core 3 and the right valve core 4, and the second ends of the two trapezoidal lead screws are respectively installed with the output shaft of the reduction motor.

[0042] The above-mentioned wellhead blowout prevention device can be further optimized and / or improved according to actual needs:

[0043] Embodiment 2: As an optimization of the above embodiment, as shown in the attached Figures 2 to 4 6 to 10 , the guide groove 5 is in an arc shape opening to the left, and the width of the left end of the guide groove 5 is smaller than the diameter of the right valve core 4.

[0044] The guide groove 5 is in an arc shape with an opening to the left, and the front outer side and the rear outer side of the guide part 6 are both arc surfaces matching the inner wall of the guide groove 5, so that when the guide part 6 and the inner wall of the guide groove 5 contact each other, the sealing performance can be improved. When the light rod 8 is not in the center of the mounting through hole 2, the guide groove 5 can guide the eccentric light rod 8, so that the light rod 8 passes through the guide groove 5 and enters the right sealing groove, and then the guide part 6 is inserted into the guide groove 5, so that the left valve core 3 and the right valve core 4 can move the light rod 8 to the center of the mounting through hole 2, and can also seal the outer side of the light rod 8.

[0045] Embodiment 3: As an optimization of the above embodiment, as shown in the attached Figures 1 to 5As shown, the driving assembly includes a left end cover 9, a left valve stem, a right end cover 10, a right valve stem 11 and a driving mechanism. The left end cover 9 is fixedly installed on the left end of the blowout prevention shell 1. A left threaded hole is provided in the center of the left end cover 9 and runs through the left and right sides. The left valve stem, whose right end is fixedly installed with the left end of the left valve core 3, is screwed into the left threaded hole. The right end cover 10 is fixedly installed on the right end of the blowout prevention shell 1. A right threaded hole is provided in the center of the right end cover 10 and runs through the left and right sides. The right valve stem 11, whose left end is fixedly installed with the right end of the right valve core 4, is screwed into the right threaded hole. The driving mechanism can drive the left valve stem and the right valve stem 11 to rotate, and when the left valve stem and the right valve stem 11 rotate, the left valve core 3 and the right valve core 4 approach or move away from each other.

[0046] During use, by setting the left threaded hole and the right threaded hole, the driving mechanism drives the left valve stem and the right valve stem 11 to rotate while the left valve stem and the right valve stem 11 move to the left or right, and the driving mechanism causes the left valve core 3 and the right valve core 4 to move relative to each other, that is, the left valve core 3 and the right valve core 4 approach each other or move away from each other, the left valve core 3 and the right valve core 4 approach each other to close the mounting hole 2, and the left valve core 3 and the right valve core 4 move away from each other to open the mounting hole 2.

[0047] Embodiment 4: As an optimization of the above embodiment, as shown in the attached Figures 1 to 5 As shown in 11 to 13, the left valve stem includes a push rod 12, a top plate 13 and a push rod 14. The left end of the left valve core 3 is provided with a mounting groove opening to the left. The outer side of the right part of the push rod 12 is inserted into the mounting groove. The left end of the push rod 12 is fixed with a top plate 13 fixedly installed together with the left part of the left valve core 3. The outer side of the right part of the push rod 14 is provided with a feed thread matching with the left threaded hole. The outer side of the right part of the push rod 14 is screwed into the left threaded hole. The left end of the top plate 13 is provided with a slot opening to the left. The slot includes a removal section 15 and a limiting section 16. The removal section 15 is in an arc shape opening downward, and the limiting section 16 is in a U shape opening upward. The lower part of the outlet section 15 is connected with the upper part of the limiting section 16, and the right end of the push rod 14 is fixedly installed with a right limiting plate 17 rotatably installed on the inner side of the lower part of the limiting section 16, and a U-shaped limiting boss 19 with an opening upward is fixed to the inner side of the left part of the limiting section 16 corresponding to the left side of the right limiting plate 17, and an annular left limiting plate 18 is fixedly installed on the outer side of the right part of the push rod 14 between the left side of the limiting boss 19 and the right side of the left end cover 9. The right valve stem 11 has the same structure as the left valve stem and is symmetrically arranged, and the driving mechanism is respectively installed with the left part of the push rod 14 and the right middle part of the right valve stem 11 corresponding to the left part of the push rod 14.

[0048] According to the requirements, the inner wall of the removal section 15 is in an arc shape with an opening facing downward, and the left limiting plate 18 and the right limiting plate 17 are both circular. The push rod 14 is then moved to the left, and the push rod 14 and the top plate 13 are separated from each other. The right end of the push rod 14 is inserted into the removal section 15, and then the push rod 14 is moved downward, so that the limiting boss 19 is stuck on the outer side of the push rod 14 between the left limiting plate 18 and the right limiting plate 17. Then the left end cover 9 is fixedly installed together with the left end of the blowout prevention housing 1 to realize the assembly of the left valve stem. When the driving mechanism is working, the right valve stem 11 and the left valve stem are driven to rotate. When the driving mechanism drives the push rod 14 to rotate, the push rod 14 moves to the right under the action of the feed thread when it rotates, and the left limit plate 18 presses the left side of the limit boss 19, thereby driving the push rod 12 and the left valve core 3 to move to the right, and similarly the right valve core 4 moves to the left, so that the left valve core 3 and the right valve core 4 can be close to the light rod 8 and sealed in contact with the outer side of the light rod 8. When the driving mechanism works to drive the right valve stem 11 and the left valve stem to rotate in the opposite direction, the driving mechanism drives the push rod 14 to rotate in the opposite direction, and the push rod 14 moves to the left under the action of the feed thread when it rotates in the opposite direction, and the right limit plate 17 presses the right side of the limit boss 19, thereby driving the push rod 12 and the left valve core 3 to move to the left, and similarly the right valve core 4 moves to the right, so that the left valve core 3 and the right valve core 4 can be away from the light rod 8.

[0049] Embodiment 5: As an optimization of the above embodiment, as shown in the attached Figure 1 , 2As shown in Figures 5 and 6, a left sealing assembly is provided between the push rod 14 and the left end cover 9, and the left sealing assembly includes a sealing sleeve 20, a sealing packing 21, a compression sleeve 22 and a pressure cover 23. The left end of the left end cover 9 is fixedly installed together with the right end of the sealing sleeve 20 sleeved on the outside of the push rod 14. A rotating ring platform 24 is fixed to the inner side of the left end of the left end cover 9, and a sealing packing 21 is installed between the inner side of the sealing sleeve 20 corresponding to the left end position of the rotating ring platform 24 and the outer side of the push rod 14. A compression sleeve 22 is sleeved on the inner side of the left part of the sealing sleeve 20 corresponding to the left end position of the sealing packing 21, and a supporting outer ring platform 25 is fixedly installed on the outer side of the left end of the compression sleeve 22. A pressure cover 23 is screwed on the outer side of the sealing sleeve 20, and a compression inner ring platform 26 sleeved on the outer side of the push rod 14 is fixed to the inner side of the left end of the pressure cover 23 corresponding to the left end position of the supporting outer ring platform 25. A right sealing assembly 27 with the same structure as the left sealing assembly and symmetrically arranged is provided between the right valve stem 11 and the right end cover 10.

[0050] According to the requirements, bearings or bushings are provided on the outer sides of the rotating ring platform 24 and the push rod 14, so that the rotation of the push rod 14 is more flexible. During use, when leakage occurs between the left end cover 9 and the push rod 14, the gland 23 can be tightened, so that the inner ring platform 26 is pressed and the outer ring platform 25 is supported, so that the compression sleeve 22 moves rightward to press the sealing packing 21. Under the limiting effect of the rotating ring platform 24, the inner side of the sealing packing 21 is in close contact with the outer side of the push rod 14, thereby preventing further leakage between the left end cover 9 and the push rod 14.

[0051] Embodiment 6: As an optimization of the above embodiment, as shown in the attached Figures 1 to 5As shown, the driving mechanism includes a support seat 28, a reduction box 29, a speed reducer 30, a first motor 31, a left driving gear 32 and a right driving gear 33. A left driven gear 39 is detachably fixedly installed on the outer side of the left portion of the push rod 14 corresponding to the left position of the gland 23, and a right driven gear 40 is fixedly installed on the portion of the right valve stem 11 corresponding to the right position of the right sealing assembly 27 corresponding to the outer side of the left portion of the push rod 14. A support seat 28 is fixedly installed on the outer side of the blowout prevention housing 1, and a speed reducer 29 is fixedly installed in the support seat 28. A speed reducer 30 is fixedly installed on the front side of the speed reducer 29, and the front side of the speed reducer 30 is fixedly installed with the rear side of the first motor 31. The front end of the input shaft of the speed reducer 30 is drivingly connected with the rear end of the output shaft of the first motor 31, and the rear end of the output shaft of the speed reducer 30 passes through the front side of the speed reducer 29. The rear end is located in the reduction box 29, and the rear end of the output shaft of the reducer 30 is fixedly installed with a driving bevel gear 34. The left and right parts of the reduction box 29 are respectively left rotating holes and right rotating holes. The left output shaft 37 is rotatably installed in the left rotating hole, and the left driven bevel gear 35 meshing with the left part of the driving bevel gear 34 is fixedly installed on the outer side of the right end of the left output shaft 37. The left driving gear 32 is fixedly installed on the outer side of the left end of the left output shaft 37. The left driven gear 39 meshes with the left part of the left main gear 32. The right output shaft 38 is rotatably installed in the right rotating hole, and the right driven bevel gear 36 meshing with the right part of the driving bevel gear 34 is fixedly installed on the outer side of the left end of the right output shaft 38. The right driving gear 33 is fixedly installed on the outer side of the right end of the right output shaft 38, and the right driven gear 40 meshes with the right part of the right driving gear 33.

[0052] According to the requirements, the first motor 31 is an existing well-known technology, such as a servo motor of the 130 series. According to the torque required for closing the valve core of the light rod 8, a motor with a power of 1.0-1.5KW and a torque greater than 5Nm is selected for matching. The electronic gear ratio of the servo motor driver can be set to 5:3, and it works in a speed control mode. The motor speed can be set at 2000 rpm. The reducer 30 can be an existing well-known ZE120 servo-specific planetary reducer. The input end flange is convenient for transmission connection with the output shaft of the first motor 31, and the output end is a light axis.

[0053] In order to reduce the weight of the support seat 28, the support seat 28 includes two fixing splints, which can be made of steel plates with a thickness of 3 mm. The front parts of the two fixing splints are respectively mounted on the left outer side and the right outer side of the reduction box 29, and the rear parts of the two fixing splints are respectively mounted on the left outer side and the right outer side of the blowout preventer shell 1. The two fixing splints are fixed together by a number of stud bolts distributed at intervals along the circumference and nuts screwed to the left and right outer sides of the stud studs. A limiting sleeve is mounted on the outer side of the stud bolts corresponding to the position between the two fixing splints. In order to prevent the fixing splints from moving left and right, limiting steps are provided on the outer side of the blowout preventer shell 1 on the right side of the left fixing splint and on the left side of the right fixing splint, or limiting blocks are mounted on the upper and lower outer sides of the blowout preventer shell 1, and the left and right sides of the limiting blocks are parallel to each other.

[0054] The outer side of the left part of the push rod 14 corresponding to the left position of the pressure cover 23 and the left driven gear 39 are connected through a key transmission, and the outer side of the push rod 14 corresponding to the left end and the right end of the left driven gear 39 are installed with retaining springs. The installation method between the right valve stem 11 and the right driven gear 40 is the same as the installation method between the left driven gear 39 and the push rod 14.

[0055] The first motor 31 can realize power output of deceleration and torque increase through the reducer 30, realize biaxial counter-rotation of the left output shaft 37 and the right output shaft 38 through the active bevel gear 34, the left driven bevel gear 35 and the right driven bevel gear 36, and respectively drive the left valve stem and the right valve stem 11 to rotate through the left active gear 32, the left driven gear 39, the right active gear 33 and the right driven gear 40. The left valve stem and the right valve stem 11 have the same structure and are symmetrically arranged, so that the rotation directions of the left valve stem and the right valve stem 11 are opposite, but the feeding directions of the left valve stem and the right valve stem 11 are approaching or moving away from each other. By controlling the rotation of the first motor 31, the left valve core 3 and the right valve core 4 can be sealed and contacted with the outer side of the light rod 8 after approaching each other, or can be separated from the light rod 8 after moving away from each other.

[0056] Embodiment 7: As an optimization of the above embodiment, as shown in the attached Figures 1 to 5 As shown, the difference between the tooth width of the left driving gear 32 and the tooth width of the left driven gear 39 is not less than 15 mm, the difference between the tooth width of the right driving gear 33 and the tooth width of the right driven gear 40 is not less than 15 mm, and the inner wall of the guide groove 5 can contact the outer side of the light rod 8 before the guide portion 6.

[0057] The power of the reducer 30 is transmitted through the left output shaft 37 and the right output shaft 38, and the left output shaft 37 and the right output shaft 38 are respectively connected to the left valve stem 11 and the right valve stem 11 through a gear pair.

[0058] During the oil well production process, the polished rod 8 cannot be kept at the center of the mounting through hole 2. When the deviation is large, the transmission ratio between the left valve stem and the left output shaft 37 is 1.25:1, the gear ratio between the left driving gear 32 and the left driven gear 39 is 1:1.25, the transmission ratio between the right valve stem 11 and the right output shaft 38 is 1.5:1, and the gear ratio between the right driving gear 33 and the right driven gear 40 is 1:1.5. In this way, when the rotation speeds of the left output shaft 37 and the right output shaft 38 are the same, the rotation speeds of the left valve stem and the right valve stem 11 are different. Since the transmission ratio between the right output shaft 38 and the right valve stem 11 is 1.5:1, and the transmission ratio between the left output shaft 37 and the left valve stem is 1.25:1, the rotation speed of the right valve stem 11 is slower than that of the left valve stem.

[0059] When the left valve core 3 and the right valve core 4 are close to each other to close the mounting through hole 2, the length of the right valve core 4 is 102mm, the distance between the left end of the left valve core 3 and the right end of the guide part 6 is 96mm, the distance between the right end of the guide part 6 and the light rod 8 is greater than the distance between the left end of the right valve core 4 and the light rod 8, the guide groove 5 will approach the light rod 8 before the guide part 6. At this time, if the light rod 8 is not in the center position of the mounting through hole 2, the eccentric light rod 8 will pass through the inner wall of the guide groove 5 and move to the inner side of the right part of the right sealing groove, so that the light rod 8 is located in the center of the mounting through hole 2. The left valve stem rotates quickly. Although the left valve core 3 is far away from the light rod 8, it moves toward the light rod 8 quickly. Finally, the offset light rod 8 can be held tightly by the successive movement of the left valve core 3 and the right valve core 4, so that the light rod 8 is located in the center of the mounting through hole 2. When the light rod 8 needs to be released, the left valve stem rotates quickly, the guide part 6 will move away from the contact surface of the light rod 8 before the guide groove 5, and the guide groove 5 then leaves the contact surface of the light rod 8.

[0060] Since the diameter of the polished rod 8 is 25 mm and the central diameter of the mounting through hole 2 is 52 mm, the moving distance of the left valve stem and the right valve stem 11 is about 13.5 mm. When the left valve core 3 and the right valve core 4 are worn (leakage occurs after the left valve core 3 and the right valve core 4 contact the outer side of the polished rod 8), it is necessary to increase the moving distance of the left valve core 3 and the right valve core 4. Therefore, the tooth width of the left driving gear 32 and the right driving gear 33 can be set to 60 mm, and the tooth width of the left driven gear 39 and the right driven gear 40 can be set to 15 mm. In this way, the maximum adjustment distance of the left driven gear 39 and the right driven gear 40 moving left and right during the rotation process can be 30 mm, which can meet the requirement that the outer side of the polished rod 8 can still be sealed when leakage occurs later.

[0061] Embodiment 8: As an optimization of the above embodiment, as shown in the attached Figure 1 , 2As shown in , 5 and 14, the driving mechanism also includes a first control module 41. A left connecting frame 42 is fixedly installed on the left end of the left end cover 9. A first proximity switch 43 and a second proximity switch 44 are fixedly installed in the left connecting frame 42 at the left and right positions corresponding to the left driving gear 32, respectively. The first proximity switch 43 and the second proximity switch 44 are both connected to the first control module 41, and the first control module 41 is connected to the first motor 31.

[0062] According to the requirements, the first proximity switch 43 and the second proximity switch 44 are both existing well-known travel switches, such as the model LXW5-11D1 micro switch. The first control module 41 is an existing well-known programmable controller. The first control module 41 can be fixedly installed in the control box of the electric pole. The left end cover 9 and the left end of the blowout prevention shell 1 are fixedly installed together by a plurality of connecting bolts distributed along the circumference. In order to improve the sealing performance between the left end cover 9 and the left end face of the blowout prevention shell 1, a sealing gasket is provided between the right end of the left end cover 9 and the left end of the blowout prevention shell 1. In order to facilitate the disassembly and assembly of the left driven gear 39, the left connecting frame 42 is located above the left driven gear 39. The left connecting frame 42 is in the shape of a Z, and the upper part of the first proximity switch 43 is fixedly installed with the left end of the left connecting frame 42 by connecting screws. The right end of the left connecting frame 42 is provided with connecting holes that pass through the left and right sides. In this way, the left connecting frame 42, the left end cover 9 and the blowout-proof shell 1 can be fixedly installed together by using one of the connecting bolts between the left end cover 9 and the left end face of the blowout-proof shell 1. If it is necessary to remove the left driven gear 39, it is only necessary to loosen the connecting screws between the first proximity switch 43 and the left connecting frame 42, rotate the left part of the left connecting frame 42, so that the first proximity switch 43 is located at the upper left side of the left driven gear 39, or remove the first proximity switch 43 to carry out the disassembly operation of the left driven gear 39.

[0063] The first proximity switch 43 and the second proximity switch 44 are fixedly installed on the inner side of the left portion of the left connecting frame 42. In order to facilitate the adjustment of the position of the second proximity switch 44, an adjustment screw hole can be provided on the right portion of the left connecting frame 42. The connecting screw of the second proximity switch 44 is screwed into the adjusting screw hole. In this way, the position of the second proximity switch 44 can be adjusted by rotating the connecting screw, which makes the adjustment more convenient. In order to fix the second proximity switch 44, a locking nut can be screwed on the outer side of the connecting screw at the right portion of the left connecting frame 42.

[0064] A handle is fixedly installed on the outer side of the left end of the push rod 14 and the outer side of the right end of the right valve stem 11. In this way, when a power outage or an unexpected failure occurs, the left driven gear 39 and the left driving gear 32, the right driven gear 40 and the right driving gear 33 are separated from each other, and the left valve core 3 and the right valve core 4 can be moved closer to or away from each other by turning the handle.

[0065] When the left valve core 3 and the right valve core 4 are close to each other to close the mounting through hole 2, the length of the right valve core 4 is 96mm, the distance between the left end of the left valve core 3 and the right end of the guide part 6 is 102mm, the distance between the right end of the guide part 6 and the light rod 8 is greater than the distance between the left end of the right valve core 4 and the light rod 8, the guide groove 5 will approach the light rod 8 before the guide part 6, at this time, if the light rod 8 is not in the center position of the mounting through hole 2, the eccentric light rod 8 will pass through the inner wall of the guide groove 5 and move to the inner side of the right part of the right sealing groove, so that the light rod 8 is located in the center of the mounting through hole 2, the left valve stem rotates quickly, although the left valve core 3 is far away from the light rod 8, but the movement speed toward the light rod 8 is fast, and finally the offset light rod 8 can be held tightly by the successive movement of the left valve core 3 and the right valve core 4, so that the light rod 8 is located in the center of the mounting through hole 2, when the left driven gear 39 touches the contact of the second proximity switch 44, the first control module 41 receives the feedback signal and sends an instruction at the same time to stop the first motor 31 from rotating.

[0066] When the light rod 8 needs to be released, the left valve stem rotates faster, and the guide portion 6 will move away from the contact surface of the light rod 8 before the guide groove 5, and the guide groove 5 will then leave the contact surface of the light rod 8. When the left driven gear 39 touches the contact of the second proximity switch 44, the first control module 41 receives a feedback signal and issues a command at the same time, and the first motor 31 stops rotating.

[0067] Initially, the distance between the first proximity switch 43 and the second proximity switch 44 is 15 mm. When the left valve core 3 and the right valve core 4 are worn (leakage occurs after the left valve core 3 and the right valve core 4 contact the outer side of the light rod 8), it is necessary to increase the moving distance of the left valve core 3 and the right valve core 4, and the stroke setting can be increased. The distance between the first proximity switch 43 and the second proximity switch 44 can be adjusted (the position of the second proximity switch 44 can be adjusted left and right on the left connecting frame 42), so that the maximum adjustment distance of the left driven gear 39 and the right driven gear 40 moving left and right during the rotation process can be 30 mm, which can meet the requirement of being able to seal the outer side of the light rod 8 when leakage occurs later.

[0068] The first control module 41 can also be connected to the monitoring center, so that the first motor 31 can be controlled by the first control module 41 on site to realize the closing or opening of the left valve core 3 and the right valve core 4 on both sides of the light rod 8, and the first control module 41 can be remotely controlled at the monitoring center to realize the closing or opening of the left valve core 3 and the right valve core 4 on both sides of the light rod 8. The servo motor is used to control the opening operation of the left valve core 3 and the right valve core 4, so that the left valve core 3 and the right valve core 4 can realize the closing action more accurately. When the light rod 8 leaks or steam blowout occurs, timely and reliable control can be performed to ensure the safe operation of the wellhead blowout preventer of the pumping unit in an unattended state and reduce the occurrence of wellhead pollution incidents.

[0069] The specific working process of this embodiment is as follows: when the first motor 31 receives the instruction from the first control module 41 to close the valve, the output shaft of the first motor 31 rotates, and the speed is reduced and the torque is increased through the reducer 30. The output shaft of the reducer 30 drives the left output shaft 37 and the right output shaft 38 to rotate respectively through the active bevel gear 34, the left driven bevel gear 35 and the right driven bevel gear 36. The left output shaft 37 rotates clockwise, driving the left active gear 32 to rotate clockwise, thereby driving the left driven gear 39 to rotate so that the left valve core 3 moves to the right and closes the left part of the installation through hole 2. At the same time, the right output shaft 38 rotates counterclockwise, driving the right active gear 33 to rotate counterclockwise, thereby driving the right driven gear 40 to rotate so that the right valve core 4 moves to the left and closes the right part of the installation through hole 2. When the left driven gear 39 moves to the right and triggers the second proximity switch 44, the left valve core 3 and the right valve core 4 completely close the installation through hole 2.

[0070] When the first motor 31 receives the instruction from the first control module 41 to open the valve, the output shaft of the first motor 31 rotates, and the output shaft of the reducer 30 drives the left output shaft 37 and the right output shaft 38 to rotate respectively through the active bevel gear 34, the left driven bevel gear 35 and the right driven bevel gear 36. The left output shaft 37 rotates counterclockwise, driving the left active gear 32 to rotate counterclockwise, thereby driving the left driven gear 39 to rotate so that the left valve core 3 moves to the left to open the left part of the mounting through hole 2. At the same time, the right output shaft 38 rotates clockwise, driving the right active gear 33 to rotate clockwise, thereby driving the right driven gear 40 to rotate so that the right valve core 4 moves to the right to open the right part of the mounting through hole 2. When the left driven gear 39 moves to the right to trigger the first proximity switch 43, the left valve core 3 and the right valve core 4 completely open the mounting through hole 2.

[0071] When manual operation is required, the left driven gear 39 and the right driven gear 40 are removed, or the left driven gear 39 and the left driving gear 32, and the right driven gear 40 and the right driving gear 33 are separated from each other. By turning the handle, the left valve core 3 and the right valve core 4 can be moved closer to each other to close the mounting hole 2 or moved away from each other to open the mounting hole 2.

[0072] Embodiment 9: As another optimization of embodiment 5, the difference between this embodiment and embodiment 6 is only in the driving mechanism. Fig.15 , 16As shown, the driving mechanism includes a left mounting frame 45, a right mounting frame 46, a second motor 47 and a third motor 48. The left mounting frame 45 is fixedly mounted on the left end of the left end cover 9, the second motor 47 is fixedly mounted on the left end of the left mounting frame 45, the right end of the output shaft of the second motor 47 is transmission-connected with the left end of the push rod 14, the right mounting frame 46 is fixedly mounted on the right end of the right end cover 10, the third motor 48 is fixedly mounted on the right end of the right mounting frame 46, the left end of the output shaft of the third motor 48 is transmission-connected with the right end of the right valve stem 11, and when the second motor 47 and the third motor 48 respectively drive the push rod 14 and the right valve stem 11 to rotate, the left valve core 3 and the right valve core 4 approach or move away from each other.

[0073] According to the requirements, the second motor 47 and the third motor 48 are both existing well-known technologies, such as a servo motor of the 130 series. In order to reduce the weight of the left mounting frame 45, the left mounting frame 45 includes four screws and four pull rod sleeves. A mounting ring is fixed to the outer side of the right end of the left end cover 9. The left end of the mounting ring is provided with a through hole corresponding to the right end base of the second motor 47. The right end of each screw passes through the mounting hole of the right end base of the second motor 47 and is screwed with a right connecting nut. The left end of each screw passes through the through hole at the corresponding position and is screwed with a left connecting nut. , a pull rod sleeve is mounted on the outer side of each screw rod corresponding to the right end of the second motor 47 and the left end of the mounting ring, a transmission sleeve is installed on the outer side of the right end of the output shaft of the second motor 47 through a key transmission, a connecting section with a regular polygonal cross section is provided at the left end of the push rod 12, and a slide groove matching the connecting section is formed on the inner side of the right end of the transmission sleeve, and the connecting section is slidably installed in the slide groove, the right mounting frame 46 and the left mounting frame 45 have the same structure and are symmetrically distributed, and the transmission connection between the third motor 48 and the right valve stem 11 is the same as the transmission connection between the second motor 47 and the left valve stem.

[0074] Embodiment 10: As an optimization of the above embodiment, as shown in the attached Fig.17 As shown, the driving mechanism further includes a second control module 49, and the second control module 49 is connected to the second motor 47 and the third motor 48 respectively.

[0075] According to the needs, the second control module 49 is an existing well-known programmable control module. The second control module 49 can be fixedly installed in the control box of the electric pole. The second control module 49 can also be connected to the monitoring center, so that the second motor 47 and the third motor 48 can be controlled by the second control module 49 on site to realize the closing or opening of the left valve core 3 and the right valve core 4 on both sides of the light rod 8, and the second control module 49 can be remotely controlled at the monitoring center to realize the closing or opening of the left valve core 3 and the right valve core 4 on both sides of the light rod 8. The servo motor is used to control the opening operation of the left valve core 3 and the right valve core 4, which can make the left valve core 3 and the right valve core 4 realize the closing action more accurately. When the light rod 8 leaks or steam blowout occurs, timely and reliable control can be performed to ensure the safe operation of the wellhead blowout preventer of the pumping unit in unattended conditions and reduce the occurrence of wellhead pollution incidents.

[0076] The specific working process of this embodiment is as follows: when the second motor 47 and the third motor 48 receive an instruction from the second control module 49 to close the valve, they will drive the left valve stem and the right valve stem 11 to rotate. When the output shafts of the second motor 47 and the third motor 48 reach a set torque value, the second motor 47 and the third motor 48 stop rotating, thereby achieving the purpose of closing the valve cores on both sides of the light rod 8; when the second motor 47 and the third motor 48 receive an instruction from the second control module 49 to open the valve, they will drive the left valve stem and the right valve stem 11 to rotate in the opposite direction. When the output shafts of the second motor 47 and the third motor 48 reach a set number of turns, the second motor 47 and the third motor 48 stop rotating, thereby achieving the purpose of opening the valve cores on both sides of the light rod 8.

[0077] The above technical features respectively constitute various embodiments of the present invention, which have strong adaptability and implementation effect. Non-essential technical features can be added or reduced according to actual needs to meet the requirements of different situations.

Claims

1. A wellhead blowout prevention device, characterized in that The blowout prevention housing comprises a left valve core, a right valve core and a driving assembly. The upper end of the blowout prevention housing is provided with an installation through hole for penetrating a polished rod. The left end of the blowout prevention housing is provided with a left sealing hole. The right end of the left sealing hole is communicated with the installation through hole. A left valve core is installed in the left sealing hole. A left sealing groove opening to the right and passing through from top to bottom is provided at the right end of the left valve core. The right end of the blowout prevention housing is provided with a right sealing hole. The left end of the right sealing hole is communicated with the installation through hole. A right valve core is installed in the right sealing hole. A right sealing groove opening to the left and passing through from top to bottom is provided on the left part of the right valve core. A guide groove is provided which opens to the left and gradually narrows from left to right, the right part of the guide groove is communicated with the left part of the right sealing groove, and a guide part matching the guide groove is fixed to the front right end and the rear right end of the left valve core corresponding to the position of the left sealing groove, and a driving component which can make the left valve core and the right valve core approach each other or move away from each other is provided on the outside of the blowout prevention housing, and when the left valve core and the right valve core approach each other, the left sealing groove, the guide part and the right sealing groove can form a polished rod sealing hole which runs through from top to bottom, and the inner wall of the polished rod sealing hole can be in sealing contact with the outer side of the polished rod; The guide groove is in an arc shape with an opening to the left, and the width of the left end of the guide groove is smaller than the diameter of the right valve core; The inner wall of the guide groove can contact the outer side of the polished rod before the guide portion; The driving assembly includes a left end cover, a left valve stem, a right end cover, a right valve stem and a driving mechanism. The left end cover is fixedly installed on the left end of the blowout prevention housing. A left threaded hole that passes through the left and right is provided in the center of the left end cover. The left valve stem whose right end is fixedly installed with the left end of the left valve core is screwed in the left threaded hole. The right end cover is fixedly installed on the right end of the blowout prevention housing. A right threaded hole that passes through the left and right is provided in the center of the right end cover. The right valve stem whose left end is fixedly installed with the right end of the right valve core is screwed in the right threaded hole. The driving mechanism can drive the left valve stem and the right valve stem to rotate, and when the left valve stem and the right valve stem rotate, the left valve core and the right valve core are close to or away from each other; The left valve stem includes a push rod, a push plate and a push rod. The left end of the left valve core is provided with a mounting groove opening to the left. The outer side of the right part of the push rod is inserted into the mounting groove. The left end of the push rod is fixed with a top plate fixedly installed together with the left part of the left valve core. The outer side of the right part of the push rod is provided with a feed thread matching with the left threaded hole. The outer side of the right part of the push rod is screwed into the left threaded hole. The left end of the top plate is provided with a slot opening to the left. The slot includes a removal section and a limiting section. The removal section is in an arc shape opening downward, and the limiting section is in a U shape opening upward. The upper part is connected to the limit section, and the right end of the push rod is fixedly installed with a right limit plate rotatably installed on the inner side of the lower part of the limit section, and a U-shaped limit boss with an opening upward is fixed to the inner side of the left part of the limit section corresponding to the left side of the right limit plate, and an annular left limit plate is fixedly installed on the outer side of the right part of the push rod between the left side of the limit boss and the right side of the left end cover. The right valve stem has the same structure as the left valve stem and is symmetrically arranged, and the driving mechanism is respectively installed with the left part of the push rod and the right middle part of the right valve stem corresponding to the left part of the push rod.

2. The wellhead blowout prevention device according to claim 1, characterized in that A left sealing assembly is provided between the push rod and the left end cover, and the left sealing assembly includes a sealing sleeve, a sealing packing, a compression sleeve and a pressure cap. The left end of the left end cover is fixedly installed together with the right end of the sealing sleeve which is sleeved on the outside of the push rod, a rotating ring platform is fixed to the inner side of the left end of the left end cover, a sealing packing is installed between the inner side of the sealing sleeve corresponding to the left end of the rotating ring platform and the outer side of the push rod, a compression sleeve is sleeved on the inner side of the left part of the sealing sleeve corresponding to the left end of the sealing packing, a supporting outer ring platform is fixedly installed on the outer side of the left end of the compression sleeve, a pressure cap is screwed on the outer side of the sealing sleeve, a compression inner ring platform which is sleeved on the outside of the push rod is fixed on the inner side of the left end of the pressure cap corresponding to the left end of the supporting outer ring platform, and a right sealing assembly which has the same structure as the left sealing assembly and is symmetrically arranged is provided between the right valve stem and the right end cover.

3. The wellhead blowout prevention device according to claim 2, characterized in that The driving mechanism includes a support seat, a reduction box, a speed reducer, a first motor, a left driving gear and a right driving gear. The left driven gear is detachably fixedly installed on the outer side of the left part of the push rod corresponding to the left position of the gland, and the right driven gear is fixedly installed on the position corresponding to the outer side of the left part of the push rod in the right valve stem corresponding to the right position of the right sealing assembly. A support seat is fixedly installed on the outer side of the blowout prevention shell, and a speed reducer is fixedly installed in the support seat. A speed reducer is fixedly installed on the front side of the speed reducer, and the front side of the speed reducer is fixedly installed with the rear side of the first motor. The front end of the input shaft of the speed reducer is drivingly connected with the rear end of the output shaft of the first motor, and the rear end of the output shaft of the speed reducer passes through the front side of the speed reducer and is located in the speed reducer A driving bevel gear is fixedly installed at the rear end of the output shaft of the reducer, and a left rotating hole and a right rotating hole are respectively installed at the left and right parts of the reduction box. The left output shaft is rotatably installed in the left rotating hole, and a left driven bevel gear meshing with the left part of the driving bevel gear is fixedly installed on the outer side of the right end of the left output shaft, and a left driving gear is fixedly installed on the outer side of the left end of the left output shaft, and the left driven gear meshes with the left part of the left main gear, and the right output shaft is rotatably installed in the right rotating hole, and a right driven bevel gear meshing with the right part of the driving bevel gear is fixedly installed on the outer side of the left end of the right output shaft, and a right driving gear is fixedly installed on the outer side of the right end of the right output shaft, and the right driven gear meshes with the right part of the right driving gear.

4. The wellhead blowout prevention device according to claim 3 is characterized in that The difference between the tooth width of the left driving gear and the tooth width of the left driven gear is not less than 15mm, and the difference between the tooth width of the right driving gear and the tooth width of the right driven gear is not less than 15mm; Or / and, the driving mechanism also includes a first control module, a left connecting frame is fixedly installed on the left end of the left end cover, and a first proximity switch and a second proximity switch are fixedly installed in the left connecting frame corresponding to the left and right positions of the left driving gear, respectively, and the first proximity switch and the second proximity switch are both connected to the first control module, and the first control module is connected to the first motor.

5. The wellhead blowout prevention device according to claim 2, characterized in that The driving mechanism includes a left mounting frame, a right mounting frame, a second motor and a third motor. The left mounting frame is fixedly mounted on the left end of the left end cover, the second motor is fixedly mounted on the left end of the left mounting frame, the right end of the output shaft of the second motor is transmission-connected to the left end of the push rod, the right mounting frame is fixedly mounted on the right end of the right end cover, the third motor is fixedly mounted on the right end of the right mounting frame, the left end of the output shaft of the third motor is transmission-connected to the right end of the right valve stem, and when the second motor and the third motor respectively drive the push rod and the right valve stem to rotate, the left valve core and the right valve core approach or move away from each other.

6. The wellhead blowout prevention device according to claim 5, characterized in that The driving mechanism also includes a second control module, and the second control module is connected to the second motor and the third motor respectively.

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