Pipe type oil well pump with constant stress anti-breaking pull rod

Abstract

The utility model provides a pipe type oil well pump with constant stress anti-breaking pull rod relates to oil well pump technical field, including plunger joint, the plunger joint is connected with pull rod in screw thread, is connected with lock nut in screw thread on pull rod, and pull rod is equipped with outer thread section, and the region of pull rod is located above outer thread section is equipped with light axle portion, lock nut is equipped with extension section of cladding light axle portion, and the inner wall of extension section is equipped with top sealing ring with pull rod outer wall, the utility model solves the problem that the traditional technology in oil well pump works, and the light axle portion D1 of pull rod processing thread section will produce stress concentration, causes the bending deformation of pull rod, and the crack of the inside of rod body material produces, along with time elapses, and the crack gradually expands, finally leads to the fatigue failure fracture of pull rod, and the corrosion medium can enter from the port of lock nut, causes the corrosion of pull rod, and when corrosion is serious, can lead to the problem of pull rod fracture.

Description

Technical Field

[0001] This utility model relates to the field of oil pump technology, specifically to a tubular oil pump with a constant stress anti-breakage tie rod. Background Technology

[0002] Due to the limited pump diameter, the sucker rod of a small-diameter conventional tubular pump cannot enter the pump barrel, necessitating the design of a tie rod. Currently, domestic tie rods generally adopt the standard structural design recommended by the petroleum machinery industry, with one end being a sucker rod threaded joint with an uplift and the other end being a plain straight threaded joint without an uplift. For most conventional well conditions, this structure can basically meet the requirements. However, for some complex well conditions, fatigue fracture often occurs at the stress relief groove of the lower thread of the tie rod. Since the lower thread of the tie rod is designed based on the rod body, the major diameter of the thread is only slightly smaller than the diameter of the tie rod body by 1 to 2 mm. This results in the lack of a tight end face at the connection between the plain straight thread of the lower tie rod and the valve cover. In order to tighten the thread, a back-tightening nut needs to be designed for back tightening, and the stress relief groove is also necessary.

[0003] like Figure 2 As shown, the pull rod 10 is provided with an external thread section 20, which is connected to the plunger joint 30. The pull rod 10 is also connected with a locking nut 40 that is opposite to the plunger joint 30, and the pull rod 10 and the plunger joint 30 are locked by the locking nut 40.

[0004] As existing devices are used, the shortcomings of this technology have gradually become apparent, mainly in the following aspects: First, when the oil pump is working, the tie rod is constantly subjected to bending torque and alternating load. Stress concentration will occur at the optical axis part D1 of the threaded section of the tie rod, causing the tie rod to bend and deform, and cracks will be generated inside the rod material. As time goes by, the cracks gradually expand, eventually leading to fatigue failure and fracture of the tie rod.

[0005] Secondly, corrosive media can enter through the lock nut port, causing corrosion of the tie rod. Severe corrosion can lead to tie rod breakage.

[0006] In conclusion, the existing technology obviously has inconveniences and defects in practical use, so it is necessary to improve it. Utility Model Content

[0007] To address the shortcomings of existing technologies, this invention solves the following problems in traditional technologies: During operation of the oil pump, the tie rod is continuously subjected to bending torque and alternating loads, causing stress concentration at the D1 point of the threaded section of the tie rod, resulting in bending deformation and internal cracks in the rod material. Over time, these cracks gradually expand, eventually leading to fatigue failure and breakage of the tie rod. Additionally, corrosive media can enter through the locking nut port, causing corrosion of the tie rod, which, in severe cases, can lead to breakage.

[0008] To solve the above problems, this utility model provides the following technical solution: A tubular oil pump with a constant stress anti-breakage tie rod includes a plunger joint, the plunger joint being threadedly connected to a tie rod, the tie rod being threadedly connected to a lock nut, the tie rod having an external thread section, and the area of ​​the tie rod above the external thread section having a smooth shaft portion; The locking nut has an extension section that covers the optical axis portion, and a top sealing ring is provided between the inner wall of the extension section and the outer wall of the pull rod.

[0009] As an optimized solution, the extension section is clearance-fitted with the tie rod.

[0010] As an optimized solution, the inner wall of the extension section has a light hole structure.

[0011] As an optimized solution, the optical axis portion is located within the optical aperture structure.

[0012] As an optimized solution, the inner wall of the extension section is provided with a top annular groove, and the top sealing ring is fitted into the top annular groove.

[0013] As an optimized solution, a bottom sealing ring is provided between the lower end of the locking nut and the upper end of the plunger joint.

[0014] As an optimized solution, the lower end of the locking nut is coaxially provided with a bottom annular groove, and the bottom sealing ring is fitted into the bottom annular groove.

[0015] As an optimized solution, the locking nut has an upper internal thread that matches the external thread section.

[0016] As an optimized solution, the plunger joint is provided with a lower internal thread that matches the external thread section.

[0017] As an optimized solution, both the top sealing ring and the bottom sealing ring are O-rings.

[0018] As an optimized solution, the outer wall of the locking nut is provided with a wrench groove.

[0019] Compared with the prior art, the beneficial effects of this utility model are: The extension section is set by locking the nut and is fitted with the pull rod to straighten the pump pull rod, so as to prevent stress concentration at the optical axis section and the phenomenon of breakage at the weakest point due to bending torque and alternating load on the pump pull rod. By setting a top sealing ring and a bottom sealing ring, a two-way seal is achieved, which enhances the sealing performance, prevents the entry of corrosive media, and reduces the impact of corrosion on the tie rod. Attached Figure Description

[0020] To more clearly illustrate the specific embodiments of this utility model or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. In all the drawings, similar elements or parts are generally identified by similar reference numerals. In the drawings, the elements or parts are not necessarily drawn to scale.

[0021] Figure 1 This is a schematic diagram of the structure of this utility model; Figure 2 This is a schematic diagram of the structure in the prior art.

[0022] In the diagram: 1-plunger connector; 2-pull rod; 3-locking nut; 4-extension section; 5-top sealing ring; 6-bottom sealing ring; 7-optical shaft section. Detailed Implementation

[0023] The embodiments of the present invention will now be described in detail with reference to the accompanying drawings. These embodiments are merely illustrative of the present invention and should not be construed as limiting the scope of protection of the present invention.

[0024] like Figure 1 As shown, a tubular oil pump with a constant stress anti-breakage tie rod includes a plunger joint 1, a tie rod 2 threadedly connected to the plunger joint 1, a lock nut 3 threadedly connected to the tie rod 2, an external thread section on the tie rod 2, and a smooth shaft portion 7 in the area above the external thread section of the tie rod 2. The locking nut 3 is provided with an extension section 4 that covers the optical axis portion 7, and a top sealing ring 5 is provided between the inner wall of the extension section 4 and the outer wall of the pull rod 2.

[0025] Extension section 4 is fitted with tie rod 2 with clearance.

[0026] The inner wall of extension 4 has a light hole structure.

[0027] The optical axis portion 7 is located within the optical aperture structure.

[0028] The inner wall of the extension section 4 is provided with a top annular groove, and the top sealing ring 5 is fitted into the top annular groove.

[0029] A bottom sealing ring 6 is provided between the lower end of the locking nut 3 and the upper end of the plunger joint 1.

[0030] The lower end of the locking nut 3 is coaxially provided with a bottom annular groove, and the bottom sealing ring 6 is fitted into the bottom annular groove.

[0031] The locking nut 3 has an upper internal thread that matches the external thread section.

[0032] The plunger connector 1 has a lower internal thread that matches the external thread section.

[0033] Both the top sealing ring 5 and the bottom sealing ring 6 are O-rings.

[0034] The outer wall of the locking nut 3 is provided with a wrench groove.

[0035] The working principle of this device is as follows: The extension section 4 is set by locking nut 3 and is clearance-fitted with pull rod 2 to straighten pump pull rod 2, so as to prevent stress concentration at optical shaft part 7 caused by bending torque and alternating load on pump pull rod 2, which could lead to breakage at the weakest point of rigidity. By setting a top sealing ring 5 and a bottom sealing ring 6, a two-way seal is achieved, which enhances the sealing performance, prevents the entry of corrosive media, and reduces the impact of corrosion on the tie rod 2.

[0036] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this utility model, and not to limit it. Although the utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this utility model, and they should all be covered within the scope of the claims and specification of this utility model.

Claims

1. A tubular oil pump with a constant stress anti-breakage tie rod, characterized in that: Includes a plunger connector (1), the plunger connector (1) is threadedly connected to a pull rod (2), the pull rod (2) is threadedly connected to a lock nut (3), the pull rod (2) is provided with an external thread section, and the area of ​​the pull rod (2) above the external thread section is provided with an optical axis portion (7). The locking nut (3) is provided with an extension section (4) covering the optical axis portion (7), and a top sealing ring (5) is provided between the inner wall of the extension section (4) and the outer wall of the pull rod (2).

2. The tubular oil pump with a constant stress anti-breakage tie rod according to claim 1, characterized in that: The extension section (4) is clearance-fitted with the tie rod (2).

3. The tubular oil pump with a constant stress anti-breakage tie rod according to claim 1, characterized in that: The inner wall of the extension section (4) has a light hole structure.

4. The tubular oil pump with a constant stress anti-breakage tie rod according to claim 3, characterized in that: The optical axis portion (7) is located within the optical aperture structure.

5. The tubular oil pump with a constant stress anti-breakage tie rod according to claim 1, characterized in that: The inner wall of the extension section (4) is provided with a top annular groove, and the top sealing ring (5) is fitted into the top annular groove.

6. The tubular oil pump with a constant stress anti-breakage tie rod according to claim 1, characterized in that: A bottom sealing ring (6) is provided between the lower end of the locking nut (3) and the upper end of the plunger joint (1).

7. The tubular oil pump with a constant stress anti-breakage tie rod according to claim 6, characterized in that: The lower end of the locking nut (3) is coaxially provided with a bottom annular groove, and the bottom sealing ring (6) is fitted into the bottom annular groove.

8. The tubular oil pump with a constant stress anti-breakage tie rod according to claim 1, characterized in that: The locking nut (3) has an upper internal thread that matches the external thread section.

9. The tubular oil pump with a constant stress anti-breakage tie rod according to claim 1, characterized in that: The plunger connector (1) is provided with a lower internal thread that matches the external thread section.

10. The tubular oil pump with a constant stress anti-breakage tie rod according to claim 6, characterized in that: Both the top sealing ring (5) and the bottom sealing ring (6) are O-rings.

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