Double-sealing structure of middle pull rod

Abstract

One end of the middle pull rod penetrates through a front wall plate of a drilling pump rack and then is connected with a piston rod, and a hoop is arranged between the middle pull rod and the piston rod. The double-sealing structure comprises a self-adaption sealing box assembly, an outer cover, a movable inner cover and an inner cover, the self-adaption sealing box assembly is installed on a front wall plate of a drilling pump rack and elastically connected with the outer wall of the middle pull rod, the inner cover is connected to the self-adaption sealing box assembly, the movable inner cover is connected to the middle pull rod, the outer cover is arranged on the periphery of the inner cover and the periphery of the movable inner cover, and the inner cover is elastically connected with the outer wall of the middle pull rod. One end of the outer cover is connected to a front wall plate of a drilling pump rack, and a gap is reserved between the inner cover and the middle pull rod. The middle pull rod has self-adaptive contact type sealing and non-contact mechanical sealing at the same time, the problems that a single sealing structure of an existing middle pull rod is prone to eccentric wear and damage, and lubricating oil of a drilling pump is prone to being polluted are well solved to a certain degree, and the operation efficiency and the environmental protection coefficient are improved.

Description

Technical Field

[0001] The invention belongs to the technical field of auxiliary structures of oil and gas equipment, and in particular relates to a double sealing structure of an intermediate pull rod. Background Art

[0002] The packing box of the middle tie rod of the drilling pump is a sealing structure that separates the mud from the lubricating oil. The sealing box is installed on the front wall of the frame. At present, the packing box seal mostly adopts a sealing method in which two lip oil seals distributed in parallel are in close contact with the outer circle of the middle tie rod (such as Figure 2 As shown in the figure, although this kind of dynamic seal has a good effect, it has a high requirement for the coaxiality between the seal ring and the intermediate tie rod. Since the crosshead connected to the intermediate tie rod continuously reciprocates and rubs on the guide plate, the crosshead sinks and the concentricity error formed when the intermediate tie rod and the seal box are installed can easily lead to an increase in the misalignment between the intermediate tie rod and the lip seal in the packing box, which in turn causes the lip seal to wear eccentrically and lose its sealing function, and eventually leads to a large amount of splashing coolant at the hydraulic end or mud leaking from the cylinder liner invading the oil pool of the drilling pump power end through the failed lip seal and contaminating the lubricating oil. Summary of the invention

[0003] The purpose of the present invention is to provide a double sealing structure for an intermediate tie rod, which solves the problem that the existing seal is easily worn, which may cause the sealing structure of the intermediate tie rod to fail easily, thereby causing contamination of the lubricating oil.

[0004] The technical solution adopted by the present invention is:

[0005] The double sealing structure of the middle tie rod is arranged in the middle tie rod assembly; the middle tie rod assembly comprises a middle tie rod, one end of the middle tie rod penetrates through the front wall plate of the drilling pump frame and is connected to the piston rod, and a clamp is arranged between the middle tie rod and the piston rod;

[0006] The double sealing structure includes an adaptive sealing box assembly, an outer cover, a movable inner cover and an inner cover. The adaptive sealing box assembly is installed on the front wall panel of the drilling pump frame. The adaptive sealing box assembly is elastically connected to the outer wall of the middle pull rod. The inner cover is connected to the adaptive sealing box assembly. The movable inner cover is connected to the middle pull rod. The outer cover is arranged on the periphery of the inner cover and the movable inner cover. One end of the outer cover is connected to the front wall panel of the drilling pump frame. A gap is left between the inner cover and the middle pull rod.

[0007] The present invention is also characterized in that:

[0008] The adaptive sealing box assembly includes an outer shell, a pin shaft, a V-shaped leaf spring, a wiper, a leakage hole, and a wiper slot. The outer shell is arranged on the front wall panel of the drilling pump frame. A plurality of wiper slots are arranged in the outer shell. Each wiper slot is provided with a plurality of wipers. A V-shaped leaf spring is arranged between each wiper and the wiper slot. The wiper and the V-shaped leaf spring are arranged in the wiper slot through a pin shaft. The wipers located in the circumference of the wiper slot are also connected by a pin shaft. The outer wall of the middle pull rod and the wiper are elastically abutted.

[0009] The wiper plate includes a wiper blade, a first clamping plate, and a second clamping plate; wherein the first clamping plate and the second clamping plate are reserved with a plurality of mounting holes, and a plurality of screws are used to stack and fix the first clamping plate and the second clamping plate through the mounting holes; the first clamping plate and the second clamping plate are reserved with reserved grooves for the wiper blades, and the wiper blades are arranged in the reserved grooves.

[0010] The outer cover is in the shape of a truncated cone-shaped cylinder, the bottom of which is mounted on the front wall plate of the drilling pump frame, and the top of the outer cover is suspended on the middle tie rod and extends to one end of the middle tie rod.

[0011] The top of the outer cover extends to the periphery of the clamp.

[0012] One end of the movable inner cover is installed on one end of the middle pull rod through a plurality of screws, and the other end is suspended on the outer wall of the middle pull rod.

[0013] One end of the inner cover is installed on the adaptive sealing box assembly, and the other end is suspended on the outer wall of the middle pull rod.

[0014] A water leakage hole is arranged on the outer shell of the adaptive sealing box assembly.

[0015] The beneficial effects of the present invention are as follows: the present invention provides a double sealing structure having both a contact seal that can float in real time with the intermediate tie rod and a contactless mechanical seal that actively protects the intermediate tie rod, wherein the contact seal that can float in real time is also different from the existing contact seal of the intermediate tie rod, and not only overcomes the problem that the existing seal is severely worn or easily fails after eccentric wear of the intermediate tie rod, but the seal can also automatically wrap around the outer cylindrical surface of the intermediate tie rod in real time, and is not affected by the eccentricity of the intermediate tie rod and the wear of the seal; in addition, the other contactless mechanical seal of the sealing structure can separate the intermediate tie rod from the outside world, and effectively avoids the problem that the splashing spray liquid and mud near the intermediate tie rod are easy to contact with it, and ensures the smoothness of the outer cylindrical surface of the intermediate tie rod, and at the same time further improves the working condition of the other contact seal, and effectively solves the problem that the existing single sealing structure of the intermediate tie rod is easy to fail and cause pollution of the lubricating oil, and has good practicality and applicability. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a structural schematic diagram of the front dead point in the double sealing structure of the intermediate pull rod of the present invention;

[0017] Figure 2 It is a schematic diagram of the existing intermediate tie rod sealing structure;

[0018] Figure 3 It is a three-dimensional cross-sectional structural schematic diagram of the double sealing structure of the intermediate pull rod of the present invention;

[0019] Figure 4 It is a structural schematic diagram of the rear dead point in the double sealing structure of the intermediate pull rod of the present invention;

[0020] Figure 5 It is a structural schematic diagram of an adaptive sealing box assembly in a double sealing structure of an intermediate pull rod of the present invention;

[0021] Figure 6 It is a schematic diagram of a three-dimensional explosion structure of an adaptive sealing box assembly in a double sealing structure of an intermediate pull rod of the present invention;

[0022] Figure 7 It is a schematic diagram of the outer shell of the adaptive sealing box assembly in the double sealing structure of the intermediate pull rod of the present invention;

[0023] Figure 8 It is a structural schematic diagram of a water scraper in a double sealing structure of an intermediate pull rod of the present invention;

[0024] Fig. 9 It is a structural schematic diagram of the outer cover in the double sealing structure of the intermediate pull rod of the present invention;

[0025] Fig.10 It is a structural schematic diagram of the inner cover in the double sealing structure of the intermediate pull rod of the present invention;

[0026] Fig.11 It is a structural schematic diagram of a movable inner cover in a double sealing structure of an intermediate pull rod of the present invention.

[0027] In the figure: 1. crosshead, 2. middle tie rod, 3. sealing box, 4. water retaining plate, 5. piston rod, 6. clamp, 7. adaptive sealing box assembly, 8. outer cover, 9. movable inner cover, 10. inner cover, 11. outer cover, 12. pin shaft, 13. V-shaped leaf spring, 14. wiper, 15. leakage hole, 16. wiper slot, 17. inner cover mounting hole, 18. outer cover mounting hole, 19. sealing box mounting hole, 20. pin hole, 21. wiper, 22. first clamp plate, 23. second clamp plate, 24. screw, 25. front wall plate of drilling pump frame. DETAILED DESCRIPTION

[0028] The double sealing structure of the intermediate pull rod of the present invention is further described in detail below in conjunction with the accompanying drawings and specific embodiments.

[0029] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0030] Embodiment 1;

[0031] like Figure 1 , Figure 3 and Figure 4 As shown, the double sealing structure of the intermediate pull rod of the present invention comprises an adaptive sealing box assembly 7, an outer cover 8, a movable inner cover 9, and an inner cover 10. Figure 5 and Figure 6 As shown, the adaptive sealing box assembly 7 is installed on the front wall plate 25 of the drilling pump frame like the existing sealing box, and mainly includes a shell 11, a pin shaft 12, a V-shaped leaf spring 13, a wiper 14, a leak hole 15, and a wiper slot 16.

[0032] The inside of the housing 11 is a slope with a certain taper to facilitate the automatic discharge of the internal liquid. At the same time, boss structures are evenly arranged in the internal circumferential direction. Each boss is designed with multiple layers of wiper slots 16. The wiper plates 14 can be installed in the four wiper slots 16 of each layer through the pin shaft 12. To avoid the wiper plates 14 from colliding with each other, the wiper plates 14 should be installed staggered in each layer of wiper slots 16 (the present invention is to install two wiper plates 14 in the same layer of wiper slots 16). The wiper plates 14 installed in the wiper slots 16 of different layers should be staggered with each other, so that the wiper plates 14 in the wiper slots 16 of different layers can wrap around the outer cylindrical surface of the entire middle pull rod 2 as many times as possible to ensure that the wiper plates 14 can scrape off the impurities and liquid on the outer cylindrical surface of the middle pull rod 2.

[0033] Embodiment 2;

[0034] like Figure 5-Figure 8As shown, the wiper blade 14 of the double sealing structure of the intermediate tie rod of the present invention mainly comprises a wiper blade 21, a first clamping plate 22, a second clamping plate 23, and a screw 24. The wiper blade 21 is installed in the groove between the first clamping plate 22 and the second clamping plate 23 by means of the screw 24, and the inner arc of the wiper blade 21 contacts the intermediate tie rod. In addition, the upper mounting hole of the wiper blade 14 is a larger long hole than the pin shaft 12, and is staggeredly installed in the wiper blade clamping groove 16 through the pin shaft 12, so that the wiper blade 14 can swing around the pin shaft 12 to a certain angle and distance. Then the V-shaped leaf spring 13 is also installed in the wiper blade slot 16 located at the rear of the wiper blade 14 through the pin shaft 12, and the spring leaves on both sides of the V-shaped leaf spring 13 are squeezed on the backs of both sides of the wiper blade 14. In this way, under the action of the V-shaped leaf spring 13, the wiper blade 14 is wrapped around the outer cylindrical surface of the intermediate pull rod 2 in real time through the wiper blade 21 to form a contact seal. In addition, since each wiper blade 14 can swing around the pin shaft 12 at a certain angle and distance, even if the intermediate pull rod 2 and the adaptive sealing box assembly 7 are out of axial alignment, the multiple wiper blades 14 that are layered and staggered can still be wrapped around the outer cylindrical surface of the intermediate pull rod 2 in real time, and will not affect the wiping function of each wiper blade 14.

[0035] like Figure 1 , Figure 3 and Figure 4 The double sealing structure of the intermediate pull rod of the present invention is a contactless mechanical sealing structure, which includes an outer cover 8, a movable inner cover 9, and an inner cover 10. The outer cover 8 (such as Fig. 9 As shown in the figure, the outer cover 8 is a conical structure with flanges at both ends. One end flange of the outer cover 8 is statically mounted on the front wall plate 25 of the drilling pump frame or the end flange of the housing 11 of the adaptive sealing box assembly 7 (the present invention is mounted on the end flange of the housing 11). The length of the outer cover 8 can reach the front dead point of the middle tie rod (as shown in the figure). Figure 1 ), and the inner hole of the small end can completely envelop the installed clamp, so that it is ensured that the middle pull rod and the clamp will not collide with the outer cover 8 when moving between the front and rear dead points, and the external splashing spray liquid and mud will hardly splash onto the middle pull rod. At the same time, its conical structure is also conducive to the automatic discharge of internal mud and coolant.

[0036] Embodiment 3;

[0037] In the double sealing structure of the intermediate tie rod of the present invention, in order to further reduce the possibility of spraying liquid and mud entering the outer cover 8, a movable inner cover 9 (such as Fig.11 As shown), the movable inner cover 9 is also a conical structure with flanges at both ends, and one end flange is installed at the end of the middle tie rod (as shown Figure 1As shown in the figure, the flange at the other end is located inside the outer cover 8 in real time, and when the middle tie rod moves to the front dead point, the gap between the flange edge of the movable inner cover 9 and the inner surface of the outer cover 8 is small, thus ensuring that even at the front dead point, the external spray liquid and mud are difficult to splash onto the middle tie rod. In addition, in order to further prevent larger impurities on the middle tie rod from entering the adaptive sealing box assembly 7, the cover plate of the adaptive sealing box assembly 7 is also designed to have a conical structure with flanged flanges at both ends, that is, the inner cover 10 (as shown in the figure). Fig.10 As shown), the larger flange at one end of the inner cover 10 is installed in the housing 11 of the adaptive sealing box assembly 7 (as shown Figure 1 , 3 , 4), and at the same time, the gap between the inner hole at the small end of the inner cover 10 and the outer circle of the intermediate pull rod is small, so that the inner cover 10 can not only block the large particles of impurities and liquid on the outer circle of the intermediate pull rod 2, but also the intermediate pull rod 2 is within a distance of the rear dead point reversal, because there is a section of overlap between the conical surface of the inner cover 10 and the movable inner cover 9 (as shown in FIG. Figure 4 As shown in the figure, the impurities and liquids falling from the movable inner cover 9 at the moment of the middle tie rod 2 switching will be blocked outside by the inner cover 10 and will not enter the interior of the adaptive sealing box assembly 7. Finally, since the interior of each inner cover 10, outer cover 8 and the shell 11 of the adaptive sealing box assembly 7 are designed as a conical structure, the liquids retained in the outer cover 8 and the shell 11 of the adaptive sealing box assembly 7 will automatically gather at the bottom and automatically flow out through the leaking hole 15 of the shell 11 of the adaptive sealing box assembly 7, thereby well protecting the middle tie rod 2 from corrosion by external liquids and impurities and avoiding contamination of the oil at the power end of the drilling pump.

[0038] The double sealing structure of the intermediate tie rod of the present invention has both adaptive contact sealing and contactless mechanical sealing, which to a certain extent solves the problem that the single sealing structure of the existing intermediate tie rod is easily damaged by eccentric wear and easily causes pollution of the drilling pump lubricating oil, thereby improving the operation efficiency and environmental protection factor.

Claims

1. The double sealing structure of the middle tie rod is characterized by: The double sealing structure is arranged on the intermediate tie rod assembly; the intermediate tie rod assembly comprises an intermediate tie rod (2), one end of the intermediate tie rod (2) passes through the front wall plate (25) of the drilling pump frame and is connected to a piston rod (5), and a clamp (6) is arranged between the intermediate tie rod (2) and the piston rod (5); The double sealing structure comprises an adaptive sealing box assembly (7), an outer cover (8), a movable inner cover (9) and an inner cover (10), wherein the adaptive sealing box assembly (7) is mounted on the front wall panel (25) of the drilling pump frame, the adaptive sealing box assembly (7) is elastically connected to the outer wall of the intermediate tie rod (2), the inner cover (10) is connected to the adaptive sealing box assembly (7), the movable inner cover (9) is connected to the intermediate tie rod (2), the outer cover (8) is arranged on the periphery of the inner cover (10) and the movable inner cover (9), one end of the outer cover (8) is connected to the front wall panel (25) of the drilling pump frame, and a gap is left between the inner cover (10) and the intermediate tie rod (2).

2. The double sealing structure of the intermediate tie rod according to claim 1, characterized in that: The adaptive sealing box assembly (7) comprises a shell (11), a pin shaft (12), a V-shaped leaf spring (13), a wiper (14), a leaking hole (15), and a wiper slot (16). The shell (11) is arranged on the front wall plate (25) of the drilling pump frame. A plurality of wiper slots (16) are arranged in the shell (11). A plurality of wipers (14) are arranged in each of the wiper slots (16). A V-shaped leaf spring (13) is arranged between each of the wiper (14) and the wiper slot (16). The wiper (14) and the V-shaped leaf spring (13) are arranged in the wiper slot (16) via the pin shaft (12). The wipers (14) located in the circumference of the wiper slot (16) are also connected via the pin shaft (12). The outer wall of the intermediate pull rod (2) and the wiper (14) are elastically abutted against each other.

3. The double sealing structure of the intermediate tie rod according to claim 2, characterized in that: The wiper plate (14) comprises a wiper blade (21), a first clamping plate (22), and a second clamping plate (23); wherein the first clamping plate (22) and the second clamping plate (23) are reserved with a plurality of mounting holes, and a plurality of screws (24) are used to stack and fix the first clamping plate (22) and the second clamping plate (23) through the mounting holes; the first clamping plate (22) and the second clamping plate (23) are reserved with a reserved groove for the wiper blade (21), and the wiper blade (21) is arranged in the reserved groove.

4. The double sealing structure of the intermediate tie rod according to claim 1, characterized in that: The outer cover (8) has a truncated cone-shaped cylinder shape, the bottom of which is mounted on the front wall plate (25) of the drilling pump frame, and the top of the outer cover (8) is suspended on the middle pull rod (2) and extends to one end of the middle pull rod (2).

5. The double sealing structure of the intermediate tie rod according to claim 4, characterized in that: The top of the outer cover (8) extends to the periphery of the clamp (6).

6. The double sealing structure of the intermediate tie rod according to claim 1, characterized in that: One end of the movable inner cover (9) is mounted on one end of the middle pull rod (2) via a plurality of screws (24), and the other end is suspended on the outer wall of the middle pull rod (2).

7. The double sealing structure of the intermediate tie rod according to claim 1, characterized in that: One end of the inner cover (10) is mounted on the adaptive sealing box assembly (7), and the other end is suspended on the outer wall of the middle pull rod (2).

8. The double sealing structure of the intermediate tie rod according to claim 2, characterized in that: The housing (11) is provided with a water leakage hole (15).

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