Anti-loosening structure of associated valve cover of drilling pump

Abstract

The utility model discloses an anti-loosening structure of a related valve cover of a drilling pump, relates to the technical field of drilling pumps, and aims to solve the technical problems that the diameter of a thread for connecting the valve cover of the drilling pump and a valve box is very large, the value of force borne by the valve cover is very large, the borne force belongs to alternating load, and the valve cover needs to work continuously for a long time. A large-diameter thread for connecting a valve cover and a valve box is easy to relatively rotate, a drilling pump works abnormally if the large-diameter thread is light, and serious accidents of the drilling pump are caused if the large-diameter thread is heavy, so that standard parts including a cylindrical pin, a lock washer, a nut, a double-end bolt and a right-angle support with a simple structure are fully selected for solving the technical problems; the anti-loosening device for threaded connection of the valve cover and the valve box of the drilling pump is simple in structure, low in cost and safe and reliable in anti-loosening performance.

Description

Technical Field

[0001] This utility model relates to the field of drilling pump technology, and specifically to an anti-loosening structure for a drilling pump associated valve cover. Background Technology

[0002] Drilling pumps are considered the heart of drilling rigs. As shallow oil reserves dwindle and drilling progresses to deeper layers, drilling pumps are required to provide higher pressure and larger displacement of mud, placing increasingly higher demands on their hydraulic components.

[0003] The valve cover is a key component of the hydraulic end of a drilling pump. Not only is the valve cover functionally important, but its lifespan directly affects the lifespan of the hydraulic end.

[0004] Each valve box in the hydraulic end of the drilling pump is designed with a pair of valves to control the opening and closing of the mud liquid. The valves operate under very harsh conditions and are the most vulnerable parts with the shortest lifespan in the hydraulic end of the drilling pump. They need to be inspected and replaced frequently. When inspecting or replacing valves, the valve cover on the valve box must be opened to operate. The frequency of valve inspection and replacement is very high, and the frequency of opening and closing the valve cover is also very high.

[0005] Replacing valves on the hydraulic end of a drilling pump requires removing the valve cover; the valve cover must be closed when the hydraulic end is operating, as it is essential for controlling the normal operation of the valve; to shorten the auxiliary time for replacing hydraulic end valves, the valve cover must be quick to install and remove; the valve cover must be safe and reliable during use and have a long service life.

[0006] The working characteristics of drilling pump valve covers are as follows:

[0007] 1. To ensure the replacement of valves with large diameters on drilling pumps, the valve cover diameter is also large. The larger the valve cover diameter, the greater the pressure it can withstand from the mud.

[0008] 2. Drilling pumps are designed for long-term, continuous operation.

[0009] 3. Characteristics of pressure fluctuations in the drilling pump valve box: During the suction phase, the pressure inside the valve box is very low, and the pressure on the valve cover decreases. During the discharge phase, the pressure inside the valve box is very high, and the pressure on the valve cover increases. The valve cover is subjected to the impact of alternating loads, and this situation is more severe when the pump is suctioned into the valve box.

[0010] The failure modes of drilling pump valve covers include relative rotation of the threads connecting the valve cover and the valve box. Tightening the threads provides a self-locking function because the threaded connection maintains sufficient frictional resistance to prevent relative movement. This frictional resistance remains unchanged only under static loads. However, when the drilling pump valve cover and valve box connection are subjected to continuous vibration, impact, and variable loads, especially in high-temperature environments, the frictional resistance between the threaded connections decreases. Repeated occurrences of this phenomenon can gradually loosen the connection. Once the threads connecting the drilling pump valve cover and valve box are loose, relative rotation can occur. This can lead to malfunctions or, in severe cases, serious accidents. Therefore, preventing loosening of the threaded connection between the drilling pump valve cover and valve box is a crucial design consideration. Summary of the Invention

[0011] The purpose of this invention is to provide an anti-loosening structure for the associated valve cover of a drilling pump.

[0012] The technical solution of this utility model is as follows:

[0013] The technical solution of this utility model includes a cylindrical pin, a right-angle support, an anti-loosening washer, a nut, a double-ended bolt, a suction valve box, a valve cover, and the cylindrical pin and right-angle support combined into one part. The cylindrical pin has an outer circle, the right-angle support has a bottom surface, a vertical hole, a horizontal hole, and a force-bearing surface. The suction valve box has an internal thread, the valve cover has an external thread, the valve cover has an upper surface, a vertical hole on the upper surface, the valve cover has a loosening rotation direction, the cylindrical pin portion of the combined cylindrical pin and right-angle support, and the horizontal hole portion of the combined cylindrical pin and right-angle support. Its characteristic is:

[0014] The external threads of the two adjacent valve covers are screwed into the internal threads of the suction valve box. After the torque value of the engagement between the external threads of the valve cover and the internal threads of the suction valve box reaches the specified value, the two cylindrical pins are respectively inserted into the vertical holes on the upper plane of the two adjacent valve covers. The two right-angle support vertical holes respectively mate with the outer circles of the two cylindrical pins. The bottom surfaces of the two right-angle supports respectively contact the upper plane of the valve cover. The two double-ended bolts respectively pass through the horizontal holes of the two right-angle supports. The two anti-loosening washers are respectively fitted onto the double-ended bolts from both ends and respectively contact the force-bearing surfaces of the two right-angle supports. The two nuts are respectively screwed onto the threads at both ends of the double-ended bolts, respectively pressing the anti-loosening washers at both ends, and tightening the two nuts.

[0015] The principle of inserting two cylindrical pins into the vertical holes on the upper plane of the two adjacent valve covers is that when the two valve covers tend to loosen in the direction of rotation, the distance between the two right-angle supports will increase, so as to play a role in preventing loosening.

[0016] The outer circle of the cylindrical pin and the vertical hole of the right-angle support are an interference fit; the outer circle of the cylindrical pin and the vertical hole on the upper plane of the valve cover are a clearance fit; the double-ended bolt and the horizontal hole of the right-angle support are a clearance fit.

[0017] The anti-loosening structure of the drilling pump associated valve cover in this embodiment is based on the following:

[0018] Drilling pumps have multiple valve boxes, with the most common being 3 or 5 valve boxes. Drilling pumps with 3 valve boxes are called three-cylinder drilling pumps, and those with 5 valve boxes are called five-cylinder drilling pumps.

[0019] 1. Regardless of whether it's a three-cylinder or five-cylinder drilling pump, the valve boxes do not work simultaneously, but in a specific sequence. For example, in a three-cylinder drilling pump, the sequence of the three valve boxes is: first valve box works – third valve box works – second valve box works, with a relative angular interval of one-third of 360 degrees, or 120 degrees. In a five-cylinder drilling pump, the sequence of the five valve boxes is: first valve box works – third valve box works – fifth valve box works – fourth valve box works – second valve box works, with a relative angular interval of one-fifth of 360 degrees, or 72 degrees. Therefore, the valve covers of the five valve boxes do not loosen simultaneously. When one valve cover shows signs of loosening, the adjacent valve covers will not loosen; the valve covers of adjacent valve boxes remain fixed. The anti-loosening structure of this invention achieves the desired anti-loosening effect.

[0020] 2. The anti-loosening structure of this utility model applies force to both ends of the double-ended bolt simultaneously. Finite element analysis of this structure shows that the deformation and stress are very small, making it very safe and reliable.

[0021] By fully utilizing standard parts such as cylindrical pins 1, anti-loosening washers 3, nuts 4, double-ended bolts 5, and simple right-angle supports 2, the problem of anti-loosening technology in the threaded connection between the drilling pump valve cover and the valve box can be solved. The structure is simple, the cost is low, and the anti-loosening performance is safe and reliable. Attached Figure Description

[0022] Figure 1 — Exploded view of the anti-loosening structure of the associated valve cover of the drilling pump;

[0023] Figure 2 — Side view of the intake valve box;

[0024] Figure 3 — Side view of the valve cover;

[0025] Figure 4 — Side view of right-angle support and cylindrical pin;

[0026] Figure 5 — Schematic diagram of the anti-loosening principle of the associated valve cover of the drilling pump (side view);

[0027] Figure 6— Schematic diagram of the anti-loosening principle of the drilling pump associated valve cover (front view);

[0028] Figure 7 — Schematic diagram of the anti-loosening principle of the valve cover associated with the drilling pump ( Figure 6 (AA sectional view);

[0029] Figure 8 — Anti-loosening side view of the three associated valve covers;

[0030] Figure 9 — Anti-loosening side view of the five associated valve covers;

[0031] Figure 10 —The cylindrical pin and the right-angle support are combined into a single main view and AA section view of the part;

[0032] Figure 11 —Stress distribution diagram in the finite element analysis of the anti-loosening structure of the associated valve cover of the drilling pump;

[0033] Figure 12 —Strain distribution diagram in the finite element analysis of the anti-loosening structure of the associated valve cover of the drilling pump.

[0034] 1-Cylindrical pin, 2-Right-angle support, 3-Anti-loosening washer, 4-Nut, 5-Double-ended bolt, 6-Suction valve box, 7-Valve cover, 8-Cylindrical pin and right-angle support combined into one part, 1.1-Outer circle of cylindrical pin, 2.1 Bottom surface of right-angle support, 2.2-Vertical hole of right-angle support, 2.3-Horizontal hole of right-angle support, 2.4-Force-bearing surface of right-angle support, 6.1-Internal thread of suction valve box, 7.1-External thread of valve cover, 7.2-Upper plane of valve cover, 7.3-Vertical hole of upper plane of valve cover, 7.4-Direction of rotation of valve cover when loose, 8.1-Cylindrical pin part of cylindrical pin and right-angle support combined into one part, 8.2-Horizontal hole part of cylindrical pin and right-angle support combined into one part. Detailed Implementation

[0035] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0036] The embodiments of this utility model are not limited to the following examples. All changes made without departing from the spirit of this utility model are within the protection scope of this utility model.

[0037] The pressure fluctuation characteristics of the drilling pump valve box are as follows: during the suction phase, the pressure inside the valve box is very low, and the pressure on the valve cover decreases. During the discharge phase, the pressure inside the valve box is very high, and the pressure on the valve cover increases. The valve cover is subjected to the impact of alternating loads. This situation is more serious when the pump is suctioned into the valve box. Therefore, the drilling pump mainly designs the valve cover anti-loosening structure for the suction valve box.

[0038] Please see Figures 1-10The anti-loosening structure of the drilling pump associated valve cover in this embodiment includes a cylindrical pin 1, a right-angle support 2, an anti-loosening washer 3, a nut 4, a double-ended bolt 5, a suction valve box 6, a valve cover 7, a cylindrical pin and a right-angle support combined into one part 8, the outer circle of the cylindrical pin 1.1, the bottom surface of the right-angle support 2.1, the vertical hole of the right-angle support 2.2, the horizontal hole of the right-angle support 2.3, the force-bearing surface of the right-angle support 2.4, the internal thread of the suction valve box 6.1, the external thread of the valve cover 7.1, the upper surface of the valve cover 7.2, the vertical hole of the upper surface of the valve cover 7.3, the direction of rotation for loosening the valve cover 7.4, the cylindrical pin portion 8.1 of the cylindrical pin and right-angle support combined into one part, and the horizontal hole portion 8.2 of the cylindrical pin and right-angle support combined into one part; its characteristic is:

[0039] The external threads 7.1 of the two adjacent valve covers 7 are screwed into the internal threads 6.1 of the suction valve box 6. After the torque value of the combination of the external threads 7.1 of the valve cover and the internal threads 6.1 of the suction valve box reaches the specified value, the two cylindrical pins 1 are respectively inserted into the vertical holes 7.3 on the upper plane of the valve cover of the two adjacent valve covers 7. The two right-angle support vertical holes 2.2 are respectively engaged with the outer circles 1.1 of the two cylindrical pins. The bottom surfaces 2.1 of the two right-angle supports are respectively in contact with the upper plane 7.2 of the valve cover. The two double-headed bolts 5 pass through the horizontal holes 2.3 of the two right-angle supports. The two anti-loosening washers 3 are respectively put on the double-headed bolts 5 from both ends of the double-headed bolts 5 and respectively in contact with the force-bearing surfaces 2.4 of the two right-angle supports. The two nuts 4 are respectively screwed on from the threads at both ends of the double-headed bolts (5) and respectively press the anti-loosening washers 3 at both ends and tighten the two nuts 4.

[0040] The principle of inserting the two cylindrical pins 1 into the vertical holes 7.3 on the upper plane of the two adjacent valve covers 7 is that when the two valve covers 7 have a tendency to loosen in the direction of rotation 7.4, the distance between the two right-angle supports 2 will increase, so as to play a role in preventing loosening.

[0041] The outer circle 1.1 of the cylindrical pin and the vertical hole 2.2 of the right-angle support are interference fit; the outer circle 1.1 of the cylindrical pin and the vertical hole 7.3 on the upper plane of the valve cover are clearance fit; the double-ended bolt 5 and the horizontal hole 2.3 of the right-angle support are clearance fit.

[0042] The cylindrical pin 1 and the right-angle support 2 can be combined to form a single part 8. The cylindrical pin part 8.1 and the transverse hole part 8.2 of the single part are the same as the cylindrical pin and the right-angle support when they are separate.

[0043] The anti-loosening structure of the drilling pump associated valve cover in this embodiment is based on the following:

[0044] Please see Figure 5 , Figure 6 , Figure 7 , Figure 8 , Figure 9,in Figure 5 This is a side view of the anti-loosening principle diagram of the valve cover associated with the drilling pump. Figure 6 This is the front view of the anti-loosening principle diagram of the associated valve cover of the drilling pump. Figure 7 This is a schematic diagram of the anti-loosening principle of the drilling pump associated valve cover. Figure 6 AA section view, Figure 8 This is a side view of the three associated valve covers to prevent loosening. Figure 9 This is a side view of the anti-loosening mechanism of the five associated valve covers. Drilling pumps have multiple valve boxes, with the most common being 3 and 5 valve boxes. Drilling pumps with 3 valve boxes are called three-cylinder drilling pumps, and those with 5 valve boxes are called five-cylinder drilling pumps.

[0045] 3. Regardless of whether it's a three-cylinder or five-cylinder drilling pump, the valve boxes do not work simultaneously, but in a specific sequence. For example, in a three-cylinder drilling pump, the sequence of the three valve boxes is: first valve box works – third valve box works – second valve box works, with a relative angular interval of one-third of 360 degrees, or 120 degrees. In a five-cylinder drilling pump, the sequence of the five valve boxes is: first valve box works – third valve box works – fifth valve box works – fourth valve box works – second valve box works, with a relative angular interval of one-fifth of 360 degrees, or 72 degrees. Therefore, the valve covers of the five valve boxes do not loosen simultaneously. When one valve cover shows signs of loosening, the adjacent valve covers will not loosen; the valve covers of adjacent valve boxes remain fixed. The anti-loosening structure of this invention achieves the anti-loosening effect.

[0046] 4. Using the anti-loosening structure of this utility model, force is applied simultaneously to both ends of the double-ended bolt 5. Finite element analysis is performed on this structure to analyze stress and deformation. See [the relevant documentation]. Figure 11 and Figure 12 The deformation is very small, and the stress is very small. Figure 11 This is a stress distribution diagram from the finite element analysis of the anti-loosening structure of the drilling pump's associated valve cover. The maximum stress is 51.431 MPa, and the allowable stress of the double-ended bolt is 465 MPa. Figure 12 This is the strain distribution diagram from the finite element analysis of the anti-loosening structure of the associated valve cover of the drilling pump. The maximum deformation is 0.03mm, so it is very safe and reliable.

[0047] In this embodiment, the cylindrical pin 1 and the right-angle support 2 are preferentially separated into two parts, rather than being combined into one part. The reason for combining the cylindrical pin 1 and the right-angle support into one part 8 is to reduce manufacturing costs by using standard parts as much as possible while meeting functional requirements. Figure 9Taking the anti-loosening structure of five associated valve covers as an example, it requires 4 double-ended bolts (5), 8 right-angle supports (2), 8 cylindrical pins (1), 8 anti-loosening washers (3), and 8 nuts (4). Based on market prices on Taobao or JD.com, for a 2400hp five-cylinder drilling pump, the specifications of the double-ended bolts (5) are 8.8 grade M18×300, with a unit price of 6.6 yuan per piece; the specifications of the cylindrical pins (1) are 45 steel quenched Φ16×30, with a unit price of 1.7 yuan per piece; the specifications of the anti-loosening washers (3) are M18 spring washers, with a unit price of 0.16 yuan per piece; the specifications of the nuts (4) are 8.8 grade, with a unit price of 0.7 yuan each; and the manufacturing cost of the right-angle supports (2) is 13 yuan per piece, for a total cost of 113.38 yuan. The key to these standard parts is the length of the M18 double-ended bolts. The longest available on the market is only 300mm; anything longer is not a standard part and must be manufactured separately, which is very expensive. A standard 300mm length is chosen. The length of the right-angle support 2 is adjustable. From the finite element analysis diagram of the anti-loosening structure of the drilling pump associated valve cover, the double-ended bolt 5 has the highest strength requirement, resulting in high manufacturing costs. Therefore, in this embodiment, it is preferable to separate the cylindrical pin 1 and the right-angle support 2 into two parts, with both the double-ended bolt 5 and the cylindrical pin 1 being standard parts, to minimize costs. If the cylindrical pin and the right-angle support were combined into a single part 8, although the function would be satisfied, the cost would increase.

[0048] By adopting this embodiment, and making full use of standard parts such as cylindrical pin 1, anti-loosening washer 3, nut 4, double-ended bolt 5, and simple right-angle support 2, the problem of anti-loosening technology for the threaded connection between the drilling pump valve cover and the valve box can be solved. The structure is simple, the cost is low, and the anti-loosening performance is safe and reliable.

[0049] The implementation of this utility model has been described in detail, but this utility model is not limited to the above embodiments. Various changes can be made within the knowledge scope of those skilled in the art, and these changes are all protected by this utility model and are also within the protection scope of this utility model.

Claims

1. A locking structure for a drilling pump associated valve cover, comprising a cylindrical pin (1), a right-angle support (2), a locking washer (3), a nut (4), a double-ended bolt (5), a suction valve box (6), a valve cover (7), a cylindrical pin and a right-angle support combined into one part (8), the outer circle of the cylindrical pin (1.1), the bottom surface of the right-angle support (2.1), the vertical hole of the right-angle support (2.2), the horizontal hole of the right-angle support (2.3), the force-bearing surface of the right-angle support (2.4), the internal thread of the suction valve box (6.1), the external thread of the valve cover (7.1), the upper surface of the valve cover (7.2), the vertical hole of the upper surface of the valve cover (7.3), the direction of rotation for loosening the valve cover (7.4), the cylindrical pin portion of the cylindrical pin and the right-angle support combined into one part (8.1), and the horizontal hole portion of the cylindrical pin and the right-angle support combined into one part (8.2); its characteristics are: The external threads (7.1) of the two adjacent valve covers (7) are screwed into the internal threads (6.1) of the suction valve box (6). After the torque value of the combination of the external threads (7.1) of the valve cover and the internal threads (6.1) of the suction valve box reaches the specified value, the two cylindrical pins (1) are respectively inserted into the vertical holes (7.3) on the upper plane of the two adjacent valve covers (7). The two right-angle support vertical holes (2.2) respectively cooperate with the outer circles (1.1) of the two cylindrical pins. The bottom surface (2.1) of the support contacts the upper surface (7.2) of the valve cover respectively. The two double-ended bolts (5) pass through the two right-angle support horizontal holes (2.3) respectively. The two anti-loosening washers (3) are respectively put on the double-ended bolts (5) from both ends and contact the two right-angle support force-bearing surfaces (2.4) respectively. The two nuts (4) are respectively screwed on from the threads at both ends of the double-ended bolts (5) to press the anti-loosening washers (3) at both ends respectively. Tighten the two nuts (4). The principle of inserting the two cylindrical pins (1) into the vertical holes (7.3) on the upper plane of the valve cover of the two adjacent valve covers (7) is that when the two valve covers (7) have a tendency to loosen in the direction of valve cover rotation (7.4), the distance between the two right-angle supports (2) will increase, so as to play the role of preventing loosening.

2. The anti-loosening structure for the drilling pump associated valve cover according to claim 1, characterized in that: The outer circle of the cylindrical pin (1.1) and the vertical hole of the right-angle support (2.2) are interference fits; the outer circle of the cylindrical pin (1.1) and the vertical hole of the upper plane of the valve cover (7.3) are clearance fits; the double-ended bolt (5) and the horizontal hole of the right-angle support (2.3) are clearance fits.

3. The anti-loosening structure for the drilling pump associated valve cover according to claim 1, characterized in that: The cylindrical pin (1) and the right-angle support (2) can be combined to form a single part (8). The cylindrical pin part (8.1) and the transverse hole part (8.2) of the single part are the same as the single part of the cylindrical pin and the right-angle support.

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