Fracturing pump spacer frame

Abstract

A fracturing pump spacer frame, comprising a hydraulic end connecting plate and a crosshead case connecting plate which are arranged spaced apart and in parallel, wherein the hydraulic end connecting plate is fixedly connected to the crosshead case connecting plate by means of support sleeves. The fracturing pump spacer frame further comprises support legs; the hydraulic end connecting plate, the crosshead case connecting plate, the support sleeves, and the support legs are integrally formed; each support leg comprises a first support leg vertical plate and a second support leg vertical plate which are vertically arranged and a first support leg bottom plate which is horizontally arranged, wherein the first support leg vertical plate is located below the hydraulic end connecting plate, the second support leg vertical plate is located below the crosshead case connecting plate, and two sides of the first support leg bottom plate are respectively connected to the lower ends of the first support leg vertical plate and the second support leg vertical plate. In the present invention, the integrally formed fracturing pump spacer frame is used to avoid the influence of welding defects on rigidity, strength, service life, etc.; and the substantially U-shaped support legs can simultaneously support the hydraulic end connecting plate and the crosshead case connecting plate, increasing support points, reducing the bending moment and the resulting deformation, and prolonging the service life.

Description

Fracturing pump spacer

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to and benefits of Chinese Patent Application No. 202310923200.3 and No. 202310923192.2 filed with the State Intellectual Property Office of China on July 26, 2023, the disclosures of which are incorporated herein by reference in their entirety. Technical Field

[0003] The invention relates to a fracturing pump spacer, and belongs to the technical field of fracturing pump manufacturing. Background Art

[0004] Fracturing pumps are widely used in the oil industry as important equipment that can increase oil and gas production. They pressurize fracturing fluid (such as cement, mud, fracturing sand or other materials) and pump it into the wellbore to fracture the production formation.

[0005] A fracturing pump primarily consists of three subsystems: the power end, the hydraulic end, and the reduction gearbox. The power end structurally connects the reduction gearbox and the hydraulic end valve box. Functionally, it converts the rotational mechanical energy transmitted from the reduction gearbox into reciprocating mechanical energy to drive the hydraulic end's suction and discharge functions. The hydraulic end, in turn, pressurizes low-pressure fluid to high-pressure fluid and outputs it to the high-pressure manifold. The power end assembly primarily consists of a housing, a crankshaft-connecting rod assembly, a crosshead pull rod assembly, and a lubrication system. The power end housing includes a crankcase and a crosshead housing, with the crankcase connected to one end of the crosshead housing.

[0006] The fracturing pump spacer is used to connect and support the crosshead box and the hydraulic end, ensuring a fixed distance between the two and providing space for the reciprocating motion of the plunger.

[0007] Traditional spacers are typically welded together by front and rear end plates, several intermediate support sleeves, and a bottom support plate. Because welding involves rapid, localized heating and cooling, the molten metal in the weld zone is constrained and restricted by the surrounding material and cannot expand or contract freely. As it gradually cools and contracts, it is subject to tensile stress from the underlying material. While the internal stresses caused by this volume change can be eliminated through heat treatment, the heat-affected but unmelted parent material around the weld (heat-affected zone) undergoes changes in its metallographic structure and mechanical properties, resulting in an uneven microstructure distribution under the effects of the welding thermal cycle. Once generated, the internal stresses generated by these microstructure changes cannot be eliminated and can easily become a source of fatigue cracks in the component. Under the cyclic alternating stresses and corrosive media of long-term, high-load operation of the fracturing pump, microcracks are easily generated in the weld heat-affected zone, which then expand into longitudinal cracks, making it difficult to meet the requirements for long-life (>10,000 hours) use.

[0008] In addition, in terms of manufacturing, the production process of welded spacers is complicated and the matching accuracy is difficult to guarantee. Welded spacers must go through a series of processes such as cutting, assembly, spot welding, preheating, welding, grinding, heat treatment, flaw detection, rough machining, secondary heat treatment and fine machining. During this process, the manufacturing accuracy and quality of each step need to be strictly guaranteed, otherwise it is very easy to cause the accumulation and amplification of size and shape errors. During the welding assembly process, the matching accuracy of each support sleeve and the two end plates directly affects the positional accuracy between the components, and requires specific clamping and positioning tooling. Not only is the matching difficult and the fixture development cost high, but the subsequent rough and fine machining is also more difficult. The errors generated in each of the above processes may lead to abnormal subsequent matching relationships, resulting in serious consequences such as local cracking, deformation vibration and sealing leakage due to uneven force on the components.

[0009] Summary of the Invention

[0010] The technical problem to be solved by the present invention is to provide a fracturing pump spacer in response to the deficiencies of the existing technology. By adopting an integrally formed fracturing pump spacer, the influence of welding defects on stiffness, strength and life, etc. is avoided; the roughly U-shaped support leg can support the hydraulic end connecting plate and the crosshead box connecting plate at the same time, which increases the support points, reduces the bending moment and the deformation caused, and increases the service life; the single-sided support leg with a supporting rib plate allows the support leg to have a certain bending deformation while strengthening the support stiffness; the variable diameter portion of the support sleeve improves the bending strength and support stiffness of the root of the support sleeve, and facilitates the implementation of the casting process.

[0011] The technical problem to be solved by the present invention is achieved through the following technical solutions:

[0012] The present invention provides a fracturing pump spacer, comprising a hydraulic end connecting plate and a crosshead box connecting plate arranged in parallel and spaced apart, the hydraulic end connecting plate and the crosshead box connecting plate being fixedly connected by a support sleeve, the fracturing pump spacer is also provided with a first bolt hole penetrating the hydraulic end connecting plate, the support sleeve and the crosshead box connecting plate, the fracturing pump spacer also includes a support leg, the hydraulic end connecting plate, the crosshead box connecting plate, the support sleeve and the support leg are integrally formed; the support leg comprises a first support leg upright plate and a second support leg upright plate arranged vertically and a first support leg bottom plate arranged horizontally, the first support leg upright plate is located below the hydraulic end connecting plate, the second support leg upright plate is located below the crosshead box connecting plate, and the two sides of the first support leg bottom plate are respectively connected to the lower ends of the first support leg upright plate and the second support leg upright plate.

[0013] To maintain balance and ensure that each leg can provide support, there are at least two legs, evenly distributed along the length of the hydraulic end connection plate. Furthermore, each of the first and second leg uprights includes a first support leg and a second support leg, with the lower ends of the first and second legs fixedly connected.

[0014] In order to reduce the longitudinal support reaction force and lower the pressure and bending moment on the support legs, the first support leg is set vertically and the second support leg is set obliquely, and the first support leg and the second support leg form an angle.

[0015] In order to enhance the structural rigidity of the connection between the spacer legs and the connecting plate, the upper ends of the first supporting legs and the second supporting legs are respectively located below different supporting sleeves.

[0016] In order to reduce the root bending of the support sleeve and increase the rigidity of the support sleeve, support leg reinforcement ribs are provided in the middle of the inner side of the first support leg and the second support leg, and the support leg reinforcement ribs are respectively provided along the length direction of the first support leg and the second support leg.

[0017] Furthermore, the edges of the support leg reinforcement ribs are provided with rounded corners.

[0018] Furthermore, a bottom plate reinforcement rib is provided on the bottom plate of the first leg in a direction parallel to the axial direction of the support sleeve, and both ends of the bottom plate reinforcement rib are respectively connected to the support foot reinforcement ribs on the first support feet of the first support leg upright plate and the second support leg upright plate.

[0019] In order to expand the bottom support area, prevent the fracturing pump spacer from tipping forward and backward, and improve stability, widened portions are provided at the outer edges of the first and second legs.

[0020] The present invention also provides another fracturing pump spacer, comprising a hydraulic end connecting plate and a crosshead box connecting plate arranged in parallel and spaced apart, the hydraulic end connecting plate and the crosshead box connecting plate being fixedly connected by a support sleeve, and the fracturing pump spacer is also provided with a first bolt hole penetrating the hydraulic end connecting plate, the support sleeve and the crosshead box connecting plate, the hydraulic end connecting plate portion extends to one side to form a support leg, the hydraulic end connecting plate, the crosshead box connecting plate, the support sleeve and the support leg are integrally formed; the support leg comprises a vertically arranged third support leg upright plate and a horizontally arranged second support leg bottom plate, a first support rib is provided at the connection between the third support leg upright plate and the support sleeve located above the third support leg upright plate, a second support rib is provided at the connection between the third support leg upright plate and the second support rib, and a gap area is provided between the first support rib and the second support rib.

[0021] In order to allow the supporting legs to have a certain degree of bending deformation and avoid mutual squeezing and shearing between the reinforcing ribs when the supporting legs are subjected to bending moments, the height of the gap area is greater than 5 mm.

[0022] In order to avoid stress concentration and reduce weight while ensuring strength, the thickness of the first support rib and the second support rib gradually decreases in the direction approaching the gap area, or the thickness of the first support rib and the second support rib gradually decreases in the direction away from the third leg vertical plate.

[0023] In order to facilitate the casting process and ensure the bending strength and support stiffness of the support sleeve root, the support sleeve includes a cylindrical portion and a reducing portion located at both ends of the cylindrical portion, and the diameter of the reducing portion gradually increases in the direction away from the center of the support sleeve.

[0024] In the above two types of fracturing pump spacers, fillets are provided at the connections between the diameter-reducing portion and the cylindrical portion, the hydraulic end connection plate and the crosshead box connection plate.

[0025] Preferably, the ratio of the length of the diameter-reducing portion along the axial direction of the support sleeve to the width of the diameter-reducing portion along the direction perpendicular to the axial direction of the support sleeve is 2:1 to 4:1.

[0026] In order to facilitate the installation and disassembly of the packing lubrication joint, etc., a hydraulic end opening is provided in the middle of the hydraulic end connecting plate, and a process hole is provided on the lower side of the hydraulic end opening.

[0027] In order to facilitate the installation and positioning of the hydraulic end connecting plate and the hydraulic end back plate, positioning pin openings are respectively provided on both sides of the hydraulic end connecting plate along the length direction, and the heights of the positioning pin openings on both sides are different.

[0028] In order to further fix the connection of the fracturing pump spacer, the crosshead box connecting plate is provided with a second bolt hole directly above the first bolt hole on its upper side and directly below the first bolt hole on its lower side; two vertically arranged third bolt holes are respectively provided on both sides of the crosshead box connecting plate along the length direction.

[0029] In order to facilitate the installation of the first bolt, a recessed platform is provided on the periphery of the second bolt hole on a side away from the crosshead box.

[0030] In order to realize the oil and air drainage function of the crosshead box, a pull rod opening is provided in the middle of the crosshead box connecting plate, and an avoidance groove is provided on the periphery of the pull rod opening on a side close to the crosshead box.

[0031] In order to improve the sealing effect, a sealing groove is provided on the side of the crosshead box connecting plate close to the crosshead box, the pull rod opening is located on the inner side of the sealing groove, the second bolt hole, the third bolt hole and the first bolt hole are located on the outer side of the sealing groove, and the sealing groove is provided close to the first bolt hole.

[0032] In summary, the present invention avoids the influence of welding defects on stiffness, strength and life by adopting an integrally formed fracturing pump spacer; the roughly U-shaped support leg can support the hydraulic end connecting plate and the crosshead box connecting plate at the same time, which increases the support points, reduces the bending moment and the deformation caused, and increases the service life; the single-sided support leg with a supporting rib plate allows the support leg to have a certain bending deformation while strengthening the support stiffness; the variable diameter portion of the support sleeve improves the bending strength and support stiffness of the root of the support sleeve, and facilitates the implementation of the casting process.

[0033] The technical solution of the present invention is described in detail below with reference to the accompanying drawings and specific embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] FIG1 is a first explosion diagram of a fracturing pump according to a first embodiment of the present invention;

[0035] FIG2 is a second explosion diagram of the fracturing pump according to the first embodiment of the present invention;

[0036] FIG3 is a schematic structural diagram of a fracturing pump spacer according to a first embodiment of the present invention;

[0037] FIG4 is a side view of the hydraulic end connection plate of the first embodiment of the present invention;

[0038] FIG5 is a side view of the crosshead box connecting plate according to the first embodiment of the present invention;

[0039] FIG6 is a partial enlarged view of the second bolt hole in the first embodiment of the present invention;

[0040] FIG7 is a side view of a fracturing pump spacer according to Embodiment 1 of the present invention;

[0041] FIG8 is a partial enlarged view of the supporting legs of the first embodiment of the present invention;

[0042] FIG9 is a cross-sectional view of the hydraulic end connection plate side of the first embodiment of the present invention;

[0043] FIG10 is a first explosion diagram of the fracturing pump according to the second embodiment of the present invention;

[0044] FIG11 is a second explosion diagram of the fracturing pump according to the second embodiment of the present invention;

[0045] FIG12 is a schematic structural diagram of a fracturing pump spacer according to a second embodiment of the present invention;

[0046] FIG13 is a side view of the hydraulic end connection plate of the second embodiment of the present invention;

[0047] FIG14 is a side view of a crosshead box connecting plate according to a second embodiment of the present invention;

[0048] FIG15 is a partial enlarged view of the second bolt hole of the second embodiment of the present invention;

[0049] FIG16 is a side view of a fracturing pump spacer according to a second embodiment of the present invention;

[0050] FIG17 is a partial enlarged view of the supporting legs of the second embodiment of the present invention. DETAILED DESCRIPTION

[0051] Example 1

[0052] FIG1 is a first exploded schematic diagram of a fracturing pump according to a first embodiment of the present invention; FIG2 is a second exploded schematic diagram of a fracturing pump according to a first embodiment of the present invention; FIG3 is a structural schematic diagram of a fracturing pump spacer according to a first embodiment of the present invention; FIG4 is a side view of a hydraulic end connecting plate according to a first embodiment of the present invention; FIG5 is a side view of a crosshead box connecting plate according to a first embodiment of the present invention; FIG6 is a partial enlarged view of a second bolt hole according to a first embodiment of the present invention; FIG7 is a side view of a fracturing pump spacer according to a first embodiment of the present invention; FIG8 is a partial enlarged view of a support leg according to a first embodiment of the present invention; and FIG9 is a cross-sectional view of a hydraulic end connecting plate according to a first embodiment of the present invention. As shown in FIG1 to FIG9, in the first embodiment of the present invention, the fracturing pump spacer includes a hydraulic end connecting plate 100 and a crosshead box connecting plate 200 arranged in parallel and spaced apart. The hydraulic end connecting plate 100 and the crosshead box connecting plate 200 are fixedly connected by a support sleeve 300. A support leg 400 is provided below the hydraulic end connecting plate 100 and the crosshead box connecting plate 200 (below the vertical direction in FIG4). The hydraulic end connection plate 100, the crosshead box connection plate 200, the support sleeve 300, and the support leg 400 are integrally formed (including but not limited to integrally cast). The material of the fracturing pump spacer is ductile iron, vermicular cast iron, gray iron, or cast steel. Preferably, the material of the fracturing pump spacer is ductile iron or vermicular cast iron.

[0053] Traditional fracturing pump spacers are assembled using a welding process. Due to inherent welding defects, the overall rigidity of the welded steel plate structure is insufficient, and local deformation and stress concentration in the welds accelerate fatigue. Compared with one-piece structures, they perform poorly in terms of long-term bending and torsion resistance. From a force perspective, the support span of the entire fracturing pump is large, and the weight of the crosshead box and hydraulic end is primarily supported by the spacer. The spacer legs are subject to large loads and bending moments, becoming stress concentration points that can easily lead to local deformation and even cracking in the welds and nearby heat-affected zones at the stress concentration points. In addition, because each cylinder crosshead alternates between the crosshead box and the reciprocating movement of the center of gravity, the bending moment at the weld changes periodically, resulting in periodic changes in deformation and potentially causing vibration in that area. Compared to the integral cast iron material, the cushioning and vibration absorption performance of welded steel plates is poor. Under the action of cyclic stress, the expansion of weld cracks is further exacerbated, ultimately leading to failure of the support function.

[0054] This invention utilizes an integrated molding process to flexibly increase the wall thickness in vulnerable areas and arbitrarily position reinforcing ribs, eliminating the complex welding and assembly manufacturing processes. This significantly improves the connection strength and support rigidity of the fracturing pump spacer. Furthermore, the cast iron material effectively cushions and absorbs vibrations, ensuring stable support and extending the service life of the fracturing pump spacer.

[0055] The hydraulic end connection plate 100 is used to connect to the hydraulic end assembly 800 (such as the hydraulic end back plate 810, etc.). A hydraulic end opening 110 is provided in the middle of the hydraulic end connection plate 100 to facilitate connection with the hydraulic end assembly (such as the packing box pressure cap 820, etc.). To ensure support strength and reduce overall weight, the hydraulic end opening 110 has semicircular ends at both ends in the horizontal direction and a rectangular middle portion, that is, the hydraulic end opening 110 has the shape of an elliptical runway. The present invention does not limit the specific shape of the hydraulic end opening 110, and those skilled in the art can design and select it according to actual conditions.

[0056] To facilitate installation and removal of the fluid end assembly 800 (e.g., a packing lubrication joint), a process hole 111 is provided below the fluid end opening 110. The process hole 111 can be located below each packing assembly. In other words, the provision of the process hole 111 allows for operation space for installation, removal, and maintenance of the packing assembly (e.g., a packing lubrication joint).

[0057] In order to remove water, oil and their mixture from the depression of the hydraulic end connecting plate 100 and prevent the connecting plate from rusting, a drainage groove 112 is further provided on the upper side of the hydraulic end opening 110. The drainage groove 112 can be provided above each group of packing assemblies.

[0058] The process hole 111 and the drainage groove 112 are preferably arc grooves, which are simple in shape and easy to cast. The present invention does not limit the shape of the grooves, and other shapes that are easy to install and disassemble can be used, such as rectangular, square, etc.

[0059] The hydraulic end connection plate 100 is provided with locating pin openings 120 on either side along its length, corresponding to the locating pins 830 on the hydraulic end assembly 800, to facilitate the installation and positioning of the hydraulic end connection plate 100 and the hydraulic end back plate 810. It should be noted that the locating pin openings 120 on either side are at different heights to prevent the locating pins 830 from being inserted even when the hydraulic end connection plate is installed upside down.

[0060] The fracturing pump spacer is provided with a first bolt hole 310 that passes through the hydraulic end connection plate 100, the support sleeve 300, and the crosshead box connection plate 200. Long bolts 920 (e.g., studs) of the crosshead box 900 are passed through the first bolt hole 310 and tightened at the end of the hydraulic end, thereby ensuring a reliable connection between the connecting surfaces (between the crosshead box connection plate and the crosshead box, and between the hydraulic end connection plate and the hydraulic end back plate).

[0061] The crosshead box connecting plate 200 is provided with second bolt holes 320 directly above the first bolt holes 310 on its upper side and directly below the first bolt holes 310 on its lower side. The first bolts 930 of the crosshead box 900 pass through the second bolt holes 320 to fix the crosshead box connecting plate 200 to the crosshead box 900.

[0062] In order to facilitate the installation of the first bolt 930 , a concave platform 321 is provided on the periphery of the second bolt hole 320 on the side away from the crosshead box 900 (as shown in FIG. 6 ).

[0063] However, due to the low rigidity and long moment arm at the connection between the crosshead box 900 and the fracturing pump spacer, there is a certain amount of flexural deformation, which may cause the crosshead box connecting plate 200 to deform and separate along its length. Therefore, two vertically arranged third bolt holes 330 are provided on both sides of the crosshead box connecting plate 200 along its length (the left and right sides in Figure 5). The second bolts 1940 of the crosshead box 900 pass through the second bolt holes 330 to securely connect the crosshead box connecting plate 200 to the crosshead box 900.

[0064] The crosshead housing connecting plate 200 is used to connect to the crosshead housing 900. A tie rod opening 210 is provided in the middle of the crosshead housing connecting plate 200. The tie rod 910 passes through the tie rod opening 210 and, driven by the crosshead, performs horizontal reciprocating motion, thereby converting the rotational motion of the crankshaft into the reciprocating motion of the plunger.

[0065] It should be noted that due to the movement characteristics of the crosshead assembly, the crosshead box 900 needs to have an oil and air drainage function. In the prior art, oil and air drainage is often achieved by reserving oil and air drainage holes on the box body of the crosshead box 900, which makes the structure of the crosshead box 900 complicated and reduces the mechanical strength of the crosshead box 900. In order to solve the above problem, the pull rod opening 210 is provided with an avoidance groove 340 on the periphery of the side close to the crosshead box 900. When the crosshead assembly moves to the position closest to the crosshead box connecting plate 200, due to the presence of the avoidance groove 340, the crosshead assembly will not contact the crosshead box connecting plate 200, and there will be a gap between the crosshead assembly and the crosshead box connecting plate 200. This gap can ensure the oil and air drainage function required by the crosshead box 900.

[0066] Furthermore, in order to prevent the lubricating oil from being carried out of the crosshead box 900 by the crosshead assembly as much as possible, a sealing assembly (not shown in the figure) and a positioning groove (not shown in the figure) installed in cooperation with the sealing assembly are provided on the side of the pull rod opening 210 away from the crosshead box 900.

[0067] As can be seen from the above, in the present invention, the crosshead box 900 and the fracturing pump spacer are connected by two bolts. The first is a long bolt 920 passing through the first bolt hole 310, which is used for overall fixation and pre-tightening; the second is a first bolt 930 and a second bolt 1940 passing through the second bolt hole 320 and the third bolt hole 330 on the crosshead box connecting plate 200, respectively, which are used for sealing and fastening between the crosshead box 900 and the fracturing pump spacer. Furthermore, in order to better ensure the sealing effect, the crosshead box connecting plate 200 is also provided with a sealing groove 350 for placing a sealing ring, a sealing ring or filling sealant on the side close to the crosshead box 900. The present invention is not limited to this, and the crosshead box connecting plate 200 and the crosshead box 900 can also be directly bonded with sealant without providing a sealing groove 350.

[0068] It should be noted that to improve sealing reliability, the length of the sealing groove 350 needs to be increased as much as possible; however, to ensure air pressure communication throughout the first bolt hole 310, the sealing groove 350 cannot completely surround the first bolt hole 310. Therefore, the tie rod opening 210 is located inside the sealing groove 350, while the second bolt hole 320, the third bolt hole 330, and the first bolt hole 310 are located outside the sealing groove 350, with the sealing groove 350 being located adjacent to the first bolt hole 310.

[0069] The present invention does not limit the molding method of the sealing groove 350. In addition to machining, other methods of removing material may also be used. In addition, it is noted that the setting position of the sealing groove 350 needs to bypass the crankcase observation window and the crosshead case exhaust cavity at the same time.

[0070] Through the above-mentioned structure, the present invention can prevent oil and gas leakage, prevent moisture-induced lubricant contamination, and prevent adverse consequences such as corrosion and wear of internal metal components. Compared to a single bolt connection seal, the dual bolt fixation and connection effectively ensures the sealing surface fits and tightens, preventing the sealing surface from disengaging and slipping due to plunger force and connecting rod lateral force, and preventing oil, gas, and oil pressure leakage.

[0071] The support sleeve 300 includes a cylindrical portion 301 and reducing portions 302 located at both ends of the cylindrical portion 301. Specifically, the reducing portions 302 are provided at the connection between the support sleeve 300, the hydraulic end connection plate 100, and the crosshead box connection plate 200. The diameter of the reducing portions 302 gradually increases as it moves away from the center of the support sleeve 300. The present invention is not limited to the specific shape of the reducing portions 302. Preferably, the reducing portions 302 are truncated cone-shaped, in which case the cross-section of the reducing portions 302 is trapezoidal. Alternatively, the reducing portions 302 are trumpet-shaped.

[0072] Furthermore, fillets are provided at the connections between the reducing portion 302 and the cylindrical portion 301 , the hydraulic end connecting plate 100 and the crosshead box connecting plate 200 .

[0073] On the one hand, because molten iron flows at high speed through a sudden corner during pouring, it can cause throttling and accumulation. As the molten iron gradually cools, it is prone to stress concentration. The provision of a diameter reducing portion 302 can achieve a gradual transition of the corner, improve the efficiency of molten iron punching, and avoid defects such as shrinkage and cold cracking caused by metal structure accumulation and stress concentration in the casting. In addition, it can also prevent erosion and damage to the sand mold corner caused by eddy currents and bubbles generated by the high-speed impact of the molten iron on the sudden corner. On the other hand, the weld where the support sleeve of the traditional welded spacer connects to the side plate will produce bending stress concentration and deformation, which can easily cause cracking in the weld. The reciprocating movement of the center of gravity when each crosshead alternately enters the crosshead box causes the bending moment at the weld to vary periodically, resulting in periodic changes in the deformation amount, which may cause vibration at this location. Under the action of cyclic stress, the expansion of the weld crack is further aggravated. The diameter reducing portion 302 increases the diameter of the root of the support sleeve 300, improving the bending strength and support stiffness of the root of the support sleeve.

[0074] To improve the strength and rigidity of the support sleeve 300 while also facilitating the casting process, the reducing portion 302 has an aspect ratio of 2:1 to 4:1. Specifically, the ratio of the length of the reducing portion 302 along the axial direction of the support sleeve 300 to its width perpendicular to the axial direction of the support sleeve 300 (the difference between the radius of the reducing portion 302 and the radius of the cylindrical portion 301) is 2:1 to 4:1. The fillet size is preferably R15 to R20.

[0075] From the above, it can be seen that due to the convenience of casting on plasticity, the wall thickness of the support sleeve 300 can change with the stress distribution, that is, the support sleeve 300 is cast into a structure that is thick at both ends (large wall thickness) and slightly thin in the middle (small wall thickness). The diameter of the first bolt hole 310 in the support sleeve 300 needs to be kept consistent, which can effectively improve the bending strength of the root of the support sleeve 300 and reduce the overall weight. This shape is also conducive to casting.

[0076] The present invention does not limit the location and number of the support sleeves 300, which can be arranged according to the number and location of the first bolts 930 of the crosshead box 900. Preferably, the support sleeves 300 are arranged in two horizontal rows, one on each side of the upper and lower sides of the tie rod opening 210.

[0077] In addition, the bottom of the support sleeve 300 can be provided with an oil pan bolt hole 322 for installing an integral oil pan, and the side of the support sleeve 300 can also be provided with a pump cover plate bolt hole 323 for installing a fracturing pump cover plate.

[0078] The fracturing pump spacer is used to connect and support the crosshead box and the hydraulic end in a fracturing pump. During fracturing operations, for high-power fracturing pumps over 4000 hp, the structure of the fracturing pump spacer with single-sided support legs (i.e., a structure with support legs only below the hydraulic end connection plate 100 or only below the crosshead box connection plate 200) is insufficient to withstand significant vibration and weight. Specifically, the fracturing pump spacer is placed between the crosshead box and the hydraulic end, and long bolts passing through the first bolt holes 310 tightly connect the crosshead box and the hydraulic end. The weight of the crosshead box and the hydraulic end, as well as the vibration during movement, are all supported and borne by the spacer. The connecting portion of the spacer is subjected to huge shear forces and bending moments, which can easily lead to structural failure under long-term operation.

[0079] In the present invention, the fracturing pump spacer utilizes a dual-sided support leg arrangement, with support legs 400 positioned beneath both the hydraulic end connection plate 100 and the crosshead box connection plate 200. Tests and practice have proven that support legs 400 provide excellent support and shock absorption, improve load bearing conditions at the connection points, and extend the service life of the fracturing pump spacer.

[0080] Specifically, the support leg 400 is generally U-shaped and includes a first support leg upright plate 410 and a second support leg upright plate 430 disposed vertically, and a first support leg bottom plate 420 disposed horizontally. The lower ends of the first support leg upright plate 410 and the second support leg upright plate 430 are respectively connected to the two sides of the first support leg bottom plate 420. The first support leg upright plate 410 is located below the hydraulic end connection plate 100, and the second support leg upright plate 430 is located below the crosshead box connection plate 200. There are at least two support legs 400, which are evenly distributed along the length of the hydraulic end connection plate 100. In this embodiment, there are two support legs 400, one at each end of the hydraulic end connection plate 100 along the length direction.

[0081] In actual operation, the side of the crosshead box 900 connected to the crankcase (the side of the crosshead box 900 away from the fracturing pump spacer) is connected by multiple bolts. The side of the crosshead box 900 connected to the crankcase is regarded as the fixed support end. In the case of a traditional fracturing pump spacer with single-sided support, the weight of the crosshead box 900, the fracturing pump spacer and the hydraulic end is supported only by the fixed support end and the single-sided support leg of the fracturing pump spacer. The fracturing pump spacer is subject to greater force. When the crosshead assembly reciprocates, the bending moment generated at the center of gravity of the crosshead assembly is the largest. When the center of gravity of the crosshead assembly moves to the position closest to the fracturing pump spacer, the bending moment at the connection between the crosshead box and the fracturing pump spacer reaches its maximum, and the tensile force on both sides of the connection surface that separates from the connection surface is also the largest. This easily leads to the risk of connection surface separation, deformation and failure of the connecting bolts, and downward sliding of the connection surface, which may lead to oil and gas leakage. On the other side of the fracturing pump spacer, due to the large weight of the hydraulic end itself, bending moment and shear force will also be generated. In addition, some vibrations are generated and received during the movement of related components. Multiple loads are coupled and loaded on the single-side support of the spacer. Under long-term operation, the connection is prone to deformation and fatigue failure.

[0082] The fracturing pump spacer in the present invention adopts a double-sided support design, and the arrangement of the first leg upright plate 410 and the second leg upright plate 430 increases the number of support points of the fracturing pump spacer. When the crosshead assembly moves to the position closest to the fracturing pump spacer, due to the addition of a set of support structures (the second leg upright plate 430), the distance between the support points on both sides of the crosshead box becomes smaller, and the bending moment at the connection between the crosshead box and the fracturing pump spacer also becomes smaller, and the outward tension on both sides of the connection surface is reduced, thereby improving the load state of the connection surface between the crosshead box and the fracturing pump spacer. For the support connection of the hydraulic end, since the fracturing pump spacer supports both sides, the force of the original single-sided leg is shared, the bending moment and the deformation caused are reduced, and the service life is increased.

[0083] The first leg base plate 420 connects the first leg upright plate 410 and the second leg upright plate 430, and is used to support and connect the first leg upright plate 410 and the second leg upright plate 430 laterally (horizontally, the direction of horizontal movement of the pull rod 910), preventing the first leg upright plate 410 and the second leg upright plate 430 from deformation and tilting, while increasing the connection area between the bottom of the fracturing pump spacer and the ground or the bottom skid, thereby improving the support stiffness and stability.

[0084] The material of the fracturing pump spacer is preferably ductile iron or vermicular cast iron. Since the elastic modulus of cast iron is lower than that of cast steel, the fracturing pump spacer made of cast iron allows the fracturing pump spacer to shake laterally (in the direction of horizontal movement of the pull rod 910), thereby avoiding stress concentration at the connection between the legs and the bottom when the fracturing pump spacer is subjected to lateral force, and reducing the friction required for the bottom bolts fixing the fracturing pump spacer. If the rigidity of the fracturing pump spacer legs is large and shaking is not allowed, stress concentration will occur at the connection of the legs that remain stationary when subjected to lateral force, and the bottom bolts will require greater friction to prevent the spacer from shaking).

[0085] At least two base plate fixing holes 422 are provided in the middle of the first leg base plate 420, distributed along the axial direction parallel to the support sleeve 300. The fracturing pump spacer can be fixed to a predetermined position (such as a bottom fixed support structure such as a bottom skid) through the base plate fixing holes 422. Preferably, there are two base plate fixing holes 422.

[0086] In order to increase the connection stiffness at the bottom plate fixing hole 422, prevent deformation of the connection there, and ensure a stable connection between the fracturing pump spacer and the bottom skid, a boss 423 is provided at the bottom plate fixing hole 422, that is, the thickness around the bottom plate fixing hole 422 is greater than the thickness at other positions of the first leg bottom plate 420.

[0087] In order to increase the bending strength of the base of the support leg 400, the oblique support can decompose the vertical downward pressure into a horizontal thrust, thereby reducing the longitudinal support reaction force and reducing the pressure and bending moment on the support leg. Therefore, the first support leg upright plate 410 and the second support leg upright plate 430 in the present invention both include a first support leg 440 and a second support leg 450. The lower ends of the first support leg 440 and the second support leg 450 are fixedly connected, and the upper ends of the second support leg 450 and the first support leg 440 are respectively connected to the hydraulic end connecting plate 100 and the crosshead box connecting plate 200. In order to reduce the longitudinal support reaction force and reduce the pressure and bending moment on the support leg, the first support leg 440 is set vertically and the second support leg 450 is set obliquely, and the first support leg 440 and the second support leg 450 form an angle.

[0088] Specifically, the upper ends of the first leg 440 and the second leg 450 of the first leg stand 410 are connected to the hydraulic end connection plate 100, and the upper ends of the first leg 440 and the second leg 450 of the second leg stand 430 are connected to the crosshead box connection plate 200. The first leg 440 and the second leg 450 form the first leg stand 410 and the second leg stand 430, which are wide at the top and narrow at the bottom (a triangle).

[0089] Note that the present invention does not limit the number of legs and feet, nor the connection method. For example, if there are three or more legs 400, they can be evenly distributed below the hydraulic end connection plate 100 and the crosshead box connection plate 200. Alternatively, the leg uprights may not be fixedly connected. For example, if there are three legs 400, the middle leg 400 may include only the vertically arranged first leg upright 410 and the second leg upright 430, without the horizontally arranged first leg bottom plate 420. Furthermore, depending on the actual situation, bottom plates may be used to fixedly connect the legs of different legs 400.

[0090] In order to enhance the structural rigidity of the connection between the spacer legs and the connecting plate, the upper ends of the first leg 440 and the second leg 450 are respectively located under different support sleeves 300. Preferably, the upper ends of the first leg 440 and the second leg 450 are respectively located under horizontally adjacent support sleeves 300.

[0091] Considering that the root bending of the support sleeve 300 above the support leg 400 is hindered by the first support leg plate 410 and the second support leg plate 430, and that the internal structures squeeze each other and cause stress concentration, the first support leg 440 and the second support leg 450 are both provided with support leg reinforcement ribs 460 in the middle of the inner side (on the side near the center of the fracturing pump spacer). The support leg reinforcement ribs 460 are arranged along the length of the first support leg 440 and the second support leg 450. The support leg reinforcement ribs 460 can reduce the root bending of the support sleeve 300 and increase the rigidity of the support sleeve 300.

[0092] More preferably, the upper end of the support leg reinforcement rib 460 is connected to the reduced diameter portion 302 of the support sleeve 300 to ensure overall support rigidity. The triangular support design of the first and second support legs 440 and 450 prevents longitudinal shaking of the pressure pump spacer. Horizontal reinforcement ribs (not shown) may also be added between two horizontally adjacent support sleeves, depending on the situation.

[0093] To ensure sufficient bending stiffness for the leg reinforcement 460 and to suppress displacement and deformation of the leg 400, the leg reinforcement 460 has a generally rectangular cross-section. This is because a rectangle has a greater moment of inertia along its major axis than a solid regular cross-section (such as a circle or square) of the same area. However, the present invention is not limited to this. The cross-section of the leg reinforcement 460 can be substituted with any other cross-sectional shape that meets support requirements and the casting process.

[0094] In order to reduce stress concentration and facilitate casting, the edges of the support leg reinforcement ribs 460 are provided with rounded corners.

[0095] Because the first and second legs 440 and 450 are tilted, through holes 470 are provided in the middle of the first and second leg uprights 410 and 430. These through holes 470 prevent stress concentration caused by compression of the internal structures near the leg reinforcement ribs 460, thereby relieving internal stress and reducing structural weight.

[0096] Furthermore, a bottom plate reinforcement rib 480 is provided on the first leg bottom plate 420 in a direction parallel to the axial direction of the support sleeve 300, and the two ends of the bottom plate reinforcement rib 480 are respectively connected to the support leg reinforcement rib 460 on the first support leg 440 of the first support leg upright plate 410 and the second support leg upright plate 430, thereby increasing the support strength and preventing the connection between the support leg 400 and the bottom from being pulled apart when the fracturing pump spacer is subjected to lateral force.

[0097] In addition, in order to expand the bottom support area, prevent the fracturing pump spacer from tipping forward and backward, and improve stability, a widened portion 490 is provided at the edge of the outer side of the first leg 440 and the second leg 450 (the side away from the center of the fracturing pump spacer), and the thickness of the widened portion 490 is greater than the thickness of the first leg 440 and the second leg 450.

[0098] Example 2

[0099] Figure 10 is a first exploded schematic diagram of a fracturing pump according to a second embodiment of the present invention; Figure 11 is a second exploded schematic diagram of a fracturing pump according to a second embodiment of the present invention; Figure 12 is a structural schematic diagram of a fracturing pump spacer according to a second embodiment of the present invention; Figure 13 is a side view of a hydraulic end connecting plate according to a second embodiment of the present invention; Figure 14 is a side view of a crosshead box connecting plate according to a second embodiment of the present invention; Figure 15 is a partial enlarged view of a second bolt hole according to a second embodiment of the present invention; Figure 16 is a side view of a fracturing pump spacer according to a second embodiment of the present invention; and Figure 17 is a partial enlarged view of a support leg according to a second embodiment of the present invention. As shown in Figures 10 to 17, in the second embodiment of the present invention, the fracturing pump spacer includes a hydraulic end connecting plate 1100 and a crosshead box connecting plate 1200 arranged in parallel and spaced apart. The hydraulic end connecting plate 1100 and the crosshead box connecting plate 1200 are fixedly connected by a support sleeve 1300, and a portion of the hydraulic end connecting plate 1100 extends to one side to form a support leg 1400. In other words, the side where the support leg 1400 is located (the lower side in the vertical direction in FIG. 13 ) is the bottom side, and the hydraulic end connecting plate 1100 partially extends downward (toward the bottom side) to form the support leg 1400. The hydraulic end connecting plate 1100, the crosshead box connecting plate 1200, the support sleeve 1300, and the support leg 1400 are integrally formed (including but not limited to integrally cast). The fracturing pump spacer is made of ductile iron, vermicular graphite iron, gray iron, or cast steel. Preferably, the fracturing pump spacer is made of ductile iron or vermicular graphite iron.

[0100] Traditional fracturing pump spacers are constructed using a welded assembly process. Due to inherent welding defects, the overall rigidity of welded steel plates is insufficient, and localized deformation and stress concentration in the welds accelerate fatigue. Compared to monolithic structures, these structures exhibit poor long-term bending and torsion resistance. From a force perspective, the entire fracturing pump has a large support span, and the weight of the crosshead housing and hydraulic end is primarily supported by the spacers. The spacer legs are subject to significant loads and bending moments, creating stress concentration points that can easily lead to localized deformation and even cracking in the welds and nearby heat-affected zones at these stress concentration points. Furthermore, as each cylinder crosshead alternates between the crosshead housing and the reciprocating movement of the center of gravity, the bending moment at the welds varies cyclically, resulting in periodic changes in deformation and potentially causing vibration. Compared to monolithic cast iron, welded steel plates offer inferior vibration damping and absorption properties. Cyclic stress can further exacerbate crack propagation in the welds, ultimately leading to failure of the support structure.

[0101] This invention utilizes an integrated molding process to flexibly enhance the wall thickness of weak bending moments and arbitrarily position reinforcing ribs, eliminating the complex welding and assembly manufacturing processes. This significantly improves the connection strength and support rigidity of the fracturing pump spacer. Furthermore, the cast iron material effectively cushions and absorbs vibrations, ensuring stable support and extending the service life of the fracturing pump spacer.

[0102] The hydraulic end connection plate 1100 is used to connect to the hydraulic end assembly 1800 (such as the hydraulic end back plate 1810, etc.). A hydraulic end opening 1110 is provided in the middle of the hydraulic end connection plate 1100 to facilitate connection with the hydraulic end assembly (such as the packing box pressure cap 1820, etc.). To ensure support strength and reduce overall weight, the hydraulic end opening 1110 has semicircular ends at both horizontal directions and a rectangular middle, that is, the hydraulic end opening 1110 has the shape of an elliptical runway. The present invention does not limit the specific shape of the hydraulic end opening 1110, and those skilled in the art can design and select it according to actual conditions.

[0103] To facilitate installation and removal of the fluid end assembly 1800 (e.g., a packing lubrication joint), a process hole (not shown) is provided below the fluid end opening 1110. The process hole can be located below each packing assembly. In other words, the process hole provides space for installation, removal, and maintenance of the packing assembly (e.g., a packing lubrication joint).

[0104] In order to collect water, oil and their mixture in the depression of the hydraulic end connecting plate 1100 and prevent the connecting plate from rusting, a drainage groove (not shown in the figure) is further provided on the upper side of the hydraulic end opening 1110. The drainage groove can be provided above each group of packing assemblies.

[0105] The process hole and the drainage groove are preferably arc grooves, which are simple in shape and easy to cast. The present invention does not limit the shape of the grooves, and other shapes that are easy to install and disassemble can be used, such as rectangular, square, etc.

[0106] The hydraulic end connection plate 1100 is provided with locating pin openings 1120 on either side along its length. These openings correspond to the locating pins 1830 on the hydraulic end assembly 1800, facilitating the installation and positioning of the hydraulic end connection plate 1100 and the hydraulic end back plate 1810. It should be noted that the locating pin openings 1120 on either side are at different heights to prevent the locating pins 1830 from being inserted even when the hydraulic end connection plate is installed upside down.

[0107] The fracturing pump spacer is provided with a first bolt hole 1310 that passes through the hydraulic end connection plate 1100, the support sleeve 1300, and the crosshead box connection plate 1200. Long bolts 1920 (e.g., studs) of the crosshead box 1900 are passed through the first bolt hole 1310 and tightened at the end of the hydraulic end, thereby ensuring a reliable connection between the contact surfaces (between the crosshead box connection plate and the crosshead box, and between the hydraulic end connection plate and the hydraulic end back plate).

[0108] The crosshead box connecting plate 1200 is provided with second bolt holes 1320 directly above the first bolt holes 1310 on its upper side and directly below the first bolt holes 1310 on its lower side. The first bolts 1930 of the crosshead box 1900 pass through the second bolt holes 1320 to fix the crosshead box connecting plate 1200 to the crosshead box 1900.

[0109] In order to facilitate the installation of the first bolt 1930 , a recess 1321 is provided on the periphery of the second bolt hole 1320 away from the crosshead box 1900 (as shown in FIG. 15 ).

[0110] However, due to the low rigidity and long moment arm at the connection between the crosshead box 1900 and the fracturing pump spacer, there is a certain amount of flexural deformation, and the crosshead box connecting plate 1200 may deform and separate along its length. Therefore, two vertically arranged third bolt holes 1330 are provided on both sides of the crosshead box connecting plate 1200 along its length (the left and right sides in Figure 14). The second bolts 1940 of the crosshead box 1900 pass through the second bolt holes 1320 to securely connect the crosshead box connecting plate 1200 to the crosshead box 1900.

[0111] The crosshead housing connecting plate 1200 is used to connect to the crosshead housing 1900. A tie rod opening 1210 is provided in the middle of the crosshead housing connecting plate 1200. The tie rod 1910 passes through the tie rod opening 1210 and, driven by the crosshead, performs horizontal reciprocating motion, thereby converting the rotational motion of the crankshaft into the reciprocating motion of the plunger.

[0112] It should be noted that due to the movement characteristics of the crosshead assembly, the crosshead box 1900 needs to have an oil and air drainage function. In the prior art, oil and air drainage is often achieved by reserving oil and air drainage holes on the box body of the crosshead box 1900, which makes the structure of the crosshead box 1900 complicated and reduces the mechanical strength of the crosshead box 1900. In order to solve the above problem, the pull rod opening 1210 is provided with an avoidance groove 1340 on the periphery of the side close to the crosshead box 1900. When the crosshead assembly moves to the position closest to the crosshead box connecting plate 1200, due to the presence of the avoidance groove 1340, the crosshead assembly will not contact the crosshead box connecting plate 1200, and a gap will exist between the crosshead assembly and the crosshead box connecting plate 1200. This gap can ensure the oil and air drainage function required by the crosshead box 1900.

[0113] Furthermore, in order to prevent the lubricating oil from being carried out of the crosshead box 1900 by the crosshead assembly as much as possible, a sealing assembly (shown in the figure) and a positioning groove (shown in the figure) installed in cooperation with the sealing assembly are provided on the side of the pull rod opening 1210 away from the crosshead box 1900.

[0114] As can be seen from the above, in the present invention, the crosshead box 1900 and the fracturing pump spacer are connected by two bolts. The first is a long bolt 1920 passing through the first bolt hole 1310, which is used for overall fixation and pre-tightening; the second is a first bolt 1930 and a second bolt 1940 passing through the second bolt hole 1320 and the third bolt hole 1330 on the crosshead box connecting plate 1200, respectively, which are used for sealing and fastening between the crosshead box 1900 and the fracturing pump spacer. Furthermore, in order to better ensure the sealing effect, the crosshead box connecting plate 1200 is also provided with a sealing groove 1350 for placing a sealing ring, a sealing ring or filling sealant on the side close to the crosshead box 1900. The present invention is not limited to this, and the crosshead box connecting plate 1200 and the crosshead box 1900 can also be directly bonded using sealant without providing a sealing groove 1350.

[0115] It should be noted that to improve sealing reliability, the length of the sealing groove 1350 needs to be increased as much as possible; however, to ensure air pressure communication throughout the first bolt hole 1310, the sealing groove 1350 cannot completely surround the first bolt hole 1310. Therefore, the tie rod opening 1210 is located inside the sealing groove 1350, while the second bolt hole 1320, the third bolt hole 1330, and the first bolt hole 1310 are located outside the sealing groove 1350, with the sealing groove 1350 being located adjacent to the first bolt hole 1310.

[0116] The present invention does not limit the molding method of the sealing groove 1350. In addition to machining, other methods of removing material can also be used. In addition, it is noted that the setting position of the sealing groove 1350 needs to bypass the crankcase observation window and the crosshead case exhaust cavity at the same time.

[0117] Through the above-mentioned structure, the present invention can prevent oil and gas leakage, prevent moisture-induced lubricant contamination, and prevent adverse consequences such as corrosion and wear of internal metal components. Compared to a single bolt connection seal, the dual bolt fixation and connection effectively ensures the sealing surface fits and tightens, preventing the sealing surface from disengaging and slipping due to plunger force and connecting rod lateral force, and preventing oil, gas, and oil pressure leakage.

[0118] The support sleeve 1300 includes a cylindrical portion 1301 and reducing portions 1302 located at both ends of the cylindrical portion 1301. Specifically, the reducing portions 1302 are provided at the connection between the support sleeve 1300, the hydraulic end connection plate 1100, and the crosshead box connection plate 1200. The diameter of the reducing portions 1302 gradually increases as it moves away from the center of the support sleeve 1300. The present invention is not limited to the specific shape of the reducing portions 1302. Preferably, the reducing portions 1302 are truncated cone-shaped, in which case the cross-section of the reducing portions 1302 is trapezoidal. Alternatively, the reducing portions 1302 are trumpet-shaped.

[0119] Furthermore, rounded corners are provided at the connections between the reducing portion 1302 and the cylindrical portion 1301 , the hydraulic end connecting plate 1100 and the crosshead box connecting plate 1200 .

[0120] On the one hand, because molten iron flows at high speed through a sudden corner during pouring, it can cause throttling and accumulation. As the molten iron gradually cools, it is prone to stress concentration. The provision of a diameter reducing portion 1302 can achieve a gradual transition of the corner, improve the efficiency of molten iron punching, and avoid defects such as shrinkage and cold cracking caused by metal structure accumulation and stress concentration in the casting. In addition, it can also prevent erosion and damage to the sand mold corner caused by eddy currents and bubbles generated by the high-speed impact of the molten iron on the sudden corner. On the other hand, the weld where the support sleeve of the traditional welded spacer connects to the side plate will produce bending stress concentration and deformation, which can easily cause cracking in the weld. The reciprocating movement of the center of gravity when each crosshead alternately enters the crosshead box causes the bending moment at the weld to vary periodically, resulting in periodic changes in the deformation amount, which may cause vibration at this location. Under the action of cyclic stress, the expansion of the weld crack is further exacerbated. The diameter reducing portion 1302 increases the diameter of the root of the support sleeve 1300, improving the bending strength and support stiffness of the root of the support sleeve.

[0121] To improve the strength and rigidity of the support sleeve 1300 while also facilitating the casting process, the reducing portion 1302 has an aspect ratio of 2:1 to 4:1. Specifically, the ratio of the reducing portion 1302's length along the axial direction of the support sleeve 1300 to its width perpendicular to the axial direction (the difference between the radius of the reducing portion 1302 and the radius of the cylindrical portion 1301) is 2:1 to 4:1. The fillet size is preferably R15 to R20.

[0122] From the above, it can be seen that due to the convenience of casting on plasticity, the wall thickness of the support sleeve 1300 can change with the stress distribution, that is, the support sleeve 1300 is cast into a structure that is thick at both ends (large wall thickness) and slightly thin in the middle (small wall thickness). The diameter of the first bolt hole 1310 in the support sleeve 1300 needs to be kept consistent, which can effectively improve the bending strength of the root of the support sleeve 1300 and reduce the overall weight. This shape is also conducive to casting.

[0123] The present invention does not limit the location and number of the support sleeves 1300, which can be arranged according to the number and location of the first bolts 1930 of the crosshead box 1900. Preferably, the support sleeves 1300 are arranged in two horizontal rows, one on each side of the upper and lower sides of the tie rod opening 1210.

[0124] In addition, bolt holes for installing an integral oil pan can be provided at the bottom of the support sleeve 1300 (not shown in the figure), and bolt holes for installing a fracturing pump cover plate can also be provided on the side of the support sleeve 1300 (not shown in the figure).

[0125] The fracturing pump spacer connects and supports the crosshead housing and hydraulic end in the fracturing pump. During fracturing operations, the spacer must withstand the vertical weight of the crosshead housing and hydraulic end, while also bearing the plunger's axial force horizontally. To prevent relative swaying between the two end plates of the fracturing pump spacer, which could affect the cylinder spacing and cause eccentric wear on the plunger, the support stiffness at key load points must be ensured.

[0126] However, considering the transportation cost and production cost of the fracturing pump, the weight of the fracturing pump needs to be reduced. For the fracturing pump spacer that only has connection and support functions, technicians hope to reduce its weight as much as possible.

[0127] In the present invention, the fracturing pump spacer utilizes a single-sided support leg arrangement, with support legs 1400 positioned only below the hydraulic end connection plate 1100. Testing and practical application have demonstrated that for low-power fracturing pumps under 4000 hp, support legs 1400 provide excellent support and shock absorption, improve load bearing conditions at the connection, and extend the service life of the fracturing pump spacer.

[0128] Specifically, the support leg 1400 is generally L-shaped, comprising a vertically disposed third support leg plate 1410 and a horizontally disposed second support leg base plate 1420. There are at least two support legs 1400, evenly distributed along the length of the hydraulic end connection plate 1100. In this embodiment, there are two support legs 1400, one located at each end of the hydraulic end connection plate 1100. The second support leg base plate 1420 is provided with base plate fixing holes 1422, through which the fracturing pump spacer can be secured in a predetermined position.

[0129] A stress analysis of the fracturing pump spacer revealed that the root of the support sleeve above leg 1400 experiences the greatest bending moment (approximately 22 kN·m), necessitating increased structural bending strength. Furthermore, because the root of the support sleeve above leg 1400 is obstructed by the third leg plate 1410 during bending, the internal structures squeeze each other, causing stress concentration. Therefore, an additional first support rib 1411 is installed at this location to reduce bending at the root, suppress bending deformation of the support sleeve, and enhance support rigidity.

[0130] Specifically, the first support rib 1411 is arranged at the connection between the third support leg upright plate 1410 and the support sleeve 1300 located above the third support leg upright plate 1410. The top of the first support rib 1411 is connected to the support sleeve 1300, and the side is connected to the third support leg upright plate 1410 and the hydraulic end connecting plate 1100.

[0131] Preferably, the length of the first supporting rib 1411 away from the hydraulic end connecting plate 1100 is less than or equal to the length of the reducing portion 1302. This structure can connect the reinforcing rib to a position with stronger bending strength and supporting stiffness, thereby achieving a better reinforcement effect and greatly improving the bending strength of the connection point (bending moment weak point).

[0132] To ensure the relative positioning of the third leg upright plate 1410 and the second leg bottom plate 1420, a second support rib 1421 is provided at the connection between the third leg upright plate 1410 and the second leg bottom plate 1420. The present invention is not limited to the number of second support ribs 1421; one or more second support ribs 1421 may be provided. Preferably, for each leg 1400, two second support ribs 1421 are provided, one on each side of each third leg upright plate 1410, avoiding the bottom plate fixing holes 1422.

[0133] It should be noted that due to the large span of the support points of the entire fracturing pump, the support stiffness of the single-sided support leg is difficult to resist the flexural displacement of the middle crosshead box, spacer and connection. Therefore, it is necessary to allow a certain degree of bending deformation of the support leg to avoid mutual squeezing and shearing between the reinforcements when the support leg is subjected to bending moment, causing local damage due to stress concentration.

[0134] Therefore, a gap area is provided between the first support rib 1411 and the second support rib 1421. The height of the gap area is preferably greater than 5 mm to allow for flexural deformation of the leg 1400. In other words, the vertical distance between the lowermost end of the first support rib 1411 and the uppermost end of the second support rib 1421 is preferably greater than 5 mm.

[0135] To avoid stress concentration and reduce weight while ensuring strength, the thickness of the first support rib 1411 and the second support rib 1421 gradually decreases as they approach the gap area. Furthermore, the thickness of the first support rib 1411 and the second support rib 1421 gradually decreases as they move away from the third leg upright 1410. Furthermore, the edges of the first support rib 1411 and the second support rib 1421 are rounded to reduce stress concentration and facilitate casting.

[0136] In summary, the present invention avoids the influence of welding defects on stiffness, strength and life by adopting an integrally formed fracturing pump spacer; the roughly U-shaped support leg can support the hydraulic end connecting plate and the crosshead box connecting plate at the same time, which increases the support points, reduces the bending moment and the deformation caused, and increases the service life; the single-sided support leg with a supporting rib plate allows the support leg to have a certain bending deformation while strengthening the support stiffness; the variable diameter portion of the support sleeve improves the bending strength and support stiffness of the root of the support sleeve, and facilitates the implementation of the casting process.

Claims

1. A fracturing pump spacer, comprising a hydraulic end connection plate and a crosshead box connection plate arranged in parallel and spaced apart, wherein the hydraulic end connection plate and the crosshead box connection plate are fixedly connected via a support sleeve, and a first bolt hole penetrating the hydraulic end connection plate, the support sleeve and the crosshead box connection plate is also provided in the fracturing pump spacer, characterized in that: The fracturing pump spacer also includes a leg, and the hydraulic end connecting plate, the crosshead box connecting plate, the support sleeve and the leg are integrally formed; the leg includes a first leg upright plate and a second leg upright plate arranged vertically and a first leg bottom plate arranged horizontally, the first leg upright plate is located below the hydraulic end connecting plate, the second leg upright plate is located below the crosshead box connecting plate, and the two sides of the first leg bottom plate are respectively connected to the lower ends of the first leg upright plate and the second leg upright plate.

2. The fracturing pump spacer according to claim 1, characterized in that: The number of the supporting legs is at least two, and they are evenly distributed along the length direction of the hydraulic end connecting plate; the first supporting leg upright plate and the second supporting leg upright plate both include a first supporting foot and a second supporting foot, and the lower ends of the first supporting foot and the second supporting foot are fixedly connected.

3. The fracturing pump spacer according to claim 2, characterized in that: The first supporting leg is vertically arranged, the second supporting leg is inclinedly arranged, and the first supporting leg and the second supporting leg form an angle.

4. The fracturing pump spacer according to claim 3, characterized in that: The upper ends of the first supporting leg and the second supporting leg are respectively located below different supporting sleeves.

5. The fracturing pump spacer according to claim 4, characterized in that: The middle parts of the inner sides of the first supporting leg and the second supporting leg are both provided with supporting leg reinforcing ribs, and the supporting leg reinforcing ribs are respectively provided along the length direction of the first supporting leg and the second supporting leg.

6. The fracturing pump spacer according to claim 5, characterized in that: The edges of the support leg reinforcement ribs are provided with rounded corners.

7. The fracturing pump spacer according to claim 5, characterized in that: A bottom plate reinforcement rib is provided on the bottom plate of the first leg in a direction parallel to the axial direction of the support sleeve, and two ends of the bottom plate reinforcement rib are respectively connected to the foot reinforcement ribs on the first feet of the first leg upright plate and the second leg upright plate.

8. The fracturing pump spacer according to claim 7, characterized in that: Widened portions are provided at outer edges of the first supporting leg and the second supporting leg.

9. A fracturing pump spacer, comprising a hydraulic end connection plate and a crosshead box connection plate arranged in parallel and spaced apart, wherein the hydraulic end connection plate and the crosshead box connection plate are fixedly connected via a support sleeve, and a first bolt hole penetrating the hydraulic end connection plate, the support sleeve and the crosshead box connection plate is also provided in the fracturing pump spacer, characterized in that: The hydraulic end connecting plate portion extends to one side to form a supporting leg, and the hydraulic end connecting plate, the crosshead box connecting plate, the supporting sleeve and the supporting leg are integrally formed; the supporting leg comprises a vertically arranged third supporting leg upright plate and a horizontally arranged second supporting leg bottom plate, a first supporting rib is arranged at the connection between the third supporting leg upright plate and the supporting sleeve located above the third supporting leg upright plate, a second supporting rib is arranged at the connection between the third supporting leg upright plate and the second supporting leg bottom plate, and a gap area is arranged between the first supporting rib and the second supporting rib.

10. The fracturing pump spacer according to claim 9, characterized in that: The height of the gap area is greater than 5 mm.

11. The fracturing pump spacer according to claim 9, characterized in that: The thickness of the first support rib and the second support rib gradually decreases along the direction approaching the gap area, or the thickness of the first support rib and the second support rib gradually decreases along the direction away from the third leg vertical plate.

12. The fracturing pump spacer according to claim 1 or 9, characterized in that: The support sleeve comprises a cylindrical portion and a diameter-reducing portion located at two ends of the cylindrical portion, and the diameter of the diameter-reducing portion gradually increases in a direction away from the center of the support sleeve.

13. The fracturing pump spacer according to claim 12, characterized in that: The connection between the diameter reducing portion and the cylindrical portion, the hydraulic end connecting plate and the crosshead box connecting plate is provided with a rounded corner.

14. The fracturing pump spacer according to claim 12, characterized in that: The ratio of the length of the diameter-reducing portion along the axial direction of the support sleeve to the width of the diameter-reducing portion along the direction perpendicular to the axial direction of the support sleeve is 2:1 to 4:

1.

15. The fracturing pump spacer according to claim 1 or 9, characterized in that: A hydraulic end opening is arranged in the middle of the hydraulic end connecting plate, and a process hole is arranged at the lower side of the hydraulic end opening.

16. The fracturing pump spacer according to claim 15, characterized in that: Positioning pin openings are respectively arranged on both sides of the hydraulic end connecting plate along the length direction, and the heights of the positioning pin openings on the two sides are different.

17. The fracturing pump spacer according to claim 1 or 9, characterized in that: The crosshead box connecting plate is provided with a second bolt hole just above the first bolt hole on its upper side and just below the first bolt hole on its lower side; and two vertically arranged third bolt holes are respectively provided on both sides of the crosshead box connecting plate along the length direction.

18. The fracturing pump spacer according to claim 17, characterized in that: A concave platform is arranged on the periphery of the second bolt hole at a side away from the cross head box.

19. The fracturing pump spacer according to claim 18, characterized in that: A pull rod opening is arranged in the middle of the cross head box connecting plate, and an avoidance groove is arranged on the periphery of the pull rod opening on one side close to the cross head box.

20. The fracturing pump spacer according to claim 19, characterized in that: A sealing groove is provided on one side of the crosshead box connecting plate close to the crosshead box, the pull rod opening is located inside the sealing groove, the second bolt hole, the third bolt hole and the first bolt hole are located outside the sealing groove, and the sealing groove is provided close to the first bolt hole.

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