Crosshead box and plunger pump

Abstract

The present disclosure relates to a crosshead box and a plunger pump. The crosshead box is a substantially rectangular box formed by an integral forming manufacturing process. The crosshead box is provided with a plurality of crosshead inner cavities, and the plurality of crosshead inner cavities are arranged in the transverse direction of the crosshead box. The crosshead box is further provided with a plurality of gas discharging cavities, and each gas discharging cavity penetrates through the crosshead box in the longitudinal direction of the crosshead box and is communicated with the corresponding crosshead inner cavity. The plunger pump is provided with the crosshead box. According to the crosshead box and the plunger pump of the present disclosure, the service life is greatly prolonged by means of integral forming, and the gas pressure in the box can be kept balanced all the time during operation, thereby improving the operation stability of the device, and thus further prolonging the service life.

Description

Crosshead box and plunger pump

[0001] Citation of Related Applications

[0002] This application claims the rights and interests of Chinese Patent Application No. 202310922712.8 filed with the State Intellectual Property Office of the People's Republic of China on July 26, 2023, Chinese Patent Application No. 202310923117.6 filed on July 26, 2023, and Chinese Patent Application No. 202310923165.5 filed on July 26, 2023, the entire contents of which are hereby incorporated by reference into this document in their entirety. Technical Field

[0003] The invention relates to a crosshead box of a plunger pump and a plunger pump provided with the crosshead box, wherein the crosshead box has an integrally formed structure. Background Art

[0004] Fracturing pumps (also known as plunger pumps) are widely used in the oil industry as important equipment to increase oil and gas production. Fracturing pumps play a crucial role in increasing production in some mid- to late-stage mature oil fields and in the development of emerging shale gas.

[0005] A fracturing pump primarily consists of three subsystems: a reduction gearbox, a power end, and a hydraulic end. The reduction gearbox is responsible for reducing the high-speed power input from a power source (including but not limited to diesel engines, electric motors, turbines, etc.) through multiple stages of deceleration, converting it into low-speed power, which is then fed into the power end. The power end, connected between the reduction gearbox and the hydraulic end valve box, is responsible for converting the rotational mechanical energy transmitted from the reduction gearbox into reciprocating mechanical energy to drive the hydraulic end's suction and discharge operations. The hydraulic end is responsible for pressurizing low-pressure fluid to high-pressure fluid and outputting it to the high-pressure manifold.

[0006] The power end assembly is mainly composed of a housing, a crank-connecting rod assembly, a crosshead pull rod assembly and a lubrication system. The power end housing mainly includes a crankcase and a crosshead case. The crankcase is connected to one end of the crosshead case, and the other end of the crosshead case is connected to the hydraulic end pump head body through a connecting device. At present, the most common fracturing pump in the industry is a five-cylinder fracturing pump, that is, its crankshaft is often an integral structure of six supports and five cranks. The crankshaft is connected to the big end of the connecting rod, and the small end of the connecting rod, the small end bearing, the shaft pin, etc. are connected to the crosshead in the crosshead case. As the crankshaft rotates, the crosshead reciprocates in the inner cavity of the crosshead case, thereby driving the connected plunger to reciprocate.

[0007] The power end housing is a key component of a fracturing pump, housing all of its components and bearing the full load they create during operation. Therefore, excellent mechanical properties of the power end housing have a crucial impact on the lifespan of the fracturing pump. Depending on the housing's structural composition, power end housings can be categorized as either integral or split.

[0008] Currently, the split structure is composed of a crankcase and a crosshead housing welded from high-strength alloy plates. Common processes are considered complete only after welding, heat treatment (stress relief annealing), rough machining, defect grinding, re-welding, heat treatment of welds, and testing. For example, the fracturing pump power end housing developed by FMC Corporation adopts a split welded structure. GD's 5000thunder power end also adopts a long stroke (11 inches) and a split structural design (crankcase + crosshead housing split design). In addition, because welding is a local rapid heating and cooling process, the weld area cannot expand and contract freely due to the constraints and restrictions of the surrounding body. When the tensile stress on the material at the weld after cooling approaches the yield limit of the material, adverse consequences such as weld cracking and shell deformation will occur. While the aforementioned weld defects can be mitigated to a certain extent through proper welding processes and heat treatment to eliminate internal stresses, the heat-affected but unmelted base material surrounding the weld (heat-affected zone) undergoes changes in its metallographic structure and mechanical properties. This uneven microstructure distribution, under the action of the welding thermal cycle, inevitably leads to weld internal stresses, which can become a source of fatigue cracks in the component. Fracturing pumps operate in extremely harsh environments, subjecting the power end housing to continuous impact from high-pressure, periodic pulse loads. Welded power end housings have poor impact resistance and are prone to cracking near the welds, which in turn can cause the housing to crack, ultimately leading to failure of the support function, compromising fracturing operation efficiency and even posing a safety hazard. Currently, existing welded power end housings have a lifespan of at most 2,000 to 3,000 hours, and even after repair, a single failure rarely exceeds the system's design lifespan of 5,000 hours. Furthermore, the gradual propagation of weld cracks significantly reduces the internal consistency and joint strength of the support material, resulting in insufficient overall rigidity and strength of the housing, which can deform under high-pressure pulse loads. This abnormal shell deformation will change the clearance between the sliding surfaces, affect the input and establishment of the lubricating oil film, and cause abnormal eccentric wear or even burns on the surfaces of key components such as the main bearing and bearing shell.

[0009] Furthermore, the high-speed reciprocating motion of the power end generates significant heat, which, if not promptly removed, could overheat and malfunction critical internal components, including the crankshaft, crosshead, tie rods, and plunger. Therefore, the design of the lubrication system is crucial to maintaining the power end's continuous operation. The fracturing pump relies on the reciprocating motion of the plunger within the cylinder, causing changes in the volume of the sealed working chamber to achieve suction and discharge, so the lubricant also serves as a secondary seal. Power end lubrication typically utilizes forced lubrication, with lubricant supplied at a constant pressure by an external lubrication system. In current welded power end housings, due to the high hardness and limited thickness of the alloy plates, the lubrication circuit primarily relies on adding external connecting pipes and internal pipes to deliver the lubricant to lubrication points (such as the crankshaft, multiple bearings, and the connecting rod small end bearing). The lubricant is then recovered, filtered, and cooled, either locally or in part, to ensure optimal performance and maximize the life of the fracturing pump. This lubrication circuit requires a large number of high- and low-pressure lubricating oil pipes, numerous joints, and a complex piping layout. Piping installation is cumbersome, and connection reliability is difficult to control, potentially leading to loosening under the pressure of the internal lubricant. Furthermore, for ease of installation, lubricant lines are often constructed using flexible hoses. Prolonged exposure to air makes them susceptible to corrosion and wear, increasing the risk of leakage and posing high maintenance costs should a leak occur. Furthermore, deformation caused by the insufficient rigidity of welded housings can alter the relative position of previously tightly contacted sealing surfaces, compromising sealing effectiveness and making it difficult to establish the pressure required for forced lubrication, thus impacting lubrication and causing oil and gas leakage. Water vapor ingress due to seal failure can also affect lubricant performance, altering viscosity, weakening the oil film's support, and accelerating oil oxidation. Hydrolysis of additives can weaken or even eliminate essential lubricant properties such as oxidation stability, extreme pressure and anti-wear properties, and detergency and dispersancy. This deteriorates the oil's anti-foaming properties, causing excessive foaming in the lubrication system and reducing lubrication effectiveness. In severe cases, it can also cause cavitation and hydrogen embrittlement of metals.

[0010] Increasing the shell thickness and increasing the size of the weld angles are relatively simple and reliable solutions to the various issues mentioned above. However, this also increases the overall pump mass, increases the load on the chassis / skid, and consumes transportation resources. Furthermore, when a shell with excessive wall thickness is loaded, large areas of internal structures will compress against each other, accumulating stress without release, leading to localized stress concentration and significantly shortening the shell's service life. Even if weight can be reduced by designing grooves in the shell's inner wall or legs, this significantly increases the number of machining steps, and the large amount of material removed results in waste, which is not conducive to cost reduction.

[0011] In terms of manufacturing, the production process of welded power end housings is very complex, typically going through a series of steps including 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 must be strictly guaranteed, otherwise it is very easy to cause the accumulation and amplification of dimensional and shape errors. Errors generated in each of these steps can lead to abnormal fitting relationships in the subsequent process, resulting in serious consequences such as connection failure, seal leakage, part wear, and housing vibration. Even if the accumulated errors caused by the above complex processes can be controlled and compensated through precision machining, the huge labor cost and time consumption are not negligible and cannot be tolerated.

[0012] Summary of the Invention

[0013] Technical problems to be solved

[0014] In view of the above-mentioned problems of the welded structure, some manufacturers have proposed to use split casting to manufacture the crosshead box. For example, the patent application US 2022 / 0163034 A1 filed by KERR discloses a crosshead box shell manufactured by split casting. However, due to problems such as design and manufacturing process, such a cast crosshead box is too heavy and bulky, making it inconvenient to transport and assemble. In addition, there are other problems, such as concentrated force on the support points, and the overall strength and rigidity are prone to failure; the overall structure is loose, resulting in a large torque during operation, which reduces the service life; the lubrication system uses a shared high and low pressure oil circuit, and some parts have insufficient lubrication oil supply while other parts have too much oil, resulting in waste, and the overall lubrication effect is poor; the lubrication pipeline is external, the process flow is increased, and the advantages of casting are not fully utilized; the overall sealing is poor, and oil and gas leakage is easy to occur.

[0015] In view of the above problems, the present disclosure hopes to provide an integrated crosshead box that can give full play to the advantages of the casting one-piece molding process, is easy to manufacture and process, has a relatively light overall weight and high structural strength and rigidity, is equipped with a more reliable and easy-to-maintain lubrication system, and has a longer service life. In addition, the present disclosure also hopes to provide an integrated crosshead box that can easily set up a more reliable and easy-to-maintain lubrication system. In addition, the present disclosure hopes to provide an integrated crosshead box that can give full play to the advantages of the casting one-piece molding process, is easy to manufacture and process, has a relatively light overall weight and high structural strength and rigidity, and has a longer service life. In addition, the present disclosure also hopes to provide an integrated crosshead box that can give full play to the advantages of the casting one-piece molding process, is easy to manufacture and process, has a good internal fluid passage, has a relatively light overall weight and high structural strength and rigidity, is equipped with a more reliable and easy-to-maintain lubrication system, and has a longer service life.

[0016] Technical solutions to technical problems

[0017] According to one aspect of the present disclosure, a crosshead box is provided. The crosshead box is a generally rectangular box formed through an integral molding process and has a front end face, a rear end face, an upper end face, a lower end face, and side end faces. The crosshead box is provided with: a plurality of crosshead cavities, each of which extends longitudinally of the crosshead box and penetrates the box body, and the plurality of crosshead cavities are arranged transversely of the crosshead box. The crosshead box is also provided with a plurality of exhaust cavities, each of which penetrates the crosshead box longitudinally and communicates with a corresponding crosshead cavity.

[0018] Preferably, the front end surface of the crosshead box may be formed with a fluid channel, which is a groove recessed inward from the front end surface in the longitudinal direction of the crosshead box and extending from the crosshead inner cavity to the exhaust cavity.

[0019] Preferably, the exhaust chamber and the corresponding crosshead inner chamber can be fluidically connected via the fluid channel, so that when the crosshead assembly moves in the crosshead inner chamber along the direction from the front end face toward the rear end face, the airflow in the exhaust chamber moves in the direction from the rear end face toward the front end face, and when the crosshead assembly moves in the crosshead inner chamber along the direction from the rear end face toward the front end face, the airflow in the exhaust chamber moves in the direction from the front end face toward the rear end face.

[0020] Preferably, the crosshead box may also be provided with a crosshead sleeve capable of being embedded in the inner cavity of the crosshead, and one end of the crosshead sleeve located on the front end surface is provided with at least one recessed portion recessed inwardly along the longitudinal direction of the crosshead box, and the recessed shape of the recessed portion matches the groove shape of the fluid channel.

[0021] Preferably, one end of the crosshead sliding sleeve located at the rear end surface may be provided with at least one protrusion protruding outward along the longitudinal direction of the crosshead sliding sleeve.

[0022] Preferably, the crosshead box may be further provided with at least one multifunctional structural hole, and each of the multifunctional structural holes extends along the longitudinal direction of the crosshead box and passes through the box body.

[0023] Preferably, the front end face of the crosshead inner cavity can be provided with a limiting groove, and the end portion of the crosshead sleeve located at one end of the front end face can be provided with a positioning pin hole, and the positioning pin hole and the limiting groove are connected via a pin shaft inserted into the pin hole to axially position the crosshead sleeve in the crosshead inner cavity.

[0024] Preferably, the crosshead housing is further provided with an embedded lubricating oil circuit, which is interconnected oil holes and oil channels formed in the casting shell of the crosshead housing, and the embedded lubricating oil circuit includes at least one main oil circuit and at least one branch oil circuit.

[0025] Preferably, the main oil passage may extend along a transverse direction of the crosshead housing, and the branch oil passage may extend along a longitudinal direction of the crosshead housing.

[0026] According to another aspect of the present disclosure, a crosshead box is provided. The crosshead box is a generally rectangular box formed by an integral molding process and has a front end face, a rear end face, an upper end face, a lower end face, and side end faces. The crosshead box is provided with a plurality of crosshead cavities, each of which extends longitudinally of the crosshead box and penetrates the box body, and the plurality of crosshead cavities are arranged transversely of the crosshead box. The crosshead box is also provided with at least one multifunctional structural hole, each of which extends longitudinally of the crosshead box and penetrates the box body.

[0027] Preferably, each of the multifunctional structural holes may be arranged at a position close to at least one of the crosshead cavities.

[0028] Preferably, at least one of the multifunctional structural holes may be provided at a position between two adjacent crosshead cavities on the front face and the rear face.

[0029] Preferably, at the front end face and the rear end face, the wall thickness around each of the multifunctional structural holes is equal.

[0030] Preferably, the crosshead housing is further provided with an embedded lubricating oil circuit, which is interconnected oil holes and oil channels formed in the casting shell of the crosshead housing, and the embedded lubricating oil circuit includes at least one main oil circuit and at least one branch oil circuit.

[0031] Preferably, the main oil passage may extend in a transverse direction of the crosshead housing, and the branch oil passage may extend in a longitudinal direction of the crosshead housing.

[0032] Preferably, the embedded lubricating oil circuit may include a high-pressure lubricating oil circuit and a low-pressure lubricating oil circuit.

[0033] According to another aspect of the present disclosure, a crosshead box is provided. The crosshead box is a generally rectangular box formed through an integral molding process and has a front end face, a rear end face, an upper end face, a lower end face, and side end faces. The crosshead box is provided with multiple crosshead cavities, each of which extends longitudinally of the crosshead box and penetrates the box body, and the multiple crosshead cavities are arranged transversely of the crosshead box. The crosshead box is also provided with an embedded lubricating oil circuit, which is a series of interconnected oil holes and oil passages formed in the cast shell of the crosshead box. The embedded lubricating oil circuit includes a main oil circuit and branch oil circuits.

[0034] Preferably, the main oil passage may extend along a transverse direction of the crosshead housing, and the branch oil passage may extend along a longitudinal direction of the crosshead housing.

[0035] Preferably, the crosshead box may further include a crosshead sleeve, which has a shape matching the crosshead inner cavity and can be embedded and installed in the crosshead inner cavity, and the crosshead sleeve is provided with an oil hole penetrating the sleeve wall, and the oil hole is part of the branch oil circuit.

[0036] Preferably, the crosshead box is further provided with a plurality of exhaust cavities and at least one multifunctional structural hole, each of the exhaust cavities passes through the crosshead box in the longitudinal direction of the crosshead box and is communicated with the corresponding crosshead inner cavity, and each of the multifunctional structural holes extends along the longitudinal direction of the crosshead box and passes through the box body.

[0037] According to yet another aspect of the present disclosure, a plunger pump is provided, comprising a crankcase, any one of the crosshead cases described above, and a spacer.

[0038] Preferably, positioning pin holes are provided on the joint end surfaces of the crankcase, the crosshead case and the spacer for aligning and positioning the crankcase, the crosshead case and the spacer.

[0039] Preferably, the plunger pump further includes a reduction box, and a support lug is provided on a mounting boss formed on a side end surface of the crosshead box, and the support lug is connected to a support assembly of the reduction box. Beneficial effects

[0040] According to one aspect of the present disclosure, a new one-piece crosshead box is provided, which greatly reduces the overall weight and improves the strength and rigidity. The deformation at the key fitting parts is small, making the lubrication, sealing and connection more reliable. The bending and torsion resistance, buffering and shock resistance are good, and the sensitivity to notch is low. In addition, the crosshead box according to one aspect of the present disclosure also has an easy-to-manufacture, more reliable and easy-to-maintain lubrication system. This greatly simplifies the manufacturing process and reduces time, labor and raw material costs. In addition, the one-piece crosshead box according to the present disclosure has a good internal fluid circulation path, so that the air pressure inside the box can always be kept balanced during operation, thereby improving the running stability and service life of the equipment. In conjunction with this one-piece crosshead box, various pump components can be improved and optimized, and a subversive fracturing pump design can also be formed, while forming a platform development concept. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] FIG1 is a perspective view illustrating a schematic structure of a crosshead box according to an embodiment of the present disclosure;

[0042] FIG2 is a perspective view illustrating a schematic structure of a crosshead box according to an embodiment of the present disclosure;

[0043] 3 is a schematic diagram illustrating the structure of a crosshead inner cavity of a crosshead box according to an embodiment of the present disclosure;

[0044] FIG4 is a schematic diagram illustrating the shape of a crosshead inner cavity of a crosshead box in the prior art as a comparative example;

[0045] 5a and 5b are schematic diagrams illustrating alternative examples of the structure of the crosshead inner cavity of the crosshead box according to an embodiment of the present disclosure;

[0046] 6 is a schematic diagram illustrating the structure of a crosshead sleeve of a crosshead box according to an embodiment of the present disclosure;

[0047] 7 is a schematic diagram illustrating the structure of a crosshead sleeve of a crosshead box according to an embodiment of the present disclosure;

[0048] FIG8 is a schematic diagram illustrating a positioning member of a crosshead sleeve of a crosshead box according to an embodiment of the present disclosure;

[0049] 9 is a schematic diagram illustrating the structure of a protruding portion of a crosshead sliding sleeve of a crosshead box according to an embodiment of the present disclosure;

[0050] 10 is a cross-sectional schematic diagram illustrating the positional matching relationship between the protrusion of the crosshead sleeve of the crosshead housing and the end of the crosshead oil groove according to an embodiment of the present disclosure;

[0051] 11 is a perspective schematic diagram illustrating the configuration of an exhaust cavity of a crosshead box according to an embodiment of the present disclosure;

[0052] 12 is a schematic end view illustrating the configuration of the exhaust cavity of the crosshead box according to an embodiment of the present disclosure;

[0053] 13 is a cross-sectional schematic diagram illustrating the configuration of an exhaust cavity of a crosshead box according to an embodiment of the present disclosure;

[0054] 14 is a partially enlarged view illustrating an exemplary structure of a fluid passage at a front end surface of a crosshead box according to an embodiment of the present disclosure;

[0055] 15 is a partially enlarged view illustrating another exemplary structure of a fluid passage at the front end surface of the crosshead box according to an embodiment of the present disclosure;

[0056] 16 is a partially enlarged view illustrating yet another exemplary structure of a fluid passage at the front end surface of the crosshead box according to an embodiment of the present disclosure;

[0057] 17 is a schematic diagram illustrating the principle of functioning of the exhaust cavity and the fluid passage of the crosshead box according to an embodiment of the present disclosure;

[0058] 18 is a schematic diagram illustrating the principle of functioning of the exhaust cavity and the fluid passage of the crosshead box according to an embodiment of the present disclosure;

[0059] FIG19 is a schematic diagram illustrating the structure of a reinforcing beam of a crosshead box according to an embodiment of the present disclosure;

[0060] FIG20 is a schematic diagram illustrating another structure of a reinforcing beam of a crosshead box according to an embodiment of the present disclosure;

[0061] 21 is a cross-sectional view illustrating an example of a cross-sectional shape of a reinforcement beam of a crosshead box according to an embodiment of the present disclosure;

[0062] 22 is a schematic diagram illustrating the structure of a transition region of a reinforcing beam of a crosshead box according to an embodiment of the present disclosure;

[0063] 23 is a cross-sectional view illustrating the structure of a multifunctional structural hole of a crosshead box according to an embodiment of the present disclosure;

[0064] 24 is a schematic cross-sectional view illustrating an inline lubrication oil passage of a crosshead box according to an embodiment of the present disclosure;

[0065] FIG25 is a schematic diagram illustrating a process for machining an inline lubrication oil passage of a crosshead housing according to an embodiment of the present disclosure;

[0066] FIG26 is a schematic diagram illustrating a process for machining an inline lubrication oil passage of a crosshead housing according to an embodiment of the present disclosure;

[0067] FIG27 is a schematic diagram illustrating the overall layout of the inline lubrication oil passage of the crosshead box according to an embodiment of the present disclosure;

[0068] 28 is a schematic diagram illustrating the alignment positions of the oil outlets of the inline lubrication oil passage of the crosshead housing according to an embodiment of the present disclosure;

[0069] 29 is a schematic diagram illustrating a lubricating oil recovery path of an inline lubricating oil passage of a crosshead box according to an embodiment of the present disclosure;

[0070] 30 is a schematic diagram illustrating the structure of an oil filling hole of a lubricating oil passage of a crosshead box according to an embodiment of the present disclosure;

[0071] FIG31 is a schematic diagram illustrating a connection end surface of a crosshead case and a crankcase according to an embodiment of the present disclosure;

[0072] FIG32 is a schematic diagram illustrating a connection end surface of a crosshead box and a spacer according to an embodiment of the present disclosure;

[0073] FIG33 is an exploded schematic diagram illustrating the connection assembly of the crosshead case, the crankcase, and the spacer according to an embodiment of the present disclosure;

[0074] 34a and 34b are schematic diagrams illustrating arrangements of connection seals between a crosshead case, a crankcase, and a spacer according to an embodiment of the present disclosure;

[0075] 35 is a schematic diagram illustrating a partial seal around an oil outlet of a lubricating oil passage of a crosshead box according to an embodiment of the present disclosure;

[0076] FIG36 is a schematic diagram illustrating the connection positioning of the crosshead case to the crankcase and the spacer according to an embodiment of the present disclosure;

[0077] 37 is a schematic diagram illustrating the structure of a process hole and / or an observation window of a crosshead box according to an embodiment of the present disclosure;

[0078] 38 is a partial enlarged view illustrating the structure of a boss of a process hole and / or an observation window of a crosshead box according to an embodiment of the present disclosure;

[0079] 39 is a schematic diagram illustrating the configuration of the mounting boss of the crosshead box and the supporting lugs and the lifting lugs mounted thereon according to an embodiment of the present disclosure. DETAILED DESCRIPTION

[0080] The technical solutions of various embodiments of the present disclosure will be described in detail below with reference to the accompanying drawings. Obviously, the described embodiments are only a portion of the embodiments of the present disclosure, and not all of them. Based on the embodiments of the present disclosure, all other embodiments derived by persons of ordinary skill in the art without inventive effort are also within the scope of protection of the present disclosure.

[0081] It should be noted that in the detailed description below, the use of expressions such as "approximately" and "approximately" is to take into account factors such as manufacturing tolerances and processing accuracy that are understood by ordinary technicians in this field, and will not lead to ambiguity in the description or unclear scope of protection. In addition, the directions or positional relationships indicated by "upper", "lower", "left", "right", "front", "back", "vertical", "horizontal", "top", "bottom", "inside", "outside", "side" and the like that appear in this article are only for the convenience of explanation and are defined in conjunction with the accompanying drawings. After reading this article, ordinary technicians in this field will obviously be able to easily know the direction corresponding to the direction described in this article when the device presents an orientation inconsistent with the orientation described in this article due to flipping or moving.

[0082] It should also be noted that, in the description of this disclosure, unless otherwise expressly specified or limited, the terms "disposed," "installed," "connected," and "connected" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integral connections; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; and internal connections between two components. Those skilled in the art will understand the specific meanings of the above terms in the present disclosure based on the specific circumstances.

[0083] Note that the same structures, elements or components in the drawings are denoted by the same reference numerals.

[0084] 1. Overview of crosshead box

[0085] Figures 1 and 2 illustrate a schematic perspective view of a crosshead box 1000 according to a preferred embodiment of the present disclosure. In Figures 1 and 2, a 5-cylinder crosshead box 1000 is used as an example for explanation. However, the crosshead box 1000 of the present disclosure can obviously also be used for crosshead boxes 1000 with other numbers of cylinders, such as 3-cylinder, 7-cylinder, etc. As shown in Figures 1 and 2, the crosshead box 1000 is generally in the shape of a rectangular parallelepiped and is manufactured in one piece through a casting process. It has a front end face 1001 connected to the spacer 3000, a rear end face 1002 connected to the crankcase 2000, an upper cover plate 1003 and a lower cover plate 1004 located above and below the main body of the crosshead box, respectively, side end plates 1005 located on both sides of the box body, and vertical plates located between each crosshead cavity. It should be noted that, in this specification, the direction in which the crosshead between the front face 1001 and the rear face 1002 reciprocates in the crosshead case 1000 is referred to as the axial direction or longitudinal direction of the crosshead case 1000, and the direction in which the multiple crossheads are arranged in the crosshead case 1000 is referred to as the transverse direction of the crosshead case 1000. Furthermore, the side of the crosshead case 1000 connected to the spacer 3000 is referred to as the front side or front end of the crosshead case 1000, and the side of the crosshead case 1000 connected to the crankcase 2000 is referred to as the rear side or rear end of the crosshead case 1000. In addition, the upper cover plate 1003, the lower cover plate 1004, the side end plate 1005 and the partition plate 1101 to be described below are all commonly used names in the art for the convenience of reading by those skilled in the art. However, it should be understood that since the crosshead box 1000 according to the embodiment of the present disclosure is integrally formed using a casting process, the upper cover plate 1003, the lower cover plate 1004, the side end plate 1005 and the partition plate 1101 are not meant to be separately provided plates in this article, but are all different components of the integrally formed box body. Therefore, the upper cover plate 1003 may sometimes be regarded as the upper end face or upper end portion of the crosshead box in this article, the lower cover plate 1004 may sometimes be regarded as the lower end face or lower end portion of the crosshead box in this article, and the side end plate 1003 may sometimes be regarded as the side end face or side end portion of the crosshead box in this article.

[0086] As can be seen in Figures 1 and 2 , according to the embodiments of the present disclosure, the entire crosshead housing 1000 is integrally formed via a casting process. This casting process avoids the defects associated with welding, ensures structural rigidity, increases fatigue strength, and prolongs service life. Furthermore, integral casting significantly reduces process complexity, saves time, labor, and raw material costs, and improves yield. It should be understood that while cast iron is used as an example casting material in this specification, other casting materials known in the art may also be used to form the crosshead housing 1000, depending on the needs.

[0087] As shown in Figures 1 and 2, a plurality of crosshead cavities 1100 are formed in the crosshead housing 1000. These cavities 1100 extend longitudinally within the crosshead housing 1000, from the front end 1001 to the rear end 1002 of the crosshead housing 1000. These cavities 1100 accommodate the crosshead assembly and the sliding sleeve described below. The crosshead assembly reciprocates within the crosshead cavities 1100 along the axial direction of the crosshead housing 1000. The plurality of crosshead cavities 1100 are arranged side by side in the transverse direction of the crosshead housing 1000. The number of crosshead cavities 1100 depends on the number of crosshead assemblies.

[0088] Preferably, exhaust cavities 1200 are provided above and / or below the crosshead cavity 1100. Each exhaust cavity 1200 has a flat polygonal or oblate shape and extends longitudinally within the crosshead housing 1000, from the front end face 1001 to the rear end face 1002 of the crosshead housing 1000. The front end of the exhaust cavity 1200 is in fluid communication with an exhaust passage (described in detail later) provided on the front end face 1001 of the crosshead housing 1000, while the rear end of the exhaust cavity 1200 is in fluid communication with the interior of the crankcase 2000.

[0089] Preferably, at least one multifunctional structural hole 1300, described in detail below, is provided at the interface between the crosshead inner cavities 1100 and 1100. Multifunctional structural hole 1300 can have, for example, a circular or, as shown, triangular shape and extend longitudinally within crosshead housing 1000, from front end face 1001 to rear end face 1002 of crosshead housing 1000. Multifunctional structural hole 1300 can be provided at the upper and / or lower portion of crosshead housing 1000 as needed.

[0090] Preferably, an internal lubrication oil circuit 1500 is provided within the crosshead housing 1000. Unlike the oil circuits provided by separately connected oil pipes and hoses in the prior art, the internal lubrication oil circuit 1500 is formed by interconnected oil holes and oil channels (e.g., formed by drilling) within the cast housing of the crosshead housing 1000. Furthermore, the internal lubrication oil circuit 1500 typically includes at least one main oil circuit and at least one branch oil circuit.

[0091] In addition, as shown in FIG. 1 and FIG. 2 , the crosshead box 1000 is further provided with components such as connection holes and observation windows, which will be described in detail below.

[0092] 2. Crosshead cavity and sleeve

[0093] 2.1 The shape of the crosshead cavity

[0094] Figure 3 schematically illustrates the structure of a crosshead cavity 1100 in a crosshead housing 1000 according to the present disclosure. As shown in Figure 3 , crosshead cavity 1100, for example, has a generally cylindrical shape. In other words, crosshead cavity 1100 has a generally circular shape in a cross section perpendicular to the axial direction of crosshead housing 1000. In this case, the spacers 1101 between crosshead cavities 1100 have a corresponding double-arc shape, thicker at the top and bottom and thinner in the middle. The cylindrical shape of crosshead cavity 1100 reduces the housing size of crosshead housing 1000, facilitating casting and facilitating subsequent assembly of the sliding sleeve.

[0095] In the prior art, the crosshead cavity 1100 typically has a shape similar to a track and field runway, as shown in Figure 4: a straight-sided elliptical shape with straight edges on the left and right sides and arcs on the top and bottom. This is because if a crosshead cavity is formed into a near-circular shape through welding, the resulting upper and lower portions are relatively flat, which requires a larger distance between cylinders. Furthermore, while the "runway" design theoretically reduces the contact surface pressure between the crosshead assembly and the crosshead cavity, and the rectangular shapes on both sides can reduce the spacing between cylinders, local deformation under heavy loads can cause the crosshead assembly and the crosshead cavity to shift from surface contact to line contact, resulting in actual surface pressure far exceeding the theoretical value. In contrast, in the crosshead housing 1000 of the present disclosure, due to the use of an integrated molding process, the spacer plates 1101 between the crosshead cavities 1100 are integrally cast with the outer shell of the crosshead housing 1000, including the side end plates 1005 and the upper and lower cover plates 1004. Therefore, the crosshead cavity 1100 can be easily cast into a roughly cylindrical shape as needed. In addition, due to the use of one-piece casting, the structure has good rigidity and can easily meet the requirements of the cylinder diameter, so there is no need to adopt a "racetrack-shaped" design, and a simpler cylindrical shape can be used.

[0096] It should be understood that the crosshead cavity 1100 according to the present disclosure can also be designed as a roughly straight-edged elliptical shape similar to those used in the prior art, or any other desired shape, fully leveraging the advantages of casting. For example, when the crosshead cavity 1100 according to the present disclosure is designed as a roughly straight-edged elliptical shape similar to those used in the prior art, as shown in Figures 5a and 5b, the spacers 1101 between each crosshead cavity 1100 can be formed as a plurality of vertically extending spacer columns 1102 arranged side by side in the crosshead axis. The gaps between the spacers allow fluid communication between two adjacent crosshead cavities 1100, which can be used for oil and gas drainage, as will be described in detail later. In this case, combined with the exhaust cavities and fluid channels described later in this article, further enhanced exhaust efficiency can be expected. Furthermore, in this case, within the two crosshead cavities 1100 located at the outermost ends of the crosshead housing 1000, there is a gap between the crosshead assembly and the side end plates 1005 on either side of the crosshead housing 1000. This gap can also serve the purpose of oil and gas drainage, as will be described in detail later. In addition, in this case, the sliding sleeve also adopts a tile-shaped upper and lower two-piece structure commonly used in the art, which will not be described in detail herein.

[0097] 2.2 Crosshead sleeve

[0098] A crosshead sleeve 1400 is provided in the crosshead inner cavity 1100. The crosshead sleeve 1400 is in contact with the crosshead and carries the reciprocating motion of the crosshead in the crosshead inner cavity 1100. In one embodiment of the crosshead box 1000 according to the present disclosure, as shown in FIG6 , the crosshead sleeve 1400 has a cylindrical shape that can be embedded in the cylindrical crosshead inner cavity 1100. Compared with the upper and lower two-piece split structure mentioned above, this integrated crosshead sleeve 1400 can enhance the bending and torsional rigidity of the structure, reduce the wear of the bearing at the crosshead position, and solve problems such as fatigue fracture of the bearing. As shown in FIG6 and FIG7 , the crosshead sleeve 1400 is designed with a sleeve oil hole 1401 that passes through the sleeve wall. The oil hole 1401 is used to communicate with the lubricating oil circuit fluid to be described below, so that the lubricating oil can flow into the interior of the sleeve. The oil hole can be set at any position other than the end of the crosshead sleeve 1400 as needed. The position, number and shape of the oil holes 1401 may be determined according to the lubrication requirements of the oil passage and the lubricated components.

[0099] In addition, as shown in Figures 7 and 8, the end portion of the crosshead sleeve 1400 near one end (i.e., the front end) of the spacer 3000 is designed with a sleeve positioning pin hole 1402, in which an elastic cylindrical pin for positioning the crosshead sleeve 1400 can be installed. The position of the pin hole 1402 is not limited, as long as it meets the positioning requirements and does not affect other structural functions. Preferably, the pin holes 1402 should not be arranged at circumferentially symmetrical positions such as directly above and directly below or directly to the left and directly to the right at the same time, so as to prevent it from being difficult to determine the correct angle and orientation when the sleeve is installed. During the assembly process of the crosshead sleeve 1400, the pin hole 1402 can, for example, cooperate with the limiting groove 1006 provided at the edge of the front end face 1001 of the crosshead box 1000 in the crosshead inner cavity 1100 to achieve the axial positioning of the crosshead sleeve 1400 along the crosshead box 1000. For example, during installation, the elastic cylindrical pin is fastened to the locating pin hole 1402 of the crosshead sleeve 1400, and the crosshead sleeve 1400 is inserted into the crosshead inner cavity 1100 axially from the front end of the crosshead box 1000 until the side of the elastic pin contacts the surface of the limit groove, and then it is installed in place. During the installation process, for example, the sleeve can be cooled with liquid nitrogen first, and the thermal expansion and contraction effect will cause the sleeve to reduce in size. Then, the cooled sleeve is inserted into the crosshead inner cavity in a relatively short time. After the sleeve temperature rises to room temperature, the size expands and forms an interference fit with the crosshead inner cavity, thereby ensuring that the sleeve will not fall out of the crosshead inner cavity during the operation of the crosshead assembly. It should be understood that the parts used for positioning are not limited to elastic cylindrical pins, and the cross-sectional dimensions of the pins can also be adjusted as needed to adapt to the changes in the size of the pin holes of the crosshead sleeve 1400 due to cold installation and warming. The shape, position, and number of the above-mentioned pins and slots can also be selected according to actual conditions, and the two can correspond. In addition, the positioning method may also be other positioning methods such as first aligning the limiting groove of the crosshead box 1000 with the positioning pin hole of the crosshead sleeve 1400 and then driving the positioning pin for positioning.

[0100] As shown in FIG7 , the front end of the crosshead sleeve 1400 is provided with an inner recess 1404. This inner recess 1404 is recessed from the front end toward the rear end of the crosshead sleeve 1400 in the axial direction of the crosshead housing 1000, thereby matching the shape of the groove in the front end face 1001 of the crosshead housing 1000 (described below) to form a fluid channel 1201 for oil and gas drainage. As shown in FIG7 and FIG9 , the top and bottom of the end (i.e., the rear end) of the crosshead sleeve 1400 connected to the crankcase 2000 are respectively formed with extended protrusions 1403. These protrusions 1403 protrude from the rear end of the crosshead sleeve 1400 toward the crankcase 2000 in the axial direction of the crosshead housing 1000. For example, when crosshead sleeve 1400 is installed in crosshead inner cavity 1100, recess 1404 and protrusion 1403 are located at the top and bottom of crosshead inner cavity 1100, respectively. As shown in FIG7 , the transition area between protrusion 1403 and the non-protruding portion of rear end face 1002 of crosshead sleeve 1400 is preferably rounded to maximize stiffness at the base of protrusion 1403 while reducing stress accumulation caused by the oil pressure in the oil groove at the bottom of the crosshead. FIG7 illustrates an example with two recesses 1404 and two protrusions 1403, but it should be understood that the number of recesses 1404 and protrusions 1403 is not limited to two and may also be one or more.

[0101] The presence of such a protrusion 1403 allows the crosshead sleeve 1400 to adapt to crosshead housings 1000 of varying lengths, ensuring the required airtight space for contact between crosshead assemblies of varying lengths and the oil film on the sleeve's contact surface. This allows for the production of crosshead housings 1000 of varying specifications using a common platform. As shown in Figure 10 , the size of protrusion 1403 is related to the size and location of the oil groove at the base of the crosshead. Specifically, during actual operation of the crosshead and crosshead housing, the sleeve's protrusion 1403 must mate with the oil groove at the base of the crosshead to form a seal. Therefore, the sleeve's protrusion 1403 must be large enough to cover the sealing length of the oil groove at the base of the crosshead. In Figure 10 , the dark shading at the base of the crosshead represents the oil groove. The "sealing length" of the oil groove refers to the length between the oil groove ends 1502 at each end of the oil groove. The portion of the oil groove beyond the oil groove ends 1502 at each end of the oil groove mates with the sleeve 1400 to form a linear seal. When the crosshead moves to the extreme position on one side of the crankcase in the crosshead sleeve 1400, a part of the oil groove may be outside the crosshead inner cavity 1100. That is, as can be seen in Figure 10, a part of the dark shadow representing the oil groove is located outside the crosshead inner cavity 1100. In this case, the existence of the protrusion 1403 of the sleeve ensures that the lubricating oil in the crosshead oil groove will not leak under a certain pressure. In other words, the protrusion 1403 needs to meet the sealing requirement of the oil groove end 1502 when the crosshead is closest to the crankcase 2000 in the crosshead box 1000. At the same time, the protrusion 1403 can adapt to plungers of different lengths and their plunger stroke amounts on a large scale. When the plunger is installed and the plunger performs stroke motion within the adaptation range, there is no need to replace the sleeve 1400 of other specifications and lengths.

[0102] It should be noted that, in the crosshead box 1000 according to the present disclosure, the above-mentioned crosshead sleeve 1400 is preferably provided, but the crosshead sleeve 1400 may also be omitted, that is, a solution is adopted in which the inner surface of the crosshead inner cavity 1100 is also used as a sleeve. This is because the crosshead box 1000 according to the embodiment of the present disclosure is made of ductile iron by adopting an integral casting process. Ductile iron material has a high spheroidization rate, and under non-lubricated conditions, ductile iron material can play a self-lubricating role. If under lubricated conditions, ductile iron material can not only absorb and preserve lubricating oil, but also maintain the continuity of the oil film, so it can also serve as a sleeve. In this case, in order to enhance the sliding effect of the crosshead, fine mesh and other oil storage structures can also be processed on the inner surface of the crosshead inner cavity 1100 to enhance the lubricating effect of the lubricating oil. Compared with the technical solution of using an integrated copper sleeve mentioned in the above embodiment, the ductile iron material of the crosshead inner cavity 1100 has better lubrication performance and a simpler structure. It does not require high-precision installation and alignment, and is therefore more economical and cost-saving.

[0103] Furthermore, when the inner surface of the crosshead cavity 1100 also serves as a sliding sleeve, the casting material must achieve the required spheroidization ratio for the sleeve's performance, and the corresponding protrusions 1403 and recesses 1404 must be cast and machined simultaneously. For example, a spheroidization ratio greater than 80% is preferred. Furthermore, component features such as oil holes, recesses that mate with the exhaust cavity 1200 (described later), and rounded surfaces and contact surfaces that require high precision or cannot be achieved using casting techniques can also be completed through post-processing or other common methods.

[0104] In the integrally cast crosshead box 1000, an exhaust cavity 1200 is provided at the connection position between the upper cover plate 1003 and the lower cover plate 1004 and the crosshead cylindrical cavity, for maintaining the air pressure balance in the crosshead cavity 1100 when the crosshead assembly reciprocates.

[0105] 3 Exhaust chamber and fluid channel

[0106] 3.1 Structure of the exhaust chamber

[0107] In the crosshead housing 1000 according to an embodiment of the present disclosure, a plurality of crosshead exhaust cavities 1200 are provided above and below the crosshead internal cavity 1100 to maintain air pressure balance within the crosshead internal cavity 1100 when the crosshead assembly reciprocates within the crosshead internal cavity 1100. The exhaust cavities 1200 extend axially through the crosshead housing 1000, with their front ends in fluid communication with fluid passages 1201 (described later) and their rear ends in fluid communication with the internal cavity of the crankcase 2000. Figures 11 to 13 are perspective, end, and cross-sectional views, respectively, illustrating exemplary configurations of the exhaust cavities 1200 of the crosshead housing 1000.

[0108] As shown in Figures 11 to 13, the exhaust cavity 1200 can be, for example, disposed between the crosshead cavity 1100 and the upper and lower panels 1003 and 1004 of the crosshead housing 1000. In other words, the exhaust cavity 1200 can be, for example, disposed between the main body of the crosshead housing 1000, in which the crosshead cavity 1100 is formed, and the upper and lower panels 1003 and 1004 of the crosshead housing 1000. The shape of the exhaust cavity 1200 can be designed as desired, with no particular requirements. In the illustrated embodiment, the exhaust cavity 1200 has a flat, polygonal shape with rounded corners in a cross section perpendicular to the axis of the crosshead housing 1000. This shape fully utilizes the space above and below the crosshead cavity 1100, allowing the exhaust cavity 1200 to fully utilize the advantages of the casting process while balancing exhaust requirements and the structural rigidity requirements of the housing. The exhaust cavity 1200 can also be disposed in other locations, as long as it does not affect the structural rigidity of the housing and the structural functions of other components.

[0109] It should be noted that the specific shape of the exhaust cavity 1200 is not limited to the above-mentioned shape shown in the figure. For example, it can also be circular or other regular or irregular shapes. When an exhaust cavity 1200 is provided above and below each crosshead cavity 1100, the shapes of the upper and lower exhaust cavities 1200 can be symmetrical or asymmetrical. From the perspective of ensuring the overall axial stiffness and bending stiffness of the crosshead box 1000, a symmetrical solution is preferred. There are no special restrictions on the number and molding method of the exhaust cavities 1200, as long as they meet the exhaust function described below, avoid the bolt load-bearing area, and do not affect other structural functions. For example, only one exhaust cavity 1200 can be provided above or below each crosshead cavity. In addition, in the illustrated embodiment, the crosshead cavity 1100 and the two exhaust cavities 1200 located above and below it are centrally symmetrical in the transverse direction of the crosshead box 1000, and are also centrally symmetrical in the vertical direction perpendicular to the transverse direction. However, the crosshead inner cavity 1100 and the two exhaust cavities 1200 located above and below it can also be arranged to be symmetrical with respect to the horizontal axis and the vertical axis according to design requirements, or even staggered in an asymmetrical manner.

[0110] 3.2 Structure of fluid channel

[0111] Figure 14 is a partially enlarged view illustrating a preferred embodiment of a fluid channel 1201 at the front end face 1001 of the crosshead housing 1000 according to an embodiment of the present disclosure. As shown in Figure 14 , a groove is formed in the housing between the crosshead inner cavity 1100 and the exhaust cavity 1200 at the front end face 1001 of the crosshead housing 1000 (i.e., the end face connected to the spacer 3000). The groove is recessed inward (i.e., toward the crankcase) in the axial direction of the crosshead housing 1000. This groove allows for fluid communication between the crosshead inner cavity 1100 and the exhaust cavity 1200 at the end face when the crosshead housing 1000 and the spacer 3000 are assembled. This groove is also referred to as a fluid channel 1201. Together with the exhaust cavity 1200, the fluid channel 1201 forms the exhaust passage of the crosshead housing 1000, discharging exhaust and oil (lubricating oil) and maintaining a balanced oil and gas pressure within the crosshead inner cavity 1100. In addition, the concave shape of the inner recess 1404 of the crosshead sleeve 1400 described above matches the cross-sectional shape of the groove of the fluid channel 1201, so that when the crosshead sleeve 1400 is installed in the crosshead inner cavity 1100, the crosshead sleeve 1400 will not obstruct the exhaust passage between the crosshead inner cavity 1100 and the exhaust cavity 1200, and the crosshead inner cavity 1100 is fluidically connected to the exhaust cavity 1200 via the inner recess 1404 and the fluid channel 1201.

[0112] The groove forming the exhaust channel shown in Figure 14 has a wave-like arc shape. This is because the inwardly concave groove is formed at the end surface, resulting in a different axial extension length of the material of the box at the groove than in the areas on either side of the groove. Therefore, during the casting process, when transitioning from the groove area to the two side areas, it is easy to generate large internal stress near the transition point between them, which will reduce the structural strength of the casting. By adopting a smooth, wave-like shape design, the length of the intersection area can be gradually changed in a smooth manner, thus reducing the risk of large internal stress near the intersection area when transitioning from the middle area to the two side areas, and thus improving the structural rigidity of this area.

[0113] It should be understood that, in addition to the wave-like arc shape shown in FIG14 , the fluid channel 1201 can also be formed into other shapes. For example, FIG15 illustrates a fluid channel 1201 having an approximately trapezoidal cross-section. FIG16 illustrates a fluid channel 1201 having an approximately rectangular cross-section. When the fluid channel 1201 has a non-circular polygonal shape such as a rectangle or trapezoid, as shown in FIG15 and FIG16 , in order to achieve the above-mentioned effect of reducing stress and improving structural rigidity as much as possible, the boundary area between the groove and the two side areas, that is, the concave bending area, is transitioned by filleting, beveling or other smooth methods as much as possible. In addition, there is no special restriction on the size of the fluid channel 1201, and it can be determined based on the size of the exhaust cavity 1200 and the principle of not affecting the structural function of the crosshead box 1000. In addition, although the drawings only show an example in which the fluid channel 1201 is formed on the front end surface 1001 of the crosshead housing 1000, it is understandable that a similar fluid channel may also be formed on the rear end surface 1002 of the crosshead housing 1000 to further facilitate communication between the crosshead inner cavity and the exhaust cavity on the connecting side of the crosshead housing and the crankcase.

[0114] 3.3 Functions and effects of exhaust chamber and fluid channel

[0115] 17 and 18 , we will now explain how the exhaust chamber 1200 and fluid passage 1201 maintain pressure balance within the crosshead cavity 1100. It should be noted that Figures 17 and 18 illustrate the state in which the crosshead housing 1000 and crankcase 2000 are joined together. This is because, in use, the majority of the internal cavities of the crosshead housing 1000 and crankcase 2000 are in fluid communication and are functionally closely linked.

[0116] FIG17 illustrates a schematic diagram of the fluid flow path within the crosshead cavity 1100 as the crosshead assembly slides toward the front end (spacer side) within the crosshead cavity 1100. As shown in FIG17 , under this operating condition, the pressure at the front end of the crosshead cavity 1100 gradually increases. The oil and gas at the front end of the crosshead cavity 1100 flow upward and downward into the exhaust chamber 1200 through the fluid channel 1201 at the front end surface, and then flow toward the crankcase through the exhaust chamber 1200. The oil and gas within the crankcase 2000 can enter the rear end of the crosshead cavity 1100 through the connecting rod movable window 2001 (see FIG33 ) in the crankcase 2000. As the crosshead assembly continues to slide toward the front end, the space at the front end of the crosshead cavity 1100 continues to decrease, and the pressure at the front end of the crosshead cavity 1100 continues to increase. The increased pressure at the front end of the crosshead is transmitted to the exhaust chamber 1200 through the fluid channel 1201, allowing a portion of the oil and gas in the exhaust chamber 1200 to enter the rear end of the crosshead cavity 1100 from the rear end of the exhaust chamber 1200 through the connecting rod movable window 2001 in the crankcase 2000. This allows another portion of the oil and gas in the exhaust chamber 1200 to flow into the crankcase 2000 and diffuse into the crankcase 2000. FIG18 illustrates a schematic diagram of the fluid flow path within the crosshead cavity 1100 as the crosshead assembly slides toward the rear end (i.e., the crankcase side) within the crosshead cavity 1100. As shown in FIG18, as the crosshead slides toward the rear end (i.e., the crankcase side) within the crosshead cavity 1100, the pressure at the rear end of the crosshead cavity 1100 gradually increases. The oil and gas at the rear end of the crosshead cavity 1100 can enter the crankcase 2000 and the rear end of the exhaust chamber 1200 of the crosshead case 1000 through the connecting rod movable window 2001 in the crankcase 2000. As the crosshead continues to slide toward the rear end, the pressure at the rear end of the crosshead inner cavity 1100 continues to increase. This pressure is transmitted to the exhaust cavity 1200, causing the oil and gas in the exhaust cavity 1200 to flow from the rear end to the front end and enter the front end of the crosshead inner cavity 1100 through the fluid channel 1201.

[0117] As described above, because the crosshead housing 1000 according to the present disclosure is integrally formed using a casting process, an exhaust passage 1201 located on the front end face 1001 of the crosshead housing 1000 and extending axially through the crosshead housing 1000 can be provided near the crosshead inner cavity 1100. This allows the oil (lubricating oil) and gas in the crosshead inner cavity 1100 to self-circulate through the fluid passage 1201, the exhaust chamber 1200, and the connecting rod movable window 2001 without the need for external circulation equipment, thereby maintaining air pressure balance in the crosshead inner cavity 1100 during the reciprocating motion of the crosshead assembly. The dedicated fluid passage 1201 and exhaust chamber 1200 also reduce the noise generated by the high-speed flow of gas during the reciprocating motion of the crosshead assembly, while also facilitating assembly and disassembly of components.

[0118] Furthermore, other designs or molding methods can be used to create a vent cavity in fluid communication with the crosshead cavity 1100 to achieve pressure balance. For example, holes or channels could be opened elsewhere within the crosshead housing 1000 to fluidly connect the front and rear ends of the crosshead cavity 1100 to facilitate ventilation. The molding method for these holes and channels is not limited, as long as their location does not affect the crosshead assembly, the cavity support structure, or the bolt fastening function.

[0119] 4. Reinforced beams and multifunctional structural holes of the crosshead box

[0120] The crosshead housing 1000 according to the embodiment of the present disclosure is integrally formed through a casting process. To overcome the common disadvantage of heavy weight in traditional castings, the crosshead housing 1000 according to the embodiment of the present disclosure has been specifically optimized to enhance rigidity and reduce weight. This ensures that, while maintaining structural rigidity, the crosshead housing 1000 according to the embodiment of the present disclosure is 10% to 16% lighter than a comparable crosshead housing 1000 produced through a welding process.

[0121] These structural optimization features of the crosshead box 1000 according to the embodiment of the present disclosure will be described in detail below with reference to the accompanying drawings.

[0122] 4.1 Strengthening beam

[0123] As shown in Figure 19 , within the exhaust cavity 1200, to reduce the weight of the crosshead box 1000, the box molding material is thinned at the portion of the crosshead box body corresponding to the crosshead inner cavity 1100 (i.e., the inner wall of the exhaust cavity 1200 located on the crosshead inner cavity 1100 side). Reinforcement beams 1210 are only provided between the front and rear end surfaces 1002, thereby forming multiple "I-shaped" frame structures to increase overall bending stiffness, ensure the rigidity and stability of the crosshead inner cavity 1100, and prevent relative displacement and deformation. It should be noted that for clarity, the upper cover 1003 is omitted in Figure 19 and subsequent related figures, and only the main body of the crosshead box 1000 is shown. In addition, it is easy to imagine that although Figure 19 only shows the reinforcing beam at the upper part of the crosshead cavity 1100, it is obvious that the same or similar reinforcing beam structure can also be formed in the exhaust cavity 1200 located at the lower part of the crosshead cavity 1100.

[0124] In this embodiment, reinforcing beams 1210 are designed in both the upper and lower exhaust cavities 1200. In addition to the I-shaped reinforcing beams 1210 shown in FIG. 19, the reinforcing beams 1210 can also adopt other shaped frame structures. The number, angle, and position of the longitudinal reinforcing beams 1210 extending along the axial direction of the crosshead housing 1000 and the transverse reinforcing beams 1210 extending along the transverse direction of the crosshead housing 1000 are not limited, as long as they can play a supporting role and do not affect the setting of the lubricating oil path and bolt setting to be described below. For example, FIG. 20 illustrates a king-shaped reinforcing beam 1210. The added middle cross beam further enhances the supporting stiffness of the middle part of the crosshead housing 1000. In addition, reinforcing beam 1210 structures such as "Ⅱ"-shaped, "Ш"-shaped, "field"-shaped, or "eye"-shaped can also be adopted. The forming method of the reinforcing beam 1210 is not limited to casting, and machining or other methods can also be used. In addition, other structures can also be used for the support of the crosshead assembly, such as irregular support plates arranged on the upper and lower sides or one side.

[0125] As shown in FIG. 21, the cross-section of the reinforcing beam 1210 has a generally rectangular shape, but the cross-section can also be other shapes such as triangular, trapezoidal, circular, etc. A rectangle is preferred because, compared with other solid regular cross-sections of the same area (such as circular, trapezoidal, triangular, etc.), the moment of inertia of the cross-section of the rectangle's long axis is larger, which can ensure that the reinforcing rib has sufficient bending stiffness and inhibit the displacement and deformation between the spacer plates 1101 located between the crosshead inner cavities 1100. <

[0126] In addition, as shown in FIG. 22, a fillet transition structure 1211 is provided at the junction of the reinforcing beam 1210 and the first bolt hole 1610 to be described below, and a fillet transition structure 1211 is also provided at the connection between the root of the reinforcing beam 1210 and the main body of the crosshead housing 1000. The fillet transition structure 1211 can increase the bending strength of the corresponding part, reduce stress concentration, and meet the requirements of the casting process. The size and shape of the fillet are mainly affected by the shape and position of the reinforcing beam 1210 and the bolt hole. For example, the transition fillet at the junction of the reinforcing beam 1210 and the bolt hole should be as concentric with the bolt hole as possible and smoothly transition to the upper surface of the reinforcing beam 1210. The transition fillet at the connection between the root of the reinforcing beam 1210 and the main body of the crosshead housing 1000 can smoothly transition to the main body of the crosshead housing 1000 at the root of the reinforcing beam 1210 according to the shape of the reinforcing beam 1210, so that the overall extended arc remains concentric with the arc segment of the inner wall of the crosshead inner cavity 1100. In actual fillet processing, chamfers or arcs (equal curvature or variable curvature) can be set according to requirements.

[0127] 4.2 Multi-functional Structural Holes

[0128] As described above, in the crosshead box 1000 according to the embodiment of the present disclosure, at least one multifunctional structural hole 1300 is also provided. As shown in Figures 1 and 2, it is preferred that a plurality of multifunctional structural holes 1300 are arranged, for example, at a portion of the crosshead box 1000 that is close to the crosshead inner cavity 1100 and has a relatively thick thickness. For example, in addition to the outermost side of the crosshead box 1000, the multifunctional structural hole 1300 can be arranged, for example, at the shoulder between two crosshead inner cavities 1100. Figure 23 illustrates a longitudinal cross-sectional view of the multifunctional structural hole 1300 taken along the axial direction of the crosshead box 1000. As can be seen from the figure, the multifunctional structural hole 1300 passes through the crosshead box 1000 along the axial direction of the crosshead box 1000. As shown in the figure, the first row of bolt holes, which will be described below, is arranged on the outer side of the multifunctional structural hole 1300. Preferably, as shown in Figures 1, 2, and 22, each multifunctional structural hole 1300 can be arranged at the shoulder position between the two crosshead cavities 1100 in a manner that is centrally aligned with the first bolt hole located outside it in a direction perpendicular to the crosshead box's transverse direction, so as to achieve a more uniform stress distribution. Of course, depending on specific design requirements, the multifunctional structural hole 1300 and the first bolt hole can also be offset from each other by a certain distance. In addition, considering the circular shape of the crosshead cavities 1100 on both sides of the multifunctional structural hole 1300 and the lubricating oil path inside the crosshead box 1000 that needs to be avoided (for example, the circular hole shown in Figure 23), the multifunctional structural hole 1300 can have any polygonal cross-sectional shape, but preferably has a triangular shape with rounded corners and can be designed to have an appropriate size. By selecting the shape and size, the wall thickness of the functional structure around the multifunctional structural hole 1300 can be uniform, that is, the thickness is substantially the same. For example, a triangular multifunctional structural hole 1300 is provided on the shoulder between two crosshead cavities 1100. One vertex of the multifunctional structural hole 1300 located on the upper shoulder of the crosshead cavity 1100 points downward, while one vertex of the multifunctional structural hole 1300 located on the lower shoulder of the crosshead cavity 1100 points upward. This ensures that the wall thickness between two adjacent crosshead cavities 1100 is the same, thus preventing damage to the crosshead box 1000 caused by support offset during operation. Two multifunctional structural holes 1300, symmetrical in vertical direction, can also be arranged on the outermost transverse edge of the crosshead box 1000 to ensure uniform force on the crosshead cavity 1100. Of course, in actual design, the shape of the multifunctional structural hole 1300 can also be circular, diamond-shaped, or other shapes, as long as it meets the above-mentioned casting structure requirements.

[0129] By providing a multifunctional structural hole 1300 in the thicker area between the two crosshead cavities 1100, the weight of the entire crosshead box 1000 is significantly reduced while meeting structural rigidity requirements. Furthermore, since the multifunctional structural hole 1300 is located between the crosshead cavity 1100 and the bolt holes, stresses acting on the crosshead cavity 1100 and the bolt holes can be released at this hole, preventing the internal structure surrounding the multifunctional structural hole 1300 from being squeezed and causing structural damage. Furthermore, the multifunctional structural hole 1300 also serves as a shrinkage prevention mechanism during the casting process. Hot cracking and cold cracking are common problems during the casting process. After liquid metal is injected into the mold cavity and begins to condense, once the crystal framework has formed and linear shrinkage begins, stress or plastic deformation will occur in the casting because the internal molten steel has not yet fully solidified and shrinkage is hindered. When the stress or deformation exceeds the material's strength limit at this high temperature, the casting will crack, which is called hot cracking. Cold cracking refers to cracking caused by localized casting stress exceeding the ultimate strength of the alloy when the casting cools to an elastic state after solidification. Cold cracking invariably occurs in areas subjected to tensile stress during the cooling process, particularly where tensile stress is concentrated. Therefore, the casting process requires the use of anti-shrinkage structures to avoid casting defects, ensure a uniform surface finish within the cylindrical crosshead cavity 1100, and mitigate stress concentrations.

[0130] Therefore, the crosshead box 1000 according to the embodiment of the present disclosure provides the multifunctional structural hole 1300 between the bolt hole and the crosshead inner cavity 1100, which not only greatly reduces the weight of the crosshead box 1000 and reduces the stress concentration in the crosshead inner cavity 1100 and the bolt hole during use, but also greatly reduces the possibility of cold cracking and hot cracking of the molding material around the bolt hole and the crosshead inner cavity 1100 during the casting process of the crosshead box 1000, thereby providing structural and functional guarantees for the design of the crosshead box 1000.

[0131] It should be noted that, in the case where a spacer column 1102 is provided between the crosshead inner cavity 1100 as shown in FIG. 5 a and FIG. 5 b instead of the spacer plate 1101 , although not shown in the figures, it is obvious that a multifunctional structural hole 1300 can also be formed at a similar position.

[0132] 4.3 Side end plate of crosshead box

[0133] The side end plates 1005 on both sides of the crosshead housing 1000 may also have curved surfaces to reduce the overall weight of the crosshead housing 1000 and to ensure that the wall thickness of the crosshead cavity 1100 is as uniform as possible, thereby reducing stress concentration. The side end plates 1005 may also optionally have other structural features such as grooves or multiple cut sections to achieve similar effects.

[0134] 5. Lubrication oil circuit

[0135] In conventional crosshead housings 1000 manufactured using welding processes, lubrication oil circuits can only be provided through additional oil pipes. This is because the alloy sheet metal has high hardness and density, and its thickness is limited, making it difficult to form oil circuits within the sheet metal using processes such as drilling. The crosshead housing 1000 of the present disclosure utilizes a casting process, resulting in a housing made of a relatively low-hardness material such as ductile iron. Furthermore, the casting process allows for flexible control of the local thickness of components, making it possible to create an embedded oil circuit structure directly within the cast material that forms the integrated crosshead housing.

[0136] FIG24 illustrates a cross-sectional schematic diagram of the embedded lubricating oil circuit 1500 of the crosshead housing 1000 according to an embodiment of the present disclosure. By machining oil holes and oil passages within the cast housing of the crosshead housing 1000, compared to external oil circuits, this eliminates a series of complex piping installation steps, simplifies the overall layout, reduces the consumption of lubricating pipes and pipe joints, ensures reliable sealing of the lubricating oil, and prevents oil and gas leakage. The main and branch oil circuits within the crosshead cavity 1100 must be arranged away from the load-bearing area of ​​the threaded holes to avoid weakening the strength of the threaded connection or deformation and blockage of the oil holes caused by screwing in the bolts. Furthermore, the functions of surrounding structures (such as the support function of the reinforcing beam 1210) must also be avoided. As long as the above conditions are met, the angle, extension direction, and number of oil circuits can be flexibly designed to meet lubrication needs. As shown in FIG25 , the lubricating oil circuit 1500 can be formed by machining a through-hole through the process hole / viewing window 1810 described later, or it can be formed by drilling a hole from the inside out into the crosshead cavity 1100 using a right-angle drill, as shown in FIG26 . Other methods can also be used to form the embedded oil channel according to actual needs.

[0137] In the working state, the crosshead assembly reciprocates at high speed in the crosshead box 1000, and many components require lubrication of lubricating fluid to work properly. Since the working conditions of different components are different, the required amount of lubricating oil and the flow rate are also different. Therefore, it is necessary to set up a high-pressure lubricating oil circuit 1510 and a low-pressure lubricating oil circuit 1520 respectively. For example, the high-pressure lubricating oil circuit 1510 lubricates the crosshead bearings and connecting rod bearings working in the crosshead box 1000 in the working state, and the low-pressure lubricating oil circuit 1520 lubricates the crosshead sleeve 1400. The high-pressure lubricating oil circuit 1510 is rated at a lubricating oil pressure of 200-350PSI, for example, and the low-pressure lubricating oil circuit 1520 is rated at a lubricating oil pressure of 60-150PSI, for example.

[0138] Figure 27 illustrates a schematic diagram of the overall layout of the embedded lubricating oil circuit 1500 of the crosshead housing 1000 according to an embodiment of the present disclosure. It should be noted that in Figure 27 , to clearly illustrate the layout of the embedded lubricating oil circuit, illustration of some components of the crosshead housing 1000, such as the sleeve 1400, has been omitted. As shown in Figure 27 , in the crosshead housing 1000 according to an embodiment of the present disclosure, the lubricating oil circuit 1500 is an embedded oil circuit formed by drilling holes in the housing of the crosshead housing 1000. In other words, the embedded lubricating oil circuit 1500 of the crosshead housing 1000 according to an embodiment of the present disclosure does not require additional piping components such as oil pipes and corresponding connecting components, sealing components, etc. In the embodiment shown in Figure 27 , both the low-pressure lubricating oil circuit 1520 and the high-pressure lubricating oil circuit 1510 include a main oil circuit and a branch oil circuit. Among them, the main oil circuit is the oil circuit shown in the figure that extends along the horizontal direction of the crosshead box 1000 (that is, the direction extending between the two side end surfaces), and the main oil circuit is connected to the oil inlet. The various oil circuits branching out from the main oil circuit along the longitudinal direction of the crosshead box 1000 (that is, the extension direction of the crosshead inner cavity) are branch oil circuits, which are used to supply the oil in the main oil circuit to the corresponding lubrication objects. In this embodiment, the lubricating oil of the low-pressure oil circuit is injected from the low-pressure oil inlet 1512 located on the side of the crosshead box 1000 (the side close to the speed reducer 4000 in the figure). In the embedded oil circuit, a portion of the low-pressure lubricating oil flows to the crosshead sleeves 1400 in the five crosshead inner cavities 1100 to lubricate the sleeves and the connecting rod small end bearing assembly (the low-pressure branch oil pipe flowing to the right in Figure 27). The remaining low-pressure lubricating oil flows to the rear end face of the crosshead housing 1000 (the low-pressure branch oil pipe flowing to the left in Figure 27), and then flows into the crankcase oil circuit to lubricate the roller bearings and bearing seats. For this branch oil circuit, as shown in Figure 28, the oil outlet 1503 at the rear end of the crosshead housing 1000, which leads to the outside of the crosshead housing 1000, must be aligned with the oil inlet hole of the crankshaft bearing outer ring. As for the high-pressure lubricating oil circuit 1510, as shown in Figure 27, oil enters from the high-pressure oil inlet 1511 on the side of the crosshead housing 1000 (the side near the reduction gearbox 4000 in the figure), flows through the oil channel to the crosshead, and then enters the connecting rod small end through the crosshead internal oil channel and as the connecting rod swings, lubricating the small end bearing. As shown in Figure 29, the lubricating oil in the crosshead box 1000 flows into the bottom of the crosshead box 1000 through the designed gaps between the front and rear ends of the sliding sleeve and the rear end plate of the spacer frame and the front end plate of the crankcase, and then flows into the crankcase oil pan, and finally flows back to the oil tank through the return oil pipe at the bottom of the crankcase.

[0139] As shown in Figure 30, the high-pressure oil inlet 1511 and the low-pressure oil inlet 1512 provided on the side end plate of the crosshead box 1000 are both provided with a boss structure 1504 to provide a flat connection plane protruding from the side end plate. It should be noted that Figure 30 shows only part of the structure on the side of the crosshead box 1000 near the oil filling hole for the convenience of illustration. A rounded transition is used around the boss structure 1504 to improve the rigidity of the connection. The position and number of the oil filling holes are not limited, as long as they correspond to the embedded oil channel and do not affect other structural functions. As shown in Figure 30, the crosshead box 1000 and the external oil pipe are preferably connected by a flange. The interface is easy to replace, avoiding the risk of thread breakage when the internal thread connection is used in the past, and the sealing performance is guaranteed. According to actual needs, other connection methods such as ordinary threaded connection can also be selected.

[0140] As shown in Figure 27, the high-pressure oil circuit and the low-pressure oil circuit are each equipped with a filter and a relief valve 1501. When the oil pressure within the embedded oil channel of the lubricating oil circuit 1500 exceeds the set pressure, the relief valve 1501 will overflow some oil to maintain the lubricating oil pressure at the set pressure. The overflowing lubricating oil is connected to the return oil pipe through the oil pipe and ultimately flows to the oil tank for recovery, filtration, and cooling to achieve the purpose of lubricating oil recycling. For example, the filter and relief valve 1501 are both located on the other end plate 1005 of the crosshead housing 1000, opposite the side end plate 1005 with the oil inlet.

[0141] In the crosshead housing 1000 according to the embodiment of the present disclosure, the main oil circuit embedded in the crosshead housing 1000 is designed to branch into multiple branches through the side of the crosshead housing 1000 to supply oil to the crosshead housing 1000 and crankcase 2000. This reduces the volume occupied by the embedded oil circuit within the housing and avoids the thinning of the housing wall caused by excessive oil circuits. This reduces the manufacturing complexity while maintaining the rigidity of the housing. Furthermore, by supplying oil separately through two oil pumps (a high-pressure pump and a low-pressure pump), the oil supply to each oil circuit can be better guaranteed, and the lubricant can be distributed more effectively. This avoids the uneven distribution of lubricant and insufficient lubricant at each lubrication point caused by excessive lubrication branches, thereby improving lubricant utilization, reducing anomalies, and better assisting the continuous and stable operation of the high-power plunger pump.

[0142] Furthermore, it should be noted that, in addition to the above-mentioned method, the lubricating oil circuit of the crankcase 2000 can also be supplied not from the crosshead case 1000, but by drilling a separate hole on the crankcase side for oil injection, thus forming a separate circuit. This method increases the hole processing process, external piping, and oil inlet interface, increases the area occupied by the internal oil channel of the crankcase 2000 shell, and has an impact on the rigidity of the crankcase. In addition, a sealing device needs to be added to the interface between the internal and external pipelines to seal the oil pipe connection to prevent oil and gas leakage and contamination. The crankcase oil inlet position can be set at the top or bottom of the crankcase, or on the left or right side of the crankcase. The oil circuit can then change its horizontal or vertical position accordingly.

[0143] 6. Connection and sealing design

[0144] 6.1 Connection Design

[0145] In the operating state after the fracturing pump is assembled, one end of the crosshead box 1000 is connected to the crankcase 2000, and the other end is connected to the spacer 3000. As shown in Figures 31 and 32, the connection and fastening between the crosshead box 1000 and the crankcase 2000 and the crosshead box 1000 and the spacer 3000 are preferably made by double bolts. Among them, the first bolt fastening is to fix and pre-tighten the whole by the first bolt 1611 (long bolt). As shown in Figure 33, the long bolt passes through the first bolt hole 1610 provided in the crosshead box 1000, and extends to the crankcase 2000 and the spacer 3000, so as to play the role of connecting the hydraulic end and the power end of the fracturing pump. The long bolt is set with a reasonable initial axial force to ensure that the bolt joint surface of the hydraulic end and the power end is always in a connected state during the operation of the plunger pump. The second bolt used between the crosshead housing 1000 and the crankcase 2000 and the third bolt used between the crosshead housing 1000 and the spacer 3000 primarily serve the purpose of sealing and tightening. Therefore, the first bolt 1611 can also be referred to as a tightening bolt or first-line bolt, and the second and third bolts can be collectively referred to as sealing bolts or second-line bolts. It is understood that the connection between the crosshead housing 1000 and the crankcase 2000 or spacer 3000 is not limited to the threaded connection described above. Any connection method that ensures a tight connection without relative displacement between the two can be used, such as using an external clamping structure to clamp the two contact surfaces in place, or using electromagnetic suction connection, hydraulic connection, automatic connection hook, etc. Furthermore, the arrangement and number of the first and second-line bolts are not limited to the preferred embodiment described herein and can vary according to the needs of tightening and sealing.

[0146] The position and number of the first row of bolt holes 1610 (i.e., long bolt holes) for the first bolts 1611 correspond to the threaded holes for the crankcase 2000. In principle, the second row of bolt holes 1620 for the second bolts and the third row of bolt holes 1630 for the third bolts should be located away from the first row of bolt holes 1610 and on the thin wall protruding from the crosshead housing 1000. The protruding thin wall can be formed in any manner, but a rounded transition is preferred around the edges for ease of casting and increased root stiffness. This minimizes the effect of the preload force of the first bolt 1611 on the second and third bolts, ensuring a tight seal. Figure 31 illustrates the layout of the first and second row of bolt holes 1610, 1620 on the rear end face of the crosshead housing 1000, while Figure 32 illustrates the layout of the first and third bolt holes 1610, 1630 on the front end face of the crosshead housing 1000. As shown in the figure, the first row of bolt holes 1610 is located between two adjacent crosshead cavities 1100 and two adjacent exhaust cavities 1200, and is located outside the multifunctional structural hole 1300. Preferably, the first row of bolt holes 1610 and the center of the multifunctional structural hole 1300 are aligned with each other. Furthermore, as shown in the figure, in the crosshead housing 1000 according to an embodiment of the present disclosure, the number and arrangement of the second row of bolt holes 1620 at the rear end of the crosshead housing 1000 and the third row of bolt holes 1630 at the front end can be different. The crosshead housing 1000 is connected to the crankcase 2000 on the side (i.e., the rear end face) using two rows of larger bolts, one above and one below. For example, flanges can be provided on the upper and lower sides of the rear end of the crosshead housing 1000, with the second row of bolt holes 1620 provided in each flange. Furthermore, a circle of smaller bolts is provided on the side (i.e., the front end face) where the crosshead housing 1000 connects to the spacer 3000. For example, flanges can be provided on the top, bottom, left, and right sides of the front end of the crosshead housing 1000, and third bolt holes 1630 can be provided in the flanges. This is because the reciprocating range of the crosshead in the crosshead housing 1000 is more biased toward the crankcase 2000 side. Therefore, the supporting reaction force of the bolts acting on the crankcase 2000 side is greater, and the bending moment force arm is shorter. In addition, both the crankcase 2000 and the crosshead housing 1000 have high rigidity, and deformation and separation on the left and right sides of the connection surface are essentially nonexistent. Therefore, only two rows of larger bolts are arranged on the top and bottom to withstand the greater axial force. However, the connection end surface between the crosshead housing 1000 and the spacer 3000 has low rigidity, a long force arm, and is subject to some flexural deformation, which may cause deformation and separation on the lateral sides of the connection end surface. Therefore, bolts are added on the left and right sides to ensure contact surface fit. It should be understood that the second bolt hole 1620 and the third bolt hole 1630 are not necessarily provided in the flange portion, as long as they are located outside the first bolt hole 1610 and are suitable for forming an anti-loosening fastening structure together with the first bolt hole.For example, the second row of bolt holes 1620 and the third row of bolt holes 1630 may also be provided in recesses on the upper and lower panels of the crosshead housing. Since the second and third row of bolt holes are both located outside the first row of bolt holes and have similar functions, the first row of bolt holes may also be referred to as inner bolt holes, and the second and third bolt holes may be collectively referred to as outer bolt holes.

[0147] 6.2 Sealing Design

[0148] The front and rear end faces 1002 of the crosshead housing 1000 are connected to the spacer 3000 and crankcase 2000, respectively. Therefore, sealing design is required on these front and rear end faces 1002. For example, by providing sealing structures such as sealing grooves or using sealing agents such as sealants, the crosshead cavity 1100 and exhaust cavity 1200 are sealed within, ensuring an oil-gas seal between the two sides of the crosshead housing 1000 and the spacer 3000 and crankcase 2000. Figures 33, 34a, and 34b illustrate exemplary arrangements of sealing rings 1701 on the front and rear end faces of the crosshead housing 1000. The location of the sealing grooves and sealing rings 1701, as well as the placement of sealants and other multiple sealing agents, is not particularly restricted. The only requirement is to ensure that the crosshead cavity 1100 and exhaust cavity 1200 are contained within the sealed area, meet the technical requirements for oil-gas sealing surfaces, and do not affect the function of surrounding structures.

[0149] A local seal 1702 can be added at the interface between the lubricating oil circuits of the crosshead housing 1000 and the crankcase 2000. Figure 35 illustrates a sealing ring positioned around the oil outlet 1503 of the lubricating oil circuit, serving as local seal 1702. The sealing range of local seal 1702 is not limited, as long as it satisfies the required sealing requirements at the oil outlet. The form of the seal is also not particularly limited, and can include a sealing ring (of any shape) or sealant.

[0150] In addition, as shown in Figure 36, a pair of locating pin holes 1703 are provided on both side end faces of the crosshead case 1000, which are used to connect the locating pins when assembling the crosshead case 1000, the spacer 3000 and the crankcase 2000, so as to achieve mutual alignment and positioning among the three (only one end face is shown in Figure 36). Corresponding pin holes are also formed on the crankcase 2000 and the spacer 3000. The size and shape of the locating pin hole 1703 correspond to the locating pin used. The location of the locating pin hole 1703 is not limited, as long as it meets the positioning requirements and does not affect the function of the surrounding structure. It is preferably set at the diagonal end face to facilitate positioning.

[0151] 7. Other structural components of the crosshead box

[0152] 7.1 Process holes and / or observation windows

[0153] The crosshead housing 1000 is also formed with a number of process holes and / or observation windows 1810. Since the process holes and observation windows are formed through the housing of the crosshead housing 1000 and have similar functions and structures, they may also be collectively referred to as process holes in this article. For example, the upper cover 1003 and / or the lower cover 1004 may be provided with process holes and / or observation windows 1810 for processing the internal oil passages or other processes after the housing is cast, as well as for maintenance and repair during later use. Referring to the accompanying drawings, it can be seen that the process holes and / or observation windows 1810 are preferably formed on the upper cover 1003 and / or the lower cover 1004 at positions corresponding to the crosshead inner cavity 1100 to facilitate future maintenance and repair. In addition, as mentioned above, the process holes and / or observation windows 1810 are preferably formed near the embedded oil circuit 1500 to facilitate processing and maintenance of the oil circuit. In the crosshead housing 1000 according to an embodiment of the present disclosure, since lubricating oil flows from the bottom of the crosshead housing 1000 to the crankcase 2000 for recycling, as shown in Figure 37, the process holes and / or observation windows 1810 provided on the lower panel 1004 of the crosshead housing 1000 have an upwardly projecting structure 1811, such as a boss, protruding into the housing. This upwardly projecting structure prevents environmental pollution caused by the lubricating oil flowing out of the bottom of the crosshead housing 1000. This upwardly projecting structure 1811 also increases the screwing length of the fixing bolts, enhancing the tightness of this area. Furthermore, the upper process window provided on the upper panel 1003 of the crosshead housing 1000 utilizes a downwardly projecting structure 1812 protruding into the housing to increase the screwing length of the fixing bolts, enhancing the tightness of this area. Since workers often stand above the crosshead housing 1000 during equipment maintenance, an upwardly projecting structure is not selected for safety reasons and to reduce the risk of workers tripping. Figure 38 illustrates the schematic structure of the boss forming the upper convex structure 1811 or the lower convex structure 1812 of the process hole and / or observation window 1810. In this figure, other components are omitted for clarity. If other methods are used to collect lubricating oil, the bottom process hole / observation window can be designed with other structures. The number of process holes / observation windows is not limited to circular, and the location of the process holes / observation windows does not need to obstruct subsequent processing. In addition, the process holes / observation windows can be formed using other methods or not provided, depending on actual needs.

[0154] 7.2 Mounting boss and related design

[0155] On both sides of the crosshead box 1000, mounting planes for arranging the lifting lugs and support lugs are provided on the side end plates 1005. For example, as shown in FIG39 , such a mounting plane can be in the form of a mounting boss 1820. The mounting boss 1820 is integrally formed with the main body of the crosshead box 1000, and is provided with arc or bevel transitions on all sides to increase the root stiffness. The position, number, and cross-sectional shape of the mounting boss 1820 are determined according to the requirements for setting the lifting lugs and support lugs. In addition to the mounting boss 1820 (convex plane), a mounting plane (concave plane) can also be provided by thinning the surface at the lifting location according to actual conditions.

[0156] 7.3 Support lugs

[0157] The crosshead housing 1000 according to the embodiment of the present disclosure is also equipped with support lugs 1830. As shown in Figure 39, the support lugs 1830 according to this embodiment are mounted on the mounting bosses 1820 and are located at the rear end of the crosshead housing 1000, near the gearbox, for connection to the gearbox's screw support assembly. Proper placement of the support lugs 1830 can effectively reduce deformation of the gearbox toward the power transmission shaft and gravity, thereby increasing the rigidity of the gearbox housing. The position, number, and cross-sectional shape of the support lugs 1830 are not limited, as long as they are compatible with the screw support assembly.

[0158] 7.4 Lifting ear plate

[0159] According to the embodiment of the present disclosure, the crosshead box 1000 is also provided with a lifting lug 1840. As shown in FIG39 , the lifting lug 1840 according to this embodiment is installed on the mounting boss 1820 located on the upper part of the box body. When the hydraulic end is disassembled, the lifting lug 1840 can be used for the lifting operation of the crosshead box 1000 and the crankcase assembly or the crosshead box 1000 itself. The shape, position, and number of the lifting lug 1840 are not limited. It is sufficient to ensure that the force is evenly distributed during lifting and the crosshead box 1000 does not tilt. The molding method of the lifting lug 1840 is not limited, and it can be integrally molded or processed by casting or other methods. In the embodiment shown in FIG39 , the lifting lug 1840 and the support lug 1830 are integrally molded on the mounting boss located on the upper part of the box body of the crosshead box. Such a structure reduces the occupied area and processing steps of the mounting boss 1820, saving costs. It should be understood that the support ear plates 1830 and the lifting ear plates 1840 may also be formed on the mounting bosses 1820 at different positions according to design requirements.

[0160] The preferred embodiments of the one-piece crosshead box according to the present invention have been described in detail above with reference to the accompanying drawings. It should be understood that the one-piece crosshead box according to the present invention does not necessarily need to have all the technical features shown in the accompanying drawings, but rather can combine these technical features described herein as needed. For example, among the various preferred structures of the one-piece crosshead box according to the present invention described above, structures such as the exhaust chamber, the embedded oil circuit, and the multifunctional structural holes can be selectively provided according to specific needs. They are not essential structures for achieving the basic functions of the one-piece crosshead box according to the present invention. For example, the one-piece crosshead box according to the present invention can also adopt the external oil pipes used in the prior art instead of the embedded oil circuit.

[0161] For example, a crosshead box according to one embodiment of the present invention is a generally rectangular box formed through an integral molding process and having a front end face, a rear end face, an upper end face, a lower end face, and side end faces. The crosshead box is provided with multiple crosshead cavities, each of which extends longitudinally of the crosshead box and penetrates the box body, and the multiple crosshead cavities are arranged transversely of the crosshead box. The crosshead box is also provided with multiple exhaust cavities, each of which penetrates the crosshead box longitudinally and communicates with a corresponding crosshead cavity.

[0162] For example, a crosshead box according to another embodiment of the present invention is a generally rectangular box formed through an integral molding process and having a front end face, a rear end face, an upper end face, a lower end face, and side end faces. The crosshead box is provided with a plurality of crosshead cavities, each of which extends longitudinally along the crosshead box and penetrates the box body, and the plurality of crosshead cavities are arranged transversely along the crosshead box. The crosshead box is also provided with a plurality of multifunctional structural holes, each of which extends longitudinally along the crosshead box and penetrates the box body.

[0163] For example, a crosshead housing according to another embodiment of the present invention is a generally rectangular housing formed through an integral molding process and having a front end face, a rear end face, an upper end face, a lower end face, and side end faces. The crosshead housing is provided with multiple crosshead cavities, each of which extends longitudinally of the crosshead housing and penetrates the housing, and the multiple crosshead cavities are arranged transversely of the crosshead housing. The crosshead housing is also provided with an embedded lubricating oil circuit, which is a series of interconnected oil holes and oil passages formed within the cast shell of the crosshead housing, and includes a main oil circuit and branch oil circuits.

[0164] The crosshead housing disclosed herein utilizes a one-piece casting process and a platform-based design, improving the versatility and adaptability of parts. This significantly reduces the number of accessories required for different fracturing pump models, saving significant costs in purchasing accessories and maintenance. Traditional welded power end housings require complete repair or even scrapping if they are partially cracked or damaged, impacting fracturing efficiency and increasing maintenance costs. Furthermore, the one-piece crosshead housing not only improves the strength and rigidity of the power end housing, extending its lifespan and maintenance cycles, but also allows for the individual maintenance and replacement of parts, reducing repair difficulty and repair costs.

[0165] In addition, the one-piece crosshead box according to the embodiment of the present disclosure can be provided with structures such as multifunctional structural holes, thereby ensuring structural rigidity while reducing the weight of the box. The one-piece crosshead box according to the embodiment of the present disclosure can provide a dedicated exhaust cavity and fluid channel so that the interior of the box has a good fluid circulation path, so that the air pressure inside the box can always be kept balanced during operation, thereby improving the operation stability and service life of the equipment. The lubricating oil circuit of the crosshead box according to the embodiment of the present disclosure can adopt an embedded structure to replace the traditional external oil pipe arrangement, thereby eliminating a large number of flexible hoses and pipe joints, and greatly reducing the oil pressure leakage problem caused by potential risks such as pipeline oxidation corrosion and loose pipe joints. Therefore, it can effectively extend the maintenance period of the lubrication system and facilitate troubleshooting and repair.

[0166] The crosshead box disclosed herein is designed with lifting points on both sides, facilitating individual and combined lifting. The cylindrical crosshead cavity of the crosshead box enables the use of cylindrical crosshead sleeves instead of two-piece bearings, reducing the installation process and facilitating bearing inspection and replacement. Sensors are also installed on the crosshead box to monitor real-time data such as equipment vibration, housing temperature, and lubricating oil temperature and flow rate. This allows on-site personnel to promptly detect and respond to equipment anomalies at the initial stage, such as shutting down the machine for inspection or replacing components.

[0167] Furthermore, the crosshead housing according to the present disclosure may be configured as follows, for example, but the present invention is not limited thereto.

[0168] (1) A crosshead box, the crosshead box being a substantially rectangular box body formed by an integral molding process and having a front end face, a rear end face, an upper end face, a lower end face, and side end faces, the crosshead box being provided with:

[0169] A plurality of crosshead inner cavities, each of the crosshead inner cavities extending along the longitudinal direction of the crosshead box and penetrating the box body, and the plurality of crosshead inner cavities being arranged along the transverse direction of the crosshead box,

[0170] It is characterized in that the crosshead box is further provided with a plurality of exhaust cavities, each of the exhaust cavities passes through the crosshead box in the longitudinal direction of the crosshead box and is communicated with the corresponding crosshead inner cavity.

[0171] (2)

[0172] According to the crosshead box described in (1) above, a fluid channel is formed on the front end surface of the crosshead box, and the fluid channel is a groove that is recessed inward from the front end surface in the longitudinal direction of the crosshead box and extends from the crosshead inner cavity to the exhaust cavity.

[0173] (3)

[0174] According to the crosshead box described in (2) above, the exhaust chamber and the corresponding crosshead inner chamber are fluidically connected via the fluid channel, so that when the crosshead assembly moves in the crosshead inner chamber along the direction from the front end face to the rear end face, the airflow in the exhaust chamber moves in the direction from the rear end face to the front end face, and when the crosshead assembly moves in the crosshead inner chamber along the direction from the rear end face to the front end face, the airflow in the exhaust chamber moves in the direction from the front end face to the rear end face.

[0175] (4)

[0176] According to the crosshead box described in (2) above, the crosshead box is further provided with a crosshead sleeve capable of being embedded in the inner cavity of the crosshead, and one end of the crosshead sleeve located on the front end surface is provided with at least one inner concave portion that is concave inwardly along the longitudinal direction of the crosshead box, and

[0177] The concave shape of the inner recess matches the groove shape of the fluid channel.

[0178] (5)

[0179] According to the crosshead box described in (4) above, one end of the crosshead sleeve located at the rear end surface is provided with at least one protrusion protruding outward along the longitudinal direction of the crosshead sleeve.

[0180] (6)

[0181] According to the crosshead box described in (1) above, one exhaust cavity is provided above or below each crosshead inner cavity.

[0182] (7)

[0183] According to the crosshead box described in (1) above, one exhaust cavity is provided above and below each crosshead inner cavity.

[0184] (8)

[0185] According to the crosshead box described in (7) above, one crosshead inner cavity and the two exhaust cavities located above and below it are centrally symmetrical in the transverse direction of the crosshead box, and are also centrally symmetrical in the vertical direction perpendicular to the transverse direction.

[0186] (9)

[0187] According to the crosshead box described in (7) above, one crosshead inner cavity and the two exhaust cavities located above and below it are axially symmetrical in the transverse direction of the crosshead box, and are also axially symmetrical in the vertical direction perpendicular to the transverse direction.

[0188] (10)

[0189] According to the crosshead box described in any one of the above (1) to (9), a reinforcing beam is formed on the inner wall of the exhaust cavity on the side close to the crosshead inner cavity.

[0190] (11)

[0191] According to the crosshead box described in (1) above, the crosshead box is further provided with at least one multifunctional structural hole, each of the multifunctional structural holes extending along the longitudinal direction of the crosshead box and penetrating the box body.

[0192] (12)

[0193] According to the crosshead box described in (11) above, each of the multifunctional structural holes is arranged at a position close to at least one of the crosshead cavities.

[0194] (13)

[0195] According to the crosshead box described in (11) above, at least one of the multifunctional structural holes is provided at a position between two adjacent crosshead inner cavities on the front end face and the rear end face.

[0196] (14)

[0197] According to the crosshead box described in (11) above, the cross section of each of the multifunctional structural holes has a polygonal shape.

[0198] (15)

[0199] According to the crosshead box described in (14) above, the wall thicknesses around the multifunctional structural holes on the front end face and the rear end face are equal.

[0200] (16)

[0201] According to the crosshead box described in (11) above, the cross section of each of the multifunctional structural holes has a triangular shape with rounded corners.

[0202] (17)

[0203] According to the crosshead box described in (16) above, the wall thickness between each multifunctional structural hole and the two adjacent crosshead cavities on the front end face and the rear end face is substantially the same.

[0204] (18)

[0205] According to the crosshead box described in any one of the above (1) to (9), a plurality of spacer columns extending up and down are provided between each of the crosshead inner cavities, the plurality of spacer columns are arranged along the longitudinal direction of the crosshead box, and two adjacent crosshead inner cavities are connected through the gaps between the spacer columns.

[0206] (19)

[0207] According to the crosshead box described in any one of the above (1) to (9), each crosshead inner cavity is approximately cylindrical in shape.

[0208] (20)

[0209] According to the crosshead box described in any one of (11) to (17) above, the crosshead box further includes a crosshead sliding sleeve, which has a shape matching the crosshead inner cavity and can be embedded and installed in the crosshead inner cavity.

[0210] (twenty one)

[0211] According to the crosshead box described in (20) above, the crosshead sleeve is provided with an oil hole penetrating the sleeve wall.

[0212] (twenty two)

[0213] According to the crosshead box described in (20) above, one end of the crosshead sleeve is provided with at least one recessed portion recessed inwardly along the longitudinal direction of the crosshead sleeve.

[0214] (twenty three)

[0215] According to the crosshead box described in (20) above, one end of the crosshead sleeve is provided with at least one protrusion protruding outward along the longitudinal direction of the crosshead sleeve.

[0216] (twenty four)

[0217] According to the crosshead box described in (22) above, the other end of the crosshead sleeve is provided with at least one protrusion protruding outward along the longitudinal direction of the crosshead sleeve.

[0218] (25)

[0219] According to the crosshead box described in (22) above, there are two inner recesses, and

[0220] When the crosshead sliding sleeve is installed in the crosshead inner cavity, the two inner recesses are located at the top and bottom of the crosshead inner cavity.

[0221] (26)

[0222] According to the crosshead box described in (23) above, there are two protrusions, and

[0223] When the crosshead sliding sleeve is installed in the crosshead inner cavity, the two protrusions are located at the top and bottom of the crosshead inner cavity.

[0224] (27)

[0225] According to the crosshead box described in (24) above, there are two inner concave parts and two protruding parts, and

[0226] When the crosshead sleeve is installed in the crosshead inner cavity, the two inner recesses are located at the top and bottom of the crosshead inner cavity, and the two protrusions are also located at the top and bottom of the crosshead inner cavity.

[0227] (28)

[0228] According to the crosshead box described in (20) above, the front end surface of the crosshead inner cavity is provided with a limiting groove, and the end portion of the crosshead sleeve located at one end of the front end surface is provided with a positioning pin hole, and the positioning pin hole and the limiting groove are connected via a pin shaft inserted into the pin hole to axially position the crosshead sleeve in the crosshead inner cavity.

[0229] (29)

[0230] According to the crosshead box described in (1) above, the crosshead box is further provided with an embedded lubricating oil circuit, which is an interconnected oil hole and oil channel formed in the cast shell of the crosshead box, and the embedded lubricating oil circuit includes at least one main oil circuit and at least one branch oil circuit.

[0231] (30)

[0232] According to the crosshead case described in (29) above, the main oil passage extends in the transverse direction of the crosshead case, and the branch oil passage extends in the longitudinal direction of the crosshead case.

[0233] (31)

[0234] According to the crosshead box described in (29) above, the embedded lubricating oil circuit includes a high-pressure lubricating oil circuit.

[0235] (32)

[0236] According to the crosshead box described in (31) above, the high-pressure lubricating oil circuit lubricates the crosshead bearing and connecting rod bearing working in the crosshead box.

[0237] (33)

[0238] According to the crosshead box described in (31) above, the high-pressure lubricating oil circuit includes a high-pressure oil inlet provided on the side end surface of the crosshead box body.

[0239] (34)

[0240] According to the crosshead box described in (33) above, the high-pressure oil inlet is arranged on a flat connecting plane formed on the side end surface.

[0241] (35)

[0242] According to the crosshead box described in (31) above, the high-pressure lubricating oil circuit has a filter and a relief valve.

[0243] (36)

[0244] According to the crosshead box described in (29) above, the embedded lubricating oil circuit includes a low-pressure lubricating oil circuit.

[0245] (37)

[0246] According to the crosshead box described in (36) above, the crosshead box is further provided with a crosshead sliding sleeve, the crosshead sliding sleeve has a shape matching the inner cavity of the crosshead and can be embedded and installed in the inner cavity of the crosshead,

[0247] The low-pressure lubricating oil circuit lubricates the crosshead sliding sleeve.

[0248] (38)

[0249] According to the crosshead box described in (36) above, the low-pressure lubricating oil circuit includes a low-pressure oil inlet provided on the side end surface of the crosshead box body.

[0250] (39)

[0251] According to the crosshead box described in (38) above, the low-pressure oil inlet is arranged on a flat connecting plane formed on the side end surface.

[0252] (40)

[0253] According to the crosshead box described in (36) above, the low-pressure lubricating oil circuit has a filter and a relief valve.

[0254] (41)

[0255] According to the crosshead case described in (29) above, the at least one branch oil passage includes a branch oil passage for supplying oil to the crankcase, and the branch oil passage for supplying oil to the crankcase has an oil outlet leading to the crankcase on the rear end surface of the crosshead case.

[0256] (42)

[0257] According to the crosshead box described in (41) above, a sealing ring serving as a local sealing member is provided on the outer periphery of the oil outlet.

[0258] (43)

[0259] According to any one of the above (1) to (9), (11) to (17) and (29) to (42), the crosshead box is further provided with at least one first bolt hole, each of the first bolt holes is located above and below the multiple crosshead cavities and extends along the longitudinal direction of the crosshead box and penetrates the box body.

[0260] (44)

[0261] According to the crosshead box described in (43) above, the crosshead box is further provided with at least one second row of bolt holes, which extend along the longitudinal direction of the crosshead box and penetrate the box body, and on the front end face and the rear end face, the second row of bolt holes are both located outside the first row of bolt holes.

[0262] (45)

[0263] According to the crosshead box described in (44) above, the second bolt holes are also provided on the front end surface of the crosshead box at the edge portions located on both lateral sides of the crosshead box body.

[0264] (46)

[0265] According to the crosshead box described in (44) above, a flange portion is provided on the outer periphery of the crosshead box on the front end surface of the crosshead box, and the second bolt hole is provided in the flange portion.

[0266] (47)

[0267] According to the crosshead box described in (44) above, flange portions are provided on the rear end surface of the crosshead box, at both the upper edge and the lower edge of the crosshead box, and the second bolt hole is provided in the flange portion.

[0268] (48)

[0269] A crosshead box according to any one of (1) to (9), (11) to (17) and (29) to (42) above, wherein sealing grooves are respectively provided on the front end face and the rear end face of the crosshead box, and the sealing area surrounded by the sealing grooves at least includes the crosshead inner cavity and the exhaust cavity.

[0270] (49)

[0271] According to the crosshead box described in any one of the above (1) to (9) and (11) to (17), the crosshead box further includes a process hole penetrating the shell of the crosshead box.

[0272] (50)

[0273] According to the crosshead box described in (49) above, the process hole is formed at a position corresponding to the inner cavity of the crosshead.

[0274] (51)

[0275] According to the crosshead box described in any one of the above (29) to (42), the crosshead box also includes a process hole penetrating the shell of the crosshead box, and the process hole is at least arranged at a position close to the embedded lubricating oil circuit.

[0276] (52)

[0277] According to the crosshead box described in (49) above, the process hole formed on the top of the crosshead box is formed with a downward convex structure protruding toward the inner cavity of the crosshead.

[0278] (53)

[0279] According to the crosshead box described in (49) above, the process hole formed at the bottom of the crosshead box is formed with an upward convex structure protruding toward the inner cavity of the crosshead.

[0280] (54)

[0281] According to the crosshead box described in any one of the above (1) to (9), (11) and (29), the crosshead box is further provided with a mounting boss formed on the side end surface.

[0282] (55)

[0283] A plunger pump comprises a crankcase, a crosshead case as described in any one of (1) to (54) above, and a spacer.

[0284] (56)

[0285] According to the plunger pump described in (55) above, positioning pin holes are provided on the joint end surfaces between the crankcase, the crosshead case and the spacer for aligning and positioning the crankcase, the crosshead case and the spacer.

[0286] (57)

[0287] The plunger pump according to (55) or (56) above, wherein the plunger pump further comprises a reduction gearbox, and

[0288] A supporting lug is provided on a mounting boss formed on a side end surface of the crosshead box, and the supporting lug is connected to a supporting assembly of the reduction box.

[0289] While the integrated crosshead housing according to the present disclosure has been described above with reference to the accompanying drawings, the present disclosure is not limited to the aforementioned embodiments. Those skilled in the art will appreciate that various modifications, combinations, sub-combinations, and variations may be made without departing from the spirit or scope of the present disclosure as defined in the appended claims. Furthermore, the beneficial effects of the present disclosure are not limited to those described above, but may include other effects that may be conceived upon reading this disclosure.

[0290] Reference Signs List

[0291] 1000 Crosshead Box

[0292] 2000 crankcase

[0293] 3000 Spacer

[0294] 4000 reduction gearbox

[0295] 1001 front face

[0296] 1002 rear end

[0297] 1003 Upper mask, upper end surface

[0298] 1004 lower cover, lower end surface

[0299] 1005 side end plate, side end surface

[0300] 1006 limit slot

[0301] 1100 crosshead cavity

[0302] 1200 exhaust chamber

[0303] 1300 Multifunctional structural holes

[0304] 1101 Partition board

[0305] 1102 Spacer

[0306] 1400 Crosshead Sleeve

[0307] 1401 Sliding sleeve oil hole

[0308] 1402 Sleeve locating pin hole

[0309] 1403 Slide protrusion

[0310] 1404 Recessed part of sliding sleeve

[0311] 1201 Fluid Channel

[0312] 1210 reinforcement beam

[0313] 1211 Transitional Structure

[0314] 1500 Lubrication oil circuit

[0315] 1510 High-pressure lubrication oil circuit

[0316] 1520 low-pressure lubrication oil circuit

[0317] 1511 High-pressure oil inlet

[0318] 1512 Low pressure oil inlet

[0319] 1501 Relief Valve

[0320] 1502 Oil tank end

[0321] 1503 oil outlet

[0322] 1504 Boss structure

[0323] 1610 First Bolt Hole

[0324] 1620 Second bolt hole

[0325] 1630 Third bolt hole

[0326] 1611 First Bolt

[0327] 1701 sealing ring

[0328] 1702 Partial seal

[0329] 1703 positioning pin hole

[0330] 1810 process hole / observation window

[0331] 1811 Convex Structure

[0332] 1812 Convex Structure

[0333] 1820 Mounting Boss

[0334] 1830 Support lugs

[0335] 1840 Lifting Lugs

[0336] 2001 Linkage movable window

Claims

1. A crosshead box, which is a substantially rectangular box body formed by an integral molding process and has a front end face, a rear end face, an upper end face, a lower end face and a side end face, and the crosshead box is provided with: A plurality of crosshead inner cavities, each of the crosshead inner cavities extending along the longitudinal direction of the crosshead box and penetrating the box body, and the plurality of crosshead inner cavities being arranged along the transverse direction of the crosshead box, It is characterized in that The crosshead box is further provided with a plurality of exhaust cavities, each of which penetrates the crosshead box in the longitudinal direction of the crosshead box and is communicated with the corresponding crosshead inner cavity.

2. The crosshead box according to claim 1, wherein: The front end surface of the crosshead box is formed with a fluid passage, which is a groove that is recessed inward from the front end surface in the longitudinal direction of the crosshead box and extends from the crosshead inner cavity to the exhaust cavity.

3. The crosshead box according to claim 2, wherein: The exhaust chamber and the corresponding crosshead inner chamber are fluidically connected via the fluid channel, so that when the crosshead assembly moves in the crosshead inner chamber along the direction from the front end face toward the rear end face, the airflow in the exhaust chamber moves in the direction from the rear end face toward the front end face, and when the crosshead assembly moves in the crosshead inner chamber along the direction from the rear end face toward the front end face, the airflow in the exhaust chamber moves in the direction from the front end face toward the rear end face.

4. The crosshead box according to claim 2, wherein: The crosshead box is also provided with a crosshead sleeve that can be embedded in the inner cavity of the crosshead, and one end of the crosshead sleeve located on the front end surface is provided with at least one inner concave portion that is concave inwardly along the longitudinal direction of the crosshead box, and The concave shape of the inner recess matches the groove shape of the fluid channel.

5. The crosshead box according to claim 4, wherein: One end of the crosshead sliding sleeve located at the rear end surface is provided with at least one protrusion protruding outward along the longitudinal direction of the crosshead sliding sleeve.

6. The crosshead box according to claim 1, wherein: The crosshead box is also provided with at least one multifunctional structural hole, and each of the multifunctional structural holes extends along the longitudinal direction of the crosshead box and penetrates the box body.

7. The crosshead box according to claim 4, wherein: The front end surface of the crosshead inner cavity is provided with a limiting groove, and the end portion of the crosshead sleeve located at one end of the front end surface is provided with a positioning pin hole, and the positioning pin hole and the limiting groove are connected via a pin shaft inserted into the pin hole to axially position the crosshead sleeve in the crosshead inner cavity.

8. The crosshead box according to claim 1, wherein: The crosshead box is also provided with an embedded lubricating oil circuit, which is an interconnected oil hole and oil passage formed in the casting shell of the crosshead box, and the embedded lubricating oil circuit includes at least one main oil circuit and at least one branch oil circuit.

9. The crosshead box according to claim 8, wherein: The main oil passage extends in a transverse direction of the crosshead box, and the branch oil passage extends in a longitudinal direction of the crosshead box.

10. A crosshead box, the crosshead box is a substantially rectangular box body formed by an integral molding process, and has a front end face, a rear end face, an upper end face, a lower end face and a side end face, the crosshead box is provided with: A plurality of crosshead inner cavities, each of the crosshead inner cavities extending along the longitudinal direction of the crosshead box and penetrating the box body, and the plurality of crosshead inner cavities being arranged along the transverse direction of the crosshead box, It is characterized in that The crosshead box is also provided with at least one multifunctional structural hole, and each of the multifunctional structural holes extends along the longitudinal direction of the crosshead box and penetrates the box body.

11. The crosshead box according to claim 10, wherein: At least one of the multifunctional structural holes is disposed at a position between two adjacent crosshead cavities on the front end face and the rear end face.

12. The crosshead box according to claim 10, wherein: On the front end face and the rear end face, the wall thickness around each of the multifunctional structural holes is equal.

13. The crosshead box according to claim 10, wherein: The crosshead box is also provided with an embedded lubricating oil circuit, which is an interconnected oil hole and oil passage formed in the casting shell of the crosshead box, and the embedded lubricating oil circuit includes at least one main oil circuit and at least one branch oil circuit.

14. The crosshead box according to claim 13, wherein: The main oil passage extends in a transverse direction of the crosshead box, and the branch oil passage extends in a longitudinal direction of the crosshead box.

15. The crosshead box according to claim 13, wherein: The embedded lubricating oil circuit includes a high-pressure lubricating oil circuit and a low-pressure lubricating oil circuit.

16. A crosshead box, the crosshead box being a substantially rectangular box body formed by an integral molding process and having a front end face, a rear end face, an upper end face, a lower end face and a side end face, the crosshead box being provided with: A plurality of crosshead inner cavities, each of the crosshead inner cavities extending along the longitudinal direction of the crosshead box and penetrating the box body, and the plurality of crosshead inner cavities being arranged along the transverse direction of the crosshead box, It is characterized in that The crosshead box is also provided with an embedded lubricating oil circuit, which is an interconnected oil hole and oil passage formed in the casting shell of the crosshead box, and the embedded lubricating oil circuit includes a main oil circuit and a branch oil circuit.

17. The crosshead box according to claim 16, wherein: The main oil passage extends in a transverse direction of the crosshead box, and the branch oil passage extends in a longitudinal direction of the crosshead box.

18. The crosshead box according to claim 16, wherein: The crosshead box further comprises a crosshead sleeve, which has a shape matching the inner cavity of the crosshead and can be embedded and installed in the inner cavity of the crosshead, and The crosshead sleeve is provided with an oil hole penetrating the sleeve wall, and the oil hole is a part of the branch oil circuit.

19. The crosshead box according to claim 18, wherein: The embedded lubricating oil circuit includes a high-pressure lubricating oil circuit and a low-pressure lubricating oil circuit. The high-pressure lubricating oil circuit lubricates the crosshead bearing and connecting rod bearing working in the crosshead box, and the low-pressure lubricating oil circuit lubricates the crosshead sliding sleeve.

20. The crosshead box according to claim 16, wherein: The crosshead box is also provided with a plurality of exhaust cavities and at least one multifunctional structural hole. Each of the exhaust cavities penetrates the crosshead box in the longitudinal direction of the crosshead box and is communicated with the corresponding crosshead inner cavity, and each of the multifunctional structural holes extends along the longitudinal direction of the crosshead box and penetrates the box body.

Images