Power end shell for plunger pump

Abstract

The invention provides a power end shell (100) used for a plunger pump, the power end shell (100) comprises a crankshaft box body (110) used for containing a crankshaft and a crosshead box body (120) used for containing a crosshead, the crankshaft box body (110) comprises an end shell part (1101), a main shell part (1102) and a plurality of bearing seats, each bearing seat comprises a bearing seat cover (1104) and a main bearing seat body (1105), and the crosshead box body (120) is used for containing a crosshead. The main shell part (1102) and the crosshead box body (120) are integrally formed, the end shell part (1101) and the main shell part (1102) can be detachably connected, and the bearing seat cover (1104) and the main bearing seat body (1105) can be detachably connected.

Description

Technical Field

[0001] The invention relates to the technical field of oil and gas production equipment, and in particular to a power end housing for a plunger pump. Background Art

[0002] The plunger pump is an important equipment in the process of oil and gas extraction. The plunger pump usually includes a hydraulic end and a power end. The power end can transfer kinetic energy to the hydraulic end through a reduction transmission system, etc. The force generated by the high-pressure liquid inside the hydraulic end acts on the power end housing through the plunger and other components. The power end housing usually includes a crankcase and a crosshead housing. The crankcase and the crosshead housing are formed separately, that is, the two are split designs and are connected together when in use. At present, the crankcase and the crosshead housing of the power end housing are usually fixed with bolts. The movement of the plunger will generate axial force on the bolts. When the bolt clamping force is less than the plunger force, the bolt will loosen, and in severe cases, the bolt will break, making the connection function invalid. The axial separation of the crosshead housing will cause the sealing surface connection between the crankcase and the crosshead housing to fail, causing sealing leakage. On the one hand, poor sealing will affect the establishment of lubricating oil pressure, resulting in insufficient lubricating oil in parts such as bearing bushings, which is prone to early wear and ablation. On the other hand, poor sealing will cause oil and gas leakage, and the entry of water vapor will accelerate the rust and wear of the internal parts of the housing, affect the performance of the lubricating oil, change the viscosity of the oil, weaken the supporting strength of the oil film, and accelerate the oxidation of the oil.

[0003] On the other hand, when the crankshaft rotates and drives the connecting rod to swing up and down, a lateral force perpendicular to the plunger axis will be generated. The periodic lateral force will cause the elastic sealing ring to produce a pumping effect, continuously sucking in and discharging oil and gas. This process will accelerate the corrosion and oxidation of the sealing ring, leading to oil and gas leakage. The lateral force and the deadweight of the crosshead box will also drive the crosshead box to slide downward eccentrically, causing the connecting rod, crosshead, and tie rod to be not in the same center, causing the crosshead and tie rod connecting bolts to bear additional bending moment and tensile stress. Long-term misaligned operation will cause fatigue fracture of the connecting bolts and leakage at the tie rod oil seal, allowing more solid particles and impurities to enter the power end housing, resulting in wear and scratches on the key friction surface. In addition, the eccentricity of the crosshead and tie rod will also cause eccentric wear of the hydraulic end packing, causing leakage of fracturing fluid at the packing seal, affecting the fracturing operation.

[0004] In addition, when the crosshead assembly is in reciprocating motion in the crosshead box, the high-speed changing cavity needs to have a large enough channel to supply the oil and gas flow inside the front and rear of the crosshead box. For the split structure, the gas in the crosshead cavity circulates through the fluid channel, the exhaust cavity and the crankcase observation window to achieve the balance of the air pressure in the front and rear of the crosshead cavity during the reciprocating motion. However, due to the limitations of the split structure, the oil and gas are blocked by the shell above the observation window on the crankcase when passing through the exhaust cavity, resulting in a small flow area here, which is not conducive to the dynamic balance of oil and gas in the crosshead box. In addition, due to the reduction in area, the flow rate here increases sharply, increasing the noise generated by the high-speed flow of gas when the crosshead assembly reciprocates, and also increasing the degree of influence of the surrounding sound restriction range on the working environment. Since the crankcase and the crosshead box are split designs, in order to avoid additional bending moment here and ensure reliable support, support feet are arranged at the front and rear end surfaces of each support vertical plate of the crankcase where the bending moment is weak. The support point arrangement is complicated and increases the weight of the shell. High-precision machining processes are also required to ensure that the ends of each support foot are in the same plane.

[0005] On the other hand, since the connecting rod, crosshead and tie rod need to be strictly aligned during the operation of the fracturing pump to prevent the bearing bushing from being worn out due to the misalignment error of the crosshead and the seal failure caused by the wear of the hydraulic end packing, the position and size processing accuracy of the positioning pin hole on the connection surface are required to be high. In the process of controlling the processing accuracy, it is necessary to design and manufacture special clamping and positioning tooling to ensure that the processing reference surface of the pin hole is reliably positioned. The processing procedures are cumbersome and the accuracy requirements of the processing equipment and tools are strict.

[0006] In addition, the prior art also has an integral housing that forms a crankcase and a crosshead housing as one body. The bearings, crankshafts, connecting rods and crossheads inside the integral housing are difficult to install. The traditional installation method is: the main bearing adopts a cylindrical roller bearing, and the inner and outer rings are installed separately. The outer ring is cooled and shrunk by a liquid nitrogen device and then placed in the designated bearing position of the crankcase; the installation of the inner ring requires the crankshaft to be lifted and placed vertically, and the inner ring is heated and expanded by a bearing heater and then placed in the designated bearing position on one side, and then a positioning baffle is installed to prevent the inner ring from axial movement, and then the crankshaft is lifted and rotated, and the inner ring of the bearing on the other side is installed in the same way. Finally, the crankcase with the outer ring is lifted and placed vertically, and the crankshaft with the inner ring of the bearing is lifted and placed vertically. The installation process of the entire crankshaft and main bearing is cumbersome, requiring multiple hoisting of the crankshaft and the housing and heating and cooling of the bearing, which is extremely time-consuming and costly. The integral crankcase uses a disc crankshaft plus roller bearings to ensure the rotation of the crankshaft. The integral structure layout is not compact enough and the space size is large, which increases the weight of the whole machine, consumes raw materials and increases transportation costs. In addition, the cost of roller bearings is extremely high, and the use of six roller bearings as main bearings greatly increases the cost of the whole machine. Summary of the invention

[0007] In order to solve the technical problems mentioned above, the present invention proposes a power end housing for a plunger pump, characterized in that the power end housing includes a crankcase for accommodating a crankshaft and a crosshead housing for accommodating a crosshead, the crankcase includes an end shell portion, a main shell portion and a plurality of bearing seats, each of the bearing seats includes a bearing seat cover and a main bearing seat body, the main shell portion and the crosshead housing are integrally formed, the end shell portion and the main shell portion can be detachably connected, and the bearing seat cover and the main bearing seat body can be detachably connected.

[0008] Furthermore, the end shell portion and the main housing portion, as well as the bearing seat cover and the main bearing seat body, can be detachably connected by bolts.

[0009] Further, the bolts include a first group of bolts, which are arranged in a manner oriented along the axial direction of the plunger pump and connect the end shell part and the main shell part together.

[0010] Furthermore, the bolts include a second group of bolts, which are arranged in a manner oriented along the axial direction of the plunger pump and connect the bearing seat cover and the main bearing seat body together.

[0011] Further, the bolts include a third group of bolts, which are arranged at positions corresponding to the bearing seat cover on both sides of the main housing part in the vertical direction and are screwed into and passed through the main housing part from the outside of the main housing part along the vertical direction, so that the third group of bolts support both sides of the bearing seat cover in the vertical direction.

[0012] Furthermore, the bearing seat cover and the end shell portion can be integrally formed.

[0013] Furthermore, it also includes a bearing shell.

[0014] Furthermore, when viewed from the side along the axial direction of the plunger pump, the connection line between the end shell portion and the main housing portion is closer to the rear end portion of the crankcase away from the crosshead housing than the connection line between the bearing seat cover and the main bearing seat body. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 is an exploded perspective view showing a power end housing for a plunger pump according to one embodiment of the present invention;

[0016] Figure 2 It shows that according to Figure 1 A schematic side view of the power end housing along the axis of the plunger pump is shown;

[0017] Figure 3 is a schematic diagram showing the position and size relationship of the main journal, connecting rod journal and roller bearing in the integral crankcase in the prior art;

[0018] Figure 4 is a schematic diagram showing the position and size relationship of the main journal, connecting rod journal and bearing shell in a crankcase according to an embodiment of the present invention;

[0019] Figure 5 A schematic side view of an integral power end housing along the axis direction of a plunger pump according to another embodiment of the present invention is shown.

[0020] Description of reference numerals:

[0021] 100, 100': power end housing for plunger pump; 110: crankcase; 120: crosshead housing; 1101: end housing; 1102: main housing; 1103: crankshaft mounting cavity; 1201: crosshead mounting cavity; 1104: bearing seat cover; 1105: main bearing seat body; 1106, 1106': bearing shell; 1107, 1108, 1109: bolts. DETAILED DESCRIPTION

[0022] In order to make the purpose, technical solution and advantages of the present application clearer, the technical solution of the present application will be clearly and completely described below in combination with the specific embodiments of the present application and the corresponding drawings. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present application.

[0023] The technical solutions disclosed in various embodiments of the present application are described in detail below in conjunction with the accompanying drawings.

[0024] As described above, in the prior art, the crankcase and the crosshead case serving as the power end housing of the plunger pump can be formed separately, that is, the crankcase is formed as a whole, the crosshead case is formed as a whole, and then the crankcase and the crosshead case are connected together when in use, or the crankcase and the crosshead case are formed as a whole, which is called an integral power end housing of the plunger pump, wherein the crankshaft can be installed in the crankcase and connected to the crosshead in the crosshead case to realize transmission.

[0025] On the other hand, Figure 1As shown, one embodiment of the present application discloses a new power end housing 100 that is different from the power end housing in the prior art. The power end housing 100 can be used in a plunger pump to provide installation space for a crankshaft and a crosshead (not shown in the figure) in the plunger pump, and the power end housing 100 can serve as a medium for fixing the power end and the hydraulic end of the plunger pump to each other. Specifically, in the process of assembling the plunger pump, the entire power end can form a fixed connection relationship with the valve box of the hydraulic end by using the power end housing 100 through bolts and other connectors, so that a good relative fixed relationship is formed between the power end and the hydraulic end, ensuring that the plunger pump can work stably.

[0026] like Figure 1 As shown, a power end housing 100 disclosed in an embodiment of the present application includes a crankcase 110 for accommodating a crankshaft and a crosshead housing 120 for accommodating a crosshead, the crankcase 110 includes an end housing portion 1101 and a main housing portion 1102 which is opposite to the end housing portion 1101 and is integrally formed with the crosshead housing 120, such as an integrally cast one, the end housing portion 1101 and the main housing portion 1102 can be detachably connected, especially detachably connected by bolts, to form a complete crankcase, and the main housing portion 1102 and the crosshead housing 120 can be integrally formed, especially integrally formed by casting. That is to say, relative to the crankcase, the crankcase 110 according to an embodiment of the present application is designed into two parts, namely a split crankcase 110, which is completely different from the prior art in which the crankcase is designed as a whole integral crankcase. Specifically, the power end housing 100 can be formed of a material with relatively large structural strength such as metal. At the same time, in order to enable the power end housing 100 to provide installation space for the crankshaft and the crosshead, the crankcase 110 has a crankshaft mounting cavity 1103, and the crosshead case 120 has a crosshead mounting cavity 1201. The crankshaft is installed in the crankshaft mounting cavity 1103 of the crankcase, and the crosshead is installed in the crosshead mounting cavity 1201 of the crosshead case 120. The crosshead is connected to the crankshaft in transmission, and by interconnecting the crankshaft mounting cavity 1103 and the crosshead mounting cavity 1201, it is ensured that the crankshaft and crosshead in transmission connection can be installed in the crankshaft mounting cavity 1103 and the crosshead mounting cavity 1201 respectively.

[0027] As described above, the crankcase 110 according to an embodiment of the present application is actually divided into two parts, namely, the end shell part 1101 and the main shell part 1102, which is equivalent to dividing the crankcase 110 into two parts along the axial direction X of the plunger pump, and the main shell part 1102 is formed integrally with the crosshead housing 120. In this case, each bearing seat of each main bearing in the crankcase 110 can also be designed as a split type, that is, each bearing seat includes a bearing seat cover 1104 and a main bearing seat body 1105. After the main bearing is installed on the main bearing seat body 1105 in the crankcase 110, the bearing seat cover 1104 is installed, and the bearing seat cover 1104 is clamped and connected with the main bearing seat body 1105, and then the end shell part 1101 is installed on the main shell part 1102 to complete the installation of the crankshaft. Optionally, the bearing seat cover 1104 can also be integrally formed with the end shell part 1101. In this case, after the main bearing is mounted on the main bearing seat body 1105 in the crankcase 110, the bearing seat cover 1104 formed as one piece is installed on the main bearing seat body 1105 and the main housing part 1102 together with the end shell part 1101 and clamped and sealed.

[0028] In addition, according to the above embodiment, a disc crankshaft and a cylindrical roller bearing can be used in the crankcase 110. Further preferably, a crankshaft and a sliding bearing structure can also be used in the crankcase 110. In this case, the crankcase 110 uses a split clamping method to fix the main bearing on the bearing support surface (bearing seat). Figure 2The bearing shell is a left and right two-piece structure. The right bearing shell 1106' is placed on the main bearing seat body 1105, and then the crankshaft is placed on the right bearing shell 1106'. Then the left bearing shell 1106 and the right bearing shell 1106' are aligned and installed to surround the crankshaft. Finally, the bearing seat cover 1104 and the end shell part 1101 formed as one piece are installed on the main bearing seat body 1105 and the main shell part 1102 by bolts to support the bearing shell. Here, it should be noted that, in the side of the crankcase 110 along the axial direction X of the plunger pump, relative to the connection line between the left bearing 1106 and the right bearing 1106' or the connection line between the bearing seat cover 1104 and the main bearing seat body 1105, that is, the position of the crankshaft centerline, the position of the connection line between the end shell 1101 and the main housing part 1102 does not coincide with it and is separated from it by a certain distance, and is closer to the end of the crankcase 110 on the opposite side of the side connected to the crosshead housing 120. In other words, the split position between the end shell 1101 and the main housing part 1102 is located in the rear half of the entire crankcase 110 (after the split surface of the bearing), and the end shell 1101 only plays the role of oil and gas sealing to ensure that the crankshaft can be installed in the bearing seat through the split surface window. Here, the rear refers to the side of the crankcase 110 opposite to the side connected to the crosshead housing 120. A group of bolts 1107 oriented along the axial direction X of the plunger pump are provided at the connection between the end shell 1101 and the main housing 1102. The bolts 1107 are evenly arranged along the outer ring of the end shell 1101, and connect the end shell 1101 and the main housing 1102 together to clamp the two in the axial direction X of the plunger pump. The number of bolts 1107 is not limited, as long as the end shell 1101 and the main housing 1102 can be firmly connected together and avoid stress defects. In this case, a first threaded hole 1110 is provided on the outer ring of the end shell 1101, and a second threaded hole 1111 is provided on the outer ring of the main housing 1102. The positions of each first threaded hole 1110 and each second threaded hole 1111 correspond to each other, so that the bolts 1107 can simultaneously pass through the first threaded hole 1110 and the second threaded hole 1111 corresponding to each other, thereby connecting the end shell 1101 and the main housing 1102 together. In addition, a group of bolts 1108 oriented along the axial direction X of the plunger pump are also provided between the bearing seat cover 1104 and the main bearing seat body 1105. The bolts 1108 connect the bearing seat cover 1104 and the main bearing seat body 1105 together and clamp the two in the axial direction X of the plunger pump, and at the same time clamp and fix the crankshaft and the bearing shell to prevent the bearing seat cover 1104 from axially loosening, which will cause the lubrication clearance between the bearing shell and the main journal to change, resulting in abnormal oil film thickness and affecting the lubrication effect.In this case, two third threaded holes 1112 are provided on each bearing seat cover 1104, which are respectively arranged on the upper and lower sides along the central axis of the bearing seat cover 1104; and two fourth threaded holes 1113 are provided on each main bearing seat body 1105, which are respectively arranged on the upper and lower sides along the central axis of the main bearing seat body 1105, and the positions of the third threaded holes 1112 and the fourth threaded holes 1113 correspond to each other, so that the bolt 1108 can pass through the third threaded hole 1112 and the fourth threaded hole 1113 at the same time to firmly connect the bearing seat cover 1104 and the main bearing seat body 1105 together. In addition, as described above, the position of the connecting line between the end shell portion 1101 and the main housing portion 1102 does not coincide with the connecting line between the bearing seat cover 1104 and the main bearing seat body 1105 and is separated from it by a certain distance, and is closer to the end of the crankcase 110 on the opposite side of the side connected to the crosshead housing 120, that is, a portion of the bearing seat cover 1104 in the axial direction X of the plunger pump extends into the main housing portion 1102. In order to further clamp and fix the bearing seat cover 1104, another set of bolts 1109 is provided in the vertical direction Z of the crankcase 110, that is, in a direction perpendicular to the direction X and the direction Y. The bolts 1109 are arranged at positions corresponding to the bearing seat covers 1104 on both sides of the main housing 1102 in the vertical direction Z, that is, a pair of upper and lower (two) bolts 1109 are arranged correspondingly with respect to each bearing seat cover 1104, and the bolts 1109 are screwed into the outside of the main housing 1102 and clamped against both sides of the bearing seat cover 1104, further preventing the bearing seat cover 1104 from sliding longitudinally and cutting off the oil film, resulting in eccentric wear of the bearing shell. The bearing seat cover 1104 is clamped in the vertical direction Z, which further improves the clamping strength of the bearing seat cover 1104 compared with clamping only in the axial direction X of the plunger pump. On the other hand, when the end shell portion 1101 and the bearing seat cover 1104 are integrally formed, for example, integrally cast, the bolt 1109 can clamp the bearing seat cover 1104 which is part of the integrally formed or integrally cast part, thereby making the connection between the entire part including the end shell portion 1101 and the bearing seat cover 1104 and the main housing portion 1102 more secure, thereby further preventing axial separation of the end shell portion 1101 and the main housing portion 1102.

[0029] On the premise that the bearing bush manufacturing precision meets the requirements, the use of bearing bushes instead of cylindrical roller bearings can greatly reduce the overall size and weight, and reduce costs. In addition, the split structure of the crankcase can reduce the difficulty of assembly to a certain extent. The bearing bush is small in size and does not need to be hoisted. It can be directly placed on the corresponding bearing seat and pressed, reducing the number of hoisting times of the housing and crankshaft and improving assembly efficiency.

[0030] Refer to the following Figure 3 and Figure 4A comparison will be made between the integral crankcase and the split crankcase according to an embodiment of the present invention.

[0031] In the case of an integral crankcase, a disc-type crankshaft is required. Considering the manufacturing accuracy and cost of rolling bearings and sliding bearings as well as the standardized selection on the market, roller bearings are usually selected for disc-type crankshafts. Figure 3 As shown. In the integral crankcase, the crankshaft needs to extend from the bearing seat hole on one side of the crankcase along the Y direction, and penetrate the entire crankcase until each main journal reaches the corresponding bearing seat. Therefore, in order to facilitate the installation of the crankshaft, it is necessary to ensure that the main journal diameter is the largest part of the entire crankshaft, and coordinate the position and size of each connecting rod journal, resulting in a very large main journal diameter. Therefore, the size of the bearing supporting the rotation of the shaft is very large.

[0032] On the other hand, in the case of the above-mentioned split crankcase 110 according to an embodiment of the present invention, as described above, the end shell 1101 and the main shell 1102 are detachably connected. In this case, the end shell 1101 can be removed first, and the crankshaft can be installed into the corresponding bearing position in the crankcase 110 from the side where the end shell 1101 is located. In this case, it is not necessary to require the main journal diameter to be the largest part of the entire crankshaft. In order to adapt to the small-sized main journal and the split crankcase, a bearing (sliding bearing) is used to ensure the rotation of the crankshaft, which can greatly reduce the size of the entire case.

[0033] According to one embodiment of the present application, a portion of the crankcase 110 is integrally formed with the crosshead housing 120, especially integrally cast, so there is no sealing surface between the two and no weld or mechanical connection such as bolts, so the strength between the crankcase 110 and the crosshead housing 120 is greatly improved, and the problem of the sealing surface between the crankcase and the crosshead housing 120 being disengaged and slipped due to the plunger force and the lateral force of the connecting rod is fundamentally solved, and there will be no failure of connection and sealing. Although this structure still has bolt connections such as the bolt connection between the end shell part 1101 and the main shell part 1102 in the axial direction X of the plunger pump, since the position of the bolt connection is at the rear of the crankcase 100 as mentioned above, the force at this position is much lighter than the force at the connection surface between the crankcase 110 and the crosshead housing 120, so even if the bolt connection is used here, the overall service life of the power end housing is also very small, and it is convenient for the installation of internal components. In addition, this structure can more easily ensure the position of the connecting rod, crosshead, and tie rod, and avoid the eccentric wear of the crosshead bearing and packing due to improper assembly of the crosshead box and slippage of the contact surface. In addition, this structure can flexibly increase the wall thickness of the connection between the crankcase and the crosshead, improve the connection strength and support stiffness, and then omit a row of legs at the front end of the crankcase, simplifying the fulcrum arrangement.

[0034] On the other hand, from the perspective of production management, the above structure saves multiple connecting bolts, sealing components and locating pins on the contact surface between the crankcase 110 and the crosshead case 120, greatly reducing the number of parts and reducing the difficulty of assembly, management and maintenance. From the perspective of machining, the rough and fine machining of the contact surface between the crankcase and the crosshead case and the forming of the bolt holes and sealing grooves on the surface are eliminated, and there is no need for precision-machined locating pin holes to ensure the coaxiality of the crosshead and the pull rod, which greatly reduces the machining process and reduces the time and labor costs brought by machining and assembly.

[0035] According to another embodiment of the present application, Figure 5 As shown, the crankcase 110 and the crosshead case 120 may be formed in an integral manner, such as integral casting, to form an integral power end housing 100 ′ for a plunger pump.

[0036] The design of the crankcase is rounded to reduce stress concentration and give full play to the advantages of casting. The connection between the crankcase and the crosshead case adopts a large arc transition to increase the rigidity and avoid stress concentration. The support point is designed in the middle of the crankcase, and the design of increasing the area of ​​the bottom support increases the contact area between the whole equipment and the ground, which improves the stability of the overall structure. The front side of the crosshead case is supported by a spacer, and the double-sided support ensures the balance of the shell.

[0037] The above embodiments of the present application focus on describing the differences between the various embodiments. As long as the different optimization features between the various embodiments are not contradictory, they can be combined to form a better embodiment. Considering the simplicity of the text, they will not be repeated here.

[0038] The above is only an embodiment of the present application and is not intended to limit the present application. For those skilled in the art, the present application may have various changes and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application should be included in the scope of the claims of the present application.

Claims

1. A power end housing (100) for a plunger pump, characterized in that: The power end housing (100) comprises a crankcase (110) for accommodating a crankshaft and a crosshead housing (120) for accommodating a crosshead, the crankcase (110) comprising an end housing portion (1101), a main housing portion (1102) and a plurality of bearing seats, each of the bearing seats comprising a bearing seat cover (1104) and a main bearing seat body (1105), the main housing portion (1102) and the crosshead housing (120) being integrally formed, the end housing portion (1101) and the main housing portion (1102) being detachably connected, and the bearing seat cover (1104) and the main bearing seat body (1105) being detachably connected.

2. The power end housing (100) according to claim 1, characterized in that: The end shell portion (1101) and the main shell portion (1102) as well as the bearing seat cover (1104) and the main bearing seat body (1105) can be detachably connected by bolts.

3. The power end housing (100) according to claim 2, characterized in that: The bolts include a first group of bolts (1107), which are arranged in a manner oriented along the axial direction (X) of the plunger pump and connect the end shell part (1101) and the main shell part (1102) together.

4. The power end housing (100) according to claim 2, characterized in that: The bolts include a second group of bolts (1108), which are arranged in a manner oriented along the axial direction (X) of the plunger pump and connect the bearing seat cover (1104) and the main bearing seat body (1105) together.

5. The power end housing (100) according to claim 3, characterized in that: The bolts include a third group of bolts (1109), which are arranged at positions corresponding to the bearing seat cover (1104) on both sides of the main housing part (1102) in the vertical direction (Z) and are screwed into and passed through the main housing part (1102) from the outside of the main housing part (1102) along the vertical direction (Z), so that the third group of bolts (1109) support both sides of the bearing seat cover (1104) in the vertical direction (Z).

6. The power end housing (100) according to claim 1, characterized in that: The bearing seat cover (1104) and the end shell portion (1101) can be integrally formed.

7. The power end housing (100) according to claim 1, characterized in that: Also included are bearing shells (1106, 1106').

8. The power end housing (100) according to claim 1, characterized in that: When viewed from the side along the axial direction (X) of the plunger pump, the connection line between the end shell portion (1101) and the main shell portion (1102) is closer to the rear end of the crankcase (110) away from the crosshead case (120) than the connection line between the bearing seat cover (1104) and the main bearing seat body (1105).

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