Plunger pump

Abstract

The utility model discloses a plunger pump and belongs to the technical field of oil and gas exploitation, the plunger pump comprises a crankshaft, a crosshead and a connecting rod, the connecting rod is a cracking type connecting rod, the connecting rod comprises a connecting rod body and a connecting rod cover, the connecting rod body and the connecting rod cover are detachably and fixedly connected and define a connecting rod hole, the crankshaft is assembled in the connecting rod hole, and the crosshead is connected with the connecting rod body. And the crosshead is connected with one end, deviating from the connecting rod cover, of the connecting rod body. According to the plunger pump disclosed by the embodiment of the invention, the contact surfaces between the connecting rod cover and the connecting rod body in the connecting rod are relatively matched, so that the stresses at different positions of the contact surfaces between the connecting rod body and the connecting rod cover are basically equivalent, and the upper bearing limit of the connecting rod can be greatly improved.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of oil and gas exploitation, and particularly relates to a plunger pump. BACKGROUND

[0002] In the process of oil and gas exploitation, the working pressure of the plunger pump used to provide fracturing operation is higher and higher, which makes the rod load of the connecting rod increase accordingly. Generally, the connecting rod in the plunger pump is processed at the big end position of the connecting rod by wire cutting to divide the connecting rod into two parts of a connecting rod body and a connecting rod cover. Then, the opposite end faces of the connecting rod body and the connecting rod cover are processed flat, and the connecting rod body and the connecting rod cover are fastened together by bolts to make the connecting rod body and the connecting rod cover as close as possible.

[0003] However, based on the current technology, although the surface of the workpiece after cutting looks flat and smooth, there are still many small concave-convex structures on the cutting surface after magnification of a certain multiple, which will cause the stress at different positions of the contact surface between the connecting rod body and the connecting rod cover to be uneven, which greatly limits the carrying capacity of the connecting rod, thereby causing the upper limit of the carrying capacity of the connecting rod in the current plunger pump to be unable to meet the demand. CONTENT OF THE UTILITY MODEL

[0004] The purpose of the embodiment of the application is to provide a plunger pump, in which the contact surface between the connecting rod cover and the connecting rod body in the connecting rod is relatively close, so that the stress at different positions of the contact surface between the connecting rod body and the connecting rod cover is basically equivalent, thereby the upper limit of the carrying capacity of the connecting rod can be greatly improved.

[0005] The embodiment of the application discloses a plunger pump, which comprises a crankshaft, a cross head and a connecting rod, wherein the connecting rod is a broken type connecting rod, and the connecting rod comprises a connecting rod body and a connecting rod cover, the connecting rod body and the connecting rod cover are detachably fixedly connected and surround a connecting rod hole, the crankshaft is assembled in the connecting rod hole, and the cross head is connected with one end of the connecting rod body away from the connecting rod cover.

[0006] The embodiment of the present application discloses a plunger pump, the connecting rod of which comprises a connecting rod body and a connecting rod cover which are detachably fixedly connected, the connecting rod body and the connecting rod cover surround a connecting rod hole, and a crankshaft can be assembled in the connecting rod hole. The connecting rod body and the connecting rod cover are connected at one end away from the connecting rod cover, so that the cross head can be indirectly connected with the crankshaft, the power end connected with the crankshaft can transmit driving force to the cross head, and finally to the liquid end, thereby completing the delivery of liquid. Meanwhile, in the embodiment of the present application, the connecting rod is a split connecting rod, which is more efficient and relatively lower in cost. In the plunger pump disclosed in the present application, the split surface between the connecting rod body and the connecting rod cover is naturally formed, so that the gap between the connecting rod body and the connecting rod cover after reassembly is more compact, thereby reducing the machining process and cost, and the connecting rod body and the connecting rod cover can form a limiting action in the direction of the reassembly direction, which can ensure that the stress uniformity of the contact surface between the connecting rod body and the connecting rod cover is relatively high, thereby ensuring high reliability of the connecting rod and improving the load bearing performance of the connecting rod. In addition, the traditional positioning structure between the connecting rod body and the connecting rod cover is not needed, which makes the positioning between the connecting rod body and the connecting rod cover more simple and reliable.

[0007] In addition, the plunger pump disclosed in the embodiment of the present application, the split surface between each connecting rod body and connecting rod cover is unique and corresponding, so that each corresponding connecting rod body and connecting rod cover can be matched one by one during assembly, thereby avoiding the risk of mixed assembly of the connecting rod cover and the connecting rod body, and further reducing the assembly difficulty between the connecting rod cover and the connecting rod body. BRIEF DESCRIPTION OF DRAWINGS

[0008] The drawings described herein are used to provide further understanding of the present application, and form a part of the present application. The schematic embodiments of the present application and the description thereof are used to explain the present application, and do not constitute an improper limitation on the present application. In the drawings:

[0009] Figure 1 It is a structural schematic view of the plunger pump disclosed in the embodiment of the present application;

[0010] Figure 2 It is Figure 1 It is a sectional view of the plunger pump;

[0011] Figure 3 It is a machining schematic view of the connecting rod in the plunger pump disclosed in the embodiment of the present application;

[0012] Figure 4 It is a structural schematic view of the connecting rod disclosed in the embodiment of the present application;

[0013] Figure 5 An enlarged schematic view of the fracture section between the connecting rod body and the connecting rod cover disclosed by the embodiments of the present application;

[0014] Figure 6 An exploded schematic view of the connecting rod, the first bearing bush and the second bearing bush in the plunger pump disclosed by the embodiments of the present application.

[0015] Reference signs:

[0016] 1 - power end, 2 - fluid end, 3 - speed reduction mechanism, 4 - lubrication mechanism, 5 - threaded connecting piece, 6 - crankshaft, 7 - connecting rod, 71 - connecting rod body, 72 - fracture surface, 73 - connecting rod cover, 74 - prefabricated groove, 8 - crosshead, 9 - first bearing bush, 91 - first modified region, 10 - second bearing bush, 101 - second modified region, 20 - fracture equipment. DETAILED DESCRIPTION

[0017] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are some of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work fall within the scope of protection of the present application.

[0018] The terms "first", "second", and the like in the specification and claims of the present application are used to distinguish similar objects, and are not used to describe a specific order or sequence. It should be understood that the data used in this way can be interchanged under appropriate circumstances, so that the embodiments of the present application can be implemented in an order other than those illustrated or described herein, and the objects distinguished by "first", "second", etc. are generally a category, and are not limited to the number of objects, for example, the first object can be one or more. In addition, "and / or" in the specification and claims indicates at least one of the connected objects, and the character " / ", generally indicates that the front and rear associated objects are in an "or" relationship.

[0019] As Figures 1-6 shown, the embodiments of the present application disclose a plunger pump, which comprises a crankshaft 6, a crosshead 8 and a connecting rod 7, of course, the plunger pump also comprises a power end 1 and a fluid end 2, and the power end 1 is connected with the crankshaft 6 to transmit driving force to the fluid end 2 through the crankshaft 6, and the fluid end 2 is connected with the crosshead 8 to receive the driving force generated by the power end 1 through the crosshead 8. In addition, the plunger pump can also comprise a speed reduction mechanism 3 and a lubrication mechanism 4, the power end 1 is connected with the crankshaft 6 through the speed reduction mechanism 3, and the lubrication mechanism 4 is used to provide lubrication for the moving parts in the plunger pump.

[0020] Of course, the force transmission relationship also exists between the crankshaft 6 and the crosshead 8, specifically, the crankshaft 6 and the crosshead 8 are connected through the connecting rod 7, and the rotating motion of the crankshaft 6 is converted into the linear reciprocating motion of the crosshead 8. In detail, as shown in Figure 1 and Figure 2 , the connecting rod 7 includes a connecting rod body 71 and a connecting rod cover 73, and the connecting rod body 71 and the connecting rod cover 73 are detachably fixedly connected, wherein the connecting rod body 71 and the connecting rod cover 73 enclose a connecting rod hole, and the crankshaft 6 can be assembled in the connecting rod hole, so that the crankshaft 6 and the connecting rod 7 form an assembly relationship; at the same time, the crosshead 8 is connected to one end of the connecting rod 7 away from the connecting rod cover 73, so that the crosshead 8 can indirectly form a connection relationship with the crankshaft 6 through the connecting rod 7, so that the crosshead 8 can be driven to perform linear reciprocating motion during the rotating motion of the crankshaft 6 driven by the power end 1.

[0021] Specifically, the connecting rod cover 73 and the connecting rod body 71 can be detachably fixedly connected through bolts and the like, and during the assembly of the connecting rod 7 and the crankshaft 6, the connecting rod cover 73 and the connecting rod body 71 are sleeved outside the crankshaft 6, so that the connecting rod 7 and the crankshaft 6 form a reliable assembly relationship. Similarly, one end of the connecting rod body 71 away from the connecting rod cover 73 can also be provided with a through hole, and the crosshead 8 can be connected with the connecting rod body 71 through a gland and the like by using bolts and the like.

[0022] In order to ensure the reliability of the fixed relationship between the connecting rod cover 73 and the connecting rod body 71, more specifically, as shown in Figure 4 and Figure 6 , a plurality of mounting holes can be provided on the connecting rod cover 73, and a plurality of assembly holes can be provided on the connecting rod body 71, by making a plurality of threaded connecting pieces 5 pass through the plurality of mounting holes one by one and extend into the corresponding assembly holes, to fixedly connect the connecting rod cover 73 and the connecting rod body 71. That is, each threaded connecting piece 5 is provided in a corresponding mounting hole and extends into a corresponding assembly hole to achieve the purpose of fixedly connecting the connecting rod cover 73 and the connecting rod body 71. Alternatively, the number of threaded connecting pieces 5 is four or six, etc. Of course, the more the number of threaded connecting pieces 5 is not the better, in one specific embodiment of the present application, the number of threaded connecting pieces 5 is 4, and the four threaded connecting pieces 5 are arranged in two groups and symmetrically arranged, so as to ensure that the connecting rod body 71 and the connecting rod cover 73 can form a reliable assembly relationship, while minimizing the weakening effect on the structural strength of the connecting rod body 71 and the connecting rod cover 73 due to the provision of the mounting holes and the assembly holes.

[0023] It should be noted that in the embodiments of the present application, the connecting rod 7 is a split connecting rod 7. That is, the connecting rod 7 disclosed in the embodiments of the present application is formed by split processing, so that the originally integral connecting rod body 71 and the connecting rod cover 73 are processed into a split structure. In more detail, in the embodiments of the present application, the connecting rod 7 can be formed by forging or the like, and has a connecting rod hole which is a non-fractured annular closed structure. Then, the split device 20 can be installed in the connecting rod hole, and under the action of the extrusion force, the connecting rod 7 is naturally fractured into two parts, one part is the connecting rod body 71, and the other part is the connecting rod cover 73, both the connecting rod body 71 and the connecting rod cover 73 have part of the hole wall of the connecting rod hole, and as shown in Figure 5 , the fracture surfaces 72 of the two enclose each other, and the complete connecting rod hole can be reformed, but it should be noted that after splitting, the connecting rod hole is not a fractured structure, the inner wall has two fracture gaps, but the aforementioned gaps are relatively small, and since the connecting rod body 71 and the connecting rod cover 73 are a split structure formed by natural fracture, after splicing, the gap between the connecting rod body 71 and the connecting rod cover 73 can be completely corresponding and complementary.

[0024] The embodiments of the present application disclose a plunger pump, the connecting rod 7 includes a connecting rod body 71 and a connecting rod cover 73 which are detachably fixedly connected, the two enclose a connecting rod hole, and the crankshaft 6 can be assembled in the connecting rod hole, by connecting the cross head 8 with one end of the connecting rod body 71 away from the connecting rod cover 73, the cross head 8 can form an indirect connection relationship with the crankshaft 6, so that the power end 1 connected with the crankshaft 6 can transmit driving force to the cross head 8, and finally to the fluid end 2, to complete the delivery work of the liquid. At the same time, in the embodiments of the present application, the connecting rod 7 is a split connecting rod 7, which has higher processing efficiency and relatively lower cost, and in the plunger pump disclosed in the present application, since the connecting rod 7 is processed by the split process, the fracture surface 72 between the connecting rod body 71 and the connecting rod cover 73 is a naturally formed structure, so that the gap between the connecting rod body 71 and the connecting rod cover 73 after re-splicing is more compact, thereby eliminating the need for additional grinding or other processing of the fracture surface, reducing the processing procedures and costs, and in the direction around the splicing direction of the connecting rod body 71 and the connecting rod cover 73, the corresponding connecting rod body 71 and the connecting rod cover 73 can form a limiting action, on the one hand, the uniformity of the stress at any position of the contact surface between the connecting rod cover 73 and the connecting rod body 71 is relatively high, thereby under long-term impact load, the reliability of the connecting rod 7 is relatively high, the load-bearing performance of the connecting rod 7 is improved, and on the other hand, in the case of using the technical solution disclosed in the embodiments of the present application, there is no need to provide a traditional positioning structure between the connecting rod cover 73 and the connecting rod body 71, which makes the positioning mode between the connecting rod cover 73 and the connecting rod body 71 more simple and reliable.

[0025] In addition, the plunger pump disclosed in the embodiments of the present application can ensure that each corresponding connecting rod body 71 and connecting rod cover 73 can be matched with each other one by one, thereby avoiding the risk of mixed assembly of the connecting rod cover 73 and the connecting rod body 71, and further reducing the assembly difficulty between the connecting rod cover 73 and the connecting rod body 71.

[0026] As described above, the connecting rod 7 disclosed in the embodiments of the present application is processed by the breaking process. Optionally, after the connecting rod 7 is formed by casting or other processes, the breaking device 20 can be directly installed in the connecting rod hole, and the breaking force is applied to the connecting rod 7 to break the connecting rod 7. In order to improve the yield of the connecting rod 7 processed into the connecting rod cover 73 and the connecting rod body 71, in another embodiment of the present application, the end surface of the connecting rod body 71 towards the connecting rod cover 73 can include a first breaking surface and a first pre-preparation groove surface, and the end surface of the connecting rod cover 73 towards the connecting rod body 71 can include a second breaking surface and a second pre-preparation groove surface. The first pre-preparation groove surface is located outside the first breaking surface, the second pre-preparation groove surface is located outside the second breaking surface, the first pre-preparation groove surface and the second pre-preparation groove surface are arranged opposite and spaced apart, and the first breaking surface and the second breaking surface are arranged opposite and matched.

[0027] That is, in the embodiments of the present application, the pre-preparation groove 74 can be formed on the connecting rod 7 first. The pre-preparation groove 74 extends inward from the outer surface of the connecting rod 7, and the extension size (i.e. the depth of the pre-preparation groove 74) can be selected flexibly according to actual conditions, but generally, the depth of the pre-preparation groove 74 is relatively small to prevent the existence of the pre-preparation groove 74 from having a greater adverse effect on the tightness of the cooperation between the connecting rod cover 73 and the connecting rod body 71. After the pre-preparation groove 74 is formed on the connecting rod 7, the breaking device 20 is installed in the connecting rod hole to apply the extrusion force to the connecting rod 7 by the breaking device 20 to break the connecting rod 7 into the connecting rod body 71 and the connecting rod cover 73. In this case, the pre-preparation groove 74 can provide a pre-breaking effect, so that the bonding strength at the position of the pre-preparation groove 74 in the connecting rod 7 is slightly smaller than the bonding strength at other positions in the connecting rod body 71, which can greatly improve the yield of the connecting rod body 71 and the connecting rod cover 73 formed after the breaking process of the connecting rod 7.

[0028] As described above, essentially, before the connecting rod 7 is processed into the connecting rod body 71 and the connecting rod cover 73, the first preformed groove surface and the second preformed groove surface are side walls of the preformed groove 74 on the connecting rod 7, and part of the bottom wall of the two is located on the connecting rod body 71 and the other part is located on the connecting rod cover 73, and correspondingly, the first fracture surface and the second fracture surface are fracture surfaces formed after the connecting rod 7 is fractured, and therefore, after the connecting rod 7 is formed into the connecting rod body 71 and the connecting rod cover 73, the first preformed groove surface is located on the outside of the first fracture surface, and the second preformed groove surface is located on the outside of the second fracture surface, wherein the first preformed groove surface is opposite and spaced apart from the second preformed groove surface, the first fracture surface and the second fracture surface can be reassembled and tightly fit, that is, they are opposite and fit.

[0029] Optionally, in the embodiment of the present application, the above-mentioned preformed groove 74 can be formed only on one side or several sides of the connecting rod 7, and can be spaced apart between adjacent preformed grooves 74. In this case, part of the first fracture surface is located on the inside of the first preformed groove surface, and the first fracture surface includes other parts and is flush with the first preformed groove surface. Correspondingly, part of the second fracture surface is located on the inside of the second preformed groove surface, and the second fracture surface includes other parts and is flush with the second preformed groove surface.

[0030] In order to further improve the yield of the connecting rod body 71 and the connecting rod cover 73, and reduce the processing difficulty of the preformed groove 74, and improve the regularity of the connecting rod body 71 and the connecting rod cover 73, in another embodiment of the present application, the first preformed groove surface and the second preformed groove surface can also be closed loop structures, and the first preformed groove surface is arranged around the outer periphery of the first fracture surface, and the second preformed groove surface is arranged around the outer periphery of the second fracture surface. That is, in the embodiment of the present application, before the fracture process, the preformed groove 74 can be processed and formed on the connecting rod 7, and the preformed groove 74 formed by processing is a closed loop structure. Intuitively, the preformed groove 74 is arranged around the outer surface of the connecting rod 7. In this case, the overall processing difficulty of the preformed groove 74 can be reduced, and the position of the preformed groove 74 in the connecting rod 7 has a pre-fracture effect during the fracture process of the connecting rod 7, thereby further reducing the fracture difficulty and improving the yield of the fracture process.

[0031] Optionally, the preformed groove 74 is formed by machining cutting, and in another embodiment of the present application, laser cutting can also be used to form, so as to reduce the degree of deformation of the connecting rod 7 caused in the process of forming the preformed groove 74, and also can make the width of the preformed groove 74 relatively small, that is, the spacing between the first preformed groove surface and the second preformed groove surface is relatively small. Therefore, in the embodiment of the present application, the first preformed groove surface and the second preformed groove surface are formed by laser cutting.

[0032] Generally, the connecting rod 7 is formed of metal material such as steel, and in order to reduce the plastic deformation of the connecting rod 7 during the fracture process, in the embodiment of the present application, the connecting rod body 71 and the connecting rod cover 73 are formed of medium carbon non-quenched and tempered steel, in other words, the connecting rod 7 before being processed into the connecting rod body 71 and the connecting rod cover 73 is formed of medium carbon non-quenched and tempered steel. More specifically, 36MnVS4, 38MnVS6, 46MnVS6, 70MnVS4, KNF33MAM and the like can be used. In this case, the connecting rod 7 bears relatively larger load and has excellent cutting performance and easy-to-process performance.

[0033] As described above, the plunger pump includes the lubricating mechanism 4 which can provide lubricating material such as lubricating grease between the devices with relative motion in the plunger pump. Also, in the plunger pump, the crankshaft 6 is installed in the connecting rod hole of the connecting rod 7, which makes the mating surfaces between the crankshaft 6 and the hole wall of the connecting rod hole, in order to prevent the mating surfaces from rubbing against each other, the plunger pump disclosed in the embodiment of the present application includes the first bearing 9 which is formed of metal material and is clamped between the inner wall of the connecting rod hole and the crankshaft 6 to reduce the wear of the crankshaft 6 and the connecting rod 7 and ensure that the service life of the two is relatively longer. Specifically, as shown in Figure 6 the first bearing 9 is generally a circular ring structure which is sleeved outside the crankshaft 6 and embedded in the inner side of the connecting rod hole, lubricating material such as lubricating grease can be filled between the crankshaft 6 and the first bearing 9 and between the first bearing 9 and the connecting rod hole, thereby providing lubrication for the relative motion between the crankshaft 6 and the connecting rod 7 and forming an oil film with stable and good load-carrying effect to achieve the purpose of liquid lubrication.

[0034] In which, for the crankshaft 6 and the connecting rod 7, the wear of the outer surface of the crankshaft 6 is generally relatively common, for this reason, in one specific embodiment of the present application, the first modified region can be provided on the outer surface of the crankshaft 6, thereby increasing the gap between the corresponding region between the first modified region of the crankshaft 6 and the first bearing 9 to reduce the probability of friction between the two and further reduce the wear degree of the crankshaft 6 and the first bearing 9. In another embodiment of the present application, the first modified region 91 can also be provided on the inner surface of the first bearing 9, which can also increase the gap between the first modified region of the first bearing 9 and the corresponding region on the crankshaft 6. In still another embodiment of the present application, the first modified region can also be formed at the corresponding positions on the outer surface of the crankshaft 6 and the inner surface of the first bearing 9, thereby ensuring that the gap between the corresponding first modified regions of the crankshaft 6 and the first bearing 9 is relatively large.

[0035] More specifically, the first modified region is a structure formed after removing part of the original structure on the crankshaft 6 and / or the first bearing bush 9 by cutting or grinding, which essentially belongs to reducing the thickness dimension of the corresponding position on the crankshaft 6 and / or the first bearing bush 9, so that the distance between the positions with the first modified region is increased after the assembly of the crankshaft 6 and the first bearing bush 9 is completed. Of course, the number or area of the first modified region formed on the crankshaft 6 and / or the first bearing bush 9 is not limited herein, and in the actual processing process, the position and coverage area of the first modified region, as well as the surface type of the first modified region, etc. can be flexibly determined according to the specific circumstances, which will not be described in detail herein.

[0036] Similarly, in order to reduce the wear degree between the end of the connecting rod body 71 away from the connecting rod cover 73 and the crosshead 8, and to improve the service life of the connecting rod 7 and the crosshead 8, in the embodiment of the present application, the plunger pump can also include a second bearing bush 10, which is formed of a metal material, and is clamped between the outer surface of the end of the connecting rod body 71 away from the connecting rod cover 73 and the crosshead 8. Of course, since the second bearing bush 10 cooperates with the crosshead 8, the second bearing bush 10 is usually an arc-shaped plate structure, which is sleeved outside the end of the connecting rod body 71 away from the connecting rod cover 73, and is embedded between the connecting rod 7 and the crosshead 8. Similarly, lubricating materials such as grease can be filled between the connecting rod 7 and the second bearing bush 10, and between the second bearing bush 10 and the crosshead 8, so as to provide lubrication for the relative movement between the crosshead 8 and the connecting rod 7, and to form an oil film with stable and good load-carrying effect, achieving the purpose of liquid lubrication.

[0037] Among them, for the crosshead 8 and the connecting rod 7, the wear of the outer surface of the connecting rod 7 is usually relatively common, and therefore, in one specific embodiment of the present application, a second modified region can be provided on the surface of the connecting rod body 71 towards the second bearing bush 10, so as to increase the gap between the second modified region of the connecting rod body 71 and the corresponding region of the second bearing bush 10, so as to reduce the friction probability between them, and further reduce the wear degree of the connecting rod body 71 and the second bearing bush 10. In another embodiment of the present application, a second modified region 101 can also be provided on the surface of the second bearing bush 10 towards the connecting rod body 71, which can also increase the gap between the second modified region of the second bearing bush 10 and the corresponding region of the connecting rod body 71. In still another embodiment of the present application, a second modified region can also be formed at the corresponding positions on the surface of the connecting rod body 71 towards the second bearing bush 10 and the surface of the second bearing bush 10 towards the connecting rod body 71, so as to ensure that the gap between the corresponding second modified regions of the connecting rod body 71 and the second bearing bush 10 is relatively large.

[0038] Similarly, the second modified region is also formed by cutting or grinding, and the number or area of the second modified region formed on the connecting rod body 71 and / or the second bearing bush 10 is not limited herein, and in the actual processing process, the position and coverage area of the second modified region, as well as the surface type of the second modified region, can be flexibly determined according to the specific circumstances, and details are not described herein.

[0039] As described above, in the plunger pump disclosed in the embodiments of the present application, the first modified region and the second modified region are provided, so that the profiles of the crankshaft 6 and / or the first bearing bush 9, and the connecting rod body 71 and / or the second bearing bush 10 can be adaptively modified, the cooperation between the crankshaft 6 and the first bearing bush 9, and the cooperation between the connecting rod body 71 and the second bearing bush 10 are improved, so as to better adapt to the working environment and stress condition of the connecting rod 7 and the crankshaft 6, effectively reduce the wear of the connecting rod 7, the crankshaft 6, the first bearing bush 9 and the second bearing bush 10, prolong the service life of the plunger pump, improve the carrying capacity of the connecting rod 7, and also can greatly reduce the degree of performance decline of the plunger pump and the probability of accidents such as bearing bush burning caused by wear, effectively improve the lubrication effect at the first bearing bush 9 and the second bearing bush 10 of the plunger pump, and improve the overall performance and reliability of the plunger pump.

[0040] It should be noted that in this document, the terms "comprise", "comprising", or any other variant thereof are intended to cover non-exclusive inclusions, so that a process, method, article, or device that includes a series of elements not only includes those elements, but also includes other elements not explicitly listed, or inherent to such a process, method, article, or device. Without more limitations, the element defined by the statement "comprising a" does not exclude the presence of another identical element in the process, method, article, or device that includes the element. In addition, it should be pointed out that the scope of the methods and devices in the embodiments of the present application is not limited to the order of performing the functions shown or discussed, but can also include performing the functions in a substantially simultaneous manner or in reverse order, for example, the described method can be performed in an order different from that described, and various steps can also be added, omitted, or combined. In addition, the features described with reference to certain examples can be combined in other examples.

[0041] The embodiments of the present application are described above in combination with the drawings, but the present application is not limited to the above specific embodiments, and the above specific embodiments are only illustrative, not limiting, and those skilled in the art can make many forms under the inspiration of the present application without departing from the scope of the present application and the scope protected by the claims.

Claims

1. A piston pump characterized in that, The connecting rod comprises a crankshaft, a crosshead and a connecting rod, wherein the connecting rod is a broken connecting rod, and the connecting rod comprises a connecting rod body and a connecting rod cover, the connecting rod body and the connecting rod cover are detachably fixedly connected and surround a connecting rod hole, the crankshaft is assembled in the connecting rod hole, and the crosshead is connected to one end of the connecting rod body away from the connecting rod cover.

2. The piston pump of claim 1, wherein, The end surface of the connecting rod body towards the connecting rod cover comprises a first fracture surface and a first pre-prepared groove surface, the end surface of the connecting rod cover towards the connecting rod body comprises a second fracture surface and a second pre-prepared groove surface, the first pre-prepared groove surface is located outside the first fracture surface, the second pre-prepared groove surface is located outside the second fracture surface, the first pre-prepared groove surface and the second pre-prepared groove surface are oppositely and spacedly arranged, and the first fracture surface and the second fracture surface are oppositely and fittingly arranged.

3. The piston pump of claim 2, wherein, The first pre-prepared groove surface and the second pre-prepared groove surface are both closed loop structures, and the first pre-prepared groove surface is arranged around the outer periphery of the first fracture surface, and the second pre-prepared groove surface is arranged around the outer periphery of the second fracture surface.

4. The piston pump of claim 2, wherein, The first pre-prepared groove surface and the second pre-prepared groove surface are formed by laser cutting.

5. The piston pump of claim 1, wherein, The connecting rod body and the connecting rod cover are both formed by medium carbon non-quenched and tempered steel.

6. The piston pump of claim 1, wherein, The connecting rod cover is provided with a plurality of mounting holes, and the connecting rod body is provided with a plurality of assembly holes, a plurality of the threaded connectors pass through the mounting holes one by one and extend into the corresponding mounting holes to fixedly connect the connecting rod cover and the connecting rod body.

7. The piston pump of claim 1, wherein, The connecting rod comprises a first bearing, which is clamped between the inner wall of the connecting rod hole and the crankshaft.

8. The piston pump of claim 7, wherein, The outer surface of the crankshaft and / or the inner surface of the first bearing is provided with a first modified area.

9. The piston pump of claim 1, wherein, The connecting rod comprises a second bearing, which is clamped between the outer surface of one end of the connecting rod body away from the connecting rod cover and the crosshead.

10. The piston pump of claim 9, wherein, The surface of the connecting rod body towards the second bearing and / or the surface of the second bearing towards the connecting rod body is provided with a second modified area.

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