Liquid nitrogen pump power end assembly

Abstract

A liquid nitrogen pump power end assembly relates to the technical field of liquid nitrogen pumps and comprises a crankshaft box body, a crankshaft, a connecting rod and a crosshead assembly. A plurality of wallboards are arranged in the crankshaft box body, crankshaft bearing seats are mounted on the wallboards, a plurality of reinforcing ribs are fixedly arranged between the crankshaft bearing seats and the wallboards, and the crankshaft is rotationally mounted in the crankshaft bearing seats through crankshaft bearings; the crankshaft comprises a straight shaft and an eccentric wheel, the straight shaft penetrates through the crankshaft bearing seat, and the eccentric wheel is mounted on the straight shaft and connected with the connecting rod; the crosshead assembly comprises a crosshead, the inner end of the crosshead is connected with the connecting rod, the outer end of the crosshead is arranged as a mounting end, and a clamping assembly is mounted at the mounting end; the clamping assembly comprises two oppositely-arranged clamping hook pieces, and the distance between the two clamping hook pieces is adjustable in the radial direction of the installation end. The mechanical strength of the crankcase body can be improved, and the gradually-increased operation pressure in China can be met; and the device can be connected with fluid ends of various models, and the installation application range is expanded.

Description

Technical Field

[0001] This utility model relates to the field of liquid nitrogen pump technology, and in particular to the power end assembly of a liquid nitrogen pump. Background Technology

[0002] Currently, conventional liquid nitrogen pumps, as core equipment for fluid pressurization, generally operate at pressures below 16.5 MPa, significantly limiting their application range. This equipment employs a typical reciprocating pump principle: an external power source drives a crankshaft-connecting rod mechanism, converting rotary motion into reciprocating linear motion of the crosshead and plunger assembly, achieving a cyclical process of low-pressure intake and high-pressure discharge of the medium. However, as my country's oilfield fracturing technology develops towards ultra-high pressure, the required operating pressure has jumped to the 40-100 MPa range, while the crankshaft speed has simultaneously increased to the 600-900 rpm operating range. This presents a dual challenge to the power system: firstly, the load on the transmission mechanism increases exponentially, requiring the power end housing to withstand significantly increased mechanical stress; secondly, the frictional power consumption of the moving parts rises sharply, posing a severe thermal balance test to traditional lubrication and cooling systems.

[0003] Meanwhile, the hydraulic end assembly, which is a high-pressure vulnerable component, comes in a variety of models. Traditional liquid nitrogen pump power end assemblies cannot be connected to hydraulic end assemblies of different models and specifications, resulting in a limited range of applications and increased production costs. Utility Model Content

[0004] In view of this, the technical problem to be solved by this utility model is to provide a liquid nitrogen pump power end assembly that can improve the mechanical strength of the crankcase and meet the gradually increasing operating pressure in China; and can be connected to various types of hydraulic ends to expand the scope of installation application.

[0005] To solve the above-mentioned technical problems, the technical solution of this utility model is as follows:

[0006] The liquid nitrogen pump power end assembly includes a crankcase, crankshaft, connecting rod, and crosshead assembly;

[0007] The crankcase is provided with several wall panels, and a crankshaft bearing seat is installed on the wall panel. Several reinforcing ribs are fixed between the crankshaft bearing seat and the wall panel. The crankshaft is rotatably installed in the crankshaft bearing seat through the crankshaft bearing.

[0008] The crankshaft includes a straight shaft and an eccentric wheel. The straight shaft passes through the crankshaft bearing housing. The eccentric wheel is disposed between two adjacent crankshaft bearing housings and mounted on the straight shaft. The eccentric wheel is connected to the connecting rod.

[0009] The crosshead assembly includes a crosshead, the inner end of which is connected to the connecting rod via a cross pin, and the outer end of which is configured as a cylindrical mounting end, on which a snap-fit ​​assembly for connecting to the hydraulic end assembly is mounted.

[0010] The snap-fit ​​assembly includes two oppositely arranged snap hooks, and the distance between the two snap hooks is adjustable radially along the mounting end.

[0011] Preferably, the crankshaft bearing housing extends through the wall panel, and a plurality of reinforcing ribs are circumferentially arranged on the outer periphery of the crankshaft bearing housing. The crankshaft bearing housing, the wall panel, and the reinforcing ribs are integrally formed.

[0012] Preferably, a coaxially arranged snap-fit ​​boss is installed on the outer side of the mounting end. The cross-section of the snap-fit ​​boss is T-shaped, and the two snap hooks are installed on its outer periphery along the radial direction of the snap-fit ​​boss.

[0013] Preferably, the cross-section of the hook is semi-circular, the inner side of the hook is provided with a boss connecting part for connecting the snap-fit ​​boss, and the outer side of the hook is provided with a hydraulic connecting part for connecting the hydraulic end assembly.

[0014] The two hydraulic connection parts of the two hook components are connected to the same hydraulic end assembly.

[0015] Preferably, the two hooks are mounted to the locking boss by a connecting bolt.

[0016] Preferably, at least one locating pin is installed on the mounting end along its axial direction, and the locating pin is inserted into the snap-fit ​​boss.

[0017] Preferably, the snap-fit ​​boss is installed on the mounting end by fastening bolts, and a tightening bolt is installed on the snap-fit ​​boss along its radial direction, the tightening bolt abutting against the fastening bolts.

[0018] Preferably, the eccentric wheel is mounted on the straight shaft via a flat key.

[0019] Preferably, the straight shaft has a lubricating oil passage inside, the lubricating oil passage passes through both ends of the straight shaft and communicates with the outside, and the eccentric wheel has an oil outlet hole that communicates with the lubricating oil passage.

[0020] After adopting the above technical solution, the beneficial effects of this utility model are:

[0021] The liquid nitrogen pump power assembly of this application includes a crankcase, crankshaft, connecting rod, and crosshead assembly. The crankcase contains several wall plates, on which crankshaft bearing seats are mounted. Several reinforcing ribs are fixed between the crankshaft bearing seats and the wall plates. The crankshaft is rotatably mounted within the crankshaft bearing seats via crankshaft bearings. The crankshaft includes a straight shaft and an eccentric wheel. The straight shaft passes through the crankshaft bearing seats, and the eccentric wheel is positioned between two adjacent crankshaft bearing seats and mounted on the straight shaft. The eccentric wheel is connected to the connecting rod. By incorporating reinforcing ribs, the crankshaft bearing seats and wall plates are tightly connected and fixed together, enhancing the overall support strength of the crankshaft bearing seats for the crankshaft. This ensures good stability of the crankshaft during rotation, improving its performance. Simultaneously, it increases the mechanical strength of the crankcase, meeting the increasing operational pressure requirements in China.

[0022] The crosshead assembly includes a crosshead, the inner end of which is connected to a connecting rod via a cross pin. The outer end of the crosshead is a cylindrical mounting end, on which a snap-fit ​​assembly for connecting to the hydraulic end assembly is mounted. The snap-fit ​​assembly includes two opposing snap hooks, the distance between which is radially adjustable along the mounting end. By providing two radially adjustable snap hooks, they cooperate to connect with the hydraulic end assembly, meeting the requirement of the crankshaft driving the hydraulic end assembly to pump liquid nitrogen via the connecting rod and crosshead assembly. Furthermore, because of its radial adjustability, connections can be achieved for hydraulic end assemblies of different sizes by adjusting the position of the two snap hooks, expanding the range of applicable installations and reducing production costs. Attached Figure Description

[0023] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0024] Figure 1 This is a schematic diagram of the liquid nitrogen pump power end assembly according to an embodiment of the present invention;

[0025] Figure 2 yes Figure 1 Enlarged view of part A;

[0026] Figure 3 yes Figure 1 A schematic diagram of the structure of the card connector assembly;

[0027] Figure 4 yes Figure 3 Enlarged view of part B;

[0028] In the picture:

[0029] 1. Crankshaft housing; 11. Wall panel; 12. Crankshaft bearing housing; 13. Reinforcing rib;

[0030] 2. Crankshaft; 21. Straight shaft; 22. Eccentric wheel; 23. Flat key; 24. Lubricating oil passage; 25. Oil outlet;

[0031] 3. Connecting rod;

[0032] 4. Crosshead assembly; 41. Crosshead; 42. Cross pin; 43. Mounting end; 44. Locating pin; 45. Fastening bolt; 46. Tightening bolt;

[0033] 5. Snap-fit ​​assembly; 51. Snap hook; 52. Snap-fit ​​boss; 53. Boss connecting part; 54. Hydraulic connecting part; 55. Connecting bolt. Detailed Implementation

[0034] To make the objectives, technical solutions, and advantages of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present utility model and are not intended to limit the present utility model.

[0035] like Figures 1 to 4 As shown in the figure, the present invention includes a crankcase 1, a crankshaft 2, a connecting rod 3, and a crosshead assembly 4; wherein, the crankcase 1 is provided with a plurality of wall plates 11, and a crankshaft bearing seat 12 is installed on the wall plates 11, and a plurality of reinforcing ribs 13 are fixed between the crankshaft bearing seat 12 and the wall plates 11; the crankshaft 2 is rotatably mounted in the crankshaft bearing seat 12 through a crankshaft bearing (not shown in the figure); the crankshaft 2 includes a straight shaft 21 and an eccentric wheel 22, the straight shaft 21 passes through the crankshaft bearing seat 12, the eccentric wheel 22 is disposed between two adjacent crankshaft bearing seats 12 and is mounted on the straight shaft 21, and the eccentric wheel 22 is connected to the connecting rod 3. By setting reinforcing ribs 13, the crankshaft bearing housing 12 and the wall plate 11 are tightly connected and fixed together, which enhances the support strength of the entire crankshaft bearing housing 12 for the crankshaft 2. When the crankshaft 2 rotates, it can ensure that the crankshaft 2 has good stability and improve the performance of the crankshaft 2. At the same time, it improves the mechanical strength of the crankshaft housing 1 and meets the increasing operating pressure in China.

[0036] Preferably, the crankshaft bearing housing 12 is disposed through the wall plate 11, and a plurality of reinforcing ribs 13 are circumferentially and equidistantly arranged on the outer periphery of the crankshaft bearing housing 12. The crankshaft bearing housing 12, the wall plate 11, and the reinforcing ribs 13 are integrally formed. The crankshaft bearing housing 12, the wall plate 11, and the reinforcing ribs 13 are integrally cast, resulting in high structural strength and enhancing the mechanical strength of the crankshaft housing 1.

[0037] The eccentric wheel 22 is mounted on the straight shaft 21 via a flat key 23. The straight shaft 21 has an internal lubrication oil passage 24 that extends through both ends of the shaft and connects to the outside. The eccentric wheel 22 has an oil outlet 25 that communicates with the lubrication oil passage 24. Preferably, rotary joints are installed at both ends of the straight shaft 21 to connect the lubrication oil passage 24 to the outside. External lubricating oil enters the lubrication oil passage 24 and is discharged through the oil outlet 25.

[0038] The crosshead assembly 4 includes a crosshead 41. The inner end of the crosshead 41 is connected to the connecting rod 3 via a cross pin 42. The outer end of the crosshead 41 is a cylindrical mounting end 43. A snap-fit ​​assembly 5 for connecting to the hydraulic end assembly is mounted on the mounting end 43. The snap-fit ​​assembly 5 includes two opposing snap hooks 51, and the distance between the two snap hooks 51 is radially adjustable along the mounting end 43. Because the mounting end 43 is a cylindrical structure, and the two snap hooks 51 are radially adjustable, the distance between the two snap hooks 51 can be adjusted. By setting two radially adjustable snap hooks 51, the two snap hooks 51 cooperate with each other to connect with the hydraulic end assembly, meeting the requirement of the crankshaft 2 driving the hydraulic end assembly to pump liquid nitrogen via the connecting rod 3 and the crosshead assembly 4. At the same time, because it is radially adjustable, it can be connected to hydraulic end assemblies of different sizes by adjusting the position of the two snap hooks 51, expanding the installation applicability and reducing production costs.

[0039] Preferably, a coaxially arranged snap-fit ​​boss 52 is installed on the outer side of the mounting end 43. The snap-fit ​​boss 52 has a T-shaped cross-section, and two snap hooks 51 are installed radially on its outer periphery. By providing the snap-fit ​​boss 52 and installing the two snap hooks 51 on its outer periphery, it is convenient to maintain and replace the snap-fit ​​assembly 5, reducing the difficulty of later maintenance. Among them, the cross-section of the snap hook 51 is semi-annular. The inner side of the snap hook 51 is provided with a boss connecting part 53 for connecting the snap-fit ​​boss 52, and the outer side of the snap hook 51 is provided with a hydraulic connecting part 54 for connecting the hydraulic end assembly. The two hydraulic connecting parts 54 of the two snap hooks 51 are connected to the same hydraulic end assembly.

[0040] By providing the boss connecting part 53 and the hydraulic connecting part 54, it is convenient to detachably connect the crosshead assembly 4 and the hydraulic end assembly together by means of the hook part 51. Specifically, the hydraulic end assembly is also provided with a T-shaped structure similar to the hook boss 52, and the hydraulic end assembly is hooked into the hydraulic connecting part 54.

[0041] Two hook pieces 51 are mounted on the locking boss 52 by a connecting bolt 55. One connecting bolt 55 controls two hook pieces 51, which is simple in structure, easy to operate and maintain.

[0042] At least one locating pin 44 is installed on the mounting end 43 along its axial direction, and the locating pin 44 is inserted into the snap-fit ​​boss 52. The locating pin 44 restricts the snap-fit ​​boss 52 from rotating around its own axis, prevents circumferential friction between the snap-fit ​​boss 52 and the boss connection part 53, and extends the service life of the hook part 51.

[0043] The snap-fit ​​boss 52 is mounted on the mounting end 43 by fastening bolts 45. A tightening bolt 46 is installed on the snap-fit ​​boss 52 along its radial direction, and the tightening bolt 46 abuts against the fastening bolt 45.

[0044] In this application, by setting reinforcing ribs 13, the crankshaft bearing housing 12 and the wall plate 11 are tightly connected and fixed together, which enhances the support strength of the entire crankshaft bearing housing 12 for the crankshaft 2. When the crankshaft 2 rotates, it can ensure that the crankshaft 2 has good stability and improve the performance of the crankshaft 2. At the same time, it improves the mechanical strength of the crankshaft housing 1 and meets the gradually increasing operating pressure in China.

[0045] Meanwhile, in use, by rotating the connecting bolt 55, the hydraulic connection parts 54 of the two hook pieces 51 are hooked onto the same hydraulic end assembly, and the locking boss 52 is connected by the boss connection part 53, connecting the crosshead 41, the locking boss 52 and the hydraulic end assembly together, so that the crankshaft 2 can drive the hydraulic end assembly to pump liquid nitrogen through the connecting rod 3, which meets the pumping requirements. During the connection process, the two hook pieces 51 are connected to hydraulic end assemblies of different sizes by the connecting bolt 55, which expands the scope of installation application and reduces production costs.

[0046] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A liquid nitrogen pump power end assembly, characterized in that, Includes crankcase, crankshaft, connecting rod and crosshead assembly; The crankcase is provided with several wall panels, and a crankshaft bearing seat is installed on the wall panel. Several reinforcing ribs are fixed between the crankshaft bearing seat and the wall panel. The crankshaft is rotatably installed in the crankshaft bearing seat through the crankshaft bearing. The crankshaft includes a straight shaft and an eccentric wheel. The straight shaft passes through the crankshaft bearing housing. The eccentric wheel is disposed between two adjacent crankshaft bearing housings and mounted on the straight shaft. The eccentric wheel is connected to the connecting rod. The crosshead assembly includes a crosshead, the inner end of which is connected to the connecting rod via a cross pin, and the outer end of which is configured as a cylindrical mounting end, on which a snap-fit ​​assembly for connecting to the hydraulic end assembly is mounted. The snap-fit ​​assembly includes two oppositely arranged snap hooks, and the distance between the two snap hooks is adjustable radially along the mounting end.

2. The liquid nitrogen pump power end assembly as described in claim 1, characterized in that, The crankshaft bearing housing is disposed through the wall panel, and a plurality of reinforcing ribs are circumferentially arranged on the outer periphery of the crankshaft bearing housing. The crankshaft bearing housing, the wall panel, and the reinforcing ribs are integrally formed.

3. The liquid nitrogen pump power end assembly as described in claim 1, characterized in that, A coaxially arranged snap-fit ​​boss is installed on the outer side of the mounting end. The cross-section of the snap-fit ​​boss is T-shaped, and the two snap hooks are installed on its outer periphery along the radial direction of the snap-fit ​​boss.

4. The liquid nitrogen pump power end assembly as described in claim 3, characterized in that, The cross-section of the hook is semi-circular. The inner side of the hook is provided with a boss connecting part for connecting the snap-fit ​​boss, and the outer side of the hook is provided with a hydraulic connecting part for connecting the hydraulic end assembly. The two hydraulic connection parts of the two hook components are connected to the same hydraulic end assembly.

5. The liquid nitrogen pump power end assembly as described in claim 4, characterized in that, The two hooks are mounted to the locking boss by a connecting bolt.

6. The liquid nitrogen pump power end assembly as described in claim 3, characterized in that, At least one locating pin is installed on the mounting end along its axial direction, and the locating pin is inserted into the snap-fit ​​boss.

7. The liquid nitrogen pump power end assembly as described in claim 6, characterized in that, The snap-fit ​​boss is installed on the mounting end by fastening bolts. A tightening bolt is installed on the snap-fit ​​boss along its radial direction, and the tightening bolt abuts against the fastening bolts.

8. The liquid nitrogen pump power end assembly as described in claim 1, characterized in that, The eccentric wheel is mounted on the straight shaft via a flat key.

9. The liquid nitrogen pump power end assembly as described in claim 8, characterized in that, The straight shaft has a lubricating oil passage inside, which passes through both ends of the straight shaft and communicates with the outside. The eccentric wheel has an oil outlet hole that communicates with the lubricating oil passage.

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