Crankshaft assembly for plunger pump, plunger pump, and plunger pump station

Abstract

Provided are a crankshaft assembly for a plunger pump, a plunger pump, and a plunger pump station. The crankshaft assembly comprises a crankshaft, a first gear, and a second gear. The crankshaft comprises a first connecting rod journal, a second connecting rod journal, a third connecting rod journal, a fourth connecting rod journal, a fifth connecting rod journal, a sixth connecting rod journal, a seventh connecting rod journal, a first journal, a second journal, a third journal, a fourth journal, a fifth journal, a sixth journal, a seventh journal, and an eighth journal. The first gear is arranged on the third journal, and the second gear is arranged on the sixth journal.

Description

Crankshaft assembly for plunger pump, plunger pump and plunger pump station

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This disclosure claims priority to Chinese patent application No. 2023111101363 filed in China on August 30, 2023, the entire contents of which are incorporated herein by reference. Technical Field

[0003] The present disclosure relates to the technical field of emulsion pumps, and in particular to a crankshaft assembly for a plunger pump, a plunger pump, and a plunger pump station. Background Art

[0004] As an important power source in the field of coal mining machinery, the high-flow multi-plunger emulsion pump is the core equipment to achieve the coal production industry's requirements for high performance, high efficiency, high stability and high reliability.

[0005] In recent years, the coal industry has seen a growing demand for high-flow emulsion pumps capable of meeting mining volumes of tens of millions of tons. The five-plunger emulsion pumps used in related technologies have low output flow and large flow pulses, which cannot meet future power requirements for large coal face mining. Increasing the number of plungers requires a longer crankshaft length, which creates a technical challenge: high crankshaft stress that cannot meet usage requirements.

[0006] Summary of the Invention

[0007] The present disclosure is based on the inventors' findings and understanding of the following facts and problems:

[0008] The five-plunger emulsion pump in the related technology has a small output flow rate and a large flow pulse, which cannot meet the future power demand for large coal face mining. If the number of plungers is increased, the number of connecting rod necks needs to be increased, and the crankshaft length becomes longer, which will lead to technical difficulties such as high crankshaft stress and failure to meet the use requirements.

[0009] The embodiments of the present disclosure aim to at least partially address one of the technical problems in the related art. To this end, the embodiments of the present disclosure provide a plunger pump crankshaft assembly, a plunger pump, and a plunger pump station that can increase output flow while ensuring output flow stability and reducing crankshaft stress.

[0010] An embodiment of the present disclosure discloses a crankshaft assembly for a plunger pump, the crankshaft assembly comprising: a crankshaft, a first gear and a second gear; the crankshaft comprises a connecting rod neck and a journal, the connecting rod neck comprising a first connecting rod neck, a second connecting rod neck, a third connecting rod neck, a fourth connecting rod neck, a fifth connecting rod neck, a sixth connecting rod neck and a seventh connecting rod neck; the journal comprises a first journal, a second journal, a third journal, a fourth journal, a fifth journal, a sixth journal, a seventh journal and an eighth journal; wherein, the first journal, the first connecting rod neck, the second journal, the second connecting rod neck, the third journal, the third connecting rod neck, the fourth journal, the fourth connecting journal, the fifth journal, the fifth connecting rod neck, the sixth journal, the sixth connecting journal, the seventh journal, the seventh connecting journal and the eighth journal are distributed in sequence in the axial direction; the first gear is arranged on the third journal, and the second gear is arranged on the sixth journal.

[0011] In some embodiments, the phase angle of the first connecting rod journal is θ1, the phase angle of the second connecting rod journal is θ2, the phase angle of the third connecting rod journal is θ3, the phase angle of the fourth connecting rod journal is θ4, the phase angle of the fifth connecting rod journal is θ5, the phase angle of the sixth connecting rod journal is θ6, and the phase angle of the seventh connecting rod journal is θ7, wherein θ4-θ1=θ7-θ4=θ2-θ7=θ5-θ2=θ3-θ5=θ6-θ3=θ1-θ6=(360 / 7)° or θ2-θ1=θ3-θ2=θ4-θ3=θ5-θ4=θ6-θ5=θ7-θ6=θ1-θ7=(360 / 7)°.

[0012] In some embodiments, the crankshaft assembly includes crankshaft bearings mounted on the first journal, the second journal, the fourth journal, the fifth journal, the seventh journal, and the eighth journal, respectively.

[0013] In some embodiments, the crankshaft includes an oil passage running through the axial ends of the crankshaft in the axial direction of the crankshaft, and the circumferential surfaces of the first journal, the first connecting rod journal, the second journal, the second connecting rod journal, the third connecting rod journal, the fourth journal, the fourth connecting rod journal, the fifth journal, the fifth connecting rod journal, the sixth connecting rod journal, the seventh journal, the seventh connecting rod journal and the eighth journal are all provided with oil holes, and the oil holes are connected to the oil passage; wherein, the oil passage includes a first straight oil passage, a second straight oil passage and an oblique oil passage that are connected to each other, and in the axial direction, the oblique oil passage is located between the first straight oil passage and the second straight oil passage, and the diameter of the oblique oil passage is larger than the diameters of the first straight oil passage and the second straight oil passage.

[0014] In some embodiments, the first straight oil passage includes a first axial straight oil passage and a second axial straight oil passage, the first axial straight oil passage axially passes through the first journal and the first connecting rod journal in sequence and extends into the second journal, the first axial straight oil passage passes through the central axis of the first connecting rod journal; the second axial straight oil passage axially passes through the second journal and the second connecting rod journal in sequence and extends into the third journal, the second axial straight oil passage passes through the central axis of the second connecting rod journal, wherein the first axial straight oil passage and the second axial straight oil passage are connected to each other by a first radial oil passage radially passing through the second journal. The second straight oil passage includes a third axial straight oil passage and a fourth axial straight oil passage, the third axial straight oil passage axially penetrates the eighth journal and the seventh connecting rod journal in sequence and extends into the seventh journal, and the third axial straight oil passage passes through the central axis of the seventh connecting rod journal; the fourth axial straight oil passage axially penetrates the seventh journal and the sixth connecting rod journal in sequence and extends into the sixth journal, and the fourth axial straight oil passage passes through the central axis of the sixth connecting rod journal, wherein the third axial straight oil passage and the fourth axial straight oil passage are connected via a second radial oil passage radially provided in the seventh journal.

[0015] In some embodiments, the inclined oil passage includes a first inclined oil passage, a second inclined oil passage, and a third inclined oil passage, the first inclined oil passage obliquely passes through the fourth journal and the third connecting rod journal in sequence and extends into the third journal and is communicated with the second axial straight oil passage, the first inclined oil passage passes through the central axis of the third connecting rod journal; the second oblique oil passage obliquely passes through the fifth journal and the fourth connecting rod journal in sequence and extends into the fourth journal and is communicated with the first oblique oil passage, the second oblique oil passage passes through the central axis of the fourth connecting rod journal; the third oblique oil passage obliquely passes through the fifth journal and the fifth connecting rod journal in sequence and extends into the sixth journal and is communicated with the fourth axial straight oil passage, the third oblique oil passage passes through the central axis of the fifth connecting rod journal, wherein the second oblique oil passage and The third oblique oil passage is connected through a third radial oil passage radially penetrated in the fifth journal; the oil hole on the first journal, the oil hole on the first connecting rod journal, and the oil hole on the second journal are all connected to the first axial straight oil passage; the oil hole on the second connecting rod journal is connected to the second axial straight oil passage; the oil hole on the third connecting rod journal and the oil hole on the fourth journal are both connected to the first oblique oil passage; the oil hole on the fourth connecting rod journal is connected to the second oblique oil passage; the oil hole on the fifth journal and the oil hole on the fifth connecting rod journal are both connected to the third oblique oil passage; the oil hole on the sixth connecting rod journal and the oil hole on the seventh journal are both connected to the fourth axial straight oil passage; the oil hole on the seventh connecting rod journal and the oil hole on the eighth journal are both connected to the third axial straight oil passage.

[0016] The present disclosure also discloses a plunger pump, comprising: a transmission device and a hydraulic device, wherein the transmission device comprises: a housing; a main shaft assembly, wherein the main shaft assembly comprises a main shaft, wherein the main shaft is provided with first helical teeth and second helical teeth, and wherein the main shaft is rotatably arranged in the housing via a main shaft bearing; a crankshaft assembly, wherein the crankshaft assembly is the crankshaft assembly as described in any of the above embodiments, wherein the crankshaft is rotatably arranged in the housing via a crankshaft bearing, wherein the first gear is engaged with the first helical teeth, and the second gear is engaged with the second helical teeth; and a plurality of connecting rods. An assembly, wherein the connecting rod assembly corresponds to the connecting rod neck one-to-one, and one end of the connecting rod assembly is connected to the corresponding connecting rod neck; the hydraulic device includes: a pump body, wherein the pump body is arranged in the box body, and the pump body includes a liquid inlet, a liquid discharge port, a liquid return port and a plurality of cylinder holes connected to the liquid inlet, the liquid discharge port and the liquid return port, and the cylinder holes are distributed along the axial direction; a plurality of piston assemblies, wherein the piston assemblies correspond to the cylinder holes one-to-one, and each of the piston assemblies is slidably arranged in the corresponding cylinder hole and is connected to the other end of the corresponding connecting rod assembly.

[0017] In some embodiments, the box body includes an upper box body and a lower box body, and a joint surface between the upper box body and the lower box body is provided with a seam pin parallel to the joint surface.

[0018] In some embodiments, the liquid inlet is located below the liquid discharge port, and the liquid inlet includes a first liquid inlet and a second liquid inlet, and the first liquid inlet and the second liquid inlet are respectively arranged at two ends of the pump body in the axial direction.

[0019] In some embodiments, each of the piston assemblies includes a piston and a steel sleeve sleeved on the piston, an outer circumferential surface of the steel sleeve is provided with an oil groove, and the steel sleeve is slidably disposed in the cylinder hole.

[0020] In some embodiments, the box body is provided with seven slides; each of the connecting rod assemblies includes: a slider, which is slidably arranged in the corresponding slide; a connecting rod, one end of which is connected to the corresponding connecting rod neck, and the other end of each connecting rod is connected to the corresponding slider; and an intermediate rod, one end of which is connected to the corresponding slider, and the other end of the intermediate rod is connected to the corresponding piston.

[0021] The presently disclosed embodiment also discloses a plunger pump station, comprising: a base; a plunger pump, the plunger pump being the plunger pump as described in any of the above embodiments, the plunger pump being arranged on the base; a liquid inlet pipeline and a liquid return pipeline, the liquid inlet pipeline being connected to the liquid inlet, the liquid return pipeline being connected to the liquid return port; a motor, the motor being arranged on the base, the output end of the motor being connected to the main shaft.

[0022] The crankshaft assembly for the plunger pump, the plunger pump, and the plunger pump station of the embodiments of the present disclosure have the following technical effects:

[0023] The crankshaft assembly uses unevenly distributed connecting rod necks, and the first gear and second gear are arranged on the third journal and the sixth journal respectively. Compared with the crankshaft with five connecting rod necks, it not only has a large output flow, smaller flow pulsation, and more stable flow output, but also can effectively balance the component forces during the movement of different connecting rod necks, greatly reducing the load stress of the entire crankshaft and improving reliability. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] FIG1 is a schematic structural diagram of a crankshaft assembly according to some embodiments of the present disclosure;

[0025] FIG2 is a schematic structural diagram of a crankshaft according to some embodiments of the present disclosure;

[0026] FIG3 is a schematic structural diagram of a plunger pump according to some embodiments of the present disclosure;

[0027] FIG4 is a cross-sectional view of a plunger pump according to some embodiments of the present disclosure;

[0028] FIG5 is a schematic diagram of the structure of the crankshaft assembly and the main shaft according to some embodiments of the present disclosure;

[0029] FIG6 is a schematic structural diagram of a box provided according to some embodiments of the present disclosure;

[0030] FIG7 is a schematic structural diagram of a steel sleeve according to some embodiments of the present disclosure;

[0031] FIG8 is a schematic structural diagram of a plunger pump station according to some embodiments of the present disclosure;

[0032] Figures 9 to 11 are crankshaft stress simulation diagrams in related art;

[0033] FIG12 is a crankshaft stress simulation diagram of an embodiment of the present disclosure. DETAILED DESCRIPTION

[0034] The embodiments of the present disclosure are described in detail below, and examples of the embodiments are shown in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to be used to explain the embodiments of the present disclosure, but should not be understood as limiting the embodiments of the present disclosure.

[0035] 1 and 2 , an embodiment of the present disclosure discloses a crankshaft assembly 100 for a plunger pump. The crankshaft assembly 100 for a plunger pump includes a crankshaft 3 , a first gear 301 , and a first gear 302 .

[0036] The crankshaft 3 includes connecting rod journals and journals. The connecting rod journals include a first connecting rod journal 21, a second connecting rod journal 22, a third connecting rod journal 23, a fourth connecting rod journal 24, a fifth connecting rod journal 25, a sixth connecting rod journal 26, and a seventh connecting rod journal 27. The journals include a first journal 11, a second journal 12, a third journal 13, a fourth journal 14, a fifth journal 15, a sixth journal 16, a seventh journal 17, and an eighth journal 18. The first journal 11, the first connecting rod journal 21, the second journal 12, the second connecting rod journal 22, the third journal 13, the third connecting rod journal 23, the fourth journal 14, the fourth connecting rod journal 24, the fifth journal 15, the fifth connecting rod journal 25, the sixth journal 16, the sixth connecting rod journal 26, the seventh journal 17, the seventh connecting rod journal 27, and the eighth journal 18 are arranged in order from right to left in the axial direction A. The first gear 301 is disposed on the third journal 13 , and the first gear 302 is disposed on the sixth journal 16 .

[0037] The crankshaft assembly 100 for the plunger pump of the disclosed embodiment can be applied to an emulsion pump, and can drive seven plungers to do work. Compared with the work output flow of the related five-plunger emulsion pump, it has a significant improvement and can better adapt to the power requirements of the coal mining machine for large coal mining faces; and, because the phase difference of the seven plungers is smaller, the flow pulsation is smaller, thereby improving the stability of the liquid supply.

[0038] Furthermore, referring to Figures 9 to 12, in Figure 9, the two gears are arranged on the second journal 12 and the seventh journal 17, respectively. The maximum crankshaft stress occurs where the first connecting rod journal enters dead center, and simulation data indicates a maximum stress of 143 MPa. In Figure 10, the two gears are arranged on the third journal and the sixth journal, respectively. The maximum crankshaft stress occurs where the third connecting rod journal enters dead center, and simulation data indicates a maximum stress of 97 MPa. In Figure 11, the two gears are arranged on the third journal 13 and the sixth journal 16, respectively. The maximum crankshaft stress occurs where the third connecting rod journal enters dead center, and simulation data indicates a maximum stress of 97 MPa. It can be seen that the maximum crankshaft stress when the two gears are arranged on the third journal 13 and the sixth journal 16 is significantly lower than when the two gears are arranged on the second journal 12 and the seventh journal 17, respectively.

[0039] In some embodiments, the phase angle of the first connecting journal 21 is θ1, the phase angle of the second connecting journal 22 is θ2, the phase angle of the third connecting journal 23 is θ3, the phase angle of the fourth connecting journal 24 is θ4, the phase angle of the fifth connecting journal 25 is θ5, the phase angle of the sixth connecting journal 26 is θ6, and the phase angle of the seventh connecting journal 27 is θ7, where θ4 - θ1 = θ7 - θ4 = θ2 - θ7 = θ5 - θ2 = θ3 - θ5 = θ6 - θ3 = θ1 - θ6 = (360 / 7) degrees. An initial phase angle can be determined, and the phase angles of the other connecting journals can be derived based on the aforementioned phase angle differences, thereby forming seven unevenly distributed connecting journals. The seven unevenly distributed connecting rod necks mean that the phase angles of the seven connecting rod necks are not sequentially different by (360 / 7)° in the axial direction A of the crankshaft 30, which is different from the five evenly distributed connecting rod necks in the related art, that is, the phase angles of the five evenly distributed connecting rod necks satisfy θ2-θ1=θ3-θ2=θ4-θ3=θ5-θ4=(360 / 5)°.

[0040] The crankshaft in Figure 9 uses seven unevenly distributed connecting rod journals, with two gears arranged on the second journal 12 and the seventh journal 17. The maximum stress in the crankshaft occurs where the first connecting rod journal enters the dead center, and simulation data shows that the maximum stress is 143 MPa.

[0041] The crankshaft in Figure 10 uses seven evenly spaced connecting rod journals. The phase difference between the seven connecting rod journals from right to left in the axial direction A is (360 / 7) degrees. The two gears are placed on the third and sixth journals, respectively. The maximum crankshaft stress occurs where the third connecting rod journal enters dead center, and simulation data indicates a maximum stress of 97 MPa. The maximum stress in the crankshaft in Figure 11 is lower than that in Figure 10.

[0042] The crankshaft shown in Figure 11 utilizes seven unevenly spaced connecting rod journals according to the disclosed embodiment, with first gear 301 and second gear 302 positioned on third journal 13 and sixth journal 16, respectively. Maximum crankshaft stress occurs where third connecting rod journal 23 enters dead center. Simulation data indicates a maximum stress of 82.31 MPa, a 16.8% reduction compared to the maximum stress achieved with the seven evenly spaced connecting rod journals shown in Figure 10.

[0043] The crankshaft in Figure 12 uses five evenly distributed connecting rod necks. The maximum stress of the crankshaft occurs at the position where the second connecting rod neck enters the dead center, and the maximum stress is 87 MPa, which meets the operating conditions. It can be seen that the maximum stress of the crankshaft in the embodiment of the present disclosure in Figure 11 is smaller than the maximum stress of the crankshaft in Figure 12. Therefore, the crankshaft assembly of the embodiment of the present disclosure uses seven connecting rod necks. Under the premise of increasing the number of connecting rod necks and increasing the overall length of the crankshaft, the arrangement of seven unevenly distributed connecting rod necks and the first gear 301 and the first gear 302 are respectively arranged on the third journal 13 and the sixth journal 16, compared with the shorter crankshaft with five connecting rod necks, the stress is reduced, not only the output flow is large, the flow pulsation is smaller, and the output flow is more stable.

[0044] The crankshaft assembly of the disclosed embodiment adopts an arrangement in which seven unevenly distributed connecting rod necks and the first gear 301 and the first gear 302 are respectively arranged on the third journal 13 and the sixth journal 16. Compared with the shorter crankshaft with five connecting rod necks, it effectively balances the component forces during the movement of different connecting rod necks, greatly reduces the load stress of the entire crankshaft, and improves reliability. In other embodiments, θ2-θ1=θ3-θ2=θ4-θ3=θ5-θ4=θ6-θ5=θ7-θ6=θ6-θ1=θ1-θ7=(360 / 7)°. An initial phase angle θ1 can be determined first, and the phase angles θ2, θ3, θ4, θ5, θ6, and θ7 of each other connecting rod neck are obtained based on the above phase angle difference, thereby forming seven evenly distributed connecting rod necks. Seven evenly distributed connecting rod necks means that the phase angles of the seven connecting rod necks differ by (360 / 7)° in the axial direction A of the crankshaft 30.

[0045] As mentioned above, the crankshaft in Figure 10 utilizes seven evenly spaced connecting rod journals, with the phase difference between the seven connecting rod journals from right to left in the axial direction A being (360 / 7) degrees. The two gears are located on the third and sixth journals, respectively. Maximum crankshaft stress occurs where the third connecting rod journal enters dead center, with simulation data demonstrating a maximum stress of 97 MPa. Compared to the crankshaft in Figure 9, which utilizes seven unevenly spaced connecting rod journals and has two gears located on the second and seventh journals, 17, respectively, the maximum stress is significantly reduced.

[0046] 1 and 2 , in some embodiments, the crankshaft assembly includes crankshaft bearings 303 mounted on the first journal 11, the second journal 12, the fourth journal 14, the fifth journal 15, the seventh journal 17, and the eighth journal 18. The crankshaft 30 is rotated by the first gear 301 and the second gear 302, and is supported by the crankshaft bearings 303.

[0047] In some embodiments, referring to FIG2 , the crankshaft 30 includes oil passages extending through both ends of the crankshaft 30 in the axial direction A. The first journal 11, the first connecting rod journal 21, the second journal 12, the second connecting rod journal 22, the third connecting rod journal 23, the fourth journal 14, the fourth connecting rod journal 24, the fifth journal 15, the fifth connecting rod journal 25, the sixth connecting rod journal 26, the seventh journal 17, the seventh connecting rod journal 27, and the eighth journal 18 are all provided with oil holes on their circumferential surfaces, which communicate with the oil passages. The oil passages include a first straight oil passage, a second straight oil passage, and an oblique oil passage. In the axial direction A, the oblique oil passage is located between the first straight oil passage and the second straight oil passage, and its diameter is larger than that of the first straight oil passage and the second straight oil passage.

[0048] Because the crankshaft 30 of the disclosed embodiment includes seven unevenly spaced connecting rod necks, making it longer than a conventional crankshaft with five connecting rod necks, and the unique arrangement of the connecting rod necks, oil channel machining becomes more difficult. Drilling too deep can easily break the drill bit. To address this, the disclosed embodiment utilizes straight oil channels on both sides of the crankshaft 30 in the axial direction A and an inclined oil channel in the middle, effectively reducing machining difficulty. The diameter of the inclined oil channel is larger than that of the straight oil channel, making it easier for the inclined oil channel to intersect and connect with the straight oil channel, further reducing machining difficulty.

[0049] In some embodiments, referring to FIG2 , the first straight oil passage includes a first axial straight oil passage 31 and a second axial straight oil passage 32. The first axial straight oil passage 31 sequentially penetrates the first journal 11 and the first connecting rod journal 21 along the axial direction A and extends into the second journal 12. The first axial straight oil passage 31 passes through the central axis of the first connecting rod journal 21. During machining, a hole is drilled from the right end surface of the first journal 11, aligned with the central axis of the first connecting rod journal 21, and toward the left in the axial direction A. The drill bit sequentially penetrates the first journal 11 and the first connecting rod journal 21 until it enters the second journal 12.

[0050] The second axial straight oil passage 32 axially penetrates the second journal 12 and the second connecting rod journal 22 in sequence and extends into the third journal 13. The second axial straight oil passage 32 passes through the central axis of the second connecting rod journal 22. The first axial straight oil passage 31 and the second axial straight oil passage 32 are connected by a first radial oil passage 12a extending radially through the second journal 12. During machining, a hole is drilled from the right end surface of the first journal 11, aligned with the central axis of the second connecting rod journal 22, toward the left in the axial direction A. The drill bit sequentially penetrates the first journal 11, the second journal 12, and the second connecting rod journal 22 until it enters the third journal 13. Then, a hole is drilled radially from the circumference of the second journal 12, passing through the first axial straight oil passage 31 and the second axial straight oil passage 32 in sequence, connecting the first axial straight oil passage 31 and the second axial straight oil passage 32 through the first radial oil passage 12a.

[0051] The second straight oil passage includes a third axial straight oil passage 37 and a fourth axial straight oil passage 36. The third axial straight oil passage 37 axially penetrates the eighth journal 18 and the seventh connecting journal 27 in sequence and extends into the seventh journal 17. The third axial straight oil passage 37 passes through the center axis of the seventh connecting journal 27. During machining, a hole is drilled axially to the right from the left end surface of the eighth journal 18, aligned with the center axis of the seventh connecting journal 27. The drill bit sequentially penetrates the eighth journal 18 and the seventh connecting journal 27 until it enters the seventh journal 17.

[0052] The fourth axial straight oil passage 36 axially penetrates the seventh journal 17 and the sixth connecting journal 26 in sequence and extends into the sixth journal 16. The fourth axial straight oil passage 36 passes through the central axis of the sixth connecting journal 26. The third axial straight oil passage 37 and the fourth axial straight oil passage 36 are connected by a second radial oil passage 17a extending radially through the seventh journal 17. During machining, a hole is drilled from the left end surface of the eighth journal 18, aligned with the central axis of the sixth connecting journal 26, toward the right in the axial direction A. The drill bit sequentially penetrates the eighth journal 18, the seventh journal 17, and the sixth connecting journal 26 until it enters the sixth journal 16. Then, a hole is drilled radially from the circumference of the seventh journal 17, sequentially passing through the third axial straight oil passage 37 and the fourth axial straight oil passage 36, connecting the third axial straight oil passage 37 and the fourth axial straight oil passage 36 via the second radial oil passage 17a.

[0053] The inclined oil passages include a first inclined oil passage 33, a second inclined oil passage 34, and a third inclined oil passage 35. The first inclined oil passage 33 obliquely penetrates the fourth journal 14 and the third connecting rod journal 23, extending into the third journal 13 to connect with the second axial straight oil passage 32. During machining, a hole is drilled obliquely to the right from the circumference of the fourth journal 14, passing through the fourth journal 14 and the third connecting rod journal 23 in sequence until it enters the third journal 13. Then, a hole is drilled radially from the circumference of the third journal 13, passing through the second axial straight oil passage 32 and the first inclined oil passage 33, connecting the second axial straight oil passage 32 and the first inclined oil passage 33 via the third radial oil passage 13a.

[0054] The second inclined oil passage 34 obliquely penetrates the fifth journal 15 and the fourth connecting rod journal 24 in sequence, extending into the fourth journal 14 to connect with the first oblique oil passage 33. During machining, a hole is drilled obliquely to the right from the circumference of the fifth journal 15, with the drill bit sequentially penetrating the fifth journal 15 and the fourth connecting rod journal 24 until it enters the fourth journal 14. A hole is then drilled radially from the circumference of the fourth journal 14, passing through the first and second oblique oil passages 33, 34, connecting the first and second oblique oil passages 33, 34 via the fourth radial oil passage 14a.

[0055] The third inclined oil passage 35 obliquely penetrates the fifth journal 15 and the fifth connecting rod journal 25 in sequence, extending into the sixth journal 16 to communicate with the fourth axial straight oil passage 36. The second oblique oil passage 34 and the third oblique oil passage 35 are connected via a fifth radial oil passage 15a extending radially through the fifth journal 15. During machining, a hole is drilled obliquely to the left from the circumference of the fifth journal 15, with the drill bit sequentially penetrating the fifth journal 15 and the fifth connecting rod journal 25 until it enters the sixth journal 16 and passes through the fourth axial straight oil passage 36. A hole is then drilled radially around the circumference of the fifth journal 15, passing through the second oblique oil passage 34 and the third oblique oil passage 35, connecting the second oblique oil passage 34 and the third oblique oil passage 35 via the fifth radial oil passage 15a.

[0056] The oil holes on the first journal 11, the oil holes on the first connecting rod journal 21, and the oil holes on the second journal 12 are all connected to the first axial straight oil passage 31; the oil holes on the second connecting rod journal 22 are connected to the second axial straight oil passage 32; the oil holes on the third connecting rod journal 23 and the oil holes on the fourth journal 14 are all connected to the first oblique oil passage 33; the oil holes on the fourth connecting rod journal 24 are connected to the second oblique oil passage 34; the oil holes on the fifth journal 15 and the oil holes on the fifth connecting rod journal 25 are all connected to the third oblique oil passage 35; the oil holes on the sixth connecting rod journal 26 and the oil holes on the seventh journal 17 are all connected to the fourth axial straight oil passage 36; the oil holes on the seventh connecting rod journal 27 and the oil holes on the eighth journal 18 are all connected to the third axial straight oil passage 37.

[0057] 3 to 7 , the present disclosure also discloses a plunger pump 200, comprising a transmission device 1 and a hydraulic device 2. The transmission device 1 comprises a housing 101, a main shaft assembly, a crankshaft assembly, and seven connecting rod assemblies.

[0058] The main shaft assembly includes a main shaft 4 and first and second helical teeth 41 and 42 disposed thereon. The main shaft 4 is rotatably mounted on the housing 101. The crankshaft assembly is the same as the crankshaft assembly described above, wherein the crankshaft 3 is rotatably mounted on the housing 101, the first gear 301 meshes with the first helical teeth 41, and the first gear 302 meshes with the second helical teeth 42. Seven connecting rod assemblies correspond one to each of the seven connecting rod journals of the crankshaft 3, with one end of each connecting rod assembly connected to the corresponding connecting rod journal.

[0059] The hydraulic device 2 includes a pump body 201 and seven piston assemblies. The pump body 201 is mounted within the housing 101 and includes a liquid inlet, a liquid outlet 204, a liquid return port 205, and seven cylinder bores 206 communicating with the inlet, outlet 204, and liquid return port 205. The seven cylinder bores 206 are distributed axially. In other words, each cylinder bore 206 communicates with each of the liquid inlet, outlet 204, and liquid return port 205. The seven piston assemblies correspond one-to-one to the seven cylinder bores 206. Each piston assembly slides within its corresponding cylinder bore 206 and is connected to the other end of its corresponding connecting rod assembly.

[0060] The rotation of the main shaft 4 drives the crankshaft 3 to rotate, and the connecting rod neck on the crankshaft 3 drives the corresponding piston assembly to move back and forth in the corresponding cylinder hole 206 through the corresponding connecting rod assembly, thereby achieving liquid suction from the liquid inlet, liquid discharge from the liquid outlet 204 and liquid return to the liquid return port 205.

[0061] The plunger pump 200 of the disclosed embodiment not only has a large output flow rate, reduced flow pulsation, and a smoother output flow rate, but also effectively balances the forces generated during the movement of the different connecting rod necks, significantly reducing the load stress on the entire crankshaft and improving reliability. Specifically, the main shaft 4 can be supported by the main shaft bearing 5.

[0062] In some embodiments, housing 101 includes an upper housing 101a and a lower housing 101b. A flush pin 101c parallel to the joint surface between upper housing 101a and lower housing 101b is provided. This flush pin 101c positions upper housing 101a and lower housing 101b, preventing vertical misalignment that could affect the coaxiality of the bearing seat.

[0063] In some embodiments, referring to Figure 8, the liquid inlet is located below the liquid discharge port 204, and the liquid inlet includes a first liquid inlet 202 and a second liquid inlet 203. The first liquid inlet 202 and the second liquid inlet 203 are respectively arranged at both ends of the pump body 201 in the axial direction, and liquid is introduced from the two liquid inlets to increase the liquid suction flow rate.

[0064] In some embodiments, each piston assembly includes a piston 10 and a steel sleeve 111 sleeved on the piston 10. The outer circumferential surface of the steel sleeve 111 is provided with an oil groove 111a. The steel sleeve 111 is slidably mounted in the cylinder bore 206. The oil groove 111a is used to store lubricating oil. The lubricating oil in the oil groove 11a not only lubricates the steel sleeve 111 as it slides in the cylinder bore 206, but also facilitates the installation of the steel sleeve 111.

[0065] In some embodiments, the housing 101 is provided with seven slideways 102. Each connecting rod assembly includes a connecting rod 7, a slider 8, and an intermediate rod 9. One end of the connecting rod 7 is connected to the corresponding connecting rod neck, and the other end of the connecting rod 7 is connected to the corresponding slider 8; the slider 8 is slidably disposed in the corresponding slideway 102; one end of the intermediate rod 9 is connected to the corresponding slider 8, and the other end of the intermediate rod 9 is connected to the corresponding piston 10.

[0066] The present disclosure also discloses a plunger pump station, which, referring to FIG. 8 , includes a base 181 , a plunger pump, a liquid inlet pipeline 171 , a liquid return pipeline 20 , and a motor.

[0067] The plunger pump is the plunger pump mentioned above, and is arranged on the base 181. The liquid inlet pipe 171 is connected to the liquid inlet, and the liquid return pipe 20 is connected to the liquid return port 205; the output end of the motor is connected to the main shaft 4.

[0068] In the description of the embodiments of the present disclosure, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like to indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the embodiments of the present disclosure and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the embodiments of the present disclosure.

[0069] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of the features. In the description of the embodiments of the present disclosure, the meaning of "plurality" is at least two, for example, two, three, etc., unless otherwise clearly and specifically defined.

[0070] In the embodiments of the present disclosure, unless otherwise expressly specified or limited, the terms "installed," "connected," "connected," "fixed," and the like should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integration; they may refer to mechanical connections, electrical connections, or communication between them; they may refer to direct connections or indirect connections through an intermediate medium; they may refer to internal communication between two elements or interaction between two elements, unless otherwise expressly limited. Those skilled in the art can understand the specific meanings of the above terms in the embodiments of the present disclosure based on specific circumstances.

[0071] In the embodiments of the present disclosure, unless otherwise expressly specified or limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or that the first and second features are in indirect contact through an intermediate medium. Furthermore, a first feature being "above," "above," and "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is at a higher level than the second feature. A first feature being "below," "below," and "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is at a lower level than the second feature.

[0072] In the embodiments of the present disclosure, the terms "one embodiment", "some embodiments", "examples", "specific examples", or "some examples" mean that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the embodiments of the present disclosure. In this specification, the schematic expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine different embodiments or examples described in this specification and the features of different embodiments or examples, unless they are contradictory.

[0073] Although the above embodiments have been shown and described, it is understood that the above embodiments are illustrative and are not to be construed as limitations on the embodiments of the present disclosure. Changes, modifications, substitutions and variations of the above embodiments by those skilled in the art are all within the scope of protection of the embodiments of the present disclosure.

Claims

1. A crankshaft assembly for a plunger pump, characterized in that: The crankshaft assembly comprises: a crankshaft (3), a first gear (301) and a second gear (302); The crankshaft (3) comprises a connecting rod neck and a journal, The connecting rod neck includes a first connecting rod neck (21), a second connecting rod neck (22), a third connecting rod neck (23), a fourth connecting rod neck (24), a fifth connecting rod neck (25), a sixth connecting rod neck (26) and a seventh connecting rod neck (27); the journal includes a first journal (11), a second journal (12), a third journal (13), a fourth journal (14), a fifth journal (15), a sixth journal (16), a seventh journal (17) and an eighth journal (18); Wherein, the first journal (11), the first connecting rod journal (21), the second journal (12), the second connecting rod journal (22), the third journal (13), the third connecting rod journal (23), the fourth journal (14), the fourth connecting rod journal (24), the fifth journal (15), the fifth connecting rod journal (25), the sixth journal (16), the sixth connecting rod journal (26), the seventh journal (17), the seventh connecting rod journal (27) and the eighth journal (18) are sequentially distributed in the axial direction (A); The first gear (301) is arranged on the third shaft journal (13), and the second gear (302) is arranged on the sixth shaft journal (16).

2. The crankshaft assembly for a plunger pump according to claim 1, characterized in that: The phase angle of the first connecting rod journal (21) is θ1, the phase angle of the second connecting rod journal (22) is θ2, the phase angle of the third connecting rod journal (23) is θ3, the phase angle of the fourth connecting rod journal (24) is θ4, the phase angle of the fifth connecting rod journal (25) is θ5, the phase angle of the sixth connecting rod journal (26) is θ6, and the phase angle of the seventh connecting rod journal (27) is θ7. Among them, θ4-θ1=θ7-θ4=θ2-θ7=θ5-θ2=θ3-θ5=θ6-θ3=θ1-θ6=(360 / 7)°; or θ2-θ1=θ3-θ2=θ4-θ3=θ5-θ4=θ6-θ5=θ7-θ6=θ6-θ1=θ1-θ7=(360 / 7)°.

3. The crankshaft assembly for a plunger pump according to claim 1 or 2, characterized in that: The crankshaft assembly comprises crankshaft bearings (33) respectively mounted on the first journal, the second journal, the fourth journal, the fifth journal, the seventh journal and the eighth journal.

4. The crankshaft assembly for a plunger pump according to any one of claims 1 to 3, characterized in that: The crankshaft comprises an oil passage which passes through the axial ends of the crankshaft in the axial (A) direction of the crankshaft, and the circumferential surfaces of the first journal (11), the first connecting rod journal (21), the second journal (12), the second connecting rod journal (22), the third connecting rod journal (23), the fourth journal (14), the fourth connecting rod journal (24), the fifth journal (15), the fifth connecting rod journal (25), the sixth connecting rod journal (26), the seventh journal (17), the seventh connecting rod journal (27) and the eighth journal (18) are all provided with oil holes, and the oil holes are connected to the oil passage; The oil passage comprises a first straight oil passage, a second straight oil passage and an oblique oil passage which are connected to each other. In the axial (A) direction, the oblique oil passage is located between the first straight oil passage and the second straight oil passage. The diameter of the oblique oil passage is greater than the diameters of the first straight oil passage (31) and the second straight oil passage (35).

5. The crankshaft assembly for a plunger pump according to claim 4, characterized in that: The first straight oil passage comprises a first axial straight oil passage (31) and a second axial straight oil passage (32); the first axial straight oil passage (31) axially penetrates the first journal (11) and the first connecting rod journal (21) in sequence and extends into the second journal (12); the first axial straight oil passage (31) passes through the central axis of the first connecting rod journal (21); the second axial straight oil passage (32) axially penetrates the second journal (12) and the second connecting rod journal (22) in sequence and extends into the third journal (13); the second axial straight oil passage (32) passes through the central axis of the second connecting rod journal (22); the first axial straight oil passage (31) and the second axial straight oil passage (32) are connected via a first radial oil passage (12a) radially penetrated in the second journal (12); The second straight oil passage comprises a third axial straight oil passage (37) and a fourth axial straight oil passage (36); the third axial straight oil passage (37) axially penetrates the eighth journal (18) and the seventh connecting rod journal (27) in sequence and extends into the seventh journal (17); the third axial straight oil passage (37) passes through the central axis of the seventh connecting rod journal (27); the fourth axial straight oil passage (36) axially penetrates the seventh journal (17) and the sixth connecting rod journal (26) in sequence and extends into the sixth journal (16); the fourth axial straight oil passage (36) passes through the central axis of the sixth connecting rod journal (26); the third axial straight oil passage (37) and the fourth axial straight oil passage (36) are connected via a second radial oil passage (17a) radially penetrated in the seventh journal (17).

6. The crankshaft assembly for a plunger pump according to claim 5, characterized in that: The inclined oil passage comprises a first inclined oil passage (33), a second inclined oil passage (34) and a third inclined oil passage (35); the first inclined oil passage (33) obliquely penetrates the fourth journal (14) and the third connecting rod journal (23) in sequence and extends into the third journal (13) to communicate with the second axial straight oil passage (32); the first inclined oil passage (33) passes through the central axis of the third connecting rod journal (23); the second inclined oil passage (34) obliquely penetrates the fifth journal (15) and the fourth connecting rod journal (24) in sequence and extends into the fourth journal (14) to communicate with the first inclined oil passage (35); The oil passage (33) is connected with the fourth connecting rod journal (24); the second inclined oil passage (34) passes through the central axis of the fourth connecting rod journal (24); the third inclined oil passage (35) obliquely penetrates the fifth journal (15) and the fifth connecting rod journal (25) in sequence and extends into the sixth journal (16) to communicate with the fourth axial straight oil passage (36); the third inclined oil passage (35) passes through the central axis of the fifth connecting rod journal (25), wherein the second inclined oil passage (34) and the third inclined oil passage (35) are connected via a fifth radial oil passage (15a) radially penetrated in the fifth journal (15); The oil hole on the first journal (11), the oil hole on the first connecting rod journal (21), and the oil hole on the second journal (12) are all connected to the first axial straight oil passage (31); the oil hole on the second connecting rod journal (22) is connected to the second axial straight oil passage (32); the oil hole on the third connecting rod journal (23) and the oil hole on the fourth journal (14) are connected to the oil hole on the third connecting rod journal (23). The oil holes on the fourth connecting rod journal (24) are connected to the first inclined oil passage (33); the oil hole on the fourth connecting rod journal (24) is connected to the second inclined oil passage (34); the oil hole on the fifth journal (15) and the oil hole on the fifth connecting rod journal (25) are connected to the third inclined oil passage (35); the oil hole on the sixth connecting rod journal (26) and the oil hole on the seventh journal (17) are connected to the fourth axial straight oil passage (36); the oil hole on the seventh connecting rod journal (27) and the oil hole on the eighth journal (18) are connected to the third axial straight oil passage (37).

7. A plunger pump, characterized in that: include: Transmission device (1) and hydraulic device (2), The transmission device (1) comprises: Box body (101); A main shaft assembly, the main shaft assembly comprising a main shaft (4), the main shaft being provided with a first helical tooth (41) and a second helical tooth (42), the main shaft being rotatably arranged on the housing; A crankshaft assembly, the crankshaft assembly being a crankshaft assembly for a plunger pump according to any one of claims 1 to 6, wherein the crankshaft (3) is rotatably arranged on the housing (101), the first gear (301) is meshed with the first helical teeth (41), and the second gear (302) is meshed with the second helical teeth (42); A plurality of connecting rod assemblies, wherein the connecting rod assemblies correspond to the connecting rod necks one by one, and one end of the connecting rod assembly is connected to the corresponding connecting rod neck; The hydraulic device (2) comprises: A pump body (201), the pump body (201) being arranged on the box body (101), the pump body comprising a liquid inlet, a liquid discharge port (204), a liquid return port (205), and a plurality of cylinder holes (206) communicating with the liquid inlet, the liquid discharge port, and the liquid return port, the cylinder holes (206) being distributed along the axial direction; A plurality of piston assemblies are provided, each of the piston assemblies corresponds to the cylinder holes one by one, and each of the piston assemblies is slidably disposed in the corresponding cylinder hole and is connected to the other end of the corresponding connecting rod assembly.

8. The plunger pump according to claim 7, characterized in that The box body (101) comprises an upper box body (101a) and a lower box body (101b), and a joint surface between the upper box body and the lower box body is provided with a seam pin (101c) parallel to the joint surface.

9. The plunger pump according to claim 7 or 8, characterized in that: The liquid inlet is located below the liquid discharge port (204), and the liquid inlet comprises a first liquid inlet (202) and a second liquid inlet (203), wherein the first liquid inlet (202) and the second liquid inlet (203) are respectively arranged at two ends of the pump body in the axial direction; Each of the piston assemblies comprises a piston (10) and a steel sleeve (111) sleeved on the piston, an outer peripheral surface of the steel sleeve being provided with an oil groove (111a), and the steel sleeve being slidably disposed in the cylinder hole (206); The box body (101) is provided with seven slideways (102); Each of the connecting rod assemblies comprises: A slider (8), the slider (8) being slidably disposed in the corresponding slideway (102); A connecting rod (7), one end of the connecting rod (7) is connected to the corresponding connecting rod neck, and the other end of each connecting rod (7) is connected to the corresponding slider (8); and An intermediate rod (9), one end of which is connected to the corresponding slider (8), and the other end of which is connected to the corresponding piston (10).

10. A plunger pump station, characterized in that: include: Base (18); A plunger pump, wherein the plunger pump is the plunger pump according to any one of claims 6 to 9, and the plunger pump is arranged on the base; a liquid inlet pipeline (17) and a liquid return pipeline (20), wherein the liquid inlet pipeline (17) is connected to the liquid inlet port, and the liquid return pipeline (20) is connected to the liquid return port (205); and A motor (16), the output end of which is connected to the main shaft (4).

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