Hydraulic multi-stage piston liquid lifting mechanism

Abstract

Hydraulic multi-stage piston liquid lifting mechanism, including a housing assembly, an oil cylinder, a push-pull rod A, a push-pull rod B, a coupling joint, a piston A and a piston B; the housing assembly is successively provided with a drainage and oil section, a double-wall oil cylinder section, an upper bidirectional communication section, a repeating unit section, a lower double-wall water cylinder section and a lower bidirectional communication section from one end to the other end; the cylinder body of the oil cylinder is fixedly installed at the front end of the oil cylinder installation cavity, and the piston rod of the oil cylinder extends towards the rear end of the oil cylinder installation cavity; the push-pull rod A is hermetically and slidably installed in the moving guide channel A; the push-pull rod B is hermetically and slidably installed in the moving guide channel B; the piston A is hermetically and slidably installed in the middle piston cavity; the piston B is hermetically and slidably installed in the lower piston cavity. The present invention is used for pumping the leaching solution in the in-situ leaching uranium mine, and can meet the requirement of a pumping liquid flow rate of 6-10 m<supgt;3< / supgt> / h. When the water lifting depth is below 250 m, compared with the traditional deep submersible pump, it has the advantages of large pumping liquid flow rate, relatively low power consumption and relatively low cost.

Description

Technical Field

[0001] The invention relates to the field of machinery related to in-situ uranium leaching, in particular to a hydraulic multi-stage piston liquid extraction mechanism suitable for extracting leaching liquid in an in-situ uranium mine. Background Art

[0002] In-situ leaching of uranium is a very advanced mining technology in the world. Its basic principle is to arrange in-situ leaching uranium wells (including injection wells and extraction wells) according to a certain grid for in-situ leachable sandstone uranium ores, inject in-situ leaching liquid from the injection wells, and allow the in-situ leaching liquid to fully react with the uranium ore to form a solution containing uranium ions. The solution containing uranium ions penetrates through the formation into the extraction wells, and the solution containing uranium ions is extracted to the surface through the extraction wells and input into the ion exchange tower for further uranium extraction.

[0003] The uranium mining enterprises require the in-situ uranium mine pumping flow rate to be 6-10m 3 / h. If the pumping speed is too low, it will not meet the economic requirements of in-situ uranium mining. The depth of in-situ uranium mines can usually reach 200-500m. At present, deep well submersible pumps are usually used to extract the leachate in the well. Since there is a certain gap between the pump body and the blades of the deep well submersible pump (vane pump), the deep well submersible pump has an unavoidable gap leakage (internal leakage) problem. Moreover, with the increase of diving depth (lift), the gap leakage problem of the deep well submersible pump becomes more and more serious, resulting in more serious flow loss.

[0004] In summary, there are the following problems to be solved in extracting leachate from in-situ uranium mines: 1. With the increase of diving depth, the number of deep well submersible pumps required to achieve the specified pumping flow rate is higher, and its purchase cost and operating power consumption also increase accordingly; 2. When the diving depth reaches 250m, the deep well submersible pump can no longer meet the pumping flow rate requirements of in-situ uranium mines due to flow loss. Summary of the invention

[0005] The purpose of the present invention is to overcome the shortcomings of the prior art and provide a hydraulic multi-stage piston liquid extraction mechanism, which solves the problem that the existing deep well submersible pump is used to extract the leaching liquid from deep water in the in-situ uranium mine, the cost and power consumption are high, and the pumping flow rate is difficult to meet the requirements.

[0006] The technical solution of the present invention is: a hydraulic multi-stage piston liquid lifting mechanism, comprising a housing assembly, a cylinder, a push-pull rod A, a push-pull rod B, a connecting head, a piston A and a piston B;

[0007] The shell assembly is provided with a drainage and oil section, a double-walled oil cylinder section, an upper two-way communication section, a repeating unit section, a lower double-walled water cylinder section and a lower two-way communication section in sequence from one end to the other; the drainage and oil section is provided with oil passages and a water outlet channel that are not connected to each other; the double-walled oil cylinder section is provided with an oil cylinder installation cavity and an annular water cavity A that are not connected to each other; the upper two-way communication section is provided with a water inlet channel A, a drainage channel A and a moving guide channel A; the repeating unit section includes a middle double-walled water cylinder section and a middle two-way communication section that are connected to each other; the middle double-walled water cylinder section is provided with a middle piston cavity and annular water cavity B that are not connected to each other; the middle two-way communication section is provided with a water inlet channel B, a drainage channel B and a moving guide channel B; the lower double-walled water cylinder section is provided with a lower piston cavity and annular water cavity C that are not connected to each other; the lower two-way communication section is provided with a water inlet channel C and a drainage channel C that are not connected to each other;

[0008] The cylinder body of the oil cylinder is fixedly installed at the front end of the oil cylinder installation cavity, and the piston rod of the oil cylinder extends to the rear end of the oil cylinder installation cavity; the inside of the cylinder body of the oil cylinder is connected with the rear end of the oil passage;

[0009] The push-pull rod A is sealed and slidably installed in the moving guide channel A, and its front and rear ends extend into the oil cylinder installation cavity and the middle piston cavity respectively;

[0010] The push-pull rod B is sealed and slidably installed in the moving guide channel B, and its front and rear ends extend into the middle piston cavity and the lower piston cavity respectively;

[0011] The coupling head is arranged between the front end of the push-pull rod A and the piston rod of the oil cylinder, which connects the front end of the push-pull rod A and the piston rod of the oil cylinder as a whole, so as to realize the synchronous movement of the oil cylinder and the push-pull rod A;

[0012] The piston A is sealed and slidably installed in the middle piston cavity, and its two ends are respectively connected to the rear end of the push-pull rod A and the front end of the push-pull rod B;

[0013] The piston B is sealed and slidably installed in the lower piston chamber and is connected to the rear end of the push-pull rod B.

[0014] A further technical solution of the present invention is that the housing assembly is cylindrical;

[0015] In the drainage and oil section, the front ends of the oil passage and the water-collecting passage are both connected to the end face of the shell assembly; in the double-walled oil cylinder section, an annular water cavity A is arranged around the outside of the oil cylinder mounting cavity, the front end of the annular water cavity A is connected to the rear end of the water-collecting passage, and the front end of the oil cylinder mounting cavity is connected to the rear end of the oil passage; in the upper two-way communication section, the water inlet channel A, the drainage channel A and the moving guide channel A are not connected to each other; the front end of the water inlet channel A is connected to the outer cylindrical surface of the shell assembly to form a water inlet A, and a first one-way valve is provided in the water inlet channel A; the front end of the drainage channel A is connected to the rear end of the annular water cavity A, and the rear end of the drainage channel A is provided with a first water inlet branch and a second water inlet branch, and a second one-way valve is provided in the second water inlet branch; the front end of the moving guide channel A is connected to the rear end of the oil cylinder mounting cavity;

[0016] In the middle double-wall water cylinder section, an annular water cavity B is arranged around the outside of the middle piston cavity, the front end of the annular water cavity B is connected to the first water inlet branch of the drainage channel A, and the front end of the middle piston cavity is respectively connected to the second water inlet branch of the drainage channel A, the rear end of the water inlet channel A and the rear end of the moving guide channel A;

[0017] In the middle two-way communication section, the water inlet channel B, the drainage channel B and the movable guide channel B are not connected to each other; the middle of the water inlet channel B is provided with a water inlet B connected to the outer cylindrical surface of the shell assembly, and the two ends of the water inlet channel B are respectively provided with a third one-way valve and a fourth one-way valve, and one end of the water inlet channel B provided with the third one-way valve is connected to the rear end of the middle piston cavity; the front end of the drainage channel B is provided with a third water inlet branch and a confluent channel section, and the third water inlet branch is provided with a fifth one-way valve, the third water inlet branch is connected with the rear end of the middle piston cavity, the confluent channel section of the drainage channel B is connected with the rear end of the annular water cavity B, the rear end of the drainage channel B is provided with a fourth water inlet branch and a fifth water inlet branch, and the fourth water inlet branch is provided with a sixth one-way valve; the front end of the movable guide channel B is connected with the rear end of the middle piston cavity;

[0018] In the lower double-wall water cylinder section, an annular water chamber C is arranged around the outer side of the lower piston chamber, the front end of the annular water chamber C is connected to the fifth water inlet branch of the drainage channel B, and the front end of the lower piston chamber is respectively connected to one end of the water inlet channel B provided with a fourth one-way valve, the fourth water inlet branch of the drainage channel B and the rear end of the moving guide channel B;

[0019] In the lower two-way communication section, a seventh one-way valve is provided in the water inlet channel C, the front end of the water inlet channel C is connected to the outer cylindrical surface of the shell assembly to form a water inlet C, and the rear end of the water inlet channel C is connected to the rear end of the lower piston chamber; an eighth one-way valve is provided in the drainage channel C, the front end of the drainage channel C is connected to the rear end of the lower piston chamber, and the rear end of the drainage channel C is connected to the rear end of the annular water chamber C.

[0020] A further technical solution of the present invention is: the piston A divides the middle piston cavity into a middle front cavity relatively close to the front end of the middle piston cavity and a middle rear cavity relatively close to the rear end of the middle piston cavity; the piston A comprises a rotating body A, a rotating body B, a spherical bearing A and a first anti-wear ring; the rotating body A is in the shape of a sleeve with two open ends, and a first sealing section, a first annular boss, a first external thread section and a second sealing section are arranged on its outer circumferential surface from the front end to the rear end in sequence, and a first mounting section, a first axial end positioning section, a sealing plate connecting section and a second axial end positioning section are arranged on its inner hole from the front end to the rear end in sequence, and a sealing plate is welded to the sealing plate section of the inner hole of the rotating body A, and the sealing plate divides the inner hole of the rotating body A into two blind holes that are not connected to each other; the rotating body B is in the shape of a sleeve with two open ends, and a second mounting section, a second annular boss and a third sealing section are arranged on its outer circumferential surface from the front end to the rear end in sequence, and a first internal thread section, a fourth sealing section and a third mounting section are arranged on its inner hole from the front end to the rear end in sequence; the rotating body A The first external thread section is threadedly connected with the first internal thread section of the rotating body B, and the second sealing section on the outer cylindrical surface of the rotating body A and the fourth sealing section in the inner hole of the rotating body B are opposite to each other, and are sealed by an O-ring arranged therebetween; the two spherical bearings A are movably mounted in the first mounting section of the rotating body A and the third mounting section of the rotating body B, respectively, and are axially positioned at both ends; the first anti-wear ring is mounted on the second mounting section of the rotating body B, and its two ends are respectively abutted against the first annular boss of the rotating body A and the second annular boss of the rotating body B, and are axially positioned; the piston A is slidably mounted in the middle piston cavity through the first anti-wear ring, the rotating body A faces the middle front cavity at the front end of the middle piston cavity, and the rotating body B faces the middle rear cavity at the rear end of the middle piston cavity; the Y-type sealing ring mounted on the first sealing section of the outer cylindrical surface of the rotating body A and the Y-type sealing ring mounted on the third sealing section of the outer cylindrical surface of the rotating body B jointly realize the sealing between the piston A and the middle piston cavity;

[0021] Correspondingly, the rear end of the push-pull rod A passes through the joint bearing A in the inner hole of the rotating body A and extends into the first axial end positioning section in the inner hole of the rotating body A, and then the washer and nut installed at the rear end of the push-pull rod A provide axial positioning for the push-pull rod A;

[0022] Correspondingly, the front end of the push-pull rod B passes through the joint bearing A in the inner hole of the rotating body B and extends into the second axial end positioning section in the inner hole of the rotating body A, and then the push-pull rod B is provided with axial positioning by the washer and nut installed at the front end of the push-pull rod B.

[0023] A further technical solution of the present invention is: the piston B divides the lower piston chamber into a lower front chamber relatively close to the front end of the lower piston chamber and a lower rear chamber relatively close to the rear end of the lower piston chamber; the piston B includes a rotating body C, a rotating body D, a spherical bearing B and a second anti-wear ring; the rotating body C is in the shape of a sleeve with both ends open, and a fifth sealing section, a third annular boss, a second external thread section and a sixth sealing section are arranged on its outer circumferential surface from the front end to the rear end, and a fourth mounting section and a third axial end positioning section are arranged on its inner hole from the front end to the rear end; the rotating body D is in the shape of a sleeve with one end open and the other end closed, and a fifth mounting section, a fourth annular boss and a seventh sealing section are arranged on its outer circumferential surface from the front end to the rear end, and a second internal thread section and an eighth sealing section are arranged on its inner hole from the front end to the rear end; the rotating body C is connected to the second internal thread section of the rotating body D through the second external thread section Threaded connection, the sixth sealing section on the outer cylindrical surface of the rotating body C and the eighth sealing section in the inner hole of the rotating body D are opposite to each other, and are sealed by an O-ring arranged therebetween; the spherical bearing B is movably installed in the fourth mounting section of the rotating body C and is axially positioned at both ends; the second anti-wear ring is installed on the fifth mounting section of the rotating body D, and its two ends are respectively abutted against the third annular boss of the rotating body C and the fourth annular boss of the rotating body D, and are axially positioned; the piston B is slidably installed in the lower piston cavity through the second anti-wear ring, the rotating body C faces the lower front cavity at the front end of the lower piston cavity, and the rotating body D faces the lower rear cavity at the rear end of the lower piston cavity; the Y-type sealing ring installed on the fifth sealing section of the outer cylindrical surface of the rotating body C and the Y-type sealing ring installed on the seventh sealing section of the outer cylindrical surface of the rotating body D jointly realize the sealing between the piston B and the lower piston cavity;

[0024] Correspondingly, the rear end of the push-pull rod B passes through the joint bearing B in the inner hole of the rotating body C and extends into the third axial end positioning section in the inner hole of the rotating body C, and then the push-pull rod B is provided with axial positioning by the washer and nut installed at the rear end of the push-pull rod B.

[0025] A further technical solution of the present invention is: the movable guide channel A in the upper bidirectional connecting section is arranged centrally, the number of water inlet channels A and drainage channels A is the same, four respectively; all water inlet channels A and all drainage channels A are uniformly distributed in a ring around the movable guide channel A.

[0026] A further technical solution of the present invention is: the movable guide channel B in the middle bidirectional connecting section is centrally arranged, the number of water inlet channels B and drainage channels B is the same, four respectively; all water inlet channels B and all drainage channels B are uniformly distributed in a ring around the movable guide channel B.

[0027] A further technical solution of the present invention is: any two adjacent sections among the drainage and oil section, double-walled oil cylinder section, upper two-way communication section, repeating unit section, lower double-walled water cylinder section and lower two-way communication section included in the shell assembly are threadedly connected by a tightening sleeve; the middle double-walled water cylinder section and the middle two-way communication section included in the repeating unit section are also threadedly connected by a tightening sleeve; the tightening sleeve includes a semi-annular split A, a semi-annular split B and a locking screw, and the outer walls of the semi-annular split A and the semi-annular split B are respectively provided with half of the external thread, and the semi-annular split A and the semi-annular split B are respectively provided with a wrench positioning hole, the semi-annular split A and the semi-annular split B are surrounded and embraced to form a sleeve, so that half of the external thread on the semi-annular split A and half of the external thread on the semi-annular split B are spliced ​​to form a complete external thread, and then the semi-annular split A and the semi-annular split B are connected as a whole by the locking screw.

[0028] A further technical solution of the present invention is that the number of the repeating unit segments is 1 segment.

[0029] Compared with the prior art, the present invention has the following advantages:

[0030] 1. It is used to extract the leaching liquid from deep water in uranium mines, and can meet the pumping flow rate of 6-10m 3 When the water lifting depth is below 250m, it has the advantages of large pumping flow, relatively low power consumption and relatively low cost compared with traditional deep-water submersible pumps.

[0031] 2. Considering that the inner diameter of the underground uranium mine is relatively narrow (the inner diameter of the well is less than 150mm), when designing the waterway, on the one hand, it is necessary to meet the space feasibility as much as possible, and on the other hand, it is necessary to expand the cross-sectional area of ​​water inlet and outlet as much as possible under the premise of meeting the structural strength. Therefore, an annular water cavity is designed in the section where the oil cylinder and piston (including piston A and piston B) are set inside the shell assembly for water drainage; and a plurality of annularly evenly distributed water inlet channels and drainage channels are designed in the section where the water inlet (including water inlet A, water inlet B and water inlet C) is set outside the shell assembly for water inlet and drainage. Compared with the use of a single water inlet and drainage channel, this waterway design can make fuller use of the internal space of the shell assembly on the one hand, and can provide a relatively larger cross-sectional area of ​​water inlet and drainage on the other hand. 0016.3. The piston adopts a split threaded connection structure, which is easy to install and assemble; two groups of Y-rings and one group of O-rings are set on the piston to fully meet the sealing needs when the piston slides; the anti-wear ring is set in the middle of the piston. On the one hand, it plays a guiding role when the piston moves, avoiding unilateral wear of the Y-ring and thus causing sealing failure. On the other hand, it can reduce the probability of wear of the piston body and play a certain protective role on the piston body.

[0032] 4. When the number of repeating unit segments is 1 (as shown in Example 1), it is a two-stage piston structure, which can meet the pumping flow rate of 6-10m 3 / h requirement. When the number of repeated unit segments is 2, it is a three-stage piston structure. On the one hand, this will increase the pressure in the annular water cavity, and the walls on both sides of the annular water cavity will also need to be thickened accordingly, and the overall radial size of the housing assembly will also increase accordingly, making it difficult to meet the requirements of space feasibility. On the other hand, this also puts higher requirements on the sealing performance of the seal, and the grade and cost of the seal will also increase accordingly. On the other hand, the force required when the oil cylinder is running will also be greater, which will cause the wall of the oil pipeline to be designed to be thicker, so that the overall radial size of the housing assembly will increase accordingly, making it difficult to meet the requirements of space feasibility. In summary, the number of repeated unit segments is 1, which is the most preferred.

[0033] 5. Its application scenario is an in-situ uranium mine with a depth of 200-300m. The shell assembly is subjected to a large water pressure, so the channels at each location cannot be designed to be too thin (that is, there is a minimum requirement for the channel wall thickness). Therefore, a channel style based on central symmetry is adopted in the upper two-way interconnection section and the middle two-way interconnection section, and the number of inlet and outlet channels is set to four respectively; based on the above arrangement, on the one hand, the internal space of the upper two-way interconnection section and the middle two-way interconnection section is fully utilized, and a relatively larger inlet cross-sectional area and outlet cross-sectional area are provided within the limited design space, in order to meet the theoretical design of inlet and outlet volume (6-10m 3 / h) requirements, on the other hand, this channel pattern based on the central symmetric arrangement helps to keep the center of gravity of the shell assembly centered and the stability during the water lifting operation, avoiding the lateral (radial) tilt of the shell assembly during the water lifting operation or when it is stationary. 0019. The present invention is further described below in conjunction with the figures and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 It is a schematic diagram of the end surface structure of the present invention;

[0035] Figure 2 for Figure 1 AA section view;

[0036] Figure 3 for Figure 1 BB cross-sectional view;

[0037] Figure 4 for Figure 2 Enlarged view of section Ⅰ;

[0038] Figure 5 for Figure 2 Enlarged view of paragraph II;

[0039] Figure 6 for Figure 2Enlarged view of section III;

[0040] Figure 7 for Figure 2 Enlarged view of segment IV;

[0041] Figure 8 for Figure 3 Enlarged view of section Ⅰ;

[0042] Fig. 9 for Figure 3 Enlarged view of paragraph II;

[0043] Fig.10 for Figure 3 Enlarged view of section III;

[0044] Fig.11 for Figure 3 Enlarged view of segment IV;

[0045] Fig.12 for Figure 5 AA section view;

[0046] Fig.13 for Figure 6 BB cross-sectional view;

[0047] Fig.14 for Figure 7 CC section view;

[0048] Fig.15 for Fig. 9 DD cross-sectional view;

[0049] Fig.16 It is a structural schematic diagram of piston A;

[0050] Fig.17 It is a structural schematic diagram of piston B;

[0051] Fig.18 It is a schematic diagram of the structure of the rotating body A in the piston A;

[0052] Fig.19 It is a schematic diagram of the structure of the rotating body B in the piston A;

[0053] Fig. 20 It is a schematic diagram of the structure of the rotating body C in the piston B;

[0054] Fig.21 It is a schematic diagram of the structure of the rotating body D in the piston B;

[0055] Fig. 22 It is a radial cross-sectional view of the tightening sleeve.

[0056] Legend: Drainage and oil section 11; oil channel 111; water outlet channel 112; double-walled oil cylinder section 12; oil cylinder installation chamber 121; annular water chamber A122; upper two-way communication section 13; water inlet channel A131; drainage channel A132; first water inlet branch 1321; second water inlet branch 1322; first one-way valve 133; second one-way valve 134; middle double-walled water cylinder section 14; middle front chamber 1411; middle rear chamber 1412; annular water chamber B142; middle two-way communication section 15; water inlet channel B151; drainage channel channel B152; third water inlet branch 1521; confluence channel section 1522; fourth water inlet branch 1523; fifth water inlet branch 1524; third one-way valve 153; fourth one-way valve 154; fifth one-way valve 155; sixth one-way valve 156; lower double-wall water cylinder section 16; lower front cavity 1611; lower rear cavity 1612; annular water cavity C162; lower two-way communication section 17; water inlet channel C171; drainage channel C172; seventh one-way valve 173; eighth one-way valve 174; oil cylinder 2; push-pull rod A3; push-pull rod B4; connection Head 5; piston A6; rotating body A61; first sealing section 611; first annular boss 612; first external thread section 613; second sealing section 614; first mounting section 615; first shaft end positioning section 616; sealing plate 617; second shaft end positioning section 618; rotating body B62; second mounting section 621; second annular boss 622; third sealing section 623; first internal thread section 624; fourth sealing section 625; third mounting section 626; spherical bearing A63; first anti-wear ring 64; piston B7; rotating body C71; fifth sealing section 711; third annular boss 712; second external thread section 713; sixth sealing section 714; fourth mounting section 715; third shaft end positioning section 716; rotating body D72; fifth mounting section 721; fourth annular boss 722; seventh sealing section 723; second internal thread section 724; eighth sealing section 725; spherical bearing B73; second anti-wear ring 74; tightening sleeve 8; semi-annular split A81; semi-annular split B82; locking screw 83; water inlet A100; water inlet B200; water inlet C300; wrench positioning hole 400.

[0057] Note: Due to the large aspect ratio of the present invention, the Figure 2-3 ) makes it difficult to see the internal structure, so the axial length of each component is shortened when drawing (without changing the structure of each component), and in the general diagram ( Figure 2-3 ) divides the present invention into four sections, Ⅰ, Ⅱ, Ⅲ, and Ⅳ, along the axial direction, and then draws diagrams for these four sections respectively, so as to clearly show the internal structure of the present invention. Figure 2-11 The arrow in the figure indicates the flow direction of the waterway. Implementation

[0058] Embodiment 1:

[0059] like Figure 1-22 As shown, the hydraulic multi-stage piston liquid lifting mechanism includes a housing assembly, a cylinder 2, a push-pull rod A3, a push-pull rod B4, a connecting head 5, a piston A6 and a piston B7.

[0060] The shell assembly is cylindrical as a whole, and is provided with a drainage and oil section 11, a double-walled oil cylinder section 12, an upper two-way communication section 13, a repeating unit section, a lower double-walled water cylinder section 16 and a lower two-way communication section 17 in sequence from one end to the other.

[0061] An oil passage 111 and a water outlet passage 112 which are not connected to each other are provided inside the drainage and oil passage section 11 . The front ends of the oil passage 111 and the water outlet passage 112 are both connected to the end surface of the housing assembly.

[0062] The double-walled oil cylinder section 12 is provided with an oil cylinder installation chamber 121 and an annular water chamber A122 which are not connected to each other. The annular water chamber A122 is arranged around the outside of the oil cylinder installation chamber 121. The front end of the annular water chamber A122 is connected to the rear end of the water outlet channel 112, and the front end of the oil cylinder installation chamber 121 is connected to the rear end of the oil channel 111. 0027. The upper two-way communication section 13 is provided with a water inlet channel A131, a drainage channel A132 and a moving guide channel A. The water inlet channel A131, the drainage channel A132 and the moving guide channel A are not connected to each other. The front end of the water inlet channel A131 is connected to the outer cylindrical surface of the shell assembly to form a water inlet A100, and a first one-way valve 133 is provided in the water inlet channel A131. The front end of the drainage channel A132 is connected to the rear end of the annular water cavity A122. The rear end of the drainage channel A132 is provided with a first water inlet branch 1321 and a second water inlet branch 1322. The second water inlet branch 1322 is provided with a second one-way valve 134. The front end of the movable guide channel A is connected to the rear end of the oil cylinder installation cavity 121. 0028. The repeating unit segment includes a middle double-walled water cylinder segment 14 and a middle two-way connecting segment 15 that are connected to each other. The middle double-walled water cylinder segment 14 is provided with a middle piston cavity and an annular water cavity B142 that are not connected to each other. The annular water cavity B142 is arranged around the outside of the middle piston cavity. The front end of the annular water cavity B142 is connected to the first water inlet branch 1321 of the drainage channel A132. The front end of the middle piston cavity is respectively connected to the second water inlet branch 1322 of the drainage channel A132, the rear end of the water inlet channel A131 and the rear end of the movable guide channel A. The middle two-way communication section 15 is provided with a water inlet channel B151, a drainage channel B152 and a moving guide channel B. The water inlet channel B151, the drainage channel B152 and the moving guide channel B are not connected to each other. A water inlet B200 connected to the outer cylindrical surface of the housing assembly is provided in the middle of the water inlet channel B151, and a third one-way valve 153 and a fourth one-way valve 154 are provided at both ends of the water inlet channel B151, respectively. One end of the water inlet channel B151 provided with the third one-way valve 153 is connected to the rear end of the middle piston chamber. The front end of the drainage channel B152 is provided with a third water inlet branch 1521 and a confluent channel section 1522, a fifth one-way valve 155 is provided in the third water inlet branch 1521, the third water inlet branch 1521 is communicated with the rear end of the middle piston cavity, the confluent channel section 1522 of the drainage channel B152 is communicated with the rear end of the annular water cavity B142, a fourth water inlet branch 1523 and a fifth water inlet branch 1524 are provided at the rear end of the drainage channel B152, and a sixth one-way valve 156 is provided in the fourth water inlet branch 1523. The front end of the moving guide channel B is communicated with the rear end of the middle piston cavity.

[0063] The lower double-wall water cylinder section is provided with a lower piston chamber and an annular water chamber C162 which are not connected to each other. The annular water chamber C162 is arranged around the outer side of the lower piston chamber, and the front end of the annular water chamber C162 is connected to the fifth water inlet branch 1524 of the drainage channel B152, and the front end of the lower piston chamber is respectively connected to one end of the water inlet channel B151 provided with the fourth one-way valve 154, the fourth water inlet branch 1523 of the drainage channel B152 and the rear end of the moving guide channel B.

[0064] The lower two-way communication section is provided with an inlet channel C171 and a drain channel C172 which are not connected to each other. The inlet channel C171 is provided with a seventh one-way valve 173. The front end of the inlet channel C171 is connected to the outer cylindrical surface of the housing assembly to form a water inlet C300. The rear end of the inlet channel C171 is connected to the rear end of the lower piston chamber. The drain channel C172 is provided with an eighth one-way valve 174. The front end of the drain channel C172 is connected to the rear end of the lower piston chamber. The rear end of the drain channel C172 is connected to the rear end of the annular water chamber C162.

[0065] The cylinder body of the oil cylinder 2 is fixedly mounted at the front end of the oil cylinder mounting cavity 121, and the piston rod of the oil cylinder 2 extends to the rear end of the oil cylinder mounting cavity 121. Accordingly, the rear end of the oil passage 111 is connected to the inside of the cylinder body of the oil cylinder 2, thereby providing path support for the oil cylinder 2 to enter and exit the oil.

[0066] The push-pull rod A3 is sealed and slidably installed in the moving guide channel A, and its front and rear ends extend into the cylinder installation cavity 121 and the middle piston cavity respectively.

[0067] The push-pull rod B4 is sealed and slidably installed in the moving guide channel B, and its front and rear ends extend into the middle piston cavity and the lower piston cavity respectively.

[0068] The coupling head 5 is arranged between the front end of the push-pull rod A3 and the piston rod of the oil cylinder 2, which fixes the front end of the push-pull rod A3 and the piston rod of the oil cylinder 2 as a whole, so as to realize the synchronous movement of the oil cylinder 2 and the push-pull rod A3.

[0069] Piston A6 is sealed and slidably installed in the middle piston chamber, and is connected to the rear end of the push-pull rod A3 and the front end of the push-pull rod B4 at both ends respectively, which divides the middle piston chamber into a middle front chamber 1411 relatively close to the front end of the middle piston chamber and a middle rear chamber 1412 relatively close to the rear end of the middle piston chamber, thereby realizing synchronous movement of the push-pull rod A3 and the push-pull rod B4.

[0070] The piston B7 is sealingly and slidably installed in the lower piston chamber, and is connected to the rear end of the push-pull rod B4 at one end, which divides the lower piston chamber into a lower front chamber 1611 relatively close to the front end of the lower piston chamber and a lower rear chamber 1612 relatively close to the rear end of the lower piston chamber.

[0071] Preferably, the piston A6 comprises a rotating body A61, a rotating body B62, a spherical bearing A63 and a first anti-wear ring 64. The rotating body A61 is in the shape of a sleeve with both ends open, and the outer circumferential surface thereof is provided with a first sealing section 611, a first annular boss 612, a first external thread section 613 and a second sealing section 614 in sequence from the front end to the rear end, and the inner hole thereof is provided with a first mounting section 615, a first axial end positioning section 616, a sealing plate connecting section and a second axial end positioning section 618 in sequence from the front end to the rear end, and the rotating body A61 has a sealing plate 617 welded to the sealing plate section of the inner hole, and the sealing plate 617 separates the inner hole of the rotating body A61 into two blind holes that are not connected to each other. The rotating body B62 is in the shape of a sleeve with both ends open. The second mounting section 621, the second annular boss 622 and the third sealing section 623 are arranged on its outer circumferential surface from the front end to the rear end, and the first internal thread section 624, the fourth sealing section 625 and the third mounting section 626 are arranged on its inner hole from the front end to the rear end. The rotating body A61 is threadedly connected with the first internal thread section 624 of the rotating body B62 through the first external thread section 613. The second sealing section 614 on the outer circumferential surface of the rotating body A61 and the fourth sealing section 625 in the inner hole of the rotating body B62 are opposite to each other and sealed by an O-ring arranged therebetween. The two spherical bearings A63 are movably mounted in the first mounting section 615 of the rotating body A61 and the third mounting section 626 of the rotating body B62, respectively, and are axially positioned at both ends. The first anti-wear ring 64 is installed on the second installation section 621 of the rotating body B62, and its two ends are respectively against the first annular boss 612 of the rotating body A61 and the second annular boss 622 of the rotating body B62, so as to be axially positioned. The piston A6 is slidably installed in the middle piston cavity through the first anti-wear ring 64, the rotating body A61 faces the middle front cavity 1411 at the front end of the middle piston cavity, and the rotating body B62 faces the middle rear cavity 1412 at the rear end of the middle piston cavity. The Y-type sealing ring installed on the first sealing section 611 on the outer cylindrical surface of the rotating body A61 and the Y-type sealing ring installed on the third sealing section 623 on the outer cylindrical surface of the rotating body B62 jointly realize the sealing between the piston A6 and the middle piston cavity. Correspondingly, the rear end of the push-pull rod A3 passes through the joint bearing A63 in the inner hole of the rotating body A61 and extends into the first axial end positioning section 616 in the inner hole of the rotating body A61, and then the push-pull rod A3 is provided with axial positioning through the washer and nut installed at the rear end of the push-pull rod A3. Correspondingly, the front end of the push-pull rod B4 passes through the joint bearing A63 in the inner hole of the rotating body B62 and extends into the second axial end positioning section 618 in the inner hole of the rotating body A61, and then the push-pull rod B4 is provided with axial positioning through the washer and nut installed at the front end of the push-pull rod B4.

[0072] Preferably, the piston B7 includes a rotating body C71, a rotating body D72, a spherical bearing B73 and a second anti-wear ring 74. The rotating body C71 is in the shape of a sleeve with both ends open, and the outer circumferential surface thereof is provided with a fifth sealing section 711, a third annular boss 712, a second external thread section 713 and a sixth sealing section 714 in sequence from the front end to the rear end, and the inner hole thereof is provided with a fourth mounting section 715 and a third axial end positioning section 716 in sequence from the front end to the rear end. The rotating body D72 is in the shape of a sleeve with one end open and the other end closed, and the outer circumferential surface thereof is provided with a fifth mounting section 721, a fourth annular boss 722 and a seventh sealing section 723 in sequence from the front end to the rear end, and the inner hole thereof is provided with a second internal thread section 724 and an eighth sealing section 725 in sequence from the front end to the rear end. The rotating body C71 is threadedly connected with the second internal thread section 724 of the rotating body D72 through the second external thread section 713. The sixth sealing section 714 on the outer circumferential surface of the rotating body C71 and the eighth sealing section 725 in the inner hole of the rotating body D72 are opposite to each other and sealed by an O-ring disposed therebetween. The spherical bearing B73 is movably mounted in the fourth mounting section 715 of the rotating body C71 and is axially positioned at both ends. The second anti-wear ring 74 is mounted on the fifth mounting section 721 of the rotating body D72, and its two ends are respectively abutted against the third annular boss 712 of the rotating body C71 and the fourth annular boss 722 of the rotating body D72, and is axially positioned. The piston B7 is slidably mounted in the lower piston chamber through the second anti-wear ring 74, the rotating body C71 faces the lower front chamber 1611 at the front end of the lower piston chamber, and the rotating body D72 faces the lower rear chamber 1611 at the rear end of the lower piston chamber. The Y-type sealing ring installed on the fifth sealing segment 711 on the outer circumference of the rotating body C71 and the Y-type sealing ring installed on the seventh sealing segment 723 on the outer circumference of the rotating body D72 jointly realize the sealing between the piston B7 and the lower piston chamber. Correspondingly, the rear end of the push-pull rod B4 passes through the joint bearing B73 in the inner hole of the rotating body C71 and extends into the third shaft end positioning segment 716 in the inner hole of the rotating body C71, and then provides axial positioning for the push-pull rod B4 through the washer and nut installed at the rear end of the push-pull rod B4.

[0073] Preferably, the movable guide channel A in the upper two-way communication section 13 is arranged in the center, and the number of water inlet channels A131 and drainage channels A132 is the same, which are four respectively, and all water inlet channels A131 and all drainage channels A132 are evenly distributed in a ring around the movable guide channel A. Based on this arrangement, on the one hand, the internal space of the upper two-way communication section 13 is fully utilized, and the water inlet cross-sectional area and the drainage cross-sectional area are increased as much as possible within the limited design space, so as to meet the theoretical design water inlet and drainage volume (6-10m 3 / h) requirement, on the other hand, this channel style based on central symmetric arrangement helps to maintain the center of gravity of the shell assembly in the center and the stability during water lifting operation, avoiding lateral (radial) tilting of the shell assembly during water lifting operation or when it is stationary.

[0074] Preferably, the movable guide channel B in the middle two-way interconnecting section 15 is arranged in the center, the number of water inlet channels B151 and drainage channels B152 is the same, and all water inlet channels B151 and all drainage channels B152 are evenly distributed in a ring around the movable guide channel B. Based on this arrangement, on the one hand, the internal space of the middle two-way interconnecting section 15 is fully utilized, and the water inlet cross-sectional area and the drainage cross-sectional area are increased as much as possible within the limited design space, so as to meet the theoretical design water inlet and drainage volume (6-10m 3 / h) requirement, on the other hand, this channel style based on central symmetric arrangement helps to maintain the center of gravity of the shell assembly in the center and the stability during water lifting operation, avoiding lateral (radial) tilting of the shell assembly during water lifting operation or when it is stationary.

[0075] Preferably, any two adjacent sections of the water drainage and oil section 11, the double-walled oil cylinder section 12, the upper two-way communication section 13, the repeating unit section, the lower double-walled water cylinder section 16 and the lower two-way communication section 17 included in the housing assembly are threadedly connected by the tightening sleeve 8. The middle double-walled water cylinder section 14 and the middle two-way communication section 15 included in the repeating unit section are also threadedly connected by the tightening sleeve 8. The tightening sleeve 8 includes a semi-annular split A81, a semi-annular split B82 and a locking screw 83. The outer walls of the semi-annular split A81 and the semi-annular split B82 are respectively provided with half of the external thread, and the semi-annular split A81 and the semi-annular split B82 are respectively provided with a wrench positioning hole 400. The semi-annular split A81 and the semi-annular split B82 are surrounded and embraced to form a sleeve, so that the half external thread on the semi-annular split A81 and the half external thread on the semi-annular split B82 are spliced ​​to form a complete external thread, and then the semi-annular split A81 and the semi-annular split B82 are connected as a whole by the locking screw 83. The structure of the tightening sleeve 8 is convenient for the threaded connection between the two long pipes. During assembly, the tightening sleeve 8 is installed on the outer circumferential surface of one of the long pipes, and then the internal thread in the inner hole of the other long pipe is connected with the external thread of the tightening sleeve 8. Then, the threaded connection between the two long pipes can be achieved by rotating the tightening sleeve 8 with the help of a wrench (without rotating the long pipe with a relatively large weight), which greatly reduces the difficulty of assembly.

[0076] Briefly describe the application method of the present invention:

[0077] The above-mentioned hydraulic multi-stage piston liquid extraction mechanism is used to extract the leachate in the in-situ uranium mine. Before extraction, a steel cable, an oil pipeline and a water pipeline are connected to the end face of the drainage and oil section 11 of the shell assembly. The lower end of the oil pipeline is connected to the front end of the oil channel 111, and the upper end of the oil pipeline is connected to the hydraulic station on the ground. The lower end of the water pipeline is connected to the front end of the water outlet channel 112, and the upper end of the water pipeline is connected to the outside of the wellhead. The lower end of the steel cable is directly or indirectly fixedly connected to the drainage and oil section 11 of the shell assembly, and the upper end of the steel cable is connected to the reeling and releasing equipment on the ground. When the shell assembly is suspended by the steel cable, it is in a vertical state, and the drainage and oil section 11 of the shell assembly and the lower two-way connecting section 17 are located at the upper and lower ends respectively.

[0078] The hydraulic multi-stage piston liquid extraction mechanism is suspended and lowered into the in-situ uranium mine by a steel cable, and the lifting depth is determined according to the depth of the well section where the leaching liquid is to be extracted; the piston rod of the driving oil cylinder 2 is telescopically moved to realize continuous extraction of the leaching liquid.

[0079] When the piston rod of cylinder 2 extends, the following effects occur simultaneously:

[0080] 1. The piston A6 moves downward, so that the volume of the middle front chamber 1411 expands and generates negative pressure. Under the action of negative pressure, the leachate in the well enters the water inlet channel A131 through the water inlet A100, and then enters the middle front chamber 1411 through the first one-way valve 133 to achieve liquid absorption;

[0081] 2. The piston B7 moves downward, so that the volume of the lower front chamber 1611 expands and generates negative pressure. Under the action of negative pressure, the leachate in the well enters the water inlet channel B151 through the water inlet B200, and then enters the lower front chamber 1611 through the fourth one-way valve 154 to achieve liquid absorption;

[0082] 3. The piston A6 moves downward, reducing the volume of the middle rear chamber 1412 and generating positive pressure. Under the positive pressure, the liquid in the middle rear chamber 1412 passes through the third water inlet branch 1521 with the fifth one-way valve 155, the drainage channel B152, the converging channel section 1522, the annular water chamber B142, the first water inlet branch 1321, the drainage channel A132 and the annular water chamber A122 in sequence, and enters the water outlet channel 112, and is finally transported to the outside of the wellhead through the water pipeline to achieve liquid discharge;

[0083] 4. The piston B7 moves downward, reducing the volume of the lower rear chamber 1612 and generating positive pressure. Under the action of the positive pressure, the liquid in the lower rear chamber 1612 passes through the drainage channel C172 with the eighth one-way valve 174, the annular water chamber C162, the fifth water inlet branch 1524, the drainage channel B152, the converging channel section 1522, the annular water chamber B142, the first water inlet branch 1321, the drainage channel A132 and the annular water chamber A122, and enters the collective water outlet channel 112, and is finally transported to the outside of the wellhead through the water pipeline to achieve drainage.

[0084] When the piston rod of cylinder 2 retracts, the following effects occur simultaneously:

[0085] 1. The piston A6 moves upward, so that the volume of the middle rear chamber 1412 expands and generates negative pressure. Under the action of negative pressure, the leachate in the well enters the water inlet channel B151 through the water inlet B200, and then enters the middle rear chamber 1412 through the third one-way valve 153 to achieve liquid absorption;

[0086] 2. The piston B7 moves upward, so that the volume of the lower rear chamber 1612 expands and generates negative pressure. Under the action of negative pressure, the leachate in the well enters the water inlet channel C171 through the water inlet C300, and then enters the lower rear chamber 1612 through the seventh one-way valve 173 to achieve liquid absorption;

[0087] 3. The piston A6 moves upward, reducing the volume of the middle front chamber 1411 and generating positive pressure. Under the positive pressure, the liquid in the middle front chamber 1411 passes through the second water inlet branch 1322 with the second one-way valve 134, the drainage channel A132 and the annular water chamber A122 in sequence, enters the water outlet channel 112, and is finally transported to the outside of the wellhead through the water pipeline to achieve liquid discharge;

[0088] 4. The piston B7 moves upward, reducing the volume of the lower front chamber 1611 and generating positive pressure. Under the action of the positive pressure, the liquid in the lower front chamber 1611 passes through the fourth water inlet branch 1523 with the sixth one-way valve 156, the drainage channel B152, the converging channel section 1522, the annular water chamber B142, the first water inlet branch 1321, the drainage channel A132 and the annular water chamber A122 in sequence, and enters the collective water outlet channel 112, and is finally transported to the outside of the wellhead through the water pipeline to achieve liquid discharge.

Claims

1. Hydraulic multi-stage piston liquid extraction mechanism, characterized by: It includes a housing assembly, a cylinder, a push-pull rod A, a push-pull rod B, a connecting head, a piston A and a piston B; The shell assembly is provided with a drainage and oil section, a double-walled oil cylinder section, an upper two-way communication section, a repeating unit section, a lower double-walled water cylinder section and a lower two-way communication section in sequence from one end to the other; the drainage and oil section is provided with oil passages and a water outlet channel that are not connected to each other; the double-walled oil cylinder section is provided with an oil cylinder installation cavity and an annular water cavity A that are not connected to each other; the upper two-way communication section is provided with a water inlet channel A, a drainage channel A and a moving guide channel A; the repeating unit section includes a middle double-walled water cylinder section and a middle two-way communication section that are connected to each other; the middle double-walled water cylinder section is provided with a middle piston cavity and annular water cavity B that are not connected to each other; the middle two-way communication section is provided with a water inlet channel B, a drainage channel B and a moving guide channel B; the lower double-walled water cylinder section is provided with a lower piston cavity and annular water cavity C that are not connected to each other; the lower two-way communication section is provided with a water inlet channel C and a drainage channel C that are not connected to each other; The cylinder body of the oil cylinder is fixedly installed at the front end of the oil cylinder installation cavity, and the piston rod of the oil cylinder extends to the rear end of the oil cylinder installation cavity; the inside of the cylinder body of the oil cylinder is connected with the rear end of the oil passage; The push-pull rod A is sealed and slidably installed in the moving guide channel A, and its front and rear ends extend into the oil cylinder installation cavity and the middle piston cavity respectively; The push-pull rod B is sealed and slidably installed in the moving guide channel B, and its front and rear ends extend into the middle piston cavity and the lower piston cavity respectively; The coupling head is arranged between the front end of the push-pull rod A and the piston rod of the oil cylinder, which connects the front end of the push-pull rod A and the piston rod of the oil cylinder as a whole, so as to realize the synchronous movement of the oil cylinder and the push-pull rod A; The piston A is sealed and slidably installed in the middle piston cavity, and its two ends are respectively connected to the rear end of the push-pull rod A and the front end of the push-pull rod B; The piston B is sealed and slidably installed in the lower piston chamber and is connected to the rear end of the push-pull rod B.

2. The hydraulic multi-stage piston liquid extraction mechanism according to claim 1, characterized in that: The housing assembly is cylindrical; In the drainage and oil section, the front ends of the oil channel and the water outlet channel are both connected to the end surface of the housing assembly; In the double-walled oil cylinder section, an annular water cavity A is arranged around the outside of the oil cylinder installation cavity, the front end of the annular water cavity A is communicated with the rear end of the water outlet channel, and the front end of the oil cylinder installation cavity is communicated with the rear end of the oil channel; In the upper two-way communication section, the water inlet channel A, the drainage channel A and the moving guide channel A are not connected to each other; the front end of the water inlet channel A is connected to the outer cylindrical surface of the shell assembly to form a water inlet A, and a first one-way valve is provided in the water inlet channel A; the front end of the drainage channel A is connected to the rear end of the annular water cavity A, and the rear end of the drainage channel A is provided with a first water inlet branch and a second water inlet branch, and a second one-way valve is provided in the second water inlet branch; the front end of the moving guide channel A is connected to the rear end of the oil cylinder installation cavity; In the middle double-wall water cylinder section, an annular water cavity B is arranged around the outside of the middle piston cavity, the front end of the annular water cavity B is connected to the first water inlet branch of the drainage channel A, and the front end of the middle piston cavity is respectively connected to the second water inlet branch of the drainage channel A, the rear end of the water inlet channel A and the rear end of the moving guide channel A; In the middle two-way communication section, the water inlet channel B, the drainage channel B and the movable guide channel B are not connected to each other; the middle of the water inlet channel B is provided with a water inlet B connected to the outer cylindrical surface of the shell assembly, and the two ends of the water inlet channel B are respectively provided with a third one-way valve and a fourth one-way valve, and one end of the water inlet channel B provided with the third one-way valve is connected to the rear end of the middle piston cavity; the front end of the drainage channel B is provided with a third water inlet branch and a confluent channel section, and the third water inlet branch is provided with a fifth one-way valve, the third water inlet branch is connected with the rear end of the middle piston cavity, the confluent channel section of the drainage channel B is connected with the rear end of the annular water cavity B, the rear end of the drainage channel B is provided with a fourth water inlet branch and a fifth water inlet branch, and the fourth water inlet branch is provided with a sixth one-way valve; the front end of the movable guide channel B is connected with the rear end of the middle piston cavity; In the lower double-wall water cylinder section, an annular water chamber C is arranged around the outer side of the lower piston chamber, the front end of the annular water chamber C is connected to the fifth water inlet branch of the drainage channel B, and the front end of the lower piston chamber is respectively connected to one end of the water inlet channel B provided with a fourth one-way valve, the fourth water inlet branch of the drainage channel B and the rear end of the moving guide channel B; In the lower two-way communication section, a seventh one-way valve is provided in the water inlet channel C, the front end of the water inlet channel C is connected to the outer cylindrical surface of the shell assembly to form a water inlet C, and the rear end of the water inlet channel C is connected to the rear end of the lower piston chamber; an eighth one-way valve is provided in the drainage channel C, the front end of the drainage channel C is connected to the rear end of the lower piston chamber, and the rear end of the drainage channel C is connected to the rear end of the annular water chamber C.

3. The hydraulic multi-stage piston liquid extraction mechanism according to claim 2, characterized in that: Piston A divides the middle piston chamber into a middle front chamber relatively close to the front end of the middle piston chamber and a middle rear chamber relatively close to the rear end of the middle piston chamber; Piston A includes a rotating body A, a rotating body B, a spherical bearing A and a first anti-wear ring; Rotating body A is in the shape of a sleeve with open ends, and a first sealing section, a first annular boss, a first external thread section and a second sealing section are arranged on its outer circumferential surface from the front end to the rear end, and a first mounting section, a first axial end positioning section, a sealing plate connecting section and a second axial end positioning section are arranged on its inner hole from the front end to the rear end, and a sealing plate is welded to the sealing plate section of the inner hole of rotating body A, and the sealing plate divides the inner hole of rotating body A into two blind holes that are not connected to each other; Rotating body B is in the shape of a sleeve with open ends, and a second mounting section, a second annular boss and a third sealing section are arranged on its outer circumferential surface from the front end to the rear end, and a first internal thread section, a fourth sealing section and a third mounting section are arranged on its inner hole from the front end to the rear end; Rotating body A is connected to the spherical bearing by a first external thread The first segment is threadedly connected with the first internal thread segment of the rotating body B, the second sealing segment on the outer cylindrical surface of the rotating body A and the fourth sealing segment in the inner hole of the rotating body B are opposite to each other, and are sealed by an O-shaped sealing ring arranged between the two; the two spherical bearings A are movably installed in the first mounting segment of the rotating body A and the third mounting segment of the rotating body B, and are axially positioned at both ends; the first anti-wear ring is installed on the second mounting segment of the rotating body B, and its two ends are respectively against the first annular boss of the rotating body A and the second annular boss of the rotating body B, and are axially positioned; the piston A is slidably installed in the middle piston cavity through the first anti-wear ring, the rotating body A faces the middle front cavity at the front end of the middle piston cavity, and the rotating body B faces the middle rear cavity at the rear end of the middle piston cavity; the Y-type sealing ring installed on the first sealing segment of the outer cylindrical surface of the rotating body A and the Y-type sealing ring installed on the third sealing segment of the outer cylindrical surface of the rotating body B jointly realize the sealing between the piston A and the middle piston cavity; Correspondingly, the rear end of the push-pull rod A passes through the joint bearing A in the inner hole of the rotating body A and extends into the first axial end positioning section in the inner hole of the rotating body A, and then the washer and nut installed at the rear end of the push-pull rod A provide axial positioning for the push-pull rod A; Correspondingly, the front end of the push-pull rod B passes through the joint bearing A in the inner hole of the rotating body B and extends into the second axial end positioning section in the inner hole of the rotating body A, and then the push-pull rod B is provided with axial positioning by the washer and nut installed at the front end of the push-pull rod B.

4. The hydraulic multi-stage piston liquid extraction mechanism according to claim 3, characterized in that: The piston B divides the lower piston chamber into a lower front chamber relatively close to the front end of the lower piston chamber and a lower rear chamber relatively close to the rear end of the lower piston chamber; the piston B includes a rotating body C, a rotating body D, a spherical bearing B and a second anti-wear ring; the rotating body C is in the shape of a sleeve with both ends open, and a fifth sealing section, a third annular boss, a second external thread section and a sixth sealing section are arranged on its outer circumferential surface from the front end to the rear end, and a fourth mounting section and a third axial end positioning section are arranged on its inner hole from the front end to the rear end; the rotating body D is in the shape of a sleeve with one end open and the other end closed, and a fifth mounting section, a fourth annular boss and a seventh sealing section are arranged on its outer circumferential surface from the front end to the rear end, and a second internal thread section and an eighth sealing section are arranged on its inner hole from the front end to the rear end; the rotating body C is threadedly connected to the second internal thread section of the rotating body D through the second external thread section, and the rotating body D is threadedly connected to the second internal thread section of the rotating body D through the second external thread section. The sixth sealing section on the outer cylindrical surface of the body C and the eighth sealing section in the inner hole of the rotating body D are opposite to each other and are sealed by an O-shaped sealing ring arranged therebetween; the spherical bearing B is movably installed in the fourth mounting section of the rotating body C and is axially positioned at both ends; the second anti-wear ring is installed on the fifth mounting section of the rotating body D, and its two ends are respectively abutted against the third annular boss of the rotating body C and the fourth annular boss of the rotating body D, and are axially positioned; the piston B is slidably installed in the lower piston cavity through the second anti-wear ring, the rotating body C faces the lower front cavity at the front end of the lower piston cavity, and the rotating body D faces the lower rear cavity at the rear end of the lower piston cavity; the Y-type sealing ring installed on the fifth sealing section of the outer cylindrical surface of the rotating body C and the Y-type sealing ring installed on the seventh sealing section of the outer cylindrical surface of the rotating body D jointly realize the sealing between the piston B and the lower piston cavity; Correspondingly, the rear end of the push-pull rod B passes through the joint bearing B in the inner hole of the rotating body C and extends into the third axial end positioning section in the inner hole of the rotating body C, and then the push-pull rod B is provided with axial positioning by the washer and nut installed at the rear end of the push-pull rod B.

5. The hydraulic multi-stage piston liquid extraction mechanism according to claim 4, characterized in that: The movable guide channel A in the bidirectional communication section is arranged in the center, and the number of water inlet channels A and drainage channels A is the same, four respectively; all water inlet channels A and all drainage channels A are evenly distributed in a ring around the movable guide channel A.

6. The hydraulic multi-stage piston liquid extraction mechanism according to claim 5, characterized in that: The movable guide channel B in the middle bidirectional interconnecting section is centrally arranged, and the number of water inlet channels B and drainage channels B is the same, four respectively; all water inlet channels B and all drainage channels B are evenly distributed around the movable guide channel B in a ring shape.

7. The hydraulic multi-stage piston liquid extraction mechanism according to claim 6, characterized in that: Among the drainage and oil section, double-walled oil cylinder section, upper two-way communication section, repeating unit section, lower double-walled water cylinder section and lower two-way communication section included in the shell assembly, any two adjacent sections are connected by a tightening sleeve thread; the middle double-walled water cylinder section and the middle two-way communication section included in the repeating unit section are also connected by a tightening sleeve thread; the tightening sleeve includes a semi-annular split A, a semi-annular split B and a locking screw, and the outer walls of the semi-annular split A and the semi-annular split B are respectively provided with half of the external thread, and the semi-annular split A and the semi-annular split B are respectively provided with a wrench positioning hole, the semi-annular split A and the semi-annular split B are surrounded and embraced to form a sleeve, so that the half external thread on the semi-annular split A and the half external thread on the semi-annular split B are combined to form a complete external thread, and then the semi-annular split A and the semi-annular split B are connected as a whole by the locking screw.

8. The hydraulic multi-stage piston liquid extraction mechanism according to claim 7, characterized in that: The number of repeating unit segments is 1 segment.

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