Multi-stage sliding vane pump

Abstract

The multi-stage sliding vane pump comprises a first-stage pump body, at least one middle-stage pump body and a last-stage pump body which are sequentially connected, the first-stage pump body, the middle-stage pump body and the last-stage pump body are independently arranged and each provided with a rotor provided with a sliding vane, the rotors are sleeved with eccentric parts, the inner walls of the eccentric parts and the rotors are eccentrically arranged, and eccentric cavities are formed. The eccentric part is wrapped with a pump shell, an annular pump cavity is formed between the pump shell and the eccentric part, the eccentric part is provided with a plurality of flow distribution holes communicating with the pump cavity and the eccentric cavity, and the pump shell is provided with interstage holes communicating with the adjacent pump cavities. Pump shafts extending outwards are arranged at the two axial ends of the rotors, and the adjacent pump shafts are detachably connected in the axial direction, so that at least one pump shaft can rotate to drive the rotors in the first-stage pump body, the middle-stage pump body and the last-stage pump body to rotate synchronously; through the building block type framework of the first-stage pump body, the extensible middle-stage pump bodies and the last-stage pump body, the number of the middle-stage pump bodies can be linearly increased or decreased, accurate adaptation of pressure is achieved, and the pressure solidification bottleneck of a traditional multi-stage pump is broken through.

Description

Technical Field

[0001] The invention belongs to the technical field of vane pumps, and in particular relates to a multi-stage vane pump. Background Art

[0002] Currently, positive displacement vane pumps generally adopt a single-stage structure, and their pressure increase depends entirely on the single pressurization of the liquid by a single rotor. Due to the bottleneck of vane sealing and structural strength, the maximum working pressure of a single-stage pump is limited. Under high-pressure conditions, problems such as increased vane end face wear and a sharp increase in internal leakage are prone to occur, resulting in a decrease in volumetric efficiency. Although multi-stage pump technology attempts to break through pressure limitations, traditional multi-stage pumps use an integral cast pump casing to nest multiple sets of stator and rotor modules, which has three major defects: first, the number of pump stages is fixed during manufacturing, and users cannot dynamically adjust the output pressure according to working conditions; second, there are multiple stages in a single pump casing, and any damage to any component requires overall disassembly, which is time-consuming and easily causes inter-stage seal failure; third, different pressure specifications require independent production lines, and parts commonality is zero, resulting in redundant inventory types and a surge in supply chain costs; the above defects seriously restrict the application and promotion of vane pumps in medium and high pressure fields (such as hydraulic systems and chemical processes). Summary of the Invention

[0003] (1) Technical problems to be solved The invention discloses a multi-stage sliding vane pump, aiming to solve the problem of pump body pressure solidification and the like.

[0004] (2) Technical solution The present invention discloses a multi-stage vane pump, comprising a plurality of pump bodies detachably connected to each other, wherein the pump bodies comprise a first-stage pump body, at least one intermediate pump body, and a final pump body connected in sequence, wherein the output pressure is linearly adjusted by increasing or decreasing the number of the intermediate pump bodies, the first-stage pump body being provided with a pump outlet, and the final pump body being provided with a pump inlet; The first-stage pump body, the intermediate pump body and the final-stage pump body are independently arranged and are all equipped with a rotor provided with a vane, an eccentric piece is sleeved on the outside of the rotor, the inner wall of the eccentric piece is eccentrically arranged with the rotor to form an eccentric cavity, the eccentric piece is wrapped with a pump casing, an annular pump cavity is formed between the pump casing and the eccentric piece, the eccentric piece is provided with a plurality of flow distribution holes connecting the pump cavity and the eccentric cavity, and the pump casing is provided with interstage holes connecting adjacent pump cavities; Pump shafts extending outward are provided at both axial ends of the rotor, and adjacent pump shafts are axially detachably connected so that the rotation of at least one pump shaft can drive the rotors in the first-stage pump body, the middle-stage pump body and the final-stage pump body to rotate synchronously.

[0005] Furthermore, one of the adjacently connected pump shafts is provided with a protrusion extending outward, and the other is provided with an inwardly recessed groove, and the protrusion and the pump shaft are mutually engaged.

[0006] Furthermore, a first clamping groove is provided at a side end of the protrusion, a second clamping groove is provided on an inner peripheral wall of the groove, and a clamping block is provided between the first clamping groove and the second clamping groove for clamping and fixing both of them.

[0007] Furthermore, a plurality of sliding grooves are provided at intervals on the radial peripheral wall of the rotor, and the sliding vanes are slidably connected in the sliding grooves. When the rotor rotates, the sliding vanes slide outward under the action of centrifugal force and abut against the inner wall of the eccentric member, so that a volume cavity is formed between adjacent sliding vanes.

[0008] Furthermore, at least a portion of the outer peripheral wall of the rotor is in rotational contact with the inner wall of the eccentric member, so that the eccentric cavity is in a crescent-shaped cylinder.

[0009] Furthermore, the eccentric cavity of the first-stage pump body or the final-stage pump body is arranged in a staggered direction with the eccentric cavity of the adjacent intermediate-stage pump body.

[0010] Furthermore, a plurality of intermediate pump bodies are provided between the first-stage pump body and the final-stage pump body, and the eccentric cavities of adjacent intermediate pump bodies are arranged in a staggered or equidirectional manner.

[0011] Furthermore, the eccentric member is provided with two groups of the flow distribution holes, and the two groups of the flow distribution holes are symmetrically arranged on the peripheral wall of the eccentric member along the radial direction.

[0012] Furthermore, adjacent pump bodies are enclosed to form an interstage cavity, and the interstage cavity and the pump cavity are connected through the interstage hole.

[0013] Furthermore, the contact surfaces of adjacent pump bodies are combined to form an annular sealing groove, and an annular sealing ring is provided in the sealing groove.

[0014] Furthermore, a front pump cover is provided at one end of the first-stage pump body away from the intermediate pump body, and a rear pump cover is provided at one end of the final-stage pump body away from the intermediate pump body. Several fixing rods are provided between the front pump cover and the rear pump cover for fixing with threads, and the three together constitute a rigid frame for resisting axial hydraulic pressure.

[0015] Furthermore, the interface direction of the pump inlet and the pump outlet is the top end or the side end of the pump body.

[0016] Compared with the prior art, the present invention has the following beneficial effects: Through the building block architecture of "first-stage pump body + expandable intermediate pump body + final-stage pump body", the number of intermediate pump bodies can be linearly increased or decreased to achieve precise pressure adaptation and break through the pressure solidification bottleneck of traditional multi-stage pumps; each stage of the pump body is equipped with an independent rotor, eccentric, pump casing and pump shaft, breaking the constraints of traditional integration. In the event of a single-stage failure, the damaged unit can be directly replaced, shortening the maintenance time and avoiding the risk of inter-stage seal chain failure; all pump body components are manufactured according to unified standards, so that pump bodies of different pressure specifications share common parts; multi-stage pressure differential sharing reduces the single-stage working pressure differential, significantly reduces internal leakage and friction loss, and the overall energy efficiency is higher than that of traditional single-stage pumps. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 The structure of the present invention is schematically shown Figure 1 .

[0018] Figure 2 It is an exploded view of the present invention.

[0019] Figure 3 The cross-sectional view of the present invention Figure 1 .

[0020] Figure 4 The working principle of the rotor of the present invention Figure 1 .

[0021] Figure 5 The working principle of the rotor of the present invention Figure 2 .

[0022] Figure 6 The working principle of the rotor of the present invention Figure 3 .

[0023] Figure 7 The working principle of the rotor of the present invention Figure 4 .

[0024] Figure 8 The pump casing explosion of the present invention Figure 1 .

[0025] Figure 9 The pump casing explosion of the present invention Figure 2 .

[0026] Figure 10 The pump casing explosion of the present invention Figure 3 .

[0027] Figure 11 The cross-sectional view of the present invention Figure 2 .

[0028] Figure 12 The pump shaft explosion of the present invention Figure 1 .

[0029] Figure 13 The pump shaft explosion of the present invention Figure 2 .

[0030] Figure 14 This is an enlarged view of the pump shaft engaging groove of the present invention.

[0031] Figure 15 The structure of the present invention is schematically shown Figure 2 .

[0032] Figure markings: 1-first-stage pump body, 11-first-stage pump casing, 12-first-stage pump shaft, 13-pump outlet, 14-front pump, 2-intermediate pump body, 21-intermediate pump casing, 22-intermediate pump shaft, 3-final pump body, 31-final pump casing, 32-final pump shaft, 33-pump inlet, 34-rear pump cover, 4-rotor, 41-slide, 42-chute, 43-volume chamber, 5-eccentric piece, 51-eccentric chamber, 52-distribution hole, 6-pump casing, 61-pump chamber, 62-interstage hole, 63-interstage chamber, 64-sealing groove, 7-pump shaft, 71-bump, 711-first clamping groove, 72-groove, 73-clamping block, 721-second clamping groove, 8-fixing rod. DETAILED DESCRIPTION

[0033] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts shall fall within the scope of protection of the present invention.

[0034] like Figure 1-3 As shown, the present invention discloses a multi-stage vane pump, comprising a plurality of pump bodies detachably connected to each other, wherein the pump bodies include a first-stage pump body 1, a plurality of intermediate pump bodies 2 (the number of the intermediate pump bodies 2 can be determined according to actual needs, and only one intermediate pump body 2 is shown herein), and a final pump body 3, which are connected in sequence. The first-stage pump body 1 is provided with a pump outlet 13, and the final pump body 3 is provided with a pump inlet 33. Liquid enters the pump through the pump inlet 33, flows through the final pump body 3, the intermediate pump body 2, and the first-stage pump body 1 in sequence, and is finally discharged from the pump outlet 13. The first-stage pump body 1, the intermediate pump body 2 and the final pump body 3 are similar in structure and all include a rotor 4 equipped with a vane 41. The rotor 4 is cylindrical and has a pump shaft 7 fixed through the center. When the pump shaft 7 rotates, it can drive the rotor 4 to rotate synchronously. The rotor 4 is provided with an eccentric member 5 on its outer surface. The eccentric member 5 is annular, and its inner wall diameter is larger than the diameter of the rotor 4. The inner wall and the rotor 4 are eccentrically arranged, and the gap space formed by the eccentric arrangement of the two constitutes an eccentric cavity 51. A graded pump housing 6 is provided outside the eccentric member 5. The graded pump housing 6 is a cylindrical housing with an inner diameter larger than the outer diameter of the eccentric member 5, thereby wrapping the rotor 4 and the eccentric member 5 as a whole. At the same time, an annular pump cavity is formed between the inner wall of the graded pump housing 6 and the outer wall of the eccentric member 5. It is worth noting that the first-stage pump body 1, the intermediate pump body 2 and the final pump body 3 are each equipped with an independent graded pump housing 6. The eccentric member 5 is provided with a plurality of distribution holes 52 for connecting the pump chamber 61 with the eccentric chamber 51. It is worth noting that the pump chamber 61 and the eccentric chamber 51 can only be connected through the distribution holes 52. At the same time, the staged pump housing 6 is provided with a plurality of interstage holes 62 (the interstage holes 62 can be any one of radial holes, inclined holes, special-shaped hollow holes, or a combination of several), which are used to connect the pump chamber of the current stage with the outside of the staged pump housing 6 (usually pointing to the interstage holes 62 of the next stage pump body), and the liquid transmission between adjacent pump bodies is transmitted through the interstage holes 62. The center of the rotor 4 is fixedly connected to a pump shaft 7, which passes through the rotor 4, eccentric piece 5 and staged pump casing 6. The first-stage pump body 1, multiple intermediate pump bodies 2 and final pump body 3 are each equipped with their own independent rotor 4, eccentric piece 5, staged pump casing 6 and pump shaft 7. These structural components are produced using unified standards and are universal. The difference between the pump bodies at each stage lies mainly in the slight differences in assembly structure. The pump bodies of each stage are coaxially and fixedly connected in series through their respective pump shafts 7 to form a continuous transmission shaft. When the pump shaft 7 of the first-stage pump body 1 rotates, it drives all the pump shafts 7 in series to rotate synchronously, thereby driving the rotors 4 of each stage to rotate simultaneously. During this process, the eccentric member 5 and the staged pump housing 6 remain stationary, and relative rotational motion occurs between them and the rotating pump shaft 7 and rotor 4. When the multi-stage vane pump is in operation, the liquid enters the final pump body 3 from the pump inlet 33, and then enters the intermediate pump body 2 from the final pump body 3. In the intermediate pump body 2, the liquid flows through one end of the pump chamber 61 and the distribution hole 52 in sequence and enters the eccentric chamber 5. Driven by the rotation of the rotor 4, the vane 41 transfers mechanical energy to the liquid, thereby increasing its pressure. The pressurized liquid enters the other end of the pump chamber 61 through the distribution hole 52, and then flows into the intermediate pump body 2 through the interstage hole 62. When the liquid flows through each stage of the pump body (intermediate pump body 2 and first-stage pump body 1), the above process is repeated: it circulates between the pump chamber 61 and the eccentric chamber 5, and is pressurized by the rotor 4 of this stage. As a result, the pressure of the liquid can be accumulated step by step. Finally, the liquid reaching the required pressure is discharged from the pump outlet 13 of the first-stage pump body 1, completing the pressurized delivery process.

[0035] Most of the mainstream positive displacement vane pumps on the market are single-stage structures, relying only on the single-stage rotor 4 to pressurize the liquid. Limited by the sealing and structural strength of the vane 41, the pressure difference of the single-stage structure is limited (conventionally <0.5MPa). The efficiency of high-pressure working conditions is severely attenuated (the flow rate drops significantly), and under high-pressure working conditions, problems such as increased internal leakage and a sudden drop in volumetric efficiency are prone to occur. The multi-stage vane pump adopts a multi-stage series design, so that the liquid flowing through each stage is independently pressurized to achieve pressure accumulation, which can easily meet medium and high pressure requirements; at the same time, the multi-stage pressure differential is shared to reduce the single-stage working pressure difference, significantly reduce internal leakage and friction loss, and simultaneously improve volumetric efficiency and mechanical efficiency; in addition, the self-priming performance of the single-stage structure is limited by the single-stage vacuum degree (conventionally <0.08MPa).

[0036] However, traditional multi-stage vane pumps have several structural flaws: First, they utilize a monolithic cast pump casing with multiple stator-rotor modules nested within it. The pump stages are fixed at the factory, preventing users from adjusting the pressure level based on operating conditions. Second, multiple stages are linked within a single pump casing, and damage to any component (such as the vanes or bearings) requires complete disassembly, which is time-consuming to repair and can easily cause interstage seal failure. Third, different pressure specifications require separate production lines, resulting in zero parts commonality, redundant inventory, and a surge in supply chain costs. In order to solve the above problems, the multi-stage vane pump of the present application provides a disruptive solution: First, modular pressure customization: adopting the "first-stage pump body 1 + expandable intermediate pump body 2 + final-stage pump body 3" architecture, the output pressure is linearly adjusted by increasing or decreasing the number of intermediate pump bodies to achieve precise pressure adaptation; second, fully independent unit design: each stage is equipped with an independent rotor 4, eccentric 5, graded pump casing 6 and pump shaft 7, breaking the constraints of traditional integration; third, building block-style rapid assembly: adjacent pump bodies only need to connect the pump shaft 7 to complete the integration of the whole machine; fourth, standardization of parts: all pump body components are produced with unified standards, which greatly reduces production costs and spare parts inventory, and supports single-stage rapid replacement during maintenance.

[0037] Specifically, if Figure 4-7 As shown, in one embodiment of the present invention, each of the rotors 4 is provided with a plurality of slide grooves 42 radiating outward from the center, and the slide grooves 42 are rectangular grooves. The slide vanes 41, which are also rectangular in structure, can be placed in the slide grooves 42 and can slide freely along the slide grooves toward the outside of the rotor 4, and the friction between the slide vanes 41 and the slide grooves 42 is extremely small. When the rotor 4 rotates driven by the pump shaft 7, the slide vanes 41 slide outward along the slide grooves 42 under the action of centrifugal force until their outer ends abut against the inner wall of the eccentric member 5. At the same time, there are a total of 9 slide vanes 41 and corresponding slide grooves 42, which are evenly distributed around the center of the rotor 4.

[0038] Furthermore, the inner wall of the eccentric member 5 of the first-stage pump body 1 and the final-stage pump body 3 abuts against the outer wall of the rotor 4 at the side end close to the pump inlet 33, forming a crescent-shaped eccentric cavity 51. The crescent-shaped structure of the eccentric cavity 51 includes symmetrical and asymmetrical types. In contrast, the inner wall of the eccentric member 5 of the intermediate pump body 2 abuts against the outer wall of the rotor 4 at the side end away from the pump inlet 33. Therefore, the crescent direction of its eccentric cavity 51 is opposite to that of the first-stage pump body 1 and the final-stage pump body 3. Each eccentric member 5 is provided with two groups of distribution holes 52, each group comprising a plurality of holes. The two groups of distribution holes 52 are respectively located at the top and bottom ends of the eccentric member 5, i.e., the two narrowest places of the crescent-shaped eccentric cavity 51. When the rotor 4 rotates, two adjacent sliding vanes 41 and the inner wall of the eccentric member 5 together form a volume cavity 43. All the sliding vanes 41 divide the eccentric cavity 51 into a plurality of such volume cavities 43. Since the eccentric cavity 51 is crescent-shaped, the volume of each volume cavity 43 continuously changes as the rotor 4 rotates. Taking the intermediate pump body 2 as an example, liquid enters the eccentric chamber 51 through the distribution hole 52 at the bottom of the eccentric member 5. As the volume chamber 43 moves from the bottom to the side of the eccentric chamber 51, its volume gradually increases. At this time, the volume chamber 43 is still connected to the distribution hole 52 at the bottom. The increase in volume causes the pressure in the chamber to decrease, thereby generating suction, drawing the liquid into the chamber. As the rotor 4 continues to rotate, the volume chamber 43 moves from the side end of the eccentric chamber 51 to the top end. During this process, the volume of the volume chamber 43 gradually decreases, and the pressure inside the chamber increases accordingly. When the volume chamber 43 reaches the top end and communicates with the distribution hole 52 there, the internal pressure is higher than the pressure outside the eccentric member 5 (the pump chamber 61). This pressure difference generates thrust, which presses the liquid from the volume chamber 43 into the pump chamber 61. It is worth noting that when several intermediate pump bodies 2 are stacked, in other embodiments, such as Figure 6 As shown, the crescent-shaped eccentric cavity 51 can be set in the same direction. In other embodiments, as shown in FIG. Figure 7 As shown, the crescent-shaped eccentric cavities 51 are arranged in a staggered direction, which can achieve the above-mentioned effect.

[0039] Specifically, such as Figure 8-11As shown, in one embodiment of the present invention, the staged pump casing 6 includes a first-stage pump casing 11, a middle-stage pump casing 21, and a last-stage pump casing 31 corresponding to the first-stage pump body 1, the plurality of middle-stage pump bodies 2, and the last-stage pump body 3, respectively. The pump outlet 13 is provided at the top end of the first-stage pump casing 11 and communicates with the pump cavity 61 of the first-stage pump casing 11. The pump inlet 33 is provided at the side end of the last-stage pump casing 31 and communicates with the pump cavity 61 of the last-stage pump casing 31. The first-stage pump casing 1, the intermediate pump casing 21 and the final pump casing 31 are adjacent to each other to form an interstage cavity 63, and the interstage cavity 63 and the pump cavity 61 are communicated with each other through the interstage hole 62. The first-stage pump casing 11 and the final pump casing 31 are respectively provided with a group of interstage holes 62 facing the intermediate pump casing 21, and both are arranged at the lower ends of the first-stage pump casing 11 and the final pump casing 31. The intermediate pump casing 21 is provided with two groups of interstage holes 62, one group facing the first-stage pump casing 11 and arranged at the lower end of the intermediate pump casing 21, and the other group facing the final pump casing 31 and arranged at the upper end of the intermediate pump casing 21; The liquid enters the interstage cavity 63 between the final-stage pump body 3 and the intermediate pump body 2 through the interstage hole 62 at the lower end of the final-stage pump body 3, and then enters the pump cavity 61 of the pump body through the interstage hole 62 at the upper end of the intermediate pump body 2. After being pressurized by the intermediate pump body 2, the liquid flows out from the interstage hole 62 at its lower end and enters the interstage cavity 63 between the intermediate pump body 2 and the first-stage pump body 1. Then, the liquid enters the pump cavity 61 through the interstage hole 62 at the lower end of the first-stage pump body 1, and after completing the final pressurization in the final-stage pump body 3, it is output from the pump outlet 13 at the top.

[0040] Furthermore, the contact surfaces of adjacent pump bodies are provided with a step structure, and the adjacent step structures do not match each other, but are enclosed to form an annular sealing groove 64. The sealing groove 64 is filled with a sealing ring, and the sealing ring is made of elastic material and has a volume larger than the volume of the sealing groove 64. This structural design increases the sealing performance, so that the interstage cavity 63 is isolated from the outside of the pump body to avoid liquid leakage.

[0041] Specifically, such as Figure 12-14 As shown, in one embodiment of the present invention, the pump shaft 7 includes a first-stage pump shaft 12, an intermediate pump shaft 22 and a final-stage pump shaft 32 corresponding to the first-stage pump body 1, the plurality of intermediate pump bodies 2 and the final-stage pump body 3 respectively. The first-stage pump shaft 12 is provided with a convex block 71 facing the intermediate pump shaft 22, and the final-stage pump shaft 32 is provided with a groove 72 facing the intermediate pump shaft 22. Both ends of the intermediate pump shaft 22 are respectively provided with a groove 72 facing the first-stage pump shaft 12 and a convex block 71 facing the final-stage pump shaft 32. The convex blocks 71 are inserted into the corresponding grooves 72 to achieve a snap connection. The end of the first-stage pump shaft 12 away from the intermediate pump shaft 22 is connected to a driving device. When the driving device drives the first-stage pump shaft 12 to rotate, the cooperation between the protrusion 71 and the groove 72 drives the intermediate pump shaft 22 and the final pump shaft 32 to rotate synchronously.

[0042] Furthermore, if Figure 14 As shown, a first engaging groove 711 extending toward the center of the protrusion 71 is defined on the side end thereof, and a second engaging groove 721 extending outward is defined on the inner peripheral wall of the groove 72. The centers of the first engaging groove 711, the second engaging groove 721, and the protrusion 71 are located on the same straight line, and a engaging block 73 is embedded between the first engaging groove 711 and the second engaging groove 721. The engaging block 73 is simultaneously filled in both grooves, thereby forming a reliable engaging structure. The driving device drives the first-stage pump shaft 12 to rotate, and transmits torque through the clamping structure (including the clamping block) of the protrusion 71 and the groove 72, so that the intermediate pump shaft 22 and the final pump shaft 32 rotate synchronously. The eccentric member 5 and the staged pump housing 6 remain stationary, forming a dynamic seal with the rotating parts. In other embodiments, the detachable connection structure between adjacent pump shafts 7 may also be a spline coupling or a flange bolt connection, which can also achieve the above-mentioned effects.

[0043] Specifically, if Figure 15 As shown, in one embodiment of the present invention, a front pump cover 14 is installed at one end of the first-stage pump body 1 away from the intermediate pump body 2, and a rear pump cover 34 is installed at one end of the final-stage pump body 3 away from the intermediate pump body 2. The front pump cover 14 and the rear pump cover 34 sandwich several pump bodies. At the same time, four fixing rods 8 are connected between the front pump cover 14 and the rear pump cover 34. The four fixing rods 8 together form a cavity for accommodating and supporting the assembled first-stage pump body 1, intermediate pump body 2 and final-stage pump body 3, forming a rigid frame that resists axial hydraulic force. The fixing rods 8 are fixed to the front pump cover 14 and the rear pump cover 34 by threads.

[0044] The working principle of the present invention is described in detail below: The liquid enters the final pump chamber 61 from the pump inlet 33, enters the interstage cavity 63 through the interstage hole 62 at the lower end, and then flows into the pump chamber 61 through the interstage hole 62 at the upper end of the intermediate pump body 2, and then flows into the eccentric cavity 51 through the distribution hole 52. The rotor 4 rotates under the drive of the pump shaft 7. The slide 41 extends outward under the action of centrifugal force and abuts against the inner wall of the eccentric member 5, dividing the eccentric cavity into a plurality of volume cavities 43. When the volume cavity 43 turns from the crescent-shaped narrow area to the wide area, the liquid flows into the pump chamber 61 through the interstage hole 62 at the upper end of the intermediate pump body 2, and then flows into the eccentric cavity 51 through the distribution hole 52. When the pressure is increased, the volume of the cavity increases to form a negative pressure, sucking in liquid. When it moves to the narrow area, the volume is compressed, the pressure increases, and the liquid is pressed into the pump cavity 61 through the distribution hole 52; the pressurized liquid enters the second interstage cavity 63 through the interstage hole 62 at the lower end, and then enters the next pump body from the interstage cavity 63. The liquid repeats the "pump cavity → eccentric cavity → pressurization → pump cavity" process in the pump body 2, and the pressure continues to increase; finally, it enters the first-stage pump body 1 for the last pressurization and is discharged from the pump outlet 13 at the top.

[0045] The innovation of the present invention is: Modular pressure customization: Through the building block architecture of "first-stage pump body + expandable intermediate pump body + final-stage pump body", the number of intermediate pump bodies can be linearly increased or decreased to achieve precise pressure adaptation, breaking through the pressure solidification bottleneck of traditional multi-stage pumps; Fully independent unit design: Each stage of the pump is equipped with an independent rotor, eccentric, pump casing and pump shaft, breaking the constraints of traditional integrated design. In the event of a single-stage failure, the damaged unit can be directly replaced, shortening maintenance time and avoiding the risk of inter-stage seal cascading failure. Universal production system: All pump components are manufactured according to unified standards, allowing pumps of different pressure specifications to share common parts, while supporting the flexible manufacturing model of "assembly on demand"; High-efficiency transmission mechanism: Multi-stage pressure differential sharing reduces the single-stage working pressure differential, significantly reduces internal leakage and friction loss, and the overall energy efficiency is higher than that of traditional single-stage pumps.

[0046] In addition, it should be understood that although this specification is described in terms of implementation methods, not every implementation method contains only one independent technical solution. This narrative method of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other implementations that can be understood by those skilled in the art.

[0047] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above and that the invention can be embodied in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered in all respects as illustrative and non-restrictive, and the scope of the invention is defined by the appended claims, not the foregoing description, and all variations within the meaning and range of equivalents of the claims are intended to be included therein. Any reference sign in a claim should not be construed as limiting the claim to which it relates.

Claims

1. A multi-stage vane pump, characterized in that: The invention comprises a plurality of pump bodies detachably connected to each other, wherein the pump bodies comprise a first-stage pump body (1), at least one intermediate pump body (2) and a final pump body (3) connected in sequence, wherein linear adjustment of the output pressure is achieved by increasing or decreasing the number of the intermediate pump bodies (2), the first-stage pump body (1) is provided with a pump outlet (13), and the final pump body (3) is provided with a pump inlet (33); The first-stage pump body (1), the intermediate pump body (2) and the final-stage pump body (3) are independently arranged and are all equipped with a rotor (4) provided with a sliding vane (41); an eccentric member (5) is provided on the outside of the rotor (4); the inner wall of the eccentric member (5) is eccentrically arranged with the rotor (4) to form an eccentric cavity (51); a graded pump housing (6) is provided on the outside of the eccentric member (5); an annular pump cavity (61) is formed between the graded pump housing (6) and the eccentric member (5); the eccentric member (5) is provided with a plurality of distribution holes (52) communicating with the pump cavity (61) and the eccentric cavity (51); and an interstage hole (62) communicating with adjacent pump cavities (61) is provided on the graded pump housing (6); Pump shafts (7) extending outward are provided at both axial ends of the rotor (4), and adjacent pump shafts (7) are axially detachably connected, so that the rotation of at least one of the pump shafts (7) can drive the rotors (4) in the first-stage pump body (1), the intermediate pump body (2), and the final pump body (3) to rotate synchronously.

2. A multi-stage vane pump according to claim 1, characterized in that: One of the adjacently connected pump shafts (7) is provided with an outwardly extending protrusion (71), and the other is provided with an inwardly recessed groove (72), and the protrusion (71) and the (72) are mutually engaged.

3. A multi-stage vane pump according to claim 2, characterized in that: A first clamping groove (711) is provided at the side end of the protrusion (71), a second clamping groove (721) is provided on the inner peripheral wall of the groove (72), and a clamping block (73) is provided between the first clamping groove (711) and the second clamping groove (721) for clamping and fixing the first clamping groove (711) and the second clamping groove (721).

4. A multi-stage vane pump according to claim 1, characterized in that: A plurality of slide grooves (42) are provided at intervals on the radial peripheral wall of the rotor (4), and the slide vanes (41) are slidably connected in the slide grooves (42). When the rotor (4) rotates, the slide vanes (41) slide outward under the action of centrifugal force and abut against the inner wall of the eccentric member (5), so that a volume cavity (43) is formed between adjacent slide vanes (41).

5. A multi-stage vane pump according to claim 4, characterized in that: At least a portion of the outer peripheral wall of the rotor (4) is in rotational contact with the inner wall of the eccentric member (5), so that the eccentric cavity (51) is in the shape of a crescent tube.

6. A multi-stage vane pump according to claim 5, characterized in that: The arrangement direction of the eccentric chamber (51) of the first-stage pump body (1) or the final-stage pump body (3) is staggered with the arrangement direction of the eccentric chamber (51) of the adjacent intermediate-stage pump body (2).

7. A multi-stage vane pump according to claim 6, characterized in that: A plurality of intermediate pump bodies (2) are provided between the first-stage pump body (1) and the final-stage pump body (3), and the eccentric chambers (51) of adjacent intermediate pump bodies (2) are arranged in a staggered or unidirectional manner.

8. The multi-stage vane pump according to claim 1, characterized in that: The eccentric member (5) is provided with two groups of distribution holes (52), and the two groups of distribution holes (52) are symmetrically arranged on the peripheral wall of the eccentric member (5) along the radial direction.

9. The multi-stage vane pump according to claim 1, characterized in that: Adjacent pump bodies enclose an interstage cavity (63), and the interstage cavity (63) and the pump cavity (61) are connected via the interstage hole (62).

10. The multi-stage vane pump according to claim 1, characterized in that The contact surfaces of adjacent pump bodies are combined to form an annular sealing groove (64), and an annular sealing ring is provided in the sealing groove (64).

11. The multi-stage vane pump according to claim 1, characterized in that The end of the first-stage pump body (1) away from the intermediate pump body (2) is provided with a front pump cover (14), and the end of the final-stage pump body (3) away from the intermediate pump body (2) is provided with a rear pump cover (34). A plurality of fixing rods (8) are provided between the front pump cover (14) and the rear pump cover (34) to be fixedly connected by threads. The three together constitute a rigid frame for resisting axial hydraulic pressure.

12. The multi-stage vane pump according to claim 1, characterized in that The interface direction of the pump outlet (13) and the pump inlet (33) is the top end or the side end of the pump body.

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