Micro-flow-resistance centrifugal pump

Abstract

The utility model discloses a micro-flow-resistance centrifugal pump, relates to the technical field of centrifugal pumps, and solves the problems that in the prior art, when a centrifugal pump does not work and the relative flow of overflowing media is large, a pump body generates large flow resistance, and more energy is consumed. The centrifugal pump comprises a pump body, a worm cavity is formed in the pump body, a power shaft is rotationally arranged on the pump body, the worm cavity comprises a working cavity and a containing cavity which are communicated, an impeller is arranged on the power shaft in a sliding mode, the power shaft can drive the impeller to rotate, and the impeller can be switched between the working cavity and the containing cavity through sliding. The middle of the working cavity is communicated with the suction inlet, the liquid inlet direction of the suction inlet faces the impeller, and an extrusion opening is formed in the side wall of the working cavity. The relative positions of the impeller on the power shaft and the working cavity and the containing cavity are automatically changed along with the working state of the centrifugal pump, so that the flow resistance can be reduced when the centrifugal pump does not work and the relative flow of overflowing media is large, the energy consumption is reduced, and the normal pumping capacity is maintained to work on the media when the centrifugal pump works.

Description

Technical Field

[0001] The utility model relates to the technical field of centrifugal pumps, in particular to a micro-fluid resistance centrifugal pump. Background Art

[0002] The traditional centrifugal pump structure is that the impeller and the power shaft are fastened together, and the relative position of the impeller and the volute cavity is fixed. The disadvantage of this traditional structure is that when the centrifugal pump is not working and the relative flow rate of the flow is large, the pump body will produce a large flow resistance and consume more energy. In addition, the tongue placement angle is located at the beginning of the spiral part of the volute chamber, which is a structure that separates the spiral part from the diffuser. The size of the tongue placement angle of the traditional medium and high specific speed centrifugal pump is generally selected within the range of 25°~38° to take the larger value.

[0003] For example, the Chinese utility model patent with publication number CN110500314A discloses an impeller, a centrifugal pump and a vehicle, wherein the centrifugal pump comprises a pump body, the pump body comprises a volute and an impeller mounted in the volute, the impeller comprises a mounting plate, a plurality of front blades are mounted on the front side of the mounting plate, and the plurality of front blades are circumferentially spaced on the mounting plate, the front blade wrap angle is α, and 106°≤α≤111°, the front blade outlet placement angle is β, and 35°≤β≤38°, the front blade outlet width is d, and 4mm≤d≤5mm, the volute inlet width is b, and 4.5mm≤b≤5.5mm, the volute tongue placement angle is θ, and 25.5°≤θ≤26.5°. The centrifugal pump has high pump efficiency and head, and is suitable for small flow and high head occasions, but is not suitable for small specific speed centrifugal pump scenarios.

[0004] Similarly, the centrifugal pump still has the problem that when the centrifugal pump is not working and the flow rate of the flowing medium in the connected pipeline is large, the existence of the impeller will produce a large flow resistance and consume more capacity. Utility Model Content

[0005] In view of the deficiencies in the above-mentioned background technology, the utility model proposes a micro-resistance centrifugal pump, which solves the problem in the prior art that when the centrifugal pump is not working and the relative flow rate of the flowing medium is large, the pump body will generate large flow resistance and consume more energy.

[0006] The technical solution of the utility model is achieved as follows: a micro-resistance centrifugal pump includes a pump body, a volute cavity is arranged in the pump body, a power shaft is rotatably arranged on the pump body, the volute cavity includes a connected working chamber and a receiving chamber, an impeller is slidably arranged on the power shaft and the power shaft can drive the impeller to rotate, the impeller can switch between the working chamber and the receiving chamber by sliding, the middle part of the working chamber is connected with the suction port and the liquid inlet direction of the suction port is toward the impeller, and a pressure outlet is arranged on the side wall of the working chamber.

[0007] Preferably, the impeller comprises a shaft sleeve, a blade disk is arranged on the shaft sleeve, and a plurality of blades are circumferentially arranged at equal intervals on a side of the blade disk facing the suction port.

[0008] Preferably, a spiral blade is provided on the side of the impeller facing away from the suction port, the spiral direction of the spiral blade is consistent with the rotation direction of the power shaft, and the blade density is greater than the spiral blade density.

[0009] Preferably, the power shaft is provided with a sliding fit section, the sleeve is slidingly fitted with the sliding fit section of the power shaft, and a keyway and a key are provided between the sleeve and the sliding fit section to limit the relative rotation of the two, and the power shaft is detachably provided with a limit piece for axially limiting the sleeve.

[0010] Preferably, the limiting member is a retaining spring fixed on the power shaft or a retaining ring threadedly connected to the power shaft.

[0011] Preferably, the length of the sliding fitting section in the receiving cavity is greater than or equal to the length of the impeller, so that the impeller can completely enter the receiving cavity.

[0012] Preferably, when the end of the sleeve is flush with one end of the sliding fit section in the working chamber, the blade disk corresponds to the connection between the working chamber and the receiving chamber, and the blade corresponds to the pressure outlet. The working chamber and the receiving chamber are both rotary chambers.

[0013] Preferably, the pressure outlet is arranged along the tangent direction of the working chamber, and the placement angle of the partition tongue corresponding to the pressure outlet is 40° to 50°.

[0014] Preferably, the suction port is coaxially arranged with the power shaft.

[0015] The beneficial effects of the utility model are as follows: by sliding the impeller on the power shaft, the impeller can slide and switch in the working chamber and the receiving chamber. When the centrifugal pump is not working, the flowing medium pushes the impeller to move axially into the receiving chamber, and the medium only passes through the working chamber to enter and exit the pump body. Since there is no impeller to block it, the flow resistance coefficient is very small. When the centrifugal pump is working, the power shaft drives the impeller to rotate. Since the pressure of the impeller on the suction side is small and the pressure on the receiving chamber side is large, liquid pressure is generated, which pushes the impeller to move axially to a position that matches the working chamber, forming an assembly position relationship consistent with that of a traditional centrifugal pump, and doing work on the medium. Further, a spiral blade is arranged on the impeller, so that thrust can be generated on the impeller when it rotates, and the thrust superimposed on the liquid pressure further maintains the impeller rotating in the working chamber. The relative positions of the impeller on the power shaft and the working chamber and the receiving chamber automatically change with the working state of the centrifugal pump, thereby reducing the flow resistance and energy consumption when the centrifugal pump is not working and the relative flow rate of the flowing medium is large. When the centrifugal pump is working, the normal pumping capacity is maintained to work on the medium. The impeller position switching process is automatically carried out with the opening and closing of the centrifugal pump. It is easy to use and highly practical. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the embodiments of the present utility model, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0017] Figure 1 This is a cross-sectional structural diagram of the working state of the centrifugal pump of the utility model;

[0018] Figure 2 This is a schematic diagram of the cross-sectional structure of the centrifugal pump of the utility model in a non-working state;

[0019] Figure 3 This is a schematic diagram of the impeller structure of the utility model;

[0020] Figure 4 It is a schematic diagram of the cross-sectional structure of the diaphragm placement angle of a traditional small specific speed centrifugal pump;

[0021] Figure 5 It is a schematic diagram of the cross-sectional structure of the centrifugal pump of the utility model when the partition tongue is placed at an angle of 41°.

[0022] In the figure: 1: pump body, 2: power shaft, 3: impeller, 4: working chamber, 5: receiving chamber, 6: suction port, 7: pressure outlet, 8: sleeve, 9: impeller, 10: blade, 11: spiral blade. DETAILED DESCRIPTION

[0023] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0024] like Figure 1 , 2 As shown, in Example 1, a micro-fluidic centrifugal pump comprises a pump body 1, a volute cavity is provided in the pump body 1, and a power shaft 2 is rotatably provided on the pump body 1. The volute cavity comprises a working chamber 4 and a receiving chamber 5 which are connected to each other. In this embodiment, the working chamber 4 and the receiving chamber 5 are both rotating chambers. An impeller 3 is slidably provided on the power shaft 2 and the power shaft 2 can drive the impeller 3 to rotate. In this embodiment, the length of the power shaft in the volute cavity is increased. When there is an axial force, the impeller can slide in the axial direction to switch between the working chamber 4 and the receiving chamber 5.

[0025] The middle of the working chamber 4 is connected to the suction port 6, and a pressure outlet 7 is provided on the side wall of the working chamber 4. In this embodiment, the suction port 6 is coaxially arranged with the power shaft 2, so that the liquid inlet direction of the suction port 6 is toward the impeller 3. When the centrifugal pump is not working, the medium of the specified flow rate enters the working chamber from the suction port, and at the same time pushes the impeller to move axially into the receiving chamber. The impeller completely leaves the working chamber and enters the receiving chamber. Then the medium passes through the working chamber and the tongue structure and is discharged from the pump body from the pressure outlet 7. Since there is no impeller obstruction, the flow resistance coefficient is very small. As an optional implementation, a diffusion pipe is provided at the pressure outlet to facilitate the outflow of the medium.

[0026] In this embodiment, as a conventional implementation, a drive motor is provided on one side of the pump body, and the output shaft of the drive motor is connected to the power shaft through a coupling, so as to drive the power shaft to rotate. Figure 1 As shown, the output shaft of the driving motor is directly extended as the power shaft 2. The driving motor is fixed on one side of the pump body, and the end of the output shaft is inserted into the pump body as the power shaft 2. When the driving motor of the centrifugal pump is working, the power shaft drives the impeller to rotate. When the impeller rotates, the centrifugal force generated by the impeller rotation discharges the liquid through the pressure outlet. Therefore, the pressure on the suction side is small, and the pressure on the receiving chamber side is large, thereby generating liquid pressure in the axial direction, pushing the impeller to move axially to the matching position of the impeller and the working chamber, forming an assembly position relationship consistent with the traditional centrifugal pump, and doing work on the medium during the continuous rotation process to pump the continuous medium out through the pressure outlet.

[0027] In this embodiment, the relative positions of the impeller on the power shaft and the working chamber and the storage chamber automatically change with the working state of the centrifugal pump, thereby reducing the flow resistance and energy consumption when the centrifugal pump is not working and the relative flow rate of the flowing medium is large, and maintaining the normal pumping capacity to work on the medium when the centrifugal pump is working. The impeller position switching process is automatically carried out with the opening and closing of the centrifugal pump, which is convenient to use and highly practical.

[0028] Embodiment 2, a micro flow resistance centrifugal pump, based on embodiment 1, as Figure 3 As shown, the impeller 3 includes a shaft sleeve 8, a blade disc 9 is arranged on the shaft sleeve 8, and a plurality of blades 10 are arranged at equal intervals in the circumferential direction on the side of the blade disc 9 facing the suction port 6. In this embodiment, the blade disc is located at one end of the shaft sleeve close to the suction port, and the blades are located on the side of the blade disc close to the suction port. The blades are all streamline arc structures, and the bending directions of the plurality of blades are consistent.

[0029] In this embodiment, the large and small blades are arranged alternately, such as Figure 3As shown, a total of four large blades and four small blades are arranged, and the large and small blades are arranged alternately on the blade disk, and the blade layout is more reasonable, which is conducive to the pumping out of the medium. A sliding fit section is provided on the power shaft 2, and the sleeve 8 slides with the sliding fit section of the power shaft 2. In this embodiment, the inner wall of the sleeve and the outer wall of the sliding fit section of the power shaft are relatively smooth, so that the friction coefficient is small, thereby reducing the friction force when the sleeve slides on the power shaft. In addition, in this embodiment, a keyway and a key are provided between the sleeve 8 and the sliding fit section, and the keyway and the key are used to limit the relative rotation of the two under the premise of being able to slide, so that the impeller can be driven to rotate synchronously when the power shaft rotates. A stopper for axially limiting the sleeve is detachably provided on the power shaft 2. Stoppers can be optionally provided on the power shaft at both ends of the sliding fit section to limit the movement range of the sleeve of the impeller. At the same time, it is optional to set a stopper only at one end of the power shaft close to the suction port, and no stopper is provided at the other end, and only the pump body or the receiving chamber is used to limit the impeller. The detachable connection between the stopper and the power shaft can facilitate the removal and installation of the impeller. The stopper is a retaining ring 12 fixed on the power shaft 2 or threadedly connected to the power shaft 2. In this embodiment, the retaining ring 12 is used for limiting, and a threaded connection portion is provided at the end of the power shaft. The retaining ring is threadedly connected to the threaded connection portion. The outer diameter of the retaining ring is larger than the inner diameter of the shaft sleeve, and the retaining ring is chamfered to provide a larger suction space range at the suction port corresponding to the retaining ring to reduce the suction resistance.

[0030] In this embodiment, the length of the sliding fit section in the receiving chamber 5 is greater than or equal to the length of the impeller 3, so that the impeller 3 can completely enter the receiving chamber when the centrifugal pump is not in operation, and the impeller can be prevented from causing resistance to the flow of the medium in the working chamber as much as possible. In addition, when the centrifugal pump is in operation, the impeller moves to the position where the sleeve contacts the limiter, at which time the end of the sleeve 8 is flush with one end of the sliding fit section in the working chamber 4, and at the same time, the blade 9 corresponds to the connection between the working chamber 4 and the receiving chamber 5, and the blade 10 corresponds to the pressure outlet 7. As the impeller rotates, the medium under the centrifugal diversion of the blade is pumped out through the pressure outlet.

[0031] As a further optional embodiment, a spiral blade 11 is provided on the side of the impeller 3 facing away from the suction port 6, and the density of the blade 10 is greater than that of the spiral blade 11. In this embodiment, two spiral blades are provided, and the two spiral blades are centrally symmetrically provided on the surface of the sleeve. The spiral direction of the spiral blade 11 is consistent with the rotation direction of the power shaft 2, and can generate thrust on the impeller when rotating. The thrust is superimposed on the axial liquid pressure generated by the hydraulic pressure difference on both sides of the impeller disc 9 when the impeller pumps out the medium, and the impeller is acted on together, further maintaining the contact end of the sleeve with the limiter, so that the blade part of the impeller continues to rotate in the working chamber, and the medium with a specific flow rate and pressure is maintained to be output. Specifically, in this embodiment, when the driving motor is working, it drives the impeller to rotate, and the blades of the impeller do work on the medium to generate hydraulic pressure. The medium with hydraulic pressure enters the back of the impeller. The pressure on the inlet side of the impeller is lower than the atmospheric pressure. The impeller is pushed by the liquid pressure generated by the hydraulic pressure on the back side and the vacuum pressure on the inlet side. At the same time, the spiral blades on the back side of the impeller generate axial thrust. Under the action of these two forces, the impeller moves toward the inlet and enters the working chamber, forming a traditional centrifugal pump structure, doing work on the medium and outputting a medium with a specific flow rate pressure.

[0032] Embodiment 3, a micro flow resistance centrifugal pump, based on embodiment 2, as Figure 4 , 5 As shown, the pressure outlet 7 is arranged along the tangent direction of the working chamber 4, and the pressure outlet 7 corresponds to a partition tongue placement angle of 40° to 50°. In this embodiment, the partition tongue placement angle is 41°. Figure 4 The figure shows a cross-sectional schematic diagram of the placement angle of the partition tongue of a conventional low specific speed centrifugal pump. The conventional partition tongue placement angle is mostly 20°, and the flow resistance coefficient is relatively large. This embodiment increases the angle of the partition tongue placement of the volute cavity to increase the flow area of ​​the flow channel in the volute cavity, thereby reducing the flow resistance coefficient of the low specific speed pump in the non-working state.

[0033] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A micro-resistance centrifugal pump, comprising a pump body (1), wherein a volute is provided in the pump body (1), and a power shaft (2) is rotatably provided on the pump body (1), characterized in that: The volute cavity comprises a working cavity (4) and a receiving cavity (5) which are connected to each other. An impeller (3) is slidably provided on the power shaft (2) and the power shaft (2) can drive the impeller (3) to rotate. The impeller (3) can be switched between the working cavity (4) and the receiving cavity (5) by sliding. The middle of the working cavity (4) is connected to a suction port (6) and the liquid inlet direction of the suction port (6) faces the impeller (3). A pressure outlet (7) is provided on a side wall of the working cavity (4).

2. The microfluidic centrifugal pump according to claim 1, characterized in that: The impeller (3) comprises a shaft sleeve (8), a blade disk (9) is provided on the shaft sleeve (8), and a plurality of blades (10) are circumferentially arranged at equal intervals on a side of the blade disk (9) facing the suction port (6).

3. The micro-fluidic centrifugal pump according to claim 2, characterized in that: A spiral blade (11) is provided on the side of the impeller (3) facing away from the suction port (6); the spiral direction of the spiral blade (11) is consistent with the spiral direction of the power shaft (2); and the density of the blade (10) is greater than the density of the spiral blade (11).

4. The microfluidic centrifugal pump according to claim 2 or 3, characterized in that: The power shaft (2) is provided with a sliding fit section, the shaft sleeve (8) is slidingly fitted with the sliding fit section of the power shaft (2), and a keyway and a key are provided between the shaft sleeve (8) and the sliding fit section for limiting relative rotation between the two, and a stopper for axially limiting the shaft sleeve (8) is detachably provided on the power shaft (2).

5. The microfluidic centrifugal pump according to claim 4, characterized in that: The limiting member is a retaining spring fixed on the power shaft (2) or a retaining ring (12) threadedly connected to the power shaft (2).

6. The microfluidic centrifugal pump according to claim 4, characterized in that: The length of the sliding fit section within the receiving chamber (5) is greater than or equal to the length of the impeller (3), so that the impeller (3) can completely enter the receiving chamber.

7. The micro-fluidic centrifugal pump according to claim 4, characterized in that: When the end of the shaft sleeve (8) is flush with one end of the sliding fitting section in the working chamber (4), the blade disk (9) corresponds to the connection between the working chamber (4) and the receiving chamber (5), and the blade (10) corresponds to the pressure outlet (7).

8. The micro-fluidic centrifugal pump according to any one of claims 1 to 3 and 5 to 7, characterized in that: The working chamber (4) and the receiving chamber (5) are both rotary chambers.

9. The micro-fluidic centrifugal pump according to claim 8, characterized in that: The pressure outlet (7) is arranged along the tangent direction of the working chamber (4), and the partition tongue placement angle corresponding to the pressure outlet (7) is 40° to 50°.

10. The micro-fluidic centrifugal pump according to claim 9, characterized in that: The suction port (6) is coaxially arranged with the power shaft (2).

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