Centrifugal pump

Abstract

The embodiment of the present application provides a centrifugal pump, which comprises a pump shell, a first driving mechanism, a second driving mechanism, a pump shaft and an impeller arranged in the pump shell; the pump shell comprises a first chamber and a second chamber which are communicated with each other, the shaft center of the pump shaft coincides with the shaft center of the first chamber and the second chamber, the inner diameter of the second chamber is larger than that of the first chamber, the impeller is connected to the end of the pump shaft, the first driving mechanism and the second driving mechanism are connected with the pump shaft and are located on the side of the pump shaft which is away from the impeller, the first driving mechanism is used to drive the pump shaft to rotate, the second driving mechanism is used to drive the pump shaft to move along the shaft center, and the impeller is used to rotate in the first chamber or the second chamber under the driving of the pump shaft. The embodiment of the present application provides a centrifugal pump which can meet the requirements of high lift and high reliability of the pump.

Description

Technical Field

[0001] This application relates to the field of mechanical engineering pump technology, and more particularly to a centrifugal pump. Background Technology

[0002] A pump is a machine that transports or pressurizes fluids. It increases the fluid's energy by transferring the mechanical energy of a prime mover or other external energy to the liquid. Pumps that transfer mechanical energy to the transported liquid by driving the liquid to rotate at high speed with an impeller are called impeller pumps. Impeller pumps include centrifugal pumps, which are pumps that transport liquids by the centrifugal force generated when the impeller rotates.

[0003] In related technologies, a centrifugal pump may include a pump casing, a motor, a pump shaft, and an impeller. The motor drives the pump shaft and causes the impeller to rotate within the working chamber of the pump casing. The centrifugal force generated by the rotation of the impeller can discharge liquid from the working chamber to the drain pipe.

[0004] In centrifugal pumps, a smaller clearance between the impeller and the working chamber corresponds to higher head and higher performance efficiency, but the impeller is prone to jamming, resulting in poor reliability. In other words, there is a fundamental contradiction between the head and reliability of a centrifugal pump, making it difficult for centrifugal pumps in related technologies to simultaneously meet the requirements of high head and high reliability. Summary of the Invention

[0005] This application provides a centrifugal pump that can simultaneously meet the requirements of high head and high reliability.

[0006] One embodiment of this application provides a centrifugal pump, including: a pump casing and a first drive mechanism, a second drive mechanism, a pump shaft, and an impeller disposed within the pump casing;

[0007] The pump casing includes a first chamber and a second chamber that are interconnected. The axis of the pump shaft coincides with the axis of the first chamber and the second chamber. The inner diameter of the second chamber is larger than the inner diameter of the first chamber. The impeller is connected to the end of the pump shaft. The first drive mechanism and the second drive mechanism are connected to the pump shaft and are located on the side of the pump shaft away from the impeller. The first drive mechanism is used to drive the pump shaft to rotate, and the second drive mechanism is used to drive the pump shaft to move along the axis. The impeller is used to rotate in the first chamber or the second chamber under the drive of the pump shaft.

[0008] This application provides a centrifugal pump with two chambers of different inner diameters inside the pump casing. A drive mechanism moves the impeller between the two chambers. In the first chamber, the gap between the impeller and the inner wall is small, allowing the centrifugal pump to achieve high flow rate and high head. When large particles of impurities jam the impeller, the drive mechanism moves the impeller to the second chamber, where the gap between the impeller and the inner wall is large, providing strong resistance to impurities and releasing the jammed state. By controlling the switching between the two operating modes, the centrifugal pump can simultaneously achieve high performance and high reliability.

[0009] In one possible implementation, the first drive mechanism includes a first bearing, a motor, and a second bearing connected in sequence to the pump shaft. The motor is used to drive the pump shaft to rotate. The first bearing and the second bearing are sleeved on the outside of the pump shaft, and the first bearing is located on the side of the pump shaft away from the impeller.

[0010] The motor can drive the pump shaft to rotate. The first and second bearings are used to support the rotating pump shaft, reduce the coefficient of friction during the rotation process, and ensure the rotational accuracy of the pump shaft.

[0011] In one possible implementation, the first drive mechanism further includes a first slide and a second slide, the first slide and the second slide being fixed inside the pump housing, the first bearing being connected in the first slide and being able to slide within the first slide along the axial direction of the pump shaft, and the second bearing being connected in the second slide and being able to slide within the second slide along the axial direction of the pump shaft.

[0012] The first slide rail secures the first bearing to the pump housing and allows for axial movement of the first bearing. Similarly, the second slide rail secures the second bearing to the pump housing and allows for axial movement of the second bearing. The first and second slide rails work together to facilitate the sliding of the first and second bearings, making the pump shaft move more smoothly and the centrifugal pump's operating mode switching more seamless.

[0013] In one possible implementation, the second drive mechanism includes a coil, a spring, and an armature. The armature is disposed on the side of the first bearing away from the motor. The armature and the first bearing are connected by the spring. The spring's contraction direction is parallel to or coincides with the axial direction of the pump shaft. The coil is connected to the armature, and the coil can be energized to make the armature form a magnetic attraction structure.

[0014] When the coil is energized, a magnetic field is formed, and the armature can form a magnetic attraction. The armature can attract the first bearing, and the spring 32 is compressed, thereby causing the first bearing, the second bearing, the pump shaft and the impeller to move as a whole, so that the impeller can switch between moving in the first chamber or the second chamber.

[0015] In one possible implementation, the centrifugal pump further includes an ammeter and a tachometer, and the second drive mechanism further includes a controller connected to the coil. The controller is connected to the ammeter or the tachometer and is used to receive a current signal from the ammeter or a speed signal from the tachometer, and to control the coil to be energized or de-energized according to the current signal or the speed signal.

[0016] By setting the controller to detect abnormalities in current or speed signals, and controlling the energization or de-energization of the coil, the impeller jamming state can be resolved in a timely manner, improving the performance and reliability of the centrifugal pump.

[0017] In one possible implementation, the second drive mechanism further includes a manual switch connected to the coil for controlling the coil to be energized or de-energized.

[0018] The coil is energized or de-energized by a manual switch, which is convenient for operators, can relieve impeller jamming, and improve the performance and reliability of the centrifugal pump.

[0019] In one possible implementation, the second chamber is located on the side of the first chamber opposite to the first drive mechanism.

[0020] The second chamber, with a larger inner diameter, is located at the bottom of the pump casing, which improves the pump's appearance and lowers the overall center of gravity, thus enhancing its stability.

[0021] In one possible implementation, the centrifugal pump further includes a first branch pipe and a second branch pipe, the first branch pipe being connected to the side wall of the first chamber and the second branch pipe being connected to the side wall of the second chamber, the first branch pipe and the second branch pipe converging and communicating with a drain pipe.

[0022] By setting a first branch pipe and a second branch pipe on the side walls of the first chamber and the second chamber respectively, it is beneficial to facilitate the smooth discharge of liquid in both working modes. Compared with setting only one drain pipe, the drainage efficiency is higher.

[0023] In one possible implementation, a first check valve is provided on the first branch pipe, and a second check valve is provided on the second branch pipe.

[0024] By installing one-way valves on the first and second branch pipes respectively, it can be ensured that in the first working mode, the liquid is discharged only from the first branch pipe, and in the second working mode, the liquid is discharged only from the second branch pipe, thus preventing the backflow of liquid in the other branch pipe and ensuring the drainage effect.

[0025] In one possible implementation, the centrifugal pump is a vertical pump, with the pump casing and the pump shaft arranged vertically relative to the horizontal plane.

[0026] When the vertical centrifugal pump is working, the first and second chambers are filled with liquid, the impeller is immersed in the liquid, and the first bearing, motor and second bearing can be arranged in sequence from top to bottom, located at the top of the pump casing and detached from the liquid surface.

[0027] This application provides a centrifugal pump with two chambers of different inner diameters within the pump casing. A drive mechanism moves an impeller between the two chambers. In the first chamber, the clearance between the impeller and the inner wall is small, allowing the centrifugal pump to achieve high flow rate and high head. When large particles of impurities jam the impeller, the drive mechanism moves the impeller to the second chamber. In the second chamber, the clearance between the impeller and the inner wall is large, providing stronger resistance to impurities and releasing the jammed state. By controlling the switching between the two operating modes, the centrifugal pump can simultaneously achieve high performance and high reliability. Furthermore, by cleverly utilizing an armature, coil, and spring to construct a magnetic drive mechanism, smooth movement of the impeller in the axial direction can be achieved. Attached Figure Description

[0028] Figure 1 A schematic diagram of a centrifugal pump provided for related technologies;

[0029] Figure 2 Another structural schematic diagram of a centrifugal pump provided for related technologies;

[0030] Figure 3 This is a schematic diagram of the structure of a centrifugal pump provided in one embodiment of this application;

[0031] Figure 4 This is a schematic diagram of another state of the centrifugal pump provided in one embodiment of this application.

[0032] Explanation of reference numerals in the attached figures:

[0033] 100 - Pump casing; 10 - Working chamber; 11 - First chamber; 12 - Second chamber;

[0034] 13-First branch pipe; 131-First check valve; 14-Second branch pipe; 141-Second check valve;

[0035] 15-Drainage pipe; 200-First drive mechanism; 21-Motor; 22-First bearing;

[0036] 23-Second bearing; 24-First slide rail; 25-Second slide rail; 300-Second drive mechanism;

[0037] 31-Coil; 32-Spring; 33-Armature; 400-Pump shaft;

[0038] 500-Impeller. Detailed Implementation

[0039] A centrifugal pump is a pump that uses the centrifugal force generated by the rotation of an impeller to transport liquids. As a common drainage device, centrifugal pumps can be used in various fields, such as in the drainage process of data center cooling systems. A centrifugal pump generally includes a pump casing, a motor, a pump shaft, and an impeller. The motor drives the pump shaft, which in turn drives the impeller to rotate within the working chamber of the pump casing. The centrifugal force generated by the impeller's rotation discharges liquid from the working chamber into a drain pipe. For centrifugal pumps, performance and reliability are two crucial parameters.

[0040] The key performance characteristic of a centrifugal pump is its head, which refers to the height to which the pump can lift water. It is an important performance parameter of the pump, also known as pressure head, and can be expressed as the increase in the pressure energy head, kinetic energy head, and potential energy head of the fluid. The head of a centrifugal pump, with the impeller centerline as the reference, consists of two parts, equal to the sum of the suction head and the discharge head. The suction head is the height to which the pump can draw water, representing the vertical height from the pump impeller centerline to the water surface of the source water source; the discharge head is the height to which the pump can push water, representing the vertical height from the pump impeller centerline to the water surface of the outlet pool.

[0041] The key characteristic of centrifugal pump reliability is resistance to impurities. During the drainage process of centrifugal pump, external impurities such as scale and gravel are inevitably present in the water. These impurities can enter the centrifugal pump and cause the pump shaft or impeller to jam, leading to the failure of the centrifugal pump and reducing its reliability.

[0042] For centrifugal pumps, both their head and impurity resistance characteristics are strongly correlated with the clearance of their internal mechanical components. There is a fundamental contradiction between the head and reliability of centrifugal pumps, making it difficult for centrifugal pumps in current technologies to simultaneously meet the requirements of high head and high reliability.

[0043] Figure 1 A schematic diagram of a centrifugal pump provided for related technologies. (Reference) Figure 1 As shown, in a related technology, a centrifugal pump may include a pump casing 100, a motor 21, a pump shaft 400, and an impeller 500. The motor 21, the pump shaft 400, and the impeller 500 are all disposed inside the pump casing 100. The motor 21 is connected to the pump shaft 400, and the impeller 500 is connected to the end of the pump shaft 400. A working chamber 10 is provided at the bottom of the pump casing 100. The side wall of the working chamber 10 is connected to a drain pipe 15. The impeller 500 is disposed inside the working chamber 10. Driven by the motor 21, the pump shaft 400 drives the impeller 500 to rotate inside the working chamber 10, thereby discharging the liquid inside the working chamber 10 from the drain pipe 15.

[0044] In this related technology, the gap between the impeller 500 and the working chamber 10 is small, resulting in a centrifugal pump with high working efficiency and a large head for the same volume and power, which can meet the requirements for high-performance applications. However, if the gap L1' between the impeller 500 and the working chamber 10 is too small, impurities in the water can easily cause the impeller to jam during operation, leading to pump failure.

[0045] Figure 2 Another schematic diagram of a centrifugal pump provided for related technologies. (Reference) Figure 2 As shown, in another related technology, a centrifugal pump may include a pump casing 100, a motor 21, a pump shaft 400, and an impeller 500, the components and their connections being similar to... Figure 1 The centrifugal pump provided in this paper is the same as the one provided in the paper. The difference is that in this related technology, the gap L2' between the impeller 500 and the working chamber 10 is larger, which can ensure that impurity particles will not jam the impeller, and the relevant hard particles will flow out of the pump body with the water, resulting in high reliability. However, due to the larger gap, the impeller's working efficiency is very low, and the head performance is poor, which will cause the performance of the centrifugal pump to decline under the same power and volume.

[0046] In summary, a smaller clearance between the impeller and the working chamber results in a higher head and higher performance efficiency for the centrifugal pump. However, impurities can easily become trapped in the clearance, causing pump failure and reducing reliability. Conversely, a larger clearance reduces the pump's head, but impurities are more easily discharged, leading to higher reliability. In other words, performance and reliability are difficult to reconcile in centrifugal pumps; existing technologies often only meet one requirement, making it challenging to simultaneously satisfy both high head and high impurity resistance.

[0047] Based on the above problems, this application provides a centrifugal pump with two chambers of different inner diameters inside the pump casing. A drive mechanism is provided to allow the impeller to switch between the two chambers. In the first chamber, the gap between the impeller and the inner wall of the chamber is small, allowing the centrifugal pump to achieve high flow rate and high head. When large particles of impurities jam the impeller, the drive mechanism drives the impeller to the second chamber, which has strong impurity resistance and allows the impeller to resume normal rotation. Thus, the centrifugal pump can simultaneously achieve high performance and high reliability.

[0048] Figure 3 This is a schematic diagram of the structure of a centrifugal pump provided in one embodiment of this application. Figure 4 This is a schematic diagram illustrating another state of the centrifugal pump provided in one embodiment of this application. (See reference...) Figure 3 and Figure 4 As shown in the figure, this application provides a centrifugal pump, which may include: a pump casing 100 and a first drive mechanism 200, a second drive mechanism 300, a pump shaft 400 and an impeller 500 disposed within the pump casing 100.

[0049] The pump casing 100 may include a first chamber 11 and a second chamber 12 that are interconnected. The axis of the pump shaft 400 coincides with the axis of the first chamber 11 and the second chamber 12. The inner diameter of the second chamber 12 is larger than the inner diameter of the first chamber 11. An impeller 500 is connected to the end of the pump shaft 400. The impeller 500 can rotate in the first chamber 11 or in the second chamber 12.

[0050] The centrifugal pump provided in this embodiment can have two operating modes. Operating mode one: the impeller 500 is located in the first chamber 11, where the gap L1 between the impeller 500 and the inner wall of the chamber is small, allowing the centrifugal pump to achieve high flow rate and high head. Operating mode two: the impeller 500 is located in the second chamber 12, where the gap L2 between the impeller 500 and the inner wall of the chamber is larger, providing strong resistance to impurities and preventing the impeller 500 from easily jamming. By controlling the impeller 500 to switch between the first chamber 11 and the second chamber 12 in different scenarios, both high performance and high reliability of the centrifugal pump can be achieved.

[0051] In this embodiment, the first drive mechanism 200 is used to achieve reliable rotation of the impeller 500. The first drive mechanism 200 is connected to the pump shaft 400 and is located on the side of the pump shaft 400 away from the impeller 500. The first drive mechanism 200 is used to drive the pump shaft 400 to rotate, thereby causing the pump shaft 400 to drive the impeller 500 to rotate.

[0052] The first drive mechanism 200 may include a motor 21 connected to the pump shaft 400, which drives the pump shaft 400 to rotate. The first drive mechanism 200 may also include a first bearing 22 and a second bearing 23, which are sequentially connected to the pump shaft 400. The first bearing 22 and the second bearing 23 are sleeved on the outside of the pump shaft 400, with the first bearing 22 located on the side of the pump shaft 400 furthest from the impeller 500. The first bearing 22 and the second bearing 23 support the rotating pump shaft 400, reducing the coefficient of friction during rotation and ensuring the rotational accuracy of the pump shaft 400.

[0053] It should be noted that the centrifugal pump can be a vertical pump, that is, the shafts of the pump casing 100 and the pump shaft 400 are vertically arranged relative to the horizontal plane. In this case, the first chamber 11 and the second chamber 12 are located at the bottom of the pump casing 100. When the centrifugal pump is working, the first chamber 11 and the second chamber 12 are filled with liquid, the impeller 500 is immersed in the liquid, and the first bearing 22, the motor 21, and the second bearing 23 can be arranged sequentially from top to bottom, located at the upper part of the pump casing 100 and detached from the liquid surface.

[0054] In addition, in this embodiment, the second drive mechanism 300 is used to move the impeller 500 along the axis. The second drive mechanism 300 is connected to the pump shaft 400 and is located on the side of the pump shaft 400 away from the impeller 500. The second drive mechanism 300 is used to drive the pump shaft 400 to move along the axis, and the impeller 500 can switch between the first chamber 11 and the second chamber 12 under the drive of the pump shaft 400.

[0055] It should be understood that the first bearing 22 and the second bearing 23 can both be sliding bearings or rolling bearings. After the first bearing 22, the second bearing 23 and the pump shaft 400 are connected, they form a whole. The impeller 500 is fixedly connected to the end of the pump shaft 400. Thus, after the first bearing 22, the second bearing 23, the pump shaft 400 and the impeller 500 are installed, they are connected as a whole and their spatial relative positions are fixed. The second drive mechanism 300 can drive the pump shaft 400 or drive the first bearing 22 to move, thereby driving the impeller 500 to move in the axial direction.

[0056] The second drive mechanism 300 may include a coil 31, a spring 32, and an armature 33. The armature 33 is located on the side of the first bearing 22 away from the motor 21, that is, on the top of the pump housing 100. The armature 33 and the first bearing 22 are connected by the spring 32. The contraction direction of the spring 32 is parallel to or coincides with the axial direction of the pump shaft 400. The coil 31 is connected to the armature 33. The coil 31 can be energized to make the armature 33 form a magnetic attraction structure.

[0057] When the coil 31 is energized, a magnetic field is formed, the armature 44 can form a magnetic attraction, and the armature 33 can attract the first bearing 22, causing the spring 32 to be compressed. This causes the first bearing 22, the second bearing 23, the pump shaft 400 and the impeller 500 to move as a whole, allowing the impeller 500 to switch between moving in the first chamber 11 or the second chamber 12.

[0058] It should be understood that the relative positions of the first chamber 11 and the second chamber 12 within the pump housing 100 are not specifically limited in this embodiment. For example, the second chamber 12 may be located on the side of the first chamber 11 opposite to the first drive mechanism 200, that is, as shown in the figure, the second chamber 12 may be located below the first chamber 11.

[0059] In this way, in the initial state where the coil 31 is not energized, the armature 33 has no magnetic attraction, and the spring 32 can be in an expanded state, pressing the first bearing 22 so that the impeller 500 can be placed in the second chamber 12. After the coil 31 is energized, the armature 33 can attract the first bearing 22 to move upward, and the pump shaft 400 and the impeller 500 move upward synchronously, so that the impeller 500 is placed in the first chamber 11.

[0060] During the switching between the two working modes, both the first bearing 22 and the second bearing 23 can perform circumferential fixing functions, and the first bearing 22 can have a thrust function, so that the pump shaft 400 can have an axial positioning function.

[0061] In addition, the first drive mechanism 200 may also include a first slide 24 and a second slide 25, the first slide 24 and the second slide 25 are fixed inside the pump housing 100, the first bearing 22 is connected in the first slide 24 and can slide in the first slide 24 along the axial direction of the pump shaft 400, and the second bearing 23 is connected in the second slide 25 and can slide in the second slide 25 along the axial direction of the pump shaft 400.

[0062] The first slide rail 24 is used to secure the first bearing 22 and the pump housing 100, and to ensure the axial movement of the first bearing 22. Similarly, the second slide rail 25 is used to secure the second bearing 23 and the pump housing 100, and to ensure the axial movement of the second bearing 23. Thus, whether the coil 31 is energized or de-energized, based on the attraction of the armature 33 or the pressure of the spring 32, the first slide rail 24 and the second slide rail 25 can cooperate with the sliding of the first bearing 22 and the second bearing 23, making the movement of the pump shaft 400 smoother and the switching of the centrifugal pump's operating mode more seamless.

[0063] The centrifugal pump provided in this application embodiment has two operating modes, which can be switched by triggering the coil 31 to be energized or de-energized in different ways.

[0064] In one possible implementation, the triggering method is automatic triggering. In this case, the centrifugal pump may also include an ammeter and a tachometer, and the second drive mechanism 300 may also include a controller connected to the coil 31. The controller is connected to the ammeter or the tachometer and is used to receive the current signal from the ammeter or the speed signal from the tachometer, and control the coil 31 to be energized or de-energized according to the current signal or the speed signal.

[0065] The ammeter in the centrifugal pump is used to detect the pump's operating current. When the impeller 500 is jammed by large particles of impurities, the current will increase compared to normal conditions. The tachometer in the centrifugal pump is used to detect the speed of the motor 21 or the pump shaft 400. When the impeller 500 is jammed by large particles of impurities, the speed will decrease or even drop to zero.

[0066] When the centrifugal pump is in operating mode one, i.e., the impeller 500 is in the first chamber 11, the coil 31 is energized. If the centrifugal pump is operating normally, the controller can detect that the current or speed signal is normal. If the controller detects an increase in current or a decrease in speed, it determines that the impeller 500 may be stuck. At this time, the controller can de-energize the coil 31. Under the action of the spring 32, the impeller 500 moves downward into the second chamber 12, and the centrifugal pump is switched to operating mode two. Due to the increased gap between the impeller 500 and the inner wall of the chamber, the stuck state of the impeller 500 is released. After running in operating mode two for a certain period of time, the controller can energize the coil 31 to return to operating mode one, so as to ensure that the centrifugal pump can perform its high flow rate and high head characteristics.

[0067] By setting the controller to detect abnormalities in the current or speed signals, the energization or de-energization of coil 31 can be controlled, which can promptly resolve the jamming state of impeller 500 and improve the performance and reliability of the centrifugal pump.

[0068] In another possible implementation, the triggering method is manual triggering. The second drive mechanism 300 may also include a manual switch connected to the coil 31 for controlling the energization or de-energization of the coil 31. The manual switch may be located outside the pump casing 100 of the centrifugal pump for easy manual operation by the user. When the user finds that the impeller 500 is stuck and the centrifugal pump is operating abnormally, operating the manual switch can control the coil 31 to be de-energized, causing the centrifugal pump to switch from operating mode one to operating mode two. After the stuck impeller is released, operating the manual switch again can control the coil 31 to be energized, causing the centrifugal pump to switch from operating mode two to operating mode one.

[0069] The centrifugal pump provided in this embodiment operates as follows: To ensure pump performance, control coil 31 is energized, keeping impeller 500 within the first chamber 11, and the pump operates in operating mode one. If impeller 500 jams, coil 31 is manually or automatically de-energized, keeping impeller 500 within the second chamber 12, and the pump operates in operating mode two. After a certain period, coil 31 can be energized again, keeping impeller 500 within the first chamber 11, and the pump operates in operating mode one.

[0070] Based on the above embodiments of this application, in this embodiment of the centrifugal pump, a first branch pipe 13 and a second branch pipe 14 are further included. The first branch pipe 13 is connected to the side wall of the first chamber 11, and the second branch pipe 14 is connected to the side wall of the second chamber 12. The first branch pipe 13 and the second branch pipe 14 converge and communicate with the drain pipe 15.

[0071] When the impeller 500 rotates in the first chamber 11, the liquid in the first chamber 11 can enter the first branch pipe 13 under the action of centrifugal force, and then be discharged through the drain pipe 15. When the impeller 500 rotates in the second chamber 12, the liquid in the second chamber 12 can enter the second branch pipe 14 under the action of centrifugal force, and then be discharged through the drain pipe 15.

[0072] By setting a first branch pipe 13 and a second branch pipe 14 on the side walls of the first chamber 11 and the second chamber 12 respectively, it is beneficial to facilitate the smooth discharge of liquid in both working modes. Compared with setting only one drain pipe, the drainage efficiency is higher.

[0073] Furthermore, a first check valve 131 can be installed on the first branch pipe 13, and a second check valve 141 can be installed on the second branch pipe 14. After the first check valve 131 is opened, the liquid flow direction can only be from the first chamber 11 to the drain pipe 15, and after the second check valve 141 is opened, the liquid flow direction can only be from the second chamber 12 to the drain pipe 15.

[0074] When the impeller 500 rotates in the first chamber 11, the first one-way valve 131 opens and the second one-way valve 141 closes. Liquid in the first chamber 11 can enter the first branch pipe 13 under centrifugal force and then be discharged through the drain pipe 15. When the impeller 500 rotates in the second chamber 12, the first one-way valve 131 closes and the second one-way valve 141 opens. Liquid in the second chamber 12 can enter the second branch pipe 14 under centrifugal force and then be discharged through the drain pipe 15.

[0075] By installing one-way valves on the first branch pipe 13 and the second branch pipe 14, it can be ensured that in the first working mode, the liquid is discharged only from the first branch pipe 13, and in the second working mode, the liquid is discharged only from the second branch pipe 14, which can prevent the liquid from flowing back into the other branch pipe and ensure the drainage effect.

[0076] The centrifugal pump provided in this embodiment has two chambers with different inner diameters inside the pump casing, and a drive mechanism to move the impeller between the two chambers. In the first chamber, the gap between the impeller and the inner wall of the chamber is small, allowing the centrifugal pump to achieve high flow rate and high head. When large particles of impurities jam the impeller, the drive mechanism moves the impeller to the second chamber, where the gap between the impeller and the inner wall of the chamber is large, providing strong resistance to impurities and releasing the jammed state. By controlling the switching between the two operating modes, the centrifugal pump can simultaneously achieve high performance and high reliability. Furthermore, by cleverly utilizing an armature, coil, and spring to construct a magnetic drive mechanism, smooth movement of the impeller in the axial direction can be achieved.

[0077] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the embodiments of this application, and are not intended to limit them; although the embodiments of this application have been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the foregoing embodiments, or make equivalent substitutions for some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application.

Claims

1. A centrifugal pump, characterized in that, include: The pump casing and a first drive mechanism, a second drive mechanism, a pump shaft, and an impeller disposed within the pump casing; The pump casing includes a first chamber and a second chamber that are interconnected. The axis of the pump shaft coincides with the axis of the first chamber and the second chamber. The inner diameter of the second chamber is larger than the inner diameter of the first chamber. The impeller is connected to the end of the pump shaft. The first drive mechanism and the second drive mechanism are connected to the pump shaft and located on the side of the pump shaft away from the impeller. The first drive mechanism is used to drive the pump shaft to rotate, and the second drive mechanism is used to drive the pump shaft to move along the axis. The impeller is used to rotate in the first chamber or the second chamber under the drive of the pump shaft. The first drive mechanism includes a first bearing, a motor, and a second bearing connected in sequence to the pump shaft. The motor is used to drive the pump shaft to rotate. The first bearing and the second bearing are sleeved on the outside of the pump shaft. The first bearing is located on the side of the pump shaft away from the impeller. The second drive mechanism includes a coil, a spring, and an armature. The armature is disposed on the side of the first bearing away from the motor. The armature and the first bearing are connected by the spring. The spring's contraction direction is parallel to or coincides with the axis of the pump shaft. The coil is connected to the armature, and the coil can be energized to make the armature form a magnetic attraction structure.

2. The centrifugal pump according to claim 1, characterized in that, The first drive mechanism further includes a first slide and a second slide, the first slide and the second slide are fixed inside the pump housing, the first bearing is connected in the first slide and can slide in the first slide along the axial direction of the pump shaft, and the second bearing is connected in the second slide and can slide in the second slide along the axial direction of the pump shaft.

3. The centrifugal pump according to claim 1, characterized in that, The centrifugal pump further includes an ammeter and a tachometer. The second drive mechanism further includes a controller connected to the coil. The controller is connected to the ammeter or the tachometer. The controller is used to receive a current signal from the ammeter or a speed signal from the tachometer, and to control the coil to be energized or de-energized according to the current signal or the speed signal.

4. The centrifugal pump according to claim 1, characterized in that, The second drive mechanism also includes a manual switch, which is connected to the coil and is used to control the coil to be energized or de-energized.

5. The centrifugal pump according to any one of claims 1-4, characterized in that, The second chamber is located on the side of the first chamber opposite to the first drive mechanism.

6. The centrifugal pump according to any one of claims 1-4, characterized in that, The centrifugal pump also includes a first branch pipe and a second branch pipe. The first branch pipe is connected to the side wall of the first chamber, and the second branch pipe is connected to the side wall of the second chamber. The first branch pipe and the second branch pipe converge and communicate with the drain pipe.

7. The centrifugal pump according to claim 6, characterized in that, A first check valve is installed on the first branch pipe, and a second check valve is installed on the second branch pipe.

8. The centrifugal pump according to any one of claims 1-4, characterized in that, The centrifugal pump is a vertical pump, and the pump casing and the axis of the pump shaft are vertically arranged relative to the horizontal plane.

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