Low-vibration vertical two-stage pump

Abstract

The utility model discloses a low-vibration vertical two-stage pump. The low-vibration vertical two-stage pump comprises a pump body, a first-stage impeller, a second-stage impeller, a space guide vane piece, a driving piece, a main shaft, an inducer and a mechanical seal. The primary impeller and the secondary impeller are arranged on the outer side of the main shaft in a sleeving manner and are arranged in a spaced manner in the direction close to the driving part; the main shaft is sleeved with the space guide vane piece, and the space guide vane piece is arranged between the first-stage impeller and the second-stage impeller. The space guide vane piece is connected to the interior of the pump body and is configured to guide fluid passing through the first-stage impeller to be transited to the second-stage impeller. The technical problems that in the prior art, a low-vibration centrifugal pump is complex in structure and large in axial size, and the cavitation characteristic of a pump set is poor are solved. The technical effects of reducing the flow loss of the pump set, reducing the axial size of the pump set and improving the cavitation characteristic of the pump set are achieved.

Description

Technical Field

[0001] The present application relates to the technical field of centrifugal pumps, and in particular to a low-vibration vertical two-stage pump. Background Art

[0002] Pumps are widely used in many project construction fields such as shipbuilding, aerospace, petrochemicals, etc., especially centrifugal pumps have a wider range of applications and scenarios in the above fields.

[0003] During the operation of a centrifugal pump, vibration and noise will be generated due to fluid excitation and motor transmission. If the vibration exceeds the standard, it will deteriorate the operating environment, destroy the fit relationship between parts, and affect the service life of the pump unit. With the continuous development of technology and increasingly stringent working conditions, in-depth research on the vibration characteristics and cavitation characteristics of centrifugal pumps is particularly important.

[0004] The research on the vibration characteristics of centrifugal pumps is mainly divided into three aspects: the first is the optimization design of the mechanical structure, the second is the design method of low-vibration hydraulics, and the third is the operation method of rotor dynamic balancing. After searching, a low-vibration centrifugal pump with the publication number CN116971994A was found. It has at least one set of dynamic and static ring assemblies designed on the front and rear covers of the impeller to balance the axial forces on both sides of the impeller, thereby reducing vibration. However, the pump body and impeller structure of this application are complex, with high precision requirements and difficult to achieve machining. In particular, the sealing groove in the pump body is difficult to machine. Improving its vibration will increase the axial size of the pump group, which limits the use scenarios of the pump group. In addition, it cannot improve the cavitation characteristics of the pump group. Therefore, it is urgent to propose a low-vibration vertical two-stage pump. Utility Model Content

[0005] The present invention provides a low-vibration vertical two-stage pump, addressing the technical issues of low-vibration centrifugal pumps in the prior art, such as their complex structure, large axial dimensions, and poor cavitation characteristics. This reduces flow losses and axial dimensions of the pump, while also improving its cavitation characteristics.

[0006] The embodiment of the present utility model provides a low-vibration vertical two-stage pump, comprising a pump body, a first-stage impeller, a secondary impeller, a space guide vane, a driving member, a main shaft, an inducer and a mechanical seal; the pump body is a hollow shell with a liquid inlet and a liquid outlet; the fixed end of the driving member is connected to one end of the pump body, the output end of the driving member is connected to one end of the main shaft, and the other end of the main shaft extends into the pump body; the first-stage impeller and the secondary impeller are both sleeved on the outside of the main shaft, and the first-stage impeller and the secondary impeller are spaced apart in the direction close to the driving member. The inducer is sleeved on the outside of the main shaft, and the inducer is connected to the end of the main shaft away from the driving member; the mechanical seal is arranged between the main shaft and the pump body, and one end of the mechanical seal abuts the driving member, and the other end of the mechanical seal abuts the secondary impeller; the space guide vane is sleeved on the outside of the main shaft, and the space guide vane is arranged between the primary impeller and the secondary impeller; the space guide vane is connected to the inside of the pump body, and is configured to guide the fluid passing through the primary impeller to transition to the secondary impeller.

[0007] In one possible implementation, the pump body includes a suction section pump casing and a main pump casing; the suction section pump casing is a hollow casing provided with the liquid inlet, and the main pump casing is a hollow casing provided with the liquid outlet; one end of the main pump casing is connected to an end of the suction section pump casing away from the liquid inlet, and the other end of the main pump casing is connected to the fixed end of the driving member; the liquid inlet and the liquid outlet are arranged in parallel; one end of the space guide vane is connected to the interior of the suction section pump casing, and the other end of the space guide vane is connected to the interior of the main pump casing.

[0008] In one possible implementation, the space guide vane member includes a space shell, a cover plate and a plurality of space guide vane blades; the space shell is arranged on the outside of the cover plate; one end of the plurality of space guide vane blades is connected to the outside of the cover plate, and the other end of the plurality of space guide vane blades is connected to the inside of the space shell; one end of the space shell is connected to the inside of the suction section pump shell, and the other end of the space shell is connected to the inside of the main pump shell; the cover plate is sleeved on the outside of the main shaft, and the cover plate is arranged between the primary impeller and the secondary impeller.

[0009] In one possible implementation, the suction section pump housing is further provided with a guide plate in the channel of the liquid inlet; the interior of the suction section pump housing is further provided with a guide cone, and the axis of the guide cone coincides with the axis of the main shaft; the interior of the suction section pump housing is further provided with an anti-rotation plate, and the anti-rotation plate is arranged on the side of the guide cone away from the liquid inlet.

[0010] In a possible implementation, the low-vibration vertical two-stage pump further includes a first-stage seal; the first-stage seal is disposed between the first-stage impeller and the pump body.

[0011] In a possible implementation, the low-vibration vertical two-stage pump further includes a secondary seal; the secondary seal is disposed between the secondary impeller and the pump body.

[0012] In one possible implementation, the low-vibration vertical two-stage pump further includes a shaft sleeve and a sliding bearing assembly; the shaft sleeve is sleeved on the outside of the main shaft, and one end of the shaft sleeve abuts against the end face of the primary impeller, and the other end of the shaft sleeve abuts against the end face of the secondary impeller; the cover plate is sleeved on the outside of the shaft sleeve; and the sliding bearing assembly is arranged between the shaft sleeve and the cover plate.

[0013] In a possible implementation, the low-vibration vertical two-stage pump further includes a back blade; the back blade is disposed between the cover plate and the first-stage impeller, and the back blade is connected to the first-stage impeller.

[0014] In a possible implementation, the liquid outlet of the main pump housing is configured as a double-tab partition.

[0015] In a possible implementation, the inlet channel of the suction section pump casing is configured as an annular water suction chamber, the longitudinal cross-section of which gradually changes from a circular shape to an elliptical shape along the flow direction of the fluid.

[0016] One or more technical solutions provided in this application have at least the following technical effects:

[0017] The present invention employs a low-vibration vertical two-stage pump comprising a pump body, a primary impeller, a secondary impeller, a space guide vane, a drive element, a main shaft, an inducer, and a mechanical seal. The pump body comprises a suction section pump casing and a main pump casing; the suction section pump casing is a hollow casing with a liquid inlet, and the main pump casing is a hollow casing with a liquid outlet; one end of the main pump casing is connected to the end of the suction section pump casing away from the liquid inlet, and the other end of the main pump casing is connected to the fixed end of the drive element; the liquid inlet and the liquid outlet are arranged in parallel; one end of the space guide vane is connected to the interior of the suction section pump casing, and the other end of the space guide vane is connected to the interior of the main pump casing. The present application also designs a coaxial direct connection between the drive element and the pump body, avoiding the use of a coupling. This method can reduce the axial size of the pump unit and improve the rigidity of the pump unit installation and the main shaft alignment. The transition flow channel between the primary impeller and the secondary impeller is designed with a spatial guide vane to guide the fluid passing through the primary impeller to the secondary impeller. The inlet channel of the suction section pump casing is configured as an annular water suction chamber, whose longitudinal cross-section gradually changes from circular to elliptical along the flow direction of the fluid. By optimizing the structure of the transition flow channel, the vibration characteristics of the pump unit can be improved, and flow losses can also be reduced, thereby improving the cavitation characteristics of the pump unit. The present application solves the technical problems of the prior art low-vibration centrifugal pumps that are relatively complex in structure, large in axial dimension, and have poor cavitation characteristics of the pump unit. The technical effects of reducing the flow loss of the pump unit, reducing the axial dimension of the pump unit, and improving the cavitation characteristics of the pump unit are achieved. At the same time, the low-vibration vertical two-stage pump of the present application has a small number of parts, a simple part structure, is easy to process and manufacture, and is easy to disassemble and assemble the pump unit, facilitating subsequent maintenance. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for use in the description of the embodiments of the present invention. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0019] Figure 1 An axonometric diagram of a low-vibration vertical two-stage pump provided in an embodiment of the present application;

[0020] Figure 2 A front view of a low-vibration vertical two-stage pump provided in an embodiment of the present application;

[0021] Figure 3 for Figure 2 AA section view;

[0022] Figure 4 This is an axonometric view of the spatial guide vane provided in an embodiment of the present application.

[0023] Icons: 1- pump body; 11- suction section pump casing; 111- liquid inlet; 12- main pump casing; 121- liquid outlet; 2- first stage impeller; 3- secondary impeller; 4- space guide vane; 41- space casing; 42- cover plate; 43- space guide vane blade; 5- driving part; 6- main shaft; 7- inducer; 8- mechanical seal; 90- guide plate; 91- guide cone; 92- anti-rotation plate; 93- first stage seal; 94- secondary seal; 95- bushing; 96- sliding bearing assembly; 97- back blade; 98- lifting ring; 99- double tongue partition; 991- reinforcing rib; 992- key; 993- plug; 994- exhaust hole; 995- machine foot connecting plate. DETAILED DESCRIPTION

[0024] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are 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 are within the scope of protection of the present invention.

[0025] In the description of the embodiments of the present invention, it should be noted that the terms "center", "up", "down", "left", "right", "vertical", "horizontal", "inside", "outside" and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the embodiments of the present invention and simplifying the description, and do not indicate or imply that the devices or components referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limitations on the present invention. The terms "first", "second" and "third" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance. In addition, the terms "installed", "connected" and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or an indirect connection through an intermediate medium, or it can be a communication between the internal parts of two components. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the present invention can be understood according to the specific circumstances.

[0026] The embodiment of the present utility model provides a low-vibration vertical two-stage pump, comprising a pump body 1, a first-stage impeller 2, a secondary impeller 3, a space guide vane 4, a driving member 5, a main shaft 6, an inducer 7 and a mechanical seal 8; the pump body 1 is a hollow shell with a liquid inlet 111 and a liquid outlet 121; the fixed end of the driving member 5 is connected to one end of the pump body 1, the output end of the driving member 5 is connected to one end of the main shaft 6, and the other end of the main shaft 6 extends into the pump body 1; the first-stage impeller 2 and the secondary impeller 3 are both sleeved on the outside of the main shaft 6, and the first-stage impeller 2 and the secondary impeller 3 are along the outer side of the main shaft 6, and the first-stage impeller 2 and the secondary impeller 3 are along the inner ... The direction of the driving member 5 is spaced apart; the inducer 7 is sleeved on the outside of the main shaft 6, and the inducer 7 is connected to the end of the main shaft 6 away from the driving member 5; the mechanical seal 8 is arranged between the main shaft 6 and the pump body 1, and one end of the mechanical seal 8 abuts against the driving member 5, and the other end of the mechanical seal 8 abuts against the secondary impeller 3; the space guide vane 4 is sleeved on the outside of the main shaft 6, and the space guide vane 4 is arranged between the primary impeller 2 and the secondary impeller 3; the space guide vane 4 is connected to the inside of the pump body 1, and is configured to guide the fluid passing through the primary impeller 2 to transition to the secondary impeller 3.

[0027] Exemplarily, the driving component 5 is a motor, and the traditional coupling connection method between the motor and the pump group is eliminated. The motor of this application and the pump body 1 are positioned by a stopper and fixedly connected with a double-headed stud. The motor, the first-stage impeller 2, and the secondary impeller 3 all share a main shaft 6, which can improve the rigidity and centering of the pump group structure, and can also compress the axial dimension of the pump group, thereby reducing the influence of the shaft frequency and frequency harmonics on the vibration of the pump group.

[0028] Exemplarily, the cooling method of the driving member 5 is water cooling. A water source is connected to the outside of the driving member 5. A cooling water inlet and a cooling water outlet are provided on the driving member 5. Water flows in from the cooling water inlet and flows out from the cooling water outlet, thereby taking away the heat of the driving member 5.

[0029] Illustratively, the liquid inlet 111 and the liquid outlet 121 of the pump group are horizontally arranged on both sides of the pump group, which can improve the installation rigidity and centering accuracy of the pump group and effectively reduce the vibration problem of the pump group.

[0030] For example, an exhaust hole 994 is further provided on the main pump casing 12. The exhaust hole 994 is formed by thickening and drilling any reinforcing rib 991 that does not interfere with the outlet of the pump body 1, and an exhaust valve is installed at the exhaust hole 994 to facilitate exhaust operation before starting the pump group.

[0031] For example, before the pump unit is started, the exhaust valve is opened, and the air in the pump body 1 is exhausted through the exhaust hole 994. The pump body 1 is filled with liquid to ensure that there is no air discharged from the exhaust hole 994. Then, the exhaust valve is closed and the pump unit is started. When the pump unit is operating normally, the fluid enters from the liquid inlet 111. Under the guidance of the guide plate 90 and the guide cone 91 and the derotation effect of the anti-rotation plate 92, the fluid flows into the inducer 7. The inducer 7 can do work on the fluid and transport the fluid to the first-stage impeller 2. The fluid after passing through the first-stage impeller 2 is in the space guide vane. 4, the fluid flowing out of the guide vane 4 is divided into two parts. One part, under the action of the pressure differential, flows through the lubrication groove into the gap of the sliding bearing assembly 96, thereby improving the support performance of the sliding bearing assembly 96 on the main shaft 6. The fluid flowing through the sliding bearing assembly 96 is then combined with the main flow after being worked by the back blades 97 of the primary impeller 2. The other part of the fluid is further worked by the secondary impeller 3, and is collected and pressurized in the double-flange volute flow channel before flowing out of the liquid outlet 121, thus providing the required flow and pressure for the downstream side of the pump unit. It should be noted that only a small part of the fluid flows into the gap of the sliding bearing assembly 96; the majority of the fluid passes through the secondary impeller 3 to further work.

[0032] Exemplarily, the low-vibration vertical two-stage pump further includes a lifting ring 98 , which is disposed above the driving member 5 .

[0033] Exemplarily, the primary impeller 2 is connected to the main shaft 6 via a key 992 , and the secondary impeller 3 is connected to the main shaft 6 via a key 992 .

[0034] In the embodiment of this application, Figure 1-4 As shown, the pump body 1 includes a suction section pump casing 11 and a main pump casing 12; the suction section pump casing 11 is a hollow casing with a liquid inlet 111, and the main pump casing 12 is a hollow casing with a liquid outlet 121; one end of the main pump casing 12 is connected to the end of the suction section pump casing 11 away from the liquid inlet 111, and the other end of the main pump casing 12 is connected to the fixed end of the driving member 5; the liquid inlet 111 and the liquid outlet 121 are arranged in parallel; one end of the spatial guide vane member 4 is connected to the interior of the suction section pump casing 11, and the other end of the spatial guide vane member 4 is connected to the interior of the main pump casing 12.

[0035] Exemplarily, the pump group is installed vertically with lumbar support, and the pump group is provided with a horizontal liquid inlet 111 and a horizontal liquid outlet 121. The liquid inlet 111 and the liquid outlet 121 maintain an angle of 180°. This arrangement can balance the mass on both sides of the pump group, thereby reducing the impact of the center of mass offset on the vibration of the pump group.

[0036] Exemplarily, a first sealing ring is further included, which is arranged between the suction section pump housing 11 and the main pump housing 12. The suction section pump housing 11 and the main pump housing 12 are positioned and connected by a stopper, and the first sealing ring plays a sealing role.

[0037] In the embodiment of this application, Figure 1-4 As shown, the space guide vane member 4 includes a space shell 41, a cover plate 42 and a plurality of space guide vane blades 43; the space shell 41 is arranged on the outside of the cover plate 42; one end of the plurality of space guide vane blades 43 is connected to the outside of the cover plate 42, and the other end of the plurality of space guide vane blades 43 is connected to the inside of the space shell 41; one end of the space shell 41 is connected to the inside of the suction section pump shell 11, and the other end of the space shell 41 is connected to the inside of the main pump shell 12; the cover plate 42 is sleeved on the outside of the main shaft 6, and the cover plate 42 is arranged between the primary impeller 2 and the secondary impeller 3.

[0038] For example, the spatial guide vane member 4 can be formed by any method such as casting, 3D printing, milling and welding.

[0039] Exemplarily, the number of blades of the spatial guide vanes 43 is coprime with the number of blades of the first-stage impeller 2 , thereby reducing the probability of resonance.

[0040] For example, the axial distance between the inlet of the spatial guide vane 4 and the outlet of the first-stage impeller 2 is L1. Generally, the best flow guidance effect is achieved when L1 is 1 / 10 of the outlet width of the first-stage impeller 2.

[0041] Exemplarily, the space guide vane member 4 is provided with a sealing groove on the outer end face on the outlet side, and the sealing groove is used to install a second sealing ring, which can achieve sealing between the space guide vane member 4 and the main pump casing 12. The inlet side of the space guide vane member 4 cooperates with the suction section pump casing 11, and an annular groove is provided on the end face of the suction section pump casing 11. The annular groove is used to install an adjustment gasket, which can adjust the axial size of the pump group and perform axial positioning. The adjustment gasket can also play a role of secondary sealing; the present application is provided with an anti-rotation pin between the space guide vane member 4 and the suction section pump casing 11, and the anti-rotation pin can perform circumferential positioning of the space guide vane member 4.

[0042] In the embodiment of this application, Figure 1-4 As shown, the suction section pump housing 11 is further provided with a guide plate 90 in the channel of the liquid inlet 111; the interior of the suction section pump housing 11 is further provided with a guide cone 91, and the axis of the guide cone 91 coincides with the axis of the main shaft 6; the interior of the suction section pump housing 11 is further provided with an anti-rotation plate 92, and the anti-rotation plate 92 is arranged on the side of the guide cone 91 away from the liquid inlet 111.

[0043] Exemplarily, guide plate 90 is a straight cascade centrally located on the side of suction section pump housing 11 near liquid inlet 111. Guide cone 91 is a conical structure located at the bottom of suction section pump housing 11, with the axis of guide cone 91 coinciding with the axis of main shaft 6. Anti-rotation plate 92 is a straight cascade centrally located on the side of guide cone 91 away from liquid inlet 111. The functions of guide plate 90, guide cone 91, and anti-rotation plate 92 are to guide the fluid to smoothly transition into the flow path of inducer 7 and prevent the fluid from generating vortices and excitation, thereby reducing vibration of the pump unit.

[0044] Exemplarily, a wire plug 993 is also provided on the suction section pump housing 11.

[0045] In the embodiment of this application, Figure 1-4 As shown, a first-stage seal 93 is also included; the first-stage seal 93 is arranged between the first-stage impeller 2 and the pump body 1.

[0046] In the embodiment of this application, Figure 1-4 As shown, a secondary seal 94 is also included; the secondary seal 94 is arranged between the secondary impeller 3 and the pump body 1.

[0047] In the embodiment of this application, Figure 1-4 As shown, it also includes a sleeve 95 and a sliding bearing assembly 96; the sleeve 95 is sleeved on the outside of the main shaft 6, and one end of the sleeve 95 abuts against the end face of the first-stage impeller 2, and the other end of the sleeve 95 abuts against the end face of the secondary impeller 3; the cover plate 42 is sleeved on the outside of the sleeve 95; the sliding bearing assembly 96 is arranged between the sleeve 95 and the cover plate 42.

[0048] For example, the first-stage impeller 2 and the secondary impeller 3 are coaxially installed on the outside of the main shaft 6 and are axially positioned by the middle sleeve 95. The flow channels of the first-stage impeller 2 and the secondary impeller 3 are connected through the spatial guide vane 4. The fluid enters the secondary impeller 3 after being guided and pressurized from the first-stage impeller 2 through the spatial guide vane 4.

[0049] Exemplarily, the sliding bearing assembly 96 is composed of a metal matrix and graphite. The sliding bearing assembly 96 is arranged between the first-stage impeller 2 and the secondary impeller 3. The fluid flows from the outlet of the space guide vane 4 through the gap of the sliding bearing assembly 96, and after doing work through the back blade 97 of the first-stage impeller 2, it merges into the mainstream. The fluid circulates. The flow mode of the fluid in this application can improve the support and stability of the main shaft 6.

[0050] Exemplarily, the graphite inner hole of the sliding bearing assembly 96 is provided with a plurality of lubrication grooves, the number of which is generally 3-6. The lubrication grooves cooperate with the shaft sleeve 95 to form a radial clearance, and the single-side clearance is 0.03mm-0.10mm.

[0051] In the embodiment of this application, Figure 1-4As shown, it also includes a back blade 97 ; the back blade 97 is arranged between the cover plate 42 and the first-stage impeller 2 , and the back blade 97 is connected to the first-stage impeller 2 .

[0052] Illustratively, a back blade 97 is provided on the rear cover plate of the first-stage impeller 2 , and the back blade 97 can increase the pressure difference on both sides of the sliding bearing assembly 96 , thereby enhancing the supporting performance of the sliding bearing assembly 96 .

[0053] Illustratively, a rear ring is provided on the rear cover plate of the first-stage impeller 2, and a balancing hole is also provided on the first-stage impeller 2. The rear ring can increase the pressure difference on both sides of the sliding bearing assembly 96, thereby enhancing the supporting performance of the sliding bearing assembly 96.

[0054] Exemplarily, the fluid flowing out of the space guide vane member 4 is divided into two parts, one of which flows into the gap of the sliding bearing assembly 96 through the lubrication groove under the action of the pressure difference, thereby improving the support performance of the sliding bearing assembly 96 on the main shaft 6. The fluid flowing through the sliding bearing assembly 96 flows out along the balance hole of the first-stage impeller 2 and merges into the main flow; the other part of the fluid further performs work through the secondary impeller 3, is collected and pressurized through the double-blade volute flow channel, and flows out from the liquid outlet 121, thereby providing the required flow and pressure for the downstream of the pump group. It should be noted that only a small part of the fluid flows into the gap of the sliding bearing assembly 96, and most of the fluid further performs work through the secondary impeller 3. Exemplarily, the inlet edge of the space guide vane member 4 is appropriately away from the outlet edge of the first-stage impeller 2, and the inlet edge of the space guide vane member 4 maintains an angle of 60-90° with the outlet edge of the first-stage impeller 2. This setting can reduce the dynamic and static interference between the first-stage impeller 2 and the space guide vane member 4, thereby further reducing the vibration of the pump group.

[0055] In the embodiment of this application, Figure 1-4 As shown, the liquid outlet 121 of the main pump housing 12 is provided with a double-tongue partition 99 .

[0056] Exemplarily, the liquid outlet 121 of the main pump housing 12 is configured as a double-flank volute flow channel, thereby balancing the radial excitation force of the fluid.

[0057] Exemplarily, a machine foot connecting plate 995 is provided on the main pump housing 12. The plane shape of the machine foot connecting plate 995 is rectangular. The machine foot connecting plate 995 is used to install and fix the pump group. The bottom of the pump group is evenly distributed with reinforcing ribs 991 around the circumference. The reinforcing ribs 991 can improve the rigidity of the pump group.

[0058] For example, the liquid outlet 121 of the main pump housing 12 adopts a double-flank volute flow channel with an offset design. This design can compress the axial size of the pump unit.

[0059] In the embodiment of this application, Figure 1-4As shown, the inlet channel of the suction section pump housing 11 is configured as an annular water suction chamber, the longitudinal cross section of which gradually changes from a circular shape to an elliptical shape along the flow direction of the fluid.

[0060] For example, the inlet channel of the suction section pump housing 11 is an annular water suction chamber, and the cross section gradually changes from a circular streamlined shape to an elliptical shape. This design can reduce the flow loss of the fluid.

[0061] For example, the center of the inlet passage of the suction section pump casing 11 is appropriately raised, which can reduce the axial dimension of the pump group, thereby improving the cavitation performance of the pump group.

[0062] Exemplarily, the inlet channel of the suction section pump casing 11 is set as an annular water suction chamber, and the center of the inlet channel of the suction section pump casing 11 is appropriately raised. The guide plate 90, the guide cone 91 and the anti-rotation plate 92 can guide the fluid to smoothly transition to the flow channel of the inducer 7, thereby reducing the axial size of the pump group, improving the cavitation performance of the pump group, and reducing flow losses.

[0063] For example, the transition flow channel between the first-stage impeller 2 and the secondary impeller 3 eliminates the traditional radial positive and negative guide vanes, and designs a spatial guide vane 4 to guide the fluid to transition streamlined and smoothly to the inlet of the secondary impeller 3. The spatial guide vane 4 can reduce the local loss and impact loss of the fluid, and reduce the impact of dynamic and static interference on the vibration of the pump group.

[0064] The various embodiments in this specification are described in a progressive manner, and the same or similar parts between the various embodiments can be referenced to each other. Each embodiment focuses on the differences from other embodiments.

[0065] The above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit the present application. Although the present application has been described in detail with reference to the aforementioned embodiments, a person of ordinary skill in the art should understand that the technical solutions described in the aforementioned embodiments can still be modified, or some or all of the technical features therein can be replaced by equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the present application.

Claims

1. A low-vibration vertical two-stage pump, characterized in that: It includes a pump body (1), a first-stage impeller (2), a secondary impeller (3), a space guide vane (4), a driving member (5), a main shaft (6), an inducer (7) and a mechanical seal (8); The pump body (1) is a hollow shell having a liquid inlet (111) and a liquid outlet (121); The fixed end of the driving member (5) is connected to one end of the pump body (1), the output end of the driving member (5) is connected to one end of the main shaft (6), and the other end of the main shaft (6) extends into the pump body (1); The first-stage impeller (2) and the secondary impeller (3) are both sleeved on the outside of the main shaft (6), and the first-stage impeller (2) and the secondary impeller (3) are spaced apart in a direction close to the driving member (5); The inducer wheel (7) is sleeved on the outside of the main shaft (6), and the inducer wheel (7) is connected to an end of the main shaft (6) away from the driving member (5); The mechanical seal (8) is provided between the main shaft (6) and the pump body (1), and one end of the mechanical seal (8) abuts against the driving member (5), and the other end of the mechanical seal (8) abuts against the secondary impeller (3); The spatial guide vane member (4) is sleeved on the outside of the main shaft (6), and the spatial guide vane member (4) is arranged between the primary impeller (2) and the secondary impeller (3); The spatial guide vane member (4) is connected to the interior of the pump body (1) and is configured to guide the fluid passing through the primary impeller (2) to transition to the secondary impeller (3).

2. The low-vibration vertical two-stage pump according to claim 1, characterized in that: The pump body (1) comprises a suction section pump casing (11) and a main body pump casing (12); The suction section pump housing (11) is a hollow housing provided with the liquid inlet (111), and the main body pump housing (12) is a hollow housing provided with the liquid outlet (121); One end of the main pump housing (12) is connected to an end of the suction section pump housing (11) away from the liquid inlet (111), and the other end of the main pump housing (12) is connected to a fixed end of the driving member (5); The liquid inlet (111) and the liquid outlet (121) are arranged in parallel; One end of the space guide vane member (4) is connected to the interior of the suction section pump casing (11), and the other end of the space guide vane member (4) is connected to the interior of the main pump casing (12).

3. The low-vibration vertical two-stage pump according to claim 2, characterized in that: The space guide vane member (4) comprises a space shell (41), a cover plate (42) and a plurality of space guide vane blades (43); The space shell (41) is arranged on the outside of the cover plate (42); One end of the plurality of space guide vanes (43) is connected to the outer side of the cover plate (42), and the other end of the plurality of space guide vanes (43) is connected to the inner side of the space shell (41); One end of the space shell (41) is connected to the interior of the suction section pump shell (11), and the other end of the space shell (41) is connected to the interior of the main pump shell (12); The cover plate (42) is sleeved on the outside of the main shaft (6), and the cover plate (42) is arranged between the primary impeller (2) and the secondary impeller (3).

4. The low-vibration vertical two-stage pump according to claim 2, characterized in that: The suction section pump housing (11) is further provided with a guide plate (90) in the channel of the liquid inlet (111); A guide cone (91) is further provided inside the suction section pump housing (11), and the axis of the guide cone (91) coincides with the axis of the main shaft (6); An anti-rotation plate (92) is further provided inside the suction section pump housing (11), and the anti-rotation plate (92) is provided on a side of the guide cone (91) away from the liquid inlet (111).

5. The low-vibration vertical two-stage pump according to claim 1, characterized in that: Also included is a first-stage seal (93); The first-stage seal (93) is arranged between the first-stage impeller (2) and the pump body (1).

6. The low-vibration vertical two-stage pump according to claim 1, characterized in that: Also included is a secondary seal (94); The secondary seal (94) is arranged between the secondary impeller (3) and the pump body (1).

7. The low-vibration vertical two-stage pump according to claim 3, characterized in that: Also included is a shaft sleeve (95) and a sliding bearing assembly (96); The shaft sleeve (95) is sleeved on the outside of the main shaft (6), and one end of the shaft sleeve (95) abuts against the end surface of the primary impeller (2), and the other end of the shaft sleeve (95) abuts against the end surface of the secondary impeller (3); The cover plate (42) is sleeved on the outer side of the shaft sleeve (95); The sliding bearing assembly (96) is arranged between the shaft sleeve (95) and the cover plate (42).

8. The low-vibration vertical two-stage pump according to claim 3, characterized in that: Also included are the dorsal blades (97); The back blade (97) is arranged between the cover plate (42) and the first-stage impeller (2), and the back blade (97) is connected to the first-stage impeller (2).

9. The low-vibration vertical two-stage pump according to claim 2, characterized in that: The liquid outlet (121) of the main pump housing (12) is provided with a double-tab partition (99).

10. The low-vibration vertical two-stage pump according to claim 2, characterized in that: The inlet channel of the suction section pump housing (11) is configured as an annular water suction chamber, the longitudinal cross-section of which gradually changes from a circular shape to an elliptical shape along the flow direction of the fluid.

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