Vertical inline centrifugal pump

Abstract

This utility model relates to a vertical pipeline centrifugal pump, including a drive source, a pump body, a shaft system, an impeller, and a sealing component. The drive source has an output shaft; the pump body is connected to the drive source and has a suction channel; the shaft system is mounted on the output shaft; the impeller is mounted in the pump body, and the end of the shaft system facing away from the drive source is connected to the impeller; the sealing component is located at the mating point between the shaft system and the pump body; a streamlined guide boss is provided in the area of ​​the suction channel of the pump body near the impeller inlet, and the guide boss gradually contracts along the liquid flow direction; different areas of the pump body have differentiated wall thicknesses, and reinforcing ribs are provided in the areas of concentrated stress on the pump body, with the reinforcing ribs integrally formed with the pump body. This utility model guides the liquid flow evenly into the impeller through the streamlined guide boss in the suction channel, reducing eddies and low-pressure areas, thus reducing the net positive suction head (NPSH) and extending the impeller life; the differentiated wall thickness adapts to the stress in different areas, and the reinforcing ribs can disperse stress and solve the problem of deformation and cracking.

Description

Technical Field

[0001] This utility model relates to the field of vertical centrifugal pump technology, and in particular to a vertical pipeline centrifugal pump. Background Technology

[0002] Vertical inline centrifugal pumps are widely used in water supply and drainage, HVAC, and industrial processes, undertaking the core function of liquid transportation. With the development of industrial efficiency and energy conservation, the requirements for pump operational stability, lifespan, and reliability are becoming increasingly stringent. However, existing pump structures, under complex operating conditions, struggle to balance optimized fluid flow characteristics with structural strength, becoming a bottleneck for performance improvement.

[0003] In current vertical inline centrifugal pump designs, the suction channel is often a simple constriction or straight cylindrical structure. When liquid enters the pump body's suction channel from the pipe, the abrupt change in channel morphology (such as discontinuous inlet section contraction or micro-steps on the inner wall) easily causes vortices and impact flow. When the liquid reaches the impeller inlet junction, the velocity distribution is severely uneven. The liquid near the channel wall experiences high frictional resistance, resulting in a lower velocity; the velocity in the central region of the channel is excessively high, forming a local low-pressure zone. According to the cavitation mechanism, when the local pressure is lower than the liquid's saturated vapor pressure, the liquid vaporizes to produce bubbles. These bubbles collapse after entering the high-pressure zone of the impeller with the liquid flow, impacting the impeller surface at high frequency and causing cavitation damage. In the short term, this leads to pitting and erosion on the impeller surface; in the long term, it thins the impeller wall, reduces its strength, and may even cause cracks, directly shortening the pump's service life. Simultaneously, the high-frequency vibrations generated by cavitation are transmitted to the pump body, causing abnormal wear of bearings and seals, increasing operating noise, and in severe cases, causing pump unit failure and shutdown, significantly reducing system operational stability.

[0004] Furthermore, the pump body, as the core load-bearing component of the centrifugal pump, must withstand the radial and axial pressures of the internal high-pressure liquid, as well as the dynamic loads generated by the impeller rotation. In existing designs, the pump body uses uniform wall thickness or empirically determined wall thickness distribution, which does not precisely match the stress characteristics of different areas: for example, the liquid velocity and pressure gradient are high at the suction end, and thin-walled areas are prone to deformation due to stress concentration, which disrupts the flow channel morphology and further aggravates the liquid flow turbulence; at the discharge end, the liquid pressure changes abruptly after being pressurized by the impeller, and although a thick-walled design can enhance strength, it increases material costs and pump body weight, and is prone to vibration due to uneven structural stiffness; the connection between the pump body and the intermediate bearing is a critical link between the pump body and the motor and bearing assembly, and is affected by the superposition of assembly stress and liquid pressure. Existing planar or simple boss connection structures are difficult to effectively disperse stress, and fatigue cracking is likely to occur during long-term operation; the bottom of the pump body bears the weight of the pump body itself, the static pressure of the liquid, and the reaction force of the pipeline connection. Stress concentration leads to deformation at the bottom, causing the connection between the pump body and the foundation to fail, resulting in excessive vibration of the whole machine and reducing operational reliability.

[0005] In summary, the existing vertical pipeline centrifugal pump body suffers from cavitation hazards due to insufficient liquid flow control in the suction channel, as well as deformation and cracking problems caused by unreasonable structural strength distribution. These issues have become key factors restricting the efficient and stable operation of pump sets, and breakthroughs urgently need to be achieved through structural innovation. Utility Model Content

[0006] Therefore, the technical problem to be solved by this utility model is to overcome the cavitation hazards caused by insufficient control of the liquid flow in the suction channel and the deformation and cracking problems caused by unreasonable distribution of structural strength in the existing technology, and proposes a vertical pipeline centrifugal pump.

[0007] To solve the above technical problems, this utility model provides a vertical pipeline centrifugal pump, comprising:

[0008] The drive source has an output shaft;

[0009] A pump body, which is connected to the drive source via a connecting support component, has an intake channel and an exhaust channel;

[0010] A shaft system component, which is disposed on the output shaft;

[0011] An impeller is disposed in the pump body, and the end of the shaft system component facing away from the drive source passes through the connecting support component and is connected to the impeller;

[0012] A sealing component is disposed at the mating point between the shaft component and the pump body;

[0013] The pump body has a streamlined guide protrusion in the area of ​​the suction channel near the impeller inlet, and the guide protrusion gradually contracts along the liquid flow direction.

[0014] Different regions of the pump body have different wall thicknesses, and the areas of concentrated stress on the pump body are provided with reinforcing ribs, which are integrally formed with the pump body.

[0015] In one embodiment of this utility model, the height of the guide protrusion is 1 / 10 to 1 / 8 of the diameter of the suction channel.

[0016] In one embodiment of this utility model, the wall thickness of the pump body's suction channel end is 8-10mm, the wall thickness of the discharge channel end is 12-15mm, the wall thickness of the connection part between the pump body and the connecting support component is 15-18mm, and the wall thickness of the bottom of the pump body is 12-14mm.

[0017] In one embodiment of this utility model, the reinforcing ribs are arranged radially on the pump body, and the number of reinforcing ribs is 6-8.

[0018] In one embodiment of this utility model, the cross-section of the reinforcing rib is trapezoidal, with an upper base width of 8-10mm, a lower base width of 12-15mm, and a height of 10-12mm.

[0019] In one embodiment of this utility model, the connecting support component includes a connecting plate and a middle bearing. One end of the connecting plate is connected to the drive source, and the other end of the connecting plate is connected to the middle bearing. The end of the middle bearing away from the connecting plate is connected to the pump body and provides support and positioning for the shaft system component.

[0020] In one embodiment of the present invention, the shaft system component includes a shaft extension and a shaft sleeve, the shaft sleeve being fitted onto the shaft extension, and the shaft extension being connected to the impeller via a key.

[0021] In one embodiment of the present invention, the sealing component includes a mechanical seal, an O-ring, and a sealing ring. The mechanical seal is disposed between the shaft component and the pump body, and the O-ring and the sealing ring are respectively disposed in the sealing groove of the pump body.

[0022] The above-mentioned technical solution of this utility model has the following advantages compared with the prior art:

[0023] This invention guides the liquid flow evenly into the impeller through a streamlined guide protrusion in the suction channel, reducing eddies and low-pressure areas, thereby lowering the net positive suction head (NPSH) by 0.3-0.5 μm, extending impeller life by more than 30%, and reducing noise by 3-5 dB(A). Simultaneously, it optimizes the liquid flow matching accuracy, increasing pump efficiency by 5%-8% and significantly enhancing operational stability. Furthermore, the differentiated wall thickness design adapts to different stress areas, and the reinforcing rib design can disperse more than 50% of the stress. The maximum deformation under 1.5 times the rated pressure is ≤0.05 mm, solving the problem of deformation and cracking and greatly improving reliability. Attached Figure Description

[0024] To make the content of this utility model easier to understand, the present utility model will be further described in detail below with reference to specific embodiments and accompanying drawings.

[0025] Figure 1 This is a schematic diagram of the structure of a vertical pipeline centrifugal pump proposed in an embodiment of this utility model.

[0026] Figure 2 yes Figure 1 A schematic diagram of the structure along the upper K direction.

[0027] Figure 3 This is a schematic diagram of the guide boss structure in the suction channel.

[0028] Figure 4 This is a schematic diagram of the pump body reinforcing rib structure.

[0029] The following are the annotations in the accompanying drawings: 1. Drive source; 2. Pump body; 21. Suction channel; 22. Discharge channel; 23. Guide boss; 24. Reinforcing rib; 3. Impeller; 41. Shaft extension; 42. Shaft sleeve; 51. Connecting plate; 52. Intermediate bearing; 61. Mechanical seal; 62. O-ring; 63. Sealing ring; Detailed Implementation

[0030] The present invention will be further described below with reference to the accompanying drawings and specific embodiments, so that those skilled in the art can better understand and implement the present invention. However, the embodiments are not intended to limit the present invention.

[0031] Reference Figures 1 to 4 As shown, this utility model embodiment provides a vertical pipeline centrifugal pump, including a drive source 1, a pump body 2, a shaft system component, an impeller 3, and a sealing component. The drive source 1 has an output shaft. The pump body 2 is connected to the drive source 1 through a connecting support component and has an suction channel 21 and a discharge channel 22. The shaft system component is disposed on the output shaft. The impeller 3 is disposed inside the pump body 2, and one end of the shaft system component facing away from the drive source 1 passes through the connecting support component and is connected to the impeller 3. The sealing component is disposed at the mating point between the shaft system component and the pump body 2. The suction channel 21 of the pump body 2 is provided with a streamlined guide boss 23 near the inlet of the impeller 3, and the guide boss 23 gradually contracts along the liquid flow direction. Different regions of the pump body 2 have different wall thicknesses, and the areas of concentrated stress of the pump body 2 are provided with reinforcing ribs 24, which are integrally formed with the pump body 2.

[0032] This invention guides the liquid flow evenly into the impeller 3 through the streamlined guide protrusion 23 of the suction channel 21, reducing eddies and low-pressure areas, thereby reducing the net positive suction head (NPSH) by 0.3-0.5 μm, extending the impeller 3 life by more than 30%, and reducing noise by 3-5 dB(A). At the same time, it optimizes the liquid flow matching accuracy, improves pump efficiency by 5%-8%, and significantly enhances operational stability. Furthermore, the differentiated wall thickness design adapts to different stress areas, and the reinforcing ribs 24 can disperse more than 50% of the stress. The maximum deformation under 1.5 times the rated pressure is ≤0.05 mm, solving the problem of deformation and cracking and greatly improving reliability.

[0033] In one embodiment, the height of the guide boss 23 is 1 / 10 to 1 / 8 of the diameter of the suction channel 21 of the pump body 2. Within this range, the boss can effectively intervene in the flow field distribution, avoiding both insufficient height leading to limited rectification effect and excessive height causing additional flow resistance. Furthermore, the guide boss 23 gradually contracts along the liquid flow direction, i.e., the boss gradually contracts along the liquid flow direction using a cubic spline curve, with the profile equation being y = a0 + a1x + a2x2 + a3x3; where the coefficients a0, a1, a2, and a3 are determined through CFD optimization, creating a continuous velocity gradient on the boss surface and preventing boundary layer separation. When the liquid enters the suction channel 21, the guide boss 23 forces the mainstream liquid flow to diffuse evenly to both sides, forming a symmetrical velocity distribution, while the flow velocity near the channel wall slows down and the pressure increases, thus balancing the pressure distribution across the entire cross-section. According to measured data, at the rated flow rate, the velocity non-uniformity at the impeller 3 inlet cross-section is reduced from 45% in the traditional design to less than 18%.

[0034] In one embodiment, the wall thickness of the pump body 2 at the suction channel 21 end is 8-10mm, the wall thickness of the discharge channel 22 end is 12-15mm, the wall thickness of the connection between the pump body 2 and the connecting support component is 15-18mm, and the wall thickness of the bottom of the pump body 2 is 12-14mm. This differentiated wall thickness design is specifically adjusted based on the actual stress conditions in each area of ​​the pump body 2: the suction channel 21 end has low pressure and low stress, so an 8-10mm thin wall can meet the strength requirements; the discharge channel 22 end has high pressure and large pulsation, so a 12-15mm thick wall enhances the resistance to internal pressure; the connection part is subject to assembly stress and combined loads, so a 15-18mm thick wall, combined with transition rounded corners, disperses the stress; and the bottom bears the weight of the entire machine, so a 12-14mm thick wall improves bending stiffness. The above design ensures that the maximum deformation of the pump body 2 is ≤0.05mm under 1.5 times the rated pressure, and the stress concentration factor is reduced by more than 50%. It solves the problems of "excessive redundancy" or "excessive failure" in traditional equal wall thickness design, and there is no risk of deformation or cracking during long-term operation, improving reliability by 40%.

[0035] In one embodiment, the reinforcing ribs 24 are arranged radially on the pump body 2, with 6-8 ribs in total. This radial arrangement ensures the ribs 24 are symmetrically distributed around the center of the pump body 2, uniformly transferring concentrated stresses (such as liquid pressure, assembly load, and vibration impact) from the bottom and connecting parts of the pump body 2 to the periphery of the pump body 2, preventing localized stress accumulation. Furthermore, the reinforcing ribs 24 have a trapezoidal cross-section, with an upper base width of 8-10mm, a lower base width of 12-15mm, and a height of 10-12mm. The trapezoidal cross-section (narrower upper base, wider lower base) provides a larger load-bearing area at the connection root between the reinforcing rib 24 and the pump body 2. The 12-15mm root width ensures the rib forms a rigid integral with the pump body 2, preventing rib detachment due to stress concentration. The 8-10mm top width reduces material redundancy while maintaining strength, and the 10-12mm height provides sufficient moment of inertia (approximately 2800-4500mm). 4 This design keeps the bottom deflection of the pump body 2 within 0.03 mm / m, which improves the bending resistance by 20% compared to rectangular cross-section ribs, and effectively suppresses the resonance phenomenon of the pump body 2 under high-frequency vibration.

[0036] In one embodiment, the connecting support component includes a connecting plate 51 and a middle bearing 52. One end of the connecting plate 51 is connected to the drive source 1, and the other end of the connecting plate 51 is connected to the middle bearing 52. The end of the middle bearing 52 away from the connecting plate 51 is connected to the pump body 2 and provides support and positioning for the shaft system components. Preferably, the drive source 1 is a motor. The torque output by the motor is transmitted to the impeller 3 through the shaft system components, while the axial force (such as the water thrust of the impeller 3) is transmitted sequentially through the middle bearing 52 → connecting plate 51 → motor end cover, forming a separate load path of "torque transmission through the shaft system and force transmission through the support component". By replacing the connecting plate 51 with different thicknesses (8mm / 10mm / 12mm), the axial distance between the motor and the pump body 2 can be flexibly adjusted to adapt to different motor models with power ranging from 5.5-37kW, without the need to redesign the structure of the pump body 2.

[0037] In one embodiment, the sealing components include a mechanical seal 61, an O-ring 62, and a sealing ring 63. The mechanical seal 61 is disposed between the shaft components and the pump body 2. The O-ring and sealing ring 63 are respectively disposed in the sealing groove of the pump body 2. When the shaft rotates, the end faces of the moving ring and the stationary ring of the mechanical seal 61 are tightly fitted under the action of spring force and medium pressure to form a micron-level sealing film. The O-ring forms a "line seal" on the stop mating surface between the pump body 2 and the intermediate bearing 52. The high elasticity of the rubber material can compensate for assembly errors and at the same time prevent external dust and moisture from entering. The sealing ring 63 forms a "face seal" on the flange connection surface. Through the above design, the sealing components achieve the dual goals of "dynamic sealing to prevent dripping and static sealing to prevent seepage", providing core protection for the stable operation of the pump body 2 under high pressure, high temperature, and multi-media conditions.

[0038] Furthermore, the shaft system components include a shaft extension 41 and a shaft sleeve 42. The shaft sleeve 42 is fitted onto the shaft extension 41, and the shaft extension 41 is connected to the impeller 3 via a key. The motor output torque is transmitted to the shaft extension 41 via a coupling, and the shaft extension 41 transmits the torque to the impeller 3 via a key, driving the impeller 3 to rotate and do work. The interference fit between the shaft sleeve 42 and the shaft extension 41 forms a damping structure, which can absorb the vibration energy caused by the imbalance of the impeller 3.

[0039] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the protection scope of this invention.

Claims

1. A vertical pipeline centrifugal pump, characterized in that, include: The drive source has an output shaft; A pump body, which is connected to the drive source via a connecting support component, has an intake channel and an exhaust channel; A shaft system component, which is disposed on the output shaft; An impeller is disposed in the pump body, and the end of the shaft system component facing away from the drive source passes through the connecting support component and is connected to the impeller; A sealing component is disposed at the mating point between the shaft component and the pump body; The pump body has a streamlined guide protrusion in the region of the suction channel near the impeller inlet, and the guide protrusion gradually contracts along the liquid flow direction. Different regions of the pump body have different wall thicknesses, and the areas of concentrated stress on the pump body are provided with reinforcing ribs, which are integrally formed with the pump body.

2. A vertical pipeline centrifugal pump according to claim 1, characterized in that: The height of the guide boss is 1 / 10 to 1 / 8 of the diameter of the suction channel.

3. A vertical pipeline centrifugal pump according to claim 1 or 2, characterized in that: The wall thickness of the pump body at the suction flow channel end is 8-10mm, the wall thickness of the discharge flow channel end is 12-15mm, the wall thickness of the connection part between the pump body and the connecting support component is 15-18mm, and the wall thickness of the bottom of the pump body is 12-14mm.

4. A vertical pipeline centrifugal pump according to claim 1 or 2, characterized in that: The reinforcing ribs are arranged radially on the pump body, and the number of reinforcing ribs is 6-8.

5. A vertical pipeline centrifugal pump according to claim 4, characterized in that: The cross-section of the reinforcing rib is trapezoidal, with an upper base width of 8-10mm, a lower base width of 12-15mm, and a height of 10-12mm.

6. A vertical pipeline centrifugal pump according to claim 1 or 2, characterized in that: The connecting support component includes a connecting plate and a central bearing. One end of the connecting plate is connected to the drive source, and the other end of the connecting plate is connected to the central bearing. The end of the central bearing away from the connecting plate is connected to the pump body and provides support and positioning for the shaft system component.

7. A vertical pipeline centrifugal pump according to claim 1 or 2, characterized in that: The shaft system component includes a shaft extension and a shaft sleeve, the shaft sleeve being fitted onto the shaft extension, and the shaft extension being connected to the impeller via a key.

8. A vertical pipeline centrifugal pump according to claim 1 or 2, characterized in that: The sealing components include a mechanical seal, an O-ring, and a sealing ring. The mechanical seal is disposed between the shaft system component and the pump body, and the O-ring and the sealing ring are respectively disposed in the sealing groove of the pump body.

Images