Front guide wheel rolling bearing supporting structure of obliquely or horizontally mounted pump

Abstract

The utility model discloses a front guide wheel rolling bearing supporting structure of an inclined or horizontal installation pump, which relates to the technical field of water pumps and comprises a mechanical seal component, a seal positioning sleeve, an oil injection ring, a rolling bearing and a locking nut which are coaxially arranged on a pump spindle. The mechanical sealing assembly is axially connected with the rolling bearing through the sealing positioning sleeve and the oil injection ring; the flow guide sealing assembly comprises a flow guide cover connected with the flange pipe body, the flow guide cover is fixedly connected with the flange pipe body through a plurality of groups of flow guide rib plates, and each flow guide rib plate is provided with a streamline section and an axial through hole; and the locking nut adopts a bidirectional locking structure to be matched with the retaining sheet and is used for fixing the shaft system and bearing axial water thrust. Axial force balance and efficient sealing are achieved, the bearing stability of the bearing is improved, and the fluid leakage risk is reduced.

Description

Technical Field

[0001] This utility model relates to the field of water pump technology, and more specifically to a guide wheel rolling bearing support structure for a pump installed in an inclined or horizontal manner. Background Technology

[0002] In the structural design of large horizontal and inclined-shaft axial-flow pumps and mixed-flow pumps, conventional cantilever shaft support schemes have significant limitations. These pumps, with their ultra-long flow channel structure (typically 3-5 times the impeller diameter) formed by the suction inlet, impeller, guide vanes, and discharge bend, cause the impeller end cantilever length to exceed conventional design thresholds. Especially in the suction-side flow channel region where the impeller is mounted on the pump shaft, the strict constraints imposed by hydraulic characteristics on the clearance of the flow components make traditional cantilever supports insufficient for structural stability. Therefore, shaft support schemes with integrated sliding bearings within the guide vanes are commonly adopted, with the bearing materials often being wear-resistant composite materials such as copper-based alloys or engineering plastics.

[0003] This support structure faces multiple mechanical challenges in actual operation: First, the large impeller assembly (weighing up to several tons) and long shaft system generate significant drooping moments when installed at an angle or horizontal position; second, the hydraulic imbalance caused by the pre-swirl effect, combined with the centrifugal force generated by the mass eccentricity of the rotating components, creates a composite radial load (typically reaching tens of kilonewtons). Theoretically, sliding bearings need to rely on the lubricating medium to form a hydrodynamic oil film to achieve non-contact support, but in actual working conditions, the viscosity of the circulating water medium is only 1 / 20 to 1 / 50 of that of the lubricating oil (hydrodynamic viscosity is about 1 mPa·s), which is insufficient to establish an effective load-bearing liquid film, resulting in the friction pair being in a state of boundary lubrication or even dry friction for a long time.

[0004] When the pump unit speed exceeds 375 r / min (corresponding to a linear velocity > 3 m / s), this solid-solid contact friction will cause accelerated wear of the bearing material. Monitoring data shows that a wear of 0.5 mm in the guide bearing can lead to a shaft subsidence of more than 0.3 mm, which in turn causes an exponential increase in the dynamic eccentricity of the rotor system. This vicious cycle manifests as: shaft center trajectory deviation, a sharp increase in radial load, an increase in frictional power consumption, thermal expansion and deformation, and excessive vibration intensity (common vibration velocity values ​​increase sharply from 2.8 mm / s to over 11 mm / s), ultimately leading to structural failures such as bushing scoring and bearing alloy layer peeling, forcing the unit to shut down unplanned (MTBF is usually less than 8000 hours).

[0005] Existing improvement solutions, such as the elimination of guide vane structures, can shorten the cantilever length (by approximately 40%), but this disrupts the hydraulic performance of the flow field, leading to a 15%-20% decrease in efficiency. These solutions are only suitable for inefficient applications with a head <3m and power <200kW (such as some salt industry circulating pumps). For mainstream industrial pumps with heads of 3-15m and power of 500-3000kW, there is an urgent need to develop new shaft support technologies. Based on fluid-structure coupling simulation and engineering verification, an innovative integrated rolling bearing support scheme for the guide wheel is proposed: a guide wheel assembly with guide vanes is added to the impeller inlet section, and an angular contact ball bearing assembly is arranged in its hub cavity. By optimizing the bearing span (L / D = 2.5-3.2) and preload (50-80μm interference), the radial stiffness of the shaft system is increased by 2-3 times (measured value reaches 8-12kN / μm), and the sliding friction coefficient is successfully reduced from 0.1-0.3 to 0.001-0.003 rolling friction level. After 20,000 hours of industrial verification, the vibration value is stable within the B zone standard of ISO 10816-3. Utility Model Content

[0006] The purpose of this utility model is to solve the technical problems of wear caused by liquid film failure in existing sliding bearings, vibration caused by radial load, poor structural stability, and limited efficiency. This utility model provides a guide wheel rolling bearing support structure for inclined or horizontal pump installation.

[0007] The technical solution adopted in this utility model is as follows: a guide wheel rolling bearing support structure for a slanted or horizontally mounted pump, comprising:

[0008] A mechanical seal assembly, a sealing positioning sleeve, an oil injection ring, a rolling bearing, and a lock nut are coaxially mounted on the pump main shaft. The mechanical seal assembly is axially connected to the rolling bearing through the sealing positioning sleeve and the oil injection ring.

[0009] A flow guiding and sealing assembly includes a flow guiding cover connected to a flange pipe body. The flow guiding cover is fixedly connected to the flange pipe body by multiple sets of flow guiding ribs. The flow guiding ribs have a streamlined cross-section and are provided with axial through holes.

[0010] The locking nut employs a two-way locking structure in conjunction with a retaining plate to secure the shaft system and withstand axial water thrust. A double seal is formed by the axially tandem arrangement of the mechanical seal assembly and the rolling bearing, working in conjunction with the flow-guiding seal assembly. The two-way locking of the locking nut prevents shaft displacement. This achieves axial force balance and efficient sealing, improves bearing load stability, and reduces the risk of fluid leakage.

[0011] Preferably, a third sealing ring is provided at the joint between the sealing positioning sleeve and the mechanical seal assembly, a first sealing ring is provided at the splicing part of the flow guide, and a second sealing ring is provided at the oil injection ring. The first, second, and third sealing rings form a multi-level sealing barrier at the splicing part of the flow guide, the oil injection ring, and the sealing positioning sleeve, respectively. This layered sealing significantly enhances the anti-leakage capability and adapts to pressure fluctuations under complex operating conditions.

[0012] Preferably, the oil injection ring is provided with a grease injection through-hole with a 90° deflection. The outlet end of the grease injection through-hole leads to the lubrication cavity of the rolling bearing, and the inlet end of the grease injection through-hole communicates with the axial through-hole located in the upper guide rib plate. The 90° deflection of the grease injection through-hole guides the grease input from the axial through-hole of the upper guide rib plate to the bearing cavity. This achieves grease injection without disassembly, extends bearing life, and prevents the intrusion of external contaminants.

[0013] Preferably, the guide ribs adopt a three-piece circumferentially distributed structure, with the lower guide rib having an axial through hole for drainage. The three-piece circumferentially distributed guide ribs optimize structural strength, and the lower drainage hole utilizes gravity to discharge impurities. This balances the fluid load distribution and prevents flow channel blockage caused by particle accumulation.

[0014] Preferably, the inner cavity of the flow guide shroud and the flow channel of the flange pipe body form a continuous flow guiding channel. The smooth transition between the inner cavity of the flow guide shroud and the flow channel of the flange pipe body eliminates abrupt changes in cross-section. This reduces turbulence and vortex losses, improves pumping efficiency, and reduces the risk of cavitation.

[0015] Preferably, the rolling bearing is a double-row angular contact ball bearing with a contact angle of 25°-40°, and the two rows of raceways are arranged back-to-back to withstand bidirectional axial loads. The back-to-back arrangement of the double-row angular contact ball bearings disperses bidirectional axial loads, and the contact angle design enhances rigidity. This significantly improves the bearing's impact resistance and adapts to complex stress conditions in oblique / horizontal installations.

[0016] Preferably, the bidirectional locking structure includes reverse threaded sections at both ends of the locking nut, wherein the inner threaded section engages with the pump main shaft for locking, and the outer threaded section engages with the groove of the anti-loosening plate to prevent loosening. The reverse threaded section and the anti-loosening plate form a double locking, and the outer threaded anti-loosening engagement resists vibration-induced loosening. This ensures axial locking reliability and avoids shaft movement caused by water thrust.

[0017] Preferably, the outer surface of the flow guide is coated with a polymer material with a surface roughness Ra≤0.8μm and a tapered flow-guiding surface along the fluid direction. The polymer coating reduces surface friction, and the tapered flow-guiding surface guides the fluid smoothly and accelerates it. This reduces hydraulic loss by 10%-15% while inhibiting surface corrosion and microbial adhesion.

[0018] Preferably, the streamlined cross-section of the guide rib has an aspect ratio of 3:1-5:1, and its leading edge is arranged at an angle of attack of 15°-25° to the fluid flow direction. The specific aspect ratio of the streamlined cross-section and the angle of attack optimizes the fluid stripping point and reduces flow resistance. This improves flow guiding efficiency by more than 20%, reduces energy loss, and suppresses vibration and noise.

[0019] Preferably, a self-sealing check valve is embedded in the drain hole. The opening pressure of the check valve is set to 0.05-0.1 MPa, and a drain pipe extending to the outside of the pump body is connected to the outlet end of the drain hole. The self-sealing check valve opens to drain under the preset pressure, and the drain pipe directs impurities out. This achieves automatic drainage and prevents fluid backflow, reducing maintenance frequency by more than 50%.

[0020] In summary, due to the adoption of the above technical solution, the beneficial effects of this utility model are:

[0021] 1. Significantly improved structural reliability and sealing performance: Through the axial series design of the mechanical seal assembly, sealing positioning sleeve, and oil injection ring, combined with the three-dimensional sealing layout of three sealing rings (first, second, and third sealing rings), a three-level sealing protection system is constructed. The innovative 90° directional grease injection hole design of the oil injection ring enables directional delivery of grease and effective maintenance of sealing pressure. Combined with the double-row angular contact structure of the rolling bearing (contact angle 25°-40°), the bearing can maintain a stable lubrication environment even when subjected to bidirectional axial loads.

[0022] 2. Optimized fluid dynamics performance: The gradually narrowing guide surface (Ra≤0.8μm) formed by the guide shield and flange body, combined with three circumferentially distributed streamlined guide ribs (length-to-width ratio 3:1-5:1), arranged at 15°-25° angles of attack, increases the flow channel efficiency to over 92%. The lubrication channel network formed by the axial through holes inside the guide ribs innovatively integrates bearing lubrication with the fluid channel, reducing hydraulic losses by 18%-25%. A specially designed drain hole equipped with a self-sealing check valve (opening pressure 0.05-0.1MPa) automatically discharges impurities when the system is shut down, extending maintenance cycles by three times.

[0023] 3. Innovative shaft system stability design: Utilizing a composite anti-loosening structure of a two-way locking nut and anti-loosening plate, the axial fixation strength is increased by over 50% through the two-way locking effect of the reverse thread section. This structure effectively absorbs the pulsating impact generated during pump operation, and tests showed no axial displacement during 2000 hours of continuous operation. The dual anti-vibration system formed by the polymer-coated guide surface and the back-to-back bearing arrangement keeps the unit's vibration value within the Class B range of the ISO 10816-3 standard.

[0024] 4. Breakthrough in maintenance convenience: The modular design of the flow-guiding and sealing components reduces bearing maintenance time by 60%, and the integrated arrangement of the grease injection channel and drain pipe enables "online maintenance." The specially designed drain hole system can clean impurities without shutting down the machine, reducing maintenance downtime by 90% compared to traditional structures.

[0025] In summary, this utility model, through innovative system integration design, has achieved breakthrough improvements in key indicators such as load-bearing capacity, operating efficiency, and maintenance costs, and is particularly suitable for the working conditions of inclined / horizontal pumps with large flow rates and high heads. Attached Figure Description

[0026] This utility model will be described by way of example and with reference to the accompanying drawings, wherein:

[0027] Figure 1 This is a schematic diagram of the structure of this utility model;

[0028] Figure 2 This is an enlarged structural diagram of point A of this utility model;

[0029] Figure 3 This is a schematic diagram of the right-side structure of this utility model;

[0030] Figure 4 This is a schematic diagram of the structure of this utility model in use;

[0031] The components in the diagram are labeled as follows: 1-Guide shield, 2-Isolation plate, 3-Rolling bearing, 4-Guide rib, 5-Oil injection ring, 6-Sealing positioning sleeve, 7-Mechanical seal assembly, 8-Locking nut, 9-First sealing ring, 10-Second sealing ring, 11-Drainage hole, 12-Third sealing ring, 13-Flange body, 14-Pump main shaft. Detailed Implementation

[0032] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, not all embodiments. The components of the embodiments of this utility model described and shown in the accompanying drawings can typically be arranged and designed in various different configurations.

[0033] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0034] In one embodiment of this utility model, such as Figure 1-4 As shown, this embodiment provides a guide roller bearing support structure for a slanted or horizontally mounted pump, comprising:

[0035] The mechanical seal assembly 7, sealing positioning sleeve 6, oil injection ring 5, rolling bearing 3 and locking nut 8 are coaxially mounted on the pump main shaft 14. The mechanical seal assembly 7 is axially connected to the rolling bearing 3 through the sealing positioning sleeve 6 and the oil injection ring 5.

[0036] The flow guiding and sealing assembly includes a flow guiding cover 1 connected to the flange tube body 13. The flow guiding cover 1 is fixedly connected to the flange tube body 13 through multiple sets of flow guiding ribs 4. The flow guiding ribs 4 have a streamlined cross-section and are provided with axial through holes. The ends of the flow guiding ribs (4) are precisely connected to the flange tube body (13) through positioning pin holes. The lubrication channel extends to the outer wall of the flange tube body to form a grease injection port. A detachable pin sealing structure is designed to keep the pin sealed during daily operation. When lubrication maintenance is required, the pin can be quickly removed and a special grease can be injected through the channel. After the grease injection is completed, the pin can be reset to restore the sealing state. This optimized solution achieves both flow field optimization and convenient maintenance while ensuring structural strength.

[0037] The locking nut 8 employs a bidirectional locking structure in conjunction with the anti-reverse plate 2 to fix the shaft system and withstand axial water thrust. The mechanical seal assembly 7 and the rolling bearing 3 are axially connected in series, forming a double seal in conjunction with the flow-guiding seal assembly. The bidirectional locking of the locking nut 8 prevents shaft displacement. This achieves axial force balance and efficient sealing, improves bearing load stability, and reduces the risk of fluid leakage.

[0038] In another embodiment of this utility model, a third sealing ring 12 is provided at the joint between the sealing positioning sleeve 6 and the mechanical seal assembly 7, a first sealing ring 9 is provided at the splicing part of the flow guide 1, and a second sealing ring 10 is provided at the oil injection ring 5. The first, second, and third sealing rings 12 form a multi-level sealing barrier at the splicing part of the flow guide 1, the oil injection ring 5, and the sealing positioning sleeve 6, respectively. The layered sealing significantly enhances the anti-leakage capability and adapts to pressure fluctuations under complex working conditions.

[0039] In another embodiment of this invention, the oil injection ring 5 is provided with a grease injection through-hole with a 90° rotation. The outlet end of the grease injection through-hole leads to the lubrication cavity of the rolling bearing 3, and the inlet end of the grease injection through-hole communicates with the axial through-hole located in the upper guide rib plate 4. The 90° rotation of the grease injection through-hole guides the grease input into the axial through-hole of the upper guide rib plate 4 to the bearing cavity. This achieves grease injection without disassembly, extends the bearing life, and prevents the intrusion of external contaminants.

[0040] In another embodiment of this utility model, the flow guide plate 4 adopts a three-piece circumferentially distributed structure, and the axial through hole of the lower flow guide plate 4 is provided with a drainage through hole 11. The three-piece circumferentially distributed flow guide plate 4 optimizes the structural strength, and the lower drainage through hole 11 uses gravity to discharge impurities. This balances the fluid load distribution and prevents flow channel blockage caused by particle accumulation.

[0041] In another embodiment of this invention, the inner cavity of the flow guide shroud 1 and the flow channel of the flange pipe body 13 form a continuous flow guiding channel. The smooth transition between the inner cavity of the flow guide shroud 1 and the flow channel of the flange pipe body 13 eliminates abrupt changes in cross-section. This reduces turbulence and vortex losses, improves pumping efficiency, and reduces the risk of cavitation.

[0042] In another embodiment of this utility model, the rolling bearing 3 is a double-row angular contact ball bearing with a contact angle of 25°-40°, and the two rows of raceways are arranged back-to-back to withstand bidirectional axial loads. The back-to-back arrangement of the double-row angular contact ball bearings disperses the bidirectional axial loads, and the contact angle design enhances rigidity. This significantly improves the bearing's impact resistance and adapts to complex stress conditions in oblique / horizontal installations.

[0043] In another embodiment of this utility model, the bidirectional locking structure includes reverse threaded sections at both ends of the locking nut 8, wherein the inner threaded section engages with the pump main shaft 14 for locking, and the outer threaded section engages with the groove of the anti-loosening plate 2 to prevent loosening. The reverse threaded section and the anti-loosening plate 2 form a double locking, and the outer threaded anti-loosening engagement resists vibration and loosening. This ensures the reliability of axial locking and avoids shaft movement caused by water thrust.

[0044] In another embodiment of this invention, the outer surface of the flow guide shroud 1 is coated with a polymer material with a surface roughness Ra≤0.8μm and a tapered flow guide surface along the fluid direction. The polymer coating reduces surface friction, and the tapered flow guide surface smoothly and accelerates the fluid. This reduces hydraulic loss by 10%-15% while inhibiting surface corrosion and microbial adhesion.

[0045] In another embodiment of this invention, the streamlined cross-section of the guide rib 4 has an aspect ratio of 3:1-5:1, and its leading edge is arranged at an angle of attack of 15°-25° to the fluid flow direction. The specific aspect ratio of the streamlined cross-section and the angle of attack optimizes the fluid stripping point and reduces flow resistance. This improves the guiding efficiency by more than 20%, reduces energy loss, and suppresses vibration and noise.

[0046] In another embodiment of this utility model, a self-sealing check valve is embedded in the drain hole 11. The opening pressure of the check valve is set to 0.05-0.1 MPa, and a drain pipe extending to the outside of the pump body is connected to the outlet end of the hole. The self-sealing check valve opens to drain under the preset pressure, and the drain pipe directionally discharges impurities. This achieves automatic drainage and prevents fluid backflow, reducing maintenance frequency by more than 50%.

[0047] The working principle of this utility model is as follows: This utility model forms a three-stage sealing system through the axial connection of the mechanical seal assembly 7 and the sealing positioning sleeve 6: the first sealing ring 9 prevents media leakage, the second sealing ring 10 seals the oil injection channel, and the third sealing ring 12 isolates the bearing lubrication cavity. The locking nut 8 adopts a bidirectional thread structure; the inner thread engages with the main shaft to achieve axial pre-tightening, and the outer thread engages with the anti-loosening plate 2. This double locking mechanism can withstand bidirectional axial water thrust (up to 180kN), and simultaneously achieves automatic shaft alignment through a 45° conical surface engagement. The oil injection ring 5 has a built-in 90° directional grease injection through-hole, guiding the grease (pressure 0.2-0.5MPa) input through the axial through-hole of the upper guide rib plate 4 to the bearing lubrication cavity. The lower guide rib plate 4 is equipped with a self-sealing one-way valve (opening pressure 0.08MPa), which automatically opens when the lubrication cavity pressure exceeds the set value, discharging deteriorated grease through the extended drain pipe. This circulation system can keep the bearing temperature rise below 35°C and extend the grease replacement cycle to 8000 hours.

Claims

1. A rolling bearing support structure for a guide wheel of a pump installed in an inclined or horizontal manner, characterized in that, include: A mechanical seal assembly (7), a sealing positioning sleeve (6), an oil injection ring (5), a rolling bearing (3), and a lock nut (8) are coaxially mounted on the pump main shaft (14). The mechanical seal assembly (7) is axially connected to the rolling bearing (3) through the sealing positioning sleeve (6) and the oil injection ring (5). The flow guiding and sealing assembly includes a flow guiding cover (1) connected to the flange pipe body (13). The flow guiding cover (1) is fixedly connected to the flange pipe body (13) through multiple sets of flow guiding ribs (4). The flow guiding ribs (4) have a streamlined cross section and are provided with axial through holes. The locking nut (8) adopts a two-way locking structure and cooperates with the anti-reverse plate (2) to fix the shaft system and withstand axial water thrust.

2. The support structure according to claim 1, characterized in that, The sealing positioning sleeve (6) and the mechanical seal assembly (7) are provided with a third sealing ring (12), the splice part of the flow guide (1) is provided with a first sealing ring (9), and the oil injection ring (5) is provided with a second sealing ring (10).

3. The support structure according to claim 1, characterized in that, The oil injection ring (5) is provided with a grease injection through hole with a 90° rotation. The outlet end of the grease injection through hole leads to the lubrication cavity of the rolling bearing (3), and the inlet end of the grease injection through hole is connected to the axial through hole located in the upper guide rib plate (4).

4. The support structure according to claim 1, characterized in that, The guide rib plate (4) adopts a three-piece circumferentially distributed structure, and the guide rib plate (4) located at the bottom has an axial through hole with a discharge through hole (11).

5. The support structure according to claim 1, characterized in that, The inner cavity of the flow guide shroud (1) and the flow channel of the flange tube body (13) form a continuous flow guide channel.

6. The support structure according to claim 1, characterized in that, The rolling bearing (3) is a double-row angular contact ball bearing with a contact angle of 25°-40°, and the two rows of raceways are arranged back to back to bear bidirectional axial loads.

7. The support structure according to claim 1, characterized in that, The bidirectional locking structure includes reverse threaded sections at both ends of the locking nut (8), wherein the inner threaded section is locked in conjunction with the pump spindle (14), and the outer threaded section is engaged with the groove of the anti-loosening plate (2) to prevent loosening.

8. The support structure according to claim 1, characterized in that, The outer surface of the flow guide (1) is coated with a polymer material and presents a tapered flow guide surface along the fluid direction.

9. The support structure according to claim 4, characterized in that, The streamlined cross-section of the guide rib (4) has a length-to-width ratio of 3:1-5:1, and its leading edge is arranged at an angle of attack of 15°-25° with the fluid flow direction.

10. The support structure according to claim 4, characterized in that, The drain hole (11) is equipped with a self-sealing check valve. The opening pressure of the check valve is set to 0.05-0.1MPa, and the outlet end of the hole is connected to a drain pipe extending to the outside of the pump body.

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