Marine vertical two-stage double-outlet centrifugal pump

Abstract

The invention discloses a marine vertical two-stage double-outlet centrifugal pump which is characterized in that a pump body, a bearing seat and an impeller ring are all of an axial split type split structure, and a liquid inlet, a first-stage liquid outlet and a second-stage liquid outlet are all formed in a rear pump body. Therefore, the front pump body can be detached, the pump body can be opened for internal maintenance, the front bearing seat can be detached for bearing maintenance, the rear pump body is kept in situ, various pipelines and valves connected with the rear pump body and a motor on the upper portion of the pump do not need to be detached, and maintenance is convenient; in addition, the two half bodies of the wear ring are fixed to the front pump body and the rear pump body respectively, no gap exists between the wear ring and the pump bodies, fluid leakage from a high-pressure area to a low-pressure area is reduced, the pump bodies and the wear ring are prevented from being eroded and damaged, and the service life is prolonged.

Description

Technical Field

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

[0002] Due to limited space in a ship's bilge, a bilge firefighting pump typically combines multiple functions: bilge pump, firefighting pump, and general service pump. The basic structure of this type of pump is: a two-stage impeller is axially arranged within the pump body. When used as a bilge pump and general service pump, i.e., when a lower head is required, the incoming liquid is discharged through the primary flow channel by the first-stage impeller, and the outlet of the secondary flow channel is closed. When used as a firefighting pump, i.e., when a higher head is required, the incoming liquid is discharged from the first-stage impeller to the second-stage impeller and then discharged through the secondary flow channel, and the outlet of the primary flow channel is closed.

[0003] However, the existing pump of the above structure has the following defects:

[0004] First, since the pump is installed at the bottom of the cabin, it is surrounded by various pipes and valves and has a narrow space. The pump body and bearing seat in existing products are both integral structures, which makes it inconvenient to disassemble, repair and maintain.

[0005] Second, an intermediate mouth ring is provided in the pump body between the first-stage impeller and the second-stage impeller. During the operation of the pump, there is a pressure difference between the first-stage flow channel and the second-stage flow channel. Under the action of pressure, the intermediate mouth ring is prone to fluid leakage from the high-pressure area to the low-pressure area, causing internal leakage and reducing the efficiency of the pump. At the same time, after long-term use, the pump body and the mouth ring will also be scrapped due to erosion due to fluid leakage. Summary of the Invention

[0006] In view of this, the present invention provides a marine vertical two-stage double-outlet centrifugal pump to solve the problems of the prior art in that the pump body is inconvenient to disassemble, repair and maintain, fluid leakage from the high-pressure area to the low-pressure area is easy to occur, and the pump body and the mouth ring are easily scrapped due to erosion due to fluid leakage.

[0007] The present invention provides a marine vertical two-stage dual-outlet centrifugal pump, comprising a pump body and an impeller assembly disposed in the pump body, wherein the impeller assembly comprises a first-stage impeller and a second-stage impeller, the pump body being provided with a liquid inlet and a first-stage liquid outlet and a second-stage liquid outlet corresponding to the first-stage impeller and the second-stage impeller, the first-stage impeller and the second-stage impeller being arranged in series on a pump shaft, and the pump shaft being connected to a drive device via a coupling.

[0008] A pump shaft insertion hole is provided on the top of the pump body, and a fixing bracket is fixedly provided around the pump shaft insertion hole;

[0009] The pump body adopts an axially split split structure, and is composed of a front pump body and a rear pump body relatively assembled, and the liquid inlet, the first-level liquid outlet and the second-level liquid outlet are all arranged on the rear pump body;

[0010] The inner cavity of the pump body is divided into a primary flow channel and a secondary flow channel by a pump body partition wall, the primary impeller and the secondary impeller are rotatably arranged in the primary flow channel and the secondary flow channel respectively, an intermediate sleeve is provided between the primary impeller and the secondary impeller, the intermediate sleeve is fixed on the pump shaft, and a mouth ring is respectively provided between the inlet of the primary impeller and the pump body, between the outlet of the secondary impeller and the pump body, and between the intermediate sleeve and the inner wall of the shaft hole of the pump body partition wall, the mouth ring consists of two symmetrical halves, and the two halves are respectively fixed to the front pump body and the rear pump body by fastening screws;

[0011] The upper end and lower end of the pump shaft are respectively provided with an upper bearing assembly and a lower bearing assembly. The upper bearing assembly includes a bearing seat and a rolling bearing arranged in the bearing seat. The bearing seat adopts an axially split structure, including a front bearing seat and a rear bearing seat. The rear bearing seat is fixed on the fixed bracket.

[0012] In the above technical solution, preferably, the lower portion of the rear bearing seat is provided with an arc-shaped connecting seat arranged around the outer side surface thereof, and the arc-shaped connecting seat is fixed on the fixing bracket.

[0013] In the above technical solution, preferably, the lower end of the pump body is fixed on the base, the driving device is fixed to the fixed bracket via a motor bracket, and the motor bracket and the base are connected via a column.

[0014] In the above technical solution, preferably, the first-stage impeller and the second-stage impeller have the same structure and are arranged axially symmetrically.

[0015] In the above technical solution, preferably, the primary flow channel and the secondary flow channel are arranged radially symmetrically.

[0016] In the above technical solution, preferably, a bearing sleeve is provided in the bearing seat, and the rolling bearing is installed in the bearing sleeve.

[0017] In the above technical solution, preferably, a mechanical shaft seal and a throttling bushing are provided in the pump shaft socket, and the throttling bushing is provided below the mechanical shaft seal.

[0018] In the above technical solution, preferably, the coupling includes a motor coupling arranged on the output shaft of the drive device, and a pump shaft connector arranged at the upper end of the pump shaft, and the motor coupling is axially connected and fixed to the pump shaft connector.

[0019] From the above technical solution, it can be seen that the vertical two-stage dual-outlet centrifugal pump for marine use provided by the present invention solves the problem of inconvenient repair and maintenance in the prior art. Compared with the prior art, the present invention has the following advantages:

[0020] Beneficial effects:

[0021] The pump body, bearing seat and mouth ring all adopt an axially split structure. The liquid inlet, first-level liquid outlet and second-level liquid outlet are all arranged on the rear pump body. The front pump body can be removed and opened for internal repair and maintenance. The front bearing seat can be removed to repair and maintain the bearings. Since the rear pump body remains in place, the various pipes and valves connected to the rear pump body and the motor on the top of the pump do not need to be removed, which facilitates repair and maintenance and reduces workload and labor intensity.

[0022] In addition, the two halves of the mouth ring are fixed to the front pump body and the rear pump body respectively. There is no gap between the mouth ring and the pump body, which reduces the leakage of fluid from the high-pressure area to the low-pressure area, avoids erosion damage to the pump body and the mouth ring, and extends the service life. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] To more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces and describes the drawings required for use in the embodiments of the present invention or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention, and those skilled in the art can derive other drawings based on these drawings without inventive effort.

[0024] Figure 1 A cross-sectional view of the marine vertical two-stage double-outlet centrifugal pump provided by the present invention;

[0025] Figure 2 for Figure 1 A top view of the assembled pump body and base of the vertical two-stage, double-outlet marine centrifugal pump shown;

[0026] Figure 3 for Figure 1 A magnified view of part A in FIG;

[0027] Figure 4 This is a schematic diagram of the traditional circular integral mouth ring after installation;

[0028] Figure 5 A schematic diagram of the mouth ring with two symmetrical halves after installation in the present invention;

[0029] Figure 6 for Figure 1 A magnified view of part B in FIG;

[0030] Figure 7 is a cross-sectional view of the bearing seat in the present invention;

[0031] Figure 8 for Figure 7 Top view of the bearing housing shown.

[0032] Figures 1-8 In the figure, the corresponding relationship between the parts is as follows:

[0033] Pump body 10, drive device 30, base 40, coupling 50, upper bearing assembly 60, lower bearing assembly 70;

[0034] Liquid inlet 11, first-level liquid outlet 12, second-level liquid outlet 13, pump body partition 14, fixing bracket 16, front pump body 17, rear pump body 18;

[0035] A first flange 171, a second flange 181;

[0036] First-stage impeller 21, second-stage impeller 22, pump shaft 23, middle spacer 24, mouth ring 25;

[0037] Motor bracket 31;

[0038] Motor coupling 51, pump shaft connector 52;

[0039] Bearing seat 61, rolling bearing 62, bearing lock nut 63, bearing gland 64, bearing sleeve 65, mechanical shaft seal 66, throttling bushing 67;

[0040] Front bearing seat 611, rear bearing seat 612, arc-shaped connecting seat 613;

[0041] Bushing 71. DETAILED DESCRIPTION

[0042] The following will clearly and completely describe the technical solutions of the embodiments of the present invention in conjunction with the accompanying drawings of the embodiments of the present invention. Obviously, the embodiments described below are only 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 shall fall within the scope of protection of the present invention.

[0043] In order to more clearly explain and illustrate the technical solution and implementation of the present invention, several preferred specific embodiments for implementing the technical solution of the present invention are introduced below.

[0044] It should be noted that the directional words such as "inside, outside", "front, back" and "left, right" in this article are expressed based on the product usage status. Obviously, the use of the corresponding directional words does not constitute a limitation on the scope of protection of this scheme.

[0045] like Figure 1 、 Figure 2As shown, the present invention provides a marine vertical two-stage double-outlet centrifugal pump, which includes a pump body 10, an impeller assembly and a drive device 30. The lower end of the pump body 10 is fixed on a base 40 for bearing the weight of the centrifugal pump and connecting to the hull.

[0046] The outer wall of the pump body 10 is provided with a liquid inlet 11, a primary liquid outlet 12, and a secondary liquid outlet 13. The inner cavity of the pump body 10 is divided into a primary flow channel and a secondary flow channel by a pump body partition wall 14. The primary flow channel connects the liquid inlet 11 and the primary liquid outlet 12, and the secondary flow channel connects the primary liquid outlet 12 and the secondary liquid outlet 13.

[0047] The impeller assembly includes a primary impeller 21 and a secondary impeller 22, which are configured correspondingly to the primary and secondary flow channels. The primary impeller 21 and the secondary impeller 22 are arranged in series via a pump shaft 23 and are rotatably disposed within the pump body 10, with the primary impeller 21 located below the secondary impeller 22. An intermediate spacer 24 is provided between the primary impeller 21 and the secondary impeller 22, and the intermediate spacer 24 is fixed to the pump shaft 23.

[0048] In the present invention, the pump body 10 adopts an axially split structure, consisting of a front pump body 17 and a rear pump body 18. The liquid inlet 11, the first liquid outlet 12, and the second liquid outlet 13 are all provided on the rear pump body 18. Specifically, a first flange 171 and a second flange 181 are respectively provided on the mating surfaces of the front pump body 17 and the rear pump body 18. The first flange 171 and the second flange 181 are relatively abutted and fastened by pump body bolts to form the pump body 10.

[0049] Because the marine bilge master pump is located at the bottom of the engine room, it is surrounded by a dense network of pipes and valves, creating a confined space. In particular, the pipes are pressure-tested for tightness and are generally hard-connected. Traditional marine bilge master pumps feature a one-piece pump body, requiring disassembly of the pipes for maintenance. Once disassembled, reconnecting the pipes is prone to leaks, creating significant additional workload. Furthermore, the accompanying motor is large and heavy, while the lifting equipment available on board is relatively simple and rudimentary. Lifting the motor is both cumbersome and dangerous. Furthermore, the cables in the motor junction box must be removed, and because marine cables are thick and rigid, both removal and reinstallation are time-consuming and labor-intensive.

[0050] In the present application, the pump body 10 adopts an axially split structure, that is, the pump body is divided into a front pump body and a rear pump body, and the liquid inlet 11, the first-level liquid outlet 12 and the second-level liquid outlet 13 are all arranged on the rear pump body 18. The front pump body can be removed by removing the pump body bolts, thereby opening the pump body for internal repair and maintenance. Since the rear pump body 18 remains in place, the various pipes and valves connected to the rear pump body 18 and the motor on the top of the pump do not need to be removed, which makes repair and maintenance convenient and reduces workload and labor intensity.

[0051] For example Figure 1 、 Figure 3 As shown, mouth rings 25 (also called sealing rings or wear-resistant rings) are respectively provided between the inlet of the first-stage impeller 21 and the pump body 10, between the outlet of the second-stage impeller 22 and the pump body 10, and between the middle spacer 24 and the inner wall of the shaft hole of the pump body partition wall 14, which are used to reduce the leakage of fluid from the high-pressure area to the low-pressure area.

[0052] Furthermore, in the present application, the mouth ring 25 is composed of two symmetrical halves, which are fixed to the front pump body 17 and the rear pump body 18 by fastening screws. Specifically, the outer circumferential surfaces of the two halves of the mouth ring 25 are respectively provided with flanges, and the front pump body 17 and the rear pump body 18 are respectively provided with grooves that match the flanges. The flanges are embedded in the grooves and fixed in the grooves by multiple fastening screws arranged circumferentially.

[0053] like Figure 4 As shown, in traditional designs, the mouth ring is a one-piece circular structure secured to the pump body by anti-rotation screws. Due to the pressure difference between the primary and secondary flow channels, high-speed fluid can pass through the gap between the outer diameter of the mouth ring and the pump body, causing internal leakage. Furthermore, the anti-rotation screws can be corroded and eroded by continuous high-speed fluid flow over time, losing their anti-rotation function. This causes the mouth ring to rotate erratically due to the impeller, causing friction and wear against the pump body, ultimately leading to its failure. Furthermore, the pump body and mouth ring where the mouth ring is mounted are also susceptible to erosion and wear.

[0054] In the present application, the mouth ring is designed as a symmetrical two-half structure, which is fixed to the front and rear pump bodies with multiple fastening screws respectively. During operation, the mouth ring will not produce relative movement with the pump body and will not wear the pump body. In addition, there is no gap between the mouth ring and the pump body, which reduces the leakage of fluid from the high-pressure area to the low-pressure area, avoids erosion of the pump body and the mouth ring, and extends the service life.

[0055] The working mechanism of the other two mouth rings is the same as above and will not be repeated here.

[0056] See also Figure 1 In the present application, the driving device 30 adopts a motor, which is connected to the pump shaft 23 through a coupling 50. The coupling 50 includes a motor coupling 51 arranged on the motor output shaft and a pump shaft connector 52 arranged at the upper end of the pump shaft 23, and the two are axially connected and fixed.

[0057] An upper bearing assembly 60 is provided on the upper portion of the pump shaft 23 , and a lower bearing assembly 70 is provided on the lower end thereof. The upper bearing assembly 60 is located below the pump shaft connector 52 .

[0058] like Figure 6 、 Figure 7 、 Figure 8As shown, in this application, the upper bearing assembly 60 includes a bearing seat 61 and a rolling bearing 62 arranged in the bearing seat 61. The rolling bearing 62 is fixed to the pump shaft 23 through a bearing lock nut 63. A bearing cover 64 is provided on the top surface of the bearing seat 61.

[0059] The bearing seat 61 also adopts an axially split structure, including a front bearing seat 611 and a rear bearing seat 612. The rear bearing seat 612 is fixed on the fixed bracket 16. The front bearing seat 611 and the rear bearing seat 612 are fixed on the docking surface by docking bolts.

[0060] The lower portion of the rear bearing seat 612 is provided with an arc-shaped connecting seat 613 arranged around the outer side surface thereof, and the arc-shaped connecting seat 613 is fixed on the fixing bracket 16.

[0061] This design structure of the bearing seat 61 allows the front bearing seat 611 to be removed in half like the pump body 10, making it easy to repair and maintain the rolling bearing.

[0062] In the present application, a bearing sleeve 65 is further added in the bearing seat 61, and the rolling bearing 62 is installed in the bearing sleeve 65. The bearing sleeve 65 plays a role in protecting the bearing seat 61.

[0063] In traditional designs, the bearings are installed directly in the bearing seat 61. Because the bearings bear various axial and radial loads, they heat and expand during operation. To prevent the bearings from locking due to expansion, a certain gap is reserved between the outer diameter of the bearing and the inner bore of the bearing seat 61 to allow the bearings sufficient room for expansion. When the pump is just starting up and the bearings have not yet heated and expanded, relative movement occurs between the outer diameter of the bearing and the inner bore of the bearing seat 61, generating friction until the bearings heat and expand, and the relative movement ceases. With this design, the outer diameter of the bearing can easily wear the inner bore of the bearing seat 61, rendering the bearing seat 61 scrapped.

[0064] To avoid this problem, the present invention installs a bearing sleeve 65 in the inner hole of the bearing seat 61, transferring the relative motion between the outer diameter of the bearing and the inner hole of the bearing sleeve. As a result, the relatively low-value bearing sleeve 65 is worn out, thus protecting the bearing seat 61. When the bearing sleeve 65 is worn too much, it can be replaced, thereby reducing maintenance costs.

[0065] In the present application, the first-stage impeller 21 and the second-stage impeller 22 have the same structure and are arranged axially symmetrically to balance the axial load, thereby minimizing the axial load borne by the bearing.

[0066] The primary and secondary flow channels are arranged radially symmetrically to balance the radial forces, thereby minimizing the radial forces borne by the bearings.

[0067] See also Figure 1A pump shaft socket is provided on the top of the pump body 10 , and the pump shaft 23 passes through the pump shaft socket and is inserted into the pump body 10 to connect the first-stage impeller 21 and the second-stage impeller 22 .

[0068] A fixing bracket 16 is located at the top of the pump body 10, surrounding the pump shaft insertion hole. The drive unit 30 is secured to the fixing bracket 16 via a motor bracket 31. A column (not shown) connects the motor bracket 31 to the base 40, which is used to adjust the coaxiality between the impeller assembly and the motor. This also transfers some of the motor's weight to the base 40, freeing the pump body 10 from bearing the full weight of the motor and preventing deformation due to excessive weight.

[0069] A mechanical shaft seal 66 is provided in the pump shaft socket, and a throttle bushing 67 is provided below the mechanical shaft seal 66. The throttle bushing 67 can prevent the medium (seawater) from gushing out of the pump in large quantities when the mechanical shaft seal 66 fails. In addition, it can prevent particulate impurities from entering the mechanical shaft seal cavity and damaging the mechanical shaft seal. At the same time, it can also play a certain role in straightening the pump shaft.

[0070] The lower bearing assembly 70 includes a sialon bearing and a sleeve 71. The sialon bearing has the characteristics of wear resistance, corrosion resistance and low friction coefficient. The lower bearing assembly 70 and the sleeve 71 constitute a friction pair, which is used to straighten the pump shaft 23, reduce the deflection of the pump shaft 23, and enhance the rigidity of the pump shaft 23, thereby increasing the critical speed of the impeller assembly and enhancing the reliability of the operation of the impeller assembly.

[0071] Based on the description of the above specific embodiments, the marine vertical two-stage dual-outlet centrifugal pump provided by the present invention has the following advantages compared with the prior art:

[0072] First, the pump body, bearing seat and mouth ring all adopt an axially split structure. The front pump body can be removed and opened for internal repair and maintenance. Since the rear pump body remains in place, the various pipes and valves connected to the rear pump body and the motor on the top of the pump do not need to be removed, making repair and maintenance convenient.

[0073] Second, the mouth ring is designed as a symmetrical two-halves structure, with multiple fastening screws on the front and rear pump bodies respectively. During the operation of the pump, the mouth ring will not produce relative movement with the pump body and will not wear the pump body. In addition, there is no gap between the mouth ring and the pump body, which avoids erosion damage to the pump body and the mouth ring and extends the service life.

[0074] Finally, it should be noted that the terms "comprise," "include," or any other variations thereof, as used herein, are intended to encompass non-exclusive inclusion, such that a process, method, article, or apparatus comprising a list of elements includes not only those elements but also other elements not explicitly listed, or elements inherent to such process, method, article, or apparatus. In the absence of further limitations, an element defined by the phrase "comprising a..." does not preclude the presence of additional identical elements in the process, method, article, or apparatus comprising the element.

[0075] The present invention is not limited to the above-mentioned optimal implementation mode. Anyone should be aware that any structural changes made under the inspiration of the present invention, and any technical solutions that are the same or similar to the present invention, fall within the scope of protection of the present invention.

Claims

1. A marine vertical two-stage, dual-outlet centrifugal pump, comprising a pump body and an impeller assembly disposed within the pump body, the impeller assembly comprising a primary impeller and a secondary impeller, the pump body being provided with a liquid inlet and a primary liquid outlet and a secondary liquid outlet corresponding to the primary and secondary impellers, the primary and secondary impellers being arranged in series on a pump shaft, the pump shaft being connected to a drive device via a coupling, characterized in that: A pump shaft insertion hole is provided on the top of the pump body, and a fixing bracket is fixedly provided around the pump shaft insertion hole; The pump body adopts an axially split split structure, and is composed of a front pump body and a rear pump body relatively assembled, and the liquid inlet, the first-level liquid outlet and the second-level liquid outlet are all arranged on the rear pump body; The inner cavity of the pump body is divided into a primary flow channel and a secondary flow channel by a pump body partition wall, the primary impeller and the secondary impeller are rotatably arranged in the primary flow channel and the secondary flow channel respectively, an intermediate sleeve is provided between the primary impeller and the secondary impeller, the intermediate sleeve is fixed on the pump shaft, and a mouth ring is respectively provided between the inlet of the primary impeller and the pump body, between the outlet of the secondary impeller and the pump body, and between the intermediate sleeve and the inner wall of the shaft hole of the pump body partition wall, the mouth ring consists of two symmetrical halves, and the two halves are respectively fixed to the front pump body and the rear pump body by fastening screws; The upper end and lower end of the pump shaft are respectively provided with an upper bearing assembly and a lower bearing assembly. The upper bearing assembly includes a bearing seat and a rolling bearing arranged in the bearing seat. The bearing seat adopts an axially split structure, including a front bearing seat and a rear bearing seat. The rear bearing seat is fixed on the fixed bracket.

2. The marine vertical two-stage double-outlet centrifugal pump according to claim 1, characterized in that: The lower part of the rear bearing seat is provided with an arc-shaped connecting seat arranged around the outer side surface thereof, and the arc-shaped connecting seat is fixed on the fixing bracket.

3. The marine vertical two-stage double-outlet centrifugal pump according to claim 1, characterized in that: The lower end of the pump body is fixed on the base, the driving device is fixed on the fixing bracket via a motor bracket, and the motor bracket and the base are connected via a column.

4. The marine vertical two-stage double-outlet centrifugal pump according to claim 1, characterized in that: The first-stage impeller and the second-stage impeller have the same structure and are arranged axially symmetrically.

5. The marine vertical two-stage double-outlet centrifugal pump according to claim 1, characterized in that: The primary flow channel and the secondary flow channel are arranged radially symmetrically.

6. The marine vertical two-stage double-outlet centrifugal pump according to claim 1, characterized in that: A bearing sleeve is provided in the bearing seat, and the rolling bearing is installed in the bearing sleeve.

7. The marine vertical two-stage double-outlet centrifugal pump according to claim 1, characterized in that: A mechanical shaft seal and a throttling bushing are arranged in the pump shaft socket, and the throttling bushing is arranged below the mechanical shaft seal.

8. The marine vertical two-stage dual-outlet centrifugal pump according to claim 1, characterized in that: The coupling includes a motor coupling arranged on the output shaft of the driving device and a pump shaft connector arranged on the upper end of the pump shaft, and the motor coupling is axially connected and fixed to the pump shaft connector.

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