An axially split segmented multistage pump and its manufacturing method

Abstract

The present invention discloses an axially split segmented multistage pump and its manufacturing method, which includes a pump cover, a segmented pump core assembly, and a pump body. The pump cover and the pump body are assembled together through their joint surfaces to form the housing of the pump. The housing has a hollow cavity, and the segmented pump core assembly is placed in the hollow cavity of the housing and is coaxial with the housing. A gasket is arranged between the joint surfaces of the pump cover and the pump body to play a sealing role. The pump cover and the pump body are connected by bolts and positioned by two conical pins arranged diagonally. The segmented pump core assembly has an outer cylindrical surface and an outer conical surface on each of the left and right sides. The pump body is provided with a horizontal inlet and a flange, and the suction section is provided with a horizontal water inlet, and the horizontal inlet is directly opposite to the horizontal water inlet. The pump cover is provided with a vertical outlet and a flange, and the outlet section is provided with a vertical water outlet, and the vertical outlet is directly opposite to the vertical water outlet. The pump has good overall stiffness, reliable sealing, and good part versatility. The present invention is more suitable for high-temperature and high-pressure occasions.

Description

Technical Field

[0001] The present invention relates to the field of water pumps, and particularly to an axially split sectional multi-stage pump and a manufacturing method thereof. Background Art

[0002] Multi-stage pumps are a relatively common type of pump, widely used in fields such as electric power, metallurgy, mining, municipal engineering, ships, petroleum, and chemical industry. Multi-stage pumps are usually divided into axially split multi-stage pumps and sectional multi-stage pumps.

[0003] In the existing sectional multi-stage pump, the inner and outer stop surfaces between the suction section, the middle section, and the discharge section are stacked step by step for positioning. As the number of stages increases, the axial length of the pump increases, the positioning error accumulates greatly, the stiffness of the pump decreases, the vibration is large, and mechanical failures increase; there is a static seal at each stop surface position. When the number of stages increases, there are many sealing positions, and of course, there are many potential leakage points. As the temperature and pressure increase, the stiffness decreases, and the sealing points are more likely to fail. Therefore, the existing axially split multi-stage pump is not suitable for high-temperature and high-pressure occasions.

[0004] Although the existing axially split multi-stage pump has good stiffness, its interchangeability is poor, and there are few common parts, which becomes particularly prominent as the number of stages increases. This makes the technical economy of this type of multi-stage pump relatively poor. Summary of the Invention

[0005] In order to solve the above problems, the present invention provides an axially split sectional multi-stage pump, which has both the advantages of a compact structure and good stiffness of an axially split multi-stage pump, and the advantages of good interchangeability of a sectional multi-stage pump, and has the characteristics of safety, reliability, and convenient maintenance.

[0006] The technical solution adopted by the present invention is as follows:

[0007] An axially split sectional multi-stage pump includes a pump cover, a sectional pump core assembly, and a pump body. The pump cover and the pump body are assembled together through their joint surfaces to form the housing of the pump. The housing has a hollow cavity. The sectional pump core assembly is placed in the hollow cavity of the housing and is coaxial with the housing. A gasket is provided between the joint surfaces of the pump cover and the pump body to play a sealing role. The pump cover and the pump body are connected by bolts and positioned by two tapered pins arranged diagonally.

[0008] As a further improvement of the present invention, the sectional pump core assembly includes a suction section, a middle section, a radial guide vane, an impeller, a pump shaft, and a discharge section. The sectional pump core assembly has an outer cylindrical surface and an outer tapered surface on each side. The suction section, the middle section, the radial guide vane, and the discharge section are connected to each other through stop surfaces.

[0009] As a further improvement of the present invention, the shell formed by the pump cover and the pump body has an inner cylindrical surface and an inner conical surface on the left and right. The segmented pump core assembly is positioned in the inner cylindrical surface and is tightened by the axial force of the inner conical surface acting on the outer conical surface.

[0010] As a further improvement of the present invention, the O-ring is embedded in the outer circular grooves of the suction section and the outlet section to seal the segmented pump core assembly and the pump housing.

[0011] As a further improvement of the present invention, the pump body is provided with a horizontal inlet and a flange, the suction section is provided with a horizontal water inlet, and the horizontal inlet is directly opposite to the horizontal water inlet; the pump cover is provided with a vertical outlet and a flange, the outlet section is provided with a vertical water outlet, and the vertical outlet is directly opposite to the vertical water outlet.

[0012] As a further improvement of the present invention, no static seal is provided at the stop openings of the suction section, the middle section and the outlet section.

[0013] As a further improvement of the present invention, no tensioning element such as a screw is provided between the suction section and the outlet section.

[0014] The present invention also provides a method for manufacturing the above-mentioned axially split segmented multi-stage pump, comprising the following steps: after the segmented pump core assembly is assembled, the outer cylindrical surface and two left and right outer conical surfaces are processed at one time with the axis as the reference; the processing method of the pump body and pump cover is to first mill out the joint surfaces of the pump body and the pump cover respectively, clamp the sealing gasket between the two joint surfaces of the pump body and the pump cover and tighten and fix them with a clamp, drill bolt holes, and then insert bolts to fix them, then drill two diagonal conical pin holes, and drive conical pins into them, and finally process the left and right cylindrical holes, the inner conical surface and the middle inner cylindrical surface at one time on a boring machine; the assembly order of the axially split segmented multi-stage pump is to first assemble the segmented pump core assembly, place the segmented pump core assembly on the pump body, add the sealing gasket, close the pump cover, drive the positioning conical pin, and tighten the pump body and the pump cover with bolts.

[0015] Compared with the prior art, the axially split segmented multistage pump and the manufacturing method thereof described in the present invention have the following beneficial effects:

[0016] 1. The pump has good overall rigidity and high positioning accuracy: the shell formed by the pump cover and the pump body has an inner cylindrical surface and an inner conical surface on each side. The segmented pump core assembly is positioned in the inner cylindrical surface. The suction section, middle section and outlet section are uniformly positioned by a common reference inner cylindrical surface. The positioning accuracy is very high and there will be no cumulative error like the existing technology. At the same time, the axial force generated by the inner conical surface of the shell acting on the outer conical surface of the segmented pump core assembly is pressed, and the pump as a whole has good rigidity.

[0017] 2. Less potential leakage hazards and reliable sealing: There are only two static sealing parts between the pump and the outside world. One is the static seal between the pump cover and the pump body (the sealing part is a gasket), and the other is the static seal between the housing and the segmented pump core assembly (the sealing part is an O-ring). The number of static sealing parts does not increase with the increase in the number of stages.

[0018] 3. Good part versatility and high interchangeability: The impellers, middle sections, and radial diffusers do not change with the increase in the number of stages, and they have good interchangeability and versatility.

[0019] 4. High-precision machining methods, convenient installation, and high installation accuracy are ensured.

[0020] In summary, for the axially split segmented multistage pump and its manufacturing method described in the present invention, it has high positioning accuracy, good stiffness, reliable sealing, and good part versatility. Therefore, the present invention is more suitable for high-temperature and high-pressure occasions. Brief Description of the Drawings

[0021] The present invention will be further described below in conjunction with the drawings and embodiments.

[0022] Figure 1 is a schematic diagram of the overall structure of the present invention.

[0023] Figure 2 is a left view of the present invention.

[0024] Figure 3 is a top view of the present invention.

[0025] Figure 4 is the segmented pump core assembly of the present invention.

[0026] Figure 5 is a schematic diagram of the combined installation of the pump cover and the pump body of the present invention.

[0027] In the figure: 1. O-ring seal, 2. Pump cover, 3. Segmented pump core assembly, 4. Pump body, 5. Gasket, 6. Taper pin, 7. Bolt, 31. Suction section, 32. Middle section, 33. Radial diffuser, 34. Impeller, 35. Pump shaft, 36. Outlet section, 100. Outer conical surface, 101. Outer cylindrical surface, 102. Inner conical surface, 103. Inner cylindrical surface Detailed Embodiments

[0028] It should be noted that, without conflict, the embodiments in the present invention and the features in the embodiments can be combined with each other. The present invention will be described in detail below with reference to the drawings and embodiments.

[0029] As Figures 1 to 5An axially split segmented multistage pump as shown includes a pump cover 2, a segmented pump core assembly 3, and a pump body 4. The pump cover 2 and the pump body 4 are assembled together through their joint surfaces to form the housing of the pump. The housing has a hollow cavity, and the segmented pump core assembly 3 is placed in the hollow cavity of the housing and is coaxial with the housing. A gasket 5 is located between the joint surfaces of the pump cover 2 and the pump body 4 to play a sealing role. The pump cover 2 and the pump body 4 are connected by bolts 7 and positioned by two taper pins 6 arranged diagonally. In the present invention, the static seals of the housing are only the O-ring 1 and the gasket 5, and compared with the existing segmented multistage pumps, it has the characteristic of less leakage risk.

[0030] The segmented pump core assembly 3 includes a suction section 31, a middle section 32, a radial diffuser 33, an impeller 34, a pump shaft 35, and a discharge section 36. The segmented pump core assembly 3 has an outer cylindrical surface 101 and an outer tapered surface 100 at each of the left and right sides; the suction section 31, the middle section 32, the radial diffuser 33, and the discharge section 36 are connected to each other through a spigot. The outer tapered surface 100 and the outer cylindrical surface 101 are formed by machining in one time, and the positioning accuracy is relatively high.

[0031] The housing formed by assembling the pump cover 2 and the pump body 4 has an inner cylindrical surface and an inner tapered surface at each of the left and right sides. The segmented pump core assembly 3 is positioned in the inner cylindrical surface 103 and is pressed by the axial force of the inner tapered surface 102 acting on the outer tapered surface 100. The positioning mainly relies on the inner tapered surface 102 and the outer tapered surface 100, and the inner cylindrical surface 103 and the outer cylindrical surface 101 play an auxiliary positioning role. Therefore, the segmented pump core assembly 3 has high rigidity. The inner tapered surface 102 and the inner cylindrical surface 103 are formed by machining in one time, and the positioning accuracy is relatively high.

[0032] In the present invention, the O-ring 1 is embedded in the outer circular grooves of the suction section 31 and the discharge section 36 to seal the segmented pump core assembly 3 and the housing of the pump.

[0033] In the present invention, the pump body 4 is provided with a horizontal inlet and a flange, the suction section 31 is provided with a horizontal water inlet, and the horizontal inlet is directly opposite to the horizontal water inlet; the pump cover 2 is provided with a vertical outlet and a flange, the discharge section 36 is provided with a vertical water outlet, and the vertical outlet is directly opposite to the vertical water outlet. When the present invention is operating, the liquid is sucked in from the horizontal inlet, enters the suction section 31 through the horizontal water inlet, and then is sucked into the first-stage impeller 34 for pressurization, and then enters the first-stage radial diffuser 33, and then enters the next-stage impeller 34 for step-by-step pressurization, and finally enters the discharge section 36, and flows out through the vertical water outlet of the discharge section 36 and the vertical outlet of the pump cover 2.

[0034] No static seals are provided at the spigot positions of the suction section 31, the middle section 32, and the discharge section 36. No tensioning elements such as lead screws are provided between the suction section 31 and the discharge section 36.

[0035] Manufacturing method of axially split segmented multistage pump: after the segmented pump core assembly is assembled, the outer cylindrical surface and the left and right outer conical surfaces are processed at one time with the axis as the reference; the processing method of the pump body and pump cover is to first mill out the joint surfaces of the pump body and the pump cover respectively, clamp the sealing gasket between the two joint surfaces of the pump body and the pump cover and tighten and fix them with a clamp, drill bolt holes, and then insert bolts to fix them, then drill two diagonal conical pin holes and drive conical pins, and finally process the left and right cylindrical holes, the inner conical surface and the middle inner cylindrical surface on a boring machine at one time; the assembly order of the axially split segmented multistage pump is to first assemble the segmented pump core assembly, place the segmented pump core assembly on the pump body, add the sealing gasket, close the pump cover, drive the positioning conical pin, and tighten the pump body and the pump cover with bolts.

[0036] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with 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 embodiments of the present invention.

Claims

1. An axially split segmented multistage pump, characterized in that: It includes a pump cover, a segmented pump core assembly, and a pump body. The pump cover and the pump body are assembled together through their joint surfaces to form the housing of the pump. The housing has a hollow cavity. The segmented pump core assembly is placed in the hollow cavity of the housing and is coaxial with the housing. A gasket is placed between the joint surfaces of the pump cover and the pump body to play a sealing role. The pump cover and the pump body are connected by bolts and positioned by two taper pins arranged diagonally. The segmented pump core assembly includes a suction section, a middle section, a radial guide vane, an impeller, a pump shaft, and an outlet section. The segmented pump core assembly has an outer cylindrical surface and an outer tapered surface on each of the left and right sides. The suction section, the middle section, the radial guide vane, and the outlet section are connected to each other through a spigot. The housing formed by the assembly of the pump cover and the pump body has an inner cylindrical surface and an inner tapered surface on each of the left and right sides. The segmented pump core assembly is positioned inside the inner cylindrical surface and is pressed by the axial force of the inner tapered surface acting on the outer tapered surface.

2. The axially split segmented multistage pump according to claim 1, characterized in that: An O-ring seal is embedded in the outer circular grooves of the suction section and the outlet section to seal the segmented pump core assembly and the housing of the pump.

3. The axially split segmented multistage pump according to claim 1, characterized in that: The pump body is provided with a horizontal inlet and a flange. The suction section is provided with a horizontal water inlet, and the horizontal inlet is directly opposite to the horizontal water inlet. The pump cover is provided with a vertical outlet and a flange. The outlet section is provided with a vertical water outlet, and the vertical outlet is directly opposite to the vertical water outlet.

4. The axially split segmented multistage pump according to claim 1, characterized in that: No static seal is provided at the spigot of the suction section, the middle section, and the outlet section.

5. The axially split segmented multistage pump according to claim 1, characterized in that: No tensioning element is provided between the suction section and the outlet section.

6. A manufacturing method implemented based on the axially split segmented multistage pump according to any one of claims 1-5, characterized in that: After the segmented pump core assembly is assembled, with the axis as the reference, the outer cylindrical surface and the two outer tapered surfaces on the left and right are machined in one go. The processing method of the pump body and the pump cover is as follows: First, the joint surfaces of the pump body and the pump cover are respectively milled. The gasket is clamped between the two joint surfaces of the pump body and the pump cover and fixed tightly with a fixture. Bolt holes are drilled, and then bolts are inserted and fixed. Then, two diagonal taper pin holes are drilled and taper pins are driven in. Finally, the two cylindrical holes on the left and right, the inner tapered surfaces, and the middle inner cylindrical surface are machined in one go on a boring machine. The assembly sequence of the axially split segmented multistage pump is as follows: First, assemble the segmented pump core assembly, place the segmented pump core assembly on the pump body, add a gasket, close the pump cover, drive in the positioning taper pins, and tighten the pump body and the pump cover with bolts.

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