Slurry pump

Abstract

To provide a slurry pump capable of improving maintenance workability of a liquid contact part of a casing.SOLUTION: In a slurry pump 100, a casing liner 9 made of rubber is installed in a casing 1. The casing 1 includes a back casing 12 made of iron and a front casing 11 made of an aluminum alloy. The casing liner 9 is sandwiched between the back casing 12 and the front casing 11 from the front and rear in the axial direction by a plurality of bolt fastening portions 18.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a slurry pump having a casing fitted with a rubber liner and used for pumping slurry, and more particularly to a casing structure for this type of slurry pump. [Background technology]

[0002] This type of slurry pump is sometimes used to pump highly corrosive slurries, so the rubber liner is a consumable part, and maintenance of the liquid-contacting parts is therefore required periodically or depending on the wear state of the rubber liner (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Special Publication No. 2007-511698 Summary of the Invention [Problem to be solved by the invention]

[0004] When performing maintenance on the liquid-contacting parts, it is necessary to remove the front casing that forms the front of the casing and open the liquid-contacting parts. However, for medium-sized or larger slurry pumps (for example, those with a cast iron front casing weighing 23 kg or more), the front casing of a conventional cast iron (FC200) casing weighs 20 kg or more. This makes maintenance difficult for a single worker, requiring multiple workers or a crane or other lifting equipment. Therefore, there is a strong demand for improved maintenance work on the liquid-contacting parts, especially in factories that handle a large number of pumps.

[0005] The present invention has been made in view of the above-mentioned problems, and it is an object of the present invention to provide a slurry pump which can improve the ease of maintenance of the liquid-contacting parts of the casing. [Means for solving the problem]

[0006] In order to solve the above problems, one aspect of the present invention provides a slurry pump having a rubber casing liner installed inside a casing, the casing comprising an iron back casing and an aluminum alloy front casing, and the casing liner is clamped between the back casing and the front casing from the front and rear in the axial direction by a plurality of bolt fastening portions. [Effects of the Invention]

[0007] According to the present invention, since the front casing is made of an aluminum alloy, the maintenance workability of the liquid-contacting parts of the casing is improved. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is an illustration of an embodiment of a slurry pump according to an aspect of the present invention, showing a cross section along the axis of the shaft. [Figure 2] 2A and 2B are explanatory views of the front casing of FIG. 1, in which FIG. 2A is a front view, FIG. 2B is a cross-sectional view taken along the line A, B, C, and D in FIG. 2A, FIG. 2C is a rear view, and FIG. 2D is a plan view showing the flange portion in FIG. [Figure 3] 2 is a perspective view illustrating the disassembly and assembly process of the front casing portion of FIG. 1. FIG. [Figure 4] FIG. 1 is an explanatory diagram of an example of a slurry pump equipped with a conventional front casing, showing a cross section along the axis of the shaft. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. Note that the drawings are schematic. Therefore, it should be noted that the relationship between thickness and planar dimensions, ratios, etc. differ from the actual ones, and the drawings also include portions where the relationship and ratio of dimensions differ from each other. Furthermore, the embodiments described below are intended to exemplify devices and methods for embodying the technical ideas of the present invention, and the technical ideas of the present invention do not limit the materials, shapes, structures, arrangements, etc. of the components to the embodiments described below.

[0010] As shown in FIG. 1, the slurry pump 100 of this embodiment includes a frame 8, a casing 1 provided in front of the frame 8, an impeller 2 supported on the tip of a shaft 3 protruding into the casing 1, and a gland packing 10 wrapped around the shaft 3 behind the impeller 2.

[0011] The casing 1 has a discharge port 1b formed at the top, and a suction port 1a formed at the axial center thereof, which protrudes forward along the axial direction. The casing 1 of this embodiment includes a front casing 11 and a back casing 12 that are divided into front and rear halves near the axial center of the impeller 2. The rear portion of the back casing 12 is fixed to the front surface of the frame 8 with bolts and nuts 13.

[0012] Furthermore, the front casing 11 and the back casing 12 are fixed to each other in the axial direction by casing bolts 14 and casing nuts 15 so as to sandwich the rubber casing liner 9, and an accommodation space for the impeller 2 is defined inside the casing liner 9. The casing liner 9 has a front liner 9a and a back liner 9b. The front liner 9a has a core and a rubber part covering the core, and a part of the core is a part where a fastener to the front casing 11 is attached.

[0013] The base end side of the shaft (rotating shaft) 3 passes through the rear of the casing 1 and extends into the frame 8. A journal support 7 having two bearings 7a, 7b spaced apart in the axial direction is provided within the frame 8. The base end side of the shaft 3 is rotatably supported by this journal support 7. An output shaft of a motor is connected to the base end of the shaft 3 so as to transmit driving force.

[0014] The slurry pump 100 of this embodiment has a gland packing 10 that seals the tip end of the shaft 3, located at the center of the back surface of the back casing 12. The gland packing 10 is provided at the position of the shaft sleeve 4 between the back surface of the casing 1 and the above-mentioned bearing portion 7 of the shaft 3.

[0015] The gland packing 10 of this embodiment is disposed inside the stuffing box 50.

[0016] Here, in the casing 1 of this embodiment, the back casing 12 is made of iron (in this example, made of cast iron (FC200)). In contrast, the front casing 11 is made of an aluminum alloy, and has a mass (e.g., 11 kg) that is approximately half the mass (e.g., 23 kg) of a front casing made of cast iron (FC200).

[0017] 2, in the front casing 11 of this embodiment, the three bolt mounting grooves 22 in the discharge side flange 21 extend in the same direction in consideration of ease of demolding. In this embodiment, the two left and right bolt mounting grooves 22 in the discharge side flange 21 are formed so that the groove extension direction, together with the central bolt mounting groove 22, opens forward along the axis of the shaft 3. In other words, the groove extension direction of the three bolt mounting grooves 22 in all three locations is the same as the axial direction of the casing 1.

[0018] In this case, if the outer shape of the discharge side flange 21 were a simple circle, pointed edges would stand up around the outer edges of the grooves, making it impossible to secure a sufficient bearing surface for the fastening bolts of the discharge side flange 21, and the pointed edges at the ends of the two left and right bolt mounting grooves 22 could cause molding defects. Therefore, in the front casing 11 of this embodiment, the discharge side flange 21 is provided with padding portions 23 with outer surfaces parallel to the extending direction of the grooves around the outer edges of each of the two left and right bolt mounting grooves 22.

[0019] Furthermore, in the front casing 11 of this embodiment, if it is simply made of an aluminum alloy, the pressure resistance will decrease. Therefore, in order to improve the pressure resistance performance, an auxiliary bolt fastening portion 24 is provided as a fifth bolt fastening portion for an auxiliary bolt in the neck portion 25 of the discharge-side flange 21, as shown in FIG. In the slurry pump 100 of this embodiment, in other parts where the back casing 12 and the front casing 11 are made of different materials, an insulating sleeve is interposed along the axial direction at the four bolt fastening portions 18 of each casing bolt 14, and an insulating washer is interposed on the contact surface of each bolt fastening portion 18.

[0020] As shown in FIG. 4, in a conventional slurry pump 100 having a front casing 211 made of cast iron (FC200), a reinforcing rib 226 is provided around a neck portion 225 of a discharge side flange 221. In contrast, in slurry pump 100 of this embodiment, the neck portion 25 of discharge-side flange 21 can be shortened by employing the above-mentioned auxiliary bolts and thick-walled outer peripheral structure 27, thereby ensuring the strength of discharge-side flange 21 itself. Therefore, in this embodiment, as shown in Fig. 2, the reinforcing rib on neck portion 25 of discharge-side flange 21 is eliminated, improving the workability of installing bolts into bolt mounting grooves 22.

[0021] In addition, in the slurry pump 100 of this embodiment, the axial front faces of the four bolt fastening portions 18 are formed as the same surface that is continuous with the annular rib 40 arranged on the outer edge of the front casing 11 (the outer edge of the clamping surface 30 described later). The annular rib 40 is formed in a generally annular shape in the region indicated by annular hatching in Fig. 2(a) . Therefore, the annular rib 40 is formed in a region on the outer edge of the front casing 11 that is more inward than the four bolt fastening portions 18. Furthermore, in the slurry pump 100 of this embodiment, when an aluminum alloy front casing 11 is used, in order to make the front casing 11 as light as possible, a plurality of lightening portions 26 (26a to 26d) are formed around almost the entire circumference in the circumferential direction, as shown in FIG. 2, within the range where pressure resistance performance can be maintained. However, in consideration of pressure resistance, the axial thickness is a predetermined thickness to avoid molding defects, and in order to allow the multiple lightening portions 26 (26a to 26d) to function as gripping portions during attachment and detachment operations, the front surfaces of the four bolt fastening portions 18 are made flush with each other to form a thick structure.

[0022] Furthermore, in the slurry pump 100 of this embodiment, although the casing 1 is provided with a plurality of lightening portions 26 (26a to 26d) along the circumferential direction thereof, the four liner fastening portions 28 experience locally high stress due to bolt fastening by the fasteners 16. Therefore, while an aluminum alloy front casing 11 is used, in order to secure the section modulus at key points, as shown in FIG. 2, a thick-walled liner fastening portion structure 29 is provided at the liner fastening portion 28 and its vicinity, in which the axial front side is formed into a trapezoidal convex shape and is thicker than other portions including the lightening portions 26 (26a to 26d).

[0023] Furthermore, in a casing structure that clamps a rubber casing liner 9 as in this embodiment, the slurry pump 100 of this embodiment has a clamping surface 30 that clamps the liner ear portion 9c of the front liner 9a that constitutes the casing liner 9 from the front and rear in the axial direction, and has multiple protrusions 31 (31a to 31d) that protrude axially toward the back side, as shown in the exploded oblique view of Figure 3.

[0024] As a result, in the slurry pump 100 of this embodiment, deformation of the liner ear portion 9c in the direction of expanding the diameter is more reliably suppressed, making it possible to ensure pressure resistance at key points even while using a front casing 11 made of aluminum alloy. Since the entire rubber casing liner 9 can distribute the surface pressure over the entire inner surface of the casing 1, as shown in Figure 2, the thickness of the conical surface 32 of the front casing 11 is made as thin as possible within the range where pressure resistance performance can be maintained. Furthermore, in the casing 1 of this embodiment, the front casing 11 is made of aluminum alloy, which makes it lighter than when the front casing is made of cast iron (compared to conventional casings). This makes it easier to increase the diameter and area of ​​the clamping surface 30, making it possible to suppress liquid leakage and improve pressure resistance.

[0025] Furthermore, in this type of slurry pump, as shown in Figure 3, during the assembly work of clamping the casing liner 9 from the front and rear in the axial direction, in order to maintain the housing position of the casing liner 9, it is necessary to tighten the casing bolts 14 and casing nuts 15 while pulling up the liner ear portions 9c. In contrast, in the slurry pump 100 of this embodiment, as shown in Fig. 2, a plurality of openings for lifting and holding the lifted portions 9d, 9e, and 9f (see Fig. 3) of the liner ear 9c are formed on the upper left and right sides in the direction of gravity between the plurality of protruding portions 31 (31a to 31d) on the clamping surface 30. As a result, the protruding portions 31b, 31c, and 31d form walls that are separated by the four bolt fastening portions 18 and that support the lifted portions 9d, 9e, and 9f of the liner ear 9c at three locations spaced apart in the circumferential direction.

[0026] As a result, according to the slurry pump 100 of this embodiment, the stored orientation of the casing liner 9 can be stably maintained on the lower side in the direction of gravity during assembly. Furthermore, when the pump is operating with the front casing 11 in the usage orientation, the protrusions 31b, 31c, and 31d that support the raised portions 9d, 9e, and 9f of the three liner ear portions 9c function as liner pressers and act as ribs that suppress deformation of the casing liner 9 in the radial direction, improving the support rigidity.

[0027] Next, the effects of the slurry pump 100 of this embodiment will be described. As described above, in the slurry pump 100 of this embodiment, the front casing 11 that forms the front side of the casing 1 is made of aluminum alloy, so that the mass can be reduced to approximately half (e.g., 11 kg) of that of a steel casing (e.g., approximately 23 kg for cast iron). As a result, with slurry pump 100 of this embodiment, when performing maintenance on the liquid-contacting parts, a single worker can remove front casing 11 made of a relatively lightweight aluminum alloy to expose the liquid-contacting parts, thereby improving the ease of maintenance of the liquid-contacting parts [Invention 1].

[0028] However, in a structure in which different materials with different ionization tendencies are combined, such as the casing 1 of this embodiment, there is a problem that electrolytic corrosion may occur. In view of this point, this embodiment basically adopts a slurry pump from among various pumps. As a result, in the slurry pump 100 of this embodiment, a rubber casing liner 9 is interposed at the joining surface between the back casing 12 made of iron (cast iron FC200) and the front casing 11 made of aluminum alloy, so that even though the structure is a combination of different materials, electrolytic corrosion at the joining surface itself is basically prevented or suppressed.

[0029] Furthermore, in the front casing 11, the axial front surfaces of the four bolt fastening portions 18 are formed as a single surface that is continuous with the annular rib 40. This makes it possible to suppress deformation of the clamping surface 30, that is, the entire periphery of the portion that clamps and presses the casing liner 9. In the slurry pump 100 of this embodiment, the three bolt mounting grooves 22 in the discharge side flange 21 of the front casing 11 all extend in the same direction (the same direction as the axial direction of the casing 1), and the two bolt mounting grooves 22 on the left and right of the discharge side flange 21 extend in the same direction as the central bolt mounting groove 22, making it easier to demold the front casing 11 during production and further improving the productivity of the front casing 11 [Invention 2].

[0030] Furthermore, in the slurry pump 100 of this embodiment, a padding portion 23 having a side surface parallel to the extending direction of the groove is provided around the outer end of the two bolt mounting grooves 22 on the left and right of the discharge side flange 21. Therefore, when an aluminum alloy front casing 11 is used, the bolt bearing surface is secured and formability is further improved [Invention 3].

[0031] Furthermore, in the slurry pump 100 of this embodiment, an auxiliary bolt fastening portion 24 is provided on the discharge side flange 21 of the front casing 11 for an auxiliary bolt, which is more suitable for maintaining or improving the pressure resistance performance while making the front casing 11 out of an aluminum alloy [Invention 4].

[0032] Conversely, in a conventional front casing made of cast iron (FC200), as shown in Figure 4, a reinforcing rib 226 was provided around the neck 225 of the discharge side flange 221. However, in the slurry pump 100 of this embodiment, the strength of the discharge side flange 21 itself can be ensured by employing a thick outer surface structure 27 at the neck 25 of the discharge side flange 21 of the front casing 11, in combination with the employment of the auxiliary bolts described above. As a result, the neck 25 of the discharge side flange does not have reinforcing ribs except for the auxiliary bolt fastening portion 24. This makes it possible to eliminate the reinforcing ribs, thereby improving the workability of the bolt fastening operation [Invention 5].

[0033] Furthermore, in the slurry pump 100 of this embodiment, the front surface of the front casing 11 is provided with lightening holes 26 (26a to 26d) along the circumferential direction, and the bolt fastening portion 18 and its vicinity are made thicker than other portions including the lightening holes 26 (26a to 26d). As a result, when a single worker is attaching or detaching the front casing 11, the lightening holes 26 (26a to 26d) of the front casing 11 function as gripping parts during maintenance work on the liquid-contacting parts, further improving the ease of maintenance work. Furthermore, at the four bolt fastening portions 18, the bolt fastening causes localized high stress, but according to the slurry pump 100 of this embodiment, the multiple bolt fastening portions 18 have a thicker structure than the hollowed-out portions 26 (26a to 26d) (in particular, the multiple bolt fastening portions 18 are flush with each other), so even though an aluminum alloy front casing 11 is used, it has excellent formability and can secure a sufficient cross-sectional modulus at key points [Invention 6].

[0034] Furthermore, in the slurry pump 100 of this embodiment, the front casing 11 is provided with a protruding portion 31 that protrudes in the axial direction on the back side of the clamping surface 30 that clamps the liner ear portion 9c of the rubber casing liner 9 from the front and rear in the axial direction. This more reliably suppresses deformation of the liner ear portion 9c in the direction in which the diameter expands, and ensures pressure resistance at key points even while using a front casing 11 made of aluminum alloy [Invention 7]. As for the entire casing liner 9, since the surface pressure can be distributed over the entire inner surface of the casing 1, the thickness of the front casing 11 can be made as thin as possible within the range where pressure resistance performance can be maintained.

[0035] Furthermore, in this type of slurry pump, during the assembly work of clamping the casing liner 9 from the front and rear in the axial direction, in order to maintain the storage position of the casing liner 9, it is necessary to tighten the casing bolt 14 and casing nut 15 of the bolt fastening portion 18 while pulling up the lifting portions 9d, 9e, 9f of the liner ear portion 9c. In contrast, in the slurry pump 100 of this embodiment, as described above, openings for pulling up and holding the pulled-up portions 9d, 9e, and 9f of the liner ear 9c are formed on the left and right upper sides in the direction of gravity between the multiple overhanging portions 31 (31a to 31d). In addition, the overhanging portions 31b, 31c, and 31d form walls that are separated by the four bolt fastening portions 18 and that support the pulled-up portions 9d, 9e, and 9f of the liner ear 9c at three locations circumferentially spaced apart from each other.

[0036] As a result, according to the slurry pump 100 of this embodiment, the casing liner 9 can be stably maintained in a stored position at the lower side in the direction of gravity during assembly of the casing 1. Furthermore, when the slurry pump 100 is operating with the front casing 11 in a usage position, the three protrusions 31b, 31c, and 31d function as liner holders, and act as ribs that suppress deformation of the casing liner 9 in the radial direction, thereby exhibiting the excellent effect of improving support rigidity [Invention 8].

[0037] Furthermore, in the slurry pump 100 of this embodiment, in other parts of the casing 1, which is a combination of dissimilar materials consisting of the back casing 12 and the front casing 11, an insulating sleeve is interposed along the axial direction of each bolt fastening portion 18, and an insulating washer is interposed on the contact surface of each bolt fastening portion 18, which is more suitable for preventing or suppressing electrolytic corrosion [first half of invention 9].

[0038] In the above embodiment, an example was shown in which an insulating sleeve or insulating washer was interposed in each bolted portion 18, but this is not limiting, and as long as it is possible to prevent or suppress galvanic corrosion at the joints of dissimilar materials, the surfaces of the casing bolts 14 that constitute each bolted portion 18 can be subjected to a surface treatment that includes a function of preventing galvanic corrosion, and insulating washers can be interposed on the abutting surfaces of each bolted portion 18 [Invention 9, latter part]. Also, the surface of the front casing 11 can be subjected to a surface treatment that includes a function of preventing galvanic corrosion [Invention 10].

[0039] As described above, according to the slurry pump 100 of this embodiment, the front casing 11 is made of an aluminum alloy, which improves the ease of maintenance of the liquid-contacting parts of the casing 1. It should be noted that the slurry pump according to the present invention is not limited to the above embodiment, and various modifications are possible without departing from the spirit of the present invention. [Explanation of symbols]

[0040] 1 casing 1a Intake port 1b Outlet 2 impellers 3 Shaft (rotating axis) 4 shaft sleeve 7 axis branches 8 frames 9 Casing liner 10 Gland packing 11 Front casing 12 Back casing 13 Bolts and nuts 14 Casing bolt (bolt fastening part) 15 Casing nut (bolt fastening part) 16 Fasteners 18 Bolt fastening part 21 Discharge flange 22 Bolt mounting groove 23 Meat Section 24 Auxiliary bolt fastening section 25 Neck 26 Cutout 27 Thick wall structure on outer circumference 28 Liner fastening part 29 Thick-walled structure of liner fastening part 30 Clamping surface 31 Overhang 32 Conical Surface 40 Annular rib 50 stuffing box 100 Slurry Pump

Claims

1. A slurry pump in which a rubber casing liner is installed inside the casing, The casing includes a back casing made of iron and a front casing made of aluminum alloy, The slurry pump is characterized in that the casing liner is sandwiched between the back casing and the front casing by a plurality of bolt fastening portions from the front and rear in the axial direction.

2. The discharge side flange of the front casing has bolt mounting grooves at three locations: the center and two on either side of the center.

2. The slurry pump according to claim 1, wherein the three bolt mounting grooves all extend in the same direction as the axial direction of the casing.

3. 3. A slurry pump according to claim 2, wherein said discharge flange is provided with padding portions having outer surfaces parallel to the extending direction of said grooves around the outer ends of the two bolt mounting grooves on the left and right.

4. 2. The slurry pump according to claim 1, wherein the front casing has a discharge side flange, and an auxiliary bolt fastening portion for an auxiliary bolt is provided at a neck portion of the discharge side flange.

5. 5. The slurry pump according to claim 4, wherein the neck portion of the discharge side flange does not have a reinforcing rib in a portion other than the auxiliary bolt fastening portion.

6. A recessed portion is formed in the front surface of the front casing in the axial direction along the circumferential direction of the casing, 2. The slurry pump according to claim 1, wherein the bolt fastening portions are formed so that their surfaces facing forward are flush with one another and are thicker in the axial direction than the recessed portion.

7. 2. The slurry pump according to claim 1, wherein the front casing has a protruding portion that protrudes in the axial direction on the back side of a clamping surface that clamps the liner ear portion of the casing liner together with the back casing from the front and rear in the axial direction.

8. 8. The slurry pump according to claim 7, wherein the front casing has openings formed on the left and right upper sides of the overhanging portion in the direction of gravity for lifting and holding liner ear portions of the casing liner.

9. 2. The slurry pump according to claim 1, wherein an insulating sleeve is interposed along the axial direction at each bolt fastening portion between the back casing and the front casing, and an insulating washer is interposed on the abutting surface of each bolt fastening portion, or wherein a surface treatment including an anti-corrosion function is applied to the surface of the casing bolt constituting each bolt fastening portion, and an insulating washer is interposed on the abutting surface of each bolt fastening portion.

10. 2. The slurry pump according to claim 1, wherein the surface of said front casing is subjected to a surface treatment including a function of preventing electrolytic corrosion.

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