Suction packing and pump equipped with same

Abstract

To provide a pump which is improved in maintenance performance.SOLUTION: A suction packing 40 of a pump 10 is interposed between opposing end faces of flange connection parts 24, Sj which oppose each other in a portion of a suction port 21k, and has a circular arc-shaped rubber-made seal main body part 41 sandwiched between the opposing end faces, and a posture holding part 43 hanging out to the inside of the suction port 21k rather than an inside end face of the seal main body part 41, and fit to the flange connection part 24 side.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a pump, and more particularly to a suction packing that is interposed between a flange connection portion of a suction pipe connected to a suction port of a casing and a flange connection portion on the pump side. [Background technology]

[0002] This type of pump includes an impeller having a plurality of blades and a casing that houses the impeller in a space defined within the casing (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2012-140875 Summary of the Invention [Problem to be solved by the invention]

[0004] In this type of pump, a suction packing is interposed between a flange connection portion of the casing provided with a suction port and a flange connection portion of the suction pipe connected thereto. However, in the case of a pump whose axis is arranged horizontally, when assembling the flange connection parts, there is a problem in that the suction packing in a temporarily installed state is likely to come off when tightening multiple bolts to secure the flange connection parts to each other, and the installed position of the suction packing is likely to shift.

[0005] Therefore, the present invention has been made with an eye on such problems, and its object is to provide a suction packing and a pump equipped with the same that can perform the assembly work of the flange connection parts between the suction port of the casing and the suction pipe more safely and smoothly, thereby improving maintainability. [Means for solving the problem]

[0006] In order to solve the above problems, one aspect of the present invention provides a suction packing that is used in a pump having a casing with a flange connection portion where a suction port is provided in the center of a cylinder whose axis is arranged horizontally, and is interposed between the flange connection portion of the casing and the flange connection portion of the suction pipe that is detachably connected opposite the suction port, and is characterized by having: a ring-shaped rubber seal main body that is sandwiched between the end faces of the opposing flange connection portions when interposed; and a posture retaining portion that protrudes from the inner end face of the seal main body toward the suction port and is fitted into the flange connection portion of the casing when interposed.

[0007] In addition, in order to solve the above-mentioned problems, a pump according to one aspect of the present invention is a pump having a casing with a flange connection part with a suction port provided in the center of the cylinder, the axis of the flange connection part being arranged horizontally, and characterized in that it is equipped with a suction packing according to one aspect of the present invention as a suction packing interposed between the flange connection part of the casing and the flange connection part of a suction pipe connected to the flange connection part. [Effects of the Invention]

[0008] According to the present invention, the suction packing is provided with a position-maintaining portion that is fitted into the flange connection portion of the casing when the packing is installed, thereby improving the maintainability of the pump. [Brief explanation of the drawings]

[0009] [Figure 1] 1 is an explanatory diagram of a centrifugal pump according to a first embodiment of a pump according to an aspect of the present invention, showing a cross section taken along an axis. [Figure 2] 1A and 1B are explanatory views of a first embodiment of a suction packing according to one aspect of the present invention, in which FIG. 1A is a cross-sectional view taken along the axis, and FIG. 1B is a right side view of FIG. 1A. [Figure 3] 1 is an explanatory diagram of a mounted state of a first embodiment of a suction packing according to an aspect of the present invention. FIG. [Figure 4]10A and 10B are explanatory diagrams of a modified example (first modified example) of the attitude maintaining section in the first embodiment, in which FIG. 10A is a cross-sectional view along the axis, and FIG. 10B is a right side view of FIG. [Figure 5] 10A and 10B are explanatory diagrams of a modified example (second modified example) of the attitude maintaining section in the first embodiment, in which FIG. 10A is a cross-sectional view along the axis, and FIG. 10B is a right side view of FIG. [Figure 6] 10A and 10B are explanatory diagrams of a second embodiment of a suction packing according to an aspect of the present invention and its installed state. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, embodiments 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 relationships and ratios between thickness and planar dimensions may differ from the actual ones, and the drawings may also include portions where the relationships and ratios between dimensions differ. Furthermore, the embodiments described below are intended to exemplify devices and methods for embodying the technical concept of the present invention, and the technical concept of the present invention does not limit the materials, shapes, structures, arrangements, etc. of the components to the embodiments described below.

[0011] [First embodiment] As shown in Figure 1, a pump 10 of the first embodiment includes a frame 2, a housing (bearing housing) 3 mounted and fixed on the upper part of the frame 2, and a casing 20 fixed to the front side of the frame 2. The housing 3 rotatably supports a drive shaft 1 whose axis is arranged horizontally. The housing 3 is fixed to a predetermined position on the frame 2 by two housing holders 7 at the front and rear.

[0012] A tip end 1s of the drive shaft 1 projects from the center of the back surface of the casing 20 into the interior of the casing 20, and an impeller 8 is cantilevered on the tip end 1s of the drive shaft 1 and is housed in a defined space within the casing 20. A shaft seal device 4 is disposed on the axial back side of the impeller 8 between the casing 20 and the housing 3 so as to surround the drive shaft 1. The base end side of the drive shaft 1 projects rearward from the rear end of the housing 3, and this projecting portion is connected to the output shaft of a motor (not shown) so as to be able to transmit driving force.

[0013] The casing 20 of the first embodiment is divided into three parts at appropriate locations along a plane perpendicular to the drive shaft 1, and is configured to have, in order from the front side in the axial direction (the left side in the figure), an intake cover 21, a casing main body 22, and a casing side wall portion 23. The intake cover 21, the casing main body 22, and the casing side wall portion 23 are detachably fixed to one another in the axial direction around the periphery of the divided surface using a plurality of bolts and nuts.

[0014] In the casing 20 of this embodiment, the suction portion 5 is provided on the axial front side of the impeller 8, and the discharge portion 6 is provided radially above the impeller 8. The discharge portion 6 is provided at the center of the upper part of the casing main body 22, so that the fluid F is sucked in through the suction portion 5 by the rotation of the impeller 8 and discharged from the discharge portion 6.

[0015] The suction unit 5 of this embodiment has an suction port 21k in the center of the suction cover 21. The suction port 21k faces the tip 1s of the drive shaft 1, and its cylindrical inner circumferential surface 21n is formed coaxially with the drive shaft 1. In the present embodiment, a flange connection portion 24 that protrudes radially in an annular shape is formed around the front end of the suction port 21k in the suction cover 21. In addition, a convex annular inner edge step portion 25 is formed on the front end surface of the flange connection portion 24 of the suction cover 21.

[0016] 3, in the casing 20 of the first embodiment, the suction pipe S is connected to the flange connection portion 24 at the front end of the suction port 21k of the suction cover 21, and a substantially annular suction packing 40 is interposed between the opposing surfaces of the flange connection portion Sj of the suction pipe S and the flange connection portion 24 of the suction cover 21. The flange connection portion 24 and the flange connection portion Sj of the suction pipe S are detachably fixed around their peripheries using a plurality of bolts and nuts (not shown).

[0017] As shown in Figures 2 and 3, the suction packing 40 of the first embodiment has a circular rubber seal body 41 and a posture retaining portion 43 that is formed integrally with the seal body 41 and protrudes further inward than the side end face of the seal body 41 toward the inside of the suction port 21k. The seal body 41 is an annular portion that is sandwiched between the end faces of the flange connection portion 24 and the opposing flange connection portion Sj of the suction pipe S when installed. Both surfaces of the seal body 41 form sealing surfaces 41a, 41b when installed (see FIG. 2).

[0018] When the posture maintaining portion 43 is installed, as shown in Figure 3, it is arranged so as to protrude radially toward the suction port 21k beyond the side end face of the seal main body portion 41, and also so as to protrude axially downstream of the suction port 21k. As a result, the attitude maintaining part 43 is configured to be insertable into the inner peripheral surface 21n of the suction port 21k of the suction cover 21. In other words, the attitude maintaining part 43 is provided in a portion that comes into contact with the liquid in the flow path after assembly.

[0019] 2, outer surface 43s of attitude maintaining portion 43 is provided in a cylindrical shape that is inserted into the inner circumferential surface of suction port 21k of suction cover 21 and fitted into inner circumferential surface 21n of suction port 21k. The dimensions of outer surface 43s of attitude maintaining portion 43 are controlled so that the temporary placement state fitted into inner circumferential surface 21n of suction port 21k is maintained. Furthermore, an inner surface 43n of the attitude maintaining portion 43 is provided in a truncated cone shape from the axial rear side to a substantially central position, the diameter of which increases toward the downstream side of the suction port 21k of the suction cover 21. The portion axially forward of the truncated cone-shaped inner surface 43n is formed as a cylindrical surface 43p.

[0020] Next, the installation procedure and the effects of the pump 10 shown in the first embodiment will be described. In the pump 10 shown in the first embodiment, when assembling the flange connection portion 24 of the suction port 21k on the casing 20 side with the flange connection portion Sj of the suction pipe S, first, the posture-maintaining portion 43 of the suction packing 40 is inserted into the inner surface 21n of the suction port 21k from the front in the axial direction relative to the flange connection portion 24, and is placed in a temporary position where it is fitted into the inner surface 21n of the suction port 21k.

[0021] Next, in this temporarily placed state, the flange connection portion Sj of the suction pipe S is held facing the flange connection portion 24 and detachably fixed using a plurality of bolts and nuts (not shown). As a result, the suction packing 40 has both sealing surfaces 41a, 41b of the seal body 41 sandwiched between them, thereby exerting the required sealing function.

[0022] During this assembly work, reducing the time required for disassembly and assembly of the flange connection portion 24, Sj, with the suction pipe S has a significant impact on maintainability. In contrast, according to the suction packing 40 of the first embodiment, as shown in Figures 2 and 3, the cylindrical attitude maintaining portion 43 protrudes further toward the suction port 21k than the side end face of the seal main body 41, and is formed so as to be insertable into the inner circumferential surface 21n of the suction port 21k of the suction cover 21. As a result, with the suction packing 40 temporarily placed on the inner circumferential surface 21n of the suction port 21k of the suction cover 21 as shown in Figure 3, this attitude maintaining portion 43 improves the ability to prevent it from falling off during temporary placement.

[0023] Therefore, according to the suction packing 40 of the first embodiment and the pump 10 of the first embodiment equipped with the same, the assembly work of the flange connection portions between the suction port 21k of the casing 20 and the suction pipe S can be carried out more safely and smoothly, thereby improving maintainability.

[0024] Furthermore, according to the suction packing 40 of the first embodiment, even if there is eccentricity between the inner peripheral surface 21n of the suction port 21k and the attitude maintaining portion 43 of the suction packing 40, there is no particular restriction on the radial installation position of the seal main body 41. Therefore, when temporarily placing the suction packing 40, the attitude maintaining portion 43 can be easily inserted, and the attitude of the suction packing 40 in temporary placement can be easily maintained by smoothly inserting the attitude maintaining portion 43 from the axial front.

[0025] After the flange connection parts are assembled, the attitude maintaining part 43 will be located inside the pump flow path, so a material that will not cause any problems when in contact with the corresponding fluid should be selected. Furthermore, in the suction packing 40 of the first embodiment, the inner surface of the attitude maintaining part 43 is formed in a truncated cone shape that widens toward the downstream side of the suction port 21k of the casing 20, which is suitable for minimizing obstruction to the flow of the pumped fluid.

[0026] Furthermore, when transferring a fluid containing a slurry or the like, it is conceivable that the attitude-maintaining portion 43 may wear out and be lost, but the function and effect of the attitude-maintaining portion 43 of the first embodiment is to improve the ease of assembling the flange connecting portions together. Therefore, there is no problem even if the attitude-maintaining portion 43 is worn out by operation of the pump after the flange connecting portions are assembled.

[0027] The suction packing or pump according to the present invention is not limited to the first embodiment described above, and it goes without saying that various modifications are possible without departing from the spirit of the present invention. In other words, the posture-maintaining portion of the present invention protrudes from the inner end face of the seal body toward the suction port, and can be fitted into the flange connection portion during bolt tightening work, and various configurations can be adopted as long as they can maintain the posture of the suction packing in a temporarily installed state.

[0028] For example, in a first modified example shown in Fig. 4, one or more slits 48 are formed along the axial direction in the attitude maintaining portion 43 of the suction packing 40A. The attitude maintaining portion 43 of the first modified example has a plurality of slits 48 (in this example, two slits at positions opposite each other in the radial direction) formed along the axial direction, spaced apart in the circumferential direction of the protruding cylindrical shape. With this configuration, for example, the insertability of the attitude maintaining portion 43 is improved when there is misalignment.

[0029] Furthermore, for example, in the first embodiment described above, the position maintaining portion 43 is formed in an annular shape and is integrally formed with the seal main body 41, but this is not limiting. For example, the position maintaining portion 43 may be a component separate from the seal main body 41. In a second modified example shown in Fig. 5, the position maintaining portion is made up of a plurality of metal claws.

[0030] As shown in the same figure, in the second modified suction packing 40B, the posture maintaining portion 43 is formed into an approximately L-shape in side view from a metal plate member that is a separate part from the seal main body portion 41, and is provided in two locations, above and below the seal main body portion 41. Each of the posture maintaining portions 43 has a substantially L-shaped base end portion 43b on one side and an insertion portion 43a extending axially on the other side. As in the first embodiment, the insertion portion 43a is formed so as to be insertable into the inner circumferential surface 24n of the suction port 24. Each of the position-maintaining portions 43 is disposed at two radially opposing locations, spaced apart, and has its base end 43b fitted into and vulcanized bonded to the inner circumferential surface of the seal main body 41. As a result, the insertion portion 43a is provided along the inner circumferential surface of the seal main body 41 and protrudes further inward into the suction port 24 than the end face of the seal main body 41. Therefore, the position-maintaining portions 43 also improve the ability to prevent the seal from falling off during temporary placement.

[0031] Furthermore, the posture maintaining unit according to the present invention is not limited to being inserted into the inner peripheral surface of the suction port, and various other configurations can be adopted as long as it is fitted into the flange connection side of the casing when interposed. A second embodiment will be described below. Note that the following description will focus on differences from the first embodiment, and descriptions of the same or similar configurations will be omitted.

[0032] [Second embodiment] As shown in FIG. 6, the suction packing 140 of the second embodiment is composed of a ring-shaped rubber seal body 141 and a ring-shaped protrusion 142 formed integrally with the seal body 141.

[0033] On the other hand, the suction cover 121 of the second embodiment has an suction port 121k in its center, and its cylindrical inner peripheral surface 121n is formed coaxially with the drive shaft. A flange connection portion 124 that protrudes radially in an annular shape is formed around the front end of the suction port 121k. In this second embodiment, an inner edge step portion 125 formed by a concave annular groove is formed on the flange connection portion 124 side in a position axially opposite the annular protrusion 142 that serves as a posture maintaining portion.

[0034] When assembling the suction pipe S using the suction packing 140 of the second embodiment, as shown in the same figure, the annular convex portion 142 of the suction packing 140 is used as a posture maintaining portion, and is fitted from the axial front into the concave annular inner edge step portion 125 formed on the flange connection portion 124, placing the suction packing 140 in a temporary placement state, and the flange connection portion Sj of the suction pipe S can be opposed in this temporary placement state to perform the assembly work. This improves the ability to prevent the suction packing 140 from falling off during temporary placement, according to the second embodiment, which is temporarily placed at the front end of the suction port 121k of the suction cover 121. Therefore, according to the suction packing 140 of the second embodiment and the pump including the same, as in the first embodiment, the assembly work of the flange connecting portions can be performed more safely and smoothly, improving maintainability. In addition, as with the modified example of the first embodiment, the annular convex portion 142, which is the posture maintaining portion in the second embodiment, can of course be constructed from separate parts, or the annular convex portion 142 can be provided with a slit along its axial direction or with a divided structure, as well.

[0035] However, in the second embodiment, if the main focus is on stabilizing the temporary placement state of the suction packing 140 at the flange connection portion 124 of the suction cover 121, it is sufficient to increase the depth L2 of the inner edge step portion 125 of the suction cover 121, as shown by the dashed line above the center line in the same figure. However, if this depth L2 is increased, the thickness M2 of the flange connection portion 124 will become thinner accordingly.

[0036] Therefore, the strong force acting when the flanges are fastened to each other increases the risk of the flange connection portion 124 breaking from the corner of the inner edge step portion 125, so in the second embodiment, there is a problem that the depth L2 of the inner edge step portion 125 cannot be made too deep. Also, there is a problem that increasing the thickness M2 of the flange connection portion 124 itself increases the size of the device.

[0037] On the other hand, in the second embodiment, if the focus is on the strength of the flange connection portion 124 of the suction cover 121, by making the depth L2 of the inner edge step 125 of the suction cover 121 shallow, it is possible to maintain the size of the device while also ensuring the thickness M2 of the flange connection portion 124. However, in this case, as shown below the center line in the figure, the axial fitting length between the annular protrusion 142 of the suction packing 140 and the inner edge step 125 becomes shorter. This reduces the installation stability of the suction packing 140 in a temporary placement state, which causes a problem of reduced maintainability during assembly work.

[0038] In contrast, according to the suction packing 40 of the first embodiment described above, as shown in Figures 2 and 3, the cylindrical posture-maintaining portion 43 protrudes further toward the suction port 21k than the side end face of the seal main body, and is formed so that it can be inserted into the inner surface 21n of the suction port 21k of the suction cover 21.

[0039] As a result, with the configuration of the first embodiment, as shown in Figure 3, it is not necessary to process the inner edge step 125 itself as in the second embodiment for the suction cover 21, which eliminates strength issues such as breakage at this step and problems such as the device becoming larger.In addition, the suction packing 40, which is temporarily placed on the inner surface 21n of the suction port 21k, can be prevented from falling off during temporary placement by this posture maintaining portion 43.

[0040] In this way, according to the suction packing 40 of the first embodiment, the stability of the suction packing 40 in a temporary placement state is improved, thereby significantly improving the ease of axial assembly, and it is not necessary to process the suction cover 121 end face with the recessed inner edge step 125 as shown in the second embodiment, which makes it possible to ensure the necessary thickness of the flange connection portion 24 and provide the necessary strength while maintaining the equipment compact. [Explanation of symbols]

[0041] 1 drive shaft 2 frames 3 Housing (bearing box) 4 Shaft sealing device 5. Intake section 6 Discharge part 7 Housing holder 8 impeller 10 Pump 20 Casing 21 Intake cover 21k Intake port (of intake cover) 21n Inner surface (of suction port) 22 Casing body 23 Casing side wall 24 Flange connection 24n Inner surface 25 Inner edge step 40 Suction packing 41 Seal body 41a, 41b sealing surfaces 43 Posture holding part 43n inner surface 43s exterior 125 Inner edge step 140 Suction packing 141 Seal body 142 Annular convex part F fluid M1 wall thickness M2 wall thickness S suction pipe Sj flange connection

Claims

1. A suction packing is used in a pump having a casing with a flange connection part having a suction port provided at a cylindrical center part whose axis is horizontally disposed, and is interposed between the flange connection part of a suction pipe detachably connected opposite the suction port and the flange connection part of the casing having a concave annular groove, a rubber seal body having an annular shape that is sandwiched between the end faces of the opposing flange connection portions when the flange connection portions are interposed; a position-retaining portion that protrudes in an annular shape from the outer end surface of the seal body toward the flange connection portion of the casing and is fitted into an inner edge step portion of the concave annular groove when the seal body is installed; A suction packing characterized by having:

2. A pump having a casing with a flange connection part having a suction port at a cylindrical center, the axis of the flange connection part being horizontally disposed, 2. A pump comprising the suction packing according to claim 1 as a suction packing interposed between a flange connection portion of the casing and a flange connection portion of a suction pipe connected to the flange connection portion.

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