pump

Abstract

To disclose one example of a pump which can withstand a load by a self weight of an electric motor in addition to an inner pressure.SOLUTION: A plate 25 is provided with a plurality of first wall-like ribs 27 connected to an outer periphery of an attachment flange 26 and extending toward an outer periphery side of the plate 25. The first wall-like ribs 27 are configured such that a rib height H on the attachment flange 26 is larger than a rib height H on the outer periphery side. With this configuration, in the casing, the plate 25 to which a motor part is installed is reinforced by the plurality of first wall-like ribs 27. Further, the first wall-like ribs 27 are configured such that a rib height H on the attachment flange 26 is larger than a rib height H on the outer periphery side, and connected to the outer periphery of the attachment flange 26 and extending toward the outer periphery side of the plate 25, thereby enabling effective reinforcement of the plate 25.SELECTED DRAWING: Figure 5

Description

Technical Field

[0006] , , , ,

[0001] The present disclosure relates to a pump driven by an electric motor.

Background Art

[0002] For example, in the pump described in Patent Document 1, a plurality of ribs extending radially are provided on the casing body. Note that the casing body refers to a portion where a fluid suction port is provided.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] The casing that houses the impeller usually includes the above-described casing body and a cover or the like fixed to the casing body. The cover is provided with a mounting flange portion to which an electric motor can be mounted. Therefore, in addition to the pressure generated during the rotation of the impeller (hereinafter referred to as internal pressure), a load due to the weight of the electric motor acts on the cover.

[0005] In view of the above points, the present disclosure discloses an example of a pump that can withstand a load due to the weight of an electric motor in addition to internal pressure.

Means for Solving the Problems

[0006] The pump preferably includes at least one of the following constituent elements, for example. In other words, the constituent elements are an impeller (21) rotated by an electric motor (10), and a casing (22) that houses the impeller (21), the casing (22) having a casing body (23) provided with an intake port (23A), a cover plate (25) positioned on the opposite side of the casing body (23) from the impeller (21) and fixed to the casing body (23), and a mounting provided on the center side of the cover plate (25) and positioned at a location offset from the cover plate (25) toward the electric motor (10). The flange portion (26) comprises an annular mounting flange portion (26) on which the electric motor (10) can be mounted, and a plurality of wall-shaped ribs (27) provided on the cover plate (25), the plurality of wall-shaped ribs (27) connected to the outer circumference of the mounting flange portion (26) and extending toward the outer circumference of the cover plate (25), the electric motor (10) being positioned on the opposite side of the cover plate (25) from the casing body (23), and the rib height (H) on the mounting flange portion (26) side being greater than the rib height (H) on the outer circumference side. The rib height (H) refers to the dimension of the outer dimensions of the wall-shaped ribs (27) in the portion parallel to the central axis (Lo) of the impeller (21).

[0007] As a result, in the casing, the cover plate (25) on which the electric motor (10) is mounted is reinforced by multiple wall-like ribs (27). Moreover, the rib height (H) on the mounting flange portion (26) side of these wall-like ribs (27) is greater than the rib height (H) on the outer circumference side of the cover plate (25), and they are connected to the outer circumference of the mounting flange portion (26) and extend toward the outer circumference side of the cover plate (25), making it possible to effectively reinforce the cover plate (25).

[0008] Incidentally, the symbols in each of the parentheses above are just examples showing the correspondence with the specific configurations etc. described in the embodiments described later, and this disclosure is not limited to the specific configurations etc. indicated by the symbols in the parentheses above. [Brief explanation of the drawing]

[0009] [Figure 1]This is a diagram showing the structure of the pump according to the first embodiment. [Figure 2] This is an exploded perspective view of the pump according to the first embodiment. [Figure 3] This is a diagram showing a coverput according to the first embodiment. [Figure 4] This is a diagram showing a coverput according to the first embodiment. [Figure 5] This is a diagram showing a coverput according to the first embodiment. [Figure 6] This figure shows the structure of the coverput according to the first embodiment. [Figure 7] This is a diagram showing a coverput according to the first embodiment. [Figure 8] This figure shows a coverput according to the second embodiment. [Figure 9] This is a diagram showing a coverput according to the third embodiment. [Modes for carrying out the invention]

[0010] The following "Embodiments of the Invention" are examples of embodiments that fall within the technical scope of this disclosure. In other words, the features defining the invention as described in the claims are not limited to the specific configurations and structures shown in the embodiments below.

[0011] The arrows and diagonal lines indicating direction in each figure are included to facilitate understanding of the relationships between the figures and the shapes of each component or part. Therefore, the inventions shown in this disclosure are not limited to the directions indicated in each figure.

[0012] At least one of the components or parts described with reference numerals is provided unless otherwise specified, such as "one". In other words, if there is no such specification, such as "one", there may be two or more such components. The pumps shown in this disclosure include at least one of the components, such as the components or parts described with reference numerals, and at least one of the illustrated structural parts.

[0013] (First Embodiment) <1. Overview of the pump> In this embodiment, an example of the pump according to the present disclosure is applied to an electric pump for water supply. As shown in FIG. 1, the pump 1 includes at least a motor unit 10 and a pump unit 20. The motor unit 10 is composed of an electric motor such as an electric motor.

[0014] <Pump unit> As shown in FIG. 2, the pump unit 20 includes at least an impeller 21 and a casing 22. The impeller 21 is an impeller that is rotationally driven by the motor unit 10. The impeller 21 is directly connected to the output shaft 11 of the motor unit 10.

[0015] As shown in FIG. 1, the pump 1 according to this embodiment is installed such that the central axis Lo of the output shaft 11 and the impeller 21 substantially coincides with the horizontal direction. Then, after the pump unit 20 sucks fluid from a direction parallel to the central axis Lo, the sucked fluid is discharged in a direction perpendicular to the central axis Lo.

[0016] The casing 22 houses the impeller 21. The casing 22 has at least a casing main body 23 and a casing cover 24 (hereinafter abbreviated as cover 24). The cover 24 is fixed to the casing main body 23 by a plurality of bolts B1 (see FIG. 2).

[0017] As shown in FIG. 1, at least a fluid suction port 23A is provided in the casing main body 23. In the pump unit 20 according to this embodiment, the center of the suction port 23A is set at a position higher than the central axis Lo.

[0018] Thereby, when the impeller 21 rotates, a self - suction force is generated by the priming water filled in the casing 22. The priming water injection port 24C is provided at the upper part of the casing main body 23 (in this embodiment, near the discharge port 23B).

[0019] The cover 24 is positioned on the opposite side of the casing body 23 from the impeller 21 and is fixed to the casing body 23 with multiple bolts B1. The cover 24 works in cooperation with the casing body 23 to form a space for housing the impeller 21.

[0020] <2. Cover Details> As shown in Figure 3, the cover 24 includes at least a cover plate 25, a first wall-like rib 27, a connecting rib 28, an outer peripheral rib 29, a second wall-like rib 30, a nut portion 31, a fastening flange portion 32, and a leg portion 33.

[0021] In this embodiment, the cover 24 is a single-piece product in which the cover plate 25, first wall-shaped rib 27, connecting rib 28, outer peripheral rib 29, second wall-shaped rib 30, nut portion 31, fastening flange portion 32, and leg portion 33 are integrally molded from an iron-based metal such as FC material.

[0022] <2.1 Cover Plate> The cover plate 25 (hereinafter abbreviated as plate 25) is a part configured in a roughly disc shape. A shaft hole 25A is provided on the center side of the plate 25. The shaft hole 25A is a through hole into which the output shaft 11 is inserted.

[0023] Furthermore, a bulge 25B is provided in the portion of the plate 25 where the shaft hole 25A is located. The bulge 25B is a portion that bulges out from the substantially disc-shaped surface of the plate 25 in the direction of the central axis Lo (towards the motor section 10 in this embodiment) (see Figure 1).

[0024] The shaft hole 25A is formed at the most protruding point in the direction of the central axis Lo. The gap between the shaft hole 25A and the output shaft 11 is sealed by a shaft sealing device (not shown), such as a mechanical seal. This shaft sealing device is assembled so as to be in contact with the impeller 21 side of the protruding portion 25B.

[0025] <2.2 Mounting flange section> The mounting flange portion 26 is an annular portion on which the motor portion 10 can be mounted. As shown in Figure 5, the mounting flange portion 26 is located offset from the plate 25 towards the motor portion 10 side (to the right in Figure 5).

[0026] In other words, the electric motor 10 is positioned on the opposite side of the casing body 23, with the plate 25 in between. Therefore, the mounting flange portion 26 is located on the opposite side of the casing body 23, with the plate 25 in between, that is, in a position shifted toward the motor portion 10 relative to the plate 25.

[0027] In this embodiment, the mounting flange portion 26 is further offset towards the motor portion 10 than the bulging portion 25B (see Figure 1). The mounting flange portion 26 is provided with a plurality of bolt holes 26A (see Figure 5). These bolt holes 26A are through holes into which bolts (not shown) that fix the motor portion 10 are inserted.

[0028] <2.3 First Wall-like Rib> The plate 25 is provided with a plurality of first wall-like ribs 27. Each of these plurality of first wall-like ribs 27 is a wall-like portion that extends radially from the side of the shaft hole 25A, that is, from the center side of the plate 25, toward the outer circumference of the plate 25, as shown in Figure 4.

[0029] Each first wall-like rib 27 is connected to the outer circumference of the mounting flange portion 26, as shown in Figure 3. Furthermore, each first wall-like rib 27 is configured such that the rib height H on the mounting flange portion 26 side is greater than the rib height H on the outer circumference side, as shown in Figure 5.

[0030] Specifically, each first wall-shaped rib 27 is configured such that the ridge portion 27A of the first wall-shaped rib 27 substantially coincides with the straight line connecting the mounting flange portion 26 and the nut portion 31. Therefore, the height H of each rib increases linearly as it approaches the mounting flange portion 26.

[0031] The rib height H of the first wall-like rib 27 refers to the dimension of the portion of the first wall-like rib 27 parallel to the central axis Lo. The ridge portion 27A refers to the portion where the tops of the first wall-like rib 27 are connected. The top of the first wall-like rib 27 refers to the end of the first wall-like rib 27 that is opposite to the plate 25.

[0032] <2.4 Connecting Ribs> As shown in Figures 4 and 5, the connecting rib 28 is a portion that connects two first wall-shaped ribs 27 that are adjacent in the rotational direction of the impeller 21, the mounting flange portion 26, and the plate 25 from among a plurality of first wall-shaped ribs 27.

[0033] In this embodiment, multiple connecting ribs 28 are provided. Each connecting rib 28 is a curved plate-like (for example, tile-like) portion that connects two adjacent first wall-like ribs 27, the mounting flange portion 26, and the plate 25 with a curved surface.

[0034] Furthermore, as shown in Figure 4, a window portion 28A is provided between two adjacent connecting ribs 28 in the direction of rotation of the impeller 21. In other words, the window portions 28A and the connecting ribs 28 are arranged alternately in that direction of rotation.

[0035] Each window section 28A is an opening that allows the side of the connecting rib 28 facing the shaft hole 25A (hereinafter referred to as the back surface of the connecting rib 28) and the second wall-like rib 30 to be visible, while also preventing the space around the shaft hole 25A from becoming sealed.

[0036] <2.5 Outer Rib> As shown in Figure 6, the outer peripheral rib 29 is provided on the outer periphery of the plate 25. The outer peripheral rib 29 is an annular projection that extends around the entire circumference of the plate 25 at its outermost edge.

[0037] <2.6 Second Wall-like Rib> The second wall-like rib 30 is a wall-like portion that extends from the first wall-like rib 27 toward the shaft hole 25A side, that is, toward the output shaft 11 side. In this embodiment, multiple second wall-like ribs 30 are provided. Note that the number of second wall-like ribs 30 is less than the number of first wall-like ribs 27 (see Figure 7).

[0038] Specifically, in this embodiment, among the plurality of first wall-like ribs 27, the first wall-like ribs 27 whose angle θ1 (see Figure 7) between the extension direction of the first wall-like rib 27 and the vertical direction is less than or equal to a predetermined angle (for example, 45 degrees) extend to form the second wall-like rib 30.

[0039] <2.6 Nut section> In this embodiment, the nut portions 31 are provided on the outer circumference of the plate 25 in the same number as the bolts B1. Each nut portion 31 is a cap nut-shaped part that connects to the male threaded portion (not shown) of the corresponding bolt B1.

[0040] A cap nut is a nut in which the female threaded hole does not go all the way through, as shown in, for example, "JIS B 1183". Each nut portion 31 is integrated with the plate 25. Therefore, each nut portion 31 does not have a part corresponding to a hexagonal nut.

[0041] Each first wall-like rib 27 extends to the nut portion 31 and is connected to the nut portion 31 (see Figure 6). In other words, the ridge portion 27A of the first wall-like rib 27 linearly connects the mounting flange portion 26 and the nut portion 31.

[0042] <2.6 Fastening Flange Section> The fastening flange portion 32 is an annular portion (the roughly shaded area in Figure 7) provided on the outer circumference of the plate 25. The fastening flange portion 32 is configured in an annular shape to connect adjacent nut portions 31 in the rotational direction of the impeller 21.

[0043] In this embodiment, the outer peripheral rib 29 is also configured in an annular shape on the outer peripheral side of the plate 25. Therefore, in this embodiment, adjacent nut portions 31 are connected via the outer peripheral rib 29 and the fastening flange portion 32.

[0044] <2.7 Legs> As shown in Figure 7, the leg portions 33 are provided on the lower end side of the plate 25 and are for supporting and fixing the casing 22. Specifically, the leg portions 33 are provided on the plate 25 at symmetrical lower positions on either side of the vertical line L1. The vertical line L1 is a hypothetical vertical line passing through the center of the shaft hole 25A.

[0045] Each leg portion 33, as shown in Figure 6, is composed of a horizontal plate-shaped fixing portion 33A and a vertical plate-shaped connecting portion 33B, etc. The fixing portion 33A and the outer peripheral rib 29 are offset in the vertical direction. The connecting portion 33B connects the fixing portion 33A and the outer peripheral surface of the outer peripheral rib 29. The two leg portions 33 are symmetrical with respect to the vertical line L1.

[0046] Of the multiple first wall-like ribs 27, two first wall-like ribs (hereinafter referred to as third wall-like ribs 27B) extend toward the leg portion 33. Each third wall-like rib 27B is connected to the corresponding leg portion 33. In this embodiment, each third wall-like rib 27B is connected to the ends of each leg portion 33 that face each other, that is, the ends that face the imaginary vertical line L1.

[0047] Specifically, as shown in Figure 6, the third wall-shaped rib 27B is connected to the fixing portion 33A and the nut portion 31. Therefore, the third wall-shaped rib 27B is also connected to the outer peripheral rib 29 and the fastening flange portion 32 via the nut portion 31. Furthermore, the third wall-shaped rib 27B is connected to the connecting rib 28 and the fixing portion 33A so as to traverse the upper surface of the nut portion 31 on the motor portion 10 side.

[0048] In this embodiment, the second wall-shaped rib 30 is provided at a position symmetrical to the second wall-shaped rib 30 extending from the third wall-shaped rib 27B, with respect to the central axis Lo of the shaft hole 25A. In other words, in this embodiment, two second wall-shaped ribs 30 are provided, and these second wall-shaped ribs 30 are provided in a substantially straight line with respect to the central axis Lo.

[0049] <3. Features of the pump (especially the casing) according to this embodiment> The plate 25 is provided with a plurality of first wall-like ribs 27 that are connected to the outer circumference of the mounting flange portion 26 and extend toward the outer circumference of the plate 25. The rib height H on the mounting flange portion 26 side of these first wall-like ribs 27 is greater than the rib height H on the outer circumference side.

[0050] As a result, in the casing 22, the plate 25 on which the motor unit 10 is mounted is reinforced by a plurality of first wall-like ribs 27. Moreover, the rib height H on the mounting flange portion 26 side of these first wall-like ribs 27 is greater than the rib height H on the outer circumference side, and they are connected to the outer circumference of the mounting flange portion 26 and extend toward the outer circumference of the plate 25, making it possible to effectively reinforce the plate 25.

[0051] The impeller 21 includes two adjacent first wall-shaped ribs 27 from among the multiple first wall-shaped ribs 27, a mounting flange portion 26, and a connecting rib 28 that connects the plate 25. This can further improve the rigidity of the plate 25.

[0052] The outer circumference of the plate 25 is provided with an outer circumference rib 29, which is composed of protruding ridges that extend around the entire outer circumference of the plate 25. This can further improve the rigidity of the plate 25.

[0053] The plate 25 is provided with a second wall-like rib 30 extending from the first wall-like rib 27 toward the output shaft 11 side of the motor section 10. This can further improve the rigidity of the plate 25. In particular, in a configuration where the central axis Lo is set to substantially coincide with the horizontal direction, if the second wall-like rib 30 is provided in the vertical direction, it can effectively counteract the moment due to the weight of the motor section 10 acting on the mounting flange section 26.

[0054] The outer circumference of the first wall-like rib 27 extends to the nut portion 31 and is connected to the nut portion 31. This can further improve the rigidity of the plate 25. The outer circumference of the plate 25 is provided with an annular fastening flange portion 32 that connects adjacent nut portions 31 in the rotational direction of the impeller 21. This can further improve the rigidity of the plate 25.

[0055] The third wall-like rib 27B extends toward the leg portion 33 and is connected to the leg portion 33. This can further improve the rigidity of the plate 25. Therefore, it can effectively counteract the moment caused by the weight of the motor portion 10 acting on the mounting flange portion 26.

[0056] A window portion 28A is provided to allow visibility of the back surface of the connecting rib 28 and the second wall-like rib 30. This allows the manufacturing personnel to visually confirm the back surface of the connecting rib 28 and the second wall-like rib 30 through the window portion 28A when the casting process of the plate 25 is completed.

[0057] Furthermore, for example, electrical wiring for electrical components can be routed to the outside through the opening of one window section 28A, through the space around the shaft hole 25A, and through the other window section 28A. Furthermore, the wall portion of the second wall-like rib 30, which is partially inclined, has the function of guiding the wiring. In addition, wiring can be passed through the inclined, cut-out space, straddling the second wall-like rib 30.

[0058] Each connecting rib 28 is connected to the mounting flange portion 26. This can suppress the need for a large core mold in the area where a core mold for casting is required, that is, the core mold that constitutes the space on the plate 25 side of the mounting flange portion 26.

[0059] Each nut portion 31 is a cap nut. As a result, the male thread of the bolt B1 is covered by the nut portion 31, which suppresses the progression of corrosion of the male thread compared to a configuration in which the male thread is directly exposed to the atmosphere such as the outside air.

[0060] (Second Embodiment) In the above-described embodiment, the "other first wall-shaped ribs 27" among the plurality of first wall-shaped ribs 27, excluding the third wall-shaped rib 27B, were indirectly connected to the outer peripheral rib 29 via the nut portion 31.

[0061] In contrast, the "other first wall-like rib 27" according to this embodiment, as shown in Figure 8, extends to the outer peripheral rib 29 and is directly connected to the outer peripheral rib 29, similar to the third wall-like rib 27B.

[0062] Note that components identical to those in the above-described embodiments are denoted by the same reference numerals. Therefore, redundant explanations are omitted in this embodiment. (Third embodiment) In the above-described embodiment, the first wall-shaped rib 27 was connected to the nut portion 31. In contrast, in this embodiment, as shown in Figure 9, the first wall-shaped rib 27 is connected to the outer peripheral rib 29 at a position offset from the portion where the bolt B1 is inserted.

[0063] In Figure 9, the nut portion 31 is eliminated, and the bolt hole is a simple through hole 31A. Components identical to those in the above-described embodiment are denoted by the same reference numerals. Therefore, redundant explanations are omitted in this embodiment.

[0064] (Other embodiments) The cover 24 according to the above embodiment was integrally molded from FC material, comprising a plate 25, a first wall-like rib 27, a connecting rib 28, an outer peripheral rib 29, a second wall-like rib 30, a nut portion 31, a fastening flange portion 32, and a leg portion 33, etc. However, the disclosure is not limited thereto.

[0065] In other words, the disclosure may be a configuration in which, for example, at least one of the first wall-like rib 27, connecting rib 28, outer peripheral rib 29, second wall-like rib 30, nut portion 31, fastening flange portion 32, and leg portion 33 is eliminated, or a configuration in which these are manufactured separately and then integrated.

[0066] In the embodiment described above, the third wall-like rib 27B extends toward the leg portion 33 and is connected to the leg portion 33. However, the disclosure is not limited thereto. That is, the disclosure may also include, for example, a configuration in which the third wall-like rib 27B is omitted.

[0067] The pump according to the above embodiment had a configuration in which the central axis Lo was positioned substantially horizontally. However, the disclosure is not limited thereto. That is, the disclosure may also have a configuration in which, for example, the central axis Lo is positioned substantially vertically.

[0068] The third embodiment described above had a configuration in which the nut portion 31 was eliminated. However, the disclosure is not limited thereto. That is, the disclosure may also have a configuration in which the nut portion 31 is provided at the position of the through hole 31A.

[0069] In the embodiment described above, the first wall-shaped rib 27 was configured such that the ridge portion 27A, formed by connecting the tops of the first wall-shaped rib 27, substantially coincided with the straight line connecting the mounting flange portion 26 and the nut portion 31. However, the disclosure is not limited thereto.

[0070] In other words, the disclosure may be a configuration in which the ridge portion 27A is curved in a convex or concave shape and the rib height H changes continuously in a curved manner, a configuration in which the ridge portion 27A is stepped and the rib height H changes discontinuously, or a configuration in which the rib height H is constant.

[0071] In the embodiment described above, the connecting rib 28 was configured in the shape of a roof tile. However, the disclosure is not limited thereto. That is, since the connecting rib 28 has the function of connecting two adjacent first wall-shaped ribs 27, the mounting flange portion 26, and the plate 25, it may also be configured such that, for example, a hole is provided through the connecting rib 28.

[0072] In the embodiment described above, the second wall-like rib 30 extended toward the shaft hole 25A so as to extend from the first wall-like rib 27. However, the disclosure is not limited thereto. That is, the disclosure may also include, for example, a configuration in which the second wall-like rib 30 is eliminated, or a configuration in which the second wall-like rib 30 extends toward the shaft hole 25A so as to extend from the connecting rib 28.

[0073] In the embodiment described above, the window portions 28A and connecting ribs 28 were arranged alternately. However, the disclosure is not limited thereto. That is, the disclosure may also include, for example, a configuration in which the window portions 28A are eliminated, or a configuration in which one window portion 28A is provided.

[0074] In the above-described embodiment, the first wall-like rib 27 also served as the third wall-like rib 27B. However, this disclosure is not limited thereto. That is, the disclosure may also describe a configuration in which the third wall-like rib 27B is a separate wall-like rib independent of the first wall-like rib 27. In this case, the first wall-like rib 27 may be eliminated.

[0075] Furthermore, this disclosure is not limited to the embodiments described above, but is sufficient to be consistent with the intent of the disclosures described in the embodiments described above. Therefore, it may be a configuration in which at least two of the embodiments described above are combined, or a configuration in which any of the illustrated components or components described with reference numerals in the embodiments described above are omitted. [Explanation of Symbols]

[0076] 1... Pump 10... Motor section 11... Output shaft 20... Pump section 21… Impeller 22… Casing 23… Casing body 23A… Suction port 23B… Discharge port 24… Casing cover (cover) 25… Cover plate (plate) 26… Mounting flange 27… First wall-like rib 27B… Third wall-like rib 28… Connecting rib 29… Outer perimeter rib 30… Second wall-like rib 31… Nut section 32…Fastening flange portion 33…Leg portion

Claims

1. An impeller that is driven to rotate by an electric motor, A casing for housing the impeller, comprising a casing body provided with an intake port, and a cover plate positioned on the opposite side of the casing body from the impeller and fixed to the casing body, A mounting flange portion provided on the central side of the cover plate and located offset from the cover plate toward the electric motor, comprising an annular mounting flange portion on which the electric motor can be mounted, The cover plate comprises a plurality of wall-shaped ribs, each connected to the outer circumference of the mounting flange portion and extending toward the outer circumference of the cover plate. The electric motor is positioned on the opposite side of the casing body from the cover plate, When the dimension of the outer dimensions of the wall-shaped rib, specifically the dimension of the portion parallel to the central axis of the impeller, is defined as the rib height, The rib height on the mounting flange side is greater than the rib height on the outer circumference side. Furthermore, the central axis is substantially aligned with the horizontal direction, and the lower end of the cover plate is provided with legs for supporting and fixing the casing, and at least one of the plurality of wall-like ribs extends toward the leg and is connected to the leg.

2. The cover plate is provided with connecting ribs, The pump according to claim 1, wherein the connecting rib connects two wall-shaped ribs that are adjacent in the rotational direction of the impeller, the mounting flange portion, and the cover plate from among the plurality of wall-shaped ribs.

3. The outer circumference of the cover plate is provided with outer ribs. The pump according to claim 2, wherein the outer peripheral rib is an annular portion of a protrusion extending over the entire outer circumference of the cover plate.

4. The pump according to claim 2, further comprising a second wall-like rib extending from the connecting rib or the wall-like rib toward the output shaft side of the electric motor.

5. The pump according to claim 2, wherein a window portion, which is an opening, is provided between two adjacent connecting ribs in the direction of rotation of the impeller.

6. The casing body and the cover plate are fastened and secured to each other by a plurality of bolts arranged on the outer circumference. The cover plate is provided with a cap nut-shaped nut portion that connects to the bolt, Furthermore, the pump according to any one of claims 1 to 5, wherein the outer circumference of the wall-shaped rib extends to the nut portion and is connected to the nut portion.

7. The number of nuts provided is the same as the number of bolts. An annular fastening flange portion is provided on the outer circumference of the cover plate. Furthermore, the fastening flange portion connects adjacent nut portions among the plurality of nut portions in the direction of rotation of the impeller, as described in claim 6.

Images