JP7758510B2 - centrifugal pump - Google Patents

Description

The present invention relates to centrifugal pumps, and in particular to the drain structure of pump frames.

As shown in FIG. 5, the centrifugal pump includes a frame 150 that rotatably supports a drive shaft 120, a casing 110 that is fixed to the front surface of the frame 150, and an impeller 130 that is housed within the casing 110 and is provided coaxially at the tip of the drive shaft 120.
In this type of centrifugal pump, a shaft seal 160 that seals the periphery of the drive shaft 120 is provided in the center of the rear part of the casing 110. In the example shown in the figure, the legs 151 of the frame 150 are integrally formed in the front and rear axial directions.

Conventionally, as shown in the figure, an oil pan 200 is defined by the frame 150 itself below the shaft seal 160, and waste liquid that leaks from the shaft seal 160 over time or for other reasons is stored in the oil pan 200 through the drain space DS. A drain hole 200d for cleaning is provided on the side of the oil pan 200.

JP 2004-245134 A (paragraph 0006)

However, while the oil pan 200 functions adequately in the short term, over the long term the amount of waste liquid leaking from the shaft seal 160 will gradually increase, requiring more frequent maintenance. As a result, depending on the maintenance conditions, the waste liquid W overflowing from the oil pan 200 will not only soil the outside of the legs 151R, 151L, but will also spread onto the upper surfaces of the legs 151R, 151L and the installation surface GL of the frame 150. Note that the shaded symbol W in Figure 1(b) represents an image of waste liquid W overflowing from the oil pan 200.

In particular, at sites where multiple centrifugal pumps of this type are installed, it is hygienic for workers to manually clean each individual oil pan 200. Furthermore, the cleaning drain hole 200d can sometimes become clogged with slurry, making cleaning the oil pan 200 even more difficult. For this reason, at many sites, the pump installation environment is often prepared by cleaning the exterior and top surfaces of the legs 151R and 151L, as well as the installation surface GL of the frame 150.

The present invention was developed to address these issues, and aims to provide a centrifugal pump equipped with a frame that has a drain structure that improves cleanability.

In order to solve the above problems, one aspect of the present invention provides a centrifugal pump comprising a frame that rotatably supports a drive shaft, a casing fixed to the front of the frame, an impeller housed within the casing and mounted coaxially on the tip of the drive shaft, and a shaft seal mounted in the rear center of the casing to seal the periphery of the drive shaft. The drive shaft rotates the impeller within the casing, thereby sending fluid from an inlet port formed in the casing to a discharge port. In an installed position, the frame has a plurality of legs located below the frame and spaced apart axially in the front-to-back or left-to-right directions, and the separated spaces between the plurality of legs communicate in the direction of gravity with a drain space where the shaft seal directly faces the installation surface of the frame.

In a centrifugal pump according to one aspect of the present invention, the drain space is provided in the space between the multiple legs so as to be connected in the direction of gravity, thereby eliminating the need for an oil pan on the frame and providing a drain structure in which waste liquid leaking from the shaft seal falls directly from the drain space onto the installation surface of the frame.
As a result, although the pump installation environment itself still needs to be prepared by cleaning the frame installation surface, as before, even at sites where multiple centrifugal pumps are installed, there is no need for workers to manually clean each individual oil pan, and since the waste liquid falls directly from the drain space onto the frame installation surface, there is also no need to clean the outside or top of the legs.

Furthermore, in a centrifugal pump according to one aspect of the present invention, multiple legs are provided surrounding the drain space, which prevents waste liquid from scattering from the drain space to the surrounding area and allows the nozzle of a high-pressure washer, for example, to be easily inserted into the waste liquid in the drain space that has accumulated on the installation surface of the frame. This is therefore advantageous in that it allows for easy cleaning from the spaces between the multiple legs.

In one embodiment of the drain structure for a pump frame according to the present invention, the multiple legs preferably include four legs independently provided on the lower part of the frame in the axial direction, front and rear, and left and right, when the frame is in an installed position, and the separated spaces between the front and rear legs, between the left and right front legs, and between the left and right rear legs communicate in the direction of gravity with the drain space where the shaft seal directly faces the installation surface of the frame. It is also preferable that drain guide surfaces be formed above the left and right front legs, sloping downward toward the drain space.

Furthermore, in the drain structure for a pump frame according to one aspect of the present invention, it is preferable that each of the four legs has a footer surface to which a fixing bolt is attached for fixing to the installation surface of the frame, and that an obstruction surface is provided between the footer surface and the drain space to separate the footer surface from the drain space.

With this configuration, an obstruction surface that separates the drain space from the footer surface of each leg is formed on the drain space side, which is ideal for preventing or minimizing contamination of the bolt portion on the footer surface of each leg due to waste liquid leaking from the shaft seal.

It is also preferable that a clearance adjustment section for adjusting the opposing gap between the inner surface of the casing and the impeller is provided between the left and right rear legs, and that the clearance adjustment section is provided between the left and right rear legs and the clearance adjustment section so that the rear vertical surface that separates the clearance adjustment section from the drain space hangs down from the top.

With this configuration, the rear vertical surface that separates the clearance adjustment unit from the drain space is arranged to hang down from the top, which is ideal for preventing or suppressing contamination of the clearance adjustment unit and its surrounding area by waste liquid.

As described above, the present invention provides a centrifugal pump equipped with a frame having a drain structure that improves cleanability.

1A and 1B are explanatory diagrams of a centrifugal pump, which is one embodiment of a pump equipped with a pump frame according to one aspect of the present invention, in which FIG. 1A shows a cross section along the axis, and FIG. 1B shows a Z-Z cross section in FIG. 2 is an explanatory diagram of the main part of the pump shown in FIG. 1, and is a view of the end portion as seen from the arrow A in FIG. 1. 1A to 1G are diagrams illustrating a pump frame according to one embodiment of the present invention, in which FIG. 1A is a front view, FIG. 1B is a right side view, FIG. 1C is a rear view, FIG. 1D is a plan view, and FIG. 1E is a bottom view. 3A and 3B are diagrams illustrating a pump frame according to one embodiment of the present invention, in which FIG. 3A is a cross-sectional view taken along line XX in FIG. 3B, and FIG. 3B is a cross-sectional view taken along line YY in FIG. 3B. 1A and 1B are explanatory diagrams of an example of a pump equipped with a conventional pump frame, in which FIG. 1A shows a cross section of the main part along the axis, and FIG. 1B shows a ZZ cross section of FIG. 1A.

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.

1, the centrifugal pump of this embodiment includes a frame 50 that rotatably supports a shaft (drive shaft) 20. The casing 10 is fixed to a casing mounting surface 54 on the front surface of the frame 50.
A bearing housing portion 40 is provided on the upper portion of the frame 50. The upper front end of the bearing housing portion 40 is connected to the back surface of the casing mounting surface 54 by a connecting rib 55 having a generally T-shaped cross section. An impeller 30 is rotatably housed within the casing 10 and is provided coaxially at the tip of the shaft 20.

The base end of the shaft 20 passes through the rear of the casing 10 and extends into the bearing housing 40. Inside the bearing housing 40, a support 42 is provided, which has two bearings 42a, 42b spaced apart in the axial direction. The support 42 supports the base end of the shaft 20 horizontally and rotatably.

The rear end of the shaft 20 is connected to the output shaft of a motor (not shown) so as to transmit driving force. The casing 10 has an intake port 10in at its front that protrudes forward along the axial direction, and an exhaust port 10out at its top center. A shaft seal 60 that seals the periphery of the shaft 20 is provided at the rear center of the casing 10.

The casing 10 of this embodiment is a split type that is divided into two along a plane perpendicular to the shaft 20, and is composed of a front casing 11 on the axial front side and a back casing 12 on the axial rear side.
The back surface of the back casing 12 is fixed to the casing mounting surface 54 of the frame 50 with fixing bolts 82. The front casing 11 is fixed to the front surface of the back casing 12 with bolts 72 of fastening parts 70. In this embodiment, the fastening parts 70 are provided at four locations spaced apart in the circumferential direction.

In this embodiment, the centrifugal pump is capable of pumping fluid from the suction port 10in formed in the casing 10 to the discharge port 10out by rotating the impeller 30 within the casing 10 as a result of the shaft 20 being driven.

The configuration of the frame 50 of this embodiment, particularly the drain structure, will be described in detail below.
3 and 4, the frame 50 of this embodiment has four legs 51R, 51L, 52R, and 52L provided independently at the front, rear, left, and right in the axial direction at the lower part of the frame 50 in the installed position. As shown in FIGS. 1 and 4, the centrifugal pump of this embodiment has a clearance adjustment part 90 between the left and right rear legs 52R and 52L for adjusting the opposing gap between the inner surface of the casing 10 and the impeller 30, and the axial position of the shaft 20 can be adjusted along a clearance adjustment bolt 92.

Here, as shown in Figures 3 and 4, the frame 50 of this embodiment has separation spaces S between the front legs 51R, 51L and the rear legs 52R, 52L, between the left and right front legs 51R, 51L, and between the left and right rear legs 52R, 52L.
The drain structure of the frame 50 of this embodiment is such that the drain space DS, in which the shaft seal portion 60 (particularly the rear end portion) directly faces the installation surface GL of the frame 50, is connected to the separated space S of the four legs 51R, 51L, 52R, and 52L in the direction of gravity (particularly at the position of the Z-Z cross section).

In the drain structure of the frame 50 of this embodiment, drain guide surfaces 51Rd, 51Ld are formed above the left and right front legs 51R, 51L, sloping downward toward the drain space DS. Furthermore, the footer surfaces 51Rf, 51Lf, 52Rf, 52Lf, to which the fixing bolts B of the four legs 51R, 51L, 52R, 52L are attached, are located higher than the installation surface GL of the frame 50.

Furthermore, obstruction surfaces 51Rj, 51Lj, 52Rj, 52Lj that are separated from the drain space DS are provided between the footer surfaces 51Rf, 51Lf, 52Rf, 52Lf and the drain space DS. In this embodiment, rear vertical surfaces 53 that are separated from the drain space DS are provided so as to hang downward from the top between the left and right rear legs 52R, 52L and the clearance adjustment section 90.

Next, the operation and effects of the centrifugal pump of this embodiment will be described.
In the centrifugal pump of this embodiment, the impeller 30 is rotated to increase the pressure of the fluid being pumped, and the fluid is transferred from the suction port 10 in of the casing 10 to the discharge port 10 out.
In a conventional centrifugal pump, as shown in FIG. 5, an oil pan 200 is defined by the frame 150 itself below the shaft seal 160, and waste liquid that leaks from the shaft seal 160 over time or for other reasons is stored in the oil pan 200.

However, although the oil pan 200 functions adequately in the short term, over the long term the amount of waste liquid leaking from the shaft seal 160 will gradually increase, requiring more frequent maintenance. Therefore, as shown in Figure 5(b), depending on the maintenance conditions, waste liquid W overflowing from the oil pan 200 will not only soil the outside of the legs 151, but will also spread onto the top surfaces of the legs and the installation surface GL of the frame 150.

Furthermore, cleaning each individual oil pan 200 by hand is difficult from a hygienic standpoint, and the drain hole 200d used for cleaning can sometimes become clogged with slurry, making cleaning the oil pan area even more difficult. For this reason, in many cases, the pump installation environment is often prepared by cleaning the outside and top surfaces of the legs, as well as the frame installation surface.

In contrast, with the centrifugal pump of this embodiment, in the installed position, the drain space DS is provided in communication with the separated spaces S of the four legs 51R, 51L, 52R, and 52L in the direction of gravity, eliminating the need for an oil pan on the frame 50 and creating a drain structure in which waste liquid leaking from the shaft seal 60 falls directly from the drain space DS onto the installation surface GL of the frame 50.

As a result, with the centrifugal pump of this embodiment, while it is still necessary to prepare the pump installation environment by cleaning the installation surface GL of the frame 50, as with conventional pumps, the cleaning work of manually cleaning each individual oil pan by an operator is no longer necessary.

Furthermore, with the centrifugal pump of this embodiment, waste liquid leaking from the shaft seal 60 falls directly from the drain space DS onto the installation surface GL, eliminating the need to clean the outside of each leg 51R, 51L, 52R, 52L or the footer surfaces 51Rf, 51Lf, 52Rf, 52Lf, which are the upper surfaces of each leg 51R, 51L, 52R, 52L.

Furthermore, with the centrifugal pump of this embodiment, the frame 50 has four legs 51R, 51L, 52R, and 52L that are independently arranged on the front, rear, left, and right sides of the drain space DS to surround the drain space DS, thereby preventing waste liquid from scattering from the drain space DS to the surrounding area.

Furthermore, the nozzle of a high-pressure washer, for example, can be easily inserted into the waste liquid in the drain space DS that accumulates on the installation surface GL of the frame 50. This is therefore advantageous in that it allows for easy cleaning from the separation spaces S between the four legs 51R, 51L, 52R, and 52L. Furthermore, by providing a waste liquid path that can direct waste liquid to the installation surface GL of the frame 50, maintenance and cleaning of the pump installation environment can be carried out more efficiently.

Furthermore, a rear vertical surface 53 that is separated from the drain space DS is provided between the left and right rear legs 52R, 52L and the clearance adjustment unit 90 so that it hangs down from above, which is ideal for preventing or suppressing contamination of the clearance adjustment unit 90 and its surrounding area by waste liquid.

Furthermore, the space around the shaft seal 60 is not only a maintenance space for the shaft seal 60 itself, but also a work space when attaching and detaching the casing 10. With the frame 50 of this embodiment, the adoption of the drain structure described above greatly improves the ease of maintenance of the shaft seal 60 itself and the ease of attaching and detaching the casing 10.

In other words, as is clear from comparing Figures 1(b) and 5(b), the design concept of the conventional drain structure is to position the oil pan 200 as close as possible to the shaft seal portion 160 while still allowing for ease of maintenance and removal and installation. This results in a dimensional conflict in the maintenance opening L1 shown in Figure 5(b), which not only narrows the opening L1 but also shortens the distance to the fixing bolts (82) near the oil pan 200, significantly affecting the ease of removal and installation of the casing 10.

In contrast, with the drain structure of the frame 50 of this embodiment, as shown in Figure 1(b), the oil pan itself is eliminated, and the drain space DS is connected in the direction of gravity to the separated spaces S of the four legs 51R, 51L, 52R, and 52L, making it possible to ensure a sufficiently wide open area L2 for maintenance, greatly improving the maintainability of the shaft seal unit 60 itself and the ease of attaching and removing the casing 10.

In addition, the connecting rib 55 has a generally T-shaped cross section, and drain guide surfaces 51Rd, 51Ld are formed above the left and right front legs 51R, 51L, sloping downward toward the drain space DS. These features also contribute to ensuring sufficient space for inserting and removing the tool T and for rotating it, improving the ease of maintenance, such as the ease of attaching and removing the casing 10.

As explained above, the frame 50 of this embodiment can provide a centrifugal pump equipped with a frame having a drain structure that improves cleanability. It should be noted that the pump frame 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.

For example, in the above embodiment, four legs 51R, 51L, 52R, 52L are independently provided on the lower part of the frame 50 in the axial direction, front and rear, and left and right, and separation spaces S are provided between the front legs 51R, 51L and the rear legs 52R, 52L, between the left and right front legs 51R, 51L, and between the left and right rear legs 52R, 52L, but this is not limited to this example.

In other words, in the present invention, if a plurality of legs are provided at the bottom of the frame, spaced apart in the axial front-to-back or left-to-right directions, and the space between these legs is connected in the direction of gravity to the drain space in which the shaft seal portion directly faces the installation surface of the frame, the desired effects can be achieved.
Therefore, for example, as in the conventional example shown in Figure 5, it is applicable to a specification in which the legs of the frame are of an integral structure in the front and rear axial directions (in this case, the separated legs are bipedal), and it is also applicable to a specification in which the front or rear axial directions are of an integral structure in the left and right directions (in this case, the separated legs are tripodal).

10 Casing 10 in Suction port 10 out Discharge port 11 Front casing 12 Back casing 20 Shaft (drive shaft)
30 Impeller 40 Bearing housing portion 42 Support portion 50 Frame 51R, 51L Front legs 51Rd, 51Ld Drain guide surface 51Rf, 51Lf Footer surface 51Rj, 51Lj Baffle surface 52R, 52L Rear legs 52Rf, 52Lf Footer surface 52Rj, 52Lj Baffle surface 53 Rear vertical surface 54 Casing mounting surface 55 Connecting rib 60 Shaft seal portion 70 Fastening portion 72 Fastening bolt 82 Fixing bolt 90 Clearance adjustment portion 92 Clearance adjustment bolt B Fixing bolt S Separation space DS Drain space GL Frame installation surface

Claims (5)

A centrifugal pump comprising: a frame that rotatably supports a drive shaft; a casing fixed to the front surface of the frame; an impeller housed within the casing and provided coaxially at the tip of the drive shaft; and a shaft seal provided in the center of the rear of the casing for sealing the periphery of the drive shaft, wherein the impeller rotates within the casing when driven by the drive shaft, thereby sending fluid from an inlet to a discharge port formed in the casing,
The frame has a plurality of legs provided at a lower portion of the frame in an installed position, the legs being spaced apart from each other in the front-rear or left-right directions in the axial direction,
a separation space between the plurality of legs and a drain space in which the shaft seal portion directly faces the installation surface of the frame are communicated in the direction of gravity;
A centrifugal pump characterized in that it has a drain structure in which waste liquid leaking from the shaft seal portion falls directly from the drain space onto the installation surface of the frame . The plurality of legs are provided independently of one another at the front and rear and left and right sides in the axial direction at a lower part of the frame when the frame is in an installed position,
2. The centrifugal pump according to claim 1, wherein the separated spaces between the front legs and rear legs, between the left and right front legs, and between the left and right rear legs are connected in the direction of gravity to a drain space in which the shaft seal portion directly faces the installation surface of the frame. A centrifugal pump as described in claim 2, wherein drain guide surfaces that slope downward toward the drain space are formed above the left and right front legs. The four legs each have a footer surface to which a fixing bolt is attached for fixing to an installation surface of the frame,
4. The centrifugal pump according to claim 2, wherein a baffle surface is provided between the footer surface and the drain space to separate the footer surface from the drain space. a clearance adjustment portion for adjusting a facing gap between the inner surface of the casing and the impeller is provided between the left and right rear legs,
The centrifugal pump according to any one of claims 2 to 4, wherein a rear vertical surface that separates the clearance adjustment portion from the drain space is provided between the left and right rear legs and the clearance adjustment portion so as to hang downward from an upper portion.