JP7477446B2 - Fixture for shaft assembly of horizontal rotating machinery - Google Patents

Description

The present invention relates to horizontal rotating machines such as pumps and fans in which the axis of the shaft is supported horizontally, and in particular to a jig for shaft assembly of this type of rotating machine.

For example, the technology described in Patent Document 1 is disclosed as a jig used when disassembling and assembling a horizontal rotating machine in which the axis of the shaft is supported horizontally. This document proposes a technology that allows even an unskilled person to easily and reliably replace a pump frame plate, including centering.

JP 2019-007404 A

However, although the jig described in this document improves the work of replacing the frame plate, it does not improve the workability in the process of inserting and removing the shaft assembly with the bearing mounted on the shaft.
Therefore, the present invention has been made with attention to such problems, and an object of the present invention is to provide a jig for a shaft assembly that improves the workability in the insertion and removal process of a shaft assembly in a horizontal rotating machine when a bearing is mounted on the shaft.

In order to solve the above problems, a jig for a shaft assembly of a horizontal rotating machine according to one aspect of the present invention is used in a rotating machine in which the axis of the shaft is supported horizontally, and is a jig for assisting the insertion and removal process of inserting or removing a shaft assembly with a bearing mounted on the shaft into or from the frame of the rotating machine body, and is characterized in that it is configured to be installable at the bottom of the oil chamber of the frame and has two guide plates with slide guide surfaces that are parallel to the axis of the shaft when placed in the oil chamber, and two holding plates that are installed in the oil chamber to maintain the position of the two guide plates and have oil holes that allow oil to circulate.

Here, in a jig for a shaft assembly of a horizontal rotating machine according to one aspect of the present invention, it is preferable that the guide plate and the retaining plate have a separable structure that allows them to be disassembled and assembled from each other within the oil chamber.

The jig for shaft assemblies of horizontal rotating machines according to the present invention can improve the workability of the process of inserting and removing shaft assemblies with bearings mounted on the shaft.

1 is an explanatory diagram of a centrifugal pump, which is an embodiment of a horizontal rotary machine according to an aspect of the present invention, and shows a cross section taken along an axis line. FIG. 1 is an oblique view illustrating the installation state of one embodiment of a jig for a shaft assembly according to one aspect of the present invention, the figure showing a view of the frame from above and rearward with a portion cut away, with the shaft assembly removed. FIG. 2 is an explanatory diagram showing one embodiment of a guide plate constituting a jig for a shaft assembly according to one aspect of the present invention. FIG. 2 is an explanatory diagram showing one embodiment of a retaining plate constituting a jig for a shaft assembly according to one aspect of the present invention. FIG. 2 is a perspective view illustrating an assembly process of an embodiment of a jig for a shaft assembly according to an aspect of the present invention, with a portion of the jig cut away. 1A and 1B are explanatory diagrams of an assembly process in one embodiment of a jig for a shaft assembly according to one aspect of the present invention, in which FIG. 1A is a perspective view showing a part broken away, and FIG. 1B is a side view showing a frame broken away along the axial direction. 1A and 1B are explanatory diagrams of an assembly process in one embodiment of a jig for a shaft assembly according to one aspect of the present invention, in which FIG. 1A is a perspective view showing a part broken away, and FIG. 1B is a side view showing a frame broken away along the axial direction. 1A and 1B are explanatory diagrams of an assembly process in one embodiment of a jig for a shaft assembly according to one aspect of the present invention, in which FIG. 1A is a perspective view showing a part broken away, and FIG. 1B is a side view showing a frame broken away along the axial direction. FIG. 1 is an explanatory diagram showing an example of inserting and removing a shaft assembly without using a jig for a shaft assembly according to one embodiment of the present invention, in which the frame is shown cut along the axial direction.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings as appropriate. This embodiment is an example of a centrifugal pump as an example of a horizontal rotary machine. Note that the drawings are schematic. Therefore, it should be noted that the relationship and ratio between thickness and planar dimensions are different from the actual ones, and the drawings include parts where the relationship and ratio of dimensions are different from each other.
Furthermore, the embodiments described below are merely examples of 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.

As shown in FIG. 1, the pump 10 of this embodiment includes a base 2, a frame (bearing housing) 3 mounted and fixed to the top of the base 2, and a casing 20 fixed to the front side of the base 2. The frame 3 is arranged so that the axis of the shaft 1 is horizontal, and supports the shaft 1 rotatably via front and rear bearing units 9A, 9B. The frame 3 has an oil chamber 4 between the front and rear bearing units 9A, 9B.

A tip 1 s of the shaft 1 protrudes from the center of the back surface of the casing 20 into the inside of the casing 20 , and an impeller (impeller) 21 is cantilevered on the tip 1 s of the shaft 1 and is housed in a defined space within the casing 20 .
A shaft seal device 7 is disposed between the casing 20 and the frame 3 on the axial rear side of the impeller 21 so as to surround the shaft 1. The base end side of the shaft 1 protrudes rearward from the rear end of the frame 3, and this protruding portion is connected to the output shaft of a motor (not shown) so as to be able to transmit driving force.

In this embodiment, the casing 20 has a suction section 5 on the axial front side of the impeller 21, and a discharge section 6 above the impeller 21 in the radial direction. The discharge section 6 is located at the center of the upper part of the casing 20, so that the rotation of the impeller 21 sucks in fluid from the suction section 5 and discharges the fluid from the discharge section 6.

When servicing the pump 10 of this embodiment, the shaft assembly 8 (having a mass of, for example, a dozen kilograms to several tens of kilograms or more) with the bearing units 9A, 9B assembled to the shaft 1 is inserted and removed from the frame 3 of the pump 10 through an opening at the axial rear of the oil chamber 4. During this insertion and removal process, the worker inserts and removes the shaft 1 from the rear of the frame 3 in a cantilevered position, supporting the rear end of the shaft 1 with his hand.

However, the center of gravity of the shaft assembly 8 is located inside the frame 3, far from the operator, during the insertion and removal process. Therefore, it is extremely difficult for a single operator to support the axis of the shaft 1 horizontally, and the shaft assembly 8 falls into the oil chamber 4 in the center of the frame 3, as shown in Figure 9.
Therefore, in the past, when two workers were performing insertion, one of them had to reach out his hand from the shaft seal device 7 side to pull up the tip of the shaft 1 and support the axis horizontally. The same is true in the reverse process of pulling the shaft assembly 8 axially backward from the frame 3. Thus, in the past, the insertion and removal work of the shaft assembly 8 required two workers, although it was desirable for one worker to perform the work.

In contrast, as shown in FIG. 2, the jig 30 of this embodiment is a jig for facilitating the insertion/removal process of inserting or removing the shaft assembly 8, in which the bearing units 9A and 9B are assembled to the shaft 1, into or from the frame 3 of the rotating machine body, and is configured to be installable at the bottom of the oil chamber 4 of the frame 3. In particular, the jig 30 of this embodiment has a split structure that allows it to be disassembled and assembled within the oil chamber 4 of the frame 3.

In detail, as shown in FIG. 2, the jig 30 of this embodiment has two guide plates 40 arranged in the oil chamber 4 parallel to the shaft 1, and two retaining plates 50 installed at the bottom of the oil chamber 4 to maintain the arrangement posture of the two guide plates 40 and having oil holes opened therein to allow oil to circulate.
As shown in Fig. 3, each guide plate 40 is formed from a rectangular plate member made of heat-resistant resin. The upper surface of the plate member is a slide guide surface 41, and when assembled into the oil chamber 4, both end surfaces 48 in the longitudinal direction of the plate member are assembled as the front and rear. In the assembled state, the two left and right slide guide surfaces 41 are surfaces whose height is set so as to maintain a height according to the outer diameter of the outer peripheral surface of the bearing unit 9A.

Two slits 42 are formed in the lower surface 47 of each guide plate 40, spaced apart in the longitudinal direction of the plate member. The groove width of each slit 42 is set to a width that allows the insertion of a holding plate 50. Corner cutting surfaces 46 are formed at two corners on both sides of the lower surface 47 of each guide plate 40.
A circular oil hole 44 is formed in the center of the main surface 49, and two oil holes 43, which are smaller in shape than the oil hole 44, are formed on the left and right sides of the main surface 49. In addition, two concave semicircular oil holes 45 are formed in the lower part of the main surface 49, between the two slits 42.

As shown in FIG. 4, each retaining plate 50 is formed from a rectangular heat-resistant resin plate member. A large concave arc-shaped relief surface 54 is formed on the upper surface 51 of the plate member, and when the plate member is installed in the oil chamber 4, both end surfaces 58 in the longitudinal direction of the plate member are installed as left and right.

Two slits 52 are formed in the relief surface 54 of each holding plate 50, spaced apart in the longitudinal direction of the plate member. The relief surface 54 prevents interference with the bearing unit 9A when inserting or removing the plate. The groove width of each slit 52 is set to a width that allows the guide plate 40 to be inserted.
Corner cutting surfaces 56 are formed at two corners on both sides of the lower surface 57 of each retaining plate 50. Four circular oil holes 53 are formed in the main surface 59 at intervals in the longitudinal direction of the plate member. Also, one concave semicircular oil hole 55 is formed in the center of the lower part of the main surface 59.

Next, a procedure for assembling the jig 30 of this embodiment and a procedure for inserting the shaft assembly 8 will be described.
As shown in Figure 5, first, two holding plates 50 that maintain the position of each guide plate 40 are arranged horizontally from the rear opening of the frame 3 to the bottom of the oil chamber 4, spaced apart from each other in the axial direction, and then the two guide plates 40 are arranged vertically along the axial direction, spaced apart from each other on the left and right.

Next, in the oil chamber 4, the slits 42 of the two guide plates 40 are inserted into the slits 52 of the two holding plates 50 from above until the slits 42, 52 fit deep into the grooves, and assembled into a crisscross frame.
At this time, since each guide plate 40 and holding plate 50 is a rectangular plate member before being assembled into a frame, they can be easily arranged in the oil chamber 4 even if the oil chamber 4 is narrow. The posture of the jig 30 in the oil chamber 4 is maintained because the shape of the jig 30 fits into the bottom recess of the oil chamber 4.

After assembling the jig 30 into a crisscross frame, the frame-shaped jig 30 is temporarily positioned by hand from above the intended position at the bottom of the oil chamber 4, as shown in FIG. 2. In this temporary position, there may be a slight gap between the bottom surface of the oil chamber 4 and the jig 30 may be slightly tilted. This allows a sliding guide surface 41 for work to be provided within the oil chamber 4 of the frame 3.

6 and 7, the shaft assembly 8 is inserted in a cantilevered state along the axial direction from the rear of the frame 3. At this time, the outer peripheral surface of the bearing unit 9A is temporarily placed on the two slide guide surfaces 41 on the upper surfaces of the two guide plates 40, and the outer peripheral surface of the bearing unit 9A of the shaft assembly 8 is placed on it and slid axially forward along the slide guide surfaces 41.
Here, the support range of the bearing unit 9A by the slide guide surface 41 extends from the front end of the bearing unit 9A to a position where at least the middle portion on the forward side is supported by the fitting portion of the bearing unit 9A formed on the frame 3.

As a result, as shown in FIG. 8, the shaft assembly 8 can be moved axially to the desired position without dropping the shaft assembly 8 within the oil chamber 4. The load of the shaft assembly 8 then ensures that the bottom surface of the frame-shaped jig 30 abuts against the bottom surface within the oil chamber 4, and the jig 30 is also positioned in the desired position.

As described above, according to the jig 30 of this embodiment, the two slide guide surfaces 41 on the top surface of the guide plate 40 are arranged in parallel along the axial direction within the oil chamber 4 of the frame 3, so that, as shown in Figures 6 to 7, the outer peripheral surface portions of the bearing units 9A and 9B can be slid along the slide guide surfaces 41 on the guide plate 40, allowing even a single worker to insert and remove the shaft assembly 8. This improves the ease of operation during the process of inserting and removing the shaft assembly 8.

For example, the slide guide surface can be configured by using a simple cylindrical pipe material cut to an appropriate length and placing it in the oil chamber 4, which will provide a slide guide function. However, if the pipe material is left in the oil chamber 4 after installation, there is a problem that the oil circulation function will be hindered. In addition, the desired fixture function needs to be provided within the limited, narrow space of the oil chamber 4 of the frame 3.

In contrast, the jig 30 of this embodiment has a simple configuration having two guide plates 40 and two retaining plates 50, as shown in Figure 2, and these four rectangular plate members are combined with each other as a slit engagement structure, with the slits inserted alternately to form a criss-cross frame shape, which makes it possible to disassemble and assemble the jig within the oil chamber 4, which is a small space.
Furthermore, as shown in Figures 2 to 4, the two retaining plates 50 are formed with a number of oil holes 53, 55 that allow oil to circulate. Therefore, even if the jig 30 is left in the oil chamber 4 after installation, oil stagnation is prevented and the necessary circulation performance is maintained.

For example, if the basic structure of the frame 3 is such that the oil chamber 4 portion acting as a bearing box is detachable together with the shaft assembly 8, the maintainability of the shaft assembly 8 in this portion will be improved, but the concentricity with the casing 20 will be reduced.
Therefore, for small to medium-sized pumps that can be manually inserted and removed, the centrifugal pump 10 of this embodiment and the corresponding jig 30 of this embodiment are superior in terms of providing a frame structure that maintains the concentricity required for pump performance and improving workability in the process of inserting and removing the shaft assembly 8.

As described above, the jig 30 of this embodiment can improve the workability in the process of inserting and removing the shaft assembly 8 in a state in which the bearing units 9A, 9B are mounted on the shaft 1.
The jig for a shaft assembly according to the present invention is not limited to the above-described embodiment, and various modifications are possible without departing from the spirit of the present invention.
For example, in the above embodiment, the centrifugal pump 10 has been described as an example of a horizontal rotating machine, but the present invention is not limited to this, and the present invention can be applied to a process of inserting or extracting a shaft assembly with bearings mounted on the shaft into or from a frame of the rotating machine body in rotating machines such as various pumps and fans, as long as the axis is supported horizontally.

1 Shaft 2 Base 3 Frame (bearing box)
Reference Signs List 4 Oil chamber 5 Suction section 6 Discharge section 7 Shaft seal device 8 Shaft assembly 9A, 9B Bearing unit 10 Pump (horizontal rotating machine)
20 Casing 21 Impeller 30 Jig 40 Guide plate 50 Holding plate

Claims (2)

A jig for use in a rotary machine in which an axis of a shaft is supported horizontally, the jig being for assisting an insertion/removal process of inserting or removing a shaft assembly having a bearing mounted on the shaft into or from a frame of a rotary machine body, the jig comprising:
The oil chamber is configured to be installed at the bottom of the frame,
A jig for a shaft assembly of a horizontal rotating machine, comprising: two guide plates having slide guide surfaces that are parallel to the axis of the shaft when positioned in the oil chamber; and two retaining plates that are installed in the oil chamber to maintain the orientation of the two guide plates and have oil holes that allow oil to circulate. The jig for a shaft assembly of a horizontal rotating machine according to claim 1, wherein the guide plate and the retaining plate have a separable structure that allows them to be disassembled and assembled from each other within the oil chamber.

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