JP7394012B2 - How to determine the tilt of a vertical shaft pump - Google Patents

Description

The present invention relates to a method for determining the inclination of a vertical shaft pump.

A vertical shaft pump is installed by fixing a pump casing to an installation floor made of concrete or the like. The pump casing of an installed vertical shaft pump may tilt relative to the installation floor due to deterioration over time.

BACKGROUND ART Conventionally, a vertical shaft pump that can readjust the inclination of a pump casing when the inclination occurs is known (see, for example, Patent Document 1).

However, in the conventional vertical shaft pump, there is no clear standard for determining the degree of inclination of the pump casing that requires readjustment.

Japanese Patent Application Publication No. 2015-105569

An object of the present invention is to provide a method for determining the inclination of a vertical shaft pump that can accurately determine the degree of inclination due to aging deterioration after installation.

As a means for solving the above problem, the present invention has a water pump fixed to an installation floor and suspended from the installation floor, and an external bearing support, which is connected to an upper opening of the water pump. a pump casing including a discharge elbow, a rotating shaft that extends vertically through the discharge elbow and has an impeller disposed in the pump casing at a lower end; and a bearing rotatably supporting the rotating shaft, the bearing comprising a first bearing provided on the bearing support base and an upper side of the pump casing. The distance from the center of the first bearing to the center of the second bearing measured immediately after installation, including a second bearing provided inside and a third bearing provided inside the lower side of the pump casing. L, a method for determining the inclination of a vertical shaft pump, in which the degree of inclination of the pump casing after installation is determined using δ/L as a reference value , where δ is the gap between the rotating shaft and the second bearing measured immediately after installation ; I will provide a.

If the maximum inclination of the installation floor is Δmax, the inclination level of the installation floor may be determined to require caution by satisfying δ/L<Δmax≦δ/L×2.

If the maximum inclination Δmax satisfies δ/L×2<Δmax, it may be determined that the inclination level of the installation floor requires adjustment.

A weight suspended from the bearing support base and a measurement surface that is parallel to the installation floor and tilts together with the pump casing, the measurement surface being flat when the pump casing is not tilted. It has a reference circle including a center position that visually matches the center position of the weight, and based on the amount of deviation between the center position of the reference circle of the measurement surface and the center position of the weight due to the inclination of the measurement surface. , the degree of inclination of the pump casing after installation may be determined.

According to the present invention, the inclination of the vertical shaft pump can be accurately determined by using the ratio of the distance from the first bearing to the second bearing and the gap between the rotating shaft and the second bearing as a reference value.

FIG. 1 is a schematic diagram of a vertical shaft pump according to the present embodiment. FIG. 2 is a plan view of the base plate of FIG. 1; FIG. 6 is a partially enlarged view of a vertical shaft pump according to another embodiment. FIG. 3B is a plan view of the measurement plate of FIG. 3A. FIG. 3 is a schematic diagram of a vertical shaft pump according to another embodiment.

Embodiments of the present invention will be described below with reference to the accompanying drawings. Note that the following description is essentially just an example, and is not intended to limit the present invention, its applications, or its uses. Further, the drawings are schematic, and the ratio of each dimension is different from the actual one.

FIG. 1 shows a schematic diagram of a vertical shaft pump 1 according to this embodiment. This vertical shaft pump 1 is installed at a pump station.

The pump station is provided by pouring concrete or the like, and includes a water absorption tank 2 into which rainwater and the like flow in through an inflow pipe (not shown). An upper opening of the water absorption tank 2 is covered by an installation floor 3. A pump insertion hole 4 is formed in the installation floor 3. The pump insertion hole 4 includes a large-diameter recess 4a and an opening 4b passing through the inner bottom surface of the recess 4a. A steel base plate 8 formed in an annular shape is arranged in the recess 4a. The base plate 8 is fixed to the installation floor 3 by foundation bolts 100 that are arranged at eight equal locations in the circumferential direction and pass through the installation floor 3 (see FIG. 2). After fixing with the foundation bolts 100, the base plate 8 is hardened by applying mortar, and the inclination cannot be adjusted thereafter. In this embodiment, the term "installation floor" is used to refer to any structure that can support the vertical shaft pump 1.

The vertical shaft pump 1 includes a pump casing 5. The pump casing 5 has a water pump 6, a discharge elbow 7, and a base plate seat 9 that connects these. Although details are not shown, the base plate seat 9 is cylindrical, and its upper and lower ends are flange portions 9a and 9b that expand outward in the radial direction. The pump casing 5 is completed by fixing the flanges 6a and 7a of the lift pipe 6 and the discharge elbow 7 to the flanges 9a and 9b at the upper and lower ends of the base plate seat 9, respectively (by bolts). Further, the upper flange portion 9a of the base plate seat 9 expands toward the outer diameter side, and is placed on the base plate 8 and fixed with bolts 101. At the time of initial installation, the water pumping pipe 6 is placed in the water absorption tank 2 and adjusted so that its center line CL coincides with the vertical direction, and the other end side of the discharge elbow 7 is placed above the installation floor 3 to pump water. It extends in the horizontal direction orthogonal to the center line CL of the tube 6.

A rotating shaft 10 passes through the discharge elbow 7. The upper end side of the rotating shaft 10 is rotatably supported by a first bearing 11 (outer bearing). Here, a rolling bearing is used as the first bearing 11. For example, if the inner diameter of the first bearing 11 is 100 mm, the gap between the first bearing 11 and the rotating shaft 10 is 0.01 mm to 0.03 mm. There is. The first bearing 11 is fixed to a bearing support 12 attached to the upper side of the discharge elbow 7. The lower side of the rotating shaft 10 is rotatably supported by a second bearing 13 (upper underwater bearing) and a third bearing 14 (lower underwater bearing) provided in the lift pipe 6. The second bearing 13 is arranged on the upper side within the water pump 6. Here, a sliding bearing is used as the second bearing 13. For example, if the inner diameter of the second bearing 13 is 100 mm, the gap between the second bearing 13 and the rotating shaft 11 is 0.2 mm to 0.5 mm. There is. The third bearing 14 is arranged on the lower side within the water pump 6. The second bearing 13 and the third bearing 14 are attached to a support portion (not shown) extending from the inner surface of the water pump 6. The rotating shaft 10 is positioned so that its axial center coincides with the center line CL of the water pump 6 when supported by each of the bearings. An impeller 15 is fixed to the lower end of the rotating shaft 10, which is disposed in a lower region within the pump casing 5 (specifically, a discharge bowl connected to the lower end of the pumping pipe 6). The impeller 15 rotates as power is transmitted to the rotating shaft 10 from a drive means such as a motor (not shown) provided above the bearing support base 12 .

In the vertical shaft pump 1 having the above configuration, the pump casing 5 may tilt with respect to the base plate 8 due to deterioration over time. Specifically, the contact surfaces between the base plate 8 and the base plate seat 9 are worn out due to vibrations caused by the driving of the driving means, and the pump casing 5 may be tilted depending on the location of the wear. In particular, since the weight of the bent and extended portion of the discharge elbow 7 is large, the contact pressure on this side of the contact surface between the base plate 8 and the base plate seat 9 tends to be large, and the amount of wear tends to increase. In this case, although the pump casing 5 is tilted, the rotating shaft 10 is directed vertically downward. That is, the rotating shaft 10 is suspended by being supported by a supported portion (not shown) on the upper end side thereof. A slight gap is formed between the rotating shaft 10 and the second bearing 13. Therefore, the rotary shaft 10 is maintained in a vertically downward direction due to its own weight with respect to the inclination of the pump casing 5. Therefore, between the axial center of the rotating shaft 10 and the center line CL of the water pump 6, there is a portion supported by the first bearing 11 (strictly speaking, it is a supported portion, but the first bearing 11 and the rotating shaft 10 Since there is almost no gap between the pump casing 5 and the pump casing 5, an angular deviation occurs around the pump casing 5, which can be considered as being substantially the same. If this angular deviation increases, vibrations when driving the vertical shaft pump 1 will increase, and in some cases, the rotation range of the rotary shaft 10 will exceed the gap size with the second bearing 13, damaging the second bearing 13. Sometimes.

Therefore, the inclination of the pump casing 5 is determined by appropriately detecting the inclination of the base plate 8 using a spirit level. Here, as shown in FIG. 2, when the base plate 8 is viewed from above, the direction in which the other end of the discharge elbow 7 extends is defined as the X axis, and the direction perpendicular to this and passing through the center line of the lift pipe 6 is defined as the Y axis. The tilt in the direction of is detected. By detecting the inclinations in two orthogonal directions, the direction with the largest inclination and its gradient can be determined. Specifically, if the inclination in the X-axis direction is at an angle θ1 and the inclination in the Y-axis direction is at an angle θ2, the maximum inclination direction D and the maximum inclination Δmax are as follows.
D=arctan(tanθ2/sinθ1)
Δmax=arccos(cosθ1・cosθ2)
becomes. That is, the direction tilted from the X-axis by an angle arctan (tan θ2/sin θ1) in plan view is the maximum inclination direction D, and at that time, the angle arccos (cos θ1·cos θ2) is the maximum inclination Δmax.

Here, it is determined as follows whether the maximum slope Δmax is within an allowable range. The reference value Sv is set to δ/L. L is the distance from (the center of) the first bearing 11 to (the center of) the second bearing 13, and δ is the gap between the second bearing 13 and the rotating shaft 10. Then, it is evaluated to which of the following ranges the maximum slope Δmax belongs with respect to the reference value Sv.
Δmax≦Sv
Sv<Δmax≦Sv×2
Sv×2<Δmax

If the maximum inclination Δmax satisfies Δmax≦Sv (=δ/L), the inclination of the pump casing 5 is within the permissible range, and the condition that the inner surface of the second bearing 13 does not come into contact with the rotating shaft 10 is satisfied. That means you are doing it. In this case, it is determined that the installation state of the pump casing 5 is good. If the maximum slope Δmax satisfies Sv<Δmax, it is further determined whether the maximum slope Δmax satisfies Sv×2<Δmax.

If the maximum inclination Δmax satisfies Sv<Δmax≦Sv×2, there is a possibility that the inner surface of the second bearing 13 will come into contact with the rotating shaft 10. In this case, it is determined that the installation state of the pump casing 5 requires caution. If it is determined that caution is required, you can continue to use it as is, but the rotating shaft 10 may hit the second bearing 13 unevenly, causing vibration or damaging the second bearing 13 itself. obtain. Therefore, it is preferable to perform adjustment so that this inclination is eliminated. That is, a shim (not shown) is interposed between the tightening part of the bolt 101 (between the base plate 8 and the base plate seat 9) that is the most inclined and lowest when viewed from the center line CL of the pumping pipe 6. Just adjust it. If the maximum inclination Δmax satisfies Δmax≦Sv, the inclination of the pump casing 5 has been corrected, and the rotational state of the rotating shaft 10 has been corrected to a favorable state.

If the maximum slope Δmax satisfies Sv×2<Δmax, it is determined that adjustment is required. If it is determined that an adjustment is required, it is difficult to make the adjustment simply by interposing a shim at the part tightened by the bolt. In this case, it is necessary to disassemble the vertical shaft pump 1 for maintenance, and to readjust the installation state of the base plate seat 9 on the base plate 8.

As described above, in the vertical shaft pump 1 according to the present embodiment, attention is paid to the distance L from the first bearing 11 to the second bearing 13 and the gap δ between the second bearing 13 and the rotating shaft 10. Then, it can be determined whether the pump casing 5 is properly installed or not based on the magnitude of the maximum inclination Δmax with respect to the reference value δ/L. Therefore, it is possible to appropriately determine and evaluate the degree of inclination of the pump casing 5, which has been an ambiguous standard in the past.

Note that the present invention is not limited to the configuration described in the above embodiments, and various changes are possible.

In the embodiment described above, an example has been described in which the inclination of the pump casing 5 is detected using a spirit level, but the type of spirit level does not matter, and various types of spirit levels such as a laser level can be used. It is also possible to measure as follows.

As shown in FIG. 3A, a weight 16 is suspended from the bearing support stand 12, and a measurement plate 17 having a measurement surface is placed at a corresponding position on the installation floor 3. A reference circle is drawn on the measurement surface, and the center position of the weight 16 matches the center position of the reference circle when the pump casing 5 is not tilted immediately after installation. As shown in FIG. 3B, the reference circle may be composed of a first reference circle C1 and a second reference circle C2 drawn at the position where the slope Δ is Sv and the position where the slope is Sv×2, respectively, as described above. . As a result, if the pump casing 5 is tilted, the center position of the reference circle will shift from the center position of the weight 16 extending vertically downward in plan view. If the amount of deviation from the center position of the weight 16 is not large and falls within the first reference circle C1 in plan view, it is determined to be good. If it is between the first reference circle C1 and the second reference circle C2, it is determined that caution is required, and if it is outside the second reference circle C2, it is determined that adjustment is required.

In this way, if the weight 16 is suspended from the bearing support base 12 and a reference circle is drawn on the measurement surface, it is only necessary to check in which region the center position of the weight 16 is located in a plan view. , the degree of inclination of the pump casing 5 (discharge elbow 7) can be evaluated. For this reason, it becomes possible to determine the degree of inclination of the pump casing 5 more easily than measurement using a spirit level.

Further, in addition to the above configuration, an imaging means such as a camera may be provided for detecting the position of the weight 16 with respect to the reference circle in plan view. According to this, the imaging results can be grasped remotely via the Internet or the like. It is also possible to automatically analyze the imaging results using a computer or the like to determine whether the condition is good, requires attention, or requires adjustment.

Furthermore, instead of the above configuration, a tilt sensor may be provided to directly detect the tilt of the pump casing 5. In this case, similarly to the above, the configuration may be such that the imaging results can be grasped remotely via the Internet or the like or automatically analyzed.

In the embodiment, the vertical shaft pump 1 has a configuration in which the rotating shaft 10 is rotatably supported by the second bearing 13 and the third bearing 14 inside the pump, and the first bearing 11 disposed above the discharge elbow 7. However, even with the vertical shaft pump 1 having the following configuration, the inclination of the pump casing 5 in the installed state can be determined in the same manner.

FIG. 4 shows a vertical shaft pump 1 of a type in which a rotating shaft 10 is rotatably supported by a motor-side bearing disposed above a discharge elbow 7. As shown in FIG. Since the basic configuration of this vertical shaft pump 1 is the same as that described in the above embodiment, corresponding members are given the same reference numerals and explanation thereof will be omitted, and only the differences will be explained below.

That is, a pump bed 18 is formed above the installation floor 3, and a drive machine 19 is installed on this pump bed 18. The drive machine 19 is provided with a fourth bearing 20 on the upper side and a fifth bearing 21 on the lower side, which rotatably support the rotating shaft 10.

In the above type of vertical shaft pump 1, the reference value Sv is calculated by taking the distance from the fifth bearing 21 to the second bearing 13 as L, and dividing the gap δ between the second bearing 13 and the rotating shaft 10. There is. Based on this reference value Sv, it is possible to determine whether the inclination of the pump casing 5 is within the permissible range, requires caution, or requires adjustment, in the same manner as described above.

In the embodiment described above, the inclination is measured in two directions, the X-axis direction and the Y-axis direction, and the inclination direction and slope of the pump casing 5 are determined. However, if the inclination is determined in three or more directions, it will be more accurate. The tilt direction and slope can be specified.

In the above embodiment, the height is adjusted using shims, but the invention is not limited to this. For example, a spherical washer may be placed at the tightening portion of each bolt, and the inclination may be adjusted by adjusting the tightening condition of each bolt. good.

In the embodiment described above, the discharge elbow 7 and the base plate seat 9 are configured as separate members and connected to each other, but they may be configured as an integrated unit.

1... Vertical shaft pump 2... Water suction tank 3... Installation floor 4... Pump insertion hole 5... Pump casing 6... Lifting pipe 7... Discharge elbow 8... Base plate 9... Base plate seat 10... Rotating shaft 11... First bearing (outer bearing)
12...Bearing support stand 13...Second bearing (upper underwater bearing)
14...Third bearing (lower underwater bearing)
15... Impeller 16... Weight 17... Measuring plate 18... Pump floor 19... Drive machine 20... Fourth bearing 21... Fifth bearing 100... Foundation bolt 101... Bolt

Claims (4)

a pump casing that is fixed to an installation floor and includes a lift pipe suspended from the installation floor, and a discharge elbow that has an external bearing support and is connected to an upper opening of the lift pipe;
a rotating shaft extending vertically through the discharge elbow and having an impeller disposed in the pump casing at a lower end;
a drive means for rotating the impeller via the rotation shaft;
A vertical shaft pump comprising: a bearing rotatably supporting the rotating shaft;
The bearing includes a first bearing provided on the bearing support, a second bearing provided inside the upper side of the pump casing, and a third bearing provided inside the lower side of the pump casing. ,
When the distance from the center of the first bearing to the center of the second bearing measured immediately after installation is L, and the gap between the rotating shaft and the second bearing measured immediately after installation is δ, δ/L is the standard. A method for determining the inclination of a vertical shaft pump, which determines, as a value, the degree of inclination of the pump casing after installation . The vertical shaft pump according to claim 1, wherein, when the maximum inclination of the pump casing is Δmax, the inclination level of the pump casing is determined to require attention by satisfying δ/L<Δmax≦δ/L×2. Tilt determination method. The vertical shaft pump inclination determination method according to claim 2, wherein the inclination level of the pump casing is determined to require adjustment when the maximum inclination Δmax satisfies δ/L×2<Δmax. a weight suspended from the bearing support;
a measurement surface parallel to the installation floor and inclined together with the pump casing;
The measurement surface has a reference circle including a center position that matches the center position of the weight in plan view when the pump casing is not tilted;
4. The method according to claim 1, wherein the degree of inclination of the pump casing after installation is determined based on the amount of deviation between the center position of the reference circle on the measurement surface and the center position of the weight due to the inclination of the measurement surface. The method for determining the inclination of a vertical shaft pump according to any one of the items.

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