JP2017031949A - pump - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a pump which can simply exchange a mechanical seal.SOLUTION: A pump is equipped with a frame 30; an annular cover portion 100 which has a hole portion 100a; an impeller 40; a seal cover 50 which has a through-hole 50a having a smaller diameter than the hole portion of the annular cover portion; a pump shaft 60 which passes through the through-hole, is removably fixed on an upper part of the impeller at a lower end portion, and opposes to a lower end portion of a motor shaft 11 of a motor while keeping a clearance through which the seal cover can pass, at an upper end portion; a coupling 70 which couples the lower end portion of the motor shaft and the upper end portion of the pump shaft; and a mechanical seal 80 which seals a clearance between an inner peripheral surface of the through-hole of the seal cover and the pump shaft, on a lower side to the seal cover.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a pump that can be used for cold / hot water circulation and the like.

Conventionally, the pump shaft is connected to the motor shaft via a coupling (shaft coupling), and a mechanical seal is provided between the seal cover (seal retainer plate) provided around the pump shaft and the pump shaft. A known pump is known (for example, Patent Document 1).
The mechanical seal may be replaced during maintenance of the pump because the wear of the stationary ring and the rotating ring gradually slide with each other due to the operation of the pump over a long period of time. In the pump of Patent Document 1, when exchanging the mechanical seal, first, the coupling and the motor are removed, and the seal cover and the mechanical seal are extracted from the pump shaft.

JP 2005-120862 A

  However, in the pump configuration as described above, for example, when the weight of the pump is several hundred kg or more, it is difficult or impossible for a maintenance worker to remove the motor, and the replacement work of the mechanical seal is complicated. There was a problem of becoming.

  The present invention has been made to solve the above-described problems, and an object of the present invention is to provide a pump that can easily replace a mechanical seal.

  In order to achieve the above object, the gist of the present invention is as follows.

The pump of the present invention is
A casing that forms a flow path and is open at the top;
A motor disposed above the casing;
A frame which is provided between the casing and the motor and holds the height of the motor relative to the casing;
An annular cover portion configured integrally or separately with the frame, having a hole portion extending vertically and covering the opened upper portion of the casing;
An impeller housed in the casing;
A seal cover having a through-hole having a smaller diameter than the hole portion of the annular cover portion and removably fixed to the annular cover portion so as to cover the hole portion from above;
Through the through hole of the seal cover, the lower end is fixed to the upper part of the impeller so as to be removable, and the upper end faces the lower end of the motor shaft of the motor with a gap through which the seal cover can pass. The pump shaft,
A coupling connecting the lower end of the motor shaft and the upper end of the pump shaft;
A mechanical seal that seals a gap between an inner peripheral surface defining the through-hole of the seal cover and the pump shaft on a lower side with respect to the seal cover;
It is provided with.
According to the pump of the present invention, the mechanical seal can be easily replaced.

In the pump of the present invention,
The lower end portion of the pump shaft is provided with a flange portion extending toward the outer peripheral side of the pump shaft,
The flange portion is fastened to the top of the impeller by a fastening member from above,
It is preferable that the hole portion of the annular cover portion is formed so as to allow the flange portion to pass therethrough.
According to this, the removal and attachment work of a pump shaft becomes easy, and replacement | exchange of a mechanical seal can be performed more easily.

In the pump of the present invention,
It is preferable that the gap L between the lower end portion of the motor shaft and the upper end portion of the pump shaft is 20 to 30 mm.
According to this, the enlargement of the pump can be suppressed.

  ADVANTAGE OF THE INVENTION According to this invention, the pump which can replace | exchange a mechanical seal easily can be provided.

It is a side view which shows the pump of one Embodiment of this invention. It is a partial longitudinal cross-sectional view in alignment with the AA line containing a rotating shaft line which shows the pump of FIG. It is a partial longitudinal cross-sectional view which shows the state which removed the pin and the coupling from the pump of FIG. It is a partial longitudinal cross-sectional view which shows the state which removed the seal cover from the pump of FIG. It is a partial longitudinal cross-sectional view which shows the state which removed the pump shaft from the pump of FIG. It is a partial longitudinal cross-sectional view which shows the modification of the pump of one Embodiment of this invention.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

A pump according to an embodiment of the present invention will be described with reference to FIGS. FIG. 1 is a side view showing a pump 1 according to the present embodiment, and FIG. 2 shows a main part of the pump 1 according to the present embodiment along the line AA in FIG. 1 including the rotation axis C1 of the pump 1. FIG.
The pump 1 of this embodiment includes a casing 20 that forms a flow path 23, a motor 10 that is disposed above the casing 20, and a frame 30 that is provided between the casing 20 and the motor 10. It is configured as a vertical pump and can be suitably used for, for example, cold / hot water circulation, water supply pressurization, various machine sets, industrial water pressurization, general water supply, and the like.
The rotation axis C1 of the pump 1 is the same as the central axis of the motor shaft 11 (output shaft of the motor 10) located at the lower end of the motor 10.

  In addition to the casing 20, the motor 10, and the frame 30, the pump 1 of this embodiment includes an annular cover portion 100, an impeller 40, a seal cover 50, a pump shaft 60, a coupling 70, and a mechanical seal 80. And.

The casing 20 has a suction port 20 a and a discharge port 20 b at both ends of the flow path 23 formed by the casing 20. When the impeller 40 is rotated by the rotation of the motor 10 during the operation of the pump 1, the fluid (water in this example) sucked into the flow path 23 from the suction port 20 a is pressurized by the impeller 40, After exiting the vehicle 40, it passes through the spiral flow path 23 and then exits from the discharge port 20b. The pump 1 of this example is configured as an in-line type pump. Specifically, the central axis C2 of the suction port 20a and the central axis C3 of the discharge port 20b coincide with each other, and the suction port 20a and the discharge port 20b are directed opposite to each other in the direction along the central axes C2 and C3. Thereby, the pump 1 can be easily attached to a part of a straight pipe line.
However, the pump 1 of the present example does not have to be configured in an inline type. That is, the central axis C2 of the suction port 20a and the central axis C3 of the discharge port 20b do not have to coincide with each other, and the suction port 20a and the discharge port b may face in any direction.

The casing 20 accommodates the impeller 40 inside (and thus in the flow path 23), and an upper portion corresponding to the impeller 40 is opened. Through the opened upper portion of the casing 20, the flow path 23 in the casing 20 communicates with the outside of the casing 20 (more specifically, the inside of the frame 30). Since the upper part of the casing 20 corresponding to the impeller 40 is opened, the impeller 40 can be inserted into the casing 20 from the opened upper part of the casing 20 when the pump 1 is assembled. Yes.
An annular cover portion 100 is provided on the opened upper portion of the casing 20 so as to cover from above. The annular cover portion 100 has a hole portion 100a penetrating vertically along the rotation axis C1, and as a result, is configured in an annular shape around the rotation axis C1. As will be described later, in this example, the annular cover portion 100 is integrally formed with the frame 30 at the lower portion of the frame 30, and the annular cover portion 100 and the frame 30 integrally constitute an intermediate frame member 90. .
In this example, the impeller 40 is in contact with each of the inner surface of the casing 20 and the lower end portion of the annular cover portion 100 via the O-ring 24.

  The motor 10 is held at a predetermined height with respect to the casing 20 by the frame 30. In this example, the frame 30 is configured in a substantially inverted cup shape. More specifically, the frame 30 is connected to the cylindrical peripheral wall portion 31 connected to the upper end portion of the annular cover portion 100 and the upper end portion of the peripheral wall portion 31. The upper wall portion 32 is provided. A motor 10 mounted thereon is attached to the upper wall portion 32 of the frame 30, and a motor shaft 11 that is an output shaft of the motor 10 penetrates vertically. The central axis of the motor shaft 11 is the rotation axis C <b> 1 of the pump 1.

The casing 20 and the frame 30 each have the above-described functions (the function of forming the flow path 23 for the casing 20; the function of maintaining the height of the motor 10 with respect to the casing 20 for the frame 30). Each configuration can be arbitrary.
For example, in this example, the annular cover portion 100 and the frame 30 integrally form the intermediate frame member 90, whereby the annular cover portion 100 and the frame 30 are configured separately. In comparison, the number of parts of the pump 1 can be reduced, and the cost can be reduced. However, the annular cover portion 100 and the frame 30 may be configured separately from each other.

  As described above, the motor shaft 11 passes through the upper wall portion 32 of the frame 30 and extends below the upper wall portion 32. Inside the frame 30, a lower end portion of the motor shaft 11 and an upper end portion of the pump shaft 60 are disposed so as to be opposed to each other in the vertical direction, and the lower end portion of the motor shaft 11 and the upper end portion of the pump shaft 60 are arranged. A coupling (shaft coupling) 70 is connected. The rotation of the motor shaft 11 is transmitted to the pump shaft 60 by the coupling 70. The central axis of the pump shaft 60 coincides with the central axis (rotation axis C1) of the motor shaft 11. In this example, a pin 71 is horizontally inserted into the coupling 70 and the upper end portion of the pump shaft 60. In this example, the pin 71 is a parallel pin.

  The peripheral wall portion 31 of the frame 30 has a window 30a that is partially opened. The window 30a is formed so that the coupling 70, the seal cover 50, and the pump shaft 60 can pass therethrough.

  The seal cover 50 is formed in a plate shape (in this example, a disc shape), has a through hole 50a along the rotation axis C1 having a smaller diameter than the hole portion 100a of the annular cover portion 100, and the annular cover portion 100. The fastening member 52 is detachably fixed to the annular cover part 100 so as to cover the hole part 100a from above. In FIG. 2, the fastening member 52 on the left side of the drawing is omitted. The fastening member 52 is a bolt in this example.

  In this example, the seal cover 50 is formed with an air hole 50b that connects the inside of the frame 30 and the inside of the casing 20 (and thus the flow path 23), and an air vent valve 51 is provided in the air hole 50b. It is attached. The air vent valve 51 is used for venting air in the flow path 23 of the pump 1 when the operation of the pump 1 is started. More specifically, the air vent valve 51 is opened by an operator when the operation of the pump 1 is started, during which water is supplied into the flow path 23 of the pump 1. When it can be confirmed that water comes out of the air vent valve 51, the air is completely removed from the flow path 23.

  The pump shaft 60 passes through the through hole 50 a of the seal cover 50. A lower end portion of the pump shaft 60 located inside the casing 20 is detachably fixed to an upper portion of the impeller 40. More specifically, in this example, the pump shaft 60 is directed from the main body portion 61 having substantially the same diameter over the entire length and the lower end portion of the pump shaft 60 positioned below the main body portion 61 toward the outer peripheral side of the pump shaft 60. And the flange portion 62 is fastened to the upper portion of the impeller 40 by a fastening member 63 from above. Thereby, the removal operation | work from the impeller 40 of the pump shaft 60 and the attachment operation | work to the impeller 40 become easy, and the replacement | exchange operation | work of the mechanical seal 80 becomes easy by extension. In FIG. 2, the fastening member 63 on the left side of the drawing is omitted. The fastening member 63 is a bolt in this example.

  In this example, the pump 1 is configured as a single-stage pump having only one impeller 40, but the pump 1 is configured as a multi-stage pump in which a plurality of impellers 40 are stacked on the upper and lower stages. May be. When the pump 1 is configured as a multistage pump, the lower end portion of the pump shaft 60 (more specifically, the flange portion 62 in this example) is fixed to the upper portion of the uppermost impeller 40.

The hole portion 100a of the annular cover portion 100 is formed so that the flange portion 62 of the pump shaft 60 can be passed therethrough. More specifically, in this example, the hole 100a of the annular cover 100 and the flange 62 of the pump shaft 60 each have a circular planar shape, and the inner diameter of the hole 100a of the annular cover 100 is The outer diameter of the flange portion 62 of the pump shaft 60 is equal to or greater than that.
The inner diameter of the through hole 50 a of the seal cover 50 is smaller than the outer diameter of the flange portion 62 of the pump shaft 60 and slightly larger than the outer diameter of the main body portion 61 of the pump shaft 60.

The upper end portion of the pump shaft 60 faces the lower end portion of the motor shaft 11 of the motor 10 in the vertical direction with a gap through which the seal cover 50 can pass.
The gap L between the lower end of the motor shaft 11 and the upper end of the pump shaft 60 does not exceed the minimum length required to allow the seal cover 50 to pass through the gap by about 5 mm or more. It is preferable, for example, 20-30 mm is preferable. Thereby, the height of the pump 1 becomes uselessly high, and by extension, the enlargement of the pump 1 can be suppressed. Further, if the distance from the upper end of the motor shaft 11 to the lower end of the pump shaft 60 is excessively long, the shaft may run around during the rotation of the pump 1. Therefore, by reducing the distance L between the motor shaft 11 and the pump shaft 60 as much as possible, the shaft swing of the pump 1 can be suppressed.
From the same viewpoint, the length obtained by subtracting the maximum value of the thickness T of the portion of the seal cover 50 that can be passed through the gap between the pump shaft 60 and the motor shaft 11 from the distance L is 5 mm. The following is preferable.

  The mechanical seal 80 is provided around the main body portion 61 of the pump shaft 60, and on the lower side of the seal cover 50, the inner peripheral surface of the seal cover 50 that defines the through hole 50 a and the main body portion 61 of the pump shaft 60. Is sealed (shaft sealed) to prevent water from the casing 20 from leaking to the upper side of the seal cover 50 (and thus in the frame 30). The mechanical seal 80 has a fixed ring 81 and a rotating ring 82. The fixed ring 81 is attached to the lower end portion of the inner peripheral surface that defines the through hole 50 a of the seal cover 50 and is not rotated when the pump 1 is rotated. The rotary ring 82 is attached to the outer peripheral surface of the main body 61 of the pump shaft 60 below the fixed ring 81 and rotates together with the pump shaft 60 when the pump 1 rotates. The lower surface of the fixed ring 81 and the upper surface of the rotating ring 82 are in contact with each other. When the pump 1 rotates, the upper surface of the rotary ring 82 slides on the lower surface of the fixed ring 81, and the outer peripheral surface of the main body 61 of the pump shaft 60 slides on the inner peripheral surface of the fixed ring 81.

In addition, although other members, such as a sleeve, may be interposed between the mechanical seal 80 and the pump shaft 60, from the viewpoint of reducing the number of parts, the mechanical seal 80 and the pump shaft 60 are It is preferable that no other member be interposed between them.
If a sleeve is interposed between the mechanical seal 80 and the pump shaft 60, in addition to increasing the cost of the sleeve itself, the size of the mechanical seal 80 is increased by the size of the sleeve, leading to an increase in cost. . In that case, it is necessary to provide an O-ring together with the sleeve, but if the O-ring is not properly assembled, it may cause water leakage or dust or foreign matter may enter between the O-ring and the sleeve. There is sex. Further, since the O-ring is a consumable item, it is necessary to replace the O-ring.

  In this example, a drain hole 90 a that connects the inside of the frame 30 and the outside of the pump 1 is formed at the lower end portion of the intermediate frame member 90 that is configured integrally with the frame 30 and the annular cover portion 100. When water leaks from the mechanical seal 80 into the frame 30 by the drain hole 90 a, the water is not accumulated inside the frame 30 but is discharged to the outside of the pump 1.

In this example, as described above, the impeller 40 is in contact with the lower end portion of the annular cover portion 100 via the O-ring 24. The annular cover portion 100 includes, on the upper side with respect to the O-ring 24, the flow path 23 facing the mechanical seal 80 on the upper side of the impeller 40 and on the inner peripheral side of the O-ring 24, and the outer peripheral side of the impeller 40 and A narrow channel 100b that connects the channel 23 on the outer peripheral side of the O-ring 24 is formed. According to the narrow channel 100 b of the annular cover part 100, the mechanical seal 80 can be cooled by supplying water around the mechanical seal 80 during operation of the pump 1.
In this example, a narrow channel 40 a penetrating vertically is formed in the upper part of the impeller 40. According to the narrow flow path 40a of the impeller 40, the pressure difference generated at the upper and lower positions of the impeller 40 can be reduced, and consequently the downward thrust load generated by the pressure difference can be suppressed.

Next, the procedure for exchanging the mechanical seal 80 in the pump 1 having the above-described configuration will be described with reference to FIGS. The worker performs an exchange operation while putting a hand, a tool, or the like into the frame 30 or the casing 20 from the window 30a of the frame 30.
First, the bolts fixing the coupling 70 are removed, the coupling 70 is removed from the pump shaft 60 and the motor shaft 11, and is taken out of the window 30 a of the frame 30. Thereafter, the pin 71 is pulled out of the pump shaft 60 and taken out of the window 30a of the frame 30. FIG. 3 shows a state in which the coupling 70 and the pin 71 are removed from the pump 1.
Next, the fastening member 52 fixing the seal cover 50 to the annular cover portion 100 is removed from the upper side, and the seal cover 50 is slid upward along the main body portion 61 of the pump shaft 60 as shown in FIG. And extracted from the gap between the pump shaft 60 and the motor shaft 11 and out of the window 30a of the frame 30.
Next, the fastening member 63 that fixes the flange portion 62 of the pump shaft 60 to the upper portion of the impeller 40 is removed from the upper side, and the pump shaft 60 is detached from the impeller 40 as shown in FIG. Go out of 30 windows 30a.
Then, the fixed ring 81 of the mechanical seal 80 mounted on the seal cover 50 is replaced with a new one, and the rotating ring 82 of the mechanical seal 80 mounted on the pump shaft 60 is replaced with a new one.
Thereafter, the replacement work is completed by assembling the pump 1 in the reverse order of the above disassembling procedure.

  As described above, according to the pump 1 of this embodiment, when the mechanical seal 80 is replaced, a large-scale operation such as removing the motor 10 is unnecessary, and the fastening members 52 and 63 for fixing the seal cover 50 and the pump shaft 60. It is only necessary to perform simple operations such as removing Therefore, even if the pump 1 has a weight of several hundred kg or more, the mechanical seal 80 can be easily replaced.

In addition, the pump 1 of this embodiment is not restricted to the example mentioned above, Various modifications are possible.
For example, the seal cover 50 and the pump shaft 60 are only required to be detachably fixed to the upper portions of the annular cover portion 100 and the impeller 40 from the upper side, respectively. Such bolt fastening is not essential.
For example, as in the modification shown in FIG. 6, the fastening member 63 for fixing the flange portion 62 of the pump shaft 60 to the upper portion of the impeller 40 is a stud bolt whose one end is fixed to the upper portion of the impeller 40 in advance. And a nut. In this case, when fixing the flange portion 62 of the pump shaft 60 to the upper portion of the impeller 40, the stud bolt is passed through the flange portion 62 of the pump shaft 60, and the nut is tightened around the stud bolt from above. In addition, although illustration is abbreviate | omitted, the fastening member 52 for fixing the seal cover 50 to the cyclic | annular cover part 100 similarly is also the implantation bolt by which one end part was previously fixed to the upper part of the cyclic | annular cover part 100, a nut, May be configured.
Alternatively, for example, without providing the flange portion 62 at the lower end portion of the pump shaft 60, a screw (male screw) is formed on the outer peripheral surface of the lower end portion of the pump shaft 60, and a concave portion is formed at the upper portion of the impeller 40, A screw (female screw) may be formed on the inner peripheral surface of the recess, and the pump shaft 60 may be detachably fixed by screwing to the impeller 40.

  In addition, liquids (for example, seawater, oil, etc.) other than water and gas can also be used for the pump of this invention.

  The pump of the present invention can be suitably used for, for example, cold / hot water circulation, water supply pressurization, various machine sets, industrial water pressurization, and general water supply.

DESCRIPTION OF SYMBOLS 1 Pump 10 Motor 11 Motor shaft 20 Casing 20a Suction port 20b Discharge port 23 Flow path 24 O-ring 30 Frame 30a Window 31 Frame peripheral wall part 32 Frame upper wall part 40 Impeller 40a Impeller narrow channel 50 Seal cover 50a Through Hole 50b Air hole 51 Air venting valves 52, 63 Fastening member 60 Pump shaft 61 Pump shaft main body 62 Pump shaft flange 70 Coupling 71 Pin 80 Mechanical seal 81 Fixed ring 82 Rotating ring 90 Intermediate frame member 90a Drain hole 100 Annular cover part 100a Annular cover part hole 100b Annular cover part narrow channel C1 Rotating axis C2 Suction port center axis C3 Discharge port center axis

Claims (3)

A casing that forms a flow path and is open at the top;
A motor disposed above the casing;
A frame which is provided between the casing and the motor and holds the height of the motor relative to the casing;
An annular cover portion configured integrally or separately with the frame, having a hole portion extending vertically and covering the opened upper portion of the casing;
An impeller housed in the casing;
A seal cover having a through-hole having a smaller diameter than the hole portion of the annular cover portion and removably fixed to the annular cover portion so as to cover the hole portion from above;
Through the through hole of the seal cover, a lower end portion is detachably fixed to an upper portion of the impeller, and an upper end portion is spaced from the lower end portion of the motor shaft of the motor with a gap through which the seal cover can pass. Opposite the pump shaft,
A coupling connecting the lower end of the motor shaft and the upper end of the pump shaft;
A mechanical seal that seals a gap between an inner peripheral surface defining the through-hole of the seal cover and the pump shaft on a lower side with respect to the seal cover;
A pump comprising: The lower end portion of the pump shaft is provided with a flange portion extending toward the outer peripheral side of the pump shaft,
The flange portion is fastened to the top of the impeller by a fastening member from above,
The pump according to claim 1, wherein the hole portion of the annular cover portion is formed so as to allow the flange portion to pass therethrough.   The pump according to claim 1 or 2, wherein an interval L of the gap between the lower end portion of the motor shaft and the upper end portion of the pump shaft is 20 to 30 mm.

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