JP2017180241A - Pump and liner ring - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a pump capable of reducing a leakage flow rate and improving a pump efficiency.SOLUTION: A pump 1 comprises: an impeller 11 where fluid is sucked from an axial direction and discharged from a radial direction; a casing 12 storing the impeller 11; and a liner ring 13 attached at a clearance between the impeller 11 and the casing 12. The liner ring 13 is arranged at a position outside in a radial direction of the impeller 11. The position outside the radial direction of the impeller 11 shows a lower static pressure difference as compared with that at a position inside the radial direction, so that it is possible to reduce a leakage flow rate as compared with that the liner ring 13 is arranged at the position inside the radial direction and it is possible to improve a pump efficiency.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a pump and a liner ring used for the pump.

  2. Description of the Related Art Conventionally, a horizontal axis centrifugal pump (so-called horizontal axis dual suction centrifugal pump) equipped with a double suction impeller has been used in pump facilities for water and sewage and agriculture. In both conventional suction centrifugal pumps, a liner ring is provided in the gap between the impeller and the casing (see, for example, Patent Document 1). The liner ring serves as a partition between the discharge side and the suction side. Further, the liner ring has a role as a separator between the movable part and the stationary part. By providing a liner ring and reducing the gap, the leakage flow rate is reduced and the pump efficiency is improved.

JP 2014-37807 A

  However, in the conventional pump, the liner ring is provided on the radially inner side (near the suction position) of the impeller. Since there is a large static pressure difference inside the impeller in the radial direction, there is a problem that unless some measures are taken, the leakage flow rate increases and the pump efficiency decreases. In order to reduce the leakage flow rate, precise machining (high dimensional accuracy) and assembly accuracy are required, leading to higher cost of the pump.

  This invention is made | formed in view of said subject, and it aims at providing the pump which can reduce a leakage flow rate and can improve pump efficiency.

  The pump of the present invention includes an impeller from which fluid is sucked from the axial direction and discharged from the radial direction, a casing that houses the impeller, and a liner ring that is attached to a gap between the impeller and the casing. The liner ring is disposed at a position radially outward of the impeller.

  According to this structure, the liner ring attached to the clearance gap between an impeller and a casing is arrange | positioned in the radial direction outer side position of an impeller. The position on the radially outer side of the impeller has a smaller static pressure difference than the position on the radially inner side. Therefore, the leakage flow rate can be reduced and the pump efficiency can be improved as compared with the case where the liner ring is arranged at the radially inner position as in the prior art. In this case, since the liner ring is disposed at a position where the static pressure difference is small, the permissible gap is larger than in the case where the liner ring is disposed at the radially inner position as in the prior art. Therefore, high dimensional accuracy and assembly accuracy are not required, and cost reduction can be achieved. Further, since the allowable gap is large, the replacement frequency of the liner ring can be reduced, and the maintenance cost can be reduced.

  In the pump of the present invention, the liner ring is attached so as to be in contact with the outer peripheral surface of the impeller in the radial direction, and is in contact with the inner peripheral surface of the casing facing the outer peripheral surface of the impeller. Also good.

  According to this configuration, the liner ring is attached to the gap between the outer peripheral surface of the impeller and the inner peripheral surface of the casing at a position outside the impeller in the radial direction. Thereby, compared with the case where a liner ring is arrange | positioned in the position inside radial direction like the past, a leakage flow rate can be reduced and pump efficiency can be improved.

  Further, in the pump of the present invention, the liner ring is attached so as to be in contact with an axial side surface of the impeller in the radial direction, and is in contact with an inner surface of the casing facing the axial side surface of the impeller. Also good.

  According to this configuration, the liner ring is attached to the gap between the axial side surface of the impeller and the inner surface of the casing at a position on the radially outer side of the impeller. Thereby, compared with the case where a liner ring is arrange | positioned in the position inside radial direction like the past, a leakage flow rate can be reduced and pump efficiency can be improved.

  In the pump of the present invention, the liner ring is attached so as to be in contact with an outer peripheral surface and an axial side surface of the impeller in the radial direction, and an inner periphery of the casing facing the outer peripheral surface of the impeller. You may contact a surface and the inner surface of the casing facing the axial side surface of the impeller.

  According to this configuration, the liner ring is attached to the gap between the outer peripheral surface of the impeller and the inner peripheral surface of the casing at a position radially outside the impeller, and the axial side surface of the impeller and the casing It is attached to the gap between the inner surface. Thereby, compared with the case where a liner ring is arrange | positioned in the position inside radial direction like the past, a leakage flow rate can be reduced and pump efficiency can be improved.

  The liner ring of the present invention is a liner ring used in a pump including an impeller from which fluid is sucked in from an axial direction and discharged from a radial direction, and a casing that houses the impeller. It attaches to the clearance gap between the said casings, and is arrange | positioned in the position of the radial direction outer side of the said impeller.

  This liner ring is also arranged at a position radially outside the impeller. The position on the radially outer side of the impeller has a smaller static pressure difference than the position on the radially inner side. Therefore, the leakage flow rate can be reduced and the pump efficiency can be improved as compared with the case where the liner ring is arranged at the radially inner position as in the prior art. In this case, since the liner ring is disposed at a position where the static pressure difference is small, the permissible gap is larger than in the case where the liner ring is disposed at the radially inner position as in the prior art. Therefore, high dimensional accuracy and assembly accuracy are not required, and cost reduction can be achieved. Further, since the allowable gap is large, the replacement frequency of the liner ring can be reduced, and the maintenance cost can be reduced.

  According to the present invention, by arranging the liner ring at a position on the radially outer side of the impeller, the leakage flow rate can be reduced and the pump efficiency can be improved.

It is sectional drawing of the pump in embodiment of this invention. It is the figure which expanded the principal part of the pump in embodiment of this invention. It is the figure which expanded the principal part of the modification of the pump in embodiment of this invention. It is the figure which expanded the principal part of the other modification of the pump in embodiment of this invention.

  Hereinafter, a pump according to an embodiment of the present invention will be described with reference to the drawings. In the present embodiment, the case of a horizontal axis centrifugal pump (horizontal axis dual suction centrifugal pump) provided with both suction impellers is illustrated. The horizontal-axis double suction centrifugal pump is used for pump facilities for water and sewage and agriculture, for example.

  The configuration of the pump according to the embodiment of the present invention will be described with reference to the drawings. FIG. 1 is a sectional view showing a pump according to the present embodiment, and FIG. 2 is an enlarged view of a main part of the pump. As shown in FIG. 1, a pump 10 according to the present embodiment includes an impeller 11 in which fluid is sucked from the axial direction and discharged from the radial direction, a casing 12 that houses the impeller 11, an impeller 11 and a casing. A liner ring 13 is provided that is attached to a gap between the two.

  The casing 12 can be divided into an upper casing 12a and a lower casing 12b. The upper casing 12a and the lower casing 12b are fastened to each other using bolts while facing each other.

  The impeller 11 has a substantially disk shape. In the illustrated example, the impeller 11 is disposed between the upper casing 12a and the lower casing 12b in a posture in which the center axis is parallel to the left-right direction. . A main shaft 14 is provided at the center of the impeller 11 so as to extend to the left and right sides along the central axis of the impeller 11. The main shaft 14 is supported on both ends of the casing 12 via a bearing.

  One end (right end in FIG. 1) of the main shaft 14 extends to the outside of the casing 12 and is connected to an electric motor (not shown) that transmits rotational power. When the main shaft 14 and the impeller 11 are integrally rotated inside the casing 12 by the rotational power from the electric motor, the fluid inside the casing 12 is sucked in from the left and right suction ports of the impeller 11, and the impeller. 11 is discharged from the discharge port on the outer periphery.

  As shown in FIG. 2, the liner ring 13 is arranged at a position outside the impeller 11 in the radial direction (upper side in FIG. 2). In this case, the liner ring 13 is attached so as to be in contact with the outer peripheral surface (the upper side surface in FIG. 2) on the radially outer side of the impeller 11, and the inner peripheral surface (see FIG. 2 on the lower side). The liner ring 13 is a metal ring-shaped member. As a material of the liner ring 13, for example, a copper alloy or stainless steel is used.

  Next, a method for assembling the pump 10 will be described. First, the liner ring 13 is put on the radially outer position of the impeller 11, and the impeller 11 and the liner ring 13 are accommodated together inside the lower casing 12b. The liner ring is fixed to the lower casing 12b using a knock pin so as not to rotate inside the casing 12. Subsequently, the upper casing 12a is placed so as to cover the impeller 11, and the upper casing 12a and the lower casing 12b are fastened to each other using bolts.

  In the pump 10 of this embodiment, the liner ring 13 attached to the gap between the impeller 11 and the casing 12 is disposed at a position on the radially outer side of the impeller 11. In this case, the liner ring 13 is attached to a gap between the outer peripheral surface of the impeller 11 and the inner peripheral surface of the casing 12 at a position on the radially outer side of the impeller 11. The position on the radially outer side of the impeller 11 has a smaller static pressure difference than the position on the radially inner side. Therefore, the leakage flow rate can be reduced and the pump efficiency can be improved as compared with the conventional case where the liner ring 13 is disposed at the radially inner position.

  Further, in the pump 10 of the present embodiment, the liner ring 13 is disposed at a position where the static pressure difference is small, so that it is permissible compared to the case where the liner ring 13 is disposed at a radially inner position as in the prior art. The gap is large. Therefore, high dimensional accuracy and assembly accuracy are not required, and cost reduction can be achieved. Further, since the allowable gap is large, the replacement frequency of the liner ring 13 can be low, and the maintenance cost can be reduced.

  The embodiments of the present invention have been described above by way of example, but the scope of the present invention is not limited to these embodiments, and can be changed or modified according to the purpose within the scope of the claims. is there.

  For example, FIG. 3 shows a modification of the pump 10. In the example of FIG. 3, the liner ring 13 is attached so as to be in contact with the radially outer axial side surface (the left side surface in FIG. 3) of the impeller 11, and the casing 12 is opposed to the axial side surface of the impeller 11. It is in contact with the inner surface (the right side surface in FIG. 3).

  Also in this case, the liner ring 13 is attached to the gap between the axial side surface of the impeller 11 and the inner surface of the casing 12 at a position on the radially outer side of the impeller 11. Therefore, the leakage flow rate can be reduced and the pump efficiency can be improved as compared with the conventional case where the liner ring 13 is disposed at the radially inner position.

  FIG. 4 shows another modification of the pump 10. In the example of FIG. 4, the liner ring 13 having an L-shaped cross section is in contact with the radially outer peripheral surface (upper side surface in FIG. 4) and the axial side surface (left side surface in FIG. 4) of the impeller 11. Attached to the inner peripheral surface (lower side surface in FIG. 4) of the casing 12 facing the outer peripheral surface of the impeller 11 and the inner surface (right side surface in FIG. 4) of the casing 12 facing the axial side surface of the impeller 11. doing.

  Also in this case, the liner ring 13 is attached to the gap between the outer peripheral surface of the impeller 11 and the inner peripheral surface of the casing 12 at a position on the radially outer side of the impeller 11, and the axial side surface of the impeller 11. And a gap between the inner surface of the casing 12. Therefore, the leakage flow rate can be reduced and the pump efficiency can be improved as compared with the conventional case where the liner ring 13 is disposed at the radially inner position.

  As described above, the pump according to the present invention has the effect that the leakage flow rate can be reduced and the pump efficiency can be improved, and it is useful for water and sewage and agricultural pump equipment. is there.

DESCRIPTION OF SYMBOLS 10 Pump 11 Impeller 12 Casing 12a Upper casing 12b Lower casing 13 Liner ring 14 Spindle

Claims (5)

An impeller in which fluid is sucked from the axial direction and discharged from the radial direction;
A casing for housing the impeller,
A liner ring attached to a gap between the impeller and the casing;
With
The said liner ring is a pump arrange | positioned in the position of the radial direction outer side of the said impeller.   The said liner ring is attached so that it may contact the outer peripheral surface of the radial direction outer side of the said impeller, and is contacting the inner peripheral surface of the said casing facing the outer peripheral surface of the said impeller. pump.   The said liner ring is attached so that it may contact the axial direction side surface of the radial direction outer side of the said impeller, and is contacting the inner surface of the said casing facing the axial direction side surface of the said impeller. pump.   The liner ring is attached so as to be in contact with the radially outer peripheral surface and the axial side surface of the impeller, and the inner peripheral surface of the casing and the axial direction of the impeller facing the outer peripheral surface of the impeller. The pump according to claim 1, which is in contact with an inner surface of the casing facing a side surface. A liner ring used in a pump including an impeller in which fluid is sucked from an axial direction and discharged from a radial direction, and a casing that houses the impeller,
A liner ring that is attached to a gap between the impeller and the casing and is disposed at a position radially outward of the impeller.

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