JP5164558B2 - Fluid machinery and pumps - Google Patents

Description

  The present invention relates to a fluid machine and a pump, and relates to a technology for manufacturing a blade of a fluid machine such as a pump or a water wheel for handling a fluid (seawater, rainwater, drainage, etc.). Is.

  As an example of the configuration of a conventional pump device, a vertical shaft mixed flow pump device is shown in FIGS. 6-8, the pump casing 2 of the vertical-shaft mixed-flow pump apparatus 1 is comprised from the lower end in order from the suction bell mouth 3, the bowl part 4, and the pumping pipe 5, and the bend pipe | tube 6 is arrange | positioned at the upper end.

  A rotating shaft 7 is inserted into the casing 2, an impeller 8 attached to the lower end of the rotating shaft 7 is positioned inside the suction bell mouth 3 and the bowl portion 4, and the rotating shaft 7 is connected to a plurality of bearing devices 9. Is supporting.

  A guide vane 10 is arranged inside the bowl portion 4, and the guide vane 10 is composed of a plurality of blades 13. The tip of the blade 13 is joined to the outer cylinder 11 of the bowl portion 4, and the boss side is joined to the inner cylinder 12. doing.

The impeller and the pump casing are main components that affect the pump performance, and the shape of the blade is a three-dimensional complicated curved surface.
For this reason, in the past, guide blades of impellers and pump casings were manufactured by casting, and the manufacturing flow was as follows. First, a wooden model was manufactured, and then a mold was manufactured. Forming and assembling, casting molten metal into the mold, casting the casting, sand casting shot blasting to the released casting, grinding and cleaning, followed by heat treatment and roughing processing and inspection there were.

  However, the guide blade usually requires 6 to 10 blades, and when the diameter is large, the casting cost and the processing cost become high. Further, in casting production, the thickness is determined for each material and diameter range due to production problems, and there is a casting limit. For this reason, it becomes easy to become an excessive thickness, and it becomes an excessive quality and a cost increase.

For this reason, it has been proposed that the guide vanes are made of steel plates and attached by welding.
For example, in Patent Document 1, the outflow angle at the blade outlet of the impeller is substantially the same from the hub side to the tip side, and the sheet metal guide blades are divided into a plurality of front and rear parts so that the cross section has an arc shape with respective radii. A configuration in which they are attached while being shifted from each other in the rotational direction is disclosed.

Further, in Patent Document 2, a reference line that is orthogonal to the hub surface and intersects the rotation axis is assumed, a plurality of parallel planes are hypothesized to be orthogonal to the reference line, and the intersection line between these planes and the impeller blades is obtained. Approximate each of the circular arcs of the same radius so that the center points of the circles are on the same straight line, and imaginary elliptic cylinders having these approximate circular arcs on the peripheral surface and having the central axis on the straight line. Approximate the peripheral surface of the part with the approximate arc of the elliptic cylinder with a cylinder having a central axis parallel to the straight line, and cut out a part of the peripheral surface of this cylinder to make an impeller blade, and if necessary, impeller blade A configuration is disclosed in which the diameter of the cylinder and the direction of the central axis are adjusted so that the inlet angle of the inlet side and the outlet angle of the outlet side coincide with the flow angle of the fluid. There exist patent documents 3-8 as other prior art documents.
JP-A-6-213189 JP 2002-147390 A Japanese Patent Laid-Open No. 10-18997 JP 2002-195185 A JP 2001-107897 A JP 2005-83232 A JP 2001-123994 A JP 2000-145607 A

  By the way, a blade shape (hereinafter referred to as a cast shape) related to casting production has a three-dimensional complicated curved shape, but it is difficult to make a can as it is. For this reason, in each of the above-mentioned Patent Documents 1 to 8, the guide vanes of the pump casing to be made are divided, and various contrivances are made to the blade shape (hereinafter referred to as the can-making shape).

  However, in order to realize an ideal three-dimensional curved surface by can manufacturing, a mold such as a mold having a complicated structure is required, and the manufacturing cost thereof is high. For this reason, the conventional can-shaped guide vanes have a larger fluid loss than the casting-shaped guide vanes, which is a factor in reducing the pump performance.

  The present invention solves the above-described problems, and a fluid machine and a pump capable of simplifying the meridian shape of a blade in consideration of moldability by can manufacturing and suppressing deterioration of fluid machine performance due to can manufacturing The purpose is to provide.

In order to solve the above problems, a fluid machine of the present invention includes a boss portion disposed coaxially in a casing, and a plurality of blades disposed at predetermined angular intervals around the axis of the boss portion. The plate material is formed into a predetermined shape by a can, and the boss side is joined to the boss portion, and the tip side wing tip and the boss side wing tip are curved into the same curved shape, and the tip side A blade surface shape composed of a combination of a plurality of different curved surfaces having the same blade angle on the blade surface and the blade angle on the boss side, and the inlet side on the tip side is predetermined upstream of the boss side in the flow direction. A shape extending in a length is formed, and a shape extending in a planar shape along a tangential direction at the reference point is formed from a reference point that ends the curved surface shape of the blade surface .
The fluid machine of the present invention includes a boss portion arranged coaxially in the casing, and a plurality of blades arranged at predetermined angular intervals around the axis of the boss portion. The boss side is joined to the boss portion, and the tip side blade tip and the boss side blade tip are curved in the same curved shape, and the blade angle on the tip side blade surface and the boss The blade surface shape is a combination of a plurality of different curved surfaces with the same blade angle on the side blade surface, and the outlet portion has the same edge position on the tip side and the boss side in the casing axial direction. It is characterized in that it has a shape that is aligned with.

Further, the wing is characterized in that the wing surface shape is a combination of two cylindrical surfaces having different curvatures .

The pump according to the present invention is the fluid machine described above, wherein the blade is a blade of a stationary guide blade provided in the vicinity of the rotary impeller.

  The pump of the present invention is the fluid machine described above, and is characterized in that the blades form the blades of a rotating impeller that rotates in a casing.

  As described above, according to the present invention, the wing has a curved wing surface curved in the same curved shape on the tip side and the boss side, and is not a complicated shape changing in a three-dimensional three-axis direction. Therefore, the meridian shape (cross-sectional shape including the shaft center of the pump) is simplified, easy moldability is achieved in making cans, and the mold is simplified or unnecessary. And can be manufactured at low cost.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the present embodiment, the case where the present invention is applied to the guide blades of the vertical shaft mixed flow pump shown in FIG. 8 will be described previously, and the same components are denoted by the same reference numerals and description thereof will be omitted. In addition, this invention is applicable not only to the guide blade of a vertical axis diagonal flow pump but to manufacture of the rotary blade of the fluid machine which handles fluids (seawater, rainwater, drainage, etc.). It can also be applied to the guide vanes and runners of water wheels.

  1 to 3 show a guide blade made of a plate material such as a steel plate according to the present embodiment. In FIG. 1 to FIG. 3, the guide vane 21 includes a plurality of blades 24 disposed between the outer cylinder 22 and the inner cylinder 23 of the bowl portion 4 of the pump casing (an example of the casing) 2. The cylinder 22 is joined by welding, and the boss side is joined to the inner cylinder 23 by welding.

  The guide vane 21 according to the present embodiment has a simplified meridian shape (a cross-sectional shape including the shaft center of the pump) in consideration of the moldability of the can. Further, the outer cylinder 22 and the inner cylinder 23 forming the bowl portion 4 of the pump casing 2 are composed of upper cone portions 22a and 23a, cylindrical portions 22b and 23b, and lower cone portions 22c and 23c. A plate material is formed into a predetermined shape by can making, and a shape in which a curved shape is eliminated in the axial direction of the pump casing 2 is formed.

  Further, in FIG. 5 and FIG. 6, in consideration of fluid loss and dynamic pressure recovery in the Meridian shape, as shown by comparing the guide vanes made in the present embodiment with the guide vanes of conventional casting production. The blade 24 has a shape in which the shape of the outlet portion is such that the edge on the outlet side on the tip side and the boss side is aligned at the same position in the pump axis direction, and the edge on the outlet side is orthogonal to the axis of the pump casing 2. It has a linear shape along the direction, and here, the edge on the outlet side is on a plane including the boundary between the upper conical portions 22a and 23a and the cylindrical portions 22b and 23b. As a result, it is possible to design the bowl portion 4 to have a shorter surface.

  3A shows a blade section on the boss side of the blade, and FIG. 3B shows a blade section on the tip side of the blade. In the figure, the broken line indicates a blade section of a guide blade according to conventional casting production.

  As shown in FIG. 3, the blade 24 is a cylinder whose blade surface shape has two curvatures Ra and Rb in sections corresponding to the cylindrical portions 22 b and 23 b and the lower cone portions 22 c and 23 c of the outer cylinder 22 and the inner cylinder 23. The curved surfaces 24a and 24b forming the surfaces are joined at the joining point P, and the tip side blade tip joined to the outer tube 22 and the boss side blade tip joined to the inner tube 23 have the same curvature Ra, By curving into the curved shape of Rb, the blade angle on the blade surface on the tip side and the blade angle on the blade surface on the boss side form the same blade surface shape. However, the curved surface shape of the blade surface is not limited to a combination of two cylindrical surfaces having different curvatures Ra and Rb, but two curved surfaces 24a and 24b having different curvatures and types such as a cylindrical surface, a parabolic column surface, and an elliptical column surface are joined. Of course, it is also possible to connect and combine at the point P.

As shown as a comparison, the blade cross section of the guide vane according to the conventional casting production is different in shape on the tip side and the boss side.
In this way, the wing 24 has a curved wing surface curved into a curved shape with the same curvature on the tip side and the boss side, so that the wing 24 is not a complicated shape changing in a three-dimensional three-axis direction, Since it has a shape that changes only in the two-dimensional biaxial direction, it has become easy to form in can manufacturing and can be manufactured at low cost by simplifying the mold.

  In addition, the design concept in which the design parameters are set can be constructed by forming the blade 24 in a shape combining two curved surfaces having different curvatures Ra and Rb. In other words, pumps with different ratings can be easily designed by changing the curvature. Furthermore, it is possible to suppress a decrease in pump performance as compared with the case where the entire blade 24 is formed by a single curved surface. Moreover, the fall of performance can be suppressed rather than the case where a guide blade | wing is divided | segmented, and workability | operativity also improves.

  As shown in FIGS. 1 to 2, the blade 24 has a shape in which the shape of the inlet portion extends a predetermined length below the lower conical portion 23 c of the inner cylinder 23 of the bowl portion 4, that is, upstream in the flow direction. None, and a shape extending flatly from the reference point that terminates the curved surface shape of the blade surface along the tangential direction at this reference point. The blade angle of the flat blade surface 24c at the inlet portion of the blade 24 is the same blade inlet angle on the tip side and the boss side on the basis of the blade angle on the blade surface on the tip side where the circumferential velocity component due to centrifugal force is large. It is set. The position of each blade 24 is set with reference to the inner cylinder 23 on the boss side.

  As described above, by setting the blade angle of the planar blade surface at the inlet portion of the blade 24, the influence of the angle of attack on the tip side due to the flow can be reduced. There is a slight angle of attack on the boss side compared to the chip side, but there is a gap. It can be assumed that there is no effect on performance. This is clear from the analysis results shown in Table 1 and the velocity vector diagram shown in FIG.

  In the said Example, although demonstrated by the example which joined two cylindrical curved surfaces, three or more curved surfaces may be combined and the combination of a cylindrical surface and a parabolic column surface may be sufficient. In addition, the curved surface used here is a concept including a plane with curvature ≈0.

図４において、（ａ）はチップ側における速度ベクトルの分布を示し、（ｂ）はボス側における速度ベクトルの分布を示している。図４に示すように、チップ側においては翼２４の羽根角度α１に対して流れ角度α２は小さくなり、ボス側においては翼２４の羽根角度α１に対して流れ角度α３は大きくなる。しかしながら、α１、α２、α３の角度差は数度で僅かである。

4A shows the velocity vector distribution on the chip side, and FIG. 4B shows the velocity vector distribution on the boss side. As shown in FIG. 4, the flow angle α2 is smaller than the blade angle α1 of the blade 24 on the tip side, and the flow angle α3 is larger than the blade angle α1 of the blade 24 on the boss side. However, the angular difference between α1, α2, and α3 is only a few degrees.

The front view which shows the guide blade in embodiment of this invention Sectional view showing the blade cross section on the tip side of the guide vane (A) is a sectional view showing a blade section on the boss side, (b) is a sectional view showing a blade section on the tip side Velocity vector diagram showing analysis results The front view which shows the guide blade seen from the other angle in embodiment of this invention Front view showing guide vanes according to conventional casting production The guide vane which concerns on the conventional casting manufacture is shown, (a) is sectional drawing which passes along an axis line, (b) is AA arrow sectional drawing of (a). Sectional view showing a conventional vertical shaft mixed flow pump Flow diagram showing conventional casting production process

Explanation of symbols

1 Vertical shaft mixed flow pump device 2 Pump casing (an example of casing)
DESCRIPTION OF SYMBOLS 3 Suction bell mouth 4 Bowl part 5 Pumping pipe 6 Bend pipe 7 Rotating shaft 8 Impeller 9 Bearing device 10 Guide vane 11 Outer cylinder 12 Inner cylinder 13 Wing 21 Guide vane 22 Outer cylinder 22a, 23a Upper cone part 22b, 23b Cylindrical part 22c, 23c Lower cone part 23 Inner cylinder 24 Wings 24a, 24b Curved surface 24c Planar blade surface P Joint point

Claims (5)

A boss portion arranged coaxially in the casing, and a plurality of wings arranged at predetermined angular intervals around the axis of the boss portion,
The wing is formed by forming a plate material into a predetermined shape by making a can, and the boss side is joined to the boss portion, and is curved in the same curved shape at the tip side wing tip and the boss side wing tip, The blade surface shape is a combination of a plurality of different curved surfaces with the same blade angle on the tip-side blade surface and the blade angle on the boss-side blade surface , and the tip-side inlet is upstream in the flow direction from the boss side. A fluid machine characterized by having a shape extending to a predetermined length and having a shape extending flatly from a reference point that terminates the curved surface shape of the blade surface along a tangential direction at the reference point . A boss portion arranged coaxially in the casing, and a plurality of wings arranged at predetermined angular intervals around the axis of the boss portion,
The wing is formed by forming a plate material into a predetermined shape by making a can, and the boss side is joined to the boss portion, and is curved in the same curved shape at the tip side wing tip and the boss side wing tip, The blade surface shape is a combination of a plurality of different curved surfaces where the blade angle on the tip side blade surface and the blade angle on the boss side blade surface are the same, and the shape of the outlet portion is on the outlet side on the tip side and the boss side. A fluid machine having a shape in which edges are aligned at the same position in a casing axial direction .   The fluid machine according to claim 1, wherein the wing includes a combination of two cylindrical surfaces having different wing surface shapes and different curvatures.   4. The pump according to claim 1, wherein the blade forms a stationary guide blade provided in the vicinity of the rotary impeller. 5.   The pump according to any one of claims 1 to 3, wherein the blade forms a blade of a rotary impeller that rotates in a casing.

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