JP2017223175A - Screw pump, and manufacturing method thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a shaft divided screw pump structured to easily perform shaft core adjustment of a screw shaft, and a manufacturing method thereof.SOLUTION: The present invention relates to a shaft divided screw pump 100 comprising: a cylindrical first screw shaft 8 with which a screw blade 9 is mounted on its outer peripheral surface; and a cylindrical second screw shaft 13 with which a screw blade 14 is mounted on its outer peripheral surface and which is coupled to the first screw shaft 8. The first screw shaft 8 and the second screw shaft 13 are coupled to each other via a pair of flanges 12 and 15 of which the opposing faces are recessed and projected. The first screw shaft 8 includes a short pipe 8a (first short pipe part) with which the recessed-side flange 12 is mounted on an inner face of an axial end, and a length of the first short pipe part is equal to or shorter than 1000 mm.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a shaft-split screw pump and a method for manufacturing the same.

  As this type of technology, there is one described in Patent Document 1 below. The prior art is configured as follows. The joint flanges are welded and fixed to the ends of the two split screws by adjusting the parallelism and axial center of both. This joining flange is welded and fixed to the inner surface of each split screw shaft.

  By dividing the screw into two divided screws, the screw can be divided and transported, so that the screw can be easily conveyed from the factory to the site or from the site to the factory. Further, since the upstream side of the screw is a portion that is repeatedly submerged or exposed to the atmosphere, the upstream screw blade is more likely to corrode than the downstream screw blade. If the screw is divided into two divided screws, it is easy to take a partial anti-corrosion measure only on the upstream screw blade where corrosion is likely to proceed.

Japanese Patent Laying-Open No. 2015-40529

  The above prior art has the following problems. In order to align the axis of the two split screws, it is necessary to make the right angle of the joint surface of the joint flange with respect to the axis of the split screw shaft and to adjust the axis of the split screw shaft and the axis of the joint flange. There is.

  Here, the total length of the screw shaft is determined from the pump head, the tilt angle, and the like, and is, for example, about 6 m to 12 m. Therefore, the length of the split screw is, for example, about 3 m to 6 m. It is not easy to accurately fix the joining flange to the end of the split screw having such a length dimension so that the axial centers of the two split screws are aligned.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a shaft-divided screw pump having a structure that allows easy adjustment of the axis of the screw shaft, and a method for manufacturing the shaft pump.

  The present invention includes a cylindrical first screw shaft having screw blades attached to the outer peripheral surface, and a cylindrical second screw shaft connected to the first screw shaft while screw blades are attached to the outer peripheral surface. A shaft split type screw pump provided. The first screw shaft and the second screw shaft are configured such that opposing surfaces are connected to each other via a set of concave and convex flanges, and the concave flange of the set of flanges is the A convex flange is attached to the inner surface of the axial end of the second screw shaft, and is attached to the inner surface of the axial end of the first screw shaft. The first screw shaft has a first short tube portion to which the concave flange is attached to an inner surface of an axial end portion, and the length of the first short tube portion is 1000 mm or less. And

  In the screw pump manufacturing method according to the present invention, the concave flange is machined into the concave flange after attaching the concave flange unprocessed to the inner surface of the axial end of the first short pipe portion. Flange mounting that is formed by machining, and is formed by machining the convex flange on the convex flange after attaching the convex flange on the inner surface of the axial end of the second screw shaft. A screw shaft forming step of connecting the first screw shaft to which the concave flange is attached and the second screw shaft to which the convex flange is attached to form a screw shaft; and the first screw A blade attaching step of welding and fixing a screw blade to each of the shaft and the outer peripheral surface of the second screw shaft.

  A short pipe (first short pipe portion) having a length of 1000 mm or less is easily mounted on, for example, a milling machine. By placing the short pipe on the milling machine, it is easy to machine the concave flange attached to the inner surface of the axial end of the short pipe (first short pipe portion). That is, according to the present invention, it is easy to adjust the axis of the screw shaft.

It is a side view of the screw pump concerning one embodiment of the present invention. It is the A section enlarged view of FIG. It is a figure which shows the manufacture procedure of the short pipe with a flange which has a convex side flange. It is a figure which shows the manufacture procedure of a screw main body. It is a figure which shows the manufacture procedure of a screw main body. It is a figure which shows the manufacture procedure of a screw main body. It is a figure which shows the manufacture procedure of a screw main body.

  Hereinafter, embodiments for carrying out the present invention will be described with reference to the drawings. The screw pump of the present invention is an open-type pump that pumps water with a rotating screw, and is used, for example, as a pump in a rainwater pump station, a pump facility in a sewage treatment plant, or the like.

  The screw pump of the present invention is a shaft split type screw pump. The screw pump of the present invention can also be applied to a new screw pump, and the screw pump of the present invention can also be applied to an existing screw pump, such as replacing only a corroded screw portion of an existing screw pump.

(Configuration of screw pump)
As shown in FIG. 1, the screw pump 100 includes a screw body 1 installed in a trough 50 inclined obliquely with respect to the horizontal direction, and an upper bearing 4 and a lower bearing 2 that support the screw body 1. Yes. An upper spindle 3 is attached to the upper end of the screw body 1, and the screw body 1 is supported by being suspended by the upper bearing 4 through the upper spindle 3. A driving device (not shown) such as an engine or an electric motor that rotates the screw main body 1 transmits a rotational driving force to the screw main body 1 via the gear coupling 5.

  The screw body 1 is a split-type screw body composed of a first screw 6 on the lower side (upstream side) and a second screw 7 on the upper side (downstream side).

  The first screw 6 has a cylindrical first screw shaft 8 to which a first screw blade 9 is attached on the outer peripheral surface, and a conical cylinder 10 is attached to one end (lower side) of the first screw shaft 8. A lower end plate 11 is attached. A concave flange 12 out of a pair of flanges 12 and 15 having a concavity and convexity (marked) is attached to the other end.

  The second screw 7 has a cylindrical second screw shaft 13 to which the second screw blade 14 is attached on the outer peripheral surface, and has a convex portion corresponding to the concave flange 12 described above at one end (lower side). A side flange 15 is attached, and an upper end plate 16 is attached to the other end.

  The screw shafts 8 and 13 are made of, for example, STPY (arc welded steel pipe), and the screw blades 9 and 14 are made of, for example, SS. The material of the screw shafts 8 and 13 and the screw blades is not limited to this. Regarding the first screw blade 9 installed at the lower part of the trough 50 which is easily corroded, it is also preferable that the first screw blade 9 is made of stainless steel (for example, made of SUS304) as a countermeasure against corrosion. It is also preferable to apply FRP lining to the first screw blade 9 made of SS. In this case, it is also preferable to improve the adhesiveness of the FRP lining by subjecting the edge of the blade to R processing with a predetermined dimension. Note that it is not always necessary to make all the first screw blades 9 made of stainless steel or to apply an FRP lining to all the first screw blades 9, and the lower end portion (upstream end) that repeatedly submerges and is exposed to the atmosphere. The above-mentioned countermeasures may be performed only for (part). Furthermore, instead of the FRP lining, anti-corrosion coating or other anti-corrosion treatment may be applied to all of the first screw blades 9 or the lower end portion (upstream end portion).

<Structure of screw shaft connecting part>
FIG. 2 is an enlarged view of part A in FIG. The concave flange 12 is attached to the inner surface of the axial end portion of the first screw shaft 8, and the convex flange 15 is attached to the inner surface of the axial end portion of the second screw shaft 13.

  The concave flange 12 is a ring-shaped flange in which a concave portion 12c is formed. The convex flange 15 is a ring-shaped flange having a convex portion 15c.

  The concave flange 12 and the convex flange 15 are connected and fixed by a plurality of connecting bolts 17 and nuts 18 in a state where the convex portion 15c is fitted in the concave portion 12c. As shown in the plan view of the convex flange 15 in FIG. 3, the convex flange 15 is provided with a plurality of bolt holes 22 into which the connecting bolts 17 are inserted, and in the circumferential direction. Two pin holes 23 into which parallel pins (not shown) as positioning members (phase determining members) are respectively inserted are provided. Although not shown, the concave side flange 12 is also provided with a large number (a plurality of) bolt holes 22 and two pin holes 23 in the same manner as the convex side flange 15. As shown in FIG. 2, an annular groove into which a ring-shaped gasket 19 (seal) is fitted is formed on the surface of the concave flange 12 facing the convex flange 15.

(Manufacturing procedure of screw body)
The manufacturing procedure of the screw body 1 will be described with reference to FIGS.

  The total length of the screw shaft formed by connecting the first screw shaft 8 and the second screw shaft 13 is determined from the pump head, the tilt angle, etc., and is, for example, about 6 m to 12 m. The shaft diameter is, for example, about 0.6 m to 1.8 m. As shown in FIG. 4, the first screw shaft 8 is formed by joining pipes 8a, 8b, 8c (cylindrical members) formed by bending and welding steel plates by welding. The second screw shaft 13 is formed by welding pipes 13a, 13b, 13c, 13d, and 13e (cylindrical members) formed by bending and welding steel plates.

  Here, in the screw shaft of the present embodiment, the tube 8a constituting the first screw shaft 8 and the tube 13a constituting the second screw shaft 13 of the plurality of tubes joined together in the axial direction are Also, for example, short tubes 8a and 13a having a length of 800 mm are used. The length of the short tubes 8a and 13a is preferably 1000 mm or less, and the lower limit of the length is about 200 mm.

  The flange mounting process will be described with reference to FIGS. Note that this process is the same for the short tube 13 a constituting the second screw shaft 13 and the short tube 8 a constituting the first screw shaft 8, so that the short tube 13 a constituting the second screw shaft 13 is representative. This is shown in FIG. The short pipe 8 a is a first short pipe part that constitutes the first screw shaft 8, and the short pipe 13 a is a second short pipe part that constitutes the second screw shaft 13. The “first” of the first short tube portion means the short tube portion of the “first” screw shaft, and the “second” of the second short tube portion is the short tube of the “second” screw shaft. It means that it is a part.

<Flange mounting process>
First, the inner surface of the end portion in the axial direction of the short pipe 13a is machined to form an annular step 24. After that, the convex flange 15 is attached to the short tube 13a by inserting and welding the convex flange 15 which is not processed with the convex portion 15c (not yet formed with the convex portion 15c) into the stepped portion 24. At this time, the convex flange 15 is inserted into the step portion 24 of the short tube 13a from above the short tube 13a laid sideways (the axial direction of the short tube 13a is the vertical direction). After the convex flange 15 is placed and fine adjustment is performed to align the axis of the short pipe 13a with the axis of the convex flange 15, the convex flange 15 is welded and fixed to the short pipe 13a.

  As described above, since the short pipe 13a is a pipe formed by bending and welding a steel plate, the inner surface may not be a perfect circle (the roundness may be low). Therefore, machining is performed on the inner surface of the end portion in the axial direction of the short tube 13 a to form an annular stepped portion 24. As a result, when the convex flange 15 is inserted into the short tube 13a, the convex flange 15 is forcibly pushed into the short tube 13a so that the short tube 13a is damaged or the short tube 13a is deformed. It is possible to prevent the short tube 13a from being applied. Further, there is an advantage that the convex flange 15 can be temporarily received by the stepped portion 24.

  Next, by machining using a milling machine or the like, the convex portion 15c is formed with a convex portion 15c (not limited to a perfect circle but may be an ellipse or a polygon, and the concave portion 12c of the concave flange 12 is also formed). The axial end surface 25 of the peripheral edge of the flange 15 and the axial end surface e of the short tube 13a (second screw shaft 13) are made to be integrated (by simultaneous machining). Thereby, the short tube 20 with a flange by which the convex side flange 15 is attached to the inner surface of the edge part of the short tube 13a is formed. A flanged short tube 21 (see FIG. 4) in which the concave flange 12 is attached to the inner surface (step 26) of the end of the short tube 8a by the same (similar) method as the method of forming the flanged short tube 20. Is formed.

  The step 24 is a second step formed on the inner surface of the axial end of the second screw shaft 13, and the step 26 shown in FIG. 2 is the axial direction of the first screw shaft 8. It is the 1st step part formed in the inner surface of the edge part. The “first” of the first step means the step of the “first” screw shaft, and the “second” of the second step is the step of the “second” screw shaft. Means.

<Screw shaft forming process>
First, the flanged short pipe 21 (the concave flange 12 to which the short pipe 8a is attached) and the flanged short pipe 20 (the convex side flange 15 to which the short pipe 13a is attached) are marked. (Recesses 12 c and protrusions 15 c) are fitted together and connected with connecting bolts 17 and nuts 18, and parallel pins are inserted into the pin holes 23. Subsequently, the tubes 8b and 8c are joined to the short tube 8a (flange short tube 21) in this order by welding, and the tubes 13b, 13c, 13d and 13e are connected in this order to the short tube 13a (flange short tube 20). ) By welding. As a result, a screw shaft composed of the first screw shaft 8 and the second screw shaft 13 is formed.

<Bane installation process>
Next, as shown in FIG. 5, the first screw blade 9 formed by bending the steel plate is welded and fixed to the outer peripheral surface of the first screw shaft 8, and the second screw blade 14 formed by bending the steel plate is fixed. The outer peripheral surface of the second screw shaft 13 is fixed by welding. At this time, the screw shaft is placed on the mount 40 on which the roller 40a is arranged at the upper end, and the screw blades are attached by welding while rotating the screw shaft in a timely manner. The boundary portion 30 between the first screw blade 9 welded and fixed to the first screw shaft 8 and the second screw blade 14 welded and fixed to the second screw shaft 13 is the first screw blade 9 and the second screw blade 14. Is finely adjusted so as to continue smoothly, and this portion is temporarily fixed by spot welding. Note that the temporary fixing method is not limited to spot welding.

<Upper and lower end plate mounting process>
Thereafter, as shown in FIG. 6, the conical cylinder 10 is attached to the end of the first screw shaft 8, and the lower end plate 11 is attached to the end of the conical cylinder 10. An upper end plate 16 is attached to the end of the second screw shaft 13. Thereby, the screw main body 1 is formed.

<Blade tip cutting process>
Thereafter, as shown in FIG. 7, the gantry that supports the screw body 1 is changed from the gantry 40 to the gantry 41. The screw body 1 is supported so that both ends of the screw body 1 are sandwiched between the rotating jigs 41 a of the gantry 41. A concave portion (not shown) is provided at the center of the upper and lower end plates 16, 11, and the tapered tip end portion of the rotating jig 41a is applied to the concave portion. A belt 42 is hung on the outer peripheral surface of the screw shaft (second screw shaft 13), and the belt 42 is rotated by a belt driving device 43, whereby the screw body 1 is rotated around the axis.

  A rail 45 supported by a plurality of legs 44 is disposed on the side of the screw body 1 in parallel with the screw body 1, and a cutting machine 46 (for example, a plasma torch) runs on the rail 45. It is supposed to be.

  The cutting machine 46 is run while rotating the screw body 1 (screw shaft) around its axis, and the tip ends of the screw blades 9 and 14 are cut by the cutting machine 46, and the outer diameters of the screw blades 9 and 14. The dimensions are set to predetermined dimensions and the outer diameter dimensions are aligned. After the blade tip processing, the lower end plate 11 and the upper end plate 16 are machined. By machining the both ends of the screw in an integrated state, it is easy to reproduce the shaft core in the local assembly after division.

<Coating process, division process>
Thereafter, the screw body 1 is painted. When transporting to the site, the spot welding portion for temporarily fixing the first screw blade 9 and the second screw blade 14 is cut, the connecting bolt 17 and the parallel pin are removed, and the first screw 6 and the second screw are removed. The screw body 1 is divided into the screw 7.

(Modification)
The parallel pins inserted into the pin holes 23 of the convex flange 15 (see FIG. 3 and the corresponding concave flange 12 are the same) are arranged so that the first screw blade 9 and the second screw blade 14 are smoothly continuous. It is a member for performing phase alignment in the rotational direction of the first screw 6 and the second screw 7. As a member for performing phase alignment in the rotation direction, a key, a reamer bolt, a phase determining piece (block), or the like may be used instead of the parallel pin.

  Although the screw main body 1 of the above-described embodiment is a two-split screw main body constituted by the first screw 6 and the second screw 7, it may be a screw main body divided into three or more.

  In the embodiment described above, the concave flange 12 is attached to the end face of the upstream screw shaft 8 and the convex flange 15 is attached to the end face of the downstream screw shaft 13. The convex flange 15 may be attached to the end face of the screw shaft 8, and the concave flange 12 may be attached to the end face of the downstream screw shaft 13.

  In the above-described embodiment, each of the first screw shaft 8 and the second screw shaft 13 has the short pipes (8a, 13a) (short pipe portion of 1000 mm or less), but the first screw shaft 8 and the second screw Only one of the shafts 13 may have a short pipe (short pipe part).

  In the above-described embodiment, the annular step portions 26 and 24 are respectively provided on the inner surfaces of the axial ends of the short tube 8a (first screw shaft 8) and the short tube 13a (second screw shaft 13). The step portions 26 and 24 may be omitted. If the roundness of the short pipes (8a, 13a) (screw shafts 8, 13) is high, the short pipes (8a, 13a) (screw shafts 8, 13) are impossible even without the step portions 26, 24. It is possible to insert the flanges (12, 15) into the short pipes (8a, 13a) (screw shafts 8, 13) without applying a special force.

  In the above-described embodiment, the axial end surface 25 of the peripheral edge of the convex flange 15 and the axial end surface e of the short tube 13a (second screw shaft 13) are flush with each other (the concave flange 12 and the short flange 12). The same applies to the tube 8a (first screw shaft 8). Instead of this, the end face 25 in the axial direction of the peripheral portion of the convex flange 15 may protrude from the end face e in the axial direction of the short pipe 13a (second screw shaft 13). Furthermore, the axial end surface 25 of the peripheral edge portion of the convex flange 15 may be in a position recessed from the axial end surface e of the short tube 13a (second screw shaft 13) (the concave flange 12 and The same applies to the short pipe 8a (first screw shaft 8)).

(Action / Effect)
The first screw shaft 8 has a short tube 8a (first short tube portion) having a length of 1000 mm or less to which a concave flange 12 is attached to the inner surface of the end portion in the axial direction. Here, a short tube having a length of 1000 mm or less is easily placed on a milling machine. By placing the short tube 8a to which the concave flange 12 is attached on a milling machine, machining of the concave flange is easily performed while adjusting the axial center of the screw shaft and the axial axis of the concave flange 12 to be aligned. be able to. That is, according to the present invention, it is easy to adjust the axis of the screw shaft.

  In the screw pump of the present invention, as in the above-described embodiment, the axial end surface of the peripheral edge of the concave flange 12 facing the convex flange 15 and the axial end surface of the first screw shaft 8 are: The axial end surface 25 of the peripheral edge of the convex flange 15 facing the concave flange 12 and the axial end surface e of the second screw shaft 13 are flush with each other. It is preferable. According to this configuration, a recess or the like is not formed in the connecting portion between the first screw shaft 8 and the second screw shaft 13. In other words, the outer peripheral surface of the connecting portion is a continuous surface. Thereby, it is possible to prevent dust and the like from sticking to the connecting portion. This will prevent corrosion of the connecting part.

  Moreover, like the above-mentioned embodiment, it is preferable that the annular step part (26, 24) is formed in the inner surface of the axial direction edge part of a screw shaft, and a flange is attached to this step part. According to this configuration, when the flange is inserted into the screw shaft, it is possible to prevent the screw shaft from being forcibly pushed and damaged or deformed. There is also an advantage that the flange can be provisionally received at the step.

  Regarding the manufacture of the screw body 1, in the present invention, a flange (or projection) unprocessed flange is attached to the inner surface of the axial end of the screw shaft, and then a recess (or projection) is formed on the flange by machining. (Flange mounting process). According to this procedure, after the flanges 12 and 15 are attached to the screw shaft by welding or the like, the unevenness (marking) is processed, so that the mounting error when the flanges 12 and 15 are attached to the screw shaft (in the case of welding) Errors due to welding distortion, etc.) can be canceled by subsequent recess (or protrusion) machining. That is, it is easy to adjust the axis of the screw shaft.

  Further, regarding the manufacture of the screw body 1, as in the above-described embodiment, the concave flange 12 (the flanged short pipe 21) to which the first short pipe portion 8a is attached and the convex side to which the second short pipe portion 13a is attached. After connecting the flange 15 (the flanged short tube 20), the first short tube portion 8a and the second short tube portion 13a are respectively connected to the tubes 8b and 8c (cylindrical member) and the tubes 13b, 13c, 13d, and 13e ( It is preferable to form a screw shaft by attaching a cylindrical member). According to this configuration, the screw shaft is formed so as to extend on both sides of the flanged short pipes 20 and 21 with the shaft cores aligned with each other. Easy to raise.

  In addition, regarding the manufacture of the screw body 1, as in the above-described embodiment, in the flange mounting step, the concave side flange 12 that has not been processed into the concave portion is attached to the inner surface of the axial end portion of the first screw shaft 8. The side flange 12 is machined so that the axial end surface of the peripheral edge facing the convex flange 15 and the axial end surface of the first screw shaft 8 are integrally flush with each other, and the second screw shaft 13, after attaching the convex flange 15 with the unprojected convex portion to the inner surface of the axial end portion, the axial end surface of the convex portion flange 15 facing the concave flange 12, and the second screw It is preferable to perform machining so that the end face of the shaft 13 in the axial direction is flush with the shaft. According to this configuration, the axial end surfaces of the peripheral edges of the flanges 12 and 15 and the axial end surfaces of the screw shafts 8 and 13 are adjusted to be flush with each other with high precision while adjusting the axial center of the screw shaft. Can be.

  Further, regarding the manufacture of the screw body 1, as in the above-described embodiment, the first screw blade 9 welded and fixed to the first screw shaft 8 and the second screw blade 14 fixed to the second screw shaft 13 by welding are provided. After temporarily fixing by spot welding, it is preferable to cut the tips of the screw blades 9 and 14 so that the outer diameters of the screw blades 9 and 14 are set to predetermined dimensions and the outer diameters are made uniform. According to this structure, the continuity with the 1st screw blade | wing 9 and the 2nd screw blade | wing 14 can be improved.

  Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various modifications can be made as long as they are described in the claims. .

1: Screw body 2: Lower bearing 3: Upper spindle 4: Upper bearing 5: Gear coupling 6: First screw 7: Second screw 8: First screw shaft 8a: Short pipe (first short pipe section)
9: First screw blade 10: Conical cylinder 11: Lower end plate 12: Concave flange 12c: Concave part 13: Second screw shaft 13a: Short pipe (second short pipe part)
14: Second screw blade 15: Convex flange 15c: Convex portion 16: Upper end plate 24: Second step portion 26: First step portion 100: Screw pump

Claims (10)

A cylindrical first screw shaft having screw blades attached to the outer peripheral surface;
A screw blade is attached to the outer peripheral surface, and a cylindrical second screw shaft connected to the first screw shaft;
A shaft split type screw pump comprising:
The first screw shaft and the second screw shaft are configured such that opposing surfaces are connected to each other via a set of concave and convex flanges,
The concave flange of the set of flanges is attached to the inner surface of the axial end portion of the first screw shaft, and the convex flange is attached to the inner surface of the axial end portion of the second screw shaft. ,
The first screw shaft has a first short pipe portion to which the concave flange is attached to an inner surface of an axial end portion;
The screw pump characterized in that the length of the first short tube portion is 1000 mm or less. A cylindrical first screw shaft having screw blades attached to the outer peripheral surface;
A screw blade is attached to the outer peripheral surface, and a cylindrical second screw shaft connected to the first screw shaft;
A shaft split type screw pump comprising:
The first screw shaft and the second screw shaft are configured such that opposing surfaces are connected to each other via a set of concave and convex flanges,
The concave flange of the set of flanges is attached to the inner surface of the axial end portion of the first screw shaft, and the convex flange is attached to the inner surface of the axial end portion of the second screw shaft. ,
The second screw shaft has a second short pipe portion to which the convex flange is attached to the inner surface of the axial end portion;
The screw pump, wherein the length of the second short tube portion is 1000 mm or less. The screw pump according to claim 1, wherein
The second screw shaft has a second short pipe portion to which the convex flange is attached to the inner surface of the axial end portion;
The screw pump, wherein the length of the second short tube portion is 1000 mm or less. In the screw pump according to claims 1-3,
An annular first step portion is formed on the inner surface of the axial end portion of the first screw shaft,
The screw pump, wherein the concave flange is attached to the first step portion. In the screw pump according to claims 1 to 4,
An annular second step portion is formed on the inner surface of the axial end portion of the second screw shaft,
The screw pump, wherein the convex flange is attached to the second step portion. A cylindrical first screw shaft having screw blades attached to the outer peripheral surface;
A screw blade is attached to the outer peripheral surface, and a cylindrical second screw shaft connected to the first screw shaft, and
The first screw shaft and the second screw shaft are configured such that opposing surfaces are connected to each other via a set of concave and convex flanges,
The concave flange of the set of flanges is attached to the inner surface of the axial end portion of the first screw shaft, and the convex flange is attached to the inner surface of the axial end portion of the second screw shaft. ,
The first screw shaft has a first short tube portion to which the concave flange is attached to an inner surface of an axial end portion, and the length of the first short tube portion is 1000 mm or less. A screw pump manufacturing method of
After attaching the concave flange-side unprocessed concave flange to the inner surface of the axial end of the first short tube portion, the concave portion is formed in the concave flange by machining, and the shaft of the second screw shaft A flange mounting step of forming a convex portion on the convex flange by machining after attaching the convex flange on the inner surface of the end portion in the direction,
A screw shaft forming step of connecting the first screw shaft to which the concave flange is attached and the second screw shaft to which the convex flange is attached to form a screw shaft;
A blade attachment step of welding and fixing a screw blade to each of the outer peripheral surfaces of the first screw shaft and the second screw shaft;
A method for producing a screw pump, comprising: A cylindrical first screw shaft having screw blades attached to the outer peripheral surface;
A screw blade is attached to the outer peripheral surface, and a cylindrical second screw shaft connected to the first screw shaft, and
The first screw shaft and the second screw shaft are configured such that opposing surfaces are connected to each other via a set of concave and convex flanges,
The concave flange of the set of flanges is attached to the inner surface of the axial end portion of the first screw shaft, and the convex flange is attached to the inner surface of the axial end portion of the second screw shaft. ,
The second screw shaft has a second short pipe portion to which the convex flange is attached to the inner surface of the end portion in the axial direction, and the length of the second short pipe portion is 1000 mm or less. A screw pump manufacturing method of
After attaching the concave flange-side unprocessed concave flange to the inner surface of the axial end portion of the first screw shaft, the concave portion is formed in the concave flange by machining, and the shaft of the second short pipe portion A flange mounting step of forming a convex portion on the convex flange by machining after attaching the convex flange on the inner surface of the end portion in the direction,
A screw shaft forming step of connecting the first screw shaft to which the concave flange is attached and the second screw shaft to which the convex flange is attached to form a screw shaft;
A blade attachment step of welding and fixing a screw blade to each of the outer peripheral surfaces of the first screw shaft and the second screw shaft;
A method for producing a screw pump, comprising: In the manufacturing method of the screw pump according to claim 6,
The second screw shaft has a second short tube portion to which the convex flange is attached to an inner surface of an axial end portion, and the length of the second short tube portion is 1000 mm or less,
In the flange mounting step, the concave flange is formed on the concave flange by machining after attaching the concave flange unprocessed to the inner surface of the axial end of the first short pipe portion, A step of forming a convex portion on the convex flange by machining after attaching the convex flange, which is not processed with a convex portion, to the inner surface of the end portion in the axial direction of the second short pipe portion;
The screw shaft forming step includes connecting the concave flange to which the first short pipe part is attached and the convex flange to which the second short pipe part is attached, and then the first short pipe part and the A method for manufacturing a screw pump, characterized in that the screw shaft is formed by attaching a cylindrical member to each of the second short pipe portions. In the manufacturing method of the screw pump in any one of Claims 6-8,
In the flange mounting step, after mounting the concave flange unprocessed on the inner surface of the axial end portion of the first screw shaft, the peripheral flange portion of the concave flange facing the convex flange is mounted. Machining is performed so that the axial end face and the axial end face of the first screw shaft are flush with each other, and a convex portion is not formed on the inner surface of the axial end portion of the second screw shaft. After the convex flange is attached, the axial end surface of the peripheral edge of the convex flange facing the concave flange and the axial end surface of the second screw shaft are integrally made flush with each other. A screw pump manufacturing method, characterized by performing machining. In the manufacturing method of the screw pump in any one of Claims 6-9,
In order to set the outer diameter of the screw blades welded and fixed to the outer peripheral surfaces of the first screw shaft and the second screw shaft to a predetermined size, the tip end portion of the screw blade while rotating the screw shaft around its axis Further comprising a blade tip cutting step for cutting,
In the blade attaching step, the screw blade welded and fixed to the first screw shaft and the screw blade welded and fixed to the second screw shaft are temporarily fixed, and the screw pump manufacturing method is characterized in that .

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