JP2011127429A - Multistage turbine pump - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a multistage turbine pump easy in assembling, and capable of easily absorbing a difference in thermal expansion between an outer cylinder and a bolt even when fluid is at high temperatures. <P>SOLUTION: This multistage turbine pump has a structure for connecting a motor 11 to one end of a pump shaft 10 for driving an impeller 3, by supporting an intermediate casing 4 by a suction side casing 6 and a delivery side casing 8, by fastening the suction side casing 6 and the delivery side casing 8 by a bolt 9, by arranging the suction side casing 6 having a suction port 5 in one end opening part of the outer cylinder 1 and the delivery side casing 8 having a delivery port 7 in the other end opening part, by stacking and arranging a plurality of impellers 3 and the intermediate casing 4 in a multistage shape in a pump room 2, by forming the inside of the cylindrical outer cylinder 1 as the pump room 2. A nonrestricting part 15 is arranged between an inside surface of the delivery side casing 8 and an outside surface of an intermediate casing 4a of the rearmost stage, and a nonrestricting part 21 for allowing the movement in the axial direction of the outer cylinder 1, is also arranged between the suction side casing 6 and the delivery side casing 8 fastened by the bolt 9 and both ends of the outer cylinder 1. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a multistage turbine pump provided with a plurality of impellers.

  Conventionally, as shown in FIG. 6, the inside of a cylindrical outer cylinder 1 is used as a pump chamber 2, and a plurality of impellers 3 and intermediate casings 4 are stacked in a multistage manner in the pump chamber 2. 1, a suction side casing 6 having a suction port 5 at one end opening portion and a discharge side casing 8 having a discharge port 7 at the other end opening portion are arranged, and the suction side casing 6 and the discharge side casing 8 are fastened by bolts 9. A multi-stage turbine pump having a structure in which an intermediate casing 4 is supported by a suction-side casing 6 and a discharge-side casing 8 and a motor 11 is connected to one end of a pump shaft 10 that drives an impeller 3 is known.

  In the multistage turbine pump having this structure, the impeller 3 is attached to the pump shaft 10 connected to the drive shaft 12 of the motor 11 via the coupling 13, and the intermediate casing 4 is disposed via the bearing 14. In addition, the outer surface of the intermediate casing 4a at the last stage and the discharge-side casing 8 are in a restrained state. Further, the fastening of the suction side casing 6 arranged at one end opening portion of the outer cylinder 1 and the bolt 9 of the discharge side casing 8 arranged at the other end opening portion with the end face 1a of the outer cylinder 1 as a fastening fulcrum (for example, Patent Documents) 1 and 2).

  In the multistage turbine pump having such a structure, the drive shaft 12 of the motor 11, the pump shaft 10 connected to the drive shaft 12 via the coupling 13, the intermediate casing 4 arranged on the pump shaft 10 via the bearing 14, If there is a misalignment between the axial centers of the discharge side casing 8, when the motor 11 is driven and the pump shaft 10 is rotated, the coupling 13 and the pump shaft 10 connecting the drive shaft 12 and the pump shaft 10 An uneven load is applied to the bearings 14 between the intermediate casings 4 and there is a risk of causing early wear and damage of the parts.

  Therefore, in assembling the multi-stage turbine pump having the above structure, the drive shaft 12, the pump shaft 10, the intermediate casing 4, and the discharge-side casing 8 of the motor 11 need to coincide with each other. If the parts are assembled as they are due to variations in geometrical tolerances in the parts, the shafts of the drive shaft 12, the pump shaft 10, the intermediate casing 4, and the discharge-side casing 8 of the motor 11 will be misaligned. For example, when the shaft center of the discharge side casing 8 fastened to the suction side casing 6 by the bolt 9 and the shaft center of the pump shaft 10 are misaligned, the shaft of the last intermediate casing 4a restrained by the discharge side casing 8 The center also deviates from the axis of the pump shaft 10, and the axis of the other intermediate casing 4 superimposed on the last intermediate casing 4 a also deviates from the axis of the pump shaft 10. For this reason, the assembly of the multi-stage turbine pump is a troublesome work such as assembling while aligning the shaft center using a jig, and it takes a long time to assemble.

  Moreover, although the fastening by the volt | bolt 9 of the suction side casing 6 arrange | positioned at the one end opening part of the said outer cylinder 1 and the discharge side casing 8 arrange | positioned at the other end opening part is clamped in several places, the end surface 1a of the outer cylinder 1 is clamped. Since it is a fastening fulcrum, the outer cylinder 1 may be inclined with respect to the pump shaft 10 if the outer cylinder 1, the suction-side casing 6, and the discharge-side casing 8 have manufacturing variations or tightening variations. Further, when the fluid is hot, the suction side casing 6 and the discharge side casing 8 are pulled by the bolt 9 due to the difference in thermal expansion between the outer cylinder 1 and the bolt 9 which have different temperature effects, and the suction side casing 6 is caused by the bending stress. The discharge-side casing 8 may be damaged, and conventionally, in order to avoid such a situation, the sucked high-temperature fluid is passed through the bolt 9 (see, for example, Patent Document 2). ).

Japanese Utility Model Publication No.7-10076 JP 2000-130400 A

As described above, in the multi-stage turbine pump having the structure disclosed in Patent Documents 1 and 2, the assembly is troublesome work such as assembling while aligning the shaft center using a jig. There was a problem of taking time.
Moreover, although the fastening by the volt | bolt 9 of the suction side casing 6 arrange | positioned at the one end opening part of the said outer cylinder 1 and the discharge side casing 8 arrange | positioned at the other end opening part is clamped in several places, the end surface 1a of the outer cylinder 1 is clamped. Since it is a fastening fulcrum, the outer cylinder 1, the suction-side casing 6, and the discharge-side casing 8 may vary in manufacture, or if the tightening varies, the outer cylinder 1 may be inclined with respect to the pump shaft 10. There was a problem. Further, when the fluid is high temperature, the suction side casing 6 and the discharge side casing 8 are pulled by the bolt 9 due to the difference in thermal expansion between the outer cylinder 1 and the bolt 9 which are influenced by the temperature of the fluid, and the suction side casing is caused by the bending stress. 6 and the discharge-side casing 8 may be damaged. Conventionally, in order to avoid such a situation, the sucked high-temperature fluid is also passed through the bolt 9, but the structure becomes complicated and the assembly becomes more troublesome.

  The present invention is intended to solve these problems, and is easy to assemble, and can easily absorb the difference in thermal expansion between the outer shell and the bolt even when the fluid is hot. An object of the present invention is to provide a multistage turbine pump.

  In order to achieve the above object, according to the first aspect of the present invention, the inside of a cylindrical outer trunk is used as a pump chamber, and a plurality of impellers and intermediate casings are stacked in a multistage manner in the pump chamber. A suction side casing having a suction port at one end opening of the outer body, a discharge side casing having a discharge port at the other end opening, and fastening the suction side casing and the discharge side casing with a bolt, the suction side In the multi-stage turbine pump having a structure in which the intermediate casing is supported by the casing and the discharge side casing, and a motor is connected to one end of a pump shaft that drives the impeller, the inner surface of the discharge side casing and the intermediate casing of the last stage An unconstrained portion is provided between the outer surface and the outer surface.

  According to a second aspect of the present invention, the inside of a cylindrical outer cylinder is used as a pump chamber, a plurality of impellers and intermediate casings are stacked in a plurality of stages in the pump chamber, and are arranged at one end opening of the outer cylinder. A suction-side casing having a suction port, a discharge-side casing having a discharge port at the other end opening portion are arranged, the suction-side casing and the discharge-side casing are fastened with bolts, and the suction-side casing and the discharge-side casing are In a multistage turbine pump having a structure in which an intermediate casing is supported and a motor is connected to one end of a pump shaft that drives the impeller, both ends of the suction-side casing, the discharge-side casing, and the outer body fastened by the bolts The non-restraining part which permits the movement of the outer cylinder in the axial direction is provided between the two.

  According to a third aspect of the present invention, the inside of a cylindrical outer cylinder is used as a pump chamber, a plurality of impellers and intermediate casings are stacked in a multi-stage manner in the pump chamber, and the one end opening of the outer cylinder is arranged. A suction-side casing having a suction port, a discharge-side casing having a discharge port at the other end opening portion are arranged, the suction-side casing and the discharge-side casing are fastened with bolts, and the suction-side casing and the discharge-side casing are In a multi-stage turbine pump having a structure in which an intermediate casing is supported and a motor is connected to one end of a pump shaft that drives the impeller, the inner surface of the discharge-side casing and the outer surface of the last-stage intermediate casing are not restrained. The outer cylinder is moved in the axial direction between the suction-side casing and the discharge-side casing, which are fastened by the bolts, and both ends of the outer cylinder. Characterized in that a non-restraining portion tolerated.

  According to a fourth aspect of the present invention, the unconstrained portion according to the first, second, or third aspect is a gap portion.

  The invention described in claim 5 is characterized in that the unconstrained portion described in claim 1, 2 or 3 is a cushioning material.

  According to a sixth aspect of the present invention, the unconstrained portion that allows the outer cylinder to move in the axial direction is provided on both sides of the bolt that fastens the suction side casing and the discharge side casing. Forming a step portion as a fastening fulcrum of the suction side casing and the discharge side casing, and the length between the inner end surfaces of the suction side casing and the discharge side casing is made longer than the axial length of the outer cylinder, It is formed with a difference in thickness.

  According to the multistage turbine pump of the first aspect, since the non-restraining portion is provided between the inner side surface of the discharge casing and the outer side surface of the final intermediate casing, a plurality of multistage turbine pumps are provided in the pump chamber when the multistage turbine pump is assembled. The impeller and the intermediate casing are stacked and arranged in multiple stages, a suction side casing having a suction port is arranged at one end opening of the outer body, and a discharge side casing having a discharge port is arranged at the other end opening, When fastening the suction-side casing and discharge-side casing with bolts, before completely fastening, the intermediate shafts arranged in the pump chamber move in the axial direction of the pump shaft by rotating the pump shaft. The shaft center of the pump shaft is aligned with the shaft center of the pump shaft, and the last intermediate casing supported by the discharge side casing also has a pump shaft on the discharge side casing due to the presence of the non-restraining portion. Since it moves in the axial direction and the axial center coincides with the axial center of the pump shaft, in this state, the suction-side casing and the discharge-side casing are completely fastened with bolts, so that it is temporarily a component of the multistage turbine pump. Even if there is a variation in geometrical tolerances, it is possible to assemble with the shaft center reliably aligned between the pump shaft and each intermediate casing. In the assembling work, as described above, the pump shaft and each intermediate casing can be easily connected by rotating the pump shaft before completely fastening the suction side casing and the discharge side casing with the bolts. Since the centering can be performed, it can be performed easily and in a short time.

  According to the multistage turbine pump of claim 2, the non-restraining portion that allows the outer cylinder to move in the axial direction is provided between the suction casing and the discharge casing that are fastened by bolts and both ends of the outer cylinder. Therefore, even if the fluid is at a high temperature, the difference in thermal expansion between the outer cylinder and the bolt can be easily absorbed by the non-restraining portion, and damage to the suction side casing and the discharge side casing can be prevented.

According to the multistage turbine pump of the third aspect, since the non-restraining portion is provided between the inner side surface of the discharge casing and the outer side surface of the last stage intermediate casing, a plurality of multistage turbine pumps are provided in the pump chamber when the multistage turbine pump is assembled. The impeller and the intermediate casing are stacked and arranged in a multi-stage shape, the suction side casing having a suction port at one end opening of the outer body, and the discharge side casing having a discharge port at the other end opening are arranged. When the pump casing is fastened with bolts, the intermediate casing disposed in the pump chamber is moved in the axial direction of the pump shaft by rotating the pump shaft before being completely fastened. Coincides with the shaft center of the pump shaft, and the last intermediate casing supported by the discharge side casing also has a non-restraining part on the discharge side casing. Since the shaft center coincides with the shaft center of the pump shaft in this state, the geometrical tolerance of the components of the multi-stage turbine pump may vary due to complete fastening of the suction casing and the discharge casing with bolts. Even if there exists, it can assemble in the state which made the shaft center match | combine reliably between a pump shaft and each intermediate casing. In the assembling work, as described above, the pump shaft and each intermediate casing can be easily assembled by rotating the pump shaft before completely fastening the suction side casing and the discharge side casing with the bolts. Therefore, it can be performed easily and in a short time.
In addition, a non-restraining part that allows the outer cylinder to move in the axial direction is provided between the suction casing and the discharge casing, which are fastened with bolts, and both ends of the outer cylinder. The difference in thermal expansion between the barrel and the bolt can be easily absorbed by the non-restraining portion, and damage to the suction side casing and the discharge side casing can be prevented.

  According to the multistage turbine pump of the fourth aspect, since the non-restraining portion is the gap portion according to the first, second, or third aspect, the final intermediate casing supported by the discharge-side casing and the bolt Any of the outer cylinders between the suction casing and the discharge casing that are fastened in the above can freely move within the range of the gap.

  According to the multistage turbine pump of the fifth aspect, since the non-restraining portion is the cushioning material according to the first, second, or third aspect, the last stage intermediate casing supported by the discharge side casing and the bolt Any of the outer cylinders between the suction casing and the discharge casing fastened in the above can freely move within a bufferable range by the buffering action of the buffer material.

  According to the multistage turbine pump of the sixth aspect, the non-constraint portion that allows the outer cylinder to move in the axial direction is the bolt that fastens the suction side casing and the discharge side casing. Steps are formed on both sides, and the step is used as a fastening fulcrum for the suction-side casing and the discharge-side casing, and the length between the inner end faces of the suction-side casing and the discharge-side casing is made longer than the axial length of the outer cylinder. The difference between the lengths of the suction side casing and the discharge side casing is within the range of the difference between the length between the inner end face of the suction side casing and the discharge side casing and the length of the outer cylinder in the axial direction. The outer cylinder in the middle can move freely, even if the suction side casing and the discharge side casing are fastened with bolts, or even if there is a difference in thermal expansion between the outer case and bolts due to high temperature fluid Side casing and spout Since the bending stress in the side casing does not occur, it is possible to avoid a situation breakage of suction casing and the discharge-side casing by bending stress.

It is a vertical side view which shows one Example of the multistage turbine pump which concerns on this invention. It is a principal part enlarged view of FIG. It is the other principal part enlarged view of FIG. It is an expanded sectional view which shows the other example of the structure of the non-restraining part provided between the inner surface of the discharge side casing in the multistage turbine pump which concerns on this invention, and the outer surface of the last stage intermediate casing. It is an expanded sectional view which shows the other example of the structure of the non-restraining part provided between the suction side casing and the discharge side casing currently fastened with the volt | bolt in the multistage turbine pump which concerns on this invention, and the both ends of an outer cylinder. It is a vertical side view which shows one Example of the conventional multistage turbine pump.

Hereinafter, an example for carrying out the multistage turbine pump concerning the present invention is explained in detail with reference to drawings.
1 is a longitudinal side view showing an embodiment of a multi-stage turbine pump according to the present invention, FIG. 2 is an enlarged view of a main part of FIG. 1, and FIG. 3 is an enlarged view of another main part of FIG. Note that portions corresponding to those in FIG. 6 described above are denoted by the same reference numerals.

  As shown in FIG. 1, the multistage turbine pump of this example uses a cylindrical outer body 1 as a pump chamber 2. A plurality of impellers 3 and intermediate casings 4 are stacked in a multistage manner in the pump chamber 2. And the suction side casing 6 which has the suction inlet 5 in the one end opening part of the outer cylinder 1 and the discharge side casing 8 which has the discharge outlet 7 in the other end opening part are arrange | positioned, and the suction side casing 6 and the discharge side casing 8 are bolted. The intermediate casing 4 is supported by the suction side casing 6 and the discharge side casing 8. The suction-side casing 6 and the discharge-side casing 8 are fastened with bolts 9 at 3 to 4 locations equally in the circumferential direction. In this example, it is fastened at three locations. The impeller 3 is fixed to the pump shaft 10, and the intermediate casing 4 is disposed on the pump shaft 10 via a bearing 14. The pump shaft 10 is directly connected to the drive shaft 12 of the motor 11 in an integral structure.

  The non-restraining portion 15 is provided between the inner surface of the discharge-side casing 8 and the outer surface of the last-stage intermediate casing 4a in the multi-stage turbine pump configured as described above. The non-restraining portion 15, as will be described later, is arranged such that when the pump shaft 10 is rotated, the last intermediate casing 4 a supported by the discharge-side casing 8 moves over the discharge-side casing 8 on the axial center side of the pump shaft 10. In this example, the non-restraining portion 15 is composed of a gap portion 16.

  More specifically, in this example, a tray 19 having a flange 18 on the inner periphery of one end of the cylindrical side wall 17 is fitted to the outer periphery of the last intermediate casing 4a. The casing 4 a is supported by the discharge side casing 8. Then, the gap portion 16 constituting the non-restraining portion 15 is formed between the outer side surface of the cylindrical side wall 17 of the tray 19 and the inner side surface of the discharge-side casing 8 fitted to the outer periphery of the intermediate casing 4a at the last stage. Is provided.

  In this example, a buffer member 20 is interposed between the lower end of the last intermediate casing 4a and the flange 18 of the tray 19, and the last intermediate casing 4a is moved in the axial direction. In addition, the tray 19 can maintain a state in which the flange 18 of the tray 19 is in contact with the end surface of the discharge-side casing 8 by the elastic force of the buffer member 20. In this example, a wave spring is used as the buffer member 20, the tip of the pump shaft 10 is in pressure contact with the wave spring serving as the buffer member 20, and the flange 18 of the tray 19 is connected to the discharge side casing by the restoring force of the wave spring. 8 is pressed against the end face.

  In this example, the non-restraining portion 21 that allows the outer cylinder 1 to move in the axial direction is provided between the suction-side casing 6 and the discharge-side casing 8 that are fastened by the bolts 9 and both ends of the outer cylinder 1. Provided. The unconstrained portion 21 can absorb a difference in thermal expansion between the outer cylinder 1 and the bolt 9 when the fluid is high, as described later. In this example, the unconstrained portion 21 is composed of a gap portion 22.

More specifically, in this example, the bolt 9 for fastening the suction-side casing 6 and the discharge-side casing 8 is formed with step portions 23 and 24 on both sides thereof, and a small-diameter male screw portion is formed from the step portions 23 and 24. 25 and 26 are formed in a protruding shape. Then, the male screw portion 25 on one end side of the bolt 9 is screwed into the female screw portion 27 formed on the discharge side casing 8 until the step portion 23 comes into contact with the end surface of the discharge side casing 8. The end-side male thread portion 26 is inserted into a through-hole 28 formed in the suction-side casing 6 and protrudes from the through-hole 28 in the suction-side casing 6 with the stepped portion 24 being in contact with the end surface of the suction-side casing 6. The suction-side casing 6 and the discharge-side casing 8 are fastened with the stepped portions 23 and 24 as fastening fulcrums by screwing the nut 29 into the male screw portion 26.
And the length between the inner side end surfaces 30 and 31 of the suction side casing 6 and the discharge side casing 8 fastened in this way is made longer than the length of the outer cylinder 1 in the axial direction, and the unconstrained portion is determined by the difference in length. A gap 22 that becomes 21 is formed.

  The multi-stage turbine pump of the present example configured as described above is assembled as follows. In this example, the drive shaft 12 of the motor 11 and the pump shaft 10 are directly connected in an integrated structure. The suction side casing 6 is attached to the motor 11 side configured as described above. The intermediate casing 4 and the impeller 3 are alternately arranged on the pump shaft 10, and the receiving tray 19 is fitted on the outer periphery of the last intermediate casing 4 a with a buffer member 20 interposed.

  When the intermediate casing 4 and the impeller 3 are arranged on the pump shaft 10 in this way, the outer cylinder 1 is fitted to the outer periphery thereof, and the discharge-side casing 8 is brought into contact with the intermediate casing 4a at the last stage via the tray 19. Then, the suction casing 6 and the discharge casing 8 are fastened with bolts 9 to support the intermediate casing 4.

  When the suction-side casing 6 and the discharge-side casing 8 are fastened, the drive shaft 12 and the pump shaft 10 are rotated by driving the motor 11 before being completely fastened. The shafts of the drive shaft 12 and the pump shaft 10 pass through the rotation of the drive shaft 12 and the pump shaft 10, and each intermediate casing 4 moves in the axial direction of the pump shaft 10. The intermediate casing 4a at the last stage that is matched and supported by the discharge-side casing 8 is also outside the cylindrical side wall 17 of the tray 19 that is fitted to the non-restraining portion 15, in this example, the outer periphery of the intermediate casing 4a at the last stage. Due to the presence of the gap 16 between the side surface and the inner side surface of the discharge side casing 8, it moves on the discharge side casing 8 in the axial direction of the pump shaft 10, and its axis coincides with the axis of the pump shaft 10. To do. In this state, the suction-side casing 6 and the discharge-side casing 8 are completely fastened with the bolts 9, so that even if there is a variation in geometric tolerance among the components of the multistage turbine pump, the pump shaft 10 and each intermediate casing 4 It is possible to assemble with the axial center reliably aligned between the two.

  Thus, in this example, the non-restraining portion 15 is formed between the outer side surface of the cylindrical side wall 17 of the tray 19 and the inner side surface of the discharge-side casing 8 that are fitted to the outer periphery of the intermediate casing 4a at the last stage. Since the gap portion 16 is provided, during assembly work, the pump shaft 10 can be easily rotated before the suction-side casing 6 and the discharge-side casing 8 are completely fastened with the bolts 9 as described above. Since the shaft center of the pump shaft 10 and each intermediate casing 4 can be aligned with a simple operation, it can be performed easily and in a short time.

  In this example, a buffer member 20 is interposed between the lower end of the last intermediate casing 4a and the flange 18 of the tray 19, and the last intermediate casing 4a is moved in the axial direction. In addition, since the receiving tray 19 can maintain the state in which the flange 18 of the receiving tray 19 is in contact with the end surface of the discharge-side casing 8 by the elastic force of the buffer member 20, the seal between the receiving tray 19 and the discharge-side casing 8 is maintained. Sex can be achieved.

  Moreover, in this example, the non-restraining portion 21 that allows the outer cylinder 1 to move in the axial direction is provided between the suction-side casing 6 and the discharge-side casing 8 fastened by the bolts 9 and both ends of the outer cylinder 1. A gap portion 22 is provided, and this gap portion 22 can absorb the difference in thermal expansion between the outer cylinder 1 and the bolt 9 when the fluid is at a high temperature, that is, the outer space due to the difference in thermal expansion. Since it is configured with a range that allows the movement of the cylinder 1, the gap 22 can easily absorb the difference in thermal expansion between the outer cylinder 1 and the bolt 9 even when the fluid is at a high temperature. Breakage of the side casing 8 can be prevented.

  In this example, the gap 22 constituting the non-restraining portion 21 that allows the outer cylinder 1 to move in the axial direction is formed with step portions 23 and 24 on both sides of the bolt 9, and sucks with the step portions 23 and 24. As a fastening fulcrum between the side casing 6 and the discharge side casing 8, the length between the inner end faces 30, 31 of the suction side casing 6 and the discharge side casing 8 is made longer than the length in the axial direction of the outer cylinder 1, and the difference between the lengths The suction side casing 6 and the discharge side casing 8 are within the range of the difference between the length between the inner end faces 30 and 31 of the suction side casing 6 and the discharge side casing 8 and the length of the outer cylinder 1 in the axial direction. The outer cylinder 1 between them can move freely. Even if the suction-side casing 6 and the discharge-side casing 8 are fastened with the bolts 9, the thermal expansion of the outer cylinder 1 and the bolts 9 is caused by the high temperature of the fluid. If there is a difference between the suction side casing 6 and the discharge side case Since bending stress ring 8 is not generated, it is possible to avoid a situation breakage of the suction-side casing 6 and the discharge-side casing 8 by bending stress.

In this example, the non-restraining portion 15 provided between the outer side surface of the cylindrical side wall 17 of the tray 19 and the inner side surface of the discharge-side casing 8 fitted to the outer periphery of the intermediate casing 4a at the last stage, The non-restraining portion 21 provided between the suction-side casing 6, the discharge-side casing 8, and both ends of the outer body 1 is composed of gap portions 16 and 22, and is shown in FIGS. 4 and 5. Thus, it may be composed of the cushioning materials 32 and 33. When the non-restraining portions 15 and 21 are constituted by the buffer materials 32 and 33, the suction-side casing 6 fastened by the bolt 9 and the intermediate casing 4a at the last stage supported by the discharge-side casing 8 and the discharge side The outer cylinder 1 between the casing 8 and the casing 8 can freely move as described above within a bufferable range by the buffering action of the buffer members 32 and 33. As the buffer materials 32 and 33, for example, rubber, a spring, or a sponge is used.
Further, in this example, the drive shaft 12 of the motor 11 and the pump shaft 10 are directly connected in an integral structure. However, the present invention is not limited to this, and the present invention is not limited to this. The present invention can also be applied to a structure in which the shaft 10 is connected via a coupling.

DESCRIPTION OF SYMBOLS 1 Outer cylinder 1a End surface 2 Pump chamber 3 Impeller 4 Intermediate casing 4a Last stage intermediate casing 5 Suction port 6 Suction side casing 7 Discharge port 8 Discharge side casing 9 Bolt 10 Pump shaft 11 Motor 12 Drive shaft 13 Coupling 14 Bearing 15 Non-restraining portion 16 Cavity portion 17 Cylindrical side wall 18 Flange 19 Receptacle 20 Buffer member 21 Non-constraint portion 22 Cavity portion 23, 24 Step portion 25, 26 Male thread portion 27 Female thread portion 28 Through hole 30, 31 Inner end surface 32, 33 Cushioning material

Claims (6)

The inside of the cylindrical outer cylinder is used as a pump chamber, and a plurality of impellers and intermediate casings are stacked and arranged in a multistage shape in the pump chamber, and a suction side casing having a suction port at one end opening of the outer cylinder, A discharge-side casing having a discharge port is disposed at the other end opening, the suction-side casing and the discharge-side casing are fastened with bolts, the intermediate casing is supported by the suction-side casing and the discharge-side casing, and the impeller In a multi-stage turbine pump having a structure in which a motor is connected to one end of a pump shaft that drives
A multi-stage turbine pump, wherein a non-restraining portion is provided between an inner surface of the discharge-side casing and an outer surface of the last intermediate casing. The inside of the cylindrical outer cylinder is used as a pump chamber, and a plurality of impellers and intermediate casings are stacked and arranged in a multistage shape in the pump chamber, and a suction side casing having a suction port at one end opening of the outer cylinder, A discharge-side casing having a discharge port is disposed at the other end opening, the suction-side casing and the discharge-side casing are fastened with bolts, the intermediate casing is supported by the suction-side casing and the discharge-side casing, and the impeller In a multi-stage turbine pump having a structure in which a motor is connected to one end of a pump shaft that drives
An unconstrained portion that allows movement of the outer cylinder in the axial direction is provided between the suction-side casing and the discharge-side casing that are fastened by the bolts and both ends of the outer cylinder. Multistage turbine pump. The inside of the cylindrical outer cylinder is used as a pump chamber, and a plurality of impellers and intermediate casings are stacked and arranged in a multistage shape in the pump chamber, and a suction side casing having a suction port at one end opening of the outer cylinder, A discharge-side casing having a discharge port is disposed at the other end opening, the suction-side casing and the discharge-side casing are fastened with bolts, the intermediate casing is supported by the suction-side casing and the discharge-side casing, and the impeller In a multi-stage turbine pump having a structure in which a motor is connected to one end of a pump shaft that drives
A non-restraining portion is provided between the inner side surface of the discharge side casing and the outer side surface of the last intermediate casing, and the suction side casing and the discharge side casing and both ends of the outer cylinder are fastened by the bolts. A multi-stage turbine pump characterized in that a non-restraining portion that allows movement of the outer cylinder in the axial direction is provided between the outer cylinder and the outer cylinder.   The multistage turbine pump according to claim 1, wherein the non-restraining portion is a gap portion.   The multistage turbine pump according to claim 1, wherein the non-restraining portion is a buffer material.   The non-restraining portion that allows the outer cylinder to move in the axial direction is formed with stepped portions on both sides of a bolt that fastens the suction side casing and the discharge side casing, and the suction side casing and the discharge side casing are fastened with the stepped portion. The length between the inner end faces of the suction-side casing and the discharge-side casing is made longer than the axial length of the outer cylinder, and is formed with a difference between the lengths. The multistage turbine pump according to 3.

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