JP2006029242A - Motor pump - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a motor pump capable of surely preventing liquid from infiltrating into a bearing existing on the motor side, even if the liquid leaks from a mechanical seal, by using a standard mechanical seal available on the market, without requiring to perform machining in advance on a part for applying spline machining of a pump shaft for installing an impeller. <P>SOLUTION: This motor pump has at least one impeller 11 installed on a main shaft 4 composed of an electric motor shaft 41 and the pump shaft 10, and at least one casing 1 arranged in response to the impeller 11; and has a pump head 3 for sealing the opening end of the casing 1 and having a delivery port 3a, the bearings 48 and 49 held by the pump head 3 and supporting the main shaft 4, a sheet metal bearing plate 52 adjacently arranged to the bearing 49, and a draining ring 53 arranged on the anti-bearing side of the bearing plate 52 and installed on the main shaft 4. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a motor pump, and more particularly, to a motor pump including at least one impeller attached to a pump shaft extending from an electric motor shaft and at least one casing for housing the impeller. .

  As one type of motor pump, a multistage pump is known that includes a plurality of impellers attached to a pump shaft that extends an electric motor shaft and a plurality of intermediate casings that accommodate the impellers. As one type of multistage pump, there is a multistage pump in which a plurality of impellers are attached to a pump shaft composed of a spline shaft, and each impeller is accommodated in an intermediate casing formed by press-molding a steel plate. In this type of multistage pump, a plurality of impellers are fixed to the pump shaft via splines. In this case, since the pump shaft is splined, the portion where the mechanical seal is mounted is usually formed with a larger outer diameter than the splined portion. Therefore, before the spline is processed, the pump shaft needs to be machined so that the splined portion has a smaller outer diameter than the portion to which the mechanical seal is attached, which increases the processing cost of the pump shaft. There is a problem.

  Also, without machining the splined part, a pump shaft having the same outer diameter is used for the part where the mechanical seal is mounted and the part to be splined. Sometimes it is applied. In this case, the splined part has a larger outer diameter than the part where the mechanical seal is mounted, so a standard mechanical seal cannot be used, and a special mechanical seal must be manufactured separately. There is a problem that the production cost increases.

  In the above-described multistage pump, it is assumed that the liquid leaks from the mechanical seal and enters the motor side from the pump casing side, and the member for draining the infiltrated liquid is a pump shaft (or motor shaft). It is attached to. This draining member usually consists only of a ring-shaped member fitted in the pump shaft, and there is a problem that the liquid gets over the ring-shaped member and enters a ball bearing or the like on the motor side.

  The present invention has been made in view of the above-described circumstances, and it is not necessary to perform machining in advance on a portion of the pump shaft on which the impeller is to be splined, and a commercially available standard mechanical seal is used. It is an object of the present invention to provide a motor pump that can reliably prevent liquid from entering a bearing or the like on the motor side even if liquid leaks from a mechanical seal.

  In order to achieve the above-described object, a motor pump according to the present invention includes at least one impeller attached to a main shaft including an electric motor shaft and a pump shaft, and at least one casing provided corresponding to the impeller. A pump head that seals the open end of the casing and includes a discharge port; a bearing that is held by the pump head and supports the main shaft; and a sheet metal that is provided adjacent to the bearing. And a water draining ring provided on the opposite side of the bearing plate and mounted on the main shaft.

The draining ring is made of a rubber V-ring.
Further, the main shaft has a step whose diameter is narrowed on the side opposite to the bearing plate, a positioning member that is positioned in the axial direction by the step is provided, and the position of the draining ring is determined by the end surface of the positioning member. Features.
Further, the motor shaft and the pump shaft are configured as separate parts, and the step is formed by press-fitting the pump shaft into the motor shaft.

  Another aspect of the motor pump of the present invention is a motor pump comprising at least one impeller attached to a main shaft including an electric motor shaft and a pump shaft, and at least one casing provided corresponding to the impeller. The pump shaft has a spline portion that holds the impeller, and is provided with a positioning member that is positioned at a step at a joint portion between the electric motor shaft and the pump shaft, and is fitted to the spline portion and the positioning member. The thin plate sleeve is provided, the rotating side member of the mechanical seal is held on the sleeve, and an O-ring is mounted in the gap between the sleeve and the pump shaft.

The sleeve is positioned by a ring-shaped member attached to a groove provided in a spline portion of the main shaft.
In addition, at least one of a portion of the sleeve that is fitted to the spline portion, a portion that is fitted to the positioning member, and a portion that holds the rotation side member of the mechanical seal is formed by contraction or expansion. It is characterized by being.

  According to the present invention, since the draining ring is provided on the pump side of the bearing that supports the pump shaft of the motor pump, even if the liquid leaks from the mechanical seal, the liquid can be reliably prevented from entering the bearing on the motor side. be able to. In addition, since a sleeve is provided in the spline portion of the pump shaft and a standard mechanical seal is attached to the sleeve, it is not necessary to perform machining in advance on the portion to be splined, and a commercially available standard mechanical seal Can be used.

  Embodiments of a motor pump according to the present invention will be described below with reference to FIGS. In the embodiment, as an embodiment of the motor pump of the present invention, a horizontal multi-stage motor pump in which a plurality of intermediate casings formed by press forming steel plates are stacked in multiple stages, and an impeller is accommodated inside each intermediate casing. The embodiment will be described. 1 to 4, the same or corresponding components are denoted by the same reference numerals, and redundant description is omitted.

  FIG. 1 is a longitudinal sectional view showing a horizontal multistage motor pump according to an embodiment of the present invention. The horizontal multi-stage motor pump in this embodiment includes a plurality of intermediate casings 1 formed by press-molding steel plates and stacked in multiple stages, and suction casings 2 and pumps provided on the left and right of the intermediate casings 1 stacked in multiple stages. And a head 3. A motor 40 is connected to the pump head 3 by a plurality of bolts 60.

  The flange 2 f of the suction casing 2 and the pump head 3 are connected by a plurality of casing bolts 8. That is, by inserting the casing bolt 8 from the bolt hole 2h formed in the flange 2f of the suction casing 2 and screwing the lower end of the casing bolt 8 into the pump head 3, the multi-stage intermediate casing 1, the suction casing 2 and The pump head 3 is integrally connected.

An impeller 11 fixed to the pump shaft 10 is accommodated in the suction casing 2 and each intermediate casing 1. The pump shaft 10 is a spline shaft, and the inner peripheral portion of the impeller 11 has a plurality of grooves fitted to the spline shaft.
A mechanical seal 12 is attached to the end of the pump shaft 10, and the shaft seal (shaft seal) of the portion where the pump shaft 10 penetrates the pump head 3 is performed by the mechanical seal 12. The end of the pump shaft 10 is press-fitted into a motor shaft 41 of the motor 40, and the pump shaft 10 and the motor shaft 41 are integrally connected to constitute the main shaft 4. The motor 40 includes a stator 43 in a motor casing 42, a rotor 44 fixed to the motor shaft 41, and a fan 45 fixed to the end of the motor shaft 41. The motor casing 42 includes a substantially cylindrical motor frame 46 and an end cover 47 that closes the end of the motor frame 46.

The motor shaft 41 of the motor 40 is rotatably supported by a bearing 48 held by the end cover 47 and a bearing 49 held by a bearing housing portion 3 c provided in the pump head 3. Since the motor shaft 41 and the pump shaft 10 are integrated by press fitting to form the main shaft 4, the integrated main shaft 4 is also rotatably supported by the bearings 48 and 49. The bearings 48 and 49 are ball bearings.
A suction port 2 a is formed in the suction casing 2, and a discharge port 3 a is formed in the pump head 3.

  FIG. 2 is a partially enlarged view showing a structure in the vicinity of the intermediate casing shown in FIG. As shown in FIG. 2, the intermediate casing 1 in the present embodiment is formed in a substantially cylindrical container shape, and includes a cylindrical side surface portion 21 and a protruding portion 22 that protrudes radially outward from the cylindrical side surface portion 21. , A step plane portion 23 extending radially inward from the protrusion 22, a step side portion 24 extending in the axial direction from the step plane portion 23, and a bottom portion 25 extending radially inward from the step side portion 24. . The intermediate casing 1 is manufactured by press forming a stainless steel plate.

  The protruding portion 22 has an outer diameter larger than the outer diameter of the cylindrical side surface portion 21, and the stepped side surface portion 24 has an outer diameter slightly smaller than the inner diameter of the cylindrical side surface portion 21. Further, the step plane portion 23 is formed at a right angle to the cylindrical side surface portion 21, and substantially the entire axial end surface 21 a of the cylindrical side surface portion 21 of the adjacent intermediate casing 1 abuts on the step plane portion 23. It is like that. In addition, as long as the area of the contact surface with the end surface 21a of the cylindrical side surface portion 21 can be secured, the stepped plane portion 23 may be inclined with respect to the cylindrical side surface portion 21 by a predetermined angle instead of a right angle.

  The bottom surface portion 25 of the intermediate casing 1 is formed in a hemispherical or substantially hemispherical shape in the axial direction of the intermediate casing 1. A suction plate 30 is attached to the bottom portion 25 by welding, and a return blade 34 is sandwiched and welded between the suction plate 30 and the side plate 32. The suction plate 30 is curved and formed in the same hemisphere shape or substantially hemispherical shape as the bottom surface portion 25. An end face 30 a on the outer peripheral side of the suction plate 30 is in contact with the inner peripheral surface of the cylindrical side surface portion 21 of the adjacent intermediate casing 1, and the suction plate 30, the step side surface portion 24, the step plane portion 23, and the adjacent one. A space for mounting the O-ring 27 is formed by the inner peripheral surface of the cylindrical side surface portion 21 of the intermediate casing 1. As described above, according to the present invention, since a simple structure that facilitates press molding is obtained, the groove for the O-ring between the intermediate casings can be formed easily and with high accuracy, and stable sealing performance and accuracy can be obtained. be able to. In addition, since the shape of the groove for the O-ring can be easily changed in accordance with the commercially available O-ring, the cost can be reduced by using a commercially available O-ring that is easily available. And since the bottom face part 25 of the intermediate casing 1 is formed in a hemispherical or substantially hemispherical shape, the intermediate casing 1 is excellent in pressure resistance.

  A liner ring 28 is attached to the inner peripheral edge 26 of the bottom surface 25 of the intermediate casing 1, and this liner ring 28 prevents leakage of high-pressure water to the impeller suction side. A liner ring 28 is also attached to the inner end of the suction port 2 a of the suction casing 2.

  Inside the intermediate casing 1, a baffle 36 is provided so as to cover the outer peripheral portions of the protruding portion 22, the stepped flat surface portion 23, the stepped side surface portion 24, and the bottom surface portion 25. The baffle 36 is joined to the bottom surface portion 25 of the intermediate casing 1 by welding, and even if solid matter such as stone flows into the intermediate casing 1 by the baffle 36, the protruding portion 22, the step plane portion 23, and the step side surface from the solid matter. The parts on the outer peripheral side of the part 24 and the bottom part 25 are protected. In particular, the baffle 36 protects the corner molding portion of the intermediate casing 1. The baffle 36 may be omitted depending on the use of the pump.

  FIG. 3 is a view showing the inside of the intermediate casing, and is a view taken along arrow III in FIG. As shown in FIG. 3, the inner peripheral side of the baffle 36 has a spline structure in which a number of grooves 36a extending outward in the radial direction are formed. Accordingly, the bottom surface portion 25 of the intermediate casing 1 is exposed at the locations of these grooves 36a, and the bottom surface portion 25 is covered by the baffle 36 at the locations where these grooves 36a are not present. As a result, an uneven portion is formed on the bottom surface portion 25 by a thickness corresponding to the plate thickness of the baffle 36 on the surface facing the impeller 11. Therefore, the liquid existing in the space between the impeller 11 and the bottom surface portion 25 is given rotational energy as the impeller 11 rotates, but the surface of the bottom surface portion 25 formed by the groove 36 a of the baffle 36. The rotational energy of the liquid is attenuated by the uneven portions. As a result, the static pressure drop of the liquid existing in the space between the impeller 11 and the bottom surface portion 25 is prevented, and the thrust force applied to the impeller 11 can be reduced.

  Next, referring to FIG. 1 and FIG. 4, the peripheral parts of the bearing 49 for supporting the pump shaft 10 and the mechanical seal 12 for shaft sealing (shaft seal) of the portion where the pump shaft 10 penetrates the pump casing are referred to. I will explain. FIG. 4 is an enlarged cross-sectional view of the main part of FIG.

  A bearing 49 that supports the main shaft 4 including the pump shaft 10 and the motor shaft 41 integrated by press-fitting is fixed to the bearing housing portion 3 c of the pump head 3 by a retaining ring 51. A bearing plate 52 made of sheet metal is attached to the motor shaft 41 adjacent to the bearing 49, and a draining ring 53 is attached adjacent to the bearing plate 52. A positioning member 55 is installed at a joint portion between the motor shaft 41 and the pump shaft 10 by using a step portion 41 s on the end surface of the motor shaft 41. That is, the positioning member 55 is attached to the motor shaft 41 so as to contact the stepped portion 41 s of the motor shaft 41, and the end surface 55 a of the positioning member 55 positions the draining ring 53. Therefore, the draining ring 53 is pressed by the end surface 55 a of the positioning member 55, and the draining ring 53 rotates integrally with the motor shaft 41 as the motor shaft 41 rotates. Thereby, even if liquid leaks from the mechanical seal 12, it is prevented from draining by the draining ring 53 and entering the motor side.

  On the other hand, the mechanical seal 12 includes a sleeve 61 made of a thin pipe provided so as to cover the spline portion 10 s of the pump shaft 10, a rotation side member 62 including a rotation side seal ring attached to the sleeve 61, and a rotation side seal. A fixed side member 63 including a fixed side seal ring that slides relative to the ring. One end of the sleeve 61 is expanded and fitted to the positioning member 55, and the other end of the sleeve 61 is reduced and fitted to the outer periphery of the spline portion 10s. In addition, an O-ring 65 is attached to the pump shaft 10 in order to seal a gap between the inner periphery of the sleeve 61 and the outer periphery of the pump shaft 10.

The sleeve 61 has an inner diameter d ₁ that is fitted to the spline portion 10 s, an outer diameter D that can use a standard mechanical seal, and an inner diameter d ₂ that is expanded by the outer diameter D and that can use a standard O-ring. Are formed. Specifically, the sleeve 61 is used a thin pipe standards having an outer diameter D, one end of the sleeve 61 is swaged to the inner diameter d ₁ as fitted to the spline part 10s, the sleeve 61 The other end is expanded to an inner diameter d ₂ so that a commercially available O-ring 65 can be used.

By the way, the sleeve 61 is formed by expanding and contracting from a thin pipe having an outer diameter in the vicinity of d ₁ to d ₂ .
For example, when the material diameter is between d _{1 and} D, the d ₁ part is a contraction tube, and the D and d ₂ parts are a tube expansion. Further, when the material diameter is D to d ₂ , the d ₁ part and the D part are contracted and the d ₂ part is expanded. In any case, the inner diameter of d ₁ is fitted to the main shaft diameter, the outer diameter of D is shaped as the inner diameter of the mechanical seal, and the inner diameter of d ₂ is shaped so that a commercially available O-ring 65 can be used.

  The sleeve 61 is positioned by having one end abutting on the positioning member 55 and the other end abutting on a C-shaped ring 64 mounted in a groove 10g provided in the spline portion 10s. In addition, the ring-shaped member 66 which covers the edge part of the rotation side member of the mechanical seal 12 is mounted | worn with the spline part 10s.

  According to the present invention, a sleeve 61 made of a thin pipe is provided so as to cover the spline portion 10 s of the pump shaft 10, and a standard mechanical seal can be attached to this sleeve, and the inner periphery of the sleeve 61 and the pump shaft 10 can be mounted. A commercially available O-ring 65 can be used to seal the gap between the outer circumference of the two.

Next, the operation of the multistage pump shown in FIGS. 1 to 4 will be briefly described.
The liquid sucked from the suction port 2 a during the operation of the pump is introduced into the suction casing 2 and pressurized by the first stage impeller 11 in the suction casing 2. The liquid discharged from the first stage impeller 11 passes through a flow path formed by the return blade 34 sandwiched between the suction plate 30 and the side plate 32, and the next stage impeller in the intermediate casing 1. 11 suction parts. In this way, the pressure of the liquid is increased by the impeller 11 of each stage, the pressure is recovered while passing through the flow path formed by the return vane 34 of each stage, and the pressure is increased by the impeller 11 of the final stage. The ink is discharged from the discharge port 3a of the head 3 to the outside. In addition, although embodiment mentioned above demonstrated the horizontal type multistage motor pump, the motor pump of this invention can be used also as a vertical type pump.

It is a longitudinal cross-sectional view which shows the horizontal type multistage motor pump in one Embodiment of this invention. It is the elements on larger scale which show the structure of the intermediate casing vicinity shown in FIG. It is a figure which shows the inside of an intermediate | middle casing, and is III arrow directional view of FIG. It is a principal part expanded sectional view of FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Intermediate casing 2 Suction casing 2a Suction port 2f, 40f Flange 2h Bolt hole 3 Pump head 3a Discharge port 3c Bearing housing part 4 Main shaft 8 Casing bolt 10 Pump shaft 10g Groove 10s Spline part 11 Impeller 12 Mechanical seal 21 Side part 21a Shaft Direction end face 22 Projection part 23 Step plane part 24 Step side part 25 Bottom part 26 Edge part 27 O ring 28 Liner ring 30 Suction plate 30a End face 32 Side plate 34 Return vane 36 Baffle 36a Groove 40 Motor 41 Motor shaft 41s Step part 42 Motor casing 43 Stator 44 Rotor 45 Fan 46 Motor frame 47 End cover 48, 49 Bearing 51 Retaining ring 52 Bearing plate 53 Water draining ring 55 Positioning member 55a End face 60 Bolt 61 Sleeve 6 2 Rotating member 63 Fixed member 64 C ring 65 O ring 66 Ring member

Claims (7)

At least one impeller mounted on a main shaft comprising an electric motor shaft and a pump shaft;
In a motor pump comprising at least one casing provided corresponding to the impeller,
A pump head that seals the open end of the casing and has a discharge port;
A bearing held by the pump head and supporting the main shaft;
A sheet metal bearing plate provided adjacent to the bearing;
A motor pump comprising: a draining ring provided on the side opposite to the bearing plate and mounted on the main shaft.   The motor pump according to claim 1, wherein the draining ring is made of a rubber V-ring. The main shaft has a step with a reduced diameter on the side opposite to the bearing plate,
A positioning member positioned in the axial direction by the step is provided;
The motor pump according to claim 1 or 2, wherein a position of the draining ring is determined by an end face of the positioning member.   4. The motor pump according to claim 3, wherein the motor shaft and the pump shaft are configured as separate parts, and the step is formed by press-fitting the pump shaft into the motor shaft. At least one impeller mounted on a main shaft comprising an electric motor shaft and a pump shaft;
In a motor pump comprising at least one casing provided corresponding to the impeller,
The pump shaft has a spline portion that holds an impeller, and a positioning member that is positioned at a step at a joint portion between the electric motor shaft and the pump shaft is provided.
A thin sleeve that is fitted to the spline part and the positioning member is provided,
A motor pump characterized in that a rotating side member of a mechanical seal is held on the sleeve, and an O-ring is mounted in a gap between the sleeve and a pump shaft.   6. The motor pump according to claim 5, wherein the sleeve is positioned by a ring-shaped member attached to a groove provided in a spline portion of the main shaft.   At least one of a portion of the sleeve fitted to the spline portion, a portion fitted to the positioning member, and a portion holding the rotating side member of the mechanical seal is formed by contraction or expansion. The motor pump according to claim 5 or 6.

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