JP6535500B2 - Eddy current pump - Google Patents

Description

  The present invention relates to a vortex pump having a plurality of impellers.

  As a pump device for increasing the pressure of water, there is known an eddy current pump capable of reducing the internal leak by narrowing the gap between the impeller and the casing, and obtaining high lift with a low output motor. As such an eddy current pump, a technique is known in which an impeller provided with a plurality of blades on one main surface is used in a single plate (single stage). However, such an impeller becomes larger in diameter and thinner with respect to the diameter when the discharge pressure of the vortex pump is increased, and the mechanical strength is low, and the rotation applied to the impeller when the vortex pump is driven There is a possibility that it can not withstand torque.

  For this reason, a multistage vortex flow pump using a plurality of the impellers is known. In addition, a multistage vortex flow pump (see, for example, Patent Documents 1 to 3) provided with an impeller provided with a plurality of blades on both surfaces of the impeller is also known.

  However, in the case of a multistage vortex pump, the discharge pressure can be high, but the boss of the first stage impeller, in other words, the central part of the casing and the second stage impeller boss, in other words the motor A high pressure difference is generated between the connection and the mechanical seal chamber of the connecting part. For this reason, there is a problem that the life of the bearing that supports the main shaft is reduced because a high axial load is applied.

  Further, by the high pressure, a radial load is applied to the main shaft from the discharge side to the suction side via the impeller. In the vortex pump, the gap between the impeller and the casing is set to be narrow, so the main shaft may be bent by the radial load, and the impeller and the casing may be in contact with each other.

  For this reason, there is also known a technique to cope with excessive radial load and axial load by bearing-supporting the main shaft through a plurality of impellers.

Japanese Utility Model Publication No. 58-156195 Japanese Patent Application Laid-Open No. 09-209864 JP, 2014-20322, A

  If the main shaft is supported as in the case of the above-described vortex pump, the main shaft becomes long and the casing also becomes large, and since the shaft coupling etc. is required, the vortex pump becomes large and complicated, and manufacturing There is a problem that the cost is also high.

  Then, an object of this invention is to provide the eddy current pump which can reduce the load which generate | occur | produces at the time of a drive.

As one aspect of the present invention, a vortex flow pump includes a rotary shaft, a casing having an opening at one end, a casing cover covering the opening of the casing, and an intermediate casing provided in the casing and forming a pump chamber with the casing. It has a disk-like base provided in the pump chamber, a boss provided at the center of the base and into which the rotary shaft is inserted, and a plurality of blades provided on the outer peripheral edge of the base, the boss The impeller includes: a plurality of impellers whose main surfaces are in contact with the other bosses; and a through hole provided in the bosses and passing between the main surfaces of the bosses ; Through holes communicate with each other and are fixed to the rotary shaft, and the boss portion of the impeller has an annular groove portion in which the through hole is disposed on the main surface facing the boss portion of another adjacent impeller For example, the through hole is provided at a position different from the through-hole of the boss portion adjacent communicates through the groove.

  According to the present invention, it is possible to provide an eddy current pump capable of reducing the load generated at the time of driving.

BRIEF DESCRIPTION OF THE DRAWINGS Sectional drawing which shows the structure of the eddy current pump which concerns on one Embodiment of this invention. Sectional drawing which shows the structure of the pump part of the same eddy current pump. Sectional drawing which shows the structure of the pump part. Sectional drawing which shows the structure of the impeller used for the pump part. The top view which shows the structure of the same impeller.

Hereinafter, a vortex flow pump 1 according to an embodiment of the present invention will be described using FIGS. 1 to 5.
FIG. 1 is a cross-sectional view showing the structure of the eddy current pump 1 according to an embodiment of the present invention, FIG. 2 is a cross-sectional view showing the structure of the pump portion 12 of the eddy current pump 1, and FIG. 3 is a cross section showing the structure of the pump portion 12 FIG. 4 is a cross-sectional view showing the configuration of the impeller 33 used for the pump unit 12, and FIG. 5 is a plan view showing the configuration of the impeller 33. As shown in FIG.

  As shown in FIG. 1, the eddy current pump 1 includes a motor 11 and a pump unit 12. The eddy current pump 1 is a so-called cascade pump which can pressurize a liquid, for example water, and supply it to the secondary side.

  The motor 11 includes a motor frame 21, a stator 22 fixed in the motor frame 21, a rotor 23 rotated by the stator 22, and a rotating shaft 24 fixed to the rotor 23. . The motor 11 is provided with a pair of bearings 25 that support the rotating shaft 24 at two points across the rotor 23.

  The rotating shaft 24 is disposed to project from the motor frame 21. The rotary shaft 24 has a protruding end disposed in the pump portion 12. The rotary shaft 24 is provided with a key 24 a on the end side disposed in the pump unit 12.

  As shown in FIGS. 1 to 3, the pump unit 12 is provided in the casing cover 30, the casing 31, the casing 31, the intermediate casing 32 constituting the pump chamber 32 a, and a plurality of casings accommodated in the casing 31. For example, two impellers 33, a seal member 34 for disposing the end of the rotary shaft 24 in a fluid tight manner in the casing 31, and a bearing member 35 for supporting the end of the rotary shaft 24 disposed in the casing 31. , And a retaining ring 36 for fixing the impeller 33.

  The casing cover 30 includes an opening 30a into which the rotary shaft 24 is inserted, and a seal groove 30b provided around the opening 30a. The motor 11 and the casing 31 are fixed to the casing cover 30.

  The opening 30 a is provided on the surface of the casing cover 30 facing the motor 11 and is formed so that the rotation shaft 24 can be inserted. The seal groove 30 b is disposed in the casing cover 30 around the opening 30 a. The seal groove 30 b is formed so that the seal member 34 can be disposed.

  The casing 31 is formed in a substantially cylindrical shape that is open at one end side facing the motor 11, and the opening is covered by the casing cover 30. The casing 31 is formed so that the casing cover 30 can be attached and detached along the axial center direction of the rotating shaft 24 to be inserted. The casing 31 is provided with a suction port 31a in communication with a portion of the pump chamber 32a, a discharge port 31b in communication with a portion of the pump chamber 32a, and a bearing provided at a position facing the seal groove 30b of the casing cover 30. And a mounting portion 31c. The casing 31 is open at one end facing the motor 11, and the opening is covered by the casing cover 30.

  The suction port 31 a is formed so as to be connectable to a pipe or the like disposed on the primary side of the vortex flow pump 1. The discharge port 31 b is formed to be connectable to a pipe or the like disposed on the secondary side of the eddy current pump 1.

  The bearing mounting portion 31 c is formed so as to be able to accommodate the end of the rotary shaft 24 and to arrange the bearing member 35. The bearing mounting portion 31 c has an inner diameter larger than the outer diameter of the rotary shaft 24 and is formed in an inner diameter that can be fitted with the bearing member 35, and has a cylindrical recess (groove) with an end closed. It is. The bearing mounting portion 31 c is provided with a pin 31 d on the surface facing the bearing member 35.

  The intermediate casing 32 is provided in the casing 31 and forms a pump chamber 32 a that accommodates the plurality of impellers 33 together with the casing cover 30 and the casing 31. Specifically, the intermediate casing 32 divides the pump chamber 32a into two by the partition wall 32b extending in a direction orthogonal to the axial direction, and the first pump chamber 32c of the first stage and the second pump chamber 32d of the two-stage surface Form

  The middle casing 32 is formed so that the rotation shaft 24 and a boss portion 33b, which will be described later, of the impeller 33 can be disposed at the center of the middle casing 32 by opening the center of the partition 32b. By making the gap between the inner surface of the intermediate casing 32 and the outer surface of the impeller 33 minute, the intermediate casing 32 shuts off between the first pump chamber 32c and the second pump chamber 32d. In addition, the intermediate casing 32 has a communication hole 32e for communicating the first pump chamber 32c and the second pump chamber 32d.

  The first pump chamber 32c is one space of the pump chamber 32a separated by the partition wall 32b. The first pump chamber 32c is connected to the suction port 31a. The first pump chamber 32c forms a flow path from the suction port 31a to the communication hole 32e.

  The second pump chamber 32d is the other space of the pump chamber 32a separated by the partition wall 32b, and is connected to the discharge port 31b. The second pump chamber 32d is provided on the secondary side of the first pump chamber 32c. The second pump chamber 32d forms a flow path from the communication hole 32e to the discharge port 31b.

  The first pump chamber 32c and the second pump chamber 32d are fluidly connected by the communication hole 32e. In other words, the space between the first pump chamber 32c, the second pump chamber 32d and the communication hole 32e is divided into two, and the two spaces form the fluidly continuous pump chamber 32a.

  The communication hole 32e is disposed on the secondary side of the flow path formed in the first pump chamber 32c and on the primary side of the flow path formed in the second pump chamber 32d.

  The impeller 33 is provided with a flat base 33a, a boss 33b provided at the center of the base 33a, and a plurality of blades 33c provided on one outer surface of the base 33a and at the outer peripheral edge.

  The boss portion 33b has an insertion hole 33d for inserting the rotary shaft 24 formed at its center, a through hole 33e formed between the main surfaces in the axial center direction of the boss portion 33b, and a main portion on one side of the boss portion 33b. And a groove 33f provided on the surface.

  The insertion hole 33 d has a key groove 33 g formed on the inner circumferential surface thereof to be engaged with the key 24 a. The through holes 33 e are provided to penetrate between the main surfaces of the bosses 33 b. The through hole 33 e is formed in an inner diameter where the water passing through the through hole 33 e becomes a throttling flow, in other words, an inner diameter which has an orifice effect. The through hole 33 e is formed to have, for example, 0.8 mm to 1.5 mm.

  The groove 33f is an annular groove centered on the axial center of the boss 33b. The groove 33f is formed to have a diameter at which the through hole 33e is disposed in a part thereof. In other words, the through hole 33e is disposed on the groove 33f of the boss 33b. The groove 33f has, for example, a depth from the main surface of the boss 33b that is substantially the same as the radius of the through hole 33e.

  The groove 33f is a main surface of the boss 33b on the same side as the main surface of the base 33a on which the blades 33c are provided, or a main surface of the boss 33b facing the main surface of the boss 33b of another adjacent impeller 33. It is provided on the surface. The vanes 33c are formed by cutting or the like at a plurality of locations along the circumferential direction of one main surface of the base 33a.

  The two impellers 33 are disposed on the rotation shaft 24 so that, for example, the through holes 33e of the boss 33b face each other, in other words, the through holes 33e face each other, for example, coaxially. As a result, the main surfaces of the bosses 33 b of the two impellers 33 in contact with each other are in contact with each other, and the impeller 33 is disposed on the rotation shaft 24. In the impeller 33, the key groove 33g is disposed such that the through holes 33e face each other. Further, for example, in the base 33a of the impeller 33, a plurality of pressure balance holes 33h capable of adjusting the pressure on both main surfaces of the base 33a at a constant level are provided.

  The seal member 34 is formed so as to be able to seal between the outer peripheral surface of the rotating shaft 24 and the opening 30 a of the casing cover 30. The seal member 34 is, for example, a mechanical seal. The seal member 34 includes a rotary ring provided on the outer peripheral surface of the rotary shaft 24 and a fixed ring fixed to the seal groove 30b, and the rotary ring and the fixed ring slide to form the rotary shaft 24 and the casing cover. Seal for 30 minutes.

  The bearing member 35 includes a sleeve 35 a fixed to the rotating shaft 24 and an underwater bearing 35 b fixed to the bearing mounting portion 31 c. The sleeve 35a is formed of a material excellent in wear resistance, for example, a ceramic material.

  The sleeve 35a is formed in a cylindrical shape. The sleeve 35a is a rotating ring. The sleeve 35 a is disposed between the center side of the main surface of the boss 33 b of the impeller 33 provided in the first pump chamber 32 c and the retaining ring 36. The outer diameter of the sleeve 35a is smaller than the diameter of a circle passing through the through hole 33e from the center of the boss 33b.

  The submersible bearing 35b is formed of a material having excellent wear resistance, such as a ceramic material. The underwater bearing 35 b is formed in a cylindrical shape. The underwater bearing 35 b is a fixed ring. The submersible bearing 35b is fitted and fixed to the bearing mounting portion 31c. The submersible bearing 35b has an inner diameter substantially equal to the outer diameter of the sleeve 34a. The submersible bearing 35b is formed such that its inner peripheral surface can slide on the outer peripheral surface of the sleeve 34a. The underwater bearing 35b is circumferentially fixed by a pin or the like provided on the bearing mounting portion 31c, and its rotation is restricted with respect to the bearing mounting portion 31c.

  The retaining ring 36 is formed so as to be insertable into the rotating shaft 24. The retaining ring 36 is fixed to the rotating shaft 24 by, for example, a set screw 36 a called a so-called hollow set or a set screw. The retaining ring 36 is fixed to the rotating shaft 24 to fix the two impellers 33 and the sleeves 35 a to the rotating shaft 24.

  The retaining ring 36 is inserted into the end of the rotary shaft 24 and fixed to the rotary shaft 24 by a set screw 36a at a predetermined position so that the sleeve 35a and the impeller 33 can be fixed at the predetermined position of the rotary shaft 24. It is formed. Here, the predetermined position is a position that is appropriately set or adjusted according to the gap between the casing cover 30, the casing 31, the intermediate casing 32, and the impeller 33.

  Next, the pressurized water supply by the eddy current pump 1 configured as described above will be described. First, when the motor 11 is driven, the two impellers 33 rotate via the rotation shaft 24. By this rotation, the water sucked from the suction port 31a is pressurized in the first pump chamber 32c, and moves to the second pump chamber 32d through the communication hole 32e. Further, the water moved to the second pump chamber 32d is pressurized in the second pump chamber 32d and discharged from the discharge port 31b.

  At this time, the pressure in the second pump chamber 32d is increased more than the pressure in the first pump chamber 32c. Further, water pressurized in the first pump chamber 32 c from the gap between the inner surface of the first pump chamber 32 c and the outer surface of the impeller 33, in other words, the gap between the inner surfaces of the casing 31 and the intermediate casing 32 and the outer surface of the impeller 33 A part of these leaks and infiltrates into the bearing mounting portion 31c.

  Here, the pressure of the gap between the casing 31 and one main surface of the base 33a of the impeller 33 and the pressure of the gap between the intermediate casing 32 and the other main surface of the base 33a of the impeller 33 are pressure balance holes 33h. It becomes almost constant. That is, the pressure balance hole 33 h substantially eliminates the pressure difference between the main surfaces of the base 33 a of the impeller 33 and the casing 31 and the intermediate casing 32.

  Also, the pressure is increased in the second pump chamber 32d from the gap between the inner surface of the second pump chamber 32d and the outer surface of the impeller 33, in other words, the gap between the inner surfaces of the casing cover 30 and the intermediate casing 32 and the outer surface of the impeller 33. A part of the water leaks and infiltrates into the seal groove 30b.

  However, between the seal groove 30b and the bearing attachment portion 31c, in other words, the fluid is continuously connected by the through holes 33e provided in the impellers 33, so that the seal groove 30b and the bearing attachment portion 31c have a constant pressure. Become. For this reason, the impeller 33 rotates in a state of being balanced in the axial center direction of the rotating shaft 24.

  According to the eddy current pump 1 configured in this manner, the through holes 33 e penetrating the bosses 33 b of the impeller 33 are provided, and the opposing main surfaces of the bosses 33 b of the plurality of impellers 33 are continuous by the through holes 33 e. Let In other words, the through holes 33 e and the groove portions 33 f of the two impellers 33 constitute a flow path for fluidly communicating between the boss portions 33 b.

  With this configuration, even if water leaked from the gap between the casing cover 30, the casing 31, and the intermediate casing 32 and the impeller 33 moves to the space on the seal member 34 side and the bearing member 35 side of the impeller 33, the pressure of the space is It becomes possible to make it substantially constant.

  Thereby, even if the pressure in the second pump chamber 32 d becomes higher than the pressure in the first pump chamber 32 c by providing the plurality of impellers 33 in the pump unit 12, the leaked water is sealed by the sealing member 34. Since the pressure is substantially equal on the side and the bearing member 35 side, it is possible to prevent the thrust load from being generated in the impeller 33. As a result, the impeller 33 does not move in the axial direction of the rotating shaft 24 from the predetermined position. For this reason, even if the gaps between the casing 31 and the intermediate casing 32 and the impeller 33 caused by the thrust load are minutely designed, the casing 31 and the intermediate casing 32 can be prevented from contacting the impeller 33.

  In addition, since the through hole 33 e is formed to have an inner diameter to be a throttling flow, it is possible to reduce the flow rate flowing through the through hole 33 e, and the gap between the casing cover 30, the casing 31 and the intermediate casing 32 and the impeller 33 It is possible to control the amount of leakage of

  The groove 33f of the end face where the bosses 33b face each other is formed in an annular groove passing through the through hole 33e. For this reason, even if there is variation in accuracy in the position of the through hole 33e provided in the boss portion 33b, more specifically, the position of the through hole 33e provided in the boss portion 33b with respect to the key groove 33g, the through hole 33 e can be fluidly continued through the groove 33 f.

  Further, the pump portion 12 supports the end portion of the rotary shaft 24 in the casing 31 by the bearing member 35 so that the rotary shaft 24 can be a bearing 25 in the motor 11 and the rotary shaft 24 in the casing 31. The shaft can be supported by the bearing member 35 at the end of the shaft. Accordingly, the bearing 25 and the bearing member 35 are supported in a double support structure, and it is possible to support an excessive radial load generated on the rotary shaft 24 in the horizontal direction from the discharge side to the suction side of the pump chamber 32a. As a result, it is possible to prevent the deformation of the rotating shaft 24 and extend the life of the bearing 25. In addition, contact between the casing cover 30, the casing 31, and the intermediate casing 32 and the impeller 33 in the radial direction can be prevented.

  Furthermore, since the end of the rotating shaft 24 is supported by the bearing member 35 provided in the bearing mounting portion 31 c in the casing 31, the end of the rotating shaft 24 does not protrude from the casing 31. There is no need to provide a separate seal member. Therefore, the eddy current pump 1 can be miniaturized.

  As described above, according to the eddy current pump 1 according to the embodiment, the thrust load generated at the time of driving is reduced, and the radial load applied to the rotating shaft 24 from the discharge side to the suction side is reduced by the bearing 25 and the bearing member 35 It becomes possible to support and reduce the radial load applied to the rotating shaft 24.

  The present invention is not limited to the above embodiment. For example, in the above-described example, the groove 33f has a configuration in which the passing water is formed into an inner diameter where the throttling flow occurs, in other words, an inner diameter having an orifice effect (throttling effect). For example, the groove 33f is formed to a depth at which the two grooves 33f face each other so as to make the throttle flow, and a position where the through holes 33e do not face, for example, 180 ° when the impeller 33 is arranged on the rotating shaft 24. It may be arranged at a phased position. In this case, the position of the through hole 33e with respect to the key groove 33g may be designed so that the through holes 33e of the respective impellers 33 are arranged 180 degrees out of phase.

  With such a configuration, the orifice effect can be obtained by the two groove portions 33f, and the same effect as that of the above-described vortex flow pump 1 can be obtained. Further, for example, the inner diameter of the through hole 33e having poor processability is set as the inner diameter that does not obtain the throttling effect, and the depth of the groove 33f having good processability is managed so that the throttling effect can be obtained by the two groove portions 33f facing each other It becomes possible to set it as a structure.

  That is, even with the impeller 33 provided with the through hole 33e and the groove 33f, it is possible to prevent the decrease in processability and the increase in manufacturing cost as much as possible. In particular, when drilling through holes 33 e, there is a high possibility that the drill may be broken when forming holes with a minute diameter, but mass productivity is enhanced by adopting a configuration in which the throttling effect is obtained by the groove 33 f. It becomes possible.

  Further, the through hole 33e and the groove 33f may be configured such that the water passing therethrough is a throttling flow by either one of them, for example, one of the through hole 33e and the groove 33f is formed in a size and shape having the orifice effect. It may be That is, it is only necessary that the throttling effect be obtained when water flows through one of the through hole 33 e and the groove 33 f.

  Moreover, in the example mentioned above, the through holes 33 e of the two impellers 33 are not limited to the same number and the same inner diameter. That is, according to the pressure in the first pump chamber 32c and the pressure in the second pump chamber 32d, the number and the inner diameter of the through holes 33e are appropriately set to seal the casing cover 30 of water leaking from the pump chamber 32d. It is possible to control the differential pressure between the pressure on the member 34 side and the pressure on the bearing member 35 side. For example, when the clearance between the casing 31 and the intermediate casing 32 is set to be extremely small when the boss 33b of the impeller 33 abuts against the snap ring 36, the pressure on the seal member 34 side of the casing cover 30 is The pressure difference may be set to be higher than the pressure on the bearing member 35 side.

  Moreover, although the example using two impellers 33 was demonstrated in the example mentioned above, it is not limited to this, The structure which has three or more impellers 33 may be sufficient. In the case of such a configuration, the through holes 33 e of the plurality of impellers 33 are in fluid communication, so that the same effects as those of the above-described embodiment can be obtained.

Further, in the above-described example, the groove 33f of the impeller 33 has been described as being provided only on one main surface of the boss 33b. However, the invention is not limited to this. Even if the groove 33f is provided on both main surfaces of the boss 33b Good. In addition, the impeller 33 may be configured to have a plurality of blades 33 c on both sides of the base 33 a. Besides the above, various modifications can be made without departing from the scope of the present invention.
In the following, a description equivalent to the invention described in the original claims of the present application is appended.
[1] With rotation axis,
A casing whose one end is open;
A casing cover covering the opening of the casing;
An intermediate casing provided in a casing and forming a pump chamber with the casing;
It has a disk-like base provided in the pump chamber, a boss provided at the center of the base and into which the rotary shaft is inserted, and a plurality of blades provided on the outer peripheral edge of the base, the boss A plurality of impellers in which the main surface of the part abuts on the other boss part;
A through hole provided in the boss and penetrating between main surfaces of the boss;
An eddy current pump comprising:
[2] The vortex flow pump according to [1], wherein the plurality of impellers are fixed to the rotating shaft by communicating the through holes.
[3] The boss portion of the impeller is characterized in that the main surface facing the boss portion of another adjacent impeller is provided with an annular groove portion in which the through hole is disposed [2] ] The eddy current pump as described in [].
[4] The vortex flow pump according to [3], wherein the through holes of the plurality of impellers are disposed to face each other.
[5] The eddy current pump according to [4], wherein the through hole is provided at a position different from the through hole of the adjacent boss portion, and is communicated via the groove portion.
[6] The vortex flow pump according to [1], wherein the impeller has a plurality of holes formed in the base.
[7] A motor having a rotor fixed to the rotating shaft,
A bearing provided on the motor and supporting the rotating shaft;
A bearing member provided in the casing and supporting an end of the rotating shaft located in the casing;
The vortex pump according to [1], comprising:

DESCRIPTION OF SYMBOLS 1 ... Vortex pump, 11 ... Motor, 12 ... Pump part, 21 ... Motor frame, 22 ... Stator, 23 ... Rotor, 24 ... Rotation axis, 24a ... Key, 25 ... Bearing, 30 ... Casing cover 30, 30a ... Opening portion 30b Seal groove 31 Casing 31a Suction port 31b Discharge port 31c Bearing mounting portion 31d Pin 32 Intermediate casing 32a Pump chamber 32b Partition wall 32c First Pump chamber 32d: second pump chamber 32e: communication hole 33: impeller 33a: base 33b: boss 33c: blade 33d: insertion hole 33e: through hole 33f: groove 33g: key groove , 33h: pressure balance hole, 34: seal member, 34a: sleeve, 35: bearing member, 35a: sleeve, 35b: submersible bearing, 36: retaining ring.

Claims (3)

With the rotation axis,
A casing whose one end is open;
A casing cover covering the opening of the casing;
An intermediate casing which forms a pump chamber together with the casing is provided in the casing,
It has a disk-like base provided in the pump chamber, a boss provided at the center of the base and into which the rotary shaft is inserted, and a plurality of blades provided on the outer peripheral edge of the base, the boss A plurality of impellers whose main surfaces of the part abut each other and the boss part
A through hole provided in the boss and penetrating between main surfaces of the boss;
Equipped with
The plurality of impellers are fixed to the rotating shaft by communicating the through holes.
The boss portion of the impeller has an annular groove portion in which the through hole is disposed on the main surface facing the boss portion of another adjacent impeller,
The said through hole is provided in the position different from the said through hole of the said adjacent boss | hub part, It communicates through the said groove part, The eddy current pump characterized by the above-mentioned .   The vortex pump according to claim 1, wherein the impeller has a plurality of holes formed in the base. A motor having a rotor fixed to the rotating shaft;
A bearing provided on the motor and supporting the rotating shaft;
A bearing member provided in the casing and supporting an end of the rotating shaft located in the casing;
The vortex pump according to claim 1, comprising: