JP2022059177A - Motor pump - Google Patents

Abstract

To provide a motor pump that can operate efficiently.SOLUTION: A motor pump comprises an impeller body 50 housing a permanent magnet 5 and a magnet yoke 19. The impeller body 50 comprises a side plate 51 extending inward from an inner peripheral surface 19a of the magnet yoke 19.SELECTED DRAWING: Figure 1

Description

The present invention relates to a motor pump.

There is a demand for miniaturization of pumps, such as applications for incorporation into equipment. In such a case, it is necessary to secure a high lift by means such as high-speed rotation of the impeller and multi-stage pumping.

Japanese Unexamined Patent Publication No. 2016-169734 Japanese Unexamined Patent Publication No. 01-066490

There is a motor pump that rotates an impeller in which a permanent magnet is embedded by a magnetic field generated by a motor stator (see, for example, Patent Document 1). However, in such a motor pump, the impeller has a large thickness, so when the impeller is rotated at high speed, the impeller is greatly affected by friction. As a result, the impeller suffers a loss due to rotation.

In addition, an eddy current is generated in the magnet yoke embedded in the impeller, but since the magnet yoke is covered with a resin impeller, the impeller generates a temperature rise due to the eddy current. .. This temperature rise is one of the causes of thermal demagnetization.

As described above, the friction and thermal demagnetization generated in the impeller become factors that hinder the operating efficiency of the motor pump.

Therefore, an object of the present invention is to provide a motor pump that can be operated efficiently.

In one aspect, a motor pump comprising an impeller assembly and a pump casing accommodating the impeller assembly is provided. The impeller assembly includes a permanent magnet, a magnet yoke arranged adjacent to the permanent magnet, and an impeller body for accommodating the permanent magnet and the magnet yoke. , A side plate extending inward from the inner peripheral surface of the magnet yoke is provided.

In one aspect, the magnet yoke and the side plates are arranged in the same plane.
In one aspect, the magnet yoke and the side plate have a first flow path surface that forms part of the liquid flow path, and the impeller body is a second flow path surface that faces the first flow path surface. The main plate is provided with a blade arranged between the first flow path surface and the second flow path surface.
In one aspect, the magnet yoke is made of a metal material having corrosion resistance, and the blade is made of a metal material having a three-dimensional shape that can be connected to the magnet yoke.

In one aspect, the impeller assembly comprises a sealing member disposed between the impeller body and the magnet yoke.
In one aspect, the impeller assembly comprises a coating member that covers the permanent magnets.
In one aspect, the magnet yoke and the side plate are integrally molded members.
In one aspect, the magnet yoke and the side plate are made of separate members.

According to the present invention, the length of the impeller assembly in the thickness direction can be reduced. Therefore, the influence of friction and thermal demagnetization generated by the operation of the impeller assembly can be reduced. As a result, the motor pump can improve its operating efficiency.

It is sectional drawing which shows one Embodiment of a motor pump. It is an enlarged view of a part of an impeller assembly. It is a schematic view when the side plate and a wing are seen from the front. It is a figure for demonstrating the effect of the impeller assembly which concerns on this embodiment. It is a figure which shows the other embodiment of the impeller assembly. It is a figure which shows the still other embodiment of an impeller assembly.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a cross-sectional view showing an embodiment of a motor pump. As shown in FIG. 1, the motor pump includes an impeller assembly 1 and a pump casing 2 that houses the impeller assembly 1.

The impeller assembly 1 includes a plurality of permanent magnets 5, a magnet yoke 19 arranged adjacent to the plurality of permanent magnets 5, and an impeller body 50 accommodating the plurality of permanent magnets 5 and the magnet yoke 19. It is equipped with.

The motor pump includes a motor stator 6 that generates a magnetic force acting on a permanent magnet 5, a motor casing 3 that houses the motor stator 6, and a bearing 10 that supports the radial load and the thrust load of the impeller assembly 1. It is equipped with. The motor stator 6 and the bearing 10 are arranged on the suction side of the impeller assembly 1. The impeller assembly 1 and the motor stator 6 are arranged concentrically with the bearing 10.

The pump casing 2 and the motor casing 3 are fixed to each other by a plurality of connecting bolts (not shown). An O-ring 9 as a sealing member is provided between the pump casing 2 and the motor casing 3. The impeller assembly 1 and the motor casing 3 face each other through a minute gap, and the impeller assembly 1 rotates by the rotating magnetic field generated by the motor stator 6 acting on the permanent magnet 5. ..

The impeller assembly 1 is rotatably supported by a single bearing 10. The bearing 10 is a slide bearing (dynamic pressure bearing) that utilizes the dynamic pressure of a liquid. The bearing 10 is composed of a combination of a rotary side bearing element 11 and a fixed side bearing element 12 that are loosely engaged with each other.

The rotary side bearing element 11 is fixed to the impeller assembly 1 (more specifically, the impeller body 50), and is arranged so as to surround the liquid inlet of the impeller assembly 1. The fixed-side bearing element 12 is fixed to the motor casing 3 and is arranged on the suction side of the rotary-side bearing element 11.

A part of the liquid discharged from the impeller assembly 1 is guided to the bearing 10 through a minute gap between the impeller assembly 1 and the motor casing 3. When the rotary side bearing element 11 rotates together with the impeller assembly 1, a dynamic pressure of liquid is generated between the rotary side bearing element 11 and the fixed side bearing element 12, whereby the impeller assembly 1 is not affected by the bearing 10. Supported by contact.

A suction port 15 having a suction port 15a is fixed to the motor casing 3. The suction port 15 is made of metal such as stainless steel and is connected to a suction line (not shown). A liquid flow path is formed in each of the suction port 15, the motor casing 3, and the central portion of the bearing 10. These liquid flow paths are connected in a row and form one liquid flow path extending from the suction port 15a to the liquid inlet of the impeller assembly 1.

A discharge port 16 having a discharge port 16a is provided on the outer surface of the pump casing 2, and the liquid boosted by the rotating impeller assembly 1 is discharged through the discharge port 16a. The motor pump according to the present embodiment is a so-called end-top type motor pump in which the suction port 15a and the discharge port 16a are orthogonal to each other.

The motor stator 6 includes a stator core 6A and a stator coil 6B. As shown in FIG. 1, the motor pump includes a stator core 6A of the motor stator 6 and a heat dissipation member 20 in contact with the suction port 15. The heat radiating member 20 is made of a material having a higher thermal conductivity than the motor casing 3. Such materials are, for example, metals such as stainless steel or aluminum, or ceramics.

The motor stator 6 is accommodated in an accommodation space formed in the motor casing 3, and this accommodation space is closed by the heat radiating member 20. Therefore, the heat radiating member 20 of the present embodiment is used as a motor cover that closes the accommodation space of the motor stator 6.

When a current is passed through the stator coil 6B of the motor stator 6, the stator coil 6B generates heat. A part of the heat is transferred to the liquid through the side wall portion 32 of the motor casing 3, and the other part is dissipated to the outside air through the motor casing 3 and the heat radiating member 20. The heat generated by the motor stator 6 comes into contact with the stator core 6A of the motor stator 6 and is transmitted to the heat radiating member 20 having a higher thermal conductivity than the motor casing 3, and the heat radiating member 20 efficiently releases outside air. Is dissipated to.

As described above, the operating efficiency of the motor pump is affected by the friction and thermal demagnetization generated when the impeller assembly 1 rotates. The motor pump (more specifically, the impeller assembly 1) according to the present embodiment has a structure capable of being operated efficiently. Hereinafter, the details of the impeller assembly 1 having such a structure will be described with reference to the drawings.

FIG. 2 is an enlarged view of a part of the impeller assembly 1. As shown in FIG. 2, the impeller body 50 includes a side plate 51 extending inward from the inner peripheral surface 19a of the magnet yoke 19 having an annular shape. The side plate 51 has an annular plate shape. The magnet yoke 19 and the side plate 51 are arranged concentrically with the bearing 10.

In the present embodiment, the magnet yoke 19 and the side plate 51 are integrally molded members. In other words, the magnet yoke 19 also has a function as a side plate while maintaining its own function. The magnet yoke 19 is made of a magnetic material, and may be made of a metal material having corrosion resistance (for example, stainless steel (SUS403), rolled steel for general structure (SS), etc.) depending on the type of transport liquid. .. In one embodiment, the magnet yoke 19 and the side plate 51 may be composed of separate members. In this case, the side plate 51 is connected to the inner peripheral surface 19a of the magnet yoke 19 by means such as welding or adhesion.

As shown in FIGS. 1 and 2, the side end surface 19b of the magnet yoke 19 and the side end surface 51a of the side plate 51 are arranged on the same plane. Therefore, the magnet yoke 19 and the side plate 51 have a first flow path surface 52 that forms a part of the liquid flow path. In the present embodiment, the first flow path surface 52 extends perpendicular to the axial CL, but the first flow path surface 52 is an inclined surface (that is, a taper) inclined at a predetermined angle with respect to the axial CL. It may be a surface).

The impeller body 50 includes a main plate 55 having a second flow path surface 53 facing the first flow path surface 52, blades 56 arranged between the first flow path surface 52 and the second flow path surface 53, and a magnet yoke 19. And a storage cover 57 for accommodating the permanent magnet 5.

The accommodation cover 57 is arranged concentrically with the bearing 10 and has an annular groove 57a in which the permanent magnet 5 and the magnet yoke 19 are mounted. The rotary side bearing element 11 is fixed to the accommodating cover 57 of the impeller body 50.

FIG. 3 is a schematic view of the side plate 51 and the wing 56 when viewed from the front. The main plate 55 and the blade 56 are arranged in parallel with the magnet yoke 19 and the side plate 51 along the axial direction CL (see FIG. 2). As shown in FIG. 3, the blade 56 has a spiral shape extending from the center side of the magnet yoke 19 toward the outer peripheral side. The blade 56 may be made of a metal material connectable to the magnet yoke 19. By constructing the wing 56 from a metal material, the designer can design the shape of the wing 56 relatively freely.

If the wing 56 is made of resin, the wing 56 is manufactured by means such as injection molding, so that the shape of the wing 56 is limited by the manufacturing means. Therefore, the designer cannot freely design the shape of the wing 56. On the other hand, since the wing 56 is made of a metal material, the wing 56 is not limited by the manufacturing means as described above, so that the designer can design the shape of the wing 56 relatively freely. .. Therefore, the metal spiral blade 56 can have a three-dimensional shape (that is, a shape twisted at a predetermined angle) that improves the operating efficiency of the motor pump.

The main plate 55 may also be made of a metal material like the wing 56. In this case, the main plate 55 and the blade 56 may be manufactured by means such as press molding or welding. In one embodiment, the main plate 55 and the wings 56 may be made of a non-metal material such as resin.

When transporting a hot liquid, the heat of the liquid is taken away by the impeller assembly 1. Since the main plate 55 and the blade 56 made of a metal material have high thermal conductivity, the heat of the liquid is largely taken away. As a result, the temperature of the outflowing liquid will be lower than the temperature of the inflowing liquid. Therefore, when transporting a high-temperature liquid, the main plate 55 and the blade 56 may be made of a non-metal material having a low thermal conductivity in order to reduce the temperature difference between the inflowing liquid and the outflowing liquid. ..

When the impeller assembly 1 rotates, the liquid is introduced into the motor pump from the suction port 15a of the motor pump. The liquid passes through the liquid flow path (see FIG. 1) and is introduced into the liquid inlet of the impeller assembly 1. After that, the liquid boosted by the rotation of the impeller assembly 1 passes through the flow path between the first flow path surface 52 and the second flow path surface 53, and is discharged from the discharge port 16a. The motor pump is electrically connected to the inverter via a connector, and the operation of the motor pump is controlled based on the operation of the inverter.

FIG. 4 is a diagram for explaining the effect of the impeller assembly 1 according to the present embodiment. In FIG. 4, an impeller assembly 1 and an impeller assembly 100 as a comparative example are drawn. As described above, the impeller body 50 includes a side plate 51 extending inward from the inner peripheral surface 19a of the magnet yoke 19. On the other hand, the impeller assembly 100 includes a side plate 102 that covers the entire side surface (that is, the exposed surface) of the magnet yoke 101, and the blade 103 and the main plate 104 are attached to the side plate 102.

In the present embodiment, since the side plate 51 is connected to the inner peripheral surface 19a of the magnet yoke 19, the length in the thickness direction of the impeller assembly 1 is the thickness direction of the impeller assembly 100 as a comparative example. Less than the length of (see distance D). For example, the length of the impeller assembly 1 in the thickness direction can be reduced by about 20% to 30% with respect to the length of the impeller assembly 100 in the thickness direction.

By reducing the length of the impeller assembly 1 in the thickness direction, the impeller assembly 1 has friction generated when the impeller assembly 1 is rotated as compared with the impeller assembly 100 (compared to the impeller assembly 100). More specifically, the influence of cylindrical friction) can be reduced. As a result, the motor pump can reduce the loss generated in the impeller assembly 1, and can improve the operating efficiency of the motor pump.

Further, by reducing the length of the impeller assembly 1 in the thickness direction, the overall size of the motor pump can be reduced. As a result, a compact motor pump can be realized.

Further, in the present embodiment, the impeller assembly 1 has a first flow path surface 52 formed by a side end surface 19b of the magnet yoke 19 and a side end surface 51a of the side plate 51. The liquid passing through the flow path between the first flow path surface 52 and the second flow path surface 53 comes into contact with the magnet yoke 19. Therefore, the magnet yoke 19 is cooled by the transferred liquid, and the influence of thermal demagnetization due to the temperature rise can be reduced. As a result, the motor pump can reduce the loss due to thermal demagnetization and improve the operating efficiency of the motor pump.

The magnet yoke 19 has an outer end surface 19c connected to the side end surface 19b, and this outer end surface 19c also comes into contact with the liquid to be transferred. The outer end surface 19c is the outermost end surface of the magnet yoke 19 that forms a part of the outer peripheral surface of the impeller assembly 1.

The magnet yoke 19 and the side plate 51, which are integrally molded members, can increase the contact area of the magnet yoke 19 with the liquid. Therefore, the cooling effect of the magnet yoke 19 can be improved.

FIG. 5 is a diagram showing another embodiment of the impeller assembly 1. As shown in FIG. 5, the impeller assembly 1 includes seal members 60A and 60B arranged between the impeller body 50 (more specifically, the accommodation cover 57) and the magnet yoke 19.

Each of the seal members 60A and 60B is, for example, an O-ring. An annular seal groove 61 is formed on the inner peripheral surface 19a of the magnet yoke 19, and an annular seal groove 62 is formed on the outer peripheral surface 19d of the magnet yoke 19. Each of the seal members 60A and 60B mounted on the seal grooves 61 and 62 can prevent the liquid from coming into contact with the permanent magnet 5.

FIG. 6 is a diagram showing still another embodiment of the impeller assembly 1. As shown in FIG. 6, the impeller assembly 1 includes a coating member 65 that covers the permanent magnet 5. In the embodiment shown in FIG. 6, the impeller body 50 does not include a housing cover 57, instead the permanent magnet 5 is covered with a coating member 65. The coating member 65 is connected to the magnet yoke 19. The coating member 65 that covers the permanent magnet 5 can prevent the liquid from coming into contact with the permanent magnet 5.

The above-described embodiments have been described for the purpose of allowing a person having ordinary knowledge in the technical field to which the present invention belongs to carry out the present invention. Various modifications of the above embodiment can be naturally made by those skilled in the art, and the technical idea of the present invention can be applied to other embodiments. Accordingly, the invention is not limited to the described embodiments, but is to be construed in the broadest range in accordance with the technical ideas defined by the claims.

1 Impeller assembly 2 Pump casing 3 Motor casing 5 Permanent magnet 6 Motor stator 6A Stator core 6B Stator coil 9 Seal member 10 Bearing 11 Rotating side bearing element 12 Stator side bearing element 15 Suction port 15a Suction port 16 Discharge Port 16a Discharge port 19 Magnet yoke 19a Inner peripheral surface 19b Side end surface 19c Outer end surface 19d Outer end surface 20 Heat dissipation member 32 Side wall 50 Impeller body 51 Side plate 51a Side end surface 52 First flow path surface 53 Second flow path surface 55 Main plate 56 Wings 57 Accommodation cover 57a Circular groove 60A, 60B Seal member 61, 62 Seal groove 65 Coating member 100 Impeller assembly 101 Magnet yoke 102 Side plate 103 Wing 104 Main plate

Claims (8)

With the impeller assembly,
A pump casing for accommodating the impeller assembly and
The impeller assembly is
With permanent magnets
A magnet yoke placed adjacent to the permanent magnet and
The permanent magnet and the impeller body for accommodating the magnet yoke are provided.
The impeller body is a motor pump including a side plate extending inward from the inner peripheral surface of the magnet yoke. The motor pump according to claim 1, wherein the magnet yoke and the side plate are arranged on the same plane. The magnet yoke and the side plate have a first flow path surface that forms part of the liquid flow path.
The impeller body
A main plate having a second flow path surface facing the first flow path surface,
The motor pump according to claim 1 or 2, comprising a blade disposed between the first flow path surface and the second flow path surface. The magnet yoke is made of a metal material having corrosion resistance.
The motor pump according to claim 3, wherein the blade is made of a metal material having a three-dimensional shape that can be connected to the magnet yoke. The motor pump according to any one of claims 1 to 4, wherein the impeller assembly includes a sealing member arranged between the impeller body and the magnet yoke. The motor pump according to any one of claims 1 to 4, wherein the impeller assembly includes a coating member that covers the permanent magnet. The motor pump according to any one of claims 1 to 6, wherein the magnet yoke and the side plate are integrally molded members. The motor pump according to any one of claims 1 to 6, wherein the magnet yoke and the side plate are made of separate members.

Images