WO2023013255A1 - Motor pump - Google Patents

Abstract

The present invention relates to a motor pump. This motor pump (MP) includes a motor casing. The motor casing (3) is provided with a motor can (3A) including a housing recess section (65) housing only a tip portion (60) of a teeth section (6A-1) and opposing an impeller (1).

Description

motor pump

The present invention relates to motor pumps.

Axial gap type canned motor pumps are known, in which an impeller having a permanent magnet is rotated by a magnetic field generated by a motor stator. Due to their compact structure, such motor-pumps are sometimes incorporated into various devices such as temperature control devices (chillers).

JP 2010-048162 A JP 2019-120158 A JP-A-61-178595 JP-A-61-178596

Such a motor pump has a structure in which the handled liquid (liquid) flows inside the motor pump to cool the motor. Therefore, when a low-temperature liquid is transferred, the liquid handled may be affected by the heat of the motor (more specifically, the stator coil), and as a result, the temperature of the liquid handled may rise.

On the other hand, when transferring a high-temperature liquid, the motor (more specifically, the stator coil) may be affected by the heat of the liquid and the temperature of the motor may rise. As a result, the motor may fail due to its temperature rise.

Therefore, an object of the present invention is to provide a motor pump that can eliminate the influence of heat between the liquid to be handled and the motor.

In one aspect, an impeller housing a permanent magnet, a pump casing housing the impeller, a motor stator having teeth around which stator coils are wound, a motor casing housing the motor stator, A motor pump is provided comprising: The motor casing includes a motor can that accommodates only tip portions of the teeth and has an accommodation recess facing the impeller.

In one aspect, the tip section extends further toward the impeller than the stator coil.
In one aspect, the motor can forms at least part of an impeller-facing portion in which the housing recess is formed, and a liquid flow path connected to the impeller-facing portion and extending to a liquid inlet of the impeller. and a flow path forming portion.
In one aspect, the impeller facing portion and the flow path forming portion are configured from separate members.

In one aspect, the impeller facing portion and the flow path forming portion are integrally molded members.
In one aspect, the motor casing includes a motor frame connected to the motor can, the motor frame being constructed of a material having a higher thermal conductivity than the motor can.
In one aspect, the motor can is constructed from a heat insulating material.

In one aspect, the motor stator includes a heat insulating material covering the tip portion.
In one aspect, the tip portion is accommodated in the accommodation recess via a space formed between the tip portion and the accommodation recess.

The motor pump has a structure in which the stator coil is arranged apart from the flow path of the handled liquid. Therefore, the motor pump can eliminate the influence of heat between the handled liquid and the motor.

FIG. 3 illustrates one embodiment of a motor-pump; 4 is a partially enlarged view of the motor casing; FIG. FIG. 10 is a diagram showing another embodiment of a motor can; FIG. 4 is a diagram for explaining the transfer of heat generated from stator coils; FIG. 11 shows another embodiment of a motor-pump; FIG. 4 is a diagram showing an insulating coating portion covering a contact portion of a stator core with a stator coil; FIG. 10 is a diagram showing another embodiment of a tooth portion;

Embodiments of the motor pump will be described below with reference to the drawings. In the following embodiments, the same or corresponding constituent elements are denoted by the same reference numerals, and redundant explanations are omitted.

FIG. 1 is a diagram showing one embodiment of a motor pump. As shown in FIG. 1, the motor pump MP includes an impeller 1 housing a permanent magnet 5, a motor stator 6 generating a magnetic force acting on the permanent magnet 5, a pump casing 2 housing the impeller 1, It has a motor casing 3 that houses a motor stator 6 and bearings 10 that support the radial load and thrust load of the impeller 1 . Motor stator 6 and bearing 10 are arranged on the suction side of impeller 1 .

The pump casing 2 and motor casing 3 are connected to each other by a plurality of connecting bolts (not shown). Between the pump casing 2 and the motor casing 3 (more specifically, the motor can 3A), a seal member (for example, an O-ring) 9 is arranged to prevent liquid leakage. The structure of the motor casing 3 including the motor can 3A will be described later.

The impeller 1 and the motor can 3A of the motor casing 3 face each other with a minute gap therebetween, and the impeller 1 rotates when a rotating magnetic field generated by the motor stator 6 acts on the permanent magnet 5. . In this embodiment, the permanent magnet 5 is a ring-shaped permanent magnet magnetized with a plurality of magnetic poles, but a plurality of permanent magnets 5 may be provided. The motor pump MP further includes an annular magnet yoke 19 (magnetic body) arranged adjacent to the permanent magnet 5 . The permanent magnet 5 is arranged on the suction side of the magnet yoke 19 .

The impeller 1 is rotatably supported by a single bearing 10. The bearing 10 is a slide bearing (dynamic pressure bearing) that utilizes dynamic pressure of liquid. The bearing 10 includes a rotation side bearing body 11 fixed to the impeller 1 and a fixed side bearing body 12 fixed to the motor can 3A of the motor casing 3 . The rotation-side bearing body 11 is arranged so as to surround the liquid inlet of the impeller 1 . The fixed-side bearing 12 is arranged on the suction side of the rotary-side bearing 11 .

The fixed-side bearing body 12 has a radial surface 12 a that supports the radial load of the impeller 1 and a thrust surface 12 b that supports the thrust load of the impeller 1 . The radial surface 12a extends parallel to the direction of the axis CL of the motor pump MP (that is, the axis of the impeller 1), and the thrust surface 12b extends perpendicular to the direction of the axis CL.

The rotation-side bearing body 11 has an annular shape. The inner peripheral surface 11 a of the rotating bearing 11 faces the radial surface 12 a of the fixed bearing 12 , and the side surface 11 b of the rotating bearing 11 faces the thrust surface 12 b of the fixed bearing 12 .

The motor pump MP includes a suction port 15 having a suction port 15a, which is fixed to the motor can 3A of the motor casing 3 (more specifically, the flow path forming portion 3A-2 described later). A liquid flow path LC1 is formed in the suction port 15, the motor can 3A (more specifically, the flow path forming portion 3A-2), and the central portion of the bearing . The liquid flow path LC1 extends parallel to the direction of the axis CL of the motor pump MP, and constitutes one flow path extending from the suction port 15a to the liquid inlet of the impeller 1 .

The motor pump MP has a discharge port 16 fixed to the pump casing 2 and having a discharge port 16a. The liquid pressurized by the rotating impeller 1 is discharged to the outside of the motor pump MP through the discharge port 16a. The discharge port 16a is arranged radially outward of the impeller 1, and the suction port 15a is arranged in a direction perpendicular to the radial direction of the impeller 1 (that is, in the direction of the axis CL). Thus, the motor pump MP in which the suction port 15a and the discharge port 16a are perpendicular to each other is a so-called end-top type motor pump.

A part of the liquid discharged from the impeller 1 is guided to the bearing 10 through a minute gap (that is, the liquid flow path LC2) between the impeller 1 and the motor can 3A of the motor casing 3. When the rotary-side bearing 11 rotates together with the impeller 1 , fluid dynamic pressure is generated between the rotary-side bearing 11 and the fixed-side bearing 12 , and the impeller 1 is supported by the bearing 10 in a non-contact manner. Since the fixed-side bearing 12 supports the rotating-side bearing 11 with the radial surface 12 a and the thrust surface 12 b orthogonal to each other, the tilting of the impeller 1 is restricted by the bearing 10 .

As shown in FIG. 1, the motor stator 6 includes a stator core 6A and a plurality of stator coils 6B attached to the stator core 6A. The stator core 6A includes a plurality of teeth 6A-1 around which a plurality of stator coils 6B are wound, and a yoke 6A-2 connected to the teeth 6A-1. The plurality of teeth portions 6A-1 and yoke portions 6A-2 may be integrally constructed dust core bodies, or may be electromagnetic steel sheet laminates joined together. The yoke portion 6A-2 has an annular shape. The tooth portions 6A-1 extend from the yoke portion 6A-2 in the direction of the axis CL, and are arranged at equal intervals along the circumferential direction of the yoke portion 6A-2.

In the stator coils 6B, extensions of windings from the stator coils 6B are respectively connected to a substrate 50, and the substrate 50 is printed with connection patterns for driving the plurality of stator coils 6B. there is A lead wire 40 is further connected to the substrate 50 and connected to a power supply (not shown) external to the motor pump MP.

The motor stator 6 is a heating element. More specifically, when a current is passed through the stator coil 6B of the motor stator 6, the stator coil 6B generates heat. If the stator coil 6B, which is a heating element, is arranged close to the flow path of the liquid, one of the liquid and the stator coil 6B may be affected by the heat of the other. Therefore, in this embodiment, the motor pump MP has a structure that can eliminate the influence of heat between the stator coil 6B and the liquid.

FIG. 2 is a partially enlarged view of the motor casing. As shown in FIGS. 1 and 2, the motor casing 3 includes a motor can 3A that accommodates only the tip portions 60 of the tooth portions 6A-1 and has an accommodation recess 65 that faces the impeller 1, and a and a connected motor frame 3B.

The motor can 3A includes an impeller-facing portion 3A-1 in which a housing recess 65 is formed, and at least a portion of a liquid flow path LC1 connected to the impeller-facing portion 3A-1 and extending to the liquid inlet of the impeller 1. and a flow path forming portion 3A-2 to be formed. The impeller facing portion 3A-1 may have a number of housing recesses 65 corresponding to the number of teeth 6A-1, or may have annular housing recesses 65. FIG. In this embodiment, the flow path forming part 3A-2 forms a part of the liquid flow path LC1, but it may form the entire liquid flow path LC1 depending on the structure of the motor pump.

The impeller facing portion 3A-1 has an annular shape, and the flow path forming portion 3A-2 has a cylindrical shape. The impeller facing portion 3A-1 and the flow path forming portion 3A-2 are arranged concentrically with the liquid flow path LC1. The flow path forming portion 3A-2 is connected to the inner peripheral side of the impeller facing portion 3A-1, and is located between the impeller facing portion 3A-1, the flow path forming portion 3A-2, and the fixed side bearing 12. A sealing member (for example, an O-ring) 59 for preventing leakage of liquid is arranged at .

FIG. 3 is a diagram showing another embodiment of the motor can. In the embodiment shown in FIG. 2, the impeller facing portion 3A-1 and the flow path forming portion 3A-2 are configured from separate members, but in one embodiment, the impeller facing portion 3A-1 and flow path forming Section 3A-2 may be a unitary molded member (see FIG. 3). In this case, the seal member 59 may be omitted.

Returning to FIG. 2, a motor frame 3B having a cylindrical shape is arranged radially outside the flow path forming portion 3A-2. The motor frame 3B is arranged concentrically with the liquid flow path LC1. Between the motor frame 3B and the impeller-facing portion 3A-1, a sealing member (for example, an O-ring) 58 is arranged to prevent liquid from entering from the outside.

The stator coil 6B is arranged on the base end portion 61 side of the tooth portion 6A-1, and the tip end portion 60 of the tooth portion 6A-1 extends toward the impeller 1 from the stator coil 6B. A proximal end portion 61 of the tooth portion 6A-1 is arranged on the opposite side to the distal end portion 60 and is connected to the yoke portion 6A-2.

Thus, when the stator coil 6B is attached to the stator core 6A, the teeth 6A-1 protrude from the stator coil 6B. Therefore, the tip portion 60 of the tooth portion 6A-1 protruding from the stator coil 6B is accommodated in the accommodation recess 65 of the impeller facing portion 3A-1. A stator coil 6B attached to the stator core 6A is arranged adjacent to the impeller facing portion 3A-1.

As shown in FIGS. 1 and 2, a liquid flow path LC2 communicating with the bearing 10 is formed in the gap between the impeller 1 and the impeller facing portion 3A-1. In the present embodiment, the stator coil 6B can be arranged apart from the liquid flow path LC2 by accommodating only the tip portion 60 of the tooth portion 6A-1 in the accommodation recess 65. FIG.

Therefore, when transferring a low-temperature liquid, the liquid passing through the liquid flow path LC2 is not affected by the heat of the stator coil 6B. When transferring a high-temperature liquid, the stator coil 6B is not affected by the heat of the liquid passing through the liquid flow path LC2. As a result, the motor pump MP can eliminate thermal effects between the liquid and the stator coils 6B.

In general, when the distance between the motor stator 6 and the permanent magnet 5 increases, the transmission loss of the rotational torque of the impeller 1 increases, and the impeller 1 cannot generate sufficient rotational torque. may not be possible. According to this embodiment, the tip portion 60 of the tooth portion 6A-1 that generates the rotating magnetic field is adjacent to the permanent magnet 5 via the liquid flow path LC2. Therefore, the motor stator 6 can reliably cause the rotating magnetic field generated by itself to act on the permanent magnet 5 . As a result, the impeller 1 can generate sufficient rotational torque.

The stator coil 6B attached to the stator core 6A is arranged between the flow path forming portion 3A-2 and the motor frame 3B. The motor frame 3B is made of a material (eg, aluminum, copper) having a higher thermal conductivity than the motor can 3A (that is, the impeller facing portion 3A-1 and the flow path forming portion 3A-2). The motor can 3A is made of a heat insulating material (for example, resin).

FIG. 4 is a diagram for explaining the transfer of heat generated from the stator coils. As shown in FIG. 4, the flow path forming portion 3A-2 made of heat insulating material can prevent the heat generated from the stator coil 6B from being transferred to the liquid flowing through the liquid flow path LC1. Similarly, the impeller facing portion 3A-1 made of heat insulating material can prevent the heat generated from the stator coil 6B from being transferred to the liquid flowing through the liquid flow path LC2. On the other hand, heat generated from the stator coil 6B is radiated to the outside of the motor pump MP through the motor frame 3B. Therefore, the motor pump MP can more reliably eliminate the influence of heat between the liquid and the stator coil 6B.

The motor pump MP has a heat radiating member 20 that closes the open end of the motor casing 3 . The heat dissipation member 20 is arranged between the motor casing 3 and the suction port 15 . The heat radiating member 20 is made of a material (for example, aluminum, copper) having higher thermal conductivity than the motor can 3A. In one embodiment, the heat dissipation member 20 may be constructed from the same material as the motor frame 3B. The heat radiation member 20 can more efficiently radiate the heat generated from the stator coil 6B to the outside of the motor pump MP.

FIG. 5 is a diagram showing another embodiment of the motor pump. As shown in FIG. 5 , the motor pump MP may further include heat radiating fins 80 fixed to the surface of the heat radiating member 20 . By fixing the heat radiation fins 80 to the heat radiation member 20, the heat generated from the stator coils 6B can be more efficiently radiated. The heat radiating fins 80 may be fixed to the entire surface of the heat radiating member 20 or may be fixed to a part of the heat radiating member 20 . The heat radiating fins 80 may be formed integrally with the heat radiating member 20 .

In one embodiment, the heat radiating fins 80 may be fixed not only to the heat radiating member 20 but also to the motor frame 3B, and instead of being fixed to the heat radiating member 20, they may be fixed to the motor frame 3B. The heat radiating fins 80 may be formed integrally with the motor frame 3B.

FIG. 6 is a diagram showing the insulating coating portion covering the contact portion of the stator core with the stator coil. As shown in FIG. 6, the motor stator 6 has an insulating coating portion 71 covering a contact portion 70 of the stator core 6A with the stator coil 6B.

The contact portion 70 is part of the base end portion 61 of the tooth portion 6A-1 and the yoke portion 6A-2, and the contact portion 70 is covered with the insulating coating portion 71. With such a configuration, the insulating coating portion 71 can ensure insulation between the stator core 6A and the stator coil 6B. The insulating coating portion 71 may be a thin film made of resin.

As shown in FIG. 6, the motor stator 6 may be provided with a heat insulating material 75 covering the tip portion 60 of the tooth portion 6A-1. An example of the heat insulating material 75 is resin. By covering the tip portion 60 with the heat insulating material 75, the motor pump MP can more reliably eliminate the influence of heat between the motor stator 6 and the liquid passing through the liquid flow path LC2. In one embodiment, the insulating material 75 may correspond to the insulating coating 71 and the insulating coating 71 may cover the tip section 60 .

FIG. 7 is a diagram showing another embodiment of the tooth portion. As shown in FIG. 7, the tip portion 60 of the tooth portion 6A-1 is accommodated in the accommodation recess 65 via a space formed between the tip portion 60 and the accommodation recess 65. As shown in FIG. With such a configuration, an air layer is formed between the tip portion 60 and the accommodation recess 65 . This air layer has the same effect as the heat insulating material 75 . Therefore, by forming an air layer, the embodiment shown in FIG. 7 can achieve the same effect as the embodiment shown in FIG.

In one embodiment, the embodiment shown in FIG. 6 and the embodiment shown in FIG. 7 may be combined. In this case, the motor stator 6 is provided with a heat insulating material 75 , and a space (a layer of air) is formed between the tip portion 60 covered with the heat insulating material 75 and the housing recess 65 .

Although the embodiments of the present invention have been described so far, the present invention is not limited to the above-described embodiments, and can of course be implemented in various different forms within the scope of its technical concept.

The present invention can be used for motor pumps.

1 Impeller 2 Pump casing 3 Motor casing 3A Motor can 3A-1 Impeller facing part 3A-2 Flow path forming part 3B Motor frame 5 Permanent magnet 6 Motor stator 6A Stator core 6A-1 Teeth part 6A-2 Yoke part 6B stator coil 9 sealing member 10 bearing 11 rotating side bearing body 11a inner peripheral surface 11b side surface 12 stationary side bearing body 12a radial surface 12b thrust surface 15 suction port 15a suction port 16 discharge port 16a discharge port 19 magnet yoke 20 heat dissipation member 40 Lead wire 50 Substrate 58 Sealing member 59 Sealing member 60 Tip portion 61 Base end portion 65 Accommodating recess 70 Insulating portion 71 Insulating coating portion 75 Heat insulating material 80 Radiation fin MP Motor pump LC1 Liquid channel LC2 Liquid channel

Claims (9)

an impeller containing a permanent magnet;
a pump casing housing the impeller;
a motor stator having teeth around which stator coils are wound;
a motor casing that houses the motor stator;
The motor pump, wherein the motor casing includes a motor can that accommodates only tip portions of the teeth and has an accommodation recess facing the impeller. The motor pump according to claim 1, wherein the tip portion extends toward the impeller from the stator coil. The motor can
an impeller-facing portion in which the accommodation recess is formed;
3. The motor according to claim 1, further comprising a flow path forming portion connected to the impeller facing portion and forming at least part of a liquid flow path extending to a liquid inlet of the impeller. pump. The motor pump according to claim 3, wherein the impeller-facing portion and the flow path forming portion are formed from separate members. The motor pump according to claim 3, wherein the impeller facing portion and the flow path forming portion are integrally molded members. The motor casing includes a motor frame connected to the motor can,
The motor pump according to any one of claims 1 to 5, wherein the motor frame is made of a material having a higher thermal conductivity than the motor can. The motor pump according to any one of claims 1 to 6, wherein the motor can is made of a heat insulating material. The motor pump according to any one of claims 1 to 7, wherein the motor stator has a heat insulating material covering the tip portion. The motor pump according to any one of claims 1 to 8, wherein the tip portion is accommodated in the accommodation recess via a space formed between the tip portion and the accommodation recess. .

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