motor pump

Abstract

To provide a motor pump which can eliminate the influence of heat between a liquid being handled and a motor.SOLUTION: A motor pump MP comprises a motor casing 3. The motor casing 3 comprises a motor can 3A having an accommodation recess 65 which accommodates only a tip portion 60 of a tooth part 6A-1 and lies opposite an impeller 1.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a motor pump. [Background technology]

[0002] Axial gap canned motor pumps are known, in which an impeller with a permanent magnet is rotated by the magnetic field generated by the motor stator. Because of their compact structure, these motor pumps are often incorporated into various devices such as temperature control devices (chillers). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2010-048162 [Patent Document 2] Japanese Patent Application Publication No. 2019-120158 [Patent Document 3] Japanese Patent Publication No. 178595 / 1983 [Patent Document 4] Japanese Patent Publication No. 61-178596 Summary of the Invention [Problem to be solved by the invention]

[0004] Such motor pumps are designed so that the pumped fluid flows through the motor to cool the motor. Therefore, when transporting low-temperature fluid, the pumped fluid is affected by the heat of the motor (more specifically, the stator coil), which can result in a rise in the temperature of the pumped fluid.

[0005] 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, causing the temperature of the motor to rise, which may result in the motor breaking down.

[0006] SUMMARY OF THE INVENTION It is therefore an object of the present invention to provide a motor pump that can eliminate the influence of heat between the pumped fluid and the motor. [Means for solving the problem]

[0007] In one aspect, a motor pump is provided that includes an impeller that houses a permanent magnet, a pump casing that houses the impeller, a motor stator having teeth with stator coils wound around them, and a motor casing that houses the motor stator. The motor casing includes a motor can that houses only the tip portions of the teeth and has an accommodation recess facing the impeller.

[0008] In one aspect, the tip portion extends further toward the impeller than the stator coil. In one aspect, the motor can includes an impeller-facing portion in which the accommodating recess is formed, and a flow path forming portion that is connected to the impeller-facing portion and forms at least a portion of a liquid flow path that extends to the liquid inlet of the impeller. In one embodiment, the impeller-facing portion and the flow path forming portion are formed from separate members.

[0009] In one embodiment, 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 made of a material having a higher thermal conductivity than the motor can. In one embodiment, the motor can is made of a thermal insulating material.

[0010] In one aspect, the motor stator includes a thermal insulator covering the tip portion. In one embodiment, the tip portion is housed in the housing recess via a space formed between the tip portion and the housing recess. [Effects of the Invention]

[0011] The motor pump has a structure in which the stator coil is disposed away from the flow path of the pumped fluid, thereby eliminating the influence of heat between the pumped fluid and the motor. [Brief explanation of the drawings]

[0012] [Figure 1] FIG. 1 illustrates an embodiment of a motor pump. [Figure 2] FIG. [Figure 3] 10A and 10B are diagrams illustrating another embodiment of the motor can. [Figure 4] FIG. 2 is a diagram illustrating the transfer of heat generated from a stator coil. [Figure 5] FIG. 10 is a diagram showing another embodiment of the motor pump. [Figure 6] 10 is a diagram showing an insulating coating portion that covers the contact portion of the stator core with the stator coil. FIG. [Figure 7] 10A and 10B are diagrams illustrating another embodiment of the teeth portion. DETAILED DESCRIPTION OF THE INVENTION

[0013] Hereinafter, embodiments of the motor pump will be described with reference to the drawings. In the following embodiments, the same or corresponding components are designated by the same reference numerals, and redundant description will be omitted.

[0014] 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 that houses a permanent magnet 5, a motor stator 6 that generates a magnetic force acting on the permanent magnet 5, a pump casing 2 that houses the impeller 1, a motor casing 3 that houses the motor stator 6, and a bearing 10 that supports the radial load and thrust load of the impeller 1. The motor stator 6 and bearing 10 are arranged on the suction side of the impeller 1.

[0015] The pump casing 2 and the motor casing 3 are connected to each other by a plurality of connecting bolts (not shown). A seal member (e.g., an O-ring) 9 is disposed between the pump casing 2 and the motor casing 3 (more specifically, the motor can 3A) to prevent leakage of liquid. The structure of the motor casing 3 including the motor can 3A will be described later.

[0016] The impeller 1 and the motor can 3A of the motor casing 3 face each other with a small gap between them, and the impeller 1 rotates when the rotating magnetic field generated by the motor stator 6 acts on the permanent magnet 5. In this embodiment, the permanent magnet 5 is a single annular permanent magnet magnetized with multiple magnetic poles, but multiple permanent magnets 5 may be provided. The motor pump MP further includes an annular magnet yoke 19 (magnetic body) disposed adjacent to the permanent magnet 5. The permanent magnet 5 is disposed on the suction side of the magnet yoke 19.

[0017] The impeller 1 is rotatably supported by a single bearing 10. The bearing 10 is a sliding bearing (dynamic pressure bearing) that utilizes the dynamic pressure of the liquid. The bearing 10 comprises a rotating-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 rotating-side bearing body 11 is arranged to surround the liquid inlet of the impeller 1. The fixed-side bearing body 12 is arranged on the suction side of the rotating-side bearing body 11.

[0018] The fixed-side bearing body 12 has a radial surface 12a that supports the radial load of the impeller 1, and a thrust surface 12b that supports the thrust load of the impeller 1. The radial surface 12a extends parallel to the axis CL of the motor pump MP (i.e., the axis of the impeller 1), and the thrust surface 12b extends perpendicular to the axis CL.

[0019] The rotating-side bearing body 11 has an annular shape. An inner peripheral surface 11a of the rotating-side bearing body 11 faces a radial surface 12a of the fixed-side bearing body 12, and a side surface 11b of the rotating-side bearing body 11 faces a thrust surface 12b of the fixed-side bearing body 12.

[0020] The motor pump MP is provided with a suction port 15 having a suction port 15a fixed to the motor can 3A (more specifically, the flow path forming portion 3A-2, which will be described later) of the motor casing 3. A liquid flow path LC1 is formed in the center of the suction port 15, the motor can 3A (more specifically, the flow path forming portion 3A-2), and the bearing 10. The liquid flow path LC1 extends parallel to the axis CL of the motor pump MP, and forms a single flow path extending from the suction port 15a to the liquid inlet of the impeller 1.

[0021] The motor pump MP is equipped with a discharge port 16 having a discharge port 16a fixed to the pump casing 2. 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 disposed radially outward of the impeller 1, and the suction port 15a is disposed in a direction perpendicular to the radial direction of the impeller 1 (i.e., in the direction of the axis CL). In this way, the motor pump MP, in which the suction port 15a and the discharge port 16a intersect at right angles, is a so-called end-top type motor pump.

[0022] A portion of the liquid discharged from the impeller 1 passes through a minute gap (i.e., liquid flow path LC2) between the impeller 1 and the motor can 3A of the motor casing 3 and is guided to the bearing 10. When the rotating-side bearing 11 rotates together with the impeller 1, dynamic pressure of the liquid is generated between the rotating-side bearing 11 and the fixed-side bearing 12, and the impeller 1 is supported without contact by the bearing 10. The fixed-side bearing 12 supports the rotating-side bearing 11 by means of a radial surface 12a and a thrust surface 12b that are orthogonal to each other, so tilting of the impeller 1 is restricted by the bearing 10.

[0023] 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 the plurality of stator coils 6B are wound, and a yoke 6A-2 connected to the plurality of teeth 6A-1. The plurality of teeth 6A-1 and the yoke 6A-2 may be integrally formed powder cores or may be laminated electromagnetic steel sheets joined together. The yoke 6A-2 has an annular shape. The teeth 6A-1 extend from the yoke 6A-2 in the direction of the axis CL and are arranged at equal intervals along the circumferential direction of the yoke 6A-2.

[0024] The extensions of the windings from the stator coils 6B are connected to a substrate 50, and a wiring pattern for driving the multiple stator coils 6B is printed on the substrate 50. Lead wires 40 are also connected to the substrate 50, and are connected to an external power source (not shown) of the motor pump MP.

[0025] The motor stator 6 is a heat generating 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 heat generating element, is located close to a liquid flow path, there is a risk that 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.

[0026] 2 is a partially enlarged view of the motor casing. As shown in Fig. 1 and Fig. 2, the motor casing 3 includes a motor can 3A that houses only the tip end portions 60 of the teeth 6A-1 and has a housing recess 65 facing the impeller 1, and a motor frame 3B connected to the motor can 3A.

[0027] The motor can 3A includes an impeller-facing portion 3A-1 in which an accommodating recess 65 is formed, and a flow path forming portion 3A-2 that is connected to the impeller-facing portion 3A-1 and forms at least a part of a liquid flow path LC1 that extends to the liquid inlet of the impeller 1. The impeller-facing portion 3A-1 may have the number of accommodating recesses 65 corresponding to the number of teeth 6A-1, or may have an annular accommodating recess 65. In this embodiment, the flow path forming portion 3A-2 forms a part of the liquid flow path LC1, but may also form the entire liquid flow path LC1 depending on the structure of the motor pump.

[0028] The impeller-opposing portion 3A-1 has an annular shape, and the flow path forming portion 3A-2 has a cylindrical shape. The impeller-opposing 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-opposing portion 3A-1, and a seal member (e.g., an O-ring) 59 is arranged between the impeller-opposing portion 3A-1, the flow path forming portion 3A-2, and the fixed-side bearing body 12 to prevent leakage of liquid.

[0029] 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 as separate members, but in one embodiment, the impeller-facing portion 3A-1 and the flow path forming portion 3A-2 may be integrally molded members (see Fig. 3). In this case, the seal member 59 may be omitted.

[0030] Returning to Figure 2, a cylindrical motor frame 3B is disposed radially outward of the flow path forming portion 3A-2. The motor frame 3B is disposed concentrically with the liquid flow path LC1. A seal member (e.g., an O-ring) 58 is disposed between the motor frame 3B and the impeller-facing portion 3A-1 to prevent liquid from entering from the outside.

[0031] The stator coil 6B is disposed 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 further toward the impeller 1 than the stator coil 6B. The base end portion 61 of the tooth portion 6A-1 is disposed on the opposite side to the tip end portion 60 and is connected to the yoke portion 6A-2.

[0032] In this way, 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 portions 60 of the teeth 6A-1 protruding from the stator coil 6B are accommodated in the accommodation recesses 65 of the impeller-facing portion 3A-1. The stator coil 6B attached to the stator core 6A is disposed adjacent to the impeller-facing portion 3A-1.

[0033] 1 and 2, a liquid flow path LC2 that communicates with the bearing 10 is formed in the gap between the impeller 1 and the impeller facing portion 3A-1. In this embodiment, by accommodating only the tip portion 60 of the tooth portion 6A-1 in the accommodating recess 65, the stator coil 6B can be disposed away from the liquid flow path LC2.

[0034] Therefore, when transferring low-temperature liquid, the liquid passing through liquid flow path LC2 is not affected by the heat of the stator coil 6B. When transferring high-temperature liquid, the stator coil 6B is not affected by the heat of the liquid passing through liquid flow path LC2. As a result, the motor pump MP can eliminate the influence of heat between the liquid and the stator coil 6B.

[0035] Generally, as 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 may not be able to generate sufficient rotational torque. According to this embodiment, the tip portions 60 of the teeth 6A-1 that generate a rotating magnetic field are adjacent to the permanent magnet 5 via the liquid flow path LC2. Therefore, the motor stator 6 can reliably apply the rotating magnetic field generated by itself to the permanent magnet 5. As a result, the impeller 1 can generate sufficient rotational torque.

[0036] The stator coil 6B attached to the stator core 6A is disposed between the flow passage forming portion 3A-2 and the motor frame 3B. The motor frame 3B is made of a material (e.g., aluminum or copper) having a higher thermal conductivity than the motor can 3A (i.e., the impeller facing portion 3A-1 and the flow passage forming portion 3A-2). The motor can 3A is made of a heat insulating material (e.g., resin).

[0037] FIG. 4 is a diagram illustrating the transfer of heat generated from the stator coil. As shown in FIG. 4, the flow path forming portion 3A-2 made of a heat insulating material can prevent the transfer of heat generated from the stator coil 6B to the liquid flowing through the liquid flow path LC1. Similarly, the impeller facing portion 3A-1 made of a heat insulating material can prevent the transfer of heat generated from the stator coil 6B to the liquid flowing through the liquid flow path LC2. Meanwhile, the heat generated from the stator coil 6B is dissipated 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.

[0038] The motor pump MP includes a heat dissipation member 20 that closes the open end of the motor casing 3. The heat dissipation member 20 is disposed between the motor casing 3 and the suction port 15. The heat dissipation member 20 is made of a material (e.g., aluminum or copper) that has a higher thermal conductivity than the motor can 3A. In one embodiment, the heat dissipation member 20 may be made of the same material as the motor frame 3B. The heat dissipation member 20 can more efficiently dissipate heat generated from the stator coil 6B to the outside of the motor pump MP.

[0039] 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 dissipation fins 80 fixed to the surface of the heat dissipation member 20. By fixing the heat dissipation fins 80 to the heat dissipation member 20, heat generated from the stator coil 6B can be dissipated more efficiently. The heat dissipation fins 80 may be fixed to the entire surface of the heat dissipation member 20, or may be fixed to a part of the heat dissipation member 20. The heat dissipation fins 80 may be formed integrally with the heat dissipation member 20.

[0040] In one embodiment, the heat dissipation fins 80 may be fixed not only to the heat dissipation member 20 but also to the motor frame 3B, or may be fixed to the motor frame 3B instead of being fixed to the heat dissipation member 20. The heat dissipation fins 80 may be formed as an integral part of the motor frame 3B.

[0041] Fig. 6 is a diagram showing an insulating coating portion that covers 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 that covers the contact portion 70 of the stator core 6A with the stator coil 6B.

[0042] The contact portions 70 are the base end portions 61 of the teeth 6A-1 and a part of the yoke portion 6A-2, and the insulating coating portions 71 cover the contact portions 70. With this configuration, the insulating coating portions 71 can ensure insulation between the stator core 6A and the stator coil 6B. The insulating coating portions 71 may be thin films made of resin.

[0043] 6, the motor stator 6 may include a heat insulating material 75 that covers the tip end portion 60 of the tooth portion 6A-1. An example of the heat insulating material 75 is resin. By covering the tip end 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 heat insulating material 75 corresponds to the insulating coating portion 71, and the insulating coating portion 71 may cover the tip end portion 60.

[0044] 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. With this 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 the air layer, the embodiment shown in Fig. 7 can achieve the same effect as the embodiment shown in Fig. 6.

[0045] 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 (air layer) is formed between the tip portion 60 covered with the heat insulating material 75 and the accommodating recess 65.

[0046] Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and may of course be embodied in various different forms within the scope of the technical concept thereof. [Explanation of symbols]

[0047] 1 impeller 2 Pump casing 3 Motor casing 3A motor can 3A-1 Impeller facing part 3A-2 Flow path forming section 3B motor frame 5. Permanent magnets 6 Motor stator 6A stator core 6A-1 Teeth part 6A-2 Yoke 6B Stator coil 9 Sealing material 10 Bearings 11 Rotating side bearing body 11a Inner surface 11b Side 12 Fixed side bearing body 12a Radial surface 12b Thrust surface 15 Suction port 15a Intake port 16 Discharge port 16a Discharge port 19 Magnetic Yoke 20 Heat dissipation material 40 lead wire 50 boards 58 Sealing material 59 Sealing material 60 Tip part 61 Proximal part 65 Storage recess 70 Insulation parts 71 Insulation coating section 75 Insulation 80 Heat dissipation fin MP motor pump LC1 Liquid Flow Path LC2 Liquid Flow Path

Claims

1. an impeller containing a permanent magnet; a pump casing that houses the impeller; a motor stator having teeth around which stator coils are wound; a motor casing that houses the motor stator, the motor casing includes a motor can having an accommodation recess that accommodates only tip portions of the teeth and faces the impeller, The motor pump, wherein the tip portion extends further toward the impeller than the stator coil.

2. The motor can is an impeller-facing portion in which the accommodation recess is formed; 2. The motor pump according to claim 1, further comprising: a flow path forming portion connected to the impeller opposing portion and forming at least a portion of a liquid flow path extending to a liquid inlet of the impeller.

3. The motor pump according to claim 2 , wherein the impeller-opposing portion and the flow passage forming portion are formed from separate members.

4. The motor pump according to claim 2 , wherein the impeller-opposing portion and the flow passage forming portion are formed as an integrally molded member.

5. the motor casing includes a motor frame connected to the motor can, The motor pump according to any one of claims 1 to 4, wherein the motor frame is made of a material having a higher thermal conductivity than the motor can.

6. The motor pump according to any one of claims 1 to 5, wherein the motor can is made of a heat insulating material.

7. The motor pump according to any one of claims 1 to 6, wherein the motor stator is provided with a heat insulating material covering the tip portion.

8. The motor pump according to any one of claims 1 to 7, wherein the tip portion is accommodated in the accommodating recess via a space formed between the tip portion and the accommodating recess.

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