WO2023074038A1

WO2023074038A1 - Fixed bearing structure and motor pump

Info

Publication number: WO2023074038A1
Application number: PCT/JP2022/023883
Authority: WO
Inventors: 新帥范; 裕之川▲崎▼; 智大今井; 啓雅宮田
Original assignee: 株式会社荏原製作所
Priority date: 2021-10-26
Filing date: 2022-06-15
Publication date: 2023-05-04
Also published as: TW202338213A; JP2023064205A

Abstract

The present invention relates to a fixed bearing structure and a motor pump. The fixed bearing structure (12) comprises a fixed bearing body (40) and a blocking body (41) of a size that enables a circulation flow path (R2) of a motor casing (30) to be blocked.

Description

Fixed side bearing structure and motor pump

The present invention relates to a fixed side bearing structure and a motor pump.

A canned motor pump, in which the motor and pump are integrated, does not require a shaft sealing device to seal the gap between the rotating shaft and the pump casing, so liquid leakage does not occur. Therefore, canned motor pumps are widely used in fields where liquid leakage is averse.

Japanese Patent Application Laid-Open No. 2018-13040 JP 2017-180754 A JP-A-5-187386

Such a motor-pump may have a liquid circulation channel extending from the liquid outlet of the impeller to the liquid inlet for cooling the motor. However, when the liquid to be handled is at a low temperature, a part of the liquid discharged from the impeller is reduced to the liquid in the impeller by forming a circulation flow path for the liquid, although the cooling of the motor is unnecessary. You will be returned to the entrance. As a result, the pump efficiency of the motor pump is reduced.

It is conceivable to modify the overall structure of the motor pump in order to construct a motor pump that does not have a liquid circulation flow path, but such modification of the structure costs a lot of money.

Therefore, an object of the present invention is to provide a fixed-side bearing structure and a motor pump that can improve pump efficiency at low cost.

In one aspect, a fixed-side bearing body that can be arranged radially inward of a rotation-side bearing; a blocking body having a size that can block a circulation flow path of a motor can that is arranged to face the fixed-side bearing body; A fixed-side bearing structure is provided, comprising:

In one aspect, the fixed-side bearing body has a non-blocking portion arranged opposite to the circulation flow path, and the blocking bodies are fixed to the fixed-side bearing body and adjacent to each other. An occluding projection is provided between the non-occluded portions.
In one aspect, the fixed-side bearing structure has an open state in which the non-blocking portion faces the circulation flow path to open the circulation flow path by its rotation, and an open state in which the blocking protrusion faces the circulation flow path. It is configured to switch between a closed state in which the closed state is closed by closing the circulation flow path.
In one aspect, the blocking protrusions have a number corresponding to the number of the circulation channels.

In one aspect, the closure comprises an annular projection having an annular shape.
In one aspect, the closure includes a closure ring that is a separate member from the fixed-side bearing body.

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 bearing assembly that supports the impeller, and a motor casing that houses a motor stator. be done. The bearing assembly includes the fixed-side bearing structure and a rotation-side bearing arranged around the fixed-side bearing structure, and the motor casing faces the fixed-side bearing structure. It has a motor can with a circulation flow path arranged in the same direction.

The fixed-side bearing structure has a blocking body that blocks the circulation flow path of the motor can. The fixed-side bearing structure having such a structure can improve the pump efficiency with a simple structure that only includes the blocking body, and can contribute to cost reduction.

1 is a diagram showing an embodiment of a motor-pump in which a motor and a pump are integrally constructed; FIG. FIG. 4 is a diagram showing circulation channels formed in a motor can; FIG. 3A is a diagram showing a fixed-side bearing structure. FIG. 3B is a view of FIG. 3A viewed from line A. FIG. FIG. 10 is a diagram showing a circulation channel blocked by a blocking projection; FIG. 10 is a diagram showing a circulation channel opened by a non-blocking portion; FIG. 6A is a diagram showing another embodiment of the fixed-side bearing structure. FIG. 6B is a view of FIG. 6A viewed from line B. FIG. FIG. 10 is a diagram showing another embodiment of the fixed-side bearing structure;

Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the drawings described below, the same or corresponding components are denoted by the same reference numerals, and redundant description is omitted. In the multiple embodiments described below, the configuration of one embodiment that is not particularly described is the same as that of the other embodiments, so redundant description thereof will be omitted.

FIG. 1 is a diagram showing an embodiment of a motor-pump in which a motor and a pump are integrally constructed. As shown in FIG. 1, the motor pump MP is a canned motor pump equipped with an axial gap type PM motor. The motor pump MP includes an impeller 1 in which a plurality of permanent magnets 5 are embedded, a motor stator 6 that generates a magnetic force acting on the permanent magnets 5, a pump casing 2 that houses the impeller 1, and a motor fixing device. It comprises a motor casing 3 that houses the element 6 and a bearing assembly 10 that supports the radial and thrust loads of the impeller 1 .

The motor stator 6 and bearing assembly 10 are arranged on the suction side of the impeller 1 . Although a plurality of permanent magnets 5 are provided in this embodiment, the present invention is not limited to this embodiment, and one permanent magnet having a plurality of magnetic poles may be used. More specifically, one ring-shaped permanent magnet having a plurality of magnetic poles in which S poles and N poles are alternately magnetized may be used.

The motor pump MP has an O-ring 9 as a sealing member arranged between the pump casing 2 and the motor casing 3 . The O-ring 9 can prevent liquid leakage from between the pump casing 2 and the motor casing 3 .

The motor casing 3 includes a motor can 30 that houses the motor stator 6, and a suction port 15 that is connected to the motor can 30 and has a suction port 15a. The suction port 15 has a flange shape and is connected to a suction line (not shown).

The motor pump MP has a suction port 15, a motor can 30, and a liquid flow path R1 formed in the center of the bearing assembly 10. The liquid flow path R1 extends from the suction port 15a to the liquid inlet of the impeller 1 along the direction of the center line CL of the motor pump MP and communicates with the liquid inlet of the impeller 1 . The motor pump MP is a canned motor pump equipped with an axial gap type PM motor in which a permanent magnet 5 and a motor stator 6 are arranged along the liquid flow path R1.

The pump casing 2 has a discharge port 16 having a discharge port 16a formed on its side surface. The liquid pressurized by the rotating impeller 1 is discharged through the discharge port 16a. The motor pump MP according to the embodiment shown in FIG. 1 is a so-called end-top type motor pump in which the suction port 15a and the discharge port 16a are perpendicular to each other.

The impeller 1 is made of a non-magnetic material that is slippery and hard to wear. For example, resins such as PTFE (polytetrafluoroethylene) and PPS (polyphenylene sulfide), and ceramics are preferably used. Pump casing 2 and motor casing 3 may be made of the same material as impeller 1 .

The motor stator 6 has a stator core 6A and a plurality of stator coils 6B. The plurality of stator coils 6B are arranged in a ring. Impeller 1 and motor stator 6 are arranged concentrically with bearing assembly 10 and suction port 15a.

The motor pump MP includes an inverter device (control board) 21 that supplies current to the motor stator 6 . The stator coil 6B is connected to the inverter device 21 via lead wires 25. As shown in FIG. The inverter device 21 is housed in a motor can 30 , and the open end of the motor can 30 is closed by a closing member 20 .

The inverter device 21 supplies a current to the stator coil 6B of the motor stator 6 to cause the motor stator 6 to generate a rotating magnetic field. This rotating magnetic field acts on the permanent magnets 5 embedded in the impeller 1 to drive the impeller 1 to rotate. As the impeller 1 rotates, liquid is introduced into the liquid inlet of the impeller 1 through the suction port 15a. The liquid is pressurized by the rotation of the impeller 1 and discharged from the discharge port 16a. While the impeller 1 is transferring the liquid, the rear surface of the impeller 1 is pressed toward the suction side (ie, toward the suction port 15a) by the pressurized liquid. Since the bearing assembly 10 is arranged on the suction side of the impeller 1, it supports the thrust load of the impeller 1 from the suction side.

The impeller 1 is rotatably supported by a single bearing assembly 10. The bearing assembly 10 is a slide bearing (dynamic pressure bearing) that utilizes dynamic pressure of liquid. The bearing assembly 10 includes a fixed-side bearing structure 12 and a rotation-side bearing 11 arranged around the fixed-side bearing structure 12 . In other words, the fixed-side bearing structure 12 is arranged radially inside the rotary-side bearing 11 .

The fixed-side bearing structure 12 has a cylindrical fixed-side radial surface 12a and a fixed-side thrust surface 12b located radially outside the fixed-side radial surface 12a. The rotation-side bearing 11 has a cylindrical rotation-side radial surface 11a surrounding the fixed-side radial surface 12a, and a rotation-side thrust surface 11b located radially outside the rotation-side radial surface 11a.

The rotation-side bearing 11 is fixed to the impeller 1 by an O-ring 18 as a sealing member, and is arranged so as to surround the liquid inlet of the impeller 1 . The fixed-side bearing structure 12 is fixed to the motor can 30 and arranged on the suction side of the rotary-side bearing 11 . The motor pump MP includes an O-ring 31 as a sealing member arranged between the motor can 30 and the fixed side bearing structure 12 .

The rotating-side radial surface 11a and the fixed-side radial surface 12a are radial surfaces that support the radial load of the impeller 1, and the rotating-side thrust surface 11b and the fixed-side thrust surface 12b are thrust surfaces that support the thrust load of the impeller 1. be. The rotating-side radial surface 11a and the fixed-side radial surface 12a are parallel to the axis of the impeller 1 (that is, the direction of the axis CL), and the rotating-side thrust surface 11b and the fixed-side thrust surface 12b are parallel to the axis of the impeller 1. vertical. The rotation-side radial surface 11a and the rotation-side thrust surface 11b are perpendicular to each other, and the stationary-side radial surface 12a and the stationary-side thrust surface 12b are perpendicular to each other.

A part of the liquid discharged from the impeller 1 is led to the bearing assembly 10 through a minute gap between the impeller 1 and the motor can 30. When the rotating side bearing 11 rotates together with the impeller 1 , fluid dynamic pressure is generated between the rotating side bearing 11 and the fixed side bearing structure 12 , thereby supporting the impeller 1 by the bearing assembly 10 in a non-contact manner. be done.

FIG. 2 is a diagram showing circulation channels formed in the motor can. As shown in FIGS. 1 and 2, the motor can 30 has a circulation flow path R2 arranged to face the fixed-side bearing structure 12. As shown in FIG. The circulation flow path R2 is formed on a facing surface 30a of the motor can 30 that faces the fixed-side bearing structure 12. As shown in FIG.

In the embodiment shown in FIG. 2, the motor can 30 has three circulation passages R2 arranged at equal intervals along the inner peripheral surface thereof, but the number of circulation passages R2 varies according to this embodiment. is not limited. In one embodiment, at least one circulation channel R2 may be formed.

A part of the liquid discharged from the impeller 1 passes through the circulation flow path R2 and is returned to the liquid flow path R1. The liquid flowing through the circulation flow path R2 can cool the stator coil 6B as a heating element. However, if the liquid to be transported by the motor pump MP is cold (eg, liquid below 0° C.), cooling of the stator coils 6B is unnecessary. Nevertheless, part of the liquid discharged from the impeller 1 is returned to the liquid inlet of the impeller 1 through the circulation flow path R2. Therefore, the pump efficiency of the motor pump MP is lowered.

Therefore, the fixed-side bearing structure 12 has a structure that blocks the circulation flow path R2 and prevents the liquid from flowing back to the liquid flow path R1. The structure of the fixed-side bearing structure 12 will be described below with reference to the drawings.

　Fig. 3A is a diagram showing a fixed-side bearing structure, and Fig. 3B is a diagram of Fig. 3A viewed from the direction of line A. The fixed-side bearing structure 12 can block the circulation flow path R2 of the fixed-side bearing body 40 that can be arranged radially inside the rotation-side bearing 11 and the motor can 30 that is arranged to face the fixed-side bearing body 40. and a closure 41 having a similar size.

The fixed-side bearing main body 40 has an overall cylindrical shape, and the fixed-side radial surface 12a and the fixed-side thrust surface 12b are formed in the fixed-side bearing main body 40. The blocking body 41 has a plurality of blocking protrusions 42 fixed to the fixed-side bearing body 40 .

Although three blocking projections 42 are formed in this embodiment, the number of blocking projections 42 is not limited to this embodiment. The number of blocking projections 42 is opposed to the number of circulation channels R2. Therefore, for example, when one circulation flow path R2 is formed, the blocking body 41 has a single blocking projection 42. As shown in FIG.

The fixed-side bearing main body 40 has a non-blocking portion 40a arranged facing the circulation flow path R2. The non-closed portion 40 a is a facing surface of the stationary bearing body 40 that faces the facing surface 30 a of the motor can 30 when the stationary bearing structure 12 is attached to the motor can 30 .

The blocking protrusions 42 are fixed to the non-blocking portion (that is, the facing surface) 40a of the fixed-side bearing body 40, and are arranged at equal intervals along the circumference of the fixed-side bearing body 40. Each of the plurality of blocking projections 42 is arranged between adjacent non-blocking portions 40a. In other words, the plurality of blocking protrusions 42 and non-blocking portions 40 a are alternately arranged along the circumferential direction of the fixed-side bearing body 40 .

FIG. 4 is a diagram showing a circulation channel blocked by a blocking protrusion. FIG. 5 is a diagram showing a circulation channel opened by a non-blocking portion. As shown in FIGS. 4 and 5, the fixed-side bearing structure 12 rotates to open the circulation flow path R2 by causing the non-blocking portion 40a to face the circulation flow path R2 (see FIG. 5). , and a closed state (see FIG. 4) in which the blocking projection 42 is opposed to the circulation flow path R2 to block the circulation flow path R2.

When the liquid handled by the motor pump MP is at a low temperature, it is desirable to close the circulation flow path R2 in order to improve the pump efficiency. In this case, as shown in FIG. 4, the operator mounts the fixed-side bearing structure 12 on the motor can 30 so that the blocking projection 42 fits into the circulation flow path R2. Therefore, the blocking protrusion 42 blocks the circulation channel R2 and prevents the liquid from flowing back to the liquid channel R1. As a result, the motor pump MP can improve its pump efficiency.

According to this embodiment, the pump efficiency can be improved with a simple structure in which the closing body 41 is formed in the fixed side bearing body 40 . Furthermore, according to this embodiment, there is no need to modify the overall structure of the motor pump MP, and the pump efficiency can be improved at a low cost by simply applying the fixed-side bearing structure 12 to the motor pump MP.

A mark S (see FIGS. 3A and 4) is formed on the fixed-side thrust surface 12b of the fixed-side bearing body 40 facing the blocking projection 42. As shown in FIG. Therefore, the operator can fit the blocking protrusion 42 into the circulation flow path R2 without visually checking the blocking protrusion 42 .

When the temperature of the liquid handled by the motor pump MP is high, it is desirable to open the circulation flow path R2 and return the handled liquid to the liquid flow path R1. Since the temperature of the stator coil 6B is higher than the temperature of the liquid to be handled, the liquid to be handled can take heat from the stator coil 6B. In this case, as shown in FIG. 5, the operator rotates the fixed-side bearing body 40 so that the non-blocking portion 40a faces the circulation flow path R2. As a result, the non-blocking portion 40a faces the facing surface 30a of the motor can 30. As shown in FIG.

As described above, the O-ring 31 is arranged between the motor can 30 and the fixed side bearing structure 12 . Therefore, in one embodiment, the operator may rotate the stationary bearing structure 12 by a predetermined angle after removing the stationary bearing structure 12 from the motor can 30 .

In the above-described embodiment, the fixed bearing structure 12 includes the blocking projection 42 fixed to the fixed bearing body 40, but in one embodiment, the blocking projection 42 is a separate member from the fixed bearing body 40. may be

FIG. 6A is a diagram showing another embodiment of the fixed-side bearing structure, and FIG. 6B is a diagram of FIG. 6A viewed from line B. FIG. As shown in Figures 6A and 6B, the closure 41 may comprise an annular protrusion 43 having an annular shape. The annular projection 43 is arranged concentrically with the impeller 1 and the suction port 15a. According to this embodiment, by mounting the fixed-side bearing structure 12 to the motor can 30, the annular protrusion 43 can block all the circulation channels R2 regardless of the number of the circulation channels R2. .

In this embodiment, when the temperature of the liquid to be handled by the motor pump MP is high, the operator removes the fixed side bearing structure 12 and replaces it with the fixed side bearing body 40 without the blocking member 41 on the motor can 30. By mounting, the circulation channel R2 can be opened. As a result, the liquid to be handled can take heat from the stator coil 6B.

FIG. 7 is a diagram showing another embodiment of the fixed-side bearing structure. As shown in FIG. 7 , the closing body 41 has a closing ring 44 which is a separate member from the fixed-side bearing main body 40 . The operator mounts the stationary bearing structure 12 on the motor can 30 with the closing ring 44 arranged between the non-closing portion 40 a of the stationary bearing main body 40 and the facing surface 30 a of the motor can 30 . Such attachment allows the closing ring 44 to close the circulation flow path R2. Also in this embodiment, the blocking ring 44 can block all the circulation channels R2 regardless of the number of the circulation channels R2.

In this embodiment, when the temperature of the liquid handled by the motor pump MP is high, the operator removes the closing ring 44 and attaches the fixed side bearing main body 40 to the motor can 30 to open the circulation flow path R2. can be done. As a result, the liquid to be handled can take heat from the stator coil 6B.

The above-described embodiments are described for the purpose of enabling those who have ordinary knowledge in the technical field to which the present invention belongs to implement the present invention. Various modifications of the above embodiments can be made by those skilled in the art, and the technical idea of the present invention can be applied to other embodiments. Accordingly, the present invention is not limited to the described embodiments, but is to be construed in its broadest scope in accordance with the technical spirit defined by the claims.

The present invention can be used for fixed-side bearing structures and motor pumps.

1 Impeller 2 Pump casing 3 Motor casing 5 Permanent magnet 6 Motor stator 6A Stator core 6B Stator coil 9 O-ring 10 Bearing assembly 11 Rotating side bearing 11a Rotating side radial surface 11b Rotating side thrust surface 12 Fixed side bearing structure Body 12a Fixed-side radial surface 12b Fixed-side thrust surface 15 Suction port 15a Suction port 16 Discharge port 16a Discharge port 18 O-ring 20 Closing member 21 Inverter device (control board)
25 Lead wire 30 Motor can 30a Opposing surface 31 O-ring 40 Fixed-side bearing main body 40a Non-blocking part 41 Blocking body 42 Blocking projection 43 Annular projection 44 Blocking ring MP Motor pump R1 Liquid channel R2 Circulating channel S Mark

Claims

a fixed-side bearing body that can be arranged radially inside the rotating-side bearing;
a blocking body having a size capable of blocking a circulation flow path of a motor can arranged opposite to the fixed side bearing main body.
The fixed-side bearing main body has a non-blocking portion disposed facing the circulation flow path,
2. The fixed-side bearing structure according to claim 1, wherein said blocking body is fixed to said fixed-side bearing body and has blocking projections disposed between said non-blocking portions adjacent to each other.
The fixed-side bearing structure rotates to form an open state in which the non-blocking portion faces the circulation flow path to open the circulation flow path, and an open state in which the blocking protrusion faces the circulation flow path to open the circulation flow path. 3. The fixed-side bearing structure according to claim 2, configured to switch between a closed state in which the flow path is closed and a closed state.
The fixed side bearing structure according to claim 2 or claim 3, wherein the blocking protrusions have a number corresponding to the number of the circulation passages.
The fixed-side bearing structure according to claim 1, wherein the closing body has an annular projection having an annular shape.
The fixed side bearing structure according to claim 1, wherein the closing body comprises a closing ring that is a separate member from the fixed side bearing main body.
an impeller containing a permanent magnet;
a pump casing housing the impeller;
a bearing assembly supporting the impeller;
a motor casing housing the motor stator;
The bearing assembly is
a fixed side bearing structure according to any one of claims 1 to 6;
a rotation side bearing arranged around the fixed side bearing structure,
The motor pump, wherein the motor casing includes a motor can having a circulation flow path disposed facing the fixed-side bearing structure.