KR20240004667A - Bearing structure of canned motor pump - Google Patents

Abstract

A rotating shaft (2) that rotates integrally with the rotor (12) of the motor unit (11) and a rotating shaft are inserted into the casing side bearing housings (32a) and (32b) formed in the pump unit (31) via an elastic thin plate material (33). A rotating shaft (2) between the bearings (3a) and (3b) and the rotor (12) of the motor unit (11) and the bearings (3a) and (3b) that support (2) so that it can rotate freely in the vertical direction. ) and an impeller that rotates integrally with the bearing support members (4a), (4b), which are axially supported so that they can rotate freely by bearings (3a), (3b) and the rotation shaft (2). A cand motor pump (6a), (6b) and a cand motor pump ( 8), wherein when the bearings (3a) and (3b) are pressed against the rotor (12) by the bearing support members (4a) and (4b), an elastic reaction force is applied in the axial direction to the canned motor pump. bearing structure.

Description

Bearing structure of canned motor pump

The present invention relates to a bearing structure of a canned motor pump.

This application claims priority based on Japanese Patent Application No. 2021-094287, filed in Japan on June 4, 2021, and uses the content here.

Conventionally, a canned motor pump is known in which a part of the pump liquid is flowed between a rotating shaft and a bearing and used as a lubricant (see, for example, Patent Document 1).

The canned motor pump disclosed in Patent Document 1 includes a sliding bearing (hereinafter referred to as “radial bearing”) that supports the rotating shaft in a direction perpendicular to the axial direction, and a sliding bearing (hereinafter referred to as “thrust direction”) fixed to the rotating shaft. It is equipped with a “bearing”). The thrust bearing restricts the movement of the rotating shaft in the axial direction by bringing its abutting surface into axial contact with the side surface of the radial bearing.

A certain gap is formed between the rotating shaft and the radial direction bearing to allow a portion of the pump liquid to flow. In addition, although it is not described in the same document, in most cases, the radial direction bearing is inserted into the bearing housing through an elastic thin plate material such as a tolerance ring.

Japanese Patent No. 3897931

In the bearing structure of the canned motor pump, due to the influence of dimensional tolerances of each part, the contact surfaces of the side surfaces of the radial bearing and the thrust direction bearing are relatively inclined, and there are cases where surface contact does not occur when they contact each other. In this case, wear of part of the side surface of the radial bearing or part of the contact surface of the thrust bearing progresses, and the clearance in the original axial direction of the rotating shaft or the inclination of the rotating shaft relative to the original axial direction gradually increases. As a result, there was a risk that the performance of the pump would deteriorate.

The present invention was created in view of the above problems, and is a cand motor pump that uses a part of the supplied liquid as a lubricant between a rotating shaft and a bearing (radial bearing) that supports the rotating shaft in a direction perpendicular to the axial direction. Providing a bearing structure for a canned motor pump configured to facilitate surface contact between the side surface of the bearing (radial bearing) and the contact surface of the bearing support member (thrust direction bearing) fixed axially with respect to the rotating shaft. The purpose is to

The bearing structure of the canned motor pump according to the first aspect of the present invention includes a rotating shaft that rotates integrally with the rotor of the motor section, a casing side bearing housing formed in the pump section, fitted through an elastic thin plate material, and the rotating shaft is rotated in the axial direction. a bearing that is supported so that it can freely rotate in a direction perpendicular to the bearing, and a bearing support that is mounted on the rotation axis between the rotor of the motor unit and the bearing and is axially supported so that it can rotate freely by the bearing. It is provided with a member and an impeller that rotates integrally with the rotating shaft, provided that a part of the liquid conveyed by rotation of the impeller flows between the rotating shaft and the bearing, and the bearing is connected to the bearing support member. An elastic structure is formed that provides an elastic reaction force in the axial direction to one or both of the bearing and the bearing support member when pressed against the rotor of the motor unit.

The bearing structure of the canned motor pump according to the second aspect of the present invention is the bearing structure of the canned motor pump according to the first aspect, wherein the elastic structure provides the elastic reaction force in the axial direction with respect to the bearing, It is an elastic body formed between the side of the bearing opposite to the rotor of the motor section and the bearing housing on the casing side.

The bearing structure of the canned motor pump according to the third aspect of the present invention is the bearing structure of the canned motor pump according to the first aspect, wherein the bearing support member is mounted on the rotating shaft via a housing for bearing support members. It is done. The elastic structure provides the elastic reaction force in the axial direction with respect to the bearing support member, and is an elastic body formed between the housing for the bearing support member and the rotor side of the motor portion of the bearing support member. .

The bearing structure of the canned motor pump according to the fourth aspect of the present invention is the bearing structure of the canned motor pump according to the first aspect, wherein the elastic structure is located on a side of the bearing opposite to the rotor of the motor portion and on the casing side of the bearing. A plate is formed between the housing and the housing. The casing-side bearing housing provides the elastic reaction force to the bearing in the axial direction by supporting only a portion of the surface of the plate opposite to the bearing in the axial direction.

The bearing structure of the canned motor pump according to the fifth aspect of the present invention is the bearing structure of the canned motor pump according to the first aspect, wherein the bearing support member is connected to the rotating shaft via a housing for bearing support members. It is fixed in the axial direction. The elastic structure is such that a plate is formed between the rotor side of the motor portion of the bearing support member and the housing for the bearing support member, and the housing for the bearing support member is formed on the bearing support member of the plate. By supporting only a part of the surface opposite to the axial direction, the elastic reaction force is applied to the bearing support member in the axial direction.

According to the present invention, it becomes easy for the bearing and the bearing support member to come into surface contact with each other.

1 is a partial cross-sectional view of a canned motor pump related to this embodiment.
Fig. 2 is an enlarged cross-sectional view around the first bearing according to the present embodiment.
Figure 3 is an enlarged view of part A of Figure 1.
Figure 4 is an enlarged view of part B of Figure 1.
Figure 5 is an enlarged cross-sectional view around a connecting pipe related to another embodiment.
Figure 6 is an enlarged cross-sectional view around an elastic structure related to another embodiment.
Fig. 7 is an enlarged cross-sectional view around the elastic structure related to this embodiment.
Figure 8 is an enlarged cross-sectional view around an elastic structure related to another embodiment.
Fig. 9 is an enlarged cross-sectional view around the elastic structure related to this embodiment.

Hereinafter, the bearing structure of the canned motor pump according to the embodiment of the present invention will be described with reference to the drawings. 1 to 4, the bearing structure 1 of the canned motor pump includes a rotating shaft 2, bearings 3a, 3b, and bearing support members 4a, which are included in the canned motor pump 8. 4b), impeller (6a, 6b), elastic structure (7), etc.

As shown in FIG. 1 , the canned motor pump 8 includes a motor unit 11 and a pump unit 31 driven by the motor unit 11. The motor unit 11 is a canned motor consisting of a rotor 12 with a magnet 27 and a stator 13 on the outer periphery of the rotor 12, and the rotation shaft 2 on which the rotor 12 is fixed is located on the casing side. Bearings 3a and 3b mounted on bearing housings 32a and 32b are supported via sleeves 25. The pump unit 31 includes impellers 6a, 6b fixed to the rotating shaft 2, and pump casings 16a, 16b having impeller accommodating spaces 14a, 14b for accommodating the impellers 6a, 6b. do. The rotor 12 of the motor unit 11 is accommodated inside the stator can 9. The stator 13 of the motor unit 11 is located at a position corresponding to the rotor 12 in the stator can 9, and is aligned with the outer peripheral surface 17 of the stator can 9 and the inner peripheral surface of the cylindrical motor frame 18 ( 19) is accepted among. The motor frame 18 contains a stator can 9. The stator can 9 and the stator side plates 10 formed at both ends of the motor frame 18 are sealed and connected by welding. The motor frame 18 and the stator side plates 10 formed at both ends of the motor frame 18 are sealed with O-rings 5 and are sealed and connected by partial welding. The stator side plate 10 and the casing side bearing housings 32a and 32b seal the internal space 66 with O-rings 15 arranged at both ends of the stator side plate 10. The pump casings (16a, 16b) and the casing-side bearing housings (32a, 32b) seal the impeller accommodation spaces (14a, 14b) with O-rings (20) disposed at both ends of the casing-side bearing housings (32a, 32b). there is. Additionally, since a small gap is formed between the inner peripheral surfaces of the bearings 3a and 3b and the sleeve 25, the bearings 3a and 3b can be inclined at a small angle with respect to the axis. Hereinafter, the pump casing 16a is referred to as the “first pump casing 16a”, and the pump casing 16b is referred to as the “second pump casing 16b”.

Additionally, the portion on the outer peripheral surface 17 of the stator can 9 where the stator core 21 is not present is covered with the support can 22. The support can 22 has a cylindrical shape along the outer peripheral surface 17 of the stator can 9.

The motor unit 11 includes a rotor 12 and a stator 13. The rotor 12 is comprised of a rotor can 23, a rotor side plate 24, a rotor body 26, a magnet 27, a yoke 28, etc. The rotor 12 is fixed to the rotating shaft 2 so as to rotate integrally with the rotating shaft 2. The rotating shaft 2 is supported via a sleeve 25 on bearings 3a and 3b mounted on the casing side bearing housings 32a and 32b. The rotor 12 includes a rotor body 26 fixed to the rotating shaft 2, a yoke 28 supported on the rotor body 26, a magnet 27, a rotor side plate 24, and a rotor can 23. Equipped with The rotor can 23 is joined to the rotor body 26 and the rotor side plate 24 by welding, and the magnet 27 and the yoke 28 are sealed. The rotor 12 is accommodated inside the stator can 9 of the can motor pump 8.

The stator 13 is composed of an electromagnetic coil 29, etc., and when a drive current is supplied to the stator 13, the rotor 12 and the rotation shaft 2 are rotated.

The rotor 12 of the motor unit 11 is fixed to the rotation shaft 2 and rotates integrally with the rotor 12 of the motor unit 11.

As shown in FIGS. 1 to 4, the bearings 3a and 3b are fitted into the casing side bearing housings 32a and 32b formed in the pump unit 31 via an elastic thin plate material 33. The bearings 3a and 3b support the rotating shaft 2 so that it can freely rotate in a direction perpendicular to the axial direction. Bearings 3a, 3b are cylindrical. In the bearings 3a and 3b, a groove 76 extending in the radial direction is formed on the axial end surface 34, and a spiral groove 74 is formed on the inner peripheral wall 36. Both grooves 74 and 76 are formed to allow liquid to flow. As a material for the bearings 3a and 3b, for example, SiC (silicon carbide), which has excellent heat resistance and durability, is used.

In this embodiment, the bearings 3a and 3b are arranged on the outer periphery of the sleeve 25, which is a part of the rotating shaft 2. As for the material of the sleeve 25, like the bearings 3a and 3b, a material excellent in heat resistance and durability is used.

Bearings 3a and 3b are formed on both sides of the rotor 12 of the motor unit 11 in the axial direction of the rotating shaft 2. Hereinafter, the bearing 3a is referred to as the “first bearing 3a”, and the bearing 3b is referred to as the “second bearing 3b”.

Bearings 3a and 3b are inserted into the casing side bearing housings 32a and 32b. Casing side bearing housings 32a, 32b are formed in the pump portion 31.

The casing side bearing housings 32a and 32b are formed on both sides of the rotor 12 of the motor unit 11 in the axial direction of the rotation shaft 2. Hereinafter, the two casing side housings 32 are referred to as the “first casing side bearing housing 32a” and the “second casing side bearing housing 32b,” respectively.

In this embodiment, a tolerance ring is used as the elastic thin plate material 33. Since the bearings 3a, 3b are inserted into the casing side bearing housings 32a, 32b via the elastic thin plate material 33, the bearings 3a, 3b do not rattle against the casing side bearing housings 32a, 32b. Steering is prevented, and the difference in thermal expansion coefficient between the casing side bearing housings 32a and 32b and the bearings 3a and 3b is absorbed.

On the rotating shaft 2 and the rotor 12, housings 38a and 38b for bearing support members are formed to accommodate bearing support members 4a and 4b. The bearing support members 4a, 4b are fitted into the bearing support member housings 38a, 38b via the elastic thin plate material 35 for bearing support members. In this embodiment, a tolerance ring is also used for the elastic thin plate material 35 for bearing support members. Housings 38a, 38b for bearing support members are fixed relative to the rotation axis 2 in the axial direction. The bearing support members 4a and 4b are mounted on the rotating shaft 2 via housings 38a and 38b for bearing support members. Therefore, the rotating shaft 2 is supported by the bearings 3a and 3b in the axial direction via the bearing support members 4a and 4b and the bearing support member housings 38a and 38b. Additionally, a gap of a predetermined size is formed between the inner peripheral surfaces of the bearing support members 4a, 4b and the housings 38a, 38b for bearing support members, and the bearing support members 4a, 4b are positioned relative to the axis. Small angle tilt is possible.

Bearing support members 4a and 4b are also formed on both sides of the rotor 12 of the motor unit 11 in the axial direction of the rotation shaft 2. Specifically, the bearing support members 4a, 4b are mounted on the rotating shaft 2 between the rotor 12 of the motor unit 11 and the bearings 3a, 3b, and the bearings 3a, 3b ) is supported in the axial direction so that it can rotate freely. As a material for the bearing support members 4a and 4b, for example, SiC, which has excellent heat resistance and durability, is used.

Hereinafter, the bearing support member 4a supported by the first bearing 3a is referred to as the “first bearing support member 4a,” and the bearing support member 4b supported by the second bearing 3b is referred to as “first bearing support member 4a.” It is referred to as “second bearing support member 4b”.

The impellers 6a and 6b rotate integrally with the rotation shaft 2. As shown in FIGS. 2 and 4, the impellers 6a and 6b include cylindrical impeller boss parts 39a and 39b fixed to the rotating shaft 2 and annular rings connected to the impeller boss parts 39a and 39b. It is provided with plate-shaped impeller wings (45a, 45b). The impeller boss parts 39a, 39b are cylindrical and have a rotating shaft fixing part 47 that fixes the impeller boss parts 39a, 39b to the rotating shaft 2, and a rotating shaft fixing part from the outer peripheral surface of the rotating shaft fixing part 47. It is shaped like an annular plate extending in the radial direction of (47) and has an impeller blade connecting portion (48) connected to the impeller blade portions (45a, 45b). The impeller boss portions 39a and 39b are connected to the rotation center side end portions 46 of the impeller blade portions 45a and 45b at the impeller blade connection portion 48. Impeller boss through-holes 49a, 49b penetrating in the axial direction are formed in the impeller blade connection portion 48 of the impeller boss portions 39a, 39b. The liquid flowing back from the stator can 9 side passes through the impeller boss through holes 49a and 49b. Additionally, annular-shaped impeller boss projections 51a and 51b extending toward the stator can 9, which prevent backflow of liquid, are formed on the impeller blade connecting portions 48 of the impeller boss portions 39a and 39b. The impeller boss projections 51a, 51b are inserted into the annular recesses 53a, 53b formed on the inner wall surface 52 of the pump casing 16a, 16b.

In the can motor pump 8 in this embodiment, one impeller 6a, 6b is formed at both ends of the stator can 9 in the axial direction. Hereinafter, the impeller 6a is referred to as the “first impeller 6a”, and the impeller 6b is referred to as the “second impeller 6b”.

A first inlet 56 is formed on the side of the first pump casing 16a where the first impeller 6a is accommodated. Additionally, a liquid delivery port 57 is formed on the upper surface of the first pump casing 16a to send the liquid flowing into the first pump casing 16a to the second pump casing 16b.

The first casing side bearing housing 32a has a first communication passage 67 that communicates the first impeller accommodation space 14a with the internal space 66 of the stator can 9. The first communication passage opening 64 of the first communication passage 67 is a wall surface 63 on the stator can 9 side of the first impeller accommodation space 14a, and has a first impeller boss projection 51a. It is formed near the first impeller boss through hole 49a at a position closer to the rotation axis 2.

The first casing side bearing housing 32a forms the first impeller accommodation space 14a together with the first pump casing 16a. The first casing side bearing housing 32a has a first concave portion 53a in the wall surface 63 on the stator can 9 side forming the first impeller accommodation space 14a. The first impeller boss portion protrusion 51a formed on the first impeller boss portion 39a is inserted into the first concave portion 53a.

Additionally, a cylindrical first blocking plate 78 whose center is coaxial with the rotating shaft 2 is formed on the first impeller blade portion 45a. The first blocking plate 78 extends in the axial direction of the rotating shaft 2 in the direction of the first inlet 56, and has its outer peripheral surface and the inner wall of the first inlet 56 in the first pump casing 16a. (77) The gap between and is being made smaller. The first blocking plate 78 is a space formed by the outer wall 79 on the side of the first blocking plate 78 in the first impeller blade 45a and the inner wall 54 of the first pump casing 16a. and the space at the first inlet 56 is blocked.

As shown in FIG. 4, the second impeller 6b, which is the other impeller, includes a second impeller boss portion 39b fixed to the rotating shaft 2 and a second impeller connected to the second impeller boss portion 39b. It is provided with a wing portion 45b. In the second impeller boss portion 39b, an annular second impeller boss portion protrusion 51b extending in the axial direction toward the stator can 9 is formed.

A second inlet 58 is formed on the side of the second pump casing 16b in which the second impeller 6b is accommodated. The second inlet 58 is cylindrical and has a central axis coaxial with the rotation axis 2, and allows the liquid sent from the first impeller 6a to flow in. Additionally, a discharge port 61 is formed on the upper surface side of the second pump casing 16b for discharging the liquid flowing into the second pump casing 16b out of the second pump casing 16b.

The second casing side bearing housing (32b) has a second communication path (71) that communicates the second impeller accommodation space (14b) with the internal space (66) of the stator can (9). The second communication passage opening 69 of the second communication passage 71 is a wall surface 68 on the stator can 9 side of the second impeller accommodation space 14b, and has a second impeller boss projection 51b. It is formed near the second impeller boss through hole 49b at a position closer to the rotation axis 2.

The second casing side bearing housing 32b forms a second impeller accommodation space 14b together with the second pump casing 16b. The second casing side bearing housing 32b has a second concave portion 53b on the wall surface 68 on the stator can 9 side forming the second impeller accommodation space 14b. The second impeller boss portion projection piece 51b formed on the second impeller boss portion 39b is inserted into the second concave portion 53b.

Additionally, a cylindrical second blocking plate 82 whose center is coaxial with the rotation axis 2 is formed on the second impeller blade portion 45b. The second blocking plate 82 extends in the axial direction of the rotating shaft 2 in the direction of the second inlet 58, and has its outer peripheral surface and the inner wall of the second inlet 58 in the second pump casing 16b. (81) The gap between and is being made smaller. The second blocking plate 82 is a space formed by the outer wall 83 on the second blocking plate 82 side in the second impeller wing portion 45b and the inner wall 59 of the second pump casing 16b. and the space between the second inlet 58 is blocked.

The first pump casing 16a and the second pump casing 16b are connected by a connecting pipe 62 that forms a flow path for sending liquid from the first impeller 6a to the second impeller 6b. . The connection pipe 62 passes through the outside of the motor frame 18 and connects the liquid discharged from the liquid delivery port 57 of the first pump casing 16a to the second inlet port 58 of the second pump casing 16b. send.

In the can motor pump 8 in this embodiment, as shown in Figs. 3 and 4, a part of the liquid conveyed by rotation of the impellers 6a and 6b is connected to the rotating shaft 2 and the bearings 3a and 3a. 3b) It flows as indicated by the double-dash line arrow.

The liquid flowing into the first pump casing (16a) from the first inlet (56) passes through the flow path (72) within the first impeller blade of the first impeller (6a) by the rotational force of the first impeller (6a), and is connected. It passes through the pipe 62 and flows into the second pump casing 16b from the second inlet 58.

The liquid flowing into the second pump casing (16b) branches in two directions, and one branched liquid flows into the flow path (73) within the second impeller blade of the second impeller (6b) by the rotational force of the second impeller (6b). ), and is discharged out of the second pump casing (16b) from the discharge port (61). The other branched liquid passes through the second impeller boss through hole 49b of the second impeller 6b and is sent into the stator can 9.

The liquid sent from the second pump casing 16b into the stator can 9 further branches in two directions. One side of the branched liquid passes through the second communication passage 71 formed in the second pump casing 16b and passes the space between the stator can 9 and the rotor 12 in the direction of the first bearing 3a. Head towards and pass through. The other side of the branched liquid passes between the sleeve 25 of the rotating shaft 2 and the second bearing 3b.

The liquid that has passed between the sleeve 25 of the rotating shaft 2 and the second bearing 3b passes between the second bearing 3b and the second bearing support member 4b, and is stored in the stator can 9. ) and passes through the space between the rotor 12 in the direction of the first bearing 3a. When the liquid passes between the sleeve 25 of the rotating shaft 2 and the second bearing 3b, and when the liquid passes between the second bearing 3b and the second bearing support member 4b, The liquid mainly passes through the grooves 76 and 74 formed in the second bearing 3b. When the liquid passes between the sleeve 25 of the rotating shaft 2 and the second bearing 3b and between the second bearing 3b and the second bearing support member 4b, the liquid passes through the rotating shaft 2 ) It is a lubricant between the sleeve 25 and the second bearing 3b and between the second bearing 3b and the second bearing support member 4b.

The liquid that passes through the space between the stator can 9 and the rotor 12 branches in two directions. One liquid passes through the first communication passage 67 of the first pump casing 16a and the first impeller boss through hole 49a of the first impeller boss part 39a, and flows into the first impeller 6a. It enters the passage 72 within the first impeller blade. The other liquid passes between the first bearing 3a and the first bearing support member 4a, and passes between the first bearing 3a and the sleeve 25 of the rotating shaft 2. When the liquid passes between the first bearing 3a and the first bearing support member 4a, and when the liquid passes between the first bearing 3a and the sleeve 25 of the rotating shaft 2 , the liquid mainly passes through the grooves 74 and 76 formed in the first bearing 3a. When the liquid passes between the first bearing 3a and the first bearing support member 4a, and when the liquid passes between the first bearing 3a and the sleeve 25 of the rotating shaft 2, the liquid serves as a lubricant between the first bearing 3a and the first bearing support member 4a, and between the first bearing 3a and the sleeve 25 of the rotating shaft 2. The liquid that has passed between the first bearing (3a) and the sleeve (25) of the rotating shaft (2) passes through the first impeller boss portion through hole (49a) of the first impeller boss portion (39a) and enters the first impeller ( It enters the flow path 72 within the first impeller blade of 6a).

As shown in FIG. 5, the first pump casing 16a and the connecting pipe 62 have a first discharge passage 84 formed on the secondary side of the liquid delivery port 57 on the upper surface side of the first pump casing 16a. It is connected through intervening. The first discharge passage 84 and the connecting pipe 62 are connected by bolting flanges 86 and 87 formed at opposite ends of each other with bolts.

The second pump casing 16b and the connecting pipe 62 are connected via a second suction flow path 88 formed on the primary side of the second inlet 58 in the second pump casing 16b. The second suction passage 88 and the connecting pipe 62 are connected by bolting flanges 89 and 91 formed at opposite ends of each other with bolts.

As shown in Figs. 6, 7, and 8, the elastic structure 7 (7A, 7B, and 7C) is such that the bearings 3a, 3b are supported by the motor unit 11 by the bearing support members 4a, 4b. When pressed against the side opposite to the rotor 12, an elastic reaction force is applied to one or both of the bearings 3a and 3b and the bearing support members 4a and 4b in the axial direction.

The rotating shaft 2 moves by the amount of clearance toward the first impeller 6a due to the axial pressure difference, and the bearings 3a, 3b and the bearing support members 4a, 4b press each other in the axial direction. At this time, even if there is a dimensional error on the inner peripheral surface of the bearing support member housings 38a, 38b and the inner peripheral surface of the casing side bearing housings 32a, 32b, since the elastic structure 7 is formed, the bearings 3a, 3b And/or the bearing support members 4a, 4b come into contact with each other while tilting at a small angle with respect to the axial direction so that the surfaces opposing each other make surface contact. In this way, the bearings 3a, 3b and the bearing support members 4a, 4b are in surface contact, thereby preventing wear caused by the bearings 3a, 3b locally contacting the bearing support members 4a, 4b. .

Figure 6 shows an example in which the elastic structure 7B is composed of an elastic body formed between the side opposite to the rotor 12 of the motor portion 11 of the bearing 3a and the casing side bearing housing 32a, and , shows an example in which the elastic structure 7B is formed between the housing 38a for the bearing-bearing support member and the rotor 12 side of the motor portion 11 of the bearing-bearing support member 4a. The elastic body shown in the same figure is a coil spring. The coil spring has a diameter equal to or smaller than the radial thickness of the bearing 3a and the bearing support member 4a. Additionally, a plurality of coil springs are formed at regular intervals in the respective circumferential directions of the bearing 3a and the bearing support member 4a. 6 shows only the elastic structure 7B on the first impeller 6a side and omits the illustration of the elastic structure 7B on the second impeller 6b side. The elastic structure 7B (not shown) on the second impeller 6b side has a structure that is axially symmetrical with the elastic structure 7B on the first impeller 6a side, with the rotor 12 as the center. .

The elastic structure 7C shown in FIG. 8 is one in which the plurality of coil springs forming the elastic structure 7B in the example shown in FIG. 6 are replaced with one coil spring. The coil spring constituting the elastic structure 7C is arranged at a concentric position with the rotation axis 2. The coil spring in FIG. 8 presses the vicinity of the radial center of each cross section of the bearings 3a, 3b and the bearing support members 4a, 4b. 8 shows only the elastic structure 7C on the first impeller 6a side and omits the illustration of the elastic structure 7C on the second impeller 6b side. The elastic structure 7C (not shown) on the second impeller 6b side has a structure that is axially symmetrical with the elastic structure 7C on the first impeller 6a side, with the rotor 12 as the center. .

Additionally, instead of the coil spring forming the elastic structure (7B, 7C), a spring washer, disc spring washer, wave washer, etc. can also be employed.

7 shows that the elastic structure 7A is formed on the side opposite to the rotor 12 of the motor section 11 of the bearing 3a and a plate 92 is formed between the casing side bearing housing 32a, and the casing The side bearing housing 32a axially supports only a portion of the surface of the plate 92 opposite to the bearing 3a, thereby providing an elastic reaction force to the bearing 3a in the axial direction. For the plate 92, a thin plate made of metal, for example, a washer made of metal, etc. can be used. In this case, a bearing-side gap 93 is formed between the casing-side bearing housing 32a and the plate 92. In addition, in Figure 7, the degree of bending of the plate 92 and the inclination of the bearing 3a and the bearing support member 4a are expressed with emphasis. In addition, FIG. 7 shows only the elastic structure 7A on the first impeller 6a side. As shown in FIG. 2, the elastic structure 7A on the second impeller 6b side is axially symmetrical with the elastic structure 7A on the first impeller 6a side with the rotor 12 as the center. It has a structure.

In this embodiment, the bearing side clearance 93 is formed on one side of the inner diameter side of the plate material 92, and the outer diameter side of the plate material 92 is connected to the bearings 3a and 3b and the casing side bearing housings 32a and 32b. ) is sandwiched between. The bearing-side gap 93 is formed only on one side of the inner diameter side of the plate 92, so that when the bearings 3a and 3b are inclined with respect to the rotation axis 2, the plate 92 moves toward the bearing-side gap 93. It bends and generates elastic force.

Also, in Fig. 7, as an additional layer of elastic structure 7D, a plate ( 92) is formed, and the housing 38a for the bearing support member axially supports only a part of the surface of the plate 92 opposite to the bearing support member 4a, thereby supporting the bearing support member 4a. It indicates that an elastic reaction force is applied in the axial direction. Here too, for example, a thin metal plate such as a metal washer can be used as the plate 92, and the bearing support member housing 38a has a gap (gap on the bearing support member side) between the plate 92 and the plate 92. 94) is formed. In addition, FIG. 7 shows only the elastic structure 7D on the first impeller 6a side. As shown in FIG. 4, the elastic structure 7D on the second impeller 6b side is axially symmetrical with the elastic structure 7D on the first impeller 6a side with the rotor 12 as the center. It has a structure.

In this embodiment, the bearing support member side gap 94 is formed on one side of the outer diameter side of the plate material 92, and the inner diameter side of the plate material 92 is formed between the bearing support members 4a and 4b and the bearing support members 4a, 4b. It is sandwiched between housings 38a and 38b for the support member. The gap 94 on the bearing support member side is formed only on the one side of the outer diameter side of the plate 92, so that when the bearing support members 4a, 4b are inclined with respect to the rotation axis 2, the plate 92 is supported. It bends toward the gap 94 on the bearing support member side to generate elastic force.

FIG. 9 is a diagram showing a state in which the bearing 3a and the bearing support member 4a are in surface contact in a state slightly inclined with respect to the rotation axis 2. However, only the degree of bending of the plate 92 is expressed with emphasis, and the inclination of the bearing 3a and the bearing support member 4a is expressed without emphasis.

Since the plate 92 can be bent toward the bearing side gap 93 or the bearing support member side gap 94 at any position in the circumferential direction, the bearings 3a, 3b and the bearing support member ( When 4a, 4b) are pressed in the axial direction without surface contact with each other, the bearings 3a, 3b and bearing support members 4a, 4b each tilt with respect to the axial direction, as shown in FIG. 9. At the same time, a part of the plate material 92 is bent toward the bearing side gap 93 side or the bearing support member side gap 94 side, and as a result, the bearings 3a, 3b and the bearing support members 4a, 4b are , interview each other. Furthermore, in the example shown in FIG. 9, the upper outer diameter side of the bearing support member 4a in the drawing presses the plate material 92 toward the bearing support member side gap 94, and the upper portion of the bearing 3a in the drawing presses the plate material 92 toward the gap 94 on the bearing support member side. Since the inner diameter side of the plate material 92 is pressed against the bearing side gap 93 side, each plate material 92 is bent.

As a modification of the above embodiment, in the above embodiment, the plate material 92 is between the bearings 3a and 3b and the casing side bearing housings 32a and 32b, and between the bearing support members 4a and 4b. It may be formed only on one of the bearing support member housings 38a and 38b.

The present invention can be implemented in various other forms without departing from its spirit, main principles, or main features. Therefore, the above-described embodiment is merely an example in all respects and should not be interpreted limitedly.

The present invention can be applied to, for example, canned motor pumps.

1: Bearing structure of canned motor pump
2: rotation axis
3a, 3b: Bearing
4a, 4b: bearing support member
6a, 6b: Impeller
7A, 7B, 7C, 7D: Elastic structure
8: Canned motor pump
11: motor part
12: rotor
31: pump part
32a, 32b: Casing side bearing housing
33: Elastic sheet material
38a, 38b: Housing for bearing support member
92: plate

Claims (5)

A rotating shaft that rotates integrally with the rotor of the motor unit,
A bearing that is inserted into the casing-side bearing housing formed in the pump unit through an elastic thin plate material and supports the rotation shaft so that it can freely rotate in a direction perpendicular to the axial direction;
a bearing support member mounted on the rotation axis between the rotor of the motor unit and the bearing and supported in the axial direction so as to rotate freely by the bearing;
Provided with an impeller that rotates integrally with the rotation shaft,
In the canned motor pump, a part of the liquid conveyed by rotation of the impeller flows between the rotation shaft and the bearing,
When the bearing is pressed against the rotor of the motor unit by the bearing support member, an elastic structure is formed that provides an elastic reaction force in the axial direction to one or both of the bearing and the bearing support member. Bearing structure of canned motor pump. According to claim 1,
The elastic structure provides the elastic reaction force in the axial direction with respect to the bearing, and is an elastic body formed between a side of the bearing opposite to the rotor of the motor part and the bearing housing on the casing side. bearing structure. According to claim 1,
The bearing support member is mounted with respect to the rotation shaft via a housing for the bearing support member,
The elastic structure provides the elastic reaction force in the axial direction with respect to the bearing support member, and is an elastic chain formed between the housing for the bearing support member and the rotor side of the motor portion of the bearing support member. Bearing structure of a canned motor pump, characterized in that. According to claim 1,
The elastic structure is,
A plate is formed between a side of the bearing opposite to the rotor of the motor section and the bearing housing on the casing side,
A bearing structure for a canned motor pump, wherein the casing-side bearing housing axially supports only a portion of a surface of the plate opposite to the bearing, thereby imparting the elastic reaction force to the bearing in the axial direction. According to claim 1,
The bearing support member is axially fixed to the rotation axis via a housing for the bearing support member,
The elastic structure is,
A plate is formed between the rotor side of the motor portion of the bearing support member and the housing for the bearing support member,
Characterized in that the housing for the bearing support member provides the elastic reaction force to the bearing support member in the axial direction by supporting only a portion of the surface of the plate opposite to the bearing support member in the axial direction. Bearing structure of canned motor pump.

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