WO2008069124A1

WO2008069124A1 - Centrifugal pump

Info

Publication number: WO2008069124A1
Application number: PCT/JP2007/073172
Authority: WO
Inventors: Tetsuya Fukuda; Motohiko Matsuguma
Original assignee: Panasonic Electric Works Co., Ltd.
Priority date: 2006-12-07
Filing date: 2007-11-30
Publication date: 2008-06-12
Also published as: TWI329709B; KR101115362B1; JPWO2008069124A1; TW200839104A; KR20090078843A; JP4883093B2

Abstract

A centrifugal pump has a casing (8) having a suction opening (80), a shaft support part (84) fixed to the inside of the casing, a shaft (5) supported by the shaft support part, an impeller (7) rotatably supported by the shaft, having a flow passage (70) penetrating from the inner peripheral surface of the impeller to the outer peripheral surface, and discharging liquid, which flows from the suction opening into the casing, to the outside through the flow passage, and a drive part for rotating the impeller. The shaft support part (84) has a cone-shaped projection (840a) formed on the surface on the suction opening side and projecting toward the suction opening and also has a peripheral edge part (841) installed around the bottom of the projection. A surface (841a), which is on the suction opening side, of the peripheral edge part extends from the bottom of the projection toward an opening, which is on the inner peripheral surface side, of the flow passage, and the surface (841a) has an outer diameter larger than the inner diameter of the suction opening.

Description

Technical field

[0001] The present invention relates to a centrifugal pump.

Background art

[0002] As shown in FIG. 8, Japanese Patent Publication No. 2006-200427 discloses a centrifugal pump. The centrifugal pump includes a stator block 1, and the stator block 1 is made of a mold resin in which a stator 2 including a core and a coil, a control circuit 3, and a partition plate 4 are insert-molded. The partition plate 4 is located on the inner peripheral side of the stator 2 and has a recess 40 at the center thereof, and one end of the shaft 5 is supported by the recess 40. A rotor 6 is attached to the outer periphery of the shaft 5. In the rotor 6, the bearing 60 on the inner peripheral portion and the permanent magnet 61 on the outer peripheral side are integrally formed, and the impeller 7 is formed in a body on one end side in the axial direction.

This centrifugal pump further includes a casing 8. The casing 8 is fixed to the stator block 1 with screws, and a pump chamber for accommodating the impeller 7 is formed between the casing 8 and the partition plate 4. The casing 8 includes a discharge port 81 on the outer peripheral side and a suction port 80 in the center. The casing 8 includes a shaft support portion 100 that supports the other end of the shaft 5, and the shaft support portion 100 is supported by a support rib 101 extending from the casing 8 around the suction port 80 toward the inside of the casing 8. Supported. A conical protrusion 100a that guides the water flow to the impeller 7 side is formed on the surface of the shaft support 100 on the suction port 80 side.

[0004] This centrifugal pump has an advantage that the number of parts can be reduced because the shaft support portion 100 that supports the other end of the shaft 5 is formed integrally with the casing 8. However, there is a large gap between the outer peripheral surface of the shaft support portion 100 and the inner peripheral surface of the impeller 7, and there is a problem that air accumulates in this portion and it is difficult to discharge the air.

Disclosure of the invention

[0005] The present invention has been invented in view of the above-mentioned problems, and an object of the present invention is to provide a centrifugal pump that allows air to accumulate in the casing and efficiently discharge liquid containing bubbles. It is to provide. [0006] The centrifugal pump of the present invention includes a casing having a suction port and a suction port, a shaft support portion fixed to the inside of the casing, a shaft supported by the shaft support portion, and a self-rotating shaft. An impeller that includes a flow path that is supported by the inner surface and penetrates from the inner peripheral surface to the outer peripheral surface, and that discharges the liquid flowing into the casing from the suction port to the outside through the flow path; And a driving unit for rotating the motor. A feature of the present invention is that the shaft support portion is provided around a cone-shaped projecting portion formed on a surface on the suction port side and projecting toward the suction port, and a bottom portion of the projecting portion. The suction port side surface of the peripheral edge extends from the bottom of the protrusion toward the opening on the inner peripheral surface side of the flow path, and the outer diameter is larger than the inner diameter of the suction port. There is also a big point.

[0007] In the centrifugal pump of the present invention, the gap between the outer surface of the shaft support portion and the inner peripheral surface of the impeller can be filled with the peripheral edge portion, and air accumulates in the casing. The liquid flowing from the suction inlet to the impeller flow path is formed by the cone-shaped protrusion and the peripheral suction part, the inlet side surface, and the inlet of the impeller flow path (the inner circumference of the flow path). It is guided to the vicinity of the opening on the surface side, and as a result, the liquid mixed with bubbles can be discharged efficiently.

[0008] Preferably, the shaft support portion is formed integrally with the casing and includes a shaft support portion main body provided with the cone-shaped protruding portion, and an outer periphery of the shaft support portion main body. It consists of a ring.

In this case, the peripheral edge can be easily formed by attaching a ring to the outer periphery of the shaft support body.

[0010] Alternatively, the shaft support portion may be formed separately from the casing, and may be fixed to the peripheral edge of the suction port on the inner surface of the casing. As described above, when the casing and the shaft support main body are integrally formed, for the sake of die-cutting at the time of molding of the casing, suction is performed.

V, it is difficult to make the diameter (inner diameter) of the slot smaller than the outer diameter of the shaft support body. Therefore, by forming the shaft support portion and the casing separately, it is possible to freely reduce the diameter of the suction port regardless of the size of the shaft support portion. As a result, for example, the force S can be reduced by reducing the diameter of the suction port while maintaining the strength of the shaft support portion and providing a centrifugal pump corresponding to a low flow rate.

[0011] Preferably, a surface on the suction port side of the peripheral edge portion impellers a flow path of the impeller. It is located in the area extended to the center side of the.

[0012] In this case, even if the impeller is displaced toward the casing due to bearing wear or the like,

The water flow from the inlet can be smoothly guided to the inlet of the impeller.

[0013] Preferably, a spiral step portion is formed on the outer surface of the cone-shaped protrusion.

[0014] In this case, the suction loca can also rotate the inflowing water, and it can be controlled by the ability to draw out the liquid more efficiently.

Brief Description of Drawings

FIG. 1 is a cross-sectional view of a centrifugal pump that exerts a force on a first embodiment of the present invention.

FIG. 2A is a partially cutaway front view of the casing and ring of the centrifugal pump of FIG.

2B is a partially cutaway front view showing a state where a ring is attached to the casing of FIG. 2A.

FIG. 3 is an enlarged view of the main part of FIG.

4 is a partial front view showing an example in which a spiral stepped portion is formed on the protruding portion of FIG.

FIG. 5 is a cross-sectional view of a centrifugal pump that applies force to a second embodiment of the present invention.

6 is a step view of the casing and shaft support of the centrifugal pump of FIG.

FIG. 7 is a cross-sectional view showing a modified example in which the diameter of the suction port is reduced in the centrifugal pump of FIG.

FIG. 8 is a cross-sectional view of a conventional centrifugal pump.

BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.

(First embodiment)

The basic structure of the centrifugal pump of the present embodiment is the same as that of the conventional example shown in FIG. 8. As shown in FIG. 1, the stator block 1, the casing 8 having the suction port 80, and the inside of the casing 8 are fixed. The shaft support 84 is supported by the shaft support 84, the shaft 5 supported at one end by the shaft support 84 and supported by the recess 40 of the stator block 1, and the shaft 5 via the rotor 6. And impeller 7.

The stator block 1 is made of a mold resin in which a stator 2 including a core and a coil, a control circuit 3, and a partition plate 4 are insert-molded. The stator 2 and the control circuit 3 constitute a drive unit for rotating the impeller 7. The partition plate 4 is located on the inner peripheral side of the stator 2 and In the central portion, the above-described recess 40 for supporting the other end of the shaft 5 is formed. A rotor 6 is attached to the outer periphery of the shaft 5. In the rotor 6, an inner peripheral bearing 60 and an outer peripheral permanent magnet 61 are integrally formed, and an impeller 7 is formed in a body on the casing 8 side in the axial direction.

The casing 8 is fixed to the stator block 1 with screws, and a pump chamber for accommodating the impeller 7 is formed between the casing 8 and the partition plate 4. The casing 8 is provided with a discharge port 8 1 (see FIG. 2A) on the outer peripheral side and a suction port / inlet 80 at the center.

The shaft support portion 84 is arranged at a position facing the suction port 80 inside the pump chamber. The configuration of the shaft support portion 84 will be described later in detail.

[0020] The impeller 7 is driven by a drive unit and rotates around the shaft 5 together with the rotor 6. The impeller 7 includes a flow path 70 penetrating from the inner peripheral surface to the outer peripheral surface, and discharges water flowing into the casing from the suction port 80 to the outside through the flow channel 70 from the discharge port 81.

Hereinafter, the shaft support portion 84 will be described in detail.

As shown in FIGS. 2A and 2B, the shaft support portion 84 of this embodiment includes a shaft support portion main body 840 and a ring 841 attached to the outer periphery of the shaft support portion 840.

[0023] The shaft support body 840 is composed of a plurality of (three in the illustrated example) support ribs 83 extending toward the inside of the casing 8 from the suction of the casing 8 at the periphery of the end of the inlet 80. It is formed in one piece with the casing 8. The shaft support body 840 has a cone-shaped protrusion 840a protruding toward the suction port 80 on the surface on the suction port 80 side, and a shaft 5 on the surface opposite to the suction port 80. A bearing portion 850 that supports one end of the bearing.

[0024] The ring 841 is for expanding the outer diameter of the shaft support portion main body 840 and forming a wide peripheral edge portion around the bottom of the protruding portion 840a. The ring 841 has a plurality of grooves 842 corresponding to the support ribs 83 and is mounted around the shaft support body 840 so that the support ribs 83 are fitted in the grooves 842. The ring 841 is prevented from rotating by the engagement of the support rib 83 and the groove 842, and the step 85 provided at the end of the shaft support body 840 and the step provided at the bottom of the ring 841 (see FIG. (Not shown) is engaged with each other, thereby positioning in the axial direction. The ring 841 is fixed around the shaft support body 840 by, for example, ultrasonic welding.

[0025] When the ring 841 is mounted around the shaft support body 840, the suction port side of the ring 841 One surface 841a gently extends from the bottom of the protrusion 840a toward the opening 71 on the inner peripheral surface side of the flow path 70 of the impeller 7, and the outer diameter of the surface 841a (that is, the outer diameter of the ring 841) is It is larger than the inner diameter of the suction port 80. The outer peripheral surface of the ring 841 faces the inner peripheral surface of the impeller 7 through a minute gap.

[0026] Since the centrifugal pump of this embodiment has the ring 841 mounted around the shaft support body 840, a ring is formed between the outer surface of the shaft support body 840 and the inner peripheral surface of the impeller 7. It is possible to fill with 841 S, and air accumulates in the casing. Then, the directional force and water from the suction port 80 to the impeller channel 70 are smoothly guided to the vicinity of the opening 71 of the channel 70 by the cone-shaped protrusion 840a and the surface 841a of the ring 841 on the suction port side. As a result, the liquid mixed with bubbles can be discharged efficiently.

[0027] When the casing 8 and the shaft support portion 84 are formed integrally, it is difficult to make the outer diameter of the shaft support portion 84 larger than the inner diameter of the inlet port 80 for the sake of mold removal. ! / ヽ (In other words, it is difficult to make the inner diameter of the suction port 80 smaller than the outer diameter of the shaft support portion 84). Therefore, as in this embodiment, the shaft support portion 84 is composed of the shaft support portion main body 840 and the ring 841 attached around the shaft support portion main body 840, so that the suction port 80 has a small inner diameter. In addition, the outer diameter of the shaft support portion 84 can be easily expanded.

[0028] As shown in FIG. 3, the surface 841a of the ring (that is, the peripheral edge) 841 on the suction port side is located in a region S in which the flow path 70 of the impeller extends to the center side of the impeller. Is preferred. In other words, the surface 841a on the suction port side of the ring is preferably located closer to the casing 8 side than the bottom surface 70a of the flow path 70. In this case, even if the position of the impeller is shifted toward the casing due to wear of the bearing 60 or the like, the water flowing from the suction port 80 can be smoothly guided to the flow path 70 of the impeller.

In addition, as shown in FIG. 4, it is also preferable to form a spiral stepped portion 88 on the outer surface of the cone-shaped protruding portion 840a. The stepped portion 88 is formed so as to draw a spiral in accordance with the rotation direction X of the impeller 7. In this case, the water flowing from the suction port 80 can be rotated by the cone-shaped protrusion 840a to be sent to the impeller 7 side, and the force that guides the water mixed with bubbles to the impeller 7 more efficiently S I'll do it.

[0030] (Second Embodiment) The basic structure of the centrifugal pump of the present embodiment is the same as that of the first embodiment except for the shaft support portion 84, and the same parts are denoted by the same reference numerals, and redundant description is omitted.

As shown in FIGS. 5 and 6, the shaft support portion 84 ′ of the present embodiment is formed separately from the casing 8, and is sucked by the inner surface of the casing 8. Fixed.

More specifically, the shaft support portion 84 ′ is formed in one block shape, and includes a cone-shaped protrusion 84 Oa ′ and a peripheral edge portion 841 ′ provided around the bottom of the protrusion 840 a ′. And a bearing portion 850 ′ for supporting one end of the shaft 5. The shaft support portion 84 ′ is formed such that the outer diameter D 1 of the peripheral edge portion 841 ′ is larger than the inner diameter D 2 of the suction port 80. The shaft support 84 ′ is attached along the axial direction to the periphery of the end of the suction port 80 on the inner surface of the casing 8, and is fixed by ultrasonic welding or the like.

When the shaft support portion 84 ′ is fixed to the casing 8, the surface 84 la ′ on the suction port side of the peripheral portion 841 ′ opens from the bottom portion of the protrusion 840 a ′ to the opening 71 on the inner peripheral surface side of the flow path 70. The outer peripheral surface of the peripheral edge portion 841 ′ faces the inner peripheral surface of the impeller 7 through a minute gap.

[0034] In the centrifugal pump of the present embodiment, the gap between the outer surface of the shaft support portion 84 'and the inner peripheral surface of the impeller 7 can be filled with the peripheral edge portion 841', and air does not easily accumulate in the casing. Become. The suction force from the suction port 80 to the flow path 70 of the impeller is filled with condensate by the cone-shaped protrusion 840a 'and the surface 841a' on the suction port side of the peripheral portion 841 'near the opening 71 of the flow path 70. As a result, the liquid containing bubbles can be efficiently discharged.

[0035] As described in the first embodiment, when the casing 8 and the shaft support portion are integrally formed, the inner diameter of the suction port 80 may be made smaller than the outer diameter of the shaft support portion for convenience of die cutting. Difficult. However, in the centrifugal pump of this embodiment, since the shaft support portion 84 ′ and the casing 8 are formed separately, the diameter D2 of the suction port 80 is freely reduced regardless of the size of the shaft support portion 84. That power S. For example, as shown in FIG. 7, the shaft strength is maintained by reducing the inner diameter D2 of the suction port 80 while keeping the inner diameter D3 of the bearing portion 850 ′ of the shaft support portion 84 at the same size as FIG. Moreover, the pump corresponding to the lower flow rate can be provided.

In the present embodiment as well, as in the first embodiment, the suction port side surface 841a ′ of the peripheral edge portion 841 ′ is within the region where the impeller channel 70 is extended to the center side of the impeller. It is preferable to be located. [0037] It is also preferable to form a spiral step on the outer surface of the cone-shaped protrusion 840a '.

Claims

The scope of the claims

[1] Centrifugal pump with the following configuration:

A casing with a suction port,

A shaft support fixed inside the casing;

A shaft supported by the shaft support,

An impeller that is rotatably supported by the shaft and includes a flow path that penetrates from the inner peripheral surface to the outer peripheral surface, and that discharges liquid that has flowed into the casing from the suction port to the outside through the flow path. ,

A drive unit for rotating the impeller,

In the above,

The shaft support portion includes a cone-shaped protrusion that is formed on a surface on the suction port side and protrudes toward the suction port, and a peripheral edge provided around the bottom of the protrusion.

The surface of the peripheral edge on the suction port side extends from the bottom of the protrusion toward the opening on the inner peripheral surface side of the flow path of the impeller, and has an outer diameter larger than the inner diameter of the suction port. Features.

[2] The centrifugal pump according to claim 1! /,

The shaft support is

A shaft support body formed integrally with the casing and provided with the cone-shaped protrusion;

It comprises a ring that is mounted on the outer periphery of the shaft support body and that constitutes the peripheral edge.

[3] The centrifugal pump according to claim 1! /,

The shaft support portion is formed separately from the casing, and is fixed to the peripheral edge of the inlet / outlet opening on the inner surface of the casing.

[4] The centrifugal pump according to claim 1! /,

The surface on the suction port side of the peripheral edge portion is located in a region where the flow path of the impeller extends to the center side of the impeller. The centrifugal pump according to claim 1,

A spiral step portion is formed on the outer surface of the cone-shaped protrusion.