JP2649764B2 - Permanent magnet rotor of canned motor pump - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a canned motor pump,
Particularly, the present invention relates to a permanent magnet rotor used for a canned motor pump suitable for a hot water circulation pump or the like.

[0002]

2. Description of the Related Art The contents and structure of the prior art will be described with reference to FIG. FIG. 7 is a sectional view showing an example of the structure of a conventional canned motor pump.
-108140. In this example, the space between the motor casing 2 and the cup-shaped partition 5 is a stator chamber, in which the stator 1 of the drive motor is disposed, and the space between the opposite surface of the partition 5 and the pump casing 6 is provided. The space is a rotor chamber 4 and a pump chamber 8 connected thereto, in which a rotor and an impeller 9 integral therewith are arranged.

Since the pump chamber 8 serving as a fluid passage has an airtight structure except for the fluid inlet / outlet port 18, a sealing surface such as an O-ring 7 is provided on the contact surface between the partition wall 5 and the pump casing 6. The members are used together.

A boss 9-1 extending from the impeller 9
A shaft 13 for rotatably supporting the impeller 9 which is integral with the rotor permanent magnet 10 by means of the bearing 13 is mounted on the inner peripheral end of the shaft 14 at both ends thereof. And a plurality of feet 6-6 at the center of the pump casing 6 on the opposite side.
1 and is fixedly held by a shaft holding portion 6-2 integral with the shaft 1.

In the canned motor pump shown in this example, a rotor exposed to a fluid inside a pump chamber 8 is formed integrally with an impeller 9 so as to be concentric with the outer peripheral surface of a cylindrical boss extending from the impeller. A rotor yoke is arranged, a plurality of segment-shaped permanent magnets are arranged at equal intervals on an outer peripheral surface of the rotor yoke, and these are integrally molded with resin, and are arranged on an outer portion of the rotating portion. In order to secure the permanent magnet, it is necessary to increase the thickness of the rotor cover formed of a resin covering the outer peripheral surface of the permanent magnet.

[0006]

In the conventional structure as described above, the air gap between the rotor and the stator must be increased, the efficiency cannot be reduced, and the rotor formed by resin molding cannot be avoided. There was a problem that the strength reliability of the cover was not sufficient.

[0007]

The permanent magnet rotor used in the canned motor pump according to the present invention has a cylindrical boss extending from the impeller and a rotary concentrically disposed on the outer periphery of the cylindrical boss. A rotor yoke, and a plurality of segmented permanent magnets arranged at equal intervals on the outer peripheral surface of the rotor yoke, wherein the inner diameter of the pipe is a nonmagnetic thin metal member covering the outer peripheral surface of the permanent magnet. Has a plurality of small projections slightly larger than the outer diameter of the permanent magnet and protruding in the axial center direction at portions except for both ends of the pipe, and the tips of the small projections contact the outer peripheral surface of the permanent magnet. The rotor yoke, the permanent magnet, and the pipe are integrally formed of resin with the impeller.

[0008]

In the above construction, since the space between the stator and the rotor can be reduced by making the holding means for the permanent magnet thin, the efficiency can be improved, and the tip of the small protrusion having flexibility is realized. There is an operational effect that the permanent magnet can be reliably pressed and held while absorbing the dimensional error by pressing.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The structure of a permanent magnet rotor according to the present invention will be described below with reference to the drawings. FIG. 1 is a sectional view showing the structure of a first embodiment of a permanent magnet rotor of a canned pump motor according to the present invention, wherein 20 is a plurality of segment type permanent magnets, 11 is a rotor yoke, and 9-1 is an impeller. The boss portion, 21 is a stainless steel pipe, and 21-1 are a plurality of small projections provided on the inner peripheral surface of the pipe, extending in the axial direction and circumferentially long. FIG. 2 is a perspective view of a single body of the pipe 21. The inner diameter of the pipe 21 is slightly larger than the outer diameter of the permanent magnet 20, and the inner diameter of the plurality of small protrusions 21-1 provided on the inner peripheral surface of the pipe. The size is formed slightly smaller than the outer diameter of the permanent magnet 20.

In the permanent magnet rotor shown in FIG. 1, a plurality (four in the illustrated example) of segment-shaped permanent magnets 20 abut on the outer peripheral surface of a rotor yoke 11, and a stainless steel pipe 2 is used.
When a united product in which the rotor yoke 11 and the permanent magnet 20 are brought into contact with each other is press-fitted into the pipe 1, only the inner peripheral surface of the plurality of small projections 21-1 protruding from the inner peripheral surface of the pipe 21 is a permanent magnet. The other part of the pipe 21 is in contact with the outer peripheral surface of the permanent magnet 20, and is separated from the outer peripheral surface of the permanent magnet 20. Therefore, irregularities in the outer diameter of the sintered permanent magnet 20 are absorbed by the elasticity of the small projections 21-1 of the pipe without impairing the roundness of the pipe.
After press-fitting the resin 1 and the permanent magnet 20 and inserting the resin into the mold of the resin molding machine and injecting the resin, the impeller 9, the boss portion 9-1 of the impeller, the permanent magnet 20, and the rotor yoke 11 are integrally formed with the resin. The permanent magnet rotor of the canned motor pump molded in is completed. In FIG. 1, the small projections 21-1 are long and continuously provided in the circumferential direction of the pipe. However, the small projections 21-1 may be formed of short small projections intermittently connected.

A second embodiment of the present invention will be described.
FIG. 3 is a perspective view of a single pipe made of stainless steel used in the second embodiment. The inner diameter of the pipe 22 is formed slightly larger than the outer diameter of the permanent magnet 20, and the inner circumference except for both ends is formed. A plurality of small protrusions 22-1 extending toward the axis and extending in the axial direction are provided on the inner surface of the pipe at positions facing the joints of a plurality of (four in the illustrated example) segment-shaped permanent magnets. It is provided. FIG. 4 is a partial sectional view showing the second embodiment, and FIG. 5 is a sectional view taken along line AA of FIG. Abuts on the pipe 22 and press-fits the plurality of segment-shaped permanent magnets 20 to the positions of the small protrusions 22-1 provided on the inner peripheral surface thereof, with the positions of the chamfered surfaces of the adjacent joints aligned, The segment type permanent magnet 20
After the resin and the rotor yoke 11 are pressed and fixed to each other and inserted into a mold of a resin molding machine to inject resin, the impeller 9, the boss portion 9-1 of the impeller, the permanent magnet 20, and the rotor yoke 11 are integrally formed. The permanent magnet rotor of the canned motor pump molded with resin is completed.

Although the small projections 22-1 shown in FIG. 3 are provided continuously long in the axial direction of the pipe, they are formed so as to consist of short small projections 22-2 intermittently connected as shown in FIG. May be.

[0013]

According to the permanent magnet rotor of the canned motor pump according to the present invention, the outer peripheral surface of the plurality of segment-shaped permanent magnets is covered with a pipe made of a non-magnetic metal thin member in the above-described configuration. A small protrusion protruding from the peripheral surface abutting on the outer peripheral surface of the permanent magnet, or the small protrusion is formed to be long in the axial direction and provided in accordance with the position of the adjacent joint portion of the segment-shaped permanent magnet; And the segment-shaped permanent magnet and the pipe are molded integrally with the impeller with resin, so irregularities in the outer diameter of the segment-shaped permanent magnet are absorbed by the elasticity of the small projections of the pipe, and a perfect circle is maintained. Therefore, the length of the gap between the inner diameter of the stator and the outer diameter of the rotor can be shortened, so that there is an effect that the efficiency of the motor is increased and a highly reliable permanent magnet rotor can be obtained. .

[Brief description of the drawings]

FIG. 1 is a partial sectional view showing a first example of a permanent magnet rotor of a canned motor pump according to the present invention.

FIG. 2 is a perspective view of a single pipe of the example shown in FIG.

FIG. 3 is a perspective view of a single pipe of a second embodiment of the permanent magnet rotor of the canned motor pump according to the present invention.

FIG. 4 is a partial sectional view showing a second example of the permanent magnet rotor of the canned motor pump according to the present invention.

FIG. 5 is a sectional view taken along the line A-A ′ of FIG. 4;

FIG. 6 is a perspective view of another example of the pipe alone of the second example of the permanent magnet rotor of the canned motor pump according to the present invention.

FIG. 7 is a cross-sectional view showing a structure of a conventionally implemented canned motor pump.

[Explanation of symbols]

1: Stator 2: Motor casing 3: Stator chamber 4: Rotor chamber 5: Partition wall 5-1: Bottom surface 5-2: One shaft holding section 5-3: Cylindrical section 6: Pump casing 6-1: Multiple 6-2: The other shaft holding part 7: O-ring 8: Pump chamber 9: Impeller 9-1: Boss part of impeller 10: Permanent magnet 11: Rotor yoke 12: Rotor cover 13: Bearing 14: Shaft 18: Hot water inlet / outlet 20: Segment type permanent magnet 21: Stainless steel pipe 21-1: Small projection provided on the inner peripheral surface of pipe 20 and extending in the circumferential direction 22: Stainless steel pipe 22-1: Pipe 22 22-2: Small projections extending in the axial direction provided intermittently provided on the inner peripheral surface of

Claims (5)

(57) [Claims] 1. A motor housing and a cup-shaped partition forming a stator housing stator chamber of a drive motor, and are connected to the rotor housing rotor chamber and the open rotor chamber of the motor which are integral with the impeller. A permanent magnet rotor for use in a canned motor pump including a pump casing forming a pump chamber for accommodating the impeller, and a cylindrical boss extending from the impeller and disposed concentrically around the outer periphery of the cylindrical boss. Provided with a rotor yoke and a plurality of segment-shaped permanent magnets arranged at equal intervals on the outer peripheral surface of the rotor yoke, and a pipe made of a non-magnetic thin metal member covering the outer peripheral surface of the permanent magnet. The inner diameter is slightly larger than the outer diameter of the permanent magnet, and a plurality of small protrusions projecting in the direction of the axial center are formed at portions other than both ends of the pipe, and the tips of the small protrusions are So as to abut against the outer peripheral surface of the permanent magnet, the rotor yoke and the permanent magnet and the permanent magnet rotor of a canned motor pump and pipes that are formed integrally with the impeller in the resin, characterized by. 2. A plurality of small projections formed on the pipe,
The rotor of the canned motor pump according to claim 1, wherein the rotor is a small protrusion that is long in a circumferential direction. 3. A plurality of small projections formed on the pipe,
2. The permanent magnet rotor for a canned motor pump according to claim 1, wherein the small projections are intermittently continuous in a circumferential direction. 4. A motor housing and a cup-shaped partition forming a stator housing stator chamber of a drive motor, and are connected to the rotor housing rotor chamber and the open rotor chamber of the motor which are integral with the impeller. A permanent magnet rotor for use in a canned motor pump including a pump casing forming a pump chamber for accommodating the impeller, and a cylindrical boss extending from the impeller and disposed concentrically around the outer periphery of the cylindrical boss. Provided with a rotor yoke and a plurality of segment-shaped permanent magnets arranged at equal intervals on the outer peripheral surface of the rotor yoke, and a pipe made of a non-magnetic thin metal member covering the outer peripheral surface of the permanent magnet. The inner diameter is slightly larger than the outer diameter of the permanent magnet, and the same number of small protrusions as the segment-type permanent magnets are formed at portions other than both ends of the pipe, protruding in the axial center direction. And, so as to abut the joint the small projections adjacent said permanent magnet, said rotor yoke,
A permanent magnet rotor for a canned motor pump, wherein a permanent magnet and a pipe are integrally formed of resin with the impeller. 5. A plurality of small projections formed on the pipe,
5. The permanent magnet rotor of the canned motor pump according to claim 4, wherein the small projections are intermittently continuous in the axial direction.