JPH0577595U - Canned motor pump - Google Patents

Abstract

(57) [Abstract] [Purpose] It is difficult for the air that accumulates in the space between the bottom surface of the partition wall and the rotor to be discharged by the operation of the pump, and because the air accumulates and the bearing and shaft run idle, and there is a sliding contact part. The temperature rises and the attraction force of the permanent magnet of the rotor prevents rotation defects when magnetic impurities such as iron pieces contained in the pumped liquid are sucked. In a canned motor pump, an outer circumference of the rotor is covered with a rotor cover, and a spiral groove extending in the axial direction is formed on an outer peripheral surface of the rotor cover. In this case, the boss portion of the impeller into which the bearing is fitted has a cylindrical shape, and an axial groove is formed on the outer peripheral portion of the bearing.
It is preferable that one or a plurality of them be formed so that the bearing chambers closed by the bearings at both ends are communicated with the outside by this groove, and that the rotor cover is made of resin.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a canned motor pump, particularly a canned motor pump applied to a hot water circulation pump and the like.

[0002]

[Prior Art]

 A conventional canned motor pump is constructed as shown in Japanese Patent Application No. 3-108140. This will be described with reference to FIG. 3. The stator winding is provided in the stator chamber 3 in a space surrounded by the inner peripheral surface of the motor casing 2 and the outer peripheral surface of the cylindrical portion of the partition wall 5 having a bottomed cup shape. A stator 1 including 1-1 is provided. The partition wall 5 and the pump casing 6 are pressure-bonded to each other via a seal member, for example, an O-ring 7 to form a pump chamber 8 which is shielded from the outside air except for the inlet pipe 8a and the outlet pipe 8b for the pumped liquid. .. A rotor chamber 4 is integrally formed in the pump chamber 8, and a cylindrical rotor yoke 11 and a permanent magnet 10 are integrally formed with the rotor cover 12 to form a rotor 15. ing. The boss portion 9-1 which is integrated with the impeller 9 arranged in the pump chamber 8 has a cylindrical shape, and this cylindrical portion is inserted into the inner surface of the rotor 15 and is fixed by a fixing means such as adhesion to rotate the boss. The child 15 is fixedly held, and the bearing 13 is fitted to both ends of the inner peripheral surface of the boss portion 9-1. The rotor 14 and the shaft 14 that rotatably supports the impeller 9 integral with the rotor 15 have one shaft holding portion 5-2 formed at the center of the bottom surface 5-1 of the partition wall 5 and the pump casing. -Fixed by the other shaft holding part 6-2 held by the plurality of supports 6-1 at the center of the thing 6. When the stator winding 1-1 is energized by a control circuit (not shown), a rotating magnetic field is generated on the inner peripheral surface of the stator 1 and is concentrically and rotatably supported by the cylindrical portion 5-3 of the partition wall 5. Since the driven rotor 15 is driven, the impeller 9 integrated with the rotor 15 is driven to function as a pump. By the way, in the above configuration, since the stator chamber 3 on the side of the stator 1 which is the current-carrying part and the pump chamber 8 through which the hot water flows are separated by the partition wall 5, the hot water affects the insulation of the stator. There is no.

[0003]

[Problems to be solved by the device]

 In the conventional case, as described above, the impeller 9 and the rotor 15 which is integral with the impeller 9 eliminate the narrow gap between the inner peripheral surface of the cylindrical portion 5-3 of the partition wall 5 and the outer peripheral surface of the rotor 15. Since the rotor chamber 4 is semi-shielded, there is a problem that the air accumulated in the space between the bottom surface 5-1 of the partition wall 5 and the rotor 15 is not easily discharged by the operation of the pump. .. Further, when air is accumulated, the bearing 13 and the shaft 14 run idle, which raises the temperature of the sliding contact portion, significantly shortening the bearing life, and causing the generation of rotating noise. Further, when the magnetic force of the permanent magnet 10 of the rotor 15 attracts magnetic impurities such as iron pieces contained in the pumped liquid and adheres to the surface of the rotor cover 12 covering the permanent magnet 10. However, there is a problem that the narrow space between the inner peripheral surface of the cylindrical portion 5-3 of the partition wall 5 and the outer peripheral surface of the rotor 15 is filled, and when rotating, it contacts the cylindrical portion of the partition wall and causes a rotation failure. It was It is an object of the present invention to provide a canned motor pump which solves the above-mentioned problems (problems) of the conventional one.

[0004]

[Means for Solving the Problems]

 The canned motor pump according to the present invention has a spiral groove extending in the axial direction on the outer peripheral surface of the rotor cover that constitutes the rotor, and the winding direction of the spiral groove is pumped by the rotation of the rotor. It is configured to guide the liquid from the impeller side to the depth of the rotor chamber, and an axial groove is formed between the bearing and the impeller on which the bearing is fitted, on the inner peripheral surface of the boss. Configured.

[0005]

[Action]

 In the device of the present invention, the pumping action of the impeller causes the pumping liquid in the pump chamber to be sucked and discharged from the outlet pipe of the pump casing by the rotation of the rotor, but a very small amount of pumping liquid is discharged to the outer peripheral surface of the rotor cover. By the pumping action of the spiral groove provided, it is conveyed through the gap between the inner peripheral surface of the partition wall cylindrical surface and the outer peripheral surface of the rotor, from the impeller side to the depth of the rotor chamber near the bottom surface of the partition wall. It is returned to the vicinity of the center of the impeller through a groove formed on the outer circumference of the bearing. For this reason, ventilation in the rotor chamber is facilitated, and the discharge of air accumulated in the rotor chamber is promoted. Also, when foreign matter such as iron pieces adheres to the rotor surface, the foreign matter contacts the inner circumference of the partition wall and rolls on the rotor cover while receiving some contact resistance. Since it is housed inside, the rotor cannot rotate due to contact between foreign matter and the cylindrical part of the partition wall.

[0006]

【Example】

 Hereinafter, the present invention will be described in detail with reference to the embodiments shown in FIGS. FIG. 1 is a perspective view of an impeller integrated with a rotor of a canned motor pump according to the present invention. The rotor cover 12 is made of resin, and if the distance between the stator 1 and the rotor 15 is widened, the motor efficiency is reduced. Therefore, the thickness of the rotor cover 12 is 1 to 2 mm. Is appropriate. Reference numeral 16 is a spiral groove provided on the surface of the rotor cover 12 in the axial direction. The depth of the groove 16 is about half of the wall thickness of the rotor cover 12 and is subjected to turning or forming. Sometimes provided by a mold. The spiral groove 16 is wound in a direction in which the pumped liquid is conveyed from the impeller 9 side to the bottom surface 5-1 side of the partition wall 5 at the back of the rotor chamber 4 by rotation. FIG. 2 is a transverse cross-sectional view showing a structure on the outer peripheral side of the bearing 13 necessary for the structure according to the present invention, and this figure corresponds to the A-A 'cross section of the conventional canned motor pump of FIG. As shown in the figure, the boss portion 9-1 of the impeller 9 into which the bearing 13 is fitted has a cylindrical shape, and the outer peripheral portion of the bearing 13 has one or more axial grooves 17 (see FIG. 2 has 4 pieces), and the groove 17 serves to ventilate the bearing chamber 18 closed by the bearings 13 at both ends and the outside. The other structure is the same as the conventional structure shown in FIG. In the above structure, when the winding 1-1 of the stator 1 is energized, a rotating magnetic field is generated on the inner peripheral surface of the stator 1, and the rotor 15 is driven in a state in synchronism with the rotating magnetic field. The impeller 9 that is integral with is driven. The impeller 9 sucks the pumped liquid from the inlet pipe 8a of the pump casing 6 in the central portion of the pump chamber 8 by the centrifugal force due to the rotation and discharges it from the outlet pipe 8b extending on the outer tangent line of the pump casing 6. A part of the pumped liquid is guided from the pump chamber 8 through the back side of the impeller 9 to the gap between the cylindrical portion 5-3 of the partition wall 5 and the rotor 19, and a spiral groove on the outer circumference of the rotor cover 12. According to the rotation of 16, the liquid with the viscosity of the pumping liquid is conveyed to the inner part of the rotor chamber 4. Further, the pumped liquid returns to the vicinity of the center of the impeller 9 where the pressure in the pump chamber 8 is the lowest through a passage formed by the bearing 13 and the groove 17 extending to the boss portion 9-1 into which the bearing 13 is fitted. Then, as a part of the pump pumping, the cycle in which energy is applied by the impeller 9 is repeated again. At this time, the air stagnant in the cylindrical portion 5-3 of the partition wall 5 and the air in the bearing chamber 18 are introduced into the pump chamber 8 in a state of being entrained in the water flow, and the outlet pipe 8b of the pump casing 6 is introduced. Will be discharged from.

[0007]

[Effect of the device]

 Since the canned motor pump according to the present invention is constructed as described above, it has excellent effects as described below. Part of the pumped liquid passes from the pump chamber through the space between the inner peripheral surface of the partition wall cylindrical surface and the outer peripheral surface of the rotor, and is carried to the inner part of the rotor chamber near the bottom surface of the partition wall, and the outer periphery of the bearing. Since it is conveyed again to the pump chamber at the center of the impeller through the spiral groove formed in the section, ventilation is facilitated and the air accumulated in the rotor chamber can be discharged easily. Since foreign matters such as iron pieces are also accumulated in the spiral groove formed on the outer circumference of the bearing, the rotor does not become unrotatable due to contact with the cylindrical part of the partition wall, and the reliability of the equipment is greatly improved. Can be improved. If the rotor cover is made of resin, it can be easily manufactured not only when forming the entire structure including the spiral groove, but also when cutting.

[Brief description of drawings]

FIG. 1 is a perspective view showing the structure of a rotor and an impeller of a canned motor pump according to the present invention.

FIG. 2 is a vertical sectional front view showing the relationship between the rotor and the bearing of the present invention.

FIG. 3 is a vertical sectional front view showing the structure of a conventional canned motor pump.

[Explanation of symbols]

 1: Stator 2: Motor casing 3: Stator chamber 4: Rotor chamber 5: Partition wall 6: Pump casing 9: Impeller 12: Rotor cover 13: Bearing 14: Shaft 15: Rotor 16: Spiral groove 17: Groove on inner peripheral surface of impeller boss 18: Bearing chamber

Claims (3)

[Scope of utility model registration request] 1. A motor casing and a cup-shaped internal partition wall and a pump casing, and a space surrounded by an inner peripheral surface of the motor casing and an outer peripheral surface of the partition wall. At least a permanent magnet and a rotor yoke are provided in a space surrounded by a stator chamber in which a stator having a stator winding is arranged, an inner peripheral surface of the partition wall and an inner side surface of the pump casing. In a canned motor pump comprising: a rotor and a pump chamber in which an impeller integrally supported by the rotor and rotatably supported is arranged, the outer circumference of the rotor is covered with a rotor cover, and the rotor cover is covered. A canned motor pump characterized in that a helical groove extending in the axial direction is formed on the outer peripheral surface of the −. 2. A boss portion of an impeller into which the bearing is fitted has a cylindrical shape, and an axial groove is formed on an outer peripheral portion of the bearing.
2. A canned motor pump according to claim 1, wherein one or a plurality of grooves are formed, and the groove communicates the bearing chamber closed by the bearings at both ends with the outside. 3. The canned motor pump according to claim 1, wherein the rotor cover is made of resin.