US20070280837A1

US20070280837A1 - Vortex pump

Info

Publication number: US20070280837A1
Application number: US11/755,304
Authority: US
Inventors: Takeshi Ozawa
Original assignee: Nidec Sankyo Corp
Current assignee: Nidec Sankyo Corp
Priority date: 2006-06-06
Filing date: 2007-05-30
Publication date: 2007-12-06
Also published as: TWI404865B; TW200809092A; KR20070116742A; KR101300887B1; JP2008014300A; JP5112741B2; CN101086259B; CN101086259A

Abstract

A vortex pump comprises: an impeller that includes a plurality of blades at an outer circumference and a rotor magnet placed at an inner circumference; a shaft fixed at a center of the impeller; a bearing component placed at an outer circumference of the shaft; a motor stator placed at an inner circumference side of the rotor magnet; and a case structural component having a suction port and a discharge port that functions to house the impeller and furthermore to divide the impeller and the motor stator. A motor stator side surface of the case structural component is covered with an adhesive material to cause the motor stator to adhere to the motor stator side surface.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority of Japanese Application No. 2006-156859, filed Jun. 6, 2006 and Japanese Application No. 2007-123958, filed May 8, 2007, the complete disclosures of which are hereby incorporated by reference.

BACKGROUND OF THE INVENTION

a) Field of the Invention
The present invention relates to a vortex pump in which a fluid sucked through a suction port by revolution of an impeller passes through a fluid path and gets discharged from a discharge port; and furthermore in detail, the invention relates to such a vortex pump provided with a structure that enables the vortex pump to become further low-profile designed.
b) Description of the Related Art
In recent years, as a method of efficiently cooling down CPUs and so on of notebook-sized personal computers and so forth, a system that circulates a refrigerant in it by using a pump for refrigerant circulation has been under research. For a pump to be used in such a system, it is required to have a long operating life, and also to be provided with low-profile design in the same way as a trend of low-profile design of notebook-sized personal computers. Furthermore in recent years, a fuel battery to be used in notebook-sized personal computers and so on has also been under research. Also in a fuel supplying unit that supplies such a fuel battery with fuel (oxygen, air, water, and so forth), a small-sized pump is used. For a pump to be used for a fuel battery, it is especially desired to use a model with less power consumption for the purpose of reducing the power consumption of the pump itself as much as possible.
As one of small-sized pumps of conventional models, a vortex pump described in Japanese Unexamined Patent Publication (Kokai) No. 2003-161284, for example, includes: an impeller in which a large number of blades are formed at an outer circumference and a rotor magnet is placed at an inner circumference; a shaft on which the impeller revolves; a motor stator that is placed at an inner circumference side of the rotor magnet; and a pump casing that divides the impeller and the motor stator air-tightly and has a suction port and a discharge port. The vortex pump is provided with a motor structure including a structure of an outer rotor. In the vortex pump, the impeller and the motor stator are combined together and air-tightly divided so as to materialize compact design and low-profile design.

SUMMARY AND OBJECT OF THE INVENTION

a) Problem to be Solved

Considering a trend of compact design and weight saving of portable devices represented by notebook-sized personal computers and so forth in recent years, further compact design and low-profile design are still requested even in the vortex pump described in the reference above and so on. Under such circumstances; in the course of an examination of thinning a thickness of each structural member down to its limit in order to thinly shape a vortex pump still further, the inventor of the present invention has noticed that, when a wall thickness of a pump casing air-tightly dividing an impeller and a motor stator is made thinner, micro vibration during revolution of the impeller causes sympathetic vibration with the thin-walled pump casing so as to generate a large noise. Generation of such a noise is a significant problem especially when a portable device is concerned, and countermeasures for the problem are critical. However, if the wall thickness of the pump casing is made thicker for the purpose of solving the problem of noise generation, there arises a problem that low-shaping an entire profile of the vortex pump can no longer be achieved.

b) Primary Object

The present invention aims at solving the problem identified above, and it is a primary object of the present invention to provide a vortex pump equipped with a structure that enables the vortex pump to further become low-shaped.

c) Summary of the Invention

To solve the problem identified above, a vortex pump of the present invention includes: an impeller that has a plurality of blades at an outer circumference and a rotor magnet placed at an inner circumference; a shaft fixed at a center of the impeller; a bearing component placed at an outer circumference of the shaft; a motor stator placed at an inner circumference side of the rotor magnet; and a case structural component having a suction port and a discharge port that works to house the impeller and furthermore to divide the impeller and the motor stator; wherein a motor stator side surface of the case structural component is covered with an adhesive material to cause the motor stator to adhere to the motor stator side surface. For another case, it is also possible to have the motor stator adhered and fixed with an adhesive material onto a surface of the case structural component that faces the motor stator. In this case; it is possible that the motor stator is equipped with a protruded pole part in which a wire-wound coil is formed, and at least all the wire-wound coil is adhered and fixed with an adhesive material onto a surface of the case structural component that faces the motor stator. Still further, it is also possible to have all the wire-wound coil and the protruded pole part adhered and fixed with an adhesive material onto a surface of the case structural component that faces the motor stator.
According to the present invention; the motor stator side surface of the case structural component is covered with the adhesive material, or the motor stator is adhered and fixed onto the surface of the case structural component at the side of the motor stator. Therefore, even if thickness of a section of the case structural component that divides the impeller and the motor stator is thin, sympathetic vibration of the case structural component can be restrained. As a result, compact design and low-profile design of the vortex pump can be achieved. Therefore, even if a wall in a thrust direction of the case structural component that constructs the surface section (hereinafter called a thrust-direction wall) is thin enough so as to be at least 0.2 mm and thinner than 1.5 mm, noise generation because of sympathetic vibration of the thin-walled thrust-direction wall caused with micro vibration during revolution of the impeller can be restrained and then low-profile design can be realized as an entire profile of the pump. As a result, a low-shaped vortex pump can be provided while securing stable revolution of the pump for a long time.
A vortex pump of the present invention is especially effective when thickness of a wall of the case structural component at a side, which divides the impeller and the motor stator, (the thrust-direction wall) is at least 0.2 mm and thinner than 1.5 mm.
In a vortex pump of the present invention, it is preferable that the bearing component is a ball bearing, and a circular protruded section centered at the shaft is placed at an outer circumference section, which is outside a position including an outer race of the ball bearing and at a lower surface of a motor stator side of the impeller.
According to the invention, since a ball bearing is used as the bearing component, and the ball bearing is effective for preventing any play from arising. Furthermore, since a circular protruded section centered at the shaft is placed, it is possible for a space surrounded by the protruded section and the shaft to retain a lubricant material for the ball bearing, such as grease and so on, without evaporation or scattering away. As a result, a low-shaped vortex pump can be provided while securing stable revolution of the pump for a long time.
In a vortex pump of the present invention, it is preferable that a lid component placed on the case structural component that houses the impeller is welded onto the case structural component.
According to the invention, a mounting structure for placement of the lid component is not a conventional screw-fastening structure using an O-ring, which is disadvantageous to low-profile design, so that an entire profile of the vortex pump can be low-profiled.
To solve the above-referenced problem, another vortex pump relating to the present invention includes: an impeller that has a plurality of blades at an outer circumference and a rotor magnet placed at an inner circumference; a shaft fixed at a center of the impeller; a bearing component placed at an outer circumference of the shaft; a motor stator placed under the impeller and at an inner circumference side of the rotor magnet; and an integral-type case structural component having a suction port and a discharge port which works to house the impeller, and furthermore in which the motor stator is embedded. In this case; it is possible that the motor stator is equipped with a protruded pole part in which a wire-wound coil is formed, and all the wire-wound coil and the protruded pole part are embedded with a resin material so as to construct the integral-type case structural component.
According to the invention; even if the thickness of a wall at a side that divides the impeller and the motor stator is thin, sympathetic vibration of the wall can be restrained so that compact design and low-profile design of the vortex pump can be materialized.
In a vortex pump according to the present invention, even if the thickness of the thrust-direction wall that constructs a surface of the case structural component at the motor stator side is thin, noise generation because of sympathetic vibration of the thin-walled thrust-direction wall caused with micro vibration during revolution of the impeller can be restrained and then low-profile design can be realized as an entire profile of the pump. Therefore, a low-shaped vortex pump can be provided while securing stable revolution of the pump for a long time. As a result, the pump can be used preferably as a low-shaped pump with a long operation life for cooling down a CPU of a portable device, such as a notebook-sized personal computer and so on, as well as for a fuel battery.
Preferred embodiments of the present invention are described below with reference to the accompanying drawings. Further, needless to say, a vortex pump of the present invention is not limited to the example of the preferred embodiment described below as far as the vortex pump has technical characteristics of the present invention.

BRIEF DESCRIPTION OF THE DRAWINGS

In the drawings:

FIG. 1 is an exploded perspective view showing an example of a vortex pump relating to the present invention;

FIG. 2 is an A-A cross-sectional drawing of the vortex pump shown by FIG. 1;

FIG. 3 includes perspective views of a case structural component, which is a constitutional element of the present invention, when it is viewed from a side of a motor stator;

FIG. 4 is an explanatory drawing to show an example of adhesive joining configuration of an adhesive material that covers a surface at a side of the motor stator of the case structural component;

FIG. 5 is an explanatory drawing to show another example of adhesive joining configuration of an adhesive material that covers a surface at a side of the motor stator of the case structural component;

FIG. 6 is an explanatory drawing to show an example of a configuration including an integral-type case structural component in which the motor stator is integrated and embedded; and

FIG. 7 is an explanatory drawing to describe a preload given onto the bearing component constructed by using the couple of ball bearings that are stacked up.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

FIG. 1 is an exploded perspective view showing an example of a vortex pump relating to the present invention, and meanwhile FIG. 2 is an A-A cross-sectional drawing of the vortex pump shown by FIG. 1 when it is in assembled condition. FIG. 3 includes perspective views of a case structural component, which is a constitutional element of the present invention, when it is viewed from a side of a motor stator; and meanwhile, FIG. 4 and FIG. 5 are explanatory drawings showing condition of adhesive joining configuration of an adhesive material that covers a surface at a side of the motor stator of the case structural component.
As shown in FIG. 1 and FIG. 2, a vortex pump 1 of the present invention is a pump in which a fluid (gas or liquid) is introduced from a suction port 61 and discharged from a discharge port 62; and the pump is equipped with; an impeller 20 that includes a plurality of blades 22 at an outer circumference and a rotor magnet 40 placed at an inner circumference; a shaft 41 fixed at a center of the impeller 20; a bearing component 50 (supplied as a couple of ball bearings 50 a and 50 b in FIG. 1) placed at an outer circumference of the shaft 41; a motor stator 70 placed under the impeller 20 and at an inner circumference side of the rotor magnet 40; a case structural component 60 having the suction port 61 and the discharge port 62 that works to house the impeller 20 and furthermore to divide the impeller 20 and the motor stator 70; and a lid component 10 placed on the case structural component 60 that houses the impeller 20. A feature of the present invention is that a motor stator side surface 65 of the case structural component 60 is glued, or in other words, covered with an adhesive material 69 that cause the motor stator 70 to adhere to the motor stator side surface 65. Incidentally, a member with a reference numeral 80 in FIG. 1 and FIG. 2 is a substrate positioned under the motor stator 70.
In the present application; the terms of “on”, “under”, “inner”, and “outer” as well as “above”, “bottom surface”, “inner circumference”, and “outer circumference” and so on each represent “a higher position”, “a lower position”, “an inner position”, and “an outer position” under condition where the drawings including FIG. 1, FIG. 2 and so on are each viewed as a plane view while the lid component 10 is located at a higher position in comparison with the case structural components (the reference numeral 60, and another reference numeral 75). Therefore, the description “under” in the “under the impeller 20” described above represents “a lower position”, i.e., “a position closer to the substrate 80” in FIG. 2 under condition where the drawing is viewed in the same manner as defined above. Meanwhile, the description “on” in the “on the case structural component 60 that houses the impeller 20” described above represents “a higher position”, i.e., “a position closer to the lid component 10” in FIG. 2 under condition where the drawing is viewed in the same manner as defined above. Furthermore, the description “a bottom surface” in a description “a bottom surface at a motor stator side of the impeller 20” represents “a bottom surface” under condition where the drawing is viewed in the same manner as defined above. Still further, the description “an inner circumference side” in the “at an inner circumference side of the rotor magnet 40” described above represents “an inner circumference side”, i.e., “a position closer to the shaft” under condition where the drawing is viewed in the same manner as defined above. Meanwhile, in the same manner; a description “an outer circumference side” contrarily represents “a position more distant from the shaft”.
The impeller 20 is a disk-shaped body of revolution equipped with a plurality of blades 22 at an outer circumference, and as FIG. 1 and FIG. 2 show, the impeller 20 includes a ring-shaped blade component 21, a disk-shaped rotor yoke 30 whose outer circumference is equipped with the blade component 21, and a ring-shaped rotor magnet 40 placed at an inner surface side of an outer circumference wall 32 of the rotor yoke 30. The impeller 20 is fixed to the shaft 41, which is supported by the bearing component 50 mounted on the case structural component 60. Thus the impeller 20 is housed within a space that the lid component 10 and the case structural component 60 comprise, and a vortex flow of a fluid can be generated by revolution of the impeller.
The blade component 21 is, a ring-shaped component made of heat resistance plastic (PPS: poly-phenylene-sulfide), for example, and so on; and the blade component is fixed on an outer circumference surface of the outer circumference wall 32 of the disk-shaped rotor yoke 30 with an adhesive material and so on. The blades 22 formed on the blade component 21 are in a form of a plurality of grooves 23 placed along a circumferential direction at an outer circumference of the blade component 21. The grooves 23 are formed at both edge sections, where end surfaces (i.e., upper and lower surfaces) of the blade component 21 intersect with an outer circumference surface, and the grooves are formed by cutting the edge sections of the blade component 21 into fan-shaped forms. No particular restriction exists on the number of the blades 22, and usually the blades are placed at an optional pitch according to the size of the blade component 21.
The rotor yoke 30 is a disk-shaped component at which the blade component 21 is mounted on an outer circumference surface of the outer circumference wall 32; and it is preferable that the rotor yoke is made of a magnetic material such as, for example, an SK material (tool carbon steel) on which anti-corrosion surface treatment is done. The outer circumference surface of the rotor yoke 30 is formed with a dimension that makes it possible to mount the blade component 21. Furthermore, it is preferable that, as FIG. 1 and FIG. 2 show, a protrusion edge part 36 is formed, for example, at a bottom edge of the outer circumference surface, for the purpose of locating the blade component 21 in engagement at a specified position.
The rotor magnet 40 is a ring-shaped component placed at an inner surface side of the outer circumference wall 32 of the rotor yoke 30 by using an adhesive material and so on. For the rotor magnet, a permanent magnet such as, for example, a neodymium-bond magnet and so on is used. The rotor magnet 40 is located at a position which, being under the impeller 20, faces the motor stator 70 placed at an inner circumference side of the rotor magnet 40; and in cooperation with the motor stator 70, the rotor magnet makes the impeller 20 revolve in driving. Preferably used in the present invention is an outer-rotor-type motor in which the rotor magnet 40 positioned at an outer circumference side revolves.
The impeller 20 constructed as described above is fixed to the shaft 41, which is supported by the bearing component 50. No particular restriction exists on a configuration of the bearing component 50. For example, a ball-bearing-type component as shown in FIG. 1 and FIG. 2 is preferably used; but a sleeve-type component, which is not illustrated, can also be used instead.
In cooperation with the lid component 10, the case structural component 60 makes up a space, in which the impeller 20 is housed. The case structural component 60 has the suction port 61 to suck a fluid, a fluid path 63 through which the fluid made into a vortex flow by revolution of the impeller 20 flows, and the discharge port 62 to discharge the fluid. Incidentally, no particular restriction exists on a material for the case structural component 60 and the lid component 10, however, it is preferable that, from the viewpoint of reduction in size and weight, a light metal such as an aluminum material or an aluminum alloy and so on, or a heat resistance plastic material (PPS) is used.
The fluid path 63 constructed by the case structural component 60 and the lid component 10 is formed with a wide width so as to surround a fringe of the blades 22, and a cross-section of the fluid path 63 is shaped into size with which an outer section of the blades 22 is surrounded so as to have a wide clearance. In a configuration example shown in FIG. 2, while having the blades 22 almost located at its center position, the fluid path 63 is formed to be about oval-shaped. At both ends of the fluid path 63, the suction port 61 and the discharge port 62 are formed. In the present invention; when the impeller 20 is revolved, a fluid existing in the grooves 23 that the blade component 21 includes is pressed so as to flow into the fluid path 63 by centrifugal movement, meanwhile a fluid existing in the fluid path 63 is contrarily sucked to flow into the blade component 21, so that the fluid is transferred from the suction port 61 to the discharge port 62 while forming a vortex flow. As a result, usually the fluid path 63 in a vicinity of the suction port 61 is under a negative pressure condition, while the fluid path 63 in a vicinity of the discharge port 62 is under a positive pressure condition
On the case structural component 60 that houses the impeller 20, the lid component 10 is mounted in order to shield a space built up by the lid component 10 and the case structural component 60. For mounting the lid component 10 onto the case structural component 60, various means can be applied. However, from the viewpoint of compact design and low-profile design, as shown in FIG. 1 & FIG. 2, it is preferable that the lid component 10 is welded onto the case structural component 60. For use as a welding method, preferably selected for example is a method; where the case structural component 60 including a protrusion for welding 91 formed on an edge surface 92 that contacts the lid component 10 is used, and the lid component 10 is mounted on the case structural component 60, and then laser radiation (for example, YAG laser and so on) from a position above the lid component 10 is carried out along the protrusion for welding 91 in order to weld together the lid component 10 and the case structural component 60. Furthermore, for use as another welding method, ultrasonic welding can also be applied. Though no particular restriction exists on size of the protrusion for welding 91, a width from 0.5 mm to 2.5 mm and a height from 0.05 mm to 0.15 mm as the size can be exemplified when entirely compact and low-profile design is taken into consideration.
Thus, when a mounting structure for placement of the lid component 10 by welding is applied instead of any other structure such as a conventional screw-fastening structure using an O-ring that is disadvantageous to low-profile design, an entire profile of the vortex pump can be low-profiled. However, if there is a spare space in size, it is still possible to apply any conventional method using an O-ring or a sheet-shaped sealing material (a silicone sheet and so on), a press-fit method, an adhering method that uses an adhesive agent, and so on.
Although FIG. 1 shows an example where a through-hole 90 is formed for the purpose of mounting the vortex pump 1 of the present invention onto another component (such as a substrate not illustrated, and so on) by using a bolt and nut and so forth, no restriction particularly exists on a method of fastening the vortex pump 1.
The motor stator 70 is placed under the case structural component 60 and at an inner circumference side of the rotor magnet 40. In a stator yoke 71 included in the motor stator 70; a wire winding section for forming a wire-wound coil, i.e., a protruded pole part 711, is placed at certain intervals, and then a wire-wound coil 72 is formed in the wire winding section. In the present application, an example where 9 wire winding sections are uniformly laid out is exemplified, as FIG. 1 and FIG. 3 show. An outer circumference surface of the protruded pole part 711 of the motor stator 70 is placed at a position that faces the rotor magnet 40. Then, in order to make it possible to restrain the impeller 20 from vibrating, a center level in a thickness direction of the rotor magnet 40 is located a bit higher than a center level in a thickness direction of the stator yoke 71, namely, of the protruded pole part 711. Incidentally, size of the stator yoke 71 corresponds to what can be housed in a lower space of the case structural component 60, as shown in FIG. 3. Furthermore, it is preferable that a material of the stator yoke is a magnetic material, as the foregoing material of the rotor yoke 30 of the impeller 20 is.
Described next is a characteristic structure of the present invention, i.e., an adhering configuration of the adhesive material 69 to be glued onto the motor stator side surface of the case structural component 60. A wall in a thrust direction (hereinafter called a thrust-direction wall 66) of the case structural component 60 is designed to be, for example, about at least 0.2 mm and thinner than 1.0 mm in thickness for the purpose of realization of further-low-profile design of a vortex pump. When the thin thrust-direction wall 66 is made to be even thinner, micro vibration during revolution of the impeller 20 causes sympathetic vibration with the thin-walled thrust-direction wall 66 so as to generate a large noise that becomes a significant problem especially in a case where the pump is used for a portable device and so on. In the present invention, as shown in FIG. 2 to FIG. 5, a construction is given in such a way that the motor stator side surface 65 of the case structural component 60 adheres to and gets fixed to the motor stator, or in other words, the motor stator side surface is covered with the adhesive material 69 in order to solve the problem described above.
That is to say, it is preferable in the present invention that strength of the thin thrust-direction wall 66 be increased by covering the motor stator side surface 65 of the case structural component 60, without any void part, with the adhesive material 69 so that, despite micro vibration during revolution of the impeller 20, no sympathetic vibration with the thrust-direction wall 66 is caused. The adhesive material 69 preferably covers the motor stator side surface 65 (hereinafter called “the wall surface 65” in short), without any void part. In this occasion, “to cover the surface without any void part” means that: if the wire-wound coil 72 which is a structural component of the motor stator 70 does not contact the wall surface 65, only the adhesive material covers the wall surface 65 without any void part; meanwhile if a structural component of the motor stator 70 (for example, the wire-wound coil 72) contacts the wall surface 65, the adhesive material covers any other section, without any void part, except a section where the wire-wound coil 72 and the wall surface 65 contact each other so that the adhesive material 69 cannot enter there.
The adhesive material is to be used for the purpose of fixing the motor stator 70 to the lower space of the case structural component 60 by applying the adhesive material. For use as the adhesive material, various kinds of adhesive materials, for example epoxy-base materials, acryl-base materials and so on, can be used; including furthermore, one-component type adhesive materials as well as two-component reactive type adhesive materials and light-curable type adhesive materials, without any restriction on the type indeed. After all, an important point is that viscosity and other properties of the adhesive material are controlled in order to make it possible to cover the motor stator side surface 65 of the case structural component 60, without any void part.
Usually, as shown in FIG. 3A and FIG. 3B, the motor stator 70 is pressed into the lower space of the case structural component 60 until the wire-wound coil 72 of the motor stator 70 contacts the wall surface 65, and then the adhesive material 69 is fed through a void space of the wire-wound coil 72 so that the adhesive material 69 is applied evenly all over the wall surface 65. By the way, the motor stator 70 is pressed into the lower space while contacting an outer circumference wall (hereinafter called a “radial-direction wall 67”) of the case structural component 60 and/or a shaft side wall (hereinafter called a “shaft side wall 68”) of the case structural component 60. Therefore, the motor stator does not move even without any adhesive material, and furthermore the motor stator does not move while the adhesive material 69 is being charged and/or hardened.
Thus, the adhesive material 69 covering the wall surface 65 may be placed, as FIG. 2 shows for example, so as to cover a position of the stator yoke 71 included in the motor stator 70, namely a position of the protruded pole part 711, so that an entire part of the protruded pole part 711 adheres to and gets fixed to the motor stator side surface 65 of the case structural component 60 with the adhesive material 69. Furthermore, the adhesive material may be placed, as FIG. 4 shows for example, so as to have a thickness that is thinner than a thickness of the stator yoke 71 included in the motor stator 70 so that only the wire-wound coil 72 adheres to and gets fixed to the motor stator side surface 65 of the case structural component 60 with the adhesive material 69. Still further, it is also possible, as FIG. 5 shows, to cover an entire part of the motor stator 70 with the adhesive material. In order to fix the motor stator 70 to the lower space of the case structural component 60 by using the adhesive material 69, it is possible only to drop the adhesive material at several spots for each wire-wound coil 72 or each combination of the wire-wound coil 72 and protruded pole part 711. However, to surely restrain the thin thrust-direction wall 66 from having any sympathetic vibration, it is preferable that a configuration is made up so as to have no exposure of the wall surface 65 and have the wall surface 65 contacted by at least one of the adhesive material 69 and any structural component of the motor stator 70. In order to surely restrain the thrust-direction wall 66 from having any sympathetic vibration, it is preferable that the adhesive material 69 covers the wall surface 65 with thickness of the adhesive material that is greater than 1.0 mm including thickness of the thrust-direction wall 66.
Incidentally, sympathetic vibration of the case structural component 60 mainly comes up at the thrust-direction wall 66, and therefore no restriction exists on an adhesive material that covers other sections including the radial-direction wall 67 and the shaft side wall 68 so that various adhering configuration can be applied for those sections. With the vortex pump 1 constructed as described above, low-profile design can be realized as an entire profile of the pump, and eventually a low-shaped vortex pump can be provided while securing stable revolution of the pump for a long time.
Described next is another preferred embodiment of the present invention. In a configuration shown in FIG. 5 described above, the adhesive material 69 is charged so as to cover the motor stator 70. Meanwhile, FIG. 6 is an explanatory drawing to show an example of a configuration including an integral-type (which can also be expressed as “embedded-type”) case structural component 75 in which the motor stator 70 is embedded.
In a vortex pump of the present invention, as shown in FIG. 6, the integral-type case structural component 75, in which the motor stator 70 is integrated with a case structural component, can also be used as a structural component of the vortex pump 1. The integral-type case structural component 75 is usually formed through an integral molding process; in which a metal mold for injection molding provided with a specified shape is prepared, and the motor stator 70 is placed in the metal mold for injection molding, and then a mold resin material is injected through an injection gate into the metal mold to make up the integral-type case structural component. Therefore, the integral-type case structural component 75 shown in FIG. 6 corresponds to a configuration in which the adhesive material 69 in the configuration of FIG. 5 is replaced with the same material as a structural resin material of the case structural component 60. Incidentally, a structure of any other section of the vortex pump of this configuration is the same as what is described by using FIG. 1 and so on, and therefore the same reference numerals are used in the drawing and explanation is omitted.
In the same manner as described above, a vortex pump using the integral-type case structural component 75 is a pump in which a fluid (gas or liquid) is introduced from the suction port 61 and discharged from the discharge port 62; and the pump is equipped with; the impeller 20 that includes the plurality of blades 22 at an outer circumference and the rotor magnet 40 placed at an inner circumference; the shaft 41 fixed at a center of the impeller 20; the bearing component 50 (supplied as the couple of ball bearings 50 a and 50 b) placed at an outer circumference of the shaft 41; the motor stator 70 placed under the impeller 20 and at an inner circumference side of the rotor magnet 40; the integral-type case structural component 75 having the suction port 61 and the discharge port 62 that works to house the impeller 20 and furthermore to embed the motor stator 70; and the lid component 10 placed on the integral-type case structural component 75 that houses the impeller 20.
A feature of a vortex pump according to this configuration includes; having the integral-type case structural component 75, and thickness “T” of a wall (thrust-direction wall) 66 of the integral-type case structural component 75 positioned at a side dividing the impeller 20 and the motor stator 70, with which it becomes possible to restrain sympathetic vibration of the thrust-direction wall 66. In the integral-type case structural component 75 of a configuration shown in FIG. 6, the thickness “T” of the thrust-direction wall 66 is expressed as a distance between the wall surface 65 of the wire-wound coil 72, positioned at a side of the impeller, and a surface of a side facing the impeller 20 in the motor stator 70. The vortex pump according to the configuration does not have sympathetic vibration of the thrust-direction wall 66 caused. Even if the thickness “T” of the thrust-direction wall 66 is thin, sympathetic vibration of the thrust-direction wall 66 can be restrained. Therefore, compact design and low-profile design of the vortex pump can be achieved.
Described next are circular protruded sections (i.e., reference numerals of 31, 32, 55 and 56). As shown in FIG. 2, the circular protruded sections (the reference numerals of 31, 32, 55 and 56) centered at the shaft 41 are placed at an outer circumference section, which is outside a position including an outer race of a ball bearing as the bearing component 50, and including at least a lower surface of a motor stator side of the impeller 20. The circular protruded sections play a sealing role in preventing a lubricant material from evaporating or scattering away into an outer circumference direction of the impeller 20 when the bearing component 50 is supplied with the lubricant material, such as grease and so on. The reason why the expression “at least” is used in the above explanation is that the condition includes not only a case where the circular protruded sections are placed at the lower surface of the impeller 20 at the motor stator side but also another case where the circular protruded sections are placed at both the lower surface of the impeller 20 at the motor stator side and a surface of another component facing the objective surface.
Adequate condition is to have at least one circular protruded section (at least one of a first protruded section 31 and a second protruded section 32) at the lower surface of the impeller 20 at the motor stator side. However, it is preferable that; particularly (1) at least one couple of protruded sections facing each other are placed, like a couple of the first protruded section 31 and a third protruded section 55 or another couple of the second protruded section 32 and a fourth protruded section 56; and still further it is preferable that; (2) two or more couples of protruded sections in which the protruded sections face each other are prepared as FIG. 2 shows. These circular protruded sections (the reference numerals of 31, 32, 55 and 56) play a sealing role in preventing the lubricant material from evaporating or scattering away, as described above, and the circular protruded sections also have an effect on prevention against any fluid to get into the shaft 41.
More specifically, as shown in FIG. 2, two circular-shaped protrusion sections, i.e., the first protruded section 31 and the second protruded section 32 are formed at a lower surface of the motor stator side of the disk-shaped rotor yoke 30 included in the impeller 20 while being provided with a specified clearance (for example, a clearance of 1 mm). On the other hand, at an opposite side facing the first protruded section 31 and the second protruded section 32; two circular-shaped protrusion sections, i.e., the third protruded section 55 and the fourth protruded section 56, having the same circular-shaped profiles as the first protruded section 31 and the second protruded section 32 have, are formed at each position opposite to the first protruded section 31 and the second protruded section 32 while being provided with a specified clearance (for example, a clearance of 1 mm). A clearance between the first protruded section 31 and the third protruded section 55 as well as another clearance between the second protruded section 32 and the fourth protruded section 56 are each approximately 200 microns. A first space 58 and a second space 59; surrounded by the protruded sections of 31, 32, 55 and 56; function as a sealing section 590. The sealing section 590 is preferably filled with a lubricant material, such as grease and so on, as described above. Filling the first space 58 with a lubricant material, such as grease and so on, makes it possible to prevent evaporating or scattering away of a lubricant material out of a bearing component section at an inner side and furthermore to prevent a fluid coming in out of an outer side and also preferably a liquid coming in. Thus, the sealing section 590 prevents the lubricant material charged in the second space 59 at the bearing component side from evaporating or scattering away in order to secure good lubricating condition of the shaft and the bearing component. Moreover, the sealing section 590 can effectively prevent a fluid from getting into the shaft 41.
In the embodiment shown in FIG. 2, the fourth protruded section 56 is formed to be circular on a surface of the case structural component 60 at a side of the rotor yoke 30, while the third protruded section 55 is constructed by an upper end of a ring component 54 mounted at a surface of the case structural component 60 at a side of the bearing component 50.
By the way, in FIG. 2, the sealing section 590 is formed at, or in a vicinity of the bearing component. When the protruded sections of the sealing section are formed at any other position, e.g., at around a middle position toward a circumferential edge of the rotor yoke 30, or at an outer circumference side; the sealing section becomes preferred as far as run-out and tilt of the impeller 20 are concerned. When the protruded sections are located at an outer circumference position, a better effect is especially expected. However, it is usually preferable that the sealing section is formed at or in a vicinity of the bearing component, as shown in FIG. 2. The reason is that forming the protruded sections at such a position is relatively easier in terms of thickness of components; and furthermore when the protruded sections are formed at an outer circumference position, grease and so on of the sealing section 590 becomes a resistance to revolving operation and creates a load, so that effective revolving operation with low power consumption is hampered.
Furthermore, although a configuration in which the circular protruded sections are placed is explained as a preferred one in the embodiment described above, a labyrinth structure including a plurality of combinations of protruded sections and caved section may be used instead of such a configuration.
Explained next is an effect of the present invention in a case where a ball bearing is used as the bearing component 50. FIG. 7 is an explanatory drawing to describe a preload “F” given onto the bearing component 50 constructed with the couple of ball bearings of 50 a and 50 b that are stacked up. Outer circumference rings of the ball bearings of 50 a and 50 b are fixed to the ring component 54 mounted onto the case structural component 60 by using an adhesive material and so on at a side of the bearing component 50, while inner rings of the ball bearings of 50 a and 50 b are fixed to the shaft 41.
As described above, the center level in the thickness direction of the rotor magnet 40 is located a bit higher than the center level in the thickness direction of the stator yoke 71. Therefore, while the impeller 20 is revolving, a downward force “F” acts on the impeller. Since the force “F” acts so as to press the shaft 41 downward, other downward forces “F1” and “F3” also act on inner circumference rings of the ball bearings of 50 a and 50 b that are fixed to the shaft 41. Furthermore, other downward forces “F2” and “F4” also act on balls included in the ball bearings of 50 a and 50 b.
By operations of the forces “F1” and “F3 as well as “F2” and “F4” described above, a load (preload) is given to upper contacting sections “P” and “R” between the inner circumference rings and balls included in the ball bearings of 50 a and 50 b, while a load (preload) is given to lower contacting sections “Q” and “S” between the inner circumference rings and balls included in the ball bearings of 50 a and 50 b. Since the loads (preloads) given to the upper contacting sections “P” and “R” as well as the lower contacting sections “Q” and “S” stabilize revolving operations of the ball bearings of 50 a and 50 b, revolution free from any play can be realized.
In the bearing component 50 configured as shown in FIG. 7, a ratio of length “L” of the bearing component to inner diameter “D” thereof (LID) is usually 2 or greater. However, in a vortex pump of the present invention, because of actions of the loads (preloads) given to the upper contacting sections “P” and “R” as well as the lower contacting sections “Q” and “S”, revolution of the impeller 20 can be stabilized, and furthermore reduction in size and weight can be realized. Consequently, it also becomes possible to make the ratio “L/D” less than 2.0 (as a matter of course, it is possible to make it 2.0 or greater).
While the foregoing description and drawings represent the present invention, it will be obvious to those skilled in the art that various changes may be made therein without departing from the true spirit and scope of the present invention.

REFERENCE NUMERALS

1. Vortex Pump
10. Lid Component
20. Impeller
21. Blade Component
22. Blades
23. Grooves
30. Rotor Yoke
31. & 32. Protruded sections
36. Protrusion Edge Part
40. Rotor Magnet
41. Shaft
50. Bearing Component
50 a & 50 b. Ball bearings
54. Ring Component
55. & 56. Protruded sections
58. First Space
59. Second Space
60. Case Structural Component
61. Suction Port
62. Discharge Port
63. Fluid Path
64. Lead Wire Path
65. Motor stator side surface of the case structural component
66. Wall of the case structural component (Thrust-direction wall)
67. Outer circumference wall of the case structural component (Radial-direction wall)
68. Shaft side wall of the case structural component (Shaft side wall)
69. Adhesive Material
70. Motor Stator
71. Stator Yoke
72. Wire-Wound Coil
75. Integral-type case structural component
80. Substrate
90. Through-Hole
91. Protrusion for Welding
92. Edge Surface
P. & R. Upper contacting sections
Q. & S. Lower contacting sections
F, F1, F2, F3, & F4. Forces

Claims

1. A vortex pump comprising:

an impeller that includes a plurality of blades at an outer circumference and a rotor magnet placed at an inner circumference;

a shaft fixed at a center of the impeller;

a bearing component placed at an outer circumference of the shaft;

a motor stator placed at an inner circumference side of the rotor magnet; and

a case structural component having a suction port and a discharge port that functions to house the impeller and furthermore to divide the impeller and the motor stator;

wherein a motor stator side surface of the case structural component is covered with an adhesive material to cause the motor stator to adhere to the motor stator side surface.

2. The vortex pump according to claim 1 wherein thickness of a wall of the case structural component at a side, which divides the impeller and the motor stator, is at least 0.2 mm and thinner than 1.5 mm.

3. The vortex pump according to claim 1 wherein the bearing component is a ball bearing, and a circular protruded section centered at the shaft is placed at an outer circumference section, which is outside a position including an outer race of the ball bearing and at a lower surface of a motor stator side of the impeller.

4. The vortex pump according to claim 1 wherein a lid component placed on the case structural component that houses the impeller is welded onto the case structural component.

5. A vortex pump comprising:

a shaft fixed at a center of the impeller;

a bearing component placed at an outer circumference of the shaft;

a motor stator placed at an inner circumference side of the rotor magnet; and

a case structural component having a suction port and a discharge port that works to house the impeller and furthermore to divide the impeller and the motor stator;

wherein the motor stator is adhered and fixed with an adhesive material onto a surface of the case structural component that faces the motor stator.

6. The vortex pump according to claim 5 wherein the motor stator is equipped with a protruded pole part in which a wire-wound coil is formed, and at least all the wire-wound coil is adhered and fixed with an adhesive material onto a surface of the case structural component that faces the motor stator.

7. The vortex pump according to claim 6 wherein all the wire-wound coil and the protruded pole part are adhered and fixed with an adhesive material onto a surface of the case structural component that faces the motor stator.

8. The vortex pump according to claim 6 wherein thickness of a wall of the case structural component at a side, which divides the impeller and the motor stator, is at least 0.2 mm and thinner than 1.5 mm.

9. The vortex pump according to claim 8 wherein the motor stator is equipped with a protruded pole part in which a wire-wound coil is formed, and all the wire-wound coil and the protruded pole part are embedded with a resin material so as to construct the integral-type case structural component.

10. The vortex pump according to claim 6 wherein the bearing component is a ball bearing, and a circular protruded section centered at the shaft is placed at an outer circumference section, which is outside a position including an outer race of the ball bearing and at a lower surface of a motor stator side of the impeller.

11. A vortex pump comprising:

a shaft fixed at a center of the impeller;

a bearing component placed at an outer circumference of the shaft;

a motor stator placed under the impeller and at an inner circumference side of the rotor magnet; and

an integral-type case structural component having a suction port and a discharge port, which functions to house the impeller, and furthermore in which the motor stator is embedded.