JP2009008055A - Thin electric pump - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a thin electric pump serving as a circulating pump for cooling fluid of a notebook-size personal computer or the like required to be thin and capable of satisfy requirement for thinning of a higher order. <P>SOLUTION: The centrifugal type thin electric pump 1 having a thin and flat outside configuration is stored in a pump chamber A with an impeller 4 rotatably supported. The impeller 4 is equipped with a plurality of blades 5 and is rotatably supported through a slide bearing 7 on a hollow fixed shaft 6 erectly provided at a central part of a base 2. A magnet 8 is attached to a wall surface on an opposite side of the impeller 4 from a side equipped with the plurality of blades 5 and a coil 9 is provided in the base 2 to face the magnet 8 while being embedded by resin mold in the base 2 made of synthetic resin. A passage 10 for letting the cooling fluid flow in the pump chamber A is formed in a wall of the base 2 to communicate with a hollow passage 6a of the hollow fixed shaft 6. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The invention of the present application relates to a thin electric pump, and in particular, the thin electric pump is further reduced in thickness, and is preferably used as a cooling fluid circulation pump for various electronic devices such as notebook computers that are required to be thin. About.

  Conventionally, a centrifugal electric pump 01 having a thin flat outer shape as shown in FIG. 6 is used as a cooling fluid circulation pump for various electronic devices such as notebook computers that are required to be thin. Yes. In the electric pump 01, an impeller 04 is rotatably supported and accommodated in a pump chamber A sealed by a base 02 and a casing 03. The impeller 04 is provided with a plurality of blades 05 for imparting centrifugal force to the cooling fluid at equal intervals in the circumferential direction, and a fixed shaft 06 erected at the center of the base 02 via a slide bearing 07. And is rotatably supported. The majority of the fixed shaft 06 is embedded in the central portion of the synthetic resin base 02 by a resin mold, and is erected there.

  The cooling fluid passage 010 is formed in the ceiling wall of the casing 03 above the impeller 04 so as to open toward the center of the impeller 04. The opening of the portion facing the central portion of the impeller of the passage 010 formed in this way is indicated by reference numeral 012. The cooling fluid flows through the passage 010 from the inlet 011 to the opening 012 facing the center of the impeller, and flows into the pump chamber A therefrom.

  The motor unit that rotates the impeller 04 is configured as follows. A magnet 08 is attached to the inner peripheral surface of the cylindrical skirt portion 04a on the outer peripheral portion of the impeller 04. The coil 09 is embedded in the base 02 with a resin mold so as to face the magnet 08 in the radial direction. Actually, the magnet 08 includes a magnet yoke, and the coil 09 is wound and fixed around a back yoke (stator core) and embedded in the base 02, but these magnet yoke and back yoke are not shown. . These magnet 08, magnet yoke, coil 09, and back yoke constitute a radial gap type electric motor (motor).

  Therefore, now, when the coil 09 is energized, a rotational torque is applied to the magnet 08 by the drive magnetic field formed thereby, and the impeller 04 rotates. Then, the cooling fluid in the pump chamber A is pressurized and discharged from the discharge port 013 through the discharge passage connected to the pump chamber A.

  Here, in the conventional radial gap type electric motor 01 as described above, the passage 010 for allowing the cooling fluid to flow into the pump chamber A is provided in the ceiling wall of the casing 03 above the impeller 04. Since it is formed so as to open toward the center portion, the thickness of the casing 03 is increased by the size of the passage 010, making it difficult to meet the demand for thinning. For this reason, although it varies depending on the pump size, in one example, it has been the limit to reduce the thickness of the pump 01 to about 9 mm. Such a problem arises when a structure is adopted in which a passage 010 for allowing the cooling fluid to flow into the pump chamber A is formed by piping and the piping is fixed to the casing 03 or fixed thereto. It will be even bigger.

Some passages for allowing the cooling fluid to flow into the pump chamber are formed on the coil and stator core side below the impeller so as to pass through them (Patent Document 1). Is connected to the inflow passage wall in parallel with the impeller rotation shaft, so that it is difficult to make the pump thinner.
JP 2000-145682 A

  The invention of the present application solves the above-mentioned problems of conventional thin electric pumps, and further thinning them, and higher-order thinning of various electronic devices such as notebook personal computers that are required to be thinned. It is an object of the present invention to provide a thin electric pump that can meet the demands of making it easier.

  The above problems can be solved by the following invention described in each claim of the present application. That is, according to the first aspect of the present invention, an impeller is rotatably supported and accommodated in a sealed pump chamber surrounded by a base and a casing, and the impeller is cooled in the pump chamber. A plurality of blades for applying centrifugal force to the working fluid are provided at equal intervals in the circumferential direction, and are rotatably supported via a slide bearing on a hollow fixed shaft standing at the center of the base. In the centrifugal thin electric pump having a thin flat outer shape, a magnet is attached to a wall surface of the impeller opposite to the side provided with the plurality of blades, and the base A coil is embedded in the synthetic resin base with a resin mold so as to face the magnet, and a passage for allowing cooling fluid to flow into the pump chamber is provided. So as to communicate with the hollow portion passageway of said hollow fixed shaft, a thin electric pump, characterized in that it is formed in a wall body of the base.

  Since the invention described in claim 1 is configured as described above, a passage for allowing the cooling fluid to flow into the pump chamber can be taken into the wall of the base, and piping for forming the passage is provided. Therefore, the thickness of the thin electric pump can be further reduced.

  The invention described in claim 2 is the thin electric pump according to claim 1, wherein the passage for allowing the cooling fluid to flow into the pump chamber is in the wall of the base, and the circumferential direction of the coil It is characterized by being formed in the intermittent part.

  According to the second aspect of the present invention, with this configuration, a passage for allowing the cooling fluid to flow into the pump chamber can be easily formed in the wall of the base, and the thin electric pump can be further reduced in thickness. become.

  The invention described in claim 3 is the thin electric pump according to claim 1 or 2, wherein the inner wall surface of the casing faces the opening of the hollow fixed shaft so that the hollow fixed shaft is hollow. A short cylindrical or dome-shaped shroud having an inner diameter larger than the inner diameter of the section is suspended from the opening of the hollow fixed shaft, leaving a predetermined gap in the axial direction.

  According to the third aspect of the invention, with this configuration, the cooling fluid flowing out of the opening of the hollow fixed shaft and flowing into the pump chamber can be rectified by the shroud and efficiently flow radially into the impeller. Since the fluid leaking into the gap between the casing and the impeller can be lost, the pump efficiency can be improved.

  Further, the invention described in claim 4 is the thin electric pump according to any one of claims 1 to 3, wherein the impeller has a wall surface on the side opposite to the side on which the plurality of blades are provided. A first auxiliary magnet is attached along the peripheral edge, and a second auxiliary magnet is attached to the base so as to face the first auxiliary magnet along the outer peripheral edge thereof. The magnet and the second auxiliary magnet are characterized in that the same poles are opposed to each other.

  In the invention described in claim 4, the first auxiliary magnet and the second auxiliary magnet are repelled by this configuration, so that a force for separating the impeller from the base is generated. This force is generated when the motor model of the thin electric pump is changed to the axial gap type, and the rotor magnet (the magnet attached to the impeller) and the stator part (the back yoke embedded in the base and the winding around it)・ A large axial magnetic force acting between the fixed coil) and the thrust bearing of the slide bearing is alleviated, preventing an increase in the size of the slide bearing and improving durability. In addition, the sliding frictional resistance can be reduced to reduce power consumption.

  As described above, according to the thin electric pump of the invention of the present application, the passage for allowing the cooling fluid to flow into the pump chamber can be taken into the wall of the base, and the thickness of the pipe for forming the passage can be reduced. Therefore, it is possible to further reduce the thickness of the thin electric pump.

  Further, when the passage for allowing the cooling fluid to flow into the pump chamber is formed in the circumferential wall intermittent portion of the coil in the base wall, the cooling fluid is allowed to flow into the pump chamber. The passage can be easily formed in the wall of the base, and the thin electric pump can be further thinned.

  Further, a short cylindrical or dome-shaped shroud having an inner diameter larger than the inner diameter of the hollow portion of the hollow fixed shaft is formed on the inner wall surface of the casing so as to face the opening of the hollow fixed shaft. In the case of being suspended in a predetermined gap in the axial direction, the cooling fluid flowing out of the opening of the hollow fixed shaft and flowing into the pump chamber is rectified by the shroud and efficiently flows radially into the impeller. Since the fluid leaking into the gap between the casing and the impeller can be lost, the pump efficiency can be improved.

  Further, a first auxiliary magnet is attached to the wall surface of the impeller opposite to the side provided with the plurality of blades along the outer peripheral edge, and the first auxiliary magnet is attached to the base along the outer peripheral edge. The second auxiliary magnet is attached so as to face the auxiliary magnet of the first auxiliary magnet, and when the same polarity of the first auxiliary magnet and the second auxiliary magnet is opposed to each other, the first auxiliary magnet is attached. Since the auxiliary magnet and the second auxiliary magnet repel each other, a force is generated to pull the impeller away from the base, but this force is changed from the motor type of the thin electric pump to the axial gap type. The rotor magnet (the magnet attached to the impeller) and the stator (the back yoke embedded in the base, and the winding / fixing) To reduce the load on the thrust bearing portion of the slide bearing, thereby preventing an increase in the size of the slide bearing and improving its durability. In addition, the sliding frictional resistance can be reduced and the power consumption can be reduced.

  An impeller is rotatably supported and accommodated in a sealed pump chamber surrounded by a base and a casing, and the impeller includes a plurality of blades for applying centrifugal force to a cooling fluid in the pump chamber. Is a centrifugal type thin electric pump having a thin flat outer shape that is rotatably supported via a slide bearing on a hollow fixed shaft standing in the center of the base. Is configured as follows.

  A magnet is attached to the wall surface of the impeller opposite to the side provided with a plurality of blades, and the coil is embedded in the base made of synthetic resin by a resin mold so as to face the magnet. Provide as follows. Further, a passage for allowing the cooling fluid to flow into the pump chamber is formed in the wall of the base so as to communicate with the hollow portion passage of the hollow fixed shaft. In this case, the passage is formed in the wall of the base and in the intermittent portion in the circumferential direction of the coil.

  On the inner wall surface of the casing, a short cylindrical or dome-shaped shroud having an inner diameter larger than the inner diameter of the hollow portion of the hollow fixed shaft so as to be opposed to the opening of the hollow fixed shaft is axially aligned with the opening of the hollow fixed shaft. Leaving with a predetermined gap left.

  Further, a first auxiliary magnet is attached to the wall surface of the impeller opposite to the side provided with the plurality of blades along the outer peripheral edge, and the first auxiliary magnet is attached to the base along the outer peripheral edge. A second auxiliary magnet is attached so as to face the auxiliary magnet. In this case, the first auxiliary magnet and the second auxiliary magnet have the same polarity facing each other.

Next, an embodiment (Embodiment 1) of the present invention will be described.
FIG. 1 is a perspective sectional view of the thin electric pump of the first embodiment, FIG. 2 is a perspective view of an impeller that is a component of the thin electric pump, and FIG. 3 is a stator portion that is a component of the thin electric pump. FIG. 4 is a diagram showing various shapes of shrouds that are suspended from the casing inner wall surface of the thin electric pump and used to rectify the cooling fluid. .

  The thin electric pump of the first embodiment is suitably used as a cooling fluid circulation pump for various electronic devices such as laptop computers that are particularly required to be thin. However, the present invention is not limited to this, and the present invention can be used as a circulating fluid circulation pump for various devices and apparatuses that require similar thinning.

  As shown in FIG. 1, the thin electric pump 1 according to the first embodiment is thin (FIG. 1 is enlarged for easy understanding). A centrifugal electric pump having a flat outer shape. The structure of the pump is as follows. An impeller 4 is rotatably supported and accommodated in a pump chamber A enclosed by a base 2 and a casing 3 and sealed. As shown in FIG. 1 and FIG. 2, a hollow fixed shaft provided with a plurality of blades 5 for imparting centrifugal force to the cooling fluid at equal intervals in the circumferential direction and erected in the central portion of the base 2 6 is rotatably supported via a slide bearing 7. A magnet 8 is attached to the wall surface of the impeller 4 on the side opposite to the side where the plurality of blades 5 are provided, and the base 2 is opposed to the magnet 8. The coil 9 is provided by being embedded in a synthetic resin base 2 by a resin mold. The impeller 4 and the magnet 8 constitute a rotor portion of an electric motor (motor) that operates the thin electric pump 1.

  The passage 10 for allowing the cooling fluid to flow into the pump chamber A is formed in the wall of the base 2 so that the tip dead end portion communicates with the hollow portion passage 6 a of the hollow fixed shaft 6. The coil 9 is not embedded in the base 2 at the place where the passage 10 is formed in the wall of the base 2, and the intermittent portion 18 of the coil 9 that is missing the coil 9 in the circumferential direction of the base 2 only here. (See FIG. 3). As shown in detail in FIG. 3, the coil 9 is wound and fixed around the back yoke 17 and is embedded in the base 2 by a resin mold. The coil 9 and the back yoke 17 constitute a stator portion of an electric motor (motor) that operates the thin electric pump 1.

  Note that the cross section of the coil 9 does not appear in the cross section cut perpendicularly to the back yoke 17 at the position where the passage 10 is formed in the wall of the base 2 as is apparent from FIG. Therefore, in FIG. 1, the coil 9 is drawn by a two-dot chain line, which shows that the coil 9 is located at some position on the circumference passing through the position as an imaginary line. .

  As shown in FIG. 1, the inlet vent portion 19 having a fluid inlet side passage connected to the passage 10 is formed integrally with the casing 3, and the outer end protruding in the radial direction has a flow of cooling fluid. The inlet 11 is connected to an external pipe (not shown).

  The hollow fixed shaft 6 has a cylindrical shape with a flange, and a part of the flange (flange) is buried in the base 2 and is erected at the center of the base 2. Also, the slide bearing 7 attached to the hollow fixed shaft 6 has a cylindrical shape with a flange similarly to the hollow fixed shaft 6, and the flange (flange) portion constitutes a thrust bearing portion.

  A short cylindrical or dome-shaped shroud 14 having an inner diameter larger than the inner diameter of the hollow portion of the hollow fixed shaft 6 is hollowly fixed to the inner wall surface of the casing 3 so as to face the opening of the hollow fixed shaft 6. The shaft 6 is vertically suspended integrally with the opening of the shaft 6 so as to leave a predetermined gap in the axial direction. The size of the gap is such that the cooling fluid flowing out of the opening of the hollow fixed shaft 6 and flowing into the pump chamber A does not leak directly into the gap between the casing 3 and the impeller 4 in a short circuit. Set appropriately.

  FIG. 4 illustrates various shapes of the shroud 14. (A) is an example in which the shroud 14 is formed in a cylindrical shape. Moreover, both (b) and (c) are examples in which the shroud 14 is formed in a dome shape. In these cases, the inner surface of the shroud 14 is formed in a dome shape. There is a difference between (b) and (c) whether the lower end of the shroud 14 has a sharp shape ((b)) or a shape with an annular surface left ((c)). In (b) and (c), the outer peripheral surface may be formed in a cylindrical shape. In order to rectify the cooling fluid in the pump chamber A by the shroud 14 and efficiently flow it radially into the impeller 4, it is desirable to select the shape (b) or (c).

Next, the operation of the thin electric pump 1 of the first embodiment will be described.
Now, when the coil 9 is energized from an external drive circuit (not shown), a rotational torque is applied to the magnet 8 by the drive magnetic field formed thereby, and the impeller 4 rotates. Then, the cooling fluid in the pump chamber A is pressurized and discharged from the discharge port 13 through the discharge passage connected to the pump chamber A. At the same time, a new cooling fluid is sucked into the pump chamber A through the inlet 11, the passage 10, and the hollow portion passage 6 a of the hollow fixed shaft 6. The cooling fluid flowing into the pump chamber A is rectified by the shroud 14, flows uniformly into the impeller 4 radially, and is pressurized by the impeller 4. In this way, the cooling action of the cooling fluid is continued.

Since the thin electric pump 1 of the first embodiment is configured as described above, the following effects can be obtained.
Since the passage 10 for allowing the cooling fluid to flow into the pump chamber A can be taken into the wall of the base 2 and the thickness of the pipe for forming the passage can be suppressed, the thin electric pump 1 Further thinning becomes possible. In this case, the passage 10 is formed in the wall of the base 2 and is formed in the intermittent portion of the coil 9 in the circumferential direction. Therefore, the passage 10 can be easily formed in the wall of the base 2. In addition, the thin electric pump 1 can be further reduced in thickness. According to an example, the thickness of the conventional thin electric pump 01 is limited to about 9 mm, but the thickness of the thin electric pump 1 of the first embodiment is about 7.5 mm. It was possible to reduce the thickness.

  A short cylindrical or dome-shaped shroud 14 having an inner diameter larger than the inner diameter of the hollow portion of the hollow fixed shaft 6 is hollowly fixed to the inner wall surface of the casing 3 so as to face the opening of the hollow fixed shaft 6. The cooling fluid flowing out of the opening of the hollow fixed shaft 6 and flowing into the pump chamber A is rectified by the shroud 14 because it is suspended from the opening of the shaft 6 so as to leave a predetermined gap in the axial direction. Since the fluid can efficiently flow radially into the impeller 4 and the fluid leaking directly into the gap between the casing 3 and the impeller 4 can be lost, the pump efficiency can be improved.

Next, another embodiment (embodiment 2) of the present invention will be described.
FIG. 5 is a perspective cross-sectional view of the thin electric pump according to the second embodiment. Parts corresponding to those of the thin electric pump according to the first embodiment are denoted by the same reference numerals.

  In the thin electric pump 1 ′ of the second embodiment, as shown in FIG. 5, along the outer peripheral edge of the impeller 4 on the wall surface opposite to the side on which the plurality of blades 5 are provided. One auxiliary magnet 15 is attached. A second auxiliary magnet 16 is attached to the base 2 so as to face the first auxiliary magnet 15 along the outer peripheral edge thereof. In this case, the first auxiliary magnet 15 and the second auxiliary magnet 16 have the same polarity, for example, the N-pole and the N-pole are opposed to each other as described above. It is attached. Since these magnets are attached in this way, these magnets repel each other, and a force for pulling the impeller 4 away from the base 2 is generated. Note that the outer peripheral edge of the same wall surface of the impeller 4 to which the first auxiliary magnet 15 is attached is naturally located outward in the radial direction from the position where the magnet 8 is attached to the same wall surface.

  The thin electric pump 1 ′ according to the second embodiment is different from the thin electric pump 1 according to the first embodiment in the above points, but there is no difference in other points, and thus detailed description thereof is omitted.

Since the thin electric pump 1 ′ of the second embodiment is configured as described above, the following effects can be achieved.
The force for pulling the impeller 4 away from the base 2 is generated when the motor type of the thin electric pump 1 'is changed from the conventional radial gap type to the axial gap type, which is a rotor magnet (attached to the impeller 4). Axial direction acting between the stator 8 (the back yoke 17 embedded in the base 2 and the coil 9 wound and fixed thereto) corresponds to this. Since the large magnetic attraction force is alleviated and the load on the flange (flange portion) that becomes the thrust bearing portion of the slide bearing 7 is reduced, the slide bearing 7 can be prevented from being enlarged and the durability can be improved. . Moreover, the sliding frictional resistance of the slide bearing 7 can be reduced, and the power consumption can be reduced.

  The invention of the present application is not limited to the above embodiments, and various modifications can be made without departing from the scope of the invention.

It is a perspective sectional view of a thin electric pump of one example (Example 1) of the invention of this application. It is a perspective view of the impeller which is a component of the thin electric pump. It is a perspective view of the stator part (consisting of a coil and a back yoke) that is a component of the thin electric pump. It is a figure which shows various shapes of the shroud suspended from the casing inner wall surface of the thin electric pump and used for rectifying the cooling fluid. It is a perspective sectional view of the thin electric pump of other examples (Example 2) of the invention of this application. It is a figure which shows a prior art example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1, 1 '... Thin electric pump, 2 ... Base, 3 ... Casing, 4 ... Impeller, 5 ... Blade | wing, 6 ... Hollow fixed axis | shaft, 6a ... Hollow part passage, 7 ... Slide bearing, 8 ... Magnet, 9 ... Coil, DESCRIPTION OF SYMBOLS 10 ... Cooling fluid path, 11 ... Inlet, 13 ... Discharge port, 14 ... Shroud, 15 ... 1st auxiliary magnet, 16 ... 2nd auxiliary magnet, 17 ... Back yoke, 18 ... Intermittent part, 19 ... Inlet Vent part, A ... Pump room.

Claims (4)

An impeller is rotatably supported and accommodated in a sealed pump chamber surrounded by a base and a casing, and the impeller includes a plurality of sheets for applying centrifugal force to the cooling fluid in the pump chamber. Centrifugal thin type with a thin flat outer shape, provided with vanes at equal intervals in the circumferential direction and rotatably supported via a slide bearing on a hollow fixed shaft standing at the center of the base In electric pump,
A magnet is attached to the wall surface of the impeller opposite to the side provided with the plurality of blades,
The base is provided with a coil embedded in the base made of synthetic resin by a resin mold so as to face the magnet.
A thin electric pump characterized in that a passage for allowing cooling fluid to flow into the pump chamber is formed in the wall of the base so as to communicate with the hollow passage of the hollow fixed shaft.   2. The thin electric pump according to claim 1, wherein the passage for allowing a cooling fluid to flow into the pump chamber is formed in a circumferentially intermittent portion of the coil in the wall of the base. .   A short cylindrical or dome-shaped shroud having an inner diameter larger than the inner diameter of the hollow portion of the hollow fixed shaft is provided on the inner wall surface of the casing so as to face the opening of the hollow fixed shaft. The thin electric pump according to claim 1 or 2, wherein the electric pump is vertically suspended with a predetermined gap left in the axial direction. A first auxiliary magnet is attached to the wall surface of the impeller opposite to the side provided with the plurality of blades along the outer peripheral edge thereof.
A second auxiliary magnet is attached to the base along the outer peripheral edge so as to face the first auxiliary magnet,
The thin electric pump according to any one of claims 1 to 3, wherein the first auxiliary magnet and the second auxiliary magnet have the same polarity opposed to each other.

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