JP2003201985A - Ultra thin pump - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an ultra thin pump with high performance, a long service life, and low noise. <P>SOLUTION: This ultra thin pump is characterized in that a central position 9 of the thickness of a magnet rotor 3 is displaced to a gravity direction from the central position 9 of the thickness of a motor stator, and the magnetic force generated by this displacement cancels the action force to an impeller 3A. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to an ultra-thin pump.

[0002]

2. Description of the Related Art In recent years, a cooling system that efficiently cools electronic parts such as a CPU has been desired, and as a cooling method corresponding thereto, a refrigerant cooling system that circulates and cools a refrigerant has been drawing attention. Further, the refrigerant circulation pump of such a cooling system has many restrictions on the mounting space, and thus there is an increasing demand for reduction in size and thickness.

As a conventional small pump, Japanese Patent Laid-Open No. 2001-2001
There is a small centrifugal pump described in Japanese Patent No. 132699. Hereinafter, a conventional small centrifugal pump will be described with reference to FIG. FIG. 4 is a structural diagram of a conventional small centrifugal pump. Reference numeral 101 is an impeller, 102 is a fixed shaft that rotatably supports the impeller 101, 103 is an end of the fixed shaft 102 fixed, and the impeller 101 is housed at the same time as the impeller 10
1. A pump casing having a pump chamber for recovering the kinetic energy given to the fluid by 1 and guiding it to the discharge port.
Reference numeral 04 denotes a rear shroud which forms a part of the impeller 101, and 10
5 is a front shroud which also forms a part of the impeller 101 and has a water absorption opening formed in the center of the impeller 101, 106 is a rotor magnet fixed to the rear shroud 104 of the impeller 101, and 107 is an inner circumference of the rotor magnet 106. The motor stator 108 is provided on the side, a waterproof partition wall 108 is provided between the rotor magnet 106 and the motor stator to seal the pump chamber, 109 is a suction port, and 110 is a discharge port.

The operation of this conventional centrifugal pump will be described. When electric power is supplied from an external power source, a current controlled by an electric circuit provided in the centrifugal pump is applied to the coil 10.
6 and a rotating magnetic field is generated. When this rotating magnetic field acts on the rotor magnet 106, the rotor magnet 106
Physical force is generated in. By the way, the rotor magnet 106 is fixed to the impeller 101.
Is rotatably supported by the fixed shaft 102, a rotational torque acts on the impeller 101, and the impeller 101 starts rotating due to this rotational torque. The blades provided between the front shroud 105 and the rear shroud 104 of the impeller 101 change the momentum of the fluid by the rotation of the impeller 101, and the fluid flowing from the suction port 109 receives the kinetic energy from the impeller 101. become. Of course, if the flow passage area is expanded in the impeller 101 toward the blade outlet, the pressure will be partially recovered in the impeller 101. The fluid flowing out from the blade outlet of the impeller 101 recovers pressure of the kinetic energy given by the diffuser provided in the casing 103, and is guided to the discharge port 110.

As described above, in the conventional small-sized centrifugal pump, the thin impeller is driven by the outer rotor system to reduce the size and thickness of the pump. However, in such a conventional small-sized centrifugal pump, an axial suction portion is required in the pump chamber in order to supply the fluid to the water intake opening at the center of the impeller, so that the length of the entire pump in the rotation axis direction is reduced. This is an obstacle to the purpose, that is, to reduce the thickness. A vortex pump (friction pump) suitable for thinning the structure that sucks in from the radial direction and discharges in the radial direction is also known, but even if the pump is a vortex pump, the impeller is connected to the central fixed shaft. For this reason, a disk shape is required, and a waterproof partition wall for sealing the pump chamber is required above and below it, and the motor stator, the waterproof partition wall and the impeller overlap each other in the direction of the rotation axis.

Therefore, as a solution to such problems, the present inventors have proposed the following technique prior to the present invention. Hereinafter, the ultra-thin pump investigated by the present inventors will be described in detail with reference to the drawings. FIG. 5 is a cross-sectional view showing the overall configuration of the ultra-thin pump examined by the present inventors.

Reference numeral 201 denotes a ring-shaped impeller having a large number of blades 202 formed on the outer circumference and the rotor magnet 2 on the inner circumference.
03 is provided. 204 is a rotor magnet 20
The motor stator 205 provided on the inner peripheral side of the ring 3 accommodates the ring-shaped impeller 201 and at the same time the ring-shaped impeller 2
A pump casing having a pump chamber for recovering the pressure of the kinetic energy 01 applied to the fluid to the discharge port,
Reference numeral 206 denotes a casing cover that forms a part of the pump casing and houses the ring-shaped impeller 201 and then seals the pump chamber. The pump casing 205 is provided with a cylindrical portion 207 which is disposed between the motor stator 204 and the rotor magnet 203 and rotatably supports the ring-shaped impeller 201.
Plate 208 for receiving the thrust load on the side of the vehicle
Are formed. The thrust plate 208 is also formed on the casing cover 206 side. 209 is a suction port, 21
Reference numeral 0 is a discharge port.

Next, the operation of this ultra-thin pump will be described. When electric power is supplied from an external power source, a current controlled by an electric circuit provided in the ultra-thin pump flows through the coil of the motor stator 204. , A rotating magnetic field is generated. When this rotating magnetic field acts on the rotor magnet 203, a physical force is generated on the rotor magnet 203. By the way, the rotor magnet 203 is integrated with the ring impeller 201, and the ring impeller 201 is rotatably supported by the cylindrical portion 207 of the pump casing 205. And the ring-shaped impeller 201 starts to rotate due to this rotation torque. Blades 20 provided on the outer circumference of the ring-shaped impeller 201
2 is a suction port 209 by the rotation of the ring-shaped impeller 201.
The kinetic energy is applied to the fluid flowing in from, and the pressure of the fluid in the pump casing 205 is gradually increased by the kinetic energy and is discharged from the discharge port 210.

As described above, in this thin pump, the blade, the rotor magnet, and the rotary shaft are integrated to form a ring-shaped impeller, and the motor stator is inserted into the ring-shaped impeller, whereby the length of the entire pump in the rotary shaft direction is increased. Has been made as small as possible to realize an ultra-thin pump.

[0010]

However, in such a conventional ultra-thin pump, when the ring-shaped impeller rotates, both side surfaces and the inner peripheral surface of the ring slide on the thrust plate and the cylindrical portion of the pump casing. There is a problem that the reduction in performance due to friction loss cannot be ignored compared to the conventional small-sized centrifugal pump that has a large sliding area due to movement and has a shaft with an extremely small diameter in the center and has few sliding parts. In addition, there are problems such as shortened life due to wear and increased vibration and noise due to sliding contact. And, these problems are essential problems that cannot be avoided in order to realize a highly efficient pump with an ultra-thin pump of a few cm order and a few mm order, which has not been considered in the past. It was

Therefore, it is an object of the present invention to provide an ultra-thin pump capable of achieving high performance, long life and low noise while achieving ultra-thinness.

[0012]

In order to solve this problem, in the ultra-thin pump of the present invention, the center position of the thickness of the magnet rotor is displaced from the center position of the thickness of the motor stator in the direction of gravity, and this deviation occurs. It is characterized in that the force acting on the impeller is canceled by the magnetic force due to.

As a result, high performance, long life, and low noise can be realized while achieving ultra-thinness.

[0014]

BEST MODE FOR CARRYING OUT THE INVENTION The invention according to claim 1 of the present invention is a ring-shaped impeller in which a large number of blades are formed on the outer circumference and a rotor magnet is provided on the inner circumference, and the inner circumference side of the rotor magnet. And a pump casing having a cylindrical portion disposed between the motor stator and the rotor magnet and accommodating the impeller inside, wherein the impeller is rotatable in the cylindrical portion. An ultra-thin pump in which the center of the thickness of the magnet rotor is displaced in the direction of gravity from the center of the thickness of the motor stator, and the impeller is driven by the magnetic force due to this displacement. Since it is an ultra-thin pump characterized by canceling the force that acts on, the magnetic force due to the deviation trying to align the two center positions is applied to the impeller's own weight and buoyancy. It be balanced Te can, because though the upper and lower surfaces of the magnet rotor can be rotated as floating in a non-contact manner the pump casing,
It is possible to realize high performance, long life and low noise of the ultra-thin pump.

The invention according to claim 2 of the present invention is the ultra-thin pump according to claim 1, wherein the magnetic pole position sensor for detecting the magnetic pole position of the magnet rotor and the stator based on the output signal of the magnetic pole position sensor. A supercharger characterized by comprising a current controller for controlling the current flowing through the winding, the magnetic pole position sensor and the current controller being mounted on a substrate, and the substrate being mounted on the side surface of the stator core on the lower side in the direction of gravity. Since it is a thin pump, even when the board on which these electric components are mounted is mounted on the stator core, even if the tip of the electric component projects beyond the thickness of the pump casing,
Due to the shift of the center position of the two thicknesses, a space below the gravity direction with a margin can be used as a storage space, and the size obtained by adding the thickness of the electronic component to the thickness of the board is absorbed by the size shifted from the center position. Therefore, the ultra-thin pump can be further thinned.

The invention according to claim 3 of the present invention is characterized in that the pump casing is provided with a first projection which can be press-fitted when the stator core is press-fitted. Since it is an ultra-thin pump, it is possible to prevent the stator core from being press-fitted, so it is possible to eliminate the variation in the amount of deviation between the two center positions, and also to fix the board, which makes it easy to assemble. The mass productivity of the pump can be improved.

According to a fourth aspect of the present invention, the pump casing is provided with a second protrusion for positioning when mounting the substrate and for sandwiching the substrate with the stator core. Since the ultra-thin pump according to claim 2 or 3, the substrate can be positioned and fixed by the second protrusion and can be easily assembled, so that the mass productivity of the ultra-thin pump can be improved. it can.

FIG. 1 shows an embodiment of the present invention.
~ It demonstrates using FIG.

(First Embodiment) FIG. 1 is a side sectional view of an ultra-thin pump according to the first embodiment of the present invention, and FIG. 2 is a center position of a stator core and a center of a magnet rotor according to the first embodiment of the present invention. 6 is a graph showing the relationship between the amount of displacement from the position and the magnet center force.

As shown in FIGS. 1 and 2, 1 is a stator core, 2 is a stator winding formed on the stator core 1, 3 is a ring-shaped magnet rotor, and 3A is a magnet rotor 3 integrated on the inner peripheral side. It is a ring-shaped impeller. Rotational torque in a certain direction is generated by attraction and repulsion between the electromagnet and the magnet rotor 3 formed by passing a current through the stator winding 2. The magnet rotor 3, that is, the impeller 3A, rotates at a position where this rotational torque is balanced with the load torque.

As shown in FIG. 1, the pump of the first embodiment is a vortex pump, and a large number of blades arranged in a ring shape are provided in the impeller 3A at a predetermined pitch with a concave portion between the blades sandwiched therebetween. ing. The motor is an outer rotor type D in which the magnet rotor 3 rotates around the outer periphery of the stator core 1.
It is a C brushless motor. Reference numeral 4 denotes a magnetic pole position sensor that detects the magnetic pole position of the magnet rotor 3 in order to control the timing and direction of the current flowing through the stator winding 2.
At this time, since the magnetic flux detected by the magnetic pole position sensor 4 is the leakage magnetic flux from the magnet rotor 3, the magnetic pole position sensor 4
It is desirable that the position of is a position where the leakage magnetic flux is as large as possible,
It is suitable to provide it at a position close to the magnet rotor 3. A drive IC 6 (current control unit of the present invention) that controls the current flowing through the stator winding 2 is provided in order to efficiently generate a rotational torque in a fixed direction upon receiving the output signal of the magnetic pole position sensor 4. Magnetic pole position sensor 4 and drive IC
5 are electrically connected and arranged on the substrate 6.

Reference numeral 7 designates a pump casing which constitutes a pump chamber for accommodating the impeller 3A, and 7A designates this pump chamber,
It is a cylindrical portion of the pump casing 7 arranged between the pump chamber and the motor stator. The cylindrical portion 7A pivotally supports the magnet rotor 3 to freely rotate in the pump chamber. Although the impeller 3A is directly immersed in the pump handling liquid in the pump casing 7, the stator core 1, the stator winding 2, the electric components on the substrate 6, the magnetic pole position sensor 4, the drive IC 6 are provided.
Are separated from the handling liquid by the cylindrical portion 7A. The pump having the configuration shown in FIG. 1 is generally called a sealless pump because it does not use a shaft seal, and the pump casing 7 separates the motor stator and the pump chamber by the cylindrical portion 7A to separate the liquid and the motor. There is. This cylindrical part 7
Since A and the pump casing 7 are called a can as a waterproof partition, it is also called a canned motor pump. The sealless pump has no shaft seal material for the motor and is characterized in that it is sealed by the cylindrical portion 7A in this way, which makes it a long-life pump. However, as shown in FIG. That is, when the rotating shaft is placed vertically with the direction of gravity directed, when the lower surface (upper surface depending on how the pump is placed) of the impeller 3A rotates while making mechanical contact with the inner surface of the pump casing 7, friction is generated. As a result, efficiency and life are reduced, and the desired characteristics cannot be obtained.

Therefore, according to the present invention, as shown in FIG. 1, the rotary shaft is vertically installed and used, and the relationship between the center position 8 of the stator core and the center position 9 of the magnet rotor 3 is based on the center position 9. The center position 8 is displaced in the direction opposite to the gravity acting on the magnet rotor 3.
As a result, a magnet center force (a magnetic force due to a deviation in attempting to align the two center positions) is generated, so that the magnet center force becomes a resultant force against the weight of the magnet rotor 3 as well as the buoyancy in the liquid of the magnet rotor 3. Acting to balance the weight and the resultant force of the magnet rotor 3 so that the magnet rotor 3 floats in the handled liquid, so that the magnet rotor 3 can be mechanically rotated without contact. . by this,
It is possible to provide a highly efficient pump that realizes a long service life, which is an original feature of a sealless pump, and reduces mechanical loss. Since the buoyancy and weight are handled, the impeller 3A rather than the center position 9 of the magnet rotor 3 is handled.
The center position of may be more appropriate, but since the magnetic force of the magnet participates as the magnet center force,
This is described as the center position 9 of the magnet rotor 3.

FIG. 2 is a graph of the amount of deviation between the center positions of the motor stator and the magnet rotor of the pump and the magnet center force in the first embodiment. As shown in FIG. 2, the center position 8 of the stator core and the magnet rotor 3 are
The amount of deviation from the center position 9 is set to D1, and the relationship with the magnet center force at this time is actually measured. In a region where the shift amount D1 is small, a substantially linear relationship is established.

The actual weight of the measured impeller 3A of the pump is 5 g.
f, the volume is 1 cm ³ , and the handling liquid is water. in this case,
The buoyancy acting on the impeller 3A is 1 gf, and it is necessary to generate a magnet center force of 4 gf in order to levitate the impeller 3A. At this time, as shown in FIG.
It can be seen that if 0.4 mm is adopted as 1, it can be balanced. Then, when the power consumption was actually measured when the displacement amount D1 was 0 mm and 0.4 mm, the power consumption at the rated point of the pump was 1.4 W and 1.0 W, respectively, and in the case of 0.4 mm, it was about 30. %, The power consumption can be reduced and a highly efficient pump can be obtained.

Further, in FIG. 2, reference numeral 11 denotes a range of force obtained by converting the amount of vibration into a magnet center force when the amount of vibration applied to the pump is ± 0.5 G and the viscosity of the liquid to be handled is ignored. , 12 are amplitude amounts of how much the impeller 3A is shaken at its maximum. That is, assuming that the clearance D2 between the magnet rotor 3 and the pump casing 7 in FIG. 1 is 0.25 mm read from FIG. 2, this pump incorporated in an electronic device or the like has a vertical direction of ± 0.5 G.
It can be seen that even if the vibration of 1 is applied, the upper surface and the lower surface of the impeller 3A can rotate mechanically and non-contact with the pump casing 8.

(Second Embodiment) FIG. 3 is a side sectional view of an ultrathin pump according to a second embodiment of the present invention. Figure 3
The second embodiment of the present invention will be described with reference to FIG. 7. However, the same reference numerals as those in the first embodiment have the same contents, and thus the description thereof will be omitted.

In FIG. 3, reference numeral 13a is a first projection provided for preventing press-fitting when the stator core 1 is press-fitted and fixed to the pump casing 7. Stator core 1
It is the aim of the first protrusion 13a to secure a deviation amount D1 between the center position 8 and the center position 9 of the magnet rotor 3. By providing the first protrusion 13a, the press-fitting position of the stator core 1 is determined, and it is possible to eliminate the variation in the center position 8 that occurs during assembly.

Reference numeral 13b is a second projection for fixing the board provided on the pump casing 7, and is for sandwiching and fixing the board 6 with the stator core 1.
Therefore, there is a distance corresponding to the thickness of the substrate 6 between the position of the first protrusion 13a and the position of the second protrusion 13b. Since the second protrusion 13b is provided at such a position, the motor can be thinned for the reason described below.

That is, the magnetic pole position sensor 4 and the drive I
When the board 6 on which the C5 is mounted is installed on the stator core 1, in order to reduce the thickness of the motor, as can be seen from FIG. 3, the highest electric component on the board 6 is located outside the surface of the pump casing 7. It is necessary to prevent it from sticking out. Moreover, since the impeller 3A needs to be rotated in a non-contact manner in order to obtain a highly efficient ultra-thin pump, a deviation amount D1 between the center position 8 of the stator core 1 and the center position 9 of the magnet rotor 3 is applied in order to apply a magnet center force. Must be secured.

Therefore, the second protrusion 13b is arranged to fix the substrate 6 on the side surface of the stator core 1 on the gravity direction side of the magnet rotor 3 by utilizing the side having a spatial allowance. By positioning the board 6 between the protrusion 13b and the stator core 1 and sandwiching and fixing the board 6, the thickness of the pump portion is set to D4, and the thickness of the board 6, the maximum height of the electric component, and the half thickness of the stator core 1 are added. D is taken
When set to 3, D4 / 2> D3-D1 can be easily satisfied. That is, the center position 9 of the magnet rotor 3 comes to almost the center of the thickness D4 of the pump portion due to the balance of forces, but the center position 8 of the stator core 1 is located higher than this position by the shift amount D1, and the shift amount. It is possible to absorb the height occupied by the substrate 6 and the electric component by an amount corresponding to D1 so that the highest-height portion of the electric component does not project outward from the surface of the pump casing 7.

Even if the electronic components are the same, if the substrate 6 is provided on the opposite surface of the stator core 1, D4 /
There is a possibility that 2 <D3 + D1, and the thinning of the pump is impaired by the width of D1. Therefore, by arranging the substrate 6 on the stator core 1 on the gravity direction side of the impeller 3A and sandwiching and fixing the substrate 6 with the protrusions 13b, it is possible to simultaneously realize the thinness, high efficiency, and long life of the pump.

[0033]

As described above, according to the present invention, it is possible to balance the self-weight and buoyancy of the impeller by applying the magnetic force due to the deviation that attempts to align the two center positions,
Since the upper and lower surfaces of the magnet rotor can be rotated as if they were floating without contacting the pump casing, the ultra-thin pump can have higher performance, longer life, and lower noise.

Further, when the substrate on which the electric component is mounted is mounted on the stator core, even if the tip of the electric component protrudes beyond the thickness of the pump casing, 2
Because of the shift of the center position of the two thicknesses, a space below the gravitational direction can be used as a storage space, and the size in which the thickness of the electronic component is added to the thickness of the board is absorbed by the size with the center position shifted. It is possible to further reduce the thickness of the ultra-thin pump.

Since the stator core can be press-fitted and stopped, 2
Since it is possible to eliminate the variation in the amount of deviation between the two center positions and also to easily assemble the substrate while also fixing the substrate, it is possible to improve the mass productivity of the ultra-thin pump. Further, since the substrate can be positioned and fixed and can be easily assembled, mass productivity of the ultra-thin pump can be improved.

[Brief description of drawings]

FIG. 1 is a side sectional view of an ultra-thin pump according to a first embodiment of the present invention.

FIG. 2 is a graph showing the relationship between the amount of deviation between the center position of the stator core and the center position of the magnet rotor and the magnet center force in the first embodiment of the present invention.

FIG. 3 is a side sectional view of an ultra-thin pump according to Embodiment 2 of the present invention.

FIG. 4 is a structural diagram of a conventional small centrifugal pump.

FIG. 5 is a sectional view showing the overall configuration of an ultra-thin pump.

[Explanation of symbols]

1 Stator core 2 stator winding 3 magnet rotor 3A impeller 4 Magnetic pole position sensor 5 Drive IC (current control unit) 6 substrate 7 Pump casing 7A cylindrical part 8, 9 Center position 11 Excitation amount 12 Amplitude 13a First protrusion 13b Second protrusion

Continued front page    (72) Inventor Aizono Jitsumitsu             1006 Kadoma, Kadoma-shi, Osaka Matsushita Electric             Sangyo Co., Ltd. (72) Inventor Shigeru Narakino             1006 Kadoma, Kadoma-shi, Osaka Matsushita Electric             Sangyo Co., Ltd. F-term (reference) 3H022 AA01 BA01 BA03 BA07 CA50                       DA11 DA13 DA15 DA20                 3H034 AA01 AA11 BB01 BB04 CC03                       CC05 CC07 DD01 EE05 EE06                       EE10 EE11 EE12 EE18

Claims (4)

[Claims] 1. A ring-shaped impeller having a large number of blades formed on the outer circumference and a rotor magnet provided on the inner circumference, a motor stator having a stator core provided on the inner circumference side of the rotor magnet, and the motor. A pump casing having a cylindrical portion disposed between the stator and the rotor magnet and accommodating the impeller therein, the cylindrical portion rotatably supporting the impeller, and An ultra-thin pump placed vertically, wherein the center position of the thickness of the magnet rotor is displaced in the direction of gravity from the center position of the thickness of the motor stator,
An ultra-thin pump characterized by canceling the force acting on the impeller by the magnetic force due to this displacement. 2. The ultra-thin pump according to claim 1, wherein a magnetic pole position sensor for detecting a magnetic pole position of the magnet rotor and a current flowing through the stator winding are controlled based on an output signal of the magnetic pole position sensor. An ultra-thin pump including a current control unit, the magnetic pole position sensor and the current control unit being mounted on a substrate, and the substrate being mounted on a side surface of the stator core on the lower side in the direction of gravity. 3. The ultra-thin pump according to claim 1, wherein the pump casing is provided with a first protrusion that can be press-fitted when the stator core is press-fitted. 4. The pump casing is provided with a second protrusion for positioning the substrate when mounting the substrate and for sandwiching the substrate with the stator core. The ultra-thin pump described in 3.