JP2001050186A - Electric pump - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce cost and to miniaturize a device itself by reducing the number of parts and to simplify an assembling process by mounting it on a printed wiring board. SOLUTION: An electric pump is constituted of a coil 11 to generate a rotating magnetic field and an impeller 10 having a permanent magnet 12, and it rotates the impeller 10 by receiving the rotating magnetic field. It becomes possible to miniaturize the electric pump and to simplify an assembling process by arranging the coil 11 on the printed wiring board 17 and to provide freedom on mounting by miniaturization of the device.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric pump having an impeller driven by receiving a rotating magnetic field generated by a coil.

[0002]

2. Description of the Related Art FIG. 12 shows a configuration diagram of a conventional electric pump. The electric pump shown in FIG. 12 has a motor 1, a permanent magnet 2 directly connected to a shaft of the motor 1, and a permanent magnet 5 attached to an impeller 4 with a non-magnetic waterproof plate 3 interposed therebetween. A water inlet 6 for inflow and a water outlet 7 provided on the outer periphery of the impeller 4 are provided. Permanent magnet 2 and permanent magnet 5
Are magnetically coupled.

When a user performs a water discharge operation, the motor 1 rotates together with the permanent magnet 2 directly connected to the motor shaft, and receives the magnetic flux of the permanent magnet to rotate the permanent magnet 5 attached to the impeller 4 so that the impeller rotates. 4 also rotates. Thus, the liquid existing around the impeller 4 flowing from the water inlet 6 is discharged from the water outlet 7.

[0004]

The electric pump is required to have safety in water discharge operation, compactness, low price, freedom of installation location and form, and the like. The conventional electric pump has a problem that the size of the motor is large due to the large size of the motor. Also, the degree of freedom in the arrangement of the electric pump was small. Further, there is a problem that the structure is complicated and the performance decreases with use. The present invention aims to solve these problems.

[0005]

SUMMARY OF THE INVENTION In order to solve this problem, the present invention provides an electric pump having an impeller, rotating magnetic field generating means having a plurality of coils, and inverter driving means for driving the rotating magnetic field generating means. It is intended to reduce the size of the electric pump. Further, since the impeller is removable, the performance of the pump can be maintained by cleaning the impeller. In addition, the cost can be reduced by reducing the number of components.

[0006]

BEST MODE FOR CARRYING OUT THE INVENTION
An electric pump having an impeller, a rotating magnetic field generating means having a plurality of coils, and an inverter driving means for driving the rotating magnetic field generating means, wherein a rotating magnetic field is applied to the rotating magnetic field generating means by the inverter driving means. The impeller has the function of generating the impeller and receiving the rotating magnetic field to rotate the impeller.

According to a second aspect of the present invention, there is provided the electric pump according to the first aspect, wherein the impeller has a permanent magnet, and when the rotating magnetic field generating means generates a rotating magnetic field, the rotating magnetic field receiving means receives the rotating magnetic field. It has the effect that the impeller rotates.

According to a third aspect of the present invention, there is provided the electric pump according to any one of the first and second aspects, further comprising a water inlet through which a liquid flows, and a water outlet provided on an outer periphery of the impeller. In response to this, the impeller rotates,
It has the effect of discharging the liquid around the impeller that has flowed in from the water inlet through the water outlet.

According to a fourth aspect of the present invention, the electric pump has a cover for covering the impeller, and the impeller is detachable by opening the cover by a user. And the impeller can be attached and detached.

According to a fifth aspect of the present invention, when the electric pump is started, the speed of the rotating magnetic field generated by the rotating magnetic field generating means is reduced by lowering the output frequency of the inverter driving means as compared with the steady state. The electric pump according to any one of claims 1 to 4, wherein the electric pump has an effect of reducing the number of revolutions at the time of starting rotation of the impeller.

According to a sixth aspect of the present invention, the coil is provided at least on a printed wiring board.
In this case, the electric pump described in the section is used, and the step of assembling the electric pump can be simplified.

[0012]

Next, specific examples of the present invention will be described.

(Embodiment 1) FIG. 1 is a block diagram of an electric pump according to one embodiment of the present invention. In FIG. 1, the water outlet 9 serves to discharge the liquid discharged by the impeller 10 from around the impeller 10. The impeller 10 has a permanent magnet 12, and performs an operation of discharging liquid by rotating the permanent magnet 12. This liquid is not limited to water, but may be a pump that pumps liquid other than water.

The rotating magnetic field generating means 13 has a coil 11 and an inverter driving means 14, and the coil 11 performs an operation of generating a rotating magnetic field by a current supplied from the inverter driving means 14. The permanent magnet 12
It performs the function of rotating by receiving a rotating magnetic field. In this embodiment, the impeller 10 is centered on a stainless steel rotation shaft 18 fixedly attached to the cover 16.
The tubular portion of the impeller 10 having an inner diameter slightly larger than the outer diameter of the rotating shaft 18 is rotatable so that it rotates with friction.

The water inlet 15 serves to guide the liquid to the periphery of the impeller 10. In the present embodiment, the cover 16 functions as a bearing for the rotating shaft 18, thereby forming a part of a structure for functioning as an electric pump together with the impeller 10, and keeping the safety of the user. Since the electric pump basically operates as a centrifugal pump, the water suction port 15 is provided near the center of the cover 16, and the rotary shaft 18 made of stainless steel is attached to the cover 16. ing.

FIG. 2 is a configuration diagram of the electric pump of the first embodiment with the cover 16 opened. That is, in the first embodiment, as described in claim 4, the opening of the cover 16 by the user makes the impeller 10 detachable. Therefore, when the performance of the pump is deteriorated due to the adhesion of water scale or the like, the user can remove and wash the impeller 10, so that the effect of preventing friction against the rotational movement between the impeller 10 and the rotating shaft 18 can be improved. Thereby, the performance of the electric pump can be maintained. Also, for example, when this electric pump is used for an electric water heater,
It is sanitary because the user can wash the impeller even if the scale is attached.

Here, in this embodiment, the coil 11
Is the printed wiring board 17 together with the inverter driving means 14.
Since it is provided on the upper side, there is an effect that the assembly of the device can be very easily performed.

However, the coil 11 is not necessarily limited to being mounted on the same printed wiring board 17 as the inverter driving means 14. For example, the coil 11 and the inverter driving means 1 are mounted on separate printed wiring boards 17.
4 may be provided, and a flexible printed wiring material called a flexible substrate may be used to connect them.

FIG. 3 is a side view of the movable portion of the electric pump.
As shown in FIG. 3, a yoke 19 made of an iron plate having a thickness of 1 mm is attached to the permanent magnet 12 in order to constitute a magnetic circuit having a low magnetic resistance, and the impeller 10 is attached to the yoke 19.

In this embodiment, the magnetic resistance of the magnetic path is effectively reduced by the yoke 19, so that a large magnetic flux can be passed through the coil 11, and a small but high-efficiency driving performance is exhibited. And a high-performance device can be realized.

FIG. 4 shows the inverter driving means 1 of this embodiment.
4 is a block diagram of FIG. The rotating magnetic field generating means 13 for generating a rotating magnetic field includes an inverter driving means 14 shown in FIG.
Is connected. The inverter driving means 14 shown in FIG. 4 includes a power supply 20 of AC100V, a rectifier circuit 21, a power supply circuit 22, a microcomputer 23, a drive circuit 24, and a rotation detection circuit 25. The switching element 26a is controlled by a control signal of the microcomputer 23. The current supplied to the coil 11 is instantaneously changed by sequentially turning on and off the 26b and 26c by the drive circuit 24, and the rotating magnetic field generating means 13 generates a rotating magnetic field.

The rotation detection circuit 25 detects the position of the magnetic pole by detecting the induced electromotive force generated in the coil 11 by the rotation of the permanent magnet 12 during the rotation of the impeller 10.
The signal is sent to the microcomputer 23.

In this embodiment, the inverter driving means 14 outputs a signal from the microcomputer 23 to start rotation as a synchronous motor at the start of the electric pump, regardless of the output of the rotation detection circuit 25, and outputs the output frequency. Of the rotating magnetic field generating means 13
The speed of the rotating magnetic field, which generates turbulence, is set low, and rapid liquid discharge is suppressed to ensure safety.

Then, as the frequency rises, about 50
When the rotation reaches 0, the rotation detection circuit 25
Receiving the induced electromotive force generated in the coil 11 by the rotation of 2,
Since the operation of issuing a position output signal can be performed, the microcomputer 23 thereafter switches the switching elements 26a and 26
The operation of turning on and off the b and 26c is performed, and the motor rotates as a motor having substantially the same characteristics as a DC motor.

FIG. 5 is an inverter timing chart when the rotation speed of the impeller of this embodiment is 3000 rpm. As shown in FIG. 5, the switching element 26a is turned on during a period from t3 to t4 by a signal from the microcomputer 23, the switching element 26b is turned on from t2 to t3, and the switching element 26c is turned on from t1 to t4.
The period of 2 is turned on.

In this embodiment, the switching elements 26a, 26b and 26c are turned on and off while the position of the permanent magnet 12 is detected by the rotation detecting circuit 25. However, the present invention is not particularly limited to such a configuration. For example, without using the rotation detection circuit 25, a pulse train is generated from the microcomputer 23 at an increasing drive signal frequency consistently immediately after startup. By outputting the signal, the motor may be driven as a synchronous motor from start to finish. In this case, the efficiency is slightly inferior to that of the present embodiment, but the rotation detection circuit 25 is unnecessary. Therefore, there is an advantage that an apparatus having a simple configuration and a small number of parts can be assembled.

Further, for example, a device for magnetically detecting the rotation of the permanent magnet 12 using a magnetic sensor such as a Hall element or a Hall IC may be used.
That is, even when no induced electromotive force is generated in the coil 11, a current corresponding to the position of the magnetic pole is supplied to the coil 11, and excellent power characteristics almost always equivalent to those of the DC motor are obtained. Thus, it is possible to obtain a good characteristic that a problem peculiar to a synchronous motor is not caused.

Further, in this embodiment, since the motor has a three-phase half-wave configuration using three switching elements 26a, 26b, and 26c, the number of elements is small, and the number of components is small. Although it is possible to realize a low-cost device with a simple configuration and low cost, this is not particularly limited to such a configuration as well, for example, an inverter configuration for driving a three-phase motor And the number of phases is not limited to three, and may be a single phase, two phases, four phases, five phases, or the like. Absent.

FIG. 6 is a bottom view of the permanent magnet according to the first embodiment.
The permanent magnet 12 has a configuration in which S poles and N poles are alternately magnetized into four poles. In this embodiment, the number of poles is four, but the number of poles need not be four. The rotation shaft 18 is arranged at the center.

FIG. 7 is a top view of the impeller according to the first embodiment.
A vane 28 is radially mounted about the rotation shaft 18. In FIG. 7, although four flat plates are used, it is not necessary to be flat plates, and the number and arrangement of the wing plates 28 can be changed.

FIG. 8 is a top view of the coil according to the first embodiment, in which a winding 30 is wound around a teeth portion 29 of an iron core.
Six windings 30a to 30f are arranged at equal intervals on the circumference. In the present embodiment, the iron plate 31 indicated by a dotted line is indicated by a dashed line because the printed wiring board 17 cannot be directly viewed because the printed wiring board 17 is provided between the teeth portion 29 and the iron plate 31.

FIG. 9 is a wiring diagram of windings according to the first embodiment. A black circle indicates the polarity of the winding, and when a current flows from the black circle side of the winding, the winding becomes an N pole. Therefore, for example, when a current flows from the black circle side of the winding 30a, the winding 30a and the winding 30d become N poles, and the winding 30b and the winding 30e
Become a pole. In this case, no current flows through the windings 30c and 30f. The windings are arranged as shown in FIG. 8 and wired as shown in FIG. 9 to generate a rotating magnetic field.

With such a configuration, a concentrated winding configuration in which the electrical angle of the width of one winding is 120 degrees is provided, so that the coil end is short, and the electrical resistance of the coil 11 is reduced, resulting in a copper loss. Is reduced, and an excellent effect of reducing the number of assembling steps can be achieved.However, the present invention is not particularly limited to the configuration of the present embodiment. A coil configuration having an overlap (overlap) may be used.

FIG. 10 is a side view of the coil.
Of the printed wiring board 1
7 and the wiring is performed in a copper pattern. By mounting the printed wiring board 17, a pump is formed, leading to an improvement in productivity, and the number of components can be reduced. The iron plate 31 functions as the yoke 19 for passing the magnetic flux from each of the teeth portions 29. The iron plate 31 lowers the magnetic resistance of the magnetic circuit and increases the amount of the magnetic flux passing through the teeth portion 29 by the permanent magnet 12 to thereby increase the predetermined amount. The magnetomotive force required for obtaining torque can be reduced, and the efficiency of the pump can be increased. But,
It is also possible to reduce costs by making the air core. In the present embodiment, the teeth 29 and the iron plate 31 are arranged on both sides of the printed wiring board 17. However, the teeth 29 and the iron plate 31 are directly adhered, and the teeth 29 and the iron plate 31 are placed on the printed wiring board 17 or printed. A configuration in which the connection is made such that it is embedded in the wiring board 17 is also conceivable.

(Embodiment 2) FIG. 11 shows a configuration diagram of an electric pump according to another embodiment of the present invention. FIG.
In this embodiment, the configuration of the water outlet 9, the impeller 10, the coil 11, the permanent magnet 12, the inverter driving means 14, the water inlet 15, the cover 16, and the printed wiring board 17 is the same as that of the first embodiment.

In FIG. 11, the permanent magnet 12 embedded in the impeller 10 is arranged at a position horizontal to the coil 11, and the permanent magnet 12 is of an outer rotor type rotating outside the coil 11. In this arrangement, the permanent magnet is
However, this electric pump is effective when the space in the rotation axis direction cannot be sufficiently obtained.

In the first and second embodiments, the permanent magnet 12 is used to generate an electromagnetic force between the coil 11 and the permanent magnet 12 to obtain torque. For example, there are induction (induction) type having a secondary coil short-circuited to an impeller, reluctance type having a magnetic unevenness in the impeller, and hysteresis type using a magnetic material having large hysteresis in the impeller. In other words, it can be realized in another configuration as long as it generates torque between the coil and generates power.

[0038]

As described above, according to the present invention, the liquid in the container of the electric pump can be led out by rotating the impeller having the permanent magnet by the rotating magnetic field.

The impeller is detachable by removing the cover by the user, and the performance can be maintained by cleaning the impeller. Then, by suppressing the number of rotations of the rotating magnetic field when the electric pump is started, rapid discharge of the liquid can be suppressed and safety can be secured.

Further, by providing the coil on at least the printed wiring board, productivity is improved.
Also, an advantageous effect that the number of parts can be reduced can be obtained.

[Brief description of the drawings]

FIG. 1 is a configuration diagram illustrating an electric pump according to a first embodiment of the present invention.

FIG. 2 is a configuration diagram showing an electric pump with a cover opened according to the first embodiment of the present invention.

FIG. 3 is a side view of a movable portion of the electric pump according to the present invention.

FIG. 4 is a block diagram of an inverter driving means of the electric pump according to the present invention.

FIG. 5 is an inverter timing chart of the electric pump of the present invention.

FIG. 6 is a bottom view of a permanent magnet of the electric pump of the present invention.

FIG. 7 is a top view of the impeller of the electric pump according to the present invention.

FIG. 8 is a top view of a coil of the electric pump according to the present invention.

FIG. 9 is a wiring diagram of coils in Embodiment 1 of the electric pump of the present invention.

FIG. 10 is a side view of the same coil.

FIG. 11 is a configuration diagram illustrating an electric pump according to a second embodiment of the present invention.

FIG. 12 is a configuration diagram showing a conventional electric pump.

[Explanation of symbols]

 2, 5, 12 permanent magnet 4 impeller 6 water inlet 7 water outlet 10 impeller 11 coil 13 rotating magnetic field generating means 14 inverter driving means 16 cover 17 printed wiring board

Continuing from the front page (72) Inventor Hideki Ryuko 1006 Kazuma Kadoma, Kazuma, Osaka Prefecture Inside Matsushita Electric Industrial Co., Ltd. Reference) 3H020 BA02 BA15 CA05 DA05 EA01 EA12 EA14 3H022 AA01 BA04 CA50 DA07 DA09 DA16 3H033 AA01 BB01 BB06 CC01 DD06 DD29 EE05 EE15 EE16

Claims (6)

[Claims] 1. An electric pump comprising: an impeller; rotating magnetic field generating means having a plurality of coils; and inverter driving means for driving the rotating magnetic field generating means. 2. The electric pump according to claim 1, wherein the impeller has a permanent magnet. 3. The electric pump according to claim 1, further comprising a water inlet through which a liquid flows, and a water outlet provided on an outer periphery of the impeller. 4. The electric pump according to claim 3, wherein the electric pump has a cover for covering the impeller, and the user opens and closes the cover so that the impeller is detachable. 5. When the electric pump is started, the output frequency of the inverter driving means is made lower than that in a steady state,
The electric pump according to any one of claims 1 to 4, wherein a speed of the rotating magnetic field generated by the rotating magnetic field generating means is reduced. 6. The electric pump according to claim 1, wherein the coil is provided at least on a printed wiring board.