JPH05336769A - Miniature motor - Google Patents

Abstract

PURPOSE:To obtain a miniature motor in which an exciting coil is eliminated, and an entirety is reduced in size by altering a gap between a rotor and a stator by an actuator to be displaced by applying a voltage thereto. CONSTITUTION:When a voltage is so applied through electrodes of actuators 9, 12 as to reduce the actuators in a radial direction, a stator 3 is extended in cooperation with the actuator 9, and a stator 6 is extended outside in cooperation with the actuator 12. Accordingly, a gap between an N-pole of the rotor 1 and the stator 6 and a gap between an S-pole of the rotor and the stator 3 are extended, and magnetoresistances therebetween are increased. Thus, a gradient of a magnetic potential is so generated as to reduce an entire magnetoresistance. As a result, the rotor 1 is rotated by one step, and steadily stabilized at a minimum point of the magnetoresistance of a gap 18 between the stators 7 and 8 and a gap 19 between stators 4 and 5. In this manner, a large exciting coil in which an exciting current flows is not required.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to the construction of a microminiature motor in an actuator of a miniaturized machine by ultraprecision machining.

[0002]

2. Description of the Related Art A conventional small-sized motor, like a large-sized motor, is constructed by winding an exciting coil made of copper wire on a part of a stator to form a motor and supplying an exciting current to the exciting coil to generate a driving force. It occurs and rotates.

[0003]

However, in order to generate the driving force in the above-mentioned conventional motor, the exciting coil is necessary.

For this reason, the coil requires a considerable number of windings. Further, if the wire diameter of the coil is reduced for downsizing, the coil is easily broken when the wire diameter is 10 μm or less, and the coil is attached to the stator. Becomes very difficult to wind.

Therefore, the exciting coil becomes thick and large as a result, and there is a problem that it is difficult to downsize the whole.

In order to solve this problem, an object of the present invention is to provide an ultra-compact motor which can be miniaturized as a whole by eliminating the exciting coil.

[0007]

In order to achieve the above-mentioned object, the microminiature motor of the present invention adopts the structure described below.

The microminiature motor of the present invention includes a rotor made of a permanent magnet, an actuator that is displaced by applied energy, and a stator that is made of a magnetic material that surrounds the outer circumference of the rotor and is displaced in the radial direction in conjunction with the actuator. And is provided.

The micro motor of the present invention is a stator composed of a rotor made of a magnetic material, an actuator that is displaced by applied energy, and a permanent magnet that surrounds the outer circumference of the rotor and that is radially displaced in conjunction with the actuator. And is provided.

The micro motor according to the present invention includes a rotor made of a permanent magnet, an actuator that is displaced by applied energy, and a stator that is surrounded by the rotor and is made of a magnetic material that is axially displaced in conjunction with the actuator. And is provided.

The micro motor of the present invention is a stator composed of a rotor made of a magnetic material, an actuator which is displaced by applied energy, and a permanent magnet which surrounds the upper and lower sides of the rotor and is axially displaced in conjunction with the actuator. And is provided.

[0012]

In the micro motor of the present invention, the rotor is made of a permanent magnet that can rotate about the rotation axis, a plurality of actuators that are displaced by the applied energy, and the rotor is surrounded and fixed in conjunction with the actuators. A stator made of a magnetic material that is displaced in the direction.

Then, a voltage is sequentially applied as the applied energy to the plurality of actuators to change the distance between the corresponding stator and the rotor to change the magnetic attraction force, and to change the change. From the perspective, rotating clockwise or counterclockwise allows the rotor to rotate in one direction.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment according to the present invention will be described below with reference to the drawings. 1 and 2 are plan views of a microminiature motor according to the present invention. FIG. 1 shows a stationary state and FIG. 2 shows a state during one step rotation.

As shown in FIG. 1, a rotor 1 composed of a permanent magnet having a pair of two-pole magnetic poles of an N pole and an S pole is configured to be rotatable around a rotary shaft 15.

The stators 2, 3, 4, 5, made of magnetic material
6, 7 are arranged so as to surround the outer circumference of the rotor 1.

Further, each stator 2, 3, 4, 5,
Actuators 8, 9, 10, 11, 12, 13 corresponding to 6, 7 using, for example, piezoelectric elements are arranged outside the stator.

Further, one end of each actuator is at each stator, and the other end of each actuator is at the outer frame 14.
Is glued to.

Each actuator 8, 9, 10, 1
1, 12, 13 are polarized in the radial direction indicated by the arrow,
Although not shown in FIG. 1, the actuator is configured to be displaced in the radial direction by applying a voltage between the two electrodes of the actuator.

The rotor 1 comprises a rotor 1 and a stator 2,
The magnetic circuit composed of 3, 4, 5, 6, and 7 stably stands still at the point where the magnetic potential is minimized.

As shown in FIG. 1, it is assumed that the N pole of the rotor 1 is at the gap 16 position of the stators 6 and 7, and the S pole is at the gap 17 position of the stators 3 and 4.

In the state as shown in FIG. 1,
One of the magnetic fluxes emitted from the N pole of the rotor 1 is the stator 6, 5, 4
To return to the S pole, and the other magnetic flux passes through the stator 7, 8, 9
Returning to the S pole through, the gap between the stators on both sides becomes the minimum of two places, the magnetic resistance is the smallest, and the magnetic potential is also the smallest.

What happens is that if the N pole of the rotor 1 is brought to the center of the stator 7 and the S pole is brought to the center of the stator 4, it becomes N
One of the magnetic fluxes from the poles passes through the stators 7, 6, 5, 4 and returns to the S pole, and the other magnetic flux passes through the stators 7, 8, 9, 10 and returns to the S pole.

Therefore, in both cases, there are three gaps between the stators on the way, the magnetic resistance also increases and the magnetic potential also increases, and the rotor cannot be stopped at this position. Therefore, the stable point coincides with the gap position between the stators.

As shown in FIG. 2, the actuators 9, 1
When voltage is applied so that each actuator contracts in the radial direction through electrodes not shown in FIG.
The stator 3 is expanded in conjunction with the actuator 9 and the stator 6 is expanded outward in cooperation with the actuator 12.

Therefore, the gap between the north pole of the rotor 1 and the stator 6 and the gap between the south pole of the rotor and the stator 3 are widened, and the magnetic resistance therebetween is increased.

Therefore, since the magnetic resistance between the N pole of the rotor 1 and the stator 7 and the magnetic resistance between the S pole of the rotor 1 and the stator 4 are the same as before, the total magnetic resistance is A magnetic potential gradient is generated so as to lower the magnetic potential.

As a result, the rotor 1 is rotated one step by receiving the clockwise rotating force, and the gap 18 between the stators 7 and 8 and the gap 19 between the stators 4 and 5 shown in FIG. Stabilizes at the minimum point of magnetic resistance.

The voltage applied to the actuator may be applied until the rotor stabilizes at rest, but may be applied for a shorter time until the rotor stabilizes at rest.

Similarly, one step rotates at an angle of 60 degrees, and the rotor 1 makes one rotation in six steps.

3 to 6 show a micro motor according to a second embodiment of the present invention, FIGS. 3 and 4 are a sectional view and a plan view showing a stationary state, and FIGS. 5 and 6 show one step. It is sectional drawing and the top view showing the state at the time of rotation. Hereinafter, description will be given by alternately referring to FIGS. 3, 4, 5, and 6.

As shown in FIG. 3, a rotor 21 made of a permanent magnet having two pairs of four magnetic poles, an N-pole and an S-pole magnetized in the axial direction, is rotatable about a rotary shaft 30. Constitute.

Further, six stators 22, 23, 24, 25, ... Made of a magnetic material are arranged above and below the rotor 21 so as to sandwich the rotor 21, respectively. ing.

Further, actuators 26, 27, 28, 29, ... Corresponding to the respective stators have one end bonded to the stator and the other end bonded to the outer frame 14.

FIG. 4 shows a plan view taken along the line AA in FIG.

As in the first embodiment described with reference to FIGS. 1 and 2, the N pole of the rotor 21 shown in FIG. 4 is stationary with the gap 31 between the stators as a stable point, and the S pole is Gap 3
It is stationary with 2 as the stable point. The cross section taken along the line BB of FIG. 4 corresponds to the cross sectional view of FIG.

Here, as shown in FIG. 5, the stator 24,
25, and actuators 28, 29 corresponding to the stators (stators 35, 36 shown in FIG. 6) that are axially symmetric to the actuators 25,
When a voltage is applied so as to shrink in the axial direction to widen the gap between the stator and the rotor, the magnetic resistance changes and the magnetic potential changes due to the change in the magnetic potential, as described in the first embodiment. A rotating force is generated, and the rotor 21 rotates by an angle of 60 degrees as shown in FIG. 6 and becomes stationary and stable at the stable points 33 and 34.

In the embodiment described above, an example in which six or twelve fixed stators are used has been shown, but the number of stators is not limited to this, and the voltage application time to the actuator is appropriately set. If selected, at least two stators are possible, and the rotor is not limited to two poles or four poles, but may be any one pole of N pole or S pole or more.

The output of the motor of this embodiment can be changed by changing the voltage applied to the actuator interlocking with the stator to change the gap between the rotor and the stator.

The piezoelectric element used as the actuator used in this embodiment is a piezoelectric ceramic (barium titanate, lead zircotitanate, multi-component solid solution ceramics).
Any substance having piezoelectricity such as barium titanate single crystal, crystal, or Rochelle salt may be used.

Furthermore, in order to increase the displacement of the stator and reduce the driving voltage, the combination of the stator and the actuator is a bending displacement type monomorph, unimorph, bimorph,
It is also possible to use a multimorph or linear displacement type laminated type.

In addition to the pulse motor, a continuous rotation motor can be formed by continuously applying a voltage. Particularly, by utilizing the resonance frequency of the stator and the actuator, the continuous rotation motor with low power consumption can be obtained. Can be realized.

[0043]

As is apparent from the above description, the microminiature motor according to the present invention obtains the driving force by changing the gap between the rotor and the stator by the actuator that is displaced by the applied voltage. For this reason, a large exciting coil for supplying an exciting current is not necessary, and therefore, the size can be reduced as compared with the conventional one. In the above description, an example in which a piezoelectric element is used as the actuator has been described, but any actuator that can be displaced by input energy such as a shape memory alloy can be applied.

[Brief description of drawings]

FIG. 1 is a plan view showing a stationary state of a micro motor according to a first embodiment of the present invention.

FIG. 2 is a plan view showing a state during one step rotation of the microminiature motor according to the first embodiment of the present invention.

FIG. 3 is a cross-sectional view showing a stationary state of a micro motor according to a second embodiment of the present invention.

FIG. 4 is a plan view showing a state in which the micro motor according to the second embodiment of the present invention is at rest.

FIG. 5 is a cross-sectional view showing a state during one step rotation of the microminiature motor according to the second embodiment of the present invention.

FIG. 6 is a plan view showing a state during one step rotation of a micro motor according to a second embodiment of the present invention.

[Explanation of symbols]

1, 21 rotors 2, 3, 4, 5, 6, 7, 22, 23, 24, 25 stators 8, 9, 10, 11, 12, 13, 26, 27, 28,
29 actuator 14 outer frame 15, 30 rotating shaft

Claims (4)

[Claims] 1. A rotor comprising a permanent magnet, an actuator that is displaced by applied energy, and a stator that is formed of a magnetic material that surrounds the outer periphery of the rotor and that is radially displaced in conjunction with the actuator. An ultra-compact motor. 2. A rotor comprising a magnetic material, an actuator that is displaced by applied energy, and a stator that is a permanent magnet that surrounds the outer periphery of the rotor and that is radially displaced in conjunction with the actuator. An ultra-compact motor. 3. A rotor comprising a permanent magnet, an actuator which is displaced by applied energy, and a stator made of a magnetic material which surrounds the upper and lower sides of the rotor and is axially displaced in conjunction with the actuator. An ultra-compact motor. 4. A rotor comprising a magnetic material, an actuator that is displaced by applied energy, and a stator that is a permanent magnet that surrounds the upper and lower sides of the rotor and is axially displaced in conjunction with the actuator. An ultra-compact motor.