JP2009095130A - Motor and electronic equipment using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a motor having improved efficiency, and electronic equipment using the same. <P>SOLUTION: In order to achieve the purpose, the motor is provided with: a stator 3 having a plurality of magnetic poles 3a arranged on an external circumference with a predetermined first interval; and a rotor 4 arranged on the external circumference of the stator 3, wherein a magnet 5 magnetized at different portion for each second predetermined interval is arranged on the internal circumference of the rotor 4, the magnetic poles 3a of the stator 3 each have an extending portion 3b extending from its magnetic pole base 3c in a direction substantially parallel to the magnet 5, and an opening 10 is formed on the extending portion 3b. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a motor and an electronic apparatus using the motor.

  In an electronic device, for example, a laser printer, a paper feed roller (driven body) provided in a main body case is connected to a motor, and by driving the motor, the paper feed roller is rotated to feed paper to a predetermined portion. ing.

  The motor includes a stator in which a plurality of magnetic poles are arranged at a first predetermined interval on an outer peripheral portion, and a rotor that is rotatably arranged on the outer periphery of the stator. It has a structure in which magnets magnetized with different polarities are arranged at intervals.

  Further, the magnetic pole of the stator has an extending portion extending from the magnetic pole base portion in a direction substantially parallel to the magnet, thereby improving driving efficiency.

  That is, the width of the magnet (in the direction orthogonal to the circumferential direction) is larger than the width of the stator in the same direction in order to make it as close as possible to the magnetic detection element that magnetically detects the rotation of the rotor.

For this reason, the extension of the magnetic pole of the stator is extended from the magnetic pole base in a direction substantially parallel to the magnet, thereby increasing the facing area between the magnetic pole of the stator and the magnet of the rotor. It is trying to increase power and drive efficiency. (A similar technique is described in, for example, Patent Document 1 below.)
Japanese Patent Laid-Open No. 9-285044

  As described above, in the conventional motor in which the extension of the magnetic pole of the stator extending from the magnetic pole base portion in a direction substantially parallel to the magnet is formed, the facing area between the magnetic pole of the stator and the magnet of the rotor increases. Although the driving force increases, further improvement is necessary to increase the driving efficiency.

  That is, since the extension portion from the magnetic pole base portion of the stator is substantially parallel to the magnet, the magnetic flux from the magnet passing through the extension portion passes through the extension portion in a vertical state. An excessive eddy current is generated in the extension portion, and heat is generated due to iron loss, which leads to a decrease in driving efficiency.

  In view of the above, an object of the present invention is to improve driving efficiency.

  In order to achieve this object, the present invention comprises a stator in which a plurality of magnetic poles are arranged at a first predetermined interval on the outer periphery, and a rotor that is rotatably arranged on the outer periphery of the stator. Around the circumference, magnets magnetized with different polarities at every second predetermined interval are arranged, and on the magnetic pole of the stator, an extension portion extending in a direction substantially parallel to the magnet is formed from the magnetic pole base portion, An opening is formed in this extension, thereby achieving the intended purpose.

  As described above, according to the present invention, since an extension portion extending in a direction substantially parallel to the magnet is provided from the magnetic pole base portion of the stator, and an opening is formed in the extension portion, the extension portion receives a magnetic flux from the magnet. Even if it passes in the vertical direction, the existence of an opening in this extension part will cause the eddy current to be generated to be interrupted, and as a result, the eddy current and the resulting heat generation become extremely small. Drive efficiency can be improved.

  Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings.

  In FIG. 1, reference numeral 1 denotes a wiring board of an electronic device (for example, a laser printer), which is arranged in a horizontal direction in a main body case (not shown).

  A motor 2 is mounted on the wiring board 1 by a fixture (not shown).

  The motor 2 includes a stator 3 formed by laminating plate-like bodies as shown in FIG. 2, and a cylindrical rotor 4 disposed on the outer periphery of the stator 3 and having an open lower surface. A ring-shaped magnet 5 magnetized alternately at N poles and S poles (adjacent poles are different from each other) at predetermined intervals is fixed integrally.

  A plurality of magnetic poles 3a are arranged at predetermined intervals on the outer peripheral portion of the stator 3, and an electromagnet coil 6 is wound around the magnetic circuit portion inside each magnetic pole 3a as shown in FIG. .

  That is, by applying AC power to the coil 6, each magnetic pole 3a is alternately magnetized to the N pole and the S pole, and an attractive force and a repulsive force are generated between the magnet 5 existing on the outer periphery thereof. The rotational driving force of the rotor 4 is configured.

  Although not shown in FIG. 1, the stator 3 is fixed on the wiring board 1 by the fixture (not shown) as described above, and the bearing 7 is provided on the inner periphery of the stator 3.

  A drive shaft 8 is provided through the bearing 7 in the vertical direction, and the upper end of the drive shaft 8 is fixed to the top surface 4 a of the rotor 4.

  Therefore, if AC power is applied to the coil 6, the magnetic poles 3a are alternately magnetized to the N and S poles, and an attractive force and a repulsive force are generated between the magnet 5 and the rotor 4 is driven. The shaft 8 rotates around the shaft 8, and the rotational force is transmitted through the drive shaft 8.

  Specifically, in the present embodiment, the lower end of the drive shaft 8 extends through the through hole 1a of the wiring board 1 and extends below the wiring board 1, and a gear (not shown) is attached to the lower portion thereof. A gear box (not shown) is coupled to the plurality of paper feed rollers (not shown), thereby rotating the paper.

  In addition, a Hall IC 9 is mounted as an example of a magnetic detection element on a portion corresponding to the lower end of the magnet 5 on the wiring board 1. As is well known, the Hall IC 9 detects the rotation speed and the rotation position of the rotor 4. It has become.

  Further, in order to make the magnet 5 as close as possible to the Hall IC 9, the lower end thereof is extended to the vicinity of the Hall IC 9, and further, in order to avoid the balance deviation with respect to the stator 3 when the lower end of the magnet 5 is extended downward in this way. Moreover, the upper end of the magnet 5 also extends upward by the same amount.

In the present embodiment, as shown in FIGS. 1 to 3, the magnetic pole 3a of the stator 3 has an extension portion 3b extending from the magnetic pole base portion 3c in a direction substantially parallel to the magnet 5 and extending downward. It is integrally formed. (See especially Figure 2 and Figure 3)
Specifically, the extended portion 3b has an outer peripheral portion of the upper and lower surfaces (outermost layer) of the stacked plate-like members constituting the stator 3 in a direction substantially parallel to the magnet 5. Each of them is formed by bending at an approximately right angle in the upward and downward directions.

  The feature of the present embodiment is that the opening 10 is formed by a kerf from the bent base of the extension 3b toward the bent tip.

    That is, among the plurality of stacked plate-like bodies constituting the stator 3, the outer peripheral portions of the upper and lower (outermost layer) plate-like bodies are substantially perpendicular to the magnet 5 in the upward and downward directions, respectively. When the extension portion 3b is formed by bending in the direction as shown in FIG. 1, the area facing the upper and lower magnets 5 increases as shown in FIG. 1, and as a result, a large driving force is applied to the rotor 4. .

At this time, the magnetic flux from the magnet 5 penetrates the extension 3b portion of the stator 3 in a direction perpendicular to the stator 3,
There is concern about the generation of large eddy currents.

  However, in the present embodiment, as shown in FIG. 3, the extension 3b portion of the stator 3 is formed with an opening 10 by a kerf from the bent base of the extension 3b toward the bent tip, so that the eddy current is divided. As a conclusion, a large eddy current does not flow through the extension 3b.

  For this reason, the state in which the driving efficiency is lowered due to the heat generated by the large eddy current flowing through the extension 3b in the past does not occur, and as a result, the driving efficiency is improved.

  Further, if an opening 10 is formed in the extension 3b of the stator 3 by a kerf, the opening 10 increases the heat radiation area of the stator 3 or facilitates the flow of cooling air, thereby improving the heat radiation effect. It will be.

  The opening 10 may not be formed by the kerf shown in FIG. 3, but may be an opening 10a formed by a horizontal kerf as shown in FIG. 4, or may be formed by providing a plurality of circular through holes. .

  That is, the eddy current flowing through the extension 3b is divided by the openings 10 and 10a, and as a result, the eddy current may be reduced.

  Moreover, in this embodiment, since the opening 10 and 10a were provided in the extension part 3b as mentioned above, the rigidity as the extension part 3b becomes small. For this reason, when it is feared that the extension 3b deforms to the magnet 5 side due to some stress during long-term use and contacts the rotor 4 during rotation, the bending tip side of the extension 3b is compared with the bending root. The bending amount is increased so as to be arranged on the inner side of the stator 3.

  That is, since there is only a very small gap of, for example, only 0.3 mm between the inner surface of the magnet 5 of the rotor 4 and the magnetic pole base 3c of the stator 3, the above contact may be a concern. Therefore, in such a case, as described above, the bending amount is increased so that the bending tip side of the extension portion 3b is disposed on the inner side of the stator 3 as compared with the bending root portion, thereby the rotor 4 The distance between the inner surface of the magnet 5 and the extension 3b of the stator 3 is increased to make it difficult to cause contact when the rotor 4 rotates.

  Further, when such an extension 3b is deformed to the magnet 5 side and there is a risk of contact when the rotor 4 rotates, the extension 3b is moved slightly from the position of FIG. You may start up from that position.

    Furthermore, in the said embodiment, among the several laminated | stacked plate-shaped bodies which comprise the stator 3, the outer peripheral part of the plate-shaped body of an upper surface and a lower surface (outermost layer) is each on a substantially parallel direction with the said magnet 5, respectively, The extension 3b is formed by bending it downward at a substantially right angle, but forming a plurality of stacked extensions 3b by bending each of the upper and lower surfaces upward and downward at a substantially right angle. However, this may increase the strength of the extension 3b and suppress deformation due to stress during long-term use.

  FIG. 5 shows another embodiment of the present invention, in which the bending tip end side of the extension portion 3b has a smaller width in the circumferential direction than the bending root portion.

  Specifically, the opening 10 formed by the kerf is made narrower toward the bending tip side of the extension portion 3b, and thereby, the width of the bending tip side of the extension portion 3b is made smaller than the bending root portion in the circumferential direction. In this way, the four extension portions 3b are processed so as to be inclined toward the center side.

  And if it is set as the above structure, the width | variety of the opening 10 will not spread by long-term use by the work hardening by the front-end | tip part of the four extension parts 3b being deform | transformed inward, that is, the extension part 3b and The area facing the magnet 5 does not change, and as a result, the characteristics of the motor do not change.

  In FIG. 5, the tip portions of the extension portion 3b are made smaller in the opening size of the opening 10 by the groove, but the tip portions of the extension portions 3b adjacent to each other in the groove portion are connected to enhance the strength. You may do it.

  Each of the openings 10 and 10a in FIGS. 3 to 5 is formed by punching from the coil 6 side to the magnet 5 side (left side to right side in FIG. 1), and the opening is the punching start side. The opening on the (left side) is wider than the punching end side (right side). For this reason, the opposing area of the magnetic pole 3a (the magnetic pole base 3c / extension part 3b) and the magnet 5 becomes large, and the driving efficiency is also high from this point.

As described above, the present invention includes a stator in which a plurality of magnetic poles are arranged on the outer peripheral portion at a first predetermined interval, and a rotor that is rotatably arranged on the outer periphery of the stator. Two magnets magnetized with different polarities are arranged at predetermined intervals, and the magnetic pole of the stator forms an extended portion extending in a direction substantially parallel to the magnet from the magnetic pole base portion. An opening is formed, and eddy currents and heat generated by the eddy currents are extremely small, thereby improving driving efficiency.

  Therefore, it is possible to contribute to improving the driving efficiency of various electronic devices.

Half sectional view of one embodiment of the present invention The perspective view of the stator of one Embodiment of this invention The front view of the stator of one embodiment of the present invention Front view of a stator according to another embodiment of the present invention The front view of the stator of further another embodiment of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Wiring board 2 Motor 3 Stator 3a Magnetic pole 3b Extension part 3c Magnetic pole base 4 Rotor 5 Magnet 6 Coil 7 Bearing 8 Drive shaft 9 Hall IC
10 opening

Claims (11)

A stator having a plurality of magnetic poles arranged on the outer periphery at a first predetermined interval, and a rotor arranged rotatably on the outer periphery of the stator. The inner periphery of the rotor is different at every second predetermined interval. A motor in which a magnet magnetized in a pole is disposed, and an extension portion extending in a direction substantially parallel to the magnet is formed on a magnetic pole of the stator from a magnetic pole base portion, and an opening is formed in the extension portion. The motor according to claim 1, wherein the opening is formed by a kerf or a through hole. 3. The motor according to claim 1, wherein the stator is formed by laminating plate-like bodies, and at least the outermost plate-like body of the laminate is bent in a direction substantially parallel to the magnet to form an extension portion. The stator is formed by laminating plate-like bodies, and a plurality of laminated plate-like bodies including at least the outermost layer of the laminate are bent in a direction substantially parallel to the magnet to form an extension. 2. The motor according to 2. The motor according to claim 3 or 4, wherein an opening by a kerf is formed from a bent base portion of the extended portion toward a bent tip. The motor according to any one of claims 3 to 5, wherein a bent distal end side of the extension portion is disposed on an inner side of the stator as compared with a bent root portion. The motor according to any one of claims 3 to 6, wherein a bending front end side of the extension portion has a smaller width in the circumferential direction than the bending root portion. The motor according to claim 1, wherein the extension portion of the stator is formed inward from the outermost peripheral portion of the magnetic pole. An electronic apparatus comprising: a main body case; a driven body provided in the main body case; and a motor coupled to the driven body, wherein the motor according to any one of claims 1 to 8 is used as the motor. . The electronic device according to claim 9, wherein a wiring board is provided in the main body case, a motor is attached to the wiring board, and a magnetic detection element is provided on a portion of the wiring board facing the magnet of the motor. The electronic device according to claim 10, wherein a Hall IC is used as the magnetic detection element.

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