JP3748679B2 - Stepping motor - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a structure of a small stepping motor advantageous for installation in a narrow space.
[0002]
[Prior art]
There are various types of stepping motors, but the stepping motor targeted by the present invention has a rotor composed of cylindrical permanent magnets magnetized in multiple poles in the radial direction. However, this is a stepping motor of the type configured by a coil arranged so as to surround the entire circumferential surface of the rotor and a plurality of magnetic pole pieces arranged in a comb-tooth shape so as to face the circumferential surface of the rotor. A conventional example of such a type of stepping motor is described in Japanese Utility Model Laid-Open No. 3-117367, and its configuration will be described with reference to an exploded perspective view of FIG.
[0003]
The rotor 21 is made of a cylindrical permanent magnet magnetized in multiple poles in the radial direction. The stator includes two blocks having the same configuration, and each block includes a bearing 22, a mounting plate 23, a yoke case 24, a coil body 25, and a yoke plate 26. Among these, each yoke case 24 is integrated with a mounting plate 23 to which a bearing 22 is attached, and has a plurality of magnetic pole pieces 24 a disposed to face the peripheral surface of the rotor 21. Each coil body 25 is a hollow and annular case that accommodates the coil, and the coil is wound along the annular shape of the case, that is, surrounding the circumferential surface of the rotor 21. Further, each yoke plate 26 is formed with a plurality of magnetic pole pieces 26a extending in the opposite direction to the magnetic pole pieces 24a and arranged alternately with the magnetic pole pieces 24a. The coil body 25 and the yoke plate 26 are housed in two yoke cases 24 together with the rotor 21, and the yoke cases 24 are attached to each other by appropriate means such as welding.
[0004]
In this conventional example, the stator is constituted by two blocks as described above, but there is a motor constituted by one block. That is, there are two configurations in this case. In the first configuration, the rotor 21 is arranged between the yoke case 24 of the upper block and the yoke plate 26 in FIG. The bearing 22 and the mounting plate 23 (not explicitly shown in the drawing) integrated with the case 24 are integrated with the yoke plate 26 of the upper block. In the second configuration, the upper plate yoke plate 26 and the lower block coil body 25 and yoke plate 26 are removed.
[0005]
[Problems to be solved by the invention]
In general, stepping motors configured as described above are often used in devices that require relatively compactness, such as optical devices, information devices, and acoustic devices. For this reason, downsizing is required so that layout in a narrow space inside the device is advantageous. However, if the circular shape as shown in FIG. There is a problem that either or both of the number of turns of the coil and both of them must be reduced, and the driving force is greatly reduced.
[0006]
The present invention has been made to solve such problems, and an object of the present invention is to provide a circular motor case without reducing the diameter of the rotor and the number of turns of the coil. It is an object of the present invention to provide a stepping motor having a configuration that can be miniaturized by deforming a portion.
[0007]
[Means for Solving the Problems]
To achieve the above object, the stepping motor of the present invention is placed so as to be substantially equidistant Shi pairs on the peripheral surface of the rotor has a permanent magnet magnetized in multipolar of the rotor to the rotary shaft with which possess a cylindrical wall which is formed to surround the plurality of pole pieces and the plurality of pole pieces in parallel with the rotary shaft are formed by and extending in the same direction The planar shape viewed in a vertical plane has a shape having a defect portion in which a part of a substantially circular shape is missing with a straight line, the defect is not formed with the wall, and the rotor of the defect portion A coil is wound around a coil bobbin so as to surround the first yoke member not formed with the magnetic pole piece on the side, and between the magnetic pole piece and the wall so as to surround the entire circumferential surface of the rotor . The coil is wound at a position corresponding to the defect portion so as to be parallel to the defect portion. A coil body formed, in the opposite direction to the pole piece of the rotary shaft and parallel to and the first yoke member placed by pre SL rotor so as to be paired Shi substantially equal intervals in the circumferential surface of the rotor the planar shape viewed in a plane perpendicular to the axis of rotation of the rotor with the pole pieces stretched formed the first yoke member and have a plurality of pole pieces disposed alternately first The second yoke member has substantially the same shape as the one yoke member, and the defect portion thereof is arranged in alignment with the defect portion of the first yoke member, and the pole piece is not formed on the rotor side of the defect portion . to Tei so that with the yoke member.
In the stepping motor of the present invention, preferably, the second yoke member has a cylindrical wall formed so as to surround each of the magnetic pole pieces except for the defective portion. To do.
In the stepping motor according to the present invention, preferably, each yoke member has another defective portion formed symmetrically on the opposite side of each of the defective portions with the rotor interposed therebetween. And the coil bobbin is configured such that the wall is not formed in the other defect part and the magnetic pole piece is not formed on the rotor side of the other defect part. The coil is wound so as to be parallel to the other defect part even at a position corresponding to the other defect part .
Also, in order to achieve the above object, another stepping motor of the present invention, the first block, the are arranged substantially equidistantly Shi pairs on the peripheral surface of the multi-pole permanent magnet rotor the rotating together are closed and a cylindrical wall which is formed to surround the plurality of pole pieces and the plurality of pole pieces are formed by extending the axis of rotation parallel to and the same direction of the rotor The planar shape as viewed in a plane perpendicular to the axis has a shape having a defect part in which a part of a substantially circular shape is missing with a straight line, the wall is not formed in the defect part, and the defect part On the rotor side , a coil is wound around a coil bobbin disposed between the first yoke case not formed with the magnetic pole piece and the magnetic pole piece and the wall so as to surround the entire circumferential surface of the rotor . set to be parallel to the defect is with that at a position corresponding to the defect A first coil body formed by winding a coil, opposite to the pole piece of the rotor of the relative circumferential surface is arranged substantially equidistant parallel to the rotational axis of the rotor and the first yoke case planar shape viewed in a plane perpendicular to the axis of rotation of the rotor together with the formed by extending in the direction the pole pieces of the first yoke case that have a plurality of pole pieces arranged alternately Has substantially the same shape as that of the first yoke case, and the defect portion thereof is arranged in alignment with the defect portion of the first yoke case, and the magnetic pole piece is formed on the rotor side of the defect portion. A second yoke case, a second coil body, and a second coil body having the same configuration as the first yoke case, the first coil body, and the first yoke plate, respectively. It has a yoke plate, and the first block and the second block The click, to be adjacent the first yoke plate and the second yoke plate to Tei so that attached to each other.
In the stepping motor of the present invention, it is preferable that each yoke case and each yoke plate be symmetrically formed on the opposite side of each of the defective portions with the rotor interposed therebetween. The other defect part is not formed with the wall, and the other defect part is configured so that the pole piece is not formed on the rotor side , Each coil bobbin is wound around each coil so as to be parallel to the other defect portion even at a position corresponding to the other defect portion .
Stepping motor further, the present invention, it is preferable that the each yoke plate, respectively, notch on one of the defect is, though the bent portion is formed in the other defect, and the first block The second block is attached to each other by engaging the notch portion and the bent portion of each yoke plate.
[0008]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described with reference to the examples shown in FIGS. FIG. 1 is a front view of the embodiment, and FIG. 2 is a left side view of FIG. Also, FIG. 3 shows the upper and lower components separated in FIG. 1, and the direction of the arrow A is seen in FIG. 3, and the direction of the arrow B is seen in FIG. FIG. 5 is a view. FIG. 6 is an exploded perspective view of the embodiment. FIG. 7 is a single view of the yoke plate shown in FIG. 6, in which FIG. 7 (a) is a plan view and FIG. 7 (b) is a side view.
[0009]
The rotor 1 of the present embodiment is made of a permanent magnet and is magnetized to 10 poles in the radial direction. The stator consists of two blocks that are symmetrically configured in the same way. First, the upper block will be described mainly with reference to FIG. The bearing 2 is for bearing the upper end of the rotating shaft of the rotor 1, and is press-fitted into the mounting plate 3. The mounting plate 3 is attached to the upper surface of the yoke case 4 by welding, and the product name, model number, etc. are written on the surface. The yoke case 4 is shaped like a cylinder cut by two parallel straight lines parallel to the axis, and the outer shape of the plane is oval. And window part 4b, 4c is formed in the wall part 4a of the two defect | deletion parts cut | disconnected as mentioned above, respectively. Further, a window portion 4d whose vertical dimension is smaller than the window portions 4b and 4c is formed on the left wall portion 4a in FIG. Further, although it is difficult to understand in FIG. 6, the yoke case 4 is formed with one pole piece 4 e bent downward by bending so as to form one on the left side of the rotor 1 and two on the right side.
[0010]
The coil body of this embodiment disposed between the wall 4a of the yoke case 4 and the magnetic pole piece 4e is composed of a coil bobbin 5 and a coil wound around the coil bobbin 5, but the illustration of the coil is omitted. ing. The coil bobbin 5 is formed with terminal portions 5a and 5b for connecting the coil to an external circuit. The yoke plate 6 has a downward bent portion 6a formed in one of the defective portions, and a notched portion 6b formed in the other of the defective portions. Further, on the yoke plate 6, two pole pieces 6 c bent upward are formed on the left side of the rotor 1 and one on the right side. The two left magnetic pole pieces 6c are arranged so as to sandwich the left magnetic pole piece 4e of the yoke case 4 described above, and the right magnetic pole piece 6c of the yoke plate 6 is arranged on the right side of the yoke case 4 described above. The magnetic pole pieces 4e and 6c are opposed to the circumferential surface of the rotor 1 at equal intervals. Therefore, the block above the stator has six poles, and no pole piece exists in the missing part.
[0011]
Next, the lower block in FIG. 6 will be described. As described above, the upper block and the lower block have a symmetric configuration. A bearing 7 supporting the lower end of the rotating shaft of the rotor 1 is press-fitted into a mounting plate 8, and the mounting plate 8 is welded to the lower surface of the yoke case 9. As with the yoke case 4 described above, the yoke case 9 has an oval outer shape. And the window part 9b, 9c is formed in the wall part 9a of two defect | deletion parts, respectively, and the window part 9d is formed in the left wall part 9a. The yoke case 9 is formed with one pole piece 9e bent upward and one on the left side of the rotor 1 and two on the right side (only one is visible in FIG. 6).
[0012]
Also in the lower block, the coil body is composed of a coil bobbin 10 and a coil wound around the coil bobbin 10, and terminal portions 10a and 10b are formed on the coil bobbin 10, but the illustration of the coil is omitted. As clearly shown in FIG. 7, the yoke plate 11 has an upward bent portion 11a formed in one of the defective portions, and a notched portion 11b formed in the other defective portion. Further, on the yoke plate 11, two pole pieces 11 c bent downward are formed on the left side of the rotor 1 and one on the right side. The two left magnetic pole pieces 11c sandwich the one magnetic pole piece 9e on the left side of the yoke case 9, and the right magnetic pole piece 11c on the yoke plate 11 has two magnetic pole pieces on the right side of the yoke case 9. It arrange | positions so that it may be pinched | interposed into the piece 11e, and each magnetic pole piece 9e, 11c is opposed with respect to the surrounding surface of the rotor 1 at equal intervals. Therefore, the block below the stator also has 6 poles, and there is no pole piece in the missing part.
[0013]
As can be understood from the above description, in the present embodiment, the two blocks are configured in a completely symmetrical manner, so that each component can be shared. In the final assembly, the bent portion 6a of the yoke plate 6 is engaged with the notched portion 11b of the yoke plate 11, and the bent portion 11a of the yoke plate 11 is engaged with the notched portion 6b of the yoke plate 6. As a result, the 12-pole magnetic pole pieces of the two blocks are arranged at regular intervals in the rotation direction of the rotor 1, 6 poles on the left and right, respectively, as shown in FIG. In this embodiment, these engaging operations can be performed while visually confirming from the window portions 4b and 9c and the window portions 4c and 9b, which is very convenient.
[0014]
Further, the coil bobbins 5 and 10 sandwich the yoke plates 6 and 11, and as can be seen from FIG. 2, the terminal portions 5a, 5b, 10a and 10b are alternately fitted from above and below, and the window portions 4d and 9d are inserted. Project outside. In this way, after assembling the two blocks, the yoke cases 4 and 9 are attached to each other by appropriate means. In a normal case, such a small motor is disassembled and repaired. Since it does not do this, it is usually fixed by welding. In addition, when the motor is manufactured in this way and then assembled to various devices, either of the yoke cases 4 and 9 may be welded to the device, but as shown by the one-dot chain line in FIG. The plate 8 may be extended to the left and right and fixed by screws or welding.
[0015]
As described above, according to the present embodiment, two defect portions are formed in the yoke cases 4 and 9 and the yoke plates 6 and 11, and the magnetic pole pieces 4e and 9e are not formed in these defect portions. Since the configuration is adopted, the outer shape on the plane can be reduced without reducing the diameter of the rotor 1 or reducing the number of turns of the coil wound around the coil bobbins 5 and 10. Further, the window portions 4b, 4c, 9b, 9c may not be formed in the missing portions of the yoke cases 4, 9, and the wall portion 4a may be formed over the entire circumference. Although it is slightly inferior to the above-mentioned embodiment, it is better in that the magnetic field is hardly affected from the outside. Furthermore, even if there is only one defective portion, it is possible to reduce the size as compared with the conventional example described above.
[0016]
In the above embodiment, the stator is composed of two blocks. However, the present invention can also be applied to a stepping motor in which the stator is composed of a single block. That is, in the above embodiment, when only the upper block is used, as one method, the mounting plate 8 and the bearing 7 may be attached to the lower surface of the yoke plate 6, and as another method, The yoke plates 6 and 11 and the coil bobbin 10 in the embodiment can be removed. However, in the latter case, it is necessary to form two pole pieces 9e formed on the yoke case 9 on the left side of the rotor 1 and one on the right side. Even in the case of such a configuration, it is possible to reduce the size compared with the conventional example even if the window portion is not necessarily formed in the defect portion or only one defect portion is formed. Further, in the case of the former configuration, since the yoke plate 6 is a plate material, it is possible to obtain a certain effect for downsizing without forming a defect portion there.
[0017]
【The invention's effect】
As described above, according to the present invention, a defect portion obtained by cutting a part of a circular shape substantially linearly is formed in a yoke case that has been circular in plan according to the shape of the rotor. Since the magnetic pole piece opposed to the peripheral surface of the rotor is not formed in the defective portion, the outer shape on the plane can be reduced without reducing the diameter of the rotor or the number of turns of the coil. Can be reduced.
[Brief description of the drawings]
FIG. 1 is a front view of an embodiment.
FIG. 2 is a left side view of FIG.
FIG. 3 is a diagram in which the upper and lower components are separated from each other in FIG.
4 is a view in which the upper and lower components are separated from each other in FIG.
5 is a view of FIG. 3 and FIG. 4 as viewed from above in FIG.
FIG. 6 is an exploded perspective view of the embodiment.
7 is a single product view of the yoke plate shown in FIG. 6, in which FIG. 7 (a) is a plan view and FIG. 7 (b) is a side view.
FIG. 8 is an exploded perspective view of a conventional example.
[Explanation of symbols]
1,21 Rotor 2,7,22 Bearing 3,8,23 Mounting plate 4,9,24 Yoke case 4a, 9a Wall 4b, 4c, 4d, 9b, 9c, 9d Window 4e, 6c, 9e, 11c , 54a, 56a Pole pieces 5, 10 Coil bobbins 5a, 5b, 10a, 10b Terminal portions 6, 11, 26 Yoke plates 6a, 11a Bent portions 6b, 11b Notch portion 25 Coil body

Claims (6)

It is placed so as to be paired Shi substantially equal intervals in the circumferential surface of the rotor having a magnetized permanent magnet multipole are formed by extending the axis of rotation parallel to and the same direction of the rotor a portion of substantially circular planar shape as viewed in a plane perpendicular to the rotating shaft with and have a plurality of pole pieces and the plurality of pole pieces to enclose so formed with have a cylindrical wall A first yoke member having a shape having a defect portion that is broken in a straight line, the wall is not formed in the defect portion, and the magnetic pole piece is not formed on the rotor side of the defect portion ; The coil is wound around the coil bobbin so as to be disposed between the magnetic pole piece and the wall so as to surround the entire circumferential surface of the rotor, and at a position corresponding to the defect part, is parallel to the defect part. to a coil body formed by winding the coil, so that a pair Shi substantially equal intervals in the circumferential surface of the rotor Multiple pole piece parallel to the rotation axis of the front SL rotor is placed and the first yoke member and the pole piece formed by extending in the opposite direction the first yoke member disposed alternately of the first yoke member the defect have substantially the same shape as the plane shape of the first yoke member as viewed in a plane perpendicular to the axis of rotation of the rotor with which have a pole piece a stepping motor for a second yoke member not forming the magnetic pole pieces on the rotor side of the該欠loss portion is arranged to fit into the defect, characterized in Tei Rukoto equipped with. 2. The stepping motor according to claim 1, wherein the second yoke member has a cylindrical wall formed so as to surround each of the magnetic pole pieces except for the defective portion . Each yoke member has another defect portion formed symmetrically on the opposite side of each defect portion with the rotor interposed therebetween, and the wall is formed in the other defect portion. The magnetic pole piece is not formed on the rotor side of the other defective portion, and the coil bobbin is disposed at the position corresponding to the other defective portion. The stepping motor according to claim 1, wherein the coil is wound so as to be parallel to the deficient portion. First block, a plurality of magnetic poles arranged so as to be paired Shi substantially equal intervals in the circumferential surface are formed by extending the axis of rotation parallel to and the same direction of the rotor of the multi-pole permanent magnet rotor deficient planar shape viewed in a plane perpendicular to the rotating shaft with and have a cylindrical wall which is formed so as to surround the strip and the plurality of pole pieces by a straight line portion of the substantially circular A first yoke case having a shape having a defective portion, the wall is not formed in the defective portion, and the magnetic pole piece is not formed on the rotor side of the defective portion; A coil is wound around a coil bobbin so as to surround the entire circumferential surface of the rotor and is disposed between the piece and the wall, and at a position corresponding to the defect part, the coil is parallel to the defect part. a first coil body formed by winding a coil, a substantially equal interval with respect to the circumferential surface of the rotor A plurality of magnetic poles and sea urchin arranged pole pieces of the rotor of the rotating shaft parallel to and pole pieces of the first yoke case formed by extending in the opposite direction the first yoke case arranged alternately defect of the first yoke case the defect have substantially the same shape as the plane shape of the first yoke case viewed in a plane perpendicular to the axis of rotation of the rotor with which have a single And a first yoke plate that does not form the magnetic pole piece on the rotor side of the missing portion , and the second block includes the first yoke case and the first yoke case. A second yoke case, a second coil body, and a second yoke plate having the same configuration as the coil body and the first yoke plate are provided. The first block and the second block are the first yoke plate and the second yoke plate. Adjacent to each other Stepping motor according to claim Tei Rukoto be. Wherein each yoke case and each yoke plate, on the side opposite to the respective defects by between the rotor, have another defect that is symmetrically formed, the said other defect is The wall is not formed, and the magnetic pole piece is not formed on the rotor side of the other defect portion, and each coil bobbin corresponds to the other defect portion. 5. The stepping motor according to claim 4 , wherein each coil is wound so as to be parallel to the other defect portion even at a position. Each yoke plate is formed with a notch in one defect and a bent part in the other defect, and the first block and the second block are notches in each yoke plate. The stepping motor according to claim 4 , wherein the stepping motor is attached to each other by engaging the bent portion with the bent portion.

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