JP2019050696A - Geared motor - Google Patents

Abstract

To provide a geared motor capable of preventing a positional deviation of planetary gears and internal gears at the time of assembly.SOLUTION: A geared motor includes a motor having a motor shaft, and a gear reduction mechanism 7 for decreasing a rotating speed of the motor shaft. The gear reduction mechanism 7 comprises: a sun gear 30; planetary gears 31, 31 engaged with the sun gear 30 to rotate with rotation of the sun gear 30; a carrier 40 for rotatably holding the planetary gears 31, 31; a fixed inner gear 10 and a movable inner gear 20 rotatably and revolvably holding the planetary gears 31, 31 on the sun gear 30. The fixed inner gear 10 has a guide part 13 making a sliding contact with a projecting part 44 formed on an annular plate part 43 of the carrier 40, and the movable inner gear 20 has a guide part 25 making a sliding contact with a projecting part 48 formed on an annular plate part 47 of the carrier 40.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a geared motor, and more particularly to a geared motor including a gear reduction mechanism having a plurality of gears.

  As such a geared motor, there is known, for example, a geared motor provided with a planetary gear reduction mechanism or a strange planetary gear reduction mechanism (see, for example, Patent Document 1). In such a geared motor, it is preferable that the planetary gear and the internal gear that holds the planetary gear be in precise mesh. However, in the conventional geared motor, when assembling, particularly when the number of planetary gears is small (three or less), the carrier to which the planetary gears are attached may be shifted with respect to the internal gear, and as a result, There was a problem that the planetary gear and the internal gear were assembled at the wrong position. In particular, in a geared motor provided with a strange planetary gear mechanism, such misalignment of the gear position at the time of assembly tends to cause a decrease in performance and the like.

Japanese Patent Application Publication No. 2007-037363

  The present invention has been made in view of the problems of the prior art as described above, and it is an object of the present invention to provide a geared motor capable of preventing positional deviation of a planetary gear and an internal gear at the time of assembly.

  According to an aspect of the present invention, there is provided a geared motor capable of preventing misalignment of a planetary gear and an internal gear during assembly. The geared motor includes a motor having a motor shaft and a gear reduction mechanism that reduces the rotational speed of the motor shaft. The gear reduction mechanism rotates a sun gear that rotates with the rotation of the motor shaft, and at least one planetary gear that meshes with the sun gear and rotates with the rotation of the sun gear, and rotates the at least one planetary gear. A carrier for enabling the holding, and an internal gear for holding the at least one planetary gear in a rotatable manner around the sun gear. The carrier has an annular plate portion rotatable around the sun gear. In addition, the internal gear has internal teeth that mesh with the at least one planetary gear outside the sun gear, and a guide portion that slidably contacts the positioning portion formed on the outer peripheral edge of the annular plate portion of the carrier. .

  According to such a configuration, since the guide portion of the internal gear and the positioning portion of the carrier are provided in sliding contact, when assembling the planetary gear attached to the carrier to the internal gear, the carrier It is positioned against. Therefore, the internal gear and the planetary gear are prevented from shifting when assembling the geared motor.

  Here, it is preferable that the positioning portion be constituted by at least one protrusion protruding radially outward. By thus configuring the positioning portion as the projecting portion, the contact area between the guide portion and the positioning portion is reduced, so that the friction between the guide portion and the positioning portion is reduced.

  The at least one planet gear may be two planet gears positioned on opposite sides of the sun gear. In this case, the at least one protrusion preferably includes two protrusions formed at positions of 90 degrees from the two planetary gears centering on the sun gear. With such a configuration, the reduction ratio of the output shaft of the geared motor can be increased, and the positional deviation of the internal gear and the planetary gear can be effectively suppressed.

  The at least one planet gear may be a single planet gear. In this case, the at least one protrusion preferably includes three protrusions formed at positions of 60 degrees, 180 degrees, and 300 degrees respectively from the single planetary gear about the sun gear. . With such a configuration, the reduction ratio of the output shaft of the geared motor can be further increased, and the positional deviation of the internal gear and the planetary gear can be effectively suppressed.

  In the above-mentioned guide part of the above-mentioned internal gear, a gate mark of a mold used for molding the above-mentioned internal gear may be located. By arranging the gate in the thick guide portion, the material for forming the internal gear can be easily poured into the entire mold.

  According to the present invention, since the guide portion of the internal gear and the positioning portion of the carrier are in sliding contact with each other, positional deviation of the internal gear and the planetary gear can be prevented.

FIG. 1 is an exploded perspective view showing a geared motor according to a first embodiment of the present invention. FIG. 2 is an exploded perspective view showing a gear reduction mechanism of the geared motor shown in FIG. FIG. 3 is a longitudinal sectional view along an axis showing the gear reduction mechanism shown in FIG. FIG. 4 is an enlarged perspective view of a carrier of the gear reduction mechanism shown in FIG. FIG. 5 is a top perspective view showing a fixed internal gear and the like of the gear reduction mechanism shown in FIG. 6 is a lower perspective view showing movable internal gears and the like of the gear reduction mechanism shown in FIG. FIG. 7 is a lower perspective view showing a movable internal gear and the like of a geared motor according to a second embodiment of the present invention.

  Hereinafter, an embodiment of a geared motor according to the present invention will be described in detail with reference to FIGS. 1 to 7. Note that, in FIG. 1 to FIG. 7, the same or corresponding components are given the same reference numerals, and duplicate explanations will be omitted. Further, in FIGS. 1 to 7, the scale and dimensions of each component may be exaggerated and shown, or some components may be omitted.

  FIG. 1 is an exploded perspective view showing a geared motor 1 according to a first embodiment of the present invention. As shown in FIG. 1, the geared motor 1 includes a motor 3, a gear reduction mechanism 7, and a substantially rectangular case body 2 that houses and holds the motor 3 and the gear reduction mechanism 7 therein. The geared motor 1 is configured to have an axis L of the motor 3 as a central axis. In this specification, the direction in which the axis L extends is taken as the Z direction, and the + Z direction side is referred to as “upper”, “upper side”, or “upper”, etc., and the −Z direction side is “lower” and “lower side”. Or "lower" and so on.

  The motor 3 has a motor shaft 3A extending along the axis L. Further, the motor 3 is held by the motor holder 4, and is fixed to the case body 2 via the motor holder 4. On an upper surface of the motor 3, a flange 6 having a through hole through which the motor shaft 3A penetrates formed at its center is fixed by a screw 8. An upper surface of the flange 6 is provided with a flat cylindrical portion 6A projecting upward, and an outer peripheral edge of the flat cylindrical portion 6A is a pair of keys 6B projecting on opposite sides with respect to the motor shaft 3A. , 6B are provided.

  The gear reduction mechanism 7 includes a hollow cylindrical fixed internal gear 10 centered on the axis L and a movable internal gear 20 positioned above the fixed internal gear 10, and is configured as a wonder planetary gear reduction mechanism There is. The movable internal gear 20 has a hollow cylindrical main body 28 having an outer diameter substantially the same as the fixed internal gear 10 and centered on the axis L, and an upper portion along the axis L from the center of the upper wall 24 of the main body 28. And a stem 21 extending in The movable internal gear 20 is rotatably attached to the fixed internal gear 10.

  A pair of key grooves 16 and 16 is formed at a position opposite to the axis L on the lower part of the outer peripheral surface of the fixed internal gear 10. The fixed internal gear 10 is fixed to the flange 6 by fitting the key grooves 16 and 16 to the keys 6B and 6B of the flange 6 described above. That is, the fixed internal gear 10 is fixed to the case body 2 via the flange 6.

  The case body 2 is formed in a substantially rectangular parallelepiped hollow inside. A gear reduction mechanism 7 and a motor 3 held by a motor holder 4 are accommodated in the internal space of the case body 2. A bush 5 in which a through hole is formed at the center is fixed to the top 2A of the case body 2, and the shaft 21 of the movable internal gear 20 penetrates the through hole of the bush 5 and the outside of the case 2 Projected into With such a configuration, the shaft portion 21 of the movable internal gear 20 is rotatably held by the bush 5 and operates as an output shaft that decelerates and outputs the rotational speed of the motor shaft 3A.

  Next, the configuration of the gear reduction mechanism 7 will be described in more detail. Here, FIG. 2 is an exploded perspective view showing the gear reduction mechanism 7, and FIG. 3 is a longitudinal sectional view along an axis L showing the gear reduction mechanism 7. As shown in FIGS. 2 and 3, the gear reduction mechanism 7 includes a lower fixed internal gear 10, an upper movable internal gear 20, and a sun gear located at a central portion in the X direction in FIG. 30, two planet gears 31, 31 meshing with the sun gear 30, and a carrier 40 rotatably holding the planet gears 31, 31. As shown in FIG. 3, a part of the sun gear 30 (gear portion 33), the planetary gears 31 and 31, and the carrier 40 are accommodated inside the fixed internal gear 10 and the movable internal gear 20.

  As shown in FIG. 2, the sun gear 30 includes a gear portion 33 located on the upper side and a hollow cylindrical portion 34 located on the lower side. The motor shaft 3A (see FIG. 1) of the motor 3 is fitted in the internal space of the hollow cylindrical portion 34, whereby the sun gear 30 (gear portion 33) rotates integrally with the motor shaft 3A. It has become. On the other hand, the gear portion 33 extends upward from the center of the upper surface of the hollow cylindrical portion 34 along the axis L, and meshes with each of the planetary gears 31, 31.

  Here, FIG. 4 is an enlarged perspective view showing the sun gear 30, the planetary gears 31, 31 and the carrier 40 of the gear reduction mechanism 7. As shown in FIG. As shown in FIGS. 2 and 4, the planetary gears 31, 31 are aligned in the Y direction perpendicular to the Z direction. That is, the planetary gears 31, 31 mesh with the gear portion 33 on the + Y side and the −Y side with respect to the gear portion 33 of the sun gear 30. With such a configuration, each of the planetary gears 31, 31 rotates (rotation) as the sun gear 30 rotates. The gear portion 33 is configured to have a smaller number of teeth than the planetary gears 31, 31.

  As shown in FIGS. 2 and 4, the carrier 40 includes a lower mounting member 41 and an upper mounting member 45. The attachment members 41 and 45 are formed to have substantially the same outer shape and the same size. The lower mounting member 41 includes an annular plate portion 43 formed in a substantially perfect circle centered on the axis L, and two shaft portions 42 and 42 extending upward from the annular plate portion 43. On the other hand, the upper attachment member 45 includes an annular plate portion 47 formed in a substantially perfect circle centered on the axis L, and two shaft portions 46 and 46 extending downward from the annular plate portion 47.

  The shaft portions 42 and 42 of the lower mounting member 41 are arranged in the Y direction with the axis L interposed therebetween, and each of the tip portions is fitted to the annular plate portion 47 of the upper mounting member 45. On the other hand, the shaft portions 46 and 46 of the upper mounting member 45 are arranged in the X direction with the axis L interposed therebetween, and the tip portions thereof are fitted in the annular plate portion 43 of the lower mounting member 41. In the present embodiment, the planetary gear 31 is rotatably attached to each of the shaft portions 42 and 42 of the lower attachment member 41.

  As shown in FIG. 3 and FIG. 4, a pair of projecting portions 44, 44 projecting outward in the radial direction of the annular plate portion 43 is provided on the outer peripheral edge of the annular plate portion 43 of the lower mounting member 41. . These projecting portions 44 and 44 are located on opposite sides of the sun gear 30 and are located at 90 degrees from each of the planetary gears 31 and 31 with the sun gear 30 as a center, that is, sandwiching the sun gear 30. Are provided on the + X direction side and the −X direction side.

  Similarly, as shown in FIG. 3 and FIG. 4, on the outer peripheral edge of the annular plate portion 47 of the upper mounting member 45, a pair of projecting portions 48, 48 projecting outward in the radial direction of the annular plate portion 47 is provided. ing. These projecting portions 48, 48 are located on opposite sides of the sun gear 30, and at a position of 90 ° from each of the planet gears 31, 31 with the sun gear 30 as a center, ie, sandwiching the sun gear 30. Are provided on the + X direction side and the −X direction side.

  As described above, the gear portion 33 of the sun gear 30, the planetary gears 31 and 31, and the carrier 40 are accommodated inside the fixed internal gear 10 and the movable internal gear 20. Here, FIG. 5 includes the fixed internal gear 10, the sun gear 30 (gear portion 33) housed inside the fixed internal gear 10, the planetary gears 31 and 31, and the lower mounting member 41 of the carrier 40. It is a top perspective view shown.

  The fixed internal gear 10 is formed of, for example, resin, plastic or the like. As shown in FIG. 3 and FIG. 5, the fixed internal gear 10 has a bottom wall 14 formed at its central portion with a through hole through which the gear portion 33 of the sun gear 30 penetrates, and from the outer peripheral edge of the bottom wall 14 It includes an extending cylindrical wall 12 and an internal tooth 11 consisting of a plurality of teeth projecting radially inward of the fixed internal gear 10 from the inner circumferential surface 12A of the cylindrical wall 12. The lower mounting member 41 of the carrier 40 is mounted on the bottom wall 14.

  As shown in FIGS. 3 and 5, the internal teeth 11 are provided over the entire circumference of the fixed internal gear 10 and extend from a position slightly below the top of the cylindrical wall 12 to near the lower end of the planetary gear 31. There is. The substantially lower half of each of the planetary gears 31 and 31 meshes with the internal teeth 11 on the opposite side of the gear portion 33 of the sun gear 30. Between the lower end of the internal tooth 11 and the bottom wall 14, a guide portion 13 extending radially inward of the fixed internal gear 10 is provided. The guide portion 13 is provided over the entire circumference of the fixed internal gear 10, and is configured such that the projecting portions 44, 44 of the lower mounting member 41 slide (slide) when the geared motor 1 operates. There is.

  In addition, a molding material can be easily flowed in the whole metal mold | die by arrange | positioning the gate of the metal mold | die used at the time of shaping | molding of the fixed internal gearwheel 10 to the guide part 13 of the fixed internal gearwheel 10. In this case, a gate trace (not shown) of the mold is positioned at the guide portion 13 of the fixed internal gear 10.

  Next, the movable internal gear 20 will be described. Here, FIG. 6 is a lower perspective view showing the movable internal gear 20, the planetary gears 31 and 31 accommodated inside the movable internal gear 20, and the upper attachment member 45 of the carrier 40. In FIG. 6, the sun gear 30 is not shown to facilitate understanding.

  The movable internal gear 20 is formed of, for example, resin, plastic, or the like, similarly to the fixed internal gear 10. As shown in FIGS. 3 and 6, the main body portion 28 of the movable internal gear 20 projects radially inward of the main body portion 28 from the inner surface of the cylindrical wall 22 extending downward from the outer peripheral edge of the upper wall 24. And an inner tooth 23 consisting of a plurality of teeth. The internal teeth 23 are provided inside the cylindrical wall 22 over the entire circumference of the main body portion 28 and are formed to have a different number of teeth than the internal teeth 11 of the fixed internal gear 10. Further, the internal teeth 23 extend further to the lower side than the lower end of the cylindrical wall 22, and are configured to mesh with substantially upper halves of the planetary gears 31, 31.

  As shown in FIGS. 1 and 3, the lower internal teeth 23A of the internal teeth 23 located below the cylindrical wall 22 have an upper surface 11A of the internal teeth 11 of the fixed internal gear 10 and an inner periphery of the cylindrical wall 12. It is slidably fitted in the recess defined by the surface 12A.

  As shown in FIGS. 3 and 6, a guide 25 extending radially inward of the main body 28 is provided between the inner teeth 23 and the upper wall 24. The guide portion 25 is provided over the entire circumference of the main body portion 28 and configured such that the projecting portions 48 and 48 of the upper attachment member 45 slide (slide) when the geared motor 1 operates.

  The molding material can be easily flowed into the entire mold by arranging the gate of the mold used when molding the movable internal gear 20 on the guide portion 25 of the movable internal gear 20. In this case, a gate trace (not shown) of the mold is positioned at the guide portion 25 of the movable internal gear 20.

  Next, the operation of such a geared motor 1 will be described. That is, when the motor 3 is operated, the motor shaft 3A rotates, and the sun gear 30 rotates accordingly. Further, when the sun gear 30 rotates, the two planetary gears 31 31 meshing with the sun gear 30 rotate (rotation). By the way, since these planetary gears 31, 31 are also meshed with the internal teeth 11 of the fixed internal gear 10 and the internal teeth 23 of the movable internal gear 20 on the opposite side of the sun gear 30, they only rotate as described above. Rather, it is guided by the internal teeth 11, 23 and revolves around the gear portion 33 of the sun gear 30.

  Then, with such revolution of the planetary gears 31, 31, the carrier 40 (annular plate portions 43, 47) holding the planetary gears 31, 31 rotates around the axis L (that is, around the sun gear 30). Do. Under the present circumstances, according to this embodiment, the protrusion parts 44 and 44 of the lower side attachment member 41 are provided so that it may slide-contact with the guide part 13 of the fixed internal gearwheel 10, and the protrusion part 48 of the upper side attachment member 45 is also provided. , 48 are provided so as to be in sliding contact with the guide portion 25 of the movable internal gear 20, the protrusions 44 and 48 are guided by the guide portions 13 and 25 when the carrier 40 is rotated. It slides and rotates with respect to the portions 13 and 25.

  Further, along with the revolution of the planetary gears 31, 31, the movable internal gear 20 (that is, the shaft portion 21 of the movable internal gear 20) is also rotated. Here, according to the present embodiment, since the number of teeth of the fixed internal gear 10 and the movable internal gear 20 is different, the reduction ratio of the shaft portion 21 (output shaft) with respect to the rotational speed of the motor shaft 3A becomes extremely large.

  In particular, the gear reduction mechanism 7 in the present embodiment is configured by two planetary gears, and is configured by a smaller number of planetary gears as compared to, for example, the case where the number of planetary gears is three. Therefore, a larger reduction ratio can be obtained as compared to the case where the number of planetary gears is large (three or more).

  By the way, when there are only two planetary gears as in the present embodiment, the planetary gear is less in area meshing with the internal gear as compared with the case where the planetary gear is three or more. At the time of assembling, the carrier and the internal gear are easily displaced. As a result, there is a possibility that the planetary gear and the internal gear may be assembled at an incorrect position.

  However, according to the present embodiment, as shown in FIG. 5 and FIG. 6, when the carrier is provided with the protrusion slidingly contacting the guide of the internal gear, when assembling the internal gear and the planetary gear In addition, since the protruding portion of the carrier is positioned in sliding contact with the guide portion of the internal gear, it is possible to prevent the planetary gear and the internal gear from being assembled at an incorrect position.

  As described above, the projecting portions 44 and 48 of the carrier 40 in the present embodiment prevent the planetary gear 31 and the internal gears 10 and 20 from being assembled at an incorrect position, and thus the planetary gear 31 (carrier 40) Functions as a positioning unit for positioning the

  By the way, according to the example of this embodiment, since the two planetary gears 31 and 31 are arranged in the Y direction, the shift of the carrier 40 in the Y direction is unlikely to occur. On the other hand, since the planetary gear is not disposed in the X direction perpendicular to the Y direction, the carrier 40 is easily displaced in the X direction. However, according to the present embodiment, the protrusions 44, 44 are provided on the + X direction side and the −X direction side across the sun gear 30 (see FIG. 5), and similarly, the protrusions 48, 48 are also the sun Since the gear 30 is provided on the + X direction side and the −X direction side (see FIG. 6), the shift of the carrier 40 in the X direction is effectively suppressed.

  As described above, according to the geared motor 1 in the present embodiment, not only can a large reduction ratio be obtained by reducing the number of planetary gears, but the planetary gears 31, 31 and the internal gears 10, 20 are erroneous. Because there is almost no chance of being assembled at the same position, problems such as performance degradation are less likely to occur.

  Further, according to the fixed internal gear 10 in the present embodiment, as shown in FIG. 3, the thickness between the bottom wall 14 and the internal teeth 11 is made by the guide portion 13 that exists between the bottom wall 14 and the internal teeth 11. Is getting bigger. That is, in the mold for molding the fixed internal gear 10, a thick portion corresponding to the guide portion 13 exists. Therefore, by arranging the gate in this thick portion and pouring in a material such as resin or plastic, the material easily penetrates the entire mold, so that the fixed internal gear 10 can be formed efficiently. The same applies to the movable internal gear 20.

  In the first embodiment described above, an example in which the number of planetary gears is two has been described, but the number of planetary gears may be one in order to obtain a larger reduction ratio than the first embodiment. Second Embodiment FIG. 7 is a lower perspective view showing the movable internal gear 20 and the like of the geared motor 100 according to the second embodiment.

  The geared motor 100 has the same configuration as the geared motor 1 except that the number of planetary gears is one and the number and position of the protrusions of the carrier are different. Therefore, below, the explanation about composition common to geared motor 1 is omitted.

  As shown in FIG. 7, the geared motor 100 has a movable internal gear 20 and a carrier 40 that holds a single planetary gear 131. The upper mounting member 45 of the carrier 40 is provided with three projecting portions 148A, 148B, 148C which project outward in the radial direction from the outer peripheral edge of the annular plate portion 47. The projecting portions 148A to 148C are configured to be in sliding contact with the guide portion 25 of the movable internal gear 20.

  As shown in FIG. 7, the protrusions 148A, 148B, and 148C are provided at each vertex of an equilateral triangle centered on the axis L of the geared motor 100 (that is, centered on the sun gear). That is, the protrusion 148A is provided at a position of 60 degrees from the planetary gear 131 centering on the sun gear, the protrusion 148B is provided at a position of 180 degrees, and the protrusion 148C is provided at a position of 300 degrees. ing.

  Although not shown, the lower mounting member 41 of the carrier 40 also has three protrusions arranged in the same positional relationship as the protrusions 148A, 148B and 148C.

  Thus, according to the present embodiment, three protrusions are disposed on an equilateral triangle including the portion on the opposite side of the planetary gear 131 with respect to the axis L. Therefore, even when there is only one planetary gear and the area in which the planetary gear and the internal gear mesh with each other is smaller than in the case where there are two planetary gears, when assembling the internal gear and the planetary gear, Since the three protrusions are positioned in sliding contact with the guide portion of the internal gear, the planetary gear and the internal gear are prevented from being assembled at an incorrect position. That is, according to the present embodiment, it is possible to configure a geared motor having a large reduction ratio as compared with the first embodiment while preventing the internal gear and the planetary gear from being assembled at the wrong position. it can.

  In addition, although the above-mentioned embodiment demonstrated the case where the number of planet gears was two or less, the number of planet gears may be three or more. For example, in addition to the two planetary gears 31, 31, the planetary gear may be attached to one of the shaft portions 46, 46 of the upper attachment member 45, and a geared motor having three planetary gears may be configured. In this case, for example, one protrusion may be provided on the outer peripheral edge of each of the annular plate portions 43 and 47 located in the vicinity of the other shaft portion 46. Thereby, positional deviation of the carrier can be effectively suppressed.

  Moreover, although the above-mentioned embodiment demonstrated the example which comprises the above-mentioned positioning part by at least one protrusion, it replaces with such a protrusion, and the outer peripheral surface of a cyclic | annular plate part contacts a guide part. The diameter of the annular plate portion may be increased, and the entire outer peripheral surface may be used as the positioning portion. However, in the case where the positioning portion is constituted by the projecting portion, the contact area between the guide portion and the positioning portion is smaller than in the case where the positioning portion is constituted by the outer peripheral surface of the annular plate portion. And the friction between them is reduced.

  Moreover, in the above-mentioned embodiment, although the example which provided the guide part in both a fixed internal gear and a movable internal gear and provided the positioning part in both the lower side attachment member and the upper side attachment member of a carrier was demonstrated, A guide is provided on only one of the internal gear and the movable internal gear, and a positioning part is provided on only one of the lower mounting member and the upper mounting member (that is, only on the mounting member corresponding to the internal gear provided with the guide). It is also good.

  Further, in the above embodiment, an example of a geared motor provided with a strange planetary gear mechanism has been described, but the present invention relates to a geared motor provided with a planetary gear reduction mechanism, and both a strange planetary gear reduction mechanism and a planetary gear reduction mechanism. It is needless to say that the invention can be applied to a geared motor having the

  The terms “lower”, “upper”, “bottom”, “upper”, “lower”, “upper”, “lower”, and other terms used in this specification indicate the positional relationship shown in the drawings. It is used in connection with the form, and it changes with the relative positional relationship of an apparatus.

  Although the preferred embodiments of the present invention have been described above, it is needless to say that the present invention is not limited to the above-described embodiments and may be implemented in various different forms within the scope of the technical idea thereof.

Reference Signs List 1 geared motor 2 case 3 motor 3A motor shaft 4 motor holder 5 bush 6 flange 6A cylindrical portion 6B key 7 gear reduction mechanism 10 fixed internal gear 11 internal tooth 12 cylindrical wall 13 guide portion 16 key groove 20 movable internal gear 21 shaft portion (Output axis)
Reference Signs List 22 cylindrical wall 23 internal teeth 25 guide portion 28 main body portion 30 sun gear 31 planetary gear 33 gear portion 34 hollow cylindrical portion 40 carrier 41 lower mounting member 42 shaft portion 43 annular plate portion 44 projecting portion (positioning portion)
45 upper mounting member 46 shaft portion 47 annular plate portion 48 protruding portion (positioning portion)
100 Geared Motor 131 Planetary Gears 148A to 148C Protrusions (Positioning Part)
L axis

Claims (5)

In a geared motor including a motor having a motor shaft, and a gear reduction mechanism for reducing the rotational speed of the motor shaft,
The gear reduction mechanism is
A sun gear that rotates with the rotation of the motor shaft;
At least one planet gear that meshes with the sun gear and rotates with the rotation of the sun gear;
A carrier rotatably holding the at least one planetary gear;
And an internal gear rotatably retaining the at least one planetary gear around the sun gear.
The carrier has an annular plate portion rotatable around the sun gear.
The internal gear is
An internal toothing that meshes with the at least one planet gear outside the sun gear;
And a guide portion slidably in contact with a positioning portion formed on an outer peripheral edge of the annular plate portion of the carrier.
Geared motor.   The geared motor according to claim 1, wherein the positioning portion is configured by at least one protrusion protruding radially outward. The at least one planetary gear comprises two planetary gears positioned on opposite sides of the sun gear,
The at least one protrusion includes two protrusions formed at positions of 90 degrees from the two planetary gears centering on the sun gear,
The geared motor according to claim 2. The at least one planet gear comprises a single planet gear,
The at least one protrusion includes three protrusions formed at positions 60 degrees, 180 degrees, and 300 degrees respectively from the single planetary gear about the sun gear.
The geared motor according to claim 2.   The geared motor according to any one of claims 1 to 4, wherein a gate mark of a mold used to mold the internal gear is located in the guide portion of the internal gear.

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