JP2019049325A - Bear box and geared motor - Google Patents

Abstract

To provide a gear box capable of shortening the total length in an axial direction without causing damage.SOLUTION: A gear box 10 includes: a mount plate 80 fixed on an upper end surface 2A of a motor 2; a flange 70 fixed to the mount plate 80 by a screw 90; and a gear case 11. A flange 70 includes engaging claws 75, 76 projecting toward radially outside. The gear case 11 includes: a cylindrical part 12 storing a gear mechanism 110 inside; and extention parts 13, 14 extending toward the upper end surface 2A of the motor 2 from the cylindrical part 12 so as to cover an outer peripheral surface of the flange 70. At the extension parts 13, 14 of the gear case 11, engagement holes 15, 16 are formed in which the engaging claws 75, 76 are fitted by the extension parts 13, 14 elastically deforming. The mount plate 80 includes a small diameter part 82 so that the extension parts 13, 14 of the gear case 11 are located radially outside of the mount plate 80.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a gearbox, and more particularly to a gearbox that houses a gear mechanism therein.

  When attaching the gearbox to a motor such as a direct current (DC) motor, for example, as shown in FIG. 4, the flange 330 is fixed to the motor 400, and the gearbox 300 is attached to the flange 330 by attaching the gear case 310. Fixing to the motor 400 is performed. More specifically, by elastically deforming the peripheral wall 311 of the gear case 310, the engagement claw 340 formed on the flange 330 is fitted into the engagement hole formed on the peripheral wall 311 of the gear case 310 (snap fit) Thus, the gear case 310 is attached to the flange 330 (see, for example, Patent Document 1).

  Here, when the motor diameter is large to a certain extent, a screw hole can be formed in the end surface of the motor 400 to directly fix the flange 330 to the motor 400. However, when reducing the motor diameter, the end surface of the motor 400 It becomes difficult to secure a space for forming such a screw hole. Therefore, as shown in FIG. 4, a metal mount plate 320 having screw holes formed therein is fixed (welded) to the end face of the motor 400, and the flange 330 is fixed to the mount plate 320 using a screw 500. It is

  However, in recent years, it has been required to reduce the overall length in the axial direction due to the demand for miniaturization of the gearbox 300 attached to such a motor. In the conventional structure shown in FIG. The total length of the gearbox 300 is increased by the thickness of 320, and the gearbox 300 is upsized. On the other hand, when the peripheral wall 311 of the gear case 310 is shortened, the elasticity of the peripheral wall 311 is insufficient, and when the gear case 310 is fixed to the flange 330, the gear case 310 may be damaged.

Japanese Patent Application Publication No. 2003-130146

  SUMMARY OF THE INVENTION It is a first object of the present invention to provide a gearbox capable of shortening the overall axial length without causing breakage or the like.

  Another object of the present invention is to provide a miniaturized geared motor.

  According to an aspect of the present invention, there is provided a gearbox gearbox capable of shortening the overall axial length without damage or the like. The gearbox is attached to the motor. The gear box includes a mount plate fixed to an end face of the motor, a flange having an engagement claw projecting radially outward from an outer peripheral surface, and a gear case. The flange is fixed to the mount plate by a fixture. Further, the gear case includes a cylindrical portion accommodating a gear mechanism therein, and at least one extending portion extending in the axial direction from the cylindrical portion toward the end surface of the motor so as to cover the outer peripheral surface of the flange. And. The at least one extension of the gear case is formed with an engagement hole in which the engagement claw of the flange is fitted by elastic deformation of the at least one extension. Further, the mount plate has a small diameter portion at least partially having a small diameter such that the at least one extension of the gear case is located radially outward of the mount plate.

  According to such a gear box, the extension portion of the gear case can be positioned on the radially outer side of the mount plate by providing the mount plate in which the small diameter portion having a small diameter is formed at least partially. The overall length of the gear box can be shortened by the thickness of the mount plate without shortening the overall length of the extension (that is, without reducing the elasticity of the extension). Therefore, the overall axial length of the gearbox can be shortened without causing breakage of the gearbox when the gear case is fixed to the flange by snap fitting.

  Further, since the flange can be fixed to the motor via the mounting plate, it is not necessary to secure a space for attaching a fixing tool (screw) to the motor. Therefore, the motor can be miniaturized or the output of the motor can be increased.

  The mount plate may have a large diameter portion larger in diameter than the small diameter portion. In this case, the fixture is preferably attached to the large diameter portion of the mount plate. With such a configuration, a sufficient space can be secured for the mounting plate on the mounting plate. Here, a screw may be applied as the fixing tool.

  The at least one extension may include a plurality of extensions arranged along the circumferential direction. In this case, the outer edge portion of the large diameter portion of the mount plate is preferably located between the plurality of extension portions. This facilitates positioning of the gear case. Further, it is further preferable that the plurality of extension portions be disposed at symmetrical positions with respect to the axis. Such a configuration allows the gearbox to be firmly fixed to the motor.

  Here, the gear mechanism may include a plurality of planetary gear reduction mechanisms. When the gearbox includes a planetary gear reduction mechanism having a plurality of stages, the overall axial length of the gearbox is increased, but according to the present invention, the overall axial length of the gearbox is equal to the thickness of the mount plate as described above. Since the length can be shortened, the enlargement of the geared motor including the planetary gear reduction mechanism of multiple stages can be effectively suppressed.

  According to an aspect of the present invention, a miniaturized geared motor can be provided. The geared motor includes the above-described gearbox and a motor in which the mount plate of the gearbox is fixed to an end face.

  According to the gear box of the present invention, by providing the mount plate having the small diameter portion, the overall length of the gear box can be shortened by the thickness of the mount plate without reducing the elasticity of the extension portion, The snap fit makes it possible to shorten the overall axial length of the gearbox without damaging the gearbox when securing the gear case to the flange.

FIG. 1 is a front view showing a geared motor in an embodiment of the present invention. FIG. 2 is an exploded perspective view of the geared motor shown in FIG. FIG. 3 is a longitudinal sectional view along the axis of the geared motor shown in FIG. FIG. 4 is a front view showing a conventional geared motor.

  Hereinafter, an embodiment of a geared motor according to the present invention will be described in detail with reference to FIGS. 1 to 3. In FIG. 1 to FIG. 3, the same or corresponding components are given the same reference numerals, and duplicate explanations are omitted. Moreover, in FIG. 1 to FIG. 3, the scale and dimensions of each component may be exaggerated and shown, or some components may be omitted.

  1 is a front view showing a geared motor 1 according to an embodiment of the present invention, FIG. 2 is an exploded perspective view showing the geared motor 1, and FIG. 3 is a longitudinal sectional view of the geared motor 1 along an axis L of the geared motor 1. In the present specification, the + Z direction side (the side far from the motor 2) is referred to as "upper", "upper", "upper side", etc., and the -Z direction side (the side closer to the motor 2) is "lower", " There are cases such as “below” and “below”.

  As shown in FIGS. 1 to 3, the geared motor 1 has a substantially cylindrical outer shape whose central axis is an axis L extending in the Z direction (axial direction). The geared motor 1 includes a motor 2 located on the lower side and a gearbox 10 located on the upper side. The motor 2 has a motor shaft 2B projecting upward along the axis L from the center of the upper end surface 2A. On the other hand, the gear box 10 accommodates the gear mechanism 110 inside. The output shaft 22 of the gear mechanism 110 protrudes along the axis L from the top surface of the gearbox 10.

  The gear box 10 includes a mount plate 80 fixed to the upper end surface 2A of the motor 2, a flange 70 mounted on the upper surface of the mount plate 80, a gear mechanism 110 located above the flange 70, and a gear mechanism 110. And a gear case 11 housed inside. A through hole centered on the axis L is formed in the central portion of the mount plate 80 and the central portion of the flange 70, and the motor shaft 2B penetrates the center of these through holes.

  In the present embodiment, the mount plate 80 is made of metal and is fixed to the upper end surface 2A of the motor 2 by welding. As shown in FIG. 2, the mount plate 80 includes a small diameter portion 82 with a small diameter centered on the axis L and two large diameter portions 83 and 83 with a large diameter centered on the axis L. The large diameter portions 83, 83 project from the outer peripheral surface 82A of the small diameter portion 82 to the opposite sides in the X direction perpendicular to the Z direction. That is, one of the large diameter portions 83, 83 protrudes to the + X direction side, and the other protrudes to the -X direction side. Each of these large diameter parts 83, 83 is formed with a screw hole 84 into which a screw 90 as a fixing tool can be screwed.

  As shown in FIG. 2, the flange 70 has a slightly larger dimension than the mounting plate 80. That is, the flange 70 has a small diameter portion 77 corresponding to the small diameter portion 82 of the mount plate 80 and large diameter portions 73, 73 corresponding to the large diameter portions 83, 83. Each of the large diameter portions 73, 73 has an insertion hole 74 through which the screw 90 can be inserted.

  As shown in FIG. 2, in the flange 70, two cylindrical walls 71 and 72 are provided upright between the large diameter portions 73 and 73, that is, along the outer peripheral edge of the small diameter portion 77. The cylindrical walls 71 and 72 oppose each other in the Y direction perpendicular to the Z direction and the X direction, and the cylindrical wall 71 is located on the -Y side with respect to the axis L, and the cylindrical wall 72 on the + Y side. Is located.

  As shown in FIGS. 2 and 3, the small diameter portion 82 of the mount plate 80 and the small diameter portion 77 of the flange 70 are in contact, and the cylindrical walls 71 and 72 are located outside the outer peripheral surface 82A of the small diameter portion 82. There is. Further, as shown in FIG. 1, the large diameter portions 83, 83 of the mount plate 80 and the large diameter portions 73, 73 of the flange 70 are in contact, and as shown in FIG. , 84 and the insertion holes 74, 74 of the flange 70 communicate with each other.

  According to the present embodiment, as shown in FIGS. 1 and 2, the screw 90 as a fixing tool is inserted into the insertion hole 74 of the flange 70, and the screw 90 is screwed into the screw hole 84 of the mount plate 80. Thus, the flange 70 is fixed to the mounting plate 80.

  As shown in FIGS. 2 and 3, on the outer peripheral surface of the cylindrical wall 71 of the flange 70, two engaging claws 75, 75 projecting outward in the radial direction of the cylindrical wall 71 are provided. On the outer peripheral surface of 72, two engaging claws 76, 76 projecting radially outward of the cylindrical wall 72 are provided. The number of engagement claws 75 and 76 is not limited to two, and any number may be provided.

  As shown in FIGS. 1 to 3, the gear case 11 has a cylindrical portion 12 for housing the gear mechanism 110 therein, and two extending portions 13 extending downward from the lower end of the cylindrical portion 12 by a predetermined length. , 14 and so on. The extension portions 13 and 14 face each other in the Y direction, the extension portion 13 is located on the -Y direction side with respect to the axis L, and the extension portion 14 is located on the + Y direction side. In the present embodiment, such a gear case 11 is formed of an elastic resin.

  As shown in FIGS. 2 and 3, the extension portions 13 and 14 are thinner than the cylindrical portion 12. That is, the extension portions 13 and 14 are formed thinner than the cylindrical portion 12 in addition to being formed of an elastic resin and extending in the Z direction by a predetermined length. By this, it is possible to elastically deform. In the extension portion 13, two engagement holes 15, 15 to which two engagement claws 75, 75 of the flange 70 can be fitted are formed, and in the extension portion 14, the flange 70 is formed. Two engagement holes 16 and 16 are formed in which the two engagement claws 76 and 76 can be fitted. The number of engagement holes 15, 16 may be any number corresponding to the number of engagement claws 75, 76.

  As described above, according to the gear box 10 in the present embodiment, the engagement holes 15 and 16 in which the engagement claws 75 and 76 can be fitted into the extension portions 13 and 14 of the gear case 11 are formed. In addition to the above, since the extension portions 13 and 14 are formed so as to be elastically deformable, when attaching the gear case 11 to the flange 70, the engagement claws of the flange 70 are elastically deformed by the extension portions 13 and 14 being elastically deformed. 75 and 76 fit into the engagement holes 15 and 16 of the gear case 11, respectively, and the gear case 11 is attached to the flange 70 by a so-called snap fit. More specifically, the extension 13 is firmly fixed to the flange 70 at the radially outer side of the cylindrical wall 71 of the flange 70, and the extension 14 is firmly fixed to the flange 70 at the radial outer side of the cylindrical wall 72. It is fixed. Furthermore, each of the extension parts 13 and 14 is firmly fixed to the flange 70 at a position between the large diameter parts 73 and 73 of the flange 70 (and between the large diameter parts 83 and 83 of the mount plate 80). ing. As described above, according to the gear box 10 in the present embodiment, the gear case 11 is firmly fixed to the flange 70 by the snap fit.

  Further, as shown in FIG. 3, according to the gear box 10 in the present embodiment, the small diameter portion 82 of the mount plate 80 is located between the cylindrical walls 71 and 72 of the flange 70, and inside the flange 70. It is housed. The extending portions 13 and 14 of the gear case 11 are located on the radially outer side of the cylindrical walls 71 and 72, and the lower ends 13A and 14A of these are close to the upper end surface 2A of the motor 2. .

  Next, the gear mechanism 110 in the present embodiment will be described. As shown in FIGS. 2 and 3, the gear mechanism 110 is composed of two planetary gear reduction mechanisms. That is, according to the gear mechanism 110 in the present embodiment, with respect to the internal teeth 17 formed over the entire circumference on the inner surface of the cylindrical portion 12 of the gear case 11, three planetary gear reduction mechanisms of the first stage (downward) are provided. The planetary gears 31, 31, 31 are configured to mesh with the three planetary gears 30, 30, 30 of the second stage (upper) planetary gear reduction mechanism.

  As shown in FIGS. 2 and 3, the first stage planetary gear reduction mechanism includes a first pinion 60 (sun gear) fixed to the motor shaft 2 B and rotated with the motor shaft 2 B, and a first pinion 60. The three planetary gears 31, 31 and 31 arranged around and meshing with the first pinion 60 and the above-mentioned ones meshing with the three planetary gears 31, 31 and 31 on the opposite side of the first pinion 60 A tooth 17 and a first carrier 40 rotatably holding the planet gear 31 are included. Each of the planetary gears 31, 31 and 31 is mounted on the flange 70 via a washer 50.

  The first carrier 40 has a disc portion 41 and three planetary gear shafts 43, 43 and 43 extending downward from the disc portion 41. The planetary gears 31, 31, 31 are rotatably supported on the first carrier 40 by the planetary gear shafts 43, 43, 43. A second pinion 42 having an axis L as a central axis is fixed to the upper surface of the disc portion 41 of the first carrier 40.

  As shown in FIGS. 2 and 3, the second stage planetary gear reduction mechanism is disposed around the second pinion 42 (sun gear) described above and the second pinion 42 and is disposed on the second pinion 42. The planetary gear 30, rotatably supporting the planetary gear 30, and the internal teeth 17 meshing with the three planetary gears 30, 30, 30 opposite to the second pinion 42 and the three planetary gears 30, 30, 30, respectively. And a second carrier 20.

  The second carrier 20 includes a disc portion 21, the above-described output shaft 22 extending upward from the center of the top surface of the disc portion 21, and three planetary gear shafts 23 and 23 extending downward from the bottom surface of the disc portion 21. And 23). The planetary gears 30, 30, 30 are rotatably supported on the second carrier 20 by the planetary gear shafts 23, 23, 23.

  With the above configuration, the gear mechanism 110 operates as follows. That is, when the first pinion 60 is rotated by the rotation of the motor shaft 2B, the three planetary gears 31, 31 and 31 meshing with the first pinion 60 are rotated about the planetary gear shafts 43, 43 and 43 ( To rotate). In addition, each of the planetary gears 31, 31 and 31 meshes with the internal teeth 17 on the opposite side of the first pinion 60, and therefore revolves around the first pinion 60 along the internal teeth 17. The first carrier 40, that is, the second pinion 42 rotates as the planetary gears 31, 31 and 31 revolve.

  When the second pinion 42 rotates, the three planetary gears 30, 30, 30 meshing with the second pinion rotate about the planetary gear shafts 23, 23, 23 (rotation). In addition, each of the planetary gears 30, 30, 30 meshes with the internal teeth 17 on the opposite side of the second pinion 42, and therefore revolves around the second pinion 42 along the internal teeth 17. Then, along with the revolution of the planetary gears 30, 30, 30, the second carrier 20, that is, the output shaft 22 rotates.

  As described above, according to the present embodiment, since the gear mechanism 110 includes two planetary gear reduction mechanisms, the rotational speed of the motor shaft 2B is effectively reduced, and the torque of the output shaft 22 is increased.

  By the way, in a geared motor provided with a plurality of planetary gear reduction mechanisms such as the geared motor 1, the overall length in the axial direction of the gear box becomes longer compared to the case where there is one planetary gear reduction mechanism. It will In addition, if the axial length of the extension is shortened in order to shorten the overall length of the gearbox, the elasticity of the extension will be insufficient. However, according to the gear box 10 in the present embodiment, as described above, the small diameter portion 82 of the mount plate 80 is accommodated inside the flange 70, and the extension portion 13 of the gear case 11 is outside the flange 70. , 14, the lower ends 13 A, 14 A of the extension portions 13, 14 (that is, the lower ends of the gearbox 10) are in a state in which they are close to the upper end surface 2 A of the motor 2. That is, the position of the gearbox 10 is lowered by the thickness of the mount plate 80. More specifically, the overall length of the gear box is reduced by the thickness of the mount plate 80 while maintaining the overall axial length of the extensions 13 and 14 (that is, maintaining the elasticity of the extensions). (See Figures 1 and 4). Therefore, according to the present embodiment, breakage or the like of the gear case 11 when attaching the gear case 11 is suppressed, the gear case 11 is firmly fixed to the flange 70, and the geared motor can be miniaturized (see FIG. 1 and FIG. 4).

  As described above, according to this embodiment, a large reduction ratio can be obtained by providing a plurality of planetary gear reduction mechanisms. In addition, by forming the small diameter portion 82 on the mount plate 80, the gearbox 10 can be firmly fixed to the motor 2, and the geared motor 1 can be miniaturized.

  Further, according to the present embodiment, since the flange 70 can be fixed to the motor 2 via the mount plate 80, it is not necessary to form a screw hole for fixing the flange 70 to the motor 2. Therefore, the motor 2 can be made smaller, and the geared motor 1 can be further miniaturized. Alternatively, since it is not necessary to form a screw hole in the motor 2, a coil can be provided in the space forming the screw hole, and in this case, the output of the motor 2 can be increased.

  Further, according to the present embodiment, the two extending portions 13 and 14 are provided along the circumferential direction of the gear case 11 so that the large diameter portion 83 is positioned therebetween. More specifically, two extending portions 13 and 14 are provided along the circumferential direction of the gear case 11 so as to be disposed symmetrically with respect to the axis L. Therefore, the snap fit acts from both sides of the axis L, and the gear case 11 is fixed to the flange 70 more firmly.

  Furthermore, according to the present embodiment, since the extension portions 13 and 14 are positioned between the large diameter portions 83 and 83 of the mount plate 80 (and between the large diameter portions 73 and 73 of the flange 70), the gear The case 11 is firmly positioned, and displacement of the gear case 11 in the circumferential direction is suppressed.

  In addition, according to the present embodiment, the mount plate 80 includes the large diameter portion 83 expanding to the outside of the small diameter portion 82, and similarly, the flange 70 expands to the outside of the small diameter portion 77. Since 73 is included, sufficient space for forming a screw hole can be secured.

  In the above embodiment, an example of the gear box including the gear case 11 including the two extending portions 13 and 14 has been described, but if the gear case is firmly fixed to the flange, such an extension The number of protrusions may be one, or three or more.

  In the above-described embodiment, the example of the gearbox 10 including the mount plate 80 including the large diameter portion 83 which expands in diameter to the outer side of the small diameter portion 82 has been described, but a screw hole can be formed in the mount plate 80 It is not always necessary to form the large diameter portion 73 in the mount plate 80.

  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.

  The terms “lower”, “upper”, “upper”, “lower”, “upper”, “lower”, and other terms used in the present specification indicate the relationship with the illustrated embodiment. And are changed by the relative positional relationship of the devices.

DESCRIPTION OF SYMBOLS 1 geared motor 2 motor 2A motor upper end surface 10 gear box 11 gear case 12 cylindrical part 13, 14 extension part 15, 16 engagement hole 17 internal tooth 20 2nd carrier 21, 41 disc part 22 output shaft 23, 43 Planetary gear shaft 30, 31 Planetary gear 40 First carrier 42 Second pinion 50 Washer 60 First pinion 70 Flange 71, 72 Cylindrical wall 73 Large diameter portion 74 Insertion hole 75, 76 Engaging claw 77 Small diameter portion 80 Mount Plate 82 Small diameter portion 83 Large diameter portion 84 Screw hole 90 Screw 110 Gear mechanism L Axis

Claims (7)

A gearbox attached to the motor,
A mounting plate fixed to an end face of the motor;
A flange having an engaging claw projecting radially outward from an outer peripheral surface, and fixed to the mounting plate by a fixing device;
A gear case including: a cylindrical portion accommodating a gear mechanism therein; and at least one extending portion axially extending from the cylindrical portion toward the end face of the motor so as to cover the outer peripheral surface of the flange Equipped
The at least one extension of the gear case is formed with an engagement hole into which the engagement claw of the flange is fitted by elastic deformation of the at least one extension.
The mounting plate has a small diameter portion at least partially small in diameter such that the at least one extension of the gear case is located radially outward of the mounting plate.
Gearbox. The mount plate has a large diameter portion larger in diameter than the small diameter portion.
The fixture is attached to the large diameter portion of the mount plate.
A gearbox according to any one of the preceding claims.   The gearbox of claim 2, wherein the fastener is a screw. The at least one extension includes a plurality of extensions arranged along a circumferential direction,
An outer edge portion of the large diameter portion of the mount plate is located between the plurality of extension portions.
The gearbox of claim 2 or 3.   The gearbox according to claim 4, wherein the plurality of extension parts are arranged at symmetrical positions with respect to an axis.   The gear box according to any one of claims 1 to 5, wherein the gear mechanism includes a multistage planetary gear reduction mechanism. A gearbox according to any one of claims 1 to 6;
A geared motor comprising: a motor in which the mount plate of the gearbox is fixed to an end face.

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