JP2017011975A - Geared motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a geared motor in which a torque limiter can be built in without increasing the number of components, while preventing breakdown for a large load applied to the output shaft, and saving the space.SOLUTION: A geared motor 1 includes a motor 10, and a gear transmission section 20 including a planetary gear transmission mechanism having an output shaft 21. The gear transmission section 20 includes a carrier 24 for transmitting the revolution of the planetary gear, about an input sun gear 22 driven by the motor 10, to the output side. The carrier 24 includes a first carrier member 24X having an engaging part and a carrier pin 24A for pivotally supporting the planetary gear, and a second carrier member 24Y having an engaged part engaging with the engaging part and an output transmission element (intermediate sun gear 25). The engaging part and engaged part are set to be disengaged by an overload applied to the output transmission element (intermediate sun gear 25).SELECTED DRAWING: Figure 1

Description

  The present invention relates to a geared motor that outputs rotation of a motor via a gear transmission mechanism.

  As an electric mechanism of various devices (or devices), a geared motor is used that decelerates and outputs the rotational output of the motor by a gear transmission mechanism. Some geared motors have an output shaft that is coaxial or parallel to the rotational axis of the motor, and such geared motors are known in which a planetary gear speed reduction mechanism is provided in a gear case (for example, the following patent document). 1 and 2).

JP 2007-37363 A JP 2007-159237 A

  In a geared motor incorporated in various devices, even if a large load is applied to the output shaft and a gear is damaged, it may be difficult to replace parts. In order to cope with this, it is conceivable to incorporate a torque limiter in the gear transmission mechanism, but this requires a space for providing the torque limiter, and the number of parts is greatly increased. For this reason, it is difficult to reduce the size of the geared motor, and there arises a problem that the demand for space saving cannot be met.

  This invention makes it an example of a subject to cope with such a problem. That is, in the geared motor, it is possible to incorporate a torque limiter without significantly increasing the number of components, to obtain a geared motor capable of preventing damage to a large load applied to the output shaft and saving space. Is the purpose.

In order to achieve such an object, a geared motor according to the present invention has the following configuration.
A motor unit and a gear transmission unit including a planetary gear transmission mechanism having an output shaft, the gear transmission unit transmitting the revolution of the planetary gear around the input sun gear driven by the motor unit to the output side The carrier includes a first carrier member having an engaging portion and a carrier pin that pivotally supports the planetary gear, an engaged portion engaging with the engaging portion, and an output transmission element. A geared motor comprising: a second carrier member, wherein the engagement portion and the engaged portion are disengaged by an overload applied to the output transmission element.

  The geared motor of the present invention having such a feature can incorporate a torque limiter without greatly increasing the number of parts in the geared motor, and can prevent damage to a large load applied to the output shaft and can save space. A geared motor can be obtained.

It is a disassembled perspective view of the geared motor which concerns on embodiment of this invention. The carrier ((a) is a 1st carrier member and (b) is a 2nd carrier member) of the geared motor which concerns on embodiment of this invention is shown. It is explanatory drawing which shows the portable electronic device provided with the electrically-driven mechanism driven by the output of the geared motor which concerns on embodiment of this invention.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 shows a geared motor according to an embodiment of the present invention. The geared motor 1 includes a motor unit 10 and a gear transmission unit 20, and the motor unit 10 and the output shaft 21 of the gear transmission unit 20 are coaxial.

  The motor unit 10 is a stepping motor including a rotor including a rotating shaft (not shown) and a stator including a frame 11 disposed around the rotor. A bracket 12 is attached to the frame body 11. An input terminal 13 is provided on the outer periphery of the frame body 11. An input sun gear 22 is attached to the motor unit 10. In this example, the input sun gear 22 is mounted on the rotating shaft of the motor unit 10 and driven by the motor unit 10, but is driven from the rotating shaft of the motor unit 10 via a transmission mechanism such as a gear. May be.

  The gear transmission unit 20 includes a planetary gear transmission mechanism having an output shaft 21 coaxial with the motor unit 10. The planetary gear transmission mechanism includes an input sun gear 22, a first planetary gear 23, a first carrier 24, an intermediate sun gear (output transmission element) 25, a second planetary gear 26, and a second carrier that are driven by the motor unit 10. 27, a gear case 28 having a fixed internal gear is provided. In the illustrated example, the output shaft 21 is coaxial with the motor unit 10. However, the present invention is not limited thereto, and the output shaft 21 may be arranged in parallel with the rotation axis of the motor unit 10. .

  In the illustrated example, a first planetary gear unit is configured by the first planetary gear 23, the first carrier 24, and the intermediate sun gear 25, and the second planetary gear 26, the second carrier 27, and the output shaft 21 are the second planetary gear unit. Although the planetary gear unit is configured, the planetary gear mechanism may be configured by only the first planetary gear unit using the intermediate sun gear 25 as an output transmission element as an output shaft.

  Here, the first carrier 24 includes a first carrier member 24X and a second carrier member 24Y. The first planetary gear 23 is pivotally supported on the carrier pin 24A of the first carrier member 24X, and the second carrier member. The second carrier member 24Y and the intermediate sun gear (output transmission element) 25 are integrated so as to be coaxial with the center of 24Y. The second planetary gear 26 is pivotally supported on the carrier pin 27A of the second carrier 27, and the second carrier 27 and the output shaft 21 are integrated so as to be coaxial with the center of the second carrier 27.

  A fixed internal gear that meshes with the first planetary gear 23 and the second planetary gear 26 is formed inside the gear case 28. The gear case 28 includes an opening 28A, and the output shaft 21 protrudes from the opening 28A. The output shaft 21 is provided with a stop portion 21A, and the gear case 28 is prevented from coming off by fitting a ring 29 to the stop portion 21A. Further, the gear case 28 includes an engaged portion (engaged hole) 28B at an end portion on the motor portion 10 side, and the engaged portion 28B is engaged with the engaging portion 12A in the bracket 12 of the motor portion 10. As a result, the gear case 28 is attached to the motor unit 10.

  FIG. 2 shows a configuration example of the first carrier 24. In the figure, (a) shows the second carrier member 24Y, and (b) shows the first carrier member 24X. The first carrier member 24 </ b> X includes a slide base 24 </ b> B that slides on the slide surface 12 </ b> B of the bracket 12 of the motor unit 10. The slide base 24B has an opening 24B1 at the center, and the input sun gear 22 is inserted through the opening 24B1. The sliding pedestal 24 </ b> B includes a carrier pin 24 </ b> A for arranging the first planetary gear 23 at an equal angle around the input sun gear 22, and a leg portion 24 </ b> C extending along the axial direction of the input sun gear 22. Provided. Here, the carrier pins 24A and the leg portions 24C are alternately arranged at equal intervals around the opening 24B1. Thereby, the leg portion 24 </ b> C is disposed in the space between the first planetary gears 23.

  A plurality of legs 24C provided on the slide base 24B of the first carrier member 24X are arranged around the input sun gear 22 and extend along the axial direction of the input sun gear 22 and are engaged on the inner surface thereof. 24D is provided. On the other hand, the second carrier member 24Y includes a disk portion 24E orthogonal to the axis of the intermediate sun gear 25 that is an output transmission element, and an engaged portion 24F is provided on the outer peripheral surface of the disk portion 24E. Then, the engaging portion 24D and the engaged portion 24F are engaged, whereby the first carrier member 24X and the second carrier member 24Y are united and rotate around the input sun gear 22 as the first carrier 24.

  Here, the engaging portion 24D and the engaged portion 24F constitute a torque limiter. That is, when an overload is applied to the intermediate sun gear 25 that is the output transmission element, the engagement portion 24D and the engaged portion 24F are disengaged, and the rotation of the motor portion 10 is caused by the rotation of the first carrier 24. The structure does not transmit to the output side.

  In the illustrated example, the engaging portion 24D provided on the inner surface of the leg portion 24C is a plurality of convex portions (or concave portions) provided around the input sun gear 22, and the engaged portion provided on the outer peripheral surface of the disk portion 24E. 24F is a plurality of concave portions (or convex portions) provided around the intermediate sun gear 25 that is an output transmission element, and the convex portions (or concave portions) of the engaging portion 24D and the concave portions (or convex portions of the engaged portion 24F). The limit value of the transmission torque is set according to the degree of fitting.

  Further, since the engaging portion 24D is provided at the free end of the leg portion 24C that is cantilevered by the slide base 24B, the limit value of the transmission torque in the first carrier 24 is set by the bending rigidity of the leg portion 24C. The In the illustrated example, the leg portion 24C includes a rib 24G that protrudes toward the center of the input sun gear 22 and extends along the axial direction of the input sun gear 22. Therefore, the shape (section modulus) of the rib 24G Is set appropriately, the limit value of the torque transmitted by the first carrier 24 can be set.

  Such a gear transmission unit 20 is configured such that the first planetary gear 23 meshes with the input sun gear 22 driven by the motor unit 10, and the first planetary gear 23 meshes with the fixed internal gear 28 of the gear case 28. The first planetary gear 23 revolves around the input sun gear 22 by the rotation of the input sun gear 22 that is driven by the rotation of the input sun gear 22, and the first carrier 24 rotates coaxially with the input sun gear 22 by the revolution. The intermediate sun gear 25 that rotates integrally with the first carrier 24 meshes with the second planetary gear 26, and the second planetary gear 26 meshes with the fixed internal gear of the gear case 28, thereby integrating with the first carrier 24. The rotation of the intermediate sun gear 25 causes the second planetary gear 26 to revolve around the intermediate sun gear 25, and the revolution causes the second carrier 27 to rotate coaxially with the input sun gear 22. Thereby, the rotation of the motor unit 10 is decelerated and transmitted to the output shaft 21 integral with the second carrier 27.

  In a state where the gear transmission unit 20 is assembled to the motor unit 10, the input sun gear 22 is press-fitted into the rotation shaft of the motor unit 10, and the sliding base 24 </ b> B of the first carrier member 24 </ b> X is mounted on the sliding surface 12 </ b> B of the bracket 12. The carrier pin 24 </ b> A provided on the slide base 24 </ b> B pivotally supports the first planetary gear 23. Further, the engaged portion 24F of the second carrier member 24Y is engaged with the engaging portion 24D of the first carrier member 24X to integrate the first carrier 24, so that the second planetary gear 26 is the second carrier. The second planetary gear 26 is placed on the disk portion 24E of the member 24Y, the second planetary gear 26 meshes with the intermediate sun gear 25, and the second planetary gear 26 is pivotally supported by the carrier pin 27A of the second carrier 27. In the gear case 28, the fixed internal gear inside thereof is engaged with the first planetary gear 23 and the second planetary gear 26, and the engaged portion 28 </ b> B provided in the gear case 28 is engaged with the engaging portion 12 </ b> A of the bracket 12. Thus, the gear case 28 is attached to the motor unit 10.

  Here, the motor unit 10 and the gear transmission unit 20 are assembled by integrating the second carrier 27, the second planetary gear 26, and the first planetary gear 23 inside the gear case 28 upside down. The first carrier 24 is sequentially inserted, and finally the motor unit 10 with the input sun gear 22 attached is inserted, and the engaged portion 28B of the gear case 28 and the engaging portion 12A of the motor unit 10 are engaged.

  According to such a geared motor 1, when a large load is applied to the output shaft 21, the torque limiter incorporated in the first carrier 24 works to disengage the engaging portion 24 </ b> D from the engaged portion 24 </ b> F. Damage to the transmission unit 20 is avoided. At this time, the torque limiter divides the first carrier 24 into the first carrier member 24X and the second carrier member Y, and the first carrier member 24X is provided with the engaging portion 24D, and the second carrier member 24Y is engaged. Since it has a simple structure provided with the joint portion 24F, the torque limiter can be incorporated into the gear transmission portion 20 without increasing the number of parts.

  The engagement between the engaging portion 24D of the first carrier member 24X and the engaged portion 24F of the second carrier member 24Y does not form an additional space along the axial direction of the motor unit 10, and the gear Since the transmission elements in the transmission unit 20 are arranged without leaving a space along the axial direction, the total length in the axial direction can be shortened. As a result, a geared motor 1 capable of saving space can be obtained.

  FIG. 3 shows a portable electronic device 100 including an electric mechanism that is driven by the output of the geared motor 1 according to the embodiment of the present invention. The portable electronic device 100 such as a smart phone includes a camera unit (operation unit) 101, and the geared motor 1 can be used as an electric mechanism for adjusting a photographing direction in the camera unit 101. Moreover, the geared motor 1 can also be used as an electric mechanism which provides the cover (operation | movement part) which covers the screen of the portable electronic device 100, and opens and closes this cover. Since the total length of the geared motor 1 can be shortened, the installation occupation space in the portable electronic device 100 can be minimized, and the functionality of the portable electronic device 100 can be enhanced.

  As described above, the embodiments of the present invention have been described in detail with reference to the drawings. However, the specific configuration is not limited to these embodiments, and the design can be changed without departing from the scope of the present invention. Is included in the present invention.

1: Geared motor,
10: motor part, 11: frame,
12: bracket, 12A: engaging portion, 12B: sliding surface, 13: input terminal,
20: Gear transmission part, 21: Output shaft, 21A: Stop part,
22: Input sun gear,
23: first planetary gear, 24: first carrier, 24A: carrier pin,
24B: Slide base, 24B1: Opening, 24C: Leg part, 24D: Engagement part,
24E: disk part, 24F: engaged part, 24G: rib,
24X: first carrier member, 24Y: second carrier member,
25: Intermediate sun gear (output transmission element), 26: Second planetary gear,
27: Second carrier, 27A: Carrier pin,
28: gear case, 28A: opening, 28B: engaged portion (engaged hole),
29: Ring, 100: Portable electronic device, 101: Camera unit (operation part)

Claims (6)

A motor unit and a gear transmission unit including a planetary gear transmission mechanism having an output shaft;
The gear transmission is
A carrier for transmitting the revolution of the planetary gear around the input sun gear driven by the motor unit to the output side;
The carrier has a first carrier member having an engaging portion and a carrier pin that pivotally supports the planetary gear, a second carrier having an engaged portion engaging with the engaging portion and an output transmission element. With members,
A geared motor, wherein the engagement portion and the engaged portion are set so as to be disengaged by an overload applied to the output transmission element. The engaging portion is a plurality of convex portions or concave portions provided around the input sun gear,
The geared motor according to claim 1, wherein the engaged portion is a plurality of concave portions or convex portions provided around the output transmission element. The first carrier member includes a plurality of legs arranged around the input sun gear and extending along the axial direction of the input sun gear, and the engaging portion is provided on an inner surface of the leg.
3. The geared motor according to claim 1, wherein the second carrier member includes a disk portion orthogonal to the axis of the output transmission element, and the engaged portion is provided on an outer peripheral surface of the disk portion. The planetary gears are arranged equiangularly around the input sun gear;
The geared motor according to claim 3, wherein the leg portion is provided in a space between the planetary gears.   5. The geared motor according to claim 3, wherein the leg portion includes a rib protruding toward the center of the input sun gear and extending along an axial direction of the input sun gear.   A portable electronic device comprising: the geared motor according to claim 1; and an operation unit that is operated by the geared motor.

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