JP7417250B2 - geared motor - Google Patents

Description

The present invention relates to a geared motor with excellent quietness and low vibration.

Conventionally, a transmission (reducer) that employs a planetary gear reduction mechanism that includes a sun gear, a planetary gear that externally meshes with the sun gear, and a fixed internal gear that internally meshes with the planetary gear, and a motor are integrated. Geared motors equipped with this type of motor have been widely put into practical use.

For example, in a conventional geared motor speed reduction mechanism, the outer circumferential surface of the geared motor is non-floating and rotatably supported, and an internal gear with a sun gear attached to one side and an external gear formed at the tip of the motor shaft are placed at the regular gear meshing position. On the other hand, a rotary disk is fixed to the base end of the output shaft, and at least three planetary gears that mesh with the fixed internal gear fixed to the cover of the geared motor are rotated at equal angular intervals on the rotary disk. The three or more planetary gears mesh with each other so as to hold the center of the sun gear (for example, see Patent Document 1).

In addition, in a conventional planetary geared motor, a rotating shaft of a motor equipped with a drive gear and a planetary carrier of a speed reduction mechanism are engaged with each other so as to be rotatable with each other and movable along the axial direction of the rotating shaft of the motor. When the motor section and the reduction mechanism section are connected by providing an engaging section to engage the drive gear and the planetary gear, the length of the tip of the rotating shaft beyond the drive gear mounting position of the motor is is at least larger than the axial length of the first-stage planetary gear, and is arranged such that the tip of the rotating shaft of the motor is inserted into the engagement portion at the rotation center of the first-stage planetary carrier to support the rotational axis of the planetary carrier. (For example, see Patent Document 2).

Japanese Unexamined Patent Publication No. 55-119249 Japanese Patent Application Publication No. 2002-349643

Geared motors using such planetary gear reduction mechanisms are used for various purposes, and depending on the environment in which they are used, quietness and low vibration may be required.

However, in the above-mentioned geared motor, when a radial load is generated due to the meshing of the gears, there is a problem that noise and vibration are generated due to contact between the fixed internal gear and the inner circumferential surface of the housing.

The present invention was made in order to solve the above problems, and provides a geared motor that is excellent in quietness and has low vibration.

A geared motor according to the present invention is provided integrally with an electric motor having a drive shaft, and a transmission section that changes the speed of the driving force inputted using the drive shaft of the electric motor as an input shaft and outputs it from the output shaft, The transmission section is a geared motor having at least one stage of a planetary gear reduction mechanism, and the planetary gear reduction mechanism is externally meshed with a sun gear that rotates in response to the rotational force of the electric motor and rotates. The system includes a plurality of planetary gears that drive the output shaft accordingly, and a fixed internal gear that is fixedly supported on the inner circumferential surface of the cylindrical housing of the transmission section and internally meshes with the planetary gears. It is characterized in that a buffer section made of an elastic body is disposed between the two.

As described above, in the present invention, the planetary gear reduction mechanism includes a sun gear that rotates in response to rotational force from an electric motor, and a plurality of planetary gears that are externally meshed with the sun gear and drive an output shaft as the sun gear rotates. , a fixed internal gear is fixedly supported on the inner circumferential surface of a cylindrical housing of the transmission part and internally meshes with the planetary gear, and a buffer section made of an elastic body is disposed between the housing and the fixed internal gear. Because of this, when the fixed internal gear disposed radially outermost from the axis, which transmits the radial load generated by the meshing of the gears of the planetary gear reduction mechanism, comes into contact with the inner peripheral surface of the housing, This radial load is absorbed by the buffer section made of an elastic body, which has the effect of suppressing noise and vibration caused by direct contact between the fixed internal gear and the inner circumferential surface of the housing.

In the geared motor according to the present invention, if necessary, the buffer portion is disposed in a large diameter portion formed by enlarging the inner diameter of the end of the casing on the electric motor side.

In this way, in the present invention, since the buffer section is disposed in the large diameter section formed by enlarging the inner diameter of the end of the housing on the electric motor side, the The shock absorber absorbs the radial load generated at the portion most affected by the high-speed rotation of the electric motor, and has the effect of suppressing noise and vibration generated by the geared motor.

In the geared motor according to the present invention, the buffer portion may include a large-diameter portion formed by expanding the inner diameter of the end of the casing on the electric motor side, and a storage portion of the casing and the large-diameter portion. It is arranged in the stepped part that connects the

As described above, in the present invention, the buffer section includes a large diameter section formed by expanding the inner diameter of the end of the casing on the electric motor side, and a stepped section connecting the housing section and the large diameter section of the casing. The fixed internal gear, which is located radially outermost from the axis and which transmits the thrust load generated by the meshing of the gears of the planetary gear reduction mechanism, comes into contact with the inner circumferential surface of the housing. At this time, this thrust load is absorbed by the buffer section made of an elastic body, which has the effect of suppressing noise and vibration caused by direct contact between the fixed internal gear and the inner peripheral surface of the housing.

In the geared motor according to the present invention, the stepped portion is formed in a tapered shape whose diameter decreases from the large diameter portion toward the storage portion, if necessary.

In this way, in the present invention, the stepped portion is formed in a tapered shape that decreases in diameter from the large diameter portion toward the storage portion, so even if there are design errors in various gears, the thrust load can be reduced. As a result, the fixed internal gear is pushed toward the output shaft side along the tapered surface of the stepped part, and the fixed internal gear can be fixed to the buffer part of the stepped part, reducing noise and vibration caused by a reduction in meshing ratio due to design errors, etc. This has the effect of suppressing the

In the geared motor according to the present invention, an annular recess is formed between the large diameter portion and the stepped portion, if necessary.

In this way, in the present invention, since the annular recess is formed between the large diameter part and the stepped part, the buffer part made of an elastic body is arranged along the annular recess. In addition to stably fixing the elastic body to the housing, it can also function as a relief mechanism for the expanded portion when the elastic body expands thermally, and has the effect of suppressing noise and vibration caused by peeling of the buffer section, etc. has.

In the geared motor according to the present invention, the sun gear, the planetary gear, and the fixed internal gear are helical gears or helical gears, if necessary.

In this way, in the present invention, since the sun gear, planetary gear, and fixed internal gear are helical gears or mountain gears, it is possible to improve the meshing ratio between the gears, thereby reducing noise and vibration. It has the effect of being able to suppress

In the geared motor according to the present invention, if necessary, the electric motor includes a motor body and a motor casing that accommodates the motor body, and a bearing made of an elastic body is provided between the motor body and the motor casing. A holding buffer is provided.

Thus, in the present invention, the electric motor includes a motor body and a motor casing that houses the motor body, and a bearing holding buffer made of an elastic body is disposed between the motor body and the motor casing. Due to the fact that the electric motor is equipped with a Since the noise and vibration of the electric motor are absorbed by the bearing holding buffer made of an elastic body, it is possible to suppress the noise and vibration of the electric motor.

FIG. 2 is a longitudinal cross-sectional view along the axis of the geared motor according to the present embodiment. FIG. 2 is an enlarged vertical cross-sectional view along the axis of a first stage planetary gear reduction mechanism portion according to the first embodiment. FIG. 7 is an enlarged vertical cross-sectional view along the axis of the first stage planetary gear reduction mechanism portion according to the second embodiment. FIG. 7 is an enlarged vertical cross-sectional view along the axis of a first stage planetary gear reduction mechanism portion according to a third embodiment. FIG. 7 is an enlarged vertical cross-sectional view along the axis of a first stage planetary gear reduction mechanism portion according to a fourth embodiment.

Embodiments of the present invention will be described below. Further, the same elements are given the same reference numerals throughout this embodiment.

(First embodiment)
A geared motor according to this embodiment will be explained using FIGS. 1 and 2. FIG. 1 is a vertical cross-sectional view along the axis of the geared motor according to the present embodiment, and FIG. 2 is an enlarged vertical cross-sectional view along the axis of the first stage planetary gear reduction mechanism.

As shown in FIGS. 1 and 2, the geared motor 1 includes an electric motor 2 and a transmission section 3, and the electric motor 2 and transmission section 3 are integrally provided. The geared motor 1 has a substantially cylindrical outer shape with an axis A as the central axis.
The electric motor 2 has a drive shaft 21 extending from the center of one end surface along the axis A to the transmission section 3 side.
The transmission section 3 has an output shaft 31 that protrudes along the axis A and that changes the speed of the driving force that is input using the drive shaft 21 of the electric motor 2 as an input shaft and outputs the same.

The electric motor 2 includes a motor body 22 and a substantially cylindrical motor housing 23 that accommodates the motor body 22 therein. The drive shaft 21 is rotatably supported by the motor housing 23 via a bearing 24 .
Further, the electric motor 2 includes a bearing holding buffer section 25 made of an elastic body between the motor body 22 and the motor housing 23. The bearing holding buffer section 25 is interposed between the bearing 24 that pivotally supports the drive shaft 21 and the lid section 26 of the motor housing 23 at least at both ends of the drive shaft 21, and is arranged between the bearing 24 and the lid section 25. They are separated.

The transmission section 3 includes a mount plate 32 fixed to an end surface of the electric motor 2, a flange 34 fixed to the mount plate 32 with screws 33, a gear mechanism 40 disposed above the flange 34, and this gear mechanism. 40 is housed therein, and the flange 34 is fixed by a spring pin 35.
A through hole centered on the axis A is formed in the center of the mount plate 32 and the flange 34, and the drive shaft 21 of the electric motor 2 is inserted through this through hole.

The gear mechanism 40 includes three stages of planetary gear reduction mechanisms 50, 60, and 70.

The first stage planetary gear reduction mechanism 50 includes a first sun gear 51 that is fixed to the drive shaft 21 of the electric motor 2 and rotates together with the drive shaft 21 in response to the rotational force of the electric motor 2; A plurality of (for example, four) planetary gears 52 are disposed around the gear 51 and externally mesh with the first sun gear 51, and are fixedly supported over the entire inner peripheral surface of a cylindrical housing 36, It includes a fixed internal gear 53 that internally meshes with a plurality of planetary gears 52, and a buffer section 54 made of an elastic body provided between the housing 36 and the fixed internal gear 53. The plurality of planetary gears 52 are rotatably held by a first carrier 55.

The housing 36 includes a storage section 38 centered on the axis A, which is provided from the vicinity of the second-stage planetary gear reduction mechanism 60 to the output shaft 31 side, which will be described later, and an electric motor from the vicinity of the first-stage planetary gear reduction mechanism 50. On the inner peripheral surface of the second side, the inner diameter of the end portion is enlarged to have a larger diameter than the storage portion 38, and a large diameter portion 37 centered on the axis A, and a step portion 39 connecting the large diameter portion 37 and the storage portion 38 are provided. have.

The buffer portion 54 includes a circumferential portion 54a disposed along the large diameter portion 37 of the housing 36, and a bottom portion 54b which is fixed onto the flange 34 via a washer 56 and has an annular shape. The material and type of the buffer section 54 are not particularly limited, and any material may be used as long as it supports the radial load from the first stage planetary gear reduction mechanism and suppresses and absorbs vibrations caused by this radial load, for example. Synthetic rubber such as butyl rubber. Note that the buffer portion 54 only needs to be provided between the housing 36 and the fixed internal gear 53, that is, it only needs to have at least the circumferential portion 54a.

The first carrier 55 has a plurality of input holding shafts 55a that rotatably support each planetary gear 52, and each of the input holding shafts 55a is fixed to one side at equal intervals in the circumferential direction around the axis A. A disk portion 55b consisting of a disk body, and a second sun gear 61 of a second stage planetary gear reduction mechanism 60 rotatably centered on the axis A on the other side of the disk body of the disk portion 55b. The output holding shaft 55c is fixedly supported. The second sun gear 61 rotates in synchronization with the first carrier 55.

The second stage planetary gear reduction mechanism 60 includes a second sun gear 61 and a plurality of (for example, three) gears arranged around the second sun gear 61 and externally meshing with the second sun gear 61. A planetary gear 62, a fixed internal gear 63 that is fixedly supported by the storage portion 38 of the housing 36 and internally meshes with the plurality of planetary gears 62, and a second carrier 64 that rotatably holds the plurality of planetary gears 62. It is equipped with

The second carrier 64 has a plurality of input holding shafts 64a that rotatably support the respective planetary gears 62, and the input holding shafts 64a are fixed to one side at equal intervals in the circumferential direction around the axis A. A disk portion 64b consisting of a disk body, and a third sun gear 71 of the third stage planetary gear reduction mechanism 70 rotatably centered on the axis A on the other side of the disk body of the disk portion 64b. The output holding shaft 64c is fixedly supported. The third sun gear 71 rotates in synchronization with the second carrier 64.

The third stage planetary gear reduction mechanism 70 includes a third sun gear 71 and a plurality of (for example, four) gears disposed around the third sun gear 71 and externally meshing with the third sun gear 71. A planetary gear 72, a fixed internal gear 73 that is fixedly supported by the storage portion 38 of the housing 36 and internally meshes with the plurality of planetary gears 72, and a third carrier 74 that rotatably holds the plurality of planetary gears 72. It is equipped with

The third carrier 74 has a plurality of input holding shafts 74a that rotatably support the respective planetary gears 72, and each of the input holding shafts 74a is fixed to one side at equal intervals in the circumferential direction around the axis A. A disc portion 74b formed of a disc body is formed. The output shaft 31 of the transmission section 3 is fixedly supported around the axis A on the other side of the disk body of the disk section 64b. The output shaft 31 rotates in synchronization with the third carrier 74.

The types of sun gears, planetary gears, and fixed internal gears are not particularly limited, and may be spur gears, helical gears, or double helical gears. From the viewpoints of strength), quietness, etc., a helical gear or a helical gear is preferable. For example, the first-stage planetary gear reduction mechanism may employ helical gears, and the second- and third-stage planetary gear reduction mechanisms may employ spur gears.

Note that the geared motor 1 according to the present embodiment only needs to include at least the first stage planetary gear reduction mechanism 50 described above.

Next, the operation of the geared motor 1 according to this embodiment will be explained.

When the electric motor 2 is energized and operated, the first sun gear 51 rotates due to the rotation of the drive shaft 21. Then, the plurality of planetary gears 52 that are externally meshed with the first sun gear 51 rotate (rotate) about the input holding shaft 55a. At the same time, since the planetary gear 52 is internally meshed with the fixed internal gear 53, it rotates (revolutions) around the first sun gear 51 along the fixed internal gear 53. Since this fixed internal gear 53 is fixed to the large diameter portion 37 of the housing 36 and supports the rotation of the plurality of planetary gears 52, the rotational stress between the planetary gears 52 and the first sun gear 51 is The vibration generated between the fixed internal gear 53 and the housing 36 is absorbed by the elastic force of the buffer section 54 interposed between the fixed internal gear 53 and the large diameter section 37, and the vibration is suppressed. , noise can be reduced.
In this way, a rotational force is applied to the planetary gear 52 whose vibration is suppressed, and as the planetary gear 52 revolves, the first carrier 55, that is, the second sun gear 61, rotates.

When the second sun gear 61 rotates, the plurality of planetary gears 62 that are externally meshed with the second sun gear 61 rotate (rotate) about the input holding shaft 64a. At the same time, since the planetary gear 62 is internally meshed with the fixed internal gear 63, it rotates (revolutions) around the second sun gear 61 along the fixed internal gear 63. As the planetary gear 62 revolves, the second carrier 64, that is, the third sun gear 71, rotates.

When the third sun gear 71 rotates, the plurality of planetary gears 72 that are externally meshed with the third sun gear 71 rotate (rotate) about the input holding shaft 74a. At the same time, since the planetary gear 72 is internally meshed with the fixed internal gear 73, it rotates (revolutions) around the third sun gear 71 along the fixed internal gear 73. As the planetary gear 72 rotates, the third carrier 74, that is, the output shaft 31 of the transmission section 3 rotates.

As described above, since the gear mechanism 40 includes the three-stage planetary gear reduction mechanism 50, 60, and 70, the rotational speed of the drive shaft 21 of the electric motor 2 is effectively reduced, and the output shaft of the transmission section 3 is 31 torque can be increased, and vibrations can be absorbed by the elastic force of the buffer section 54 interposed between the fixed internal gear 53 and the large diameter section 37 of the housing 36, thereby reducing overall vibration. It prevents noise and "beating" caused by resonance, making it possible to realize a quiet device.

(Second embodiment)
The geared motor according to this embodiment will be explained using FIG. 3. FIG. 3 is an enlarged vertical cross-sectional view along the axis of the first stage planetary gear reduction mechanism portion according to the second embodiment.
Note that in this embodiment, explanations that overlap with those of the first embodiment will be omitted.

Unlike the first embodiment, the geared motor according to the present embodiment has a sun gear, a planetary gear, and a fixed internal gear formed by helical gears or convex gears, and a buffer portion having a substantially U-shaped cross section. This is the configuration that will be used.
Below, an example will be described in which helical gears are used as the sun gear, planetary gear, and fixed internal gear.

The first sun gear 81 is a left-handed helical gear with tooth traces rising to the left, and as the drive shaft 21 of the electric motor 2 rotates, the first sun gear 81 rotates clockwise when viewed from the output shaft 31 side of the transmission section 3. Rotate.
The plurality of planetary gears 82 are right-handed helical gears with tooth traces rising to the right, and rotate (rotate) counterclockwise when viewed from the output shaft 31 side, and when viewed from the output shaft 31 side of the transmission section 3. It rotates (revolutions) around the first sun gear 81 clockwise.
The fixed internal gear 83 is a left-handed helical gear with tooth traces rising to the left.

As shown in FIG. 3, the buffer part 84 is fixed on the flange 34 via a circumferential part 84a disposed circumferentially along the large diameter part 37 of the housing 36 and a washer 56. It has an annular bottom portion 84b and an annular top plate portion 84c disposed along the stepped portion 39 of the housing 36. That is, in the present embodiment, the buffer portion 84 surrounds the fixed internal gear 83 so that the fixed internal gear 83 and the housing 36 do not come into direct contact with each other, so that at least the large diameter portion 37 and the step of the housing 36 are protected. It is arranged in section 39.

As mentioned above, if helical gears (or angle gears) are used as the sun gear, planetary gear, and fixed internal gear, advantages such as meshing ratio, strength (surface pressure strength), and quietness can be enjoyed. On the other hand, the problem of thrust load occurs due to the meshing of the gears.
That is, when the electric motor 2 is operated, in the above example, a thrust load is generated on the output shaft 31 side of the first sun gear 81, and an output is generated on the plurality of planetary gears 82 meshing with the first sun gear 81. A thrust load is generated on the side opposite to the shaft 31 (on the drive shaft 21 side). A thrust load is generated on the output shaft 31 side of the fixed internal gear 83 that meshes with the planetary gear 82.
Due to this thrust load on the output shaft 31 side of the fixed internal gear 83, the fixed internal gear 83 and the stepped portion 39 come into contact, and there is a concern that noise and vibrations due to this contact may occur. On the other hand, in the geared motor 1 according to the present embodiment, since the step portion 39 is also provided with the buffer portion 84, the bottom portion 84b absorbs the thrust load generated from the plurality of planetary gears 82 toward the drive shaft 21. On the other hand, the thrust load generated from the fixed internal gear 83 toward the output shaft 31 side can be supported by the top plate portion 84c to absorb vibrations, etc. As a result, it is possible to ensure quietness and low vibration when the motor is driven.

(Third embodiment)
The geared motor according to this embodiment will be explained using FIG. 4. FIG. 4 is an enlarged vertical cross-sectional view along the axis of the first stage planetary gear reduction mechanism portion according to the third embodiment.
Note that in this embodiment, explanations that overlap with those of the above embodiments will be omitted.

As shown in FIG. 4, the difference between the geared motor 1 according to the present embodiment and the geared motor 1 according to the second embodiment is that the stepped portion 85 on the inner peripheral surface of the housing 36 of the transmission section 3 is It is formed in a tapered shape whose diameter decreases from the side toward the output shaft 31 side.

As described above, the drive of the electric motor 2 generates a thrust load on the output shaft 31 side in the fixed internal gear 83. At this time, if there is no gap between the step portion 39 made of the vertical side wall and the fixed internal gear 83 in the first or second embodiment, noise etc. during motor drive can be further suppressed, but design errors In some cases, it may be difficult to completely eliminate this gap due to assembly errors, etc.
In this embodiment, since the stepped portion 85 is formed in a tapered shape, a thrust load is applied to the fixed internal gear 83 during driving, and the fixed internal gear 83 is pushed toward the output shaft 31 side along the tapered surface of the stepped portion 85. By doing so, it is possible to eliminate design errors and the like, and to further suppress the generation of noise and vibration during driving.

(Fourth embodiment)
The geared motor according to this embodiment will be explained using FIG. 5. FIG. 5 is an enlarged vertical cross-sectional view along the axis of the first stage planetary gear reduction mechanism portion according to the fourth embodiment.
Note that in this embodiment, explanations that overlap with those of the above embodiments will be omitted.

As shown in FIG. 5, the geared motor 1 according to the present embodiment differs from the geared motor 1 according to the third embodiment in that an annular recess 86 is formed between the stepped portion 85 and the large diameter portion 37. The point is that The buffer portion 84 is bent along the side surface of the annular recess 86 from the large diameter portion 37 to the stepped portion 85 .

Note that the configurations shown in each of the above-described embodiments can be applied in appropriate combinations.

1 Geared motor 2 Electric motor 3 Speed change section 21 Drive shaft 22 Motor main body 23 Motor housing 24 Bearing 25 Bearing holding buffer section 26 Lid section 31 Output shaft 32 Mount plate 33 Screw 34 Flange 35 Spring pin 36 Housing 37 Large diameter section 38 Storage parts 39, 85 Step part 40 Gear mechanism 50, 60, 70 Planetary gear reduction mechanism 51, 81 First sun gear 52, 82 Planetary gear 53, 83 Fixed internal gear 54 Buffer part 54a Circumferential part 54b Bottom part 55 First Carrier 55a Input holding shaft 55b Disk portion 55c Output holding shaft 56 Washer 61 Second sun gear 62 Planetary gear 63 Fixed internal gear 64 Second carrier 64a Input holding shaft 64b Disk portion 64c Output holding shaft 71 Second Sun gear 72 Planetary gear 73 Fixed internal gear 74 Second carrier 74a Input holding shaft 74b Disc part 84 Buffer part 84a Circumferential part 84b Bottom part 84c Top plate part 86 Annular recess A Axis

Claims (3)

An electric motor having a drive shaft and a transmission section that changes the speed of the driving force that is input using the drive shaft of the electric motor as an input shaft and outputs it from the output shaft are integrally provided, and the transmission section has at least one stage. A geared motor having a planetary gear reduction mechanism,
The planetary gear reduction mechanism includes a sun gear that rotates in response to the rotational force of the electric motor, a plurality of planetary gears that are externally meshed with the sun gear and drive the output shaft as the gear rotates, and a plurality of planetary gears that drive the output shaft as the gear rotates. a fixed internal gear fixedly supported on the inner peripheral surface of a cylindrical housing and internally meshing with the planetary gear;
A buffer section made of an elastic body is disposed between the housing and the fixed internal gear ,
The sun gear, the planetary gear, and the fixed internal gear are helical gears,
The buffer section includes a large diameter section formed by enlarging the inner diameter of the end of the casing on the electric motor side, and connects the storage section of the casing and the large diameter section, and connects the large diameter section to the large diameter section. A geared motor characterized in that the geared motor is disposed along a stepped portion formed in a tapered shape whose diameter decreases toward the storage portion . The geared motor according to claim 1 ,
A geared motor characterized in that an annular recess is formed between the large diameter portion and the stepped portion . The geared motor according to claim 1 or 2 ,
The electric motor includes a motor body and a motor housing that houses the motor body,
A geared motor characterized in that a bearing holding buffer made of an elastic body is disposed between the motor main body and the motor housing .

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