JP7457490B2 - planetary gear system - Google Patents

Description

The present invention relates to a planetary gear system.

BACKGROUND ART Conventionally, a speed reducer has been used to reduce the rotational speed of an output shaft of a drive source such as a motor. As a reduction gear, for example, a compound planetary gear device is known, which includes a sun gear, an internal gear, and a plurality of coaxial stages of planetary gears provided between the sun gear and the internal gear (see Patent Document 1). ).

Japanese Patent Application Publication No. 2002-221259

Incidentally, in a compound planetary gear device, a phase occurs because a plurality of stages of planetary gears having different numbers of teeth are coaxially connected. At this time, each planetary gear is designed to mesh with the mating gear in consideration of the phase, but in reality, an error from the designed value, a so-called phase error, occurs. Due to this phase error, one of the planetary gears may interfere with the other gear and cannot be assembled, or even if it is assembled, it may cause a decrease in efficiency, an increase in starting torque, and significant gear wear.

Conventionally, the method of absorbing this phase error has been to ensure a large amount of backlash to avoid interference, but setting the backlash too large has the problem of reducing the angular accuracy during rotation.

The present invention takes the above-mentioned problem as an example, and provides a planetary gear device that can be assembled without requiring backlash to absorb the phase error even if there is a phase error in the planetary gear. The purpose is to

In order to achieve the above object, a planetary gear device according to the present invention includes an input shaft, a first planetary gear that rotates by rotation of the input shaft, and a first planetary gear that is provided coaxially with the first planetary gear, and that is provided coaxially with the first planetary gear. a second planetary gear connected to the planetary gear in the axial direction so as to rotate together with the planetary gear; a plurality of planetary gear units including the first planetary gear and the second planetary gear; and a plurality of planetary gear units fixed to the fixed member. A planetary gear device comprising: a first internal gear that meshes with the first planetary gear; a second internal gear that meshes with the second planetary gear; and an output section that is rotatable around an axis together with the second internal gear. The second internal gear and the second planetary gear have a different number of teeth from the first internal gear and the first planetary gear, and the first internal gear, the first planetary gear, the second internal gear, and the second planetary gear is configured by a helical gear having a predetermined helix angle with respect to the axial direction, and at least one of the plurality of planetary gear units is configured to be movable in the axial direction. ing.

In the planetary gear device according to one aspect of the present invention, the helix angle of the helical gears constituting the first internal gear and the first planetary gear, and the helix angle of the helical gear constituting the second internal gear and the second planetary gear. The helix angles of the gears are different.

In a planetary gear device according to one aspect of the present invention, at least one of the planetary gear units is provided with a movement restriction portion that restricts movement in the axial direction.

In the planetary gear device according to one aspect of the present invention, a sun gear that meshes with the first planetary gear is provided on the outer periphery of the input shaft, and a carrier that rotatably supports each of the plurality of planetary gear units is provided. .

The planetary gear device of the present invention can be assembled without the need for backlash to absorb phase errors, even if the planetary gears have phase errors.

1 is a perspective view schematically showing the configuration of a drive device including a planetary gear device according to an embodiment of the present invention. 1 is a cross-sectional view along an axial direction schematically showing the configuration of a planetary gear device. 2 is a sectional view taken along line AA of the planetary gear device shown in FIG. 1. FIG. 2 is a cross-sectional view taken along the line AA of FIG. 1 showing the sun gear, the planetary gear unit, the first internal gear, and the second internal gear provided in the planetary gear device shown in FIG. 1 . FIG. 2 is a plan view showing a first planetary gear and a first internal gear included in the planetary gear device shown in FIG. 1 . 2 is a plan view showing a second planetary gear and a second internal gear included in the planetary gear device shown in FIG. 1. FIG. 2 is a side view showing a sun gear, a planetary gear unit, and a carrier included in the planetary gear device shown in FIG. 1. FIG. 2 is a side view showing a planetary gear unit included in the planetary gear apparatus shown in FIG. 1. FIG. FIG. 2 is a plan view showing a relationship between phase angles of a first planetary gear and a second planetary gear included in the planetary gear device shown in FIG. 1. FIG.

Hereinafter, a planetary gear device according to an embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is a perspective view schematically showing the configuration of a drive device 1 including a planetary gear device 2 according to an embodiment of the present invention. As shown in FIG. 1, a drive device 1 includes a planetary gear device 2 according to an embodiment of the present invention and a motor 3 as a drive source.

[Structure of planetary gear device]
Next, the configuration of the planetary gear device 2 according to the present embodiment included in the drive device 1 will be described.

FIG. 2 is a cross-sectional view along the axial direction schematically showing the configuration of the planetary gear device 2. As shown in FIG. Further, FIG. 3 is a sectional view taken along the line AA of the planetary gear device 2. As shown in FIG.

Hereinafter, for convenience of explanation, in the planetary gear device 2, the output side (the side in the direction of the arrow a in FIG. 2) is referred to as the outside, and the input side (the side in the direction of the arrow b in FIG. 2) is referred to as the inside. Further, for convenience of explanation, each configuration of the planetary gear device 2 and the drive device 1 will be explained based on the axis x of the input shaft 20 in the planetary gear device 2 and the drive device 1. The gears constituting the planetary gear system 2 each have an axis.

As shown in FIGS. 2 and 3, the planetary gear device 2 according to the present embodiment includes a sun gear 110 provided on the outer periphery of the input shaft 20 and fixed to the housing section 10 as a fixed member. and a first internal gear 120 provided on the radially outer side of the sun gear 110. The planetary gear device 2 also includes a plurality of first planetary gears 130, 140, 150, 160 that are provided on the outside of the sun gear 110 in the radial direction and mesh with both the sun gear 110 and the first internal gear 120, and It has a plurality of second planetary gears 230, 240, 250, 260 provided on the radially outer side of the sun gear 110, a set of first planetary gears 130, 140, 150, 160 and a second planetary gear 230, A plurality of planetary gear units 310, 320, 330, and 340 are connected in the axis x direction so that the planetary gear units 240, 250, and 260 rotate together. Furthermore, the planetary gear device 2 includes a carrier 170 that supports the plurality of planetary gear units 310, 320, 330, and 340 such that they can rotate and revolve around each other. The planetary gear device 2 also includes a second internal gear 220 that is provided on the radially outer side of the plurality of second planetary gears 230, 240, 250, and 260 and meshes with the plurality of second planetary gears; It also includes an output section 40 that is rotatable around the axis x. The second internal gear 220 and the second planetary gears 230, 240, 250, 260 have different numbers of teeth from the first internal gear 120 and the first planetary gears 130, 140, 150, 160. The sun gear 110, the first internal gear 120, the first planetary gears 130, 140, 150, 160, the second internal gear 220, and the second planetary gears 230, 240, 250, 260 are arranged at predetermined positions with respect to the axis x direction. It consists of a helical gear with a helix angle of . At least one of the plurality of planetary gear units 310, 320, 330, and 340 is configured to be movable in the axis x direction. The configuration and operation of the planetary gear device 2 will be specifically described below.

The housing section 10 has an input side housing 11 that covers the input side (inside b) of the planetary gear device 2, and an output side housing 12 that covers the output side (outside a) of the planetary gear device 2. . The input side housing 11 accommodates components, such as a part of the input shaft 20, that are arranged on the input side near the motor 3 among the components of the planetary gear device 2. The input side housing 11 is provided with an input side opening 13 at the input side end in the axis x direction so that the input end 21 of the input shaft 20 can be exposed. Output side housing 12 is a component arranged on the output side on the opposite side to motor 3 in the axis x direction among the components of planetary gear device 2, such as output section 40 and second internal gear 220. It accommodates. The output side housing 12 is provided with an output side opening 14 at the output side end in the axis x direction so that the output end 41 of the output section 40 can be exposed.

The housing section 10 accommodates the components of the planetary gear device 2 by abutting and joining an input side housing 11 and an output side housing 12. In the housing portion 10, a clamping rib 121 provided on the radially outer side of the first internal gear 120 is sandwiched between the input side housing 11 and the output side housing 12 in the axis x direction. The housing part 10 functions as a fixing member for the first internal gear 120 by butting and joining the input side housing 11 and the output side housing 12 with the holding ribs 121 in between.

The input shaft 20 is arranged inside the input side housing 11 of the housing unit 10 so as to coincide or approximately coincide with the axis x. The input shaft 20 is rotatably connected at its input end 21 to a rotating shaft (not shown) of the motor 3, so that the rotational force from the motor 3 is input. The input shaft 20 is, for example, a hollow shaft with a cavity 22 provided at the center of the shaft on the radially inner side. Note that the input shaft 20 is not limited to a hollow shaft, and may be a solid shaft without a cavity. A sun gear 110 is formed on the radially outer side of the input shaft 20.

FIG. 4 is an AA sectional view showing the sun gear 110, the planetary gear units 310, 320, 330, 340, the first internal gear 120, and the second internal gear 220 included in the planetary gear device 2.

As shown in FIG. 4, the planetary gear device 2 is a 3K type consisting of a sun gear 110, planetary gear units 310, 320, 330, and 340 each having a plurality of stages of planetary gears, and a plurality of stages of internal gears. It is a composite planetary gear mechanism. Specifically, the multiple stage planetary gears are, for example, first planetary gears 130, 140, 150, 160 and second planetary gears 230, 240, 250, 260. Further, the multi-stage internal gear is specifically, for example, the first internal gear 120 and the second internal gear 220. In this embodiment, the number of stages of the planetary gear mechanism is not limited to the example of the planetary gear device 2.

As described above, the sun gear 110, the first internal gear 120, the first planetary gears 130, 140, 150, 160, the second internal gear 220, and the second planetary gears 230, 240, 250, 260 are all helical gears having predetermined twist angles β1 and β2 with respect to the axis x direction. In the following description, the first internal gear 120 and the first planetary gears 130, 140, 150, 160, which are the input gears in the planetary gear device 2, are also referred to as the first stage planetary gear mechanism (hereinafter, the "first planetary gear mechanism 100") of the multi-stage planetary gear mechanism. In the following description, the second internal gear 220 and the second planetary gears 230, 240, 250, 260 are also referred to as the second stage planetary gear mechanism (hereinafter, the "second planetary gear mechanism 200") of the multi-stage planetary gear mechanism.

The sun gear 110 is formed on the radially outer side of the input shaft 20. The sun gear 110 meshes with first planetary gears 130, 140, 150, 160 forming planetary gear units 310, 320, 330, 340. Therefore, in addition to the helix angle β1, the sun gear 110 has the same basic gear specifications such as module and pressure angle with the first internal gear 120 and the first planetary gears 130, 140, 150, and 160. It is a helical gear.

FIG. 5 is a plan view showing the first planetary gears 130, 140, 150, 160 and the first internal gear 120 included in the planetary gear device 2.

As shown in FIGS. 2 to 5, the first internal gear 120 is provided outside the input shaft 20 in the radial direction. The first internal gear 120 has a first internal gear main body 122 provided on the radially inner side facing the sun gear 110 and the first planetary gears 130, 140, 150, 160, , 160. For this reason, the first internal gear 120 has the sun gear 110 and the first planetary gear 130 in the first internal gear main body 122, in addition to the helix angle β1, the basic specifications of the gear such as the module and the pressure angle. , 140, 150, and 160 are configured with helical gears. The first internal gear 120 is fixed to the housing section 10 by being held by the housing section 10 by the clamping ribs 121 provided on the outside in the radial direction, as described above.

FIG. 6 is a plan view showing the second planetary gears 230, 240, 250, 260 and the second internal gear 220 included in the planetary gear device 2.

As shown in FIGS. 2 to 4 and 6, the second internal gear 220 is provided on the outside in the radial direction of the input shaft 20 and on the output side with respect to the first internal gear 120 in the axis x direction. ing. The second internal gear 220 faces the second planetary gears 230, 240, 250, 260 and meshes with the second planetary gears 230, 240, 250, 260. Therefore, the second internal gear 220 has, in addition to the helix angle β2, the basic specifications of the gear such as the module and the pressure angle on the radially inner side of the second planetary gears 230, 240, 250, and 260. A second internal gear main body 221, which is a common helical gear, is configured. In the second internal gear 220, a second internal gear shaft portion 222 is configured on the output side of a second internal gear main body 221. The second internal gear 220 is supported by a bearing 50 attached to the output side housing 12. The second internal gear 220 is supported by the bearing 50 and is configured to be rotatable according to the rotational force transmitted from the second planetary gears 230, 240, 250, and 260. The second internal gear 220 has an annular hole 223 centered on the axis x to form a through hole communicating in the direction of the axis x with the input shaft 20, which is a hollow shaft, at the position of the axis x. It is provided.

FIG. 7 is a side view showing the sun gear 110, the planetary gear units 310, 320, 330, 340, and the carriers 170, 270 included in the planetary gear device 2. Moreover, FIG. 8 is a side view for showing the planetary gear units 310, 320, 330, and 340 with which the planetary gear apparatus 2 is provided.

As shown in FIGS. 7 and 8, the plurality of planetary gear units 310, 320, 330, 340 are arranged radially outward of the sun gear 110 and in the radial direction of the first internal gear 120, with an axis parallel to the axis x as an axis. placed inside. The plurality of planetary gear units 310, 320, 330, and 340 each have first planetary gears 130, 140, 150, and 160 on the input side in the axis x direction. The first planetary gears 130, 140, 150, and 160 mesh with both the sun gear 110 and the first internal gear 120. Therefore, the first planetary gears 130, 140, 150, and 160 have the same specifications as the sun gear 110 and the first internal gear 120, such as the helix angle β1, the module, the pressure angle, and other basic gear specifications. It is made up of helical gears.

Further, the planetary gear units 310, 320, 330, and 340 each include second planetary gears 230, 240, 250, and 260 on the output side in the axis x direction. The second planetary gears 230, 240, 250, and 260 mesh with the second internal gear 220. Therefore, the second planetary gears 230, 240, 250, and 260 have in common with the second internal gear 220 the basic specifications of gears such as the helix angle β2, module, and pressure angle. Consists of helical gears.

As described above, in the planetary gear units 310, 320, 330, 340, the helix angle β1 of the first planetary gears 130, 140, 150, 160 is equal to the helix angle β2 of the second planetary gears 230, 240, 250, 260. It's different.

In the planetary gear units 310, 320, 330, 340, a bearing is provided between the planetary gear shaft portion 311, 321, 331, 341 and each planetary gear, and the first planetary gear 130, 140, 150, 160 , and the second planetary gears 230, 240, 250, and 260 rotate integrally with respect to the planetary gear shaft portions 311, 321, 331, and 341, respectively.

The planetary gear units 310, 320, 330, and 340 are arranged at equal intervals in the circumferential direction at predetermined angles θ. The angle θ is determined depending on the number of planetary gear units 310, 320, 330, and 340. The planetary gear units 310, 320, 330, 340 are rotatably supported by planetary gear shafts 311, 321, 331, 341 fixed to the carrier 170, and are rotated by the rotational force transmitted from the sun gear 110. It rotates and revolves around the axis x.

Here, among the planetary gear units 310, 320, 330, and 340, the planetary gear unit 320 moves between the output end 321a of the planetary gear shaft 321 and the output side end 240a of the second planetary gear 240. A spacer section 322 functioning as a regulating section is provided. The spacer portion 322 eliminates the gap (play) that occurs between the output side end 170a of the carrier 170 and the end 240a of the second planetary gear 240 when the planetary gear unit 320 is supported by the carrier 170. are doing.

In the planetary gear unit 320, a spacer portion 323 functioning as a movement restriction portion is provided between the input end portion 321b of the planetary gear shaft portion 321 and the input side end portion 140b of the first planetary gear 140. The spacer portion 323 eliminates the gap (play) that occurs between the input side end 170b of the carrier 170 and the end 140b of the first planetary gear 140 when the planetary gear unit 320 is supported by the carrier 170. are doing.

In the planetary gear device 2, the planetary gear unit provided with the spacer portion is not limited to the planetary gear unit 310 described above, and may be provided in other planetary gear units 320, 330, and 340. Further, since the number of planetary gear units provided with a spacer portion may be at least one planetary gear unit, a plurality of planetary gear units 310, 320, 330, 340 may be provided with a spacer portion. .

In the planetary gear units 310, 320, 330, 340, the first planetary gears 130, 140, 150, 160, the second planetary gears 230, 240, 250, 260, and the planetary gear shafts 311, 321, 331, 341 may be assembled from separate members, or may be integrally molded by cutting or the like. In the planetary gear device 2, the number of planetary gear units 310, 320, 330, 340 mounted is not limited to the above-mentioned four, and may be selected as appropriate.

FIG. 9 is a plan view showing the phase angle relationship of the first planetary gears 130, 140, 150, 160 and the second planetary gears 230, 240, 250, 260 included in the planetary gear device 2.

As shown in FIG. 9, the planetary gear units 310, 320, 330, 340 are arranged such that the positions of the teeth of the first planetary gears 130, 140, 150, 160 and the teeth of the second planetary gears 230, 240, 250, 260 are different from each other. The angular difference (phase difference) in the circumferential direction with respect to the position is, for example, configured by appropriately combining 0° (no phase difference), α1, and α2. In FIG. 9, the phase difference between the first planetary gear 130 and the second planetary gear 230 of the planetary gear unit 310 is α1. Further, the phase difference between the first planetary gear 140 and the second planetary gear 240 of the planetary gear unit 320 is also α1. The phase difference between the first planetary gear 150 and the second planetary gear 250 of the planetary gear unit 330 is α2. The phase difference between the first planetary gear 160 and the second planetary gear 240 of the planetary gear unit 340 is 0° by design. In addition, the phases of the tooth positions of the first planetary gears 130, 140, 150, 160 and the second planetary gears 230, 240, 250, 260 in the planetary gear units 310, 320, 330, 340 are as described above. There is no particular limitation on the value, and there is no particular limitation on how the planetary gear units 310, 320, 330, 340 having different phases are combined. In addition, each of the planetary gear units 310, 320, 330, 340 has a designed phase difference between the first planetary gear 130, 140, 150, 160 and the second planetary gear 230, 240, 250, 260. It doesn't have to be.

As mentioned above, when there are planetary gear units with different phase differences, if each planetary gear unit is actually formed with the designed phase difference, the multiple planetary gear units can be combined into the sun gear and It is easy to assemble them so that they mesh properly with the internal gears. However, since the actual planetary gear unit is formed with some error from the design value, a so-called phase error occurs. Therefore, even if you try to assemble multiple planetary gear units so that they mesh with the sun gear and internal gear, due to phase errors, the sun gear or internal gear and the planetary gear may not mesh properly, or the gears may interfere with each other. This may cause problems such as not being able to do so.

Therefore, in the present invention, a gap (play) generated between the input side end 170a of the carrier 170 and the end 240a of the second planetary gear 240, and a gap (play) generated between the input side end 170a of the carrier 170 and the output side end 170b of the carrier 170 are A gap (play) is provided between the first planetary gear 140 and the end 140b of the first planetary gear 140, so that each planetary gear unit 310, 320, 330, 340 can be moved in the axis x direction during assembly. Due to this gap, even if the planetary gear units 310, 320, 330, 340 have a phase error, since each gear is a helical gear, the planetary gear units 310, 320, 330, 340 By moving to , a position where the sun gear 110, the first internal gear 120, and the second internal gear 220 can mesh appropriately can be obtained. After the planetary gear units 310, 320, 330, and 340 are installed at appropriate positions in this way, as described above, the gaps are filled with other materials to form spacer parts 322 and 323, and the spacers are moved in the axis x direction. By restricting movement, the planetary gear units 310, 320, 330, and 340 can be maintained at appropriate positions during operation as the planetary gear device 2.

The output unit 40 is arranged so as to coincide or approximately coincide with the axis x inside the output side housing 12 of the housing unit 10. The output end 41 of the output unit 40 is connected to the output side end of the second internal gear shaft portion 222 of the second internal gear 220. The output end 42 of the output unit 40 is connected to be rotatable around the axis x in cooperation with the output side rotating shaft (not shown). Therefore, the rotational force from the motor 3 is output from the output end 42 of the output unit 40. The output unit 40 is, for example, a hollow shaft with a cavity portion 43 provided at the center of the shaft on the radial inner side. Note that the output unit 40 is not limited to a hollow shaft, and may be a solid shaft without a cavity portion. It is also possible to directly use the second internal gear shaft portion 222 of the second internal gear 220 as the output side rotating shaft without providing the output unit 40.

[Operation of the planetary gear device]
Next, the operation of the planetary gear device 2 having the above-described configuration will be described.

In the planetary gear device 2, as shown in FIGS. 1 and 2, the input shaft 20 is rotated by the rotational force from the motor 3 because the input end 21 is connected to the rotation shaft (not shown) of the motor 3. do. In the plurality of planetary gear units 310, 320, 330, 340, the sun gear 110 formed on the radially outer side of the input shaft 20 and the plurality of first planetary gears 130, 140, 150, 160 mesh with each other. Rotation of the shaft 20 causes rotation between the sun gear 110 and the first internal gear 120.

Since the second internal gear 220 meshes with the second planetary gears 230, 240, 250, 260 of the planetary gear units 310, 320, 330, 340, the rotation of the planetary gear units 310, 320, 330, 340 causes Rotate. Here, the second internal gear 220 is a combination of the first planetary gears 130, 140, 150, 160 and the second planetary gears 230, 240, 250, 260 that are configured in the planetary gear units 310, 320, 330, 340. It rotates at a reduced speed due to the difference in the number of teeth. Since the output section 40 is configured to be rotatable together with the second internal gear 220, it rotates when the second internal gear 220 rotates.

In the planetary gear device 2, the helix angle β1 of the sun gear 110, the first internal gear 120, and the first planetary gears 130, 140, 150, 160 constituting the first planetary gear mechanism 100 is different from the helix angle β2 of the second internal gear 220 and the second planetary gears 230, 240, 250, 260 constituting the second planetary gear mechanism 200. In this way, by making the helix angle β1 of the first planetary gears 130, 140, 150, 160 and the helix angle β2 of the second planetary gears 230, 240, 250, 260 different angles, it is possible to reduce the amount of movement in the z-axis direction to obtain an appropriate meshing position when there is a phase error.

Further, in the planetary gear device 2, at least one of the planetary gear units 310, 320, 330, and 340, for example, the planetary gear unit 320, is provided with spacer portions 322, 323. When assembling the planetary gear unit 320, the spacer parts 322 and 323 move along the axis x direction using the gap (play) that occurs between the carrier 170 and the planetary gear unit 320, so that the planetary gear unit 320 Even if there is a phase error, it is possible to arrange the gear at a position where it can appropriately mesh with the sun gear 110, the first internal gear 120, and the second internal gear 220.

With the above configuration, in the use state, the planetary gear unit 2 is configured such that the planetary gear unit 320 is provided with the spacer parts 322 and 323, whereas the planetary gear unit 310 is not provided with the spacer part. , 330, 340 are movable in the axis x direction. With the configuration described above, the planetary gear device 2 allows the planetary gear units 310, 320, 330, and 340 to have phase errors, even if these gears have phase errors. Since the gears are helical gears, the planetary gear units 310, 330, 340, which are not provided with spacer portions, move in the direction of the axis x due to rotational force relative to the planetary gear unit 320, which is provided with spacer portions 322, 323. This allows the teeth to hit in the proper position and mesh evenly. For this reason, when assembling the plurality of planetary gear units 310, 320, 330, and 340 so as to mesh with the sun gear 110, the first internal gear 120, and the second internal gear 220, the planetary gear device 2 has problems such as insufficient meshing or Interference between gears is suppressed and assembly is easy . In addition, according to the planetary gear system 2, since each gear meshes equally at an appropriate position, the load applied to each gear can be equally distributed, so that the strength and life of the device expected at the time of device design can be maintained. Obtainable.

Therefore, according to the planetary gear device 2 in which at least one of the plurality of planetary gear units 310, 320, 330, 340 is configured to be movable in the axis x direction, even if there is a phase error in the planetary gears, , it is possible to suppress an increase in backlash.

In addition, those skilled in the art can modify the present invention as appropriate based on conventionally known knowledge. As long as such modifications still have the structure of the present invention, they are, of course, included within the scope of the present invention.

DESCRIPTION OF SYMBOLS 1... Drive device, 2... Planetary gear device, 3... Motor, 10... Housing part, 11... Input side housing, 12... Output side housing, 13... Input side opening, 14... Output side opening, 20 ...Input shaft, 21...Input end, 22...Cavity, 30...Bearing, 31...Planetary gear shaft, 40...Output part, 41...Output end, 42...Output end, 43...Cavity, 100... First planetary gear mechanism, 110... Sun gear, 120... First internal gear, 121... Clamping rib, 122... First internal gear body, 130, 140, 150, 160... First planetary gear, 140b... End, 170 ...Carrier, 170a...End, 200...Second planetary gear mechanism, 220...Second internal gear, 221...Second internal gear main body, 222...Second internal gear shaft, 223...Hole, 230, 240, 250 , 260... Second planetary gear, 240a... End, 270... Carrier, 270b... End, 310, 320, 330, 340... Planetary gear unit, 311, 321, 331, 341... Planetary gear shaft, 321a... Output End part, 321b...Input end part, 322, 323... Spacer part

Claims (3)

An input shaft;
a first planetary gear that rotates by rotation of the input shaft;
a second planetary gear provided coaxially with the first planetary gear and axially connected to the first planetary gear so as to rotate integrally with the first planetary gear;
a plurality of planetary gear units each including the first planetary gear and the second planetary gear;
a first internal gear fixed to a fixed member and meshing with the first planetary gear;
a second internal gear that meshes with the second planetary gear;
an output portion rotatable about an axis together with the second internal gear;
A planetary gear device comprising:
the second internal gear and the second planetary gear have numbers of teeth different from those of the first internal gear and the first planetary gear,
the first internal gear, the first planetary gear, the second internal gear, and the second planetary gear are configured as helical gears having a predetermined helix angle with respect to an axial direction,
At least one of the plurality of planetary gear units is configured to be movable in an axial direction,
At least one of the plurality of planetary gear units is provided with a movement restricting portion that restricts movement in an axial direction,
the movement restricting portion allows movement of two or more of the plurality of planetary gear units in the axial direction during assembly, and restricts movement of at least one of the planetary gear units in the axial direction in a usage state.
Planetary gear set. The helix angles of the helical gears constituting the first internal gear and the first planetary gear and the helical gears constituting the second internal gear and the second planetary gear are different,
The planetary gear system according to claim 1. A sun gear that meshes with the first planetary gear is provided on the outer periphery of the input shaft,
comprising a carrier that rotatably supports each of the plurality of planetary gear units;
The planetary gear device according to claim 1 or 2.

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