JP2015036569A - Speed reducer - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable a higher gear reduction ratio of a speed reducer to be attained without accompanying any large-sized formation of the speed reducer and its maintenance characteristic to be improved.SOLUTION: Screw grooves 121a and 161a are provided between the circumferential surface of a front stage first outer gear 12 and the circumferential surface of a front stage housing 16, the front stage first outer gear 12 and the front stage housing 16 are threadably engaged to each other by the screw grooves 121a and 161a; screw grooves 222b and 162a are provided between the circumferential surface of a rear stage first outer gear 22 and the circumferential surface of the front stage housing 16; the rear stage first outer gear 22 and the front stage housing 16 are threadably engaged to each other by the screw grooves 222b and 162a; screw grooves 261a and 222a are provided between the circumferential surface of a rear stage housing 26 and the circumferential surface of the rear stage first outer gear 22; and the rear stage housing 26 and the rear stage first outer gear 22 are threadably engaged to each other by the screw grooves 261a and 222a.

Description

  The present invention relates to a reduction gear that outputs to the outside in a state where the rotation of a rotary actuator such as an electric motor is reduced.

  Some of these types of reduction gears are provided with a planetary gear mechanism. The speed reduction device provided with the planetary gear mechanism can arrange the planetary gear mechanism around the drive shaft of the rotary actuator. Therefore, compared with the speed reduction mechanism configured by meshing a plurality of spur gears, There are effects such as the ability to keep the radial dimension small. In addition, as in the reduction gear described in Patent Document 1, there is also provided a device in which a higher reduction ratio is obtained by connecting a plurality of stages of planetary gear mechanisms in series.

JP-A-6-337043

  By the way, it is preferable that the housing provided in the outer peripheral part of the planetary gear mechanism is detachably attached to the casing of the rotary actuator in consideration of the maintenance of the planetary gear mechanism. For example, as described in Patent Document 1, according to a reduction gear device that attaches a housing to a casing by screwing a mounting screw into a casing of a rotary actuator through a screw hole provided in the housing. By loosening the mounting screws, the housing can be removed, and maintenance work can be easily performed on the internal planetary gear mechanism.

  However, when the housing is attached to the casing with attachment screws, the outer dimensions of the housing must be increased by the space for providing the screw holes, leading to an increase in the size of the reduction gear.

  In view of the above circumstances, an object of the present invention is to provide a reduction gear that can obtain a higher reduction ratio without increasing the size of the device and that can improve maintenance.

  In order to achieve the above object, a reduction gear according to the present invention includes a plurality of planetary gear mechanisms connected to each other, and outputs the rotation of a rotary actuator to the outside via these planetary gear mechanisms. A screw groove is provided between the peripheral surface of the front stage fixed element provided between the input element and the output element of the planetary gear mechanism as the front stage and the peripheral surface of the front stage housing covering the outer periphery of the planetary gear mechanism as the front stage. The front-stage fixing element and the front-stage housing are screwed together by the thread groove, and the peripheral surface of the rear-stage fixing element provided between the input element and the output element of the planetary gear mechanism as the rear stage, and the front-stage housing And a rear housing that covers the outer peripheral portion of the planetary gear mechanism as the rear stage by screwing between the rear stage fixing element and the front housing by the thread groove. And the peripheral surface of the ring, the thread groove is provided between the peripheral surface of the rear stage stationary element, characterized in that between the subsequent fixing element and the subsequent housing by the thread groove is screwed to one another.

  Further, according to the present invention, in the speed reducer described above, an inner peripheral surface of a fixed element provided between an input element and an output element of the planetary gear mechanism is provided between the planetary gear mechanism as a first stage and the casing of the rotary actuator. A screw groove provided between the casing and the outer peripheral surface of the casing is screwed together.

  Further, according to the present invention, in the speed reducer described above, the planetary gear mechanism of the plurality of stages is configured as a wonder gear mechanism having two outer gears each having a different number of teeth, and is fixed in the wonder gear mechanism of the preceding stage. The front stage fixed outer gear which is the side is screwed into the front stage housing, and the rear stage fixed outer gear which is the fixed side in the mysterious gear mechanism of the rear stage is screwed to the front stage housing and the rear stage housing, respectively.

  Further, according to the present invention, in the above-described reduction gear, in each of the mysterious gear mechanisms, a screw groove is formed between the outer peripheral surface of the fixed outer gear and the inner peripheral surface of the housing that covers the outer peripheral portion of the mysterious gear mechanism, In addition, a screw groove is formed between the inner peripheral surface of the rear fixed outer gear and the outer peripheral surface of the front housing between the front magic gear mechanism and the rear magic gear mechanism.

  Further, according to the present invention, in the speed reducer described above, the shaft portion of the front-stage output outer gear serving as the rotation side in the front-stage mysterious gear mechanism is rotatably supported by the rear-stage output outer gear serving as the rotation-side in the rear-stage mysterious gear mechanism. A bearing portion is provided.

  According to the present invention, since a screw groove is provided in each connecting portion and screwed together without requiring a separate mounting screw, a space for providing a screw hole in each connecting portion becomes unnecessary, and the size of the apparatus is increased. Therefore, a higher reduction ratio can be obtained and maintenance can be improved.

FIG. 1 is a cross-sectional side view of a speed reducer according to an embodiment of the present invention. FIG. 2 is an exploded cross-sectional side view of the reduction gear shown in FIG. FIG. 3 is a diagram illustrating an appearance of the speed reduction device illustrated in FIG. 1.

  Exemplary embodiments of a speed reducer according to the present invention will be described below in detail with reference to the accompanying drawings.

  1 to 3 show a speed reducer according to an embodiment of the present invention. The speed reducer illustrated here includes two sets of strange gear mechanisms 10 and 20 for decelerating the rotation of the electric motor M that is a rotary actuator. As shown in FIGS. 1 and 2, the two sets of the strange gear mechanisms 10 and 20 include sun gears 11 and 21, first outer gears 12 and 22, second outer gears 13 and 23, and a plurality of planetary gears 14 and 24, respectively. It is configured.

  The sun gears 11 and 21 are small-diameter gears positioned at the center of each of the mysterious gear mechanisms 10 and 20, and a plurality of planetary gears 14 and 24 mesh with teeth provided on the outer periphery thereof. The planetary gears 14 and 24 are supported by the planetary carriers 15 and 25, can be rotated (rotated) around the respective axis centers, and can revolve around the axis centers of the sun gears 11 and 21. The first outer gears 12, 22 and the second outer gears 13, 23 form an annular shape having teeth on their inner peripheral surfaces, and individual teeth mesh with the planetary gears 14, 24. Although not clearly shown in the drawing, the first outer gears 12 and 22 and the second outer gears 13 and 23 are configured to have different numbers of teeth.

  One wonder gear mechanism (front stage planetary gear mechanism) 10 is a front stage to which rotation from the electric motor M is directly input, and the other wonder gear mechanism (second stage planetary gear mechanism) 20 This is the latter stage where the rotation after being decelerated by the mysterious gear mechanism 10 is further decelerated and output to the outside. In the following, when the two sets of the wonder gear mechanisms 10 and 20 and their constituent elements 11, 12, 13, 14, 15, 21, 21, 22, 23, 24, and 25 are distinguished, the wonder gear mechanism 10 as the preceding stage and its The term “front stage” is given to the heads of the names of the constituent elements 11, 12, 13, 14, and 15, so On the other hand, the term “subsequent” is given to the head of each name.

  In the front-stage wonder gear mechanism 10, the front-stage sun gear (input element) 11 is attached to the drive shaft m of the electric motor M, and the front-stage first outer gear (pre-stage fixed element: front-stage fixed outer gear) 12 is attached to the casing MC of the electric motor M. It is attached.

  The casing MC of the electric motor M to which the first outer gear 12 is attached is provided with a mounting plate MC2 at the tip of the main body case MC1 from which the drive shaft m protrudes. The mounting plate MC2 has a substantially disk shape having an insertion hole H in the center and a holding outer peripheral thread groove n on the outer peripheral surface of the tip, and the electric motor is connected via a plurality of fixing screws B. It is fixed to the M body case MC1. The holding outer peripheral thread groove n is formed so as to be screwed when the mounting plate MC2 is rotated around the axis.

  The front-stage first outer gear 12 includes a front-stage first gear main body 121 that forms an annular shape with teeth on the inner peripheral surface, and a front-stage first gear holding body 122 that holds the front-stage first gear main body 121. . The front first gear holding body 122 has a substantially cylindrical shape, and has a front housing outer peripheral thread groove 121a on the outer peripheral surface of the front end portion, and an inner peripheral thread groove for motor on the inner peripheral surface of the base end portion. 121b. The above-described first-stage first gear main body 121 is fixed to the inner peripheral surface of the front end portion of the first-stage first gear holding body 122. The outer peripheral screw groove 121a for the front housing and the inner peripheral screw groove 121b for the motor are formed so as to be screwed when the front first gear holding body 122 is rotated around the axis of the cylinder. The front-stage first outer gear 12 is configured such that the motor inner peripheral thread groove 121b provided at the base end portion of the front-stage first gear holding body 122 is screwed into the holding outer peripheral thread groove n of the mounting plate MC2, whereby the electric motor M The casing MC is held.

  A front housing 16 is attached to the front first outer gear 12 so as to cover the outer periphery of the front mysterious gear mechanism 10. The front housing 16 includes a front housing base 161 having a substantially cylindrical shape with a large diameter, and a front gear support portion having a substantially cylindrical shape with a diameter smaller than that of the front housing base 161 and continuously provided at the tip of the front housing base 161. 162 is integrally molded. The front-stage housing 16 is held by the front-stage first outer gear 12 by screwing a front-stage housing inner peripheral thread groove 161a formed on the inner peripheral surface of the base end portion of the front-stage housing base section 161 into the front-stage housing outer peripheral thread groove 121a. . A peripheral gear groove 162a for the second gear is provided on the outer peripheral surface of the front end portion of the front gear support portion 162 so as to be screwed when the front housing 16 is rotated around the axis of the cylinder.

  A front-stage second outer gear (output element: front-stage output outer gear) 13 of the front-stage mysterious gear mechanism 10 is attached to a front-stage second gear body 131 having an annular shape with teeth on the inner peripheral surface, and a front-stage second gear body 131. A front output shaft 132 is provided. The front-stage output shaft 132 is formed by integrally forming the front-stage flange portion 132a, the support shaft portion 132b, and the shaft main body 132c so as to be on the same axis, and the front-stage output shaft 132 is connected to the front-stage second gear main body 131 via the front-stage flange portion 132a. It is attached to the inner peripheral surface of the tip. The front flange portion 132 a has a disk shape that is thicker than the inner diameter of the front gear support portion 162 provided in the front housing 16. The support shaft portion 132b has a columnar shape with a diameter smaller than the inner diameter of the front gear support portion 162, and is provided in a manner protruding from the tip surface of the front flange portion 132a. The shaft main body 132c has a columnar shape with a diameter smaller than that of the support shaft portion 132b, and is provided on the distal end surface of the support shaft portion 132b. At the base end portion of the front output shaft 132, a front bearing portion 132d for rotatably supporting the shaft portion 11a of the front sun gear 11 is provided. The front-stage second outer gear 13 is in a state where the shaft main body 132c of the front-stage output shaft 132 protrudes outside from the front-stage gear support portion 162 of the front-stage housing 16, and the front-stage second gear main body 131 is accommodated in the front-stage housing base 161. The front housing 16 is rotatably supported by a bearing b1 interposed between the support shaft portion 132b and the front gear support portion 162. A shaft portion 11a of the front sun gear 11 is rotatably disposed on the front bearing portion 132d of the front output shaft 132 via a bearing b2.

  In the rear stage mysterious gear mechanism 20, the rear stage sun gear (input element) 21 is attached to the front stage output shaft 132 of the front stage second outer gear 13 protruding from the front stage housing 16, and the rear stage first outer gear (rear stage fixed element: rear stage fixed outer gear). 22 is attached to the front gear support 162 of the front housing 16.

  The rear-stage first outer gear 22 includes a rear-stage first gear main body 221 that forms an annular shape having teeth on the inner peripheral surface, and a rear-stage first gear holding body 222 that holds the rear-stage first gear main body 221. . The rear first gear holder 222 has a substantially cylindrical shape, and has a rear housing outer peripheral thread groove 222a on the outer peripheral surface of the distal end portion, and an inner peripheral screw for the front housing on the inner peripheral surface of the base end portion. A groove 222b is provided. The above-described first-stage first gear main body 221 is fixed to the inner peripheral surface of the front end portion of the first-stage first gear holder 222. The rear housing outer peripheral thread groove 222a and the front housing inner peripheral thread groove 222b are formed so as to be screwed when the rear first gear holder 222 is rotated around the axis of the cylinder. The rear stage first outer gear 22 has a front gear inner peripheral thread groove 222 b provided at the proximal end of the rear stage first gear holder 222 and a second gear outer peripheral thread groove provided in the front gear support part 162 of the front housing 16. It is held by the front housing 16 by being screwed to 162a.

  A rear housing 26 is attached to the rear first outer gear 22 so as to cover the outer periphery of the rear mysterious gear mechanism 20. The rear housing 26 includes a rear housing base portion 261 having a substantially cylindrical shape with a large diameter, and a rear gear support portion having a substantially cylindrical shape with a diameter smaller than that of the rear housing base portion 261 and connected to the distal end portion of the rear housing base portion 261. 262 is integrally molded. In the present embodiment, the outer diameter of the rear housing base 261 is configured to match the outer diameter of the front housing base 161. The rear housing 26 is held by the rear first outer gear 22 by screwing a rear housing inner peripheral thread groove 261a formed on the inner peripheral surface of the rear end of the rear housing base 261 into the rear housing outer peripheral thread groove 222a. .

  A rear second outer gear (output element: rear output outer gear) 23 of the rear mysterious gear mechanism 20 is attached to the rear second gear main body 231 having an annular shape with teeth on the inner peripheral surface, and the rear second gear main body 231. A rear output shaft 232 is provided. The rear-stage output shaft 232 is formed by integrally forming the rear-stage flange portion 232a and the support shaft body 232b so as to be on the same axis, and the inner peripheral surface of the front end portion of the second-stage second gear main body 231 via the rear-stage flange portion 232a. It is attached to. The rear flange portion 232 a has a disk shape that is thicker than the inner diameter of the rear gear support portion 262 provided in the rear housing 26. The support shaft main body 232b is formed in a columnar shape having a diameter smaller than the inner diameter of the rear gear support portion 262, and is provided in a manner protruding from the front end surface of the rear flange portion 232a. A rear stage bearing portion 232c for rotatably supporting the distal end portion of the front stage output shaft 132 provided with the rear stage sun gear 21 is provided at the base end portion of the rear stage output shaft 232.

  The rear stage second outer gear 23 is in a state where the support shaft main body 232b of the rear stage output shaft 232 protrudes from the rear stage gear support portion 262 of the rear stage housing 26 and the rear stage second gear main body 231 is accommodated in the rear stage housing base 261. The rear housing 26 is rotatably supported by a bearing b3 interposed between the support shaft body 232b and the rear gear support portion 262. A front stage output shaft 132 is rotatably disposed on a rear stage bearing portion 232c of the rear stage output shaft 232 via a bearing b4. In addition, the code | symbol EC in a figure is the retaining member fitted to the back | latter stage output shaft 232. FIG.

  In the reduction gear configured as described above, when the electric motor M is driven and the front sun gear 11 is rotated by the rotation of the drive shaft m, the front first outer gear 12 is attached to the casing MC of the electric motor M. The planetary gear 14 revolves around the axis of the front sun gear 11 while rotating, and the front second outer gear 13 meshing with the front planetary gear 14 rotates around the axis of the drive shaft m. When the rear stage sun gear 21 is rotated by the rotation of the rear stage second outer gear 23, the rear stage first outer gear 22 is attached to the casing MC of the electric motor M via the front stage housing 16, so that the rear stage planetary gear 24 rotates while the rear stage sun gear 21 rotates. And the second-stage second outer gear 23 meshing with the second-stage planetary gear 24 rotates around the axis of the drive shaft m. That is, when the electric motor M is driven, the rotation of the drive shaft m is decelerated at a high reduction ratio by the two strange gear mechanisms 10 and 20 and is output from the second outer gear 23 at the rear stage.

  Furthermore, in the speed reducer described above, if the respective housings 16 and 26 are rotated around the axis of the drive shaft m with respect to the casing MC of the electric motor M, they can be removed from the casing MC and housed inside. It becomes possible to easily maintain the magic gear mechanisms 10 and 20. In addition, when the housings 16 and 26 are attached and detached, as described above, the screw grooves 121a, 161a, 222a, and 261a are provided in the respective connecting portions 12, 16, 22, and 26 without requiring additional mounting screws. A space for providing a screw hole in each of the connecting portions 12, 16, 22, and 26 is not necessary, and there is no risk of increasing the size of the apparatus.

  In the above-described embodiment, the speed reduction device is exemplified by the wonder gear mechanism having two outer gears. However, the speed reduction device is not necessarily a wonder gear mechanism, and the speed reduction device is not necessarily required by the planetary gear mechanism having only the outer gear. It may be configured. In this case, a planetary gear mechanism having only an outer gear and a strange gear mechanism having two outer gears may be mixed.

  In the above-described embodiment, the speed reduction device including the two-stage planetary gear mechanism is illustrated. However, the planetary gear mechanism does not need to be two-stage, and can be assembled by assembling in the same manner as the embodiment. It is also possible to configure the speed reducer with a planetary gear mechanism having more than one stage. Needless to say, the speed reduction device including the planetary gear mechanism having three or more stages can achieve the same effects as the embodiment.

  Furthermore, in the embodiment described above, the gear main body and the gear holder are separately molded and integrated in consideration of the workability of the first outer gear and the second outer gear. Of course, it may be molded as.

  DESCRIPTION OF SYMBOLS 10 Front stage mysterious gear mechanism, 11 Front stage sun gear, 12 Front stage 1st outer gear, 121 Front stage 1st gear main body, 121a Outer housing outer periphery screw groove, 121b Motor inner periphery screw groove, 122 Previous stage first gear holding body, 13 Previous stage first 2 outer gear, 131 front stage second gear main body, 132 front stage output shaft, 132a front stage flange part, 132b support shaft part, 132c shaft main body, 132d front stage bearing part, 14 front stage planetary gear, 15, 25 planetary carrier, 16 front stage housing, 161 front stage Housing base, 161a Front housing inner peripheral thread groove, 162 Front gear support section, 162a Second gear outer peripheral thread groove, 20 Rear stage gear mechanism, 21 Rear stage sun gear, 22 Rear stage first outer gear, 221 Rear stage first gear body, 222 Rear first gear holder, 222 a rear outer peripheral thread groove for rear housing, 222b inner peripheral thread groove for front housing, 23 rear second outer gear, 231 rear second gear body, 232 rear output shaft, 232a rear flange portion, 232b support shaft main body, 232c rear bearing portion, 24 Rear planetary gear, 26 Rear housing, 261 Rear housing base, 261a Rear housing inner thread groove, 262 Rear gear support, M electric motor, MC casing, MC1 body case, MC2 mounting plate, m drive shaft, n outer periphery for holding Thread groove

Claims (5)

In a speed reducer comprising a plurality of planetary gear mechanisms connected to each other and outputting the rotation of a rotary actuator to the outside via these planetary gear mechanisms,
A screw groove is provided between the peripheral surface of the front stage fixed element provided between the input element and the output element of the planetary gear mechanism as the front stage and the peripheral surface of the front stage housing covering the outer periphery of the planetary gear mechanism as the front stage. , And screwing between the front stage fixing element and the front stage housing by the thread groove,
A screw groove is provided between the peripheral surface of the rear stage fixing element provided between the input element and the output element of the planetary gear mechanism as the rear stage and the peripheral surface of the front stage housing, and the rear stage fixing element and the Screw together between the front housing,
A screw groove is provided between the peripheral surface of the rear housing that covers the outer periphery of the planetary gear mechanism that is the rear stage and the peripheral surface of the rear stage fixing element, and the screw groove allows the gap between the rear housing and the rear stage fixing element. A speed reducer characterized by being screwed together.   A screw provided between the inner peripheral surface of the fixed element provided between the input element and the output element of the planetary gear mechanism and the outer peripheral surface of the casing is provided between the planetary gear mechanism as the preceding stage and the casing of the rotary actuator. The speed reducer according to claim 1, wherein the speed reducer is screwed together by a groove.   The multi-stage planetary gear mechanism is configured as a wonder gear mechanism having two outer gears each having a different number of teeth, and a front-stage fixed outer gear serving as a fixed side in the front-stage wonder gear mechanism is screwed onto the front-stage housing. 2. The speed reducer according to claim 1, wherein a rear stage fixed outer gear which is a fixed side in the rear stage mysterious gear mechanism is screwed into the front stage housing and the rear stage housing, respectively.   In each of the mysterious gear mechanisms, a screw groove is formed between the outer peripheral surface of the fixed outer gear and the inner peripheral surface of the housing covering the outer peripheral portion of the mysterious gear mechanism, and the mysterious gear mechanism at the front stage and the mysterious gear mechanism at the rear stage. 4. The speed reducer according to claim 3, wherein a thread groove is formed between an inner peripheral surface of the rear fixed outer gear and an outer peripheral surface of the front housing.   The rear output outer gear, which is the rotation side in the rear-stage magic gear mechanism, is provided with a bearing portion that rotatably supports the shaft portion of the front-stage output outer gear that is the rotation side in the front-stage magic gear mechanism. 3. The speed reducer according to 3.

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