JP2015113922A - Reduction gear - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a reduction gear which is high in a reduction rate and easy in design and manufacturing.SOLUTION: A second input shaft 22 of a second planetary gear mechanism 21 is arranged so as to rotatably penetrate a first input shaft 12 of a first planetary gear mechanism 11, a first internal gear 14 and a second internal gear 24 of both the planetary gear mechanisms 11, 21 are integrally formed, a first carrier 16 of the first planetary gear mechanism 11 is fixed to a housing 1, a second carrier 26 of the second planetary gear mechanism 21 is connected to an output shaft 2, and different numbers of rotations are input to the first input shaft 12 and the second input shaft 22. By this constitution, by properly setting a difference between the rotation numbers of both the input shafts 12, 22, a very high reduction rate can be obtained, and by making gear specifications of both the planetary gear mechanisms 11, 21 be the same, the gear design and component manufacturing of the planetary gear mechanisms 11, 21 can be efficiently performed.

Description

  The present invention relates to a speed reducer that decelerates rotation of an input shaft by a planetary gear mechanism and transmits it to an output shaft.

  In recent years, various devices have been electrified due to energy saving and environmental measures, and the use of motor drive by electric control has been advanced in the drive unit. In the case of motor drive, a high-speed motor is often used to reduce the size of the drive unit and improve efficiency. What has a high rate is required.

  In response to such a demand, a plurality of first planetary gears that mesh with both the first sun gear provided on the outer periphery of the input shaft and the first internal gear arranged on the outer side in the radial direction are used as a reduction gear with a high reduction rate. A plurality of second planetary gears that mesh with both a first planetary gear mechanism that is rotatably supported by a first carrier, a second sun gear that is provided on the outer periphery of the input shaft, and a second internal gear that is disposed radially outward of the second planetary gear. And a second planetary gear mechanism that is rotatably supported by a second carrier, the first internal gear and the second internal gear are integrated, the first carrier is fixed to a fixing member, and the second carrier is output. When the input shaft rotates with the shaft connected to the shaft, the first planetary gear and the second internal gear are integrally rotated in the direction opposite to the input shaft by the rotation of the first planetary gear, and the second planetary gear is rotated Proposed to transmit to the output shaft via two carriers Are (e.g., see Patent Documents 1 and 2.).

  According to this configuration, the revolution of the second planetary gear is partially canceled by the reverse rotation of the second internal gear, and the rotation of the output shaft is slowed accordingly, so that a general speed reducer having a single planetary gear mechanism Higher deceleration rate can be obtained.

JP-A-2-245543 Japanese Patent No. 5263860

  However, in the reduction gear having the two planetary gear mechanisms as described above, it is necessary to make at least a part of the gear specifications different between the first planetary gear mechanism and the second planetary gear mechanism, and according to the required reduction rate. It takes a lot of work to design separate gears and parts for both planetary gear mechanisms.

  Then, this invention makes it a subject to provide the reduction gear with a high reduction rate and easy design and manufacture.

  In order to solve the above problems, a speed reducer according to the present invention is arranged on a first input shaft, a first sun gear provided on an outer periphery of the first input shaft, and a radially outer side of the first sun gear. A first planetary gear comprising a first internal gear, a plurality of first planetary gears that mesh with both the first sun gear and the first internal gear, and a first carrier that rotatably supports the first planetary gears. A second input shaft rotatably passing through the first input shaft, a second sun gear provided on an outer periphery of a protruding portion of the second input shaft protruding from one end of the first input shaft, A second internal gear that is arranged radially outside the two sun gears and rotates integrally with the first internal gear; a plurality of second planetary gears that mesh with both the second sun gear and the second internal gear; A second planetary gear mechanism comprising a second carrier that rotatably supports each second planetary gear; It said first secure the carrier to the fixing member, wherein the second carrier is connected to the output shaft, than it was configured to the different rotational speed of the rotating the first input shaft and the second input shaft is inputted.

  According to the above configuration, when the first input shaft rotates and the first planetary gear and the second internal gear integrally rotate in the opposite direction to the first input shaft by the rotation of the first planetary gear, the second input Since the shaft rotates at a different rotational speed than the first input shaft, the second planetary gear revolves without changing the gear specifications between the first planetary gear mechanism and the second planetary gear mechanism, and the first input shaft and the second input gear A deceleration rate corresponding to the difference in the rotational speeds of the two input shafts can be obtained. Therefore, a high reduction rate can be obtained by appropriately setting the difference in the rotational speed between the first input shaft and the second input shaft, and the gear specifications of the first planetary gear mechanism and the second planetary gear mechanism can be made the same. The gear design and parts production of each planetary gear mechanism can be performed efficiently.

  As means for allowing rotations having different rotational speeds to be input to the first input shaft and the second input shaft, a first transmission gear is provided on the outer periphery of the first input shaft, A second transmission gear having a gear specification different from that of the first transmission gear is provided on the outer periphery of the protruding portion of the second input shaft protruding from the end, and provided on the outer periphery of the drive shaft so as to mesh with each of the transmission gears. A configuration in which rotation is input to the input shafts from the two input gears via the transmission gears can be employed. If it does in this way, a reduction rate can be changed easily only by changing the gear specification of one input gear which meshes with one of the 1st transmission gear and the 2nd transmission gear. Further, by engaging each transmission gear with the input gear, it is possible to reduce the speed at the front stage of the speed reducer, thereby suppressing the number of rotations of each part in each planetary gear mechanism and suppressing heat generation and extending the life.

  As described above, the speed reducer according to the present invention is configured so that rotations having different rotational speeds are input to the first input shaft of the first planetary gear mechanism and the second input shaft of the second planetary gear mechanism, so that both planets are rotated. Even if the gear specifications are not different in the gear mechanism, a reduction rate corresponding to the difference in the rotation speed between the first input shaft and the second input shaft can be obtained. By appropriately setting the gear ratio, a high reduction rate can be obtained, and the gear specifications of both planetary gear mechanisms can be made the same, so that the gear design and parts manufacture of each planetary gear mechanism can be performed efficiently.

Longitudinal front view of reducer of embodiment Sectional view along the line II-II in FIG. Sectional view along line III-III in FIG.

  Hereinafter, embodiments of the present invention will be described with reference to FIGS. 1 to 3. In this reduction gear, a first planetary gear mechanism 11 and a second planetary gear mechanism 21 are arranged in the axial direction inside a covered cylindrical housing (fixing member) 1. A lid 3 through which the output shaft 2 passes is fitted on the inner periphery of the opening side of the housing 1.

  The first planetary gear mechanism 11 includes a cylindrical first input shaft 12, a first sun gear 13 provided on the outer periphery of the first input shaft 12, and a first sun gear 13 disposed radially outside the first sun gear 13. 1 internal gear 14, a plurality of first planetary gears 15 meshing with both the first sun gear 13 and the first internal gear 14, and a support shaft 16a passed through the center of each first planetary gear 15, The first planetary gear 15 includes a first carrier 16 that supports the first planetary gear 15 so as to be capable of rotating.

  The first input shaft 12 of the first planetary gear mechanism 11 is formed integrally with the first sun gear 13, and the first carrier 16 is formed integrally with the lid portion 1 a of the housing 1. The first input shaft 12 passes through the center of the first carrier 16 and is rotatably supported by the first carrier 16, and the first transmission gear 4 is fitted to the outer periphery of the protruding portion from the first carrier 16. It is fixed. The first input shaft 12 and the first sun gear 13, the first carrier 16 and the housing lid 1a may be formed separately and fixedly attached.

  The second planetary gear mechanism 21 includes a second input shaft 22 that rotatably penetrates the first input shaft 12 of the first planetary gear mechanism 11 and a second input shaft 22 that protrudes from one end of the first input shaft 12. A second sun gear 23 provided on the outer periphery of the projecting portion, a second internal gear 24 that is disposed on the radially outer side of the second sun gear 23 and formed integrally with the first internal gear 14, and the second sun gear 23 And a plurality of second planetary gears 25 that mesh with both the second internal gears 24 and a support shaft 26a that passes through the center of each second planetary gear 25, and supports each second planetary gear 25 so that it can rotate. The second carrier 26 is included.

  The second input shaft 22 of the second planetary gear mechanism 21 is formed integrally with the second sun gear 23, and the second carrier 26 is formed integrally with the output shaft 2. In the second input shaft 22, the second transmission gear 5 is fitted and fixed to the outer periphery of a protruding portion protruding from the other end of the first input shaft 12. The output shaft 2 is rotatably supported by a lid 3 fitted on the inner periphery of the housing 1. And the protrusion part 22a from the 2nd sun gear 23 of the 2nd input shaft 22 is rotatably inserted in the engagement hole 27 provided in the center of the inner surface of the output shaft 2 and the 2nd carrier 26, and the 1st The first input shaft 12, the second input shaft 22, and the output shaft 2 rotate concentrically and smoothly. The second input shaft 22 and the second sun gear 23 may be formed separately and fixedly attached, and the second carrier 26 and the output shaft 2 may be formed separately and rotate integrally. You may connect.

  The gear specifications of the respective parts of the first planetary gear mechanism 11 and the second planetary gear mechanism 21 are the same, and the gear specifications of the first transmission gear 4 and the second transmission gear 5 are different. The first transmission gear 4 and the second transmission gear 5 mesh with the first input gear 8 and the second input gear 9 that are fitted and fixed to the outer periphery of the main shaft (drive shaft) 7 of the drive motor 6, respectively. Thereby, the rotation is transmitted from the drive motor 6 to the input shafts 12 and 22 via the input gears 8 and 9 and the transmission gears 4 and 5, and the first input shaft 12 and the second input shaft 22 are rotated differently. A number of rotations are entered simultaneously.

  Next, the operation of the speed reducer will be described. First, when the drive motor 6 is driven, the first input shaft 12 and the second input shaft 22 rotate at different rotational speeds as described above. Then, since the first carrier 16 is fixed in the first planetary gear mechanism 11, the first planetary gear 15 rotates while being constrained to revolve, and the first internal gear 14 is connected to the first input shaft 12. Rotate in the opposite direction. In the second planetary gear mechanism 21, the second internal gear 24 rotates integrally with the first internal gear 14, so that the second planetary gear 25 rotates between the first input shaft 12 and the second input shaft 22. Revolution is made in accordance with the difference in rotational speed, and the revolution of the second planetary gear 25 is transmitted to the output shaft 2 via the second carrier 26. At this time, if the rotation speed of the second input shaft 22 is higher than the rotation speed of the first input shaft 12, the output shaft 2 rotates in the same direction as the input shafts 12 and 22, as shown in FIGS. If the rotational speed of the second input shaft 22 is lower than that of the first input shaft 12, the output shaft 2 rotates in the reverse direction.

  This speed reducer has the above-described configuration, and a speed reduction rate corresponding to the difference in rotation speed between the first input shaft 12 and the second input shaft 22 can be obtained. By setting to, a very high deceleration rate can be obtained. In addition, since the gear specifications of the planetary gear mechanisms 11 and 21 are the same, the gear design and parts manufacture of each planetary gear mechanism 11 and 21 can be performed efficiently. In addition, the reduction rate can be easily changed by simply changing the gear specification of one of the first transmission gear 4 and the second transmission gear 5 and one input gear (8 or 9) meshing with the first transmission gear 4. The rotation direction of the output shaft 2 with respect to the shafts 12 and 22 can also be changed.

1 Housing (fixing member)
2 Output shaft 4 First transmission gear 5 Second transmission gear 6 Drive motor 7 Main shaft (drive shaft)
8 First input gear 9 Second input gear 11 First planetary gear mechanism 12 First input shaft 13 First sun gear 14 First internal gear 15 First planetary gear 16 First carrier 21 Second planetary gear mechanism 22 Second input Shaft 23 Second sun gear 24 Second internal gear 25 Second planetary gear 26 Second carrier

Claims (2)

A first sun gear provided on an outer periphery of the first input shaft; a first internal gear disposed radially outside the first sun gear; the first sun gear and a first inner gear; A first planetary gear mechanism comprising a plurality of first planetary gears meshing with both gears and a first carrier that rotatably supports each first planetary gear;
A second input shaft that rotatably penetrates the first input shaft; a second sun gear provided on an outer periphery of a protruding portion of the second input shaft that protrudes from one end of the first input shaft; and the second sun gear. A second internal gear that is disposed radially outward of the first internal gear and rotates together with the first internal gear, a plurality of second planetary gears that mesh with both the second sun gear and the second internal gear, and each second A second planetary gear mechanism comprising a second carrier that rotatably supports the planetary gear;
A speed reducer in which the first carrier is fixed to a fixing member, the second carrier is connected to an output shaft, and rotations having different rotational speeds are input to the first input shaft and the second input shaft.   The means for inputting rotations having different rotational speeds to the first input shaft and the second input shaft is provided with a first transmission gear on the outer periphery of the first input shaft, and the other end of the first input shaft. A second transmission gear having a gear specification different from that of the first transmission gear is provided on the outer periphery of the projecting portion of the second input shaft that projects from the second input shaft, and is provided on the outer periphery of the drive shaft so as to mesh with each of the transmission gears. The speed reducer according to claim 1, wherein rotation is input to each input shaft from each of the two input gears via each transmission gear.

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