JP2015025560A - Swing planetary gear device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a swing planetary gear device capable of easily securing an arrangement space for pipes, wiring lines, etc. in a central portion of the device for any purpose and achieving further smoothing of power transmission.SOLUTION: A swing planetary gear device 100 having a central portion of a hollow structure and including a plurality of eccentric body shafts 114A to 114C, comprises: eccentric body shaft gears 112 provided on the eccentric body shafts 114A to 114C, respectively; a transmission outer gear 110 with which the plurality of eccentric body shaft gears 112 is engaged; a drive source-side pinion arranged at a different position from a position of a rotational center axis of the transmission outer gear 110 in parallel to the transmission outer gear 110. By rotating the drive source-side pinion, the eccentric body shaft gears 112 and the transmission outer gear 110 are drive and an axial center of the drive source-side pinion is not arranged on a line connecting an axial center of the transmission outer gear 110 to an axial center of each of the eccentric body shafts 114A to 114C.

Description

  The present invention relates to an oscillating planetary gear device.

  Conventionally, planetary gear devices are advantageous in that they can transmit a large torque and a large reduction ratio can be obtained.

  For example, the input shaft can be rotated by swinging and rotating an internal gear rocking body (hereinafter also referred to as an internal gear) that is a rocking gear having a slight difference in the number of teeth from the external gear around the external gear. An oscillating planetary gear device that decelerates and takes out from an output member is known (see, for example, Patent Document 1).

  An example of the gear device will be described with reference to FIGS.

  In the figure, reference numeral 1 denotes a casing, which has a first support block 1A and a second support block 1B that are coupled to each other by inserting fastening members (not shown) such as bolts and pins into the fastening holes 2. Reference numeral 5 denotes an input shaft, and a pinion 6 is provided at an end of the input shaft 5. The pinion 6 includes a plurality of eccentric body shaft gears (for driving eccentric body shafts) arranged at equal angles around the input shaft 5. Gear) 7.

  The casing 1 is provided with three eccentric body shafts 10 at equal angular intervals (120 degree intervals) in the circumferential direction. The eccentric body shaft 10 is rotatably supported by bearings 8 and 9 at both ends in the axial direction, and has eccentric bodies 10A and 10B at an intermediate portion in the axial direction. The eccentric body shaft gears 7 are coupled to the end portions of the eccentric body shafts 10, and the eccentric body shaft gears 7 are rotated by the rotation of the input shaft 5 so that the eccentric body shafts 10 are rotated. It has become.

  Each eccentric body shaft 10 passes through the eccentric body holes 11A and 11B of the two internal teeth rocking bodies 12A and 12B housed in the casing 1, and is adjacent to each other in the axial direction of each eccentric body shaft 10. Rollers 14A and 14B are provided between the outer peripheries of the stepped eccentric bodies 10A and 10B and the inner peripheries of the through-holes of the internal gear rockers 12A and 12B.

  On the other hand, an external gear 21 integrated with the end of the output shaft 20 is disposed at the center of the casing 1, and the external teeth 23 of the external gear 21 are connected to the internal gear rockers 12 </ b> A and 12 </ b> B. Internal teeth 13 made of pins are engaged. The difference in the number of teeth between the external teeth 23 of the external gear 21 and the internal teeth 13 of the internal gear rockers 12A and 12B is set to be small (for example, about 1 to 4).

  This gear device operates as follows.

  The rotation of the input shaft 5 is given to the eccentric body shaft gear 7 through the pinion 6, and the eccentric body shaft 10 is rotated by the eccentric body shaft gear 7. When the eccentric bodies 10A and 10B are rotated by the rotation of the eccentric body shaft 10, the internal tooth rocking bodies 12A and 12B are rocked and rotated by the rotation of the eccentric bodies 10A and 10B. Since the rotation of the internal tooth rocking bodies 12A and 12B is restricted, the external gear 21 that meshes with the internal tooth rocking bodies 12A and 12B is rotated by one swing rotation of the internal tooth rocking bodies 12A and 12B. The phase is shifted by the difference in the number of teeth, and the rotation component corresponding to the phase difference is the (deceleration) rotation of the external gear 21, and the deceleration output is taken out from the output shaft 20.

  In addition, as an oscillating planetary gear device, for example, in FIGS. 10 to 13 of Patent Document 2, a structure including an undriven eccentric shaft is disclosed.

Japanese Patent No. 2607937 JP 2000-65158 A

  However, in the gear device disclosed in the above-mentioned Patent Document 1, the input shaft is rotated because the three eccentric body shaft gears 7 arranged at equal intervals in the circumferential direction are rotated by one input shaft 5 (the pinion 6). Since it is arranged coaxially with the output shaft, there is a problem that it is difficult to design a hollow shaft that penetrates the entire gear device. For example, when used as a gear device for joint drive of an industrial robot or a gear device for driving a precision machine, a wire harness or a pipe for cooling water is connected to the other machine (driven machine) side through the gear device. There is often a demand to pass through. In such a case, in order to make the input shaft a through hole, it means that a drive source such as a motor connected to the input shaft also needs to be a through hole, and in effect, a large hollow shaft is formed. It was almost impossible.

  In this regard, if the configuration as described in Patent Document 2 is adopted, the input shaft does not necessarily have to be arranged coaxially with the output shaft, so that a hollow shaft having a larger diameter can be formed. . However, a structure including a non-driven eccentric body shaft has a problem that smooth power transmission is difficult.

  The present invention has been made to solve such a problem, and according to the usage, it is possible to easily secure an arrangement space such as piping and wiring in the center of the apparatus, and to transmit power. It is an object of the present invention to provide an oscillating planetary gear device that can be further smoothed.

  The present invention relates to an oscillating planetary gear device having a hollow structure at the center and having a plurality of eccentric body shafts, an eccentric body shaft gear provided on each of the plurality of eccentric body shafts, and the plurality of eccentric body shafts. A transmission external gear with which the gear meshes, and a drive source side pinion arranged in parallel to a position different from the rotation center axis of the transmission external gear, and by rotating the drive source side pinion, The eccentric body shaft gear and the transmission external gear are driven, and the shaft center of the drive source side pinion is not arranged on a straight line connecting the shaft center of the transmission external gear and the shaft center of the eccentric body shaft The above configuration solves the above problem.

  According to the present invention, since the pinion on the drive source side can be shifted to the radially outer position of the transmission external gear, a large-diameter hollow structure can be easily formed.

  Further, since all of the plurality of eccentric body shaft gears mesh with the transmission external gear, further smooth transmission of power can be achieved.

  According to the present invention, an oscillating planetary gear that can easily secure an arrangement space for piping, wiring, and the like in the central portion of the apparatus according to the intended use and can further facilitate power transmission. A device can be obtained.

Side sectional view of an oscillating planetary gear device according to an example of an embodiment of the present invention. Sectional view along the line II-II in FIG. Sectional drawing equivalent to FIG. 2 which shows the example of other embodiment of this invention Side sectional view of a conventional oscillating planetary gear unit Sectional drawing which follows the VV line in FIG.

  Embodiments of the present invention will be described below with reference to the drawings.

  1 and 2 are views showing an oscillating planetary gear device (hereinafter simply referred to as a gear device) 100 according to an example of an embodiment of the present invention. FIG. 1 is a side sectional view of the gear device 100. 2 is a cross-sectional view taken along line II-II in FIG.

  The gear device 100 includes a main body casing 102, an input shaft 104, a parallel shaft gear set 106, an intermediate shaft 108, a transmission external gear 110, an eccentric body shaft driving gear (eccentric body shaft gear) 112, and the eccentric body shaft driving. The three eccentric body shafts 114 (114A to 114C) driven by the first gear 112, the two internal tooth rocking bodies (internal gears) 116A and 116B which are rocking gears, and the function as an output shaft are also used. An external gear (a gear meshing with a swing gear) 118 is mainly configured.

  That is, this gear device 100 includes three eccentric body shafts 114 penetrating the internal gear rockers 116A and 116B for rocking and rotating the internal gear rockers 116A and 116B, and the input shaft 104 is rotated. All the eccentric body shafts 114A to 114C are rotated in the same phase by being distributed and transmitted to the plurality of eccentric body shafts 114A to 114C.

  A significant difference from the conventional example described above is the power transmission structure from the input shaft 104 to the eccentric body shafts 114A to 114C and the casing structure of the entire gear device. Therefore, this point will be described in detail below.

  The main casing 102 includes two first and second casings 102A and 102B arranged on the left and right in FIG. In the first and second casings 102A and 102B, as shown in FIG. 2, a plurality of bolt holes 102A1 are formed so as to penetrate them. The first and second casings 102A and 102B can be coupled to each other by bolts (not shown).

  In the main body casing 102, the input shaft 104 is disposed sideways in FIG. 1, that is, parallel to the external gear (output shaft) 118, and is rotatably supported by bearings 120 and 122. A pinion 104A is formed on one end side (left side in the figure) of the input shaft 104, and an insertion port 104B into which the output shaft of the motor M (specific illustration is omitted) is formed on the other end. Yes.

  In the main body casing 102, in addition to the input shaft 104, the intermediate shaft 108 is arranged in parallel to the external gear (output shaft) 118 at a position radially outward from the internal gear rockers 116A and 116B, and a tapered roller bearing. 124 and 124 are rotatably supported. The intermediate shaft 108 incorporates a gear 128 that meshes with the pinion 104A to form the parallel shaft gear set 106, and further incorporates an intermediate pinion (driving source side pinion in the present embodiment) 130.

  On the other hand, on the outer periphery of the external gear (output shaft) 118, a ring-shaped transmission external gear 110 is arranged coaxially with the external gear 118 via a bearing 132. The transmission external gear 110 is simultaneously meshed with the intermediate pinion 130 and the eccentric body shaft driving gear 112 incorporated in each of the three eccentric body shafts 114A to 114C. That is, the transmission external gear 110 is connected to the intermediate shaft 108 via the intermediate pinion 130 and is also connected to all the eccentric shafts 114A to 114C via the eccentric shaft driving gear 112. It will be.

  The eccentric body shafts 114A to 114C are arranged at equal intervals on the same circumference (see FIG. 2), and are supported at both ends by tapered roller bearings 136 and 136, respectively. Each of the eccentric body shafts 114A to 114C passes through the eccentric body holes 116A1 and 116B1 of the internal tooth rocking bodies 116A and 116B in the axial direction. Eccentric bodies 140A and 140B are integrally incorporated in the eccentric body shafts 114A to 114C, and the eccentric body shafts 114A to 114C are eccentric so that the three eccentric body shafts 114 can simultaneously rotate in the same direction in the same phase. The phases of the bodies 140A and 140B are aligned. Further, the two internal tooth rocking bodies 116A and 116B can swing and rotate while maintaining a phase difference of 180 ° from each other by sliding with the eccentric bodies 140A and 140B. In addition, the code | symbol 119 of a figure is an insert wheel for performing the movement control of the axial direction of the said 2 internal tooth rocking bodies 116A and 116B.

  A hollow shaft type external gear 118 also serving as an output shaft is inscribed in the internal gear rockers 116A and 116B. The external gear 118 is formed of a substantially cylindrical member having a through-hole 118D that can penetrate piping, wiring, and the like, and is rotatably supported by the main body casing 102 via tapered roller bearings 142 and 142.

  The external teeth of the external gear 118 have a structure in which an external pin 118P is rotatably incorporated in the groove 118H. The number of external pins 118P (the number of external teeth) is 90, which is smaller by 2 than the number 92 of internal teeth of the internal teeth rocking bodies 116A and 116B (a slight difference in the number of teeth). The external gear 118 includes three members: a main body 118A and end members 118B and 118C. This is because the tapered roller bearings 142 and 142 can be incorporated and axially positioned by the step portions 118B1 and 118C1 of the end members 118B and 118C.

  Next, the operation of the gear device 100 will be described.

  When the input shaft 104 is rotated by the rotation of the motor shaft (not shown) of the motor M, this rotation is decelerated at the first stage via the pinion 104A and the gear 128, and is transmitted to the intermediate shaft 108. When the intermediate shaft 108 rotates, the intermediate pinion 130 incorporated in the intermediate shaft 108 rotates, and further, the transmission external gear 110 engaged therewith rotates.

  Since the transmission external gear 110 is simultaneously engaged with the gear 112 for driving the eccentric body shaft, the gear 112 is rotated by the rotation of the transmission external gear 110. As a result, the three eccentric body shafts 114A to 114C rotate in the same phase, so that the two internal gear oscillating bodies 116A and 116B swing around the external gear 118 with their respective phases maintained at 180 °. Dynamic rotation. Since the rotation of the internal tooth rocking bodies 116A and 116B is restricted, the external gear 118 that meshes with the internal tooth rocking bodies 116A and 116B by one rocking rotation of the internal tooth rocking bodies 116A and 116B. Is out of phase by the difference in the number of teeth, and the rotation component corresponding to the phase difference is the rotation of the external gear 118, and the output is extracted to the outside. Since the eccentric body shafts 114 are arranged at equal intervals in the circumferential direction and all the eccentric body shafts 114 are driven, the internal tooth rocking bodies 116A and 116B can be rocked very smoothly.

  Here, according to the gear device 100 according to the example of the embodiment of the present invention, the intermediate shaft 108 is disposed in parallel with the external gear (output shaft) 118 at a radially outer position than the internal gear rockers 116A and 116B. The rotation of the input shaft 104 is once received by the intermediate shaft 108 and then input to the oscillator. Therefore, the input shaft 104 can be disposed not on the axis L1 (the rotation center axis of the transmission external gear 110) L1 of the gear device 100 as in the prior art but at a position moved outward in the radial direction. . As a result, the axial length of the entire apparatus can be shortened.

  Further, since neither the input shaft nor the drive source exists on the axial direction side of the gear device 100, the external gear 118 can be a large-diameter hollow shaft that penetrates the gear device 100. Since the external gear 118 also serves as an output shaft, and its rotation is extremely slow, a wire harness, a cooling water pipe, or the like can be provided without attaching a separate protective pipe or the like inside the external gear 118. It can be arranged as it is.

  In the above embodiment, the input shaft 104 has a structure having a motor shaft insertion port 104B. However, a pinion is directly formed at the tip of the motor shaft of the motor, and this is also used as the input shaft. It may be a structure.

  Further, the parallel shaft gear set 106 of the pinion 104A and the gear 128 may be omitted, and the pinion 104A of the input shaft 104 may be directly meshed with the intermediate pinion 130.

  In the above embodiment, the transmission external gear 110 is supported by the external gear 118 via the dedicated bearing 132. Instead of such a structure, for example, as shown in FIG. When the transmission external gear 210 is arranged between the two internal gear oscillating bodies 216A and 216B, the axial movement of the two internal gear oscillating bodies 216A and 216B in the transmission external gear 210 is restricted. The function of the insertion wheel 119 (see FIG. 1) can be shared. In this case, the outer pin 218P of the external gear 218 can function as a roller for supporting the transmission external gear 210, so that the transmission external gear 210 is supported on the outer periphery of the external gear 218. Therefore, a dedicated bearing 132 (see FIG. 1) for this purpose can be eliminated. However, when this configuration is not employed, for example, the internal teeth of the internal tooth rocking body may be arcuate teeth, the external teeth of the external gear may be trochoidal teeth, and each may be an involute tooth.

  In addition, since the other structure in this embodiment is substantially the same as that of previous embodiment, the same code | symbol is attached to the same part in the figure, and duplication description is abbreviate | omitted.

  In the example of the above embodiment, the input shafts 104 and 204 are arranged in parallel to the axis of the external gears (output shafts) 118 and 218 (the rotation center axis of the transmission external gear 110) L1. The present invention is not limited to this, and the input shaft may be arranged at a right angle to the shaft center of the eccentric gear, and an orthogonal shaft gear mechanism may be provided. In this case, a driving device such as a motor for driving the gear device can also be arranged in the radial direction of the gear device, and further space saving can be achieved particularly in the axial direction.

DESCRIPTION OF SYMBOLS 100 ... Swing type planetary gear apparatus 102, 202 ... Main body casing 102A, 102B, 202A, 202B ... 1st, 2nd casing 104, 204 ... Input shaft 104A, 204A ... Pinion 106, 206 ... Parallel shaft gear set 108, 208 ... Intermediate shafts 110, 210 ... Transmission external gears 112, 212 ... Eccentric body shaft gears 116A, 116B ... Internal tooth rocking bodies (internal gears)
118, 218 ... External gear (output shaft)
119 ... Insert wheel 128, 228 ... Gear 130, 230 ... Intermediate pinion

Claims (1)

In an oscillating planetary gear device having a hollow structure at the center and having a plurality of eccentric body shafts,
An eccentric shaft gear provided on each of the plurality of eccentric shafts;
A transmission external gear with which the plurality of eccentric body shaft gears mesh;
A drive-source-side pinion arranged in parallel to a position different from the rotation center axis of the transmission external gear,
By rotating the drive source side pinion, the eccentric body shaft gear and the transmission external gear are driven, and the shaft center of the drive source side pinion is the shaft center of the transmission external gear and the eccentric body. An oscillating planetary gear device, characterized in that it is not arranged on a straight line connecting the axis of the shaft.

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