JP4783666B2 - Inscribed mesh type planetary gear unit - Google Patents

Description

  The present invention relates to an intermeshing planetary gear device and a manufacturing method thereof.

  Patent Document 1 discloses an intermeshing planetary gear device as shown in FIGS. 5 and 6. The planetary gear device G0 includes an internal gear 12 serving as an output shaft, two external gears 14 (14A, 14B) that are in mesh with the internal gear 12, and the external gear 14 as an internal gear 12. And an eccentric body shaft 16 that is eccentrically swung with respect to.

  An eccentric body shaft 16 is connected to the input shaft 18 via a spline 20. The eccentric body shaft 16 is integrally provided with two eccentric body portions 16A and 16B corresponding to the number of external gears 14 (two in this example), and the external gears are provided on the outer circumferences of the eccentric body portions 16A and 16B. 14A and 14B are mounted, respectively.

  The internal gear 12 is integrated with the frame body 22 and is rotatably supported by the casing 24. An internal pin 28 is loosely fitted to the external gear 14, and the rotation of the external gear 14 is restricted by fixing a flange 23 supporting the internal pin 28 to the casing 24.

  When the input shaft 18 rotates, the eccentric body shaft 16 rotates through the spline 20, and the external gear 14 swings through the eccentric body portions 16A and 16B integrated on the outer periphery thereof. However, since the rotation of the external gear 14 is restricted by the internal pin 28, the meshing position of the external gear 14 and the internal gear 12 is sequentially shifted. As a result, the internal gear 12 slowly rotates at a reduced speed by a difference in the number of teeth from the external gear 14 each time the eccentric body shaft 16 makes one rotation.

  Here, the eccentric body portions 16A and 16B are incorporated in the eccentric body shaft 16 with a phase difference of 180 degrees in the circumferential direction. Therefore, the phases of oscillation of the external gears 14A and 14B are also shifted from each other by 180 degrees, and the meshing positions with the internal gear 12 are each shifted by 180 degrees. This is because the radial moments generated in the input shaft 18 due to the swinging are canceled with each other. The eccentric body portions 16A and 16B are formed on the eccentric body shaft 16 as one member, and consideration is given to ensuring a phase difference of 180 degrees accurately.

  In Patent Document 2, a structure is proposed in which two independent eccentric bodies are fixed to an input shaft having a D-cut tip.

JP 58-203250 A JP 2000-32900 A

  In an internally meshing planetary gear device having a plurality of external gears, if the eccentric phase of each eccentric body portion with respect to the eccentric body axis is not accurately managed, it is generated by the meshing of each external gear with the internal gear. Moments that cancel out are not canceled out smoothly, resulting in increased vibration and noise, or increased energy loss. Therefore, management of this eccentric phase is a very important matter in this kind of planetary gear device.

  However, in the planetary gear device disclosed in Patent Document 1, since a plurality of eccentric body portions are integrally provided on one eccentric body shaft, the phases are accurately varied. There is a problem that it is difficult to form (manufacture) an eccentric body shaft having each eccentric body portion, and the manufacturing cost tends to be high.

  On the other hand, in a planetary gear device as disclosed in Patent Document 2 in which a plurality of independent eccentric bodies are incorporated into an input shaft, each eccentric body accurately manages the eccentric phase with respect to the input shaft. There was the problem that it had to be incorporated in a way that could be done. More specifically, this means that each eccentric body has a different one-by-one correspondence in the eccentric direction with respect to the shape of the engagement hole to the input shaft. For this reason, although the manufacture of each eccentric body is certainly easier than the manufacture of the eccentric body shaft in which the above-mentioned eccentric body portions are united, the design and manufacture of all the eccentric bodies required considerable effort and time. .

  The present invention has been made to solve such a conventional problem, and is an intermeshing planetary gear device that can be easily manufactured and assembled and can maintain high assembly accuracy. It is an object to provide a manufacturing method thereof.

The present invention includes an internal gear, a plurality of external gears that are internally meshed with the internal gear, an eccentric body that eccentrically swings using either one of the internal gear or the external gear as a swing body, In the intermeshing planetary gear device provided with a plurality of independent eccentric bodies corresponding to the oscillating body, the plurality of eccentric bodies are shifted by 360 / N degrees in the circumferential direction. as in the state of shifting the eccentric phases are mounted on the same eccentric shaft into N radial and the and the eccentric body shaft and the eccentric body, is connected via the internal and external splines respectively Rutotomoni, inner outside Each of the splines has a number of teeth that is a multiple of N, thereby solving the above problem.

  In the present invention, first, in order to facilitate the manufacture of the eccentric body itself, a plurality of independent eccentric bodies are used instead of the eccentric body shaft in which the eccentric body portions are combined. In this case, as described above, the engagement between the eccentric body shafts and the eccentric bodies that are separately divided must be performed in a state in which the eccentric phase of each eccentric body is accurately managed.

  In the present invention, this is realized by spline coupling capable of managing the number of teeth. That is, for example, when two external gears are required to be decentered in a direction shifted by 360/2 degrees, the number of teeth of the inner and outer splines is a multiple of two, and the number of external gears is shifted by 360/3 degrees. Is set to a multiple of 3, respectively. Therefore, when incorporating the eccentric body after rotating the eccentric body by a predetermined number of teeth and incorporating it into the eccentric body axis, it is possible to automatically incorporate the phase accurately managed.

  As a result, the eccentric bodies can have the same shape, and can be formed simultaneously by one chucking. This has great significance not only in the ease of manufacturing but also in that the relative error of all the eccentric bodies can be made zero.

  It is possible to obtain an intermeshing planetary gear device that is easy to manufacture and assemble and that can maintain high assemble accuracy.

  Hereinafter, an example of an embodiment according to the present invention will be described in detail based on the drawings.

  FIG. 2 shows a longitudinal section of a geared motor GM1 in which a reduction gear (internal meshing planetary gear device) G1 and a motor (only part of which are shown) M1 according to an example of the embodiment of the present invention are connected.

  The motor M1 includes a motor shaft 40 at substantially the center thereof. The motor shaft 40 is supported by a bearing 41, and a tip of the motor shaft 40 faces the speed reducer G1 to constitute an input shaft (eccentric body shaft) 42 of the speed reducer G1.

  The reduction gear G <b> 1 has an internal gear 50, three external gears 52 (52 </ b> A to 52 </ b> C) that are internally meshed with the internal gear 50, and the external gear 52 is eccentrically swung with respect to the internal gear 50. It is comprised by the three eccentric bodies 54 (54A-54C) to be made. The configuration around the eccentric body 54 will be described in detail later.

  In the present embodiment, the internal gear 50 includes a pin 50A that constitutes an internal tooth and an internal gear body 50B that holds the pin 50A. The number of pins 50A (the number of internal teeth of the internal gear) is slightly larger (for example, 1 to 6) than the number of external teeth of the external gear 52. The internal gear main body 50 </ b> B is integrally formed with the casing 58 of the reduction gear G <b> 1, and the casing 58 and the motor casing 67 are fixed via a bolt (not shown) inserted into the bolt hole 68.

  The three external gears 52 (52A to 52C) are mounted on the outer circumferences of the eccentric bodies 54A to 54C via bearings 56A to 56C and are in mesh with the internal gear 50. Each of the external gears 52A to 52C has inner pin holes 60A to 60C penetrating in the axial direction at a plurality of positions in the circumferential direction. The inner pin holes 60A to 60C are formed as inner pins 62 and inner rollers 64. Is penetrating (free fitting).

  The flange 66 includes a support flange 66A disposed on the motor side and an output flange 66B disposed on the non-motor side. The inner pin 62 is formed integrally with the output flange 66B, and the support flange 66A and the output flange 66B are integrated by inserting the inner pin 62 into the support flange 66A and integrating them through the bolt 70. . The support flange 66A and the output flange 66B are rotatably supported by the casing 58 of the reduction gear G1 through bearings 72A and 72B, respectively. In this embodiment, the output flange 66B and a counterpart machine (not shown) to be driven are connected via a bolt (only the bolt hole 74 is shown).

  Here, the configuration related to the eccentric body 54 will be described in detail.

  The eccentric body 54 is configured by three independent eccentric bodies 54A to 54C corresponding to the three external gears 52A to 52C. FIG. 1 shows the eccentric body 54A as a representative. The eccentric bodies 54B and 54C have the same shape as a single body. The eccentric body 54A is formed with an inner spline 80A for engaging and coupling with the input shaft 42 at a position 54Ao2 that is shifted from the geometric center 54Ao1 of the eccentric body 54A by a predetermined eccentricity e in the eccentric direction r1. Yes.

  The number of teeth of the inner splines 80A to 80C of the eccentric bodies 54A to 54C is set to a multiple of “3” (36 in this embodiment) that is the number of the external gears 52A to 52C. The eccentric bodies 54A to 54C are simultaneously formed in the same shape by the same chucking including the drilling of the inner splines 80A to 80C. Or the same shape is manufactured by cold casting. On the other hand, an outer spline 82 having 36 teeth that can mesh with the inner splines 80A to 80C is formed on the input shaft 42 side. Each of the splines 80A to 80C and 82 has a tooth profile obtained by cutting a cutting edge portion of an involute curve. Note that either the manufacture of the eccentric bodies 54A to 54C and the formation of the outer spline 82 of the input shaft 42 may be performed first.

  As shown in FIG. 3, each of the eccentric bodies 54 </ b> A to 54 </ b> C shifts the respective meshing positions of the splines 80 </ b> A, 80 </ b> B, 80 </ b> C and 82 by 12 teeth, that is, in the circumferential direction. The eccentric bodies 54A to 54C are incorporated in three eccentric directions (radial directions) r1 to r3 that are shifted by 360/3 degrees respectively while shifting the phases of incorporation of the eccentric bodies 54A to 54C.

  In this embodiment, the internal gear 50 is utilized by utilizing the fact that the eccentric parts 54A to 54C move slightly in the radial direction with respect to the input shaft 42 at the meshing portions of the inner splines 80A to 80C and the outer spline 82. A configuration is adopted in which the clearance in the circumferential direction in meshing with the external gear 52 is set to a minimum (substantially zero) and the movement of both 50 and 52 in the radial direction is allowed. This minimizes the backlash in the circumferential direction between the internal gear 50 and the external gear 52 while minimizing an error occurring in the meshing portion between the external gear 52 and the external gear 52. It is for absorbing by making it move to radial direction between.

  Next, the operation of the geared motor GM1 will be described.

  When the motor shaft 40, that is, the input shaft 42 rotates, the outer spline 82 formed on the outer periphery of the input shaft 42 and the inner splines 80A to 80C formed on the inner periphery of the eccentric bodies 54A to 54C, Each eccentric body 54A to 54C rotates with a phase difference of 360 degrees / 3 = 120 degrees. By this rotation, the outer circumferences of the eccentric bodies 54A to 54C are eccentrically rotated, and the external gear 52 is oscillated and rotated via the bearings 56A to 56C. However, since the internal gear 50 is fixed integrally with the casing 58, the meshing position of the external gear 52 and the internal gear 50 is sequentially shifted, and the external gear 52 is eccentric bodies 54A to 54C. Each time the input shaft 42 rotates once (when the input shaft 42 rotates once), the internal gear 50 rotates by the difference in the number of teeth. The rotation of the external gear 52 is taken out to the support flange 66A and the output flange 66B via the inner pin 62, and transmitted to the counterpart machine connected to the output flange 66B.

  Here, since all the eccentric bodies 54A to 54C have the same shape, the manufacture is easy. Further, since all the eccentric bodies 54A to 54C can be manufactured at a time with the same chucking, it is possible to manufacture and incorporate so-called “relative error” between the eccentric bodies. Incorporation in which no relative error occurs, for example, even if a degree of eccentricity or a defect in the eccentric curve occurs due to some reason in manufacturing, the defect occurs in common with the three eccentric bodies. This means that the eccentric body always causes “common behavior” with respect to the internal gear 50. This means that the three external gears do not move apart. It is empirically known that the smaller the relative error, the better the operation is possible, and the present invention has obtained qualitatively very good characteristics in this respect.

  In addition, the eccentric bodies 54A to 54C have the same shape, and the three eccentric bodies 54A to 54C are incorporated while being eccentric in a predetermined direction (in this case, shifted by 120 degrees). While counting the number of teeth, for example, the eccentric body 54B is incorporated at a position rotated by 36 teeth / 3 = “12 teeth” from the position where the eccentric body 54A is incorporated, and further the eccentric body is rotated at a position rotated by “12 teeth”. Since it is sufficient to incorporate 54C, accurate positioning in the eccentric direction can be realized by an extremely simple method. Further, automation is possible if the input shaft is configured to be installed while being rotated by 120 degrees.

  In the case of the present embodiment, since the tooth shapes of the inner splines 80A to 80C and the outer spline 82 use normal involute curves, the manufacturing cost can be minimized.

  Furthermore, in the present embodiment, the gap between the internal teeth (pins) 50A of the internal gear 50 and the external teeth of the external gear 52 is minimized so that the backlash in the circumferential direction is substantially zero. The meshing error between the internal teeth 50A of the gear 50 and the external teeth of the external gear 52 is determined based on the meshing between the internal splines 80A to 80C of the eccentric bodies 54A to 54C and the external spline 82 of the input shaft 42. 52 can be absorbed by moving in the radial direction. Therefore, both reduction of backlash and smooth rotation are possible. This is achieved by connecting the eccentric bodies 54A to 54C and the input shaft 42 by splines, and the external gears 52 (52A to 52C) can move independently in the radial direction of the eccentric bodies 54A to 54C. This is an effect obtained as a synergistic effect of the structure mounted on the outer periphery.

  In the above-described embodiment, the reduction gear Go has a configuration in which the number of external gears 52 is three, and the external gears 52A to 52C are incorporated by being shifted by 360/3 degrees. The number of external gears in the present invention is not limited to “3”. For example, the number may be two, or four or more. When the number of external gears is two, it is reasonable to incorporate 360/2 degrees, that is, with a phase difference of 180 degrees, so the number of teeth of the spline may be set to a multiple of two. Similarly, when the number of external gears is four, it is reasonable to incorporate 360/4 degrees, that is, with a phase difference of 90 degrees, so that the number of spline teeth is a multiple of four. Set. In short, when the number of external gears is N, it is basically set to be a multiple of N.

  However, the method of incorporation is not always such that each external gear has an equal phase difference. For example, when the number of external gears is 4, the schematic diagram shown in FIG. As shown in FIG. 5B, in addition to the method of incorporating the eccentric bodies P1 to P4 with the phase shifted by 90 degrees with respect to the input shaft (eccentric body axis) Ig, as shown in FIG. The eccentric members P1, P4 and P2, P3 may be paired and each group may be incorporated at a phase of 180 degrees. That is, even if the number of external gears is M (4 in FIG. 4B), the eccentric members P1 to P4 are one or two or more groups (in the case of FIG. 4B, P1, P4). The same eccentric body axis with its eccentric phase shifted in N radial directions shifted by 360 / N degrees (in the case of FIG. 4B, N = 2) for every group of P2 and P3) (Input shaft) Sometimes attached to Ig. In this case, it is only necessary to set a multiple of the number N in the eccentric direction, not a multiple of the number M of external gears.

  The number of teeth on the inner and outer splines does not necessarily have to be the same. For example, the inner spline may be a multiple of 36, and the outer spline that can be engaged with the inner spline may be formed with a total of 18 teeth.

  Furthermore, the structure by which the outer spline of about 1 to several teeth is formed intermittently so as to be engageable with the inner spline may be employed.

  The “spline” of the present invention includes such a spline.

  In the above embodiment, an example in which the internal gear is fixed and the external gear is swung is shown, but the present invention is an internal meshing type in which the external gear is fixed and the internal gear is swung. The present invention can also be applied to a planetary gear device of a type.

  The present invention can be applied to any inscribed mesh type planetary gear device.

The front view of the eccentric member applied to the reduction gear (internal meshing type planetary gear apparatus) which concerns on an example of embodiment of this invention. A longitudinal sectional view of a geared motor in which the speed reducer and the motor are integrated. Schematic showing how to install an eccentric member Schematic diagram showing variations in the eccentric direction A longitudinal sectional view of a geared motor to which a conventional intermeshing planetary gear device is applied. Sectional drawing which follows the arrow VI-VI line of FIG.

Explanation of symbols

G1 ... Reducer (internal meshing planetary gear unit)
M1 ... motor 40 ... motor shaft 42 ... input shaft 54 (54A to 54C) ... eccentric body 50 ... internal gear 52 ... external gear 58 ... casing 60A-60C ... internal pin hole 62 ... internal pin 66 ... flange 66A ... support Flange 66B ... Output flange 80A-80C ... Inner spline 82 ... Outer spline

Claims (5)

An internal gear provided with an internal gear, a plurality of external gears internally meshing with the internal gear, and an eccentric body that eccentrically swings using either the internal gear or the external gear as a swinging body. In the meshing planetary gear device,
A plurality of independent eccentric bodies are provided corresponding to the oscillating body, and the eccentric bodies have their eccentric phases shifted in N radial directions shifted by 360 / N degrees in the circumferential direction. in it mounted on the same eccentric shaft, and wherein the eccentric body shaft and the eccentric body, is connected via the respective internal and external splines Rutotomoni, the inner outside of splines, that each have a number of teeth of a multiple of N An intermeshing planetary gear device characterized by the above. Oite to claim 1,
There are N oscillating bodies, N independent eccentric bodies are provided corresponding to the N oscillating bodies, and the N eccentric bodies are displaced by 360 / N degrees in the radial direction. Are mounted on the same eccentric body shaft with their eccentric phases shifted from each other. In claim 1 or 2 ,
There are M rocking bodies, and M eccentric bodies are provided corresponding to the M rocking bodies, and the M eccentric bodies are 360 / groups for one or more groups. An intermeshing planetary gear device, characterized in that it is mounted on the same eccentric body shaft with its eccentric phase shifted in N radial directions shifted by N degrees. In any one of Claims 1-3 ,
The internal error of the internal gear and the external gear can be absorbed by utilizing a radial relative displacement between the eccentric body and the eccentric body shaft via the internal and external splines. A meshing planetary gear unit. In any one of Claims 1-4 ,
In each of the independent eccentric bodies, the inner spline is formed by the same chucking at the same time.

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