JP2009014039A - Eccentric swing type gear device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an eccentric swing type gear device capable of having a rotation output part receiving a high moment load and allowing easy incorporation of a pair of radial bearings even when they are used back to back. <P>SOLUTION: The eccentric swing type gear device 100 is provided with: an internal gear 1; an external gear 3 engaged with the internal gear 1; a plurality of crankshafts 10 separated from the center of the internal gear 1 and having eccentric parts 7 engaged with the inner part of the external gear 3 to achieve eccentric movement of the external gear 3; and a support body 13 rotatably supporting the respective crankshafts 10 via the pair of radial bearings 11, 12. The internal gear 1 and the support body 13 are relatively rotated and the pair of radial bearings 11, 12 are assembled back to back. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to an eccentric oscillating gear device used for a joint portion of an industrial robot.

  As a conventional eccentric oscillating gear device, for example, one described in Patent Document 1 below is known.

JP-A-2005-330981

  This includes an internal gear, an external gear that meshes with the internal gear, a crankshaft that engages an eccentric portion inside the external gear and causes the external gear to move eccentrically, and a pair of conical cones. An eccentric oscillating gear device having a support that is rotatably supported via a roller bearing, the pair of tapered roller bearings being assembled face-to-face.

  Since the pair of tapered roller bearings provided between the crankshaft and the support are assembled face-to-face, the load capacity of the axial load carried by the pair of bearings is small, and the support member for the eccentric oscillating gear device In addition, a high moment load could not be applied to the rotation output portion from the internal gear and the use of the eccentric oscillating gear device was limited.

  In view of this problem, an object of the present invention is to provide an eccentric oscillating gear device that can apply a high moment load to a rotation output portion.

This invention separates the internal gear, the external gear meshing with the internal gear, and the center of the internal gear, and the eccentric portion engages the external gear to cause the external gear to move eccentrically. In an eccentric oscillating gear device having a plurality of crankshafts and a support body rotatably supporting each crankshaft via a pair of radial bearings, the internal gear and the support body rotate relatively. This is an eccentric oscillating gear device in which the radial bearing is assembled back to back.
In addition, a pair of main bearings that rotatably support the internal gear and the support, and the pair of main bearings are disposed with the external gear interposed therebetween, and one of the pair of radial bearings is inserted into the support. One support portion formed with one bearing hole and the other support portion formed with the other bearing hole into which the other of the pair of radial bearings is inserted, and the one support portion and the other support portion are connected to each other. The hole has one flange that extends radially inward on the external gear side, and the other bearing hole has the other flange that extends radially inward on the external gear, and each of the radial bearings includes an outer ring, an inner ring, and a rolling element. And one outer ring of the pair of radial bearings is inserted into the one bearing hole so as to contact the one collar part, and the other outer ring of the pair of radial bearings is inserted into the other bearing hole so as to contact the other collar part. , One inner ring of the pair of radial bearings is the shaft of the crankshaft Each crankshaft is provided with first positioning means for positioning so as not to move from the inner side toward the outer side in the axial direction, and the other inner ring of the pair of radial bearings moves from the inner side in the axial direction of the crankshaft toward the outer side in the axial direction This is an eccentric oscillating gear device in which second positioning means for positioning so as not to be provided on each crankshaft.
The eccentric oscillating gear device applies preload to the pair of radial bearings by one of the first positioning means and the second positioning means.
Also, an eccentric oscillating type in which a bearing with a cage is disposed between the inside of the external gear and the eccentric portion of each crankshaft, and the first flange portion and the other flange portion are positioned on the side surface of the bearing retainer. It is a gear device.
The eccentric oscillating gear device in which a bearing is disposed between the inside of the external gear and the eccentric portion of each crankshaft, and the one flange portion and the other flange portion are positioned on the side surface of the rolling element of the bearing. .

According to the first aspect of the present invention, an eccentric oscillating gear device capable of applying a high moment load to the rotation output portion can be provided.
According to the invention of claim 2, even if a pair of radial bearings are used on the back side, the axial direction of the bearings can be easily controlled, and the bearings can be easily incorporated into the eccentric oscillating gear device. Can do.
According to the invention of claim 3, since the preload is applied to the radial bearing using the positioning means, it is possible to apply the preload to the bearing without providing a separate preload means. Therefore, even if a pair of radial bearings are used for back-to-back, an eccentric oscillating gear device having high rigidity and a long life can be obtained.
Further, according to the invention of claim 4, even if a bearing with a cage is used between the inside of the external gear and the eccentric portion of the crankshaft, the axial direction regulating means of the cage is not separately provided, The axial direction of the cage can be restricted. Therefore, even if a bearing with a cage is used, an inexpensive eccentric oscillating gear device with a function of restricting the axial direction of the cage can be obtained.
According to the invention of claim 5, even when a bearing without a cage is used between the inside of the external gear and the eccentric portion of the crankshaft, the axial direction regulating means for the rolling element of the bearing is separately provided. In addition, the axial direction of the rolling element can be restricted. Therefore, even when a bearing without a cage is used, an inexpensive eccentric oscillating gear device having a function of restricting the rolling element in the axial direction can be provided.

Hereinafter, a first embodiment of the present invention will be described with reference to the drawings.
1 and 2, an eccentric oscillating gear device 100 includes an internal gear 1 having a plurality of internal teeth pins on the inner periphery and external teeth having a number smaller than the number of internal teeth pins on the outer periphery. Two external gears 3 meshing with the gear 1 and a pair of main bearings 5 and 6 (a pair of angular ball bearings) for back-to-back support that supports the internal gear 1 and a support body 13 described later in a relatively rotatable manner. Are separated from the center of the internal gear 1, and two eccentric portions 7 are inserted into and engaged with the external gear 3 via needle roller bearings 9 with cages 8. The internal gear 1 and the support body 13 include three crankshafts 10 that eccentrically move the crankshaft and a support body 13 that rotatably supports each crankshaft 10 via a pair of tapered roller bearings 11 and 12. Rotate relatively. And a pair of tapered roller bearings 11 and 12 are assembled | attached by back-to-back. Each of the crankshafts 9 is equally arranged around a position separated from the center of the internal gear 1 by an equal distance. The two external gears 3 form a through hole 30 at the center.
The pair of main bearings 5 and 6 are arranged with the external gear 3 interposed therebetween. The support 13 has one support portion 17 in which one of the pair of main bearings is located and one bearing hole 15 into which one of the pair of tapered roller bearings 11 is inserted, and the other six of the pair of main bearings is located. In addition, the other support portion 21 having the other bearing hole 19 into which the other 12 of the pair of tapered roller bearings is inserted is connected to the one support portion 17 and the other support portion 21. On the other hand, the support portion 17 is formed with three column portions 20 into which the external gear 3 is loosely fitted. An end surface portion of each column portion 20 is in contact with the other support portion 21. On the other hand, the support portion 17 and the other support portion 21 are positioned by pins 23 and fixed by bolts 24. On the other hand, the support portion 17 and the other support portion 21 have a through hole 70 formed in the central portion. Cables, pipes, and the like can be passed through the through hole 30 of the external gear 3 and the through hole 70 of the support 13.
On the other hand, the bearing hole 15 is provided with a first flange 25 extending radially inward on the external gear side, and the other bearing hole 19 is provided with a second flange 27 extending radially inward on the external gear side. Each of the pair of tapered roller bearings 11 and 12 includes outer rings 29a and 29b, inner rings 31a and 31b, and tapered rollers (rolling elements) 33a and 33b. One outer ring 29 a of the tapered roller bearing is inserted into the one bearing hole 15 so as to abut on one flange portion 25 of the one bearing hole 15. The other outer ring 29 b of the tapered roller bearing is inserted into the other bearing hole 19 so as to contact the other flange portion 27 of the other bearing hole 19.

The crankshaft 10 is provided with first positioning means 50 for positioning so that one inner ring 31a of the tapered roller bearing 11 does not move from the inner side in the axial direction of the crankshaft 10 toward the outer side in the axial direction. The crankshaft 10 is provided with second positioning means 60 for positioning so that the other inner ring 31b of the tapered roller bearing 12 does not move from the axially inner side to the axially outer side of the crankshaft 10.
A spur gear 35 housed in a notch 80 formed in the one support portion 17 is spline-connected to one end portion of each crankshaft 10. A spur gear 35 is a shaft retaining ring 37 fitted to the outer peripheral portion of the crankshaft 10 so that it does not fall off in the axial direction of the crankshaft 10. A distance piece 39 is provided between the spur gear 35 and one inner ring 31a. The first positioning means 50 described above is achieved by the distance piece 39, the spur gear 35, and the shaft retaining ring 37.
The cylindrical plate 40 and the cylindrical plate 41 are disposed between one inner ring 31 a and the eccentric portion 7 of the crank 10. The cylindrical plate 40 is located on the side surface of the cage 8 of the needle roller bearing 9 and serves to regulate the axial direction of the cage 8. The cylindrical plate 41 is provided to prevent the cylindrical plate 40 from moving greatly toward the one inner ring 31a. A minute gap is maintained between the inner ring 31a and the cylindrical plate 41.
A shaft retaining ring 43 is fitted on the outer peripheral portion of the other end of each crankshaft 9. The other inner ring 31 b of the tapered roller bearing 12 is prevented from dropping off to the outside in the axial direction of the crankshaft 10 by a shaft retaining ring 43. The second positioning means 60 described above is achieved by the shaft retaining ring 43. Further, the second positioning means 60 presses the inner ring 31b to apply a preload to the pair of tapered roller bearings. The adjustment of the preload is performed by adjusting, managing, or changing the thickness of the retaining ring 43 for the shaft. When the preload is applied to the pair of tapered roller bearings by the second positioning means 60, the spur gear 35 and the distance piece 39 are sandwiched and pressed between the inner ring 31a and the shaft retaining ring 37. The spur gear 35 and the distance piece 39 are restrained from moving in the axial direction, and the sound of the meshing tooth portion with the spur gear 35 can be suppressed.
When the second positioning means 60 does not apply preload to the pair of tapered roller bearings, the first positioning means 50 may apply preload to the pair of tapered roller bearings. In this case, the preload can be adjusted by any one of the spur gear 35, the distance piece 39 and the shaft retaining ring 37, or by a combination of the thicknesses. However, either the distance piece 39 or the shaft retaining ring 37 can be adjusted. On the other hand, it is preferable to adjust the preload.
When the spur gear 35 is not provided, or when the spur gear 35 is completely fixed to the crankshaft 10 with a key or a bolt, the shaft retaining ring 37 is brought close to the inner ring 31a, and the thickness of the shaft retaining ring 37 is preloaded. It is sufficient to make adjustments. More preferably, the preload is adjusted only by the distance piece 39 so that no error is accumulated. In any case, a preload can be applied to the pair of radial bearings by one of the first positioning means and the second positioning means.
The cylindrical plate 45 and the cylindrical plate 47 are disposed between the other inner ring 31 b and the eccentric portion 7 of the crank 10. The cylindrical plate 45 is located on the side surface of the cage 8 of the needle roller bearing 9 and is responsible for the axial direction regulation of the cage 8. The cylindrical plate 47 is provided so as not to move the cylindrical plate 45 greatly toward the other inner ring 31b. A minute gap is maintained between the other inner ring 31 b and the cylindrical plate 47.

An oil seal 65 is provided between the inner periphery of the internal gear 1 and the outer periphery of the one support portion 17. The inner ring of the main bearing 6 is contained in the outer circumferential groove 67 of the other support portion 21. A distance piece 69 is inserted between the end face of the inner ring of the main bearing 6 and the stepped portion of the outer circumferential groove 67. The application of the preload to the pair of main bearings 5 and 6 and the adjustment of the preload are performed by adjusting the thickness of the distance piece 69.
In the present embodiment, a pair of tapered roller bearings 112 are provided between the crankshaft 10 and the support body 13, but a pair of angular ball bearings may be used instead of the pair of tapered roller bearings. Each of the pair of angular ball bearings has an outer ring, an inner ring, and a ball (rolling element). Even in the case of providing a pair of angular ball bearings, the other configurations as the eccentric oscillating gear device are the same as those in the above-described embodiment in which the pair of tapered roller bearings 11 and 12 are provided, and thus the description of the other configurations is omitted. To do. The number of external gears 3 may be one, two, or four. The number of crankshafts 10 may be two or four. What is necessary is just to make the number of the eccentric parts of the crankshaft 10 correspond with the number of the external gears 3.
In addition, the radial bearing of the present invention refers to a bearing that can mainly receive a load in a direction perpendicular to the axial direction, such as a tapered roller bearing or an angular ball bearing shown in the embodiments.

Next, the operation of the first embodiment will be described. Since the speed reducing action of the eccentric oscillating gear device 100 is known, it will be briefly described. When rotation from a motor (not shown) is transmitted to the spur gear 35 and the crankshaft 10 is input and rotated, the external gear 3 performs an eccentric oscillating motion around the center of the internal gear 1. At this time, if the internal gear 1 is fixed, the rotational output decelerated from the support 13 can be taken out. Further, when the support 13 is fixed, the rotational output decelerated from the internal gear 1 can be taken out.
Here, the pair of tapered roller bearings 11 and 12 between the crankshaft 10 and the support 13 are assembled back to back, and the point of action of the additional load is compared to the case of assembly by conventional front alignment. Since the distance (dimension A in FIGS. 1 and 2) is long, the bearings 11 and 12 can carry a radial load and a high axial load, and the rotation output portion from the support 13 or the internal gear 1 has a high moment. Can receive a load.
Further, the outer ring 29 a of one tapered roller bearing 11 is inserted into the one bearing hole 15 so as to contact the one flange portion 25 of the one bearing hole 17, and the outer ring 29 b of the other tapered roller bearing 12 is inserted into the other of the other bearing holes 19. A first positioning that is inserted into the other bearing hole 19 so as to abut against the flange portion 27 and positions the inner ring 31a of one tapered roller bearing 11 so as not to move from the inner side in the axial direction of the crankshaft 10 toward the outer side in the axial direction. Means 50 (a distance piece 39) is provided on the crankshaft 10, and the second tapered positioning means 60 is positioned so that the inner ring 31b of the other tapered roller bearing 12 does not move from the axially inner side to the axially outer side of the crankshaft 10. A shaft retaining ring 43 is provided on the crankshaft 10. Therefore, one outer ring 29a and the other outer ring 29b can be easily inserted and assembled from the outside in the axial direction of the crankshaft 10 so as to contact the one flange part 25 and the other flange part 27. In addition, the rolling elements 33a and 33b and the inner rings 31a and 31b can be easily inserted and assembled from the outside in the axial direction of the crankshaft 10, so that the inner rings 31a and 31b do not move from the inside in the axial direction to the outside in the axial direction. Can be positioned. That is, even when a pair of tapered roller bearings are used in back-to-back alignment, the axial direction of the pair of tapered roller bearings 11 and 12 can be easily controlled, and the bearings can be easily incorporated into the eccentric oscillating gear device. .
The second positioning means 60 (shaft retaining ring 43) presses the inner ring 31b to apply a preload to the pair of tapered roller bearings 11 and 12. That is, since the preload is applied to the tapered roller bearing using one positioning means, the preload can be applied to the bearing without providing a separate preload means. Therefore, even if a pair of tapered roller bearings are used on the back side, an eccentric oscillating gear device having high rigidity and a long life can be obtained.

Next, a second embodiment of the present invention will be described with reference to the drawings. The second embodiment will mainly be described with reference to parts different from the first embodiment.
In FIG. 3, the tapered roller bearing 12 is inserted between the other bearing hole 19 of the other support portion 21 and the other end portion of each crankshaft 9 in the same manner as in the first embodiment described above. A shaft retaining ring 43 is fitted on the outer peripheral portion of the other end of each crankshaft 9.
A needle roller bearing 9 with a cage 8 is disposed between the inside of the external gear 3 and the eccentric portion 7 of each crankshaft, and the one collar portion 25 and the other collar portion 27 are connected to the cage of the needle roller bearing 9. 8 is located on the side surface. One external gear 3 may be provided, but at least two external gears 3 (see FIG. 2) are preferably provided. When at least two external gears 3 are provided, at least two eccentric portions 7 of each crankshaft 10 are provided so as to match the number of external gears 3 (see FIG. 2). Needle roller bearings 9 with cages 8 are arranged between each eccentric portion 7 of each crankshaft 10 and one roller portion 25 is located on one outer eccentric portion 7 of each eccentric portion. The bearing 9 is positioned on the side surface of the cage 8 (see FIG. 2), and the other flange portion 27 is positioned on the side surface of the cage 8 of the needle roller bearing 9 located in the eccentric portion 7 outside the other eccentric portion. Is good. Regardless of the number of external gears 3 and the number of eccentric portions, the one flange portion 25 and the other flange portion 27 are located on the side surface of the cage 8 of the needle roller bearing 9.
Further, when the needle roller bearing 9 without a cage is used between the inside of each external gear 3 and each eccentric portion 7 of each crankshaft 10, the one flange portion 25 is placed on the outer side of each eccentric portion. The needle roller of the needle roller bearing 9 is located on the side surface of the needle roller of the needle roller bearing 9 located in the eccentric portion 7 and the other flange portion 27 is located in the eccentric portion 7 on the other outer side among the eccentric portions. It should be located on the side.
In addition, since the other structure as an eccentric rocking | fluctuation type gear apparatus in this 2nd Example is the same as the above-mentioned 1st Example, description of another structure is abbreviate | omitted.

Next, the operation of the second embodiment will be described.
Since the one flange portion 25 and the other flange portion 27 are positioned on the side surfaces of the respective cages 8 facing each other, when the cage 8 attempts to move largely in the axial direction on the pair of tapered roller bearings 11 and 12 side, the cage 8 comes into contact with the first collar part 25 and the other collar part 27, and the movement thereof is restricted. Therefore, even if a bearing with a cage is used between the inside of the external gear and the eccentric portion of the crankshaft, the axial direction of the cage can be regulated without separately providing a means for regulating the axial direction of the cage. . That is, even if a bearing with a cage is used, an inexpensive eccentric oscillating gear device with a function to restrict the axial direction of the cage can be obtained.
In addition, since the one collar portion 25 and the other collar portion 27 are positioned on the side surfaces of the needle rollers facing each other, when the pair of needle rollers try to move greatly in the axial direction, the needle rollers become one collar portion 25. And it contacts the other collar 27 and its movement is restricted. Therefore, even when a bearing without a cage is used between the inside of the external gear and the eccentric portion of the crankshaft, the axial direction restriction of the needle roller is not provided without separately providing the axial direction restriction means for the needle roller. Can do. That is, even when a bearing without a cage is used, an inexpensive eccentric oscillating gear device having a function of restricting the axial direction of needle rollers can be provided.

INDUSTRIAL APPLICABILITY The present invention can be used for an eccentric oscillating gear device used in all industrial fields.
In particular, it is most suitable for an eccentric oscillating speed reduction device used in a joint part of an industrial robot, a rotary table device, or an automatic tool changer of a machine tool.

It is a figure of the 1st Example concerning the present invention. FIG. 2 is an enlarged view around a crankshaft in FIG. 1. It is a figure of the 2nd Example which concerns on this invention.

Explanation of symbols

1 ··· Internal gear 3 ··· External gears 5 and 6 ··· A pair of main bearings 7 ··· Eccentric portion 9 ··· Crank Shafts 11, 12... Pair of radial bearings 13... Support body 100... Eccentric oscillating gear device 15.・ One support part 19 ・ ・ ・ ・ ・ ・ Other bearing hole 21 ・ ・ ・ ・ ・ ・ Other support part 25 ・ ・ ・ ・ ・ ・ One collar part 27 ・ ・ ・ ・ ・ ・ Other collar parts 29a, 29b. 31a, 31b .. Inner rings 33a, 33b .. Rolling element 50... First positioning means 60.

Claims (5)

A plurality of internal gears, an external gear meshing with the internal gears, and spaced apart from the center of the internal gear, and an eccentric portion engaged with the internal gear to cause the external gears to move eccentrically. In an eccentric oscillating gear device having a crankshaft and a support that rotatably supports each crankshaft via a pair of radial bearings, the internal gear and the support rotate relatively. The eccentric oscillating gear device, wherein the pair of radial bearings are assembled back to back. A pair of main bearings that rotatably support the internal gear and the support, and the pair of main bearings are disposed with the external gear interposed therebetween, and the support is formed of the pair of radial bearings. One support part formed with one bearing hole into which one is inserted and the other support part formed with the other bearing hole into which the other of the pair of radial bearings is inserted, the one support part and the other support part being connected The one bearing hole includes a first flange extending radially inward on the external gear side, and the other bearing hole includes a second flange extending radially inward on the external gear side, and the radial Each of the bearings has an outer ring, an inner ring, and a rolling element, and is inserted into the one bearing hole so that one outer ring of the pair of radial bearings is in contact with the one flange, and the other outer ring of the pair of radial bearings Is in contact with the other buttocks Each of the crankshafts is provided with first positioning means that is inserted into the side bearing holes and positions the inner ring of one of the pair of radial bearings so as not to move from the axially inner side to the axially outer side of the crankshaft. The second positioning means for positioning the other inner ring of the pair of radial bearings so as not to move from the inner side in the axial direction to the outer side in the axial direction of the crank shaft is provided on each of the crank shafts. The eccentric oscillating gear device according to claim 1. 3. The eccentric oscillating gear device according to claim 2, wherein a preload is applied to the pair of radial bearings by one of the first positioning means and the second positioning means. A bearing with a cage is disposed between the inside of the external gear and the eccentric portion of each crankshaft, and the one collar portion and the other collar portion are positioned on the side surface of the cage of the bearing. The eccentric oscillating gear device according to any one of claims 1 to 3. A bearing is disposed between the inside of the external gear and the eccentric portion of each crankshaft, and the one flange portion and the other flange portion are positioned on the side surface of the rolling element of the bearing. The eccentric rocking | fluctuation type gear apparatus in any one of Claims 1 thru | or 3.

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