JP3788528B2 - Low gear ratio flexure meshing gear system - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a flexure meshing gear device in which both internal gears and external gears are flexible, and a reduction speed ratio is realized by utilizing the flexure of both gears.
[0002]
[Prior art]
In general, a flexure-meshing gear device is composed of a rigid internal gear, a flexible external gear disposed inside the rigid internal gear, and the external gear is bent into an elliptical shape and meshed with the internal gear. And a wave generator that moves the meshing position in the circumferential direction. In this type of flexure meshing gear device, a reduced rotational output corresponding to the difference in the number of teeth between the internal teeth and the external teeth is obtained. Generally, the difference in the number of teeth is two and the speed ratio obtained is about R = 50.
[0003]
In order to reduce the speed ratio, the difference in the number of teeth may be increased. When the difference in the number of teeth is increased, it is necessary to increase the amount of bending of the flexible external gear accordingly. However, since there is a limit in increasing the amount of flexure of the flexible external gear, there is also a limit in reducing the speed ratio.
[0004]
In view of this point, the applicant of the present invention previously described in JP-A-5-141485 and JP-A-5-141486, the internal gear is also flexible, and both the internal gear and the external gear are radiused. It has been proposed to realize a flexure meshing gear device with a small speed ratio by bending in the direction.
[0005]
[Problems to be solved by the invention]
An object of the present invention is to propose a wave generator having a new configuration for forming a flexure meshing state of both gears in a flexure meshing gear device in which both the internal gear and the external gear are flexible gears. There is to do.
[0006]
[Means for Solving the Problems]
The flexure meshing gear device of the present invention includes an annular flexible internal gear, an annular flexible external gear arranged concentrically inside the flexible internal gear, and the movable gear. A first wave generator disposed concentrically on the inside of the flexible external gear for bending the flexible external gear into an ellipse and partially meshing with the flexible internal gear And a second wave generator for bending the flexible internal gear into an elliptical shape and partially meshing with the flexible external gear.
[0007]
The first wave generator includes an elliptical rigid cam plate and a wave bearing fitted between the outer peripheral surface of the rigid cam plate and the inner peripheral surface of the flexible external gear. The one of the configuration is adopted.
[0008]
Furthermore, as the second wave generator, a pair of arm members that rotate integrally with the rigid cam plate and extend in opposite directions along the long axis direction of the rigid cam plate, and rotate at the tips of these arm members Adopting a configuration that includes a wave roller that is supported freely and can roll with the outer peripheral surface of the flexible internal gear pressed toward the center in a circumferential direction. Yes.
[0009]
In the flexure meshing gear device of the present invention configured as described above, the flexible external gear is bent into an elliptical shape by the first wave generator. On the other hand, the flexible internal gear is similarly bent into an oval shape by the second wave generator. Here, the positions of both ends in the major axis direction of the flexible external gear bent in an elliptical manner coincide with the positions of both ends in the minor axis direction of the flexible internal gear bent in an elliptical shape. . Therefore, the bending engagement state of both gears is formed by the bending of both gears. For this reason, since the relative amount of deflection can be increased, a flexure meshing gear device with a low speed ratio can be realized.
[0010]
Here, in the second wave generator, a configuration in which a pair of wave rollers are mounted at positions symmetrical with respect to the long axis extension line of the rigid cam plate as rollers supported at the respective distal ends of the arm members. Can be adopted. In this way, when the flexible internal gear is pressed inward in the radial direction at a position deviated from the position on the long-axis extension, a negatively displaced mesh can be formed. As a result, the meshing area of both gears can be widened, and torque transmission characteristics and the like can be improved.
[0011]
DETAILED DESCRIPTION OF THE INVENTION
1A and 1B show a schematic configuration of a flexure meshing gear device to which the present invention is applied. The flexure-meshing gear device 1 includes a cylindrical device housing 2, and the device housing 2 includes a flexible internal gear 3, a flexible external gear 4, and a first wave from the outside. A generator 5 is incorporated concentrically. A second wave generator 6 for bending the flexible internal gear 3 is also assembled.
[0012]
The flexible internal gear 3 has a top-hat shape as a whole, and has a cylindrical body portion 32 in which inner teeth 31 are formed on the inner peripheral surface on the tip opening side, and a side opposite to the body portion 32. An annular diaphragm 33 extending at a right angle from the opening toward the outside in the radial direction, and an annular boss 34 formed continuously on the outer peripheral edge of the diaphragm 33 are provided. The annular boss 34 is fastened and fixed to a mounting surface formed on the apparatus housing 2.
[0013]
The flexible external gear 4 has a cup shape as a whole, and includes a cylindrical barrel portion 42 having outer teeth 41 formed on the outer peripheral surface on the tip opening side, and an opening on the opposite side of the barrel portion 42. An annular diaphragm 43 extending at a right angle toward the inside in the radial direction, and an annular boss 44 formed continuously on the inner peripheral edge of the diaphragm 43 are provided. The annular boss 44 is connected to an output member (load side) (not shown).
[0014]
The first wave generator 5 is for bending the flexible external gear 4 into an elliptical shape, and has a rigid cam plate 51 having an elliptical profile fixed to an input shaft (not shown). And a wave bearing 52 fitted to the outer peripheral surface. The flexible external gear 4 bent in an elliptical shape by the first wave generator 5 has a long axis 4a positioned in a vertical direction as shown in the figure, for example.
[0015]
On the other hand, the second wave generator 6 is for bending the flexible internal gear 3 into an elliptical shape. The second wave generator 6 includes a pair of arm members 61 (only one arm member is shown in the drawing) fixed to the rigid cam plate 51 of the first wave generator 5 described above. ing. The arm member 61 is arranged along the long axis 4 a of the rigid cam plate 51 of the first wave generator 6, and its base end 61 a is fastened to the end surface 51 a of the rigid cam plate 51 by a fastening bolt.
[0016]
The tip 61b of the arm member 61 extends to a position beyond the flexible internal gear 3, and the roller shaft 62 is directed toward the outer peripheral side of the flexible internal gear 3 along the device axis 1a. It is installed in a protruding state. A wave roller 63 is rotatably supported on the roller shaft 62. The outer peripheral surface of the wave roller 63 is just located on the outer peripheral surface of the portion of the body 32 of the flexible internal gear 3 where the internal teeth 31 are formed, and this portion is directed inward in the radial direction. Is pressed.
[0017]
Thus, the flexible internal gear 3 is pressed inside by the wave roller 63 attached to the tip of the pair of arm members 61. Therefore, the flexible internal gear 3 as a whole is bent in an elliptical shape in which the direction perpendicular to the arrangement direction of the arm members 61 is the long axis 3a.
[0018]
An annular wave roller receiver 64 is disposed outside the wave roller 63 around the apparatus axis 1a, and the outer peripheral side of the wave roller receiver 64 is connected to the apparatus housing 2 via a bearing 65. The formed annular inner peripheral surface is rotatably supported.
[0019]
In the flexure meshing gear device 1 configured as described above, the flexible external gear 4 is bent in an elliptical shape by the first wave generator 5 as described above, and the long axis 4a thereof is shown in the figure, for example. Is in the vertical direction. On the other hand, the flexible internal gear 3 is bent by the second wave generator 6 into an elliptical shape with the long axis 3a being in the horizontal direction. As a result, a state is formed in which the external teeth at both ends in the major axis direction of the flexible external gear 4 and the internal teeth at both ends in the minor axis direction of the flexible internal gear 3 are engaged with each other. . That is, the corresponding gears 3 and 4 are in mesh with each other at a position where the maximum amount of deflection is generated. Therefore, the relative deflection amount of these gears can be increased.
[0020]
In this state, when the rigid cam plate 51 of the first wave generator 5 is rotated at a high speed by an input shaft (not shown), the wave roller supported by the pair of arm members 61 of the second wave generator 6. 63 also rotates and revolves around the device axis 1 a together with the rigid cam plate 51.
[0021]
As a result, the meshing position of the inner teeth and the outer teeth moves in the circumferential direction, and a relative rotation according to the difference in the number of teeth of these gears occurs between both gears. Since the flexible internal gear 3 is fixed, the flexible external gear 4 side rotates at a reduced speed, and the rotation is transmitted to the output member side (not shown).
[0022]
(Other embodiments)
FIG. 1C shows another form of the wave roller 63. In this example, in the second wave generator 6, as a wave roller supported at each tip of the arm member 61, a pair of waves are arranged at positions symmetrical with respect to the extended line of the long axis 4 a of the rigid cam plate 51. The rollers 63A and 63B are attached. In this way, when the flexible internal gear is pressed inward in the radial direction at a position deviated from the position on the long-axis extension, a negatively displaced mesh can be formed. As a result, the meshing area of both gears 3 and 4 can be widened, and torque transmission characteristics and the like can be improved.
[0023]
【The invention's effect】
As described above, in the flexibly meshing gear device of the present invention, the flexible external gear is bent into an ellipse, and the pair of rollers that revolve the flexible internal gear around the device axis. By pressing against the outer peripheral surface of the flexible internal gear, it is bent into an elliptical shape. Therefore, according to the present invention, these meshing states can be formed at the position where the maximum deflection of both gears is generated. Therefore, the amount of bending of the gear can be increased, and accordingly, the difference in the number of teeth of both gears can be increased and the speed ratio can be lowered.
[Brief description of the drawings]
FIG. 1A is a schematic cross-sectional configuration diagram of a flexure meshing gear device of the present invention, FIG. 1B is a partial side configuration diagram thereof, and FIG. 1C is a diagram illustrating a modification of a second wave generator. FIG.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Deflection meshing gear apparatus 2 Apparatus housing 3 Flexible internal gear 3a The long axis 31 of the flexible internal gear bent to ellipse Internal tooth 4 Flexible external gear 4a It is bent to ellipse Long axis 41 of flexible external gear 41 External tooth 5 First wave generator 51 Elliptical rigid cam plate 6 Second wave generator 61 Arm member 63 Wave roller

Claims (2)

An annular flexible internal gear, an annular flexible external gear arranged concentrically inside the flexible internal gear, and a concentric shape inside the flexible external gear A first wave generator for bending the flexible external gear into an elliptical shape and partially meshing with the flexible internal gear; and the flexible internal gear A second wave generator for bending elliptically and partially meshing with the flexible external gear;
The first wave generator includes an elliptical rigid cam plate, and a wave bearing fitted between the outer peripheral surface of the rigid cam plate and the inner peripheral surface of the flexible external gear,
The second wave generator rotates integrally with the rigid cam plate, and extends in the opposite direction along the long axis direction of the rigid cam plate, and freely rotatable at the tips of these arm members. A reduced speed ratio, comprising: a wave roller supported and rollable in a circumferential direction along the outer peripheral surface in a state where the outer peripheral surface of the flexible internal gear is pressed toward the center. Flexure meshing gear device. 2. The reduced speed ratio according to claim 1, wherein a pair of wave rollers are attached to the respective distal ends of the arm members at positions symmetrical with respect to the long axis extension line of the rigid cam plate. Flexure meshing gear device.

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