JP7629370B2 - Eccentric oscillating gear device - Google Patents

Description

The present invention relates to an eccentric oscillating gear device.

Patent Document 1 describes a differential reducer that reduces the rotation of an input shaft and outputs it. This reducer includes an input shaft with an eccentric portion, an external gear that meshes internally with the internal gear, an eccentric portion bearing provided between the eccentric portion and the external gear, and a pin into which the external gear is loosely inserted, and the external gear moves eccentrically relative to the internal gear. The rotation component of the external gear is output to the output section via the pin.

JP 2018-155264 A

In the reducer described in Patent Document 1, a hollow cylindrical input shaft is rotatably supported inside the casing via a ball bearing that serves as the input shaft bearing. In this reducer, grease is filled inside the casing to maintain lubrication, and an oil seal is provided between the case cover and the input shaft to prevent grease leakage. However, when making this reducer smaller, it cannot be made small enough to ensure space for the oil seal, which is disadvantageous to miniaturization.

The object of the present invention was made in consideration of these problems, and is to provide an eccentric oscillating gear device that is advantageous for miniaturization.

In order to solve the above problems, an eccentric oscillating gear device according to one embodiment of the present invention is an eccentric oscillating gear device that includes an external gear, an eccentric that oscillates the external gear, and an eccentric bearing that is disposed between the external gear and the eccentric, and has a first restricting member that restricts the axial movement of the eccentric bearing, and a second restricting member that restricts the axial movement of the external gear, and has a suppressing portion that suppresses the passage of lubricant between the first restricting member and the second restricting member.

In addition, any combination of the above components, or mutual substitution of the components or expressions of the present invention between methods, systems, etc., are also valid aspects of the present invention.

The present invention provides an eccentric oscillating gear device that is advantageous for miniaturization.

FIG. 1 is a side cross-sectional view of an eccentric oscillating gear device according to a first embodiment. 4 is an enlarged view showing the periphery of a suppression portion of the first embodiment; FIG. 13 is an enlarged view showing the periphery of a suppression portion of a second embodiment; FIG. 13 is an enlarged view showing the periphery of a suppression portion of a third embodiment. FIG. 13 is an enlarged view showing the periphery of a suppression portion of a fourth embodiment; FIG. FIG. 13 is a side cross-sectional view of an eccentric oscillating gear device according to a fifth embodiment.

The present invention will be described below based on a preferred embodiment with reference to the drawings. In the embodiments and modified examples, identical or equivalent components and parts are given the same reference numerals, and duplicated explanations will be omitted as appropriate. Furthermore, the dimensions of the parts in each drawing are shown enlarged or reduced as appropriate to facilitate understanding. Furthermore, some parts that are not important for explaining the embodiment are omitted in each drawing.

Separate components that have something in common are differentiated by adding an ordinal number such as "first" or "second" to the beginning of the component name, and these are omitted when referring to them collectively. Furthermore, terms that include ordinal numbers such as "first" or "second" are used to describe various components, but these terms are used only for the purpose of distinguishing one component from other components, and do not limit the components.

[First embodiment]
The configuration of an eccentric oscillating gear device 100 (hereinafter, sometimes simply referred to as "gear device 100") according to a first embodiment of the present invention will be described below with reference to Figures 1 and 2. Figure 1 is a side cross-sectional view that shows a schematic diagram of the eccentric oscillating gear device 100. This figure shows the gear device 100 applied to a rotating device 10. In addition to the gear device 100, the rotating device 10 includes a motor 96 and a rotating mechanism 98.

The motor 96 has a magnet rotor 962 fixed to the outer periphery of the eccentric shaft 11 (input shaft) of the gear device 100, and a stator 964 surrounding the magnet rotor 962. When energized, the stator 964 generates a field magnetic field and supplies it to the magnet rotor 962. This field magnetic field imparts a rotational driving force to the magnet rotor 962 and the eccentric shaft 11. The rotation mechanism 98 is a mechanism having a specific function. As an example, the rotation mechanism 98 may be an encoder that generates a signal corresponding to the rotation of the eccentric shaft 11, or a brake mechanism that suppresses the rotation of the eccentric shaft 11.

First, the overall configuration of the gear device 100 will be described. FIG. 2 is an enlarged view of the periphery of the suppression section 50 of the gear device 100. The gear device 100 of this embodiment mainly includes an eccentric body shaft 11, eccentric bodies 12 and 13, external gears 14 and 15, an internal gear 16, a carrier 18, a casing 22, a main bearing 24, eccentric body shaft bearings 30 and 31, eccentric body bearings 34 and 35, an inner pin 38, a first restricting member 60, and a second restricting member 70.

The gear device 100 is a center crank type planetary gear device in which the rotation of the eccentric shaft 11 causes the external gears 14, 15 to oscillate via the eccentric bearings 34, 35, and transmits the rotation of the external gears 14, 15 to the carrier 18 via the inner pin 38.

Hereinafter, the direction along the central axis La of the internal gear 16 will be referred to as the "axial direction", and the circumferential direction and radial direction of the circle centered on the central axis La will be referred to as the "circumferential direction" and the "radial direction", respectively. Also, hereinafter, for convenience, one side in the axial direction (the right side in the figure) will be referred to as the input side, and the other side (the left side in the figure) will be referred to as the anti-input side. These directional notations do not limit the usage orientation of the gear device 100, and the gear device 100 can be used in any orientation.

The gear device 100 has external gears 14, 15 and an internal gear 16 that meshes with the external gears 14, 15. By oscillating the external gears 14, 15, one of the external gears 14, 15 and the internal gear 16 rotates on its axis, and the gear device is an eccentric oscillating gear device that outputs the rotation component.

The casing 22 functions as an outer shell that houses other components of the gear device 100, such as the external gears 14 and 15. The casing 22 in this embodiment is constructed by combining multiple casing members. In this example, the casing 22 is composed of a first casing member 221, a second casing member 222 arranged on the input side of the first casing member 221, and a third casing member 223 arranged on the input side of the second casing member 222.

The eccentric shaft 11 is arranged coaxially with the central axis La of the internal gear 16 and has a hollow cylindrical shape. The eccentric shaft 11 can be rotated by the rotational power transmitted from the motor 96. The gear device 100 of this embodiment is a center crank type in which the eccentric shaft 11 is arranged at the center of the internal gear 16. In this embodiment, the eccentric shaft 11 is provided with two eccentric bodies 12 and 13 with a phase difference of 180°. The eccentric bodies 12 and 13 oscillate the external gears 14 and 15. The eccentric shaft 11 is supported by the carrier 18 and the rotation mechanism 98 via eccentric shaft bearings 30 and 31. Of the two eccentric bodies 12 and 13, the first eccentric body 12 is arranged on the anti-input side of the second eccentric body 13.

The first eccentric body shaft bearing 30 is disposed between the eccentric body shaft 11 and the carrier 18, and the second eccentric body shaft bearing 31 is disposed between the eccentric body shaft 11 and the rotation mechanism 98. There are no limitations on the configuration of the eccentric body shaft bearings 30 and 31, but in this example they are ball bearings. As the eccentric body shaft bearings 30 and 31, known bearings such as roller bearings may be used instead of ball bearings.

The axis of the eccentric bodies 12, 13 is eccentric with respect to the central axis La of the internal gear 16, and the eccentric bodies 12, 13 rotate around the central axis La to oscillate the external gears 14, 15. The external gears 14, 15 are provided individually corresponding to each of the multiple eccentric bodies 12, 13, and are rotatably supported by the corresponding eccentric bodies 12, 13 via eccentric body bearings 34, 35. Of the eccentric body bearings 34, 35, the first eccentric body bearing 34 is positioned on the anti-input side of the second eccentric body bearing 35.

The eccentric body bearings 34, 35 of this embodiment are roller bearings that do not have a dedicated inner ring, outer ring, or retainer, and the outer peripheral surfaces of the eccentric bodies 12, 13 also serve as the inner ring, and the inner peripheral surfaces of the central holes 142, 152 that axially penetrate the external gears 14, 15 also serve as the outer ring. In other words, the first eccentric body bearing 34 functions as a cylindrical member (roller) that rolls between the eccentric body 12 and the external gear 14, and the second eccentric body bearing 35 functions as a cylindrical member (roller) that rolls between the second eccentric body 13 and the second external gear 15. The eccentric body bearings 34, 35 may have a separator to form a circumferential gap between the rolling bodies.

The first eccentric body bearing 34 is disposed on the outer periphery of the first eccentric body 12, on the input side of the first eccentric body shaft bearing 30. A restricting washer 62 is disposed between the first eccentric body shaft bearing 30 and the first eccentric body bearing 34, and the axial movement of the non-input side of the first eccentric body bearing 34 toward the non-input side is restricted by the restricting washer 62 and the first eccentric body shaft bearing 30. The axial movement of the input side of the first eccentric body bearing 34 toward the input side is restricted by a circumferential protrusion 19 that protrudes radially from the outer periphery of the eccentric shaft 11.

The second eccentric bearing 35 is disposed on the outer periphery of the second eccentric 13, on the input side of the circumferential protrusion 19. The first restricting member 60 is disposed on the input side of the second eccentric bearing 35, and the retaining ring 63 is disposed on the input side of the first restricting member 60. The retaining ring 63 is an annular member that fits into a circumferential groove provided on the eccentric shaft 11, and restricts the axial movement of the first restricting member 60 toward the input side. The first restricting member 60 in this example is an annular member that fits into the outer circumferential surface of the eccentric shaft 11. The first restricting member 60 is supported in the axial direction by the retaining ring 63, and restricts the axial movement of the second eccentric bearing 35 toward the input side. The first restricting member 60 will be described later.

The external gears 14, 15 have a center hole 142, 152 that penetrates the center of the external gears 14, 15, and multiple (e.g., six) inner pin holes 143, 153 that penetrate at positions offset from the center. An inner pin 38 is inserted into the inner pin holes 143, 153. The teeth formed on the outer periphery of the external gears 14, 15 rotate while meshing with the teeth of the internal gear 16, causing the external gears 14, 15 to oscillate. Of the external gears 14, 15, the first external gear 14 is positioned on the anti-input side of the second external gear 15.

The first external gear 14 is disposed on the input side of the carrier 18, and axial movement toward the non-input side is restricted by the carrier 18. The second external gear 15 is disposed on the input side of the first external gear 14 with a spacer 68 in between. The second restricting member 70 is a thin plate-like member disposed on the input side of the second external gear 15, and restricts axial movement of the second external gear 15 toward the input side. The input side of the second restricting member 70 is covered by the third casing member 223, and the second restricting member 70 is disposed between the second external gear 15 and the third casing member 223. The second restricting member 70 will be described later.

The inner pin 38 extends axially from the input side of the carrier 18 so as to pass through the inner pin holes 143 and 153. The input side end of the inner pin 38 extends to the vicinity of the second restricting member 70.

The internal gear 16 is integrated with the casing 22. In this example, the internal gear 16 is formed by the second casing member 222.

In this embodiment, the carrier 18 is disposed on the opposite input side of the first external gear 14. The carrier 18 rotates in synchronization with the rotation components of the external gears 14 and 15, and outputs the rotation component to the driven device (not shown). Alternatively, the internal gear 16 may rotate instead of the carrier 18, and output the rotation component to the driven device via the casing 22.

The main bearing 24 supports the carrier 18 so that it can rotate freely relative to the casing 22. In this example, the main bearing 24 is disposed between the carrier 18 and the first casing member 221 on the non-input side of the external gears 14, 15. There are no limitations on the configuration of the main bearing 24, but in this example, the main bearing 24 is a cross roller bearing.

The operation of the gear device 100 will be described. When rotational power is transmitted from the motor 96 to the eccentric shaft 11, the eccentric shaft 11 rotates around the rotation center line La, and the external gears 14, 15 are oscillated by the eccentrics 12, 13. When the external gears 14, 15 oscillate, the meshing positions of the external gears 14, 15 and the internal gear 16 are shifted sequentially in the circumferential direction. As a result, with each rotation of the eccentric shaft 11, one of the external gears 14, 15 and the internal gear 16 rotates together with the carrier 18 by an amount corresponding to the difference in the number of teeth between the external gears 14, 15 and the internal gear 16. The rotation of the eccentric shaft 11 is decelerated at a reduction ratio according to the difference in the number of teeth between the external gears 14, 15 and the internal gear 16, and then output to the driven device via the carrier 18.

(Suppression section)
Next, the characteristic configuration of this embodiment will be described with reference to Fig. 2. In the gear device 100, a lubricant J is held in the space that houses the meshing portions of the external gears 14, 15 and the internal gear 16 and the eccentric bearings 34, 35 to lubricate these members. If the lubricant J leaks from this space, there is a risk of insufficient lubrication and a shortened lifespan. Furthermore, if the leaked lubricant J flows to the motor 96 or the rotating mechanism 98, it may have an adverse effect on these. For example, if the rotating mechanism 98 is a brake, there is a possibility that the brake performance may be reduced, and if the rotating mechanism 98 is an encoder, there is a possibility that the lubricant J adheres to a sensor or the like and reduces the performance of the encoder.

In order to prevent leakage of the lubricant J, it is possible to arrange an oil seal. However, if an oil seal is arranged, the gear device 100 becomes larger by the amount of the arrangement space, which is disadvantageous for miniaturization of the gear device 100. More specifically, the oil seal is arranged in the radial space between the outer member and the inner member. For example, in the gear device 100 of this embodiment, the oil seal is arranged so that it fits into the inner peripheral surface of the third casing member 223 and abuts the lip portion against the outer peripheral surface of the eccentric shaft 11. Therefore, it is necessary to secure an arrangement space in the radial direction, which is mainly disadvantageous for miniaturization in the radial direction. Furthermore, there is also a problem that the loss is large because the lip portion slides while being pressed against the eccentric shaft 11 rotating at high speed. Therefore, the gear device 100 of this embodiment has a suppression part 50 that suppresses the passage of the lubricant J between the first restricting member 60 that restricts the axial movement of the second eccentric bearing 35 and the second restricting member 70 that restricts the axial movement of the second external gear 15.

2, the second restricting member 70 has a disk-shaped main portion 71 extending radially along the external gear 15, a tubular portion 73 extending axially from the inner peripheral end of the main portion 71 toward the input side, and an extension portion 74 extending radially inward from the input side end of the tubular portion 73. The tubular portion 73 is tapered so that the diameter gradually decreases from the non-input side toward the input side. The outer diameter of the extension portion 74 is larger than the outer diameter of the first restricting member 60, and the inner diameter of the extension portion 74 is smaller than the outer diameter of the first restricting member 60. By having the extension portion 74, the gear device 100 can form a suppression portion 50 that suppresses the passage of the lubricant J in the radial gap and the axial gap between the extension portion 74 and the first restricting member 60. In this case, the effect of suppressing the passage of the lubricant J can be improved.

The radial gap and axial gap between the extension portion 74 and the first restricting member 60 function as a lubricant reservoir that retains the lubricant J. The radial gap and axial gap can be set by experiment or simulation so as to obtain the desired effect of suppressing the passage of the lubricant J and the lubricant retention effect.

The features of the eccentric oscillating gear device 100 configured as above will be described. The gear device 100 is an eccentric oscillating gear device 100 including an external gear 15, an eccentric body 13 that oscillates the external gear 15, and an eccentric body bearing 35 arranged between the external gear 15 and the eccentric body 13. The gear device 100 has a first restricting member 60 that restricts the axial movement of the eccentric body bearing 35, and a second restricting member 70 that restricts the axial movement of the external gear 15. The gear device 100 also has a suppressing section 50 between the first restricting member 60 and the second restricting member 70 that suppresses the passage of the lubricant J.

According to this configuration, by having the suppression section 50, leakage of the lubricant J can be reduced and a reduction in the life span can be suppressed. Since the suppression section 50 can be configured in a small space, the size of the gear device 100 can be suppressed. In addition, the impact of leaked lubricant J on the devices and members arranged around the gear device 100 can be suppressed. In addition, since no oil seal is used, loss at the oil seal can be reduced, which is also advantageous in terms of cost.

Below, the second to fifth embodiments of the present invention will be described. In the drawings and explanations of the second to fifth embodiments, the same reference numerals are used for components and members that are the same as or equivalent to those in the first embodiment. Explanations that overlap with the first embodiment will be omitted as appropriate, and the explanation will focus on the configurations that differ from the first embodiment. Therefore, the explanation of the first embodiment applies to components and members in the second to fifth embodiments that are the same as or equivalent to those in the first embodiment.

[Second embodiment]
The configuration of an eccentric oscillating gear device 100 according to a second embodiment of the present invention will be described with reference to Fig. 3. Fig. 3 is an enlarged view of the periphery of the suppression unit 50 of the gear device 100 according to this embodiment, and corresponds to Fig. 2.

The gear device 100 of this embodiment has a suppression member 80 on the opposite side of the second suppression member 70 from the first suppression member 60, and the suppression member 80 differs from the first embodiment in that it forms a second suppression section 52 that suppresses the passage of lubricant J, but the other configurations are the same. Therefore, the suppression member 80 and the second suppression section 52 will be mainly described.

As shown in FIG. 3, the suppression member 80 is disposed on the opposite side of the second restricting member 70 from the first restricting member 60, and faces the second restricting member 70 with a gap therebetween. The suppression member 80 is an annular member that surrounds the eccentric body shaft 11, and in the example of FIG. 3, it is fitted into a circumferential groove provided in the eccentric body shaft 11. The outer diameter of the suppression member 80 is larger than the diameter of the inner circumference of the extension portion 74. The suppression portion 50 includes a second suppression portion 52 formed in the axial gap between the extension portion 74 and the suppression member 80.

In this embodiment, the radial gap G1 between the second restricting member 70 and the eccentric shaft 11 is smaller than the axial gap G2 between the first restricting member 60 and the second restricting member 70. In this case, the radial gap G1 can enhance the effect of suppressing the passage of the lubricant J.

This embodiment has the same action and effect as the first embodiment. In addition, the gear device 100 of this embodiment has a suppression member 80, so that a second suppression section 52 that suppresses the passage of lubricant J in the axial gap between the extension section 74 and the suppression member 80 can be configured. In this case, the effect of suppressing the passage of lubricant J can be further improved.

[Third embodiment]
The configuration of an eccentric oscillating gear device 100 according to a third embodiment of the present invention will be described with reference to Fig. 4. Fig. 4 is an enlarged view of the periphery of the suppression unit 50 of the gear device 100 according to this embodiment, and corresponds to Fig. 2.

The gear device 100 of this embodiment differs from the second embodiment in that the suppression member 80 abuts against the second regulating member 70 in the axial direction, but the other configuration is the same as the second embodiment. Therefore, the configuration of the suppression member 80 will be mainly described.

The suppression member 80 of this embodiment is a V-ring having a cylindrical portion 81 that surrounds the eccentric shaft 11 and a conical seal lip 82 provided on the non-input side of the cylindrical portion 81. As an example, the suppression member 80 has the cylindrical portion 81 and the seal lip 82 integrally formed from a flexible resin such as nitrile rubber. The tip of the seal lip 82 abuts against the extension portion 74 of the second restricting member 70 in the axial direction. The cylindrical portion 81 is press-fitted into the eccentric shaft 11, and its contraction force maintains the axial position.

This embodiment has the same action and effect as the second embodiment. That is, since the V-ring is configured to abut against the second regulating member 70 in the axial direction, it is advantageous for radial miniaturization. Also, compared to an oil seal that presses the lip portion from the radial direction to slide, it is easier to reduce the abutment force between the seal lip 82 and the second regulating member 70, so losses can also be reduced. In addition, in the gear device 100 of this embodiment, the suppression member 80 abuts against the second regulating member 70, and this abutment portion can further suppress the passage of the lubricant J.

[Fourth embodiment]
The configuration of an eccentric oscillating gear device 100 according to a fourth embodiment of the present invention will be described with reference to Fig. 5. Fig. 5 is an enlarged view of the periphery of the suppression unit 50 of the gear device 100 according to this embodiment, and corresponds to Fig. 2.

The gear device 100 of this embodiment differs from the first embodiment in the configuration of the first regulating member 60 and the second regulating member 70, but the other configurations are the same. Therefore, the first regulating member 60 and the second regulating member 70 will be mainly described.

In this embodiment, as shown in FIG. 5, the first restricting member 60 has a radial extending portion 61 and an axial extending portion 67 that extends in the axial direction. The suppressing portion 50 is formed between the axial extending portion 67 and the second restricting member 70. In this case, the axial extending portion 67 can narrow the width of the path through which the lubricant J passes in the suppressing portion 50, thereby enhancing the passage suppression effect. In this example, the radial extending portion 61 has a hollow disk shape that fits into the outer circumferential surface of the eccentric shaft 11, and the axial extending portion 67 has a hollow cylindrical shape that extends from the outer circumferential end of the radial extending portion 61 to the input side in the axial direction.

In addition, in this embodiment, as shown in FIG. 5, the second restricting member 70 has a first radially opposed portion 75 that faces the outer peripheral surface of the axially extending portion 67, an axially opposed portion 76 that faces the axially extending portion 67, and a second radially opposed portion 78 that faces the inner peripheral surface of the axially extending portion 67.

In this example, the first radial opposing portion 75 has a hollow cylindrical shape extending axially from the inner peripheral end of the main portion 71 toward the input side, the axial opposing portion 76 has a hollow disk shape extending radially inward from the input side end of the first radial opposing portion 75, and the second radial opposing portion 78 has a hollow cylindrical shape extending axially from the inner peripheral end of the axial opposing portion 76 toward the non-input side.

This embodiment has the same action and effect as the first embodiment. In addition, the gear device 100 of this embodiment can further enhance the passage suppression effect by lengthening the path through which the lubricant J passes in the suppression section 50 due to the first radial opposing portion 75, the axial opposing portion 76, and the second radial opposing portion 78.

[Fifth embodiment]
In the above embodiment, an example has been shown in which the eccentric oscillating gear device 100 is a so-called center crank type eccentric oscillating gear device, but the present invention is not limited to this. For example, the eccentric oscillating gear device may be a flexible mesh gear device such as a cylindrical type, a cup type, or a top hat type. Below, an example in which the present invention is applied to a flexible mesh gear device will be shown as a fifth embodiment.

The configuration of an eccentric oscillating gear device 100 according to a fifth embodiment of the present invention will be described with reference to FIG. 6. FIG. 6 is a side cross-sectional view of the gear device 100 according to this embodiment, and corresponds to FIG. 1. The gear device 100 according to this embodiment mainly includes an eccentric body shaft 11, eccentric bodies 12 and 13, external gears 14 and 15, a main bearing 24, an eccentric body shaft bearing 30, eccentric body bearings 34 and 35, internal gears 16 and 17, a casing 22, an output member 20, a first restricting member 60, and a second restricting member 70. Of the internal gears 16 and 17, the first internal gear 16 is disposed on the opposite input side of the second internal gear 17.

The gear device 100 is a flexure meshing gear device that rotates the external gears 14, 15 that mesh with the internal gears 16, 17 while flexibly deforming them, causing the external gears 14, 15 to rotate on their own axes, and outputs the rotation component.

The eccentric bodies 12 and 13 are integrally formed on the outer periphery of the eccentric body shaft 11 and function as vibration exciters for the flexure mesh gear device. The eccentric bodies 12 and 13 have an elliptical outer periphery in a cross section perpendicular to the direction along the central axis La. In this specification, "ellipse" is not limited to a geometrically strict ellipse, but also includes approximate ellipses.

The external gears 14 and 15 are flexible cylindrical members. The external gears 14 and 15 are provided axially apart on the outer periphery of a cylindrical portion that functions as an external gear base. The first external gear 14 meshes with the first internal gear 16 that functions as an output internal gear, and the second external gear 15 meshes with the second internal gear 17 that functions as a reduction internal gear.

The external gears 14, 15 are flexibly deformed into an elliptical shape by the eccentric bodies 12, 13 via the eccentric body bearings 34, 35 in response to the rotation of the eccentric bodies 12, 13. At this time, the external gears 14, 15 are flexibly deformed to match the shape of the eccentric bodies 12, 13 while changing the meshing position with the internal gears 16, 17 in the circumferential direction. The eccentric body bearings 34, 35 are disposed between the eccentric bodies 12, 13 and the external gears 14, 15. In this embodiment, the eccentric body bearings 34, 35 have retainers 33, 36.

The number of teeth of the first internal gear 16 is the same as the number of teeth of the first external gear 14, and the number of teeth of the second internal gear 17 is 2i (i is a natural number equal to or greater than 1) more than the number of teeth of the second external gear 15. As a result, when the eccentric bodies 12 and 13 rotate, a rotation of the same magnitude as the rotation component of the external gears 14 and 15 is output to the first internal gear 16.

The casing 22 has a first casing member 221 that rotatably supports the first internal gear 16 via the main bearing 24, a second casing member 222 that is arranged on the input side of the first casing member 221, and a third casing member 223 that is arranged on the input side of the second casing member 222. The second internal gear 17 is integrated into the second casing member 222.

The output member 20 extracts the rotation component of the external gear 14 and transmits it to the driven device. The output member 20 includes a first output member 201 arranged on the opposite input side of the first external gear 14, and a second output member 202 arranged on the input side of the first output member 201. The second output member 202 is integrated with the first internal gear 16.

The eccentric shaft bearing 30 is disposed between the first output member 201 and the eccentric shaft 11. The eccentric shaft bearing 30 rotatably supports the eccentric shaft 11 having the eccentric bodies 12 and 13 relative to the first output member 201.

A receiving plate member 39 is disposed on the non-input side of the first external gear 14. The receiving plate member 39 is an annular plate member that surrounds the eccentric body shaft 11. The side surface on the non-input side of the receiving plate member 39 does not abut the inner ring 302 of the eccentric body shaft bearing 30, but abuts the outer ring 301 of the eccentric body shaft bearing 30 to restrict axial movement of the first external gear 14 to the non-input side. The receiving plate member 39 extends to the non-input side of the eccentric body bearing 34 to restrict axial movement of the retainer 33 to the non-input side.

The first restricting member 60 is disposed on the input side of the eccentric body bearing 35 and restricts the axial movement of the eccentric body bearing 35 towards the input side. The first restricting member 60 in FIG. 6 is a protrusion that protrudes radially outward from the outer periphery of the eccentric body shaft 11. More specifically, it restricts the axial movement of the eccentric body bearing 35 towards the input side by protruding radially outward from the outer periphery of the eccentric body 13 of the eccentric body shaft 11. In this example, the first restricting member 60 is formed integrally with the eccentric body shaft 11.

The second restricting member 70 is disposed on the input side of the external gear 15 and restricts the axial movement of the external gear 15 to the input side. The second restricting member 70 has a disk-shaped main portion 71 extending radially along the external gear 15, a tubular portion 73 extending axially from the inner peripheral end of the main portion 71 to the input side, and an extension portion 74 extending radially inward from the input side end of the tubular portion 73. The outer diameter of the extension portion 74 is larger than the outer diameter of the first restricting member 60, and the inner diameter of the extension portion 74 is smaller than the outer diameter of the first restricting member 60. By having the extension portion 74, the gear device 100 can form a suppression portion 50 that suppresses the passage of the lubricant J in the radial gap and the axial gap between the extension portion 74 and the first restricting member 60. In this case, the effect of suppressing the passage of the lubricant J can be improved.

The operation of the gear device 100 of this embodiment will be described. When the eccentric shaft 11 rotates due to the rotation of a motor (not shown), the eccentric bodies 12, 13 rotate together with the eccentric shaft 11. When the eccentric bodies 12, 13 rotate, the external gears 14, 15 are continuously flexibly deformed to match the shapes of the eccentric bodies 12, 13 while changing the meshing position with the internal gears 16, 17 in the circumferential direction. The (oscillating) external gears 14, 15 rotate (spin) relative to the second internal gear 17 by an amount equivalent to the difference in the number of teeth between the second internal gear 17 and the second external gear 15 with each rotation of the eccentric bodies 12, 13.

At this time, the rotation of the eccentric bodies 12, 13 is decelerated at a reduction ratio according to the difference in the number of teeth, and the external gears 14, 15 rotate on their axes. The first internal gear 16 has the same number of teeth as the first external gear 14. Therefore, the first internal gear 16 rotates synchronously with the external gears 14, 15 with the same rotation component as the external gears 14, 15, without changing the relative meshing position with the external gears 14, 15 before and after one rotation of the eccentric bodies 12, 13. The rotation of the first internal gear 16 is transmitted to the driven device via the first output member 201 and the second output member 202. As a result, the rotation of the eccentric bodies 12, 13 is decelerated and output from the output member 20 to the driven device.

This embodiment has the same effects as the first embodiment.

Above, examples of the embodiments of the present invention have been described in detail. All of the above-mentioned embodiments merely show specific examples of how to put the present invention into practice. The contents of the embodiments do not limit the technical scope of the present invention, and many design changes such as changing, adding, or deleting components are possible within the scope of the idea of the invention defined in the claims. In the above-mentioned embodiments, the contents for which such design changes are possible are explained with notations such as "in the embodiment" and "in the embodiment", but this does not mean that design changes are not permitted for contents without such notations. In addition, hatching on cross sections in the drawings does not limit the material of the objects to which the hatching is applied.

The following describes the modified examples. In the drawings and description of the modified examples, the same components and members as those in the embodiment are given the same reference numerals. Explanations that overlap with the embodiment will be omitted as appropriate, and the description will focus on the configurations that differ from the embodiment.

In the description of the embodiment, an example was shown in which the eccentric oscillating gear device 100 is a so-called center crank type eccentric oscillating gear device, but the present invention is not limited to this. For example, the eccentric oscillating gear device may be a so-called distribution type in which multiple eccentric shafts are arranged at positions radially offset from the center.

In the description of the embodiment, an example in which the number of eccentric bodies 12, 13 is two is shown, but the number of eccentric bodies may be one or three or more.

In the description of the fifth embodiment, an example was shown in which the first restricting member 60 was formed integrally with the eccentric shaft 11, but the first restricting member 60 may be formed separately from the eccentric shaft 11 and connected to the eccentric shaft 11.

Each of the above-mentioned modified examples provides the same effects and advantages as the embodiment.

Any combination of the components and variations of the above-described embodiments is also useful as an embodiment of the present invention. The new embodiment resulting from the combination has the combined effects of each of the combined embodiments and variations.

10 Rotation device, 11 Eccentric shaft, 12, 13 Eccentric, 14, 15 External gear, 16, 17 Internal gear, 30, 31 Eccentric shaft bearing, 34, 35 Eccentric bearing, 50 Suppression part, 52 Second suppression part, 60 First restricting member, 61 Radial extension part, 67 Axial extension part, 70 Second restricting member, 74 Extension part, 75 First radial facing part, 76 Axial facing part, 78 Second radial facing part, 80 Suppression member, 100 Eccentric oscillating gear device.

Claims (8)

An eccentric oscillating gear device comprising an external gear, an eccentric body that oscillates the external gear, and an eccentric body bearing disposed between the external gear and the eccentric body,
a first restricting member that restricts axial movement of the eccentric bearing;
a second restricting member that restricts axial movement of the external gear,
An eccentric oscillating gear device having a suppression portion that suppresses passage of lubricant between the first and second restricting members. The eccentric oscillating gear device according to claim 1, wherein the second restricting member has an extending portion extending in a radial direction, and the extending portion forms the suppressing portion. a suppressing member is provided on an opposite side of the first restricting member with the second restricting member interposed therebetween,
3. The eccentric oscillating gear device according to claim 1, wherein the suppression member forms a second suppression portion that suppresses passage of the lubricant. The eccentric oscillating gear device according to claim 3, wherein the suppression member faces the second restricting member with a gap therebetween. The eccentric oscillating gear device according to claim 3, wherein the suppression member abuts against the second restricting member in the axial direction. the first restricting member is disposed on an outer periphery of an eccentric body shaft having the eccentric body,
6. The eccentric oscillating gear device according to claim 1, wherein a radial gap between the second regulating member and the eccentric body shaft is smaller than an axial gap between the first regulating member and the second regulating member. The first restricting member has an axially extending portion extending in the axial direction,
The eccentric oscillating gear device according to claim 1 , wherein the suppression portion is formed between the axially extending portion and the second restricting member. The eccentric oscillating gear device according to claim 7, wherein the second restricting member has a first radially opposed portion opposed to the outer peripheral surface of the axially extending portion, an axially opposed portion opposed to the axial direction of the axially extending portion, and a second radially opposed portion opposed to the inner peripheral surface of the axially extending portion.

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