JP6909141B2 - Flexible meshing gear device - Google Patents

Description

The present invention relates to a flexible meshing gear device.

A flexure meshing gear device is known as a gear device that is compact, lightweight, and can obtain a high reduction ratio. Conventionally, a oscillating body, an external gear that is flexed and deformed by the oscillating body, an internal gear that meshes with the external gear, and a oscillating body bearing that is arranged between the oscillating body and the external gear. A flexible meshing gear device including the above has been proposed (for example, Patent Document 1).

Japanese Unexamined Patent Publication No. 2015-158218

In a conventional flexible meshing gear device, fretting may occur due to slippage that occurs between the outer ring of the exciter bearing and the external gear.

The present invention has been made in view of such a situation, and an object of the present invention is to provide a flexible meshing gear device capable of suppressing the occurrence of fretting.

In order to solve the above problems, the flexural meshing gear device according to an aspect of the present invention includes a oscillating body, an external gear that is flexed and deformed by the oscillating body, and an internal gear that meshes with the external gear. , A flexible meshing gear device comprising a oscillating body bearing arranged between a oscillating body and an external gear, wherein the oscillating body bearing has an outer ring fitted in the external gear. .. The flexible meshing gear device further comprises an external gear and a regulatory member axially opposed to the outer ring. The regulating member has an guiding portion that guides the lubricant at the boundary between the external gear and the outer ring.

It should be noted that any combination of the above components and those in which the components and expressions of the present invention are mutually replaced between methods, devices, systems and the like are also effective as aspects of the present invention.

According to the present invention, it is possible to provide a flexure meshing gear device capable of suppressing the occurrence of fretting.

It is sectional drawing which shows the bending mesh type gear device which concerns on embodiment. 2 (a) and 2 (b) are diagrams showing the regulating members. It is a figure which shows the positional relationship between the boundary between the outer ring of the exciter bearing and the external gear, and the lubrication pool portion. It is sectional drawing which shows the bending mesh type gear device which concerns on a modification.

Hereinafter, the same or equivalent components, members, and processes shown in the drawings shall be designated by the same reference numerals, and redundant description will be omitted as appropriate. In addition, the dimensions of the members in each drawing are shown enlarged or reduced as appropriate for easy understanding. In addition, some of the members that are not important for explaining the embodiment in each drawing are omitted and displayed.

First, an outline will be described. It includes a oscillating body, an external gear that is flexed and deformed by the oscillating body, an internal gear that meshes with the external gear, and a oscillating body bearing that is arranged between the oscillating body and the external gear. Flexible meshing gear devices are known. In a conventional flexible meshing gear device, fretting may occur due to slippage that occurs between the outer ring of the exciter bearing and the external gear.

By the way, the outer ring of the exciter bearing and the outer gear have different rigidity, and therefore the deformation mode is different. Therefore, at the time of rotation, a gap is generated between the outer ring of the exciter bearing and the external gear at the short axis position.

Therefore, in the present embodiment, the flexible meshing type gear device further includes an outer ring of the exciter bearing and a regulating member axially opposed to the external gear, and the regulating member is the outer ring of the exciter bearing. At the boundary with the external gear, there is an guide portion for guiding the lubricant enclosed in the flexible meshing gear device. As a result, the lubricant is supplied from the induction portion to the above-mentioned gap. As a result, even if slippage occurs between the outer ring of the oscillator bearing and the external gear, fretting is suppressed. Hereinafter, a specific description will be given.

FIG. 1 is a cross-sectional view showing a flexure meshing gear device 100 according to the first embodiment. The flexure meshing gear device 100 decelerates and outputs the input rotation. The flexible meshing gear device 100 of the present embodiment is a tubular flexible meshing gear device, and includes a wave generator 2, an external gear 4 that is flexed and deformed by the wave generator 2, and an external gear. A first internal gear 6 that meshes with 4, a second internal gear 8 that is arranged (side by side) axially with the first internal gear 6 and meshes with the external gear 4, a casing 10, and 2 It includes two regulating members 12, a main bearing 16, a first bearing housing 18, and a second bearing housing 20. A lubricant (for example, grease) is sealed in the flexible meshing gear device 100. The lubricant lubricates the meshing portion between the external gear 4 and the first internal gear 6 and the second internal gear 8, each bearing, and the like.

The wave generator 2 includes a oscillating body shaft 22, a first oscillating body bearing 21a arranged between the oscillating body shaft 22 and the external tooth gear 4 (the first external tooth portion 4a), and oscillating. It has a second oscillator bearing 21b arranged between the body shaft 22 and the external gear 4 (the second external tooth portion 4b). The first oscillating body bearing 21a includes a plurality of first rolling elements 24a, a first cage 26a for holding the plurality of first rolling elements 24a, and a first outer ring 28a fitted in the external gear 4. including. The second oscillating body bearing 21b includes a plurality of second rolling elements 24b, a second cage 26b for holding the plurality of second rolling elements 24b, and a second outer ring 28b internally fitted in the external tooth gear 4. including. The exciter shaft 22 is an input shaft, is connected to a rotation drive source such as a motor, and rotates about the rotation shaft R. The exciter shaft 22 is integrally formed with the exciter 22a having a substantially elliptical cross section orthogonal to the rotation axis R.

Each of the plurality of first rolling elements 24a has a substantially cylindrical shape, and is provided at intervals in the circumferential direction in a state in which the axial direction is oriented substantially parallel to the rotation axis R direction. The first rolling element 24a is rotatably held by the first cage 26a and rolls on the outer peripheral surface 22b of the oscillating body 22a. That is, the inner ring of the first oscillating body bearing 21a is integrally formed with the outer peripheral surface 22b of the oscillating body 22a, but the present invention is not limited to this, and a dedicated inner ring separate from the oscillating body 22a is provided. You may. The second rolling element 24b is configured in the same manner as the first rolling element 24a. The plurality of second rolling elements 24b are rotatably held by the second cage 26b arranged so as to be aligned with the first cage 26a, and roll on the outer peripheral surface 22b of the oscillating body 22a. That is, the inner ring of the second oscillating body bearing 21b is integrally formed with the outer peripheral surface 22b of the oscillating body 22a, but the present invention is not limited to this, and a dedicated inner ring separate from the oscillating body 22a is provided. You may.

Hereinafter, the first oscillating body bearing 21a and the second oscillating body bearing 21b are collectively referred to as "exciting body bearing 21". Further, the first rolling element 24a and the second rolling element 24b are collectively referred to as a "rolling body 24". Further, the first cage 26a and the second cage 26b are collectively referred to as a "retainer 26".

The first outer ring 28a surrounds a plurality of first rolling elements 24a. The first outer ring 28a has flexibility and is elliptically bent by the oscillating body 22a via the plurality of first rolling elements 24a. When the oscillating body 22a (that is, the oscillating body shaft 22) rotates, the first outer ring 28a continuously bends and deforms according to the shape of the oscillating body 22a. The second outer ring 28b is configured in the same manner as the first outer ring 28a. The second outer ring 28b is formed as a separate body from the first outer ring 28a. The second outer ring 28b may be integrally formed with the first outer ring 28a. Hereinafter, the first outer ring 28a and the second outer ring 28b are collectively referred to as an "outer ring 28".

The external tooth gear 4 is an annular member having flexibility, and a vibrator 22a, a rolling element 24, and an outer ring 28 are fitted inside the external gear 4. The external tooth gear 4 is bent in an elliptical shape by fitting the exciting body 22a, the rolling element 24, and the outer ring 28. When the oscillating body 22a rotates, the external tooth gear 4 continuously bends and deforms according to the shape of the oscillating body 22a. The external tooth gear 4 includes a first external tooth portion 4a located outside the first outer ring 28a, a second external tooth portion 4b located outside the second outer ring 28b, and a base material 4c. The first external tooth portion 4a and the second external tooth portion 4b are formed on a base material 4c which is a single base material, and have the same number of teeth.

The first internal tooth gear 6 is an annular member having rigidity, and a first internal tooth portion 6a is formed on the inner circumference thereof. The first internal tooth portion 6a surrounds the first external tooth portion 4a of the external tooth gear 4 bent in an elliptical shape, and the first outer tooth portion (2 regions) in a predetermined region (2 regions) near the long axis of the exciter 22a. It meshes with the tooth portion 4a. The first internal tooth portion 6a has more teeth than the first external tooth portion 4a.

The second internal gear 8 is arranged adjacent to (side by side) the first internal gear 6 in the axial direction. The second internal tooth gear 8 is a rigid cylindrical member, and a second internal tooth portion 8a is formed on the inner circumference thereof. The second internal tooth portion 8a surrounds the second external tooth portion 4b of the external tooth gear 4 bent in an elliptical shape, and the second outer tooth portion 8a is a predetermined region (two regions) in the major axis direction of the exciter 22a. It meshes with the tooth portion 4b. The second internal tooth portion 8a has the same number of teeth as the second external tooth portion 4b. Therefore, the second internal tooth gear 8 rotates in synchronization with the rotation of the second external tooth portion 4b and thus the external tooth gear 4.

The two regulating members 12 are flat ring-shaped members, and are arranged so as to sandwich the external gear 4 in the axial direction. Therefore, the two regulating members 12 face the external gear 4 and the exciter bearing 21 in the axial direction, respectively. The two regulating members 12 regulate the axial movement of the external gear 4 and the exciter bearing 21.

The casing 10 is a substantially cylindrical member and surrounds the second internal gear 8. The first internal tooth gear 6 is in-row fitted to the casing 10 and integrated with bolts (not shown). A main bearing 16 is arranged between the casing 10 and the second internal gear 8. The main bearing 16 is a cross roller bearing in the present embodiment, and includes a plurality of rollers (rollers) 46 provided at intervals in the circumferential direction. The plurality of rollers 46 roll on the rolling surface 8b of the second internal gear 8 and the rolling surface 10a of the casing 10. That is, the outer peripheral side of the second internal gear 8 functions as the inner ring of the main bearing 16, and the inner peripheral side of the casing 10 functions as the outer ring of the main bearing 16. The casing 10 supports the second internal gear 8 so as to be relatively rotatable via the main bearing 16. The type of bearing of the main bearing 16 is not particularly limited, and may be, for example, a 4-point contact ball bearing.

The first bearing housing 18 is an annular member and surrounds the exciter shaft 22. Similarly, the second bearing housing 20 is an annular member and surrounds the exciter shaft 22. The first bearing housing 18 and the second bearing housing 20 are arranged so as to axially sandwich the external gear 4, the rolling element 24, the cage 26, the outer ring 28, and the two regulating members 12. The first bearing housing 18 is in-row fitted to the first internal gear 6 and bolted. The second bearing housing 20 is in-row fitted to the second internal gear 8 and bolted. A bearing 30 is incorporated in the inner circumference of the first bearing housing 18, a bearing 32 is incorporated in the inner circumference of the second bearing housing 20, and the exciter shaft 22 is provided via the bearing 30 and the bearing 32. It is rotatably supported with respect to the first bearing housing 18 and the second bearing housing 20.

An oil seal 40 is arranged between the exciter shaft 22 and the first bearing housing 18, an O-ring 34 is arranged between the first bearing housing 18 and the first internal gear 6, and the first internal gear is arranged. An O-ring 36 is arranged between the casing 10 and the casing 10, an oil seal 42 is arranged between the casing 10 and the second internal gear 8, and the second internal gear 8 and the second bearing housing 20 are arranged. An O-ring 38 is arranged between them, and an oil seal 44 is arranged between the second bearing housing 20 and the exciter shaft 22. As a result, it is possible to prevent the lubricant in the flexible meshing gear device 100 from leaking.

The operation of the flexible meshing type gear device 100 configured as described above will be described. Here, the number of teeth of the first external tooth portion 4a is 100, the number of teeth of the second external tooth portion 4b is 100, the number of teeth of the first internal tooth portion 6a is 102, and the number of teeth of the second internal tooth portion 8a is 100. Will be described as an example. Further, a case where the second internal gear 8 and the second bearing housing 20 are connected to the driven member will be described as an example.

When the exciter shaft 22 rotates in a state where the first external tooth portion 4a is in mesh with the first internal tooth portion 6a at two points in the elliptical shape in the long axis direction, the first external tooth portion 4a and the first external tooth portion 4a are rotated accordingly. The meshing position with the first internal tooth portion 6a also moves in the circumferential direction. Since the number of teeth is different between the first external tooth portion 4a and the first internal tooth portion 6a, at this time, the first external tooth portion 4a rotates relative to the first internal tooth portion 6a. Since the first internal tooth member 7 and the first bearing housing 18 are in a fixed state, the first external tooth portion 4a rotates by the amount corresponding to the difference in the number of teeth. That is, the rotation of the exciter shaft 22 is significantly decelerated and output to the first external tooth portion 4a. The reduction ratio is as follows.
Reduction ratio = (number of teeth of the first external tooth portion 4a-number of teeth of the first internal tooth portion 6a) / number of teeth of the first external tooth portion 4a = (100-102) / 100
= -1/50

Since the second external tooth portion 4b is integrally formed with the first external tooth portion 4a, it rotates integrally with the first external tooth portion 4a. Since the second external tooth portion 4b and the second internal tooth portion 8a have the same number of teeth, relative rotation does not occur, and the second external tooth portion 4b and the second internal tooth portion 8a rotate integrally. Therefore, the same rotation as the rotation of the first external tooth portion 4a is output to the second internal tooth portion 8a. As a result, the output obtained by reducing the rotation of the exciter shaft 22 to -1/50 can be taken out from the second internal tooth member 9.

Subsequently, the configuration of the regulating member 12 will be described in more detail.

2 (a) and 2 (b) are views showing the regulating member 12. FIG. 2A is a perspective view of the regulating member 12, and FIG. 2B shows the regulating member 12 axially inside (between the first external tooth portion 4a and the second external tooth portion 4b with respect to the regulating member 12). It is a side view seen from the same side as the center of. FIG. 3 is a diagram showing the positional relationship between the boundary between the outer ring 28 of the exciter bearing 21 and the external gear 4 and the lubrication reservoir 62.

The regulating member 12 has eight guiding portions 60 for guiding the lubricant sealed in the flexible meshing gear device 100 at the boundary between the external gear 4 and the outer ring 28 of the oscillating body bearing 21. The number of induction portions 60 is not particularly limited.

Each guide portion 60 has a lubrication reservoir 62 and two guide passages 64. The number of guide passages 64 is not particularly limited.

In the present embodiment, the lubrication reservoir 62 is a recess (groove) provided in the axially inner surface (the surface facing the external gear 4 and the outer ring 28) 12a of the regulating member 12, and is viewed from the axial direction. It extends in an arc shape. The lubrication reservoir 62 is particularly located at a position overlapping the short axis direction P of the exciter 22a, in other words, at a position overlapping the extension line of the short axis Ax of the exciter 22a, the exciter bearing 21. It is provided so as to face the boundary between the outer ring 28 and the external gear 4 (see FIG. 3). The eight lubrication reservoirs 62 are arranged in the circumferential direction at equal intervals, for example. That is, the eight lubrication reservoirs 62 are intermittently provided in the circumferential direction. As a result, the external gear 4 and the outer ring 28 are compared with the case where the regulating member 12 is provided with only one guide portion 60 and the lubrication pool portion 62 of the guide portion 60 is provided in a ring shape so as to surround the central axis. The receiving surface of the regulating member 12 for regulating the above can be kept large.

The lubricant that has entered through the guide passage 64 is accumulated in the lubrication reservoir 62. The lubricant accumulated in the lubrication reservoir 62 is supplied to the gap between the external gear 4 and the outer ring 28 when the lubrication reservoir 62 is at a position where it overlaps with the short axis direction P of the oscillator 22a.

The guide passage 64 is a recess (groove) provided on the axially inner surface 12a of the regulating member 12, and from at least one of the radial outer end 12b and the radial inner end 12c of the regulating member 12 to the lubrication reservoir 62. Communicate. Preferably, in each guiding portion 60, the guiding passage 64 communicates with the lubrication reservoir 62 from only one of the radial outer end 12b and the radial inner end 12c of the regulating member 12. That is, as shown in the drawing, the guide passage 64 may communicate with the lubrication reservoir 62 only from the radial outer end 12b of the regulating member 12, or from only the radial inner end 12c of the regulating member 12 to the lubrication reservoir 62. You may communicate. The guide passage 64 of one guide portion 60 communicates with the lubrication reservoir 62 only from the radial outer end 12b of the regulation member 12, and the guide passage 64 of another guide portion 60 communicates only with the radial inner end 12c of the regulation member 12. May communicate with the lubrication reservoir 62. In any case, in each of the guide passages 64, the guide passage 64 communicates with the lubrication reservoir 62 from only one of the radial outer end 12b and the radial inner end 12c, so that the radial outer end 12b and the radial inner end 12c Since the lubricant that has entered the lubrication reservoir 62 from one side does not escape from the other side of the radial outer end 12b and the radial inner end 12c, the lubricant tends to accumulate in the lubrication reservoir 62.

The two guide passages 64 extend in a direction inclined with respect to the radial direction of the regulating member 12. The guide passage 64 located on one side in the circumferential direction (right side in FIG. 2B) is inclined to one side in the circumferential direction with respect to the radial direction of the regulating member 12. On the other hand, the guide passage 64 located on the other side in the circumferential direction (left side in FIG. 2B) is inclined to the other side in the circumferential direction with respect to the radial direction of the regulating member 12. As a result, when the regulating member 12 rotates to one side in the circumferential direction with the rotation of the other member, the lubricant can easily enter from the guide passage 64 on the one side in the circumferential direction. Further, when the regulating member 12 rotates to the other side in the circumferential direction with the rotation of the other member, the lubricant easily enters from the guide passage 64 on the other side in the circumferential direction.

The flexure meshing gear device according to the embodiment has been described above. It will be appreciated by those skilled in the art that these embodiments are exemplary and that various modifications are possible for each of these components and combinations of processing processes, and that such modifications are also within the scope of the present invention. By the way.

(Modification example 1)
The lubricating reservoir 62 may be filled with a lubricant having a viscosity higher than that of the meshing portion between the external gear and the internal gear. For example, the lubricating reservoir 62 may be filled with a highly viscous lubricant in advance, and then the regulating member 12 may be incorporated into the flexible meshing gear device 100. As a result, it is possible to prevent the lubricant in the lubrication reservoir 62 from coming out of the induction passage 64. Further, when the lubricant is pre-sealed in the lubrication reservoir 62, the guide portion 60 does not have the guide passage 64, that is, the radial outer end 12b and the radial inner end 12c of the regulating member 12, and the lubrication reservoir 62. It is not necessary to have a passage that communicates with.

(Modification 2)
FIG. 4 is a cross-sectional view showing a flexure meshing gear device 100 according to a modified example. FIG. 4 corresponds to FIG. In this modification, the lubrication pool portion 62 of the guide portion 60 is formed so as to penetrate the regulation member 12 in the axial direction. The opening of the lubrication reservoir 62 on the outer side in the axial direction (the side opposite to the center between the first outer tooth portion 4a and the second outer tooth portion 4b with respect to the regulating member 12) is closed by the bearing housing. Here, "closed" includes not only the case where the bearing housing is in close contact with the peripheral edge of the opening of the lubricating reservoir 62, but also the case where there is a gap to the extent that the lubricant accumulated in the lubricating reservoir 62 does not leak. As long as the opening on the outer side in the axial direction is closed in this way, the lubrication reservoir 62 may be a through hole penetrating in the axial direction.

(Modification example 3)
In the embodiment, the case where the regulating member 12 is separate from the first bearing housing 18 and the second bearing housing 20 has been described, but the regulating member 12 may be formed integrally with these.

(Modification example 4)
In the embodiment, the case where the flexible meshing gear device 100 is a tubular flexible meshing gear device has been described, but the type of the flexible meshing gear device is not particularly limited. The flexible meshing gear device 100 may be, for example, a cup type or a top hat type flexible meshing gear device.

(Modification 5)
In the embodiment, the case where the regulating member 12 faces the outer ring 28 and the cage 26 in the axial direction has been described, but the present invention is not limited to this, and if the axial movement of the rolling element 24 is separately regulated, the regulating member 12 may restrict the axial movement of the outer ring 28 by facing only the outer ring 28 in the axial direction.

12 Regulator, 22a oscillating body, 4 external tooth gear, 6 1st internal tooth gear, 8 2nd internal tooth gear, 21a 1st oscillating body bearing, 21b 2nd oscillating body bearing, 28 outer ring, 60 induction part , 100 Flexion mesh gear device.

Claims (7)

A oscillating body, an external gear that is flexed and deformed by the oscillating body, an internal gear that meshes with the external gear, and a oscillating body that is arranged between the oscillating body and the external gear. A flexible meshing gear device including a bearing.
The oscillating body bearing has an outer ring that is internally fitted into the external gear.
The flexible meshing gear device further comprises a regulating member that is axially opposed to both the axial end face of the external gear and the axial end face of the outer ring.
The regulating member is a flexible meshing gear device having an guiding portion for guiding a lubricant at a boundary between the external gear and the outer ring. The guide portion communicates with the lubrication reservoir portion from at least one of the radial outer end and the radial inner end of the restricting member and the lubrication reservoir portion that faces the boundary in the minor axis direction of the oscillator. The flexible meshing gear device according to claim 1, further comprising an induction passage. A oscillating body, an external gear that is flexed and deformed by the oscillating body, an internal gear that meshes with the external gear, and a oscillating body that is arranged between the oscillating body and the external gear. A flexible meshing gear device including a bearing.
The oscillating body bearing has an outer ring that is internally fitted into the external gear.
The flexible meshing gear device further includes the external gear and a restricting member axially opposed to the outer ring.
The regulating member has an guiding portion that guides the lubricant at the boundary between the external gear and the outer ring.
The guide portion communicates with the lubrication reservoir portion from at least one of the radial outer end and the radial inner end of the restricting member and the lubrication reservoir portion that faces the boundary in the minor axis direction of the oscillator. With a guide passage,
The induction passage, you and being provided from only one of the radially outer end and a radial inner end of the regulating member Deflection seen meshing type gear device. A oscillating body, an external gear that is flexed and deformed by the oscillating body, an internal gear that meshes with the external gear, and a oscillating body that is arranged between the oscillating body and the external gear. A flexible meshing gear device including a bearing.
The oscillating body bearing has an outer ring that is internally fitted into the external gear.
The flexible meshing gear device further includes the external gear and a restricting member axially opposed to the outer ring.
The regulating member has an guiding portion that guides the lubricant at the boundary between the external gear and the outer ring.
The guide portion communicates with the lubrication reservoir portion from at least one of the radial outer end and the radial inner end of the restricting member and the lubrication reservoir portion that faces the boundary in the minor axis direction of the oscillator. With a guide passage,
The lubricant reservoir portion, had FLEXIBLE seen meshing you characterized in that provided intermittently in the circumferential direction of the restricting member gearing. A oscillating body, an external gear that is flexed and deformed by the oscillating body, an internal gear that meshes with the external gear, and a oscillating body that is arranged between the oscillating body and the external gear. A flexible meshing gear device including a bearing.
The oscillating body bearing has an outer ring that is internally fitted into the external gear.
The flexible meshing gear device further includes the external gear and a restricting member axially opposed to the outer ring.
The regulating member has an guiding portion that guides the lubricant at the boundary between the external gear and the outer ring.
The guide portion communicates with the lubrication reservoir portion from at least one of the radial outer end and the radial inner end of the restricting member and the lubrication reservoir portion that faces the boundary in the minor axis direction of the oscillator. With a guide passage,
The induction passage, you and being inclined relative to the radial direction of the regulating member Deflection seen meshing type gear device. A oscillating body, an external gear that is flexed and deformed by the oscillating body, an internal gear that meshes with the external gear, and a oscillating body that is arranged between the oscillating body and the external gear. A flexible meshing gear device including a bearing.
The oscillating body bearing has an outer ring that is internally fitted into the external gear.
The flexible meshing gear device further includes the external gear and a restricting member axially opposed to the outer ring.
The regulating member has an guiding portion that guides the lubricant at the boundary between the external gear and the outer ring.
The induction portion has a lubrication reservoir portion that faces the boundary in the minor axis direction of the vibration body in the axial direction.
Wherein the lubricating reservoir, the external gear and the internal gear engagement portion of the lubricant to that flexures look meshing type gear device characterized in that high lubricant viscosity is sealed than. The flexible meshing gear device according to claim 6, wherein the regulating member does not have a passage for communicating the radial outer end and the radial inner end with the lubrication reservoir.

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