JP2020139535A - Eccentric oscillation type transmission - Google Patents

Abstract

To provide an eccentric oscillation type transmission which can improve a degree of freedom of assembling and can secure the rigidity of an input shaft.SOLUTION: An eccentric oscillation type transmission 100 comprises an eccentric body, an outer tooth gear 40, a bearing 50 and an inner tooth gear 60. The eccentric body is attached to a rotating shaft 20 which rotates with a center axis C as center. The outer tooth gear 40 is arranged outside the eccentric body in a radial direction, and comprises a plurality of outer teeth 41 at an external peripheral part. The bearing 50 is interposed between the eccentric body and the outer tooth gear 40. The inner tooth gear 60 is arranged outside the outer tooth gear 40 in the radial direction and coaxial with the center axis C, and has a plurality of inner teeth 61 engaged with the outer teeth 41 at an internal peripheral part. A tooth number of the outer teeth 41 and a tooth number of the inner teeth 61 differ from each other. The eccentric body has a part of a cylinder face with an eccentric axis D extending in parallel with the center axis C in a position deviated from the center axis C as a center. The eccentric body has a notched part 30a which is opened at a side opposite to the eccentric axis D with the center axis C sandwiched therebetween.SELECTED DRAWING: Figure 2

Description

The present invention relates to an eccentric swing type transmission.

Conventionally, an eccentric swing type transmission including an input shaft and an eccentric body coupled to the input shaft is known. A conventional eccentric swing type transmission is disclosed in, for example, Japanese Patent Application Laid-Open No. 5-44791. The eccentric swing type transmission disclosed in Japanese Patent Application Laid-Open No. 5-44791 includes an input shaft (101) and an eccentric body (103). A part of the outer circumference of the input shaft (101) is cut in parallel with the axial direction, and a cut portion (140) having a substantially D-shaped cross section is formed. Further, the eccentric body (103) has a hole portion (141) having the same shape as the cross-sectional shape of the input shaft (101) including the shape of the cut portion (140), and the hole portion (141) is fitted. It is said that the input shaft (101) and the eccentric body (103) are positioned in the circumferential direction.
Japanese Unexamined Patent Publication No. 5-44791

According to the eccentric swing type transmission as described in JP-A-5-44991, it is considered that the eccentric body can be coupled in a state of being positioned with respect to the input shaft. However, in the eccentric swing type transmission as described in Japanese Patent Application Laid-Open No. 5-44791, the eccentric body has to be attached from one side or the other side in the axial direction of the input shaft. Specifically, the axial tip of the input shaft must be inserted into the hole of the eccentric body, and the eccentric body must be slid along the axial direction of the input shaft to be attached in a predetermined position. The degree of freedom was poor. Furthermore, in an eccentric swing type transmission as described in Japanese Patent Application Laid-Open No. 5-44791, a cut portion is provided on the input shaft from the tip portion in the axial direction of the input shaft to the predetermined position. There is a need. For this reason, the radial dimension of the input shaft becomes small over a wide area, and it is difficult to maintain sufficient strength of the input shaft.

An object of the present invention is to provide an eccentric swing type transmission capable of improving the degree of freedom of assembly and ensuring the strength of the input shaft.

According to the viewpoint of the present invention, an eccentric swing type transmission having the following configuration is provided. That is, this eccentric swing type transmission includes an eccentric body, an external gear, a bearing, and an internal gear. The eccentric body is attached to a rotating shaft that rotates about a central axis. The external tooth gear is arranged radially outward of the eccentric body, and has a plurality of external teeth on the outer peripheral portion. The bearing is interposed between the eccentric body and the external gear. The internal gear is arranged radially outward of the external gear and coaxially with the central axis, and has a plurality of internal teeth that mesh with the external teeth on the inner peripheral portion. The number of teeth of the external tooth and the number of teeth of the internal tooth are different. The eccentric body has a part of a cylindrical surface centered on an eccentric axis extending parallel to the central axis at a position deviating from the central axis. The eccentric body has a notch portion that opens on the side opposite to the eccentric axis with the central axis in between.

According to the viewpoint of the present invention, there is provided an eccentric swing type transmission capable of improving the degree of freedom of assembly and ensuring the strength of the input shaft.

FIG. 1 is a vertical cross-sectional view of the eccentric swing type transmission according to the present embodiment. FIG. 2 is a sectional view taken along line II-II in FIG. FIG. 3 is a sectional view taken along line III-III in FIG. FIG. 4 is a view of the rotating shaft and the eccentric body when viewed in the axial direction.

Hereinafter, exemplary embodiments of the present application will be described with reference to the drawings. In the present application, the direction parallel to the central axis of the transmission is "axial direction", the direction orthogonal to the central axis of the transmission is "diametrical direction", and the direction along the arc centered on the central axis of the transmission is "axial direction". Circumferential direction ", respectively. Further, one side in the axial direction is referred to as "front side", and the other side in the axial direction is referred to as "rear side". However, the above-mentioned "parallel direction" also includes a substantially parallel direction. Further, the above-mentioned orthogonal directions include substantially orthogonal directions. Further, the "circumferential direction" includes a direction along a substantially arc.

<1. Embodiment>
<1-1. Overall configuration of eccentric swing type transmission>
Hereinafter, the overall configuration of the eccentric swing type transmission 100 according to the embodiment will be described with reference to FIGS. 1 to 4. FIG. 1 is a vertical sectional view of the eccentric swing type transmission 100 according to the first embodiment of the present invention. FIG. 2 is a cross-sectional view of the transmission 100 as viewed from the position II-II of FIG. FIG. 3 is a cross-sectional view of the transmission 100 as viewed from the position III-III of FIG. However, in FIGS. 1 to 3, hatching is omitted in order to simplify the drawings.

This eccentric swing type transmission 100 uses an inscribed planetary speed reduction mechanism to rotate the first rotation speed (input rotation speed) at a second rotation speed (output rotation speed) lower than the first rotation speed. Convert to the rotational movement of. The eccentric swing type transmission 100 is used for joints of small robots such as service robots that work in cooperation with humans, for example. However, transmissions having the same structure may be used for other applications such as large industrial robots, machine tools, XY tables, material cutting devices, conveyor lines, turntables, rolling rollers and the like.

As shown in FIG. 1, the eccentric swing type transmission 100 of the present embodiment includes a casing 10, a rotary shaft 20, an eccentric body 30, an external gear 40, a bearing 50, an internal gear 60, a carrier pin 70, and a carrier pin 70. The output rotating unit 80 is mainly provided.

The casing 10 is a cylindrical member extending in the axial direction about the central axis C of the eccentric swing type transmission 100. The casing 10 covers the rotary shaft 20, the eccentric body 30, the external gear 40, the bearing 50, the internal gear 60, the carrier pin 70, and the output rotating portion 80 from the outer side in the radial direction.

The rotary shaft 20 is a substantially cylindrical member extending in the axial direction about the central axis C of the eccentric swing type transmission 100. The rotary shaft 20 is connected to a motor, which is a drive source, either directly or via another power transmission mechanism. Alternatively, the rotary shaft 20 may be the output shaft itself of the motor as a drive source. When the motor is driven, the rotating shaft 20 rotates at the first rotation speed around the central axis C by the power supplied from the motor. The rotary shaft 20 is arranged at the axial center of the eccentric swing type transmission 100.

The eccentric body 30 is a member that rotates together with the rotating shaft 20 at the same rotation speed as the rotating shaft 20. The eccentric body 30 is attached to an axially intermediate portion of the rotating shaft 20. The eccentric body 30 has a part of a cylindrical surface centered on an eccentric axis D extending in parallel with the central axis C at a position deviating from the central axis C. Therefore, the distance from the central axis C to the outer peripheral surface of the eccentric body 30 differs depending on the position in the circumferential direction. When the rotating shaft 20 rotates about the central axis C, the position of the eccentric axis D of the eccentric body 30 rotates about the central axis C. At this time, the position of the eccentric body 30 also rotates about the central axis C.

As shown in FIG. 1, in the present embodiment, two eccentric bodies 30 are attached to the intermediate portion in the axial direction of the rotating shaft 20. Here, when viewed in the axial direction, the position of the eccentric axis D of one of the two eccentric bodies 30 is the eccentric axis D of the other eccentric body 30 of the two eccentric bodies 30. They are arranged in rotational symmetry with each other. As a result, in the present embodiment, the position of the center of gravity of the plurality of eccentric bodies 30 as a whole is always located on the central axis C. Therefore, the imbalance of the eccentric body 30 can be suppressed.

The external tooth gears 40 are arranged radially outward of each eccentric body 30. That is, the transmission 100 of the present embodiment includes two external gears 40. A bearing 50 is interposed between the eccentric body 30 and the external gear 40. The external gear 40 is rotatably supported by the bearing 50 about the eccentric shaft D. As shown in FIG. 2, a plurality of external teeth 41 are provided on the outer peripheral portion of the external gear 40. Each external tooth 41 extends outward in the radial direction. Further, an external interdental groove 42 recessed inward in the radial direction is provided between the external teeth 41 adjacent to each other in the circumferential direction. The external teeth 41 and the external interdental grooves 42 are alternately arranged in the circumferential direction with the eccentric axis D as the center.

Further, as shown in FIG. 2, the external gear 40 has a plurality of (10 in this embodiment) through holes 43. Each through hole 43 penetrates the external gear 40 in the axial direction. The plurality of through holes 43 are arranged at equal intervals in the circumferential direction about the eccentric axis D.

The internal gear 60 is an annular member that surrounds the external gear 40 in the radial direction. The internal gear 60 is arranged coaxially with the central axis C. In the present embodiment, the outer peripheral surface of the internal gear 60 is fixed to the inner peripheral surface of the casing 10. As shown in FIG. 2, a plurality of internal teeth 61 are provided on the inner peripheral portion of the internal gear 60. Each internal tooth 61 extends inward in the radial direction. Further, between the internal teeth 61 adjacent to each other in the circumferential direction, an internal interdental groove 62 recessed outward in the radial direction is provided. The internal teeth 61 and the internal interdental grooves 62 are alternately arranged in the circumferential direction about the central axis C.

As shown in FIG. 2, the external gear 40 and the internal gear 60 can be partially meshed with each other. Specifically, a part of the external teeth 41 is fitted into the internal interdental groove 62 of the internal gear 60, and the external teeth 41 and the internal teeth 61 mesh with each other, so that the external gear 40 and the internal gear 60 are engaged. Relative rotation.

When the rotating shaft 20 rotates about the central axis C, the external gear 40 revolves around the central axis C together with the eccentric axis D. At this time, the external gear 40 revolves while changing the meshing position between the external tooth 41 of the external gear 40 and the internal tooth 61 of the internal gear 60 in the circumferential direction. Here, the number of internal teeth 61 and the number of external teeth 41 are different. Specifically, in the present embodiment, the number of internal teeth 61 included in the internal gear 60 is larger than the number of external teeth 41 included in the external gear 40. Therefore, for each revolution of the external gear 40, the position of the external tooth 41 that meshes with the internal tooth 61 at the same position of the internal gear 60 is shifted by the difference in the number of teeth. As a result, the external gear 40 rotates in the direction opposite to the rotation direction of the rotary shaft 20 at a second rotation speed lower than the first rotation speed, about the eccentric axis D. Along with this, the position of the through hole 43 of the external gear 40 also rotates at the second rotation speed. When the eccentric swing type transmission 100 is operated, the external gear 40 performs a rotary motion that combines such revolution and rotation.

The plurality of carrier pins 70 are substantially columnar members extending in the axial direction through the external gear 40. As shown in FIGS. 2 and 3, the plurality of carrier pins 70 are arranged in an annular shape about the central axis C. Each carrier pin 70 is inserted into a through hole 43 of the external gear 40. As a result, when the external gear 40 rotates at the second rotation speed after deceleration, it is pushed by the inner peripheral surface of the through hole 43 of the external gear 40, so that the plurality of carrier pins 70 are also centered on the central axis C. , Rotates at the second rotation speed.

Return to FIG. The output rotating unit 80 has an annular front carrier member 81 and an annular rear carrier member 82. The front carrier member 81 is arranged on the front side in the axial direction with respect to the external gear 40. The front carrier member 81 is rotatably supported with respect to the rotary shaft 20. A bearing may be interposed between the front carrier member 81 and the rotary shaft 20. Further, a bearing may be interposed between the front carrier member 81 and the internal gear 60.

The rear carrier member 82 is arranged on the rear side in the axial direction with respect to the external gear 40. The rear carrier member 82 is rotatable with respect to the rotating shaft 20. A bearing may be interposed between the rear carrier member 82 and the rotary shaft 20. Further, a bearing may be interposed between the rear carrier member 82 and the internal gear 60.

The axially forward end of each carrier pin 70 is fixed to the front carrier member 81. The axially rear end of each carrier pin 70 is fixed to the rear carrier member 82. Therefore, when the plurality of carrier pins 70 rotate at the second rotation speed around the central axis C, the front carrier member 81 and the rear carrier member 82 also rotate at the second rotation speed around the central axis C. For example, press fitting is used as a method of fixing the carrier pin 70 to the front carrier member 81 and the rear carrier member 82.

The output rotating unit 80 is connected to a member to be driven, either directly or via another power transmission mechanism. With such a configuration, in the eccentric swing type transmission 100 of the present embodiment, the rotation input to the rotating shaft 20 is significantly reduced by the inscribed planet type reduction mechanism, and the rotation after deceleration is output. It can be taken out from the rotating portion 80.

In the above-mentioned eccentric swing type transmission, conventionally, when assembling an eccentric body to a rotating shaft, the tip of the rotating shaft is inserted into a hole of the eccentric body, and the eccentric body is inserted into the shaft of the rotating shaft. There was no choice but to slide it along the direction and attach it in place, and there was little freedom in assembly. Furthermore, conventionally, in order to position (stop rotation) the position of the eccentric body in the circumferential direction with respect to the rotating shaft, a cut portion is provided on the rotating shaft, but the eccentric body is made into the rotating shaft by the method as described above. For the convenience of assembling, it was necessary to provide a cut portion from the tip portion in the axial direction of the rotary shaft to the predetermined position. For this reason, the radial dimension of the rotating shaft becomes small over a wide area, and it is difficult to maintain sufficient strength of the rotating shaft.

In this respect, the eccentric swing type transmission 100 according to the present embodiment is unique in order to improve the degree of freedom of assembly of the eccentric body 30 with respect to the rotating shaft 20 and to secure the strength of the rotating shaft 20. It has the structure of. In the following, this peculiar configuration will be described in detail.

<1-2. Eccentric body composition>
First, the configuration of the eccentric body 30 will be described in detail mainly with reference to FIG. FIG. 4 is a view of the rotating shaft 20 and the eccentric body 30 when viewed in the axial direction.

The eccentric body 30 has a constant thickness in the axial direction (see FIG. 1). The eccentric body 30 is made of a resin material. The eccentric body 30 has a notch portion 30a, a first opposite side 30b, a third side 30c, and an arc surface 30e when viewed in the axial direction.

The notch portion 30a opens on the side opposite to the eccentric axis D with the central axis C in between when viewed in the axial direction. The inner surface of the notch portion 30a has a substantially rectangular shape when viewed in the axial direction. The first opposite side 30b is a pair of opposite sides of the rectangle of the notch portion 30a when viewed in the axial direction. The pair of first opposite sides 30b are parallel to each other.

The third side 30c is a side connecting a pair of first opposite sides 30b when viewed in the axial direction. The third side 30c is perpendicular to the first opposite side 30b when viewed in the axial direction. Further, as shown in FIG. 4, when viewed in the axial direction, the connection portion between the first opposite side 30b and the third side 30c has an R shape (arc shape).

The arcuate surface 30e is a part of a cylindrical surface centered on the eccentric axis D. The arcuate surface 30e is a region of the outer peripheral surface of the eccentric body 30 opposite to the opening side with the central axis C in between when viewed in the axial direction. Further, when viewed in the axial direction, the arcuate surface 30e has a continuous arcuate shape (a part of a cylinder) along the circumferential direction.

<1-3. Detailed composition of the rotating shaft>
Subsequently, the detailed configuration of the rotary shaft 20 according to the present embodiment will be described with reference to FIG.

As shown in FIG. 4, the rotating shaft 20 has a second opposite side 20a at a position on the outer peripheral surface where the eccentric body 30 is fixed. Specifically, a pair of second opposite sides 20a are provided by cutting each of the two locations on the outer peripheral surface of the rotating shaft 20 into a D shape when viewed in the axial direction. The pair of second opposite sides 20a are parallel to the central axis C, respectively. Therefore, the pair of second opposite sides 20a are parallel to each other. The pair of second opposite sides 20a are arranged line-symmetrically with respect to the virtual straight line L passing through the central axis C when viewed in the axial direction.

As shown in FIG. 1, the two eccentric bodies 30 are attached to the rotating shaft 20 in a posture that is 180 ° inverted with respect to the central axis C when viewed in the axial direction. That is, the notch portions 30a of the two eccentric bodies 30 open in opposite directions when viewed in the axial direction. However, in the present embodiment, of the two eccentric bodies 30, they are arranged on the second opposite side 20a provided at the position where the eccentric body 30 arranged on the front side in the axial direction is fixed and on the rear side in the axial direction. The second opposite side 20a provided at the position where the eccentric body 30 is fixed is a common plane. As shown in FIG. 4, the pair of second opposite sides 20a can be in surface contact with the pair of first opposite sides 30b.

In the eccentric swing type transmission 100 having the above configuration, when the eccentric body 30 is assembled to the rotating shaft 20, the eccentric body 30 is first provided with the second opposite side 20a of the rotating shaft 20. Place it outward in the radial direction of the location. Then, the first opposite side 30b of the set of the eccentric body 30 is brought into contact with the second opposite side 20a of the rotating shaft 20 so that the rotating shaft 20 is located between the first opposite side 30b of the set of the eccentric body 30. , Slide inward in the radial direction. In this way, the outer peripheral surface of the rotating shaft 20 is brought into contact with the third side 30c of the eccentric body 30. In this way, the notch portion 30a of the eccentric body 30 is fitted into the rotating shaft 20 from the radial outer side, so that the eccentric body 30 can be easily attached to the rotating shaft 20 from the radial outer side. .. After that, the bearing 50 is inserted from the tip of the rotary shaft 20 and the bearing 50 is assembled to the radial outer side of the eccentric body 30, so that the eccentric body 30 cannot be removed from the rotary shaft 20.

Further, according to the above configuration, since the second opposite side 20a is provided only in the axial direction where the eccentric body 30 is fixed in the outer peripheral surface of the rotary shaft 20, the radial direction of the rotary shaft 20 is wide. As a result, the strength of the rotating shaft 20 can be maintained.

<1-4. Summary>
As described above, the eccentric swing type transmission 100 according to the present embodiment includes an eccentric body 30, an external gear 40, a bearing 50, and an internal gear 60. The eccentric body 30 has an arcuate surface 30e which is a part of a cylindrical surface centered on an eccentric axis D extending in parallel with the central axis C at a position deviated from the central axis C. The eccentric body 30 has a notch portion 30a opened on the side opposite to the eccentric axis D with the central axis C in between. As a result, the eccentric body 30 can be attached to the rotating shaft 20 from the outer side in the radial direction by fitting the notch portion 30a into the rotating shaft 20. Therefore, the degree of freedom in assembling the eccentric swing type transmission 100 is improved. Further, when assembling the eccentric body 30 to the rotary shaft 20, the radial dimension of the rotary shaft 20 is not sacrificed, and the strength of the rotary shaft 20 can be maintained.

Further, in the eccentric swing type transmission 100 according to the present embodiment, the notch portion 30a of the eccentric body 30 has a set of first opposite sides 30b. Further, the rotary shaft 20 has a set of second opposite sides 20a. As a result, the mounting accuracy of the eccentric body 30 on the rotating shaft 20 can be improved by bringing the first opposite side 30b and the second opposite side 20a into surface contact with each other.

Further, in the eccentric swing type transmission 100 according to the present embodiment, a set of first opposite sides 30b are parallel to each other, and a set of second opposite sides 20a are parallel to each other. This facilitates the manufacture of the eccentric body 30 and the processing of the rotary shaft 20.

Further, in the eccentric swing type transmission 100 according to the present embodiment, the eccentric body 30 has a third side 30c. As a result, the eccentric body 30 has a simple shape, and the eccentric body 30 can be easily manufactured.

Further, in the eccentric swing type transmission 100 according to the present embodiment, the third side 30c is perpendicular to the first opposite side 30b. Therefore, the eccentric body 30 has a simpler shape, and the eccentric body 30 can be easily manufactured.

Further, in the eccentric swing type transmission 100 according to the present embodiment, the connection portion between the first opposite side 30b and the third side 30c is R-shaped. As a result, it is possible to reduce the local concentration of stress at the connection point between the first opposite side 30b and the third side 30c after assembling each member of the eccentric swing type transmission 100.

Further, in the eccentric swing type transmission 100 according to the present embodiment, the eccentric body 30 is made of a resin material. As a result, the eccentric body 30 can be formed by a pair of molds that open and close in a direction perpendicular to the axial direction. Therefore, it is not necessary to provide a draft slope inclined with respect to the axial direction on the outer peripheral surface of the eccentric body 30. As a result, each member of the eccentric swing type transmission 100 can be assembled accurately with a small tolerance.

Further, in the eccentric swing type transmission 100 according to the present embodiment, the second opposite side 20a is provided only on the outer peripheral surface of the rotating shaft 20 in the axial direction where the eccentric body 30 is fixed. Thereby, the position in the axial direction and the position in the circumferential direction of the eccentric body 30 with respect to the rotating shaft 20 can be positioned by the second opposite side 20a.

Further, in the eccentric swing type transmission 100 according to the present embodiment, the region of the outer peripheral surface of the eccentric body 30 opposite to the side that is open across the central axis C is a continuous circle. It has an arc shape (arc surface 30e). As a result, the external teeth 41 of the external gear 40 are satisfactorily meshed with the internal teeth 61 of the internal gear 60 by being pushed by the outer peripheral surface of the arc surface 30e of the eccentric body 30. Conversely, since the side of the eccentric body 30 with the notch portion 30a is a region where a load is difficult to be applied, between the inner surface of the notch portion 30a of the eccentric body 30 and the outer peripheral surface of the rotating shaft 20. Even if there is a gap, the rotational performance of the eccentric swing type transmission 100 is unlikely to be affected.

<2. Modification example>
In the above embodiment, the eccentric body 30 is attached to the rotating shaft 20 from the radial outer side, and then the bearing 50 is arranged on the radial outer side of the eccentric body 30, so that the eccentric body 30 is attached to the rotating shaft 20. It was attached so that it could not be removed. However, the present invention is not limited to this, and instead of the above, for example, an adhesive is applied to the contact portion between the eccentric body 30 and the rotating shaft 20, so that the eccentric body 30 cannot be removed from the rotating shaft 20. May be good.

In the above embodiment, the second opposite side 20a provided at the position where the eccentric body 30 arranged on the front side in the axial direction is fixed and the rear side in the axial direction are arranged on the outer peripheral surface of the rotating shaft 20. The second opposite side 20a provided at the position where the eccentric body 30 is fixed was a common plane. However, the present invention is not limited to this, and instead of the above, the second opposite side 20a provided at the position where the eccentric body 30 arranged on the front side in the axial direction is fixed, and the eccentric body arranged on the rear side in the axial direction. The second opposite side 20a provided at the place where the 30 is fixed may be a separate (discontinuous) plane on the outer peripheral surface of the rotating shaft 20.

The eccentric body may not have a first opposite side, the rotating shaft may not have a second opposite side, and the eccentric body may be made of an elastically deformable material. In that case, the eccentric body may have a notch having a substantially circular shape when viewed in the axial direction. In that case, the vicinity of the notch opening of the eccentric body may be widened, and the eccentric body may be fitted into the outer peripheral portion of the rotating shaft from the radial outer side of the rotating shaft.

The eccentric body 30 does not necessarily have to be made of resin. Instead of the above, the eccentric body 30 may be made of metal.

In the above embodiment, the internal gear 60 is an annular member, but the present invention is not limited to this. Instead of the above, the outer shape of the internal gear when viewed in the axial direction may be rectangular. Further, the internal teeth 61 provided on the inner peripheral portion of the internal gear 60 do not necessarily have to be a single member with the internal gear 60, and instead, a pin is fitted on the inner peripheral portion of the internal gear. A pin groove for inserting may be provided, and a pin as an internal tooth may be fitted into the pin groove.

The eccentric swing type transmission 100 of the above embodiment has two eccentric bodies 30 in the front-rear direction in the axial direction. However, the present invention is not limited to this, and instead of the above, the eccentric swing type transmission 100 may have one or three or more eccentric bodies 30 arranged in the axial direction.

In addition, each element appearing in the above-described embodiment or modification may be appropriately combined as long as there is no contradiction.

The present application can be used for an eccentric swing type transmission.

10 Casing 20 Rotating shaft 20a Second opposite side 30 Eccentric body 30a Notch 30b First opposite side 30c Third side 30e Arc surface 40 External gear 41 External tooth 42 External groove 43 Through hole 50 Bearing 60 Internal gear 61 Inside Tooth 62 Internal intergear groove 70 Carrier pin 80 Output rotating part 81 Front carrier member 82 Rear carrier member 100 Transmission C Central axis D Eccentric axis L Virtual straight line

Claims (9)

It is an eccentric swing type transmission,
An eccentric body attached to a rotating shaft that rotates around the central axis,
An external gear that is arranged radially outward of the eccentric body and has a plurality of external teeth on the outer peripheral portion.
A bearing interposed between the eccentric body and the external gear,
An internal gear that is arranged radially outward of the external gear and coaxially with the central axis and has a plurality of internal teeth that mesh with the external teeth at the inner peripheral portion.
With
The number of external teeth and the number of internal teeth are different.
The eccentric body has a part of a cylindrical surface centered on an eccentric axis extending parallel to the central axis at a position deviated from the central axis.
The eccentric body is an eccentric swing type transmission having a notch portion opened on the side opposite to the eccentric shaft with the central shaft interposed therebetween. The eccentric swing type transmission according to claim 1.
The notch has a set of first opposite sides.
The rotating shaft has a set of second opposite sides capable of surface contact with the first opposite side.
Eccentric swing type transmission. The eccentric swing type transmission according to claim 2.
An eccentric swing type transmission in which the first pair of opposite sides is parallel to each other and the second pair of opposite sides are parallel to each other. The eccentric swing type transmission according to claim 2 or 3.
The eccentric body is an eccentric swing type transmission having a third side connecting the first pair of opposite sides to each other. The eccentric swing type transmission according to claim 4.
The set of first opposite sides is parallel to each other, and the set of second opposite sides is parallel to each other.
An eccentric swing type transmission in which the third side is perpendicular to the first opposite side. The eccentric swing type transmission according to claim 4 or 5.
The connection point between the first opposite side and the third side is an R-shaped eccentric swing type transmission. The eccentric swing type transmission according to any one of claims 1 to 6.
The eccentric body is an eccentric swing type transmission made of a resin material. The eccentric swing type transmission according to any one of claims 2 to 6.
The second opposite side is an eccentric swing type transmission provided only on the outer peripheral surface of the rotating shaft where the eccentric body is fixed. The eccentric swing type transmission according to any one of claims 1 to 8.
An eccentric swing type transmission in which a region of the outer peripheral surface of the eccentric body opposite to the opening side across the central axis is a continuous arc shape.

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