WO2019013190A1 - Wave gear device - Google Patents
Wave gear device Download PDFInfo
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- WO2019013190A1 WO2019013190A1 PCT/JP2018/025988 JP2018025988W WO2019013190A1 WO 2019013190 A1 WO2019013190 A1 WO 2019013190A1 JP 2018025988 W JP2018025988 W JP 2018025988W WO 2019013190 A1 WO2019013190 A1 WO 2019013190A1
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- ball bearing
- gear device
- wave gear
- flexible external
- peripheral surface
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- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
- F16H—GEARING
- F16H1/00—Toothed gearings for conveying rotary motion
- F16H1/28—Toothed gearings for conveying rotary motion with gears having orbital motion
- F16H1/32—Toothed gearings for conveying rotary motion with gears having orbital motion in which the central axis of the gearing lies inside the periphery of an orbital gear
Definitions
- the present invention relates to a wave gear device.
- Japanese Patent No. 5734102 discloses a wave gear device for decelerating input rotation and transmitting it to the load side.
- the wave gear device described in the publication comprises a ring-shaped rigid internal gear, a flexible external gear disposed inside the rigid internal gear, and a wave generator fitted inside the flexible external gear.
- the flexible external gear is radially deflected by the wave generator and partially engages with the internal gear.
- input rotation is decelerated by relative rotation according to the number-of-tooth difference of both gears.
- the present invention is a wave gear device, comprising: a non-round cam rotating around a vertically extending center axis; and the outer round surface of the non-round cam, the non-round cam A flexible ball bearing whose length in the radial direction changes in the circumferential direction according to the rotation of the shaft, and a tubular shape extending in the axial direction, wherein the inner peripheral surface of the axially lower end portion is the ball bearing And a diameter of the flexible external gear, and a flexible external gear provided with a plurality of external teeth along the circumferential direction at a constant pitch on the peripheral surface of the lower end.
- an internal gear having an internal tooth number different from that of the plurality of external teeth and partially meshing with the flexible external gear, and an outer peripheral surface of the ball bearing The inner peripheral surface of the lower end of the flexible external gear is in surface contact with the outer peripheral surface of the ball bearing, A contact portion between the inner circumferential surface of the lower end of the serial flexible external gear at a position opposed to the ball in the radial direction of the ball bearing is space provided.
- the ball bearing changes in radial length due to the non-round cam.
- the outer circumferential surface of the ball bearing is pushed radially outward by the balls of the ball bearing and is curved.
- This curved portion penetrates into the space provided between the ball bearing and the flexible external gear. For this reason, the stress from the ball bearing is difficult to be transmitted to the flexible external gear.
- the load from the ball bearing to the flexible external gear can be reduced, and damage to the flexible external gear can be suppressed.
- FIG. 1 is a cross-sectional view of a wave gear device according to an exemplary embodiment of the present application.
- FIG. 2 is a cross-sectional view taken along line II-II of FIG.
- FIG. 3 is an enlarged view of the contact portion between the flexible external gear and the internal gear.
- FIG. 4 is an enlarged view of the contact portion between the flexible external gear and the internal gear.
- FIG. 5 is a cross-sectional view of another example wave gear device.
- axial direction a direction parallel to the central axis of the wave gear device
- radial direction a direction orthogonal to the central axis of the wave gear device
- arc centered on the central axis of the wave gear device The direction is referred to as "circumferential direction", respectively.
- shape and the positional relationship of each part will be described with the axial direction as the vertical direction and the rotational output part side up with respect to the rotational input part.
- the “parallel direction” also includes a substantially parallel direction.
- the “orthogonal direction” also includes a substantially orthogonal direction.
- FIG. 1 is a cross-sectional view of a wave gear drive 100 in accordance with an exemplary embodiment of the present application.
- FIG. 2 is a cross-sectional view taken along line II-II of FIG.
- the wave gear device 100 includes a wave generator 4 that rotates about a central axis 9.
- the wave generator 4 has a non-round cam 41 and a ball bearing 42.
- a rotation input unit (not shown) is connected to the non-round cam 41.
- a rotational force is transmitted from, for example, an electric motor, and the rotation input unit rotates in the circumferential direction about the central axis 9.
- the non-round cam 41 receives rotation from the rotation input unit, and rotates around the central axis 9 together with the rotation input unit.
- the non-perfect circular cam 41 is elliptical as viewed from the axial direction.
- the ball bearing 42 is disposed radially outward of the non-round cam 41 and mounted on the outer peripheral surface of the non-round cam 41.
- the ball bearing 42 has flexibility, and when attached to the non-perfect circular cam 41, it bends in an elliptical shape along the outer peripheral surface of the non-perfect circular cam 41 as viewed from the axial direction.
- the wave gear device 100 includes an internal gear 3.
- the internal gear 3 has a cylindrical shape surrounding the central axis 9 and is a perfect circle when viewed from the axial direction.
- the internal gear 3 is disposed radially outward of the ball bearing 42. Further, the internal gear 3 is non-rotatably fixed to, for example, a cover (not shown) of the wave gear device 100 or the like.
- a plurality of internal teeth 31 are provided on the inner peripheral surface of the internal gear 3 along the circumferential direction at a constant pitch.
- the wave gear device 100 includes a flexible external gear 5.
- the flexible external gear 5 is a cylindrical member which surrounds the central axis 9 and extends in the axial direction.
- the axially lower end 50 of the flexible external gear 5 is disposed between the ball bearing 42 and the internal gear 3.
- the inner circumferential surface of the lower end portion 50 is in contact with the outer circumferential surface of the ball bearing 42.
- a plurality of external teeth 501 having a number of teeth different from the plurality of internal teeth 31 of the internal gear 3 are provided on the outer circumferential surface of the lower end portion 50 along the circumferential direction at a constant pitch.
- the lower end 50 of the flexible external gear 5 is mounted on a ball bearing 42.
- the ball bearing 42 is elliptically bent as described above.
- the lower end 50 of the flexible external gear 5 mounted on the ball bearing 42 also bends in an elliptical shape.
- the short axis of the elliptically bent lower end 50 is shorter than the inner diameter of the perfect circular internal gear 3.
- the major axis of the lower end 50 is substantially the same as the inner diameter of the internal gear 3. Accordingly, the external teeth 501 of the flexible external gear 5 and the internal teeth 31 of the internal gear 3 mesh with each other at the major axis portion of the lower end portion 50.
- the wave gear device 100 includes an output shaft that is rotatable about the central axis 9 and connected to a load.
- the upper axial end of the flexible external gear 5 is fixed to the output shaft.
- the flexible external gear 5 rotates at a rotation speed smaller than that of the non-circular cam 41. That is, the output shaft that rotates with the flexible external gear 5 also rotates at a rotation speed smaller than that of the non-circular cam 41. In this manner, the rotation input from the motor (not shown) to the non-round cam 41 is decelerated and output to the load via the output shaft.
- the ball bearing 42 is elliptically bent by the non-round cam 41. At this time, a stress directed radially outward is generated in a portion to be the long axis of the ball bearing 42. Then, the outer peripheral surface (the outer peripheral surface of the outer ring) of the ball bearing 42 is pressed radially outward by the ball, and the pressed portion is curved. As in the prior art, when the curved portion of the outer peripheral surface of the ball bearing 42 abuts on the inner peripheral surface of the flexible external gear 5, high stress due to point contact is generated in the flexible external gear 5, The flexible external gear 5 may be damaged. For this reason, in the present embodiment, the flexible external gear 5 is configured such that the stress from the ball bearing 42 is not easily transmitted.
- FIG. 3 is an enlarged view of the contact portion between the flexible external gear 5 and the internal gear 3.
- the inner peripheral surface of the lower end 50 of the flexible external gear 5 is in contact with the outer peripheral surface of the ball bearing 42.
- the inner peripheral surface of the lower end portion 50 is provided with a recess 51 that is recessed radially outward. As shown in FIG. 2, the recess 51 is provided along the circumferential direction at a position radially opposed to the ball center point of the ball bearing 42.
- the axial length of the recess 51 is 20% to 120% of the diameter of the ball of the ball bearing 42. However, more preferably, the axial length of the recess 51 is 80% to 100% of the diameter of the ball of the ball bearing 42.
- a space 55 is provided between the inner peripheral surface of the lower end 50 and the outer peripheral surface of the ball bearing 42 by the recess 51.
- the outer circumferential surface of the ball bearing 42 is curved radially outward by the pressure from the ball. Then, the curved portion of the outer peripheral surface of the ball bearing 42 enters the space 55. For this reason, the radial apex of the curved portion does not abut the inner peripheral surface of the flexible external gear 5. Thereby, the load from the ball bearing 42 to the flexible external gear 5 is reduced, and damage to the flexible external gear 5 can be suppressed.
- Embodiment 2 The second embodiment will be described below.
- the second embodiment is different from the first embodiment in the configuration for making it difficult to transmit stress from the ball bearing 42 to the flexible external gear 5.
- FIG. 4 is an enlarged view of a contact portion between the flexible external gear 5 and the internal gear 3.
- a recess 43 that is recessed inward in the radial direction is provided at the axial center of the outer peripheral surface of the ball bearing 42.
- the recess 43 is provided at a position radially opposed to the ball center point of the ball bearing 42.
- the recessed part 43 is provided along the circumferential direction similarly to the recessed part 51 of Embodiment 1.
- the axial length of the recess 43 is 20% to 120% of the diameter of the ball of the ball bearing 42.
- the axial length of the recess 51 is 80% to 100% of the diameter of the ball of the ball bearing 42.
- the recessed portion 43 provides a space 45 between the outer peripheral surface of the ball bearing 42 and the inner peripheral surface of the lower end 50 of the flexible external gear 5.
- the curved portion generated on the surface of the recess 43 enters the space 45. For this reason, the radial apex of the curved portion does not abut the inner peripheral surface of the flexible external gear 5. Thereby, the load from the ball bearing 42 to the flexible external gear 5 is reduced, and damage to the flexible external gear 5 can be suppressed.
- FIG. 5 is a cross-sectional view of another example of the wave gear device 100A.
- the axial upper end of the flexible external gear 5A included in the wave gear device 100A is expanded radially outward.
- the output shaft connected to the load can be disposed more radially outward than in the case of FIG.
- the axial length of the spaces 45 and 55 is 20% to 120%, more preferably 80% to 100%, of the diameter of the ball of the ball bearing 42, but is limited thereto. There is nothing to do. Further, the radial length (depth) of the spaces 45 and 55 can be appropriately changed in accordance with the degree of deflection of the outer peripheral surface of the ball bearing 42. In addition, a recess may be provided on both the inner peripheral surface of the flexible external gear 5 and the outer peripheral surface of the ball bearing 42 to provide a space.
- the shape of the detail of the wave gear device 100 may be different from the shape shown in each drawing of the present application. Further, each element appearing in the above embodiment or modification may be combined appropriately as long as no contradiction occurs.
- the present application is applicable to a wave gear device.
Abstract
This wave gear device is provided with: a non-circular cam which rotates about the center axis; a flexible ball bearing which is mounted on the outer circumferential surface of the non-circular cam and which has a radial length variable in the circumferential direction according to rotation of the non-circular cam; a flexible externally toothed gear which has a cylindrical shape extending in the axial direction, of which the lower end in the axial direction has an inner circumferential surface in contact with the outer circumferential surface of the ball bearing, and which has a plurality of external teeth provided at a certain pitch in the circumferential direction on the outer circumferential surface of the lower end in the axial direction; and an internally toothed gear that is disposed radially outside the flexible externally toothed gear, that includes inner teeth the number of which is different from the number of the plurality of external teeth, and that partially meshes with the flexible externally toothed gear. The outer circumferential surface of the ball bearing and the inner circumferential surface of the lower end of the flexible externally toothed gear are in surface contact with each other. A space is provided, in the contact portion, at a position facing, in the radial direction, a ball in the ball bearing.
Description
本発明は、波動歯車装置に関する。
The present invention relates to a wave gear device.
特許第５７３４１０２号公報には、入力回転を減速して負荷側に伝達する波動歯車装置が開示されている。当該公報に記載の波動歯車装置は、円環状の剛性内歯車と、剛性内歯車の内側に配置された可撓性外歯車と、可撓性外歯車の内側に嵌められた波動発生器とを備えている。可撓性外歯車は、波動発生器によって径方向にたわみが発生し、内歯車と部分的に噛み合う。そして、両歯車の歯数差に応じた相対回転により、入力回転を減速させている。
特許第５７３４１０２号公報
Japanese Patent No. 5734102 discloses a wave gear device for decelerating input rotation and transmitting it to the load side. The wave gear device described in the publication comprises a ring-shaped rigid internal gear, a flexible external gear disposed inside the rigid internal gear, and a wave generator fitted inside the flexible external gear. Have. The flexible external gear is radially deflected by the wave generator and partially engages with the internal gear. And input rotation is decelerated by relative rotation according to the number-of-tooth difference of both gears.
Patent No. 5734102
特許第５７３４１０２号公報の波動歯車装置において、波動発生器に径方向の撓みが発生することで、波動発生器のウエーブベアリングには、径方向外側に向かう応力が発生する。これにより、可撓性外歯車が、ウエーブベアリングのボールにより、径方向外側に向かって押圧される。そして、可撓性外歯車における、ボールにより押圧された部分には高い応力がかかり、可撓性外歯車は破壊されるおそれがある。
In the wave gear device of Japanese Patent No. 5734102, radial deflection in the wave generator generates stress directed outward in the radial direction in the wave bearing of the wave generator. Thus, the flexible external gear is pushed radially outward by the balls of the wave bearing. Then, high stress is applied to the portion of the flexible external gear pressed by the ball, and the flexible external gear may be broken.
このような問題を鑑みて、本発明の目的は、軸受から可撓性外歯歯車にかかる負荷を軽減する波動歯車装置を提供することである。
In view of such problems, it is an object of the present invention to provide a wave gear device which reduces the load on the flexible external gear from the bearing.
上記課題を解決するため、本発明は波動歯車装置であって、上下に延びる中心軸を中心に回転する非真円カムと、前記非真円カムの外周面に装着され、前記非真円カムの回転に応じて、径方向の長さが周方向に変化する可撓性のボールベアリングと、軸方向に延びる筒状であって、軸方向の下側端部の内周面が前記ボールベアリングの外周面に接し、前記下側端部の外周面に、一定のピッチで複数の外歯が周方向に沿って設けられた可撓性外歯歯車と、前記可撓性外歯歯車の径方向外側に配置され、前記複数の外歯と異なる歯数の内歯を有し、前記可撓性外歯歯車と部分的に噛み合う内歯歯車と、を備え、前記ボールベアリングの外周面と、前記可撓性外歯歯車の前記下側端部の内周面とは、面接触し、前記ボールベアリングの外周面と、前記可撓性外歯歯車の前記下側端部の内周面との接触部分であって、前記ボールベアリングのボールと径方向に対向する位置には、空間が設けられている。
In order to solve the above problems, the present invention is a wave gear device, comprising: a non-round cam rotating around a vertically extending center axis; and the outer round surface of the non-round cam, the non-round cam A flexible ball bearing whose length in the radial direction changes in the circumferential direction according to the rotation of the shaft, and a tubular shape extending in the axial direction, wherein the inner peripheral surface of the axially lower end portion is the ball bearing And a diameter of the flexible external gear, and a flexible external gear provided with a plurality of external teeth along the circumferential direction at a constant pitch on the peripheral surface of the lower end. And an internal gear having an internal tooth number different from that of the plurality of external teeth and partially meshing with the flexible external gear, and an outer peripheral surface of the ball bearing, The inner peripheral surface of the lower end of the flexible external gear is in surface contact with the outer peripheral surface of the ball bearing, A contact portion between the inner circumferential surface of the lower end of the serial flexible external gear at a position opposed to the ball in the radial direction of the ball bearing is space provided.
本発明によれば、ボールベアリングは、非真円カムにより径方向の長さが変化する。この変化において、径方向の長さが長くなるとき、ボールベアリングの外周面は、ボールベアリングのボールにより、径方向外側へ押圧され、湾曲する。この湾曲部分は、ボールベアリングと、可撓性外歯歯車との間に設けられた空間に、入り込む。このため、ボールベアリングからの応力は、可撓性外歯歯車へ伝達され難くい。その結果、ボールベアリングから可撓性外歯歯車への負荷が軽減され、可撓性外歯歯車の損傷を抑制できる。
According to the present invention, the ball bearing changes in radial length due to the non-round cam. In this variation, when the radial length is increased, the outer circumferential surface of the ball bearing is pushed radially outward by the balls of the ball bearing and is curved. This curved portion penetrates into the space provided between the ball bearing and the flexible external gear. For this reason, the stress from the ball bearing is difficult to be transmitted to the flexible external gear. As a result, the load from the ball bearing to the flexible external gear can be reduced, and damage to the flexible external gear can be suppressed.
以下、本願の例示的な実施形態について、図面を参照しながら説明する。なお、本願では、波動歯車装置の中心軸と平行な方向を「軸方向」、波動歯車装置の中心軸に直交する方向を「径方向」、波動歯車装置の中心軸を中心とする円弧に沿う方向を「周方向」、とそれぞれ称する。また、本願では、軸方向を上下方向とし、回転入力部に対して回転出力部側を上として、各部の形状や位置関係を説明する。ただし、この上下方向の定義により、本願に係る波動歯車装置の使用時の向きを限定する意図はない。
Hereinafter, exemplary embodiments of the present application will be described with reference to the drawings. In the present application, a direction parallel to the central axis of the wave gear device is referred to as “axial direction”, a direction orthogonal to the central axis of the wave gear device as “radial direction”, and an arc centered on the central axis of the wave gear device The direction is referred to as "circumferential direction", respectively. Further, in the present application, the shape and the positional relationship of each part will be described with the axial direction as the vertical direction and the rotational output part side up with respect to the rotational input part. However, there is no intention to limit the direction in use of the wave gear device according to the present application based on the definition in the vertical direction.
また、本願において「平行な方向」とは、略平行な方向も含む。また、本願において「直交する方向」とは、略直交する方向も含む。
Further, in the present application, the “parallel direction” also includes a substantially parallel direction. Further, in the present application, the “orthogonal direction” also includes a substantially orthogonal direction.
＜１．実施形態１＞
＜１．１．波動歯車装置の構成＞
図１は、本願の例示的な実施形態に係る波動歯車装置１００の断面図である。図２は、図１のＩＩ－ＩＩ線における断面図である。 <1. Embodiment 1>
<1.1. Configuration of wave gear device>
FIG. 1 is a cross-sectional view of awave gear drive 100 in accordance with an exemplary embodiment of the present application. FIG. 2 is a cross-sectional view taken along line II-II of FIG.
＜１．１．波動歯車装置の構成＞
図１は、本願の例示的な実施形態に係る波動歯車装置１００の断面図である。図２は、図１のＩＩ－ＩＩ線における断面図である。 <1. Embodiment 1>
<1.1. Configuration of wave gear device>
FIG. 1 is a cross-sectional view of a
波動歯車装置１００は、中心軸９を中心に回転する波動発生器４を備えている。波動発生器４は、非真円カム４１と、ボールベアリング４２とを有している。
The wave gear device 100 includes a wave generator 4 that rotates about a central axis 9. The wave generator 4 has a non-round cam 41 and a ball bearing 42.
非真円カム４１には、不図示の回転入力部が接続される。回転入力部は、例えば電動機から回転力が伝達されて、中心軸９を中心に周方向に回転する。非真円カム４１は、回転入力部から回転が伝達され、回転入力部と共に、中心軸９を中心に回転する。非真円カム４１は、軸方向から視て楕円形である。
A rotation input unit (not shown) is connected to the non-round cam 41. A rotational force is transmitted from, for example, an electric motor, and the rotation input unit rotates in the circumferential direction about the central axis 9. The non-round cam 41 receives rotation from the rotation input unit, and rotates around the central axis 9 together with the rotation input unit. The non-perfect circular cam 41 is elliptical as viewed from the axial direction.
ボールベアリング４２は、非真円カム４１の径方向外側に配置され、非真円カム４１の外周面に装着されている。ボールベアリング４２は、可撓性を有し、非真円カム４１に装着されると、軸方向から視て、非真円カム４１の外周面に沿った楕円形に撓む。
The ball bearing 42 is disposed radially outward of the non-round cam 41 and mounted on the outer peripheral surface of the non-round cam 41. The ball bearing 42 has flexibility, and when attached to the non-perfect circular cam 41, it bends in an elliptical shape along the outer peripheral surface of the non-perfect circular cam 41 as viewed from the axial direction.
波動歯車装置１００は内歯歯車３を備えている。内歯歯車３は、中心軸９を囲む円筒状であって、軸方向から視て、真円形である。内歯歯車３は、ボールベアリング４２の径方向外側に配置されている。また、内歯歯車３は、例えば、波動歯車装置１００の不図示のカバーなどに、回転不可に固定されている。内歯歯車３の内周面には、複数の内歯３１が、一定のピッチで周方向に沿って設けられている。
The wave gear device 100 includes an internal gear 3. The internal gear 3 has a cylindrical shape surrounding the central axis 9 and is a perfect circle when viewed from the axial direction. The internal gear 3 is disposed radially outward of the ball bearing 42. Further, the internal gear 3 is non-rotatably fixed to, for example, a cover (not shown) of the wave gear device 100 or the like. A plurality of internal teeth 31 are provided on the inner peripheral surface of the internal gear 3 along the circumferential direction at a constant pitch.
波動歯車装置１００は可撓性外歯歯車５を備えている。可撓性外歯歯車５は、中心軸９を囲み、軸方向に延びる筒状部材である。可撓性外歯歯車５の軸方向の下側端部５０は、ボールベアリング４２と、内歯歯車３との間に配置されている。下側端部５０の内周面は、ボールベアリング４２の外周面と接している。下側端部５０の外周面には、内歯歯車３の複数の内歯３１と異なる歯数の複数の外歯５０１が、一定のピッチで周方向に沿って設けられている。
The wave gear device 100 includes a flexible external gear 5. The flexible external gear 5 is a cylindrical member which surrounds the central axis 9 and extends in the axial direction. The axially lower end 50 of the flexible external gear 5 is disposed between the ball bearing 42 and the internal gear 3. The inner circumferential surface of the lower end portion 50 is in contact with the outer circumferential surface of the ball bearing 42. A plurality of external teeth 501 having a number of teeth different from the plurality of internal teeth 31 of the internal gear 3 are provided on the outer circumferential surface of the lower end portion 50 along the circumferential direction at a constant pitch.
可撓性外歯歯車５の下側端部５０は、ボールベアリング４２に装着されている。ボールベアリング４２は、前記のように、楕円形に撓む。このため、ボールベアリング４２に装着された可撓性外歯歯車５の下側端部５０も、楕円形に撓む。楕円形に撓んだ下側端部５０の短軸は、真円形の内歯歯車３の内径よりも短い。また、下側端部５０の長軸は、内歯歯車３の内径と略同じである。したがって、下側端部５０の長軸部分において、可撓性外歯歯車５の外歯５０１と、内歯歯車３の内歯３１とが噛み合っている。
The lower end 50 of the flexible external gear 5 is mounted on a ball bearing 42. The ball bearing 42 is elliptically bent as described above. For this reason, the lower end 50 of the flexible external gear 5 mounted on the ball bearing 42 also bends in an elliptical shape. The short axis of the elliptically bent lower end 50 is shorter than the inner diameter of the perfect circular internal gear 3. Further, the major axis of the lower end 50 is substantially the same as the inner diameter of the internal gear 3. Accordingly, the external teeth 501 of the flexible external gear 5 and the internal teeth 31 of the internal gear 3 mesh with each other at the major axis portion of the lower end portion 50.
非真円カム４１が回転すると、可撓性外歯歯車５の径方向の長さが周方向に変位する。これにより、可撓性外歯歯車５と、内歯歯車３との噛み合わせ位置が周方向に移動する。また、内歯歯車３は回転不可に固定されている。その結果、歯数が異なる可撓性外歯歯車５と内歯歯車３とが相対回転するとき、可撓性外歯歯車５は、非真円カム４１より小さい回転数で回転する。
When the non-perfect circular cam 41 rotates, the radial length of the flexible external gear 5 is displaced in the circumferential direction. Thereby, the meshing position of the flexible external gear 5 and the internal gear 3 moves in the circumferential direction. Further, the internal gear 3 is non-rotatably fixed. As a result, when the flexible external gear 5 and the internal gear 3 having different numbers of teeth rotate relative to each other, the flexible external gear 5 rotates at a smaller rotational speed than the non-circular cam 41.
可撓性外歯歯車５の軸方向の上側端部は、径方向内側に向かって拡がっている。図示しないが、波動歯車装置１００は、中心軸９を中心に回転可能で、負荷に接続される出力軸を備えている。可撓性外歯歯車５の軸方向の上側端部は、出力軸に固定される。これにより、可撓性外歯歯車５が、中心軸９を中心に回転すると、出力軸も回転する。そして、負荷へ回転が伝達される。前記のように、可撓性外歯歯車５は、非真円カム４１より小さい回転数で回転する。つまり、可撓性外歯歯車５と共に回転する出力軸も、非真円カム４１より小さい回転数で回転する。このように、不図示の電動機から非真円カム４１へ入力された回転は、減速されて、出力軸を介して負荷へ出力される。
The upper axial end of the flexible external gear 5 extends radially inward. Although not shown, the wave gear device 100 includes an output shaft that is rotatable about the central axis 9 and connected to a load. The upper axial end of the flexible external gear 5 is fixed to the output shaft. Thereby, when the flexible external gear 5 rotates around the central axis 9, the output shaft also rotates. Then, the rotation is transmitted to the load. As described above, the flexible external gear 5 rotates at a rotation speed smaller than that of the non-circular cam 41. That is, the output shaft that rotates with the flexible external gear 5 also rotates at a rotation speed smaller than that of the non-circular cam 41. In this manner, the rotation input from the motor (not shown) to the non-round cam 41 is decelerated and output to the load via the output shaft.
＜１．２．ボールベアリング４２の応力について＞
ボールベアリング４２は、非真円カム４１により楕円形に撓む。この際、ボールベアリング４２の長軸となる部分には、径方向外側に向かう応力が生じる。そして、ボールベアリング４２の外周面（外輪の外周面）は、ボールにより径方向外側に押圧されて、押圧された部分が湾曲する。従来のように、ボールベアリング４２の外周面の湾曲部分が、可撓性外歯歯車５の内周面に当接すると、点接触による高い応力が可撓性外歯歯車５に発生し、可撓性外歯歯車５が損傷する可能性がある。このため、本実施形態では、可撓性外歯歯車５は、ボールベアリング４２からの応力が伝達され難い構成となっている。 <1.2. About stress ofball bearing 42>
Theball bearing 42 is elliptically bent by the non-round cam 41. At this time, a stress directed radially outward is generated in a portion to be the long axis of the ball bearing 42. Then, the outer peripheral surface (the outer peripheral surface of the outer ring) of the ball bearing 42 is pressed radially outward by the ball, and the pressed portion is curved. As in the prior art, when the curved portion of the outer peripheral surface of the ball bearing 42 abuts on the inner peripheral surface of the flexible external gear 5, high stress due to point contact is generated in the flexible external gear 5, The flexible external gear 5 may be damaged. For this reason, in the present embodiment, the flexible external gear 5 is configured such that the stress from the ball bearing 42 is not easily transmitted.
ボールベアリング４２は、非真円カム４１により楕円形に撓む。この際、ボールベアリング４２の長軸となる部分には、径方向外側に向かう応力が生じる。そして、ボールベアリング４２の外周面（外輪の外周面）は、ボールにより径方向外側に押圧されて、押圧された部分が湾曲する。従来のように、ボールベアリング４２の外周面の湾曲部分が、可撓性外歯歯車５の内周面に当接すると、点接触による高い応力が可撓性外歯歯車５に発生し、可撓性外歯歯車５が損傷する可能性がある。このため、本実施形態では、可撓性外歯歯車５は、ボールベアリング４２からの応力が伝達され難い構成となっている。 <1.2. About stress of
The
図３は、可撓性外歯歯車５と、内歯歯車３との接触部分の拡大図である。
FIG. 3 is an enlarged view of the contact portion between the flexible external gear 5 and the internal gear 3.
可撓性外歯歯車５の下側端部５０の内周面は、ボールベアリング４２の外周面と接している。下側端部５０の内周面には、径方向外側に凹む凹部５１が設けられている。凹部５１は、ボールベアリング４２のボール中心点と、径方向に対向する位置に、図２に示すように、周方向に沿って設けられている。凹部５１の軸方向の長さは、ボールベアリング４２のボールの直径の２０％～１２０％である。ただし、より好ましくは、凹部５１の軸方向の長さは、ボールベアリング４２のボールの直径の８０％～１００％である。凹部５１により、下側端部５０の内周面と、ボールベアリング４２の外周面との間に、空間５５が設けられる。
The inner peripheral surface of the lower end 50 of the flexible external gear 5 is in contact with the outer peripheral surface of the ball bearing 42. The inner peripheral surface of the lower end portion 50 is provided with a recess 51 that is recessed radially outward. As shown in FIG. 2, the recess 51 is provided along the circumferential direction at a position radially opposed to the ball center point of the ball bearing 42. The axial length of the recess 51 is 20% to 120% of the diameter of the ball of the ball bearing 42. However, more preferably, the axial length of the recess 51 is 80% to 100% of the diameter of the ball of the ball bearing 42. A space 55 is provided between the inner peripheral surface of the lower end 50 and the outer peripheral surface of the ball bearing 42 by the recess 51.
前記のように、ボールベアリング４２の外周面は、ボールからの押圧により、径方向外側へ湾曲する。そして、ボールベアリング４２の外周面の湾曲部分は、空間５５に入り込む。このため、湾曲部分の径方向の頂点付近は、可撓性外歯歯車５の内周面に当接しない。これにより、ボールベアリング４２から可撓性外歯歯車５への負荷が軽減され、可撓性外歯歯車５の損傷を抑制できる。
As described above, the outer circumferential surface of the ball bearing 42 is curved radially outward by the pressure from the ball. Then, the curved portion of the outer peripheral surface of the ball bearing 42 enters the space 55. For this reason, the radial apex of the curved portion does not abut the inner peripheral surface of the flexible external gear 5. Thereby, the load from the ball bearing 42 to the flexible external gear 5 is reduced, and damage to the flexible external gear 5 can be suppressed.
＜２．実施形態２＞
以下に実施形態２について説明する。実施形態２は、ボールベアリング４２から可撓性外歯歯車５への応力を伝達し難くするための構成が、実施形態１と相違する。 <2. Embodiment 2>
The second embodiment will be described below. The second embodiment is different from the first embodiment in the configuration for making it difficult to transmit stress from theball bearing 42 to the flexible external gear 5.
以下に実施形態２について説明する。実施形態２は、ボールベアリング４２から可撓性外歯歯車５への応力を伝達し難くするための構成が、実施形態１と相違する。 <2. Embodiment 2>
The second embodiment will be described below. The second embodiment is different from the first embodiment in the configuration for making it difficult to transmit stress from the
図４は、可撓性外歯歯車５と、内歯歯車３との接触部分の拡大図である。
FIG. 4 is an enlarged view of a contact portion between the flexible external gear 5 and the internal gear 3.
この例では、ボールベアリング４２の外周面の軸方向中央部に、径方向内側に凹む凹部４３が設けられている。凹部４３は、ボールベアリング４２のボール中心点と、径方向に対向する位置に設けられている。また、凹部４３は、実施形態１の凹部５１と同様に、周方向に沿って設けられている。凹部４３の軸方向の長さは、ボールベアリング４２のボールの直径の２０％～１２０％である。ただし、より好ましくは、凹部５１の軸方向の長さは、ボールベアリング４２のボールの直径の８０％～１００％である。凹部４３により、ボールベアリング４２の外周面と、可撓性外歯歯車５の下側端部５０の内周面との間に、空間４５が設けられる。
In this example, a recess 43 that is recessed inward in the radial direction is provided at the axial center of the outer peripheral surface of the ball bearing 42. The recess 43 is provided at a position radially opposed to the ball center point of the ball bearing 42. Moreover, the recessed part 43 is provided along the circumferential direction similarly to the recessed part 51 of Embodiment 1. As shown in FIG. The axial length of the recess 43 is 20% to 120% of the diameter of the ball of the ball bearing 42. However, more preferably, the axial length of the recess 51 is 80% to 100% of the diameter of the ball of the ball bearing 42. The recessed portion 43 provides a space 45 between the outer peripheral surface of the ball bearing 42 and the inner peripheral surface of the lower end 50 of the flexible external gear 5.
実施形態１と同様、ボールベアリング４２の外周面が、ボールからの押圧により径方向外側へ湾曲すると、凹部４３の表面に生じる湾曲部分は、空間４５に入り込む。このため、湾曲部分の径方向の頂点付近は、可撓性外歯歯車５の内周面に当接しない。これにより、ボールベアリング４２から可撓性外歯歯車５への負荷が軽減され、可撓性外歯歯車５の損傷を抑制できる。
As in the first embodiment, when the outer circumferential surface of the ball bearing 42 is bent radially outward by the pressure from the ball, the curved portion generated on the surface of the recess 43 enters the space 45. For this reason, the radial apex of the curved portion does not abut the inner peripheral surface of the flexible external gear 5. Thereby, the load from the ball bearing 42 to the flexible external gear 5 is reduced, and damage to the flexible external gear 5 can be suppressed.
＜３．変形例＞
以上、本発明の例示的な実施形態について説明したが、本発明は上記の実施形態には限定されない。 <3. Modified example>
Although the exemplary embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments.
以上、本発明の例示的な実施形態について説明したが、本発明は上記の実施形態には限定されない。 <3. Modified example>
Although the exemplary embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments.
図５は、別の例の波動歯車装置１００Ａの断面図である。波動歯車装置１００Ａが備える可撓性外歯歯車５Ａの軸方向の上側端部は、径方向外側に向かって拡がっている。この構成の場合、負荷に接続される出力軸を、図１の場合よりも径方向外側に、配置させることができる。
FIG. 5 is a cross-sectional view of another example of the wave gear device 100A. The axial upper end of the flexible external gear 5A included in the wave gear device 100A is expanded radially outward. In this configuration, the output shaft connected to the load can be disposed more radially outward than in the case of FIG.
実施形態１、２では、空間４５、５５の軸方向の長さは、ボールベアリング４２のボールの直径の２０％～１２０％、より好ましくは、８０％～１００％としたが、これに限定されることはない。また、空間４５、５５の径方向の長さ（深さ）は、ボールベアリング４２の外周面の撓み度合に応じて、適宜変更可能である。また、可撓性外歯歯車５の内周面と、ボールベアリング４２の外周面との両方に凹部を設け、空間を設けるようにしてもよい。
In Embodiments 1 and 2, the axial length of the spaces 45 and 55 is 20% to 120%, more preferably 80% to 100%, of the diameter of the ball of the ball bearing 42, but is limited thereto. There is nothing to do. Further, the radial length (depth) of the spaces 45 and 55 can be appropriately changed in accordance with the degree of deflection of the outer peripheral surface of the ball bearing 42. In addition, a recess may be provided on both the inner peripheral surface of the flexible external gear 5 and the outer peripheral surface of the ball bearing 42 to provide a space.
また、波動歯車装置１００の細部の形状については、本願の各図に示された形状と、相違していてもよい。また、上記の実施形態または変形例に登場した各要素を、矛盾が生じない範囲で、適宜に組み合わせてもよい。
Further, the shape of the detail of the wave gear device 100 may be different from the shape shown in each drawing of the present application. Further, each element appearing in the above embodiment or modification may be combined appropriately as long as no contradiction occurs.
本出願は、２０１７年７月１４日に出願された日本特許出願である特願２０１７－１３７６０８号に基づく優先権を主張し、当該日本特許出願に記載されたすべての記載内容を援用する。
This application claims priority based on Japanese Patent Application No. 2017-137608 filed on Jul. 14, 2017, and incorporates the entire contents described in the Japanese patent application.
本願は、波動歯車装置に利用できる。
The present application is applicable to a wave gear device.
３ ：内歯歯車
４ ：波動発生器
５ ：可撓性外歯歯車
５Ａ ：可撓性外歯歯車
９ ：中心軸
３１ ：内歯
４１ ：非真円カム
４２ ：ボールベアリング
４３ ：凹部
４５ ：空間
５０ ：下側端部
５１ ：凹部
５５ ：空間
１００ ：波動歯車装置
１００Ａ ：波動歯車装置
５０１ ：外歯
3: Internal gear 4: Wave generator 5: Flexibleexternal gear 5A: Flexible external gear 9: Central shaft 31: Internal gear 41: Non-round cam 42: Ball bearing 43: Recess 45: Space 50: lower end 51: recess 55: space 100: wave gear device 100A: wave gear device 501: external gear
４ ：波動発生器
５ ：可撓性外歯歯車
５Ａ ：可撓性外歯歯車
９ ：中心軸
３１ ：内歯
４１ ：非真円カム
４２ ：ボールベアリング
４３ ：凹部
４５ ：空間
５０ ：下側端部
５１ ：凹部
５５ ：空間
１００ ：波動歯車装置
１００Ａ ：波動歯車装置
５０１ ：外歯
3: Internal gear 4: Wave generator 5: Flexible
Claims (8)
- 上下に延びる中心軸を中心に回転する非真円カムと、
前記非真円カムの外周面に装着され、前記非真円カムの回転に応じて、径方向の長さが周方向に変化する可撓性のボールベアリングと、
軸方向に延びる筒状であって、軸方向の下側端部の内周面が前記ボールベアリングの外周面に接し、前記下側端部の外周面に、一定のピッチで複数の外歯が周方向に沿って設けられた可撓性外歯歯車と、
前記可撓性外歯歯車の径方向外側に配置され、前記複数の外歯と異なる歯数の内歯を有し、前記可撓性外歯歯車と部分的に噛み合う内歯歯車と、を備え、
前記ボールベアリングの外周面と、前記可撓性外歯歯車の前記下側端部の内周面とは、面接触し、
前記ボールベアリングの外周面と、前記可撓性外歯歯車の前記下側端部の内周面との接触部分であって、前記ボールベアリングのボールと径方向に対向する位置には、空間が設けられている、
波動歯車装置。 A non-round cam which rotates around a central axis extending up and down;
A flexible ball bearing mounted on the outer peripheral surface of the non-perfect circular cam, and whose radial length varies in the circumferential direction according to the rotation of the non-perfect circular cam;
An axially extending cylindrical shape, wherein the inner peripheral surface of the axially lower end is in contact with the outer peripheral surface of the ball bearing, and on the outer peripheral surface of the lower end, a plurality of external teeth are formed at a constant pitch A flexible external gear provided along the circumferential direction;
And an internal gear disposed radially outward of the flexible external gear, having an internal tooth number of teeth different from the plurality of external teeth, and partially meshing with the flexible external gear. ,
An outer circumferential surface of the ball bearing and an inner circumferential surface of the lower end of the flexible external gear are in surface contact with each other,
A space is a contact portion between the outer peripheral surface of the ball bearing and the inner peripheral surface of the lower end of the flexible external gear, in a position radially opposed to the ball of the ball bearing. Provided
Wave gear device. - 請求項１に記載の波動歯車装置であって、
前記可撓性外歯歯車の前記下側端部の内周面は、軸方向の中央部分が、径方向外側に凹んでいる、
波動歯車装置。 A wave gear device according to claim 1, wherein
An inner circumferential surface of the lower end of the flexible external gear has an axially central portion recessed radially outward.
Wave gear device. - 請求項１または請求項２に記載の波動歯車装置であって、
前記ボールベアリングの外周面は、軸方向の中央部分が、径方向内側に凹んでいる、
波動歯車装置。 The wave gear device according to claim 1 or 2, wherein
An axially central portion of the outer peripheral surface of the ball bearing is recessed radially inward.
Wave gear device. - 請求項１から請求項３までのいずれか一つに記載の波動歯車装置であって、
前記空間は、前記ボールベアリングのボール中心点と、径方向に対向する位置に設けられている、
波動歯車装置。 A wave gear device according to any one of claims 1 to 3, wherein
The space is provided at a position radially opposed to the ball center point of the ball bearing.
Wave gear device. - 請求項４に記載の波動歯車装置であって、
軸方向における前記空間の長さは、前記ボールベアリングのボールの直径の２０％～１２０％である、
波動歯車装置。 The wave gear device according to claim 4, wherein
The length of the space in the axial direction is 20% to 120% of the diameter of the ball of the ball bearing,
Wave gear device. - 請求項５に記載の波動歯車装置であって、
軸方向における前記空間の長さは、前記ボールベアリングのボールの直径の８０％～１００％である、
波動歯車装置。 The wave gear device according to claim 5, wherein
The length of the space in the axial direction is 80% to 100% of the diameter of the ball of the ball bearing,
Wave gear device. - 請求項１から請求項６までのいずれか一つに記載の波動歯車装置であって、
前記可撓性外歯歯車の軸方向上側端部は、径方向内側に拡がっている、
波動歯車装置。 A wave gear device according to any one of claims 1 to 6, wherein
The axially upper end portion of the flexible external gear is expanded radially inward.
Wave gear device. - 請求項１から請求項６までのいずれか一つに記載の波動歯車装置であって、
前記可撓性外歯歯車の軸方向上側端部は、径方向外側に拡がっている、
波動歯車装置。
A wave gear device according to any one of claims 1 to 6, wherein
The axially upper end of the flexible external gear is extended radially outward.
Wave gear device.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2017-137608 | 2017-07-14 | ||
| JP2017137608A JP2019019862A (en) | 2017-07-14 | 2017-07-14 | Wave gear device |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| WO2019013190A1 true WO2019013190A1 (en) | 2019-01-17 |
Family
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Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| PCT/JP2018/025988 WO2019013190A1 (en) | 2017-07-14 | 2018-07-10 | Wave gear device |
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| Country | Link |
|---|---|
| JP (1) | JP2019019862A (en) |
| TW (1) | TW201908620A (en) |
| WO (1) | WO2019013190A1 (en) |
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| US20220333653A1 (en) * | 2019-10-03 | 2022-10-20 | Sumitomo Electric Sintered Alloy, Ltd. | Sintered member and electromagnetic coupling |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE102015223419A1 (en) * | 2015-11-26 | 2016-11-10 | Schaeffler Technologies AG & Co. KG | The wave gear |
| JP2017110705A (en) * | 2015-12-15 | 2017-06-22 | 株式会社ジェイテクト | Wave gear transmission device |
-
2017
- 2017-07-14 JP JP2017137608A patent/JP2019019862A/en active Pending
-
2018
- 2018-07-10 WO PCT/JP2018/025988 patent/WO2019013190A1/en active Application Filing
- 2018-07-12 TW TW107123996A patent/TW201908620A/en unknown
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE102015223419A1 (en) * | 2015-11-26 | 2016-11-10 | Schaeffler Technologies AG & Co. KG | The wave gear |
| JP2017110705A (en) * | 2015-12-15 | 2017-06-22 | 株式会社ジェイテクト | Wave gear transmission device |
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| Publication number | Publication date |
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| TW201908620A (en) | 2019-03-01 |
| JP2019019862A (en) | 2019-02-07 |
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