WO2019009176A1 - Speed reducer - Google Patents
Speed reducer Download PDFInfo
- Publication number
- WO2019009176A1 WO2019009176A1 PCT/JP2018/024570 JP2018024570W WO2019009176A1 WO 2019009176 A1 WO2019009176 A1 WO 2019009176A1 JP 2018024570 W JP2018024570 W JP 2018024570W WO 2019009176 A1 WO2019009176 A1 WO 2019009176A1
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- WIPO (PCT)
- Prior art keywords
- crown gear
- central axis
- input
- gear
- output
- Prior art date
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Classifications
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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
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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
- F16H55/00—Elements with teeth or friction surfaces for conveying motion; Worms, pulleys or sheaves for gearing mechanisms
- F16H55/02—Toothed members; Worms
- F16H55/06—Use of materials; Use of treatments of toothed members or worms to affect their intrinsic material properties
Definitions
- the present invention relates to a reduction gear.
- the reduction gear of JP 2011-002084 A includes an annular rigid gear 9 and an annular flexible gear 5.
- the ring-shaped flexible gear 5 is deformed into a corrugated shape by the ring-shaped flexible gear rotating mechanism 2 through the flexible bearing 3. Thereby, only a part of the annular flexible gear 5 meshes with the annular rigid gear 9.
- the flexible bearing 3 is disposed between the annular flexible gear 5 and the annular flexible gear rotation mechanism 2. For this reason, in the structure of JP 2011-002084, the manufacturing cost is increased due to the expensive bearing 3, the number of parts is increased, and it is difficult to miniaturize the reduction gear. Also, the deformed bearings can be a source of noise.
- An object of the present invention is to provide a structure in which the reduction gear can be easily miniaturized by reducing the number of parts of the reduction gear.
- An exemplary embodiment of the present application is a reduction gear for converting rotational motion of an input rotational speed into rotational motion of an output rotational speed lower than the input rotational speed, wherein the input rotational speed around a central axis
- the input rotary body, the output rotary body rotating at the output rotational speed about the central axis, and the housing supporting the input rotary body and the output rotary body, the input rotary body comprising: An output shaft, an arm extending radially outward from the input shaft, and a roller rotating about an axis of rotation supported by the arm, the output rotating body being disposed on the central axis
- a movable crown gear having a plurality of first side teeth arranged in an annular shape around the central axis and extending from the center of the movable crown gear to the central axis.
- the housing including a fixed crown gear having a plurality of second side teeth that extend perpendicularly or obliquely with respect to the central axis and are annularly arranged around the central axis, the movable crown gear being movable
- the number of teeth of the first side teeth of the crown gear and the number of teeth of the second side teeth of the fixed crown gear are different, and the roller is in contact with a part of the movable crown gear in the circumferential direction.
- the fixed crown gear and the movable crown gear are partially meshed by the pressure received from the roller, and the position at which the movable crown gear and the fixed crown gear are meshed with the central axis as the input rotating body rotates.
- the center it changes in the circumferential direction at the input rotational speed, and the movable gear relative to the crown gear is determined by the difference in the number of teeth between the first side teeth and the second side teeth Ungia rotates at the output rotational speed.
- the roller is brought into contact with the movable crown gear to axially deform a circumferential portion of the movable crown gear without interposing a separately flexible bearing.
- the reduction gear can be easily miniaturized by reducing the number of parts of the reduction gear.
- FIG. 1 is a longitudinal sectional view of a reduction gear.
- FIG. 2 is a longitudinal sectional view of the reduction gear.
- FIG. 3 is a cross-sectional view of the reduction gear.
- FIG. 4 is a cross-sectional view of the housing.
- FIG. 5 is a partial longitudinal sectional view of the reduction gear.
- FIG. 6 is a longitudinal sectional view of a reduction gear according to a modification.
- a direction parallel to the central axes of the input and output rotary bodies is “axial direction”, a direction orthogonal to the central axis is “radial direction”, and a direction along an arc centered on the central axis is “peripheral It is referred to as “direction”.
- the above-mentioned "parallel direction” also includes a substantially parallel direction.
- the “orthogonal direction” described above also includes a substantially orthogonal direction.
- the input rotary body side is referred to as “input side” and the output rotary body side is referred to as “output side” along the axial direction.
- FIG. 1 and 2 are longitudinal sectional views of a reduction gear 1 according to an embodiment of the present invention.
- FIG. 3 is a cross-sectional view of the reduction gear 1.
- FIG. 1 shows a cross section of the reduction gear 1 as viewed from the position AA in FIG.
- FIG. 2 shows a cross section of the reduction gear 1 as viewed from the position BB in FIG.
- FIG. 3 shows a cross section of the reduction gear 1 as viewed from the position CC in FIG. 1 and FIG.
- the reduction gear 1 is a device that converts rotational motion of an input rotational speed obtained from an external motor into rotational motion of an output rotational speed lower than the input rotational speed.
- the speed reducer 1 is incorporated into, for example, a joint portion of a small robot that works in cooperation with a person.
- the reduction gear of the present invention may be used for other devices such as an assist suit, a wheelchair, and an automatic guided vehicle.
- the reduction gear 1 of the present embodiment has an input shaft 10, two arms 20, two rollers 30, a movable crown gear 40, an output shaft 50, and a housing 60.
- the input shaft 10, the two arm portions 20, and the two rollers 30 constitute an input rotating body 81 which rotates around the central axis 9 at an input rotational speed.
- the movable crown gear 40 and the output shaft 50 constitute an output rotating body 82 that rotates around the central axis 9 at an output rotational speed.
- the input shaft 10 is a cylindrical member extending along the central axis 9.
- the input shaft 10 is inserted into an input hole 610 of the housing 60 described later.
- the input shaft 10 is rotatably supported by the housing 60 via the bearing 11.
- a ball bearing is used for the bearing 11.
- the input end of the input shaft 10 is connected to an external motor directly or through another power transmission mechanism. When the motor is driven, the input shaft 10 rotates about the central axis 9 at an input rotational speed.
- the output side end of the input shaft 10 is located inside the housing 60.
- the output-side end of the input shaft 10 may be connected to the output shaft 50 via a bearing.
- the two arms 20 are members extending radially outward from the input shaft 10.
- the radially inner end of each arm 20 is fixed to the input shaft 10, for example, by screwing.
- the arm 20 as well as the input shaft 10 rotates at the input rotation speed about the central axis 9.
- rod-like arms 20 extending in the radial direction are provided at intervals of 180 ° around the input shaft 10.
- the shape, the number, and the circumferential position of the arm portion 20 may not be as in this embodiment.
- the arm part 20 may be connected in the circumferential direction.
- the two rollers 30 are rotating bodies held at the radially outer end of the arm 20.
- the rotation shaft 31 of the roller 30 is supported by the arm portion 20 in an attitude that is inclined with respect to the axial direction and the radial direction and is perpendicular to the circumferential direction.
- the roller 30 is rotatably attached to the rotating shaft 31.
- the roller 30 has a conical outer peripheral surface 32 centered on the rotation axis 31. The diameter of the outer circumferential surface 32 of the roller 30 increases as it is separated radially outward from the input shaft 10.
- the roller 30 is also rotated at the input rotation speed about the central axis 9 together with the input shaft 10 and the arm portion 20.
- the movable crown gear 40 is a gear which is rotatable around the central axis 9 and is flexible.
- the movable crown gear 40 is positioned more on the output side than the two rollers 30.
- the movable crown gear 40 has a thin plate-like flexible disc portion 41 and a plurality of first side teeth 42.
- the flexible disc portion 41 spreads radially outward from the input-side end of the output shaft 50.
- the flexible disc portion 41 of the present embodiment expands in a conical shape around the central axis 9.
- the flexible disc portion 41 is elastically deformable in the axial direction.
- Each of the plurality of first side teeth 42 axially protrudes from the flexible disc portion 41 toward the output side (the fixed crown gear 70 side).
- the plurality of first side teeth 42 are annularly arranged around the central axis 9. Further, the plurality of first side teeth 42 are arranged at regular intervals in the circumferential direction. When a portion in the circumferential direction of the flexible disc portion 41 is elastically deformed in the axial direction, the position of the first side teeth 42 positioned in the portion in the circumferential direction also moves in the axial direction.
- the flexible disc portion 41 of the movable crown gear 40 spreads obliquely with respect to the central axis 9.
- the flexible disc portion 41 may extend perpendicularly to the central axis 9.
- the output shaft 50 extends along the central axis 9 from the center of the movable crown gear 40 toward the output side.
- the output shaft 50 has a cylindrical outer peripheral surface.
- the output shaft 50 is inserted into an output hole 620 described later of the housing 60.
- the output shaft 50 is rotatably supported with respect to the housing 60.
- the movable crown gear 40 rotates about the central axis 9
- the output shaft 50 also rotates about the central axis 9.
- the movable crown gear 40 and the output shaft 50 are a single member.
- the movable crown gear 40 and the output shaft 50 may be prepared as separate members and fixed to each other.
- the housing 60 is a housing that supports the input rotating body 81 and the output rotating body 82.
- the housing 60 has an input side wall 61, an output side wall 62, and a peripheral wall 63.
- the input side wall portion 61 extends substantially perpendicularly to the central axis 9 on the input side of the two arm portions 20.
- an input hole 610 for passing the input shaft 10 is provided at the center of the input side wall portion 61.
- the output side wall portion 62 extends substantially perpendicularly to the central axis 9 on the output side relative to the movable crown gear 40.
- An output hole 620 for passing the output shaft 50 is provided at the center of the output side wall portion 62.
- the peripheral wall portion 63 axially extends in a cylindrical shape between the outer peripheral portion of the input side wall portion 61 and the outer peripheral portion of the output side wall portion 62.
- the peripheral wall portion 63 is located radially outward of the two arm portions 20, the two rollers 30, and the movable crown gear 40.
- the output side wall portion 62 and the peripheral wall portion 63 are configured by one member. Then, the input side wall portion 61 of another member is fixed to the cup-shaped member configured of the output side wall portion 62 and the peripheral wall portion 63.
- the input side wall 61 and the peripheral wall 63 may be formed as one member, and the output side wall 62 may be separate members.
- the input side wall 61, the output side wall 62, and the peripheral wall 63 may all be separate members.
- FIG. 4 is a cross-sectional view of the housing 60 as viewed from the CC position in FIGS. 1 and 2.
- the output sidewall 62 of the housing 60 includes a fixed crown gear 70.
- the fixed crown gear 70 has a fixed disk portion 71 and a plurality of second side teeth 72.
- the fixed disc portion 71 may extend perpendicularly to the central axis 9 or may extend obliquely with respect to the central axis 9.
- the fixed disc portion 71 is much less flexible than the flexible disc portion 41. Therefore, the fixed disc portion 71 can be regarded as a substantially nonflexible rigid body.
- Each of the plurality of second side teeth 72 axially protrudes from the fixed disc portion 71 toward the input side (the movable crown gear 40 side).
- the plurality of second side teeth 72 are annularly arranged around the central axis 9. Further, the plurality of second side teeth 72 are arranged at regular intervals in the circumferential direction.
- FIG. 5 is a partial longitudinal sectional view of the reduction gear 1.
- the above-described roller 30 contacts a part of the circumferential surface of the surface on the input side of the flexible disc portion 41 of the movable crown gear 40.
- the first side teeth 42 of some of the plurality of first side teeth 42 are displaced to the output side by the pressure received from the roller 30.
- the movable crown gear 40 and the fixed crown gear 70 mesh with each other.
- the movable crown gear 40 and the fixed crown gear 70 do not mesh with each other.
- the plurality of first side teeth 42 and the plurality of second side teeth 72 mesh with each other only at specific portions in the circumferential direction.
- the input shaft 10 rotates around the central axis 9 at the input rotational speed. Then, together with the input shaft 10, the two arm portions 20 and the two rollers 30 also rotate around the central axis 9 at an input rotational speed. The two rollers 30 respectively revolve around the central axis 9 while rotating about the rotation axis 31 by the friction force with the movable crown gear 40.
- the shape of the movable crown gear 40 changes accordingly. That is, a portion of the plurality of first side teeth 42 that is displaced to the output side rotates following the revolution of the roller 30. Therefore, among the plurality of first side teeth 42, the portion meshing with the second side teeth 72 of the fixed crown gear 70 changes in the circumferential direction at the input rotation speed centering on the central axis 9.
- the number of first side teeth 42 of the movable crown gear 40 and the number of second side teeth 72 of the fixed crown gear 70 are slightly different. Due to the difference in the number of teeth, the positions of the first side teeth 42 of the movable crown gear 40 meshing with the second side teeth 72 at the same position of the fixed crown gear 70 shift each time the roller 30 makes one revolution. Thereby, the movable crown gear 40 rotates slowly around the central axis 9 with respect to the fixed crown gear 70. As a result, the output shaft 50 rotates slowly with the movable crown gear 40. The rotation speed of the output shaft 50 at this time is an output rotation speed lower than the input rotation speed.
- the reduction gear 1 when the roller 30 is brought into contact with the movable crown gear 40, a part of the movable crown gear 40 in the circumferential direction is axially deformed.
- the roller 30 can move smoothly with respect to the movable crown gear 40 by rotating. Therefore, it is not necessary to interpose a separately flexible bearing between the roller 30 and the movable crown gear 40. Thereby, the number of parts of the reduction gear 1 can be suppressed, and the reduction gear 1 can be miniaturized.
- the arm part 20 exists only in the circumferential direction position same as the roller 30, and an arm part does not exist in another circumferential direction position. For this reason, there is no concern that the portion of the movable crown gear 40 having a small amount of displacement to the output side may come in contact with the arm portion 20. For example, there is no concern that the movable crown gear 40 and the arm 20 come in contact with each other at a position 90 ° away from the roller 30 about the central axis 9. Thereby, the reduction gear 1 can be further miniaturized. Moreover, the noise at the time of the drive of the reduction gear 1 can be suppressed.
- the posture of the roller 30 is inclined with respect to the central axis 9.
- the rotation shaft 31 of the roller 30 is inclined with respect to the axial direction and the radial direction, and extends in a direction orthogonal to the circumferential direction.
- the circumferential velocity difference in the radial direction of the portion of the outer circumferential surface 32 of the roller 30 that contacts the movable crown gear 40 matches the circumferential velocity difference in the radial direction with respect to the central axis 9.
- the slip between the roller 30 and the movable crown gear 40 is suppressed.
- energy loss in the reduction gear 1 can be reduced.
- a virtual line obtained by extending the rotation shaft 31 of the roller 30 radially inward is referred to as a “first virtual line V1”.
- a virtual line in which the contact portion with the movable crown gear 40 in the outer peripheral surface 32 of the roller 30 is extended radially inward is referred to as a "second virtual line V2”.
- the first virtual line V1 and the second virtual line V2 intersect on the central axis 9. In this way, slippage between the roller 30 and the movable crown gear 40 is further suppressed. As a result, energy loss in the reduction gear 1 can be further reduced.
- two rollers 30 are arranged at an interval of 180 ° around the central axis 9. As described above, by disposing the plurality of rollers 30 at equal intervals in the circumferential direction, it is possible to suppress the swing of the center of gravity during operation of the reduction gear 1. Note that the number of rollers 30 included in the reduction gear 1 may be three or more.
- the axial distance between the outer peripheral surface 32 of the roller 30 and the surface on the input side of the fixed disk portion 71 is d1.
- a total dimension in the axial direction of the flexible disc portion 41 and the first side teeth 42 is d2.
- the distance d1 is larger than the dimension d2.
- the roller 30 preferably has an appropriate outer diameter.
- the outer diameter of the roller 30 around the rotation shaft 31 is preferably 1/10 or more and 1/2 or less of the outer diameter around the central axis 9 of the movable crown gear 40.
- each member which comprises the reduction gear 1 metal, such as iron, is used, for example.
- metal such as iron
- some or all of the members may be made of resin. If resin is used, the reduction gear 1 can be reduced in weight as compared to the case of using metal.
- at least one of the movable crown gear 40 and the fixed crown gear 70 may be made of resin. Side teeth of these crown gears 40, 70 project in the axial direction. Therefore, the crown gears 40 and 70 can be easily manufactured by injection molding using a mold combined in the axial direction.
- the movable crown gear 40 is made of resin, it is easy to obtain the flexibility of the flexible disc portion 41.
- FIG. 6 is a longitudinal sectional view of a speed reducer 1A according to a modification.
- a hollow shaft 80A is provided at the center of the reduction gear 1A.
- the hollow shaft 80A is a cylindrical member and is disposed along the central axis 9A.
- a bearing 12A is interposed between the inner peripheral surface of the input shaft 10A and the outer peripheral surface of the hollow shaft 80A. Therefore, the input shaft 10A and the hollow shaft 80A can rotate relative to each other about the central axis 9A.
- a sliding bearing is used for the bearing 12A.
- the hollow shaft 80A is fixed to the output shaft 50A by a screw 51A. Therefore, the hollow shaft 80A, together with the output shaft 50A, rotates at an output rotational speed centering on the central axis 9A.
- the structures of the arm 20A, the roller 30A, the movable crown gear 40A, the housing 60A, and the fixed crown gear 70A are the same as those in the above embodiment.
- the reduction gear 1A power transmission is performed only on the radially outer side of the input shaft 10A and the output shaft 50A. Therefore, as shown in the example of FIG. 6, the hollow shaft 80A can be disposed radially inward of the input shaft 10A and the output shaft 50A. In this way, the space inside the hollow shaft 80A in the radial direction can be effectively used.
- a support shaft 90A for supporting the speed reducer can be passed inside the hollow shaft 80A.
- the electrical wiring of the device on which the reduction gear 1A is mounted can be passed inside the hollow shaft 80A.
- the hollow shaft 80A is fixed not to the input shaft 10A but to the output shaft 50A. In this manner, the rotational speed of the hollow shaft 80A is lower than the input rotational speed. Therefore, the rotational speed of the hollow shaft 80A can be suppressed. This makes it easier to use the radially inner space of the hollow shaft 80A.
- the shape of the detail of the reduction gear may be different from the shape shown in each drawing of the present application.
- each element appearing in the above-described embodiment and modification may be combined appropriately as long as no contradiction occurs.
- the present invention is applicable to a reduction gear.
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Abstract
This speed reducer has an input rotating body, an output rotating body, and a housing. The input rotating body includes an input shaft, an arm part, and rollers. The output rotating body includes a movable crown gear and an output shaft. The housing includes a fixed crown gear. The movable crown gear and the fixed crown gear extend perpendicular to or obliquely with respect to a center axis. Furthermore, the movable crown gear and the fixed crown gear have side-surface teeth facing each other. The rollers make contact with a portion of the movable crown gear in the circumferential direction. The movable crown gear and the fixed crown gear partially mesh with each other due to pressing force applied by the rollers. Furthermore, in conjunction with the rotation of the input rotating body, the meshing position of the movable crown gear and the fixed crown gear changes in the circumferential direction with the input rotation speed, with the center axis as the center. The movable crown gear rotates with respect to the fixed crown gear with an output rotation speed, which is determined by the difference in the number of teeth of the movable crown gear and the fixed crown gear.
Description
本発明は、減速機に関する。
The present invention relates to a reduction gear.
近年、人と協調して作業を行う小型ロボットの開発が、活発に行われている。この種のロボットには、極めて細かい動作が求められる。このため、ロボットの関節部分に組み込まれる小型で安価な減速機の需要が高まっている。従来の減速機については、例えば、特開2011-002084号公報に記載されている。
In recent years, development of small robots that work in cooperation with people has been actively conducted. This type of robot is required to have extremely fine motions. For this reason, the demand for a small and inexpensive speed reducer to be incorporated into the joint portion of a robot is increasing. The conventional reduction gear is described, for example, in Japanese Patent Application Laid-Open No. 2011-002084.
特開2011-002084号公報の減速機は、環状剛性歯車9と、環状撓性歯車5とを有する。環状撓性歯車5は、柔軟性を有する軸受3を介して、環状撓性歯車回転機構2により、波形に変形させられている。これにより、環状撓性歯車5の一部のみが、環状剛性歯車9に噛合する。
特開2011-002084号公報
The reduction gear of JP 2011-002084 A includes an annular rigid gear 9 and an annular flexible gear 5. The ring-shaped flexible gear 5 is deformed into a corrugated shape by the ring-shaped flexible gear rotating mechanism 2 through the flexible bearing 3. Thereby, only a part of the annular flexible gear 5 meshes with the annular rigid gear 9.
JP, 2011-002084, A
上記のように、特開2011-002084の構造では、環状撓性歯車5と環状撓性歯車回転機構2との間に、柔軟性を有する軸受3が配置されている。このため、特開2011-002084の構造では、高価な軸受3により製造コストが増加するとともに、部品点数が増加し、減速機の小型化が困難となる。また、変形する軸受は騒音の要因ともなり得る。
As described above, in the structure of JP 2011-002084, the flexible bearing 3 is disposed between the annular flexible gear 5 and the annular flexible gear rotation mechanism 2. For this reason, in the structure of JP 2011-002084, the manufacturing cost is increased due to the expensive bearing 3, the number of parts is increased, and it is difficult to miniaturize the reduction gear. Also, the deformed bearings can be a source of noise.
本発明の目的は、減速機の部品点数を抑えて、減速機を小型化しやすい構造を提供することである。
An object of the present invention is to provide a structure in which the reduction gear can be easily miniaturized by reducing the number of parts of the reduction gear.
本願の例示的な一実施形態は、入力回転数の回転運動を、前記入力回転数よりも低い出力回転数の回転運動に変換する減速機であって、中心軸を中心として、前記入力回転数で回転する入力回転体と、前記中心軸を中心として、前記出力回転数で回転する出力回転体と、前記入力回転体および前記出力回転体を支持するハウジングと、を備え、前記入力回転体は、入力シャフトと、前記入力シャフトから径方向外側へ向けて延びる腕部と、前記腕部に支持された回転軸を中心として回転するローラと、を含み、前記出力回転体は、前記中心軸に対して垂直または斜めに拡がるとともに、可撓性を有し、前記中心軸を中心として円環状に並ぶ複数の第1側面歯を有する可動クラウンギアと、前記可動クラウンギアの中央から前記中心軸に沿って延びる出力シャフトと、を含み、前記ハウジングは、前記中心軸に対して垂直または斜めに拡がり、前記中心軸を中心として円環状に並ぶ複数の第2側面歯を有する固定クラウンギアを含み、前記可動クラウンギアの前記第1側面歯の歯数と、前記固定クラウンギアの前記第2側面歯の歯数とが、相違し、前記可動クラウンギアの周方向の一部分に、前記ローラが接触し、前記ローラから受ける押圧によって、前記固定クラウンギアと前記可動クラウンギアとが部分的に噛み合い、前記入力回転体の回転に伴い、前記可動クラウンギアと前記固定クラウンギアとの噛み合う位置が、前記中心軸を中心として、前記入力回転数で周方向に変化し、前記第1側面歯と前記第2側面歯との歯数の差によって、前記クラウンギアに対して前記可動クラウンギアが、前記出力回転数で回転する。
An exemplary embodiment of the present application is a reduction gear for converting rotational motion of an input rotational speed into rotational motion of an output rotational speed lower than the input rotational speed, wherein the input rotational speed around a central axis The input rotary body, the output rotary body rotating at the output rotational speed about the central axis, and the housing supporting the input rotary body and the output rotary body, the input rotary body comprising: An output shaft, an arm extending radially outward from the input shaft, and a roller rotating about an axis of rotation supported by the arm, the output rotating body being disposed on the central axis And a movable crown gear having a plurality of first side teeth arranged in an annular shape around the central axis and extending from the center of the movable crown gear to the central axis. Along And an extending output shaft, the housing including a fixed crown gear having a plurality of second side teeth that extend perpendicularly or obliquely with respect to the central axis and are annularly arranged around the central axis, the movable crown gear being movable The number of teeth of the first side teeth of the crown gear and the number of teeth of the second side teeth of the fixed crown gear are different, and the roller is in contact with a part of the movable crown gear in the circumferential direction. The fixed crown gear and the movable crown gear are partially meshed by the pressure received from the roller, and the position at which the movable crown gear and the fixed crown gear are meshed with the central axis as the input rotating body rotates. As the center, it changes in the circumferential direction at the input rotational speed, and the movable gear relative to the crown gear is determined by the difference in the number of teeth between the first side teeth and the second side teeth Ungia rotates at the output rotational speed.
本願の例示的な一実施形態によれば、可動クラウンギアにローラを接触させることで、別途柔軟性を有する軸受を介在させることなく、可動クラウンギアの周方向の一部分を軸方向に変形させることができる。したがって、減速機の部品点数を抑えて、減速機を小型化しやすくなる。
According to an exemplary embodiment of the present application, the roller is brought into contact with the movable crown gear to axially deform a circumferential portion of the movable crown gear without interposing a separately flexible bearing. Can. Therefore, the reduction gear can be easily miniaturized by reducing the number of parts of the reduction gear.
以下、本発明の一実施形態について、図面を参照しながら説明する。なお、本願では、入力回転体および出力回転体の中心軸と平行な方向を「軸方向」、中心軸に直交する方向を「径方向」、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。ただし、上記の「平行な方向」は、略平行な方向も含む。また、上記の「直交する方向」は、略直交する方向も含む。また、以下では、軸方向に沿って入力回転体側を「入力側」、出力回転体側を「出力側」、とそれぞれ称する。
Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In the present application, a direction parallel to the central axes of the input and output rotary bodies is “axial direction”, a direction orthogonal to the central axis is “radial direction”, and a direction along an arc centered on the central axis is “peripheral It is referred to as “direction”. However, the above-mentioned "parallel direction" also includes a substantially parallel direction. Further, the “orthogonal direction” described above also includes a substantially orthogonal direction. Further, hereinafter, the input rotary body side is referred to as “input side” and the output rotary body side is referred to as “output side” along the axial direction.
<1.減速機の構成>
図1および図2は、本発明の一実施形態に係る減速機1の縦断面図である。図3は、減速機1の横断面図である。なお、図1は、図3中のA-A位置から見た減速機1の断面を示している。図2は、図3中のB-B位置から見た減速機1の断面を示している。図3は、図1および図2中のC-C位置から見た減速機1の断面を示している。 <1. Configuration of reduction gear>
1 and 2 are longitudinal sectional views of areduction gear 1 according to an embodiment of the present invention. FIG. 3 is a cross-sectional view of the reduction gear 1. FIG. 1 shows a cross section of the reduction gear 1 as viewed from the position AA in FIG. FIG. 2 shows a cross section of the reduction gear 1 as viewed from the position BB in FIG. FIG. 3 shows a cross section of the reduction gear 1 as viewed from the position CC in FIG. 1 and FIG.
図1および図2は、本発明の一実施形態に係る減速機1の縦断面図である。図3は、減速機1の横断面図である。なお、図1は、図3中のA-A位置から見た減速機1の断面を示している。図2は、図3中のB-B位置から見た減速機1の断面を示している。図3は、図1および図2中のC-C位置から見た減速機1の断面を示している。 <1. Configuration of reduction gear>
1 and 2 are longitudinal sectional views of a
この減速機1は、外部のモータから得られる入力回転数の回転運動を、入力回転数よりも低い出力回転数の回転運動に変換する装置である。減速機1は、例えば、人と協調して作業を行う小型ロボットの関節部分に組み込まれる。ただし、本発明の減速機は、アシストスーツ、車椅子、無人搬送車などの他の機器に使用されてもよい。
The reduction gear 1 is a device that converts rotational motion of an input rotational speed obtained from an external motor into rotational motion of an output rotational speed lower than the input rotational speed. The speed reducer 1 is incorporated into, for example, a joint portion of a small robot that works in cooperation with a person. However, the reduction gear of the present invention may be used for other devices such as an assist suit, a wheelchair, and an automatic guided vehicle.
図1に示すように、本実施形態の減速機1は、入力シャフト10、2本の腕部20、2つのローラ30、可動クラウンギア40、出力シャフト50、およびハウジング60を有する。入力シャフト10、2本の腕部20、および2つのローラ30は、中心軸9を中心として入力回転数で回転する入力回転体81を構成する。可動クラウンギア40および出力シャフト50は、中心軸9を中心として出力回転数で回転する出力回転体82を構成する。
As shown in FIG. 1, the reduction gear 1 of the present embodiment has an input shaft 10, two arms 20, two rollers 30, a movable crown gear 40, an output shaft 50, and a housing 60. The input shaft 10, the two arm portions 20, and the two rollers 30 constitute an input rotating body 81 which rotates around the central axis 9 at an input rotational speed. The movable crown gear 40 and the output shaft 50 constitute an output rotating body 82 that rotates around the central axis 9 at an output rotational speed.
入力シャフト10は、中心軸9に沿って延びる円柱状の部材である。入力シャフト10は、ハウジング60の後述する入力孔610に、挿入される。また、入力シャフト10は、ハウジング60に、軸受11を介して回転可能に支持される。軸受11には、例えばボールベアリングが用いられる。入力シャフト10の入力側の端部は、直接または他の動力伝達機構を介して、外部のモータに接続される。モータを駆動させると、入力シャフト10は、中心軸9を中心として、入力回転数で回転する。入力シャフト10の出力側の端部は、ハウジング60の内部に位置する。なお、入力シャフト10の出力側の端部は、出力シャフト50と、ベアリングを介して接続されていてもよい。
The input shaft 10 is a cylindrical member extending along the central axis 9. The input shaft 10 is inserted into an input hole 610 of the housing 60 described later. Also, the input shaft 10 is rotatably supported by the housing 60 via the bearing 11. For example, a ball bearing is used for the bearing 11. The input end of the input shaft 10 is connected to an external motor directly or through another power transmission mechanism. When the motor is driven, the input shaft 10 rotates about the central axis 9 at an input rotational speed. The output side end of the input shaft 10 is located inside the housing 60. The output-side end of the input shaft 10 may be connected to the output shaft 50 via a bearing.
2本の腕部20は、入力シャフト10から径方向外側へ向けて延びる部材である。各腕部20の径方向内側の端部は、入力シャフト10に対して、例えばねじ止めで固定される。上述したモータの駆動時には、入力シャフト10とともに腕部20も、中心軸9を中心として、入力回転数で回転する。本実施形態では、径方向に延びる棒状の腕部20が、入力シャフト10の周囲に180°間隔で設けられている。ただし、腕部20の形状、数、および周方向の位置は、本実施形態の通りでなくてもよい。また、腕部20は、周方向に繋がっていてもよい。
The two arms 20 are members extending radially outward from the input shaft 10. The radially inner end of each arm 20 is fixed to the input shaft 10, for example, by screwing. At the time of driving of the motor described above, the arm 20 as well as the input shaft 10 rotates at the input rotation speed about the central axis 9. In the present embodiment, rod-like arms 20 extending in the radial direction are provided at intervals of 180 ° around the input shaft 10. However, the shape, the number, and the circumferential position of the arm portion 20 may not be as in this embodiment. Moreover, the arm part 20 may be connected in the circumferential direction.
2つのローラ30は、腕部20の径方向外側の先端に保持された回転体である。ローラ30の回転軸31は、軸方向および径方向に対して傾斜し、かつ、周方向に対して垂直な姿勢で、腕部20に支持される。ローラ30は、当該回転軸31に、回転自在に取り付けられる。ローラ30は、回転軸31を中心とする円錐状の外周面32を有する。ローラ30の外周面32の径は、入力シャフト10から径方向外側へ離れるにつれて拡大する。上述したモータの駆動時には、入力シャフト10および腕部20とともに、ローラ30も、中心軸9を中心として入力回転数で回転する。
The two rollers 30 are rotating bodies held at the radially outer end of the arm 20. The rotation shaft 31 of the roller 30 is supported by the arm portion 20 in an attitude that is inclined with respect to the axial direction and the radial direction and is perpendicular to the circumferential direction. The roller 30 is rotatably attached to the rotating shaft 31. The roller 30 has a conical outer peripheral surface 32 centered on the rotation axis 31. The diameter of the outer circumferential surface 32 of the roller 30 increases as it is separated radially outward from the input shaft 10. At the time of driving of the motor described above, the roller 30 is also rotated at the input rotation speed about the central axis 9 together with the input shaft 10 and the arm portion 20.
可動クラウンギア40は、中心軸9を中心として回転可能であり、かつ、可撓性を有する歯車である。可動クラウンギア40は、2つのローラ30よりも出力側に位置する。図1および図2に示すように、可動クラウンギア40は、薄板状の可撓円板部41と、複数の第1側面歯42とを有する。可撓円板部41は、出力シャフト50の入力側の端部から、径方向外側へ向けて拡がる。本実施形態の可撓円板部41は、中心軸9を中心として円錐状に拡がる。また、可撓円板部41は軸方向に弾性変形可能である。複数の第1側面歯42は、それぞれ、可撓円板部41から出力側(固定クラウンギア70側)へ向けて軸方向に突出する。複数の第1側面歯42は、中心軸9を中心として円環状に並ぶ。また、複数の第1側面歯42は、周方向に一定の間隔で並ぶ。可撓円板部41の周方向の一部分が軸方向に弾性変形すると、当該周方向の一部分に位置する第1側面歯42の位置も、軸方向に移動する。
The movable crown gear 40 is a gear which is rotatable around the central axis 9 and is flexible. The movable crown gear 40 is positioned more on the output side than the two rollers 30. As shown in FIGS. 1 and 2, the movable crown gear 40 has a thin plate-like flexible disc portion 41 and a plurality of first side teeth 42. The flexible disc portion 41 spreads radially outward from the input-side end of the output shaft 50. The flexible disc portion 41 of the present embodiment expands in a conical shape around the central axis 9. The flexible disc portion 41 is elastically deformable in the axial direction. Each of the plurality of first side teeth 42 axially protrudes from the flexible disc portion 41 toward the output side (the fixed crown gear 70 side). The plurality of first side teeth 42 are annularly arranged around the central axis 9. Further, the plurality of first side teeth 42 are arranged at regular intervals in the circumferential direction. When a portion in the circumferential direction of the flexible disc portion 41 is elastically deformed in the axial direction, the position of the first side teeth 42 positioned in the portion in the circumferential direction also moves in the axial direction.
本実施形態では、可動クラウンギア40の可撓円板部41が、中心軸9に対して斜めに拡がっている。ただし、可撓円板部41は、中心軸9に対して垂直に拡がっていてもよい。
In the present embodiment, the flexible disc portion 41 of the movable crown gear 40 spreads obliquely with respect to the central axis 9. However, the flexible disc portion 41 may extend perpendicularly to the central axis 9.
出力シャフト50は、可動クラウンギア40の中央から出力側へ向けて、中心軸9に沿って延びる。出力シャフト50は、円筒状の外周面を有する。出力シャフト50は、ハウジング60の後述する出力孔620に挿入される。これにより、ハウジング60に対して出力シャフト50が、回転可能に支持される。可動クラウンギア40が中心軸9を中心として回転すると、出力シャフト50も、中心軸9を中心として回転する。本実施形態では、可動クラウンギア40と出力シャフト50とが、単一の部材となっている。ただし、可動クラウンギア40と出力シャフト50とを別部材として用意し、それらを互いに固定してもよい。
The output shaft 50 extends along the central axis 9 from the center of the movable crown gear 40 toward the output side. The output shaft 50 has a cylindrical outer peripheral surface. The output shaft 50 is inserted into an output hole 620 described later of the housing 60. Thus, the output shaft 50 is rotatably supported with respect to the housing 60. When the movable crown gear 40 rotates about the central axis 9, the output shaft 50 also rotates about the central axis 9. In the present embodiment, the movable crown gear 40 and the output shaft 50 are a single member. However, the movable crown gear 40 and the output shaft 50 may be prepared as separate members and fixed to each other.
ハウジング60は、入力回転体81および出力回転体82を支持する筐体である。ハウジング60は、入力側壁部61、出力側壁部62、および周壁部63を有する。入力側壁部61は、2本の腕部20よりも入力側において、中心軸9に対して略垂直に拡がる。入力側壁部61の中央には、入力シャフト10を通すための入力孔610が設けられている。出力側壁部62は、可動クラウンギア40よりも出力側において、中心軸9に対して略垂直に拡がる。出力側壁部62の中央には、出力シャフト50を通すための出力孔620が設けられている。周壁部63は、入力側壁部61の外周部と、出力側壁部62の外周部との間で、軸方向に円筒状に延びる。周壁部63は、2本の腕部20、2つのローラ30、および可動クラウンギア40の径方向外側に位置する。
The housing 60 is a housing that supports the input rotating body 81 and the output rotating body 82. The housing 60 has an input side wall 61, an output side wall 62, and a peripheral wall 63. The input side wall portion 61 extends substantially perpendicularly to the central axis 9 on the input side of the two arm portions 20. At the center of the input side wall portion 61, an input hole 610 for passing the input shaft 10 is provided. The output side wall portion 62 extends substantially perpendicularly to the central axis 9 on the output side relative to the movable crown gear 40. An output hole 620 for passing the output shaft 50 is provided at the center of the output side wall portion 62. The peripheral wall portion 63 axially extends in a cylindrical shape between the outer peripheral portion of the input side wall portion 61 and the outer peripheral portion of the output side wall portion 62. The peripheral wall portion 63 is located radially outward of the two arm portions 20, the two rollers 30, and the movable crown gear 40.
本実施形態では、出力側壁部62と周壁部63とが、1部材で構成されている。そして、出力側壁部62および周壁部63により構成されるカップ状の部材に対して、別部材の入力側壁部61が固定されている。ただし、入力側壁部61と周壁部63とが一部材で構成され、出力側壁部62が別部材であってもよい。また、入力側壁部61、出力側壁部62、および周壁部63が、全て別部材であってもよい。
In the present embodiment, the output side wall portion 62 and the peripheral wall portion 63 are configured by one member. Then, the input side wall portion 61 of another member is fixed to the cup-shaped member configured of the output side wall portion 62 and the peripheral wall portion 63. However, the input side wall 61 and the peripheral wall 63 may be formed as one member, and the output side wall 62 may be separate members. In addition, the input side wall 61, the output side wall 62, and the peripheral wall 63 may all be separate members.
図4は、図1および図2中のC-C位置から見たハウジング60の横断面図である。図1、図2、および図4に示すように、ハウジング60の出力側壁部62は、固定クラウンギア70を含んでいる。固定クラウンギア70は、固定円板部71と、複数の第2側面歯72とを有する。固定円板部71は、中心軸9に対して垂直に拡がっていてもよく、中心軸9に対して斜めに拡がっていてもよい。固定円板部71は、可撓円板部41に比べてはるかに可撓性が小さい。したがって、固定円板部71は、実質的に可撓性の無い剛体とみなせる。複数の第2側面歯72は、それぞれ、固定円板部71から入力側(可動クラウンギア40側)へ向けて軸方向に突出する。複数の第2側面歯72は、中心軸9を中心として円環状に並ぶ。また、複数の第2側面歯72は、周方向に一定の間隔で並ぶ。
FIG. 4 is a cross-sectional view of the housing 60 as viewed from the CC position in FIGS. 1 and 2. As shown in FIGS. 1, 2 and 4, the output sidewall 62 of the housing 60 includes a fixed crown gear 70. The fixed crown gear 70 has a fixed disk portion 71 and a plurality of second side teeth 72. The fixed disc portion 71 may extend perpendicularly to the central axis 9 or may extend obliquely with respect to the central axis 9. The fixed disc portion 71 is much less flexible than the flexible disc portion 41. Therefore, the fixed disc portion 71 can be regarded as a substantially nonflexible rigid body. Each of the plurality of second side teeth 72 axially protrudes from the fixed disc portion 71 toward the input side (the movable crown gear 40 side). The plurality of second side teeth 72 are annularly arranged around the central axis 9. Further, the plurality of second side teeth 72 are arranged at regular intervals in the circumferential direction.
図5は、減速機1の部分縦断面図である。図5中に実線で示したように、上述したローラ30は、可動クラウンギア40の可撓円板部41の入力側の面の周方向の一部分に接触する。これにより、複数の第1側面歯42のうちの一部の第1側面歯42が、ローラ30から受ける押圧によって、出力側に変位する。その結果、2つのローラ30の各々の出力側の位置において、可動クラウンギア40と固定クラウンギア70とが、互いに噛み合う。図5中に二点鎖線で示したように、周方向の他の位置では、可動クラウンギア40と固定クラウンギア70とは、互いに噛み合わない。このように、複数の第1側面歯42と、複数の第2側面歯72とは、周方向の特定の部分のみにおいて、互いに噛み合う。
FIG. 5 is a partial longitudinal sectional view of the reduction gear 1. As indicated by a solid line in FIG. 5, the above-described roller 30 contacts a part of the circumferential surface of the surface on the input side of the flexible disc portion 41 of the movable crown gear 40. Thereby, the first side teeth 42 of some of the plurality of first side teeth 42 are displaced to the output side by the pressure received from the roller 30. As a result, at the position on the output side of each of the two rollers 30, the movable crown gear 40 and the fixed crown gear 70 mesh with each other. As indicated by the two-dot chain line in FIG. 5, at other circumferential positions, the movable crown gear 40 and the fixed crown gear 70 do not mesh with each other. As described above, the plurality of first side teeth 42 and the plurality of second side teeth 72 mesh with each other only at specific portions in the circumferential direction.
減速機1の使用時には、入力シャフト10が、中心軸9を中心として、入力回転数で回転する。そうすると、入力シャフト10とともに、2本の腕部20および2つのローラ30も、中心軸9を中心として、入力回転数で回転する。2つのローラ30は、それぞれ、可動クラウンギア40との間の摩擦力によって、回転軸31を中心として自転しながら、中心軸9の周りを公転する。
When the reduction gear 1 is used, the input shaft 10 rotates around the central axis 9 at the input rotational speed. Then, together with the input shaft 10, the two arm portions 20 and the two rollers 30 also rotate around the central axis 9 at an input rotational speed. The two rollers 30 respectively revolve around the central axis 9 while rotating about the rotation axis 31 by the friction force with the movable crown gear 40.
2つのローラ30が公転すると、それに応じて、可動クラウンギア40の形状が変化する。すなわち、複数の第1側面歯42のうち、出力側へ変位する部分が、ローラ30の公転に追従して回転する。したがって、複数の第1側面歯42のうち、固定クラウンギア70の第2側面歯72と噛み合う部分が、中心軸9を中心として、入力回転数で周方向に変化する。
As the two rollers 30 revolve, the shape of the movable crown gear 40 changes accordingly. That is, a portion of the plurality of first side teeth 42 that is displaced to the output side rotates following the revolution of the roller 30. Therefore, among the plurality of first side teeth 42, the portion meshing with the second side teeth 72 of the fixed crown gear 70 changes in the circumferential direction at the input rotation speed centering on the central axis 9.
また、可動クラウンギア40の第1側面歯42の歯数と、固定クラウンギア70の第2側面歯72の歯数とは、僅かに相違する。この歯数の差によって、ローラ30が1回公転するごとに、固定クラウンギア70の同じ位置の第2側面歯72に噛み合う可動クラウンギア40の第1側面歯42の位置がずれる。これにより、固定クラウンギア70に対して可動クラウンギア40が、中心軸9を中心として、ゆっくりと回転する。その結果、可動クラウンギア40とともに出力シャフト50が、ゆっくりと回転する。このときの出力シャフト50の回転数は、入力回転数よりも低い出力回転数となる。
Further, the number of first side teeth 42 of the movable crown gear 40 and the number of second side teeth 72 of the fixed crown gear 70 are slightly different. Due to the difference in the number of teeth, the positions of the first side teeth 42 of the movable crown gear 40 meshing with the second side teeth 72 at the same position of the fixed crown gear 70 shift each time the roller 30 makes one revolution. Thereby, the movable crown gear 40 rotates slowly around the central axis 9 with respect to the fixed crown gear 70. As a result, the output shaft 50 rotates slowly with the movable crown gear 40. The rotation speed of the output shaft 50 at this time is an output rotation speed lower than the input rotation speed.
以上のように、この減速機1では、可動クラウンギア40にローラ30を接触させることで、可動クラウンギア40の周方向の一部分を軸方向に変形させる。ローラ30は、自転することによって、可動クラウンギア40に対して滑らかに移動可能である。したがって、ローラ30と可動クラウンギア40との間には、別途柔軟性を有する軸受を介在させる必要がない。これにより、減速機1の部品点数を抑えることができるとともに、減速機1を小型化できる。
As described above, in the reduction gear 1, when the roller 30 is brought into contact with the movable crown gear 40, a part of the movable crown gear 40 in the circumferential direction is axially deformed. The roller 30 can move smoothly with respect to the movable crown gear 40 by rotating. Therefore, it is not necessary to interpose a separately flexible bearing between the roller 30 and the movable crown gear 40. Thereby, the number of parts of the reduction gear 1 can be suppressed, and the reduction gear 1 can be miniaturized.
また、本実施形態では、ローラ30と同一の周方向位置にのみ腕部20が存在し、他の周方向位置には腕部が存在しない。このため、可動クラウンギア40のうち、出力側への変位量が小さい部分が、腕部20と接触する心配がない。例えば、中心軸9を中心としてローラ30から90°離れた位置において、可動クラウンギア40と腕部20とが接触する心配がない。これにより、減速機1をより小型化できる。また、減速機1の駆動時の騒音を抑えることができる。
Moreover, in this embodiment, the arm part 20 exists only in the circumferential direction position same as the roller 30, and an arm part does not exist in another circumferential direction position. For this reason, there is no concern that the portion of the movable crown gear 40 having a small amount of displacement to the output side may come in contact with the arm portion 20. For example, there is no concern that the movable crown gear 40 and the arm 20 come in contact with each other at a position 90 ° away from the roller 30 about the central axis 9. Thereby, the reduction gear 1 can be further miniaturized. Moreover, the noise at the time of the drive of the reduction gear 1 can be suppressed.
また、本実施形態では、ローラ30の姿勢が、中心軸9に対して傾斜している。具体的には、ローラ30の回転軸31が、軸方向および径方向に対して傾斜し、かつ、周方向に対して直交する方向に延びている。このようにすれば、ローラ30の外周面32のうち、可動クラウンギア40に接触する部分の径方向の周速差が、中心軸9に対する径方向の周速差と一致する。これにより、ローラ30と可動クラウンギア40との間の滑りが抑制される。その結果、減速機1におけるエネルギーロスを低減できる。
Further, in the present embodiment, the posture of the roller 30 is inclined with respect to the central axis 9. Specifically, the rotation shaft 31 of the roller 30 is inclined with respect to the axial direction and the radial direction, and extends in a direction orthogonal to the circumferential direction. In this way, the circumferential velocity difference in the radial direction of the portion of the outer circumferential surface 32 of the roller 30 that contacts the movable crown gear 40 matches the circumferential velocity difference in the radial direction with respect to the central axis 9. Thereby, the slip between the roller 30 and the movable crown gear 40 is suppressed. As a result, energy loss in the reduction gear 1 can be reduced.
ここで、図5のように、ローラ30の回転軸31を径方向内側へ延長した仮想線を「第1仮想線V1」と称する。また、ローラ30の外周面32のうち、可動クラウンギア40との接触部を径方向内側へ延長した仮想線を「第2仮想線V2」と称する。本実施形態では、第1仮想線V1と第2仮想線V2とが、中心軸9上において交差する。このようにすれば、ローラ30と可動クラウンギア40との間の滑りが、より抑制される。その結果、減速機1におけるエネルギーロスを、より低減できる。
Here, as shown in FIG. 5, a virtual line obtained by extending the rotation shaft 31 of the roller 30 radially inward is referred to as a “first virtual line V1”. In addition, a virtual line in which the contact portion with the movable crown gear 40 in the outer peripheral surface 32 of the roller 30 is extended radially inward is referred to as a "second virtual line V2". In the present embodiment, the first virtual line V1 and the second virtual line V2 intersect on the central axis 9. In this way, slippage between the roller 30 and the movable crown gear 40 is further suppressed. As a result, energy loss in the reduction gear 1 can be further reduced.
また、本実施形態では、2つのローラ30が、中心軸9の周囲において、180°間隔で配置されている。このように、複数のローラ30を周方向に等間隔に配置すれば、減速機1の動作時における重心の振れを抑制できる。なお、減速機1が有するローラ30の数は、3つ以上であってもよい。
Further, in the present embodiment, two rollers 30 are arranged at an interval of 180 ° around the central axis 9. As described above, by disposing the plurality of rollers 30 at equal intervals in the circumferential direction, it is possible to suppress the swing of the center of gravity during operation of the reduction gear 1. Note that the number of rollers 30 included in the reduction gear 1 may be three or more.
また、図5のように、ローラ30の外周面32と、固定円板部71の入力側の面との間の軸方向の距離をd1とする。また、可撓円板部41および第1側面歯42の軸方向の合計寸法をd2とする。本実施形態では、距離d1は、寸法d2よりも大きい。このようにすれば、可動クラウンギア40と固定クラウンギア70とが噛み合う位置において、第1側面歯42と第2側面歯72との間に周方向の間隙(バックラッシュ)を確保できる。これにより、複数の第1側面歯42と複数の第2側面歯72とを、滑らかに噛み合わせることができる。その結果、減速機1の動作時の騒音を、より抑制できる。
Further, as shown in FIG. 5, the axial distance between the outer peripheral surface 32 of the roller 30 and the surface on the input side of the fixed disk portion 71 is d1. Further, a total dimension in the axial direction of the flexible disc portion 41 and the first side teeth 42 is d2. In the present embodiment, the distance d1 is larger than the dimension d2. In this way, it is possible to secure a circumferential gap (backlash) between the first side teeth 42 and the second side teeth 72 at the position where the movable crown gear 40 and the fixed crown gear 70 mesh with each other. Thereby, the plurality of first side teeth 42 and the plurality of second side teeth 72 can be meshed smoothly. As a result, noise during operation of the reduction gear 1 can be further suppressed.
ローラ30の回転軸31を中心とする外径は、小さすぎると、第2側面歯72に対する第1側面歯42の噛み合う歯数が少なくなる。このため、第2側面歯72に対する第1側面歯42の噛み合いが不安定となる。一方、ローラ30の回転軸31を中心とする外径が大きすぎると、減速機1の小型化が困難となる。このため、ローラ30は、適度な外径を有していることが好ましい。ローラ30の回転軸31を中心とする外径は、可動クラウンギア40の中心軸9を中心とする外径の、1/10倍以上かつ1/2倍以下とすることが好ましい。
If the outer diameter of the roller 30 around the rotation shaft 31 is too small, the number of meshing teeth of the first side teeth 42 with respect to the second side teeth 72 decreases. Therefore, the engagement of the first side teeth 42 with the second side teeth 72 becomes unstable. On the other hand, if the outer diameter of the roller 30 around the rotation shaft 31 is too large, the reduction in size of the reduction gear 1 becomes difficult. For this reason, the roller 30 preferably has an appropriate outer diameter. The outer diameter of the roller 30 around the rotation shaft 31 is preferably 1/10 or more and 1/2 or less of the outer diameter around the central axis 9 of the movable crown gear 40.
減速機1を構成する各部材の材料には、例えば、鉄などの金属が用いられる。ただし、一部の部材または全部の部材を、樹脂製としてもよい。樹脂を用いれば、金属を用いる場合よりも、減速機1を軽量化できる。例えば、可動クラウンギア40および固定クラウンギア70の少なくとも一方を、樹脂製としてもよい。これらのクラウンギア40,70は、側面歯が軸方向に突出する。このため、軸方向に組み合わせる金型を用いた射出成形によって、クラウンギア40,70を容易に製造できる。特に、可動クラウンギア40を樹脂製にすれば、可撓円板部41の可撓性を得やすい。
As a material of each member which comprises the reduction gear 1, metal, such as iron, is used, for example. However, some or all of the members may be made of resin. If resin is used, the reduction gear 1 can be reduced in weight as compared to the case of using metal. For example, at least one of the movable crown gear 40 and the fixed crown gear 70 may be made of resin. Side teeth of these crown gears 40, 70 project in the axial direction. Therefore, the crown gears 40 and 70 can be easily manufactured by injection molding using a mold combined in the axial direction. In particular, if the movable crown gear 40 is made of resin, it is easy to obtain the flexibility of the flexible disc portion 41.
<2.変形例>
以上、本発明の一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。 <2. Modified example>
As mentioned above, although one embodiment of the present invention was described, the present invention is not limited to the above-mentioned embodiment.
以上、本発明の一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。 <2. Modified example>
As mentioned above, although one embodiment of the present invention was described, the present invention is not limited to the above-mentioned embodiment.
図6は、一変形例に係る減速機1Aの縦断面図である。図6の例では、減速機1Aの中央に、中空シャフト80Aが設けられている。中空シャフト80Aは、円筒状の部材であり、中心軸9Aに沿って配置される。入力シャフト10Aの内周面と、中空シャフト80Aの外周面との間には、軸受12Aが介在する。したがって、入力シャフト10Aと中空シャフト80Aとは、中心軸9Aを中心として、互いに相対回転可能である。軸受12Aには、例えばすべり軸受が用いられる。また、中空シャフト80Aは、出力シャフト50Aに、ねじ51Aによって固定されている。このため、中空シャフト80Aは、出力シャフト50Aとともに、中心軸9Aを中心として、出力回転数で回転する。
FIG. 6 is a longitudinal sectional view of a speed reducer 1A according to a modification. In the example of FIG. 6, a hollow shaft 80A is provided at the center of the reduction gear 1A. The hollow shaft 80A is a cylindrical member and is disposed along the central axis 9A. A bearing 12A is interposed between the inner peripheral surface of the input shaft 10A and the outer peripheral surface of the hollow shaft 80A. Therefore, the input shaft 10A and the hollow shaft 80A can rotate relative to each other about the central axis 9A. For example, a sliding bearing is used for the bearing 12A. The hollow shaft 80A is fixed to the output shaft 50A by a screw 51A. Therefore, the hollow shaft 80A, together with the output shaft 50A, rotates at an output rotational speed centering on the central axis 9A.
腕部20A、ローラ30A、可動クラウンギア40A、ハウジング60A、および固定クラウンギア70Aの構造は、上記の実施形態と同等である。この減速機1Aは、入力シャフト10Aおよび出力シャフト50Aよりも径方向外側のみにおいて、動力の伝達が行われる。このため、この図6の例のように、入力シャフト10Aおよび出力シャフト50Aの径方向内側に、中空シャフト80Aを配置することができる。このようにすれば、中空シャフト80Aの径方向内側の空間を有効に利用できる。例えば、中空シャフト80の内側に、減速機を支持するための支持シャフト90Aを通すことができる。あるいは、減速機1Aが搭載される装置の電気配線を、中空シャフト80Aの内側に通すこともできる。
The structures of the arm 20A, the roller 30A, the movable crown gear 40A, the housing 60A, and the fixed crown gear 70A are the same as those in the above embodiment. In the reduction gear 1A, power transmission is performed only on the radially outer side of the input shaft 10A and the output shaft 50A. Therefore, as shown in the example of FIG. 6, the hollow shaft 80A can be disposed radially inward of the input shaft 10A and the output shaft 50A. In this way, the space inside the hollow shaft 80A in the radial direction can be effectively used. For example, inside the hollow shaft 80, a support shaft 90A for supporting the speed reducer can be passed. Alternatively, the electrical wiring of the device on which the reduction gear 1A is mounted can be passed inside the hollow shaft 80A.
特に、図6の例では、中空シャフト80Aが、入力シャフト10Aではなく、出力シャフト50Aに固定されている。このようにすれば、中空シャフト80Aの回転数が、入力回転数よりも低い出力回転数となる。したがって、中空シャフト80Aの回転数を抑えることができる。これにより、中空シャフト80Aの径方向内側の空間を、より利用しやすくなる。
In particular, in the example of FIG. 6, the hollow shaft 80A is fixed not to the input shaft 10A but to the output shaft 50A. In this manner, the rotational speed of the hollow shaft 80A is lower than the input rotational speed. Therefore, the rotational speed of the hollow shaft 80A can be suppressed. This makes it easier to use the radially inner space of the hollow shaft 80A.
また、減速機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、上記の実施形態や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 reduction gear may be different from the shape shown in each drawing of the present application. In addition, each element appearing in the above-described embodiment and modification may be combined appropriately as long as no contradiction occurs.
本出願は、2017年7月7日に出願された日本出願である特願2017-134057号にもとづく優先権を主張し、当該日本出願に記載された全ての記載内容を援用するものである。
This application claims priority based on Japanese Patent Application No. 2017-134057, which is a Japanese application filed on Jul. 7, 2017, and uses the entire contents described in the Japanese application.
本発明は、減速機に利用できる。
The present invention is applicable to a reduction gear.
1,1A 減速機
9,9A 中心軸
10,10A 入力シャフト
11 軸受
12A 軸受
20,20A 腕部
30,30A ローラ
31 回転軸
32 外周面
40,40A 可動クラウンギア
41 可撓円板部
42 第1側面歯
50,50A 出力シャフト
60,60A ハウジング
61 入力側壁部
62 出力側壁部
63 周壁部
70,70A 固定クラウンギア
71 固定円板部
72 第2側面歯
80A 中空シャフト
81 入力回転体
82 出力回転体
610 入力孔
620 出力孔
V1 第1仮想線
V2 第2仮想線
1, 1A reduction gear 9, 9A central shaft 10, 10A input shaft 11 bearing 12A bearing 20, 20A arm 30, 30A roller 31 rotating shaft 32 outer peripheral surface 40, 40A movable crown gear 41 flexible disk portion 42 first side surface Tooth 50, 50A Output shaft 60, 60A Housing 61 Input side wall portion 62 Output side wall portion 63 Peripheral wall portion 70, 70A Fixed crown gear 71 Fixed disk portion 72 Second side teeth 80A Hollow shaft 81 Input rotating body 82 Output rotating body 610 Input Hole 620 output hole V1 first phantom line V2 second phantom line
9,9A 中心軸
10,10A 入力シャフト
11 軸受
12A 軸受
20,20A 腕部
30,30A ローラ
31 回転軸
32 外周面
40,40A 可動クラウンギア
41 可撓円板部
42 第1側面歯
50,50A 出力シャフト
60,60A ハウジング
61 入力側壁部
62 出力側壁部
63 周壁部
70,70A 固定クラウンギア
71 固定円板部
72 第2側面歯
80A 中空シャフト
81 入力回転体
82 出力回転体
610 入力孔
620 出力孔
V1 第1仮想線
V2 第2仮想線
1,
Claims (11)
- 入力回転数の回転運動を、前記入力回転数よりも低い出力回転数の回転運動に変換する減速機であって、
中心軸を中心として、前記入力回転数で回転する入力回転体と、
前記中心軸を中心として、前記出力回転数で回転する出力回転体と、
前記入力回転体および前記出力回転体を支持するハウジングと、
を備え、
前記入力回転体は、
入力シャフトと、
前記入力シャフトから径方向外側へ向けて延びる腕部と、
前記腕部に支持された回転軸を中心として回転するローラと、
を含み、
前記出力回転体は、
前記中心軸に対して垂直または斜めに拡がるとともに、可撓性を有し、前記中心軸を中心として円環状に並ぶ複数の第1側面歯を有する可動クラウンギアと、
前記可動クラウンギアの中央から前記中心軸に沿って延びる出力シャフトと、
を含み、
前記ハウジングは、
前記中心軸に対して垂直または斜めに拡がり、前記中心軸を中心として円環状に並ぶ複数の第2側面歯を有する固定クラウンギア
を含み、
前記可動クラウンギアの前記第1側面歯の歯数と、前記固定クラウンギアの前記第2側面歯の歯数とが、相違し、
前記可動クラウンギアの周方向の一部分に、前記ローラが接触し、前記ローラから受ける押圧によって、前記固定クラウンギアと前記可動クラウンギアとが部分的に噛み合い、
前記入力回転体の回転に伴い、前記可動クラウンギアと前記固定クラウンギアとの噛み合う位置が、前記中心軸を中心として、前記入力回転数で周方向に変化し、
前記第1側面歯と前記第2側面歯との歯数の差によって、前記固定クラウンギアに対して前記可動クラウンギアが、前記出力回転数で回転する減速機。 A reduction gear for converting rotational motion of an input rotational speed into rotational motion of an output rotational speed lower than the input rotational speed,
An input rotating body that rotates at the input rotation speed about a central axis;
An output rotating body that rotates at the output rotation speed about the central axis;
A housing supporting the input rotary body and the output rotary body;
Equipped with
The input rotator is
With the input shaft,
An arm extending radially outward from the input shaft;
A roller that rotates about a rotation axis supported by the arm;
Including
The output rotator is
A movable crown gear that has a plurality of first side teeth that extend in a direction perpendicular to or obliquely with respect to the central axis and that has flexibility and that is annularly arranged around the central axis;
An output shaft extending along the central axis from the center of the movable crown gear;
Including
The housing is
A fixed crown gear that extends perpendicularly or obliquely to the central axis and has a plurality of second side teeth annularly arranged around the central axis,
The number of teeth of the first side teeth of the movable crown gear and the number of teeth of the second side teeth of the fixed crown gear are different,
The roller is in contact with a part of the movable crown gear in the circumferential direction, and the fixed crown gear and the movable crown gear are partially meshed by pressure received from the roller.
With the rotation of the input rotary body, the meshing position of the movable crown gear and the fixed crown gear changes in the circumferential direction at the input rotational speed centering on the central axis,
A reduction gear in which the movable crown gear rotates at the output rotational speed with respect to the fixed crown gear due to a difference in the number of teeth between the first side teeth and the second side teeth. - 請求項1に記載の減速機であって、
前記可動クラウンギアは、前記中心軸を中心として円錐状に拡がる減速機。 The speed reducer according to claim 1, wherein
The movable crown gear is a reduction gear that is expanded conically around the central axis. - 請求項1または請求項2に記載の減速機であって、
前記ローラの前記回転軸は、前記中心軸に対する周方向に対して直交する方向に延びる減速機。 The speed reducer according to claim 1 or 2, wherein
The reduction gear extending in a direction orthogonal to a circumferential direction with respect to the central axis, wherein the rotation axis of the roller extends. - 請求項3に記載の減速機であって、
前記ローラの前記回転軸を径方向内側へ延長した第1仮想線と、
前記ローラの外周面のうち、前記可動クラウンギアとの接触部を径方向内側へ延長した第2仮想線とが、
前記中心軸上において交差する減速機。 The speed reducer according to claim 3, wherein
A first imaginary line in which the rotation axis of the roller is extended radially inward;
A second imaginary line in which a contact portion with the movable crown gear in the outer peripheral surface of the roller is extended radially inward;
A speed reducer intersecting on the central axis. - 請求項1から請求項4までのいずれか1項に記載の減速機であって、
前記入力回転体は、複数の前記ローラを有し、
複数の前記ローラは、前記中心軸の周囲において、周方向に等間隔に配置されている減速機。 The speed reducer according to any one of claims 1 to 4, wherein
The input rotating body has a plurality of the rollers,
The plurality of rollers are arranged at equal intervals in a circumferential direction around the central axis. - 請求項5に記載の減速機であって、
前記入力回転体は、2つの前記ローラを有し、
2つの前記ローラは、前記中心軸の周囲において、180°間隔で配置されている減速機。 The speed reducer according to claim 5, wherein
The input rotator comprises two of the rollers,
A reduction gear, wherein the two rollers are arranged at an interval of 180 ° around the central axis. - 請求項1から請求項6までのいずれか1項に記載の減速機であって、
前記可動クラウンギアと前記固定クラウンギアとが噛み合う位置で、
前記第1側面歯と前記第2側面歯との間に、周方向に間隙が存在する減速機。 The speed reducer according to any one of claims 1 to 6, wherein
At a position where the movable crown gear and the fixed crown gear mesh,
A reduction gear having a circumferential gap between the first side teeth and the second side teeth. - 請求項1から請求項7までのいずれか1項に記載の減速機であって、
前記ローラの前記回転軸を中心とする外径は、前記可動クラウンギアの前記中心軸を中心とする外径の、1/10倍以上かつ1/2倍以下である減速機。 The speed reducer according to any one of claims 1 to 7, wherein
The reduction gear whose outer diameter centering on the said rotating shaft of the said roller is 1/10 times or more and 1/2 times or less of the outer diameter centering on the said central axis of the said movable crown gear. - 請求項1から請求項8までのいずれか1項に記載の減速機であって、
前記可動クラウンギアおよび前記固定クラウンギアの少なくとも一方は、樹脂製である減速機。 A reduction gear according to any one of claims 1 to 8, wherein
The reduction gear in which at least one of the movable crown gear and the fixed crown gear is made of resin. - 請求項9に記載の減速機であって、
少なくとも前記可動クラウンギアは樹脂製である減速機。 The speed reducer according to claim 9, wherein
The reduction gear at least the movable crown gear is made of resin. - 請求項1から請求項10までのいずれか1項に記載の減速機であって、
前記出力回転体は、前記可動クラウンギアと前記出力シャフトとを含む単一の部材である減速機。
The speed reducer according to any one of claims 1 to 10, wherein
The reduction gear, wherein the output rotating body is a single member including the movable crown gear and the output shaft.
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Citations (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS4428570Y1 (en) * | 1969-05-20 | 1969-11-27 | ||
JPS59191458U (en) * | 1983-06-08 | 1984-12-19 | セイコーエプソン株式会社 | Thrust type harmonic drive reducer |
JPS60129455A (en) * | 1983-12-14 | 1985-07-10 | Matsushita Electric Works Ltd | Power transmission device |
JPS6389453U (en) * | 1986-11-29 | 1988-06-10 | ||
JPH04370445A (en) * | 1991-06-20 | 1992-12-22 | Koyo Seiko Co Ltd | Harmonic gear device |
WO2016027323A1 (en) * | 2014-08-20 | 2016-02-25 | 株式会社ハーモニック・ドライブ・システムズ | Facing-type strain wave gearing |
WO2016027324A1 (en) * | 2014-08-20 | 2016-02-25 | 株式会社ハーモニック・ドライブ・システムズ | Facing-type strain wave gearing |
Family Cites Families (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
KR100189281B1 (en) * | 1994-12-27 | 1999-06-01 | 미따라이 하지메 | Speed reducer |
JP4428570B2 (en) | 2005-06-22 | 2010-03-10 | 株式会社不二越 | Tape wrap device |
JP2012002237A (en) * | 2010-06-13 | 2012-01-05 | Institute Of National Colleges Of Technology Japan | Small reduction gear and small diameter high torque motor using the same |
TWI460365B (en) * | 2012-06-08 | 2014-11-11 | Univ Nat Formosa | Rigid Ring Gear and Flexible Planetary Wheel of Harmonic Reducer and Its Method |
JP2014047797A (en) * | 2012-08-29 | 2014-03-17 | Mitsubishi Heavy Ind Ltd | Actuator |
CN105473892B (en) * | 2013-08-06 | 2018-04-06 | 谐波传动***有限公司 | Revolving actuator and harmonic drive unit |
JP5968528B2 (en) * | 2013-09-11 | 2016-08-10 | 株式会社ハーモニック・ドライブ・システムズ | Wave generator and wave gear device |
-
2017
- 2017-07-07 JP JP2017134057A patent/JP2019015365A/en active Pending
-
2018
- 2018-06-05 TW TW107119308A patent/TWI683067B/en active
- 2018-06-28 CN CN201880045109.3A patent/CN110869644B/en active Active
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Patent Citations (7)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS4428570Y1 (en) * | 1969-05-20 | 1969-11-27 | ||
JPS59191458U (en) * | 1983-06-08 | 1984-12-19 | セイコーエプソン株式会社 | Thrust type harmonic drive reducer |
JPS60129455A (en) * | 1983-12-14 | 1985-07-10 | Matsushita Electric Works Ltd | Power transmission device |
JPS6389453U (en) * | 1986-11-29 | 1988-06-10 | ||
JPH04370445A (en) * | 1991-06-20 | 1992-12-22 | Koyo Seiko Co Ltd | Harmonic gear device |
WO2016027323A1 (en) * | 2014-08-20 | 2016-02-25 | 株式会社ハーモニック・ドライブ・システムズ | Facing-type strain wave gearing |
WO2016027324A1 (en) * | 2014-08-20 | 2016-02-25 | 株式会社ハーモニック・ドライブ・システムズ | Facing-type strain wave gearing |
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CN110869644B (en) | 2023-03-10 |
TW201907097A (en) | 2019-02-16 |
TWI683067B (en) | 2020-01-21 |
JP2019015365A (en) | 2019-01-31 |
CN110869644A (en) | 2020-03-06 |
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