CN119072593A - Harmonic gear device and industrial robot - Google Patents
Harmonic gear device and industrial robot Download PDFInfo
- Publication number
- CN119072593A CN119072593A CN202380035674.2A CN202380035674A CN119072593A CN 119072593 A CN119072593 A CN 119072593A CN 202380035674 A CN202380035674 A CN 202380035674A CN 119072593 A CN119072593 A CN 119072593A
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- CN
- China
- Prior art keywords
- peripheral surface
- cam
- bearing
- outer peripheral
- gear
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
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Classifications
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B25—HAND TOOLS; PORTABLE POWER-DRIVEN TOOLS; MANIPULATORS
- B25J—MANIPULATORS; CHAMBERS PROVIDED WITH MANIPULATION DEVICES
- B25J5/00—Manipulators mounted on wheels or on carriages
- B25J5/02—Manipulators mounted on wheels or on carriages travelling along a guideway
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- B—PERFORMING OPERATIONS; TRANSPORTING
- B25—HAND TOOLS; PORTABLE POWER-DRIVEN TOOLS; MANIPULATORS
- B25J—MANIPULATORS; CHAMBERS PROVIDED WITH MANIPULATION DEVICES
- B25J9/00—Programme-controlled manipulators
- B25J9/10—Programme-controlled manipulators characterised by positioning means for manipulator elements
- B25J9/102—Gears specially adapted therefor, e.g. reduction gears
- B25J9/1025—Harmonic drives
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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
- F16C—SHAFTS; FLEXIBLE SHAFTS; ELEMENTS OR CRANKSHAFT MECHANISMS; ROTARY BODIES OTHER THAN GEARING ELEMENTS; BEARINGS
- F16C35/00—Rigid support of bearing units; Housings, e.g. caps, covers
- F16C35/04—Rigid support of bearing units; Housings, e.g. caps, covers in the case of ball or roller bearings
- F16C35/06—Mounting or dismounting of ball or roller bearings; Fixing them onto shaft or in housing
- F16C35/063—Fixing them on the shaft
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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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- Engineering & Computer Science (AREA)
- Mechanical Engineering (AREA)
- General Engineering & Computer Science (AREA)
- Robotics (AREA)
- Retarders (AREA)
- Mounting Of Bearings Or Others (AREA)
- Manipulator (AREA)
Abstract
The harmonic gear device is provided with an internal gear (3), an external gear (5), and a harmonic generator (6). The harmonic generator (6) is provided with a cam (31) having a non-circular outer peripheral surface (31 a), and a 4 th bearing (32) disposed between the inner peripheral surface (21 a) of the external gear (5) and the outer peripheral surface (31 a) of the cam (31). The 4 th bearing (32) is provided with an outer ring (33), an inner ring (34), a plurality of balls (35), and a retainer (36). The harmonic gear device is provided with a restriction part (37), wherein the restriction part (37) is in contact with the inner ring (34) in a manner of avoiding contact with the retainer (36), and restricts movement of the 4 th bearing (32) in the direction of the rotation axis (C). The restricting portion (37) is formed so that the protruding length in the radial direction protruding from the outer peripheral surface (31 a) of the cam (31) is uniform over the entire periphery of the outer peripheral surface (31 a).
Description
Technical Field
The present invention relates to a harmonic gear device and an industrial robot.
The present application claims priority based on japanese patent application No. 2022-075005, filed on 28 at 2022, 4, the contents of which are incorporated herein by reference.
Background
The harmonic gear device includes an internal gear, an external gear that is partially meshed with the internal gear and has elasticity, and a harmonic generator that is in contact with an inner peripheral surface of the external gear. The harmonic generator moves the meshing position between the internal gear and the external gear in the circumferential direction about the rotation axis. The harmonic generator includes a cam having an outer peripheral surface of an elliptical shape having a major axis and a minor axis as viewed in the rotation axis direction, and a bearing disposed between the inner peripheral surface of the external gear and the outer peripheral surface of the cam.
As the bearing, for example, a deep groove ball bearing is used. Such a bearing has an elliptical shape as viewed in the rotation axis direction, corresponding to the shape of the outer peripheral surface of the cam. The bearing includes, for example, an outer ring, an inner ring, rolling elements disposed between the outer ring and the inner ring, and a cage that holds the rolling elements.
When the harmonic gear device is driven, a thrust force is generated in the harmonic generator due to elastic deformation of the external gear. If the harmonic generator moves in the rotation axis direction due to the thrust force, there is a possibility that the internal gear and the external gear mesh with each other improperly. There is a possibility that the load on the bearing is excessive and the bearing is broken. If movement of the harmonic generator in the rotation axis direction is to be restricted, for example, in the rotation axis direction of the cam, the bearing moves relative to the cam. Accordingly, a technique for improving the adhesive strength between the cam and the bearing by applying an adhesive between the cam and the bearing has been disclosed. A technique is disclosed in which a flange is provided to restrict the retainer from flying out of the bearing when thrust is generated.
Prior art literature
Patent literature
Patent document 1 International publication No. 2020/044524
Disclosure of Invention
Problems to be solved by the invention
However, in the above-mentioned conventional technique, there is a problem that it is difficult to satisfy the adhesive strength between the cam and the bearing due to the entry of oil, foreign matters, and the like.
If a flange is provided to restrict the retainer from coming out of the bearing, there is a possibility that not only the lubricity of the bearing is hindered but also the retainer is crushed to damage the bearing.
For example, when the flange portion is formed in a perfect circle as viewed in the rotation axis direction, the bearing has an elliptical shape as viewed in the rotation axis direction. Therefore, the contact range of the flange portion with the bearing is not uniform over the entire circumference. That is, for example, on the short shaft side of the bearing, the flange portion is in contact with the inner ring of the bearing. In contrast, the flange portion may not contact the inner ring of the bearing on the long axis side of the bearing. Therefore, there is a possibility that the inner ring of the bearing is bent when the inner ring of the bearing is strongly pressed against the flange portion.
The invention provides a harmonic gear device and an industrial robot capable of limiting movement of a bearing in a rotation axis direction and preventing damage of the bearing.
Solution for solving the problem
A harmonic gear device according to an aspect of the present invention includes an internal gear, an external gear disposed radially inward of the internal gear and having elasticity, a harmonic generator in contact with an inner peripheral surface of the external gear, the external gear being partially meshed with the internal gear and being relatively rotated about a rotation axis with respect to the internal gear, the harmonic generator moving a meshing position between the internal gear and the external gear in a circumferential direction about the rotation axis, the harmonic generator including a cam having a non-circular outer peripheral surface, and a bearing disposed between the inner peripheral surface of the external gear and the outer peripheral surface of the cam, the bearing including an outer ring in contact with the inner peripheral surface of the external gear, an inner ring in contact with the outer peripheral surface of the cam, a plurality of rolling elements disposed between the outer ring and the inner ring, and a retainer holding the plurality of rolling elements, the harmonic gear device including a restricting portion in contact with the inner ring of the bearing so as to avoid contact with the retainer, the restricting portion protruding from the entire length of the cam in a radial direction of the entire peripheral surface of the cam being restricted from protruding from the outer peripheral surface of the cam.
With this configuration, the movement of the bearing in the rotation axis direction can be restricted while avoiding contact with the retainer by the restricting portion. Therefore, the movement of the bearing in the rotation axis direction can be restricted, and damage to the retainer of the bearing can be prevented.
The restricting portion is formed so that a radial projecting length of the restricting portion projecting from an outer peripheral surface of the cam is uniform over an entire periphery of the outer peripheral surface. Therefore, the restricting portion is uniformly in contact with the inner ring of the bearing over the entire circumference of the inner ring of the bearing. Therefore, even when the inner ring of the bearing is strongly pressed against the restricting portion, the inner ring of the bearing can be prevented from being bent, and damage to the bearing can be prevented.
In the above configuration, the restricting portion may be formed in a flange shape protruding radially outward from the outer peripheral surface of the cam, and the outer peripheral surface of the restricting portion may be opposed to the retainer with a gap therebetween in a radial direction.
In the above configuration, the outer peripheral surface of the cam and the outer peripheral surface of the restricting portion may be formed in an elliptical shape or an oblong shape having a major axis and a minor axis, respectively, as viewed in the rotation axis direction, the major axis of the cam and the major axis of the restricting portion may be aligned, and the minor axis of the cam and the minor axis of the restricting portion may be aligned.
In the above configuration, when the outer diameter of an arbitrary portion of the cam is defined as D1, the outer diameter of a portion of the restricting portion identical to the arbitrary portion of the cam is defined as D2, and the thickness in the radial direction of the inner ring is defined as T, the outer diameters D1, D2 and the thickness T may satisfy (D2-D1)/2T.
In the above configuration, the restricting portions may be provided on both sides of the inner ring in the rotation axis direction.
In the above configuration, the restricting portion may be integrally formed with the cam.
A harmonic gear device according to another aspect of the present invention includes an internal gear, an external gear disposed radially inward of the internal gear and having elasticity, and a harmonic generator in contact with an inner circumferential surface of the external gear, the external gear being partially meshed with the internal gear and rotating relatively to the internal gear about a rotation axis, the harmonic generator moving a meshing position between the internal gear and the external gear in a circumferential direction about the rotation axis, the harmonic generator including a cam having an outer circumferential surface, and a bearing disposed between the inner circumferential surface of the external gear and the outer circumferential surface of the cam, the outer circumferential surface of the cam being formed in any one of an elliptical shape and a long circular shape having a major axis and a minor axis as viewed in a direction of the rotation axis, the bearing including an outer ring in contact with the inner circumferential surface of the external gear, an inner ring in contact with the outer circumferential surface of the cam, a plurality of rolling bodies disposed between the outer ring, and a retainer holding the plurality of rolling bodies, the rolling bodies being formed in a manner that the major axis and the major axis of the cam is uniformly projected from the outer circumferential surface of the cam is restricted in a radial direction, the major axis of the cam is formed in a straight line, and a projection of the major axis of the cam is restricted from the outer circumferential surface, and a projection of the cam is formed in a radial direction from the major axis of the cam is restricted from the major axis, and a projection of the major axis is formed in a radial direction of the major axis of the cam is located in the circumferential surface of the cam is restricted from the major axis, an outer peripheral surface of the restricting portion faces the retainer with a gap therebetween in a radial direction, and the restricting portion contacts the inner ring of the bearing to restrict movement of the bearing in the rotation axis direction.
With this configuration, the restricting portion can be configured simply, and the restricting portion can prevent contact with the retainer and restrict movement of the bearing in the rotation axis direction. Therefore, the movement of the bearing in the rotation axis direction can be restricted, and damage to the retainer of the bearing can be prevented.
The restriction portion can be easily formed so that the protruding length in the radial direction from the outer peripheral surface of the cam is uniform over the entire periphery of the outer peripheral surface. Therefore, the restricting portion is uniformly in contact with the inner ring of the bearing over the entire circumference of the inner ring of the bearing. Therefore, even when the inner ring of the bearing is strongly pressed against the restricting portion, the inner ring of the bearing can be prevented from being bent, and damage to the bearing can be prevented.
The industrial robot according to another aspect of the present invention includes a power generating unit that generates a rotational force, a harmonic gear device that includes an input unit and an output unit, and a target member that is attached to the output unit of the harmonic gear device, the output unit changes a rotational speed of the input unit to output the rotational force, the harmonic gear device includes an internal gear, an external gear that is disposed radially inside the internal gear and has elasticity, and a harmonic generator that is in contact with an inner peripheral surface of the external gear, the external gear and the internal gear are partially engaged with each other and relatively rotated about a rotational axis with respect to the internal gear, and that functions as one of the input unit and the output unit, the harmonic generator moves an engagement position between the internal gear and the internal gear in a circumferential direction about the rotational axis, the harmonic generator includes a cam that has a non-circular outer peripheral surface, and a bearing that is disposed between the inner peripheral surface of the external gear and the cam, the external peripheral surface of the external gear and the cam, and a retainer that is disposed between the external peripheral surface of the external gear and the external ring and the inner ring of the external gear, and the retainer that is in contact with the outer ring, and the retainer that is disposed between the external ring and the outer ring and the retainer that is in contact with the outer ring and the roller, the restricting portion is formed so that a protruding length in a radial direction protruding from the outer peripheral surface of the cam is uniform over an entire circumference of the outer peripheral surface of the cam, and restricts movement of the bearing in the rotation axis direction.
With this configuration, it is possible to provide an industrial robot that restricts movement of the bearing in the rotation axis direction and prevents damage to the bearing.
ADVANTAGEOUS EFFECTS OF INVENTION
The harmonic gear device and the industrial robot can limit the movement of the bearing in the direction of the rotation axis, and prevent the damage of the bearing.
Drawings
Fig. 1 is a schematic configuration diagram of an industrial robot according to an embodiment of the present invention.
Fig. 2 is a cross-sectional view of a harmonic gear device along a rotational axis in an embodiment of the invention.
Fig. 3 is a top view of the cam in the embodiment of the present invention as seen from above, and corresponds to a cross-sectional view taken along line III-III of fig. 2.
Fig. 4 is a cross-sectional view along the rotation axis showing a modification of the restricting portion in the embodiment of the present invention.
Detailed Description
Next, embodiments of the present invention will be described based on the drawings.
< Industrial robot >
Fig. 1 is a schematic configuration diagram of an industrial robot 100.
As shown in fig. 1, the industrial robot 100 includes a travel rail 101, a base unit (an example of an object member of the claims) 102 movably provided to the travel rail 101, and a robot body 103 provided to the base unit 102. Motors 106 and 113a to 113f with reducers are provided to the base unit 102 and the joints 111 and 112a to 112e of the arms (an example of the object members of the claims) 115a to 115d of the robot body 103, respectively.
The motors 106, 113a to 113f with speed reducers have the same structure. The decelerator-equipped motor 106 provided to the base unit 102 among the decelerator-equipped motors 106, 113a to 113f will be described as an example. The motor 106 with a speed reducer includes the harmonic gear device 1 and an electric motor (an example of a power generating unit in claims) 110 that imparts power to the harmonic gear device 1.
In fig. 1, the illustration of other motors 113a to 113f with speed reducers is simplified, and reference numerals of the harmonic gear device and the electric motor are omitted. In the following description, only the motor 106 with a speed reducer of the base unit 102 will be described, and the descriptions of the other motors 113a to 113f with speed reducers will be omitted.
The industrial robot 100 drives the motors 106 and 113a to 113f with speed reducers to drive the robot body 103 to travel on the travel rail 101 or to take various postures on the arms 115a to 115 d.
< Harmonic Gear device >
Next, the harmonic gear device 1 will be described with reference to fig. 2 to 3.
Fig. 2 is a sectional view of the harmonic gear device 1 along the rotation axis C. In fig. 2, the lower half is not shown centering on the rotation axis C. In the following description, the direction of the rotation axis C will be simply referred to as the axial direction, the direction around the rotation axis C will be simply referred to as the circumferential direction, and the radial direction of the harmonic gear device 1 orthogonal to the axial direction and the circumferential direction will be simply referred to as the radial direction. In the following description, the motor 106 with a speed reducer is referred to as an up direction and a down direction in a state of being fixed to the base unit 102.
As shown in fig. 2, the harmonic gear device 1 includes a housing 2, an internal gear 3 and a1 st bearing 4 fixed to the housing 2, an external gear 5 provided to the inner side in the radial direction of the internal gear 3, a harmonic generator 6 provided to the inner side in the radial direction of the external gear 5, an output plate (an example of an output portion of claims) 7 fixed to the external gear 5 together with the 1 st bearing 4, and a speed reducer shaft 8 coupled to a motor shaft 110a of the electric motor 110 to impart a rotational force to the harmonic generator 6. The motor shaft 110a of the electric motor 110 is coupled to the upper end (right side in fig. 2) of the decelerator shaft 8. An output plate 7 is disposed at the lower end (left side in fig. 2) of the decelerator shaft 8.
< Shell >
The housing 2 is fixed to the base unit 102 by a bolt, not shown. The housing 2 is formed in a disk shape. However, the shape of the housing 2 is not limited to a disk shape. A cylindrical boss portion 2c is integrally formed at the center of the housing 2 in the radial direction. The position of the motor 106 with a speed reducer with respect to the base unit 102 is determined by fitting the boss portion 2c with, for example, a through hole 102a formed in the base unit 102.
A stepped through hole 9 is formed in the hub 2c at a large part of the center in the radial direction. A speed reducer shaft 8 is inserted into the stepped through hole 9.
The stepped through hole 9 has a small diameter hole 9a formed in an upper portion (on the side of the electric motor 110), and a large diameter hole 9b formed in a lower portion (on the side opposite to the electric motor 110) than the small diameter hole 9 a. The large diameter hole 9b is connected to the small diameter hole 9a via a step 9 c. The large diameter hole 9b has an inner diameter larger than that of the small diameter hole 9 a.
A seal portion 10 for ensuring the sealing property between the hub portion 2c and the speed reducer shaft 8 is attached to the small diameter hole 9 a. As the seal portion 10, various seal members such as a rubber oil seal can be used.
The 2 nd bearing 11 is fitted into the large diameter hole 9 b. The 2 nd bearing 11 rotatably supports the upper end of the speed reducer shaft 8 on the hub portion 2c. As the 2 nd bearing 11, for example, a deep groove ball bearing is used. However, not limited thereto, a variety of bearings may be used. In the present embodiment, the outer ring 11a of the 2 nd bearing 11 is brought into contact with the stepped portion 9c of the stepped through hole 9, whereby the 2 nd bearing 11 is positioned in the axial direction of the boss portion 2c.
A gear housing recess 12 is formed in a majority of the center in the radial direction on the lower surface 2a of the housing 2. The gear housing recess 12 opens downward and radially inward. The internal gear 3 is accommodated in the gear accommodating recess 12. A plurality of through holes 2b penetrating in the axial direction are formed in the outer peripheral portion of the bottom surface 12a of the gear housing recess 12. The plurality of through holes 2b are arranged at equal intervals in the circumferential direction. The plurality of through holes 2b are used to fix the housing 2 to the base unit 102 together with the internal gear 3 and the 1 st bearing 4. Bolts, not shown, are inserted into the through holes 2b from above.
< Internal Gear >
The internal gear 3 is formed of a rigid body in a circular ring shape. The axial center of the internal gear 3 coincides with the rotation axis C. The outer peripheral surface of the internal gear 3 is fitted to the inner peripheral surface of the gear accommodating recess 12 of the housing 2. The upper surface 3a of the internal gear 3 abuts against the bottom surface 12a of the gear housing recess 12, whereby the internal gear 3 is positioned in the axial direction of the housing 2. The inner gear 3 has a through hole 3f penetrating in the axial direction. The through-hole 3f and the through-hole 2b of the housing 2 are formed coaxially with each other. These through holes 3f communicate with corresponding through holes 2b of the housing 2, respectively.
An O-ring groove 3b is formed in an inner peripheral portion of the upper surface 3a of the inner gear 3. An O-ring 13 is attached to the O-ring groove 3b. The O-ring 13 seals between the internal gear 3 and the housing 2.
An inner tooth 3c is formed on the entire inner peripheral surface of the inner gear 3. The external teeth 5a of the external gear 5, which will be discussed later, mesh with the internal teeth 3c.
A bearing accommodating recess 14 is formed in the lower surface 3d of the inner gear 3 in a majority of the outer peripheral portion. The bearing housing recess 14 opens below and radially outside. The 1 st bearing 4 is accommodated in the bearing accommodating recess 14. An O-ring groove 3e is formed in the inner peripheral portion of the bottom surface 14a of the bearing housing recess 14. An O-ring 15 is attached to the O-ring groove 3e. The O-ring 15 seals between the inner gear 3 and the 1 st bearing 4.
< 1 St bearing >
The 1 st bearing 4 includes an outer ring 16, an inner ring 17, and a plurality of balls 18 as rolling elements disposed between the outer ring 16 and the inner ring 17. The inner peripheral surface of the inner ring 17 is fitted to the outer peripheral surface of the bearing housing recess 14. The upper surface 17a of the inner ring 17 abuts against the bottom surface 14a of the bearing housing recess 14, whereby the 1 st bearing 4 is positioned in the axial direction of the internal gear 3.
On the upper surface 17a of the inner ring 17, female screw portions 17b are formed coaxially with the through hole 3f of the internal gear 3, respectively. These female screw portions 17b communicate with corresponding through holes 3f of the internal gear 3, respectively. Bolts, not shown, inserted into the through holes 2b of the housing 2 from above pass through the through holes 3f of the internal gear 3 and are fastened to the female screw portion 17b of the inner ring 17. Thus, the housing 2, the internal gear 3, and the inner race 17 of the 1 st bearing 4 are integrally fixed to the base unit 102 by bolts, not shown.
The outer ring 16 of the 1 st bearing 4 has a plurality of through holes 16a formed in an outer peripheral portion thereof so as to pass through the through holes in the axial direction. The plurality of through holes 16a are arranged at equal intervals in the circumferential direction. The plurality of through holes 16a are used to integrate the outer race 16 of the 1 st bearing 4, the external gear 5, and the output plate 7 by using bolts not shown.
A seal accommodating recess 19 is formed in an inner peripheral portion of the upper surface 16b of the outer ring 16. The seal housing recess 19 is provided with a seal portion 20. The seal portion 20 seals between the outer race 16 and the inner race 17 above the 1 st bearing 4. As the seal portion 20, various seal members such as a rubber oil seal can be used.
The lower surface 16c of the outer race 16 slightly protrudes downward with respect to the lower surface 17c of the inner race 17. An O-ring groove 16d is formed in the inner peripheral portion of the lower surface 16c of the outer ring 16. An O-ring 40 is mounted in the O-ring groove 16d. The O-ring 40 seals between the outer race 16 and the outer gear 5.
< External Gear >
The external gear 5 is formed of a member having elasticity. For example, the external gear 5 is formed of a thin-walled metal plate or the like. The external gear 5 includes a cylindrical portion 21 concentric with the internal gear 3, and an external flange portion 22 bent radially outward from the lower end of the cylindrical portion 21 and extending. The cylindrical portion 21 extends from the upper surface 3a of the internal gear 3 to the lower surface 16c of the outer race 16 of the 1 st bearing 4. External teeth 5a are formed on the outer peripheral surface of the cylindrical portion 21. The external teeth 5a are formed at positions opposed to the internal teeth 3c of the internal gear 3 in the radial direction. The external teeth 5a mesh with the internal teeth 3c of the internal gear 3. The number of teeth of the external teeth 5a is smaller than that of the internal teeth 3 c. For example, the number of teeth of the external teeth 5a is two less than the number of teeth of the internal teeth 3 c.
The outer flange 22 extends from the lower end of the cylindrical portion 21 to the outer peripheral surface of the outer ring 16 of the 1 st bearing 4. The outer peripheral portion of the outer flange 22 axially overlaps the lower surface 16c of the outer ring 16. A thick portion 22a having a wall thickness thicker than that of other portions is formed on the outer peripheral portion of the outer flange 22. The thick portion 22a is formed at a portion overlapping the outer ring 16 in the axial direction. The thick portion 22a is formed with a through hole 22b. The through hole 22b is formed coaxially with the through hole 16a of the outer ring 16. These through holes 22b communicate with corresponding through holes 16a of the outer ring 16, respectively.
< Output plate >
The output plate 7 is disposed so as to overlap the thick portion 22a of the outer flange 22 in the axial direction. The output plate 7 is formed in a disk shape. A pinion 107 for transmitting power of the motor 106 with a speed reducer to the base unit 102 is mounted on the lower surface 7a of the output plate 7, for example.
A fitting cylindrical portion 23 protruding toward the 1 st bearing 4 is formed on the outer peripheral portion of the output plate 7. An outer peripheral surface of the thick portion 22a and a part of an outer peripheral surface of the outer ring 16 of the 1 st bearing 4 are fitted to an inner peripheral surface of the fitting cylindrical portion 23. The relative positions of the housing 2, the internal gear 3, the 1 st bearing 4, the external gear 5, and the output plate 7 in the radial direction and the axial direction are determined in this way.
A through hole 7b is formed in the outer peripheral portion of the output plate 7 radially inward of the fitting cylindrical portion 23. The through hole 7b and the through hole 22b of the thick portion 22a are formed coaxially. These through holes 7b communicate with corresponding through holes 22b of the thick portion 22 a. With this configuration, for example, a bolt (not shown) is inserted from above the outer ring 16 in the order of the through hole 16a, the through hole 22b of the thick portion 22a, and the through hole 7b of the output plate 7, and the bolt is fastened to a female screw portion (not shown) formed in the pinion 107. Thus, the outer race 16 of the 1 st bearing 4, the external gear 5, and the output plate 7 are integrally fixed to the pinion 107 by bolts, not shown. In a state where the pinion 107 is removed, for example, the outer race 16 of the 1 st bearing 4, the external gear 5, and the output plate 7 may be integrated with bolts and nuts, not shown.
An O-ring groove 7d is formed in the upper surface 7c of the output plate 7. The O-ring groove 7d is formed radially inward of the through hole 7 b. An O-ring 25 is attached to the O-ring groove 7d. The O-ring 25 seals the thick portion 22a from the output plate 7.
A shaft insertion hole 24 penetrating in the axial direction is formed in the center of the output plate 7 in the radial direction. A speed reducer shaft 8 is inserted into the shaft insertion hole 24. An O-ring 25 for ensuring the sealing property between the output plate 7 and the speed reducer shaft 8 is attached to the shaft insertion hole 24 of the output plate 7.
A cylindrical bearing boss 27 protruding upward is integrally formed on the upper surface 7c of the output plate 7. The bearing boss 27 is formed radially outward of the shaft insertion hole 24. An outer peripheral surface of the 3 rd bearing 28 is fitted to an inner peripheral surface of the bearing boss 27. The 3 rd bearing 28 rotatably supports the lower end of the speed reducer shaft 8 on the output plate 7. As the 3 rd bearing 28, for example, a deep groove ball bearing is used. However, not limited thereto, a variety of bearings may be used.
< Speed reducer shaft >
The speed reducer shaft 8, which is rotatably supported at both ends by the two bearings 11 and 28, is formed in a hollow shape. The outer peripheral surface of the speed reducer shaft 8 is formed in a stepped shape. That is, the outer peripheral surface of the speed reducer shaft 8 has seal outer peripheral surfaces 8a formed at both ends, bearing outer peripheral surfaces 8b formed axially inward of the respective seal outer peripheral surfaces 8a, and shaft main body outer peripheral surfaces 8c formed between the two bearing outer peripheral surfaces 8 b.
Sealing portions 10 and 26 are attached to the respective seal outer peripheral surfaces 8 a. The 2 nd bearing 11 and the 3 rd bearing 28 are mounted on the respective bearing outer peripheral surfaces 8 b. The bearing outer peripheral surface 8b is formed so that its diameter is larger than the diameter of the seal outer peripheral surface 8a via the step portion 8 d. The shaft main body outer peripheral surface 8c is formed so that its diameter is larger than the diameter of the bearing outer peripheral surface 8b via the step portion 8 e. The bearings 11 and 28 are positioned in the axial direction of the speed reducer shaft 8 by abutting against the corresponding stepped portions 8d and 8 e.
< Harmonic Generator >
The harmonic generator 6 is disposed between the shaft main body outer circumferential surface 8c of the speed reducer shaft 8 and the external teeth 5a (the internal teeth 3c of the internal gear 3) of the external gear 5 in the radial direction. The harmonic generator 6 includes a cam 31 integrally formed with the shaft main body outer circumferential surface 8c, and a 4 th bearing (an example of a bearing in the claims) 32 disposed between the outer circumferential surface 31a of the cam 31 and the inner circumferential surface 21a of the cylindrical portion 21 of the external gear 5.
< Cam >
Fig. 3 is a plan view of the cam 31 as seen from above, and corresponds to a sectional view taken along line III-III in fig. 2.
As shown in fig. 2 and 3, the cam 31 is formed to protrude from the shaft main body outer peripheral surface 8c toward the outside in the radial direction. The outer peripheral surface 31a of the cam 31 is formed in an elliptical shape as viewed from the axial direction.
< 4 Th bearing >
The 4 th bearing 32 is, for example, a deep groove ball bearing. The 4 th bearing 32 includes an outer ring 33, an inner ring 34, balls 35 which are a plurality of rolling elements arranged between the outer ring 33 and the inner ring 34, and a retainer 36 which holds the plurality of balls 35 so as to be rotatable. The outer peripheral surface of the outer ring 33 contacts the inner peripheral surface 21a of the cylindrical portion 21 of the outer gear 5. The inner peripheral surface of the inner ring 34 is fitted to the outer peripheral surface 31a of the cam 31. The axial length L1 of the inner race 34 is shorter than the axial length L2 of the outer race 33. The axial length L3 of the cam 31 approximately coincides with the axial length L1 of the inner ring 34.
< Retainer >
The retainer 36 is an annular member that holds the plurality of balls 35 at equal intervals in the circumferential direction. The retainer 36 includes grip portions 36a that grip the ball 35 to be free to roll from the outside in the axial direction, and coupling portions, not shown, that couple the grip portions 36a adjacent in the circumferential direction. The grip 36a protrudes slightly downward from the lower end of the inner ring 34 in the axial direction as viewed in the radial direction.
< Restriction portion >
A restricting portion 37 is integrally formed at the lower end of the cam 31 on the shaft main body outer peripheral surface 8 c. The restricting portion 37 is formed in a flange shape protruding radially outward from the outer peripheral surface 31a of the cam 31. The outer peripheral surface 37a of the restricting portion 37 is formed in an elliptical shape as viewed in the axial direction so as to correspond to the shape of the outer peripheral surface 31a of the cam 31. The long axis Rla of the restricting portion 37 is aligned with the long axis CLa of the cam 31. The short axis Rsa of the restriction 37 is aligned with the short axis CSa of the cam 31. Therefore, the restricting portion 37 is formed so that the protruding length in the radial direction from the outer peripheral surface 31a of the cam 31 is uniform over the entire periphery of the outer peripheral surface 31 a.
When the outer diameter of an arbitrary portion of the cam 31 is defined as D1, the outer diameter of the same portion of the restricting portion 37 as the arbitrary portion of the cam 31 is defined as D2, and the wall thickness of the inner ring 34 of the 4 th bearing 32 is defined as T, the outer diameters D1, D2 and the thickness T satisfy (D2-D1)/2. Ltoreq.t· (1).
In addition to the above formula (1), the restricting portion 37 is integrally formed at the lower end of the cam 31, and therefore, the restricting portion 37 is radially opposed to the holder 36 (the grip portion 36 a) of the 4 th bearing 32. The contact of the restriction portion 37 with the holder 36 is reliably avoided.
The lower end of the inner ring 34 of the 4 th bearing 32 abuts against the upper surface 37b of the restricting portion 37. Thereby, the axial movement of the 4 th bearing 32 is restricted.
The restricting portion 37 is formed so that the protruding length in the radial direction from the outer peripheral surface 31a of the cam 31 is uniform over the entire circumference of the outer peripheral surface 31 a. Therefore, the restricting portion 37 uniformly abuts against the inner ring 34 of the 4 th bearing 32 over the entire circumference of the inner ring 34 of the 4 th bearing 32. The retainer 36 (grip portion 36 a) of the 4 th bearing 32 faces the restricting portion 37 across the entire periphery of the outer peripheral surface 31a of the cam 31 with a certain gap G therebetween in the radial direction. The restricting portion 37 reliably protrudes from the outer peripheral surface 31a of the cam 31 in the radial direction. Therefore, the axial movement of the 4 th bearing 32 is reliably restricted by the restricting portion 37.
< Action of harmonic Gear device >
Next, the operation of the harmonic gear device 1 of the motor 106 with a speed reducer will be described. The harmonic gear device of the other decelerator-equipped motors 113a to 113f provided to the robot body 103 also operates in the same manner as the harmonic gear device 1 of the decelerator-equipped motor 106 provided to the base unit 102.
First, the outer peripheral surface 31a of the cam 31 of the harmonic generator 6 is formed in an elliptical shape as viewed from the axial direction. Therefore, the external gear 5 is elastically deformed by the 4 th bearing 32, and the external teeth 5a are partially meshed with the internal teeth 3c of the internal gear 3. In this state, when the motor shaft 110a is rotated by driving the electric motor 110, the speed reducer shaft 8 is rotated integrally with the motor shaft 110 a. The cam 31 rotates integrally with the decelerator shaft 8. That is, the cam 31 of the harmonic generator 6 functions as an input unit for inputting the rotational force of the motor shaft 110a of the electric motor 110.
The number of teeth of the external teeth 5a is different from the number of teeth of the internal teeth 3 c. Therefore, the engaged positions are moved in the circumferential direction and rotated relative to each other about the rotation axis C due to the tooth difference. In the present embodiment, the number of teeth of the external teeth 5a is smaller than the number of teeth of the internal teeth 3 c. Therefore, the external gear 5 rotates at a rotation speed lower than that of the decelerator shaft 8. The external gear 5 rotates while being elastically deformed.
The outer flange 22 of the external gear 5 is integrated with the outer race 16 of the 1 st bearing 4 and the output plate 7. Therefore, the outer race 16 and the output plate 7 of the 1 st bearing 4 are output by decelerating the rotation of the motor shaft 110a (the speed reducer shaft 8). That is, the external gear 5 functions as an output unit that changes the rotation speed (in the case of the present embodiment, decelerates) of the cam 31 serving as an input unit and outputs the rotation speed.
The pinion 107 rotates due to the rotation of the output plate 7. Then, the base unit 102 is slidingly moved along the travel rail 101 (see fig. 1).
However, when the harmonic gear device 1 is driven, a downward thrust is generated in the harmonic generator 6 due to the elastic deformation of the external gear 5. The cam 31 in the harmonic generator 6 is integrally formed with the decelerator shaft 8. The movement in the axial direction of the speed reducer shaft 8 is restricted by the 2 nd bearing 11 and the 3 rd bearing 28 arranged to both sides in the axial direction. Accordingly, the downward thrust acts on the 4 th bearing 32 in the harmonic generator 6.
A restricting portion 37 is integrally formed at the lower end of the cam 31 on the shaft body outer peripheral surface 8c of the speed reducer shaft 8. The restricting portion 37 is formed in a flange shape protruding radially outward from the outer peripheral surface 31a of the cam 31. The lower end of the inner ring 34 of the 4 th bearing 32 abuts against such a restricting portion 37. Therefore, the movement in the axial direction of the 4 th bearing 32 is regulated by the regulating portion 37.
In this way, in the harmonic gear device 1 described above, the movement of the 4 th bearing 32 in the axial direction can be regulated by the regulating portion 37. Accordingly, the internal teeth 3c of the internal gear 3 and the external teeth 5a of the external gear 5 can be continuously and properly meshed. Thus, the harmonic gear device 1 can be stably operated.
The restricting portion 37 is formed so as to avoid contact with the retainer 36 of the 4th bearing 32. Therefore, damage to the 4th bearing 32 by the restricting portion 37 can be prevented. The restricting portion 37 is formed so that the protruding length in the radial direction from the outer peripheral surface 31a of the cam 31 is uniform over the entire circumference of the outer peripheral surface 31 a. Therefore, the upper surface 37b of the restricting portion 37 is in uniform contact with the inner ring 34 of the 4th bearing 32 over the entire circumference of the inner ring 34 of the 4th bearing 32. Therefore, even when the inner ring 34 of the 4th bearing 32 is strongly pressed against the restricting portion 37, stress is not locally applied to the inner ring 34. As a result, the inner ring 34 can be prevented from being bent, and damage to the 4th bearing 32 can be prevented.
The restricting portion 37 faces the retainer 36 (the grip portion 36 a) with a gap G therebetween in the radial direction so as to avoid contact with the retainer 36 of the 4 th bearing 32. With this configuration, the restricting portion 37 can be simply constructed while avoiding contact with the holder 36.
The outer peripheral surface 31a of the cam 31 and the outer peripheral surface 37a of the restricting portion 37 are formed in elliptical shapes as viewed from the axial direction, respectively. The long axis Rla of the restricting portion 37 is aligned with the long axis CLa of the cam 31. The short axis Rsa of the restriction 37 is aligned with the short axis CSa of the cam 31. Therefore, the protruding length of the restricting portion 37 in the radial direction protruding from the outer peripheral surface 31a of the cam 31 can be reliably made uniform over the entire circumference of the outer peripheral surface 31 a.
The outer diameter D1 of any portion of the cam 31, the outer diameter D2 of the portion of the restricting portion 37 that is the same as any portion of the cam 31, and the wall thickness T of the inner ring 34 of the 4 th bearing 32 satisfy the above formula (1). Therefore, the restricting portion 37 can be more reliably prevented from contacting the retainer 36, while the movement in the axial direction of the 4 th bearing 32 is more reliably restricted.
The restricting portion 37 is integrally formed with the shaft main body outer peripheral surface 8c and the lower end of the cam 31. Therefore, the restriction portion 37 can be easily provided.
The industrial robot 100 employs the motors 106, 113a to 113f with speed reducers using the harmonic generator 6 as described above. This can provide the industrial robot 100 with high reliability, which can prevent the damage of the 4 th bearing 32 and can perform stable operation.
The present invention is not limited to the above-described embodiments, and includes embodiments in which various modifications are applied to the above-described embodiments within the scope of the gist of the present invention.
For example, in the above-described embodiment, the case where the motors 106, 113a to 113f with speed reducers including the harmonic gear device 1 are used in the industrial robot 100 is described. However, the present invention is not limited thereto, and the harmonic gear device 1 may be used in a driving section of various industrial robots other than the industrial robot 100. Examples of the industrial robot include various processing machines such as an electric wheelchair, a traveling device, and a machine tool. For example, the harmonic gear device 1 is used in a driving unit (traveling unit) of an electric wheelchair, a traveling device, or a processing machine.
In the above embodiment, the case where the electric motor 110 is used as the power generating portion that generates the rotational force of the cam 31 as the input portion has been described. However, the present invention is not limited to this, and the power generating unit may be configured to generate a rotational force by the cam 31. For example, a hydraulic motor, an engine, or the like can be employed instead of the electric motor 110.
In the above embodiment, the description has been made of the case where the 4 th bearing 32 is, for example, a deep groove ball bearing. However, the present invention is not limited to this, and may be a bearing including an outer ring, an inner ring, rolling elements, and a cage. The rolling elements may be other than the balls 35. For example, instead of the balls 35, cylindrical rollers may be used as the rolling elements.
In the above-described embodiment, the description has been made of the case where the cam 31 of the harmonic generator 6 functions as an input unit for inputting the rotational force of the motor shaft 110a of the electric motor 110. The case where the external gear 5 functions as an output unit that changes the rotation speed of the cam 31 and outputs the change is described. However, the present invention is not limited to this, and the external gear 5 may be used as an input unit, and the cam 31 (the speed reducer shaft 8) may be used as an output unit.
In the above-described embodiment, the case where the outer peripheral surface 31a of the cam 31 is formed in an elliptical shape as viewed from the axial direction has been described. The case where the outer peripheral surface 37a of the restricting portion 37 is formed in an elliptical shape as viewed in the axial direction so as to correspond to the shape of the outer peripheral surface 31a of the cam 31 is described. However, the outer peripheral surface 31a of the cam 31 and the outer peripheral surface 37a of the restricting portion 37 are not limited thereto, and may be non-circular. For example, the outer peripheral surface 31a of the cam 31 and the outer peripheral surface 37a of the restricting portion 37 may have a polygonal shape as viewed from the axial direction. The restricting portion 37 may be formed so that the protruding length in the radial direction from the outer peripheral surface 31a of the cam 31 is uniform over the entire circumference of the outer peripheral surface 31 a. Desirably, the outer peripheral surface 31a of the cam 31 has an elliptical shape or an oblong shape having a major axis and a minor axis as viewed from the axial direction.
In the above embodiment, the case where the O-ring 13 is provided to seal the space between the internal gear 3 and the housing 2 has been described. The case where the O-ring 15 is provided to seal the space between the internal gear 3 and the 1 st bearing 4 will be described. The case where the O-ring 25 is provided to seal the thick portion 22a and the output plate 7 will be described. The case where the O-ring 40 is provided to seal the outer ring 16 and the outer gear 5 will be described. However, not limited thereto, a variety of sealing members can be used instead of the O-rings 13, 15, 25, 40.
In the above embodiment, the case where the harmonic gear device 1 includes the housing 2 is described. However, the present invention is not limited to this, and the housing 2 may not be provided. For example, the ring gear 3 may be directly attached to the base unit 102 or the like, and the speed reducer shaft 8 may be directly rotatably supported by the base unit 102 or the like.
In the above embodiment, the case where the harmonic gear device 1 includes the output plate 7 is described. The case where the rotation of the motor shaft 110a (the speed reducer shaft 8) is output via the output plate 7 is described. However, the present invention is not limited to this, and the rotation of the motor shaft 110a (the speed reducer shaft 8) may be directly output from the external gear 5.
In the above embodiment, the case where the housing 2, the internal gear 3, and the inner race 17 of the 1 st bearing 4 are integrally fixed to the base unit 102 by bolts not shown has been described. However, the method of fixing the inner ring 17 of the ring gear 3 and the 1 st bearing 4 is not limited thereto, and various methods can be adopted. For example, the internal gear 3 and the inner ring 17 of the 1 st bearing 4 may be fixed in advance. The housing 2, the internal gear 3, and the inner race 17 of the 1 st bearing 4 may be fixed in advance to the target member (for example, the base unit 102).
In the above embodiment, the case where the speed reducer shaft 8 is formed in a hollow shape has been described. However, not limited thereto, the decelerator shaft 8 may be solid. For example, a spur gear may be provided on the speed reducer shaft 8, and the rotation of the motor shaft 110a may be transmitted to the speed reducer shaft 8 via the spur gear.
In the above embodiment, the case where the restricting portion 37 is integrally formed at the lower end of the cam 31 has been described. The case where the lower end of the inner ring 34 of the 4 th bearing 32 abuts against the upper surface 37b of the restricting portion 37 is described. However, the restriction portions 37 are not limited to this, and may be provided on both sides of the inner ring 34 in the axial direction. With this configuration, the movement of the 4 th bearing 32 in the axial direction can be reliably restricted regardless of the direction of the thrust force acting on the 4 th bearing 32. The restricting portion 37 may be separate from the speed reducer shaft 8 and the cam 31. For example, the restricting portion 37 may be configured as follows.
Modification of the restriction portion
Fig. 4 is a cross-sectional view along the rotation axis C showing a modification of the restricting portion 37. Fig. 4 corresponds to fig. 2 described above.
As shown in fig. 4, the restricting portion 37 may include a restricting support portion 41 extending from the upper end of the bearing boss 27 toward the 4 th bearing 32, and a restricting portion main body 42 provided to the restricting support portion 41. The restricting portion main body 42 is fixed to the restricting support portion 41 by a bolt, welding, or the like, not shown.
The restricting portion main body 42 is formed so as to extend in the axial direction from the restricting support portion 41 and the tip end 42a thereof abuts against the inner ring 34 of the 4 th bearing 32. That is, the limiter body 42 is provided so as to avoid contact with the retainer 36 of the 4 th bearing 32. The restricting portion main body 42 restricts movement in the axial direction of the 4 th bearing 32. The regulating portion main body 42 is formed so that the radial projecting length from the outer peripheral surface 31a of the cam 31 is uniform over the entire circumference of the outer peripheral surface 31 a. Even in the case of such a configuration, the same effects as those of the foregoing embodiment can be obtained.
In the embodiment disclosed in the present specification, a member composed of a plurality of objects may be integrated with the plurality of objects, but conversely, a member composed of one object may be divided into a plurality of objects. Whether or not integrated, the present invention may be constructed so as to achieve the object of the present invention.
Description of the reference numerals
1. The gear device includes a harmonic gear device, 3, an internal gear, 5, an external gear, 6, a harmonic generator, 21, a cylindrical portion, 21a, an inner circumferential surface, 31, a cam, 31a, an outer circumferential surface, 32, a 4 th bearing (bearing), 33, an outer race, 34, an inner race, 35, a ball (rolling element), 36, a retainer, 37, a regulating portion, 37a, an outer circumferential surface, 42, a regulating portion main body (regulating portion), 100, an industrial robot, 107, a pinion (target member), 115a, 115b, 115C, 115D, an arm (target member), C, a rotation axis, CLa, a long axis of the cam, CSa, a short axis of the cam, D1, an arbitrary outer diameter of the cam, D2, an outer diameter on D1 in the regulating portion, G, a gap, RLa long axis of the regulating portion, RSa, a short axis of the regulating portion.
Claims (8)
1. A harmonic gear device, wherein,
The harmonic gear device is provided with:
An internal gear;
An external gear arranged radially inward of the internal gear and having elasticity, and
A harmonic generator in contact with an inner peripheral surface of the external gear,
The external gear is partially meshed with the internal gear and relatively rotated with respect to the internal gear about a rotation axis,
The harmonic generator moves the meshing position between the internal gear and the external gear in the circumferential direction about the rotation axis,
The harmonic generator is provided with:
a cam having a non-circular outer peripheral surface, and
A bearing disposed between the inner peripheral surface of the external gear and the outer peripheral surface of the cam,
The bearing is provided with:
An outer ring in contact with the inner peripheral surface of the outer gear;
An inner ring in contact with the outer peripheral surface of the cam;
a plurality of rolling elements arranged between the outer ring and the inner ring, and
A cage that holds the plurality of rolling elements,
The harmonic gear device is provided with a limiting part which is contacted with the inner ring of the bearing in a mode of avoiding contact with the retainer,
The restricting portion is formed in such a manner that a protruding length in a radial direction protruding from the outer peripheral surface of the cam is uniform over the entire circumference of the outer peripheral surface of the cam,
The restricting portion restricts movement of the bearing in the rotational axis direction.
2. The harmonic gear device according to claim 1, wherein,
The restricting portion is formed in a flange shape protruding radially outward from the outer peripheral surface of the cam,
The outer peripheral surface of the restricting portion faces the retainer with a gap therebetween in the radial direction.
3. The harmonic gear device according to claim 2, wherein,
The outer peripheral surface of the cam and the outer peripheral surface of the restriction portion are formed in an elliptical shape or an oblong shape having a major axis and a minor axis as viewed in the rotation axis direction,
The major axis of the cam is on the same line as the major axis of the restriction portion, and the minor axis of the cam is on the same line as the minor axis of the restriction portion.
4. The harmonic gear device according to any one of claim 1 to 3, wherein,
The outer diameter of any part of the cam is defined as D1,
When the outer diameter of the same portion of the restricting portion as an arbitrary portion of the cam is defined as D2 and the radial thickness of the inner ring is defined as T,
The outer diameters D1, D2 and the thickness T are (D2-D1)/2.ltoreq.T.
5. The harmonic gear device according to any one of claim 1 to 3, wherein,
The restricting portions are provided on both sides of the inner race in the rotation axis direction.
6. The harmonic gear device according to any one of claim 1 to 3, wherein,
The restricting portion is integrally formed with the cam.
7. A harmonic gear device, wherein,
The harmonic gear device is provided with:
An internal gear;
An external gear arranged radially inward of the internal gear and having elasticity, and
A harmonic generator in contact with an inner peripheral surface of the external gear,
The external gear is partially meshed with the internal gear and relatively rotated with respect to the internal gear about a rotation axis,
The harmonic generator moves the meshing position between the internal gear and the external gear in the circumferential direction about the rotation axis,
The harmonic generator is provided with:
a cam having an outer peripheral surface, and
A bearing disposed between the inner peripheral surface of the external gear and the outer peripheral surface of the cam,
The outer peripheral surface of the cam is formed in any one of an elliptical shape and a long circular shape having a major axis and a minor axis as seen in the rotation axis direction,
The bearing is provided with:
An outer ring in contact with the inner peripheral surface of the outer gear;
An inner ring in contact with the outer peripheral surface of the cam;
a plurality of rolling elements arranged between the outer ring and the inner ring, and
A cage that holds the plurality of rolling elements,
The harmonic gear device includes a flange-shaped restriction portion formed to protrude radially outward from the outer periphery of the cam,
The restriction portion has an outer peripheral surface formed in any one of an elliptical shape and an oblong shape having a major axis and a minor axis as seen in the rotation axis direction,
The long axis of the cam and the long axis of the limiting part are positioned on the same straight line, the short axis of the cam and the short axis of the limiting part are positioned on the same straight line,
The restricting portion is formed in such a manner that a protruding length in a radial direction protruding from the outer peripheral surface of the cam is uniform over the entire circumference of the outer peripheral surface of the cam,
The outer peripheral surface of the restricting portion is opposed to the retainer with a gap therebetween in a radial direction,
The restricting portion is in contact with the inner race of the bearing to restrict movement of the bearing in the rotation axis direction.
8. An industrial robot, wherein,
The industrial robot includes:
A power generation unit that generates a rotational force;
a harmonic gear device having an input part and an output part, and
A target member attached to the output portion of the harmonic gear device,
Inputting the rotational force of the power generation part to the input part,
The output unit changes the rotation of the input unit to output,
The harmonic gear device is provided with:
An internal gear;
An external gear arranged radially inward of the internal gear and having elasticity, and
A harmonic generator in contact with an inner peripheral surface of the external gear,
The external gear is partially meshed with the internal gear and relatively rotates with respect to the internal gear about a rotation axis, and functions as one of the input portion and the output portion,
The harmonic generator moves the meshing position between the internal gear and the external gear in the circumferential direction about the rotation axis,
The harmonic generator is provided with:
a cam having a non-circular outer peripheral surface, and
A bearing disposed between the inner peripheral surface of the external gear and the outer peripheral surface of the cam,
The cam functions as the other of the input and the output,
The bearing is provided with:
An outer ring in contact with the inner peripheral surface of the outer gear;
An inner ring in contact with the outer peripheral surface of the cam;
a plurality of rolling elements arranged between the outer ring and the inner ring, and
A cage that holds the plurality of rolling elements,
The industrial robot includes a regulating portion that is in contact with the inner ring of the bearing so as to avoid contact with the retainer,
The restricting portion is formed so that a protruding length in a radial direction protruding from the outer peripheral surface of the cam is uniform over an entire circumference of the outer peripheral surface of the cam, and restricts movement of the bearing in the rotation axis direction.
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP2022-075005 | 2022-04-28 | ||
| JP2022075005A JP2023163832A (en) | 2022-04-28 | 2022-04-28 | Wave gear device and industrial robot |
| PCT/JP2023/005188 WO2023210114A1 (en) | 2022-04-28 | 2023-02-15 | Strain-wave gearing and industrial robot |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CN119072593A true CN119072593A (en) | 2024-12-03 |
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ID=88518430
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202380035674.2A Pending CN119072593A (en) | 2022-04-28 | 2023-02-15 | Harmonic gear device and industrial robot |
Country Status (4)
| Country | Link |
|---|---|
| JP (1) | JP2023163832A (en) |
| CN (1) | CN119072593A (en) |
| DE (1) | DE112023002033T5 (en) |
| WO (1) | WO2023210114A1 (en) |
Family Cites Families (5)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS6113056A (en) * | 1984-06-27 | 1986-01-21 | Matsushita Electric Ind Co Ltd | Reduction gear |
| JP2512462Y2 (en) * | 1990-03-23 | 1996-10-02 | 株式会社ハーモニック・ドライブ・システムズ | Harmonic gear transmission wave generator |
| WO2020044524A1 (en) | 2018-08-30 | 2020-03-05 | 株式会社ハーモニック・ドライブ・システムズ | Wave motion generator for wave motion gear device |
| JP2020197264A (en) * | 2019-06-05 | 2020-12-10 | 株式会社ジェイテクト | Wave gear device |
| JP7448462B2 (en) | 2020-11-06 | 2024-03-12 | 株式会社中西製作所 | Transport method and cleaning device for items to be cleaned |
-
2022
- 2022-04-28 JP JP2022075005A patent/JP2023163832A/en active Pending
-
2023
- 2023-02-15 DE DE112023002033.7T patent/DE112023002033T5/en active Pending
- 2023-02-15 WO PCT/JP2023/005188 patent/WO2023210114A1/en active Application Filing
- 2023-02-15 CN CN202380035674.2A patent/CN119072593A/en active Pending
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| JP2023163832A (en) | 2023-11-10 |
| WO2023210114A1 (en) | 2023-11-02 |
| DE112023002033T5 (en) | 2025-02-20 |
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