CN112628291A

CN112628291A - Crossed roller bearing, harmonic reducer and robot with same

Info

Publication number: CN112628291A
Application number: CN202011430504.9A
Authority: CN
Inventors: 肖凤才; 程中甫; 谷甲甲; 袁成林; 杨繁荣; 吴婷婷
Original assignee: Gree Electric Appliances Inc of Zhuhai
Current assignee: Gree Electric Appliances Inc of Zhuhai
Priority date: 2020-12-07
Filing date: 2020-12-07
Publication date: 2021-04-09

Abstract

The application provides a crossed roller bearing, a harmonic reducer and a robot with the same, wherein the robot comprises a bearing outer ring, a bearing inner ring and a roller path; the raceway is arranged between the bearing inner ring and the bearing outer ring; the number of the roller paths is at least two; a roller is arranged in each raceway. According to the crossed roller bearing, the harmonic reducer and the robot with the same, the bearing capacity and the transmission stability can be improved.

Description

Crossed roller bearing, harmonic reducer and robot with same

Technical Field

The application belongs to the technical field of robots, and particularly relates to a crossed roller bearing, a harmonic reducer and a robot with the crossed roller bearing and the harmonic reducer.

Background

At present, a harmonic reducer is one of harmonic drive devices, and the harmonic drive device comprises a harmonic accelerator and a harmonic reducer. The harmonic reducer mainly includes: the rigid wheel, the flexible wheel and the wave generator are all absent. The wave generator consists of a cam and a flexible crossed roller bearing, wherein the cam is in an oval shape, and the flexible crossed roller bearing is in a circular shape. Therefore, it is easier to achieve miniaturization and weight reduction, and, because the number of meshing teeth is large, it is possible to generate a larger torque and to achieve more accurate positioning.

However, since the current harmonic reducers all adopt single-row roller crossed roller bearings, the single-row roller crossed roller bearings have the following disadvantages: the roller crossed roller bearing has a single supporting point, causes uneven load distribution, easily causes serious abrasion of the roller path and the roller, is accompanied with vibration during operation, has poor stability and reduces bearing torque.

Therefore, how to provide a crossed roller bearing capable of improving bearing capacity and transmission stability, a harmonic reducer and a robot with the crossed roller bearing and the harmonic reducer become problems to be solved by those skilled in the art urgently.

Disclosure of Invention

Therefore, the technical problem that this application will be solved lies in providing a cross roller bearing, harmonic speed reducer ware and have its robot, can improve bearing capacity and transmission stationarity.

In order to solve the above problem, the present application provides a crossed roller bearing including:

a bearing outer race;

a bearing inner race;

and a raceway; the raceway is arranged between the bearing inner ring and the bearing outer ring; the number of the roller paths is at least two; a roller is arranged in each raceway.

Preferably, the crossed roller bearing further comprises an oil through groove; the oil through groove is communicated with at least two raceways.

Preferably, the bearing outer ring is made of a high carbon alloy structural steel material;

and/or the bearing inner ring is made of high-carbon alloy structural steel materials.

Preferably, the roughness of the inner surface of the roller path is Ra0.05-0.2; and/or the full run-out of the raceway is less than 0.002 mm; and/or the parallelism of the two end surfaces of the crossed roller bearing is less than 0.005 mm.

Preferably, the cross roller bearing has an axial length of 51.5-79 mm.

Preferably, the number of raceways is provided as two;

and/or at least two raceways are arranged in sequence in the axial direction of the crossed roller bearing;

and/or at least two of the raceways are parallel to each other.

According to yet another aspect of the present application, there is provided a harmonic reducer comprising a crossed roller bearing, the crossed roller bearing being the crossed roller bearing described above.

Preferably, the harmonic reducer further comprises a rigid gear; the tooth hardness of the rigid gear is H1; the hardness of the crossed roller bearing is H2; wherein H1< H2.

Preferably, the harmonic reducer further comprises a middle shaft; the middle shaft is provided with an axial through hole; the axial through hole is a wire passing hole;

and/or the cross section diameter of the axial through hole is 14mm-46 mm.

According to still another aspect of the present application, there is provided a robot including a harmonic reducer, the harmonic reducer being the above-described harmonic reducer.

The application provides a cross roller bearing, harmonic speed reducer ware and have its robot for the atress strong point of bearing becomes two at least places, makes the atress even, steady. Because the stress is distributed uniformly, the pressure born by the unit area of the bearing raceway is relatively reduced, and the bearing capacity and the transmission stability of the bearing can be further improved.

Drawings

FIG. 1 is a schematic structural view of a crossed roller bearing according to an embodiment of the present application;

FIG. 2 is a schematic structural diagram of a bearing outer race according to an embodiment of the present application;

FIG. 3 is a schematic structural diagram of a bearing inner race of an embodiment of the present application;

fig. 4 is a schematic structural diagram of a harmonic reducer according to an embodiment of the present application.

The reference numerals are represented as:

11. a bearing outer race; 12. a bearing inner race; 13. a raceway; 131. an oil storage tank; 132. an oil groove is communicated; 2. a rigid gear tooth portion; 3. a middle shaft; 31. an axial through hole; 4. framework oil seal; 51. a flexible gear; 52. a rolling support bearing; 61. a hexagon socket flat round head screw; 62. a socket head cap screw; 63. a threaded hole; 64. a clamp spring for the shaft; 65. a clamp spring for the hole; 66. an input flange; 67. an output flange; 68. a flexible rolling bearing; 7. and (5) sealing rings.

Detailed Description

Referring collectively to fig. 1-3, according to an embodiment of the present application, a crossed roller bearing includes a bearing outer race 11, a bearing inner race 12, and a raceway 13; the raceway 13 is arranged between the bearing inner ring 12 and the bearing outer ring 11; the number of the raceways 13 is set to at least two; a roller is disposed in each raceway 13. The utility model provides a do not change present crossed roller bearing's overall dimension and installation connection hole site, carry out the design innovation in the inner space structure part, change single-row raceway 13 design into two raceways 13, the size of raceway 13 reduces than original, and cylindrical roller's diameter ratio reduces slightly originally, and raceway 13 is for two at least raceways 13 from a design. The bearing stress point position can be improved, so that the stress supporting points of the bearing are changed into at least two positions, and the stress is uniform and stable. And the bearing capacity is also provided because the unit contact force bearing area is increased. Because the stress is distributed uniformly, the pressure born by the bearing raceway 13 in unit area is relatively reduced, and the bearing capacity and the transmission stability can be further improved. The problems of single stress point of the bearing, insufficient transmission stability, vibration and shake phenomena of output and insufficient output torque can be solved. The crossed roller bearing not only bears radial force, but also bears axial thrust. The problems of non-uniformity of loading, and poor vibration and stability in the operation process of the single-row crossed roller bearing of the harmonic reducer in the prior art are effectively solved.

The cross section of the roller path is square, so that the surface of the crossed roller and the roller path can be completely attached and supported and stressed.

The present application also discloses embodiments in which the crossed roller bearing further includes an oil groove 132; the oil communication groove 132 communicates at least two raceways 13. An oil reservoir 131 is also provided in each raceway.

The application also discloses embodiments, the bearing outer ring 11 is made of high carbon alloy structural steel material;

the bearing inner ring 12 is made of high-carbon alloy structural steel materials, so that the rigidity of the whole speed reducer is improved, and the vibration frequency is reduced.

The application also discloses some embodiments, the roughness of the inner surface of the roller path 13 is Ra0.05-0.2; the best results are obtained when the roughness of the inner surface of the raceway 13 is ra0.2. The total runout of the roller path 13 is less than 0.002 mm; the parallelism of two end surfaces of the crossed roller bearing is less than 0.005 mm; namely, the crossed roller bearing outer ring 11 is made of high-carbon alloy structural steel materials, the whole is high in hardness, and the raceway 13 of the double-row crossed bearing is processed by ultra-fine grinding. The roughness Ra0.05-0.2 of the inner surface of the raceway 13 of the bearing outer ring 11 is the best when the roughness of the inner surface of the raceway 13 is Ra0.2. The total runout of the two roller paths 13 is less than 0.002mm, and the parallelism of the two end faces is less than 0.005 mm.

The crossed roller bearing inner ring 12 is made of high-carbon alloy structural steel materials, the raceway 13 on the bearing inner ring 12 is high in hardness, and the raceway 13 of the double-row crossed bearing is processed by ultra-precision grinding, so that the roughness of the inner surface of the raceway 13 on the bearing inner ring 12 is Ra0.05-0.2; the best results are obtained when the roughness of the inner surface of the raceway 13 is ra0.2. The total run-out is less than 0.002mm, and the parallelism of the two end faces is less than 0.005 mm.

The present application also discloses embodiments in which the cross roller bearing may have an axial length of 51.5-79 mm; the axial lengths of 79mm, 51.5mm, 52.5mm, 55.5mm, 56.5mm and 65.5mm are selected according to different bearing models, and the corresponding axial length sizes of different bearing models are different.

Under the condition of certain output torque, the size, namely the ultra-short structure design is adopted, so that the volume of the harmonic reducer is reduced, the required installation space is reduced, the harmonic reducer is suitable for being used in places with special requirements, the application range is expanded, and the problem of the installation space of a complete combined harmonic reducer can be solved. This application only adopts biserial cross roller bearing, and does not change reduction gear complete machine appearance structure, but the application places such as narrow and small space can't be satisfied to standard appearance structure reduction gear and use, compares in prior art, and the weight of this application reduces, and the occasion result of use that requires to be higher in the lightweight is better. This application has reduced the bearing volume promptly, has reduced the installation space of needs, can use to inseparabler place.

The application also discloses some embodiments, the quantity of raceway 13 sets up to two, adopts the biserial roller structural design, has improved the stability of cross roller bearing rigidity, load distribution, promotes the rigidity of reduction gear, has reduced the reduction gear vibration, has improved harmonic reduction gear's bearing capacity, has realized the high moment of torsion.

At least two raceways 13 are arranged in succession in the axial direction of the crossed roller bearing;

at least two raceways 13 are parallel to each other, and the double-row roller cross arrangement combination mode of this application has strengthened the homogeneity of bearing radial load and axial load distribution, reduces the wearing and tearing on bearing raceway 13 unit area. And meanwhile, the stress borne on the unit area is reduced, and the sliding friction coefficient is reduced. When two raceways 13 are included and the two raceways 13 are parallel to each other, the running bearing capacity is improved by about 35% compared with that of a single-row crossed roller bearing, so that the bearing capacity of the harmonic reducer is improved, namely the bearing capacity is high torque.

Referring to fig. 4 in combination, according to an embodiment of the present application, there is provided a harmonic reducer including a cross roller bearing, which is the above-described cross roller bearing. The bearing has at least two stressed support points, which are stressed evenly and stably, and the bearing raceway 13 bears relatively reduced pressure in unit area due to even distribution and stress, and the two raceway 13 surfaces are arranged in parallel, so that the abrasion of the raceway 13 surfaces is reduced in the running process. By adopting the double-row bearing, the running stability of the speed reducer can be improved, and the problems of abnormal vibration and shaking caused by poor stability of the speed reducer in the running process of the robot are solved, so that the service lives of the speed reducer and the robot are prolonged, and the effect of bearing larger axial thrust (bending moment) is realized.

And, adopt double-row roller structural design, make original single-row roller become double-row roller and rotate, improved cross roller bearing rigidity, increased load distribution's stability, reduced reduction gear vibration phenomenon, promote the bearing capacity of reduction gear, promoted the output torque of reduction gear, this novel harmonic reduction gear can use in the place of difference, if: the tool magazine rotating frame of the numerical control machining center, a tool bit for motion control of a high-end numerical control machine tool, a high-precision rotating table, a high-precision indexing table, an industrial robot and the like.

The present application also discloses some embodiments, the harmonic reducer further comprises a rigid gear; the tooth hardness of the rigid gear is H1; the hardness of the crossed roller bearing is H2; wherein, H1< H2, the rigidity gear tooth portion 2 adopts lower hardness, is convenient for profile of tooth processing, is favorable to prolonging cutter life.

The application also discloses some embodiments, the harmonic reducer further comprises a middle shaft 3; the middle shaft 3 is provided with an axial through hole 31; the axial through hole 31 is a wire passing hole;

the diameter of the cross section of the aperture of the axial through hole 31 is 14mm-46mm, and the aperture can be 14mm-46mm according to different bearing models

And the aperture corresponding to different models is different.

Compared with the prior art, the design of enlarging the hollow through hole is adopted in the application, so that the cable can pass through the hole, the problem that the cable is exposed is avoided, the friction damage of the exposed cable is avoided, and therefore the cable is attractive and elegant and brings a concise and refreshing feeling to people. The problem that the robot, the harmonic reducer encoding line and the power line are exposed can be solved.

The harmonic reducer further comprises a framework oil seal 4, a flexible gear 51, a rolling support bearing 52, an inner hexagonal flat round head screw 61, an inner hexagonal cylindrical head screw 62, a threaded hole 63, a shaft clamp spring 64, a hole clamp spring 65, an input flange 66, an output flange 67, a flexible rolling bearing 68, a sealing ring 7 and the like.

According to an embodiment of the application, a robot is provided, which comprises a harmonic reducer.

It is readily understood by a person skilled in the art that the advantageous ways described above can be freely combined, superimposed without conflict.

The present invention is not intended to be limited to the particular embodiments shown and described, but is to be accorded the widest scope consistent with the principles and novel features herein disclosed. The foregoing is only a preferred embodiment of the present application, and it should be noted that, for those skilled in the art, several modifications and variations can be made without departing from the technical principle of the present application, and these modifications and variations should also be considered as the protection scope of the present application.

Claims

1. A crossed roller bearing, comprising:

a bearing outer ring (11);

a bearing inner race (12);

and a raceway (13); the raceway (13) is arranged between the bearing inner ring (12) and the bearing outer ring (11); the number of the raceways (13) is set to be at least two; each raceway (13) is internally provided with a roller.

2. The crossed roller bearing according to claim 1, further comprising an oil through groove (132); the oil through groove (132) communicates the at least two raceways (13).

3. The crossed roller bearing according to claim 1, characterized in that the bearing outer ring (11) is made of a structural steel material of high carbon alloy;

and/or the bearing inner ring (12) is made of a high-carbon alloy structural steel material.

4. The crossed roller bearing according to claim 1, characterized in that the roughness of the inner surface of the raceway (13) is ra0.05 to 0.2; and/or the full run-out of the raceway (13) is less than 0.002 mm; and/or the parallelism of the two end surfaces of the crossed roller bearing is less than 0.005 mm.

5. A cross roller bearing as claimed in claim 3 wherein the axial length of the cross roller bearing is 51.5 to 79 mm.

6. A crossed roller bearing according to claim 1, characterized in that the number of raceways (13) is provided in two;

and/or at least two raceways (13) are arranged one behind the other in the axial direction of the cross roller bearing;

and/or at least two of said raceways (13) are parallel to each other.

7. A harmonic reducer comprising a crossed roller bearing, wherein the crossed roller bearing is as claimed in any one of claims 1 to 6.

8. The harmonic reducer of claim 7 further comprising a rigid gear; the tooth hardness of the rigid gear is H1; the hardness of the crossed roller bearing is H2; wherein H1< H2.

9. Harmonic reducer according to claim 7, characterized in that it further comprises a central shaft (3); the middle shaft (3) is provided with an axial through hole (31); the axial through hole (31) is a wire passing hole;

and/or the cross section diameter of the axial through hole (31) is 14mm-46 mm.

10. A robot comprising a harmonic reducer, wherein the harmonic reducer is as claimed in any one of claims 7 to 9.