CN115681416A - Planet cycloid pinwheel speed reducer and industrial robot - Google Patents

Abstract

The invention provides a planetary cycloidal pin wheel speed reducer and an industrial robot, belonging to the field of RV speed reducer design. On one hand, the invention improves the assembly efficiency of the whole machine; on the other hand, the eccentric shaft is prevented from inclining and deviating in the reducer, the bending moment rigidity of the crankshaft system is improved, and the bearing capacity of the conical bearing is enhanced; meanwhile, the crankshaft system can normally operate in the speed reducer, so that the operation stability and the service life of the whole machine are improved.

Description

Planetary cycloid pin wheel speed reducer and industrial robot

Technical Field

The invention belongs to the field of RV reducer design, and particularly relates to a planetary cycloidal pin wheel reducer and an industrial robot.

Background

With the continuous deepening of the manufacturing industry, industrial robots have been applied to various fields of industrial production, and gradually replace the repetitive and high-risk work performed by human beings. The reducer for the industrial robot is used as a key part of the industrial robot, occupies about one third of the production cost of the whole industrial robot, and as a key part of the industrial robot, the RV reducer (also called a planetary cycloidal pin wheel reducer) receives more and more attention in all boundaries. The reducer is used as a joint of an industrial robot for transmitting and amplifying power and plays a critical role in the service life and precision of the industrial robot, and the RV reducer is used for high-precision control in a cycloidal pin gear planetary transmission mode.

For the existing speed reducer, the integral bending rigidity of the speed reducer is mainly provided by a main bearing and a tapered roller bearing, wherein the tapered roller bearing is used as a bearing for supporting an eccentric shaft and mainly plays a role in ensuring the rigidity of a crankshaft system, so that the cycloidal gear keeps stable load in the running process and avoids the unbalance loading phenomenon. The rigidity performance of the tapered roller bearing is mainly related to the design of the structural size of the bearing and the installation and matching of the bearing, and the quality of the rigidity performance directly influences the service life of a crankshaft system of the speed reducer, so that the service life of the whole machine is greatly influenced. Therefore, the design innovation on the structure and the installation matching of the tapered roller bearing has important significance on the rigidity and the service life of a prototype. In the traditional reducer structure, the installation and matching of the crankshaft system tapered roller bearing mainly comprise a crankshaft straight shaft section, an inner ring and an outer ring of the tapered roller bearing, a clamp spring and corresponding component bearing holes, wherein the clamp spring is used for limiting the displacement space of the crankshaft in the axial direction, and the part has more structural parts and is complex to install; meanwhile, the independent assembly and matching of the inner ring and the outer ring of the bearing easily generates deformation and errors, which cause the problems of inclination and unbalance loading of the crankshaft in the reducer, and the problems of looseness and axial movement of the eccentric shaft (crankshaft) are easily caused by the deformation and axial displacement of the inner ring and the outer ring of the conical bearing under the load impact of the RV reducer.

Disclosure of Invention

Therefore, the invention provides a planetary cycloidal pin gear speed reducer and an industrial robot, which can solve the technical problems that in the prior art, a tapered roller bearing in an RV speed reducer comprises an inner ring, an outer ring, a clamp spring and the like which are independently designed and processed, the number of parts is large, the installation is complex, and deformation and errors are generated when the inner ring and the outer ring of the bearing which is independently assembled are assembled and matched, so that an eccentric shaft is inclined and unbalanced loaded.

In order to solve the above problems, the present invention provides a planetary cycloidal pin gear speed reducer, including a first casing and an eccentric shaft, wherein the first casing has a bearing conical hole integrally formed thereon, a first shaft end of the eccentric shaft has a bearing conical surface integrally formed thereon, the bearing conical surface is assembled in the bearing conical hole, a plurality of conical rollers are clamped between the bearing conical surface and the bearing conical hole, and large diameter ends of the conical rollers face an eccentric portion of the eccentric shaft.

In some embodiments, a roller limit flange is integrally formed on one end surface of the bearing conical surface facing the eccentric portion.

In some embodiments, a roller limiting end plate is connected to an end face of the first shaft end of the eccentric shaft.

In some embodiments, the roller limiting end plate comprises a plate body and a connecting column at one side of the plate body, and the roller limiting end plate is connected to the end face of the first shaft end through the connecting column in a threaded manner.

In some embodiments, the diameter of the small-diameter hole opening of the bearing conical hole is D, the diameter of the plate body is D, and D-D is more than or equal to 0.007mm and less than or equal to 0.029mm.

In some embodiments, the plate body has a force application structure on an outer side surface thereof.

In some embodiments, the planetary cycloidal pin gear reducer further comprises a second housing having a bearing chamber therein for receiving the second shaft end of the eccentric shaft, the second shaft end of the eccentric shaft being rotatably coupled within the bearing chamber by a tapered roller bearing, and an outer end surface of a bearing outer race of the tapered roller bearing being provided adjacent to a snap spring assembled within an outer end port of the bearing chamber to form an axial stop for the eccentric shaft.

In some embodiments, the first housing is one of a planet carrier and a rigid disk, and the second housing is the other of the planet carrier and the rigid disk.

The invention also provides an industrial robot which comprises the planetary cycloidal pin gear speed reducer.

According to the planet cycloid pinwheel speed reducer and the industrial robot, the bearing conical hole serves as the bearing outer ring, the bearing conical surface serves as the bearing inner ring, and the bearing conical hole and the bearing conical surface form clamping for the conical roller; on the other hand, the inner ring and the outer ring of the bearing are not assembled independently, so that the deformation and the error of installation and matching when the inner ring and the outer ring of the bearing are assembled independently are avoided, the eccentric shaft is prevented from inclining and unbalance loading in the reducer, the bending moment rigidity of the crankshaft system is improved, and the bearing capacity of the conical bearing is further enhanced; meanwhile, the integrally formed inner and outer rings of the bearing can also avoid the problems of looseness and axial movement of the eccentric shaft in the reducer due to deformation and displacement of the inner and outer rings of the cone under load impact, and ensure that the crankshaft system can normally run in the reducer, so that the running stability and the service life of the whole machine are improved. In addition, the tapered roller in the invention independently exists on the bearing conical surface and the bearing conical hole, and can meet different load bearing requirements by changing the number and size of the tapered roller, thereby improving the versatility of the reducer.

Drawings

Fig. 1 is a schematic view of an internal sectional structure of a planetary cycloidal pin gear speed reducer according to an embodiment of the present invention;

fig. 2 is an enlarged schematic view of a partial position in fig. 1.

The reference numbers are given as:

1. a first housing; 11. a bearing conical bore; 2. an eccentric shaft; 21. a bearing conical surface; 22. a roller limit flange; 23. a roller limit end plate; 231. a plate body; 232. connecting columns; 233. a force application structure; 3. a tapered roller; 4. a second housing; 41. a bearing chamber; 5. a tapered roller bearing; 51. a clamp spring; 100. a pin gear housing; 101. a main bearing; 102. a planetary gear; 103. a seal ring; 104. a needle bearing; 105. a cycloid wheel.

Detailed Description

Referring to fig. 1 to 2 in combination, according to an embodiment of the present invention, there is provided a planetary cycloidal pin gear reducer, that is, an RV reducer, including a first housing 1 and an eccentric shaft 2, the first housing 1 has a bearing conical hole 11 integrally formed thereon, a first axial end of the eccentric shaft 2 has a bearing conical surface 21 integrally formed thereon, the bearing conical surface 21 is assembled in the bearing conical hole 11, and a plurality of tapered rollers 3 are clamped between the bearing conical surface 21 and the bearing conical hole 11, a large diameter end of the tapered roller 3 faces an eccentric portion of the eccentric shaft 2, and it can be understood that a small diameter end of the tapered roller 3 faces the eccentric shaft 2 and is located outside the bearing conical hole 11. In the technical scheme, the bearing conical hole 11 serves as a bearing outer ring, the bearing conical surface 21 serves as a bearing inner ring, and the bearing conical hole and the bearing conical surface form a clamping effect on the conical roller 3, namely the technical scheme integrates the bearing inner ring and the bearing outer ring which are independently assembled in the prior art on the first shell 1 and the eccentric shaft 2 respectively, so that on one hand, the number of assembled parts is reduced, the assembly is simplified, and the assembly efficiency of the whole machine is improved; on the other hand, the inner ring and the outer ring of the bearing are not assembled independently, so that the deformation and the error of installation and matching when the inner ring and the outer ring of the bearing are assembled independently are avoided, the eccentric shaft 2 is prevented from inclining and unbalance loading in the reducer, the bending moment rigidity of the crankshaft system is improved, and the bearing capacity of the conical bearing is further enhanced; meanwhile, the integrally formed inner ring and outer ring of the bearing can also avoid the problems of looseness and axial movement of the eccentric shaft in the reducer due to deformation and displacement of the inner ring and outer ring of the cone under load impact, and ensure that the crankshaft system can normally run in the reducer, so that the running stability and the service life of the whole machine are improved. In addition, the tapered roller 3 in the invention is independent of the bearing conical surface 21 and the bearing conical hole 11, and can meet different load bearing requirements by changing the number and size of the tapered roller, thereby improving the versatility (universality) of the speed reducer. It should be particularly noted that the reducer formed by the technical scheme of the invention can bear larger overturning moment, and reduce the radial movement of the eccentric shaft 2 in the reducer, thereby ensuring the stable operation of the cycloid wheel in the reducer, and improving the rigidity and the service life of the whole planetary cycloid pin wheel reducer.

Specifically, in a planetary cycloidal pin gear reducer in the prior art, an original structure of a rigid disc is used for limiting and pre-tightening an eccentric shaft assembly by using a clamp spring groove and a clamp spring, the known structure needs to install three conical bearing outer rings and three clamp springs at one end of a planet carrier, the clamp springs need to be additionally processed to ensure a certain thickness to ensure the pre-tightening of a crankshaft assembly, and the conical bearing inner rings also need to be installed on the eccentric shaft.

In order to ensure that the eccentric shaft assembly has enough bending moment rigidity, the known eccentric shaft structure needs to process clamp springs with different sizes at two ends of the eccentric shaft according to the sizes of parts to position and pre-tighten an eccentric shaft bearing to ensure the rigidity, the method has the advantages of large number of parts, complex installation process, deformation of an outer ring of a conical bearing in the installation process, and radial play of the eccentric shaft in the operation process of the speed reducer.

Referring to fig. 1, the eccentric shaft 2 includes a straight shaft section and an eccentric portion, and in a preferred embodiment, a roller limit flange 22 is integrally formed on an end surface of the bearing conical surface 21 facing the eccentric portion to limit a large diameter end of a circular rolling towards a small diameter end, and the integrally formed roller limit flange 22 can further reduce the number of assembled parts and improve the assembly efficiency. In the actual assembly process, only need will earlier place a plurality of tapered rollers 3 in bearing circular cone hole 11, later insert eccentric shaft 2 by this bearing circular cone hole 11's big aperture one side to aperture one side, can utilize tapered roller 3's size characteristic to realize spacing an axial of eccentric shaft 2, the equipment is very simple, convenient.

Referring to fig. 2, a roller limiting end plate 23 is connected to an end surface of the first shaft end of the eccentric shaft 2, and when the eccentric shaft 2 axially moves, the roller limiting end plate 23 can drive the plurality of tapered rollers 3 on one side of the eccentric shaft to move towards the moving direction, so that the smoothness of rotation and the supporting rigidity are ensured.

In a specific embodiment, the roller-limiting end plate 23 includes a plate body 231 and a connecting column 232 at one side of the plate body 231, the roller-limiting end plate 23 is screwed to the end surface of the first shaft end through the connecting column 232, and the reliable and convenient connection of the roller-limiting end plate 23 is realized by screwing. In a preferred embodiment, a force application structure 233 is provided on an outer side surface (also referred to as an outer side end surface) of the plate body 231, and the roller limiting end plate 23 can be screwed and removed very conveniently through the force application structure 233, and the force application structure 233 may be, for example, a hexagonal groove. Of course, in some working conditions, the roller limiting end plate 23 can also be connected with the eccentric shaft 2 by means of a snap connection.

The roller limiting end plate 23 can also be used for preventing lubricating grease at the tapered roller 3 from leaking, and for this purpose, the diameter of the small-diameter hole opening of the bearing tapered hole 11 is D, the diameter of the plate body 231 is D, and D-D is more than or equal to 0.007mm and less than or equal to 0.029mm.

With reference to fig. 1, the planetary cycloidal pin gear speed reducer further includes a second housing 4, the second housing 4 has a bearing chamber 41 for accommodating a second shaft end of the eccentric shaft 2, the second shaft end of the eccentric shaft 2 is rotatably connected to the bearing chamber 41 through a tapered roller bearing 5, an outer end surface of a bearing outer ring of the tapered roller bearing 5 is adjacently provided with a snap spring 51, and the snap spring 51 is assembled in an outer end port of the bearing chamber 41 to form an axial limit for the eccentric shaft 2, that is, in this technical solution, the limit for the axial displacement of the eccentric shaft 2 is realized through shapes of the snap spring 51 and the tapered roller 3, and the assembly is simple and convenient to implement.

Specifically, the first casing 1 is one of a carrier and a rigid disk, and the second casing 4 is the other of the carrier and the rigid disk. As shown in fig. 1, the first housing 1 is a planet carrier, the second housing 4 is a rigid disk, and the RV reducer further includes a pin gear housing 100, a main bearing 101, a planetary gear 102, a seal ring 103, a needle bearing 104, and a cycloid gear 105.

According to an embodiment of the present invention, there is also provided an industrial robot including the planetary cycloidal pin gear reducer described above.

Those skilled in the art will readily appreciate that the advantageous features of the above described modes can be freely combined, superimposed without conflict.

The present invention is not limited to the above preferred embodiments, and any modifications, equivalents and improvements made within the spirit and principle of the present invention should be included in the protection scope of the present invention. The above is only a preferred embodiment of the present invention, and it should be noted that, for those skilled in the art, several improvements and modifications can be made without departing from the technical principle of the present invention, and these improvements and modifications should also be regarded as the protection scope of the present invention.

Claims (9)

1. A planet cycloid pin gear speed reducer comprises a first shell (1) and an eccentric shaft (2), and is characterized in that the first shell (1) is provided with a bearing conical hole (11) integrally formed in the first shell, the first shaft end of the eccentric shaft (2) is provided with a bearing conical surface (21) integrally formed in the eccentric shaft, the bearing conical surface (21) is assembled in the bearing conical hole (11), a plurality of conical rollers (3) are clamped between the bearing conical surface (21) and the bearing conical hole (11), and the large-diameter ends of the conical rollers (3) face an eccentric part of the eccentric shaft (2).

2. A planetary cycloidal pin gear reducer according to claim 1 in which a roller limit flange (22) is integrally formed on one side end surface of the bearing conical surface (21) facing the eccentric portion.

3. A planetary cycloidal pin gear reducer according to claim 1, in which a roller limit end plate (23) is attached to the end face of the first shaft end of the eccentric shaft (2).

4. A planetary cycloidal pin gear reducer according to claim 3, in which the roller-limiting end plate (23) comprises a plate body (231) and a connecting column (232) on one side of the plate body (231), the roller-limiting end plate (23) being screwed onto the end face of the first shaft end through the connecting column (232).

5. A planetary cycloidal pin gear reducer according to claim 4 in which the bearing conical bore (11) has a minor diameter orifice D, the plate body (231) has a diameter D, D-D is 0.007 mm-0.029 mm.

6. A planetary cycloidal pin gear reducer according to claim 4, in which the plate (231) has a force application structure (233) on its outer side.

7. A planetary cycloidal pin gear reducer according to claim 1, further comprising a second housing (4), the second housing (4) having a bearing chamber (41) therein for receiving the second shaft end of the eccentric shaft (2), the second shaft end of the eccentric shaft (2) being rotatably connected within the bearing chamber (41) by a tapered roller bearing (5), and an outer end face of a bearing outer race of the tapered roller bearing (5) being provided adjacent to a snap spring (51), the snap spring (51) being assembled within an outer end opening of the bearing chamber (41) to form an axial limit to the eccentric shaft (2).

8. A planetary cycloidal pin gear reducer according to claim 7, in which the first housing (1) is one of a planet carrier and a rigid disc and the second housing (4) is the other of a planet carrier and a rigid disc.

9. An industrial robot characterized by comprising a planetary cycloidal pin gear reducer according to any one of claims 1 to 8.

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