Transmission assembly, speed reducer and industrial robot

Abstract

The invention discloses a transmission assembly, a speed reducer and an industrial robot. The cycloidal gear is provided with a cycloidal gear bearing hole. The planet carrier is provided with a planet carrier bearing hole. And the first bearing is mounted in a cycloidal gear bearing hole. The second bearing is installed in a planet carrier bearing hole. The eccentric shaft comprises a shaft body and an eccentric part. The eccentric part is connected with the shaft. The axis of the eccentric part is parallel to the axis of the shaft body. The eccentric part is connected with the first bearing so as to penetrate through the cycloidal gear bearing hole. The shaft body is connected with the second bearing to penetrate through the planet carrier bearing hole. The eccentric portion includes a first contact surface. The shaft body comprises a second contact surface. And the hole wall of the cycloidal gear bearing hole comprises a third contact surface. And the hole wall of the planet carrier bearing hole comprises a fourth contact surface. And the first contact surface is in contact with the third contact surface through a first bearing. And the second contact surface is in contact with the fourth contact surface through a second bearing. And at least one of the first contact surface, the second contact surface, the third contact surface and the fourth contact surface is a non-cylindrical surface with a non-circular cross section.

Description

Technical Field

[0001] The present invention relates to the technical field of reduction transmission, and in particular to a transmission component, a reducer and an industrial robot. Background Art

[0002] Precision planetary cycloid reducer is the core component of industrial robots, with the advantages of high precision, high rigidity and long life. Precision planetary cycloid reducer contains two-stage reduction parts, the first part is the involute gear planetary transmission device, and the second part is the cycloid pinwheel planetary transmission device. The cycloid pinwheel planetary transmission device includes an eccentric shaft, which is connected to the cycloid wheel through a bearing, and the eccentric shaft is also connected to the planetary carrier through a bearing. However, the connected bearing is the weak link in the life of the reducer, so how to improve the life of the bearing is crucial. Summary of the invention

[0003] The embodiments of the present invention provide a transmission assembly, a reducer and an industrial robot to solve at least one of the above-mentioned technical problems.

[0004] A transmission assembly according to an embodiment of the present invention comprises:

[0005] A cycloidal wheel, wherein the cycloidal wheel is provided with a cycloidal wheel bearing hole;

[0006] A planet carrier, wherein the planet carrier is provided with a planet carrier bearing hole;

[0007] a first bearing and a second bearing, wherein the first bearing is mounted in the cycloid wheel bearing hole, and the second bearing is mounted in the planet carrier bearing hole;

[0008] An eccentric shaft, wherein the eccentric shaft comprises a shaft body and an eccentric portion, wherein the eccentric portion is connected to the shaft body, wherein the axis of the eccentric portion is parallel to the axis of the shaft body, wherein the eccentric portion is connected to the first bearing to pass through the cycloid wheel bearing hole, and wherein the shaft body is connected to the second bearing to pass through the planet carrier bearing hole;

[0009] The eccentric portion includes a first contact surface, the shaft body includes a second contact surface, the hole wall of the cycloid wheel bearing hole includes a third contact surface, the hole wall of the planet carrier bearing hole includes a fourth contact surface, the first contact surface contacts the third contact surface through the first bearing, and the second contact surface contacts the fourth contact surface through the second bearing;

[0010] At least one of the first contact surface, the second contact surface, the third contact surface, and the fourth contact surface is a non-cylindrical surface with a non-circular cross-section.

[0011] In the above-mentioned transmission assembly, by setting at least one of the first contact surface, the second contact surface, the third contact surface and the fourth contact surface as a non-cylindrical surface with a non-circular cross-section, the first contact surface contacts the third contact surface through the first bearing, and the second contact surface contacts the fourth contact surface through the second bearing, so that the contact stress at the contact point between the first contact surface and the third contact surface is evenly distributed, and the contact stress at the contact point between the second contact surface and the fourth contact surface is evenly distributed, thereby improving the strength and stability of the bearing, thereby improving the service life of the bearing.

[0012] In some embodiments, a first through hole is formed in the first bearing, and the eccentric portion passes through the first through hole so that the first contact surface contacts the first bearing.

[0013] In some embodiments, the first bearing includes a first retaining frame and a first needle roller, a plurality of the first needle rollers are arranged around the axis of the first retaining frame and are rotatably connected to the first retaining frame, the first retaining frame is provided with the first through hole, the eccentric portion passes through the first through hole, and the first contact surface contacts the outer wall of the first needle roller.

[0014] In some embodiments, along the first direction of the eccentric portion, outer side walls of at least two of the first needle rollers are in contact with the first contact surface.

[0015] In some embodiments, the second bearing is provided with a second through hole, and the shaft passes through the second through hole so that the second contact surface contacts the second bearing.

[0016] In some embodiments, the second bearing includes a second retaining frame and a second needle roller, a plurality of the second needle rollers are arranged around the axis of the second retaining frame and are rotatably connected to the second retaining frame, the second retaining frame is provided with the second through hole, the shaft body passes through the second through hole, and the second contact surface contacts the outer wall of the second needle roller.

[0017] In some embodiments, along the second direction of the shaft, outer side walls of at least two of the second rollers are in contact with the second contact surface.

[0018] In certain embodiments, the first bearing passes through the cycloidal wheel bearing hole so that an outer side wall of the first needle roller contacts the third contact surface.

[0019] In certain embodiments, the second bearing passes through the planet carrier bearing hole so that an outer sidewall of the second needle roller contacts the fourth contact surface.

[0020] A reducer according to an embodiment of the present invention includes the transmission assembly described in any one of the above embodiments.

[0021] An industrial robot according to an embodiment of the present invention includes the reducer according to the above embodiment.

[0022] In the above-mentioned reducer and industrial robot, by setting at least one of the first contact surface, the second contact surface, the third contact surface and the fourth contact surface as a non-cylindrical surface with a non-circular cross-section, the first contact surface contacts the third contact surface through the first bearing, and the second contact surface contacts the fourth contact surface through the second bearing, so that the contact stress at the contact point between the first contact surface and the third contact surface is evenly distributed, and the contact stress at the contact point between the second contact surface and the fourth contact surface is evenly distributed, thereby improving the strength and stability of the bearing, thereby improving the service life of the bearing.

[0023] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0025] Figure 1 It is one of the partial structural schematic diagrams of the transmission assembly according to the embodiment of the present invention;

[0026] Figure 2 It is a partial structural exploded schematic diagram of a transmission assembly according to an embodiment of the present invention;

[0027] Figure 3 is a schematic structural diagram of an eccentric shaft according to an embodiment of the present invention;

[0028] Figure 4 This is the second partial structural schematic diagram of the transmission assembly according to the embodiment of the present invention;

[0029] Figure 5 This is the third partial structural schematic diagram of the transmission assembly according to the embodiment of the present invention;

[0030] Figure 6 This is a fourth partial structural schematic diagram of a transmission assembly according to an embodiment of the present invention;

[0031] Figure 7 yes Figure 6 A magnified view of part A;

[0032] Figure 8 This is the fifth partial structural schematic diagram of the transmission assembly according to the embodiment of the present invention;

[0033] Fig. 9 yes Figure 8 Enlarged view of part B.

[0034] Reference numerals:

[0035] 100. Transmission assembly; 10. Eccentric shaft; 12. Eccentric part; 14. First contact surface; 16. Shaft body; 18. Second contact surface; 20. Cycloidal wheel; 22. Cycloidal wheel bearing hole; 24. Third contact surface; 26. Planet carrier; 28. Planet carrier bearing hole; 30. Fourth contact surface; 32. First bearing; 34. First needle roller; 36. First retaining frame; 38. First through hole; 40. Second bearing; 42. Second retaining frame; 44. Second through hole; 46. Second needle roller; 48. Trigonometric function curve cylinder; 50. Spline curve cylinder. DETAILED DESCRIPTION

[0036] The embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0037] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In the description of the present invention, "multiple" means two or more, unless otherwise clearly and specifically defined.

[0038] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected" and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection. It can be a mechanical connection or an electrical connection. It can be directly connected or indirectly connected through an intermediate medium. It can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0039] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may include that the first and second features are in direct contact, or may include that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, a first feature being "above", "above" and "above" a second feature includes that the first feature is directly above and obliquely above the second feature, or simply indicates that the first feature is higher in level than the second feature. A first feature being "below", "below" and "below" a second feature includes that the first feature is directly below and obliquely below the second feature, or simply indicates that the first feature is lower in level than the second feature.

[0040] The disclosure herein provides many different embodiments or examples to realize different structures of the present invention. In order to simplify the disclosure of the present invention, the parts and settings of specific examples are described herein. Of course, they are only examples, and the purpose is not to limit the present invention. In addition, the present invention can repeat reference numbers and / or reference letters in different examples, and this repetition is for the purpose of simplification and clarity, which itself does not indicate the relationship between the various embodiments and / or settings discussed. In addition, the examples of various specific processes provided by the present invention, but those of ordinary skill in the art can be aware of the application of other processes.

[0041] Please refer to Figure 1 , Figure 2 and Figure 3 A transmission assembly 100 according to an embodiment of the present invention includes a cycloid wheel 20, a planet carrier 26, a first bearing 32, a second bearing 40 and an eccentric shaft 10. The cycloid wheel 20 is provided with a cycloid wheel bearing hole 22. The planet carrier 26 is provided with a planet carrier bearing hole 28. The first bearing 32 is installed in the cycloid wheel bearing hole 22. The second bearing 40 is installed in the planet carrier bearing hole 28. The eccentric shaft 10 includes a shaft body 16 and an eccentric portion 12. The eccentric portion 12 is connected to the shaft body 16. The axis of the eccentric portion 12 is parallel to the axis of the shaft body 16. The eccentric portion 12 is connected to the first bearing 32 to pass through the cycloid wheel bearing hole 22. The shaft body 16 is connected to the second bearing 40 to pass through the planet carrier bearing hole 28. The eccentric portion 12 includes a first contact surface 14, the shaft body 16 includes a second contact surface 18, and the hole wall of the cycloid wheel bearing hole 22 includes a third contact surface 24. The hole wall of the planet carrier bearing hole 28 includes a fourth contact surface 30. The first contact surface 14 contacts the third contact surface 24 via the first bearing 32. The second contact surface 18 contacts the fourth contact surface 30 via the second bearing 40. At least one of the first contact surface 14, the second contact surface 18, the third contact surface 24 and the fourth contact surface 30 is a non-cylindrical surface with a non-circular cross section.

[0042] In the above-mentioned transmission assembly 100, by setting at least one of the first contact surface 14, the second contact surface 18, the third contact surface 24 and the fourth contact surface 30 as a non-cylindrical surface with a non-circular cross-section, the first contact surface 14 contacts the third contact surface 24 through the first bearing 32, and the second contact surface 18 contacts the fourth contact surface 30 through the second bearing 40, so that the contact stress at the contact point between the first contact surface 14 and the third contact surface 24 is evenly distributed, and the contact stress at the contact point between the second contact surface 18 and the fourth contact surface 30 is evenly distributed, thereby improving the strength and stability of the bearing, thereby improving the service life of the bearing.

[0043] Specifically, in Figure 2 In the illustrated embodiment, the cycloid wheel 20 may be in the shape of a disk. A plurality of cycloid wheel bearing holes 22 may be provided on the end surface of the cycloid wheel 20. The first bearing 32 includes a needle bearing. The first bearing 32 may be mounted in the cycloid wheel bearing hole 22 and connected to the cycloid wheel 20. The planet carrier 26 may be similar to a disk. A plurality of planet carrier bearing holes 28 may be provided on the end surface of the planet carrier 26. The number of the planet carrier bearing holes 28 may correspond to the number of the cycloid wheel bearing holes 22. The second bearing 40 includes a needle bearing. The second bearing 40 may be mounted in the planet carrier bearing hole 28 and connected to the planet carrier 26.

[0044] exist Figure 3 In the embodiment, the shaft body 16 can be fixedly connected to the eccentric part 12. Two eccentric parts 12 can be provided, and the two eccentric parts 12 can be connected to each other. The axes of the two eccentric parts 12 can be represented by P1 and P2 respectively, and the axis of the shaft body 16 can be represented by P3. The axes P1 and P2 of the two eccentric parts 12 can be parallel to the axis P3 of the shaft body 16. In one embodiment, the first bearing 32 can be sleeved on the eccentric part 12, and the eccentric part 12 can be connected to the first bearing 32, so that it can pass through the cycloid wheel bearing hole 22. In one embodiment, the second bearing 40 can be sleeved on the shaft body 16, and the shaft body 16 can be connected to the second bearing 40, so that it can pass through the planetary carrier bearing hole 28.

[0045] The outer wall of the eccentric portion 12 may be formed with a first contact surface 14. The outer wall of the shaft body 16 may be formed with a second contact surface 18. The hole wall of the cycloid wheel bearing hole 22 may be formed with a third contact surface 24. The hole wall of the planet carrier bearing hole 28 may be formed with a fourth contact surface 30. When the eccentric portion 12 is installed in the cycloid wheel bearing hole 22, the first contact surface 14 may contact the first bearing 32, and then indirectly contact the second contact surface 18 through the first bearing 32. When the shaft body 16 is installed in the planet carrier bearing hole 28, the third contact surface 24 may contact the second bearing 40, and then indirectly contact the fourth contact surface 30 through the second bearing 40.

[0046] In one example, the first contact surface 14 may be set to a non-cylindrical surface with a non-circular cross section. In one example, the second contact surface 18 may be set to a non-cylindrical surface with a non-circular cross section. In one example, the third contact surface 24 may be set to a non-cylindrical surface with a non-circular cross section. In one example, the fourth contact surface 30 may be set to a non-cylindrical surface with a non-circular cross section. In one example, any two of the first contact surface 14, the second contact surface 18, the third contact surface 24, and the fourth contact surface 30 may be set to non-cylindrical surfaces with a non-circular cross section. In one example, any three of the first contact surface 14, the second contact surface 18, the third contact surface 24, and the fourth contact surface 30 may be set to non-cylindrical surfaces with a non-circular cross section. In one example, the first contact surface 14, the second contact surface 18, the third contact surface 24, and the fourth contact surface 30 may all be set to non-cylindrical surfaces with a non-circular cross section. That is to say, by setting at least one of the first contact surface 14, the second contact surface 18, the third contact surface 24 and the fourth contact surface 30 as a non-cylindrical surface with a non-circular cross-section, the first contact surface 14 and the third contact surface 24 are connected through the first bearing 32, and the second contact surface 18 and the fourth contact surface 30 are connected through the second bearing 40, so that the contact stress at the contact point between the first contact surface 14 and the third contact surface 24 is evenly distributed, and the contact stress at the contact point between the second contact surface 18 and the fourth contact surface 30 is evenly distributed, thereby improving the strength and stability of the bearing, thereby improving the service life of the bearing.

[0047] It should be noted that stress is a force inside an object, which is generated by the external force acting on the object. In one embodiment, when the bearing is subjected to external forces of equal magnitude and the same direction, the loads borne by the rollers inside the bearing can be evenly distributed by optimizing the cross-sectional shape of the journal or outer ring, thereby reducing the maximum load and contact stress of the rollers and increasing the service life of the bearing. One embodiment is to increase the radius of curvature where the load is concentrated.

[0048] The non-circular cylindrical surface with a non-circular cross section may include an elliptical cylindrical surface, a trigonometric curve cylindrical surface 48, a spline curve cylindrical surface 50, etc. Figure 4 In the illustrated embodiment, the trigonometric function curve cylinder 48 may be in contact with the first bearing 32. Figure 5 In the illustrated embodiment, the spline cylinder 50 may be in contact with the first bearing 32. Figure 6 In the illustrated embodiment, the elliptical cylinder may contact the first bearing 32. It should be noted that the trigonometric curve cylinder 48 is an arcuate surface of a cylinder formed by a trigonometric curve. The spline curve cylinder 50 is an arcuate surface of a cylinder formed by a spline curve. In addition, the elliptical cylinder, the trigonometric curve cylinder 48 and the spline curve cylinder 50 may be non-cylindrical surfaces with non-circular cross-sections formed by slight changes in the cylindrical surface.

[0049] Please combine Figure 6 In some embodiments, the first bearing 32 is provided with a first through hole 38 . The eccentric portion 12 passes through the first through hole 38 so that the first contact surface 14 contacts the first bearing 32 .

[0050] In this way, the contact stress at the contact point where the first bearing 32 contacts the first contact surface 14 can be evenly distributed, thereby increasing the service life of the first bearing 32 .

[0051] Specifically, in Figure 6 In the embodiment, the eccentric portion 12 may be in the shape of an elliptical cylinder. The first contact surface 14 may be an arcuate surface of an elliptical cylinder. The first through hole 38 may be in a circular shape. The eccentric portion 12 may pass through the first through hole 38. The first contact surface 14 may contact and connect the first bearing 32, so that the contact stress at the contact point where the first bearing 32 contacts the first contact surface 14 may be evenly distributed, thereby increasing the service life of the first bearing 32. It should be noted that, in other embodiments, the eccentric portion 12 may also be set to be in the shape of a trigonometric function curve cylinder 48, a spline curve cylinder 50, etc.

[0052] Please combine Figure 6 and Figure 7 In some embodiments, the first bearing 32 includes a first retainer 36 and a first needle roller 34. A plurality of first needle rollers 34 are arranged around the axis of the first retainer 36 and are rotatably connected to the first retainer 36. The first retainer 36 is provided with a first through hole 38. The eccentric portion 12 passes through the first through hole 38. The first contact surface 14 contacts the outer side wall of the first needle roller 34.

[0053] In this way, the contact stress at the contact point between the outer wall of the first needle roller 34 and the first contact surface 14 can be evenly distributed, thereby increasing the service life of the first needle roller 34 and thus increasing the service life of the first bearing 32 .

[0054] Specifically, in Figure 7In the illustrated embodiment, the first retainer 36 may be cylindrical. The first retainer 36 may be provided with a first through hole 38 in a circular shape. The eccentric portion 12 may pass through the first through hole 38. The axis of the first retainer 36 may be a parallel line passing through the center point of the first through hole 38 and parallel to the opening direction of the first through hole 38. A plurality of first needle rollers 34 may be provided. A plurality of first needle rollers 34 are provided around the axis P3 of the first retainer 36. The first needle roller 34 may be rotatably connected to the first retainer 36. The contact point between the outer side wall of the first needle roller 34 and the first contact surface 14 may be represented by S1. In one embodiment, the eccentric portion 12 may pass through the first through hole 38, the outer side wall of the first needle roller 34 may contact the first contact surface 14, and the first contact surface 14 may be provided as an arc surface of an elliptical cylinder, so that the contact stress at the contact point between the outer side wall of the first needle roller 34 and the first contact surface 14 may be uniformly distributed, thereby improving the service life of the first needle roller 34, thereby improving the service life of the first bearing 32.

[0055] It should be noted that, in one embodiment, when the transmission assembly 100 is performing power transmission, the first bearing 32 may be subjected to a swinging force, and the force may be greatest in the direction of the position where the gap between the outer wall of the first needle roller 34 and the first contact surface 14 is the largest, that is, the position where the gap between the first needle roller 34 and the eccentric portion 12 is the largest. By setting the first contact surface 14 to an arc-shaped surface of an elliptical cylinder, the load on the first needle roller 34 in this force direction may be reduced, thereby reducing the contact stress at the contact point between the outer wall of the first needle roller 34 and the first contact surface 14, so that the first needle roller 34 under this force characteristic may obtain an optimal stress distribution, thereby increasing the service life of the first needle roller 34.

[0056] Please combine Figure 7 In some embodiments, along the first direction of the eccentric portion 12 , outer side walls of at least two first needle rollers 34 contact the first contact surface 14 .

[0057] In this way, the force on the first needle roller 34 in the same direction can be reduced, so that the contact stress at the contact point between the outer side wall of the first needle roller 34 and the first contact surface 14 is reduced.

[0058] Specifically, in Figure 7 In the embodiment, the eccentric portion 12 may be in the shape of an elliptical cylinder. The cross section of the eccentric portion 12 may be in the shape of an ellipse. The first direction of the eccentric portion 12 may be the short axis direction of the cross section of the eccentric portion 12, which may be represented by L1. In one embodiment, along the L1 direction of the cross section of the eccentric portion 12, the outer side walls of the two first needle rollers 34 may contact the first contact surface 14, thereby reducing the force on the first needle rollers 34 in the same direction, thereby reducing the contact stress at the contact point between the outer side walls of the first needle rollers 34 and the first contact surface 14.

[0059] In addition, it can be understood that in other embodiments, in the L1 direction, four or other numbers of outer side walls of the first needle rollers 34 may be arranged to contact the first contact surface 14. This arrangement may be made according to specific circumstances and is not specifically limited here.

[0060] Please combine Figure 8 In some embodiments, the second bearing 40 is provided with a second through hole 44 . The shaft 16 passes through the second through hole 44 so that the second contact surface 18 contacts the second bearing 40 .

[0061] In this way, the contact stress at the contact point where the second bearing 40 contacts the third contact surface 24 can be evenly distributed, thereby increasing the service life of the second bearing 40 .

[0062] Specifically, in Figure 8 In the illustrated embodiment, the shaft body 16 may be in the shape of an elliptical cylinder. The third contact surface 24 may be an arcuate surface of an elliptical cylinder. The second through hole 44 may be in a circular shape. The shaft body 16 may pass through the second through hole 44. The third contact surface 24 may contact and connect the second bearing 40, so that the contact stress at the contact point where the second bearing 40 contacts the third contact surface 24 may be evenly distributed, thereby increasing the service life of the second bearing 40. It should be noted that, in other embodiments, the shaft body 16 may also be configured to be in the shape of a trigonometric function curve cylinder 48, a spline curve cylinder 50, etc.

[0063] Please combine Figure 8 and Fig. 9 In some embodiments, the second bearing 40 includes a second retainer 42 and a second needle roller 46. A plurality of second needle rollers 46 are arranged around the axis of the second retainer 42 and are rotatably connected to the second retainer 42. The second retainer 42 is provided with a second through hole 44. The shaft 16 passes through the second through hole 44. The second contact surface 18 contacts the outer side wall of the second needle roller 46.

[0064] In this way, the contact stress at the contact point between the outer wall of the second needle roller 46 and the second contact surface 18 can be evenly distributed, thereby increasing the service life of the second needle roller 46 and thus increasing the service life of the second bearing 40 .

[0065] Specifically, in Fig. 9In the illustrated embodiment, the second retainer 42 may be cylindrical. The second retainer 42 may be provided with a second through hole 44 in a circular shape. The shaft body 16 may be arranged through the second through hole 44. The axis of the second retainer 42 may be a parallel line passing through the center point of the second through hole 44 and parallel to the opening direction of the second through hole 44. A plurality of second needle rollers 46 may be provided. A plurality of second needle rollers 46 may be arranged around the axis P4 of the second retainer 42. The second needle roller 46 may be rotatably connected to the second retainer 42. The contact point between the outer side wall of the second needle roller 46 and the second contact surface 18 may be represented by S2. In one embodiment, the shaft body 16 may be passed through the second through hole 44, and the outer side wall of the second needle roller 46 may be in contact with the second contact surface 18, and the second contact surface 18 may be set as an arc surface of an elliptical cylinder, so that the contact stress at the contact point between the outer side wall of the second needle roller 46 and the second contact surface 18 can be uniformly distributed, thereby improving the service life of the second needle roller 46, thereby improving the service life of the second bearing 40.

[0066] It should be noted that, in one embodiment, when the transmission assembly 100 is performing power transmission, the second bearing 40 may be subjected to a swinging force, and the force may be greatest in the direction of the position where the gap between the second needle roller 46 and the shaft body 16 is largest at the contact point S2 between the outer wall of the second needle roller 46 and the second contact surface 18. By setting the second contact surface 18 to an arcuate surface of an elliptical cylinder, the load on the second needle roller 46 in this force direction may be reduced, thereby reducing the contact stress at the contact point between the outer wall of the second needle roller 46 and the second contact surface 18, so that the second needle roller 46 under this force characteristic may obtain an optimal stress distribution, thereby increasing the service life of the second needle roller 46.

[0067] Please combine Fig. 9 In some embodiments, along the second direction of the shaft body 16 , outer side walls of at least two second needle rollers 46 contact the second contact surface 18 .

[0068] In this way, the force on the second needle roller 46 in the same direction can be reduced, thereby reducing the contact stress at the contact point between the outer side wall of the second needle roller 46 and the second contact surface 18.

[0069] Specifically, in Fig. 9 In the embodiment, the shaft body 16 may be in the shape of an elliptical cylinder. The cross section of the shaft body 16 may be in the shape of an ellipse. The second direction of the shaft body 16 may be the direction of the short axis of the cross section of the shaft body 16, which may be represented by L2. In one embodiment, along the L2 direction of the cross section of the shaft body 16, the outer side walls of the two second needle rollers 46 may contact the second contact surface 18, thereby reducing the force on the second needle rollers 46 in the same direction, thereby reducing the contact stress at the contact point between the outer side walls of the second needle rollers 46 and the second contact surface 18.

[0070] In addition, it can be understood that in other embodiments, in the L2 direction, four or other numbers of outer side walls of the second roller needles 46 may be provided to contact the second contact surface 18. This may be arranged according to specific circumstances and is not specifically limited here.

[0071] Please combine Figure 7 In some embodiments, the first bearing 32 passes through the cycloid wheel bearing hole 22 so that the outer side wall of the first needle roller 34 contacts the third contact surface 24 .

[0072] In this way, the contact stress at the contact point between the outer side wall of the first needle roller 34 and the third contact surface 24 can be evenly distributed, thereby increasing the service life of the first needle roller 34 and thus increasing the service life of the first bearing 32 .

[0073] Specifically, the cycloid wheel bearing hole 22 may be in the shape of an elliptical cylinder. The third contact surface 24 may be an arcuate surface of an elliptical cylinder. In one embodiment, the first bearing 32 may pass through the cycloid wheel bearing hole 22, and the outer wall of the first needle roller 34 may contact the third contact surface 24, so that the contact stress at the contact point between the outer wall of the first needle roller 34 and the third contact surface 24 can be evenly distributed, thereby improving the service life of the first needle roller 34, thereby improving the service life of the first bearing 32. It should be noted that, in other embodiments, the cycloid wheel bearing hole 22 may also be set to be in the shape of a trigonometric function curve cylinder 48, a spline curve cylinder 50, etc.

[0074] Please combine Fig. 9 In some embodiments, the second bearing 40 passes through the planet carrier bearing hole 28 so that the outer side wall of the second needle roller 46 contacts the fourth contact surface 30 .

[0075] In this way, the contact stress at the contact point between the outer wall of the second needle roller 46 and the fourth contact surface 30 can be evenly distributed, thereby increasing the service life of the second needle roller 46 and thus increasing the service life of the second bearing 40 .

[0076] Specifically, the planet carrier bearing hole 28 may be in the shape of an elliptical cylinder. The fourth contact surface 30 may be an arcuate surface of an elliptical cylinder. In one embodiment, the second bearing 40 may pass through the planet carrier bearing hole 28, and the outer side wall of the second needle roller 46 may contact the fourth contact surface 30, so that the contact stress at the contact point between the outer side wall of the second needle roller 46 and the fourth contact surface 30 can be evenly distributed, thereby improving the service life of the second needle roller 46, thereby improving the service life of the second bearing 40. It should be noted that in other embodiments, the planet carrier bearing hole 28 may also be set to be in the shape of a trigonometric function curve cylinder 48, a spline curve cylinder 50, etc.

[0077] Please refer to Figure 1 and Figure 2 A reducer according to an embodiment of the present invention includes a transmission assembly 100 according to any one of the above embodiments.

[0078] An industrial robot according to an embodiment of the present invention includes the reducer according to the above embodiment.

[0079] In the above-mentioned reducer and industrial robot, by setting at least one of the first contact surface 14, the second contact surface 18, the third contact surface 24 and the fourth contact surface 30 as a non-cylindrical surface with a non-circular cross-section, the first contact surface 14 contacts the third contact surface 24 through the first bearing 32, and the second contact surface 18 contacts the fourth contact surface 30 through the second bearing 40, so that the contact stress at the contact point between the first contact surface 14 and the third contact surface 24 is evenly distributed, and the contact stress at the contact point between the second contact surface 18 and the fourth contact surface 30 is evenly distributed, thereby improving the strength and stability of the bearing, thereby improving the service life of the bearing.

[0080] Specifically, the reducer includes a precision planetary cycloid reducer. The reducer can be driven by two stages, the first stage is an involute gear planetary drive, and the second stage is a cycloid pinwheel planetary drive. The reducer includes an RV (Rotary Vector) reducer, which is a core component of an industrial robot and has the advantages of high precision, high rigidity and long life. In one embodiment, the shaft body 16 can be connected to the second bearing 40 to pass through the planetary carrier bearing hole 28, and the eccentric portion 12 can be connected to the first bearing 32 to pass through the cycloidal wheel bearing hole 22. By setting at least one of the first contact surface 14, the second contact surface 18, the third contact surface 24 and the fourth contact surface 30 as a non-cylindrical surface with a non-circular cross-section, the first contact surface 14 contacts the third contact surface 24 through the first bearing 32, and the second contact surface 18 contacts the fourth contact surface 30 through the second bearing 40, so that the contact stress at the contact point between the first contact surface 14 and the third contact surface 24 is evenly distributed, and the contact stress at the contact point between the second contact surface 18 and the fourth contact surface 30 is evenly distributed, thereby improving the strength and stability of the bearing, thereby improving the service life of the bearing.

[0081] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials, or characteristics described in conjunction with the embodiments or examples are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0082] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the claims and their equivalents.

Claims

1. A transmission assembly, characterized in that: include: A cycloidal wheel, wherein the cycloidal wheel is provided with a cycloidal wheel bearing hole; A planet carrier, wherein the planet carrier is provided with a planet carrier bearing hole; a first bearing and a second bearing, wherein the first bearing is mounted in the cycloid wheel bearing hole, and the second bearing is mounted in the planet carrier bearing hole; An eccentric shaft, wherein the eccentric shaft comprises a shaft body and an eccentric portion, wherein the eccentric portion is connected to the shaft body, wherein the axis of the eccentric portion is parallel to the axis of the shaft body, wherein the eccentric portion is connected to the first bearing to pass through the cycloid wheel bearing hole, and wherein the shaft body is connected to the second bearing to pass through the planet carrier bearing hole; The eccentric portion includes a first contact surface, the shaft body includes a second contact surface, the hole wall of the cycloid wheel bearing hole includes a third contact surface, the hole wall of the planet carrier bearing hole includes a fourth contact surface, the first contact surface contacts the third contact surface through the first bearing, and the second contact surface contacts the fourth contact surface through the second bearing; At least one of the first contact surface, the second contact surface, the third contact surface, and the fourth contact surface is a non-cylindrical surface with a non-circular cross-section.

2. The transmission assembly according to claim 1, characterized in that: The first bearing is provided with a first through hole, and the eccentric portion passes through the first through hole so that the first contact surface contacts the first bearing.

3. The transmission assembly according to claim 2, characterized in that: The first bearing includes a first retaining frame and a first needle roller. A plurality of the first needle rollers are arranged around the axis of the first retaining frame and are rotatably connected to the first retaining frame. The first retaining frame is provided with the first through hole. The eccentric portion passes through the first through hole. The first contact surface contacts the outer wall of the first needle roller.

4. The transmission assembly according to claim 3, characterized in that: Along the first direction of the eccentric portion, outer side walls of at least two of the first needle rollers are in contact with the first contact surface.

5. The transmission assembly according to claim 1, characterized in that: The second bearing is provided with a second through hole, and the shaft body passes through the second through hole so that the second contact surface contacts the second bearing.

6. The transmission assembly according to claim 5, characterized in that: The second bearing includes a second retaining frame and a second needle roller. A plurality of the second needle rollers are arranged around the axis of the second retaining frame and are rotatably connected to the second retaining frame. The second retaining frame is provided with the second through hole. The shaft body passes through the second through hole. The second contact surface contacts the outer side wall of the second needle roller.

7. The transmission assembly according to claim 6, characterized in that: Along the second direction of the shaft body, outer side walls of at least two of the second needle rollers are in contact with the second contact surface.

8. The transmission assembly according to claim 3, characterized in that: The first bearing passes through the cycloid wheel bearing hole so that the outer side wall of the first needle roller contacts the third contact surface.

9. The transmission assembly according to claim 6, characterized in that: The second bearing passes through the planet carrier bearing hole so that the outer side wall of the second needle roller contacts the fourth contact surface.

10. A reducer, characterized in that: Comprising the transmission assembly according to any one of claims 1 to 9.

11. An industrial robot, characterized in that: Includes the reducer as described in claim 10.

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