Wave generator, harmonic reducer and robot

Abstract

The utility model discloses a wave generator, harmonic reducer and robot, relate to harmonic reducer technical field, and the wave generator includes cam and flexible bearing, and the cam is along the axial direction of cam, and the at least partial wall surface of the outer peripheral wall of cam is inclined to the axis of cam and forms the inclined surface, the flexible bearing is covered to the cam outside, and the flexible bearing is with cam interference fit, and along the axial direction of cam, and the outer peripheral wall of flexible bearing is inclined to the axis of cam and sets up, and according to the wave generator of the utility model embodiment, is used for and the flexible gear cooperation, and can improve the service life of flexible gear.

Description

Technical Field

[0001] This utility model relates to the field of harmonic reducer technology, and in particular to a wave generator, a harmonic reducer and a robot. Background Technology

[0002] In the assembly of harmonic reducers, the wave generator and the flex wheel need to be interference-fitted. At this time, the gear section of the flex wheel is deformed outward in a trumpet shape. Since the wave generator as a whole has great rigidity in the radial direction, it is in line contact with the inner wall of the flex wheel. The flex wheel will experience stress concentration, which can easily cause cracking or breakage, thus reducing the service life of the flex wheel. Utility Model Content

[0003] This invention aims to solve at least one of the technical problems existing in the prior art. To this end, this invention proposes a wave generator for use with a flexspline, which can improve the service life of the flexspline.

[0004] This utility model also proposes a harmonic reducer and a robot having the above-mentioned wave generator.

[0005] The wave generator according to an embodiment of the present invention includes a cam and a flexible bearing. The cam is axially inclined, and at least a portion of the outer peripheral wall of the cam is inclined to the axis of the cam to form an inclined surface. The flexible bearing is sleeved on the outside of the cam and is interference-fitted with the cam. The outer peripheral wall of the flexible bearing is inclined to the axis of the cam along the axial direction of the cam.

[0006] The wave generator according to the embodiments of this utility model has at least the following beneficial effects: Since the cam is along its axial direction, at least a portion of the outer peripheral wall of the cam is inclined towards the cam's axis to form an inclined surface; the flexible bearing is sleeved outside the cam, and the flexible bearing is interference-fitted with the cam. Along the axial direction of the cam, the outer peripheral wall of the flexible bearing is inclined towards the cam's axis. Therefore, when the wave generator and the flexible wheel are installed and fitted, the gear segment of the flexible wheel expands and deforms outward, matching the inclined direction of the outer peripheral wall of the flexible bearing. Thus, the outer peripheral wall of the flexible bearing fits against the inner wall of the outwardly deformed gear segment, and the two are in surface contact, reducing stress concentration between the wave generator and the flexible wheel and improving the service life of the flexible wheel.

[0007] According to one embodiment of the present invention, along the axial direction of the cam, the two ends of the inclined surface are respectively connected to the two end faces of the cam.

[0008] According to one embodiment of the present invention, along the axial direction of the cam, one end of the inclined surface is connected to one end face of the cam, and the other end is located between the two end faces of the cam.

[0009] According to one embodiment of the present invention, the cam is formed by cutting the outer peripheral wall of the cam to be processed. The design interference between the cam and the flexible bearing is δ. Along the radial direction of the cam, the distances from the outer peripheral wall of the cam to be processed to the two ends of the inclined surface are h1 and h2, respectively, satisfying: max[h1,h2]=h, 2δ≥h>0.

[0010] According to one embodiment of the present invention, the cam is formed by cutting the outer peripheral wall of the cam to be processed. The axial length of the cam is L0. The two ends of the inclined surface are connected to form an ideal side surface. The ideal side surface intersects the surface of the outer peripheral wall of the cam to be processed to form an intersection line. Along the axial direction of the cam, the distances between the intersection line and the two ends of the inclined surface are L1 and L2, respectively, satisfying: max[L1,L2]=L, 2L0≥L>0.

[0011] According to one embodiment of the present invention, in any cross-section of the cam, the outline of the inclined surface is elliptical.

[0012] According to one embodiment of the present invention, in the longitudinal section of the cam, the outline of the inclined surface is a straight line segment, a circular arc, a parabola, or a broken line.

[0013] According to an embodiment of the present invention, a harmonic reducer includes a flexible wheel, a rigid wheel, and a wave generator of the present invention. The outer peripheral wall of the flexible bearing is interference-fitted with the inner wall of the flexible wheel. The smaller end face of the cam faces away from the gear segment port of the flexible wheel. The flexible wheel meshes with the rigid wheel.

[0014] The harmonic reducer according to the embodiments of this utility model has at least the following beneficial effects: Since the wave generator can improve the service life of the flexure, and simultaneously, when the outer peripheral wall of the flexible bearing outer ring is in surface contact with the inner wall of the gear segment, the outward expansion angle of the gear segment decreases, and the effective meshing tooth width between the flexure and the rigid wheel increases, further improving the service life of the flexure. Overall, the service life of the harmonic reducer is also improved.

[0015] According to one embodiment of the present invention, the flexible wheel includes a gear segment, a transition segment and a flange segment connected in sequence, and the outer peripheral wall of the flexible bearing is interference-fitted with the inner wall of the gear segment.

[0016] The robot according to an embodiment of the present invention includes the harmonic reducer of the present invention.

[0017] The robot according to the embodiments of this utility model has at least the following beneficial effects: since the service life of the harmonic reducer is improved, the service life of the robot is also improved, which better meets the needs of customers.

[0018] Additional aspects and advantages of this invention will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of the invention. Attached Figure Description

[0019] The present invention will be further described below with reference to the accompanying drawings and embodiments, wherein:

[0020] Figure 1 This is a cross-sectional view of the cam of a wave generator according to an embodiment of the present invention;

[0021] Figure 2 This is a cross-sectional view of the cam of the wave generator according to another embodiment of the present invention;

[0022] Figure 3 This is a cross-sectional view of a harmonic reducer according to an embodiment of the present invention;

[0023] Figure 4 for Figure 3 Enlarged view of point A in the middle.

[0024] Figure label:

[0025] Harmonic reducer 1000;

[0026] Wave generator 100; Cam 110; Inclined surface 111; Intersection line 112; Flexible bearing 120;

[0027] Flexible wheel 200; gear section 210; transition section 220; flange section 230. Detailed Implementation

[0028] The embodiments of this utility model are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this utility model, and should not be construed as limiting this utility model.

[0029] In the description of this utility model, it should be understood that the orientation descriptions, such as up, down, inside, outside, etc., are based on the orientation or positional relationship shown in the drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0030] In the description of this utility model, the use of "first" and "second" is only for the purpose of distinguishing technical features and should not be construed as indicating or implying relative importance or implicitly indicating the number of technical features or the order of the technical features.

[0031] In the description of this utility model, unless otherwise explicitly defined, terms such as "setting," "installation," and "connection" should be interpreted broadly, and those skilled in the art can reasonably determine the specific meaning of the above terms in this utility model in conjunction with the specific content of the technical solution.

[0032] Harmonic reducers possess unique advantages such as high load capacity, large transmission ratio, small size, light weight, smooth transmission, and high transmission accuracy, and are widely used in fields such as industrial robots. A harmonic reducer typically consists of a wave generator, a flex wheel, and a rigid wheel. During assembly, the wave generator and flex wheel need to be interference-fitted, and the gear section of the flex wheel needs to mesh with the internal teeth of the rigid wheel.

[0033] In the interference fit between the wave generator and the flexure, the wave generator's high radial stiffness results in line contact between it and the inner wall of the flexure. This leads to an excessively large outward expansion angle of the flexure, causing stress concentration and making it prone to cracking or breakage, thus reducing its service life. Furthermore, the excessive outward expansion angle results in a smaller effective meshing tooth width when the flexure's gear section meshes with the rigid wheel's internal teeth, increasing the stress between them and further affecting the flexure's service life. Clearly, the flexure's service life affects the harmonic reducer's service life, and further, the service life of industrial robots.

[0034] Therefore, one embodiment of this utility model provides a wave generator 100, as detailed in the accompanying drawings. Figures 1 to 4 As shown.

[0035] Reference Figure 1 As shown, a wave generator 100 according to an embodiment of the present invention includes a cam 110. It should be noted that, along the axial direction of the cam 110, at least a portion of the outer peripheral wall of the cam 110 is inclined towards the axis of the cam 110 to form an inclined surface 111. It can be understood that, through the above arrangement, the area of ​​one end face of the cam 110 is larger than the area of ​​the other end face. Along the direction from the end face with the larger area to the end face with the smaller area, at least a portion of the outer peripheral wall of the cam 110 is inclined towards the axis of the cam 110.

[0036] Continue to refer to Figure 1As shown, in one embodiment, along the axial direction of the cam 110, both ends of the inclined surface 111 are connected to the two end faces of the cam 110. That is, one end of the inclined surface 111 along the axial direction of the cam 110 is connected to one end face of the cam 110, and the other end of the inclined surface 111 along the axial direction of the cam 110 is connected to the other end face of the cam 110. It can be understood that, through the above arrangement, along the axial direction of the cam 110, all the wall surfaces of the outer peripheral wall of the cam 110 are inclined towards the axis of the cam 110 to form the inclined surface 111, making the area of ​​the inclined surface 111 larger. This makes it easier to assemble with the flexible bearing 120 later. It should be noted that when both ends of the inclined surface 111 are connected to the two end faces of the cam 110 along the axial direction of the cam 110, the cam 110 is actually an elliptic frustum structure.

[0037] Reference Figure 2 As shown, in another embodiment, along the axial direction of the cam 110, one end of the inclined surface 111 is connected to one end face of the cam 110, and the other end is located between the two end faces of the cam 110. It can be understood that in this case, only a portion of the outer peripheral wall of the cam 110 is inclined along the axis of the cam 110 to form the inclined surface 111; that is, there are non-inclined wall surfaces in the outer peripheral wall of the cam 110. In fact, along the axial direction of the cam 110, one end of the inclined surface 111 is connected to one end face of the cam 110, and the other end is connected to the non-inclined wall surface in the outer peripheral wall of the cam 110. It should be noted that when one end of the inclined surface 111 is connected to one end face of the cam 110 along the axial direction of the cam 110, and the other end is located between the two end faces of the cam 110, the cam 110 is actually formed by combining an elliptical cylinder structure and an elliptical frustum structure.

[0038] In one embodiment of the wave generator 100 of this utility model, the cross-section is a surface perpendicular to the axial direction of the cam 110. It should be noted that in any cross-section of the cam 110, the outline of the inclined surface 111 is elliptical. It is understood that this configuration allows the cam 110 to perform its function more effectively. In another embodiment, in any cross-section of the cam 110, the outline of the inclined surface 111 is a closed line segment approximately elliptical, composed of multiple broken lines. It should be noted that the number of broken lines and the length of each broken line segment are not specifically limited; as long as the multiple broken lines can be connected end-to-end to form a closed line segment approximately elliptical, it is acceptable. In another embodiment, in any cross-section of the cam 110, the outline of the inclined surface 111 is a closed line segment approximately elliptical, composed of multiple wavy lines. It should be noted that the number of wavy lines and the length of each wavy line segment are not specifically limited; as long as the multiple wavy lines can be connected end-to-end to form a closed line segment approximately elliptical, it is acceptable.

[0039] In one embodiment of the wave generator 100 of this utility model, it should be noted that the cam to be processed is elliptical cylindrical, and its outer peripheral wall is machined to form a cam 110. At this time, the outer peripheral wall of the cam 110 is machined with an inclined surface 111. The machining method includes turning, grinding, etc., and is not specifically limited here. (Refer to...) Figure 1 and Figure 2 As shown, it should be noted that the design interference between cam 110 and flexible bearing 120 is δ, which is selected by the engineer when designing wave generator 100. Along the radial direction of cam 110, the distances from the outer peripheral wall of the cam to be processed to the two ends of inclined surface 111 are h1 and h2, respectively, satisfying: max[h1,h2]=h, 2δ≥h>0. That is, the maximum value of h1 and h2 is selected as h. In addition, the axial length of cam 110 is L0, and the two ends of inclined surface 111 are connected to form an ideal side surface. The ideal side surface intersects with the surface where the outer peripheral wall of the cam to be processed is located to form an intersection line 112. It should be noted that the ideal side surface refers to a surface that can extend infinitely, and the surface where the outer peripheral wall of the cam to be processed is located refers to a surface that can extend infinitely. Along the axial direction of cam 110, the distances from intersection line 112 to the two ends of inclined surface 111 are L1 and L2, respectively, satisfying: max[L1,L2]=L, 2L0≥L>0. That is, the maximum value between L1 and L2 is selected as L. It should be noted that the above range of values ​​for L and h makes the structure of the inclined surface 111 more reasonable.

[0040] Reference Figure 1 and Figure 2 As shown, the longitudinal section refers to the section along the axial direction of the cam 110. In one embodiment, the contour line of the inclined surface 111 in the longitudinal section of the cam 110 is a straight line segment. If, along the axial direction of the cam 110, the two ends of the inclined surface 111 are connected to the two end faces of the cam 110, the cam 110 as a whole is frustum-shaped. In this embodiment, in the longitudinal section of the cam 110, the distances from the outer peripheral wall contour line of the cam to be processed to the two endpoints of the straight line segment are h1 and h2, respectively, as described above. The line connecting the two endpoints of the straight line segment is the contour line of the ideal side surface in the longitudinal section of the cam 110, and in this case, the contour line of the ideal side surface in the longitudinal section of the cam 110 coincides with the straight line segment.

[0041] In another embodiment, the contour line of the inclined surface 111 in the longitudinal section of the cam 110 is an arc. It should be noted that the arc can expand outwards away from the axis of the cam 110, or it can be concave inwards towards the axis of the cam 110. When the arc expands outwards away from the axis of the cam 110, if the two ends of the inclined surface 111 are connected to the two end faces of the cam 110 along the axial direction of the cam 110, the cam 110 as a whole resembles a drum shape with one end face larger than the other. In this embodiment, in the longitudinal section of the cam 110, the distances from the outer peripheral wall contour line of the cam to be processed to the two endpoints of the arc are h1 and h2, respectively, as described above. The line connecting the two endpoints of the arc is the contour line of the ideal side surface in the longitudinal section of the cam 110; in this case, the contour line of the ideal side surface in the longitudinal section of the cam 110 does not coincide with the arc.

[0042] In another embodiment, the contour line of the inclined surface 111 in the longitudinal section of the cam 110 is a parabola. It should be noted that the parabola can expand outwards away from the axis of the cam 110, or it can be concave inwards towards the axis of the cam 110. When the parabola expands outwards away from the axis of the cam 110, if the two ends of the inclined surface 111 are connected to the two end faces of the cam 110 along the axial direction of the cam 110, the cam 110 as a whole resembles a drum shape with one end face larger than the other. In this embodiment, in the longitudinal section of the cam 110, the distances from the outer peripheral wall contour line of the cam to be processed to the two endpoints of the parabola are h1 and h2, respectively, as described above. The line connecting the two endpoints of the parabola is the contour line of the ideal side surface in the longitudinal section of the cam 110; in this case, the contour line of the ideal side surface in the longitudinal section of the cam 110 does not coincide with the parabola.

[0043] In another embodiment, the contour line of the inclined surface 111 in the longitudinal section of the cam 110 is a broken line. It should be noted that the broken line can bend outwards in a direction away from the axis of the cam 110, or it can bend inwards in a direction closer to the axis of the cam 110. When the broken line bends outwards in a direction away from the axis of the cam 110, if the two ends of the inclined surface 111 are connected to the two end faces of the cam 110 along the axial direction of the cam 110, the cam 110 as a whole resembles a combination of two frustum structures. In this embodiment, in the longitudinal section of the cam 110, the distances from the outer peripheral wall contour line of the cam to be processed to the two endpoints of the broken line are h1 and h2 as described above. The line connecting the two endpoints of the broken line is the contour line of the ideal side surface in the longitudinal section of the cam 110; in this case, the contour line of the ideal side surface in the longitudinal section of the cam 110 does not coincide with the broken line.

[0044] Reference Figure 3As shown, a wave generator 100 according to an embodiment of the present invention includes a flexible bearing 120. The flexible bearing 120 is sleeved on the outside of the cam 110, and the flexible bearing 120 and the cam 110 are interference-fitted. It should be noted that due to the pressing action of the flexible bearing 120 and the cam 110, the outer peripheral wall of the flexible bearing 120 is inclined towards the axis of the cam 110 along the axial direction of the cam 110. It should be noted that the flexible bearing 120 is a ball bearing, which includes an inner ring, an outer ring, and balls. Specifically, the outer peripheral wall of the flexible bearing 120 is inclined towards the axis of the cam 110 along the axial direction of the cam 110; the inner ring is inclined towards the axis of the cam 110, and the outer ring is inclined towards the axis of the cam 110.

[0045] Continue to refer to Figure 3 As shown, the wave generator 100 is used to cooperate with the flexible wheel 200. When the wave generator 100 and the flexible wheel 200 are installed and fitted, the gear segment 210 of the flexible wheel 200 expands and deforms outward, and mates with the inclined direction of the outer peripheral wall of the flexible bearing 120. (Refer to...) Figure 4 As shown, the outer peripheral wall of the flexible bearing 120 is attached to the inner wall of the outwardly deformed gear segment 210, and the two are in surface contact. This reduces the outward expansion angle β of the gear segment 210 of the flexible wheel 200, thereby reducing the stress concentration phenomenon between the wave generator 100 and the flexible wheel 200 and improving the service life of the flexible wheel 200.

[0046] One embodiment of this utility model provides a harmonic reducer 1000, as detailed in the accompanying drawings. Figure 3 and Figure 4 As shown, it includes a flexible wheel 200, a rigid wheel, and a wave generator 100 according to this embodiment of the invention. It should be noted that the flexible wheel 200 includes a gear section 210, a transition section 220, and a flange section 230. The gear section 210, transition section 220, and flange section 230 are connected sequentially. The flange section 230 is used for mounting the harmonic reducer 1000, and the gear section 210 is used for meshing with the internal teeth of the rigid wheel. The outer peripheral wall of the flexible wheel 200 is interference-fitted with the inner wall of the gear section 210. The smaller end face of the cam 110 faces away from the port of the gear section 210 of the flexible wheel 200, that is, towards the end of the flexible wheel 200 facing away from the port of the gear section 210.

[0047] According to the harmonic reducer 1000 of this utility model embodiment, since the wave generator 100 can improve the service life of the flexible gear 200, and at the same time, when the outer peripheral wall of the outer ring of the flexible bearing 120 is in surface contact with the inner wall of the gear segment 210, the outward expansion angle of the gear segment 210 becomes smaller, and the effective meshing tooth width between the flexible gear 200 and the rigid gear becomes larger, further improving the service life of the flexible gear 200. Overall, the service life of the harmonic reducer 1000 is also improved. Since the harmonic reducer 1000 adopts all the technical solutions of the wave generator 100 of the above embodiment, it has at least all the beneficial effects brought about by the technical solutions of the above embodiment, which will not be repeated here.

[0048] One embodiment of this utility model provides a robot, which includes a harmonic reducer 1000 according to this utility model embodiment.

[0049] According to the embodiments of this utility model, the service life of the robot is also improved because the service life of the harmonic reducer 1000 is increased, thus better meeting customer needs. Since the robot adopts all the technical solutions of the harmonic reducer 1000 of the above embodiments, it possesses at least all the beneficial effects brought about by the technical solutions of the above embodiments, which will not be elaborated further here.

[0050] The embodiments of the present utility model have been described in detail above with reference to the accompanying drawings. Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present utility model, and not to limit it. Although the present utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present utility model.

Claims

1. A wave generator, characterized in that, include: A cam, along the axial direction of the cam, at least a portion of the outer peripheral wall of the cam is inclined to the axis of the cam to form an inclined surface; A flexible bearing is sleeved on the outside of the cam. The flexible bearing is interference-fitted with the cam. Along the axial direction of the cam, the outer peripheral wall of the flexible bearing is inclined towards the axis of the cam.

2. The wave generator according to claim 1, characterized in that, Along the axial direction of the cam, the two ends of the inclined surface are respectively connected to the two end faces of the cam.

3. The wave generator according to claim 1, characterized in that, Along the axial direction of the cam, one end of the inclined surface is connected to one end face of the cam, and the other end is located between the two end faces of the cam.

4. The wave generator according to claim 1, characterized in that, The cam is formed by cutting its outer peripheral wall through a cam to be processed. The design interference between the cam and the flexible bearing is δ. Along the radial direction of the cam, the distances from the outer peripheral wall of the cam to the two ends of the inclined surface are h1 and h2, respectively, satisfying: max[h1,h2]=h, 2δ≥h>0.

5. The wave generator according to claim 1, characterized in that, The cam is formed by cutting its outer peripheral wall through a cam to be processed. The axial length of the cam is L0. The two ends of the inclined surface are connected to form an ideal side surface. The ideal side surface intersects the surface of the outer peripheral wall of the cam to be processed to form an intersection line. Along the axial direction of the cam, the distances between the intersection line and the two ends of the inclined surface are L1 and L2, respectively, satisfying: max[L1,L2]=L, 2L0≥L>0.

6. The wave generator according to claim 1, characterized in that, In any cross-section of the cam, the profile of the inclined surface is elliptical.

7. The wave generator according to claim 1, characterized in that, In the longitudinal section of the cam, the contour line of the inclined surface is a straight line segment, a circular arc, a parabola, or a broken line.

8. A harmonic reducer, characterized in that, The device includes a flexible wheel, a rigid wheel, and a wave generator as described in any one of claims 1 to 7, wherein the outer peripheral wall of the flexible bearing is interference-fitted with the inner wall of the flexible wheel, the smaller end face of the cam faces away from the gear segment port of the flexible wheel, and the flexible wheel meshes with the rigid wheel.

9. The harmonic reducer according to claim 8, characterized in that, The flexible wheel includes a gear section, a transition section, and a flange section connected in sequence, and the outer peripheral wall of the flexible bearing is interference-fitted with the inner wall of the gear section.

10. A robot, characterized in that, Includes the harmonic reducer as described in any one of claims 8 to 9.

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