Harmonic reducer

Abstract

The utility model relates to the technical field of speed reduction transmission, and provides a harmonic reducer which is characterized in that an inner ring of a flexible bearing is fixedly sleeved on the peripheral side of a cam; the flexible bearing is sleeved with the flexible gear, the flexible gear and the cam are coaxially arranged, a mounting groove is formed in the flexible gear around the axis of the flexible gear, the first side wall of the mounting groove is adjacent to the flexible bearing, the first side wall can elastically deform and is sunken towards the interior of the mounting groove under the action of the long axis part of the cam, and flexible teeth are arranged on the side, facing the mounting groove, of the first side wall; the rigid gear is annular and placed in the mounting groove, rigid teeth are arranged on the side, facing the cam, of the rigid gear, and part of the flexible teeth can be meshed with the rigid teeth. According to the harmonic reducer, the rigid gear is mounted in the flexible gear in the mode that the mounting groove is formed in the flexible gear, so that the flexible gear and the rigid gear are disengaged and engaged in the mounting groove, the axial length of the harmonic reducer in the cam direction is reduced, the overall size is reduced, and the applicability of the harmonic reducer is higher.

Description

Technical Field

[0001] The utility model relates to the technical field of speed reduction transmission, in particular to a harmonic reducer. Background Art

[0002] A harmonic reducer mainly consists of four basic components: a wave generator, a flexible gear, a flexible bearing, and a rigid gear. A harmonic drive reducer is a gear drive that relies on the wave generator assembled with a flexible bearing to cause the flexible gear to generate controllable elastic deformation and mesh with the rigid gear to transmit motion and power.

[0003] Commonly, the rigid gear and the flexible gear are respectively connected to the inner and outer rings of a crossed roller bearing. The rigid gear and the flexible gear are in a sleeved relationship, but the rigid gear, the flexible gear, and the crossed roller bearing are axially fixed, resulting in a relatively large axial dimension of the harmonic reducer and limited application scenarios.

[0004] Therefore, there is an urgent need for a harmonic reducer to solve the above technical problems. Summary of the Utility Model

[0005] The purpose of the utility model is to provide a harmonic reducer that can reduce the axial dimension of the harmonic reducer, reduce the overall volume, and improve its applicability.

[0006] To achieve the above purpose, the utility model adopts the following technical solutions:

[0007] A harmonic reducer, comprising:

[0008] A cam;

[0009] A flexible bearing, the inner ring of the flexible bearing is fixedly sleeved on the outer peripheral side of the cam;

[0010] A flexspline, the flexspline is sleeved outside the flexible bearing and is coaxially arranged with the cam. The flexspline is provided with an installation groove around its own axis. The first side wall of the installation groove is adjacent to the flexible bearing. The first side wall can undergo elastic deformation. The first side wall is recessed into the installation groove under the action of the long axis part of the cam. A flexible tooth is arranged on the side of the first side wall facing the installation groove;

[0011] A rigid gear, the rigid gear is annular and is placed in the installation groove. Rigid teeth are arranged on the side of the rigid gear facing the cam. Some of the flexible teeth can mesh with the rigid teeth.

[0012] As a preferred technical solution of the above harmonic reducer, the inner ring of the flexible bearing is in interference fit with the cam.

[0013] As a preferred technical solution of the above harmonic reducer, a lubricating member is arranged between the rigid gear and the flexspline.

[0014] As a preferred technical solution of the above harmonic reducer, a chute is provided on the rigid gear and / or the flexible gear, and balls are placed in the chute.

[0015] As a preferred technical solution of the above harmonic reducer, the depth direction of the installation groove is parallel to the axial direction of the flexible gear.

[0016] As a preferred technical solution of the above harmonic reducer, the second side wall of the installation groove is located on the side of the rigid gear facing away from the cam, and balls are provided between the second side wall and the outer side wall of the rigid gear.

[0017] As a preferred technical solution of the above harmonic reducer, the bottom wall of the installation groove connects the first side wall and the second side wall, and balls are provided between the bottom wall and the axial end face of the rigid gear.

[0018] As a preferred technical solution of the above harmonic reducer, a first connection hole is provided on the axial end face of the second side wall. A plurality of first connection holes are provided, and the plurality of first connection holes are evenly distributed around the axis of the flexible gear.

[0019] As a preferred technical solution of the above harmonic reducer, a second connection hole is provided on the axial end face of the rigid gear. A plurality of second connection holes are provided, and the plurality of second connection holes are evenly distributed around the axis of the rigid gear.

[0020] As a preferred technical solution of the above harmonic reducer, it further includes a driver, and the cam is connected to the output end of the driver through a flange structure.

[0021] Advantageous effects of the present utility model:

[0022] The present utility model provides a harmonic reducer, including a cam, a flexible bearing, a flexible gear and a rigid gear. Among them, the inner ring of the flexible bearing is fixedly sleeved on the outer peripheral side of the cam; the flexible gear is sleeved outside the flexible bearing and is coaxially arranged with the cam. The flexible gear is provided with an installation groove around its own axis. The first side wall of the installation groove is adjacent to the flexible bearing, and the first side wall can undergo elastic deformation. The first side wall is recessed into the installation groove under the action of the long axis part of the cam, and flexible teeth are provided on the side of the first side wall facing the installation groove; the rigid gear is annular and is placed in the installation groove. Rigid teeth are provided on the side of the rigid gear facing the cam, and some of the flexible teeth can mesh with the rigid teeth.

[0023] Specifically, the cam includes a long shaft and a short shaft. Along its radial direction, the length of the long shaft is greater than that of the short shaft. The flexible bearing includes an inner ring, an outer ring, and rolling elements sandwiched between the two. Both the inner ring and the outer ring of the flexible bearing are flexible components, that is, they can undergo elastic deformation. When the flexible bearing is sleeved on the outer peripheral side of the cam, it deforms and can fit the outer contour of the cam. The inner ring of the flexible bearing is fixed to the cam. That is, when the cam rotates around the axis, the inner ring of the flexible bearing can rotate together with the cam. The flexspline is sleeved on the outer peripheral side of the flexible bearing and is used to connect with the load and drive the load to rotate. The flexspline is provided with an annular installation groove, which is coaxially provided with the flexspline. A rigid gear is installed in the installation groove. The rigid gear is used to be fixed to the support member to maintain a stationary state. The first side wall of the installation groove is adjacent to the cam in the radial direction of the cam. The first side wall can undergo elastic deformation, and a flexible tooth is provided on the side of the first side wall facing the installation groove. The rigid gear is correspondingly provided with rigid teeth. The long shaft part of the cam applies a radial force to the first side wall through the flexible bearing, causing the area of the first side wall corresponding to the long shaft of the cam to sink into the installation groove, so that the flexible teeth located in this area mesh with the rigid teeth. And the area of the first side wall corresponding to the short shaft of the cam is not affected by the force, and the flexible teeth in this area are disengaged from the rigid teeth. And the flexible teeth in the area between the long shaft and the short shaft of the cam are in a transitional state of meshing and disengaging with the rigid teeth. Thus, when the cam rotates, the position of its long shaft changes in real time, that is, the flexible teeth on the flexspline that can mesh with the rigid teeth on the rigid gear also change accordingly. And because the rigid teeth are kept stationary by the support member, relative rotation of the flexible teeth relative to the rigid teeth is achieved, and the rotation direction is opposite to the rotation direction of the cam, thereby driving the load to rotate.

[0024] In this embodiment, by means of providing an installation groove on the flexspline, the rigid gear is installed inside the flexspline, so that the disengagement and meshing of the flexible teeth and the rigid teeth both occur inside the installation groove. The cam and the flexible bearing change the meshing and disengagement states of the flexible teeth and the rigid teeth through the first side wall of the installation groove, reducing the length dimension of the harmonic reducer in the axial direction of the cam and reducing the overall volume, making its applicability stronger. Description of the Drawings

[0025] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the following will briefly introduce the drawings required to be used in the description of the embodiments of the present invention. Obviously, the following drawings are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained according to the content of the embodiments of the present invention and these drawings.

[0026] Figure 1 It is a schematic structural diagram of the harmonic reducer provided by the embodiment of the present invention;

[0027] Figure 2It is a schematic structural diagram of a flexspline provided by an embodiment of the present invention;

[0028] Figure 3 It is a schematic structural diagram of a rigid spline provided by an embodiment of the present invention;

[0029] Figure 4 It is a front view of a harmonic reducer provided by an embodiment of the present invention;

[0030] Figure 5 Is Figure 4 A cross-sectional view taken along line A-A in

[0031] Figure 6 Is Figure 4 A partial enlarged view at B in

[0032] Figure 7 It is a rear view of a harmonic reducer provided by an embodiment of the present invention;

[0033] Figure 8 It is a side view of a harmonic reducer provided by an embodiment of the present invention.

[0034] In the figure:

[0035] 100. Cam; 110. Third connection hole;

[0036] 200. Flexible bearing; 210. Inner ring; 220. Outer ring;

[0037] 300. Flexspline; 310. Installation groove; 320. First side wall; 321. Flexible teeth; 330. Second side wall; 331. First sliding groove; 332. First connection hole; 340. Bottom wall;

[0038] 400. Rigid spline; 410. Rigid teeth; 420. Second sliding groove; 430. Second connection hole. Detailed implementation manners

[0039] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It can be understood that the specific embodiments described herein are only used to explain the present invention, rather than limiting the present invention. In addition, it should be noted that for the sake of description, only parts related to the present invention are shown in the drawings, rather than all the structures.

[0040] In the description of the present utility model, unless otherwise clearly defined and limited, the terms "connected", "connected to", and "fixed" shall be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or integrated; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium, and it may be the communication inside two components or the interaction relationship between two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present utility model can be understood according to specific circumstances.

[0041] In the present utility model, unless otherwise clearly defined and limited, the first feature being "above" or "below" the second feature may include the direct contact between the first and second features, or may include the situation where the first and second features are not in direct contact but in contact through other features therebetween. Moreover, the first feature being "above", "over", and "on" the second feature includes that the first feature is directly above and obliquely above the second feature, or merely indicates that the horizontal height of the first feature is higher than that of the second feature. The first feature being "below", "under", and "beneath" the second feature includes that the first feature is directly below and obliquely below the second feature, or merely indicates that the horizontal height of the first feature is lower than that of the second feature.

[0042] In the description of this embodiment, the orientation or positional relationships such as "above", "below", "right", etc. are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of description and simplifying the operation, 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. Therefore, it should not be construed as a limitation to the present utility model. In addition, the terms "first" and "second" are only used for distinction in description and have no special meaning.

[0043] As Figures 1 to 8 shown, the present utility model provides a harmonic reducer, which includes a cam 100, a flexible bearing 200, a flexspline 300, and a rigid ring 400. Among them, the inner ring 210 of the flexible bearing 200 is fixedly sleeved on the outer peripheral side of the cam 100; the flexspline 300 is sleeved outside the flexible bearing 200 and is coaxially arranged with the cam 100. The flexspline 300 is provided with an installation groove 310 around its own axis. The first side wall 320 of the installation groove 310 is adjacent to the flexible bearing 200, and the first side wall 320 can undergo elastic deformation. The first side wall 320 is recessed into the installation groove 310 under the action of the long axis part of the cam 100. A flexible tooth 321 is arranged on the side of the first side wall 320 facing the installation groove 310; the rigid ring 400 is annular and is placed in the installation groove 310. A rigid tooth 410 is arranged on the side of the rigid ring 400 facing the cam 100, and some of the flexible teeth 321 can mesh with the rigid teeth 410.

[0044] Specifically, the cam 100 includes a long axis and a short axis. Along its radial direction, the length of the long axis is greater than that of the short axis. The flexible bearing 200 includes an inner ring 210, an outer ring 220, and rolling elements sandwiched between the two. Both the inner ring 210 and the outer ring 220 of the flexible bearing 200 are flexible members, that is, they can undergo elastic deformation. When the flexible bearing 200 is sleeved on the outer peripheral side of the cam 100, it deforms and can fit the outer contour of the cam 100. The inner ring 210 of the flexible bearing 200 is fixed to the cam 100. That is, when the cam 100 rotates around its axis, the inner ring 210 of the flexible bearing 200 can rotate together with the cam 100. The flexspline 300 is sleeved on the outer peripheral side of the flexible bearing 200 and is used to connect with a load and drive the load to rotate. The flexspline 300 is provided with an annular installation groove 310, and the installation groove 310 is coaxially provided with the flexspline 300. A rigid ring 400 is installed in the installation groove 310. The rigid ring 400 is used to be fixed to a support member to maintain a stationary state. The first side wall 320 of the installation groove 310 is adjacent to the cam 100 in the radial direction of the cam 100. The first side wall 320 can undergo elastic deformation, and a flexible tooth 321 is provided on the side of the first side wall 320 facing the installation groove 310. Correspondingly, the rigid ring 400 is provided with a rigid tooth 410. The long axis part of the cam 100 applies a radial force to the first side wall 320 through the flexible bearing 200, causing the area of the first side wall 320 corresponding to the long axis of the cam 100 to sink into the installation groove 310, so that the flexible tooth 321 located in this area meshes with the rigid tooth 410. And the area of the first side wall 320 corresponding to the short axis of the cam 100 is not affected by the force, and the flexible tooth 321 in this area is disengaged from the rigid tooth 410. And the flexible teeth 321 in the area of the first side wall 320 between the long axis and the short axis of the cam 100 are in a transitional state of meshing and disengaging with the rigid teeth 410. Thus, when the cam 100 rotates, the position of its long axis changes in real time, that is, the flexible teeth 321 on the flexspline 300 that can mesh with the rigid teeth 410 on the rigid ring 400 also change accordingly. Also, since the rigid teeth 410 are kept stationary by the support member, relative rotation of the flexible teeth 321 relative to the rigid teeth 410 is achieved, and the rotation direction is opposite to the rotation direction of the cam 100, thereby driving the load to rotate.

[0045] In this embodiment, by providing the installation groove 310 in the flexspline 300, the rigid ring 400 is installed inside the flexspline 300, so that the disengagement and meshing of the flexible teeth 321 and the rigid teeth 410 both occur inside the installation groove 310. The cam 100 and the flexible bearing 200 change the meshing and disengagement states of the flexible teeth 321 and the rigid teeth 410 through the first side wall 320 of the installation groove 310, reducing the length dimension of the harmonic reducer in the axial direction of the cam 100, reducing the overall volume, and making it more applicable.

[0046] Optionally, the inner ring 210 of the flexible bearing 200 is in interference fit with the cam 100. Specifically, the aperture diameter of the inner ring 210 of the flexible bearing 200 is smaller than the radial dimension of the cam 100. When the flexible bearing 200 and the cam 100 are assembled, the flexible bearing 200 undergoes elastic deformation to achieve interference fit. In this way, the inner ring of the flexible cam 100 and the cam 100 can be relatively fixed.

[0047] In other embodiments, the inner ring 210 of the flexible bearing 200 and the cam 100 can also be fixed by means of splines or by setting up retaining plates. This is common knowledge and will not be elaborated here.

[0048] Optionally, a lubricating member is provided between the rigid gear 400 and the flexible gear 300. In this way, the friction coefficient between the rigid gear 400 and the flexible gear 300 can be reduced, and further the work done by the cam 100 to overcome the frictional force between the rigid gear 400 and the flexible gear 300 can be reduced.

[0049] Optionally, the rigid gear 400 and / or the flexible gear 300 are provided with sliding grooves, and balls are placed in the sliding grooves.

[0050] Exemplarily, the rigid gear 400 is provided with a second sliding groove 420 around its own axis, and the flexible gear 300 is provided with a first sliding groove 331 around its own axis. The first sliding groove 331 and the second sliding groove 420 enclose a guide rail, and the balls are placed in the guide rail, so that rolling friction is formed between the rigid gear 400 and the flexible gear 300, and further the frictional force generated during relative movement is reduced.

[0051] Optionally, the depth direction of the mounting groove 310 is parallel to the axial direction of the flexible gear 300.

[0052] Optionally, the second side wall 330 of the mounting groove 310 is located on the side of the rigid gear 400 facing away from the cam 100, and balls are provided between the second side wall 330 and the outer side wall of the rigid gear 400.

[0053] Since the first side wall 320 of the mounting groove 310 can undergo elastic deformation under the action of the cam 100 to change the meshing state between the flexible teeth 321 and the rigid teeth 410, the distance between the first side wall 320 and the inner side of the rigid gear 400 is constantly changing, which easily causes the balls to come out. Therefore, in this embodiment, a first sliding groove 331 is provided in the second side wall 330 of the mounting groove 310, and a second sliding groove 420 is provided in the outer side wall of the rigid gear 400.

[0054] Optionally, the bottom wall 340 of the mounting groove 310 connects the first side wall 320 and the second side wall 330, and balls are provided between the bottom wall 340 and the axial end face of the rigid gear 400. In this way, the frictional force between the rigid gear 400 and the flexible gear 300 can be further reduced.

[0055] Optionally, a first connection hole 332 is formed in the axial end face of the second side wall 330. A plurality of first connection holes 332 are formed, and the plurality of first connection holes 332 are evenly distributed around the axis of the flexspline 300. The flexspline 300 is connected to the load through a threaded fastener, and the threaded fastener is arranged in one-to-one correspondence with the first connection hole 332. After passing through the first connection hole 332, the threaded fastener is threadedly connected to the load, or after passing through the load, it is inserted into the first connection hole 332 and threadedly connected to the flexspline 300. The flexspline 300 forms the first connection hole 332 on the second side wall 330 that does not need to deform, which can make the fixation between the flexspline 300 and the load relatively reliable. Moreover, since there are a plurality of first connection holes 332, the connection reliability can be further improved. In addition, the plurality of first connection holes 332 are evenly arranged around the axis of the flexspline 300, making the force on the flexspline 300 uniform and avoiding stress concentration areas on the flexspline 300.

[0056] Optionally, a second connection hole 430 is formed in the axial end face of the rigid spline 400. A plurality of second connection holes 430 are formed, and the plurality of second connection holes 430 are evenly distributed around the axis of the rigid spline 400. The rigid spline 400 is connected to the support through a threaded fastener, and the threaded fastener is arranged in one-to-one correspondence with the second connection hole 430. After passing through the second connection hole 430, the threaded fastener is threadedly connected to the support, or after passing through the support, it is inserted into the second connection hole 430 and threadedly connected to the rigid spline 400. Since there are a plurality of second connection holes 430, the connection reliability can be further improved. In addition, the plurality of second connection holes 430 are evenly arranged around the axis of the rigid spline 400, making the force on the rigid spline 400 uniform and avoiding stress concentration areas on the rigid spline 400.

[0057] Optionally, the harmonic reducer further includes a driver, and the cam 100 is connected to the output end of the driver through a flange structure.

[0058] Specifically, the driver is used to drive the cam 100 to rotate around the axis. The cam 100 is provided with a plurality of third connection holes 110, and the plurality of third connection holes 110 are evenly distributed around the axis of the cam 100. The cam 100 is connected to the output end of the driving member through a threaded fastener, and the threaded fastener is arranged in one-to-one correspondence with the third connection hole 110. After passing through the third connection hole 110, the threaded fastener is threadedly connected to the output end of the driving member, or after passing through the output end of the driving member, it is inserted into the third connection hole 110 and threadedly connected to the cam 100. Since there are a plurality of third connection holes 110, the connection reliability can be further improved. In addition, the plurality of third connection holes 110 are evenly arranged around the axis of the cam 100, making the force on the cam 100 uniform and avoiding stress concentration areas on the cam 100.

[0059] In addition, the above is only the preferred embodiment of the present utility model and the applied technical principles. Those skilled in the art will understand that the present utility model is not limited to the specific embodiments described herein, and various obvious changes, re-adjustments and substitutions can be made by those skilled in the art without departing from the protection scope of the present utility model. Therefore, although the present utility model has been described in more detail through the above embodiments, the present utility model is not limited to the above embodiments only. Without departing from the concept of the present utility model, more other equivalent embodiments can be included, and the scope of the present utility model is determined by the scope of the appended claims.

Claims

1. Harmonic reducer, characterized in that, Comprising: A cam (100); A flexible bearing (200), the inner ring (210) of the flexible bearing (200) is fixedly sleeved on the outer peripheral side of the cam (100); A flexspline (300), the flexspline (300) is sleeved outside the flexible bearing (200), coaxially arranged with the cam (100), the flexspline (300) is provided with an installation groove (310) around its own axis, the first side wall (320) of the installation groove (310) is adjacent to the flexible bearing (200), the first side wall (320) can undergo elastic deformation, the first side wall (320) is recessed into the installation groove (310) under the action of the long axis part of the cam (100), and flexible teeth (321) are arranged on the side of the first side wall (320) facing the installation groove (310); A rigid ring (400), the rigid ring (400) is annular, placed in the installation groove (310), rigid teeth (410) are arranged on the side of the rigid ring (400) facing the cam (100), and part of the flexible teeth (321) can mesh with the rigid teeth (410).

2. The harmonic reducer according to claim 1, wherein, The inner ring (210) of the flexible bearing (200) is in interference fit with the cam (100).

3. The harmonic reducer according to claim 1, wherein A lubricating member is arranged between the rigid ring (400) and the flexspline (300).

4. The harmonic reducer according to claim 1, wherein, The rigid ring (400) and / or the flexspline (300) are provided with sliding grooves, and balls are placed in the sliding grooves.

5. The harmonic reducer according to claim 4, characterized in that, The depth direction of the installation groove (310) is parallel to the axial direction of the flexspline (300).

6. The harmonic reducer according to claim 5, characterized in that, The second side wall (330) of the installation groove (310) is located on the side of the rigid ring (400) facing away from the cam (100), and the balls are arranged between the second side wall (330) and the outer side wall of the rigid ring (400).

7. The harmonic reducer according to claim 6, characterized in that, The bottom wall (340) of the installation groove (310) connects the first side wall (320) and the second side wall (330), and the balls are arranged between the bottom wall (340) and the axial end face of the rigid ring (400).

8. The harmonic reducer according to claim 6, characterized in that, The axial end face of the second side wall (330) is provided with a plurality of first connection holes (332), and the plurality of first connection holes (332) are evenly distributed around the axis of the flexspline (300).

9. The harmonic reducer according to claim 1, wherein The axial end face of the rigid ring (400) is provided with a plurality of second connection holes (430), and the plurality of second connection holes (430) are evenly distributed around the axis of the rigid ring (400).

10. The harmonic reducer according to claim 1, wherein, It further includes a driver, and the cam (100) is connected to the output end of the driver through a flange structure.

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