Patent ID: 12228204

In the drawings:10-integrated flexible planet carrier;101-first annular part;102-second annular part;11-flexible leaf spring;12-planet gear shaft bearing hole;13-moving platform;14-first flexible hinge;15-second flexible hinge;16-planet carrier central shaft bearing hole;20-adjusting screw;21-spring;30-ring gear;31-planet gear shaft;32-bearing gland.

DETAILED DESCRIPTION OF THE EMBODIMENTS

The present disclosure will be understood more fully from the following specific embodiments, which should be read in conjunction with the accompanying drawings. Detailed embodiments of the present disclosure are disclosed herein; however, it should be understood that the disclosed embodiments are merely exemplary of the present application and that the present disclosure can be embodied in various ways. Therefore, specific functional details disclosed herein should not be construed as limitation, but only be construed as the basis of the claims and construed as a representative basis for teaching those skilled in the art to employ the present disclosure in a different way in virtually any suitable detailed embodiment.

Please referring toFIG.1toFIG.4, a flexible mechanism-based anti-backlash device for a planetary gear train disclosed by an embodiment of the present disclosure comprises an adjusting screw20and a spring21; the adjusting screw20is in threaded connection to an integrated flexible planet carrier10, the integrated flexible planet carrier10is provided with a moving platform13, a spring hole is provided on the moving platform13, and the spring21is sleeved outside the screw20and is installed in the spring hole; and one end of the spring21is pressed against a bottom face of the spring hole, and the other end of the spring is pressed against a nut of the adjusting screw20. The adjusting screw20and the spring21are both arranged along a radial direction of the integrated flexible planet carrier10. The threaded connection depth of the adjusting screw20and the integrated flexible planet carrier10can be directly adjusted through the adjusting screw20.

Further, by adjusting the threaded connection depth of the adjusting screw20and the integrated flexible planet carrier10, the adjusting screw extrudes the spring21to deform and then transmits the pressure to the moving platform13of the planet carrier10, thus making the moving platform generate elastic movement along the radial direction of the planet carrier10, and then making a planet gear shaft bearing hole in the integrated flexible planet carrier perform circumferential elastic rotate around the center of the integrated flexible planet carrier.

Further, the integrated flexible planet carrier10comprises a first annular part101, a plurality of second annular parts102symmetrically arranged around the first annular part, and two moving platforms13; the first annular part is provided with a planet carrier central shaft bearing hole16, the second annular part is provided with a planet gear shaft bearing hole12, the two moving platforms13are distributed at two sides of the integrated flexible planet carrier10, and each moving platform13is arranged between two adjacent second annular parts102; the first annular part101is connected to each second annular part102through a first elastic connector, and the moving platform13is connected to the adjacent second annular part102through a second elastic connector. Wherein the number of the second annular parts102is even. The first elastic connector is a flexible leaf spring11, the second elastic connector comprises a first flexible hinge14and a second flexible hinge15connected in sequence, and the moving platform13is connected to the adjacent second annular part102through the first flexible hinge14and the second flexible hinge15in sequence.

Wherein the first annular part, the second annular part, the moving platform, the first elastic connector and the second elastic connector are all integrally provided.

By adopting the above structure design, the integrated flexible planet carrier10can transform circumferential stiffness of each planet gear shaft bearing hole12around the center of the planet carrier10into radial stiffness of the moving platform13in a vertical direction through the flexible hinges14and15, and meanwhile, each planet gear shaft bearing hole12can generate elastic rotation around the center of the planet carrier10through the flexible leaf spring11, and the moving platform13can generate elastic movement along the radial direction of the planet carrier10through the flexible hinges14and15.

Further, radial stiffness of the planetary gear train anti-backlash device is:

KL=[(2⁢K1)-1+(2⁢K2)-1+(2⁢K3)-1+Ks-1]-1wherein K1is equivalent stiffness of the first flexible hinge14in the radial direction of the integrated flexible planet carrier10, K2is equivalent stiffness of the second flexible hinge15in the radial direction of the integrated flexible planet carrier10, K3is equivalent stiffness of the second annular part102in the radial direction of the integrated flexible planet carrier10when performing circumferential rotation through the first elastic connector, and K3is stiffness of the spring21.

More intuitively, please referring toFIG.3toFIG.4, the integrated flexible planet carrier10can transform the elastic movement of the moving platform13in the radial direction into the circumferential elastic rotation of the planet gear shaft bearing hole12around the center of the planet carrier through the flexible leaf spring11, the first flexible hinge14and the second flexible hinge15, and can remain a certain restoring force during this process.

In this embodiment, the planetary gear train anti-backlash device can be connected to a planetary shaft bearing (not shown in figure) and the planet carrier central shaft bearing (not shown in figure) in a plurality of planetary gear trains, thus supporting the planet gear shaft (not shown in figure) to perform rotational motion.FIG.5is an application of the planetary gear train anti-backlash device in an example gear train. The planetary gear train is a 3K planetary gear train, wherein even number of planet gears are employed, and the planet carrier is not used as a part for transmitting a torque in a driving chain. In accordance with the planetary gear train anti-backlash device, the adjusting screw20is used to adjust the threaded connection depth with the integrated flexible planet carrier10, and then extrudes the spring21to drive the moving platform13of the planet carrier to make the planet carrier10generate radial deformation; the radial deformation of the planet carrier is transformed into the rotation of the planet gear shaft bearing hole12around the center of the planet carrier through the flexible mechanism, thus driving two adjacent planet gear shafts31to generate reverse motion; and then a pair of adjacent planet gears remain meshed with a ring gear30and a sun gear (not shown in figure) at opposite side; the threaded connection depth of the adjusting screw20and the integrated flexible planet carrier10is continuously adjusted after the backlash elimination is finished to further compress the spring21, and at the moment, as the gear backlash has been eliminated, the planet carrier10no longer generate the elastic deformation, the deformation force of the spring21is transformed into a pre-load force applied to a meshing face of the planet gear to achieve the tight attachment of the gear face; it is guaranteed that there is always a planet gear in a meshing state when the planetary gear train operates in the forward and reverse directions, i.e., the backlash elimination of the planet gear is achieved.

Therefore, a planetary gearbox can be constructed by applying the anti-backlash device for the planetary gear train of this embodiment. Moreover, the planetary gearbox can be applied to various fields.

For example, in an application case, the planetary gearbox provided with the anti-backlash device for the planetary gear train can be used in a drive gearbox of a collaborative robot joint to drive the collaborative robot with high human-robot interaction performance.

Various aspects, embodiments, features, and examples of the present disclosure should be considered illustrative in all respects and are not intended to limit the present disclosure, and the scope of the present disclosure is defined only by the claims. Other embodiments, modifications and use will be apparent to those skilled in the art without departing from the claimed spirit and scope of the present disclosure.

The use of headings and chapters in the case of the present disclosure is not meant to limit the present disclosure; each chapter may be applied to any aspect, embodiment, or feature of the present disclosure.

Unless otherwise specifically stated, the use of the terms “include, includes, including”, “have, has or having” is generally understood to be open-ended and unlimited.

Although the present disclosure has been described with reference to illustrative embodiments, it will be understood by those skilled in the art that various other changes, omissions and/or additions may be made and the elements of the embodiment can be replaced with substantial equivalents without departing from the spirit and scope of the present disclosure. In addition, various modifications may be made without departing from the scope of the present disclosure so as to make specific conditions or materials adapt to the teaching of the present disclosure. Therefore, it is not intended herein to limit the present disclosure to the particular embodiments disclosed for executing the present disclosure, but rather it is intended to make the present disclosure encompass all embodiments that fall within the scope of the appended claims. Moreover, unless specifically stated, any use of the terms “first”, “second” does not denote any sequence or importance, but rather the terms “first”, “second” are used to distinguish one element from another.