Flexible joint based on elastic elements

Abstract

The spiral energy storage spring and the compression spring are integrated inside, or the spiral energy storage spring, the magnetic spring and the planar spring are integrated inside, so as to realize energy storage and passive flexibility, reduce driving consumption and meet the requirement of driving agility.SOLUTION: Disclosed is a flexible joint based on an elastic element, including an involute small-tooth-number difference reducer, a spiral energy storage spring, and a flexible output module / composite flexible output module. The involute small-number-of-teeth difference reduction gear employs only an eccentric input shaft, a pair of involute internal tooth rings, and an involute planetary gear to achieve oscillation and rotation motions of the involute planetary gear. The power output of the output disc is transmitted by the interaction of the column pin and the first column pin working hole of the involute planetary gear or the second column pin working hole of the output disc. The accuracy requirement can be easily met only by the meshing form of the pair of gears, the axial dimension is compact, the pair of gears adopt involute tooth profile, and the manufacturing cost is low.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention belongs to the field of robot drive joint technology, and in particular to flexible joints based on elastic elements. [Background technology]

[0002] Conventional robot drive joints often adopt rigid designs and are controlled to move along a set trajectory in a structured environment to complete a specific task. With the changing requirements for robots in a human-machine collaborative environment, the opportunities for robots to come into contact with humans when working are increasing, so there is a pressing need for a drive system that can adapt to a collaborative environment with humans, is environmentally friendly, and does not damage the external environment, and the drive joints are required to have a certain degree of flexibility.

[0003] Mobile, cable-free bionic mechanical systems such as humanoid robots, jumping robots, and quadruped robots (robot dogs) must be able to fully and rationally utilize energy such as gravitational potential energy to meet their movement needs. For example, the knee joint of a humanoid robot must store energy when it crouches and release it when it stands up, allowing it to jump higher, and must be agile, safe, have a long operating life, be energy-efficient, and achieve drive agility (greater instantaneous speed and acceleration, and greater output moment) with a limited drive angle (output drive angle < 360°). Therefore, drive joints must have a certain energy storage capacity. Summary of the Invention

[0004] SUMMARY OF THE INVENTION It is an object of the present invention to provide a flexible joint based on elastic elements, which addresses the problems of the prior art.

[0005] The technical solutions adopted by the present invention are as follows: The present invention provides a flexible joint based on an elastic element, which includes an involute small tooth differential reducer, a spiral energy storage spring and a flexible output module. The involute small tooth difference reducer includes a joint housing, an eccentric input shaft, a gear transmission mechanism and a post pin output mechanism. The gear transmission mechanism includes an involute planetary gear and an involute internal tooth ring. The pillar pin output mechanism includes a pillar pin, a support ring and an output board. The support ring is supported on one end of the inner wall of the joint housing by a first rolling bearing, and the output plate is supported on the other end of the inner wall of the joint housing by a second rolling bearing, and is connected to the inner wall of the joint housing by a spiral energy storage spring. An involute internal tooth ring is installed in the joint housing at a position between the first rolling bearing and the second rolling bearing. One end of the eccentric input shaft is supported in the support ring by a third rolling bearing, and the other end is supported in the output board by a fourth rolling bearing. The involute planetary gear is supported by a fifth rolling bearing on an eccentric shaft portion at an intermediate position of the eccentric input shaft, and meshes with an involute internal tooth ring. The involute planetary gear is provided with a plurality of bolt passing holes that are uniformly distributed along the circumferential direction and a plurality of first pole pin action holes that are uniformly distributed along the circumferential direction, and the bolt passing holes and the first pole pin action holes are distributed alternately along the circumferential direction. A hole unit consisting of a plurality of holes uniformly distributed along the circumferential direction is installed on either the support ring or the output board, and the hole unit consists of a sink hole into which a coaxially arranged bolt head is embedded and a through hole through which the rod portion of the bolt is passed, and the other is provided with a plurality of screw holes uniformly distributed along the circumferential direction. The number of hole units, bolt passing holes, and screw holes is equal, and the hole units and the screw holes aligned at circumferential positions are connected by one bolt, and each bolt passes through one bolt passing hole aligned at circumferential positions of the involute planetary gear. The center of the circumference on which the centers of the bolts uniformly distributed along the circumferential direction are located is concentric with the centers of the support ring and the output board. The inner diameter of the bolt passage hole is greater than d1+2e, where d1 is the major diameter of the bolt thread, e is the eccentric distance of the eccentric shaft portion of the eccentric input shaft, and the diameter of the circumference on which the center of each bolt passage hole and the center of each first pillar pin action hole are located is equal to the diameter of the circumference on which the center of each bolt is located. The flexible output module includes a first flexible output shaft and a compression spring. The center hole of the first flexible output shaft is clearance-fit with the hub of the output board. A fastening screw hole is provided in the center of the hub of the output plate, and the first flexible output shaft is axially restricted by the output plate and the first shaft cover, and the first shaft cover and the fastening screw hole in the center of the hub of the output plate are fixedly connected by a first screw. The first flexible output shaft and the output platen are connected by a plurality of compression springs arranged along the circumferential direction. The support ring and the output board are both provided with a plurality of second pillar pin action holes that are uniformly distributed along the circumferential direction. The second post pin operating holes of the support ring, the first post pin operating holes of the involute planetary gears, and the second post pin operating holes of the output disk are of equal quantity, and the connection manner between the second post pin operating holes of the support ring, the first post pin operating holes of the involute planetary gears, and the second post pin operating holes of the output disk and the post pins can be one of the following two types: 1. Each second column pin working hole of the support ring and one of the second column pin working holes of the output disk aligned at the circumferential position are fixedly connected by a column pin, and each column pin passes through one of the first column pin working holes of one of the involute planetary gears aligned at the circumferential position, and the cylindrical surface of the column pin abuts against the inner wall of the corresponding first column pin working hole. The inner diameter of the first column pin working hole is d2+2e, and the inner diameter of the second column pin working hole is d2, where d2 is the diameter of the column pin. 2. A pole pin is fixed in each of the first pole pin operating holes of the involute planetary gears, and the cylindrical surfaces at both ends of each pole pin abut against the inner wall of the second pole pin operating hole, which is aligned with the circumferential position of the support ring and the output disk. The inner diameter of the first pole pin operating hole is d2, and the inner diameter of the second pole pin operating hole is d2+2e.

[0006] Preferably, the flexible output module is a composite flexible output module. The composite flexible output module includes a second flexible output shaft, a planar spring, a first permanent magnet, and a second permanent magnet, and the center hole of the second flexible output shaft is clearance-fit with the hub of the output board. A flat spring is fixed to the outer end of the second flexible output shaft, and the central hole of the flat spring is clearance-fit with the outer wall of the second shaft cover. The second flexible output shaft and the flat spring are axially restricted by the output plate and the second shaft cover, and the fastening screw holes in the center of the hubs of the second shaft cover and the output plate are fixedly connected by a second screw. A plurality of first magnet mounting bases are integrally molded on the inner wall of the output board and uniformly distributed along the circumferential direction, and a plurality of second magnet mounting bases are integrally molded on the outer circular surface of the second flexible output shaft and uniformly distributed along the circumferential direction, with the first magnet mounting bases and second magnet mounting bases intersecting and distributed at intervals along the circumferential direction. One first permanent magnet is attached to each of both sides of the first magnet mounting base, and one second permanent magnet is attached to each of both sides of the second magnet mounting base. Each second permanent magnet is provided facing one first permanent magnet with a gap therebetween, and the facing pole ends of the second permanent magnet and the facing first permanent magnet have the same magnetic pole. The flat spring has a plurality of integrally molded sectors uniformly distributed along the circumferential direction, and both sides of each sector are directly opposite and spaced apart from two first magnet mounting bases. The second flexible output shaft has a plurality of output screw holes uniformly distributed along the circumferential direction, and the flat spring has a plurality of optical holes uniformly distributed along the circumferential direction, the optical holes and the output screw holes are equal in number and aligned one-to-one in the circumferential direction.

[0007] Preferably, the joint housing is provided with a plurality of mounting screw holes and a plurality of positioning holes that are uniformly distributed along the circumferential direction.

[0008] Preferably, in the small tooth difference involute planetary gear transmission unit composed of the eccentric shaft portion of the eccentric input shaft, the involute internal tooth ring, and the involute planetary gear, the involute internal tooth ring has 1 to 4 more teeth than the involute planetary gear.

[0009] Preferably, the inner end of the spiral energy storage spring is fitted into a socket provided in the outer wall of the output board, and the outer end is fitted into a socket provided in the inner wall of the joint housing.

[0010] Preferably, the first flexible output shaft has an inner end provided with a boss that is integrally formed and coaxial with the inner end.

[0011] Preferably, a countersunk groove is provided on the outer end surface of the first flexible output shaft, a stop ring integrally formed on the outer end of the first shaft cover is fitted into the countersunk groove, and a gap is provided between the stop ring and the bottom of the countersunk groove.

[0012] Preferably, the inner wall of the output plate is provided with a plurality of first spring seats that are integrally molded and uniformly distributed along the circumferential direction, and the outer circular surface of the first flexible output shaft is provided with a plurality of second spring seats that are integrally molded and uniformly distributed along the circumferential direction, the first spring seats and the second spring seats are arranged crosswise along the circumferential direction, and one compression spring is connected to each of the two first side surfaces of each first spring seat and the second side surfaces of each of the two second spring seats.

[0013] Preferably, the first flexible output shaft is provided with a plurality of output screw holes uniformly distributed along the circumferential direction.

[0014] Preferably, the sector portion of the planar spring has an arc groove on the outer edge, and radial grooves on both sides, the outer ends of both radial grooves are connected to both ends of the arc groove, and the planar spring has overhang portions formed outside the both radial grooves, and arc connecting beams formed outside the arc grooves.

[0015] The present invention has the following beneficial effects. The present invention achieves energy storage and passive flexibility by integrating a spiral energy storage spring and a compression spring, or by integrating a spiral energy storage spring, a magnetic spring, and a planar spring. For example, when squatting, the present invention stores energy in the spiral energy storage spring, and when standing up, the spiral energy storage spring releases energy and provides torque, reducing the torque required from the motor. As a result, the instantaneous rotation speed of the joint of the present invention when the eccentric input shaft rotates in the opposite direction is greater than the rotation speed when the eccentric input shaft rotates forward, outputting greater force and torque and allowing for higher jumps. Furthermore, when colliding with the outside world, the joint of the present invention can store energy within a certain range and generate flexible deformation, thereby providing cushioning protection for the human body or other objects. Furthermore, the present invention only uses a single eccentric input shaft and a pair of involute internal toothed rings and involute planetary gears to realize the oscillation and rotation of the involute planetary gears, and the tooth difference between the involute internal toothed ring and the involute planetary gears is designed to be 1 to 4, forming a monolithic planetary transmission with a small tooth difference. The power output of the output disk is transmitted through the interaction of the column pin and the first column pin operating hole of the involute planetary gear or the second column pin operating hole of the output disk. The precision requirements can be easily met using only a pair of gears meshing, and the axial dimension is more compact, making it suitable for use in situations where the transmission system space is limited. Furthermore, both the involute internal toothed ring and the involute planetary gears of the present invention use involute tooth profiles, making it easy to manufacture and low-cost. Therefore, the present invention provides a high-performance flexible joint that can store energy, has large torque, is compact in structure, and is low-cost to manufacture, and is suitable for applications such as robots. [Brief explanation of the drawings]

[0016] [Figure 1] FIG. 1 is a structural cross-sectional view of a first embodiment of the present invention. [Figure 2] FIG. 2 is a right side view of FIG. [Figure 3] FIG. 2 is a schematic diagram of the transmission relationship between an eccentric input shaft, an involute internal tooth ring, an involute planetary gear, and a pin in the first embodiment of the present invention. [Figure 4] FIG. 10 is a schematic diagram of the transmission relationship between an eccentric input shaft, an involute internal tooth ring, an involute planetary gear, and a pin in a second embodiment of the present invention. [Figure 5] FIG. 10 is an assembled perspective view of an involute planetary gear and a pin according to a second embodiment of the present invention. [Figure 6] FIG. 2 is a structural perspective view of an eccentric input shaft according to the present invention. [Figure 7] FIG. 10 is a structural cross-sectional view of a third embodiment of the present invention. [Figure 8] FIG. 8 is a right side view of FIG. 7. [Figure 9] FIG. 10 is an exploded view of the three-dimensional structure of the third embodiment of the present invention. [Figure 10] FIG. 1 is a structural schematic diagram of the composite flexible output module of the present invention after removing the planar spring. [Figure 11] 1A and 1B are schematic diagrams comparing a planar spring according to the present invention before and after deformation. DETAILED DESCRIPTION OF THE INVENTION

[0017] The technical solutions in the embodiments of the present invention are clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. It is clear that the described embodiments are only some embodiments of the present invention, and are not all embodiments. Based on the embodiments of the present invention, all other embodiments that can be obtained by those skilled in the art without creative work fall within the protection scope of the present invention.

[0018] As shown in Figures 1 and 2, a flexible joint based on an elastic element is provided, and includes an involute small tooth difference reducer, a spiral energy storage spring 13, and a flexible output module 21. The involute small tooth difference reducer includes a joint housing 1, an eccentric input shaft 7, a gear transmission mechanism, and a pole pin output mechanism. The gear transmission mechanism includes an involute planetary gear 2 and an involute internally toothed ring 17. The pole pin output mechanism includes a pole pin 3, a support ring 5, and an output plate 12. The support ring 5 is supported at one end of the inner wall of the joint housing 1 by a first rolling bearing 4, and the output plate 12 is supported at the other end of the inner wall of the joint housing 1 by a second rolling bearing 10, and is connected to the inner wall of the joint housing 1 by a spiral energy storage spring 13. The involute internally toothed ring 17 is installed in the joint housing 1 at a position between the first rolling bearing 4 and the second rolling bearing 10. One end of the eccentric input shaft 7 is supported within the support ring 5 by the third rolling bearing 6, and the other end is supported within the output platen 12 by the fourth rolling bearing 11. The involute planetary gear 2 is supported on the eccentric shaft portion at the middle position of the eccentric input shaft 7 by the fifth rolling bearing 8 or by a plurality of rollers evenly spaced circumferentially, and meshes with the involute internally toothed ring 17 (the involute planetary gear 2 is provided with external teeth 16). The involute planetary gear 2 is provided with a plurality of bolt passing holes that are uniformly distributed along the circumferential direction and a plurality of first post pin action holes 20 that are uniformly distributed along the circumferential direction, and the bolt passing holes and the first post pin action holes 20 are distributed alternately along the circumferential direction, and the center of the circumference on which the centers of the bolt passing holes and the first post pin action holes 20 are located coincides with the center of the involute planetary gear 2. One of the support ring 5 and the output plate 12 is provided with a hole unit consisting of a plurality of holes uniformly distributed along the circumferential direction, and the hole unit is composed of a coaxial recessed hole into which a bolt head is embedded and a through hole through which a bolt rod portion is passed, while the other is provided with a plurality of screw holes uniformly distributed along the circumferential direction. The numbers of hole units, bolt through holes and screw holes are equal, and one screw hole aligned with a hole unit at a circumferential position is connected by one bolt 9, and each bolt 9 passes through one bolt through hole aligned with a circumferential position of the involute planetary gear 2.The center of the circumference on which the center of each bolt 9, which is uniformly distributed along the circumferential direction, is located is concentric with the center of the support ring 5 and the output platen 12. The inner diameter of the bolt passing hole is greater than d1 + 2e, where d1 is the major diameter of the thread of the bolt 9 and e is the eccentric distance of the eccentric shaft portion of the eccentric input shaft. The diameter of the circumference on which the center of each bolt passing hole and the center of each first post pin operating hole 20 are located is equal to the diameter of the circumference on which the center of each bolt 9 is located, ensuring that each bolt 9 does not constantly contact the inner wall of its corresponding bolt passing hole during rotation of the involute planetary gear 2. The flexible output module 21 includes a first flexible output shaft 212 and a compression spring 211. The center hole of the first flexible output shaft 212 is clearance-fit with the hub of the output platen 12, so that the first flexible output shaft 212 can rotate relative to the output platen 12 when subjected to torque. A fastening screw hole is provided in the center of the hub of the output platen 12, and the first flexible output shaft 212 is axially restricted by the output platen 12 and a first shaft cover 214, and the first shaft cover 214 and the fastening screw hole in the center of the hub of the output platen 12 are fixedly connected by a first screw 213. The first flexible output shaft 212 and the output platen 12 are connected by a plurality of compression springs 211 arranged along the circumferential direction, and the output stiffness of the flexible output module can be adjusted by changing the stiffness of the compression springs. Both the support ring 5 and the output platen 12 are provided with a plurality of second pillar pin action holes uniformly distributed along the circumferential direction. The second post pin operating holes of the support ring 5, the first post pin operating holes 20 of the involute planetary gear 2, and the second post pin operating holes of the output plate 12 are of equal quantity, and the connection manner between the second post pin operating holes of the support ring 5, the first post pin operating holes 20 of the involute planetary gear 2, and the second post pin operating holes of the output plate 12 and the post pins 3 can be one of the following two types:

[0019] Embodiment 1 1 and 3, each second pillar pin action hole of the support ring 5 and one of the second pillar pin action holes aligned with a circumferential position of the output disk 12 are fixedly connected by a pillar pin 3, and each pillar pin 3 passes through one of the first pillar pin action holes 20 aligned with a circumferential position of the involute planetary gear 2, and the cylindrical surface of the pillar pin 3 abuts against the inner wall of the corresponding first pillar pin action hole 20. The inner diameter of the first pillar pin action hole 20 is d2+2e, and the inner diameter of the second pillar pin action hole is d2, where d2 is the diameter of the pillar pin 3.

[0020] Embodiment 2 4 and 5, a pillar pin 3 is fixed in each of the first pillar pin action holes 20 of the involute planetary gear 2, and the cylindrical surfaces at both ends of each pillar pin 3 abut against the inner wall of one of the second pillar pin action holes aligned with the circumferential position of the support ring 5 and the output board 12. The inner diameter of the first pillar pin action hole 20 is d2, and the inner diameter of the second pillar pin action hole is d2+2e. The flexible output module 21 may be the composite flexible output module 31 of the third embodiment.

[0021] Embodiment 3 7 to 10, the composite flexible output module 31 includes a second flexible output shaft 313, a planar spring 314, a first permanent magnet 311, and a second permanent magnet 312. The center hole of the second flexible output shaft 313 is clearance-fit with the hub of the output platen 12, so that the second flexible output shaft 313 can rotate relative to the output platen 12 when torque is applied. A planar spring 314 is fixed to the outer end of the second flexible output shaft 313, and the center hole of the planar spring 314 is clearance-fit with the outer wall of a second shaft cover 315. The second flexible output shaft 313 and the planar spring 314 are axially restricted by the output platen 12 and the second shaft cover 315, and a second screw 316 is fixedly connected to the second shaft cover 315 via a fastening screw hole in the center of the hub of the output platen 12. A plurality of first magnet mounting bases are integrally molded on the inner wall of the output board 12 and uniformly distributed along the circumferential direction, and a plurality of second magnet mounting bases are integrally molded on the outer circular surface of the second flexible output shaft 313 and uniformly distributed along the circumferential direction, with the first magnet mounting bases and second magnet mounting bases intersecting and spaced apart along the circumferential direction. One first permanent magnet 311 is attached to each side of the first magnet mounting base, and one second permanent magnet 312 is attached to each side of the second magnet mounting base. Each second permanent magnet 312 faces one first permanent magnet 311 but is spaced apart from it, and the opposing magnetic pole ends of the second permanent magnet 312 and the first permanent magnet 311 have the same magnetic polarity, so that the output rigidity of the composite flexible output module 31 can be adjusted by changing the magnetic field strength of the first permanent magnets 311 and the second permanent magnets 312. The flat spring 314 has a plurality of integrally molded sectors uniformly distributed along the circumferential direction, and both sides of each sector are opposite to and spaced apart from the two first magnet mounting bases. As shown in Figures 10 and 11, the second flexible output shaft 313 has a plurality of output screw holes uniformly distributed along the circumferential direction, and the flat spring 314 has a plurality of optical holes uniformly distributed along the circumferential direction, the optical holes and the output screw holes are equal in number and aligned one-to-one in the circumferential direction, and the output screw holes and the optical holes are used to connect the second moving member.

[0022] In a preferred embodiment, as shown in FIG. 1, the joint housing 1 is provided with a plurality of mounting screw holes 19 uniformly distributed along the circumferential direction, and a plurality of positioning holes 18, which are used to connect the first moving member.

[0023] In a preferred embodiment, in a small tooth difference involute planetary gear transmission unit composed of an eccentric shaft portion of the eccentric input shaft 7, an involute internal tooth ring 17, and an involute planetary gear 2, the involute internal tooth ring has 1 to 4 more teeth than the involute planetary gear.

[0024] In a preferred embodiment, as shown in FIGS. 1 and 6, a plurality of lightening holes 15 are provided around the shoulder of the eccentric shaft portion of the eccentric input shaft 7, and are arranged along the circumferential direction to reduce the amount of unbalance of the eccentric input shaft.

[0025] In a preferred embodiment, as shown in FIG. 1, the hollow hole of the eccentric input shaft 7 is located in the eccentric shaft portion, and a weight-reducing groove 14 is formed on the hole wall facing the eccentric direction of the eccentric input shaft 7, so that the hollow hole of the eccentric input shaft 7 and the weight-reducing groove 14 further reduce the unbalance of the eccentric input shaft 7.

[0026] In a preferred embodiment, as shown in FIG. 1, the fifth rolling bearing 8 is a roller bearing.

[0027] In a preferred embodiment, as shown in FIG. 1, the inner end of the spiral energy storage spring 13 fits into a socket provided in the outer wall of the output board 12, and the outer end fits into a socket provided in the inner wall of the joint housing 1.

[0028] In a preferred embodiment, as shown in FIG. 1, a boss is integrally formed on the inner end of the first flexible output shaft 212 and is coaxially arranged therewith, so that the boss comes into contact with the output board 12 to reduce friction.

[0029] In a preferred embodiment, as shown in FIG. 1, a recess is formed on the outer end surface of the first flexible output shaft 212, and a stop ring integrally formed on the outer end of the first shaft cover 214 is fitted into the recess, with a gap between the stop ring and the bottom of the recess.

[0030] In a preferred embodiment, as shown in FIG. 2, the inner wall of the output plate 12 is provided with a plurality of first spring seats that are integrally molded and uniformly distributed along the circumferential direction, and the outer circular surface of the first flexible output shaft 212 is provided with a plurality of second spring seats that are integrally molded and uniformly distributed along the circumferential direction, and the first spring seats and the second spring seats are arranged crosswise along the circumferential direction, and the two first side surfaces 217 of each first spring seat and the second side surfaces 216 of each second spring seat are connected by one compression spring 211 respectively.

[0031] In a preferred embodiment, as shown in FIG. 2, the first flexible output shaft 212 has a plurality of output screw holes 215 uniformly distributed along the circumferential direction, which are used to connect the second moving member.

[0032] In a preferred embodiment, as shown in FIG. 7, the inner end of the second flexible output shaft 313 is provided with a boss that is integrally molded and coaxially arranged, and the boss comes into contact with the output board 12 to reduce friction.

[0033] In a preferred embodiment, as shown in FIG. 7, a recess is formed on the outer end surface of the flat spring 314, and a stop ring is integrally formed on the outer end of the second shaft cover 315 and fitted into the recess, with a gap between the stop ring and the bottom of the recess.

[0034] In a preferred embodiment, as shown in FIG. 11 , the sector portion of the planar spring 314 has an arc groove on the outer edge, and radial grooves on both sides, with the outer ends of the two radial grooves connecting to both ends of the arc groove, and the planar spring 314 has overhang portions 318 on the outside of the two radial grooves, and an arc connecting beam 317 on the outside of the arc grooves.

[0035] When using the present invention, the joint housing 1 is fixed to the first moving member by the mounting screw holes 19 and the positioning holes 18 . Power is input from the eccentric input shaft 7 (the motor inputs power to the eccentric input shaft 7), and the involute planetary gears 2 revolve. The involute planetary gears mesh with the involute internal toothed ring 17, causing the involute planetary gears to rotate. The present invention has only one pair of gear transmissions, the involute internal toothed ring 17 and the involute planetary gears 2. The transmission ratio is the number of teeth of the involute planetary gears 2 divided by the difference in the number of teeth between the involute internal toothed ring 17 and the involute planetary gears 2. The difference in the number of teeth between the involute internal toothed ring 17 and the involute planetary gears 2 is designed to be 1 to 4, forming a monolithic planetary transmission with a small tooth difference, and the involute planetary gears 2 oscillating and rotating. When the technical solution of embodiment 1 is adopted, the involute planetary gears oscillate and rotate, driving each column pin 3 to move the support ring 5 fixedly connected to each column pin 3 and the output plate 12, causing them to perform circular motion together, and the output plate 12 outputs power. When the technical solution of embodiment 2 is adopted, the involute planetary gears drive each column pin 3 to oscillate and rotate synchronously with the involute planetary gears, so that each column pin 3 acts on the second column pin action holes of the support ring 5 and the output platen 12, causing the support ring 5 and the output platen 12 to perform circular motion together, so that the output platen 12 outputs power. Here, the rotation direction of the eccentric input shaft 7 is opposite to that of the involute planetary gears 2, the support ring 5 and the output platen 12. When the eccentric input shaft 7 rotates forward, the power output by the output platen 12 on the one hand drives and rotates the first flexible output shaft 212, and on the other hand stores energy in the spiral energy storage spring 13, and the first flexible output shaft 212 further rotates the second moving member connected via the output screw hole 215. When the eccentric input shaft 7 rotates in the opposite direction, the power output by the output plate 12 and the energy released by the volute energy storage spring 13 both rotate the first flexible output shaft 212. When the output of the eccentric input shaft 7's forward and reverse rotation does not change (i.e., when the output of the motor inputting power to the eccentric input shaft 7 does not change), the energy released by the volute energy storage spring 13 also applies torque to the second moving member (the torque supplied by the motor becomes smaller). Therefore, when the eccentric input shaft 7 rotates in the opposite direction, the rotation speed of the second moving member is higher than when the eccentric input shaft 7 rotates in the forward direction, and the rotation speed of the second moving member relative to the first moving member when the eccentric input shaft 7 rotates in the opposite direction is higher than when the eccentric input shaft 7 rotates in the forward direction. As a result, the joint of the present invention can store energy when, for example, crouching and release it when standing, thereby enabling higher jumps. Furthermore, when the external torque received by the second moving member connected to the first flexible output shaft 212 exceeds the sum of the torques generated by the compression springs 211 on the second moving member, the first flexible output shaft 212 and the output board 12 rotate relative to each other. The compression springs 211 are compressed to generate a flexible action, preventing the second moving member from colliding violently with a human body or other objects and causing injury.

[0036] Furthermore, when the flexible output module 21 is the composite flexible output module 31 of embodiment 3, when the eccentric input shaft 7 rotates forward, the power output from the output plate 12 drives the second flexible output shaft 313 to rotate, and stores energy in the spiral energy storage spring 13. The second flexible output shaft 313 also drives the second moving member connected via the output screw hole to rotate. When the eccentric input shaft 7 rotates in the reverse direction, the power output by the output plate 12 and the energy released by the volute energy storage spring 13 simultaneously drive and rotate the second flexible output shaft 313. If the forward / reverse rotation output of the eccentric input shaft 7 does not change (i.e., if the motor output that inputs power to the eccentric input shaft 7 does not change), the energy released by the volute energy storage spring 13 also applies torque to the second moving member (the torque supplied by the motor becomes smaller). Therefore, the rotational speed of the second moving member when the eccentric input shaft 7 rotates in the reverse direction is greater than the rotational speed when the eccentric input shaft 7 rotates in the forward direction, and the relative rotational speed of the second moving member with respect to the first moving member is greater than when the eccentric input shaft 7 rotates in the forward direction. In this way, the joint of the present invention can, for example, store energy when crouching and release it when standing up, thereby enabling higher jumps. Furthermore, if the external torque received by the second moving member connected to the second flexible output shaft 313 exceeds the sum of the torques generated in the second moving member by the magnetic forces of each pair of the first permanent magnets 311 and the second permanent magnets 312, the second flexible output shaft 313 and the output board 12 will rotate relative to each other, and the magnetic forces of each pair of the first permanent magnets 311 and the second permanent magnets 312 will act as a flexible support, preventing the second moving member from colliding violently with the human body or other objects and causing harm. Furthermore, the magnetic force of each of the first permanent magnets 311 and second permanent magnets 312 is finite, and unstable vibrations are likely to occur. Therefore, the parallel-connected planar spring 314, second flexible output shaft 313, and output board 12 rotate relative to each other. When each second magnet mounting base of the second flexible output shaft 313 abuts against the corresponding first magnet mounting base of the output board 12, the overhang portion 318 on one side of each sectorial ring portion of the planar spring 314 also abuts against the corresponding first magnet mounting base. This prevents the arc-shaped connecting beam 317 and overhang portion 318 of the sectorial ring portion from rotating. Furthermore, the radial grooves and the portions located inside the arc-shaped grooves of the sectorial ring portion can continue to deform, which further prevents the second moving member from violently colliding with a human body or other objects and causing injury, as shown in FIG. 11 . The present invention employs a magnetic spring (consisting of a first permanent magnet 311 and a second permanent magnet 312) in combination with a planar spring 314 to increase the rigidity of the entire composite flexible output module 31 and avoid vibration and instability caused by collision.

Claims

1. A flexible joint based on an elastic element, comprising an involute small tooth differential reducer, a volute energy storage spring and a flexible output module; The involute small tooth difference reducer includes a joint housing, an eccentric input shaft, a gear transmission mechanism, and a column pin output mechanism; The gear transmission mechanism includes an involute planetary gear and an involute internal tooth ring, The pillar pin output mechanism includes a pillar pin, a support ring, and an output board; The support ring is supported on one end of the inner wall of the joint housing by a first rolling bearing, and the output board is supported on the other end of the inner wall of the joint housing by a second rolling bearing, and is connected to the inner wall of the joint housing by a spiral energy storage spring; an involute internal tooth ring is installed in the joint housing at a position between the first rolling bearing and the second rolling bearing; One end of the eccentric input shaft is supported in the support ring by a third rolling bearing, and the other end is supported in the output board by a fourth rolling bearing; The involute planetary gear is supported by a fifth rolling bearing on an eccentric shaft portion at an intermediate position of the eccentric input shaft, and is engaged with an involute internal tooth ring; the involute planetary gear is provided with a plurality of bolt passing holes uniformly distributed along the circumferential direction and a plurality of first pole pin action holes uniformly distributed along the circumferential direction, and the bolt passing holes and the first pole pin action holes are alternately distributed along the circumferential direction; A plurality of hole units are provided on one of the support ring and the output board, the hole units being uniformly distributed along the circumferential direction, and the hole units are composed of a sinking hole into which a bolt head is embedded and a through hole through which a rod portion of the bolt is passed, which are coaxially provided, and a plurality of screw holes are provided on the other of the support ring and the output board, the screw holes being uniformly distributed along the circumferential direction; the number of hole units, bolt passing holes, and screw holes are equal, and one hole unit and one screw hole aligned at a circumferential position are connected by one bolt, and each bolt passes through one bolt passing hole aligned at a circumferential position of the involute planetary gear; The center of the circumference on which the center of each bolt, which is uniformly distributed along the circumferential direction, is located is concentric with the center of the support ring and the output board; The inner diameter of the bolt passage hole is d １ +2e, where d １ is the major diameter of the bolt thread, e is the eccentric distance of the eccentric shaft portion of the eccentric input shaft, the diameter of the circumference on which the centers of each bolt passing hole and each first post pin action hole are located is equal to the diameter of the circumference on which the centers of each bolt are located, the flexible output module includes a first flexible output shaft and a compression spring; The center hole of the first flexible output shaft is clearance-fitted with the hub of the output board; a fastening screw hole is provided in the center of the hub of the output plate, and the first flexible output shaft is axially restricted by the output plate and the first shaft cover, and the first shaft cover and the fastening screw hole in the center of the hub of the output plate are fixedly connected by a first screw; the first flexible output shaft and the output plate are connected by a plurality of compression springs arranged along a circumferential direction; The support ring and the output board are each provided with a plurality of second pillar pin action holes that are uniformly distributed along the circumferential direction, The second post pin operating holes of the support ring, the first post pin operating holes of the involute planetary gears, and the second post pin operating holes of the output disc are equal in quantity, and the connection manner between the second post pin operating holes of the support ring, the first post pin operating holes of the involute planetary gears, and the second post pin operating holes of the output disc and the post pins can be one of the following two types:

1. Each second column pin action hole of the support ring and one of the second column pin action holes of the output disc aligned with each other in the circumferential position are fixedly connected by a column pin, and each column pin passes through one of the first column pin action holes aligned with each other in the circumferential position of the involute planetary gear, and the cylindrical surface of the column pin abuts against the inner wall of the corresponding first column pin action hole, and the inner diameter of the first column pin action hole is d ２ +2e, the inner diameter of the second pillar pin action hole is d ２ So, d ２ is the diameter of the pillar pin, 2. One pole pin is fixed in each first pole pin action hole of the involute planetary gear, and the cylindrical surfaces at both ends of each pole pin abut against the inner wall of one second pole pin action hole aligned at the circumferential position of the support ring and the output board, and the inner diameter of the first pole pin action hole is d ２ The inner diameter of the second pillar pin action hole is d ２ A flexible joint based on an elastic element, characterized in that the joint is +2e.

2. The flexible output module is a composite flexible output module, the composite flexible output module includes a second flexible output shaft, a planar spring, a first permanent magnet, and a second permanent magnet, and a center hole of the second flexible output shaft is clearance-fitted with a hub of the output board; a flat spring is fixed to the outer end of the second flexible output shaft, the central hole of the flat spring is clearance-fit with the outer wall of the second shaft cover, the second flexible output shaft and the flat spring are axially restricted by the output plate and the second shaft cover, and the fastening screw holes at the center of the hub of the second shaft cover and the output plate are fixedly connected by a second screw; A plurality of first magnet mounting bases are disposed on the inner wall of the output board, and are integrally molded and uniformly distributed along the circumferential direction; a plurality of second magnet mounting bases are disposed on the outer circular surface of the second flexible output shaft, and are integrally molded and uniformly distributed along the circumferential direction; the first magnet mounting bases and the second magnet mounting bases are disposed at intervals and crosswise distributed along the circumferential direction; One first permanent magnet is attached to each of both sides of the first magnet mounting base, and one second permanent magnet is attached to each of both sides of the second magnet mounting base, Each second permanent magnet is provided facing one first permanent magnet with a gap therebetween, and the facing pole ends of the second permanent magnet and the facing first permanent magnet have the same magnetic pole; The flexible joint based on an elastic element according to claim 1, characterized in that the planar spring has a plurality of sectorial rings that are integrally molded and uniformly distributed along the circumferential direction, both sides of each sectorial ring are directly opposite and spaced apart from two first magnet mounting bases, the second flexible output shaft has a plurality of output screw holes that are uniformly distributed along the circumferential direction, the planar spring has a plurality of light holes that are uniformly distributed along the circumferential direction, the light holes and the output screw holes are equal in number and are aligned one-to-one in the circumferential position.

3. 3. The flexible joint based on an elastic element according to claim 1, wherein the joint housing is provided with a plurality of mounting screw holes and a plurality of positioning holes that are uniformly distributed along the circumferential direction.

4. 3. The flexible joint based on an elastic element according to claim 1 or 2, characterized in that in the involute planetary gear transmission unit with a small tooth number difference, which is composed of the eccentric shaft portion of the eccentric input shaft, the involute internal tooth ring, and the involute planetary gear, the involute internal tooth ring has 1 to 4 more teeth than the involute planetary gear.

5. 3. The flexible joint based on an elastic element according to claim 1 or 2, characterized in that the inner end of the spiral energy storage spring is fitted into a socket provided on the outer wall of the output board, and the outer end is fitted into a socket provided on the inner wall of the joint housing.

6. 2. The flexible joint based on an elastic element according to claim 1, wherein the inner end of the first flexible output shaft is provided with a boss that is integrally molded and coaxially arranged therewith.

7. The flexible joint based on an elastic element according to claim 1, characterized in that a sunken groove is provided on the outer end surface of the first flexible output shaft, a stop ring integrally formed on the outer end of the first shaft cover is fitted into the sunken groove, and a gap is provided between the stop ring and the bottom of the sunken groove.

8. 2. The flexible joint based on an elastic element according to claim 1, wherein the inner wall of the output plate is provided with a plurality of first spring seats that are integrally molded and uniformly distributed along the circumferential direction, the outer circular surface of the first flexible output shaft is provided with a plurality of second spring seats that are integrally molded and uniformly distributed along the circumferential direction, the first spring seats and the second spring seats are arranged crosswise along the circumferential direction, and the two first side surfaces of each first spring seat and the second side surfaces of each two second spring seats are connected by one compression spring, respectively.

9. The flexible joint based on an elastic element according to claim 1, wherein the first flexible output shaft is provided with a plurality of output screw holes that are uniformly distributed along the circumferential direction.

10. The flexible joint based on an elastic element according to claim 2, characterized in that the sector portion of the planar spring has an arc groove on the outer edge, and radial grooves are provided on both sides, the outer ends of the two radial grooves are connected to both ends of the arc groove respectively, the planar spring has overhang portions formed outside the two radial grooves, and arc connecting beams are formed outside the arc grooves.

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