Flexible joint based on elastic element

Abstract

The invention discloses a flexible joint based on an elastic element. The flexible joint comprises an involute small-tooth-difference speed reducer, a scroll energy storage spring and a flexible output assembly / composite flexible output assembly. The involute small-tooth-difference speed reducer only adopts the eccentric input shaft, the involute inner gear ring and the involute planetary gear to achieve swinging and autorotation of the involute planetary gear, and power output of the output disc is transmitted through interaction of a pin and a first pin acting hole of the involute planetary gear or a second pin acting hole of the output disc. The precision requirement can be easily met through the meshing mode of only one pair of gears, the axial size is compact, the involute planetary gear can be used when the space of a transmission system is limited, the involute inner gear ring and the involute planetary gear both adopt involute tooth profiles, and the manufacturing cost is low; a scroll energy storage spring and a compression spring or a scroll energy storage spring, a magnetic spring and a plane spring are integrated in the device, energy storage and passive flexibility are achieved, driving power consumption is reduced, and meanwhile the requirement for driving agility can be met.

Description

Technical Field

[0001] The present invention belongs to the technical field of robot driven joints, and in particular relates to a compliant joint based on elastic elements. Background Art

[0002] Traditional robot drive joints often use a rigid design, controlling their motion along predetermined trajectories within structured environments to complete specific tasks. As the requirements for robots in human-robot collaboration scenarios change, robots are increasingly coming into contact with humans during operation. There is an urgent need for a drive system that can be used in collaborative environments, is environmentally friendly, and poses no risk to the external environment. This requires a certain degree of flexibility in the drive joints.

[0003] Humanoid robots, jumping robots, quadruped robots (robot dogs), and other mobile off-cable bionic mechanical systems require full and rational utilization of energy such as gravitational potential energy. For example, the knee joint of a humanoid robot is required to store energy when squatting and release energy when standing, enabling it to jump higher. It must be flexible and safe, have a long service life, be energy-efficient, and have limited-angle drive (output drive angle <360°) to achieve agility (instantaneously greater speed and acceleration, and greater output torque). Therefore, the drive joint is required to have a certain energy storage capacity. Summary of the Invention

[0004] The purpose of the present invention is to provide a flexible joint based on elastic elements in view of the deficiencies in the prior art.

[0005] The technical solution adopted in the present invention is:

[0006] The present invention provides a flexible joint based on an elastic element, comprising an involute small-tooth-difference reducer, a scroll energy storage spring and a flexible output assembly; the involute small-tooth-difference reducer comprises a joint housing, an eccentric input shaft, a gear transmission mechanism and a pin output mechanism; the gear transmission mechanism comprises an involute planetary gear and an involute inner gear ring; the pin output mechanism comprises a pin, a load ring and an output disc; the load ring is supported on one end of the inner wall of the joint housing by a rolling bearing 1, and the output disc is supported on the other end of the inner wall of the joint housing by a rolling bearing 2, and is connected to the inner wall of the joint housing by a scroll. The coil energy storage spring is connected; the joint housing is provided with an involute inner gear ring at a position between rolling bearing 1 and rolling bearing 2; one end of the eccentric input shaft is supported in the load-bearing ring through rolling bearing 3, and the other end is supported in the output disk through rolling bearing 4; the involute planetary gear is supported on the eccentric shaft section in the middle position of the eccentric input shaft through rolling bearing 5, and meshes with the involute inner gear ring; the involute planetary gear is provided with a plurality of bolt through holes uniformly distributed along the circumference and a plurality of pin action holes uniformly distributed along the circumference, and the bolt through holes and pin action holes are alternately distributed along the circumference; the load-bearing One of the ring and the output disk is provided with a plurality of hole groups uniformly distributed along the circumference, and the hole group consists of coaxially arranged countersunk holes and through holes, and the other is provided with a plurality of threaded holes uniformly distributed along the circumference; the number of hole groups, bolt holes and threaded holes is equal, and each hole group is connected to a threaded hole aligned in the circumferential position through a bolt, and each bolt passes through a bolt hole aligned in the circumferential position on the involute planetary gear; the center of the circle on which the centers of the bolts uniformly distributed along the circumference are located is collinear with the center of the circle of the load ring and the output disk; the inner diameter of the bolt hole is greater than d1+2e, where d1 is the major diameter of the bolt thread and e is The eccentricity of the eccentric shaft section on the eccentric input shaft, the diameter of the circle where the center of each bolt through hole and the center of the pin action hole 1 are located is equal to the diameter of the circle where the center of each bolt is located; the flexible output assembly includes a flexible output shaft 1 and a compression spring; the center hole of the flexible output shaft 1 is clearance-matched with the hub of the output disk; a fastening screw hole is provided at the center of the hub of the output disk, and the flexible output shaft 1 is axially limited by the output disk and the shaft cover 1, and the shaft cover 1 is fixedly connected to the fastening screw hole at the center of the hub of the output disk by a screw 1; the flexible output shaft 1 is connected to the output disk through multiple compression springs arranged along the circumference. The load-bearing ring and the output disk are both provided with multiple pin action holes 2 evenly distributed along the circumference; the number of the pin action holes 2 of the load-bearing ring, the pin action hole 1 of the involute planetary gear and the pin action hole 2 of the output disk is equal, and the connection method between the pin action hole 2 of the load-bearing ring, the pin action hole 1 of the involute planetary gear and the pin action hole 2 of the output disk and the pin can be one of the following two methods:

[0007] ① Each pin action hole 2 of the load-bearing ring is fixedly connected to a pin action hole 2 aligned circumferentially on the output disk through a pin, and each pin passes through a pin action hole 1 aligned circumferentially on the involute planetary gear, and the cylindrical surface of the pin is tangent to the inner wall of the corresponding pin action hole 1; the inner diameter of the pin action hole 1 is d2+2e, and the inner diameter of the pin action hole 2 is d2, where d2 is the diameter of the pin.

[0008] ② A pin is fixed in each pin action hole 1 of the involute planetary gear, and the cylindrical surfaces at both ends of each pin are tangent to the inner wall of a pin action hole 2 that is circumferentially aligned on the load ring and the output disk; the inner diameter of the pin action hole 1 is d2, and the inner diameter of the pin action hole 2 is d2+2e.

[0009] Preferably, the flexible output component is replaced by a composite flexible output component; the composite flexible output component includes a flexible output shaft 2, a planar spring, a permanent magnet 1 and a permanent magnet 2; the center hole of the flexible output shaft 2 is clearance-matched with the hub of the output disk; a planar spring is fixed to the outer end of the flexible output shaft 2, the center hole of the planar spring is clearance-matched with the outer wall of the shaft cover 2, the flexible output shaft 2 and the planar spring are axially limited by the output disk and the shaft cover 2, and the shaft cover 2 is fixedly connected to the hub center of the output disk by a screw 2 through a fastening screw hole; the inner wall of the output disk is provided with a plurality of magnet mounting seats 1 that are integrally formed and evenly distributed along the circumference, and the outer cylindrical surface of the flexible output shaft 2 is provided with a plurality of magnet mounting seats that are integrally formed and evenly distributed along the circumference. Second, magnet mounting seat 1 and magnet mounting seat 2 are staggered and spaced apart in the circumferential direction; a permanent magnet 1 is mounted on both sides of magnet mounting seat 1, and a permanent magnet 2 is mounted on both sides of magnet mounting seat 2; each permanent magnet 2 is opposite to a permanent magnet 1 and spaced apart, and the opposite permanent magnet 2 has the same magnetic pole as the opposite end of the permanent magnet 1; the planar spring is provided with a plurality of integrally formed sector ring portions uniformly distributed along the circumferential direction, and both sides of each sector ring portion are opposite to the two magnet mounting seats 1 and spaced apart; the flexible output shaft 2 is provided with a plurality of output screw holes uniformly distributed along the circumferential direction, and the planar spring is provided with a plurality of light holes uniformly distributed along the circumferential direction, and the number of the light holes is equal to that of the output screw holes and the circumferential positions are aligned one by one.

[0010] Preferably, the joint housing is provided with a plurality of mounting screw holes evenly distributed along the circumference, and is also provided with a plurality of positioning holes.

[0011] Preferably, in the involute planetary gear transmission mechanism with small tooth difference composed of the eccentric shaft section of the eccentric input shaft, the involute internal gear ring and the involute planetary gears, the involute internal gear ring has 1-4 more teeth than the involute planetary gears.

[0012] Preferably, the inner end of the scroll energy storage spring is embedded in a socket provided on the outer wall of the output disk, and the outer end is embedded in a socket provided on the inner wall of the joint housing.

[0013] Preferably, the inner end of the flexible output shaft 1 is provided with an integrally formed and coaxially arranged boss.

[0014] Preferably, a countersunk groove is provided on the outer end surface of the flexible output shaft 1, a limiting ring integrally formed at the outer end of the shaft cover 1 is embedded in the countersunk groove, and a gap is provided between the limiting ring and the bottom of the countersunk groove.

[0015] Preferably, the inner wall of the output disk is provided with a plurality of spring seats 1 that are integrally formed and evenly distributed along the circumferential direction, and the outer circumferential surface of the flexible output shaft 1 is provided with a plurality of spring seats 2 that are integrally formed and evenly distributed along the circumferential direction. The spring seats 1 and the spring seats 2 are arranged alternately along the circumferential direction, and the two side faces 1 of each spring seat 1 are connected to the side faces 2 of the two spring seats 2 respectively through a compression spring.

[0016] Preferably, the flexible output shaft is provided with a plurality of output screw holes uniformly distributed along the circumferential direction.

[0017] Preferably, the fan ring portion of the planar spring is provided with an arc groove at the outer edge, and radial grooves are provided on both sides, the outer ends of the two radial grooves are respectively connected to the two ends of the arc groove, and the planar spring forms an overhang portion on the outside of the two radial grooves, and forms an arc connecting beam on the outside of the arc groove.

[0018] The present invention has the following beneficial effects:

[0019] The present invention integrates a scroll energy storage spring and a compression spring, or integrates a scroll energy storage spring, a magnetic spring and a plane spring to achieve energy storage and passive flexibility; the present invention can achieve, for example, that the scroll energy storage spring stores energy when squatting, and releases energy and provides torque when standing, and the torque that the motor needs to provide becomes smaller. Therefore, the instantaneous rotational speed of the joint of the present invention when the eccentric input shaft is reversed is greater than the rotational speed when the eccentric input shaft is forward rotating, outputting greater force and torque, and being able to jump higher; moreover, when colliding with the outside world, the joint of the present invention can store energy and produce flexible deformation within a certain range, thereby playing a buffering and protective role for the human body or other objects. Furthermore, the present invention utilizes only a single eccentric input shaft and a pair of involute internal gears and involute planetary gears to achieve the swing and rotation of the involute planetary gears. The difference in the number of teeth between the involute internal gear and the involute planetary gears is designed to be 1 to 4, forming a single-piece, small-tooth-difference planetary transmission. The power output of the output disc is transmitted by the interaction between the pin and the first pin action hole of the involute planetary gear or the second pin action hole of the output disc. The meshing of only one pair of gears makes it easy to meet precision requirements, and the axial dimensions are more compact, allowing for use even in limited transmission system space. Furthermore, the involute internal gear and involute planetary gears of the present invention both utilize involute tooth profiles, making them easy to manufacture and low-cost. Therefore, the present invention provides a high-performance, compliant joint capable of storing energy, exhibiting high torque, having a compact structure, and low manufacturing cost, suitable for applications such as robotics. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 This is a structural cross-sectional view of Example 1 of the present invention.

[0021] Figure 2 for Figure 1 Right view of .

[0022] Figure 3 Schematic diagram of the transmission relationship among the eccentric input shaft, involute internal gear ring, involute planetary gears and pins in Example 1 of the present invention.

[0023] Figure 4 Schematic diagram of the transmission relationship among the eccentric input shaft, involute internal gear ring, involute planetary gears and pins in Example 2 of the present invention.

[0024] Figure 5 This is a stereoscopic assembly diagram of the involute planetary gear and pin in Example 2 of the present invention.

[0025] Figure 6 It is a structural stereogram of the eccentric input shaft in the present invention.

[0026] Figure 7 This is a structural cross-sectional view of Example 3 of the present invention.

[0027] Figure 8 for Figure 7 Right view of .

[0028] Figure 9 This is an exploded view of the three-dimensional structure of Example 3 of the present invention.

[0029] Figure 10 This is a schematic diagram of the structure of the composite compliant output component of the present invention after removing the planar spring.

[0030] Figure 11 Schematic diagram comparing the plane spring before and after deformation in the present invention. DETAILED DESCRIPTION

[0031] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0032] like Figure 1 and Figure 2As shown, a flexible joint based on an elastic element includes an involute small-tooth difference reducer, a scroll energy storage spring 13 and a flexible output assembly 21; the involute small-tooth difference reducer includes a joint housing 1, an eccentric input shaft 7, a gear transmission mechanism and a pin output mechanism; the gear transmission mechanism includes an involute planetary gear 2 and an involute inner gear ring 17; the pin output mechanism includes a pin 3, a load ring 5 and an output disc 12; the load ring 5 is supported on one end of the inner wall of the joint housing 1 by a rolling bearing 1 4, and the output disc 12 is supported on the other end of the inner wall of the joint housing 1 by a rolling bearing 2 10, and is connected to the inner wall of the joint housing 1 by a scroll energy storage spring 13; the joint housing 1 is provided with an involute inner gear ring 17 at a position between the rolling bearing 1 4 and the rolling bearing 2 10; One end of the eccentric input shaft 7 is supported in the carrying ring 5 by a rolling bearing three 6, and the other end is supported in the output disc 12 by a rolling bearing four 11; the involute planetary gear 2 is supported on the eccentric shaft section in the middle position of the eccentric input shaft 7 by a rolling bearing five 8 or a plurality of rollers evenly distributed along the circumference, and meshes with the involute inner gear ring 17 (the involute planetary gear 2 is provided with an external tooth 16); the involute planetary gear 2 is provided with a plurality of bolt through holes evenly distributed along the circumference and a plurality of pin action holes 20 evenly distributed along the circumference, and the bolt through holes and the pin action holes 20 are alternately distributed along the circumference, and the center of the circle where the center of each bolt through hole and the center of the pin action hole 20 coincides with the center of the involute planetary gear 2; one of the carrying ring 5 and the output disc 12 is provided with a plurality of rollers evenly distributed along the circumference. Multiple hole groups are arranged, and the hole group consists of coaxially arranged countersunk holes and through holes, and the other is provided with multiple threaded holes uniformly distributed along the circumference; the number of hole groups, bolt through holes and threaded holes is equal, and each hole group is connected to a threaded hole aligned in the circumferential position through a bolt 9, and each bolt 9 passes through a bolt through hole aligned in the circumferential position on the involute planetary gear 2; the center of the circle where the center of each bolt 9 uniformly distributed in the circumference is located is collinear with the center of the bearing ring 5 and the output disk 12; the inner diameter of the bolt through hole is greater than d1+2e, where d1 is the major diameter of the thread of the bolt 9, and e is the eccentricity of the eccentric shaft section on the eccentric input shaft. The diameter of the circle where the center of each bolt through hole and the center of the pin action hole 20 are located is equal to the diameter of the circle where the center of each bolt 9 is located, ensuring that the involute planetary gear 2 During the rotation process, each bolt 9 never contacts the inner wall of the corresponding bolt through hole; the flexible output component 21 includes a flexible output shaft 212 and a compression spring 211; the center hole of the flexible output shaft 212 is clearance-matched with the hub of the output disk 12, so that the flexible output shaft 212 can rotate relative to the output disk 12 when subjected to torque; a fastening screw hole is provided at the center of the hub of the output disk 12, and the flexible output shaft 212 is axially limited by the output disk 12 and the shaft cover 214, and the shaft cover 214 is fixedly connected to the fastening screw hole at the center of the hub of the output disk 12 by a screw 213; the flexible output shaft 212 is connected to the output disk 12 by a plurality of compression springs 211 arranged along the circumferential direction, and the output stiffness of the flexible output component can be adjusted by changing the stiffness of the compression spring.Both the load-bearing ring 5 and the output disk 12 are provided with a plurality of pin action holes 2 uniformly distributed along the circumferential direction; the number of the pin action holes 2 of the load-bearing ring 5, the pin action hole 1 20 of the involute planetary gear 2 and the pin action hole 2 of the output disk 12 is equal, and the connection method of the pin action hole 2 of the load-bearing ring 5, the pin action hole 1 20 of the involute planetary gear 2 and the pin action hole 2 of the output disk 12 with the pin 3 can adopt the following two different embodiments:.

[0033] Example 1

[0034] like Figure 1 and Figure 3 As shown, each pin action hole 2 of the carrying ring 5 is fixedly connected to a pin action hole 2 aligned circumferentially on the output disk 12 through a pin 3, and each pin 3 passes through a pin action hole 1 20 aligned circumferentially on the involute planetary gear 2, and the cylindrical surface of the pin 3 is tangent to the inner wall of the corresponding pin action hole 1 20; the inner diameter of the pin action hole 1 20 is d2+2e, and the inner diameter of the pin action hole 2 is d2, and d2 is the diameter of the pin 3.

[0035] Example 2

[0036] like Figure 4 and Figure 5 As shown, a pin 3 is fixed in each pin action hole 1 20 of the involute planetary gear 2, and the cylindrical surfaces at both ends of each pin 3 are tangent to the inner wall of a pin action hole 2 that is circumferentially aligned on the load ring 5 and the output disk 12; the inner diameter of the pin action hole 1 20 is d2, and the inner diameter of the pin action hole 2 is d2+2e.

[0037] The flexible output component 21 may also be replaced by the composite flexible output component 31 in Example 3;

[0038] Example 3:

[0039] like Figures 7 to 10As shown, the composite flexible output component 31 includes a flexible output shaft 2 313, a flat spring 314, a permanent magnet 1 311 and a permanent magnet 2 312; the center hole of the flexible output shaft 2 313 is clearance-matched with the hub of the output disk 12, so that the flexible output shaft 2 313 can rotate relative to the output disk 12 when subjected to torque; a flat spring 314 is fixed to the outer end of the flexible output shaft 2 313, and the center hole of the flat spring 314 is clearance-matched with the outer wall of the shaft cover 2 315. The flexible output shaft 2 313 and the flat spring 314 are axially limited by the output disk 12 and the shaft cover 2 315, and the shaft cover 2 315 is fixedly connected to the fastening screw hole at the center of the hub of the output disk 12 by a screw 2 316; the inner wall of the output disk 12 is provided with a plurality of magnet mounting seats 1 that are integrally formed and evenly distributed along the circumference, and the flexible output The outer circumferential surface of shaft 2 313 is provided with a plurality of magnet mounting seats 2 that are integrally formed and uniformly distributed along the circumferential direction. Magnet mounting seats 1 and 2 are staggered and arranged with a distance between them along the circumference. A permanent magnet 1 311 is installed on both sides of magnet mounting seat 1, and a permanent magnet 2 312 is installed on both sides of magnet mounting seat 2. Each permanent magnet 2 312 is opposite to a permanent magnet 1 311 and is spaced apart. The opposite end magnetic poles of the permanent magnet 2 312 and the permanent magnet 1 311 are the same. Changing the magnetic field strength of the permanent magnet 1 311 and the permanent magnet 2 312 can realize the output stiffness adjustment of the composite flexible output component 31. The flat spring 314 is provided with a plurality of fan ring parts that are integrally formed and uniformly distributed along the circumferential direction. The two sides of each fan ring part are opposite to the two magnet mounting seats 1 and are spaced apart. Figure 10 and Figure 11 As shown, the flexible output shaft 2 313 is provided with a plurality of output screw holes evenly distributed along the circumference, and the planar spring 314 is provided with a plurality of light holes evenly distributed along the circumference. The number of light holes is equal to that of the output screw holes and the circumferential positions are aligned one by one. The output screw holes and the light holes are used to connect the moving part 2.

[0040] As a preferred embodiment, Figure 1 As shown, the joint housing 1 is provided with a plurality of mounting screw holes 19 evenly distributed along the circumferential direction, and is also provided with a plurality of positioning holes 18 , and the mounting screw holes 19 and the positioning holes 18 are used to connect the moving part 1.

[0041] As a preferred embodiment, in the involute planetary gear transmission mechanism with small tooth difference composed of the eccentric shaft section of the eccentric input shaft 7, the involute internal gear ring 17 and the involute planetary gear 2, the involute internal gear ring has 1-4 more teeth than the involute planetary gear.

[0042] As a preferred embodiment, Figure 1 and Figure 6 As shown, a plurality of weight-reducing holes 15 arranged along the circumferential direction are provided on the shoulder of the eccentric shaft section of the eccentric input shaft 7 to reduce the imbalance of the eccentric input shaft.

[0043] As a preferred embodiment, Figure 1As shown, the hollow hole of the eccentric input shaft 7 is located at the eccentric shaft section and a weight-reducing groove 14 is provided on the hole wall facing the eccentric direction of the eccentric input shaft 7 . The hollow hole of the eccentric input shaft 7 and the weight-reducing groove 14 further reduce the imbalance of the eccentric input shaft 7 .

[0044] As a preferred embodiment, Figure 1 As shown, the rolling bearing 5 8 adopts a roller bearing.

[0045] As a preferred embodiment, Figure 1 As shown, the inner end of the scroll energy storage spring 13 is embedded in the insertion hole opened on the outer wall of the output disk 12, and the outer end is embedded in the insertion hole opened on the inner wall of the joint housing 1.

[0046] As a preferred embodiment, Figure 1 As shown, the inner end of the flexible output shaft 1 212 is provided with an integrally formed and coaxially arranged boss, and the contact between the boss and the output disk 12 can reduce friction.

[0047] As a preferred embodiment, Figure 1 As shown, a countersunk groove is provided on the outer end surface of the flexible output shaft 1 212 , and a limiting ring integrally formed on the outer end of the shaft cover 1 214 is embedded in the countersunk groove, and a gap is provided between the limiting ring and the bottom of the countersunk groove.

[0048] As a preferred embodiment, Figure 2 As shown, the inner wall of the output disk 12 is provided with a plurality of spring seats 1 that are integrally formed and evenly distributed along the circumference, and the outer circumferential surface of the flexible output shaft 1 212 is provided with a plurality of spring seats 2 that are integrally formed and evenly distributed along the circumference. The spring seats 1 and the spring seats 2 are arranged alternately along the circumference, and the two side faces 1 217 of each spring seat 1 are connected to the two side faces 216 of the two spring seats 2 respectively through a compression spring 211.

[0049] As a preferred embodiment, Figure 2 As shown, the flexible output shaft 1 212 is provided with a plurality of output screw holes 215 evenly distributed along the circumferential direction for connecting with the moving part 2.

[0050] As a preferred embodiment, Figure 7 As shown, the inner end of the flexible output shaft 2 313 is provided with an integrally formed and coaxially arranged boss, and the contact between the boss and the output disk 12 can reduce friction.

[0051] As a preferred embodiment, Figure 7 As shown, a countersunk groove is formed on the outer end surface of the plane spring 314, and a limiting ring integrally formed on the outer end of the second shaft cover 315 is embedded in the countersunk groove, and a gap is provided between the limiting ring and the bottom of the countersunk groove.

[0052] As a preferred embodiment, Figure 11As shown, the fan ring portion of the planar spring 314 is provided with an arc groove at the outer edge, and radial grooves are provided on both sides. The outer ends of the two radial grooves are respectively connected to the two ends of the arc groove. The planar spring 314 forms an overhang portion 318 on the outside of the two radial grooves and an arc connecting beam 317 on the outside of the arc groove.

[0053] When the present invention is used, the joint housing 1 is fixed to the moving part through the mounting screw hole 19 and the positioning hole 18; the power is input by the eccentric input shaft 7 (the motor inputs power to the eccentric input shaft 7) and drives the involute planetary gear 2 to revolve, so that the involute planetary gear engages with the involute inner gear ring 17, and the involute planetary gear also rotates. The present invention only has a pair of gear transmissions, namely, the involute internal gear ring 17 and the involute planetary gear 2. The transmission ratio is the number of teeth of the involute planetary gear 2 divided by the difference in the number of teeth between the involute internal gear ring 17 and the involute planetary gear 2. The difference in the number of teeth between the involute internal gear ring 17 and the involute planetary gear 2 is designed to be 1 to 4, forming a single-piece planetary transmission with a small tooth difference, and the involute planetary gear 2 swings and rotates. When the technical solution of Example 1 is adopted, the involute planetary gear swings and rotates, driving each pin 3 to drive the load-bearing ring 5 and the output disk 12 fixedly connected to each pin 3 to perform circular motion together, and the output disk 12 outputs power. When the technical solution of Example 2 is adopted, the involute planetary gear drives each pin 3 to swing and rotate synchronously with the involute planetary gear, so that each pin 3 acts on the pin action hole 2 of the load-bearing ring 5 and the output disk 12, causing the load-bearing ring 5 and the output disk 12 to perform circular motion together, and the output disk 12 outputs power. Among them, the direction of the eccentric input shaft 7 is opposite to that of the involute planetary gear 2, the carrying ring 5 and the output disc 12. When the eccentric input shaft 7 rotates forward, the power output by the output disc 12 drives the flexible output shaft 1 212 to rotate on the one hand, and stores energy in the volute energy storage spring 13 on the other hand. The flexible output shaft 1 212 then drives the connected moving part 2 to rotate through the output screw hole 215; when the eccentric input shaft 7 rotates reversely, the power output by the output disc 12 and the energy released by the volute energy storage spring 13 simultaneously drive the flexible output shaft 1 212 to rotate. When the output power of the input shaft 7 remains unchanged during forward and reverse rotation (i.e., the output power of the motor that inputs power to the eccentric input shaft 7 remains unchanged), the vortex energy storage spring 13 releases energy and also provides torque to the moving part 2 (the torque that the motor needs to provide becomes smaller). Therefore, the speed of the moving part 2 when the eccentric input shaft 7 is reversed is greater than the speed when the eccentric input shaft 7 is forward rotated, so that the speed of the moving part 2 relative to the moving part 1 when the eccentric input shaft 7 is reversed is greater than when the eccentric input shaft 7 is forward rotated. Thus, the joint of the present invention can achieve, for example, energy storage when squatting and release when standing, and can jump higher. Moreover, when the moving part 2 connected to the flexible output shaft 1 212 is subjected to an external torque that exceeds the sum of the torques generated by the compression springs 211 on the moving part 2, the flexible output shaft 1 212 and the output disk 12 rotate relative to each other, and the compression springs 211 are compressed to produce a flexible effect, thereby preventing the moving part 2 from causing harm by hard collision with the human body or other objects.

[0054] In addition, when the flexible output component 21 is replaced by the composite flexible output component 31 in Example 3, if the eccentric input shaft 7 rotates forward, the power output by the output disk 12 drives the flexible output shaft 2 313 to rotate on the one hand, and stores energy in the scroll energy storage spring 13 on the other hand, and the flexible output shaft 2 313 then drives the connected moving part 2 to rotate through the output screw hole; when the eccentric input shaft 7 is reversed, the power output by the output disk 12 and the energy released by the scroll energy storage spring 13 simultaneously drive the flexible output shaft 2 313 to rotate, and when the eccentric input shaft 7 is forward, the power output by the output disk 12 and the energy released by the scroll energy storage spring 13 simultaneously drive the flexible output shaft 2 313 to rotate. When the reverse output power remains unchanged (i.e., the output power of the motor that inputs power to the eccentric input shaft 7 remains unchanged), the vortex energy storage spring 13 releases energy and also provides torque to the moving part 2 (the torque that the motor needs to provide becomes smaller). Therefore, the speed of the moving part 2 when the eccentric input shaft 7 is reversed is greater than the speed when the eccentric input shaft 7 is forward, so that the speed of the moving part 2 relative to the moving part 1 is greater when the eccentric input shaft 7 is reversed than when the eccentric input shaft 7 is forward, so that the joint of the present invention can achieve, for example, storing energy when squatting and releasing it when standing, and can jump higher. Moreover, when the moving part 2 connected to the flexible output shaft 2 313 is subjected to an external torque that exceeds the sum of the torques generated by the magnetic field forces of each pair of permanent magnets 1 311 and permanent magnets 2 312 on the moving part 2, the flexible output shaft 2 313 and the output disk 12 rotate relative to each other, and the magnetic field forces of each pair of permanent magnets 1 311 and permanent magnets 2 312 produce a flexible support effect, thereby preventing the moving part 2 from causing harm by hard collision with the human body or other objects; further, since the magnetic field forces of each permanent magnet 1 311 and permanent magnet 2 312 are limited, It is also easy to produce unstable excitation. For this reason, the parallel plane spring 314 is connected. When the flexible output shaft 2 313 and the output disk 12 rotate relative to each other and the magnet mounting seats 2 of the flexible output shaft 2 313 fit with the corresponding magnet mounting seats 1 on the output disk 12, the overhanging portion 318 on one side of each fan ring portion of the plane spring 314 also fits with the corresponding magnet mounting seat 1. The arc connecting beam 317 and the overhanging portion 318 of the fan ring portion no longer rotate, and the part of the fan ring portion located inside the radial groove and the arc groove can continue to deform, such as Figure 11 As shown, in order to further avoid the harm caused by the hard collision of the moving part 2 to the human body or other objects, the present invention adopts a magnetic spring (composed of permanent magnet 1 311 and permanent magnet 2 312) combined with a flat spring 314 to improve the overall stiffness of the composite flexible output component 31 and avoid oscillation and instability caused by excitation.

Claims

1. A compliant joint based on an elastic element, comprising an involute small-tooth-difference reducer, characterized in that: It also includes a scroll energy storage spring and a flexible output component; the involute small-tooth difference reducer includes a joint housing, an eccentric input shaft, a gear transmission mechanism and a pin output mechanism; the gear transmission mechanism includes an involute planetary gear and an involute inner gear ring; the pin output mechanism includes a pin, a load ring and an output disk; the load ring is supported on one end of the inner wall of the joint housing by a rolling bearing 1, and the output disk is supported on the other end of the inner wall of the joint housing by a rolling bearing 2, and is connected to the inner wall of the joint housing by a scroll energy storage spring; the joint housing is provided with an involute inner gear ring at a position between the rolling bearing 1 and the rolling bearing 2; one end of the eccentric input shaft One end is supported in the load ring by rolling bearing three, and the other end is supported in the output disk by rolling bearing four; the involute planetary gear is supported on the eccentric shaft section in the middle position of the eccentric input shaft by rolling bearing five, and meshes with the involute inner gear ring; the involute planetary gear is provided with a plurality of bolt through holes uniformly distributed along the circumference and a plurality of column pin action holes uniformly distributed along the circumference, and the bolt through holes and column pin action holes are alternately distributed along the circumference; one of the load ring and the output disk is provided with a plurality of hole groups uniformly distributed along the circumference, the hole group consisting of coaxially arranged countersunk holes and through holes, and the other is provided with a plurality of threaded holes uniformly distributed along the circumference; the number of hole groups, bolt through holes and threaded holes is equal, and Each hole group is connected to a threaded hole aligned in the circumferential position through a bolt, and each bolt passes through a bolt through hole aligned in the circumferential position on the involute planetary gear; the center of the circle where the center of each bolt is evenly distributed along the circumference is collinear with the center of the bearing ring and the output disk; the inner diameter of the bolt through hole is greater than d1+2e, wherein d1 is the major diameter of the thread of the bolt, and e is the eccentricity of the eccentric shaft section on the eccentric input shaft, and the diameter of the circle where the center of each bolt through hole and the center of the pin action hole 1 are located is equal to the diameter of the circle where the center of each bolt is located; the flexible output component includes a flexible output shaft 1 and a compression spring; the center hole of the flexible output shaft 1 is clearance-matched with the hub of the output disk; the output disk A fastening screw hole is provided at the center of the hub, and the flexible output shaft 1 is axially limited by the output disc and the shaft cover 1. The shaft cover 1 is fixedly connected to the fastening screw hole at the center of the hub of the output disc by a screw 1; the flexible output shaft 1 is connected to the output disc by a plurality of compression springs arranged along the circumferential direction; the load ring and the output disc are both provided with a plurality of pin action holes 2 uniformly distributed along the circumferential direction; the pin action holes 2 of the load ring, the pin action holes 1 of the involute planetary gear, and the pin action holes 2 of the output disc are equal in number, and the pin action holes 2 of the load ring, the pin action holes 1 of the involute planetary gear, and the pin action holes 2 of the output disc can be connected to the pins in one of the following two ways: ① Each pin action hole 2 of the load ring is fixedly connected to a pin action hole 2 aligned circumferentially on the output disc via a pin, and each pin passes through a pin action hole 1 aligned circumferentially on the involute planetary gear, with the cylindrical surface of the pin tangent to the inner wall of the corresponding pin action hole 1; the inner diameter of the pin action hole 1 is d2+2e, and the inner diameter of the pin action hole 2 is d2, where d2 is the diameter of the pin; ② A pin is fixed in each pin action hole 1 of the involute planetary gear, and the cylindrical surfaces at both ends of each pin are tangent to the inner wall of a pin action hole 2 that is circumferentially aligned on the load ring and the output disk; the inner diameter of the pin action hole 1 is d2, and the inner diameter of the pin action hole 2 is d2+2e.

2. A compliant joint based on an elastic element according to claim 1, characterized in that: The flexible output component is replaced by a composite flexible output component; the composite flexible output component includes a flexible output shaft 2, a planar spring, a permanent magnet 1 and a permanent magnet 2; the center hole of the flexible output shaft 2 is clearance-matched with the hub of the output disk; a planar spring is fixed to the outer end of the flexible output shaft 2, the center hole of the planar spring is clearance-matched with the outer wall of the shaft cover 2, the flexible output shaft 2 and the planar spring are axially limited by the output disk and the shaft cover 2, and the shaft cover 2 is fixedly connected to the hub center of the output disk by a screw 2 through a fastening screw hole; the inner wall of the output disk is provided with a plurality of magnet mounting seats 1 that are integrally formed and evenly distributed along the circumference, and the outer cylindrical surface of the flexible output shaft 2 is provided with a plurality of magnet mounting seats 2 that are integrally formed and evenly distributed along the circumference, Magnet mounting seat 1 and magnet mounting seat 2 are arranged alternately in the circumferential direction and are spaced apart; a permanent magnet 1 is mounted on both sides of magnet mounting seat 1, and a permanent magnet 2 is mounted on both sides of magnet mounting seat 2; each permanent magnet 2 is opposite to a permanent magnet 1 and is spaced apart, and the opposite permanent magnet 2 has the same magnetic pole as the opposite end of the permanent magnet 1; the planar spring is provided with a plurality of integrally formed sector ring portions uniformly distributed along the circumferential direction, and both sides of each sector ring portion are opposite to the two magnet mounting seats 1 and are spaced apart; the flexible output shaft 2 is provided with a plurality of output screw holes uniformly distributed along the circumferential direction, and the planar spring is provided with a plurality of light holes uniformly distributed along the circumferential direction, and the number of the light holes is equal to that of the output screw holes and the circumferential positions are aligned one by one.

3. A compliant joint based on an elastic element according to claim 1 or 2, characterized in that: The joint housing is provided with a plurality of mounting screw holes evenly distributed along the circumference, and is also provided with a plurality of positioning holes.

4. A compliant joint based on an elastic element according to claim 1 or 2, characterized in that: In the small tooth difference involute planetary gear transmission mechanism composed of the eccentric shaft section of the eccentric input shaft, the involute internal gear ring and the involute planetary gears, the involute internal gear ring has 1-4 more teeth than the involute planetary gears.

5. A compliant joint based on an elastic element according to claim 1 or 2, characterized in that: The inner end of the scroll energy storage spring is embedded in the insertion hole provided on the outer wall of the output disk, and the outer end is embedded in the insertion hole provided on the inner wall of the joint housing.

6. The flexible joint based on elastic elements according to claim 1, characterized in that: The inner end of the flexible output shaft 1 is provided with an integrally formed and coaxially arranged boss.

7. The flexible joint based on elastic elements according to claim 1, characterized in that: The outer end surface of the flexible output shaft 1 is provided with a countersunk groove, and a limiting ring integrally formed at the outer end of the shaft cover 1 is embedded in the countersunk groove, and a gap is provided between the limiting ring and the bottom of the countersunk groove.

8. The flexible joint based on elastic elements according to claim 1, characterized in that: The inner wall of the output disk is provided with a plurality of spring seats 1 that are integrally formed and evenly distributed along the circumferential direction, and the outer circumferential surface of the flexible output shaft 1 is provided with a plurality of spring seats 2 that are integrally formed and evenly distributed along the circumferential direction. The spring seats 1 and the spring seats 2 are arranged alternately along the circumference, and the two side faces 1 of each spring seat 1 are connected to the side faces 2 of the two spring seats 2 respectively through a compression spring.

9. The flexible joint based on elastic elements according to claim 1, characterized in that: The flexible output shaft is provided with a plurality of output screw holes uniformly distributed along the circumferential direction.

10. The flexible joint based on elastic elements according to claim 2, characterized in that: The fan ring portion of the planar spring is provided with an arc groove at the outer edge, and radial grooves are provided on both sides. The outer ends of the two radial grooves are respectively connected to the two ends of the arc groove. The planar spring forms an overhang portion on the outside of the two radial grooves and forms an arc connecting beam on the outside of the arc groove.

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