High-precision human-shaped finger joint structure

Abstract

The utility model provides a high-precision human-shaped finger joint structure, which relates to the technical field of human-shaped finger joints and comprises a first finger section and a second finger section, and a joint rotating structure is arranged between the first finger section and the second finger section. The joint rotating structure comprises a joint rotating shaft arranged in the width direction of the first finger section, harmonic speed reducers coaxial with the joint rotating shaft are installed at the two ends of the joint rotating shaft correspondingly, and the fixed ends and the output ends of the two harmonic speed reducers are connected with the first finger section and the second finger section correspondingly. A motor with the axis arranged in the length direction of the first finger section or the second finger section is installed in the first finger section or the second finger section, an output bevel gear coaxial with the motor is installed at the end, close to the joint rotating shaft, of the motor, an input bevel gear coaxial with the joint rotating shaft and located between the two harmonic speed reducers is further installed on the joint rotating shaft, and the output bevel gear is meshed with the input bevel gear. Input is achieved through the bevel gears, output is achieved through the double-harmonic speed reducers on the two sides of the finger joints, the transmission precision, rigidity and impact resistance of the joints are greatly improved, and the requirement for the performance of a motor is lowered.

Description

Technical Field

[0001] The utility model relates to the technical field of humanoid finger joints, in particular to a high-precision humanoid finger joint structure. Background Art

[0002] As an end effector, the humanoid finger in a robot plays a crucial role in the robot's interaction with the environment. It requires degrees of freedom and load-bearing capacity similar to that of a human hand. Conventional humanoid finger joints use a motor directly connected to a harmonic reducer. The output axes of the motor and the harmonic reducer are both perpendicular to the joint's rotation axis. After the motor drives the harmonic reducer input, the bevel gear mounted on the harmonic reducer's output shaft and the bevel gear mounted on the joint's rotation axis work together to achieve the desired rotation and bending effect.

[0003] During actual use of the above-mentioned humanoid finger joint structure, due to the direct connection between the motor and the harmonic reducer, high motor performance requirements are placed on the limited space of the finger; since the output shaft of the harmonic reducer is perpendicular to the joint rotation axis, when the finger is subjected to force, the load is borne by the deep groove ball bearings on both sides of the harmonic reducer, and the load capacity is weak; since a set of bevel gear commutation is used as the output, the poor output accuracy of the bevel gear leads to poor output accuracy of the entire finger joint. Utility Model Content

[0004] The purpose of the utility model is to provide a high-precision humanoid finger joint structure, which is input through a bevel gear and output through a dual harmonic reducer on both sides of the finger joint, thereby greatly improving the transmission accuracy, rigidity and impact resistance of the joint and reducing the performance requirements for the motor.

[0005] The above technical objectives of the present invention are achieved through the following technical solutions:

[0006] A high-precision humanoid finger joint structure comprises finger segment one and finger segment two, with a joint rotation structure provided between the finger segments one and two; the joint rotation structure comprises a joint rotation shaft arranged along the width direction of the finger segment one, with harmonic reducers coaxial therewith mounted at both ends of the joint rotation shaft, the fixed end and output end of the two harmonic reducers being connected to the finger segment one and finger segment two, respectively; a motor with an axis arranged along its length direction is mounted in the finger segment one or the finger segment two, an output bevel gear coaxial therewith being mounted at one end of the motor close to the joint rotation shaft, an input bevel gear coaxial therewith being mounted on the joint rotation shaft and located between the two harmonic reducers, the output bevel gear meshing with the input bevel gear.

[0007] By adopting the above technical solution, when the motor is working, it drives the output bevel gear to rotate synchronously, and the meshing action of the output bevel gear and the input bevel gear drives the joint rotation shaft to rotate. The joint rotation shaft drives the two harmonic reducers at its two ends to work. Since the fixed end and output end of the two harmonic reducers are respectively connected to finger segment one and finger segment two, when the harmonic reducer is working, it can drive the finger segment one or finger segment two connected to its output end to rotate, thereby realizing the rotation and bending of the finger joint.

[0008] In the present invention, the output bevel gear and the input bevel gear are arranged between the motor and the harmonic reducer, realizing the input of the bevel gear and the output of the two harmonic reducers. Compared with the bevel gear output in the prior art, the transmission accuracy of the joint can be greatly improved. The axes of the two harmonic reducers are coaxial with the joint rotation axis and perpendicular to the motor output axis, effectively reducing the performance requirements of the motor. At the same time, the two harmonic reducers ensure that the joint has higher rigidity and higher impact resistance. In addition, under the same processing accuracy, the smaller the harmonic reducer, the larger the tooth gap. In the present invention, the two harmonic reducers share the output end, fixed end and input shaft (i.e., the joint rotation axis). The phase angle of one of the harmonic reducers can be adjusted to reduce or eliminate the tooth gap, obtain higher accuracy, and further improve the accuracy of the joint.

[0009] Furthermore, one of the two harmonic reducers is a single-rigid-wheel harmonic reducer, and the other is a double-rigid-wheel harmonic reducer.

[0010] By adopting this technical solution, a single-gear harmonic reducer has low backlash, while a double-gear harmonic reducer has large backlash. When the joint is subjected to low forces, the joint's accuracy is primarily determined by the single-gear harmonic reducer, resulting in low backlash and high precision. A single-gear harmonic reducer has low impact resistance, while a double-gear harmonic reducer has high impact resistance. When the joint is subjected to high forces, the double-gear harmonic reducer shares the impact load, making the single-gear harmonic reducer less susceptible to damage. Furthermore, the input bevel gear exerts a downward diagonal force component on the joint's rotating axis, while the single-gear harmonic reducer exerts an upward diagonal force component. These two opposing diagonal forces are neutralized or weakened, effectively improving the life and stability of the deep groove ball bearing.

[0011] Furthermore, the single rigid wheel harmonic reducer includes a rigid wheel, a support bearing, a flexible wheel, a flexible bearing and a wave generator. The inner wall of the rigid wheel is provided with a groove that cooperates with the steel ball of the support bearing. The rigid wheel serves as the outer ring of the support bearing and is connected to the finger segment. The flexible wheel is installed on the side of the inner ring of the support bearing away from the rigid wheel, and the flexible wheel is meshed with the internal teeth of the rigid wheel. The flexible bearing is arranged between the flexible wheel and the wave generator and corresponds to the position of the internal teeth of the rigid wheel. The flexible bearing is located at one end of the wave generator close to the input bevel gear. The end of the wave generator away from the flexible bearing is provided with a deep groove ball bearing, the inner ring of the deep groove ball bearing is installed and connected to the joint rotation shaft, the outer ring of the deep groove ball bearing is provided with a connecting ring, and the inner ring of the support bearing, the flexible wheel and the connecting ring are all installed on the mounting step on the finger segment two that cooperates with it.

[0012] By adopting the above technical solution, the basic structure and operating principle of the single-rigid harmonic reducer are essentially the same as those in the prior art. In the present invention, the rigid pulley 1 is integrated with the support bearing 1 as the outer ring, which can appropriately increase the volume of the single-rigid harmonic reducer within the limited joint space. This not only facilitates the production and manufacturing of the various components of the single-rigid harmonic reducer, but also improves the performance of the single-rigid harmonic reducer. Specifically, the connecting ring 1 is used to connect the outer ring of the deep groove ball bearing 1 and the inner ring of the support bearing 1. The inner ring of the support bearing 1, the flexible pulley 1, and the connecting ring are all mounted on the mounting step on the finger segment 2 that matches it, thus achieving the connection between the single-rigid harmonic reducer and the finger segment 2 and facilitating the sequential installation of the various components in the joint.

[0013] Furthermore, the double-rigid wheel harmonic reducer includes a second rigid wheel, a third rigid wheel, a second support bearing, a second flexible wheel, two second flexible bearings and a second wave generator. The inner wall of the second rigid wheel and the outer wall of the third rigid wheel are respectively provided with grooves that cooperate with the steel balls of the second support bearing. The second rigid wheel serves as the outer ring of the second support bearing and is connected to the first finger segment. The third rigid wheel serves as the inner ring of the second support bearing. The second flexible wheel is meshed with the internal teeth of the second and third rigid wheels. The two second flexible bearings are arranged between the second flexible wheel and the second wave generator and correspond to the positions of the internal teeth of the second and third rigid wheels respectively. The end of the second wave generator away from the input bevel gear is provided with a second deep groove ball bearing. The inner ring of the second deep groove ball bearing is installed and connected to the joint rotation shaft. The outer ring of the second deep groove ball bearing is provided with a second connecting ring. The second connecting ring is integrally formed with the second finger segment, and the third rigid wheel is installed on the second connecting ring.

[0014] By adopting the above technical solution, the basic structure and operating principle of the dual-rigid harmonic reducer are essentially the same as those in the prior art. In the present utility model, rigid pulleys 2 and 3 directly serve as the inner and outer rings of support bearing 2, and are integrated with support bearing 2. This allows the volume of the dual-rigid harmonic reducer to be appropriately increased within the limited joint space, not only facilitating the production and manufacturing of various components in the dual-rigid harmonic reducer, but also improving the performance of the dual-rigid harmonic reducer. Connecting ring 2 is used to connect the outer ring of deep groove ball bearing 2 and rigid pulley 3. Rigid pulley 3 is mounted on connecting ring 2, which is integrally formed with finger segment 2, to achieve the connection between the dual-rigid harmonic reducer and finger segment 2, while ensuring the connection strength.

[0015] Furthermore, a retaining ring 1 covering the deep groove ball bearing 1 and the connecting ring 1 is provided at one end of the joint rotation axis close to the deep groove ball bearing 1, and the retaining ring 1 and the connecting ring 1 are synchronously installed on the installation step of the finger segment 2.

[0016] By adopting the above technical solution, the retaining ring is used to block the deep groove ball bearing to prevent the deep groove ball bearing from shifting along its axial direction after long-term work, thereby affecting its working effect. It is also used to seal the single-gear harmonic reducer to prevent foreign matter from entering the single-gear harmonic reducer and affecting its normal operation and service life.

[0017] Furthermore, a second retaining ring covering the second deep groove ball bearing and the second connecting ring is installed at one end of the joint rotation shaft close to the second deep groove ball bearing, and the second retaining ring is installed on the second connecting ring.

[0018] By adopting the above technical solution, the retaining ring 2 is used to block the deep groove ball bearing 2 to prevent the deep groove ball bearing 2 from shifting along its axial direction after long-term work, which affects its working effect. It is also used to seal the double-rigid wheel harmonic reducer to prevent foreign matter from entering the double-rigid wheel harmonic reducer and affecting its normal operation and service life. It cooperates with the retaining ring 1 to achieve sealing at both ends of the joint to ensure stable operation of the joint.

[0019] Furthermore, the support bearing 1 and the support bearing 2 are both four-point contact ball bearings.

[0020] By adopting the above technical solution, both the support bearing 1 and the support bearing 2 use four-point contact ball bearings, which can ensure their supporting capacity while reducing the starting torque.

[0021] Furthermore, a planetary drive gear coaxial with the motor is mounted on the output shaft of the motor, a plurality of planetary wheels meshing with the planetary drive gear are arranged in a circumferential array on the outer periphery of the planetary drive gear, the planetary wheels are mounted on the planetary carrier, and the output bevel gear is mounted on the end of the planetary carrier away from the planetary wheels.

[0022] By adopting the above technical solution, the motor drives the planetary drive gears to rotate synchronously during operation. Under the meshing action of the planetary drive gears and the plurality of planetary gears, the plurality of planetary gears rotate while also revolving around the sun, driving the planetary carrier to rotate as a whole. The planetary carrier then drives the output bevel gears to rotate, which then mesh with the input bevel gears, which in turn drive the joint rotation shaft to rotate via the input bevel gears. The meshing of the planetary drive gears with the planetary gears produces a deceleration effect, and the meshing of the output bevel gears with the input bevel gears also produces a deceleration effect, i.e., there is a two-stage reduction between the motor and the harmonic reducer. When the capacity of the two harmonic reducers increases, the capacity of the motor also needs to increase accordingly. However, the capacity of the motor is limited by its size. When the length and thickness of finger segment one or finger segment two are limited, the performance requirements of the motor can be reduced by providing a two-stage reduction between the motor and the harmonic reducer.

[0023] Furthermore, the motor is connected to an encoder coaxial with the motor, and the encoder is installed on a side of the motor away from its output shaft.

[0024] By adopting the above technical solution, an encoder is set to detect the input speed of the motor in real time, thereby improving the input accuracy of the motor. The encoder is directly connected to the motor to improve the detection accuracy.

[0025] Furthermore, an encoder with an axis parallel to the motor output axis is provided in finger segment one or finger segment two. The encoder and motor are respectively installed in finger segment one and finger segment two, and an encoding gear meshing with the input bevel gear is installed on the output shaft of the encoder.

[0026] By adopting this technical solution, when the output bevel gear meshes with the input bevel gear to drive the input bevel gear, the input bevel gear simultaneously meshes with the encoder gear, which drives the encoder to rotate. The encoder then uses this gear to detect the input speed in real time, thereby improving input accuracy. The encoder and motor are installed in finger segments one and two, respectively. This frees up space where the motor would otherwise be located, allowing for a longer motor to be installed and improve performance.

[0027] In summary, the present invention has the following beneficial effects:

[0028] 1. The present invention is provided with a motor arranged along the length direction of finger segment one or finger segment two, and a joint rotation shaft arranged along the width direction of finger segment one or finger segment two. The motor output shaft and the joint rotation shaft are commutated by an output bevel gear and an input bevel gear that mesh with each other. Harmonic reducers are respectively installed at both ends of the joint rotation shaft. In this way, the bevel gear input and the two harmonic reducers output can greatly improve the transmission accuracy of the joint, effectively reduce the performance requirements of the motor, and the joint has higher rigidity and higher impact resistance.

[0029] 2. The present invention provides two harmonic reducers with a common output end, fixed end, and input shaft. The phase angle of one of the harmonic reducers can be adjusted to reduce or eliminate backlash, achieve higher precision, and further improve the accuracy of the joint.

[0030] 3. In the present invention, one of the two harmonic reducers is a single-gear harmonic reducer and the other is a double-gear harmonic reducer. The tooth clearance of the single-gear harmonic reducer is small, while the tooth clearance of the double-gear harmonic reducer is large. When the joint is subjected to small forces, the joint accuracy is mainly determined by the single-gear harmonic reducer, and the joint can obtain low tooth clearance and high precision; the impact resistance of the single-gear harmonic reducer is small, while the impact resistance of the double-gear harmonic reducer is large. When the joint is subjected to large forces, the double-gear harmonic reducer jointly bears the impact load, and the single-gear harmonic reducer is not easily damaged; in addition, the input bevel gear has a downward oblique force component on the joint rotation axis, while the single-gear harmonic reducer has an upward oblique force component. The two oblique forces in opposite directions are neutralized or weakened, which can effectively improve the life and stability of the deep groove ball bearing;

[0031] 4. In the single-gear harmonic reducer of the present invention, the first gear is integrated with the outer ring of the support bearing 1, and the second and third gears are integrated with the outer ring and inner ring of the support bearing 2, respectively, in the double-gear harmonic reducer. Both the first and second support bearings are four-point contact ball bearings, which effectively improves the capacity of the single-gear harmonic reducer and the double-gear harmonic reducer while reducing the starting torque.

[0032] 5. In the present invention, two-stage reduction gears are provided between the motor and the joint rotating shaft, namely, a planetary drive gear meshing with a planetary gear for reduction, and an output bevel gear meshing with an input bevel gear for reduction. When the length and thickness of the finger segment one or the finger segment two are limited, the performance requirements for the motor are reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0033] Figure 1 This is a schematic structural diagram of a high-precision humanoid finger joint structure in Example 1;

[0034] Figure 2 This is a schematic structural diagram of a high-precision humanoid finger joint structure in Example 2.

[0035] In the figure, 1. Finger segment 1; 2. Finger segment 2; 3. Joint rotation axis; 31. Input bevel gear; 4. Single rigid wheel harmonic reducer; 41. Rigid wheel 1; 42. Support bearing 1; 43. Flexible wheel 1; 44. Flexible bearing 1; 45. Wave generator 1; 46. Deep groove ball bearing 1; 47. Connecting ring 1; 48. Retaining ring 1; 5. Double rigid wheel harmonic reducer; 51. Rigid wheel 2; 52. Rigid wheel 3; 53. Support bearing 2; 54. Flexible wheel 2; 55. Flexible bearing 2; 56. Wave generator 2; 57. Deep groove ball bearing 2; 58. Connecting ring 2; 59. Retaining ring 2; 6. Motor; 61. Planetary drive gear; 7. Planet carrier; 71. Planetary gear; 72. Output bevel gear; 8. Encoder; 81. Encoding gear. DETAILED DESCRIPTION

[0036] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0037] Example 1:

[0038] A high-precision humanoid finger joint structure, such as Figure 1 As shown, it includes finger segment 1 and finger segment 2, with a joint rotation structure disposed between them. This joint rotation structure can drive finger segment 1 or finger segment 2 to rotate and bend. Specifically, the joint rotation structure includes a joint rotation shaft 3 arranged along the width of finger segment 1. Coaxial harmonic reducers are mounted at both ends of the joint rotation shaft 3. The fixed end and output end of the two harmonic reducers are connected to finger segment 1 and finger segment 2, respectively. The joint rotation shaft 3 serves as the input shaft of the two harmonic reducers. One of finger segment 1 and finger segment 2 is connected to the fixed end of the two harmonic reducers as a fixed end, and the other is connected to the output end of the two harmonic reducers as an output end, enabling rotation and bending.

[0039] like Figure 1 As shown, a motor 6 with its axis arranged along its length direction is installed in finger segment 1 or finger segment 2. In this embodiment, the motor 6 is installed in finger segment 2, and an output bevel gear 72 coaxial with the joint rotation axis 3 is installed at one end of the motor 6 close to the joint rotation axis 3. An input bevel gear 31 coaxial with the joint rotation axis and located between the two harmonic reducers is also installed on the joint rotation axis 3, and the output bevel gear 72 is meshed with the input bevel gear 31.

[0040] like Figure 1As shown, when the motor 6 is working, it drives the output bevel gear 72 to rotate synchronously, and under the meshing action of the output bevel gear 72 and the input bevel gear 31, it drives the joint rotation shaft 3 to rotate, and the joint rotation shaft 3 drives the two harmonic reducers at both ends to work. Since the fixed end and the output end of the two harmonic reducers are respectively connected to the finger segment 1 and the finger segment 2 2, when the harmonic reducer is working, it can drive the finger segment 1 1 or the finger segment 2 2 connected to its output end to rotate, thereby realizing the rotation and bending of the driving finger joint.

[0041] like Figure 1 As shown, in the present invention, the output bevel gear 72 and the input bevel gear 31 are meshed for reversing input, and the two harmonic reducers are output. Compared with the bevel gear output in the prior art, the transmission accuracy of the joint can be greatly improved. The axes of the two harmonic reducers are coaxial with the joint rotation axis 3 and perpendicular to the output axis of the motor 6, which effectively reduces the performance requirements for the motor 6. At the same time, the two harmonic reducers ensure that the joint has higher rigidity and higher impact resistance. In addition, under the same processing accuracy, the smaller the harmonic reducer, the greater the tooth gap. In the present invention, the two harmonic reducers share the output end, the fixed end and the joint rotation axis 3, and the phase angle of one of the harmonic reducers can be adjusted to reduce or eliminate the tooth gap, obtain higher accuracy, and further improve the accuracy of the joint.

[0042] like Figure 1 As shown, in this embodiment, one of the two harmonic reducers is a single-wheel harmonic reducer 4, and the other is a double-wheel harmonic reducer 5. The tooth clearance of the single-wheel harmonic reducer 4 is small, and the tooth clearance of the double-wheel harmonic reducer 5 is large. When the joint is subjected to small forces, the joint accuracy is mainly determined by the single-wheel harmonic reducer 4, and the joint can obtain low tooth clearance and high precision. The impact resistance of the single-wheel harmonic reducer 4 is small, and the impact resistance of the double-wheel harmonic reducer 5 is large. When the joint is subjected to large forces, the double-wheel harmonic reducer 5 jointly bears the impact load, and the single-wheel harmonic reducer 4 is not easily damaged. In addition, the input bevel gear 31 has a downward oblique force component on the joint rotating shaft 3, while the single-wheel harmonic reducer 4 has an upward oblique force component. The two oblique forces in opposite directions are neutralized or weakened, which can effectively improve the life and stability of the deep groove ball bearing.

[0043] Of course, in other embodiments, the two harmonic reducers may both be single-gear harmonic reducers 4 or double-gear harmonic reducers 5 .

[0044] Specifically, if Figure 1As shown, the single-gear harmonic reducer 4 comprises a gear 1 (41), a support bearing 1 (42), a flexspline 1 (43), a flexible bearing 1 (44), and a wave generator 1 (45). A groove is provided on the inner wall of gear 1 (41) to mate with the steel balls of support bearing 1 (42). Gear 1 (41) serves as the outer ring of support bearing 1 (42) and is connected to finger segment 1 (1). Flexspline 1 (43) is mounted in a top-hat configuration on the inner ring of support bearing 1 (42) away from gear 1 (41), meshing with the internal teeth of gear 1 (41). Flexible bearing 1 (44) is positioned between flexspline 1 (43) and wave generator 1 (45), corresponding to the internal teeth of gear 1 (41). Flexible bearing 1 (44) is located at the end of wave generator 1 (45) near the input bevel gear 31. A deep groove ball bearing 46 is provided at one end of the wave generator 45 away from the flexible bearing 44. The inner ring of the deep groove ball bearing 46 is installed and connected to the joint rotation axis 3. The outer ring of the deep groove ball bearing 46 is provided with a connecting ring 47. The inner ring of the support bearing 42, the flexible wheel 43 and the connecting ring 47 are all installed on the mounting step on the finger segment 2 2 that matches it.

[0045] like Figure 1 As shown, the dual-rigid harmonic reducer 5 includes a second rigid wheel 51, a third rigid wheel 52, a second support bearing 53, a second flexspline 54, two second flexible bearings 55, and a second wave generator 56. Grooves are provided on the inner wall of the second rigid wheel 51 and the outer wall of the third rigid wheel 52, respectively, to mate with the steel balls of the second support bearing 53. The second rigid wheel 51 serves as the outer ring of the second support bearing 53 and is connected to the finger segment 1, while the third rigid wheel 52 serves as the inner ring of the second support bearing 53. The second flexspline 54 meshes with the internal teeth of the second rigid wheel 51 and the third rigid wheel 52. Two second flexible bearings 55 are disposed between the second flexible wheel 54 and the second wave generator 56 and correspond to the positions of the internal teeth of the second rigid wheel 51 and the third rigid wheel 52, respectively. A deep groove ball bearing 2 57 is provided at one end of the wave generator 2 56 away from the input bevel gear 31 . The inner ring of the deep groove ball bearing 2 57 is installed and connected to the joint rotation shaft 3 . The outer ring of the deep groove ball bearing 2 57 is provided with a connecting ring 2 58 . The connecting ring 2 58 is integrally formed with the finger segment 2 2 , and the rigid wheel 3 52 is installed on the connecting ring 2 58 .

[0046] like Figure 1 As shown, the basic structure and operating principle of the single-gear harmonic reducer 4 and the dual-gear harmonic reducer 5 are essentially the same as those in the prior art. The difference is that the first gear 41 is integrated with the support bearing 1 42 as the outer ring, and the second gear 51 and the third gear 52 are integrated with the support bearing 2 53 as the inner and outer rings. Within the limited joint space, the volume of the single-gear harmonic reducer 4 and the dual-gear harmonic reducer 5 can be increased, improving their load and impact resistance. In this embodiment, both the support bearing 1 42 and the support bearing 2 53 are four-point contact ball bearings, which ensure their support capacity while reducing the starting torque.

[0047] like Figure 1As shown, a retaining ring 48 is installed at the end of the joint rotating shaft 3 near deep groove ball bearing 1 46, covering deep groove ball bearing 1 46 and connecting ring 1 47. Retaining ring 1 48 and connecting ring 1 47 are simultaneously mounted on the mounting step of finger segment 2 2. A retaining ring 2 59 is installed at the end of the joint rotating shaft 3 near deep groove ball bearing 2 57, covering deep groove ball bearing 2 57 and connecting ring 2 58. Retaining ring 2 59 is mounted on connecting ring 2 58. Retaining ring 1 48 is used to retain deep groove ball bearing 1 46, while retaining ring 2 59 is used to retain deep groove ball bearing 2 57, preventing axial displacement of deep groove ball bearings 1 46 and 2 57 after prolonged operation. Furthermore, retaining ring 1 48 and retaining ring 2 59 provide a seal at both ends of the joint rotating shaft 3, preventing foreign matter from entering the single-gear harmonic reducer 4 and double-gear harmonic reducer 5, which could affect their service life.

[0048] like Figure 1 As shown, when the capacity of the two harmonic reducers increases, the capacity of the motor 6 also needs to be increased accordingly, but the capacity of the motor 6 is limited by its volume. Therefore, when the length and thickness of the finger segment 1 or the finger segment 2 are limited, a planetary drive gear 61 coaxial with the motor 6 is installed on the output shaft of the motor 6, and a plurality of planetary gears 71 meshing with the planetary drive gear 61 are provided in a circumferential array on the outer periphery of the planetary drive gear 61. The planetary gear 71 is mounted on the planetary carrier 7 through a fixed axis, and the output bevel gear 72 is mounted on the end of the planetary carrier 7 away from the planetary gear 71.

[0049] like Figure 1 As shown, when the motor 6 is in operation, it drives the planetary drive gear 61 to rotate synchronously. Under the meshing action of the planetary drive gear 61 and the plurality of planetary gears 71, the plurality of planetary gears 71 rotates while also revolving, driving the planetary carrier 7 to rotate as a whole. The planetary carrier 7 then drives the output bevel gear 72 to rotate. The output bevel gear 72 meshes with the input bevel gear 31, which in turn drives the joint rotation shaft 3 to rotate via the input bevel gear 31. The meshing of the planetary drive gear 61 and the planetary gear 71 produces a reduction effect, and the meshing of the output bevel gear 72 and the input bevel gear 31 also produces a reduction effect. The capacity of the motor 6 multiplied by the reduction ratio must be greater than or equal to the capacity of two harmonic reducers. Therefore, providing a two-stage reduction between the motor 6 and the harmonic reducer can effectively reduce the performance requirements of the motor 6.

[0050] like Figure 1 As shown, the motor 6 is also connected to an encoder 8 coaxial with it. The encoder 8 is installed on the side of the motor 6 away from its output shaft. The encoder 8 is used to detect the input speed of the motor 6 in real time to improve the input accuracy of the motor 6. The encoder 8 is directly connected to the motor 6 to improve the detection accuracy.

[0051] Example 2:

[0052] A high-precision humanoid finger joint structure, such as Figure 1 and Figure 2As shown, the difference from the first embodiment is that the encoder 8 and motor 6 are installed in finger segment 1 and finger segment 2, respectively. This saves space where motor 6 would otherwise be located, allowing for a longer motor 6 and improving its performance. Specifically, in this embodiment, motor 6 is installed in finger segment 2, and encoder 8 is installed in finger segment 1 with its axis parallel to the axis of the motor 6 output shaft. The output shaft of encoder 8 is mounted with an encoder gear 81 that meshes with the input bevel gear 31. When the output bevel gear 72 meshes with the input bevel gear 31, driving the input bevel gear 31 to rotate, the input bevel gear 31 simultaneously meshes with the encoder gear 81, driving the encoder 8 to rotate via the encoder gear 81. Encoder 8 detects the input speed in real time, thereby improving input accuracy.

[0053] The foregoing description shows and describes preferred embodiments of the present invention. As previously mentioned, it should be understood that the present invention is not limited to the form disclosed herein and should not be construed as excluding other embodiments. Instead, the present invention can be used in various other combinations, modifications, and environments and can be modified within the scope of the present invention as taught herein or through the techniques or knowledge of the relevant art. Modifications and variations made by those skilled in the art that do not depart from the spirit and scope of the present invention are intended to be protected by the claims appended hereto.

Claims

1. A high-precision humanoid finger joint structure, characterized by: The invention comprises a finger segment 1 (1) and a finger segment 2 (2), wherein a joint rotation structure is provided between the finger segment 1 (1) and the finger segment 2 (2); the joint rotation structure comprises a joint rotation shaft (3) arranged along the width direction of the finger segment 1 (1), and a harmonic reducer coaxial with the joint rotation shaft is installed at both ends of the joint rotation shaft (3), and the fixed end and the output end of the two harmonic reducers are respectively connected to the finger segment 1 (1) and the finger segment 2 (2); a motor (6) with an axis arranged along the length direction of the finger segment 1 (1) or the finger segment 2 (2) is installed in the finger segment 1 (1) or the finger segment 2 (2), and an output bevel gear (72) coaxial with the joint rotation shaft (3) is installed at one end of the motor (6) close to the joint rotation shaft (3), and an input bevel gear (31) coaxial with the joint rotation shaft and located between the two harmonic reducers is also installed on the joint rotation shaft (3), and the output bevel gear (72) is meshed with the input bevel gear (31).

2. The high-precision humanoid finger joint structure according to claim 1, characterized in that: One of the two harmonic reducers is a single-rigid-wheel harmonic reducer (4), and the other is a double-rigid-wheel harmonic reducer (5).

3. The high-precision humanoid finger joint structure according to claim 2, characterized in that: The single rigid wheel harmonic reducer (4) comprises a rigid wheel (41), a support bearing (42), a flexible wheel (43), a flexible bearing (44) and a wave generator (45). The inner wall of the rigid wheel (41) is provided with a groove matched with the steel ball of the support bearing (42). The rigid wheel (41) serves as the outer ring of the support bearing (42) and is connected to the finger segment (1). The flexible wheel (43) is installed on the side of the inner ring of the support bearing (42) away from the rigid wheel (41), and the flexible wheel is meshed with the inner teeth of the rigid wheel (41). The flexible bearing (44) is arranged between the flexible wheel (43) and the wave generator. The flexible bearing (44) is located between the wave generator (45) and corresponds to the inner tooth position of the rigid wheel (41), and the flexible bearing (44) is located at one end of the wave generator (45) close to the input bevel gear (31); the end of the wave generator (45) away from the flexible bearing (44) is provided with a deep groove ball bearing (46), the inner ring of the deep groove ball bearing (46) is installed and connected with the joint rotation shaft (3), and the outer ring of the deep groove ball bearing (46) is provided with a connecting ring (47), and the inner ring of the support bearing (42), the flexible wheel (43) and the connecting ring (47) are all installed on the mounting step matched with it on the finger segment 2 (2).

4. The high-precision humanoid finger joint structure according to claim 3, characterized in that: The double-rigid wheel harmonic reducer (5) comprises a second rigid wheel (51), a third rigid wheel (52), a second support bearing (53), a second flexible wheel (54), two second flexible bearings (55) and a second wave generator (56). The inner wall of the second rigid wheel (51) and the outer wall of the third rigid wheel (52) are respectively provided with grooves for matching with the steel balls of the second support bearing (53). The second rigid wheel (51) serves as the outer ring of the second support bearing (53) and is connected to the first finger segment (1). The third rigid wheel (52) serves as the inner ring of the second support bearing (53); the second flexible wheel (54) is connected to the inner teeth of the second rigid wheel (51) and the third rigid wheel (52). The two flexible bearings (55) are arranged between the flexible wheel (54) and the wave generator (56) and correspond to the inner tooth positions of the rigid wheel (51) and the rigid wheel (52) respectively; the end of the wave generator (56) away from the input bevel gear (31) is provided with a deep groove ball bearing (57), the inner ring of the deep groove ball bearing (57) is installed and connected with the joint rotation shaft (3), the outer ring of the deep groove ball bearing (57) is provided with a connecting ring (58), the connecting ring (58) is integrally formed with the finger segment (2), and the rigid wheel (52) is installed on the connecting ring (58).

5. The high-precision humanoid finger joint structure according to claim 3, characterized in that: The end of the joint rotation shaft (3) close to the deep groove ball bearing (46) is provided with a retaining ring (48) covering the deep groove ball bearing (46) and the connecting ring (47). The retaining ring (48) and the connecting ring (47) are synchronously installed on the installation step of the finger section (2).

6. The high-precision humanoid finger joint structure according to claim 4, characterized in that: A second retaining ring (59) covering the second deep groove ball bearing (57) and the second connecting ring (58) is installed at one end of the joint rotating shaft (3) close to the second deep groove ball bearing (57), and the second retaining ring (59) is installed on the second connecting ring (58).

7. The high-precision humanoid finger joint structure according to claim 4, characterized in that: The support bearing 1 (42) and the support bearing 2 (53) are both four-point contact ball bearings.

8. The high-precision humanoid finger joint structure according to claim 1, characterized in that: A planetary drive gear (61) coaxial with the output shaft of the motor (6) is mounted thereon; a plurality of planetary gears (71) meshing with the planetary drive gear (61) are arranged in a circular array on the outer periphery of the planetary drive gear (61); the planetary gears (71) are mounted on a planet carrier (7); and the output bevel gear (72) is mounted on an end of the planet carrier (7) away from the planetary gears (71).

9. A high-precision humanoid finger joint structure according to claim 1 or 8, characterized in that: The motor (6) is connected to an encoder (8) coaxial with the motor (6), and the encoder (8) is installed on a side of the motor (6) away from its output shaft.

10. The high-precision humanoid finger joint structure according to claim 1 or 8, characterized in that: An encoder (8) having an axis parallel to the output axis of the motor (6) is further provided in the finger segment 1 (1) or the finger segment 2 (2). The encoder (8) and the motor (6) are respectively installed in the finger segment 1 (1) and the finger segment 2 (2), and an encoding gear (81) meshing with the input bevel gear (31) is installed on the output shaft of the encoder (8).

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