Vertical orthogonal transmission conjugate planetary speed reduction structure for dexterous hand joint

Abstract

The invention discloses a vertical orthogonal transmission conjugate planetary speed reduction structure for a dexterous hand joint, and relates to the technical field of robot dexterous hands, the vertical orthogonal transmission conjugate planetary speed reduction structure comprises a power source, a steering transmission unit, a first-stage speed reduction unit and a second speed reduction unit; one end of the steering transmission unit is connected with the output end of the power source, and the power output by the power source can be vertically steered and then output; the first-stage speed reduction unit and the second-stage speed reduction unit are coaxially arranged and located at the end, away from a power source, of the steering transmission unit, and the input end of the first-stage speed reduction unit is in transmission connection with the end, away from the power source, of the steering transmission unit. The output end of the first-stage speed reduction unit is in transmission connection with the input end of the second-stage speed reduction unit, and the output end of the second-stage speed reduction unit is externally connected with transmission equipment. According to the vertical orthogonal transmission conjugate planetary speed reduction structure for the dexterous hand joint, large-torque and large-reduction-ratio vertical orthogonal transmission can be achieved in a compact space.

Description

Technical Field

[0001] This invention relates to the field of robot dexterity hand technology, and in particular to a vertical orthogonal transmission conjugate planetary deceleration structure for dexterity hand joints. Background Technology

[0002] As a core actuator in humanoid robots, service robots, medical rehabilitation robots, and industrial precision manipulation robots, the dexterous hand's finger joint transmission module needs to achieve high torque, high precision, and high reliability power output under stringent constraints of high degrees of freedom, minimal installation space, and lightweight design. This is a key component determining the dexterous hand's grasping accuracy, load capacity, and service life. Currently, mainstream transmission and reduction schemes for dexterous hand joints include worm gear drives, spur gears combined with bevel gears / bevel gears, traditional planetary gear reducers, and miniature harmonic reducers or cycloidal reducers. These schemes generally suffer from poor structural adaptability, insufficient transmission performance, and low reliability, making it difficult to meet the engineering application requirements of high-end humanoid dexterous hands. Specific problems are as follows: Worm gear transmission can directly achieve perpendicular orthogonal transmission between the input and output shafts, and its structure is relatively simple. However, it has an inherent self-locking characteristic. When the dexterous hand encounters external impact, collision, or overload, the transmission chain cannot reverse the transmission to relieve the force, resulting in excessive joint rigidity. The impact load is directly transmitted to the motor and transmission components, which can easily cause the motor to burn out, the gears to break, or the shaft system to bend and fail. At the same time, the worm gear meshing friction loss is large, the transmission efficiency is low, and the heat generation is obvious during long-term operation, which is not conducive to the dexterous hand's long-term continuous operation.

[0003] The spur gear combined with bevel / bevel gear transmission scheme uses a single-stage spur gear for initial speed reduction, followed by a 90° steering transmission via bevel or bevel gears. This was a common structure in early dexterous hand joints. However, this scheme suffers from concentrated load on a single tooth, weak bending strength at the bevel gear tooth root, and susceptibility to tooth surface wear, pitting, and even tooth breakage under high-speed, heavy-load conditions. The transmission bearings are subjected to combined radial and axial loads, resulting in short fatigue life. Furthermore, the single-stage reduction ratio is limited, leading to insufficient overall torque output capacity and making it unsuitable for heavy-load grasping scenarios.

[0004] Miniature harmonic reducers or cycloidal reducers offer advantages such as high transmission accuracy, large single-stage reduction ratio, and small backlash, making them suitable for precision transmission applications. However, the core components require extremely high machining precision, and the material and manufacturing costs are high, making large-scale application difficult. Furthermore, the parallel arrangement of the motor and output shaft makes it impossible to directly achieve perpendicular orthogonal transmission. In the narrow and compact internal space of a dexterous hand's fingers, this layout is extremely challenging, significantly increasing the axial dimensions of the joints and compromising the dexterous hand's anthropomorphic shape and movement flexibility.

[0005] Traditional planetary reduction schemes are characterized by compact structure, high transmission efficiency, and strong load-bearing capacity, but they can only achieve parallel shaft transmission. If they are to be used for vertical orthogonal transmission of dexterous hand joints, an additional steering mechanism must be installed, which increases the structural complexity and axial dimension significantly, violating the miniaturization and integration design requirements of dexterous hand joints. At the same time, the overall rigidity decreases after multiple stages are connected in series, and the assembly accuracy is difficult to guarantee, making it impossible to balance compactness and transmission performance.

[0006] In summary, existing dexterous hand joint reduction structures cannot simultaneously meet the comprehensive performance requirements of vertical orthogonal transmission, extremely small space installation, large reduction ratio, and high torque output, severely restricting the upgrading and development of humanoid dexterous hands towards lightweight, high load capacity, and high durability. Therefore, there is an urgent need to design a technical solution that can achieve high torque and high reduction ratio vertical orthogonal transmission within a compact space. Summary of the Invention

[0007] The purpose of this invention is to provide a vertical orthogonal transmission conjugate planetary reduction structure for dexterous hand joints, so as to solve the problems existing in the prior art and realize high torque and high reduction ratio vertical orthogonal transmission in a compact space.

[0008] To achieve the above objectives, the present invention provides the following solution: This invention provides a vertical orthogonal transmission conjugate planetary reduction structure for dexterous hand joints, comprising: Power source; A steering transmission unit, one end of which is connected to the output end of the power source, is capable of vertically steering the power output from the power source and then outputting it; and The system includes a primary reduction unit and a secondary reduction unit, which are coaxially arranged and located at the end of the steering transmission unit furthest from the power source. The input end of the primary reduction unit is connected to the end of the steering transmission unit furthest from the power source, and the output end of the primary reduction unit is connected to the input end of the secondary reduction unit. The output end of the secondary reduction unit is externally connected to a transmission device.

[0009] In one embodiment, the power source includes a motor, which is fixed inside a reducer housing. One end of the reducer housing is connected to a conjugate internal gear ring fixing frame, and the conjugate internal gear ring fixing frame is provided with the steering transmission unit, the first-stage reduction unit, and the second-stage reduction unit.

[0010] In one embodiment, the steering transmission unit includes an input bevel gear and an output bevel gear. The input bevel gear is fixedly connected to the output shaft of the motor, and the output bevel gear is fixedly connected to the input end of the first-stage reduction unit. The input bevel gear and the output bevel gear are meshed and driven together.

[0011] In one embodiment, the steering transmission unit includes a crown gear pair, the input end of which is fixedly connected to the output shaft of the motor, and the output end of which is fixedly connected to the input end of the first-stage reduction unit.

[0012] In one embodiment, the conjugate internal gear ring fixing frame includes an integrally formed frame body and a fixing ring. The frame body is hollow inside, and one end of it is fixedly connected to the reducer housing. The other end of the frame body is fixedly connected to the fixing ring. The axis of the fixing ring is perpendicular to the output shaft of the motor. The output shaft of the motor is located inside the frame body, and the first-stage reduction unit and the second-stage reduction unit are respectively located on both sides of the fixing ring.

[0013] In one embodiment, the first-stage reduction unit includes a first sun gear, a first planet gear, a first planet carrier, and a first internal gear ring. The first internal gear ring is coaxially fixed to one side of the fixed ring. The first sun gear is disposed inside the first internal gear ring. A plurality of first planet gears are circumferentially arranged between the first sun gear and the first internal gear ring. The axles of the first planet gears are connected to the first planet carrier. The first sun gear is coaxially fixedly connected to the output end of the steering transmission unit. The first sun gear and the output end of the steering transmission unit have a coaxial hollow channel. The output end of the first planet carrier extends through the hollow channel to the other side of the fixed ring and is drively connected to the input end of the second-stage reduction unit.

[0014] In one embodiment, the secondary reduction unit includes a second sun gear, a second planet gear, a second planet carrier, and a second internal gear ring; the second internal gear ring is coaxially fixed to the side of the fixed ring away from the primary reduction unit, the second sun gear is disposed inside the second internal gear ring, and a plurality of second planet gears are circumferentially arranged between the second sun gear and the second internal gear ring, the axles of the second planet gears are connected to the second planet carrier; the second sun gear is coaxially fixedly connected to the output end of the primary reduction unit; the output end of the second planet carrier is externally connected to a transmission device.

[0015] In one embodiment, an oil-free bearing sleeve is sealed on the side of the first-stage reduction unit away from the fixed ring and on the side of the second-stage reduction unit away from the fixed ring.

[0016] In one embodiment, the first-stage reduction unit has a reduction ratio of 3-10 and a module of 0.1-0.3; the second-stage reduction unit has a reduction ratio of 3-5 and a module of 0.3-0.6; and the steering transmission unit has a reduction ratio of 1:3.

[0017] The present invention achieves the following technical effects compared to the prior art: This invention fully utilizes the radial and axial space of the dexterous hand joint by coaxially arranging the primary and secondary reduction units and integrating the steering transmission unit between the reduction units and the power source, resulting in an extremely compact overall structure. It employs a two-stage planetary reduction system in series. The primary reduction unit uses small-module gears to achieve a high reduction ratio, while the secondary reduction unit uses large-module gears to achieve high torque output. The total reduction ratio can reach over 50, and the output torque can reach 3 N·m, meeting the driving requirements of the dexterous hand joint. The primary and secondary reduction units use planetary gear transmission, which has no self-locking characteristic. Energy can be released through reverse transmission during external impacts, avoiding damage to components from hard collisions and improving the durability of the dexterous hand. The planetary gear transmission efficiency can reach over 95%, far exceeding that of worm gear transmissions, and it avoids single-tooth load-bearing issues, resulting in high tooth root strength and transmission shaft reliability. The arrangement and number of reduction stages of the primary and secondary reduction units can be adjusted according to the specific shape of the dexterous hand's finger space, adapting to the design requirements of different joint modules. Attached Figure Description

[0018] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a schematic diagram of a vertical orthogonal transmission conjugate planetary reduction structure for dexterous hand joints in one or more embodiments of the present invention. Figure 2 This is a schematic diagram of the transmission principle of a vertical orthogonal transmission conjugate planetary reduction structure for dexterous hand joints in one or more embodiments of the present invention. Figure 3 This is a schematic diagram of a first-stage deceleration unit in one or more embodiments of the present invention; Figure 4 This is a schematic diagram of a two-stage deceleration unit in one or more embodiments of the present invention; Figure 5 for Figure 4 Schematic diagram of a partial structure; Figure 6 This is a schematic diagram of the installation of the present invention in the finger joints of a dexterous hand.

[0020] In the diagram: 1-Reducer housing, 2-Drive plate, 3-Motor, 4-Input bevel gear, 5-Conjugate internal gear ring holder, 6-First sun gear, 7-First planet gear, 8-First internal gear ring, 9-First planet carrier, 10-Oil-free bearing sleeve, 11-Second planet gear, 12-Second sun gear, 13-Second internal gear ring, 14-Second planet carrier. Detailed Implementation

[0021] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0022] The purpose of this invention is to provide a vertical orthogonal transmission conjugate planetary reduction structure for dexterous hand joints, so as to solve the problems existing in the prior art and realize high torque and high reduction ratio vertical orthogonal transmission in a compact space.

[0023] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0024] As a key actuation component of humanoid robots, the dexterous hand's finger joint module needs to output sufficiently large torque under constraints of high degrees of freedom, small size, and lightweight design. Based on this, this invention provides a vertical orthogonal transmission conjugate planetary reduction structure for dexterous hand joints, with an overall outer diameter not exceeding 15mm and an axial length not exceeding 25mm. (Refer to...) Figures 1-6 As shown, it includes a power source, a steering transmission unit, a first-stage reduction unit, and a second-stage reduction unit. One end of the steering transmission unit is connected to the output end of the power source, enabling it to vertically turn the power output from the power source and then output it. The first-stage and second-stage reduction units are arranged coaxially and located at the end of the steering transmission unit furthest from the power source. The first-stage and second-stage reduction units are located on both sides of the end of the steering transmission unit, forming a spatially symmetrical and conjugate arrangement. The input end of the first-stage reduction unit is connected to the end of the steering transmission unit furthest from the power source, and the output end of the first-stage reduction unit is connected to the input end of the second-stage reduction unit. The output end of the second-stage reduction unit is externally connected to a transmission device. In this embodiment, the transmission device is an output shaft, which is connected to the finger joints of a dexterous hand, and the output torque is 1-3 N·m.

[0025] In one embodiment, the power source includes a drive plate 2 and a motor 3 electrically connected. The motor 3 is fixed inside the reducer housing 1. One end of the reducer housing 1 is connected to a conjugate internal gear ring fixing frame 5. The drive plate 2 is externally connected to a power supply and a control terminal. The conjugate internal gear ring fixing frame 5 includes an integrally formed frame body and a fixing ring. The frame body is hollow inside, and one end of it is fixedly connected to the reducer housing. The other end of the frame body is fixedly connected to a fixing ring. The axis of the fixing ring is perpendicular to the output shaft of the motor 3. The output shaft of the motor 3 is located inside the frame body. The first-stage reduction unit and the second-stage reduction unit are respectively located on both sides of the fixing ring. By arranging the first-stage reduction unit and the second-stage reduction unit coaxially, the steering transmission unit is integrated between the reduction unit and the power source, making full use of the radial and axial space of the dexterous hand joint, and the overall structure is extremely compact.

[0026] In one embodiment, the steering transmission unit includes an input bevel gear 4 and an output bevel gear. The input bevel gear 4 is fixedly connected to the output shaft of the motor 3, and the output bevel gear is fixedly connected to the input end of the first-stage reduction unit. The input bevel gear 4 and the output bevel gear are meshed and connected in a transmission manner, and the reduction ratio of the steering transmission unit is 1:3. In another embodiment, the steering transmission unit may also adopt a crown gear pair, which is located between the first-stage reduction unit and the second-stage reduction unit, and is used to transmit the rotational motion of the input shaft of the motor 3 to the first-stage reduction unit after being rotated 90 degrees. The specific structure of the steering transmission unit of the present invention is not limited. In addition to the two structures mentioned above, other structures that can realize vertical transmission can also be used as the steering transmission unit of the present invention.

[0027] In one embodiment, the first-stage reduction unit includes a first sun gear 6, a first planetary gear 7, a first planetary carrier 9, and a first internal gear ring 8. The reduction ratio of the first-stage reduction unit is 3-10, and the module is 0.1-0.3. The second-stage reduction unit includes a second sun gear 12, a second planetary gear 11, a second planetary carrier 14, and a second internal gear ring 13. The reduction ratio of the second-stage reduction unit is 3-5, and the module is 0.3-0.6. This invention employs a two-stage planetary reduction system in series. The first-stage reduction unit uses small-module gears to achieve a high reduction ratio, while the second-stage reduction unit uses large-module gears to achieve high torque output. The total reduction ratio can reach over 50, and the output torque can reach 3 N·m, meeting the driving requirements of dexterous hand joints. The planetary gear transmission efficiency can reach over 95%, far exceeding that of worm gear transmission, and there is no single-tooth load-bearing problem. The tooth root strength and transmission shaft reliability are high. The arrangement position and reduction stage of the first-stage and second-stage reduction units can be adjusted according to the specific shape of the dexterous hand's finger space to adapt to the design requirements of different joint modules.

[0028] In this embodiment, the first internal gear ring 8 is coaxially fixed to one side of the fixed ring. The first internal gear ring 8 is provided with a first sun gear 6. A plurality of first planet gears 7 are arranged circumferentially between the first sun gear 6 and the first internal gear ring 8. The axles of the first planet gears 7 are connected to the first planet carrier 9. The first sun gear 6 is coaxially fixedly connected to the output end of the steering transmission unit. The first sun gear 6 and the output end of the steering transmission unit have a coaxial hollow channel. The output end of the first planet carrier 9 extends through the hollow channel to the other side of the fixed ring and is connected to the input end of the second-stage reduction unit. The second internal gear ring 13 is coaxially fixed to the side of the fixed ring away from the first-stage reduction unit. The second internal gear ring 13 has a second sun gear 12 inside. Multiple second planet gears 11 are arranged circumferentially between the second sun gear 12 and the second internal gear ring 13. The axles of the second planet gears 11 are connected to the second planet carrier 14. The second sun gear 12 is coaxially fixedly connected to the output end of the first-stage reduction unit. The output end of the second planet carrier 14 is externally connected to an output shaft, which drives the finger joints of the dexterous hand. In one embodiment, the structure of the second-stage reduction unit can also be designed to be exactly the same as that of the first-stage reduction unit and symmetrically arranged. That is, the second sun gear 12 of the second-stage reduction unit has a coaxial hollow channel, and the output end of the second planet carrier 14 passes through the hollow channel and is externally connected to the output shaft. The first-stage reduction unit and the second-stage reduction unit adopt planetary gear transmission, which has no self-locking characteristic. When subjected to external impact, energy can be released through reverse transmission to avoid damage to components caused by hard collisions and improve the durability of the dexterous hand. To ensure the sealing performance of the equipment, this embodiment provides an oil-free bearing sleeve 10 on the side of the first-stage reduction unit away from the fixed ring and on the side of the second-stage reduction unit away from the fixed ring, which serves to protect the first-stage and second-stage reduction units.

[0029] In one specific embodiment, the first-stage reduction unit uses a small-module gear with a module of 0.2 and a reduction ratio of 5; the second-stage reduction unit uses a large-module gear with a module of 0.4 and a reduction ratio of 4; combined with the 1:3 reduction ratio of the steering transmission unit, the total reduction ratio is 60, and the output torque can reach 3 N·m; the outer diameter of the device is 12 mm, and the axial length is 12 mm. In another specific embodiment, the first-stage reduction unit uses a two-stage planetary reduction gear with a reduction ratio of 10; the second-stage reduction unit uses a single-stage planetary reduction gear with a reduction ratio of 5; the total reduction ratio is 50; the outer diameter of the device is 14 mm, and the axial length is 12 mm. This invention achieves high reduction ratio and high torque vertical orthogonal transmission in an extremely compact space, solving the problems of traditional worm gear self-locking and easy damage of single-tooth spur gears, and is suitable for dexterous hand finger joint modules.

[0030] Specific examples have been used to illustrate the principles and implementation methods of this invention. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of this invention. Furthermore, those skilled in the art will recognize that, based on the ideas of this invention, there will be changes in the specific implementation methods and application scope. Therefore, the content of this specification should not be construed as a limitation of this invention.

Claims

1. A vertical orthogonal transmission conjugate planetary reduction structure for dexterous hand joints, characterized in that: include: Power source; A steering transmission unit, one end of which is connected to the output end of the power source, is capable of vertically steering the power output by the power source and then outputting it. as well as The system includes a primary reduction unit and a secondary reduction unit, which are coaxially arranged and located at the end of the steering transmission unit furthest from the power source. The input end of the primary reduction unit is connected to the end of the steering transmission unit furthest from the power source, and the output end of the primary reduction unit is connected to the input end of the secondary reduction unit. The output end of the secondary reduction unit is externally connected to a transmission device.

2. The vertical orthogonal transmission conjugate planetary reduction structure for dexterous hand joints according to claim 1, characterized in that: The power source includes a motor, which is fixed inside the reducer housing. One end of the reducer housing is connected to a conjugate internal gear ring fixing frame, and the conjugate internal gear ring fixing frame is provided with the steering transmission unit, the first-stage reduction unit and the second-stage reduction unit.

3. The vertical orthogonal transmission conjugate planetary reduction structure for dexterous hand joints according to claim 2, characterized in that: The steering transmission unit includes an input bevel gear and an output bevel gear. The input bevel gear is fixedly connected to the output shaft of the motor, and the output bevel gear is fixedly connected to the input end of the first-stage reduction unit. The input bevel gear and the output bevel gear are meshed and connected in a transmission manner.

4. The vertical orthogonal transmission conjugate planetary reduction structure for dexterous hand joints according to claim 2, characterized in that: The steering transmission unit includes a crown gear pair, the input end of which is fixedly connected to the output shaft of the motor, and the output end of which is fixedly connected to the input end of the first-stage reduction unit.

5. The vertical orthogonal transmission conjugate planetary reduction structure for dexterous hand joints according to claim 2, characterized in that: The conjugate internal gear ring fixing frame includes an integrally formed frame body and a fixing ring. The frame body is hollow inside, and one end of it is fixedly connected to the reducer housing. The other end of the frame body is fixedly connected to the fixing ring. The axis of the fixing ring is perpendicular to the output shaft of the motor. The output shaft of the motor is located inside the frame body. The first-stage reduction unit and the second-stage reduction unit are respectively located on both sides of the fixing ring.

6. The vertical orthogonal transmission conjugate planetary reduction structure for dexterous hand joints according to claim 5, characterized in that: The first-stage reduction unit includes a first sun gear, a first planet gear, a first planet carrier, and a first internal gear ring. The first internal gear ring is coaxially fixed to one side of the fixed ring. The first sun gear is disposed inside the first internal gear ring. A plurality of first planet gears are circumferentially arranged between the first sun gear and the first internal gear ring. The axles of the first planet gears are connected to the first planet carrier. The first sun gear is coaxially fixedly connected to the output end of the steering transmission unit. The first sun gear and the output end of the steering transmission unit have a coaxial hollow channel. The output end of the first planet carrier extends through the hollow channel to the other side of the fixed ring and is drively connected to the input end of the second-stage reduction unit.

7. The vertical orthogonal transmission conjugate planetary reduction structure for dexterous hand joints according to claim 5, characterized in that: The secondary reduction unit includes a second sun gear, a second planet gear, a second planet carrier, and a second internal gear ring. The second internal gear ring is coaxially fixed to the side of the fixed ring away from the primary reduction unit. The second sun gear is located inside the second internal gear ring. Multiple second planet gears are circumferentially arranged between the second sun gear and the second internal gear ring. The axles of the second planet gears are connected to the second planet carrier. The second sun gear is coaxially fixedly connected to the output end of the primary reduction unit. The output end of the second planet carrier is externally connected to a transmission device.

8. The vertical orthogonal transmission conjugate planetary reduction structure for dexterous hand joints according to claim 1, characterized in that: An oil-free bearing sleeve is sealed on the side of the first-stage reduction unit away from the fixed ring and on the side of the second-stage reduction unit away from the fixed ring.

Images