A drive shaft, a reducer and a dexterous hand

Abstract

This utility model discloses a transmission shaft, a reducer, and a dexterous hand, comprising: a first transmission part, a second transmission part, and a third transmission part rotatably connected in sequence; a first torsion spring is provided between the first transmission part and the second transmission part, and a second torsion spring is provided between the second transmission part and the third transmission part; a first limiting protrusion is provided on the portion of the first transmission part facing the second transmission part, and a second limiting protrusion is provided on the portion of the second transmission part corresponding to the first limiting protrusion; a third limiting protrusion is provided on the portion of the second transmission part facing the third transmission part, and a fourth limiting protrusion is provided on the portion of the third transmission part corresponding to the second limiting protrusion; through the design of the above structure, during the use of the dexterous hand, the transmission shaft can be disconnected and the impact energy converted into the elastic potential energy of the torsion spring when the knuckles encounter excessive impact force from either the outer or inner side, thereby reducing the impact on the reducer and motor and extending the service life of the dexterous hand.

Description

Technical Field

[0001] This utility model relates to the field of robot technology, and in particular to a transmission shaft, a reducer, and a dexterous hand. Background Technology

[0002] In the process of debugging or using existing dexterous hands, it is inevitable that the finger joints will collide with obstacles. Due to the large impact force, the drive mechanism will often be overloaded, thereby damaging the drive mechanism or the obstacle, which is not conducive to the interaction between the dexterous hand and the surrounding environment.

[0003] It is evident that the existing dexterous hand still has inconveniences and defects in use. Therefore, there is an urgent need to design and develop a transmission shaft, reducer, and dexterous hand to overcome the above problems. Summary of the Invention

[0004] The technical problem to be solved by this utility model is to provide a transmission shaft, a reducer and a dexterous hand, to solve the problem that the fingers and knuckles collide with obstacles during the debugging or use of the dexterous hand, thereby causing damage to the dexterous hand or the obstacles.

[0005] To solve the above-mentioned technical problems, this utility model provides a transmission shaft, comprising: a first transmission part, a second transmission part, and a third transmission part that are rotatably connected in sequence.

[0006] A first torsion spring is provided between the first transmission part and the second transmission part, and a second torsion spring is provided between the second transmission part and the third transmission part;

[0007] A first limiting protrusion is provided on the part of the first transmission part facing the second transmission part, and a second limiting protrusion is provided on the part of the second transmission part corresponding to the first limiting protrusion.

[0008] A third limiting protrusion is provided on the part of the second transmission unit facing the third transmission unit, and a fourth limiting protrusion is provided on the part of the third transmission unit corresponding to the second limiting protrusion.

[0009] Under the action of the first limiting protrusion, the second limiting protrusion and the first torsion spring, the first transmission part and the second transmission part can rotate synchronously, but when the transmitted torque is too large, the first transmission part and the second transmission part rotating around the first rotation direction will disconnect.

[0010] Under the action of the third limiting protrusion, the fourth limiting protrusion, and the second torsion spring, the second transmission part and the third transmission part can rotate synchronously. However, if the transmitted torque is too large, the second transmission part and the third transmission part rotating around the second rotation direction will disconnect.

[0011] Furthermore, one end of the first transmission part has a first countersunk hole, one end of the second transmission part has a second countersunk hole, the other end of the second transmission part is inserted into the first countersunk hole and rotatably connected thereto, one end of the third transmission part is inserted into the second countersunk hole and rotatably connected thereto, the second transmission part and the third transmission part respectively include a small diameter part, a medium diameter part and a large diameter part, the medium diameter part is located between the small diameter part and the large diameter part, the second countersunk hole is located in the large diameter part of the second transmission part, the small diameter part, the medium diameter part and the large diameter part of the second transmission part extend into the first countersunk hole in sequence, the large diameter part of the second transmission part is rotatably connected to the first countersunk hole, the small diameter part, the medium diameter part and the large diameter part of the third transmission part extend into the second countersunk hole in sequence, the large diameter part of the third transmission part is rotatably connected to the second countersunk hole.

[0012] Furthermore, the first transmission part has a torsion spring locking groove 1 at the first countersunk hole, which is connected to the first countersunk hole and the end of the first transmission part. The second transmission part has a torsion spring locking groove 3 at its small diameter section and a torsion spring locking groove 2 at the second countersunk hole, which is connected to the second countersunk hole and the end of the large diameter section of the second transmission part. The third transmission part has a torsion spring locking groove 4 at its small diameter section. One end of the first torsion spring is locked in torsion spring locking groove 1 and the other end of the first torsion spring is locked in torsion spring locking groove 3. One end of the second torsion spring is locked in torsion spring locking groove 2 and the other end of the second torsion spring is locked in torsion spring locking groove 4.

[0013] Furthermore, the first limiting protrusion is located on the inner wall of the first countersunk hole of the first transmission part, the second limiting protrusion is located on the circumferential wall of the middle diameter of the second transmission part, the third limiting protrusion is located on the inner wall of the second countersunk hole of the second transmission part, and the fourth limiting protrusion is located on the circumferential wall of the middle diameter of the third transmission part. The first limiting protrusion abuts against the second limiting protrusion, and the third limiting protrusion abuts against the fourth limiting protrusion.

[0014] Furthermore, the first torsion spring and the second torsion spring have opposite helical directions, and the first torsion spring and the second torsion spring each provide a certain preload.

[0015] A speed reducer includes a drive shaft as described in any of the above claims, and further includes a mounting housing, an indexing plate located within the mounting housing, and an input shaft. The mounting housing includes a housing and a cover. One end of the drive shaft passes through the indexing plate and is fixedly connected to the indexing plate, and this end of the drive shaft is rotatably connected to the cover. The other end of the drive shaft passes through the housing and is rotatably connected thereto. A first bearing assembly is provided at the rotatably connected portion of the drive shaft and the mounting housing.

[0016] Several mounting holes are evenly spaced on the side of the indexing plate, and cam rollers are fixedly installed in the mounting holes of the indexing plate.

[0017] Furthermore, the first bearing assembly includes: a first bearing housing and a first bearing, the first bearing housing being fixedly mounted on the mounting housing, and the drive shaft being rotatably connected to the first bearing housing via the first bearing.

[0018] Furthermore, the input shaft is perpendicular to the transmission shaft, and a cam is fixedly installed on the input shaft. The cam cooperates with the cam roller. Both ends of the input shaft are rotatably connected to the housing, and one end extends out of the housing. The housing has a through hole for the input shaft to rotatably connect. The part where the input shaft rotatably connects to the through hole of the housing is provided with a second bearing assembly.

[0019] Furthermore, the second bearing assembly includes: a second bearing housing and a second bearing. The second bearing housing is fixedly installed on the through hole of the housing. The input shaft and the second bearing housing are rotatably connected through the second bearing housing. The bearing cover plate is coaxial with the input shaft and fixedly connected to the housing to seal the through hole of the housing.

[0020] A dexterous hand, characterized in that it includes a reducer as described in any one of the above claims, wherein the reducer is combined with a motor, that is, the output shaft of the motor is connected to the input shaft of the reducer, and is used at the first or second phalanx of the dexterous hand's fingers, so that the second or third phalanx can be controlled by the output end of the reducer to achieve bending and extending movements.

[0021] With this design, the present invention has at least the following advantages:

[0022] This practical drive shaft will disconnect if the transmitted torque is too high, regardless of whether the transmission is in the first or second rotation direction. Therefore, a reducer made using this drive shaft, and a dexterous hand equipped with it, will overcome the preload of the first or second torsion spring when the finger joints are subjected to excessive impact. This allows the drive shaft to disconnect and convert the impact energy into the elastic potential energy of the torsion spring, regardless of whether the finger joints encounter excessive impact from the outside or inside. This reduces the impact on the reducer and motor, and extends the service life of the dexterous hand.

[0023] Furthermore, if the preload of the torsion spring is less than the maximum driving force of the motor on the finger joints of a dexterous hand, the drive shaft can also prevent the motor from being overloaded. Attached Figure Description

[0024] The above is merely an overview of the technical solution of this utility model. In order to better understand the technical means of this utility model, the following describes this utility model in further detail with reference to the accompanying drawings and specific embodiments.

[0025] Figure 1 This is a sectional view of the practical drive shaft;

[0026] Figure 2 This is a practical book Figure 1Sectional view at AA;

[0027] Figure 3 This is a practical book Figure 1 Sectional view at BB;

[0028] Figure 4 This is an exploded structural diagram of the transmission shaft used in this application;

[0029] Figure 5 This is the front view of this practical speed reducer;

[0030] Figure 6 This is a practical book Figure 5 Sectional view at CC;

[0031] Figure 7 This is a practical book Figure 5 Sectional view at DD;

[0032] Figure 8 This is an exploded structural diagram of the practical speed reducer.

[0033] Explanation of reference numerals in the attached figures:

[0034] 1. Drive shaft; 101. First drive unit; 1011. First countersunk hole; 1012. Torsion spring retaining groove one; 1013. First limiting protrusion; 102. Second drive unit; 1021. Second countersunk hole; 1022. Torsion spring retaining groove two; 1023. Second limiting protrusion; 1024. Third limiting protrusion; 1025. Torsion spring retaining groove three; 103. Third drive unit; 1031. Fourth limiting protrusion; 1032. Torsion spring retaining groove four; 104. First torsion spring; 105. Second torsion spring;

[0035] 2. Housing assembly; 201. Housing; 202. Cover; 3. Indexing plate; 4. Cam roller; 5. First bearing assembly; 501. First bearing housing; 502. First bearing; 6. First skeleton oil seal; 7. Input shaft; 8. Cam; 9. Second bearing assembly; 901. Second bearing housing; 902. Second bearing; 903. Bearing cover plate; 904. First sealing ring; 10. Second skeleton oil seal; 11. Second sealing ring. Detailed Implementation

[0036] The technical solution of this utility model will now be clearly and completely described in conjunction with the accompanying drawings.

[0037] The following specific examples illustrate the implementation of this disclosure. Those skilled in the art can easily understand other advantages and effects of this disclosure from the content disclosed in this specification. Obviously, the described embodiments are only a part of the embodiments of this disclosure, and not all of them. This disclosure can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of this disclosure. It should be noted that, in the absence of conflict, the following embodiments and features in the embodiments can be combined with each other. Based on the embodiments in this disclosure, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this disclosure.

[0038] It should be noted that various aspects of embodiments within the scope of the appended claims are described below. It will be apparent that the aspects described herein can be embodied in a wide variety of forms, and any particular structure and / or function described herein is merely illustrative. Based on this disclosure, those skilled in the art will understand that one aspect described herein can be implemented independently of any other aspect, and two or more of these aspects can be combined in various ways. For example, any number of aspects set forth herein can be used to implement the device and / or practice the method. Additionally, this device and / or method can be implemented using structures and / or functionalities other than one or more of the aspects set forth herein.

[0039] Furthermore, specific details are provided in the following description to facilitate a thorough understanding of the examples. However, those skilled in the art will understand that the described aspects can be practiced without these specific details.

[0040] This utility model discloses a drive shaft, a reducer, and a dexterous hand. In the current market, traditional dexterous hands inevitably experience collisions between finger joints and obstacles during adjustment or use. Due to the large impact force, this often causes a significant overload on the drive mechanism, damaging it or harming the obstacle, thus hindering the dexterous hand's interaction with its surroundings. This utility model aims to solve the problem that when the finger joints of a dexterous hand are subjected to excessive impact force, the resulting large overload on the drive mechanism hinders the dexterous hand's interaction with its surroundings and affects its lifespan.

[0041] Next, combine Figures 1 to 8 This invention describes a drive shaft, a reducer, and a dexterous hand.

[0042] like Figures 1-4As shown, a drive shaft includes: a first drive section 101, a second drive section 102 and a third drive section 103. One end of the first drive section 101 is provided with a first countersunk hole 1011, one end of the second drive section 102 is provided with a second countersunk hole 1021, the other end of the second drive section 102 is inserted into the first countersunk hole 1011 and rotatably connected thereto, and one end of the third drive section 103 is inserted into the second countersunk hole 1021 and rotatably connected thereto.

[0043] In this embodiment, such as Figure 4 As shown, the second transmission part 102 and the third transmission part 103 respectively include a small diameter part, a medium diameter part and a large diameter part. The medium diameter part is located between the small diameter part and the large diameter part. The second countersunk hole 1021 is located in the large diameter part of the second transmission part 102. The small diameter part, the medium diameter part and the large diameter part of the second transmission part 102 extend into the first countersunk hole 1011 in sequence. The large diameter part of the second transmission part 102 is rotatably connected to the first countersunk hole 1011. The small diameter part, the medium diameter part and the large diameter part of the third transmission part 103 extend into the second countersunk hole 1021 in sequence. The large diameter part of the third transmission part 103 is rotatably connected to the second countersunk hole 1021.

[0044] In this embodiment, the rotational connection between the first transmission unit 101, the second transmission unit 102, and the third transmission unit 103 is achieved through bearings.

[0045] Specifically, a first torsion spring 104 is provided between the first transmission part 101 and the second transmission part 102, and a second torsion spring 105 is provided between the second transmission part 102 and the third transmission part 103. The first torsion spring 104 and the second torsion spring 105 have opposite helical directions, and the first torsion spring 104 and the second torsion spring 105 respectively provide a certain preload. Since the first torsion spring 104 and the second torsion spring 105 have opposite helical directions, the preload provided by the first torsion spring 104 and the second torsion spring 105 are also in opposite directions.

[0046] In this embodiment, the first transmission part 101 has a torsion spring retaining groove 1012 at the first countersunk hole 1011, which communicates with the first countersunk hole 1011 and the end of the first transmission part 101. The second transmission part 102 has a torsion spring retaining groove 1025 at its small diameter, which communicates with the small diameter of the second transmission part 102. The second transmission part 102 has a torsion spring retaining groove 1022 at the second countersunk hole 1021, which communicates with the second... The countersunk hole 1021 and the large-diameter end of the second transmission part 102 are connected. The small-diameter part of the third transmission part 103 is provided with a torsion spring retaining groove 4 1032, which is connected to the small-diameter part of the third transmission part 103. During installation, one end of the first torsion spring 104 is engaged with the first torsion spring retaining groove 1012, and the other end of the first torsion spring 104 is engaged with the third torsion spring retaining groove 3 1025. One end of the second torsion spring 105 is engaged with the second torsion spring retaining groove 2 1022, and the other end of the second torsion spring 105 is engaged with the fourth torsion spring retaining groove 4 1032.

[0047] Specifically, the first transmission part 101 is provided with a first limiting protrusion 1013 facing the second transmission part 102, and the second transmission part 102 is provided with a second limiting protrusion 1023 corresponding to the first limiting protrusion 1013; the second transmission part 102 is provided with a third limiting protrusion 1024 facing the third transmission part 103, and the third transmission part 103 is provided with a fourth limiting protrusion 1031 corresponding to the second limiting protrusion 1023.

[0048] In this embodiment, the first limiting protrusion 1013 is located on the inner wall of the first countersunk hole 1011 of the first transmission part 101, the second limiting protrusion 1023 is located on the circumferential wall of the middle diameter of the second transmission part 102, the third limiting protrusion 1024 is located on the inner wall of the second countersunk hole 1021 of the second transmission part 102, and the fourth limiting protrusion 1031 is located on the circumferential wall of the middle diameter of the third transmission part 103. Under the action of the first torsion spring 104 and the second torsion spring 105 respectively, the first limiting protrusion 1013 abuts against the second limiting protrusion 1023, and the third limiting protrusion 1024 abuts against the fourth limiting protrusion 1031.

[0049] In this embodiment, there are two of each of the first limiting protrusion 1013, the second limiting protrusion 1023, the third limiting protrusion 1024, and the fourth limiting protrusion 1031, and they are symmetrically arranged about the axis of the transmission shaft 1. In this way, the force on each transmission part will be more balanced during the use of the transmission shaft 1, thereby extending the service life of the transmission shaft 1.

[0050] In this embodiment, the first limiting protrusion 1013, the second limiting protrusion 1023, the third limiting protrusion 1024, and the fourth limiting protrusion 1031 are parallel to the axis of the transmission shaft 1.

[0051] Specifically, under the action of the first limiting protrusion 1013, the second limiting protrusion 1023 and the first torsion spring 104, the first transmission part 101 and the second transmission part 102 can rotate synchronously. However, when the transmitted torque is too large, the power transmission between the first transmission part 101 and the second transmission part 102 rotating around the first rotation direction will be disconnected.

[0052] It is understandable that when the first transmission part 101 and the second transmission part 102 rotate about the second rotation direction, regardless of the amount of transmission force between the first transmission part 101 and the second transmission part 102 (provided that the transmission shaft structure is not damaged), the first transmission part 101 and the second transmission part 102 can rotate synchronously. At this time, the first limiting protrusion 1013 that abuts against the second limiting protrusion 1023 drives the second limiting protrusion 1023. When the first transmission part 101 and the second transmission part 102 rotate about the first rotation direction, if the transmission force between the first transmission part 101 and the second transmission part 102 is greater than the preload of the first torsion spring 104, the first transmission part 101 and the second transmission part 102 will overcome the preload of the first torsion spring 104, and the first transmission part 101 and the second transmission part 102 will rotate relative to each other, so that the power transmission between the first transmission part 101 and the second transmission part 102 rotating about the first rotation direction is disconnected.

[0053] That is, the power transmitted between the first transmission part 101 and the second transmission part 102 around the first rotation direction relies on the preload of the first torsion spring 104, and the power transmitted between the first transmission part 101 and the second transmission part 102 around the second rotation direction relies on the first limiting protrusion 1013 and the second limiting protrusion 1023.

[0054] Specifically, under the action of the third limiting protrusion 1024, the fourth limiting protrusion 1031 and the second torsion spring 105, the second transmission part 102 and the third transmission part 103 can rotate synchronously. However, when the transmitted torque is too large, the power transmission between the second transmission part 102 and the third transmission part 103 rotating around the second rotation direction will be disconnected.

[0055] It is understandable that when the second transmission part 102 and the third transmission part 103 rotate around the first rotation direction, regardless of the magnitude of the transmission force between the second transmission part 102 and the third transmission part 103 (provided that the transmission shaft structure is not damaged), the second transmission part 102 and the third transmission part 103 can rotate synchronously. At this time, the abutting third limiting protrusion 1024 drives the fourth limiting protrusion 1031. When the second transmission part 102 and the third transmission part 103 rotate around the second rotation direction, if the transmission force between the second transmission part 102 and the third transmission part 103 is greater than the preload of the second torsion spring 105, the second transmission part 102 and the third transmission part 103 will overcome the preload of the second torsion spring 105, and the second transmission part 102 and the third transmission part 103 will rotate relative to each other, so that the power transmission between the second transmission part 102 and the third transmission part 103 rotating around the second rotation direction is disconnected.

[0056] That is, the power transmitted by the second transmission part 102 and the third transmission part 103 around the first rotation direction is driven by the third limiting protrusion 1024 to drive the fourth limiting protrusion 1031, and the power transmitted by the second transmission part 102 and the third transmission part 103 around the second rotation direction is driven by the preload of the second torsion spring 105.

[0057] Based on the above description, for drive shaft 1, if the force transmitted is too large during the power transmission process, drive shaft 1 will disconnect.

[0058] Specifically, the first rotation direction and the second rotation direction are two opposite rotation directions.

[0059] like Figures 5-8 As shown, a reducer is constructed as follows, including the drive shaft 1 described in any of the above claims, and also including a mounting housing 2, an indexing plate 3 located inside the mounting housing 2, and an input shaft 7. The mounting housing 2 includes a housing 201 and a cover 202. One end of the drive shaft 1 passes through the indexing plate 3 and is fixedly connected to the indexing plate 3, and this end of the drive shaft 1 is rotatably connected to the cover 202. The other end of the drive shaft 1 passes through the housing 201 and is rotatably connected to it. A first bearing assembly 5 is provided at the rotatably connected part of the drive shaft 1 and the mounting housing 2.

[0060] In this embodiment, the first bearing assembly 5 includes a first bearing housing 501 and a first bearing 502. The first bearing housing 501 is fixedly mounted on the mounting housing 2, and the drive shaft 1 is rotatably connected to the first bearing housing 501 through the first bearing 502.

[0061] In this embodiment, in order to improve the sealing between the box 201 and the cover 202, a second sealing ring 11 is provided between the box 201 and the cover 202.

[0062] Specifically, several mounting holes are evenly opened on the side of the indexing plate 3, and cam rollers 5 are fixedly installed on the mounting holes of the indexing plate 3 respectively.

[0063] Specifically, the input shaft 7 is perpendicular to the transmission shaft 1. A cam 8 is fixedly installed on the input shaft 7. The cam 8 cooperates with the cam roller 5. Both ends of the input shaft 7 are rotatably connected to the housing 201, and one end extends out of the housing 201. A through hole is opened on the housing 201 for the input shaft 7 to be rotatably connected. A second bearing assembly 9 is provided at the part where the input shaft 7 is rotatably connected to the through hole of the housing 201.

[0064] In this embodiment, the second bearing assembly 9 includes: a second bearing housing 901 and a second bearing 902. The second bearing housing 901 is fixedly installed on the through hole of the housing 201. The input shaft 7 is rotatably connected to the second bearing housing 901 through the second bearing housing 901. The bearing cover plate 903 is coaxial with the input shaft 7 and is fixedly connected to the housing 201 and covers the through hole of the housing 201.

[0065] In this embodiment, the second bearing 902 is a tapered roller bearing, which can withstand both radial and axial loads simultaneously.

[0066] In this embodiment, a first skeleton oil seal 6 is provided at the point where the drive shaft 1 passes through the housing 201, a first sealing ring 904 is provided between the second bearing seat 901 and the bearing cover plate 903, and a second skeleton oil seal 10 is provided between the end of the input shaft 7 that passes through the bearing cover plate 903 and the bearing cover plate 903. Similarly, the design of the sealing ring and the oil seal is to improve the sealing performance of the mounting housing 2.

[0067] Specifically, in this reducer, the motor transmits power to the input shaft 7, and the rotating input shaft 7 drives the cam 8 to rotate. The rotating cam 8 will drive the cam roller 5 to enter and leave the drive groove in sequence through the drive groove on the cam 8, thereby driving the indexing plate 3 to rotate, and further driving the transmission shaft 1 to rotate, thereby outputting power and achieving the purpose of speed reduction and torque increase.

[0068] Furthermore, when this reducer is overloaded, the transmission shaft 1 will disconnect, thereby disconnecting the transmission to protect the motor and the reducer.

[0069] It is understandable that when the motor driving the transmission shaft 1 connected to the input shaft 7 rotates around the first rotation direction, since the first transmission part 101 and the second transmission part 102 are transmitted through the first torsion spring 104, and the second transmission part 102 and the third transmission part 103 are transmitted through the third limiting protrusion 1024 and the fourth limiting protrusion 1031, in case of overload, the preload force of the first torsion spring 104 between the first transmission part 101 and the second transmission part 1023 will be overcome, causing the first transmission part 101 and the second transmission part 1023 to rotate relative to each other, thereby disconnecting the transmission to protect the motor and the reducer.

[0070] When the motor driving transmission shaft 1 connected to the input shaft 7 rotates around the second rotation direction, since the first transmission part 101 and the second transmission part 102 are connected by the first limiting protrusion 1013 and the second limiting protrusion 1023, and the second transmission part 102 and the third transmission part 103 are connected by the second torsion spring 105, when overload occurs, the preload force of the second torsion spring 105 between the second transmission part 102 and the third transmission part 103 will be overcome, causing the second transmission part 102 and the third transmission part 103 to rotate relative to each other, thereby disconnecting the transmission to protect the motor and the reducer.

[0071] Based on the foregoing, this embodiment also discloses a dexterous hand including at least one reducer with a drive shaft 1 as described above. The reducer is combined with a motor, that is, the output shaft of the motor is connected to the input shaft 7 of the reducer. It is used at the first or second phalanx of the dexterous hand's fingers, and the output end of the reducer controls the second or third phalanx to achieve bending and extension movements.

[0072] In the description of this utility model, it should be noted that the terms "upper", "lower", "front", "rear", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0073] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0074] The above description is merely a preferred embodiment of the present utility model and is not intended to limit the present utility model in any way. Any simple modifications, equivalent changes or alterations made by those skilled in the art using the above-disclosed technical content shall fall within the protection scope of the present utility model.

Claims

1. A drive shaft, characterized in that, It includes: a first transmission part (101), a second transmission part (102) and a third transmission part (103) that are rotatably connected in sequence. A first torsion spring (104) is provided between the first transmission part (101) and the second transmission part (102), and a second torsion spring (105) is provided between the second transmission part (102) and the third transmission part (103). A first limiting protrusion (1013) is provided on the part of the first transmission part (101) facing the second transmission part (102), and a second limiting protrusion (1023) is provided on the part of the second transmission part (102) corresponding to the first limiting protrusion (1013). The second transmission part (102) is provided with a third limiting protrusion (1024) facing the third transmission part (103), and the third transmission part (103) is provided with a fourth limiting protrusion (1031) on the part corresponding to the second limiting protrusion (1023). Under the action of the first limiting protrusion (1013), the second limiting protrusion (1023) and the first torsion spring (104), the first transmission part (101) and the second transmission part (102) can rotate synchronously. However, when the transmitted torque is too large, the first transmission part (101) and the second transmission part (102) rotating around the first rotation direction will disconnect. Under the action of the third limiting protrusion (1024), the fourth limiting protrusion (1031) and the second torsion spring (105), the second transmission part (102) and the third transmission part (103) can rotate synchronously. However, when the transmitted torque is too large, the second transmission part (102) and the third transmission part (103) will disconnect when rotating around the second rotation direction.

2. The drive shaft according to claim 1, characterized in that, The first transmission part (101) has a first countersunk hole (1011) at one end, and the second transmission part (102) has a second countersunk hole (1021) at one end. The other end of the second transmission part (102) is inserted into the first countersunk hole (1011) and rotatably connected thereto. One end of the third transmission part (103) is inserted into the second countersunk hole (1021) and rotatably connected thereto. The second transmission part (102) and the third transmission part (103) respectively include a small diameter part, a medium diameter part and a large diameter part, with the medium diameter part located in the small diameter part. Between the large diameter portion and the large diameter portion, the second countersunk hole (1021) is located in the large diameter portion of the second transmission portion (102). The small diameter portion, the middle diameter portion and the large diameter portion of the second transmission portion (102) extend into the first countersunk hole (1011) in sequence. The large diameter portion of the second transmission portion (102) is rotatably connected to the first countersunk hole (1011). The small diameter portion, the middle diameter portion and the large diameter portion of the third transmission portion (103) extend into the second countersunk hole (1021) in sequence. The large diameter portion of the third transmission portion (103) is rotatably connected to the second countersunk hole (1021).

3. The drive shaft according to claim 2, characterized in that, The first transmission part (101) has a torsion spring retaining groove 1 (1012) at the first countersunk hole (1011), and the torsion spring retaining groove 1 (1012) is connected to the first countersunk hole (1011) and the end of the first transmission part (101). The second transmission part (102) has a torsion spring retaining groove 3 (1025) at its small diameter portion, and a torsion spring retaining groove 2 (1022) at the second countersunk hole (1021), and the torsion spring retaining groove 2 (1022) is connected to the second countersunk hole. (1021) The large-diameter end of the second transmission part (102) is connected, and the small-diameter part of the third transmission part (103) is provided with a torsion spring locking groove four (1032). One end of the first torsion spring (104) is locked in the first torsion spring locking groove one (1012), and the other end of the first torsion spring (104) is locked in the third torsion spring locking groove three (1025). One end of the second torsion spring (105) is locked in the second torsion spring locking groove two (1022), and the other end of the second torsion spring (105) is locked in the fourth torsion spring locking groove four (1032).

4. The drive shaft according to claim 1, characterized in that, The first limiting protrusion (1013) is located on the inner wall of the first countersunk hole (1011) of the first transmission part (101), the second limiting protrusion (1023) is located on the circumferential wall of the middle diameter of the second transmission part (102), the third limiting protrusion (1024) is located on the inner wall of the second countersunk hole (1021) of the second transmission part (102), and the fourth limiting protrusion (1031) is located on the circumferential wall of the middle diameter of the third transmission part (103). The first limiting protrusion (1013) abuts against the second limiting protrusion (1023), and the third limiting protrusion (1024) abuts against the fourth limiting protrusion (1031).

5. The drive shaft according to claim 1, characterized in that, The first torsion spring (104) and the second torsion spring (105) have opposite helical directions, and the first torsion spring (104) and the second torsion spring (105) respectively provide a certain preload.

6. A speed reducer, comprising a drive shaft (1) as described in any one of claims 1-5, and further comprising a mounting housing (2), an indexing plate (3) located within the mounting housing (2), and an input shaft (7). The mounting housing (2) comprises a housing (201) and a cover (202). One end of the drive shaft (1) passes through the indexing plate (3) and is fixedly connected to the indexing plate (3), and the end of the drive shaft (1) is rotatably connected to the cover (202). The other end of the drive shaft (1) passes through the housing (201) and is rotatably connected to it. A first bearing assembly (5) is provided at the rotatably connected portion of the drive shaft (1) and the mounting housing (2). Several mounting holes are evenly opened on the side of the indexing plate (3), and cam rollers (4) are fixedly installed on the mounting holes of the indexing plate (3).

7. The reducer according to claim 6, characterized in that, The first bearing assembly (5) includes a first bearing housing (501) and a first bearing (502). The first bearing housing (501) is fixedly mounted on the mounting housing (2), and the drive shaft (1) and the first bearing housing (501) are rotatably connected through the first bearing (502).

8. The reducer according to claim 6, characterized in that, The input shaft (7) is perpendicular to the transmission shaft (1). A cam (8) is fixedly installed on the input shaft (7). The cam (8) cooperates with the cam roller (4). Both ends of the input shaft (7) are rotatably connected to the housing (201), and one end extends out of the housing (201). A through hole is provided on the housing (201) for the input shaft (7) to rotatably connect. A second bearing assembly (9) is provided at the part where the input shaft (7) and the through hole of the housing (201) are rotatably connected.

9. The reducer according to claim 8, characterized in that, The second bearing assembly (9) includes: a second bearing housing (901), a second bearing (902), and a bearing cover plate (903). The second bearing housing (901) is fixedly installed on the through hole of the housing (201). The input shaft (7) is rotatably connected to the second bearing housing (901) through the second bearing housing (901). The bearing cover plate (903) is coaxial with the input shaft (7) and is fixedly connected to the housing (201) and covers the through hole of the housing (201).

10. A dexterous hand, characterized in that, The reducer includes any one of claims 6 to 9, wherein the reducer is combined with a motor, that is, the output shaft of the motor is connected to the input shaft 7 of the reducer, and is used at the first or second phalanx of the dexterous hand, so that the second or third phalanx is controlled by the output end of the reducer to achieve bending and extension movements.

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