Transmission mechanism, joint actuator, manipulator and robot

Abstract

The application discloses a transmission mechanism, a joint actuator, a manipulator and a robot. The transmission mechanism comprises a motor shaft, a planetary gear reduction assembly and a lead screw. The planetary gear reduction assembly comprises a first connecting end and a second connecting end. The first connecting end is connected with the motor shaft. The second connecting end comprises a socket. The lead screw is inserted into the socket and is threadedly connected with the hole wall of the socket. The motor shaft drives the first connecting end, the first connecting end drives the second connecting end through the transmission between gears, and the second connecting end drives the lead screw through the threaded connection. Since the second connecting end comprises the socket, the lead screw is inserted into the socket and is threadedly connected with the hole wall of the socket, the axial dimension of the transmission mechanism is short, the size of the transmission mechanism is reduced, and thus, the joint actuator is miniaturized. In addition, since the lead screw is inserted into the connecting mode of the output end, the second connecting end does not need to be too long, the axial dimension of the transmission mechanism is also reduced, material is saved, and the cost of the transmission mechanism is reduced.

Description

Technical Field

[0001] This application relates to the field of transmission technology, and in particular to transmission mechanisms, joint actuators, manipulators and robots. Background Technology

[0002] Robots include joint actuators. Joint actuators are used to drive the movement of the robot's joints; for example, in a dexterous hand (a type of robotic hand), joint actuators are used to drive the extension and retraction of the fingers.

[0003] Existing joint actuators include a motor and a transmission mechanism. The motor drives the transmission mechanism, which converts the motor's rotational motion into linear motion, thereby enabling the joint to extend and retract.

[0004] Joint actuators need to be miniaturized, which in turn requires miniaturization of the transmission mechanism. However, the current transmission mechanism has a relatively long axial dimension, which is not conducive to the miniaturization of joint actuators. Utility Model Content

[0005] The purpose of this application is to disclose a transmission mechanism, a joint actuator, a manipulator, and a robot. The transmission mechanism has a small axial dimension, which is beneficial for the miniaturization of the joint actuator.

[0006] In a first aspect, this application discloses a transmission mechanism. The transmission mechanism includes a motor shaft, a planetary gear reduction assembly, and a lead screw. The planetary gear reduction assembly includes a first connecting end and a second connecting end; the first connecting end is connected to the motor shaft; the second connecting end includes a insertion hole; the lead screw is inserted into the insertion hole and threadedly connected to the hole wall. The motor shaft drives the first connecting end, and the first connecting end drives the second connecting end through gear transmission; the second connecting end drives the lead screw through the threaded connection.

[0007] In some embodiments, the planetary gear reduction assembly includes a ring gear and a planet carrier, the planet carrier including the second connecting end, or the ring gear including the second connecting end.

[0008] In some embodiments, the planetary gear reduction assembly includes a sun gear, the first connecting end is the sun gear, and the sun gear is connected to the motor shaft as an integral structure.

[0009] In some embodiments, the integral structure includes a receiving hole communicating with the socket; the lead screw is also inserted into the receiving hole during retraction.

[0010] In some embodiments, the planetary carrier includes a disc for mounting planetary gears and a column extending from the disc, the second connecting end including the column and a central portion of the disc; the insertion hole includes a first insertion hole recessed into the interior of the central portion of the disc and a second insertion hole penetrating the column, the wall of the first insertion hole and at least a portion of the wall of the second insertion hole being provided with the threads.

[0011] In some embodiments, the lead screw is a trapezoidal lead screw.

[0012] Secondly, this application discloses a joint actuator. The joint actuator includes any of the aforementioned transmission mechanisms.

[0013] In some embodiments, the joint actuator includes a housing. The transmission mechanism further includes a second connecting end support; the second connecting end is rotatably connected to the housing via the second connecting end support.

[0014] In some embodiments, the housing includes a housing end. The transmission mechanism further includes an end support; the end support is located at the housing end and is passed through by the lead screw. The lead screw extends out of the housing from the housing end.

[0015] In some embodiments, the second connecting end support is a rolling bearing or a bushing; and / or, the end support is a rolling bearing or a bushing.

[0016] In some embodiments, the inner wall of the housing is provided with a mounting groove recessed radially in the motor shaft, and the second connecting end support is fixed in the mounting groove.

[0017] In some embodiments, the joint actuator includes a housing, within which the motor shaft and the planetary gear reduction assembly are located, and the lead screw extends out of the housing. The motor shaft includes a motor shaft end connected to the first connecting end; the transmission mechanism further includes a motor shaft support member, through which the motor shaft end is rotatably connected to the housing.

[0018] Thirdly, this application discloses a robotic arm, which includes any of the aforementioned joint actuators, or the robotic arm includes any of the aforementioned transmission mechanisms.

[0019] Fourthly, this application discloses a robot. The robot includes any of the aforementioned joint actuators, or the robot includes any of the aforementioned transmission mechanisms.

[0020] For the transmission mechanism, the joint actuator, the manipulator, and the robot, since the planetary gear reduction assembly includes a second connecting end with a socket, and a lead screw is inserted into the socket and threadedly connected to the wall of the socket, the axial dimension of the transmission mechanism is short, which helps to reduce the size of the transmission mechanism and thus facilitates the miniaturization of the joint actuator. Furthermore, because of the connection method of inserting a lead screw into the second connecting end and threading it, the second connecting end does not need to be too long, which also helps to reduce the axial dimension of the transmission mechanism and saves materials, thereby reducing the cost of the transmission mechanism. Attached Figure Description

[0021] Figure 1 This is a cross-sectional view of a joint actuator according to an embodiment of this application, the joint actuator including a transmission mechanism;

[0022] Figure 2 This is a schematic diagram showing a transmission mechanism in a disassembled state and viewed from a first perspective, according to an embodiment of this application.

[0023] Figure 3 yes Figure 2 The diagram shown is of the transmission mechanism in a disassembled state and viewed from a second perspective.

[0024] Figure 4 yes Figure 2 The diagram shown is of the transmission mechanism in a disassembled state and viewed from a third perspective.

[0025] Figure 5 yes Figure 2 The diagram shown is a disassembled transmission mechanism with each component in cross-section.

[0026] Figure 6 This is a cross-sectional view of another transmission mechanism in an assembled state, according to an embodiment of this application;

[0027] Figure 7 This is a schematic diagram of a planetary carrier according to an embodiment of this application;

[0028] Figure 8 This is a schematic diagram showing the overall structure of the motor shaft and the sun gear according to an embodiment of this application;

[0029] Figure 9 This is a schematic diagram showing the planetary gear and the ring gear in an assembled state according to an embodiment of this application;

[0030] Figure 10 This is a schematic diagram of a joint actuator in related technologies, showing the push rod in its initial position;

[0031] Figure 11This is a schematic diagram of a joint actuator in related technologies, showing the push rod at its maximum stroke. Detailed Implementation

[0032] The technical solutions in the embodiments (or "implementations") of this application will be clearly and completely described herein with reference to the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numbers in different drawings represent the same or similar elements.

[0033] If the embodiments of this application contain terms relating to directional indications or positional relationships (such as up, down, left, right, front, back, inside, outside, top, bottom, center, vertical, horizontal, longitudinal, transverse, length, width, counterclockwise, clockwise, axial, radial, circumferential, etc.), such terms are only used to explain the relative positional relationships and movements between components in a specific posture (as shown in the attached figures); if the specific posture changes, the directional indications or positional relationships will also change accordingly. Furthermore, the terms "first" and "second" used in the embodiments of this application are only for descriptive convenience and should not be construed as indicating or implying relative importance.

[0034] See Figure 6 and Figure 1 and combined Figures 2 to 5 This application discloses a transmission mechanism. The transmission mechanism is used in the joint actuator of a robot. The transmission mechanism 10 includes a motor shaft 11, a planetary gear reduction assembly 2, and a lead screw 3. The planetary gear reduction assembly 2 includes a first connecting end (e.g., a sun gear 22) and a second connecting end 211. The first connecting end (e.g., the sun gear 22) is connected to the motor shaft 11, so that rotation of the motor shaft 11 drives rotation of the first connecting end, thereby driving the planetary gear reduction assembly 2. Based on the reduction principle of the planetary gear reduction assembly 2, the first connecting end is not limited to the sun gear 22 of the planetary gear reduction assembly 2. In this application, the planetary gear reduction assembly 2 includes a planet carrier 21, a sun gear 22, planet gears 23, and a ring gear 24. See also... Figure 4 , Figure 5 and Figure 7 The planetary carrier 21 includes a disk 2101 for mounting planetary gears 23. More specifically, the disk 2101 is provided with a plurality of connecting posts 219, and the planetary gears 23 are mounted on the connecting posts 219. See also Figure 9 Planetary gear 23 also meshes with gear ring 24.

[0035] The planetary carrier 21 includes the second connecting end 211. (See also...) Figure 2 , Figure 3 , Figure 5 and Figure 7The second connecting end 211 includes a socket 2111. The second connecting end 211 is the part in the planetary gear reduction assembly 2 used for connection with the lead screw 3. In some embodiments, see [reference needed]. Figure 7 and combined Figure 6 The planetary carrier 21 further includes a column 2102 extending from the disk 2101. Depending on the position and function of the socket 2111, the second connecting end 211 includes at least a portion of the column 2102. In some embodiments of this application, the second connecting end 211 includes the central portion of the column 2102 and the disk 2101 (the central portion refers to a circular area with a certain radius centered on the center of the disk 2101, the radius being determined to satisfy the function of the socket 2111). See also... Figure 5 and Figure 7 The insertion hole 2111 includes a first insertion hole 21111 recessed into the center portion of the disk body and a second insertion hole 21112 penetrating the pillar 2102. The recess into the center portion of the disk body may or may not penetrate the center portion. The walls of the first insertion hole 21111 and a portion of the walls of the second insertion hole 21112 are provided with threads. In other embodiments, all walls of both the first insertion hole 21111 and the second insertion hole 21112 may be threaded.

[0036] As described above, the insertion hole 2111 includes a first insertion hole 21111 recessed into the center portion of the disc body and a second insertion hole 21112 penetrating the column 2102. The holes of the first insertion hole 21111 and at least a portion of the holes of the second insertion hole 21112 are threaded. The lead screw 3 is threaded not only to the hole wall of the second insertion hole 21112 but also to the first insertion hole 21111 of the disc body 2101, which further reduces the axial dimension of the transmission mechanism.

[0037] See Figure 1 and Figure 6 The lead screw 3 is inserted into the socket 2111 and threadedly connected to the wall of the socket 2111. This can be understood as the assembly relationship between the lead screw 3 and the socket 2111, forming the output end of the planetary gear reduction assembly 2. Thus, the motor shaft 11 drives the first connecting end (e.g., the sun gear 22), and the first connecting end drives the second connecting end 211 through the gear transmission of the planetary gear reduction assembly 2; the second connecting end 211 drives the lead screw 3 through the threaded connection.

[0038] As described above, since the planetary gear reduction assembly 2 includes a second connecting end 211, which includes a socket 2111, and the lead screw 3 is inserted into the socket 2111 and threadedly connected to the wall of the socket 2111, the axial dimension of the transmission mechanism is short, which helps to reduce the size of the transmission mechanism and thus facilitates the miniaturization of the joint actuator. Furthermore, because the connection method of inserting the lead screw 3 into the second connecting end 211 and threading it in also reduces the length of the second connecting end 211, it also helps to reduce the axial dimension of the transmission mechanism, saves materials, and reduces the cost of the transmission mechanism.

[0039] To more intuitively understand the aforementioned beneficial effects of the transmission mechanism of this application, this application will be compared with... Figure 10 and Figure 11 The relevant technologies shown are compared and analyzed as follows:

[0040] exist Figure 10 and Figure 11 In the illustrated embodiment, the planetary gear reduction assembly 2 includes a planet carrier 21. The planet carrier 21 includes a threaded section 2190. The push rod 9 is threadedly connected to the threaded section 2190 via a nut 91, and an anti-rotation structure is provided between the nut 91 and the housing 20. Thus, rotation of the motor shaft 11 will cause the planet carrier 21 to rotate, and the planet carrier 21 will drive the threaded section 2190 to rotate. Through the cooperation of the threaded section 2190 and the nut 91, and under the action of the anti-rotation structure, the push rod 9 moves linearly. Figure 11 This shows push rod 9 extended to its maximum travel. Figure 10 and Figure 11 In the illustrated embodiment, a nut 91 is required. However, in this application, the nut 91 is replaced by the wall of the insertion hole 2111 of the second connecting end 211. Therefore, at least the axial dimension of a nut 91 is saved. Furthermore, the threaded section 2190 is not required (because the thread in this application is inside the second connecting end 211, which is shorter than the threaded section 2190). This is beneficial for reducing the axial dimension of the transmission mechanism and also saves materials and thus reduces costs.

[0041] See Figures 1 to 6 The planetary carrier 21 includes the second connecting end 211. Based on the deceleration principle of the planetary gear reduction assembly 2, in some cases, the planetary carrier 21 is fixed, the sun gear 22 is active, and the ring gear 24 is passive, which can also achieve the purpose of deceleration. Therefore, in some embodiments, the ring gear 24 includes the second connecting end 211.

[0042] As described above, although both the gear ring 24 including the second connecting end 211 and the planet carrier 21 including the second connecting end 211 can achieve the aforementioned beneficial effects, the implementation of the planet carrier 21 including the second connecting end 211 makes the structure of the transmission mechanism simpler and easier to implement. In addition, because the planet carrier 21 is smaller than the gear ring 24, the implementation of the planet carrier 21 including the second connecting end 211 makes the space occupied by the transmission mechanism relatively smaller, and also makes the moment of inertia smaller and the speed ratio larger.

[0043] See Figure 8 and Figure 6 and combined Figures 1 to 5 The planetary gear reduction assembly 2 includes a sun gear 22. The sun gear 22 is the first connecting end, and the sun gear 22 is connected to the motor shaft 11 as an integral structure. The integral structure can be formed in various ways, such as integral injection molding or 3D printing, etc., and this application embodiment does not make specific limitations.

[0044] As described above, the sun gear 22 and the motor shaft 11 are connected as a single unit. This improves the concentricity between the sun gear 22 and the motor shaft 11, thereby preventing jamming and other issues caused by misalignment.

[0045] See Figure 6 and Figure 1 The integrated structure includes a receiving hole 111 communicating with the insertion hole 2111. During retraction, the lead screw 3 is also inserted into the receiving hole 111. Although the receiving hole 111 passes through the motor shaft 11 in one embodiment of this application, in other embodiments of this application, the receiving hole 111 may not pass through the motor shaft 11.

[0046] As described above, the sun gear 22 is connected to the motor shaft 11 as an integral structure, and the receiving hole 111 is formed in the integral structure. The lead screw 3 is also inserted into the receiving hole 111 during the retraction process, which helps to reduce the axial dimension of the transmission mechanism, thereby facilitating the miniaturization of the joint actuator.

[0047] In some embodiments, the lead screw 3 is a trapezoidal lead screw. Of course, in this application, the lead screw 3 is not limited to a trapezoidal lead screw.

[0048] As described above, combining the planetary gear reducer 2 with the trapezoidal lead screw reduces the cost of the lead screw 3. In some transmission mechanisms that omit the planetary gear reducer 2 and use a pure lead screw, the lack of the planetary gear reducer's speed reduction and torque amplification necessitates high transmission efficiency from the pure lead screw. In such cases, a ball / roller lead screw is required, leading to high cost. However, in this application, because the planetary gear reducer 2 is combined with the trapezoidal lead screw, the planetary gear reducer 2 already provides speed reduction and torque amplification. Therefore, the lead screw 3 does not need to use a ball / roller lead screw, resulting in lower cost.

[0049] See Figure 1 and combined Figures 2 to 6 Secondly, this application discloses a joint actuator. The joint actuator includes any of the aforementioned transmission mechanisms 10 and a motor 1. The motor 1 includes the motor shaft 11.

[0050] As described above, the joint actuator has at least the beneficial effects of the transmission mechanism, which will not be elaborated further.

[0051] See Figure 1 and combined Figures 2 to 6 The joint actuator includes a housing 20. The transmission mechanism 10 includes a second connecting end support 30. The second connecting end 211 is rotatably connected to the housing 20 via the second connecting end support 30; that is, the housing 20 remains stationary while the second connecting end 211 rotates. In this application, the second connecting end support 30 is sleeved onto the second connecting end 211, and the locking nut 90 is... Figure 7 The locking section 21021 of the column 2102 shown is threaded to limit the second connecting end support 30.

[0052] As described above, the transmission mechanism 10 can be effectively supported by the rotatable connection between the second connecting end support member 30 and the housing 20.

[0053] In some embodiments, the housing 20 includes a housing end. The transmission mechanism or the joint actuator includes an end support 40. The end support 40 is located at the housing end and is passed through by the lead screw 3. After passing through the end support 40, the lead screw 3 extends out of the housing 20 from the housing end. In this application, the threaded engagement of the lead screw 3 with the socket 2111 causes the lead screw 3 to rotate, and then the lead screw 3 moves linearly through the engagement of the lead screw 3 with the end support 40 (e.g., through a flat engagement).

[0054] As described above, by setting the second connecting end support 30 and the end support 40, the second connecting end support 30 acts as fulcrum A and the end support 40 acts as fulcrum B to support the lead screw 3. Furthermore, because the lead screw 3 is inserted into the second connecting end 211, neither fulcrum A nor fulcrum B moves during the extension and retraction of the lead screw 3, thus providing good stability and rigidity for the support of the lead screw 3. Figure 10 and Figure 11 In the illustrated embodiment, because the nut 91 engages with the threaded section 2190, the nut 91 moves, causing the distance between fulcrum A and fulcrum B to change with the movement of the push rod 9. For example, during the extension of the push rod 9, the distance between fulcrum A and fulcrum B decreases, resulting in the extended portion of the push rod 9 forming a cantilever with fulcrum B, thus leading to poor support stability and rigidity. In contrast, in this application, the distance between fulcrum A and fulcrum B does not change, preventing the aforementioned cantilever, thereby achieving good support stability and rigidity.

[0055] In some embodiments, the transmission mechanism or the joint actuator may only have the second connecting end support 30.

[0056] In some embodiments, the second connecting end support 30 is a rolling bearing or a bushing. In other embodiments, the end support 40 is a rolling bearing or a bushing.

[0057] As described above, regardless of whether the second connecting end support 30 is a rolling bearing or a bushing, or whether the end support 40 is a rolling bearing or a bushing, the joint actuator can have a simple structure, good support stability, and low friction loss.

[0058] See Figure 1 The inner wall of the housing 20 is provided with a mounting groove 201 that is recessed in the radial direction of the motor shaft, and the second connecting end support 30 is fixed in the mounting groove 201.

[0059] As described above, since the mounting groove 201 is recessed radially on the motor shaft, the second connecting end support 30 is axially constrained by fixing it within the mounting groove 201. This prevents the second connecting end support 30 from shifting during the movement of the lead screw 3, ensuring good support stability for the lead screw 3 and guaranteeing the axial movement accuracy of the lead screw 3. Furthermore, by fixing the second connecting end support 30 within the mounting groove 201, the distance between fulcrum A and fulcrum B remains unchanged during the movement of the lead screw 3, resulting in good support stability and rigidity.

[0060] See Figure 1The joint actuator includes a housing 20, the transmission mechanism 10 (motor shaft 11 and planetary gear reduction assembly 2) is located within the housing 20, and the lead screw 3 extends out of the housing 20. See also Figure 8 The motor shaft 11 includes a motor shaft end 112 connected to a first connecting end (in this embodiment, the first connecting end is the sun gear 22). See also Figure 1 and combined Figure 8 and Figure 2 The joint actuator (or the transmission mechanism 10) includes a motor shaft support 50. The end portion 112 of the motor shaft is rotatably connected to the housing 20 via the motor shaft support 50. Figure 1 In the middle, a shim 501 is provided between the planetary gear 23 and the motor shaft support 50, and the planetary gear 23 and the motor shaft support 50 are located on opposite sides of the shim 501.

[0061] As described above, since the motor shaft support 50 is provided at the end 112 of the motor shaft and the motor shaft support 50 is close to the planetary carrier 21, the concentricity between the motor shaft 11, the planetary gear reduction assembly 2 and the lead screw 3 is improved, the transmission mechanism is less likely to jam during the movement, and the lead screw 3 can move in a straight line better.

[0062] Thirdly, this application discloses a robotic hand. The robotic hand includes any of the aforementioned joint actuators, or any of the aforementioned transmission mechanisms. The robotic hand can be a dexterous hand, a robotic arm, etc.

[0063] Thirdly, this application discloses a robot. The robot includes any of the aforementioned joint actuators, or any of the aforementioned transmission mechanisms. The robot may include a robotic hand, a robotic arm, or a humanoid robot, etc.

[0064] As described above, the robot includes at least the beneficial effects of the joint actuator, or the beneficial effects of the transmission mechanism.

[0065] It should be noted that the technical solutions or features described in the above embodiments can be combined or supplemented with each other without conflict. The scope of protection of this application is not limited to the precise structures described in the above embodiments and shown in the accompanying drawings; all modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of protection of this application.

Claims

1. A transmission mechanism, characterized in that, The transmission mechanism includes a motor shaft, a planetary gear reduction assembly, and a lead screw, wherein: The planetary gear reduction assembly includes a first connecting end and a second connecting end; the first connecting end is connected to the motor shaft; the second connecting end includes a socket. The lead screw is inserted into the socket and threadedly connected to the wall of the socket; the motor shaft drives the first connecting end, and the first connecting end drives the second connecting end through gear transmission; the second connecting end drives the lead screw through the threaded connection.

2. The transmission mechanism according to claim 1, characterized in that, The planetary gear reduction assembly includes a ring gear and a planet carrier, wherein the planet carrier includes the second connecting end, or the ring gear includes the second connecting end.

3. The transmission mechanism according to claim 2, characterized in that, The planetary gear reduction assembly includes a sun gear, the first connecting end is the sun gear, and the sun gear is connected to the motor shaft as an integral structure.

4. The transmission mechanism according to claim 3, characterized in that, The integrated structure includes a receiving hole communicating with the socket; the lead screw is also inserted into the receiving hole during retraction.

5. The transmission mechanism according to any one of claims 2 to 4, characterized in that, The planetary carrier includes a disc for mounting planetary gears and a column extending from the disc. The second connecting end includes the column and a central portion of the disc. The insertion hole includes a first insertion hole recessed into the interior of the central portion of the disc and a second insertion hole penetrating the column. The wall of the first insertion hole and at least a portion of the wall of the second insertion hole are provided with the threads.

6. The transmission mechanism according to claim 1, characterized in that, The lead screw is a trapezoidal lead screw.

7. A joint actuator, characterized in that, The joint actuator includes the transmission mechanism as described in any one of claims 1 to 6.

8. The joint actuator according to claim 7, characterized in that, The joint actuator includes a housing, and the transmission mechanism further includes a second connecting end support member; the second connecting end is rotatably connected to the housing through the second connecting end support member.

9. The joint actuator according to claim 8, characterized in that, The housing includes a housing end; the transmission mechanism further includes an end support member located at the housing end and passed through by the lead screw, the lead screw extending out of the housing from the housing end.

10. The joint actuator according to claim 9, characterized in that, The second connecting end support is a rolling bearing or a bushing; And / or, the end support is a rolling bearing or a bushing.

11. The joint actuator according to claim 8, characterized in that, The inner wall of the housing is provided with a mounting groove recessed radially on the motor shaft, and the second connecting end support is fixed in the mounting groove.

12. The joint actuator according to claim 7, characterized in that, The joint actuator includes a housing, the motor shaft and the planetary gear reduction assembly are located inside the housing, and the lead screw extends out of the housing; The motor shaft includes a motor shaft end connected to the first connecting end; the transmission mechanism includes a motor shaft support member, and the motor shaft end is rotatably connected to the housing through the motor shaft support member.

13. A robotic arm, characterized in that, The robotic arm includes a joint actuator as described in any one of claims 7 to 12, or the robotic arm includes a transmission mechanism as described in any one of claims 1 to 6.

14. A robot, characterized in that, The robot includes a joint actuator as described in any one of claims 7 to 12, or a transmission mechanism as described in any one of claims 1 to 6.

Images