Joint actuators, robotic arms and robots

Abstract

This disclosure provides an articulated actuator, a manipulator, and a robot. The articulated actuator includes a housing, a drive motor, and a transmission component. The drive motor is assembled within the housing and includes a stator and a rotor, with the rotor including an output shaft. The transmission component is movably assembled within the housing and threadedly connected to the output shaft to perform axial extension and retraction motion as the output shaft rotates. Because the transmission component is directly threadedly connected to the output shaft of the drive motor to achieve axial extension and retraction, the output shaft of the drive motor acts as the nut of a lead screw assembly, and the transmission component acts as the screw of the lead screw assembly, converting the rotation of the nut into the linear motion of the screw. This reduces the space occupation and reduced transmission efficiency caused by placing transmission components between the transmission component and the drive motor, contributing to improved transmission efficiency, response speed, motion reliability, and miniaturization of the articulated actuator and robot.

Description

Technical Field

[0001] This disclosure relates to the field of robotics, and in particular to articulated actuators, manipulators, and robots. Background Technology

[0002] Lead screw drives can convert the rotational motion of the drive motor output shaft into the linear motion of the transmission components using a threaded structure. They have advantages such as high transmission accuracy, strong load-bearing capacity, and simple and reliable structure, making them suitable for linear motion scenarios such as joint actuators.

[0003] However, the structure and transmission method of the lead screw drive pair in related technologies often suffer from problems such as complex structure and low integration, which affect the miniaturization and overall reliability of joint actuators and robots. Utility Model Content

[0004] This disclosure provides an articulated actuator, a manipulator, and a robot to solve related technical problems.

[0005] The first aspect of this disclosure provides a joint actuator, comprising:

[0006] chassis;

[0007] A drive motor is assembled inside the housing; the drive motor includes a stator and a rotor, and the rotor includes an output shaft.

[0008] A transmission component is movably assembled to the housing; the transmission component is threadedly connected to the output shaft so as to extend and retract along the axial direction of the output shaft as the output shaft rotates.

[0009] Optionally, the output shaft has a travel space that extends axially from the first end of the output shaft; the inner wall of the travel space has a first threaded section, and the transmission component has a second threaded section, wherein the first threaded section and the second threaded section cooperate to make the transmission component threadedly connected to the output shaft.

[0010] Optionally, a first limiting structure is provided within the travel space to limit the retracted position of the transmission member in the axial direction.

[0011] Optionally, it also includes a sliding bearing assembled to the housing; the transmission component includes a transmission body and a second limiting structure, the transmission body passing through the bushing mating hole of the sliding bearing; the second limiting structure protrudes radially from the transmission body to limit the extension position of the transmission component in the axial direction.

[0012] Optionally, the joint actuator further includes a first bearing and a second bearing, the outer rings of the first bearing and the second bearing being fixedly assembled to the housing; the output shaft includes a first section and a second section, the inner ring of the first bearing being fitted into the first section, and the inner ring of the second bearing being fitted into the second section.

[0013] Optionally, the joint actuator further includes a sliding bearing assembled in the housing; the bushing mating hole of the sliding bearing includes at least one anti-rotation structure, and the transmission member passes through the bushing mating hole to limit the rotation of the transmission member.

[0014] Optionally, the anti-rotation structure includes a planar structure disposed on the inner wall of the bushing mating hole.

[0015] Optionally, the rotor portion includes a motor magnet assembled on the output shaft, and the joint actuator further includes an encoder disposed within the housing, the encoder obtaining high-speed end position feedback based on the motor magnet.

[0016] Optionally, the transmission component is provided with an induction magnet, and the joint actuator further includes a drive control board and a magnetic element disposed within the housing. The magnetic element obtains low-speed end position feedback based on the induction magnet; the magnetic element and / or the encoder are disposed on the drive control board.

[0017] Optionally, the center of the magnetic element is coplanar with the center of the inductive magnet; and / or, the center of the encoder is coplanar with the center of the motor magnet.

[0018] According to a second aspect of this disclosure, a robotic hand is provided, the robot comprising any of the joint actuators described in the first aspect.

[0019] A robot is provided according to a third aspect of this disclosure, the robot comprising any of the joint actuators described in the first aspect, or the manipulator described in the second aspect.

[0020] The technical solution provided in this disclosure can achieve at least the following beneficial effects:

[0021] This disclosure discloses a transmission component that is directly threaded to the output shaft of a drive motor to achieve axial telescopic motion. The output shaft of the drive motor acts as the nut of a lead screw assembly, and the transmission component acts as the screw of the lead screw assembly, converting the rotation of the nut into the linear motion of the screw. This structural design reduces the space occupation and reduced transmission efficiency caused by placing transmission components between the transmission component and the drive motor, contributing to improved motion reliability of the joint actuator and enabling miniaturization of the joint actuator and robot.

[0022] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and are not intended to limit this specification. Attached Figure Description

[0023] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with this specification and, together with the description, serve to explain the principles of this specification.

[0024] Figure 1 This is a schematic cross-sectional view of a joint actuator according to an exemplary embodiment of the present disclosure;

[0025] Figure 2 This is an exploded structural diagram of a joint actuator according to an exemplary embodiment of the present disclosure;

[0026] Figure 3 This is a schematic diagram of the cooperation structure between a transmission component and an output shaft in an exemplary embodiment of this disclosure;

[0027] Figure 4 This is a schematic diagram of the structure of a sliding bearing according to an exemplary embodiment of this disclosure. Detailed Implementation

[0028] Exemplary embodiments will now be described in detail, examples of which are illustrated in the accompanying drawings. When the following description relates to the drawings, unless otherwise indicated, the same numerals in different drawings denote the same or similar elements. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with this specification. Rather, they are merely examples of apparatuses and methods consistent with some aspects of this specification as detailed in the appended claims.

[0029] The terminology used in this disclosure is for the purpose of describing particular embodiments only and is not intended to limit the disclosure. Unless otherwise defined, the technical or scientific terms used in this specification should be understood in their ordinary sense by one of ordinary skill in the art to which this disclosure pertains. The terms “first,” “second,” and similar terms used in this specification and claims do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Similarly, “a” or “one,” and similar terms do not indicate a quantity limitation, but rather indicate the presence of one. “A plurality” or “several” indicates two or more. Unless otherwise indicated, the terms “front,” “rear,” “lower,” and / or “upper,” and similar terms are for ease of description only and are not limited to a location or spatial orientation. The terms “comprising,” “including,” and similar terms mean that the elements or objects preceding “comprising,” encompass the elements or objects listed following “comprising,” and their equivalents, and do not exclude other elements or objects. The terms “connected,” “linked,” and similar terms are not limited to physical or mechanical connections and can include electrical connections, whether direct or indirect.

[0030] The terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to be limiting of this disclosure. The singular forms “a,” “the,” and “the” as used in this specification and the appended claims are also intended to include the plural forms unless the context clearly indicates otherwise. It should also be understood that the term “and / or” as used herein refers to and includes any and all possible combinations of one or more of the associated listed items.

[0031] Lead screw drives can convert the rotational motion of the drive motor output shaft into the linear motion of the transmission component using a threaded structure. They offer advantages such as high transmission accuracy, strong load-bearing capacity, and simple and reliable structure, making them suitable for linear motion scenarios, such as articulated actuators. However, the structures and transmission methods of lead screw drives in related technologies often suffer from complex structures and low integration, affecting the miniaturization and overall reliability of articulated actuators and robots.

[0032] This disclosure provides a joint actuator. Figure 1 This is a schematic cross-sectional view of a joint actuator according to an exemplary embodiment of this disclosure. Figure 2 This is an exploded structural diagram of a joint actuator according to an exemplary embodiment of this disclosure, as shown below. Figure 1 , Figure 2As shown, the joint actuator 1 includes a housing 11, a drive motor 12, and a transmission component 13. The drive motor 12 is assembled inside the housing 11 and includes a stator portion 123 and a rotor portion 124. The rotor portion 124 includes an output shaft 121. The transmission component 13 is movably assembled to the housing 11 and is threadedly connected to the output shaft 121 to perform telescopic movement along the axial direction of the output shaft 121 as the output shaft 121 rotates.

[0033] The stator part 123 can be fixedly assembled to the housing 11, and the rotor part 124 can rotate relative to the stator part.

[0034] Since the aforementioned transmission component 13 is directly threaded to the output shaft 121 of the drive motor 12 to obtain axial extension and retraction, the output shaft 121 of the drive motor 12 is used as the nut of the lead screw pair, and the transmission component 13 is used as the screw of the lead screw pair. The rotation of the nut is converted into the linear motion of the screw. Therefore, the space occupation and transmission efficiency reduction caused by setting transmission components between the transmission component 13 and the drive motor 12 are reduced. This helps to improve the transmission efficiency, response speed, motion reliability of the joint actuator 1 and realize the miniaturization of the joint actuator 1 and the robot.

[0035] In some embodiments, such as Figures 1-3 As shown, the output shaft 121 has a travel space 1211, which extends axially from the first end of the output shaft 121. The inner wall of the travel space 1211 has a first threaded section 1214, and the transmission member 13 has a second threaded section 131. The first threaded section 1214 and the second threaded section 131 cooperate to make the transmission member 13 threadedly connected to the output shaft 121. When the output shaft 121 of the drive motor 12 rotates, the transmission member 13 obtains linear extension and retraction motion along the axial direction based on the threaded transmission of the first threaded section 1214 and the second threaded section 131. When the transmission member 13 retracts toward the drive motor 12, it can be stored in the travel space 1211. Therefore, it helps to reduce the space occupation of the transmission member 13 during the movement, improve the space utilization of the drive motor 12, and improve the integration of the joint actuator 1.

[0036] In some embodiments, such as Figure 1As shown, a first limiting structure 14 may be provided within the stroke space 1211 to limit the axial retraction position of the transmission component 13, preventing the transmission component 13 from exceeding its limit retraction position, which could lead to the failure to achieve the expected motion trajectory or cause other structural interference. The motion trajectory of the transmission component 13 can also be adjusted by the setting position and size of the first limiting structure 14. The aforementioned first limiting structure 14 may be a columnar first limiting structure 14 assembled at the second end of the stroke space 1211 away from the first end. The second end of the stroke space 1211 may be provided with a positioning groove that matches the first limiting structure 14. One end of the first limiting structure 14 is assembled into the positioning groove to improve the installation accuracy and reliability of the first limiting structure 14.

[0037] In other embodiments, a stroke hole may be provided at the end of the transmission member 13 facing the drive motor 12, and a second threaded segment 131 may be provided in the stroke hole. The output shaft 121 may have a first threaded segment 1214, which engages with the second threaded segment 131 to thread the transmission member 13 to the output shaft 121. Similarly, when the output shaft 121 of the drive motor 12 rotates, the transmission member 13 obtains linear extension and retraction along the axial direction based on the threaded transmission of the first threaded segment 1214 and the second threaded segment 131. When the transmission member 13 retracts toward the drive motor 12, the output shaft 121 can be retracted into the stroke hole, thus helping to reduce the space occupied by the transmission member 13 during movement and reduce the size of the joint actuator 1.

[0038] It should be noted that the screw pair formed between the aforementioned transmission component 13 and the output shaft 121 can be a ball screw pair, a planetary roller screw pair, a trapezoidal screw pair, etc. When the screw pair is a ball screw pair, it can be a direct or inverse ball screw. In a direct ball screw, the thread length of the second thread segment 131 on the transmission component 13 is longer than the length of the first thread segment 1214 on the output shaft 121. In an inverse ball screw, the thread length of the first nut segment on the output shaft 121 is longer than the length of the second thread segment 131 on the transmission component 13.

[0039] In some embodiments, the joint actuator 1 may further include a sliding bearing 19 assembled to the housing 11, and the transmission member 13 includes a transmission body 132 and a second limiting structure. The transmission body 132 passes through the bushing mating hole 191 of the sliding bearing 19, and the second limiting structure protrudes radially from the transmission body 132 to limit the axial extension position of the transmission member 13. The cooperation of the first limiting structure 14 and the second limiting structure can limit the extension limit position and retraction limit position of the transmission member 13 in the axial direction, thereby improving the movement reliability of the transmission member 13.

[0040] The second limiting structure can be a protrusion on the transmission body 132 or a magnet mounting base 21 assembled on the transmission body 132. This disclosure does not limit the specific setting scheme of the second limiting structure.

[0041] In some embodiments, the joint actuator 1 may further include a first bearing 15 and a second bearing 16. The outer rings of the first bearing 15 and the second bearing 16 are fixedly assembled to the housing 11. The output shaft 121 includes a first section and a second section. The inner ring of the first bearing 15 is fitted into the first section, and the inner ring of the second bearing 16 is fitted into the second section. The first bearing 15 and the second bearing 16 provide radial support for the output shaft 121 and bear axial loads, thereby improving the transmission reliability of the output shaft 121.

[0042] The connection between the outer rings of the first bearing 15 and the second bearing 16 and the housing 11 can be a fixed connection such as welding or bonding, or a detachable connection such as snap-fitting. This disclosure does not limit this connection.

[0043] It should be noted that the first bearing 15 and the second bearing 16 mentioned above can be a four-point contact bearing, a deep groove ball bearing, an angular contact ball bearing, or other types of bearings. This disclosure does not limit them.

[0044] Among them, such as Figure 1 , Figure 3 As shown, Figure 1 The dashed arrow can represent the first direction, and the dotted-line arrow can represent the second direction. The stroke space 1211 can be a through hole provided in the output shaft 121. In the above embodiment, the housing 11 can include a first housing 111 and an end cover 113 assembled to one axial end of the first housing 111. The second end of the output shaft 121 abuts against the end cover 113. The inner side of the end cover 113 is provided with an extension structure extending into the through hole to realize the positioning assembly between the end cover 113 and the output shaft 121. The inner edge of the end cover 113 can be provided with a positioning edge 1131, which is inserted into the first space 1111 enclosed by the first housing 111 to realize the positioning assembly. The outer ring of the first bearing 15 can be assembled and fixed with the positioning edge 1131, and the axial ends of the inner and outer rings of the first bearing 15 abut against the inner side of the end cover 113 to realize the axial limitation of the inner and outer rings of the first bearing 15 along the first direction. The outer side wall of the second end of the output shaft 121 may be provided with a first limiting recess 1213 for assembling the inner ring of the first bearing 15, so as to achieve axial limiting of the inner ring of the first bearing 15 along the second direction.

[0045] The first end of the output shaft 121 may be provided with a limiting protrusion 1212 protruding radially from the outer side wall. A locking nut 17 may also be mounted on the output shaft 121, forming an assembly groove with the limiting protrusion 1212. The inner ring of the second bearing 16 is installed in the aforementioned assembly groove to axially limit the inner ring of the second bearing 16 in the first and second directions. The housing 11 may be provided with a second limiting recess 1112, and the outer ring of the second bearing 16 is assembled in the second limiting recess 1112 to axially limit the outer ring of the second bearing 16 in the first and second directions.

[0046] Furthermore, such as Figure 3 As shown, the aforementioned housing 11 may include a first housing 111, a second housing 112, and a third housing 114 located radially on one side of the first housing 111 and the second housing 112. The assembly of the first housing 111, the second housing 112, and the third housing 114 to form the entire housing 11 facilitates manufacturing and also helps in the internal structural installation of the joint actuator 1. The drive motor 12 is assembled in the first space 1111 enclosed by the first housing 111 and the third housing 114. The second space 1121 enclosed by the second housing 112 and the third housing 114 can provide movement space for the transmission component 13 and also provide assembly space for other components of the joint actuator 1.

[0047] In some embodiments, such as Figure 1 , Figure 4 As shown, the joint actuator 1 also includes a sliding bearing 19 assembled in the housing 11. The transmission member 13 passes through the bearing mating hole 191 of the sliding bearing 19. The sliding bearing 19 provides axial guidance for the transmission member 13 and reduces friction. The bushing mating hole 191 of the sliding bearing 19 includes at least one anti-rotation structure 1911. The transmission member 13 passes through the bushing mating hole 191 to limit the rotation of the transmission member 13 and improve the transmission efficiency of the output shaft 121 and the transmission member 13 in converting rotation into linear motion.

[0048] The anti-rotation structure 1911 includes a planar structure disposed on the inner wall of the bushing mating hole 191. The transmission member 13 may be provided with a structure matching the axial mating hole structure, so as to guide the transmission member 13 during relative sliding with respect to the bushing mating hole 191. For example, there may be two, three or more planar structures to obtain a shape in which a circular hole contains multiple planar structures. Or, for example, there may be one planar structure to obtain a shape in which a circular hole contains one planar structure. Alternatively, the bushing mating hole 191 may also be directly formed into a polygonal structure.

[0049] The bearing housing of the aforementioned sliding bearing 19 can be assembled to the end of the housing 11 in the second direction, and the transmission component 13 extends from the bushing mating hole 191 to achieve the telescopic movement along the expected trajectory. The connection between the bearing housing of the aforementioned sliding bearing 19 and the housing 11 can be a fixed connection such as welding or bonding, or a detachable connection such as snap-fit; this disclosure does not impose any limitations on this.

[0050] In some embodiments, the rotor portion 124 includes a motor magnet 122 assembled to the output shaft 121, and the joint actuator 1 also includes an encoder 181 disposed within the housing 11. The encoder 181 obtains high-speed end position feedback based on the motor magnet 122. By utilizing the induction between the motor magnet 122 and the encoder 181 to obtain high-speed end position feedback, it is avoided to separately install the induction magnet 20 on the output shaft 121, which helps to reduce cost and space occupation.

[0051] The aforementioned motor magnet 122 can have multiple pole pairs or a single pole pair. It can be a segmented magnetic tile or an integral magnetic ring. When the motor magnet 122 is a magnetic ring, its magnetization method can be parallel magnetization or Hellbeck array magnetization. When the motor magnet 122 is magnetized by a Hellbeck array, the output shaft 121 of the drive motor 12 does not need to be made of a magnetically conductive material.

[0052] It should be noted that the drive motor 12 mentioned above can be a slotless motor or other types of motors, and this disclosure does not limit it.

[0053] In some embodiments, the transmission component 13 is provided with a sensing magnet 20, and the joint actuator 1 also includes a drive control board 18 and a magnetic element 182 disposed in the housing 11. The magnetic element 182 obtains low-speed end position feedback based on the sensing magnet 20. The magnetic element 182 and / or encoder 181 are disposed on the drive control board 18 to improve the integration and control convenience of the joint actuator 1.

[0054] The transmission component 13 can be a rod. The rod can be provided with a magnet mounting base 21 in the section located in the second space 1121, and the induction magnet 20 is fixedly assembled on the magnet mounting base 21 to achieve assembly.

[0055] The magnetic element 182 can be a linear Hall effect sensor. The linear Hall effect sensor and the induction magnet 20 are non-contact sensors with high reliability, good linearity and consistency.

[0056] In some embodiments, the center of the magnetic element 182 and the center of the induction magnet 20 may be coplanar to improve sensing accuracy. And / or, the center of the motor magnet 122 and the center of the encoder 181 may be coplanar to improve sensing accuracy. The centers of the magnetic element 182 and the induction magnet 20 may refer to their structural centers; for example, when the magnetic element 182 and the induction magnet 20 are cubic structures, their centers may be the structural centers of the cube. The center of the induction magnet 20 may also refer to the center of the magnetic field. The centers of the motor magnet 122 and the encoder 181 may refer to their structural centers; for example, when the motor magnet 122 and the encoder 181 are cubic structures, their centers may be the structural centers of the cube. The center of the motor magnet 122 may also refer to the center of the magnetic field.

[0057] One embodiment of this disclosure provides a robotic hand, the robotic hand including the aforementioned joint actuator 1. In one embodiment, taking a dexterous hand as an example, the joint actuator 1 acts as the finger joints of the dexterous hand to execute operational commands.

[0058] One embodiment of this disclosure provides a robot, which includes the aforementioned joint actuator 1, or includes the aforementioned robotic arm.

[0059] It should be noted that the aforementioned robot can be a robotic hand, robotic arm, humanoid robot, or other types or shapes of robots, and this disclosure does not impose any limitations on this. Among them, the aforementioned robotic hand can be a gripper robotic hand or a dexterous hand.

[0060] Since the aforementioned transmission component 13 is directly threaded to the output shaft 121 of the drive motor 12 to obtain axial extension and retraction, the output shaft 121 of the drive motor 12 is used as the nut of the lead screw pair, and the transmission component 13 is used as the screw of the lead screw pair. The rotation of the nut is converted into the linear motion of the screw. Therefore, the space occupation and transmission efficiency reduction caused by setting transmission components between the transmission component 13 and the drive motor 12 are reduced. This helps to improve the transmission efficiency, response speed, motion reliability of the joint actuator 1 and realize the miniaturization of the joint actuator 1 and the robot.

[0061] The above description is merely a preferred embodiment of this disclosure and is not intended to limit this disclosure in any way. Although this disclosure has been disclosed above with reference to a preferred embodiment, it is not intended to limit this disclosure. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the technical solution of this disclosure. Any simple modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of this disclosure without departing from the content of the technical solution of this disclosure shall still fall within the scope of the technical solution of this disclosure.

Claims

1. A joint actuator, characterized in that, include: chassis; A drive motor is assembled inside the housing; the drive motor includes a stator and a rotor, and the rotor includes an output shaft. A transmission component is movably assembled to the housing; the transmission component is threadedly connected to the output shaft so as to extend and retract along the axial direction of the output shaft as the output shaft rotates.

2. The joint actuator according to claim 1, characterized in that, The output shaft has a travel space that extends axially from the first end of the output shaft. The inner wall of the travel space has a first threaded section, and the transmission component has a second threaded section. The first threaded section and the second threaded section cooperate to make the transmission component threadedly connected to the output shaft.

3. The joint actuator according to claim 2, characterized in that, The travel space is provided with a first limiting structure to limit the retraction position of the transmission component in the axial direction.

4. The joint actuator according to claim 1, characterized in that, It also includes a sliding bearing assembled in the housing; the transmission component includes a transmission body and a second limiting structure, the transmission body passing through the bushing fitting hole of the sliding bearing; the second limiting structure protrudes radially from the transmission body to limit the extension position of the transmission component in the axial direction.

5. The joint actuator according to claim 1, characterized in that, It also includes a first bearing and a second bearing, the outer rings of the first bearing and the second bearing being fixedly assembled to the housing; the output shaft includes a first section and a second section, the inner ring of the first bearing being fitted into the first section, and the inner ring of the second bearing being fitted into the second section.

6. The joint actuator according to claim 1, characterized in that, It also includes a sliding bearing assembled in the housing; the bushing fitting hole of the sliding bearing includes at least one anti-rotation structure, and the transmission member passes through the bushing fitting hole to limit the rotation of the transmission member.

7. The joint actuator according to claim 6, characterized in that, The anti-rotation structure includes a planar structure disposed on the inner wall of the bushing mating hole.

8. The joint actuator according to claim 1, characterized in that, The rotor portion includes a motor magnet assembled on the output shaft, and the joint actuator also includes an encoder disposed within the housing, the encoder obtaining high-speed end position feedback based on the motor magnet.

9. The joint actuator according to claim 8, characterized in that, The transmission component is equipped with an induction magnet, and the joint actuator further includes a drive control board and a magnetic element disposed within the housing. The magnetic element obtains low-speed end position feedback based on the induction magnet. The magnetic element and / or the encoder are disposed on the drive control board.

10. The joint actuator according to claim 9, characterized in that, The center of the magnetic element is coplanar with the center of the inductive magnet; and / or, the center of the encoder is coplanar with the center of the motor magnet.

11. A robotic arm, characterized in that, Includes the joint actuator as described in any one of claims 1-10.

12. A robot, characterized in that, Includes the joint actuator as described in any one of claims 1-10, or includes the robotic arm as described in claim 11.

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