A motor driving assembly and a robot hand applying the same

Abstract

This invention relates to the field of motor technology, and particularly to a motor drive assembly and a robot hand using the same. The motor drive assembly includes a rotating shaft, a transmission device, a housing, and a drive unit housed within the housing. Specifically, the drive unit may be an axial flux motor. The transmission device includes a transmission bracket, an eccentric wheel, a first bearing, a second bearing, and a reduction gear assembly. Along the axial direction of the rotating shaft, the second bearing, the eccentric wheel, and the drive unit are arranged sequentially. The outer ring of the reduction gear assembly is fixedly connected to the inner wall of the housing, and the inner ring of the reduction gear assembly is sleeved with the eccentric wheel through the first bearing. The end of the rotating shaft extends out of the housing and is provided with a transmission bracket, which is connected to the second bearing and linked to the reduction gear assembly. The transmission bracket is also connected to a linkage motor. The entire drive assembly features a compact structure, small size, and achieves high torque density and a low reduction ratio.

Description

Technical Field

[0001] This invention relates to the field of motor technology, and in particular to a motor drive assembly and a robot hand using the same. Background Technology

[0002] With the continuous development of the manufacturing industry and the constant updating and iteration of related products, various electrical products are developing towards integration, lightweighting, and miniaturization. As an indispensable driving device in most electrical products, the motor has always been a research hotspot.

[0003] In fields such as robotics, drones, and miniature articulated robotic arms, motors, as an important component of actuators, are facing increasingly higher requirements for lightweighting, miniaturization, and response speed.

[0004] However, existing motors are usually coreless motors, brushless DC motors, servo motors, etc., and are often combined with traditional reducers (such as planetary reducers), which results in technical problems such as low torque density and low reduction ratio in the overall structure. Summary of the Invention

[0005] To address the aforementioned technical problems, this application discloses, in one aspect, a motor drive assembly, which includes a rotating shaft, a transmission device, a housing, and a drive device disposed within the housing;

[0006] The drive device includes a stator and a rotor arranged sequentially at intervals along the axial direction of the shaft;

[0007] The transmission device includes a transmission bracket, an eccentric wheel, a first bearing, a second bearing, and a reduction assembly; the second bearing, the eccentric wheel, and the drive device are arranged sequentially along the axial direction of the rotating shaft; the outer ring of the reduction assembly is fixedly connected to the inner wall of the housing, and the inner ring of the reduction assembly is sleeved with the eccentric wheel through the first bearing;

[0008] The end of the rotating shaft extends out of the housing and is provided with the transmission bracket. The transmission bracket is connected to the second bearing and is linked to the reduction assembly. The transmission bracket is also connected to the linkage motor.

[0009] When the drive device drives the rotating shaft to rotate, the rotation of the rotating shaft can drive the rotation of the eccentric wheel connected to the rotating shaft, thereby sequentially driving the reduction gear connected to the eccentric wheel to perform eccentric motion, and the rotation of the transmission bracket linked to the reduction gear.

[0010] Optionally, the reduction assembly includes external teeth, internal teeth, multiple transmission pins, and multiple third bearings;

[0011] The outer ring of the outer tooth is fixedly connected to the inner wall of the housing, and the inner ring of the outer tooth is serrated and can mesh with the outer ring of the inner tooth.

[0012] The internal tooth has a first mounting hole in the middle, and the first mounting hole is sleeved with the first shaft.

[0013] The internal teeth are also provided with a plurality of second mounting holes surrounding the first mounting hole;

[0014] One end of each of the plurality of drive pins is connected to the drive bracket, and the other end of each drive pin is disposed in a corresponding second mounting hole through a third bearing; the diameter of the second mounting hole is larger than the diameter of the third bearing.

[0015] When the internal gear rotates to a preset angle under the drive of the rotating shaft, each of the third bearings can abut against the corresponding second mounting hole.

[0016] Optionally, the transmission bracket includes a first transmission structure and a second transmission structure connected together;

[0017] The first transmission structure has a third mounting hole in the middle, and the third mounting hole is connected to the second bearing;

[0018] The first transmission structure is also provided with a plurality of fourth mounting holes surrounding the third mounting hole;

[0019] Each of the fourth mounting holes is connected to a corresponding drive pin;

[0020] The second transmission structure is located outside the housing, and the length extension direction of the second transmission structure is parallel to the axial direction of the rotating shaft;

[0021] The second transmission structure is connected to the linkage motor.

[0022] Optionally, the transmission pin includes a first connecting segment and a second connecting segment; the diameter of the first connecting segment is larger than the diameter of the second connecting segment;

[0023] The first connecting segment is connected to the first transmission structure through the corresponding fourth mounting hole;

[0024] The second connecting segment is connected to the corresponding third bearing.

[0025] Optionally, the reduction ratio of the deceleration component is less than or equal to 1 / 20.

[0026] Optional features also include locating pins;

[0027] The positioning pin is located at the connection between the deceleration assembly and the housing;

[0028] The locating pin includes opposing first and second sides;

[0029] The first side is connected to the housing;

[0030] The second side is partially connected to the outer wall of the deceleration assembly and the stator.

[0031] Optional components also include a connecting frame and magnets;

[0032] The connecting frame includes a through hole and a groove, and the connecting frame is made of a non-magnetic material;

[0033] The bottom of the grooved part is provided with a through hole, and the through hole is connected to the end face of the through hole part to form an installation cavity that passes through the through hole part and the grooved part;

[0034] The first end of the rotating shaft is inserted into the through hole and connected to the through hole; the first end is the end of the rotating shaft that is away from the deceleration assembly.

[0035] The magnet is disposed in the groove.

[0036] Optionally, a control unit may also be included;

[0037] The control unit is located in the housing near the end of the magnet;

[0038] The control unit is used to determine the rotation angle of the rotating shaft by collecting the magnetic field changes of the magnet, thereby controlling the rotation of the drive device.

[0039] Optionally, the drive device includes a first sub-stator, a first sub-rotor, a second sub-stator, a second sub-rotor, and a third sub-stator arranged sequentially at intervals along the axial direction of the rotating shaft; the first sub-stator, the second sub-stator, and the third sub-stator are respectively connected to the rotating shaft via a fourth bearing, a fifth bearing, and a sixth bearing; the fifth bearing includes a first housing; the first housing has a first groove surrounding the rotating shaft; the first groove has a plurality of rolling elements; the first bearing is tactilely connected to the rotating shaft via the plurality of rolling elements; the outer wall of the first housing is sleeved with the second sub-stator;

[0040] The first sub-stator, the second sub-stator, and the third sub-stator are all printed circuit board stators.

[0041] In another aspect, this application also discloses a robotic hand comprising at least one finger joint; wherein the finger joint is provided with the aforementioned motor drive assembly.

[0042] This application provides a motor drive assembly, which includes a rotating shaft, a transmission device, a housing, and a drive unit disposed within the housing. The drive unit includes a stator and a rotor arranged sequentially at intervals along the axial direction of the rotating shaft. The transmission device includes a transmission bracket, an eccentric wheel, a first bearing, a second bearing, and a reduction assembly. The second bearing, the eccentric wheel, and the drive unit are arranged sequentially along the axial direction of the rotating shaft. The outer ring of the reduction assembly is fixedly connected to the inner wall of the housing, and the inner ring of the reduction assembly is sleeved with the eccentric wheel through the first bearing. The end of the rotating shaft extends out of the housing and is provided with a transmission bracket, which is connected to the second bearing and linked to the reduction assembly. The transmission bracket is connected to a linkage motor. Thus, when the drive unit drives the rotating shaft to rotate, the rotation of the rotating shaft can drive the rotation of the eccentric wheel connected to the rotating shaft, which in turn drives the reduction assembly connected to the eccentric wheel to perform eccentric motion, and the transmission bracket linked to the reduction assembly to rotate. The entire drive assembly not only has a compact structure and small size, achieving high torque density and low reduction ratio, but also enables the rotor, reduction assembly and transmission bracket to rotate in different directions and at different speeds, achieving more flexible transmission control. Attached Figure Description

[0043] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0044] Figure 1 This is a cross-sectional view of an exemplary motor drive assembly of this application;

[0045] Figure 2 A perspective view of a deceleration component exemplified in this application;

[0046] Figure 3 This is a cross-sectional view of another exemplary motor drive assembly of this application;

[0047] Figure 4 A perspective view of an exemplary motor drive assembly of this application;

[0048] Figure 5 This is a cross-sectional view of an axial flux motor exemplified in this application;

[0049] Figure 6 This is a schematic diagram of the structure of a rotor as exemplarily provided in this application;

[0050] Figure 7 This is an exemplary connection diagram of a stator yoke and a magnetic conductor in this application;

[0051] Figure 8A perspective view of a printed circuit board stator exemplified in this application;

[0052] Figure 9 A perspective view of another printed circuit board stator exemplified in this application;

[0053] Figure 10 This is a schematic diagram of a bushing structure that is an example of this application.

[0054] The following is supplementary explanation of the attached figures:

[0055] 1-Shaft; 101-Second channel;

[0056] 2-Transmission device; 201-Transmission bracket; 2011-First transmission structure; 2012-Second transmission structure; 2013-Third mounting hole; 2014-Fourth mounting hole; 202-Eccentric wheel; 203-First bearing; 204-Second bearing; 205-Reduction assembly; 206-External gear; 207-Internal gear; 2071-First mounting hole; 2072-Second mounting hole; 208-Transmission pin; 209-Third bearing;

[0057] 3-Housing; 301-First housing; 302-Second housing; 303-Third housing;

[0058] 4-Drive unit; 401-Stator; 402-Rotor; 403-First sub-stator; 404-Second sub-stator; 405-Third sub-stator; 406-First sub-rotor; 407-Second sub-rotor; 408-Stator yoke; 4081-Fifth mounting hole; 4082-Sixth mounting hole; 409-Magnetic conductor; 410-Printed circuit board; 411-Seventh mounting hole; 412-Epipolar wafer;

[0059] 5-Connecting bracket; 501-Through hole component; 502-Groove component;

[0060] 6-Magnetic components;

[0061] 7-Control unit;

[0062] 8-First slot;

[0063] 9-Second slot;

[0064] 10 - Third slot;

[0065] 11-Conductive components;

[0066] 12-First flexible circuit board;

[0067] 13-Second flexible circuit board;

[0068] 14-Third flexible circuit board;

[0069] 15 - Fourth bearing;

[0070] 16-Fifth bearing; 1601-First housing; 1602-First raceway; 1603-Rolling element;

[0071] 17-Sixth bearing;

[0072] 18- Heat dissipation holes;

[0073] 19-Magnetic steel frame;

[0074] 20-Magnetic steel;

[0075] 21-Three-phase lead wires;

[0076] 22-Magnetic sheet;

[0077] 23-Sleeve; 2301-Glue guide groove;

[0078] 24-Washer;

[0079] 25-High thermal conductivity adhesive;

[0080] 26-Positioning pin. Detailed Implementation

[0081] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0082] The term "an embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of this application. In the description of this application, it should be understood that the terms "upper," "lower," "top," "bottom," etc., indicating orientation or positional relationships based on the orientation or positional relationships shown in the accompanying drawings, are only for the convenience of describing this application 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, and therefore should not be construed as a limitation of this application. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. Moreover, the terms "first," "second," etc., are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of this application described herein can be implemented in orders other than those illustrated or described herein.

[0083] When a numerical range is disclosed herein, the range is considered continuous and includes the minimum and maximum values ​​of the range, as well as every value between the minimum and maximum values. Furthermore, when the range refers to an integer, it includes every integer between the minimum and maximum values ​​of the range. Additionally, when multiple ranges are provided to describe a feature or characteristic, the ranges may be combined. In other words, unless otherwise specified, all ranges disclosed herein should be understood to include any and all subranges to which they are included. For example, a specified range from “1 to 10” should be considered to include any and all subranges between the minimum value 1 and the maximum value 10. Exemplary subranges of the range 1 to 10 include, but are not limited to, 1 to 6.1, 3.5 to 7.8, 5.5 to 10, etc.

[0084] As a core device in the electrical field, the electric motor serves as a drive unit. It is not only a key device for converting electrical energy into mechanical energy, but also an important component for driving various mechanical equipment, achieving automated control, energy conservation and environmental protection, and power transmission and distribution. With continuous technological advancements, the application areas of electric motors will continue to expand and deepen. For example, robots, small drones, and high-end medical fields all require micromotors, driving the further development of micromotors towards higher efficiency, lighter weight, and lower cost.

[0085] Taking robots as an example, the robotic hand (also known as a dexterous hand), as a novel end effector for robots, is an important topic in robotics research, and research progress has accelerated both domestically and internationally in recent years. Since the 1970s, extensive research has been conducted on dexterous hands both at home and abroad, progressing from three fingers to five fingers, from industrial applications to everyday life, and from simple grasping to dexterous manipulation. Market stakeholders have continuously advanced research on dexterous hands in order to solve increasingly complex practical problems. With the accelerated industrialization of humanoid robots, research in the field of dexterous hands has also shown an accelerating trend both domestically and internationally.

[0086] Generally, robots interact with their environment primarily through: movement, acquisition of visual information, and execution of decisions. An end effector is a general term for robot execution components, typically installed at the end of the robot's wrist, and is the device that directly performs tasks. As the final link and execution component in the robot's interaction with the environment, the end effector plays a crucial role in improving the robot's flexibility and ease of use; its performance largely determines the overall performance of the robot. A dexterous hand, modeled after the structure and function of the human hand, plays a key role in the interaction between the robot and its environment. "Dexterity" refers to the variability of hand posture; the higher the variability, the more dexterous the hand is considered. Robotic dexterous hands, structurally and functionally based on the human hand, can flexibly manipulate objects, achieve flexible grasping, and meet various work requirements. Multi-fingered dexterous hands most commonly have 3-5 fingers, each with 3 joints, and the kinematic pairs of these finger joints are all revolute joints.

[0087] Because motor drives offer both precision and economy, they can be used as drive devices for finger joints. In motor-driven systems, the motor's torque and speed are controlled by a reducer, and then the rotational motion is converted into finger bending motion via other transmission devices. The drive system mainly consists of a motor and a reducer, and its advantages include small size, fast response, convenient adjustment, good stability, high precision, and stable output torque. The motors used include coreless motors and brushless cogging motors.

[0088] However, coreless motors, brushless DC motors, servo motors and other motors still have problems such as low structural compactness and low torque density. Furthermore, the drive system based on these motors and existing reducers (such as planetary reducers) also has problems such as low reduction ratio and large space occupation.

[0089] For this purpose, please refer to Figure 1The diagram shows a cross-sectional view of an exemplary motor drive assembly of this application. The motor drive assembly provided in this application includes a rotating shaft 1, a transmission device 2, a housing 3, and a drive device 4 disposed within the housing 3. Specifically, the drive device 4 may be an axial flux motor, including a stator 401 and a rotor 402. The transmission device 2 includes a transmission bracket 201, an eccentric wheel 202, a first bearing 203, a second bearing 204, and a reduction assembly 205. The second bearing 204, the eccentric wheel 202, and the drive device 4 are sequentially arranged along the axial direction of the rotating shaft 1. The outer ring of the reduction assembly 205 is fixedly connected to the inner wall of the housing 3, and the inner ring of the reduction assembly is sleeved with the eccentric wheel 202 through the first bearing 203. The end of the rotating shaft 1 extends out of the housing 3 and is provided with a transmission bracket 201. The transmission bracket 201 is connected to the second bearing 204 and is linked to the reduction assembly 205. The transmission bracket 201 is connected to the linkage motor. Thus, when the drive device 4 drives the rotating shaft 1 to rotate, the rotation of the rotating shaft 1 can drive the rotation of the eccentric wheel 202 connected to the rotating shaft 1, and then drive the reduction assembly 205 connected to the eccentric wheel 202 to perform eccentric motion, as well as the rotation of the transmission bracket 201 linked to the reduction assembly 205. The entire drive assembly not only has a compact structure and small size, achieving high torque density and low reduction ratio, but also enables the rotor 402, the reduction assembly 205 and the transmission bracket 201 to rotate in different directions and at different speeds, achieving more flexible transmission control.

[0090] In one feasible implementation, please refer to Figure 2 The reduction assembly 205 includes an external gear 206, an internal gear 207, multiple transmission pins 208, and multiple third bearings 209. The outer ring of the external gear 206 is fixedly connected to the inner wall of the housing 3, and the inner ring of the external gear 206 is serrated and can mesh with the outer ring of the internal gear 207. The internal gear 207 has a first mounting hole 2071 in the middle, which is connected to the first bushing 23. The internal gear 207 also has multiple second mounting pins surrounding the first mounting hole 2071. Hole 2072; one end of each of the plurality of transmission pins 208 is connected to the transmission bracket 201, and the other end of each transmission pin 208 is disposed in a corresponding second mounting hole 2072 through a third bearing 209; the diameter of the second mounting hole 2072 is larger than the diameter of the third bearing 209; when the internal gear 207 rotates to a preset angle under the drive of the rotating shaft 1, each third bearing 209 can abut against the corresponding second mounting hole 2072.

[0091] For example, multiple second mounting holes 2072 can be evenly distributed around the first mounting hole 2071. The specific number and size are determined by the required torque magnitude, torque accuracy, and the dimensions of adjacent components. If the number is too small, the transmitted torque may be insufficient; if the number is too large, the torque accuracy will be reduced due to the friction between the third bearing 209 and the second mounting holes 2072. Therefore, the appropriate number and size of the second mounting holes 2072 can be selected as needed, and no limitation is made here. In this embodiment, the number of second mounting holes 2072 can be 3 to 8.

[0092] The specific number of teeth on the internal and external gears 206 can also be set according to the required reduction and torque increase. In a feasible implementation, the reduction ratio of the reduction component 205 is less than or equal to 1 / 20. Specifically, the reduction ratio can be 1 / 3, 1 / 5, 1 / 7, 1 / 10, 1 / 13, 1 / 15, 1 / 17, or 1 / 20, etc. That is, the tooth ratio of the reduction component 205 is within 1:20. Thus, this solution can adopt a combination of quasi-direct drive and low-reduction ratio reduction component, which has both high precision and high economy, making it an ideal choice for finger joint drive devices. In the quasi-direct drive mode, the motor moderately adjusts the torque and speed through a low-reduction ratio reducer, and then the rotational motion of the motor is efficiently converted into the bending motion of the finger through the transmission device.

[0093] Typically, while the mass of motors may only account for a small fraction of the total mass of a robot in robotics, in robots with high reduction ratios, the impact of motor mass on joint dynamics can be very significant. We use the term "refracted inertia" to describe the inertial load felt on the other side of the transmission, leveraging the scaling effect of the gear ratio. Specifically, the refracted inertia of the arm on the motor side is reduced by the square of the reduction ratio; while the refracted inertia of the motor on the arm side is multiplied by the square of the reduction ratio.

[0094] Reflective inertia is a state-dependent function that captures not only the inertia of the current link but also the inertial coupling between other joints; while the reflective inertia on the motor side is constant and only affects local joints.

[0095] For high reduction ratios, the inertia effect dominates, leading to two results: 1. The dynamic equations of the manipulator tend to diagonalize (the inertial coupling terms are relatively small). 2. The dynamic characteristics are relatively stable within the workspace (the state-dependent terms are relatively small). This characteristic allows for individual adjustment of the fixed feedback gain for each joint, resulting in good control performance in all configurations.

[0096] This solution, by employing a low-reduction-ratio reduction component in conjunction with collimated drive, significantly reduces inertial coupling issues compared to traditional high-reduction-ratio designs. This simplifies the entire dynamics system and improves response time, enabling lightweight and efficient joint torque control without sacrificing control performance. The collimated drive approach is not only more structurally compact but also significantly enhances the dexterity of the robot hand and its ability to perform complex tasks, making it particularly suitable for the delicate manipulation scenarios of robot end effectors. By limiting the reduction ratio to within 1:20, the advantages of quasi-direct drive actuators can be leveraged to allow the robot hand to maintain high torque sensing accuracy while reducing reactive inertia, improving control precision and stability, especially in applications involving minute force sensing.

[0097] The deceleration and torque-increasing principle of the aforementioned transmission device 2 can be explained as follows: When the rotor 402 of the drive device 4 rotates under the magnetic field of the stator 401, it will drive the rotating shaft 1 to rotate. The rotating shaft 1 serves as the input shaft of the deceleration assembly 205. Through the eccentric wheel 202, the first bearing 203, and the internal gear 207 set on it, the internal gear 207 will undergo eccentric motion. At this time, the outer ring of the internal gear 207 will undergo friction and sliding motion, which will make the rotation direction and speed of the internal gear 207 inconsistent with those of the rotor 402. The transmission bracket 201 is linked to the internal gear 207 through the pin and the third bearing 209. When the eccentric motion of the internal gear 207 causes it to rotate to a certain angle, the third bearing 209 will abut against the second mounting hole 2072 of the internal gear 207, forming a certain rotational resistance, which in turn affects the rotation of the transmission bracket 201. Therefore, under the action of the deceleration component 205, the speed of the rotor 402 acting on the rotating shaft 1 can be reduced and the torque increased. Moreover, through the above design and control, the rotor 402, the internal gear 207, and the transmission bracket 201 can also be rotated in different directions and at different speeds, so that when applied to a dexterous hand, it can achieve flexible control of the finger joints and realize more anthropomorphic movements.

[0098] In this embodiment, the external gear 206 is directly assembled with the housing 3, and the internal gear 207 is assembled with the rotating shaft 1 through the first bearing 203 and the eccentric wheel 202. This greatly reduces the axial dimension of the assembly, which can be reduced to 20 mm. Furthermore, by using the third bearing 209 and the internal gear 207 as the transmission structure between the reduction assembly 205 and the transmission bracket 201, it can have a smaller friction force, thereby improving the torque accuracy of the assembly.

[0099] In this embodiment of the application, each finger of the dexterous hand may include multiple finger joints, and each finger joint is provided with a motor drive assembly for controlling the rotation of the finger joint. The transmission bracket 201 in the motor drive assembly may be connected to the motor drive assembly of another finger joint, so that the bending, extension, and lifting of heavy objects at a fixed point can be realized by flexibly controlling each finger joint.

[0100] In the embodiments of this application, please refer to Figure 3 The stator yoke 408 of the stator 401 is partially provided with a groove structure so that the eccentric wheel 202 and the first bearing 203 are partially sunk into the stator yoke 408, which can further reduce the axial dimension of the assembly.

[0101] In this embodiment, the outer diameter of the first bearing 203 is larger than the outer diameter of the second bearing 204, so that it can provide a higher load force.

[0102] In one feasible implementation, please refer to Figure 4 The transmission bracket 201 includes a first transmission structure 2011 and a second transmission structure 2012 connected together. The first transmission structure 2011 has a third mounting hole 2013 in its middle, which connects to the second bearing 204. The first transmission structure 2011 also has multiple fourth mounting holes 2014 surrounding the third mounting hole 2013. Each fourth mounting hole 2014 connects to a corresponding transmission pin 208. The second transmission structure 2012 is located outside the housing 3, and its length extension direction is parallel to the axial direction of the rotating shaft 1. The second transmission structure 2012 is connected to the linkage motor. By configuring the transmission bracket 201 as an L-shaped structure, it can be connected to the linkage motor radially, and the second transmission structure 2012 also has mounting holes for connection to the linkage motor.

[0103] In one feasible implementation, the transmission pin 208 includes a first connecting segment and a second connecting segment; the diameter of the first connecting segment is larger than the diameter of the second connecting segment; the first connecting segment is connected to the first transmission structure 2011 through the corresponding fourth mounting hole 2014; the second connecting segment is connected to the corresponding third bearing 209. This ensures reliable torque transmission while also reducing friction between the third bearing 209 and the second mounting hole 2072 through their compatible interconnection.

[0104] In one feasible implementation, please refer to Figure 3 and Figure 4The motor drive assembly further includes a positioning pin 26; the positioning pin 26 is located at the connection between the reduction assembly 205 and the housing 3; the positioning pin 26 includes a first side and a second side opposite to each other; the first side is connected to the housing 3; the second side is partially connected to the outer wall of the reduction assembly 205 and the stator 401. Specifically, by providing a notch on the stator yoke 408 of the stator 401, the positioning pin 26 can assemble the external gear 206, the housing 3, and the stator yoke 408 together, which can meet the angular positioning requirements while preventing radial rotation of the three components.

[0105] In one feasible implementation, please refer to Figure 3 The motor drive assembly also includes a connecting frame 5 and a magnet 6. The connecting frame 5 includes a through hole 501 and a groove 502, and the connecting frame 5 is made of a non-magnetic material. The bottom of the groove 502 is provided with a through hole, and the through hole is connected to the end face of the through hole 501 to form a mounting cavity that passes through the through hole 501 and the groove 502. The first end of the rotating shaft 1 is inserted into the through hole 501 and connected to the through hole 501. The first end is the end of the rotating shaft 1 that is away from the reduction assembly 205. The magnet 6 is disposed in the groove 502. Due to the magnetic field strength distribution generated by the magnet 6 and the magnetization method, and the sinusoidal nature of the magnetic field strength signal received by the magnetic encoding chip on the control unit 7 (used to collect the magnetic field changes of the magnet 6), the rotating shaft 1 and the magnet 6 can be connected by the connecting frame 5, thereby ensuring the concentricity of the magnet and the magnetic encoding chip in the control unit 7.

[0106] In this embodiment, when the drive device 4 is a stator-rotor stator configuration, a groove structure can also be provided on the stator yoke 408 of another stator 401 so that the connecting frame 5 and the magnet 6 can be recessed into the groove structure, further reducing the axial dimension of the assembly. The stator 401 is connected to the rotating shaft 1 through a bearing. Specifically, the connecting frame 5 can be directly assembled on the inner ring of the bearing, thereby reducing the axial dimension of the magnet 6 and the chip, improving the axial distance accuracy, and making the axial integration of the entire assembly higher.

[0107] In one feasible embodiment, the motor drive assembly further includes a control unit 7; the control unit 7 is located in the housing 3 near the end of the magnet 6; the control unit 7 is used to determine the rotation angle of the rotating shaft 1 by collecting the magnetic field changes of the magnet 6, thereby realizing the control of the rotation of the drive device 4.

[0108] In this embodiment, the control unit 7 is equipped with a magnetic encoding chip, which is located close to the magnet 6. The magnet 6 rotates synchronously with the rotating shaft 1, causing the NS magnetic field distribution generated on the magnet 6 to also rotate synchronously with the motor shaft 1. Therefore, the magnetic encoding chip can sense the angular position signal of the rotating shaft 1 through magneto-electric conversion. By placing the magnet 6 within the connecting frame 5, it can be ensured that the magnetic field sensed by the magnetic encoding chip is a sinusoidal change in magnetic flux density as the rotor 402 rotates, and the magnetic flux density amplitude is within the range of the magnetic encoding received signal.

[0109] The control unit 7 also includes a three-phase power supply unit, which supplies power to the windings of the stator 401, thereby enabling the rotor 402 to rotate.

[0110] Due to the magnetic field strength distribution generated by the magnet 6 and the magnetization method, as well as the sinusoidal nature of the magnetic field strength signal received by the magnetic encoding chip of the control unit 7, it is necessary to maintain a certain distance between the magnetic encoding chip and the magnet 6 in the axial direction to avoid interference between the components on the control unit 7 and the end face of the stator yoke 408. For this purpose, a washer 24 can be set between the stator yoke 408 and the control unit 7.

[0111] In this embodiment, the drive device 4 includes a stator 401 and a rotor 402 arranged sequentially at intervals along the axial direction of the shaft 1. Optionally, the drive device 4 can be a stator-rotor configuration. To improve torque density and reduce losses on the shaft 1, it can also be configured as a stator-rotor-stator configuration, making the rotor 402 subjected to balanced forces and the forces acting on the shaft 1 more even. To further improve the torque density of the motor drive assembly, it can also be configured as a stator-rotor-stator-rotor-stator configuration; please refer to [reference needed]. Figure 3 and Figure 5 The specific details are as follows: The drive device 4 includes a first sub-stator 403, a first sub-rotor 406, a second sub-stator 404, a second sub-rotor 407, and a third sub-stator 405 arranged sequentially at intervals along the axial direction of the rotating shaft 1; the first sub-stator 403, the second sub-stator 404, and the third sub-stator 405 are respectively connected to the rotating shaft 1 via a fourth bearing 15, a fifth bearing 16, and a sixth bearing 17; the fifth bearing 16 includes a first housing 1601; the first housing 1601 has a first groove 1602 surrounding the rotating shaft 1; the first groove 1602 has a plurality of rolling elements 1603; the first bearing 203 is tactilely connected to the rotating shaft 1 via the plurality of rolling elements 1603; the outer wall of the first housing 1601 is sleeved with the second sub-stator 404; the first sub-stator 403, the second sub-stator 404, and the third sub-stator 405 are all printed circuit board stators.

[0112] In the embodiments of this application, please refer to Figure 5The housing 3 can be composed of a first housing 301, a second housing 302 and a third housing 303. The first housing 301 is provided with a first sub-stator 403, the second housing 302 is provided with a first sub-rotor 406, a second sub-stator 404 and a second sub-rotor 407, and the third housing 303 is provided with a third sub-stator 405. The first housing 301, the second housing 302 and the third housing 303 are detachably connected, which facilitates the subsequent lead-out and assembly of the three-phase wires of the stator 401 winding.

[0113] In this embodiment, after positioning and connecting the first housing 301, the second housing 302, and the third housing 303, the connection can be further achieved through ultrasonic / laser welding / adhesive bonding, thereby ensuring positioning accuracy and structural strength. Since the three-phase lead-out components of the three stators 401 are assembled before the housing assembly (i.e., the three-phase lead-out components are located on the outside of the second housing 302), the three-phase lead-out components are easily visible when installing the first sub-stator 403 and the second sub-stator 404 with their corresponding three-phase lead-out components, allowing for easy connection to the corresponding stator 401 windings, thus improving assembly efficiency.

[0114] The first sub-stator 403 and the third sub-stator 405 can be symmetrically distributed on both sides of the second housing 302 so that the first sub-stator 403 and the third sub-stator 405 can adopt the same stator 401 structure during processing and manufacturing, which reduces the overall processing cost of the motor and improves processing efficiency.

[0115] By splicing the housings together, the design achieves a high degree of compactness and solves the problem of the three-phase lead-out components of the stator 401 winding being difficult to extract. In the future, slots can be designed on the mounting surfaces of the first housing 301, the second housing 302, and the third housing 303 respectively, so that the three-phase lead-out components can be extracted from the slots. This also avoids interference with the rotor 402 during motor operation, which could lead to motor failure.

[0116] In this embodiment, the first housing 301 is fixedly connected to the first sub-stator 403, the second housing 302 is fixedly connected to the second sub-stator 404, and the third housing 303 is fixedly connected to the third housing 303, thereby ensuring the stability and electrical reliability of the entire stator 401 assembly structure.

[0117] The first housing 301, the second housing 302, and the third housing 303 in this application can be an integral cavity, that is, without internal steps. The end faces of the first housing 301 and the third housing 303 can be used as positioning and mounting surfaces, thereby improving the radial accuracy of the shaft system structure, making the operation smoother, and improving NVH.

[0118] In one feasible implementation, please refer to Figure 4The second housing 302 is provided with heat dissipation holes 18 to effectively reduce temperature rise. Optionally, the heat dissipation holes 18 can be specifically set on the second housing 302, in the area adjacent to the rotor 402, to give it a better heat dissipation effect. If necessary, heat dissipation holes 18 can also be set on the first housing 301 or the second housing 302, or on any two of the three housings. The specific size and number of heat dissipation holes 18 can be set as needed and are not limited here.

[0119] The second housing 302 includes opposing first and second end faces; see also Figure 5 In one feasible embodiment, a first notch is provided on the first end face, and the connecting end face of the first housing 301 is a flat surface, so that a first slot 8 can be formed after the first end face and the connecting end face of the first housing 301 are connected; a second notch is provided on the second end face, and the connecting end face of the third housing 303 is a flat surface, so that a second slot 9 can be formed after the second end face and the connecting end face of the third housing 303 are connected. In other embodiments, notches may be provided on any three or two of the above-mentioned first end face, second end face, connecting end face of the first housing 301, and connecting end face of the third housing 303, without limitation, as long as the first slot 8 and the second slot 9 can be formed. The first slot 8 and the second slot 9 are both located on the mounting surfaces of the first housing 301, the second housing 302, and the third housing 303. This allows the three-phase wire lead-out accessories to be centrally located on the mounting surface, avoiding their lead-out through other peripheral surfaces of the housing, further improving the structural compactness of the motor and facilitating its miniaturization.

[0120] In one feasible implementation, please refer to Figure 5 The second housing 302 has a third slot 10 and a conductive element 11 on its mounting surface. The winding of the first sub-stator 403 is electrically connected to the conductive element 11 through the first slot 8 via a first flexible circuit board 12. The winding of the second sub-stator 404 is electrically connected to the conductive element 11 through the third slot 10 via a second flexible circuit board 13. The winding of the third sub-stator 405 is electrically connected to the conductive element 11 through the second slot 9 via a third flexible circuit board 14. This configuration greatly improves the axial compactness of the motor assembly.

[0121] The conductive component 11 can be integrally formed with the second housing 302, ensuring the connection strength between the two.

[0122] Each stator 401 winding is led out through a corresponding flexible circuit board and then connected to the conductive component 11, making the entire lead-out structure compact and highly reliable. The flexible circuit board has good bending and tensile properties and a very narrow axial dimension, which allows the three-phase lead-out components (i.e., flexible circuit boards) to be designed as flat structures, reducing their axial dimensions while ensuring their current carrying capacity.

[0123] In this embodiment, the dimensions of the first slot 8, the second slot 9, and the third slot 10 can be determined based on the dimensions of the flexible circuit board. Optionally, the thickness d of the first, second, and third flexible circuit boards 14 can be 0.1 to 0.3 mm, and the width L can be 3 to 10 mm. Then, the width of the first slot 8, the second slot 9, and the third slot 10 can be 0.2 to 0.5 mm (d + 0.1 to d + 0.2 mm), and the length can be L + 0.5 to L + 1 mm (3.5 to 11 mm). This ensures convenient installation of the flexible circuit board while preventing interference with the rotor 402 during motor operation, improving the axial compactness of the motor, and further enhancing its miniaturization.

[0124] For a feasible implementation method, please refer to [link / reference needed]. Figure 5 The rotating shaft 1 is provided with a second groove 101; the plurality of rolling elements 1603 are disposed within the concave channel formed by the first groove 1602 and the second groove 101. The rolling elements 1603 are directly connected to the rotating shaft 1 and the first housing 1601, featuring a simple structure and small radial dimension, thereby allowing for a larger radial width of the rotating shaft 1, improving the deflection of the rotating shaft 1 and the overall stability of the motor. Optionally, the rotating shaft 1 can be provided with two rows of second grooves 101, and the first housing 1601 can also be provided with two rows of first grooves 1602 in conjunction with two rows of second grooves 101, to further improve the shaft strength of the motor. Specifically, the number of first grooves 1602 and the number of second grooves 101 are related to the width of the second sub-stator 404 and the required strength. The wider the width of the second sub-stator 404, the more rows of grooves can be designed to improve the shaft strength of the motor.

[0125] In this embodiment, the structures of the first sub-rotor 406 and the second sub-rotor 407 can be identical or optional. Please refer to [link / reference]. Figure 6The diagram shows a schematic representation of a rotor 402 according to an exemplary embodiment of this application. Both the first sub-rotor 406 and the second sub-rotor 407 may include a magnet frame 19 and multiple magnets 20. Adjacent magnets 20 have different polarities. The magnet frame 19 is made of a non-magnetic material, and a mounting hole is provided in the middle of the magnet frame 19. The mounting hole of the magnet frame 19 is fixedly connected to the rotating shaft 1. Optionally, the magnet frame 19 and the rotating shaft 1 can be interference-fitted or connected by bonding. Optionally, the connecting side of the magnet frame 19 and the magnets 20 is provided with a groove, and the two are connected by bonding. The groove design can further improve the bonding strength between the two.

[0126] In one feasible implementation, please refer to Figure 7 and Figure 8 The printed circuit board stator includes a stator yoke 408, multiple magnetic conductive elements 409, and stacked printed circuit boards 410. The stator yoke 408 has a first mounting hole 2071 in its center, which is connected to the rotating shaft 1 via a bushing 23. The stator yoke 408 also has multiple sixth mounting holes 4082 surrounding the fifth mounting hole 4081, each sixth mounting hole 4082 connecting to one end of a corresponding magnetic conductive element 409. The other end of the magnetic conductive element 409 has an epitaxial sheet 412. The printed circuit board 410 has multiple seventh mounting holes 411. Each through hole is sleeved with a corresponding magnetic conductive element 409. Three-phase conductors are laid on the printed circuit to form the stator 401 winding. The gap between adjacent epitaxial sheets 412 is smaller than the gap between adjacent magnetic conductive elements 409. This not only avoids magnetic leakage but also effectively reduces vibration during motor operation.

[0127] In this embodiment, the design of the epitaxial wafer 412 reduces the spacing between adjacent magnetic conductors 409, making the magnetic field change and force change between them gradual, thereby reducing vibration during motor operation.

[0128] The structure and processing of the magnetic conductor 409 with the epitaxial wafer 412 are relatively complex. Therefore, to further simplify the structure of the stator 401, after mounting the multilayer printed circuit board 410 on multiple magnetic conductors 409, the magnetic conductor sheet 22 can be placed on the surface of the printed circuit board 410. This can also reduce vibration during motor operation. Furthermore, since the magnetic conductor 409 can be a cylindrical structure, it has the advantages of simple processing and installation. Optionally, the magnetic conductor sheet 22 has multiple mounting holes that fit with the magnetic conductor 409. Optionally, the mounting holes of the magnetic conductor sheet 22 and the magnetic conductor 409 can be fixedly connected by filling adhesive. Optionally, the through holes on the printed circuit board 410 and the magnetic conductor 409 can be either interference fits or bonded with adhesive.

[0129] The axial flux motor provided in this application embodiment uses an ultra-high-order printed circuit board 410 as the stator 401 winding and a magnetic conductor 409 as the magnetic circuit composition to ensure the minimum air gap and reduce magnetic circuit losses, which can improve the torque / power density by more than 2.5 times compared with a motor of the same size. The shaft system design, rotor 402 structure design and three-phase lead wire 21 structure design have been optimized to make the product more feasible, reliable and miniaturized. The motor provides driving force for the drive assembly.

[0130] It should be noted that when the drive device 4 includes multiple stators 401, the structures of these stators 401 can be different. For example, a stator 401 can be a stator 401 with an epitaxial layer 412, or a stator 401 with a magnetic conductive layer 22. When the drive device 4 is as follows... Figure 5 In the configuration shown, in order to further reduce the motor cogging torque and achieve a very small torque amplitude, the first sub-stator 403 and the third sub-stator 405 can be configured as stator 401 with an epitaxial sheet 412, and the second sub-stator 404 can be configured as stator 401 with a magnetic conductive sheet 22. Then the slots of the three can be optimized.

[0131] In the embodiments of this application, please refer to Figure 9 The fifth mounting hole 4081 of the printed circuit board stator is connected to the rotating shaft 1 via a bushing 23. The bushing 23 is made of a non-magnetic material, thus preventing the magnetic field from magnetizing the bearing steel material inside the bearing and from interfering with the magnetic encoding signal. Compared to designing the bushing 23 and stator yoke 408 as an integrated structure, the bushing 23 and stator yoke 408 in this solution are separate structures, which reduces processing difficulty. Optional, please refer to... Figure 10 The bushing 23 has a guide groove 2301 on its side wall to enhance the bonding strength between the bushing 23 and the printed circuit board 410, and improve the torsional and tensile resistance of the entire stator 401. The various installation gaps of the printed circuit stator 401 can be sealed by filling with high thermal conductivity adhesive 25, which ensures the reliability of strength and eliminates tolerance accumulation, thus ensuring assembly accuracy.

[0132] In this embodiment, the inner ring of the fourth bearing 15 is connected to the rotating shaft 1; the outer ring of the second bearing 204 is connected to the first sub-stator 403. This further improves the load strength of the shaft system. Optionally, the fourth bearing 15 includes an inner shell, a plurality of rolling elements 1603, and a second outer shell. A rolling channel is formed between the second outer shell and the inner shell, and a plurality of rolling elements 1603 are assembled in the rolling channel. The inner shell is interference-fitted or bonded to the rotating shaft 1, allowing the rotating shaft 1 to rotate relative to the first sub-stator 403.

[0133] This application embodiment significantly improves the performance of the assembly through optimized design of the axial flux motor, eccentric wheel reduction assembly, and transmission bracket. Specifically, the axial dimension of the assembly is controlled within 20 mm, which is approximately 70% smaller than traditional designs (such as DYNAM IXEL XC330-M288-T), achieving greater structural compactness and lightweighting. Simultaneously, the reduction ratio is designed to be within 1:20, which optimizes the transparency of the transmission system, reduces the impact of inertia on the system's dynamic performance, and enables more sensitive and consistent force control in complex operations using dexterous hand joints.

[0134] This design effectively avoids the control accuracy degradation caused by amplified inertia in traditional low-reduction ratio transmission systems. In the collimated drive mode, the motor's torque and speed are appropriately adjusted by a low-reduction ratio reducer (e.g., 1:10), and then the rotational motion of the motor is efficiently converted into the bending motion of the fingers through a transmission device. The drive system consists of a motor and a low-reduction ratio reducer, and has the following significant advantages: 1. Low inertia: Due to the low reduction ratio design, the influence of inertia is significantly reduced, resulting in faster system response and better dynamic performance; 2. Independent joint control: Each joint can be driven and controlled independently, avoiding complex dynamic coupling between multiple joints; 3. Larger workspace: The low reduction ratio combined with the high dynamic response design significantly expands the workspace of the dexterous hand; 4. High precision: Collimated drive reduces the influence of nonlinear problems such as backlash and friction, ensuring high-precision operation; 5. Support for force control algorithms: The drive joints have low friction and high dynamic performance, enabling stable operation of force control algorithms and achieving sensitive force feedback and torque control.

[0135] This application also discloses a robotic hand, which includes at least one finger joint; the finger joint is equipped with the aforementioned motor drive assembly. This motor drive assembly uses a high-power-density axial flux motor combined with a reduction gear assembly 205 and a transmission bracket 201, employing multiple shaft systems to simulate the joint mechanism on a human finger. The motor drives the reduction gear assembly 205, which transmits torque through friction with a bearing mounted on the transmission bracket 201, thus rotating the transmission bracket 201. The transmission bracket 201 is mounted to simulate the joint mechanism on another finger. In this way, the drive motor can simulate the bending and straightening of a human finger, achieving multi-degree-of-freedom dexterity. Through the structural design of multiple shaft systems, different directions and speeds of rotation can be achieved for the motor rotor 402, reduction gear assembly 205, and transmission bracket 201. Furthermore, the entire assembly features high torque density, small axial dimensions, and a low reduction ratio.

[0136] The above description is only an optional embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.

Claims

1. An electric motor drive assembly, characterized by, The application is applied to a dexterous hand joint, comprising a rotating shaft, a transmission device, a casing and a driving device arranged in the casing; The driving device comprises a stator and a rotor arranged along the axial direction of the rotating shaft; The transmission device comprises a transmission support, an eccentric wheel, a first bearing, a second bearing and a speed reduction assembly; the second bearing, the eccentric wheel and the driving device are arranged along the axial direction of the rotating shaft; the outer ring of the speed reduction assembly is fixedly connected with the inner wall of the casing, and the inner ring of the speed reduction assembly is sleeved with the eccentric wheel through the first bearing; the stator yoke of the stator is partially provided with a groove structure to allow the eccentric wheel and the first bearing to be partially sunk in the stator yoke; The end of the rotating shaft penetrates through the casing and is provided with the transmission support, the transmission support is connected with the second bearing, and the transmission support is connected with the speed reduction assembly in linkage; the transmission support is connected with a linkage motor; In the case that the driving device drives the rotating shaft to rotate, the rotation of the rotating shaft can drive the rotation of the eccentric wheel connected with the rotating shaft, and then drive the eccentric motion of the speed reduction assembly connected with the eccentric wheel and the rotation of the transmission support connected with the speed reduction assembly in linkage; The speed reduction assembly comprises external teeth, internal teeth, a plurality of transmission pins and a plurality of third bearings; The outer ring of the external teeth is fixedly connected with the inner wall of the casing, and the inner ring of the external teeth is sawtooth-shaped and can be engaged with the outer ring of the internal teeth; The middle part of the internal teeth is provided with a first mounting hole, and the first mounting hole is sleeved with the first shaft; The internal teeth are further provided with a plurality of second mounting holes surrounding the first mounting hole; One end of each of the plurality of transmission pins is connected with the transmission support, and the other end of each of the transmission pins is arranged in a corresponding one of the second mounting holes through a third bearing; the diameter of the second mounting hole is greater than the diameter of the third bearing; When the internal teeth are rotated to a preset angle under the driving of the rotating shaft, each of the third bearings can abut against a corresponding one of the second mounting holes; The transmission support comprises a first transmission structure and a second transmission structure connected with each other; the second transmission structure is located outside the casing, and the length extension direction of the second transmission structure is parallel to the axial direction of the rotating shaft; and the second transmission structure is connected with the linkage motor.

2. The motor drive assembly of claim 1, wherein, The transmission support comprises a first transmission structure and a second transmission structure connected with each other; The middle part of the first transmission structure is provided with a third mounting hole, and the third mounting hole is connected with the second bearing; The first transmission structure is further provided with a plurality of fourth mounting holes surrounding the third mounting hole; Each of the fourth mounting holes is connected with a corresponding one of the transmission pins; The second transmission structure is located outside the casing, and the length extension direction of the second transmission structure is parallel to the axial direction of the rotating shaft; The second transmission structure is connected with the linkage motor.

3. The motor drive assembly of claim 2, wherein, The transmission pin comprises a first connecting segment and a second connecting segment connected with each other; the diameter of the first connecting segment is greater than the diameter of the second connecting segment; The first connecting segment is connected with the first transmission structure through a corresponding one of the fourth mounting holes; The second connecting segment is connected with a corresponding one of the third bearings.

4. The motor drive assembly of claim 1, wherein, The deceleration ratio of the deceleration assembly is less than or equal to 1 / 20.

5. The motor drive assembly of any one of claims 1-4, wherein, Further comprising a positioning pin; The positioning pin is arranged at the connection between the deceleration assembly and the casing; The positioning pin comprises opposite first and second side surfaces; The first side surface is connected with the casing; The second side surface is connected with the outer wall of the deceleration assembly and the local part of the stator.

6. The motor drive assembly of claim 1, wherein, Further comprising a connecting frame and a magnet piece; The connecting frame comprises a through hole part and a groove part, and the connecting frame is made of non-magnetic material; The bottom of the groove part is provided with a through hole, and the through hole is connected with the end surface of the through hole part to form an installation cavity penetrating through the through hole part and the groove part; The first end of the rotating shaft is inserted into the through hole part and connected with the through hole part; the first end is the end of the rotating shaft far away from the deceleration assembly; The magnet piece is arranged in the groove part.

7. The motor drive assembly of claim 6, wherein, Further comprising a control unit; The control unit is arranged in the casing near the end of the magnet piece; The control unit is used to determine the rotation angle of the rotating shaft by collecting the magnetic field change of the magnet piece, so as to realize the control of the rotation of the driving device.

8. The motor drive assembly of claim 1, wherein, The driving device comprises a first sub-stator, a first sub-rotor, a second sub-stator, a second sub-rotor and a third sub-stator arranged along the axial direction of the rotating shaft in sequence; the first sub-stator, the second sub-stator and the third sub-stator are connected with the rotating shaft through a fourth bearing, a fifth bearing and a sixth bearing respectively; the fifth bearing comprises a first housing; a first channel surrounding the rotating shaft is arranged in the first housing; a plurality of rolling bodies are arranged in the first channel; the first bearing is rolling connected with the rotating shaft through the plurality of rolling bodies; the outer wall of the first housing is sleeved with the second sub-stator; The first sub-stator, the second sub-stator and the third sub-stator are all printed circuit board stators.

9. A robotic hand, characterized by, Comprising at least one finger joint; The finger joint is provided with one motor driving assembly as claimed in any one of claims 1-8.

Images