Linear joint module and robot
By employing a design that meshes the first and second gears in the linear servo joint module, combined with an absolute encoder, the number of rotations and angular position of the motor can still be accurately recorded even when power is off, thus solving the problem of encoder count loss when power is off.
Patent Information
- Application Number
- CN202522526099.5
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-11-27
- Publication Date
- 2026-11-03
- Estimated Expiration
- 2035-11-27
AI Technical Summary
When the battery power is low, the encoder of the existing linear servo joint module cannot record the number of motor revolutions, resulting in the loss of position information after power failure.
The design employs a first gear and a second gear meshing, combined with a first absolute encoder and a second absolute encoder, to record the number of rotations and position of the motor by the difference in the number of teeth, ensuring accurate counting even after power failure.
Even in the event of a power outage, the combination of the first and second absolute encoders can still accurately record the number of rotations and angular position of the motor, thus solving the problem of encoder count loss when power is off.
Smart Images
Figure CN224935503U_ABST
Abstract
Description
Technical Field
[0001] This utility model belongs to the field of intelligent equipment technology, and more specifically, it relates to a linear joint module and a robot. Background Technology
[0002] Linear servo joint modules need to detect and record the number of motor rotations and position during operation. Currently, most linear servo joint modules use battery-powered multi-turn absolute encoders. When the battery is working normally, it can record the number of motor rotations and position. However, due to the inconsistent quality of batteries, or when the battery is not used for a long time, it may be over-discharged and its capacity may be reduced, thus losing the multi-turn counting function when the whole machine is powered off. Utility Model Content
[0003] The purpose of this utility model embodiment is to provide a linear joint module and robot to solve the technical problem in the prior art that the encoder cannot count multiple revolutions of the motor when the power is off.
[0004] To achieve the above objectives, the technical solution adopted by this utility model is as follows: a linear joint module is provided, including a motor, a transmission component, a first gear and a second gear meshing with each other, a first absolute encoder, and a second absolute encoder. The transmission component is used to convert the rotational motion of the motor into linear motion. The first gear is connected to the motion output end of the motor. The number of teeth of the first gear and the second gear are different. The first absolute encoder is used to detect the position of the first gear, and the second absolute encoder is used to detect the position of the second gear, so as to obtain the number of rotations of the first gear based on the difference in the number of teeth of the first gear and the second gear and the position of the second gear.
[0005] Optionally, the difference in the number of teeth between the second gear and the first gear is 1.
[0006] Optionally, the transmission assembly includes a planetary ball screw assembly, wherein the first gear is fixedly connected to the rotating nut of the planetary ball screw assembly, and the rated number of rotations of the rotating nut is less than the number of teeth of the second gear.
[0007] Optionally, the transmission assembly includes a rotating nut connected to the motion output end of the motor, one end of the rotating nut being threadedly connected to a threaded component, the first gear being fixed to the threaded component, and the rotation axis of the first gear being coaxially arranged with the rotation axis of the rotating nut.
[0008] Optionally, the linear joint module further includes an encoder bracket and a control board fixed to the encoder bracket. The read heads of the first absolute encoder and the second absolute encoder are both disposed on the control board, and the second gear is rotatably disposed on the encoder bracket.
[0009] Optionally, the motion output end of the transmission component is connected to a first universal joint assembly; and / or, the linear joint module further includes a tension / compression sensor, which is connected to a second universal joint assembly.
[0010] Optionally, the linear joint module further includes a joint housing, a first fixing nut, and a second fixing nut. The joint housing has internal threads at both ends in the axial direction, such that the first fixing nut is threaded to one end of the joint housing in the axial direction, and the second fixing nut is threaded to the other end of the joint housing in the axial direction. The motor, at least part of the transmission assembly, the first gear, the second gear, the first absolute encoder, and the second absolute encoder are all disposed between the first fixing nut and the second fixing nut.
[0011] Optionally, the linear joint module further includes a tension / compression sensor, a first stop shoulder is provided on the inner wall of the joint housing, one end of the tension / compression sensor abuts against the stop shoulder, and the other end of the tension / compression sensor is pressed by the first fixing nut.
[0012] Optionally, the transmission assembly includes a rotating nut connected to the motion output end of the motor, a second bearing is provided between the rotating nut and the joint housing, a second stop shoulder is provided on the inner wall of the joint housing, one end of the second bearing abuts against the second stop shoulder, and the other end of the second bearing is pressed by the second fixing nut.
[0013] This utility model also provides a robot, including the above-mentioned linear joint module.
[0014] The beneficial effects of the linear joint module and robot provided by this utility model are as follows: Compared with the prior art, the linear joint module of this utility model includes a motor, a transmission component, a first gear, a second gear, a first absolute encoder, and a second absolute encoder. The motor drives the transmission component to move to output linear motion. At the same time, the motor drives the first gear to move. The first gear and the second gear mesh with each other. The number of teeth on the first gear and the second gear are different. Therefore, when the first gear rotates one revolution, the number of revolutions of the second gear is less than or greater than one revolution. After power failure, the first absolute encoder and the second absolute encoder can still record the angular positions of the first gear and the second gear, respectively. Thus, the number of revolutions of the first gear can be calculated by recording the angular position of the second gear by the second absolute encoder, and the angular position of the first gear can be recorded by the first absolute encoder. In this way, even after the linear joint module is powered off, the number of revolutions of the motor and the angular position can still be recorded by the combined action of the first absolute encoder and the second absolute encoder. Attached Figure Description
[0015] To more clearly illustrate the technical solutions in the embodiments of this utility model, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0016] Figure 1 A cross-sectional view of a linear joint module provided in an embodiment of this utility model;
[0017] Figure 2 A schematic diagram of the structure of the first gear, the second gear, and the control board provided for an embodiment of this utility model;
[0018] Figure 3 An assembly structure diagram of the first gear provided for an embodiment of this utility model;
[0019] Figure 4 An assembly structure diagram of the second gear provided for an embodiment of this utility model;
[0020] Figure 5 for Figure 1 Enlarged structural diagram at point A in the middle;
[0021] Figure 6 for Figure 1 Enlarged structural diagram at point B;
[0022] Figure 7 A three-dimensional structural diagram of the linear joint module provided in the embodiment of this utility model.
[0023] The following are the labeling elements in the figure:
[0024] 10-Motor; 20-Transmission assembly; 21-Rotating nut; 22-Roller; 23-Lead screw; 31-First gear; 311-Threaded part; 312-Fixing pin; 32-Second gear; 33-Control board; 331-First absolute encoder; 332-Second absolute encoder; 40-Joint housing; 41-First stop shoulder; 42-Second stop shoulder; 50-Tension / compression sensor; 61-First universal joint assembly; 62-Second universal joint assembly; 71-Encoder bracket; 72-Bearing bracket; 73-First bearing; 74-Second bearing; 75-First fixing nut; 76-Second fixing nut. Detailed Implementation
[0025] To make the technical problems, technical solutions, and beneficial effects of this utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present utility model and are not intended to limit the present utility model.
[0026] It should be noted that when a component is referred to as being "fixed to" or "set on" another component, it can be directly on or indirectly on that other component. When a component is referred to as being "connected to" another component, it can be directly connected to or indirectly connected to that other component.
[0027] It should be understood that the terms "length", "width", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", and "outer" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.
[0028] 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 technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this utility model, "a plurality of" means two or more, unless otherwise explicitly specified.
[0029] Linear servo joint modules need to detect and record the number of motor rotations and position during operation. Currently, most linear servo joint modules use battery-powered multi-turn absolute encoders. When the battery is working normally, it can record the number of motor rotations and angular position. However, due to the inconsistent quality of batteries, or when the battery is not used for a long time, it may be over-discharged and its capacity may be reduced, thus losing the multi-turn counting function when the whole machine is powered off.
[0030] To alleviate or solve the above technical problems, this utility model proposes a new linear joint module and robot. The linear joint module includes a motor 10, a transmission component 20, a first gear 31, a second gear 32, a first absolute encoder 331, and a second absolute encoder 332. The motor 10 drives the first gear 31 to move, and the first gear 31 and the second gear 32 mesh with each other. The first absolute encoder 331 and the second absolute encoder 332 are used to record the number of rotations and angular positions of the first gear 31 and the second gear 32, respectively. Since the number of teeth of the first gear 31 and the second gear 32 is different, the second gear 32 does not rotate one revolution when the first gear 31 rotates one revolution. The number of rotations of the first gear 31 can be obtained from the angular position of the second gear 32. Therefore, after power failure, the angular position of the first gear 31 can be obtained through the first absolute encoder 331, and the number of rotations of the first gear 31 can be obtained through the second absolute encoder 332. Multi-revolution counting can still be achieved after power failure, and it is not affected by power failure.
[0031] The linear joint module provided in the embodiments of this utility model will now be described.
[0032] Please refer to the following: Figure 1 and Figure 2 The linear joint module includes a motor 10, a transmission assembly 20, a first gear 31 and a second gear 32 meshing with each other, a first absolute encoder 331 and a second absolute encoder 332. The transmission assembly 20 is used to convert the rotational motion of the motor 10 into linear motion. The first gear 31 is connected to the motion output end of the motor 10. The number of teeth of the first gear 31 is different from the number of teeth of the second gear 32. The first absolute encoder 331 is used to detect the position of the first gear 31, and the second absolute encoder 332 is used to detect the position of the second gear 32, so as to obtain the number of rotations of the first gear 31 based on the difference in the number of teeth of the first gear 31 and the second gear 32 and the position of the second gear 32.
[0033] Motor 10 is an electrically driven component that can output rotational motion. In the linear joint module, an encoder is needed to record the number of rotations of motor 10 and the angular position of motor 10, so as to obtain the linear motion distance of the linear joint module.
[0034] The transmission assembly 20 is a power transmission mechanism, typically composed of multiple parts. The operation of the motor 10 drives the transmission assembly 20, which converts the rotational motion of the motor 10 into linear motion, causing the linear joint module to output linear motion. The ratio of the position information of the motor 10 (number of rotations and angular position) to the linear motion distance output by the linear joint module is fixed. When the position information of the motor 10 is known, the linear motion distance output by the linear joint module is also known. Therefore, an encoder can be used to obtain the position information of the motor 10 and the motion distance of the linear joint module.
[0035] Both the first gear 31 and the second gear 32 are gear structures and mesh with each other. The first gear 31 is connected to the motor 10. Specifically, the motion output end of the motor 10 is fixedly connected to the first gear 31, and the position information of the first gear 31 reflects the position information of the motor 10. The second gear 32 meshes with each other, and their linear velocities are always the same. However, the number of teeth on the first gear 31 and the second gear 32 is not the same. When the first gear 31 rotates one revolution, the second gear 32 does not rotate one revolution. For example, the initial meshing position of the first gear 31 and the second gear 32 is the zero point position. The total number of teeth on the second gear 32 is m. When the first gear 31 rotates one revolution, the number of teeth rotated by the second gear 32 is n. After the second gear 32 rotates x revolutions, the number of teeth rotated by the second gear 32 is xn. The difference between the second gear 32 and the zero point position is (mn)x.
[0036] Both the first absolute encoder 331 and the second absolute encoder 332 are absolute encoders. Absolute encoders use photoelectric code disks for memory. They are more expensive, more accurate, and larger than incremental encoders. Absolute encoders determine the encoding based on mechanical position; they do not require memory, reference point finding, or continuous counting. When position is needed, it can be directly read without needing to start the machine to find the zero point. The first absolute encoder 331 is used to read the position information of the first gear 31, and the second absolute encoder 332 is used to read the position information of the second gear 32. When the linear distance output by the linear joint module needs to be obtained while the power is on, the first absolute encoder 331 and the second absolute encoder 332 are read directly to obtain the angular position of the first gear 31 and the angular position of the second gear 32. The number of rotations of the first gear 31 can be obtained through the angular position of the second gear 32. Thus, the position information of the first gear 31 can be obtained. Even when the power is off, the first absolute encoder 331 and the second absolute encoder 332 can still record the angular positions of the first gear 31 and the second gear 32, so as not to affect the position information recording of the motor 10, and not to affect the multi-turn counting of the motor 10 after the power is off.
[0037] The linear joint module in the above embodiment includes a motor 10, a transmission component 20, a first gear 31, a second gear 32, a first absolute encoder 331, and a second absolute encoder 332. The motor 10 drives the transmission component 20 to move to output linear motion. At the same time, the motor 10 drives the first gear 31 to move. The first gear 31 and the second gear 32 mesh with each other. The number of teeth of the first gear 31 and the second gear 32 are different. Therefore, when the first gear 31 rotates one revolution, the number of revolutions of the second gear 32 is less than or greater than one revolution. After power is cut off, the first absolute encoder 331 and the second absolute encoder 332 can still record the angular positions of the first gear 31 and the second gear 32, respectively. Thus, the number of revolutions of the first gear 31 can be calculated by recording the angular position of the second gear 32 by the second absolute encoder 332, and the angular position of the first gear 31 can be recorded by the first absolute encoder 331. In this way, even after the linear joint module is powered off, the number of rotations and angular position of the motor 10 can still be recorded through the combined action of the first absolute encoder 331 and the second absolute encoder 332.
[0038] Please refer to some embodiments of this utility model. Figure 2 The difference in the number of teeth between the second gear 32 and the first gear 31 is 1, meaning that the second gear 32 has one more tooth than the first gear 31. When the first gear 31 rotates one revolution, the second gear 32 rotates to the zero position one tooth short; when the first gear 31 rotates two revolutions, the second gear 32 rotates to the zero position two teeth short, and so on. Therefore, the number of revolutions of the first gear 31 can be obtained by the angular position of the second gear 32.
[0039] When the difference in the number of teeth between the second gear 32 and the first gear 31 is 1, the difference in the number of teeth between the second gear 32 and the zero position is the number of rotations of the first gear 31, which makes it easier to count the number of rotations of the first gear 31.
[0040] In other embodiments, the difference in the number of teeth between the second gear 32 and the first gear 31 can be 2, 3, 4, etc.
[0041] In other embodiments, the number of teeth of the second gear 32 may also be less than the number of teeth of the first gear 31.
[0042] In some embodiments, the transmission assembly 20 includes a planetary ball screw assembly. A first gear 31 is fixedly connected to a rotating nut 21 of the planetary ball screw assembly. The rated number of rotations of the rotating nut 21 is less than the number of teeth of the second gear 32. The planetary ball screw assembly includes a rotating nut 21, a screw 23, and multiple rollers 22. The rotating nut 21 is fixedly connected to the first gear 31, causing the rotating nut 21 to rotate synchronously with the first gear 31. The rotation of the rotating nut 21 drives the rollers 22 to roll, thereby causing the screw 23 to move. The screw 23 is the output structure of the planetary ball screw assembly, capable of outputting linear motion, serving as the motion output structure of the linear joint module. The rated number of rotations of the rotating nut 21 refers to the number of rotations the rotating nut 21 makes when the linear joint module moves from a first limit position to a second limit position.
[0043] By setting the rated number of rotations of the rotating nut 21 to be less than the number of teeth of the second gear 32, when the linear joint module moves within its stroke range, the number of teeth of the second gear 32 is sufficient for the first gear 31 to calculate the number of rotations, and the second gear 32 will not repeatedly appear in the same angular position after the first gear 31 has rotated multiple full rotations.
[0044] In some embodiments, please refer to Figure 1 and Figure 5 The rotating nut 21 is located inside the motor 10, which can make full use of the space inside the motor 10 and make the structure of the linear joint module more compact.
[0045] Please refer to some embodiments of this utility model. Figure 1 and Figure 5 The transmission assembly 20 includes a rotating nut 21 connected to the motion output end of the motor 10. One end of the rotating nut 21 is threadedly connected to a threaded component 311. A first gear 31 is fixed to the threaded component 311, and the rotation axis of the first gear 31 is coaxially arranged with the rotation axis of the rotating nut 21. The rotating nut 21 is part of the transmission assembly 20 and rotates under the drive of the motor 10, thereby driving the threaded component 311 and the first gear 31 to rotate synchronously, realizing the connection between the motor 10 and the first gear 31.
[0046] By connecting a threaded part 311 to one end of the rotating nut 21 and fixing the first gear 31 to the threaded part 311, the motor 10 and the first gear 31 are fixedly connected, and the motor 10's motion output end and the first gear 31 rotate synchronously.
[0047] In some embodiments, the rotating nut 21 has a hollow structure, and its inner wall is provided with internal threads. These internal threads can either cooperate with the roller 22 to convert the rotational motion of the transmission assembly 20 into linear motion, or cooperate with the threaded component 311 to achieve a fixed connection between the threaded component 311 and the rotating nut 21. This eliminates the need for additional connecting components to connect the threaded component 311 and the rotating thread, further simplifying the connection structure between the rotating nut 21 and the first gear 31.
[0048] In some embodiments, please refer to Figure 3 and Figure 5 A first gear 31 is fixed on the threaded part 311. One end of the first gear 31 is embedded in the threaded part 311, and the first gear 31 and the threaded part 311 are fixed by a fixing pin 312, etc. Specifically, the fixing pin 312 passes through the threaded part 311 radially and abuts against the first gear 31, thus achieving the fixing of the first gear 31 and the threaded part 311.
[0049] In some embodiments of this utility model, the first absolute encoder 331 and the second absolute encoder 332 are both magnetoelectric absolute encoders. Magnets are provided on both the first gear 31 and the second gear 32. The magnets generate a magnetic field, and the magnetic sensitive element senses the magnetic field and converts it into an electrical signal. The magnetic sensitive element can be a Hall element or a magnetoresistive element.
[0050] Please refer to some embodiments of this utility model. Figure 1 , Figure 4 and Figure 5 The linear joint module also includes an encoder bracket 71 and a control board 33 fixed to the encoder bracket 71. The read heads of the first absolute encoder 331 and the second absolute encoder 332 are both mounted on the control board 33. The second gear 32 is rotatably mounted on the encoder bracket 71. The encoder bracket 71 is a structural support used to fix the control board 33. The control board 33 is the main circuit component of the linear joint module and is used to control the start / stop, speed, and record or acquire position information of the motor 10 of the linear joint module. The read heads of the first absolute encoder 331 and the second absolute encoder 332 are used to acquire the angular positions of the first gear 31 and the second gear 32, respectively.
[0051] The encoder bracket 71 facilitates the installation of the second gear 32 and the control board 33, enabling the second gear 32 to rotate smoothly. Both the first gear 31 and the second gear 32 are positioned close to the control board 33 so that the reading heads of the first absolute encoder 331 and the second absolute encoder 332 can read the angular positions of the first gear 31 and the second gear 32.
[0052] In some embodiments, please refer to Figure 4 The second gear 32 is rotatably mounted on the encoder bracket 71 via a bearing. It can also be connected to the encoder bracket 71 by screws, which are used to stop the bearing and ensure that the bearing and the encoder bracket 71 are relatively fixed in the axial direction.
[0053] Please refer to some embodiments of this utility model. Figure 1 and Figure 7 The motion output end of the transmission assembly 20 is connected to a first universal joint assembly 61. The first universal joint assembly 61 can be understood as a cross-shaped hinge shaft. The first universal joint assembly 61 has two rotational degrees of freedom.
[0054] In related technologies, the motion output end of the transmission component 20 is connected to other structural components or joints of the robot (referred to as the external structure) via a universal ball joint. The motion output end of the transmission component 20 and the external structure can move in any direction. Therefore, when the linear joint module moves from the working state to the stopped state, its linear motion end stops moving, while the external structure maintains its original acceleration. This impacts the universal ball joint, causing collisions between the inner walls of the universal ball joint (ball head and spherical recess), generating noise. Similarly, when the linear joint module changes from the stopped state to the working state, collisions also occur inside the universal ball joint, generating noise.
[0055] This embodiment of the invention uses a first universal joint assembly 61 to replace the universal ball joint, combined with... Figure 7 The first universal joint assembly 61 can only rotate around the y-axis and Z-axis, but not around the x-axis. Therefore, when the linear joint module outputs movement in the x-direction or stops moving in the x-direction, the first universal joint assembly 61 and the external structure stop simultaneously. The first universal joint assembly 61 has no degree of freedom in the x-direction, thus reducing start-stop noise.
[0056] Optionally, the motion output end of the transmission assembly 20 is a lead screw 23, and one end of the lead screw 23 is connected to a first universal joint assembly 61.
[0057] Please refer to some embodiments of this utility model. Figure 1 and Figure 7 The linear joint module also includes a tension / compression sensor 50, which is connected to a second universal joint assembly 62. The tension / compression sensor 50 and the motion output end of the linear joint module are arranged opposite to each other. Understandably, the tension / compression sensor 50 and the motion output end (lead screw 23) of the linear joint module are located at opposite ends of the axial direction of the linear joint module. The opposite ends of the axial direction of the linear joint module are connected to different external structures. The tension / compression sensor 50 is connected to the external structure through the second universal joint assembly 62, which has two rotational degrees of freedom.
[0058] In related technologies, the tension / compression sensor 50 is connected to other structural components or joints of the robot (referred to as the external structure) via a universal ball joint. The tension / compression sensor 50 and the external structure can move in any direction. Therefore, when the linear joint module suddenly stops or moves, the external structure still maintains its original acceleration, which will impact the universal ball joint. The inner walls of the universal ball joint (ball head and spherical recess) will collide, generating noise.
[0059] This embodiment of the invention uses a human-shaped universal joint assembly instead of a universal ball joint, combined with... Figure 7 The second universal joint assembly 62 can only rotate around the y-axis and Z-axis, but not around the x-axis. Therefore, when the linear joint module moves in the x-direction or stops moving in the x-direction, the second universal joint assembly 62 and the external structure stop simultaneously. The second universal joint assembly 62 has no degree of freedom in the x-direction, which can reduce start-stop noise.
[0060] Please refer to some embodiments of this utility model. Figure 1 and Figure 7 The motion output end of the transmission component 20 is connected to the first universal joint component 61. At the same time, the linear joint module also includes a tension / compression sensor 50, which is connected to the second universal joint component 62.
[0061] Please refer to some embodiments of this utility model. Figure 1 The linear joint module also includes a joint housing 40, a first fixing nut 75, and a second fixing nut 76. The joint housing 40 has internal threads at both ends in the axial direction, such that the first fixing nut 75 is threaded to one axial end of the joint housing 40, and the second fixing nut 76 is threaded to the other axial end of the joint housing 40. The motor 10, at least a portion of the transmission assembly 20, the first gear 31, the second gear 32, the first absolute encoder 331, and the second absolute encoder 332 are all disposed between the first fixing nut 75 and the second fixing nut 76. The joint housing 40 is the outer shell structure of the linear joint module, with most components located inside the joint housing 40. The motion output end (lead screw 23) of the transmission assembly 20 extends at least partially to the outside of the joint housing 40. Because the inner wall of the joint housing 40 has internal threads, the first fixing nut 75 and the second fixing nut 76 are also disposed inside the joint housing 40 to axially position the components inside the joint housing 40 and to seal and shield the components inside the joint housing 40.
[0062] By setting a first fixing nut 75 and a second fixing nut 76, and directly threading the first fixing nut 75 and the second fixing nut 76 to the joint housing 40, the components inside the joint housing 40 can be axially limited. This eliminates the need for multiple circumferentially arranged screws, reduces the number of parts, and consequently reduces the weight of the linear joint module, simplifying the assembly process.
[0063] Please refer to some embodiments of this utility model. Figure 5 The linear joint module also includes a tension / compression sensor 50. A first stop shoulder 41 is provided on the inner wall of the joint housing 40. One end of the tension / compression sensor 50 abuts against the stop shoulder, and the other end of the tension / compression sensor 50 is pressed by a first fixing nut 75. The tension / compression sensor 50 is a sensor used to test the tension or compression applied to it, and is used to detect the tension or compression borne by the linear joint module. The tension / compression sensor 50 is located in the axial direction between the first fixing nut 75 and the first stop shoulder 41, and the tension / compression sensor 50 is fixed by the combined action of the first fixing nut 75 and the first stop shoulder 41.
[0064] By providing a first stop shoulder 41 on the inner wall of the joint housing 40, the first stop shoulder 41 and the first fixing nut 75 can cooperate to axially position the tension and compression sensor 50, eliminating the need for multiple small screws and the need to open connection holes on the tension and compression sensor 50 to cooperate with screws.
[0065] Please refer to some embodiments of this utility model. Figure 1 and Figure 6 The transmission assembly 20 includes a rotating nut 21 connected to the motion output end of the motor 10. A second bearing 74 is disposed between the rotating nut 21 and the joint housing 40. A second stop shoulder 42 is disposed on the inner wall of the joint housing 40. One end of the second bearing 74 abuts against the second stop shoulder 42, and the other end of the second bearing 74 is pressed by a second fixing nut 76. The second bearing 74 supports the rotating nut 21, allowing the rotating nut 21 to rotate smoothly inside the joint housing 40. The second bearing 74 is located axially between the second fixing nut 76 and the second stop shoulder 42, and the second bearing 74 is axially limited by the combined action of the second fixing nut 76 and the second stop shoulder 42.
[0066] By providing a second stop shoulder 42 on the inner wall of the joint housing 40, the second stop shoulder 42 and the second fixing nut 76 can be axially positioned by cooperating with each other, without the need to use multiple small screws or to open a connection hole on the second bearing 74 to cooperate with the screws.
[0067] In some embodiments, please refer to Figure 5The linear joint module also includes a first bearing 73 and a bearing bracket 72. The bearing bracket 72 is fixed to the inner wall of the joint housing 40 and is used to support the first bearing 73. The outer ring of the first bearing 73 is fixed to the inner wall of the bearing bracket 72. The outer periphery of the rotating nut 21 is supported by the first bearing 73 and the second bearing 74. The inner rings of the first bearing 73 and the second bearing 74 are both fixed to the outer wall of the rotating nut 21.
[0068] Please refer to some embodiments of this utility model. Figure 1 The first fixing nut 75, tension / compression sensor 50, control board 33, first gear 31 (second gear 32), first bearing 73, motor 10 (rotating nut 21 of transmission assembly 20), second bearing 74, and second fixing nut 76 are arranged sequentially along the axial direction.
[0069] This invention also provides a robot, which can be a humanoid robot. The robot includes the linear joint module in any of the above embodiments, and the linear joint module is capable of outputting linear motion. The robot may also include a leg module, a chest cavity module, an arm module, etc.
[0070] The robot provided by this utility model adopts the linear joint module in any of the above embodiments. The linear joint module includes a motor 10, a transmission component 20, a first gear 31, a second gear 32, a first absolute encoder 331, and a second absolute encoder 332. The motor 10 drives the transmission component 20 to move to output linear motion. At the same time, the motor 10 drives the first gear 31 to move. The first gear 31 and the second gear 32 mesh with each other. The number of teeth of the first gear 31 and the second gear 32 are different. Therefore, when the first gear 31 rotates one revolution, the number of revolutions of the second gear 32 is less than or greater than one revolution. After the power is turned off, the first absolute encoder 331 and the second absolute encoder 332 can still record the angular positions of the first gear 31 and the second gear 32, respectively. Thus, the number of revolutions of the first gear 31 can be calculated by recording the angular position of the second gear 32 by the second absolute encoder 332, and the angular position of the first gear 31 can be recorded by the first absolute encoder 331. In this way, even after the linear joint module is powered off, the number of rotations and angular position of the motor 10 can still be recorded through the combined action of the first absolute encoder 331 and the second absolute encoder 332.
[0071] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.
Claims
1. A linear joint module, characterized in that: The device includes a motor, a transmission assembly, a meshing first gear and a second gear, a first absolute encoder, and a second absolute encoder. The transmission assembly is used to convert the rotational motion of the motor into linear motion. The first gear is connected to the motion output end of the motor. The number of teeth on the first gear and the second gear are different. The first absolute encoder is used to detect the position of the first gear, and the second absolute encoder is used to detect the position of the second gear, so as to obtain the number of rotations of the first gear based on the difference in the number of teeth of the first gear and the second gear and the position of the second gear.
2. The linear joint module as described in claim 1, characterized in that: The difference in the number of teeth between the second gear and the first gear is 1.
3. The linear joint module as described in claim 2, characterized in that: The transmission assembly includes a planetary ball screw assembly, wherein the first gear is fixedly connected to the rotating nut of the planetary ball screw assembly, and the rated number of rotations of the rotating nut is less than the number of teeth of the second gear.
4. The linear joint module as described in claim 1, characterized in that: The transmission assembly includes a rotating nut connected to the motion output end of the motor. One end of the rotating nut is threadedly connected to a threaded component. The first gear is fixed to the threaded component, and the rotation axis of the first gear is coaxial with the rotation axis of the rotating nut.
5. The linear joint module as described in claim 1, characterized in that: The linear joint module also includes an encoder bracket and a control board fixed to the encoder bracket. The read heads of the first absolute encoder and the second absolute encoder are both disposed on the control board, and the second gear is rotatably disposed on the encoder bracket.
6. The linear joint module as described in any one of claims 1-5, characterized in that: The motion output end of the transmission component is connected to a first universal joint assembly; and / or, the linear joint module further includes a tension / compression sensor, which is connected to a second universal joint assembly.
7. The linear joint module as described in any one of claims 1-5, characterized in that: The linear joint module further includes a joint housing, a first fixing nut, and a second fixing nut. The joint housing has internal threads at both ends in the axial direction, such that the first fixing nut is threaded to one end of the joint housing in the axial direction, and the second fixing nut is threaded to the other end of the joint housing in the axial direction. The motor, at least part of the transmission assembly, the first gear, the second gear, the first absolute encoder, and the second absolute encoder are all disposed between the first fixing nut and the second fixing nut.
8. The linear joint module as described in claim 7, characterized in that: The linear joint module also includes a tension / compression sensor. A first stop shoulder is provided on the inner wall of the joint housing. One end of the tension / compression sensor abuts against the stop shoulder, and the other end of the tension / compression sensor is pressed by the first fixing nut.
9. The linear joint module as described in claim 7, characterized in that: The transmission assembly includes a rotating nut connected to the motion output end of the motor, a second bearing is provided between the rotating nut and the joint housing, a second stop shoulder is provided on the inner wall of the joint housing, one end of the second bearing abuts against the second stop shoulder, and the other end of the second bearing is pressed by the second fixing nut.
10. A robot, characterized in that: Includes the linear joint module as described in any one of claims 1-9.