Joint module and robot

Abstract

The utility model belongs to robot movement part technical field, concretely relates to a joint module and robot. The joint module includes a casing assembly (1), a speed reducer (2), a motor (3), a rotating shaft (4) and a band brake (5). The middle seat (12) of casing assembly (1) and shell main part (11) jointly enclose and form an installation cavity for accommodating motor (3) and band brake (5). The outer top wall of the disc part (42) of rotating shaft (4) is connected with the input end of speed reducer (2), and the inner top wall of the disc part (42) of rotating shaft (4) is connected with the first brake piece of band brake (5). The axial length of the whole joint module is greatly shortened, so that the structure is extremely compact. This not only reduces the overall weight of the module, but also reduces the moment of inertia, improves the dynamic response performance of the robot, and makes the overall robot more compact and efficient.

Description

Technical Field

[0001] This utility model belongs to the field of robot motion component technology, specifically relating to a joint module and a robot. Background Technology

[0002] Robot joint modules, as the core functional components constituting the motion joints of various robots such as industrial robots, collaborative robots, and service robots, directly determine the robot's load capacity, motion accuracy, and response speed. To achieve precise drive and control of the joints, joint modules typically integrate key components such as motors, reducers, encoders, and brakes for power-off protection.

[0003] In existing technical solutions, the internal structure of robot joint modules is typically arranged by stacking functional components in series along a central axis. A typical structure is one where components such as motors, reducers, brakes, and encoders are arranged in sequence, forming a long string. For example, the motor is placed in the middle, with its output shaft connected to the input of the reducer, while an additional brake device is installed at the other end of the motor (usually the rear end).

[0004] Because the main components, such as the motor, reducer, and brake, are stacked axially, the axial length of the entire joint module is significantly stretched. This results in an excessively long overall axial dimension and a non-compact structure. This poses a serious constraint for modern robots (especially collaborative robots, humanoid robots, and medical robots) that strive for lightweight design, miniaturization, and high flexibility. Excessively long joints limit the robot's range of motion and flexibility, increase its rotational inertia, and negatively impact the overall aesthetics of the structure.

[0005] Therefore, how to optimize the internal spatial layout of the joint module, effectively shorten its overall axial length without sacrificing performance, and improve the integration and compactness of the structure has become a technical problem that urgently needs to be solved in this field. Utility Model Content

[0006] In view of this, the present invention proposes a joint module and a robot, aiming to reduce the volume of the robot's joint module and make the structure of the joint module more compact.

[0007] In a first aspect, the joint module provided by this utility model includes a housing assembly, a reducer, a motor, a rotating shaft, and a brake. The housing assembly includes a housing body and a middle seat, the middle seat being connected to the bottom end of the housing body; the reducer is mounted on the outer top end of the housing body; the motor includes an outer stator and an inner rotor, the outer stator being connected to the inner sidewall of the housing body; the rotating shaft includes a shaft portion and a disc portion formed radially outward of the shaft portion, the outer annular wall of the disc portion being connected to the inner sidewall of the inner rotor, and the outer top wall of the disc portion being connected to the input end of the reducer; the brake includes a first brake element, a second brake element, and a brake seat, the first brake element being connected to the inner top wall of the disc portion, the second brake element being movably connected to the brake seat via an elastic element, and the brake seat being fixedly connected to the middle seat; wherein, the motor and the brake are disposed in an installation cavity formed between the housing body and the middle seat.

[0008] In a preferred embodiment of the joint module of this utility model, the inner rotor is located within the axial range of the outer stator.

[0009] In a preferred embodiment of the joint module of this utility model, at least a portion of the brake is located within the axial range of the outer stator, or the entire brake is located within the axial range of the outer stator.

[0010] In a preferred embodiment of the joint module of this utility model, an annular groove is formed between the outer ring wall, the inner top wall and the shaft portion of the rotating shaft; wherein, the first brake component is disposed in the annular groove, and the brake is hollow and allows the shaft portion to pass through.

[0011] In a preferred embodiment of the joint module of this utility model, the disc portion of the rotating shaft is connected to the input end of the reducer by a first bolt, which passes through the annular groove.

[0012] In a preferred embodiment of the joint module of this utility model, the reducer is a harmonic reducer, and the input end of the reducer is the bottom end of the wave generator.

[0013] In a preferred embodiment of the joint module of this utility model, the joint module further includes a first bearing and a second bearing; the first bearing is installed on the inner top wall of the housing body, the inner ring of the first bearing is connected to the circumferential side wall at the upper end of the shaft, and the first bearing is at least partially located within the axial range of the outer stator; the second bearing is installed on the top of the middle seat, and its inner ring is connected to the circumferential side wall at the lower end of the shaft, and the second bearing is located within the axial range of the housing body.

[0014] In a preferred embodiment of the joint module of this utility model, the top end of the middle seat extends into the inner side of the shell body, and the second bolt passes through the side wall of the shell body and connects to the circumferential side wall of the top end of the middle seat.

[0015] In a preferred embodiment of the joint module of this utility model, the joint module further includes a feedback shaft and an encoder assembly; the feedback shaft includes a connecting section and an extension section, the connecting section is provided with a connecting flange, which is connected to the output flange of the reducer through the connecting flange; one end of the extension section is threaded to the bottom end of the connecting section, and the other end extends out of the bottom end of the motor and the middle seat; the encoder assembly includes a first rotor disk, a second rotor disk, and a detection circuit board, the first rotor disk is connected to the bottom end of the rotating shaft; the second rotor disk is connected to the bottom end of the feedback shaft; the detection circuit board is connected to the inner bottom surface of the middle seat and is used to detect the positional changes of the first rotor disk and the second rotor disk.

[0016] Secondly, in a robot provided by this utility model, at least one motion joint of the robot is provided with a joint module as described in any of the technical solutions in the first aspect.

[0017] In the articulated module and robot provided by this utility model, the motor and brake of the articulated module are cleverly arranged in the same mounting cavity enclosed by the main body and the middle seat. The outer top wall of the rotating shaft's disc portion is connected to the input end of the reducer, and the inner top wall of the rotating shaft's disc portion is connected to the first braking component of the brake. This significantly shortens the axial length of the entire articulated module, resulting in an exceptionally compact structure. This not only reduces the overall weight of the module but also decreases the moment of inertia, improves the robot's dynamic response performance, and makes the robot more compact and efficient overall. Attached Figure Description

[0018] The preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings, so that those skilled in the art can more clearly understand the above and other features and advantages of the present invention, in which:

[0019] Figure 1 This is a schematic diagram of the external structure of a preferred embodiment of the joint module in this example.

[0020] Figure 2 This is a cross-sectional view of a preferred embodiment of the joint module in this example.

[0021] Figure 3 This is an exploded view of a preferred embodiment of the joint module in this example.

[0022] Figure 4 This is a schematic diagram of the rotating shaft in the joint module of this embodiment.

[0023] Figure 5 This is a schematic diagram of the structure of the motor used to connect to the reducer in the joint module of this embodiment.

[0024] Figure 6 This is a schematic diagram showing the assembly position relationship between the brake and the motor in the joint module of this embodiment.

[0025] Figure 7 This is a schematic diagram of the feedback shaft in the joint module of this embodiment.

[0026] The reference numerals in the attached figures are as follows:

[0027] 1-Shell assembly; 11-Shell body; 111-Second bolt; 12-Middle seat; 13-Base;

[0028] 2-Reducer; 21-Output flange;

[0029] 3-Motor; 31-Outer stator; 32-Inner rotor;

[0030] 4-Shaft; 41-Shaft portion; 42-Disc portion; 401-Annular groove;

[0031] 5-Brake;

[0032] 61 - First bearing; 62 - Second bearing;

[0033] 7-Feedback shaft; 701-Connecting flange; 71-Connecting section; 72-Extension section;

[0034] 8-Encoder assembly; 9-Drive circuit board. Detailed Implementation

[0035] To make the objectives, technical solutions, and advantages of this utility model clearer, the technical solutions of this utility model will be described in detail below. Obviously, the described embodiments are only a part of the embodiments of this utility model, and not all of them. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this utility model.

[0036] It should be noted that, in the description of this utility model, unless otherwise explicitly specified and limited, the terms "connection" and "setup" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium. Those skilled in the art can understand the specific meaning of the above terms in this utility model according to the specific circumstances.

[0037] Furthermore, it should be understood in the description of this application that the terms “center,” “upper,” “lower,” “front,” “rear,” “left,” “right,” “vertical,” “horizontal,” “top,” “bottom,” “inner,” and “outer,” etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and 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.

[0038] This embodiment provides a robot, which can be a six-axis industrial robot, a collaborative robot, a humanoid robot, an exoskeleton robot, or any other type of multi-joint automated device.

[0039] The innovation of the robot in this embodiment is that at least one of its motion joints, or even all of its motion joints, is equipped with any of the joint modules described in the following embodiments and their various variations.

[0040] Because the robot uses such a highly compact, lightweight, and highly integrated joint module, its overall performance is significantly improved. Specifically: (1) More compact structure and more flexible movement: The smaller joint size allows the robot's arm span design to be more slender, with a larger effective workspace, enabling it to enter narrower spaces for operation. (2) Lighter weight and higher energy efficiency: The lightweight joint module reduces the robot's own weight, which means that it requires less energy to drive the same load, or can drive a larger load with the same energy consumption.

[0041] This embodiment provides a highly integrated joint module. Its core design concept is to optimize the spatial layout of functional components such as motor 3 and brake 5 to significantly reduce the axial dimension of the joint module and improve its compactness.

[0042] Reference Figures 1 to 3 The joint module in this embodiment includes a housing assembly 1, a reducer 2, a motor 3, a rotating shaft 4, and a brake 5.

[0043] The housing assembly 1 serves as the supporting frame and external enclosure for the entire joint module, and can be made of a high-strength, lightweight alloy material (such as aluminum alloy). Specifically, the housing assembly 1 includes a generally cup-shaped or cylindrical housing body 11, and a central seat 12 for sealing the bottom opening of the housing body 11. The central seat 12 is connected to the housing body 11 by bolts or other fasteners, together forming a mounting cavity for accommodating the motor 3 and the brake 5.

[0044] The reducer 2 is mounted on the outer top of the housing body 11. In a preferred embodiment, the reducer 2 can be a harmonic reducer. Harmonic reducers have a large transmission ratio, high precision, compact structure, and hollow characteristics. The rigid wheel of the harmonic reducer can be fixedly connected to the housing body 11, while the flexible wheel serves as the output end, connected to an external load (such as another joint link of the robot) through its output flange 21. The input end of the harmonic reducer is a wave generator, the bottom of which is used to receive power input from the motor 3.

[0045] The motor 3 can be a frameless motor, allowing for direct integration into the housing assembly 1 and saving space. The motor 3 includes an annular outer stator 31 and an inner rotor 32 located inside it. The outer stator 31 is securely fixed to the inner wall of the housing body 11 by interference fit, bonding, or screw locking. The inner wall of the inner rotor 32 can be connected to the shaft 4.

[0046] Reference Figure 4 and Figure 5 The rotating shaft 4 is crucial for transmitting power and connecting core components. It comprises a central shaft portion 41 and a disc portion 42 integrally formed radially outward from the shaft portion 41. The outer ring wall of the disc portion 42 is connected to the inner wall of the inner rotor 32 of the motor 3, for example, by interference fit or adhesive bonding, so that the rotation of the inner rotor 32 can directly drive the entire rotating shaft 4 to rotate. The outer top wall of the disc portion 42 of the rotating shaft 4 is connected to the input end of the reducer 2 (i.e., the bottom end of the wave generator), transmitting power to the reducer 2.

[0047] The brake 5 is a power-off braking device used to provide braking torque and maintain the joint position when the motor 3 is de-energized. It includes a first brake component, a second brake component, a brake seat, and an elastic element (e.g., a spring assembly) for providing preload. The brake seat is fixedly connected to the center seat 12, serving as the stationary base of the brake 5. The second brake component is axially movable to the brake seat under the action of the elastic element. The first brake component is fixedly connected to the inner top wall of the disc portion 42 of the rotating shaft 4 and rotates with the rotating shaft 4.

[0048] Combination Figure 2 and Figure 6 In this embodiment, the motor 3 and the brake 5 are cleverly arranged in the same mounting cavity enclosed by the housing body 11 and the middle seat 12, and the motor 3 and the brake 5 are arranged to overlap in the radial and axial directions.

[0049] When motor 3 is energized, the outer stator 31 generates a rotating magnetic field, driving the inner rotor 32 and the shaft 4 fixed to it to rotate. Simultaneously, the brake 5 coil is also energized, generating electromagnetic force to overcome the elastic force of the elastic element, causing the second brake element to separate from the first brake element, releasing the brake. The shaft 4 then smoothly transmits power to the wave generator of the reducer 2. After reduction and torque amplification, the reducer 2 drives the external load through its output flange 21. When motor 3 is de-energized, the brake 5 coil loses power, the electromagnetic force disappears, and the elastic element pushes the second brake element to press against the first brake element rotating with the shaft 4, generating strong friction, thereby locking the shaft 4 and preventing the joint from moving due to external force or its own weight.

[0050] By nesting the motor 3 and the brake 5 inside the housing, and connecting the outer top wall of the disc portion 42 of the rotating shaft 4 to the input end of the reducer 2, and connecting the inner top wall of the disc portion 42 of the rotating shaft 4 to the first braking component of the brake 5, the axial length of the entire joint module is greatly shortened, resulting in an exceptionally compact structure. This not only reduces the overall weight of the module but also decreases the moment of inertia, improves the robot's dynamic response performance, and makes the robot more compact and efficient overall.

[0051] In one specific implementation, to further optimize axial space, after assembly, the inner rotor 32 of the motor 3 is positioned entirely within the axial range of the outer stator 31. In other words, from an axial projection perspective, the inner rotor 32 is completely "wrapped" by the outer stator 31. This design avoids the additional axial length occupied by the misalignment of the rotor and stator, making it a preferred solution for achieving an extremely compact design.

[0052] Similarly, to maximize axial space compression, the mounting position of the brake 5 overlaps axially with that of the motor 3 (especially the outer stator 31). In one embodiment, at least a portion of the brake 5 is located within the axial range of the outer stator 31. For example, the upper half of the brake 5 is axially aligned with the lower half of the outer stator 31. In a more optimized embodiment, the brake 5 can be entirely located within the axial range of the outer stator 31. This arrangement means that the motor 3 and the brake 5 are radially positioned outward (motor 3) and radially inward (brake 5), but are essentially on the same "floor" axially, thus maximizing space utilization.

[0053] To more cleverly accommodate the brake 5 components and optimize the assembly process, the structure of the rotating shaft 4 can be further designed so that an annular groove 401 is naturally formed between the outer ring wall, inner top wall, and central shaft portion 41 of the disc portion 42 of the rotating shaft 4. This annular groove 401 has two main functions:

[0054] (1) Accommodating the brake 5: The first brake element (usually an annular brake disc) can be precisely installed in this annular groove 401. In this way, the first brake element will not protrude axially, making the structure more flat and compact. At the same time, the entire brake 5 assembly (including the second brake element and the brake seat) can be designed as a hollow structure for the central shaft portion 41 of the rotating shaft 4 to pass through.

[0055] (2) Easy assembly: The first bolt connecting the disc part 42 of the rotating shaft 4 to the input end of the reducer 2 (such as the wave generator) can be tightened through this annular groove 401. That is, the assembly tool can be inserted into the groove 401 and the first bolt can be inserted and tightened from bottom to top. This "internal installation" design avoids complicated installation operations from the reducer 2 side, simplifies the assembly process, and makes the structural connection more reliable.

[0056] Continue to refer to Figure 2 To ensure stable and high-precision rotation of the pivot 4, bearings are required for support. The joint module also includes a first bearing 61 and a second bearing 62.

[0057] The first bearing 61 (e.g., a thin-walled deep groove ball bearing) is mounted on the inner top wall of the housing body 11, and its inner ring is connected to the circumferential side wall at the upper end of the shaft portion 41 of the rotating shaft 4. In order not to increase the additional axial dimension, the mounting position of the first bearing 61 can be designed so that it is at least partially located within the axial range of the outer stator 31, that is, overlapping the motor 3 in the axial direction.

[0058] The second bearing 62 is mounted on the top of the center seat 12, and its inner ring is connected to the circumferential sidewall at the lower end of the shaft portion 41 of the rotating shaft 4. Also for the sake of compactness, the second bearing 62 is located within the axial range of the housing body 11.

[0059] Simultaneously, a first bearing 61 and a second bearing 62 are provided to support the upper and lower ends of the rotating shaft 4 respectively, forming a double support structure, thereby greatly improving the running stability and anti-overturning torque of the rotating shaft 4.

[0060] To achieve a stable and easy-to-assemble connection between the shell body 11 and the middle seat 12, a special connection structure can be adopted. The top of the middle seat 12 can be designed as a stepped structure extending into the inner side of the shell body 11, forming a tight fit with the inner wall of the shell body 11. Then, by drilling a hole in the side wall (i.e., radially) of the shell body 11, a second bolt 111 is inserted and locked to the circumferential side wall at the top of the middle seat 12. This radial locking method provides better connection rigidity compared to the traditional end-face bolt connection, and does not occupy the installation space at the bottom of the middle seat 12, facilitating the connection of the middle seat 12 with other components.

[0061] Combination Figure 2 , Figure 3and Figure 7 In order to achieve high-precision closed-loop control, this joint module can also integrate a dual encoder feedback system, which includes a feedback shaft 7 and an encoder assembly 8.

[0062] Feedback shaft 7 is a slender rod or hollow shaft used to transmit the actual rotation of the output end of reducer 2 to the end of the joint module. It includes a connecting section 71 and an extension section 72. The connecting section 71 is provided with a connecting flange 701, which is fixedly connected to the output flange 21 of reducer 2 (i.e., the output end of the flex wheel) by bolts. One end of the extension section 72 is connected to the bottom end of the connecting section 71 by threads or other means, and the other end passes through the hollow structure of the entire module (through the wave generator of reducer 2, the shaft portion 41 of rotating shaft 4, the brake 5 and the center hole of the middle seat 12), and finally extends to the bottom of the middle seat 12.

[0063] The encoder assembly 8 is used to detect rotational position. It includes a first rotor disk, a second rotor disk, and a shared detection circuit board.

[0064] The first rotor disk (e.g., a magnetic ring or grating disk) is fixed to the bottom end of the rotating shaft 4 and is used to detect the rotational position (input position) on the side of the motor 3. The second rotor disk is fixed to the bottom end of the feedback shaft 7 and is used to detect the rotational position (output position) at the output end of the reducer 2. The detection circuit board is fixed to the inner bottom surface of the middle seat 12, and integrates sensors (such as Hall sensors or photoelectric sensors) on it, which can simultaneously and non-contactly detect the angle changes of the first and second rotor disks.

[0065] This dual-encoder design allows the control system to simultaneously obtain precise position information from both the input of motor 3 and the output of the joint module. This enables dual closed-loop control, effectively compensating for elastic deformation and potential backlash errors caused by the harmonic reducer, thereby significantly improving the absolute positioning accuracy and trajectory tracking performance of the joint module. Furthermore, this design, which integrates the feedback shaft 7 and encoder 8 into the hollow channel of the joint module, does not increase the module's radial or axial dimensions, maintaining its highly compact advantage.

[0066] In addition, continue to refer to Figures 1 to 3 The joint module also includes a base 13, which is connected to the bottom end of the middle seat 12. The encoder assembly 8 and the drive circuit board 9 are both disposed between the middle seat 12 and the base 13. The drive circuit board 9 is electrically connected to the outer stator 31 of the motor 3, and the detection circuit board of the encoder assembly 8 is also signal-connected to the drive circuit board 9.

[0067] It should be understood that although this specification is described according to various embodiments, not every embodiment or implementation method contains only one independent technical solution. This way of describing the specification is only for clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other implementation methods that can be understood by those skilled in the art.

[0068] The above descriptions are merely illustrative embodiments of this application and are not intended to limit the scope of the embodiments of this application. Any equivalent changes, modifications, and combinations made by those skilled in the art without departing from the concept and principles of the embodiments of this application should fall within the protection scope of the embodiments of this application.

Claims

1. A joint module, characterized in that, include: The housing assembly (1) includes a housing body (11) and a middle seat (12), the middle seat (12) being connected to the bottom end of the housing body (11); The reducer (2) is installed on the outer top of the housing body (11); The motor (3) includes an outer stator (31) and an inner rotor (32), wherein the outer stator (31) is connected to the inner wall of the housing body (11); The rotating shaft (4) includes a shaft portion (41) and a disc portion (42) formed on the radially outer side of the shaft portion (41). The outer ring wall of the disc portion (42) is connected to the inner side wall of the inner rotor (32), and the outer top wall of the disc portion (42) is connected to the input end of the reducer (2). The brake (5) includes a first brake component, a second brake component, and a brake seat. The first brake component is connected to the inner top wall of the disc (42). The second brake component is movably connected to the brake seat through an elastic member, and the brake seat is fixedly connected to the middle seat (12). The motor (3) and the brake (5) are disposed in the mounting cavity formed between the shell body (11) and the middle seat (12).

2. The joint module according to claim 1, characterized in that, The inner rotor (32) is located within the axial range of the outer stator (31).

3. The joint module according to claim 1, characterized in that, At least a portion of the brake (5) is located within the axial range of the outer stator (31), or the entire brake (5) is located within the axial range of the outer stator (31).

4. The joint module according to claim 1, characterized in that, An annular groove (401) is formed between the outer ring wall, the inner top wall and the shaft portion (41) of the rotating shaft (4); The first brake component is disposed in the annular groove (401), and the brake (5) is hollow and allows the shaft (41) to pass through.

5. The joint module according to claim 4, characterized in that, The disc portion (42) of the rotating shaft (4) is connected to the input end of the reducer (2) by a first bolt, which is inserted through the annular groove (401).

6. The joint module according to claim 5, characterized in that, The reducer (2) is a harmonic reducer, and the input end of the reducer (2) is the bottom end of the wave generator.

7. The joint module according to claim 1, characterized in that, Also includes: A first bearing (61) is mounted on the inner top wall of the housing body (11), the inner ring of the first bearing (61) is connected to the circumferential side wall at the upper end of the shaft portion (41), and the first bearing (61) is at least partially located within the axial range of the outer stator (31); or, A second bearing (62) is mounted on the top of the middle seat (12), and its inner ring is connected to the circumferential sidewall of the lower end of the shaft (41), and the second bearing (62) is located within the axial range of the housing body (11).

8. The joint module according to claim 7, characterized in that, The top of the middle seat (12) extends into the inner side of the shell body (11), and the second bolt (111) passes through the side wall of the shell body (11) and connects to the circumferential side wall of the top of the middle seat (12).

9. The joint module according to claim 1, characterized in that, Also includes: The feedback shaft (7) includes a connecting section (71) and an extension section (72). The connecting section (71) is provided with a connecting flange (701), which is connected to the output flange (21) of the reducer (2) through the connecting flange (701). One end of the extension section (72) is threaded to the bottom end of the connecting section (71), and the other end extends out of the bottom end of the motor (3) and the middle seat (12). The encoder assembly (8) includes a first rotor disk, a second rotor disk, and a detection circuit board. The first rotor disk is connected to the bottom end of the rotating shaft (4); the second rotor disk is connected to the bottom end of the feedback shaft (7); and the detection circuit board is connected to the inner bottom surface of the middle seat (12) and is used to detect position changes of the first rotor disk and the second rotor disk.

10. A robot, characterized in that, The robot is provided with a joint module as described in any one of claims 1 to 9 at at least one of its motion joints.

Images