Joint module and robot

Abstract

The invention relates to the technical field of robots, in particular to a joint module and a robot. The joint module mainly comprises a shell assembly (10), a first motor (11), a first speed reducer (12), a second motor (21) and a second speed reducer (22). The second motor (21) and the speed reducer of the second motor (21) are nested in the cavity of the inner stator (112) of the first motor (11), so that a motor-in-motor structure is realized. According to the design, on the premise that the radial size of the joint module is not increased, the inner space, which is usually wasted, of the inner stator (112) is utilized, so that the single joint module has the double-shaft independent output capacity, the size and the axial length of the double-shaft joint module are greatly reduced, and the power density and the space utilization rate are improved.

Description

Technical Field

[0001] This application relates to the field of robotics technology, and in particular to a joint module and a robot. Background Technology

[0002] Robotics technology is increasingly being used in industrial production, medical services, aerospace, and daily life. As the core moving component of a robot, the performance of the joint module directly determines the robot's motion accuracy, load capacity, and overall flexibility.

[0003] In existing robot designs, to achieve multi-degree-of-freedom movements at the end effector or specific parts of a robotic arm (such as wrist pitch and rotation, shoulder swing and rotation), two or more joint modules are typically required. The traditional solution is to connect two independent single-degree-of-freedom joint modules axially in series. For example, the output end of the first joint module is fixed to the base of the second joint module via a flange or connector, thus forming a dual-axis drive unit.

[0004] However, this traditional serial structure, which simply stacks two complete joint modules along the axial direction, results in a relatively long overall axial length. In applications with extremely demanding space requirements, such as collaborative robots or humanoid robot wrists or feet, excessively long joints limit the robot's range of motion and increase the risk of collisions. Furthermore, the serial structure means that the first-stage joint must not only drive the end effector load but also overcome the weight and rotational inertia of the second-stage joint module itself. This "dead weight" significantly reduces the overall load capacity of the joint module and also affects the robot's dynamic response performance.

[0005] Therefore, how to significantly reduce the volume and axial length of a dual-axis joint module while ensuring output torque, and optimize the load capacity of the joint in multi-degree-of-freedom drive scenarios, is a technical problem that urgently needs to be solved in current robot joint design. Summary of the Invention

[0006] In view of this, the present invention proposes a joint module and a robot, which aims to solve the problems of poor compactness and low power density of the multi-degree-of-freedom drive structure of the robot.

[0007] In a first aspect, a joint module provided by the present invention includes a housing assembly, a first motor, a first reducer, a second motor, and a second reducer. The housing assembly comprises a cylindrical portion, an end seat portion, and an end cover portion, the end seat portion and the end cover portion being connected to the axial ends of the cylindrical portion. The first motor is disposed inside the housing assembly and includes an outer rotor and an inner stator, with one axial end of the inner stator connected to the end seat portion. The input end of the first reducer is connected to the output end of the outer rotor, its housing is connected between the cylindrical portion and the end cover portion, and its first output flange is exposed outside the end cover portion. The second motor includes an outer stator and an inner rotor, with the outer stator coaxially connected inside the inner stator. The second reducer is connected to the output end of the inner rotor, at least partially located inside the inner stator, and its second output flange is exposed outside the first output flange.

[0008] In a preferred embodiment of the joint module provided by the present invention, the inner stator is provided with a stator support and a coil winding. A support ring is formed at one axial end of the stator support near the end cover. A plurality of extensions arranged in a ring array are provided between the support ring and the body of the stator support. The coil winding is coaxially connected to the circumferential outside of the body of the stator support.

[0009] In a preferred embodiment of the joint module provided by the present invention, a first bearing is connected between the inner ring wall of the outer rotor and the outer ring wall of the support ring portion, and a second bearing is connected between the inner ring wall of the outer rotor and the outer ring wall of the end seat portion.

[0010] In a preferred embodiment of the joint module provided by the present invention, a rotor sleeve is connected to the outer circumferential side of the body of the outer rotor, and bearing mounting grooves are formed on the inner sides of both axial ends of the rotor sleeve to install the first bearing and the second bearing.

[0011] In a preferred embodiment of the joint module provided by the present invention, the joint module further includes a flange, the outer ring of which is connected to an axial end of the rotor sleeve facing the end cover, and the inner ring of which is connected to the input end of the first reducer.

[0012] In a preferred embodiment of the joint module provided by the present invention, the joint module further includes a single encoder assembly, which includes a reading head and a code disk disposed opposite to each other. The reading head is connected to the axial end face of the housing of the second reducer facing the flange, and the code disk is connected to the axial inner side of the flange.

[0013] In a preferred embodiment of the joint module provided by the present invention, an annular partition is formed inside the inner stator, the inner rotor motor is disposed between the partition and the end seat, and the second reducer is disposed between the partition and the end cover.

[0014] In a preferred embodiment of the joint module provided by the present invention, a third bearing is provided between one axial end of the inner rotor and the shaft hole of the partition portion; a fourth bearing is provided between the other axial end of the inner rotor and the shaft hole of the end seat portion.

[0015] In a preferred embodiment of the joint module provided by the present invention, the joint module further includes a fifth bearing, which is disposed between the circumferential outer side of the first output flange and the shaft hole of the end cover.

[0016] In a preferred embodiment of the joint module provided by the present invention, the joint module further includes a sixth bearing, which is disposed between the inner circumferential side of the first output flange and the outer circumferential side of the second output flange.

[0017] Secondly, in a robot provided by the present invention, the robot is equipped with the joint module described in any of the technical solutions in the first aspect above.

[0018] In the joint module and robot provided in this application, a "motor-within-a-motor" structure is achieved by nesting the second motor and its reducer within the inner stator cavity of the first motor. This design utilizes the typically wasted internal space of the inner stator without increasing the radial dimension of the joint module, enabling a single joint module to have independent dual-axis output capabilities. This significantly reduces the volume and axial length of the dual-axis joint module, while improving power density and space utilization. Accordingly, when the robot uses this joint module, the robot's controller sends commands to the first and second motors of the joint module. The first motor drives the outer rotor to rotate, and after being slowed down by the first reducer, drives the first output flange to swing the upper arm or hand. Simultaneously, the second motor drives the inner rotor to rotate, and after being slowed down by the second reducer, drives the second output flange to move the forearm or fingers. The two movements do not interfere with each other, and their axes coincide. Attached Figure Description

[0019] Preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings, which will make the above and other features and advantages of the present invention more apparent to those skilled in the art. In the drawings:

[0020] Figure 1 This is a schematic diagram of the external structure of the joint module in this embodiment.

[0021] Figure 2This is a cross-sectional structural diagram of the joint module in this embodiment.

[0022] Figure 3 This is an exploded structural diagram of the joint module in this embodiment.

[0023] Figure 4 This is a schematic diagram of the stator support structure of the joint module in this embodiment.

[0024] Figure 5 This is a schematic diagram showing the assembly relationship between the first motor and the second motor of the joint module in this embodiment.

[0025] Figure 6 This is a schematic diagram showing the assembly relationship between the first and second reducers of the joint module in this embodiment.

[0026] Figure 7 This is a schematic diagram showing the connection relationship between the first motor and the first reducer of the joint module in this embodiment.

[0027] The accompanying figure is labeled as follows:

[0028] 10-Outer shell assembly; 101-Cylinder section; 102-End seat section; 103-End cap section;

[0029] 11-First motor;

[0030] 111-Outer rotor; 1111-Rotor sleeve; 1112-Flange;

[0031] 112-Inner stator;

[0032] 1121-Stator bracket; 11211-Support ring; 11212-Extension; 11213-Partition;

[0033] 1122 - Coil winding;

[0034] 12-First reducer; 121-First output flange;

[0035] 21-Second motor; 211-Outer stator; 212-Inner rotor;

[0036] 22-Second reducer; 221-Second output flange;

[0037] 3-Single encoder assembly; 31-Read head; 32-Code disk;

[0038] 41-First bearing; 42-Second bearing; 43-Third bearing; 44-Fourth bearing; 45-Fifth bearing; 46-Sixth bearing. Detailed Implementation

[0039] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of this invention will be described in detail below. Obviously, the described embodiments are merely some embodiments of this invention, and not all embodiments. Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this invention.

[0040] It should be noted that, in the description of this invention, unless otherwise explicitly specified and limited, the terms "connection" and "configuration" 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 invention according to the specific circumstances.

[0041] 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.

[0042] This embodiment relates to a robot equipped with the joint module described in the embodiments below. Specifically, the joint module can be configured on the part of a multi-degree-of-freedom robotic arm, the arm or leg of a humanoid robot, or the finger joint base of a dexterous hand. Robots using this joint module have smaller joints and a simpler appearance (due to the elimination of external wiring and protruding motors). Furthermore, because the two motors are concentric on both axes, the kinematics algorithm is easier to plan, resulting in better dynamic response performance.

[0043] This embodiment provides a highly integrated dual-degree-of-freedom joint module, suitable for robot joints, especially end effectors or humanoid robotic arm joints with strict limitations on size and weight.

[0044] Reference Figures 1 to 3The joint module mainly consists of a shell assembly 10, a first drive system (including a first motor 11 and a first reducer 12), and a second drive system (including a second motor 21 and a second reducer 22). The shell assembly 10 serves as the supporting skeleton of the entire module and includes a cylindrical portion 101, an end seat portion 102, and an end cap portion 103. The cylindrical portion 101 serves as the main shell; the end seat portion 102 and the end cap portion 103 seal the axial ends of the cylindrical portion 101. The end seat portion 102 typically serves as the fixed end for connection to the robot's previous limb; the end cap portion 103 is located on the output side.

[0045] First drive system (external shaft drive): The first motor 11 adopts a "external rotor + inner stator" structural layout. The first motor 11 is located inside the housing assembly 10. One axial end of the inner stator 112 is fixedly connected to the end seat portion 102 and is in a stationary state. The outer rotor 111 is sleeved on the outside of the inner stator 112 and can rotate relative to the inner stator 112. The first reducer 12 is preferably a harmonic reducer or other hollow reducer. Its input end (such as a wave generator) is connected to the output end of the outer rotor 111; its fixed housing (such as a rigid wheel) is clamped or connected between the cylindrical portion 101 and the end cover portion 103 to achieve fixation. Its first output flange 121 (such as a flexible wheel and its extension structure) passes through the end cover portion 103 and is exposed, forming the first rotational degree of freedom output of the joint module. Alternatively, the first reducer 12 can also be a planetary reducer.

[0046] Second drive system (inner shaft drive): To maximize space utilization, the second motor 21 is cleverly "nested" within the internal cavity of the inner stator 112 of the first motor 11. The second motor 21 includes an outer stator 211 and an inner rotor 212. The outer stator 211 is directly and coaxially fixed to the inner wall of the inner stator 112 of the first motor 11, or the inner stator support 1121 of the first motor 11 directly serves as the housing of the second motor 21. The second reducer 22 is preferably a miniature planetary reducer or a harmonic reducer. It is connected to the output end of the inner rotor 212 of the second motor 21. At least a portion of the main body of this reducer is housed within the internal space of the inner stator 112 of the first motor 11, thereby shortening the axial length. The second output flange 221 of the second reducer 22 coaxially passes through the central hole of the first reducer 12 and is ultimately exposed through the first output flange 121.

[0047] Technical benefits: By nesting the second motor 21 and its reducer within the cavity of the inner stator 112 of the first motor 11, a "motor-within-a-motor" structure is achieved. This design utilizes the typically wasted internal space of the inner stator 112 without increasing the radial dimension of the joint module, enabling a single joint module to have independent dual-axis output capabilities (e.g., simultaneously controlling the pitch and yaw of the robot arm, or simultaneously controlling the swing of the upper and lower arms, or simultaneously controlling the movement of the thigh or lower leg). This significantly reduces the volume and axial length of the dual-axis joint module, and improves power density and space utilization.

[0048] Accordingly, when the robot uses the joint module to work, the robot's controller sends commands to the first motor 11 and the second motor 21 of the joint module. The first motor 11 drives the outer rotor 111 to rotate, and after being reduced in speed by the first reducer 12, it drives the first output flange 121 to swing the upper arm or thigh. At the same time, the second motor 21 drives the inner rotor 212 to rotate, and after being reduced in speed by the second reducer 22, it drives the second output flange 221 to move the forearm or lower leg. The two movements do not interfere with each other, and their axes coincide.

[0049] Combination Figure 4 and Figure 5 This embodiment provides a detailed description of the stator and rotor support structure of the first motor 11. The inner stator 112 is not only a carrier for the coils but also a mounting compartment for the second motor 21. The inner stator 112 includes a stator support 1121 and a coil winding 1122. The stator support 1121 has an enlarged "support ring 11211" at one end near the end cover 103. This support ring 11211 is connected to the body of the stator support 1121 by multiple "extensions 11212" (i.e., spoke-like structures) arranged in a ring array. This hollow design (the gaps between the extensions 11212) not only reduces weight but also serves as a heat dissipation channel or wiring channel for the internal second motor 21. The coil winding 1122 is coaxially wound or mounted on the circumferential outer side of the stator support 1121 body, opposite to the magnets of the outer rotor 111.

[0050] Combination Figure 2To ensure the stability of the outer rotor 111 under high-speed rotation, this embodiment employs a dual-bearing support structure. The first bearing 41 connects the inner ring wall of the outer rotor 111 to the outer ring wall of the support ring portion 11211 of the stator bracket 1121, providing support near the output end. The second bearing 42 connects the inner ring wall of the outer rotor 111 to the outer ring wall of the end seat portion 102, providing support near the fixed end. Furthermore, to facilitate bearing installation and increase rotor rigidity, a separate rotor sleeve 1111 can be connected to the outer circumference of the outer rotor 111. Bearing mounting grooves are machined on the inner sides of both axial ends of this rotor sleeve 1111. The outer rings of the first bearing 41 and the second bearing 42 are respectively installed in these two bearing mounting grooves.

[0051] Technical benefits: This two-end supported structure (dual-bearing span arrangement) greatly improves the rotational accuracy and anti-overturning torque capability of the outer rotor 111, ensuring a uniform air gap in the motor and enhancing motor efficiency and lifespan. Meanwhile, the special design of the stator support 1121 balances structural strength with internal wiring / heat dissipation requirements.

[0052] Combination Figure 6 and Figure 7 This embodiment describes how torque is transmitted and how position feedback is achieved. The joint module also includes a flange 1112. The outer ring of the flange 1112 is connected to one end of the rotor sleeve 1111 of the first motor 11 facing the end cover 103 by screws or the like; the inner ring of the flange 1112 is connected to the input end of the first reducer 12 (e.g., the wave generator of a harmonic reducer, or the sun gear of a planetary reducer). The large-diameter rotational motion of the outer rotor 111 is transmitted to the input end of the reducer.

[0053] To detect the speed or position of the first motor 11, the joint module integrates an encoder assembly 3. A reading head 31 (sensor) is mounted on the housing of the second reducer 22 (since the housing of the second reducer 22 is fixed inside the inner stator 112 and is a stationary component), and faces the flange 1112. A code disk 32 (magnetic ring or grating disk) is mounted on the axial inner surface of the flange 1112.

[0054] When the outer rotor 111 of the first motor 11 drives the flange 1112 to rotate, the stationary reading head 31 reads the information from the code disk 32 that rotates with the flange 1112. Using the flange 1112 as an intermediary, power transmission is achieved, and a mounting surface for the code disk 32 is provided. The reading head 31 is cleverly mounted on the housing of the second reducer 22, avoiding the need for additional supports, fully utilizing the axial clearance, and achieving an extremely compact sensing layout.

[0055] Reference Figure 2 and Figure 3 This embodiment details the layout of the second drive chain inside the inner stator 112. An annular "partition portion 11213" (e.g., an inwardly flared flange) is formed within the internal cavity of the inner stator 112 of the first motor 11. This partition portion 11213 axially divides the internal space into a rear compartment and a front compartment. The rear compartment, the space between the partition portion 11213 and the end cap portion 102, is used to accommodate the electromagnetic components (stator and rotor) of the second motor 21. The front compartment, the space between the partition portion 11213 and the end cap portion 103, is used to accommodate the second reducer 22.

[0056] The inner rotor 212 of the second motor 21 also requires stable support. The inner rotor 212 is supported by a third bearing 43 and a fourth bearing 44. The third bearing 43 is located between one axial end (output end) of the inner rotor 212 and the central shaft hole of the partition 11213. The fourth bearing 44 is located between the other axial end (tail end) of the inner rotor 212 and the central shaft hole of the end seat 102.

[0057] Technical benefits: The partition 11213 not only serves as a physical divider but also acts as a mounting base for the second reducer 22 and a bearing housing for the inner rotor 212, improving the structural integration. The double-end bearing support design of the inner rotor 212 ensures the stability of the micro motor under high-speed operation.

[0058] Combination Figure 2 This embodiment provides a reinforcement support scheme for the output end (first output flange 121) of the first reducer 12 and the output end (second output flange 221) of the second reducer 22.

[0059] The fifth bearing 45 is disposed between the circumferential outer side of the first output flange 121 and the inner wall of the central shaft hole of the end cover portion 103. In this way, the external load is directly transmitted to the housing assembly 10 of the joint module through the end cover portion 103, which enhances the ability of the first output flange 121 to withstand radial forces.

[0060] The sixth bearing 46 is disposed between the inner circumferential side of the first output flange 121 and the outer circumferential side of the second output flange 221. Thus, if the second output flange 221 extends too far, this arrangement can utilize the first output flange 121 to provide auxiliary support for the second output flange 221, or form a relative rotational support relationship between the two output shafts, increasing overall coaxiality.

[0061] (Note: For bearings 41, 42, 43, 44, 45, and 46, the serial numbers here are to distinguish them from the aforementioned bearings; the actual number depends on the specific circumstances.)

[0062] 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.

[0063] 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. An articulating module, comprising: The utility model relates to a kind of motor, comprising: Housing assembly (10) is provided with barrel portion (101), end seat portion (102) and end cover portion (103), the end seat portion (102) and the end cover portion (103) are connected in the axial both ends of the barrel portion (101); First motor (11) is arranged inside the housing assembly (10), including outer rotor (111) and inner stator (112), and the axial one end of the inner stator (112) is connected to the end seat portion (102); First speed reducer (12) is connected in the output end of the outer rotor (111), its shell is connected between the barrel portion (101) and the end cover portion (103), and its first output flange (121) is exposed to the end cover portion (103); Second motor (21) includes outer stator (211) and inner rotor (212), and the outer stator (211) is coaxially connected inside the inner stator (112); Second speed reducer (22) is connected in the output end of the inner rotor (212), at least part is located inside the inner stator (112), and its second output flange (221) is exposed to the first output flange (121).

2. The joint module according to claim 1, characterized in that The inner stator (112) is provided with: Stator support (1121) is formed with support ring portion (11211) near the axial one end of the end cover portion (103), and a plurality of extension portions (11212) are arranged in annular array between the support ring portion (11211) and the body of the stator support (1121); Coil winding (1122) is coaxially connected in the annular outer portion of the body of the stator support (1121).

3. The joint module according to claim 2, characterized in that The inner annular wall of the outer rotor (111) is connected with the outer annular wall of the support ring portion (11211) by the first bearing (41), and the inner annular wall of the outer rotor (111) is connected with the outer annular wall of the end seat portion (102) by the second bearing (42).

4. The joint module according to claim 3, characterized in that The annular outer side of the body of the outer rotor (111) is connected with rotor sleeve (1111), and the inner side of the axial both ends of the rotor sleeve (1111) is formed with bearing mounting groove to mount the first bearing (41) and the second bearing (42).

5. The joint module according to claim 4, characterized in that Further comprising: Flange plate (1112) is connected in the axial end of the rotor sleeve (1111) towards the end cover portion (103) by the outer ring portion, and the inner ring portion is connected in the input end of the first speed reducer (12).

6. The joint module of claim 5, wherein, Further comprising: Single encoder assembly (3) includes oppositely arranged reading head (31) and code disc (32), the reading head (31) is connected in the axial end surface of the shell of the second speed reducer (22) towards the flange plate (1112), and the code disc (32) is connected in the axial inner side of the flange plate (1112).

7. The joint module of claim 1, wherein An annular partition portion (11213) is formed inside the inner stator (112), the inner rotor (212) motor is arranged between the partition portion (11213) and the end seat portion (102), and the second speed reducer (22) is arranged between the partition portion (11213) and the end cover portion (103).

8. The joint module of claim 7, wherein, A third bearing (43) is arranged between an axial end portion of the inner rotor (212) and a shaft hole of the partition portion (11213); A fourth bearing (44) is arranged between another axial end portion of the inner rotor (212) and a shaft hole of the end seat portion (102).

9. The joint module of claim 1, wherein, Further comprising: A fifth bearing (45) is arranged between a ring outer side of the first output flange (121) and a shaft hole of the end cover portion (103); or, A sixth bearing (46) is arranged between a ring inner side of the first output flange (121) and a ring outer side of the second output flange (221).

10. A robot, characterized in that The joint module is configured with any one of claims 1-9.

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