Joint module

Abstract

A joint module includes: a motor, comprising a housing, a rotor, a front bearing, and a rear bearing; the inner rings of the front and rear bearings are fixed to the rotor, and the outer rings of the front and rear bearings are fixed to the housing; a reducer is disposed at one end near the front bearing and is drive-connected to the rotor; an output flange is drive-connected to the reducer; and a disk holder is disposed along the axial direction of the rotor at one end near the rear bearing, the disk holder is sleeved on the rotor, and axially abuts against the inner ring of the rear bearing. Because the front and rear bearings are adjacent and housed in the same housing, the axial dimension of the entire motor is reduced, and the assembly complexity and product weight are reduced by avoiding the splicing of multiple components into a housing. Furthermore, the mutual abutment between the disk holder and the rear bearing achieves axial preload on the rear bearing, reducing axial clearance and thus improving shaft rigidity.

Description

Technical Field

[0001] This utility model relates to the field of robotics technology, specifically to a joint module. Background Technology

[0002] The joint module of a humanoid robot is a core component enabling flexible movement. In related technologies, the main components of a robot's joint module include a motor and a harmonic reducer. The motor converts electrical energy into mechanical energy, transmitting torque to the harmonic reducer via rotation. The reducer then converts the torque into harmonic motion to achieve deceleration. However, in these technologies, the assembly of the motor and harmonic reducer involves numerous parts, resulting in high assembly complexity. Furthermore, the excessive distance between the front and rear bearings of the motor leads to a large axial dimension, resulting in a large internal space occupation within the module and a loose module structure. The interconnected housing of multiple components further increases assembly complexity and product weight. Utility Model Content

[0003] The main technical problem this invention addresses is the high assembly complexity and loose structure of joint modules in related technologies, which leads to poor robot output performance.

[0004] To address the aforementioned technical problems, this application provides a joint module, including:

[0005] An electric motor includes a housing, a rotor, a front bearing, and a rear bearing; the inner rings of the front bearing and the rear bearing are fixed to the rotor, and the outer rings of the front bearing and the rear bearing are fixed to the housing;

[0006] The speed reducer is located at one end near the front bearing and is connected to the rotor drive.

[0007] The output flange is connected to the reducer.

[0008] The disk mounting bracket is fitted onto the rotor and axially abuts against the inner ring of the rear bearing.

[0009] In one embodiment, the reducer includes a wave generator, a rigid wheel, a flexible wheel, and a crossed roller bearing; the wave generator is drivenly connected to the rotor, and the rigid wheel is connected to the housing through the inner ring of the crossed roller bearing; one end of the flexible wheel is connected to the wave generator, and the other end is fixedly connected to the housing.

[0010] In one embodiment, a flexible bearing is also included, through which the wave generator is connected to the flexible wheel.

[0011] In one embodiment, the crossed roller bearing includes an inner bearing ring, an outer bearing ring, crossed rollers, and an oil seal seat. The inner bearing ring is fixedly connected to the rigid wheel, the outer bearing ring is fixedly connected to the oil seal seat, and the oil seal seat is sleeved on the inner bearing ring. The crossed rollers are disposed between the inner bearing ring and the outer bearing ring.

[0012] In one embodiment, a connecting through hole is provided at a position corresponding to the oil seal seat on the outer ring of the bearing. The crossed roller bearing further includes a connecting member, which passes through the connecting through hole to fix the outer ring of the bearing and the oil seal seat.

[0013] In one embodiment, the output flange includes a fixedly disposed plug portion and a flange portion. The plug portion is inserted into the hollow region inside the rotor along the axial direction, and the flange portion is disposed close to the reducer along the axial direction. The plug portion is connected to the wave generator via a flange bearing.

[0014] In one embodiment, the housing forms a receiving chamber, and a radially extending partition is disposed in the receiving chamber. The partition extends circumferentially within the receiving chamber and divides the receiving chamber into adjacent first chambers and second chambers along the axial direction. The first chamber and the second chamber are respectively used to accommodate the front bearing and the rear bearing.

[0015] In one embodiment, the device further includes a driver and a tail cover, the tail cover being disposed along the axial direction at one end near the rear bearing and connected to the housing, the driver being disposed inside the tail cover; the tail cover has at least one perforated structure that penetrates the cover wall of the tail cover.

[0016] In one embodiment, the disk mounting bracket includes at least two, and each disk mounting bracket is arranged sequentially along the axial direction.

[0017] In one embodiment, the mounting positions for fixing disks on adjacent disk holders are staggered along the axial direction.

[0018] According to the joint module of the above embodiment, since the front bearing and the rear bearing are arranged adjacent to each other and are located in the same housing, the axial dimension of the entire motor is reduced, and the assembly of multiple parts to form a housing is avoided, which reduces the assembly complexity and product weight. Moreover, the disk mounting bracket and the rear bearing are arranged to abut against each other, which realizes the axial preload of the rear bearing, reduces the axial clearance, and thus improves the shaft system rigidity. Attached Figure Description

[0019] Figure 1 This is a cross-sectional schematic diagram of the joint module in an embodiment of this application.

[0020] Figure 2 This is a cross-sectional view of the shell in an embodiment of this application.

[0021] Figure 3 This is a cross-sectional schematic diagram of the speed reducer in an embodiment of this application.

[0022] Figure 4 This is a schematic diagram of the reducer structure in an embodiment of this application.

[0023] Figure 5 for Figure 1 Enlarged schematic diagram of part A in the middle.

[0024] Explanation of reference numerals in the attached figures:

[0025] 1-Output flange; 101-Plug-in part; 102-Flange part; 2-Reducer; 3-Housing; 4-Disk mounting bracket; 5-Tail cover; 7-Flange bearing; 8-Rotor; 9-Motor; 10-Front bearing; 11-Rear bearing; 12-Driver; 22-Rigid wheel; 23-Wave generator; 24-Flexible bearing; 26-Oil seal seat; 27-Crossed roller bearing; 271-Bearing inner ring; 272-Bearing outer ring; 273-Crossed roller; 274-Connector; 28-Flexible wheel; 41-Internal thread; 81-External thread; 31-Accommodating chamber; 32-Separator; 34-First chamber; 35-Second chamber. Detailed Implementation

[0026] The present invention will now be described in further detail with reference to the accompanying drawings and specific embodiments. Similar elements in different embodiments are referred to by related similar element reference numerals. In the following embodiments, many details are described to facilitate a better understanding of the present application. However, those skilled in the art will readily recognize that some features may be omitted in different situations, or may be replaced by other elements, materials, or methods. In some cases, certain operations related to the present application are not shown or described in the specification. This is to avoid obscuring the core parts of the present application with excessive description. For those skilled in the art, detailed description of these related operations is not necessary; they can fully understand the related operations based on the description in the specification and general technical knowledge in the art.

[0027] Furthermore, the features, operations, or characteristics described in the specification can be combined in any suitable manner to form various embodiments. At the same time, the steps or actions in the method description can be rearranged or adjusted in a manner obvious to those skilled in the art. Therefore, the various orders in the specification and drawings are only for the clear description of a particular embodiment and do not imply a necessary order, unless otherwise stated that a particular order must be followed.

[0028] The serial numbers assigned to components in this document, such as "first" and "second," are used only to distinguish the described objects and have no sequential or technical meaning. The terms "connection" and "linkage" used in this application, unless otherwise specified, include both direct and indirect connections (linkages).

[0029] In related technologies, joint modules are typically implemented using a motor connected to a harmonic reducer. The motor outputs torque, while the harmonic reducer reduces speed and transmits torque. A motor generally consists of at least a housing, a rotor, and a stator. To maintain rotor rotational balance, two sets of bearings are usually axially mounted on the rotor, and these bearings are positioned far apart, resulting in a large axial length of the rotor. Furthermore, for assembly, the motor housing is generally formed by splicing multiple parts, especially with bearings located on different parts. Specifically, the front and rear housings of the assembled motor each have a set of bearings, which facilitate the rotational connection between the rotor and the housing. This structure not only makes assembly difficult due to the multiple parts of the housing, but the installation of bearings at both ends also leads to an excessively large axial length of the motor, resulting in a loose joint module structure, excessive weight, and poor robot output performance.

[0030] To address the issues of high assembly complexity and loose structure leading to poor robot output performance in related technologies, this application provides a joint module. Please refer to... Figure 1 and Figure 2 The joint module includes:

[0031] The motor 9 includes a housing 3, a rotor 8, a front bearing 10, and a rear bearing 11; the front bearing 10 and the rear bearing 11 are arranged adjacent to each other, and the inner rings of the front bearing 10 and the rear bearing 11 are fixedly arranged on the rotor 8, and the outer rings of the front bearing 10 and the rear bearing 11 are fixedly arranged on the housing 3.

[0032] The reducer 2 is located at one end near the front bearing 10 and is connected to the rotor 8 in a transmission manner;

[0033] Output flange 1 is connected to reducer 2 for transmission;

[0034] The disk mounting bracket 4 is fitted onto the rotor 8 and axially abuts against the inner ring of the rear bearing 11.

[0035] In this embodiment, the joint module uses either a framed motor or a frameless motor. A frameless motor, meaning a motor without a housing, can be integrated with the equipment used in the application scenario, thus saving the space occupied by the motor housing and significantly reducing the product's size. Motor 9 is the power source for the joint module; it converts electrical energy into mechanical energy through the rotation of rotor 8, and the generated torque can be output to reducer 2.

[0036] To orient and balance the rotation of the rotor 8, the motor 9 in this embodiment further includes at least two bearings, namely a front bearing 10 and a rear bearing 11. The rotor 8 has two opposite ends along its axial direction, namely a front end and a rear end, wherein the front end is located close to the reducer 2 and the rear end is located away from the reducer 2. The front bearing 10 and the rear bearing 11 are sleeved on the rotor 8 along the axial direction and are arranged adjacent to each other. This means that the distance between the front bearing 10 and the rear bearing 11 is reduced, thereby making full use of the internal space of the rotor 8, reducing the axial size of the entire motor 9, reducing the weight of the joint module, and thus improving the power density of the joint module.

[0037] The housing 3 is fitted onto the motor 9, housing the front bearing 10 and the rear bearing 11 within it, thus making full use of the internal space of the module. An accommodating chamber 31 is formed inside the housing 3, opening at both ends along the axial direction so that the housing 3 can be fitted over the front bearing 10 and the rear bearing 11. Each of the front bearing 10 and the rear bearing 11 has an outer ring and an inner ring. The inner rings of the front bearing 10 and the rear bearing 11 are fixedly connected to the rotor 8, while the outer rings of the front bearing 10 and the rear bearing 11 are fixedly connected to the housing 3 through the accommodating chamber 31. In this way, the rotor 8 can be rotatably connected to the housing 3 based on the front bearing 10 and the rear bearing 11. Furthermore, a single housing 3 can achieve the connection of the stator and rotor of the motor 9, reducing the number of assembly components and thus lowering the complexity of motor assembly and product weight.

[0038] To enable the disk encoder to detect the operating parameters of the motor 9 and the output flange 1, the joint module may also include a disk mounting bracket 4 for fixing the disk. The disk mounting bracket 4 is located at the rear end and sleeved on the rotor 8, and has mounting positions for fixing the disk. The disk mounting bracket 4 can be used to fix the disk encoder, which can provide precise feedback signals for adjusting the closed-loop control accuracy of the joint module. The disk encoder can detect the speed and position of the motor 9, ensuring that the motor 9 runs along a predetermined trajectory, and can also monitor the speed and position of the output flange 1, thus reflecting the actual motion state of the joint module. To optimize the preload method of the bearings on the motor, reduce axial clearance, and improve shaft rigidity, the disk mounting bracket 4 can be positioned axially close to the end of the rear bearing 11, abutting against the inner ring of the rear bearing 11. Since the disk holder 4 is axially close to the end of the rear bearing 11 and abuts against the inner ring of the rear bearing 11, it is equivalent to the disk holder 4 being tightly attached to the inner ring of the rear bearing 11. Therefore, the disk holder 4 can axially preload the rear bearing 11, thereby reducing axial clearance and improving shaft stiffness.

[0039] Please refer to Figure 3 and Figure 4 The reducer 2 is axially positioned at the front end and is connected to the rotor 8 via a transmission connection. The main function of the reducer 2 is to reduce the rotational speed and increase the torque, thereby enhancing the robot's positioning accuracy and load capacity. In this embodiment, the reducer 2 is axially positioned at the front end and is connected to the rotor 8 via a transmission connection. Specifically, the reducer 2 may include a wave generator 23, a rigid wheel 22, a flexible wheel 28, and a crossed roller bearing 27. The wave generator 23 is connected to the rotor 8 via a transmission connection. The rigid wheel 22 is connected to the housing 3 via the inner ring 271 of the crossed roller bearing 27. One end of the flexible wheel 28 is connected to the wave generator 23, and the other end is fixedly mounted to the housing 3. The rigid wheel 22 is made of a rigid material, while the flexible wheel 28 is made of a flexible material. Therefore, when connected, the flexible wheel 28 can deform relative to the rigid wheel 22 in a corresponding direction, thereby generating relative motion with the rigid wheel 22 and achieving a deceleration effect.

[0040] The wave generator 23 converts the rotational motion output by the rotor 8 into harmonic motion. The wave generator 23 causes the flexible wheel 28 to undergo elastic deformation, thereby generating relative motion with the rigid wheel 22 and achieving a deceleration effect. The flexible wheel 28 works in conjunction with the wave generator 23 to transmit torque through elastic deformation. The flexible design of the flexible wheel 28 maintains high precision and stability while transmitting torque. In this embodiment, a flexible bearing 24 may also be included, through which the wave generator 23 is connected to the flexible wheel 28.

[0041] In some alternative embodiments, please refer to Figure 3 and Figure 4 The crossed roller bearing 27 specifically includes an inner ring 271, an outer ring 272, crossed rollers 273, and an oil seal seat 26. The inner ring 271 is fixedly connected to the rigid wheel 22, and the outer ring 272 is fixedly connected to the oil seal seat 26, with the oil seal seat 26 sleeved on the inner ring 271. The crossed rollers 273 are disposed between the inner ring 271 and the outer ring 272. In this embodiment, the outer ring 272 of the crossed roller bearing 27 is fixedly connected to the rigid wheel 22. The crossed roller bearing 27 also includes an oil seal seat 26, which is fixedly connected to the bearing outer ring 272. Therefore, the size of the bearing outer ring 272 can be appropriately reduced, and the oil seal seat 26 can be considered as the outer ring of the crossed roller bearing 27. To reduce the weight of the entire joint module, the material density of the oil seal seat 26 can be configured to be lower than that of the bearing outer ring 272. For example, the oil seal seat 26 can be made of high-strength, low-density materials such as aluminum alloy, magnesium alloy, and titanium alloy. This reduces the weight of the joint module while ensuring structural strength. The oil seal seat 26 can mate with the bearing outer ring 272 via a stop, and then a fastening connection is achieved through a connecting piece.

[0042] To achieve a fixed connection between the bearing outer ring 272 and the oil seal seat 26, connecting through holes are provided at corresponding positions on the bearing outer ring 272 and the oil seal seat 26. The crossed roller bearing 27 also includes a connecting member 274, which passes through the connecting through holes to fix the bearing outer ring 272 and the oil seal seat 26. The connecting member 274 can be fixedly connected to the bearing outer ring 272 and the oil seal seat 26 through a threaded engagement. The connecting member 274 can be a bolt, and the connecting through hole is a threaded hole, achieving a fixed connection through the threaded engagement of the bolt and the threaded hole. Alternatively, the connecting member 274 can be a combination of a bolt and a nut. After the bolt passes through the bearing outer ring 272 and the oil seal seat 26, it is fixedly connected to the nut, thus fixing the bearing outer ring 272 and the oil seal seat 26. Alternatively, the connecting member 274 can also form a fixed connection through the connecting through holes using an interference fit or other methods. Furthermore, the connecting member 274 can also form a fixed connection through the connecting through holes using a snap-fit ​​mechanism or other similar methods.

[0043] In some optional embodiments, to transmit torque, the joint module may further include an output flange 1, wherein the output flange 1 includes a fixedly disposed plug-in portion 101 and a flange portion 102. The plug-in portion 101 is axially inserted into the hollow region inside the rotor 8, and the flange portion 102 is axially disposed close to the reducer 2. The plug-in portion 101 is connected to the wave generator 23 via a flange bearing 7. The purpose of the output flange 1 is to connect the reducer 2 to an external load, thereby transmitting torque to the external load. The output flange 1 is connected to the wave generator 23, i.e., connected to the reducer 2, via an internal mounting hole and a flange bearing 7. One or more flange bearings 7 may be provided, and the plug-in portion 101 may also be connected to the rotor 8 via the flange bearings 7.

[0044] In some alternative embodiments, please refer to Figure 2Since both the front bearing 10 and the rear bearing 11 are located within the accommodating chamber 31, a radially extending partition 32 is provided within the accommodating chamber 31 to prevent interference between them and to facilitate assembly and positioning. The partition 32 extends circumferentially within the accommodating chamber 31 and axially divides the accommodating chamber 31 into an adjacent first chamber 34 and a second chamber 35. The first chamber 34 and the second chamber 35 are used to accommodate the front bearing 10 and the rear bearing 11, respectively. In other words, in this embodiment, the accommodating chamber 31 is divided into two chambers according to the distribution of the front bearing 10 and the rear bearing 11. The first chamber 34 and the second chamber 35 are used to accommodate the front bearing 10 and the rear bearing 11 along their axial direction, respectively. The partition 32 separates the first chamber 34 and the second chamber 35, ensuring that the front bearing 10 and the rear bearing 11 are adjacent but do not contact each other to avoid interference during operation. Specifically, in the embodiments of this application, the first chamber 34 and the second chamber 35 can be integrally formed based on the shape of the shell 3. There can be one or more partitions 32. When there is one partition 32, the partition 32 can extend circumferentially and be arranged in a ring shape within the receiving chamber 31. When there are multiple partitions 32, each partition 32 can be arranged circumferentially along the inner wall of the receiving chamber 31.

[0045] In some optional embodiments, to control the operation of the motor 9, a driver 12 and a tail cover 5 may be included. The tail cover 5 is axially disposed at one end near the rear bearing 11 and connected to the housing 3. The driver 12 is disposed inside the tail cover 5. The driver 12 is fixedly connected to the rotor 8 inside the tail cover 5 and is used to control the operation of the rotor 8. For ease of maintenance, the tail cover 5 may have at least one perforated structure, which penetrates the wall of the tail cover 5. This allows operators to directly observe the internal operating status of the tail cover 5 from the outside, and to directly view and operate the driver 12 through the tail cover 5, greatly improving operational efficiency and maintenance convenience. Furthermore, by providing a perforated structure on the tail cover 5, the surface area of ​​the tail cover 5 is increased, especially the contact area with the outside air, thereby effectively improving the heat dissipation performance of the tail cover 5. This allows the heat generated during the operation of the motor 9 to dissipate more quickly through the air, improving the stability of the motor 9's operation and extending the service life of the joint module.

[0046] The disk mounting bracket 4 may include at least two, which are arranged sequentially along the axial direction. The mounting positions on adjacent disk mounting brackets 4 are staggered along the axial direction. The two disk mounting brackets 4 have reserved mounting positions, one of which can be located on the outer ring of the corresponding disk mounting bracket 4, and the other on the inner ring of the corresponding disk mounting bracket 4. This staggered mounting positions of the two disks prevents overlapping and interference between adjacent disks.

[0047] In some alternative embodiments, please refer to Figure 5 To ensure a fixed connection between the disk mounting bracket 4 and the rotor 8, the outer circumferential surface of the rotor 8 can be provided with an external thread 81, and the inner circumferential surface of the disk mounting bracket 4 can be provided with an internal thread 41. The external thread 81 and the internal thread 41 engage with each other to fix the disk mounting bracket 4 and the rotor 8. This threaded connection between the rotor 8 and the disk mounting bracket 4 eliminates the need for additional connecting parts, thus simplifying the assembly complexity and improving assembly efficiency.

[0048] According to the joint module of the above embodiment, since the front bearing 10 and the rear bearing 11 are arranged adjacently and in the same housing 3, the axial dimension of the entire motor 9 is reduced, and the assembly complexity and product weight are reduced by avoiding the splicing of multiple parts to form the housing 3. Moreover, the disk fixing bracket 4 and the rear bearing 11 are arranged to abut against each other, realizing the axial pre-tightening of the rear bearing 11, reducing the axial clearance, thereby improving the shaft system stiffness and improving the output performance.

[0049] The above-described specific examples are for illustrative purposes only and are not intended to limit the scope of this invention. Those skilled in the art to which this invention pertains can make various simple deductions, modifications, or substitutions based on the concept of this invention.

Claims

1. A joint module, characterized in that, include: An electric motor includes a housing, a rotor, a front bearing, and a rear bearing; the inner rings of the front bearing and the rear bearing are fixed to the rotor, and the outer rings of the front bearing and the rear bearing are fixed to the housing; The speed reducer is located at one end near the front bearing and is connected to the rotor drive. The output flange is connected to the reducer via a transmission. The disk mounting bracket is fitted onto the rotor and axially abuts against the inner ring of the rear bearing.

2. The joint module as described in claim 1, characterized in that, The reducer includes a wave generator, a rigid wheel, a flexible wheel, and a crossed roller bearing; the wave generator is connected to the rotor via a drive, and the rigid wheel is connected to the housing via the inner ring of the crossed roller bearing; one end of the flexible wheel is connected to the wave generator, and the other end is fixedly connected to the housing.

3. The joint module as described in claim 2, characterized in that, It also includes a flexible bearing, through which the wave generator is connected to the flexible wheel.

4. The joint module as described in claim 2, characterized in that, The crossed roller bearing includes an inner bearing ring, an outer bearing ring, crossed rollers, and an oil seal seat. The inner bearing ring is fixedly connected to the rigid wheel, the outer bearing ring is fixedly connected to the oil seal seat, and the oil seal seat is sleeved on the inner bearing ring. The crossed rollers are disposed between the inner bearing ring and the outer bearing ring.

5. The joint module as described in claim 4, characterized in that, The bearing outer ring is provided with a connecting through hole at a position corresponding to the oil seal seat. The crossed roller bearing also includes a connecting member, which passes through the connecting through hole to fix the bearing outer ring and the oil seal seat.

6. The joint module as described in claim 2, characterized in that, The output flange includes a plug-in portion and a flange portion. The plug-in portion is inserted into the hollow region inside the rotor along the axial direction, and the flange portion is disposed close to the reducer along the axial direction. The plug-in portion is connected to the wave generator through a flange bearing.

7. The joint module as described in any one of claims 1-6, characterized in that, The housing has a receiving chamber, and a radially extending partition is provided in the receiving chamber. The partition extends circumferentially within the receiving chamber and divides the receiving chamber into an adjacent first chamber and a second chamber along the axial direction. The first chamber and the second chamber are used to accommodate the front bearing and the rear bearing, respectively.

8. The joint module as described in any one of claims 1-6, characterized in that, It also includes a driver and a tail cover, the tail cover being disposed along the axial direction at one end near the rear bearing and connected to the housing, the driver being disposed inside the tail cover; the tail cover has at least one hollow structure, the hollow structure being disposed through the cover wall of the tail cover.

9. The joint module according to any one of claims 1-6, characterized in that, The disk mounting bracket includes at least two, and each disk mounting bracket is arranged sequentially along the axial direction.

10. The joint module as described in claim 9, characterized in that, The mounting positions for fixing disks on adjacent disk holders are staggered relative to each other along the axial direction.

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