Planetary joint module

Abstract

The present disclosure provides a kind of planetary joint module, including shell, motor and planetary reducer.Motor includes motor stator and motor rotor, motor stator is fixedly arranged in shell, motor rotor is arranged in motor shaft;Planetary reducer contains at least one level of reduction unit, each level of reduction unit includes sun gear, planetary gear, inner ring gear and planet carrier, inner ring gear is fixedly arranged in shell, planet carrier is located inside inner ring gear, and is provided with pin hole and gap, pin hole is installed with pin shaft, planetary gear is rotatably installed on planet carrier by pin shaft, and is limited to the inside of gap in axial direction, and the part of planetary gear is located outside gap, the part of planetary gear located outside gap is engaged with the inner tooth of inner ring gear, the part of planetary gear located inside gap is engaged with sun gear, the sun gear of first level of reduction unit is rigidly connected with motor shaft, in adjacent two reduction units, the planet carrier of upper level of reduction unit is rigidly connected with the sun gear of lower level of reduction unit.

Description

Technical Field

[0001] This disclosure relates to a planetary joint module, which belongs to the field of robotics. Background Technology

[0002] In recent years, with the rise of humanoid robots, more and more manufacturers have begun to plan and develop humanoid robots. The core structure for humanoid robots to move is the joint module of each joint. The joint module is a power structure that integrates motors, reducers and drivers. Common joint modules can be divided into harmonic joint modules, direct drive joint modules, linear joint modules and planetary joint modules according to the type of reducer.

[0003] Traditional planetary joint modules are inconvenient to use in humanoid robots because reducer manufacturers usually do not have compact requirements, resulting in large size and weight, low power density, and other issues. Utility Model Content

[0004] This disclosure provides a planetary joint module.

[0005] According to one aspect of this disclosure, a planetary joint module is provided, comprising: shell; An electric motor, comprising a stator and a rotor, wherein the stator is fixedly mounted on a housing, and the rotor is mounted on a shaft; and A planetary reducer includes at least one reduction unit. Each reduction unit includes a sun gear, planet gears, an internal gear ring, and a planet carrier. The internal gear ring is fixedly mounted on the housing. The planet carrier is located inside the internal gear ring and has a pin hole and a notch. A pin is installed in the pin hole. The planet gears are rotatably mounted on the planet carrier via the pin and are axially limited to the inside of the notch. Part of the planet gear is located outside the notch. The part of the planet gear located outside the notch meshes with the internal teeth of the internal gear ring, and the part of the planet gear located inside the notch meshes with the sun gear. In this system, the sun gear of the first-stage reduction unit is rigidly connected to the motor shaft, and in two adjacent reduction units, the planetary carrier of the previous-stage reduction unit is rigidly connected to the sun gear of the next-stage reduction unit.

[0006] According to one aspect of the technical solution disclosed herein, a planetary reducer includes at least one reduction unit. When the motor rotor drives the motor shaft to rotate, the sun gear of the first-stage reduction unit is rigidly connected to the motor shaft, so the sun gear rotates accordingly. Since the sun gear meshes with the planet gears, and the planet gears mesh with the internal gear ring, which remains stationary, according to the gear transmission principle, the planet gears will revolve and rotate around the sun gear. The rotation and revolution of the planet gears drive the planet carrier to rotate, thereby achieving speed reduction. In the case of multi-stage reduction units, in two adjacent reduction units, the planet carrier of the previous stage reduction unit is rigidly connected to the sun gear of the next stage reduction unit. Thus, the rotation of the previous stage planet carrier drives the rotation of the next stage sun gear, further reducing speed through the gear meshing relationship of the next stage reduction unit. After multiple stages of such speed reduction, the planet carrier of the final stage reduction unit rotates. The planet carrier of the final stage reduction unit is provided with an output interface, through which power is output to drive the external load. In this design, the motor stator is fixed to the housing, and the motor shaft is directly rigidly connected to the sun gear of the first-stage reduction unit, reducing unnecessary connecting parts and space occupation. In a planetary reducer, components such as the internal gear ring, planet carrier, planet gears, and sun gear are tightly integrated into a housing. The planet carrier features notches that expose the planet gears, enabling bidirectional meshing between the internal gear ring and the sun gear and reducing axial space. This structural layout achieves multi-stage reduction within a limited space, effectively reducing the overall size of the planetary joint module. The compact structure reduces unnecessary material usage, thus lightening the overall module's weight. Furthermore, the rational component layout and rigid connections avoid adding extra weight due to complex connection structures. Despite the reduced size and weight, this planetary joint module can still achieve effective deceleration and power transmission through one or more planetary reduction units, ensuring sufficient output torque and power, thereby improving power density and making it more suitable for applications in humanoid robots and other devices with strict space and weight requirements.

[0007] According to at least one embodiment of the planetary joint module of this disclosure, the planetary carrier is provided with two sets of spaced mounting portions (for example, four planetary gears are provided, and each set of mounting portions has four mounting portions). The mounting portions are provided with pin holes, and the two ends of the pin shaft are respectively disposed in the pin holes of the two sets of mounting portions. The planetary joint module also includes a rotary bearing and planetary washers. The planetary gears are rotatably mounted on the pin shafts through the rotary bearings, and the planetary washers are respectively abutted on both axial sides of the planetary gears. The planetary washers are fixedly disposed on the end face of the pin holes of the mounting portions for axial limiting of the rotary bearings and the planetary gears.

[0008] According to at least one embodiment of the planetary joint module of this disclosure, the motor rotor has a hollow structure, and at least one reduction unit is disposed inside the hollow structure of the motor rotor, which greatly improves the space utilization rate.

[0009] In the technical solution of this embodiment, the mounting part, together with the rotating bearing and the planetary washer, realizes the stable rotation of the planetary gear on the pin shaft. The axial limiting function of the planetary washer ensures that the planetary gear will not move axially during operation, thereby improving the stability and reliability of the planetary joint module.

[0010] According to at least one embodiment of the planetary joint module of the present disclosure, the planetary joint module further includes a hollow shaft, which is rigidly connected to the planet carrier of the last stage reduction unit and rotatably passes through the axis of the sun gear of each stage reduction unit. The hollow shaft is provided with an axially extending channel, the two ends of which communicate with the outside of the planetary joint module.

[0011] In the technical solution of this embodiment, the hollow shaft design allows for the arrangement of wiring or pipes inside the planetary joint module, and the connection with the outside is achieved through the axial extension channel, which facilitates the integration of the module with other devices and the wiring layout, and improves the overall space utilization and system compactness.

[0012] According to at least one embodiment of the planetary joint module of this disclosure, the planetary joint module further includes a drive plate, a high-speed side magnetic ring, and a low-speed side magnetic ring. The high-speed side magnetic ring is disposed on the motor shaft, and the low-speed side magnetic ring is disposed on the hollow shaft. The housing is fixedly provided with a motor cover for sealing the motor. The drive plate is fixedly disposed on the motor cover and is used to collect and process the rotational position signals and speed signals of the high-speed side magnetic ring and the low-speed side magnetic ring in real time, so as to detect the rotational position signals and speed signals of the motor shaft, the hollow shaft, the planetary carrier of the last stage reduction unit, and the output interface.

[0013] In the technical solution of this embodiment, by setting high-speed and low-speed magnetic rings and a drive board, and by installing and fixing the low-speed encoder on the hollow shaft, the high and low speed encoders are arranged coaxially. Data is read by a single drive board, achieving a highly compact structure. It can obtain the rotational position and speed information of the input and output ends of the planetary joint module in real time and accurately, providing data support for the closed-loop control and monitoring of the system, and helping to improve the operating accuracy and stability of the entire system.

[0014] According to at least one embodiment of the planetary joint module of this disclosure, the planetary joint module further includes a magnetic ring mounting plate, a shrinking cover, and a shrinking screw; the magnetic ring mounting plate is provided with a tapered hole and is sleeved on the outside of the hollow shaft through the tapered hole; the shrinking cover is sleeved on the outside of the hollow shaft and is provided with a tapered boss adapted to the tapered hole at the sleeve joint, the tapered boss being inserted into the inside of the tapered hole; the magnetic ring mounting plate is fixedly connected to the shrinking cover by the shrinking screw, the inner wall of the tapered hole presses against the tapered boss to clamp and fix the tapered boss to the outside of the hollow shaft; a low-speed side magnetic ring is mounted on the magnetic ring mounting plate.

[0015] In this embodiment, the use of a tapered hole and tapered boss combined with a tightening screw provides a reliable connection and fixation, ensuring that the low-speed side magnetic ring is stably mounted on the hollow shaft and will not loosen or shift during the operation of the planetary joint module, thus guaranteeing the accuracy of signal acquisition. Furthermore, loosening the tightening screw allows for adjustment of the low-speed side magnetic ring's position, improving the ease of adjustment.

[0016] According to at least one embodiment of the planetary joint module of this disclosure, the collar support is provided with a first fixing screw hole; the outer shell is fixedly provided with a joint cover at one end opposite to the collar support, and the joint cover is provided with a second fixing screw hole.

[0017] In the technical solution of this embodiment, the setting of the first and second fixing screw holes facilitates the installation and fixing of the planetary joint module with other equipment, and improves the convenience of assembly and the reliability of connection.

[0018] According to at least one embodiment of the planetary joint module of the present disclosure, the planetary reducer includes a primary reduction unit and a secondary reduction unit, wherein the planet carrier of the primary reduction unit is rigidly connected to the sun gear of the secondary reduction unit, and the planet carrier of the secondary reduction unit is provided with an output interface.

[0019] In the technical solution of this embodiment, a two-stage reduction unit design is adopted, which can be flexibly configured according to different reduction requirements to achieve a large reduction ratio and meet the requirements of power output speed and torque under different working conditions; the rigid connection ensures the stability and efficiency of power transmission.

[0020] According to at least one embodiment of the planetary joint module of the present disclosure, the secondary reduction unit is provided with a collar support, a crossed roller bearing, an outer collar pressure plate, and an inner collar pressure plate. The collar support is fixedly disposed on the internal gear ring of the secondary reduction unit. The outer ring of the crossed roller bearing is fixed to the collar support by the outer collar pressure plate, and the inner ring is fixed to the planet carrier of the secondary reduction unit by the inner collar pressure plate.

[0021] In the technical solution of this embodiment, the cross roller bearing can withstand large radial and axial loads and bending moments, which improves the support rigidity and rotational accuracy of the planetary carrier of the secondary reduction unit. The fixing method of the outer pressure plate and the inner pressure plate of the collar ensures the stable installation and reliable operation of the cross roller bearing, which is beneficial to improving the overall performance and service life of the planetary joint module.

[0022] According to at least one embodiment of the planetary joint module of the present disclosure, the outer side of the housing is provided with a conical surface and a plurality of keyways; the conical surface is arranged around the axial middle section of the housing and is used to cooperate with the conical sleeve on the joint side to achieve axial positioning and self-locking; the keyways are evenly spaced along the circumference of the housing and are used to engage with the transmission key on the joint side.

[0023] In the technical solution of this embodiment, the matching design of the conical surface and the conical sleeve realizes the precise positioning and self-locking function of the planetary joint module in the axial direction, which improves the accuracy and stability of installation; the meshing of the keyway and the transmission key can transmit rotational torque and prevent relative rotation between the housing and the external connecting rod or flange connected to the housing, thus ensuring the reliability and stability of power transmission.

[0024] According to at least one embodiment of the planetary joint module of the present disclosure, the planet carrier of the last stage reduction unit is provided with an output flange, and the output flange is provided with an output screw hole.

[0025] In the technical solution of this embodiment, the design of the output flange provides a large connection area and a standard connection method, which facilitates connection and installation with other equipment; the setting of the output screw hole further enhances the reliability and stability of the connection, and can meet the requirements of power output connection under different working conditions. Attached Figure Description

[0026] The accompanying drawings illustrate exemplary embodiments of the present disclosure and, together with the description thereof, serve to explain the principles of the present disclosure. These drawings are included to provide a further understanding of the present disclosure and are incorporated in and constitute a part of this specification.

[0027] Figure 1 This is a schematic diagram of the structure of a planetary joint module according to one embodiment of the present disclosure.

[0028] Figure 2 This is a top view of a planetary joint module according to one embodiment of the present disclosure.

[0029] Figure 3 yes Figure 2 Sectional view of section A.

[0030] Figure 4This is a schematic diagram of a single-stage reducer according to one embodiment of the present disclosure.

[0031] Figure 5 This is a cross-sectional view of a first-stage reducer according to one embodiment of the present disclosure.

[0032] Figure 6 This is a schematic diagram of a two-stage reducer according to one embodiment of the present disclosure.

[0033] Figure 7 This is a cross-sectional view of a two-stage reducer according to one embodiment of the present disclosure.

[0034] Figure 8 This is a schematic diagram of the structure of a frameless motor according to one embodiment of the present disclosure.

[0035] Figure 9 This is a schematic diagram of the structure of a magnetic ring mounting plate and a tightening cover according to one embodiment of the present disclosure.

[0036] The specific labels in the attached figures are as follows: 100 Casing 101 Grade I Internal Gear Screw 102 Motor cover screws 110 Motor Cover 120 Joint cover 121 First Oil Seal 122 Second fixing screw hole 130 key slot 140 cone 150 heat sink 200 motor 210 motor stator 220 motor rotor 230 motor shaft 231 First shaft snap ring 232-hole snap ring 233 Third Deep Groove Ball Bearing 310 Single-stage reducer 311 First-order sun gear 312 First-level planetary gears 313 First-stage internal gear ring 314 Primary Pin 315 Grade I needle roller bearing 316 First-stage planetary gasket 317 First-stage planetary support 318 First Deep Groove Ball Bearing 319 Second Deep Groove Ball Bearing 320 Two-stage reducer 321 Second-stage sun gear 321A Second Shaft Snap Ring 322 Second-stage planetary gear 323 Secondary Internal Gear Ring 323A Second-stage internal gear screw 324 Secondary Pin 325 two-stage needle roller bearing 326 Second-stage planetary washer 327 Secondary Planetary Carrier 327A Output Screw Hole 328 Fourth Deep Groove Ball Bearing 329 Bearing Cap 329A gland screw 330 collar support 331 Collar support screw 340 crossed roller bearing 341 Collar outer pressure plate 342 Collar outer screw 343 Collar Inner Pressure Plate 344 Collar Inner Screw 345 Second Oil Seal 350 hollow shaft 351 Hollow Shaft Screw 352 Magnetic Ring Mounting Plate 352A tapered bore 353 Expansion Cap 353A Conical Boss 354 Expansion Screw 360° Low-speed side magnetic ring 370 High-speed side magnetic ring 380 driver board 381 Drive board screws 382 Driver Board Connector. Detailed Implementation

[0037] The present disclosure will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are for illustrative purposes only and are not intended to limit the scope of the disclosure. Furthermore, it should be noted that, for ease of description, only the parts relevant to the present disclosure are shown in the accompanying drawings.

[0038] It should be noted that, where there is no conflict, the embodiments and features described in this disclosure can be combined with each other. The technical solutions of this disclosure will now be described in detail with reference to the accompanying drawings and embodiments.

[0039] Unless otherwise stated, the exemplary implementations / embodiments shown are to be understood as providing exemplary features of various details that provide ways in which the technical concepts of this disclosure can be implemented in practice. Therefore, unless otherwise stated, the features of various implementations / embodiments may be additionally combined, separated, interchanged and / or rearranged without departing from the technical concepts of this disclosure.

[0040] The use of crosshairs and / or shading in the accompanying drawings is generally used to clarify the boundaries between adjacent components. Thus, unless otherwise stated, the presence or absence of crosshairs or shading does not convey or indicate any preference or requirement for the specific material, material properties, dimensions, proportions, commonalities between the illustrated components, or any other characteristics, properties, etc., of the components. Furthermore, in the accompanying drawings, the dimensions and relative dimensions of components may be exaggerated for clarity and / or descriptive purposes. When exemplary embodiments can be implemented differently, a specific process sequence may be performed in a different order than that described. For example, two consecutively described processes may be performed substantially simultaneously or in the reverse order of their description. Furthermore, the same reference numerals denote the same components.

[0041] When a component is referred to as being "on" or "above" another component, "connected to," or "joined to" another component, the component may be directly on, directly connected to, or directly joined to the other component, or there may be intermediate components. However, when a component is referred to as being "directly on" another component, "directly connected to," or "directly joined to" another component, there are no intermediate components. Therefore, the term "connection" can refer to a physical connection, an electrical connection, etc., and may or may not have intermediate components.

[0042] For descriptive purposes, this disclosure may use spatial relative terms such as “below,” “under,” “below,” “down,” “above,” “above,” “higher,” and “side (e.g., in a “sidewall”)” to describe the relationship between one component and another component as shown in the accompanying drawings. In addition to the orientations depicted in the drawings, the spatial relative terms are also intended to encompass different orientations of the device during use, operation, and / or manufacture. For example, if the device in the drawings is flipped, a component described as “below” or “under” another component or feature would subsequently be positioned “above” said other component or feature. Thus, the exemplary term “below” can encompass both “above” and “below” orientations. Furthermore, the device may be otherwise positioned (e.g., rotated 90 degrees or in other orientations), thus interpreting the spatial relative descriptive terms used herein accordingly.

[0043] The terminology used herein is for the purpose of describing particular embodiments and is not intended to be limiting. As used herein, unless the context clearly indicates otherwise, the singular forms “a” and “the” are intended to include the plural forms as well. Furthermore, when the terms “comprising” and / or “including” and variations thereof are used in this specification, it indicates the presence of the stated features, integrals, steps, operations, parts, components, and / or groups thereof, but does not exclude the presence or addition of one or more other features, integrals, steps, operations, parts, components, and / or groups thereof. It should also be noted that, as used herein, the terms “substantially,” “about,” and other similar terms are used as approximate terms rather than as terms of degree, thus explaining the inherent biases in measurements, calculated values, and / or provided values ​​that would be recognized by one of ordinary skill in the art.

[0044] Common joint modules can be categorized by reducer type into harmonic joint modules, direct-drive joint modules, linear joint modules, and planetary joint modules. Traditional planetary joint modules, due to the lack of compactness requirements from reducer manufacturers, are relatively large and heavy, with low power density, making them inconvenient for humanoid robots. Harmonic joint modules offer advantages such as high transmission ratios, compact structures, and large hollow holes, leading to their widespread use in robotic arms. However, humanoid robots, due to their complex operating conditions, have high speed and torque requirements for joint modules. Generally, the minimum speed ratio of harmonic reducers can only reach 50, meaning that the output speed of harmonic joint modules is relatively low. Furthermore, humanoid robots require jumping and running, and harmonic joints, limited by the thin-walled structure of the harmonic reducer's flexible gear, have poor rigidity and weak impact resistance. Under harsh conditions, problems such as reducer breakage or gear skipping can easily occur, thus limiting their use in humanoid robots. Direct-drive joint modules use high-torque direct-drive motors without reducers, offering advantages such as simple structure, low cost, and strong impact resistance. However, due to current motor technology limitations, they cannot meet the high torque requirements of humanoid robot leg joints within a small size. They also suffer from high heat generation and are currently only used for joints with relatively low torque and speed requirements. Linear joint modules convert motor rotational torque into linear push-pull force through linear actuators such as lead screws. They offer advantages such as high push-pull force and strong impact resistance. However, the transmission ratio of linear motion is limited by the lead screw's lead, which is generally small in compact spaces, resulting in relatively low linear motion speeds. Furthermore, because the drive rods for linear motion are rigid links, they require the use of ball bearings, leading to a more complex structure, shorter lifespan, smaller range of motion, and a risk of jamming. Currently, they are only used in special areas such as fingers, waist couplings, and ankle couplings.

[0045] Figure 1 This is a schematic diagram of the structure of a planetary joint module according to one embodiment of the present disclosure. Figure 2This is a top view of a planetary joint module according to one embodiment of the present disclosure. Figure 3 yes Figure 2 Sectional view of section A.

[0046] See Figures 1 to 3 As shown, this embodiment provides a planetary joint module, the overall inventive concept of which is as follows: the planetary joint module includes: a housing 100, a motor 200, and a planetary reducer.

[0047] The stator of the motor is fixedly mounted on the housing 100, and its mover is mounted on the motor shaft 230. The planetary reducer includes at least one reduction unit. Each reduction unit includes a sun gear, planet gears, an internal gear ring, and a planet carrier. The internal gear ring is fixedly mounted on the housing 100. The planet carrier is located inside the internal gear ring and has pin holes and notches. A pin is installed in the pin hole. The planet gears are rotatably mounted on the planet carrier via the pins, and their axial direction is limited to the inside of the notch, while part of them is located on the outside of the notch. The part of the planet gear located on the outside of the notch meshes with the internal teeth of the internal gear ring, and the part of the planet gear located on the inside of the notch meshes with the sun gear. The sun gear of the first reduction unit is rigidly connected to the motor shaft 230. In two adjacent reduction units, the planet carrier of the previous reduction unit is rigidly connected to the sun gear of the next reduction unit. The planet carrier of the last reduction unit is provided with an output interface.

[0048] When the motor shaft 230 rotates, the sun gear of the first-stage reduction unit is rigidly connected to the motor shaft 230, so the sun gear rotates accordingly. Since the sun gear meshes with the planet gears, and the planet gears mesh with the internal gear ring, which remains stationary, according to the gear transmission principle, the planet gears will revolve and rotate around the sun gear. The rotation and revolution of the planet gears drive the planet carrier to rotate, thereby achieving speed reduction.

[0049] In the case of multi-stage reduction units, in adjacent reduction units, the planet carrier of the upper-stage reduction unit is rigidly connected to the sun gear of the lower-stage reduction unit. Thus, the rotation of the upper-stage planet carrier drives the rotation of the lower-stage sun gear, further reducing speed through the gear meshing of the lower-stage reduction unit. After multiple stages of this reduction process, the planet carrier of the final reduction unit rotates. The final-stage planet carrier is equipped with an output interface, through which power is output to drive the external load.

[0050] A planetary reducer can be single-stage or two-stage. This embodiment illustrates a planetary reducer with two reduction units.

[0051] The planetary reducer consists of two reduction units: a first-stage reducer 310 and a second-stage reducer 320.

[0052] Figure 4 This is a schematic diagram of a single-stage reducer according to one embodiment of the present disclosure. Figure 5 This is a cross-sectional view of a first-stage reducer according to one embodiment of the present disclosure.

[0053] See Figure 3 , Figure 4 and Figure 5 As shown, the first-stage reducer 310 consists of a first-stage sun gear 311, four first-stage planetary gears 312, a first-stage internal gear ring 313, four first-stage pins 314, four first-stage needle roller bearings 315, eight first-stage planetary washers 316, and a first-stage planetary carrier 317. The first-stage planetary carrier 317 has four pin holes and four notches on its side. Four first-stage pins 314 are installed at the pin holes, and the first-stage needle roller bearings 315 and the first-stage planetary gears 312 are housed within the notches. This provides support on both sides of the first-stage planetary gears 312, resulting in good overall rigidity. The first-stage needle roller bearings 315 act as rotary bearings, providing radial support for the first-stage planetary gears 312 and capable of withstanding large radial forces and impact loads. Two first-stage planetary washers 316 are located on each side of the first-stage planetary gears 312, providing axial constraint for the first-stage needle roller bearings 315 and the first-stage planetary gears 312.

[0054] Specifically, the planetary carrier has two sets of spaced-apart mounting sections, each with pin holes. The two ends of the primary pin 314 are respectively positioned within the pin holes of the two mounting sections. The primary planetary gear 312 is rotatably mounted on the primary pin 314 via a primary needle roller bearing 315, and primary planetary washers 316 abut against each other on both axial sides of the primary planetary gear 312. The primary planetary washers 316 are fixedly mounted on the pin hole end faces of the mounting sections, serving to axially limit the movement of the primary needle roller bearing 315 and the primary planetary gear 312. The axial limiting function of the primary planetary washers 316 ensures that the primary planetary gear 312 will not experience axial movement during operation, improving the stability and reliability of the planetary joint module.

[0055] Figure 6 This is a schematic diagram of a two-stage reducer according to one embodiment of the present disclosure. Figure 7 This is a cross-sectional view of a two-stage reducer according to one embodiment of the present disclosure.

[0056] like Figure 3 , Figure 6 and Figure 7As shown, similarly, the two-stage reducer 320 consists of a two-stage sun gear 321, four two-stage planetary gears 322, a two-stage internal gear ring 323, four two-stage pins 324, four two-stage needle roller bearings 325, eight two-stage planetary washers 326, and a two-stage planetary carrier 327. The two-stage planetary carrier 327 has four pin holes and four notches on its side. Four two-stage pins 324 are installed at the pin holes, and the two-stage needle roller bearings 325 and two-stage planetary gears 322 are housed within the notches. This provides support on both sides of the two-stage planetary gears 322, resulting in good overall rigidity. The two-stage needle roller bearings 325 provide radial support for the two-stage planetary gears 322 and can withstand large radial forces and impact loads. Two two-stage planetary washers 326 are located on each side of the two-stage planetary gears 322, providing axial constraint for the two-stage needle roller bearings 325 and the two-stage planetary gears 322.

[0057] Understandably, the number of planetary gears in the first-stage reducer 310 and the second-stage reducer 320 can be 3, 4, or 5, etc. In some cases, the needle roller bearings inside the planetary gears can also be replaced with deep groove ball bearings or sliding bearings.

[0058] Figure 8 This is a schematic diagram of the structure of a frameless motor according to one embodiment of the present disclosure.

[0059] See Figure 3 and Figure 8 As shown, the motor 200 can be a frameless motor, which consists of a motor stator 210 and a motor rotor 220. The motor stator 210 of the frameless motor is fixed inside the housing 100 by means of adhesive bonding, interference fit, or screw connection, and the motor rotor 220 is fixedly connected to the motor shaft 230 by means of adhesive bonding, interference fit, or screw connection. The housing 100 is fixedly provided with a motor cover 110 for covering the motor 200.

[0060] like Figure 3 As shown, the motor rotor 220 has a hollow structure, and at least one reduction unit is set inside the hollow structure of the motor rotor 220, which greatly improves the space utilization rate.

[0061] like Figure 3As shown, the motor shaft 230 is rigidly connected to the first-stage sun gear 311 and rotatably fixed to the first-stage internal gear ring 313 and the motor cover 110 via a first deep groove ball bearing 318 and a second deep groove ball bearing 319. The first-stage internal gear ring 313 and the motor cover 110 are connected to the housing 100 via first-stage internal gear ring screws 101 and motor cover screws 102, respectively. This achieves radial fixation of the motor shaft 230. A first shaft retaining circlip 231 is provided between the motor shaft 230 and the second deep groove ball bearing 319. The first shaft retaining circlip 231, together with the first-stage internal gear ring 313 and the motor cover 110, achieves axial fixation of the motor shaft 230. The first-stage planetary carrier 317 is rigidly connected to the second-stage sun gear 321, enabling power transmission from the first stage to the second stage. A fourth deep groove ball bearing 328 is provided on the second-stage sun gear 321. The outer ring of the fourth deep groove ball bearing 328 is mounted on the second-stage planetary carrier 327. The bearing cap 329 is fixed to the secondary planetary carrier 327 by cap screws 329A, thereby fixing the outer ring of the fourth deep groove ball bearing 328. A second shaft retaining circlip 321A is provided on the secondary sun gear 321 to fix the inner ring of the fourth deep groove ball bearing 328. In this way, the primary planetary carrier 317 and the secondary sun gear 321 are rotatably fixed on the secondary planetary carrier 327.

[0062] like Figure 3 As shown, the secondary reducer 320 is equipped with a collar support 330, a crossed roller bearing 340, an outer collar pressure plate 341, and an inner collar pressure plate 343. The collar support 330 is fixedly mounted on the internal gear ring of the secondary reduction unit. The outer ring of the crossed roller bearing 340 is fixed to the collar support 330 via the outer collar pressure plate 341, and the inner ring is fixed to the planetary carrier of the secondary reduction unit via the inner collar pressure plate 343. The collar support 330 is provided with a first fixing screw hole. A joint cover 120 is fixedly mounted on the end of the housing 100 opposite to the collar support 330, and the joint cover 120 is provided with a second fixing screw hole 122. The cross roller bearing 340 is designed to withstand large radial and axial loads, improving the support rigidity and rotational accuracy of the planetary carrier of the secondary reduction unit. The fixing method of the outer collar pressure plate 341 and the inner collar pressure plate 343 ensures the stable installation and reliable operation of the cross roller bearing 340, which is beneficial to improving the overall performance and service life of the planetary joint module.

[0063] Specifically, the secondary internal gear ring 323 is fixed to the housing 100 by secondary internal gear ring screws 323A, and the collar support 330 is fixed to the secondary internal gear ring 323 by collar support screws 331. The outer ring of the crossed roller bearing 340 is firmly connected to the collar support 330 by the outer collar pressure plate 341 and the outer collar screws 342. The inner ring of the crossed roller bearing 340 is firmly connected to the secondary planetary carrier 327 by the inner collar pressure plate 343 and the inner collar screws 344. In this way, the secondary planetary carrier 327 is rotatably fixed to the collar support 330 by the crossed roller bearing 340.

[0064] like Figure 3 As shown, a second oil seal 345 is provided between the outer pressure plate 341 and the inner pressure plate 343 of the shaft collar, which plays a sealing role, preventing external dirt from entering the secondary reducer 320, and also preventing internal lubricating grease from leaking out, thus improving service life.

[0065] The planetary joint module also includes a hollow shaft 350, which is rigidly connected to the planet carrier of the final stage reduction unit and rotatably passes through the axis of the sun gear of each stage reduction unit. The hollow shaft 350 is provided with an axially extending channel, the two ends of which connect to the outside of the planetary joint module. The design of the hollow shaft 350 allows for the internal arrangement of wiring or conduits within the planetary joint module, and the axially extending channel facilitates connection to the outside, simplifying integration with other devices and wiring layout. This improves overall space utilization and system compactness, resulting in an aesthetically pleasing appearance when applied to humanoid robots, and reducing cable wear and tear and damage, thus extending their lifespan.

[0066] like Figure 3 As shown, specifically, the hollow shaft 350 is fixed to the bearing cap 329 by hollow shaft screws 351. Since the bearing cap 329 is fixed to the secondary planetary carrier 327, the hollow shaft 350 and the secondary planetary carrier 327 are rigidly connected. A third deep groove ball bearing 233 is provided on the motor shaft 230. The third deep groove ball bearing 233 is fixed to the motor shaft 230 through a hole using a snap ring 232. The outer surface of the hollow shaft 350 mates with the inner ring of the third deep groove ball bearing 233. Therefore, the third deep groove ball bearing 233 provides radial support to the hollow shaft 350, which can prevent radial sway of the hollow shaft 350 caused by structural deformation and installation errors, thus avoiding affecting the degree accuracy and sealing effect of the low-speed encoder.

[0067] The planetary joint module also includes a drive plate 380, a high-speed side magnetic ring 370, and a low-speed side magnetic ring 360. The high-speed side magnetic ring 370 is disposed on the motor shaft 230, and the low-speed side magnetic ring 360 is disposed on the hollow shaft 350. The drive plate 380 is fixedly disposed on the motor cover 110 and is used to collect and process the rotational position signals and speed signals of the high-speed side magnetic ring 370 and the low-speed side magnetic ring 360 in real time, so as to detect the rotational position signals and speed signals of the motor shaft 230, the hollow shaft 350, the planetary carrier of the last stage reduction unit, and the output interface.

[0068] Figure 9 This is a schematic diagram of the structure of the magnetic ring mounting plate and the expansion gland according to one embodiment of the present disclosure.

[0069] like Figure 3 and Figure 9 As shown, exemplarily, the planetary joint module also includes a magnetic ring mounting plate 352, a tightening cover 353, and a tightening screw 354; the magnetic ring mounting plate 352 is provided with a tapered hole 352A, and is sleeved on the outside of the hollow shaft through the tapered hole 352A; the tightening cover 353 is sleeved on the outside of the hollow shaft, and a tapered boss 353A adapted to the tapered hole 352A is provided at the sleeve, and the tapered boss 353A is inserted into the inside of the tapered hole 352A; the magnetic ring mounting plate 352 is fixedly connected to the tightening cover 353 by the tightening screw 354, and the inner wall of the tapered hole 352A presses the tapered boss 353A so that the tapered boss 353A is clamped and fixed on the outside of the hollow shaft 350; a low-speed side magnetic ring 360 is mounted on the magnetic ring mounting plate 352.

[0070] Furthermore, the low-speed side magnetic ring 360 is fixed to the magnetic ring mounting plate 352 by adhesive bonding or interference fit. During installation, the tapered boss 353A of the expansion cap 353 is inserted into the tapered hole 352A of the magnetic ring mounting plate 352, and the two are firmly connected by the expansion screw 354. In this way, the compression action of the tapered surface 140 can firmly fix the magnetic ring mounting plate 352 to the hollow shaft 350, and the magnetic ring mounting plate 352 cannot move along the axial and rotational directions of the planetary joint module. In this way, the position and speed information of the secondary planetary carrier 327 can be transmitted to the low-speed side magnetic ring 360 through the hollow shaft 350 for detecting the position and speed of the secondary planetary carrier 327 and the output flange. If the height of the low-speed side magnetic ring 360 needs to be adjusted for debugging, simply loosen the expansion screw 354, adjust the height, and then tighten it again. As can be seen, the planetary joint module in this embodiment, secured by tapered holes 352A and tapered bosses 353A in conjunction with expansion screws 354, provides a reliable connection and fixation effect. This ensures that the low-speed side magnetic ring 360 is stably mounted on the hollow shaft 350, preventing loosening or displacement during planetary joint module operation and guaranteeing the accuracy of signal acquisition. Furthermore, the expansion-fixing method for connecting the low-speed side magnetic ring 360 results in a compact axial structure, adjustable height, convenient debugging and maintenance, and lower cost.

[0071] like Figure 3 As shown, a high-speed side magnetic ring 370 is mounted on the motor shaft 230 to detect the position and speed of the motor shaft 230. A drive plate 380 is mounted on the motor cover 110, and the two are connected together by drive plate screws 381. The drive plate 380 is used to drive and control the frameless motor and detect the speed and position information of the high-speed side magnetic ring 370 and the low-speed side magnetic ring 360. By setting up high-speed and low-speed side magnetic rings and the drive plate 380, the planetary joint module of this embodiment can accurately acquire the rotational position and speed information of different components of the planetary joint module in real time, providing data support for the precise control and monitoring of the system, and helping to improve the operating accuracy and stability of the entire system.

[0072] A driver board connector 382 is provided on the driver board 380. The driver board connector 382 passes through the square hole on the joint cover 120 and is used to connect the circuit to power the driver board 380 and communicate with the outside world.

[0073] See Figure 3 As shown, a first oil seal 121 is installed on the joint cover 120. The outer circle of the hollow shaft 350 cooperates with the first oil seal 121 to seal and protect the drive plate 380, which can prevent water vapor and dirt from entering and improve service life.

[0074] like Figure 1As shown, the secondary planetary carrier 327 serves as the output flange, with an output bolt hole 327A designed on it for connecting the output end connecting rod to the output flange. The output flange design provides a large connection area and a standard connection method, facilitating connection and installation with other equipment. The output bolt hole 327A further enhances the reliability and stability of the connection, meeting the power output connection requirements under different operating conditions. Meanwhile, the collar support 330 serves as the fixed flange, with a first fixing bolt hole for connecting the fixed end connecting rod to the fixed flange. Furthermore, a second fixing bolt hole 122 is also designed on the joint cover 120, allowing the joint cover 120 to function as a fixed flange in certain situations, connecting to the fixed end connecting rod via the second fixing bolt hole 122. In other words, both sides of the joint fixed end housing have mounting holes, facilitating installation and use in different application scenarios.

[0075] like Figure 1 As shown, the outer side of the housing 100 is provided with a conical surface 140 and multiple keyways 130. The conical surface 140 is arranged around the axial middle section of the housing 100 and is used to cooperate with the conical sleeve on the joint side to achieve axial positioning and self-locking. The keyways 130 are evenly distributed around the circumference of the housing 100 and are used to engage with the transmission key on the joint side to transmit rotational torque and prevent relative rotation between the housing 100 and the external connecting rod or flange connected to the housing 100. In other words, the conical surface 140 is used for axial positioning when the joint side is clamped, and the keyways 130 are used to withstand the radial force when the side is clamped to achieve a firm clamping fixation. The outer side of the housing 100 is also provided with heat dissipation grooves 150 for heat dissipation of the motor 200.

[0076] The working principle of the planetary joint module in this embodiment is as follows: The stator 210 of the frameless motor is rigidly connected to the outer casing 100 and remains stationary. The rotation of the motor shaft 230 drives the first-stage sun gear 311 to rotate, and the first-stage planetary gear 312 meshing with it rotates. Since the first-stage internal gear ring 313 is also fixed on the outer casing 100, the first-stage planetary gear 312 drives the first-stage planetary carrier 317 to revolve around the axis of the first-stage internal gear ring 313, achieving the first stage of deceleration. The second-stage sun gear 321 is connected to the first-stage planetary carrier 317, so the second-stage sun gear 321 also rotates at the same speed as the first-stage planetary carrier 317, driving the second-stage planetary gear 322 to rotate. Similarly, since the second-stage internal gear ring 323 is fixed on the outer casing 100 and cannot rotate, it drives the second-stage planetary carrier 327 to revolve around the axis of the second-stage internal gear ring 323, achieving the second stage of deceleration. The secondary planetary carrier 327 is rotatably fixed to the collar support 330 via a crossed roller bearing 340. Due to the inherent characteristics of the crossed roller bearing 340, the output flange, i.e., the secondary planetary carrier 327, can withstand complex loads such as large bending moments and axial forces. The high-speed side position and speed of the motor shaft 230 can be read through the high-speed side magnetic ring 370, and the low-speed side position and speed of the output flange, i.e., the secondary planetary carrier 327, can be read through the low-speed side magnetic ring 360. With this configuration, the planetary joint module of this embodiment forms a closed-loop control of position and speed, achieving high control precision.

[0077] The planetary joint module in this embodiment can use a high-torque frameless motor combined with a two-stage reducer (320) for transmission. This achieves a speed ratio less than the minimum harmonic ratio of 50, enabling high speed output while maintaining high torque. It features a compact structure, light weight, and high power density. Furthermore, the planetary gears are supported on both sides by needle roller bearings and can be engaged with steel gears, resulting in good overall rigidity, strong impact resistance, high reliability, and long service life.

[0078] In the description of this specification, the references to terms such as "one embodiment / mode," "some embodiments / modes," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment / mode or example is included in at least one embodiment / mode or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment / mode or example. Moreover, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments / modes or examples. Furthermore, without contradiction, those skilled in the art can combine and integrate the different embodiments / modes or examples described in this specification, as well as the features of different embodiments / modes or examples.

[0079] 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 at least one of that feature. In the description of this application, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0080] Those skilled in the art should understand that the above embodiments are merely for illustrating the present disclosure and are not intended to limit the scope of the disclosure. Those skilled in the art can make other changes or modifications based on the above disclosure, and these changes or modifications still fall within the scope of the present disclosure.

Claims

1. A planetary joint module, characterized in that, include: shell; An electric motor, comprising a stator and a rotor, wherein the stator is fixedly mounted on a housing and the rotor is mounted on a shaft; as well as A planetary reducer includes at least one reduction unit. Each reduction unit includes a sun gear, planet gears, an internal gear ring, and a planet carrier. The internal gear ring is fixedly mounted on the housing. The planet carrier is located inside the internal gear ring and has a pin hole and a notch. A pin is installed in the pin hole. The planet gears are rotatably mounted on the planet carrier via the pin and are axially limited to the inside of the notch. Part of the planet gear is located outside the notch. The part of the planet gear located outside the notch meshes with the internal teeth of the internal gear ring, and the part of the planet gear located inside the notch meshes with the sun gear. In this system, the sun gear of the first-stage reduction unit is rigidly connected to the motor shaft, and in two adjacent reduction units, the planetary carrier of the previous-stage reduction unit is rigidly connected to the sun gear of the next-stage reduction unit.

2. The planetary joint module according to claim 1, characterized in that, The planetary carrier is provided with two sets of spaced mounting parts, each mounting part having pin holes, and the two ends of the pin shaft are respectively disposed in the pin holes of the two sets of mounting parts. The planetary joint module also includes a rotary bearing and planetary washers; the planetary gear is rotatably mounted on the pin shaft via the rotary bearing, and the planetary washers are respectively abutted on both axial sides of the planetary gear; the planetary washers are fixedly disposed on the pin hole end face of the mounting part for axial positioning of the rotary bearing and the planetary gear.

3. The planetary joint module according to claim 1, characterized in that, The planetary joint module also includes a hollow shaft, which is rigidly connected to the planet carrier of the last stage reduction unit and rotatably passes through the axis of the sun gear of each stage reduction unit. The hollow shaft is provided with an axially extending channel, and the two ends of the channel are connected to the outside of the planetary joint module.

4. The planetary joint module according to claim 3, characterized in that, The planetary joint module also includes a drive plate, a high-speed side magnetic ring, and a low-speed side magnetic ring. The high-speed side magnetic ring is disposed on the motor shaft, and the low-speed side magnetic ring is disposed on the hollow shaft. The housing is fixedly provided with a motor cover for sealing the motor. The drive plate is fixedly disposed on the motor cover and is used to collect and process the rotational position and speed signals of the high-speed side magnetic ring and the low-speed side magnetic ring in real time, so as to detect the rotational position and speed signals of the motor shaft, the hollow shaft, the planetary carrier of the last stage reduction unit, and the output interface.

5. The planetary joint module according to claim 4, characterized in that, The planetary joint module further includes a magnetic ring mounting plate, a shrink-fit cover, and shrink-fit screws; the magnetic ring mounting plate is provided with a tapered hole and is fitted onto the outside of the hollow shaft through the tapered hole; the shrink-fit cover is fitted onto the outside of the hollow shaft and has a tapered boss at the fitting point that matches the tapered hole, the tapered boss being inserted into the inside of the tapered hole; the magnetic ring mounting plate is fixedly connected to the shrink-fit cover by the shrink-fit screws, the inner wall of the tapered hole presses against the tapered boss, so that the tapered boss is clamped and fixed onto the outside of the hollow shaft; a low-speed side magnetic ring is mounted on the magnetic ring mounting plate.

6. The planetary joint module according to claim 1, characterized in that, The planetary reducer includes a primary reduction unit and a secondary reduction unit. The planet carrier of the primary reduction unit is rigidly connected to the sun gear of the secondary reduction unit, and the planet carrier of the secondary reduction unit is provided with an output interface.

7. The planetary joint module according to claim 6, characterized in that, The secondary reduction unit is provided with a collar support, a crossed roller bearing, an outer collar pressure plate, and an inner collar pressure plate. The collar support is fixedly mounted on the internal gear ring of the secondary reduction unit. The outer ring of the crossed roller bearing is fixed to the collar support via the outer collar pressure plate, and the inner ring is fixed to the planetary carrier of the secondary reduction unit via the inner collar pressure plate.

8. The planetary joint module according to claim 7, characterized in that, The collar support is provided with a first fixing screw hole; the outer shell is fixedly provided with a joint cover at one end away from the collar support, and the joint cover is provided with a second fixing screw hole.

9. The planetary joint module according to claim 1, characterized in that, The outer side of the housing is provided with a conical surface and multiple keyways; the conical surface is arranged around the axial middle section of the housing and is used to cooperate with the conical sleeve on the joint side to achieve axial positioning and self-locking; the keyways are evenly spaced along the circumference of the housing and are used to engage with the transmission key on the joint side.

10. The planetary joint module according to claim 1, characterized in that, The planetary carrier of the final reduction unit is provided with an output flange, and the output flange is provided with an output screw hole.

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