Joint module and robot based on planetary reducer

Abstract

The utility model discloses a kind of joint modules based on planetary reducer, including motor assembly, planetary reducer, shell, support and drive plate.The motor shaft of motor assembly is connected with the sun gear of planetary reducer, the sun gear is engaged with planetary gear, and the planetary gear is simultaneously engaged with inner tooth ring, and the planetary shaft is connected with planetary gear and planet carrier.In energized state, the rotor of motor assembly rotates and drives the rotation of motor shaft to drive the rotation of sun gear, and the sun gear drives the planetary gear, and the planetary gear is engaged with inner tooth ring transmission, to drive the low-speed rotation of planet carrier and output torque.The first end of motor shaft is connected with first counting gear, and the second counting gear is engaged with transmission and fixed on support, and transmission ratio is set as multiple of planetary reducer, and the rotation angle information of input end and output end can be obtained by cooperating with encoder and program compilation.The joint module has the advantages of high integration, fast response, high control accuracy, and simple and compact structure.

Description

Technical Field

[0001] This utility model relates to the field of robot joint technology, and more specifically, to a joint module and robot based on a planetary reducer. Background Technology

[0002] With the rapid development of industrial automation, medical robots, and special service robots, joint modules, as the core unit for robot motion execution, directly affect the robot's load capacity, motion accuracy, and spatial adaptability. A typical joint module integrates a frameless torque motor, a high-precision reducer, a position / torque sensor, and an embedded controller. Through coordinated control, it achieves precise angle adjustment and torque output of the joints to meet the stringent requirements for motion smoothness, response speed, and repeatability in scenarios such as industrial assembly, precision surgery, and flexible grasping.

[0003] Currently, most mainstream joint modules adopt a motor-reducer series configuration, where the reducer is directly mounted on the front end of the motor output shaft. While this structure can achieve high torque output, it results in excessively long axial dimensions, severely restricting structural compactness, especially in multi-degree-of-freedom collaborative robots and space-constrained scenarios. Furthermore, to improve closed-loop control accuracy, a dual encoder system needs to be deployed at both the motor input and reducer output ends: the input encoder is used for motor commutation control, and the output encoder is used to compensate for reducer transmission errors. However, this design presents three major technical bottlenecks:

[0004] 1. Increased wiring complexity: Dual encoder signal lines need to pass through the inside of the rotating joint, which is susceptible to cable entanglement, electromagnetic interference and mechanical wear in a limited space;

[0005] 2. Redundant structural design: The encoder mounting cavity, sealing components and wiring channels need to be designed independently, which increases the weight of the module and the manufacturing cost;

[0006] 3. Reliability risk: Cable fatigue fracture under high bending frequency will lead to system inaccuracy and significantly increase maintenance costs.

[0007] Therefore, there is an urgent need for a new joint module configuration that is highly integrated, has low axial dimensions, and is free from complex wiring, so as to ensure high-precision torque control while breaking through the constraints of existing structures on the lightweight and compact development of robots. Utility Model Content

[0008] The main purpose of this invention is to propose a joint module based on a planetary reducer, which aims to solve the technical problems of excessively large axial dimensions and complex dual encoder structures in the prior art.

[0009] To achieve the above objectives, this utility model proposes a joint module based on a planetary reducer, including a motor assembly, a planetary reducer, a housing, a bracket, and a drive plate; the housing is fixedly connected to the bracket, and the motor assembly and the planetary reducer are both disposed inside the cavity formed by the housing and the bracket.

[0010] The motor assembly includes a stator and a rotor assembly fixedly connected to the housing. The rotor assembly includes a rotor frame and magnets arranged circumferentially along the inner wall of the rotor frame. The magnets are coaxially sleeved on the outer periphery of the stator, and a motor shaft is provided at the center of the rotor frame shaft. The rotor assembly is rotatably connected to the housing.

[0011] The planetary reducer includes a sun gear fixedly connected coaxially to the motor shaft, planet gears meshing with the sun gear, an internal gear ring fixed to the housing and meshing with the planet gears, a planet carrier coaxially arranged with the sun gear and rotatably mounted on the housing, and a planet shaft for connecting the planet gears and the planet carrier.

[0012] The first end of the motor shaft passes through the bracket and is coaxially fixedly mounted with a first counting gear. A second counting gear is fixedly mounted on the bracket. The first counting gear and the second counting gear are meshed and connected, and their transmission ratio is a multiple of the transmission ratio of the planetary reducer. The drive plate is fixedly mounted on the end of the bracket where the first counting gear is located. An input encoder that cooperates with the first counting gear and an output encoder that cooperates with the second counting gear are mounted on the drive plate.

[0013] This invention employs a single-stage planetary reducer paired with a frameless external rotor motor, featuring a low reduction ratio design that combines rapid response with high torque output. It offers faster response than traditional high reduction ratio systems, making it suitable for complex motion scenarios. Simultaneously, the joint exhibits good reverse drive capability and impact resistance. By incorporating a meshing first and second counting gear on the support frame, and utilizing their transmission relationship in conjunction with program compilation, this invention can simultaneously acquire rotation angle information from both the input and output ends. This enables closed-loop control of the joint module, improving control accuracy and avoiding the need for directly placing encoder components at the input and output ends, thus reducing structural redundancy.

[0014] Preferably, a first groove is provided at the first end of the motor shaft, and a second groove is provided on the inner wall of the first counting gear. The first groove and the second groove together form an axially arranged keyway.

[0015] The above structure allows for the use of key pins inserted into the keyway to achieve the positioning and installation of the motor shaft and the first counting gear, facilitating assembly and disassembly.

[0016] Preferably, the bracket has a through hole at its center, the first end of the motor shaft passes through the through hole and is coaxially and fixedly connected to the first counting gear, the second end of the motor shaft is fixedly connected to the sun gear, and the first end and the second end of the motor shaft are located on both sides of the rotor frame, respectively.

[0017] Preferably, the second end of the motor shaft and the sun gear are integrally formed.

[0018] Preferably, a hollow annular cylindrical portion is provided on the bottom wall of the housing extending towards the support, the stator is fixed to the outer peripheral wall of the cylindrical portion, and the internal gear ring is fixed to the inner peripheral wall of the cylindrical portion.

[0019] Preferably, the internal gear ring and the cylindrical portion are integrally formed.

[0020] Preferably, the planetary carrier includes a first annular portion and a second annular portion arranged coaxially, and a connecting arm for connecting the first annular portion and the second annular portion. The two ends of the planetary shaft are respectively fixedly connected to the first annular portion and the second annular portion. The planetary gear is rotatably mounted on the planetary shaft and located between the first annular portion and the second annular portion. The first annular portion is supported on the inner wall of the cylindrical portion by a first bearing, and the second annular portion is supported on the inner wall of the cylindrical portion by a second bearing.

[0021] Preferably, the first end of the sun gear is supported on the inner wall of the first annular portion by a third bearing, and the second end of the sun gear is supported on the inner wall of the second annular portion by a fourth bearing.

[0022] Preferably, a back cover is installed on the outside of the drive board, and the back cover is fixedly connected to the bracket.

[0023] On the other hand, this utility model also provides a robot, including any of the joint modules based on planetary reducers as described above. Attached Figure Description

[0024] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0025] Figure 1 This is a cross-sectional structural diagram of the joint module in an embodiment of the present invention;

[0026] Figure 2 This is an exploded view of the joint module in an embodiment of the present invention;

[0027] Figure 3 This is a schematic diagram of the rotor assembly in an embodiment of the present invention;

[0028] Figure 4 This is a schematic diagram of the rotor assembly from another perspective in an embodiment of this utility model;

[0029] Figure 5 This is a schematic diagram of the structure of the bracket, the first counting gear, and the second counting gear in an embodiment of this utility model.

[0030] In the attached diagram: 100-motor assembly, 110-stator, 120-rotor assembly, 121-rotor frame, 1211-magnet, 122-motor shaft, 1221-first groove, 200-planetary reducer, 210-sun gear, 211-third bearing, 212-fourth bearing, 220-planetary gear, 230-internal gear ring, 240-planetary carrier, 241-first annular portion, 242-second annular portion, 243-connecting arm, 244-first bearing, 245-second bearing, 250-planetary shaft, 300-housing, 310-cylindrical portion, 400-support, 410-first counting gear, 411-second groove, 420-second counting gear, 430-through hole, 500-drive plate, 510-input encoder, 520-output encoder, 600-rear cover.

[0031] The realization of the purpose, functional features and advantages of this utility model will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0032] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0033] In the description of this utility model, it should be understood that the terms "center," "upper," "lower," "top," "bottom," "inner," and "outer," etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the accompanying drawings and are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or component 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 utility model. In the description of this utility model, unless otherwise stated, "a plurality of" means two or more. In addition, the term "comprising" and any variations thereof mean "at least comprising."

[0034] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integrally formed connection; 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; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0035] Furthermore, it should be noted that the use of terms such as "first" and "second" to define components is merely for the purpose of distinguishing the corresponding components. Unless otherwise stated, the above terms have no special meaning and therefore cannot be construed as limiting the scope of protection of this application.

[0036] Example

[0037] like Figures 1-5 A joint module based on a planetary reducer includes a motor assembly 100, a planetary reducer 200, a housing 300, a bracket 400, and a drive plate 500. The housing 300 and the bracket 400 are fixedly connected, and the motor assembly 100 and the planetary reducer 200 are both disposed inside the cavity formed by the housing 300 and the bracket 400.

[0038] In this embodiment, the motor assembly 100 adopts a known external rotor motor. For example... Figures 1-4 As shown, the motor assembly 100 includes a stator 110 and a rotor assembly 120 fixedly connected to the housing 300. The rotor assembly 120 includes a rotor frame 121 and magnets 1211 arranged circumferentially along the inner wall of the rotor frame 121. The magnets 1211 are coaxially sleeved on the outer periphery of the stator 110 and have a uniform air gap. A motor shaft 122 is located at the center of the rotor frame 121. When the stator 110 is energized, a rotating magnetic field is generated. Under the action of the rotating magnetic field, the magnets 1211 drive the rotor frame 121 to rotate, thereby driving the motor shaft 122 to rotate. The rotor assembly 120 is rotatably connected to the housing 300.

[0039] like Figures 1-2The planetary reducer 200 includes a sun gear 210 coaxially fixedly connected to the motor shaft 122, planet gears 220 meshing with the sun gear 210, an internal gear ring 230 fixed to the housing 300 and meshing with the planet gears 220, a planet carrier 240 coaxially arranged with the sun gear 210 and rotatably mounted on the housing 300, and a planet shaft 250 for connecting the planet gears 220 and the planet carrier 240. With this structure, when the motor shaft 122 rotates, it drives the sun gear 210 to rotate at high speed. The sun gear 210 then drives the planet gears 220 to rotate. The planet gears 220 mesh with the internal gear ring 230, thereby driving the planet carrier 240 to rotate at low speed, thus achieving torque output. Specifically, the planet gears 220 can be supported on the planet shaft 250 by needle roller bearings. In this embodiment, there are three planet gears 220, evenly distributed along the axial direction of the planet carrier 240. The sun gear 210 is mounted on the central axis of the planet carrier 240 and meshes with all three planet gears 220 simultaneously.

[0040] In some preferred embodiments, the second end of the motor shaft 122 is fixedly connected to the sun gear 210, and the first and second ends of the motor shaft 122 are located on both sides of the rotor frame 121, respectively. In this embodiment, as shown... Figure 4 The second end of the motor shaft 122 and the sun gear 210 are integrally formed, meaning that a gear ring can be die-cast directly onto the outer peripheral wall of the second end of the motor shaft 122 to mesh with the planet gear 220. This structure reduces the use of connecting parts and avoids slippage between the motor shaft 122 and the sun gear 210 due to excessive torque, resulting in a more compact and stable structure.

[0041] In some preferred embodiments, such as Figures 1-2 A hollow annular cylindrical portion 310 extends from the bottom wall of the housing 300 towards the support 400. The stator 110 is fixed to the outer peripheral wall of the cylindrical portion 310, and the internal gear ring 230 is fixed to the inner peripheral wall of the cylindrical portion 310. More preferably, the internal gear ring 230 is integrally formed with the cylindrical portion 310, that is, the internal gear ring 230 is integrally die-cast into the inner ring of the cylindrical portion 310. This structure allows for a simpler and more compact structural design.

[0042] The structural design of the planetary carrier 240 is not unique. In this embodiment, a preferred embodiment of the planetary carrier 240 is provided, specifically as follows: Figure 2The planetary carrier 240 includes a first annular portion 241 and a second annular portion 242 coaxially arranged, and a connecting arm 243 for connecting the first annular portion 241 and the second annular portion 242. The two ends of the planetary shaft 250 are fixedly connected to the first annular portion 241 and the second annular portion 242, respectively. The planetary gear 220 is rotatably mounted on the planetary shaft 250 and located between the first annular portion 241 and the second annular portion 242. The planetary gear 220 can be supported on the planetary shaft 250 by needle roller bearings. Three connecting arms 243 are provided, with the space between two adjacent connecting arms 243 used to accommodate the planetary gear 220. This structure facilitates the assembly of the various components of the planetary reducer 200. Further, the first annular portion 241 is supported on the inner wall of the cylindrical portion 310 by a first bearing 244, and the second annular portion 242 is supported on the inner wall of the cylindrical portion 310 by a second bearing 245. This allows the planetary gear 220 to mesh with the internal gear ring 230 on the inner wall of the cylindrical portion 310, and the planetary carrier 240 is supported on the inner wall of the cylindrical portion 310 by the first bearing 244 and the second bearing 245, so that the planetary carrier 240 can be stably rotated and installed on the housing 300.

[0043] In this embodiment, the first end of the sun gear 210 is supported on the inner wall of the first annular portion 241 by the third bearing 211, and the second end of the sun gear 210 is supported on the inner wall of the second annular portion 242 by the fourth bearing 212. Supported by the third bearing 211 and the fourth bearing 212, the sun gear 210 stably rotates along the axis center and meshes with the planetary gear 220, ensuring a compact structure for the planetary reducer 200. Furthermore, since the sun gear 210 is integrally formed with the second end of the motor shaft 122 in this embodiment, the support of the third bearing 211 and the fourth bearing 212 also ensures a stable rotational connection between the rotor assembly 120 and the housing 300.

[0044] In this embodiment, as Figure 2 , Figure 3 and Figure 5As shown, the first end of the motor shaft 122 passes through the bracket 400 and is coaxially fixedly mounted with a first counting gear 410. In this embodiment, the bracket 400 has a through hole 430 at its center, through which the first end of the motor shaft 122 passes and is coaxially fixedly connected with the first counting gear 410. A second counting gear 420 is fixedly mounted on the bracket 400. The first counting gear 410 and the second counting gear 420 are meshed and connected, and their transmission ratio is a multiple of the transmission ratio of the planetary reducer 200. A drive plate 500 is fixedly mounted on the end of the bracket 400 where the first counting gear 410 is located. An input encoder 510 that cooperates with the first counting gear 410 and an output encoder 520 that cooperates with the second counting gear 420 are mounted on the drive plate 500. The input encoder 510 and the output encoder 520 are existing technologies and can be well-known sensors for detecting rotational position, such as photoelectric encoders and magnetic encoders.

[0045] Taking a photoelectric encoder as an example, a set of sensors includes a photoelectric code disk and a photoelectric detection device. The photoelectric code disk, as the sensed element, can be set on the first counting gear 410 and the second counting gear 420, rotating synchronously with the rotation of the two gears. The photoelectric detection device, as the sensing element, is fixedly installed on the drive board 500 to receive the light signal from the photoelectric code disk and convert it into the current rotation angle information through calculation. By reasonably setting the transmission ratio relationship between the first counting gear 410 and the second counting gear 420 and compiling the program, the rotation information of the motor shaft 122 and the two ends on the load side can be obtained, thereby realizing closed-loop control of the input and output ends. The above structure avoids directly setting the detection device at the input and output ends, simplifying the structural design, saving space, and avoiding complex wiring design.

[0046] In some preferred embodiments, such as Figure 3 and Figure 5 As shown, a first groove 1221 is provided at the first end of the motor shaft 122, and a second groove 411 is provided on the inner wall of the first counting gear 410. The first groove 1221 and the second groove 411 together form an axially arranged keyway. With the above structure, a key pin can be inserted into the keyway to achieve the positioning and installation of the motor shaft 122 and the first counting gear 410, and it is also convenient for disassembly and assembly when replacing parts.

[0047] It should be noted that a drive unit is also installed on the drive board 500, which can be electrically connected to an external source to drive the rotation of the motor assembly 100.

[0048] In some preferred embodiments, such as Figure 1 The drive board 500 is externally mounted with a back cover 600, which is fixedly connected to the bracket 400.

[0049] This utility model also provides a robot, including the aforementioned joint module based on a planetary reducer. Since this robot adopts all the technical solutions of all the above embodiments, it also possesses all the beneficial effects brought about by the technical solutions of the above embodiments, which will not be elaborated upon here.

[0050] The above description is only a preferred embodiment of the present utility model and does not limit the patent scope of the present utility model. All equivalent structural transformations made under the inventive concept of the present utility model using the contents of the present utility model specification and drawings, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present utility model.

Claims

1. A joint module based on a planetary reducer, characterized in that, It includes a motor assembly (100), a planetary reducer (200), a housing (300), a bracket (400), and a drive plate (500); the housing (300) is fixedly connected to the bracket (400), and the motor assembly (100) and the planetary reducer (200) are both disposed inside the cavity formed by the housing (300) and the bracket (400); The motor assembly (100) includes a stator (110) and a rotor assembly (120) fixedly connected to the housing (300). The rotor assembly (120) includes a rotor frame (121) and magnets (1211) arranged circumferentially along the inner wall of the rotor frame (121). The magnets (1211) are coaxially sleeved on the outer periphery of the stator (110). A motor shaft (122) is provided at the center of the rotor frame (121). The rotor assembly (120) is rotatably connected to the housing (300). The planetary reducer (200) includes a sun gear (210) coaxially fixedly connected to the motor shaft (122), planet gears (220) meshing with the sun gear (210), an internal gear ring (230) fixed to the housing (300) and meshing with the planet gears (220), a planet carrier (240) coaxially arranged with the sun gear (210) and rotatably mounted on the housing (300), and a planet shaft (250) for connecting the planet gears (220) and the planet carrier (240). The first end of the motor shaft (122) passes through the bracket (400) and is coaxially fixedly provided with a first counting gear (410). A second counting gear (420) is fixedly provided on the bracket (400). The first counting gear (410) and the second counting gear (420) are meshed and connected, and their transmission ratio is a multiple of the transmission ratio of the planetary reducer (200). The drive plate (500) is fixedly installed on the end of the bracket (400) where the first counting gear (410) is located. An input encoder (510) that cooperates with the first counting gear (410) and an output encoder (520) that cooperates with the second counting gear (420) are installed on the drive plate (500).

2. A joint module based on a planetary reducer as described in claim 1, characterized in that, The first end of the motor shaft (122) is provided with a first groove (1221), and the inner wall of the first counting gear (410) is provided with a second groove (411). The first groove (1221) and the second groove (411) together form an axially arranged keyway.

3. A joint module based on a planetary reducer as described in claim 1, characterized in that, The bracket (400) has a through hole (430) at its center. The first end of the motor shaft (122) passes through the through hole (430) and is coaxially fixedly connected to the first counting gear (410). The second end of the motor shaft (122) is fixedly connected to the sun gear (210). The first end and the second end of the motor shaft (122) are located on both sides of the rotor frame (121).

4. A joint module based on a planetary reducer as described in claim 3, characterized in that, The second end of the motor shaft (122) and the sun gear (210) are integrally formed.

5. A joint module based on a planetary reducer as described in claim 1, characterized in that, A hollow annular cylindrical portion (310) is provided on the bottom wall of the housing (300) extending toward the support (400), and the stator (110) is fixed to the outer peripheral wall of the cylindrical portion (310); the internal gear ring (230) is fixed to the inner peripheral wall of the cylindrical portion (310).

6. A joint module based on a planetary reducer as described in claim 5, characterized in that, The internal gear ring (230) and the cylindrical part (310) are integrally formed.

7. A joint module based on a planetary reducer as described in claim 1, characterized in that, The planetary carrier (240) includes a first annular portion (241) and a second annular portion (242) arranged coaxially, and a connecting arm (243) for connecting the first annular portion (241) and the second annular portion (242). The two ends of the planetary shaft (250) are fixedly connected to the first annular portion (241) and the second annular portion (242) respectively. The planetary gear (220) is rotatably mounted on the planetary shaft (250) and located between the first annular portion (241) and the second annular portion (242). The first annular portion (241) is supported on the inner wall of the cylindrical portion (310) by the first bearing (244), and the second annular portion (242) is supported on the inner wall of the cylindrical portion (310) by the second bearing (245).

8. A joint module based on a planetary reducer as described in claim 7, characterized in that, The first end of the sun gear (210) is supported on the inner wall of the first annular portion (241) by a third bearing (211), and the second end of the sun gear (210) is supported on the inner wall of the second annular portion (242) by a fourth bearing (212).

9. A joint module based on a planetary reducer as described in claim 1, characterized in that, The drive board (500) is externally mounted with a rear cover (600), which is fixedly connected to the bracket (400).

10. A robot, characterized in that, Includes the joint module based on a planetary reducer as described in any one of claims 1 to 9.

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