Planetary reducer and robot joint module

Abstract

The utility model provides a planetary reducer and a robot joint module, and relates to the technical field of transmission devices.The planetary reducer comprises a shell connected with an end plate; the end plate and the shell jointly form a first cavity; the end plate is provided with a first mounting hole, and first flow guide ports are formed around the first mounting hole; the sun gear is located in the first cavity and arranged on a sun shaft, and the sun shaft is rotationally connected with the first mounting hole; the plurality of planet gears are positioned in the first cavity, are uniformly distributed around the sun gear and are meshed with the sun gear; the planet wheel is rotationally connected with a planet shaft; the planet shaft is mounted on a planet carrier; the inner gear ring is located in the first cavity, and the planet wheel is meshed with the inner side of the inner gear ring; the planet carrier and the end plate are located on the opposite side of the first cavity, one end of the sun shaft is rotationally connected with the planet carrier, and the planet carrier is rotationally connected with the shell; the planet carrier has a second diversion port. The planetary reducer and the robot joint module are smaller in axial length and better in heat dissipation effect.

Description

Technical Field

[0001] The utility model relates to the technical field of transmission devices, in particular to a planetary reducer and a robot joint module. Background Art

[0002] In the field of robotics, joint modules are used at the joints of robots and are the core components that enable flexible robot movement. As robotic applications continue to expand, higher demands are being placed on the miniaturization, efficiency, and performance of these modules.

[0003] To meet the requirements of miniaturization and high efficiency, existing joint modules are composed of brushless motors and multi-stage planetary reducers, which amplify the output torque. However, the following defects still exist:

[0004] 1. Structural redundancy: The multi-stage planetary transmission results in an excessively long module axial length (greater than 120 mm), making it difficult to adapt to compact robot joints;

[0005] 2. Low heat dissipation efficiency: The existing joint module adopts a multi-stage transmission structure, resulting in a tight internal structure, and can only adopt an "end-in-side-out" heat dissipation method, that is, the air flow enters from one end of the joint module and flows out from the side to remove heat; however, the gas flow efficiency of "end-in-side-out" is not very high, and it is difficult to meet the heat dissipation requirements of the continuous output of 111Nm torque condition.

[0006] 3. The multi-stage planetary reducer of the existing joint module adopts a hollow structure to facilitate the arrangement of wires. However, the hollow aperture is small, only ≤5mm, which cannot meet the requirements of multi-cable threading. Although the harmonic reduction module has the advantage of a large hollow structure, it is not suitable for application in the joint module because the torque bearing capacity of the harmonic reduction module is weak (<80Nm at the same size), the heat dissipation efficiency is low, and fatigue fracture is prone to occur. Utility Model Content

[0007] In view of the above situation, the present invention provides a planetary reducer and a robot joint module, aiming to solve at least one of the defects pointed out in the above background technology.

[0008] To achieve the above objectives, the present invention provides the following technical solutions:

[0009] In a first aspect, the present invention provides a planetary reducer, comprising:

[0010] The shell is connected to an end plate; the end plate and the shell together form a first cavity; the end plate has a first mounting hole, and a first guide port is formed around the first mounting hole;

[0011] The sun gear is located in the first cavity and is arranged on the sun shaft, and the sun shaft is rotatably connected to the first mounting hole;

[0012] A plurality of planetary gears located in the first cavity are evenly distributed around the sun gear and mesh with the sun gear; the planetary gears are rotatably connected to planetary shafts, which are mounted on the planetary carrier;

[0013] An inner gear ring is located in the first cavity, and the planetary gears are meshed with the inner side of the inner gear ring;

[0014] The planet carrier and the end plate are located on opposite sides of the first cavity. One end of the sun shaft is rotatably connected to the planet carrier, and the planet carrier is rotatably connected to the housing. The planet carrier has a second guide port.

[0015] In some embodiments of the present invention, guide fins are provided on the outer wall of the shell.

[0016] In some embodiments of the present invention, the transmission ratio of the planetary reducer is i=1+Zc / Za=12.9, where Za is the number of teeth on the sun gear and Zc is the number of teeth on the inner ring gear.

[0017] In some embodiments of the present invention, the planet carrier has an output flange in the middle, the output flange has a second mounting hole in the center, and one end of the sun shaft is rotatably connected to the second mounting hole.

[0018] In some embodiments of the present invention, the planetary gear is made of carburized and hardened steel.

[0019] In some embodiments of the present invention, a through hole with a diameter of 9 mm is opened along the axial direction of the sun shaft.

[0020] In a second aspect, the utility model provides a robot joint module, a drive module and a planetary reducer, wherein one end of the sun shaft is transmission-connected to the output end of the drive module.

[0021] In some embodiments of the present invention, the end plate is disposed in the housing, and the end plate divides the internal space of the housing into a first cavity and a second cavity, and the second cavity is used to accommodate the driving module.

[0022] In some embodiments of the present invention, the driving module includes:

[0023] Motor stator;

[0024] The motor rotor is used in conjunction with the motor stator; the motor rotor is integrated with fan blades and is connected to the sun shaft;

[0025] The rear cover and the end plate are located on the opposite side of the second cavity, and the rear cover is detachably connected to the shell; the rear cover is provided with a third air guide port.

[0026] In some embodiments of the present invention, a plurality of third air guide ports are distributed in a ring shape on the back cover to form an annular air inlet, and the air inlet area of ​​the annular air inlet is ≥150 mm².

[0027] The embodiments of the present invention have at least the following advantages or beneficial effects:

[0028] 1. Smaller axial length: The planetary reducer adopts a single-stage transmission structure. The sun gear and sun shaft are directly connected to the output end of the drive module (electronic rotor), and the output flange is integrated on the planetary carrier to achieve power output. Compared with multi-stage planetary reducers, this design simplifies the transmission structure, reduces the number of parts, improves transmission efficiency and reliability, and helps reduce the axial size to ≤82mm to adapt to compact robot joints.

[0029] 2. Improved heat dissipation: The first air guide, first cavity, and second air guide are sequentially connected to form an end-to-end axial air duct. This means that after air enters the housing through the first air guide on the end plate, it carries heat from the first cavity and is discharged directly through the second air guide on the planetary carrier. This results in smoother air flow and improved heat dissipation. Furthermore, guide fins are installed on the outer wall of the housing to further enhance heat dissipation, ensuring stable temperature of the driver module during high-load operation and reducing the risk of failure due to overheating.

[0030] Other features and advantages of the present invention will be described in the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the following briefly introduces the drawings required for the description of the embodiments. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0032] Figure 1 Schematic diagram of the structure of the robot joint module provided in Examples 1 and 2 Figure 1 ;

[0033] Figure 2 Schematic diagram of the structure of the robot joint module provided in Examples 1 and 2 Figure 2 ;

[0034] Figure 3 Schematic diagram of the structure of the robot joint module provided in Examples 1 and 2 Figure 3 ;

[0035] Figure 4 for Figure 3 Cross-sectional view along AA direction;

[0036] Figure 5 Schematic diagram of the robot joint module provided in Examples 1 and 2 Figure 1 ;

[0037] Figure 6 Schematic diagram of the robot joint module provided in Examples 1 and 2 Figure 2 ;

[0038] Figure 7 is a structural schematic diagram of the shell;

[0039] Figure 8 Schematic diagram of the structure of the planetary carrier.

[0040] icon:

[0041] 1-shell, 11-guide fin, 12-end plate, 121-first mounting hole, 122-first guide port, 13-first cavity, 14-second cavity,

[0042] 2-sun gear, 21-sun shaft, 211-through hole,

[0043] 3- planetary gear, 31- planetary shaft,

[0044] 4-Inner ring gear,

[0045] 5-planet carrier, 51-cross roller bearing, 52-inner pressure cover, 53-outer pressure cover, 54-second mounting hole, 55-second guide port, 56-output flange,

[0046] 6-motor rotor, 61-fan blade,

[0047] 7-Motor stator,

[0048] 8-rear cover, 81-third air guide port. DETAILED DESCRIPTION

[0049] In the following, only certain exemplary embodiments are briefly described. As those skilled in the art will appreciate, the described embodiments may be modified in various different ways without departing from the spirit or scope of the embodiments of the present invention.

[0050] In the description of the embodiments of the present invention, it should be understood that the terms "center", "length", "inside", "outside", "axial", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings. They are only for the convenience of describing the embodiments of the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, they cannot be understood as limitations on the embodiments of the present invention.

[0051] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly specify the number of the technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of the embodiments of the present invention, "plurality" means two or more, unless otherwise specifically defined.

[0052] In the embodiments of the present invention, unless otherwise specified or limited, the terms "installed," "connected," "connected," "fixed," etc. should be understood in a broad sense. For example, they can refer to fixed connection, detachable connection, or integration; they can refer to direct connection or indirect connection through an intermediate medium; they can refer to internal communication between two components or interaction between two components. Those skilled in the art will understand the specific meanings of the above terms in the embodiments of the present invention based on specific circumstances.

[0053] The embodiments of the present utility model are described in detail below.

[0054] Example 1

[0055] See also Figures 1 to 8 This embodiment provides a robot joint module, the torque output of the robot joint module is ≥111Nm, the maximum outer diameter of the robot joint module is ≤182mm, and the axial length is ≤82mm, which achieves a compact design while ensuring high torque output.

[0056] The robot joint module includes a planetary reducer and a drive module. The input end of the planetary reducer (one end of the sun shaft 21 described below) is transmission-connected to the output end of the drive module.

[0057] The planetary reducer includes a housing 1 , a sun gear 2 , planetary gears 3 , an internal gear 4 and a planet carrier 5 .

[0058] The housing 1 is hollow and cylindrical, with guide fins 11 disposed on its outer wall. An end plate 12 is located within the housing 1, coaxial with the housing 1. This divides the interior of the housing 1 into a first cavity 13 and a second cavity 14. The first cavity 13 accommodates the sun gear 2, planetary gears 3, and ring gear 4, while the second cavity 14 accommodates the drive module. A first mounting hole 121 is defined in the center of the end plate 12, surrounded by a plurality (12) of first guide ports 122.

[0059] Sun gear 2 is mounted on sun shaft 21, which is rotatably connected to first mounting hole 121 via a bearing. One end of sun shaft 21 serves as the input of the planetary reducer and is transmission-connected to the output of the drive module. The other end is rotatably connected to planet carrier 5 via a bearing. Sun shaft 21 has a through-hole 211 with a diameter of 9 mm along its axial direction to facilitate threading. In this embodiment, sun gear 2 and sun shaft 21 are integrally designed, and sun gear 2 is obtained by machining a tooth profile on the side of sun shaft 21.

[0060] Multiple (three) planetary gears 3 are evenly distributed around and mesh with the sun gear 2. These planetary gears 3 are connected to planetary shafts 31 via bearings, which are mounted on the planetary carrier 5. The planetary gears 3 are made of carburized and hardened steel (surface hardness HRC 58-62), which enhances their strength and wear resistance, ensuring stability and durability during high-torque transmission.

[0061] The inner ring gear 4 is installed in the first cavity 13 , and the planetary gears 3 are meshed with the inner side of the inner ring gear 4 .

[0062] The planet carrier 5 and end plate 12 are located on opposite sides of the first cavity 13. The planet carrier 5 is rotatably connected to the housing 1 via a cross-roller bearing 51, which is mounted to the housing 1 via an inner gland 52 and an outer gland 53. An output flange 56 is located in the center of the planet carrier 5, with a second mounting hole 54 at its center. One end of the sun shaft 21 is rotatably connected to the second mounting hole 54 via a bearing. The side of the planet carrier 5 facing the first cavity 13 is hollowed out to reduce weight. The planet carrier 5 has three second air guide ports 55, distributed evenly around the second mounting hole 54.

[0063] The transmission ratio of the above planetary reducer is i=1+Zc / Za=12.9, where Za is the number of teeth of the sun gear (2) and Zc is the number of teeth of the inner ring gear (4). The planetary reducer can meet the high transmission ratio requirements and ensure a larger torque output in a smaller volume.

[0064] The working principles of the sun gear 2 and the planetary gear 3 are common knowledge and will not be described in detail here. The above planetary reducer has at least the following beneficial effects:

[0065] 1. Smaller axial length: The planetary reducer adopts a single-stage transmission structure. The sun gear 2 and sun shaft 21 are directly connected to the output end of the drive module. The output flange 56 is integrated on the planetary carrier 5 to achieve power output. Compared with multi-stage planetary reducers, this design simplifies the transmission structure, reduces the number of parts, improves transmission efficiency and reliability, and helps reduce the axial size to ≤82mm to adapt to compact robot joints.

[0066] 2. Improved heat dissipation: The first air guide 122, the first cavity 13, and the second air guide 55 are sequentially connected, forming an end-to-end axial air duct. This means that after air enters the housing 1 through the first air guide 122 of the end plate 12, it carries heat from the first cavity 13 and is discharged directly through the second air guide 55 of the planetary carrier 5 (the second air guide 55 is actually an air outlet). This smooths the flow of air and improves heat dissipation. Furthermore, air guide fins 11 are provided on the outer wall of the housing 1, further enhancing heat dissipation and ensuring a stable temperature for the driver module during high-load operation, reducing the risk of failure due to overheating.

[0067] 3. Improved threading capacity: The diameter of the through hole 211 is increased to 9 mm, which can support the simultaneous threading of power and signal lines. The output end can be connected to an external rotating conductive slip ring to avoid cable entanglement, meet the needs of multi-cable threading, and improve wiring flexibility and safety.

[0068] 4. The transmission ratio of the planetary reducer reaches 12.9 (generally below 10), which can meet the high transmission ratio requirements under the premise of using a single-stage transmission structure, ensuring a larger torque output (≥111Nm) in a smaller volume.

[0069] As can be seen from the above, this embodiment mainly optimizes the planetary reducer to simultaneously achieve a smaller axial length, better heat dissipation, better threading capability, and higher torque output capability.

[0070] Example 2

[0071] See also Figures 1 to 8 In this embodiment, the drive module includes a motor rotor 6, a motor stator 7, and a back cover 8. The motor rotor 6 and the motor stator 7 are used in conjunction with each other and are located in the second cavity 14. The motor rotor 6 is integrated with fan blades 61 and is connected to the sun shaft 21. A center hole of the same size as the through hole 211 is opened in the center of the motor rotor 6. The back cover 8 and the end plate 12 are located on opposite sides of the second cavity 14, and the back cover 8 is detachably connected to the housing 1. A plurality of third air guide ports 81 are distributed in an annular manner on the back cover 8. The plurality of third air guide ports 81 distributed in an annular manner on the back cover 8 form an annular air inlet, and the air inlet area of ​​the annular air inlet is ≥150mm².

[0072] The motor rotor 6 is connected to the sun shaft 21; the motor rotor 6 is integrated with the fan blades 61, and the motor rotor 6 can drive the fan blades 61 to rotate to force the external air to be sucked into the third guide port 81. The third guide port 81, the first guide port 122, the first cavity 13 and the second guide port 55 are connected in sequence to form an "end-to-end" forced axial air duct, that is, the air is forced to be sucked into the third guide port 81 (the third guide port 81 is the air inlet of the entire module), and the air flow passes through the gap between the motor rotor 6 and the motor stator 7, enters the shell 1 from the first guide port 122 of the end plate 12, and carries the heat of the first cavity 13 and is discharged directly from the second guide port 55 of the planetary carrier 5 (the second guide port 55 is the air outlet of the entire module). The gas flow is smoother, and the heat dissipation effect is improved.

[0073] Through heat dissipation designs such as axial forced air ducts and guide fins 11, the temperature rise is reduced by 35% (when the actual output is continuously 111Nm, the winding temperature of the motor stator 7 is ≤85°C), effectively solving the problem of low heat dissipation efficiency of existing modules, improving the stability and reliability of the module during continuous high-torque output, and extending its service life.

[0074] Example 3

[0075] See also Figures 1 to 8 Unlike Example 1, in this embodiment, no guide fins 11 are provided on the outer wall of the housing 1. Under the premise of adopting axial air ducts / forced axial air ducts, even without the use of guide fins 11, better heat dissipation effect can be achieved than the prior art.

[0076] Example 4

[0077] See also Figures 1 to 8 , different from Example 1, in this embodiment, the end plate 12 is located at the end of one end of the shell 1, that is, there is only the first cavity 13 in the shell 1. At this time, a separate shell can be configured for the motor rotor 6, motor stator 7, etc. of the drive module.

[0078] Example 5

[0079] See also Figures 1 to 8 , different from Example 1, in this embodiment, the robot joint module uses a harmonic reducer in the prior art to replace the planetary reducer to adapt to the scenario requirements of small torque.

[0080] Finally, it should be noted that the above are merely preferred embodiments of the present application and are not intended to limit the present application. Persons skilled in the art will readily appreciate that the present application is susceptible to various modifications and variations. The embodiments and features of the embodiments may be combined arbitrarily without conflict. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present application shall be included within the scope of protection of the present application.

Claims

1. A planetary reducer, characterized in that: include: A shell is connected to an end plate; the end plate and the shell together form a first cavity; The end plate has a first mounting hole, and a first guide port is formed around the first mounting hole; A sun gear located in the first cavity is disposed on a sun shaft, and the sun shaft is rotatably connected to the first mounting hole; A plurality of planetary gears located in the first cavity are evenly distributed around the sun gear and meshed with the sun gear; the planetary gears are rotatably connected to planetary shafts, which are mounted on a planetary carrier; an inner gear ring located in the first cavity, the planetary gears meshing with the inner side of the inner gear ring; The planet carrier and the end plate are located on the opposite side of the first cavity, and the planet carrier is rotatably connected to the housing; the planet carrier has a second guide port.

2. The planetary reducer according to claim 1, characterized in that: Guide fins are arranged on the outer wall of the shell.

3. The planetary reducer according to claim 1, characterized in that: The transmission ratio of the planetary reducer is i=1+Zc / Za=12.9, where Za is the number of teeth on the sun gear and Zc is the number of teeth on the inner ring gear.

4. The planetary reducer according to claim 1, characterized in that: An output flange is provided in the middle of the planet carrier, a second mounting hole is provided at the center of the output flange, and one end of the sun shaft is rotatably connected to the second mounting hole.

5. The planetary reducer according to claim 1, characterized in that: The material of the planetary gear is carburized and hardened steel.

6. The planetary reducer according to any one of claims 1 to 5, characterized in that: The sun shaft is provided with a through hole with a diameter of 9 mm along its axial direction.

7. A robot joint module, characterized in that: It comprises a drive module and a planetary reducer according to any one of claims 1 to 6, wherein one end of the sun shaft is drivingly connected to the output end of the drive module.

8. The robot joint module according to claim 7, characterized in that: The end plate is disposed in the housing, and the end plate divides the inner space of the housing into a first cavity and a second cavity, wherein the second cavity is used to accommodate the driving module.

9. The robot joint module according to claim 8, characterized in that: The driving module includes: Motor stator; A motor rotor, used in conjunction with the motor stator; the motor rotor is integrated with fan blades and connected to the sun shaft; The rear cover and the end plate are located on the opposite side of the second cavity, and the rear cover is detachably connected to the shell; the rear cover is provided with a third air guide port.

10. The robot joint module according to claim 9, characterized in that: The back cover is provided with a plurality of third air guide openings distributed in an annular manner to form an annular air inlet, and the air inlet area of ​​the annular air inlet is ≥150 mm².

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