A joint module and robot

Abstract

This invention relates to a joint module and a robot. The joint module includes a module housing, a motor assembly, and a two-stage planetary reduction gear assembly. The motor stator of the motor assembly is fixedly connected to the inner circumference of the module housing. The right end of the motor stator and the right end of the motor rotor form a first receiving space with an open right side. The two-stage planetary reduction gear assembly includes a first sun gear, a first planet carrier, multiple first planetary gears, a second sun gear, an internal gear ring, a second planet carrier, and multiple second planetary gears. The internal gear ring is fixedly connected to the inner circumference of the module housing. The first sun gear is connected to the motor rotor. The multiple first planetary gears mesh between the first sun gear and the left side of the internal gear ring. The second sun gear is connected to the first planet carrier. The multiple second planetary gears mesh between the right side of the internal gear ring and the second sun gear. A portion of the first planet carrier is accommodated in the first receiving space. This invention can alleviate or eliminate the problem of large axial dimensions in joint modules.

Description

Technical Field

[0001] This invention relates to the field of robotics, specifically to a joint module and a robot. Background Technology

[0002] Joint modules are crucial motion units in robots, typically integrating drivers, motors, reducers, and encoders to perform vital functions such as power transmission and precise control. However, in related technologies, joint modules often employ a coaxial integration scheme, with the motor and reducer positioned coaxially, resulting in a generally large axial dimension. Summary of the Invention

[0003] The purpose of this invention is to provide a joint module and robot to alleviate or eliminate the problem of large axial dimensions in existing joint modules.

[0004] The present invention discloses a joint module comprising a module housing, a motor assembly, and a two-stage planetary reduction gear assembly. The motor assembly includes a motor rotor and a motor stator disposed around the motor rotor. The motor stator is fixedly connected to the inner circumference of the module housing. The right end of the motor stator extends to the right beyond the right end of the motor rotor, forming a first accommodating space with an open right side with the right end of the motor stator and the right end of the motor rotor. The two-stage planetary reduction gear assembly includes a first sun gear, a first planet carrier, a plurality of first planetary gears, a second sun gear, an internal gear ring, a second planet carrier, and a plurality of second planetary gears. The internal gear ring is fixedly connected to the inner circumference of the module housing. The plurality of first planetary gears are rotatably mounted on the first planet carrier, and the plurality of second planetary gears are rotatably mounted on the second planet carrier. The first sun gear is connected to the motor rotor. The plurality of first planetary gears mesh between the first sun gear and the left side of the internal gear ring. The second sun gear is connected to the first planet carrier. The plurality of second planetary gears mesh between the right side of the internal gear ring and the second sun gear. A portion of the first planet carrier is accommodated in the first accommodating space.

[0005] Optionally, the first planetary carrier includes a planetary carrier body housed in the first housing space, and a plurality of first planetary gears are connected to the right side of the planetary carrier body.

[0006] Optionally, a plurality of the second planetary gears are connected to the left side of the second planetary carrier, and the right side of the second planetary carrier is rotatably supported on the module housing by a first bearing.

[0007] Optionally, a retaining ring is held between the right end of the internal gear ring and the inner wall of the module housing, the retaining ring being used to define the axial position of the left end of the first bearing.

[0008] Optionally, the module housing includes a motor housing and a reducer housing, with the right end of the motor housing threadedly connected to the left end of the reducer housing, the motor stator fixedly connected to the inner circumference of the motor housing, and the internal gear ring fixedly connected to the inner circumference of the reducer housing.

[0009] Optionally, a partition is provided inside the module housing, the outer periphery of the partition is sandwiched between the motor housing and the reducer housing, and the middle part of the partition is recessed into the first receiving space to form a first recessed space for accommodating a part of the first planetary carrier.

[0010] Optionally, it also includes a rotating shaft connected to the second planetary carrier at its right end, the left end of the motor stator extending to the left of the left end of the motor rotor, the left end of the motor stator and the left end of the motor rotor forming a second accommodating space with an open left side, an encoder being provided in the second accommodating space, the encoder including an encoder stator connected to the module housing, a first encoder rotor connected to the motor rotor and a second encoder rotor connected to the rotating shaft.

[0011] Optionally, the left side of the motor rotor is rotatably supported on the module housing via a second bearing, and the right side of the motor rotor is rotatably supported on the module housing via a third bearing. A disc spring is provided between the third bearing and the module housing, and the disc spring presses against the third bearing to the left.

[0012] Optionally, a detachable end cap is provided at the left end of the module housing, and a motor driver is fixedly connected to the right side of the end cap.

[0013] The present invention also proposes a robot comprising the joint module described in any of the preceding claims.

[0014] The present invention has the following features: by optimizing the structure and arrangement of the two-stage planetary reduction assembly, the axial dimension of the joint module can be reduced, and the number of parts in the joint module can be reduced; by using disc springs to apply axial preload to the motor rotor, the problem of encoder accuracy reduction or error caused by axial movement during motor rotor operation can be solved, and the problem of encoder accuracy reduction or error caused by axial deformation of the motor rotor due to temperature difference can be offset. Attached Figure Description

[0015] Figure 1 This is a cross-sectional view of the joint module disclosed in the embodiments of this application;

[0016] Figure 2 for Figure 1 A magnified view of a portion of the view;

[0017] Figure 3This is a schematic diagram of the structure of the two-stage planetary deceleration assembly disclosed in the embodiments of this application;

[0018] Figure 4 This is a schematic diagram of the structure of the first planetary carrier, the first planetary gear, and the second sun gear disclosed in an embodiment of this application;

[0019] Figure 5 This is a schematic diagram of the structure of the second planetary carrier and the second planetary gear disclosed in an embodiment of this application;

[0020] Figure 6 This is a cross-sectional view of a portion of the structure of the joint module disclosed in an embodiment of this application;

[0021] Figure 7 This is a schematic diagram of the structure of the motor rotor disclosed in the embodiments of this application;

[0022] Figure 8 This is a schematic diagram of the structure of the motor housing and motor stator disclosed in the embodiments of this application;

[0023] Figure 9 This is a schematic diagram of the driver structure disclosed in an embodiment of this application.

[0024] In the figure, 1—motor housing, 2—reducer housing, 3—end cover, 4—partition plate, 5—motor stator, 6—motor rotor, 7—first sun gear, 8—first planetary carrier, 9—first planetary gear, 10—second sun gear, 11—internal gear ring, 12—second planetary carrier, 13—second planetary gear, 14—shaft, 15—encoder, 16—motor driver, 17—first bearing, 18—retaining ring, 19—second bearing, 20—third bearing, 21—disc spring, 22—first receiving space, 23—second receiving space, 101—housing body, 102—support wall, 501—first winding end, 502—second winding end, 601—rotor body, 602—rotor support, 1501—encoder stator, 1502—first encoder rotor, 1503—second encoder rotor. Detailed Implementation

[0025] The embodiments of the present invention will be described below with reference to the accompanying drawings and preferred embodiments. Those skilled in the art can easily understand other advantages and effects of the present invention from the content disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. It should be understood that the preferred embodiments are only for illustrating the present invention and not for limiting the scope of protection of the present invention.

[0026] It should be noted that the illustrations provided in the following embodiments are only schematic representations of the basic concept of the present invention. The illustrations only show the components related to the present invention and are not drawn according to the actual number, shape and size of the components in the actual implementation. In the actual implementation, the form, quantity and proportion of each component can be arbitrarily changed, and the layout of the components may also be more complex.

[0027] The directional terms used in this invention, such as "left" and "right," are only for reference to the directions shown in the accompanying drawings. The use of directional terms is for the purpose of better and clearer explanation and understanding of this invention, and does not indicate the location of the device or component in a practical application scenario.

[0028] As described in the background section, joint modules are important motion units of robots. They typically integrate drivers, motors, reducers, and encoders, undertaking crucial functions of power transmission and precise control. However, in related technologies, joint modules usually employ a coaxial integration scheme, with the motor and reducer coaxially positioned, often resulting in a large axial dimension.

[0029] To address the aforementioned technical problems, this application proposes a joint module, please refer to [link / reference]. Figures 1 to 5 , Figure 1 This is a cross-sectional view of the joint module disclosed in the embodiments of this application; Figure 2 for Figure 1 A magnified view of a portion of the view; Figure 3 This is a schematic diagram of the structure of the two-stage planetary deceleration assembly disclosed in the embodiments of this application; Figure 4 This is a schematic diagram of the structure of the first planetary carrier 8, the first planetary gear 9, and the second sun gear 10 disclosed in the embodiments of this application; Figure 5This is a schematic diagram of the structure of the second planetary carrier 12 and the second planetary gear 13 disclosed in an embodiment of this application. The joint module includes a module housing, a motor assembly, and a two-stage planetary reduction assembly. The motor assembly and the two-stage planetary reduction assembly are coaxially arranged. The motor assembly includes a motor rotor 6 and a motor stator 5 disposed around the motor rotor 6. The motor stator 5 is fixedly connected to the inner circumference of the module housing. The right end of the motor stator 5 extends to the right beyond the right end of the motor rotor 6, forming a first accommodating space 22 with an open right side with the right end of the motor stator 5 and the right end of the motor rotor 6. The two-stage planetary reduction assembly includes a first sun gear 7, a first planetary carrier 8, multiple first planetary gears, a second sun gear 10, an internal gear ring 11, and a second planetary gear 12. The second planetary carrier 12 and multiple second planetary gears, the internal gear ring 11 are fixedly connected to the inner circumference of the module housing, multiple first planetary gears are rotatably mounted on the first planetary carrier 8, multiple second planetary gears are rotatably mounted on the second planetary carrier 12, the first sun gear 7 is connected to the motor rotor 6, multiple first planetary gears mesh between the first sun gear 7 and the left part of the internal gear ring 11, the second sun gear 10 is connected to the first planetary carrier 8, multiple second planetary gears mesh between the right part of the internal gear ring 11 and the second sun gear 10, and a part of the first planetary carrier 8 is accommodated in the first accommodating space 22.

[0030] By adopting the above technical solution, considering that the winding of the motor stator 5 has a first winding end 501 extending to the right of the motor rotor 6, the first winding end 501 forms a first receiving space 22 at the right end of the motor. This first receiving space 22 is used to accommodate a portion of the first planetary carrier 8, thus making reasonable use of the first receiving space 22 and shortening the axial dimension of the joint module. The multiple first planetary gears and multiple second planetary gears of the two-stage planetary reduction assembly share a single internal gear ring 11, which reduces the number of internal gear rings 11 compared to a traditional two-stage planetary reducer, reducing the number of components in the joint module and also contributing to a reduction in the axial dimension of the joint module. The above technical solution, by optimizing the structure and arrangement of the planetary reduction assembly, reduces the axial dimension of the joint module and the number of components in the joint module.

[0031] In some embodiments, the first planetary carrier 8 includes a planetary carrier body housed in a first housing space 22, and a plurality of first planetary gears are connected to the right side of the planetary carrier body.

[0032] By adopting the above-described technical solution, compared to the traditional two-stage planetary reducer, the first planetary carrier 8 is arranged in reverse, with the planetary carrier body positioned on the side closest to the motor assembly. This allows the first planetary carrier 8 to be accommodated more within the first accommodating space 22, thereby significantly reducing the axial dimension of the joint module. Furthermore, this solution also reduces the axial dimension requirement for the internal gear ring 11, contributing to a reduction in the axial dimension of the internal gear ring 11 and ultimately lowering the weight of the joint module.

[0033] In practice, the first planetary gear is rotatably mounted on the first planetary carrier 8 via the first pin, and the second planetary gear is rotatably mounted on the second planetary carrier 12 via the second pin.

[0034] In some embodiments, a plurality of second planetary gears are connected to the left side of the second planetary carrier 12, and the right side of the second planetary carrier 12 is rotatably supported on the module housing by a first bearing 17.

[0035] By adopting the above technical solution, the axial dimension requirement of the internal gear ring 11 is reduced, which helps to reduce the axial dimension of the internal gear ring 11 and thus the weight of the joint module. Furthermore, the second planetary carrier 12 can be used as a power output component, reducing the number of parts. For example, the right end of the second planetary carrier 12 is exposed, and a connecting hole for connecting transmission components is provided at the right end of the second planetary carrier 12.

[0036] In some embodiments, a retaining ring 18 is held between the right end of the internal gear ring 11 and the inner wall of the module housing, the retaining ring 18 being used to define the axial position of the left end of the first bearing 17.

[0037] By adopting the above technical solution, the retaining ring 18 is pressed by the right end of the internal gear ring 11, and the retaining ring 18 fastening bolts are not required. This reduces the number of parts and also reduces the axial space required to install the retaining ring 18 fastening bolts, which helps to reduce the axial dimension of the joint module.

[0038] In practical implementation, a first stepped surface facing left is provided inside the module housing, and the retaining ring 18 is clamped between the first stepped surface and the right end of the internal gear ring 11.

[0039] In some embodiments, the module housing includes a motor housing 1 and a reducer housing 2. The right end of the motor housing 1 is threadedly connected to the left end of the reducer housing 2. The motor stator 5 is fixedly connected to the inner circumference of the motor housing 1, and the internal gear ring 11 is fixedly connected to the inner circumference of the reducer housing 2.

[0040] By adopting the above technical solution, the reducer housing 2 and the motor housing 1 are connected by threads, which saves the space of radially distributed mating bolts and reduces the outer diameter of the joint module. Moreover, when tightening the reducer housing 2 and the motor housing 1, the axial clamping force can be transmitted to the internal gear ring 11 to prevent the internal gear ring 11 from being loosened due to insufficient interference with the reducer housing 2, thereby improving the reliability of the joint module.

[0041] In some embodiments, a partition 4 is provided inside the module housing. The outer periphery of the partition 4 is sandwiched between the motor housing 1 and the reducer housing 2. The middle part of the partition 4 is recessed into the first receiving space 22 to form a first recessed space for receiving a part of the first planetary carrier 8.

[0042] By adopting the above technical solution, the partition 4 can separate the motor cavity and the reducer cavity, thereby reducing the mutual influence between the oil in the motor cavity and the reducer cavity.

[0043] In specific implementation, an external thread is provided on the outer periphery of the right end of the motor housing 1, and an internal thread and a second step surface facing left are provided on the inner periphery of the left end of the reducer housing 2. The external thread and the internal thread cooperate to realize the threaded connection between the motor housing 1 and the reducer housing 2. The outer edge of the partition 4 is clamped between the right end face of the motor housing 1 and the second step surface.

[0044] In practice, the partition 4 can be used to press the internal gear ring 11 to the right to limit the axial position of the internal gear ring 11.

[0045] Please see Figure 1 and Figure 6 , Figure 6 This is a cross-sectional view of a portion of the structure of the joint module disclosed in this application. In some embodiments, the joint module further includes a rotating shaft 14 connected to the second planetary carrier 12 at its right end, and the left end of the motor stator 5 extends to the left of the left end of the motor rotor 6. The left end of the motor stator 5 and the left end of the motor rotor 6 form a second receiving space 23 with an open left side. An encoder 15 is disposed in the second receiving space 23. The encoder 15 includes an encoder stator 1501 connected to the module housing, a first encoder rotor 1502 connected to the motor rotor 6, and a second encoder rotor 1503 connected to the rotating shaft 14.

[0046] By adopting the above technical solution, considering that the winding of the motor stator 5 has a second winding end 502 that extends to the left end of the motor rotor 6, the second winding end 502 will form a second receiving space 23 at the left end of the motor. The encoder 15 is accommodated by the second receiving space 23, which makes reasonable use of the second receiving space 23 and shortens the axial dimension of the joint module.

[0047] Furthermore, by setting a rotating shaft 14 that rotates synchronously with the second planetary carrier 12, a mounting point is provided for the second encoder rotor 1503, forming an encoder 15 with two rotors. This encoder can simultaneously detect the actual rotation state of the motor rotor 6 and the reducer output, thereby achieving full closed-loop precise control and improving the control accuracy and operational reliability of the joint module.

[0048] In practice, the right end of the rotating shaft 14 passes through the motor rotor 6, the first sun gear 7, the first planetary carrier 8, and the second sun gear 10 and connects to the second planetary carrier 12. The left side of the rotating shaft 14 can be supported in the motor rotor 6 or the first sun gear 7 by a bearing.

[0049] Please see Figure 1 , Figure 6 and Figure 8 , Figure 8This is a schematic diagram of the structure of the motor housing 1 and the motor stator 5 disclosed in the embodiments of this application. The motor housing 1 includes a housing body 101 and a support wall 102 connected inside the housing body 101. The motor stator 5 is fixedly connected to the housing body 101. The middle part of the support wall 102 is recessed into the second accommodating space 23 to form a second recessed space for accommodating the encoder 15. The support wall 102 can provide mounting points and support for the encoder stator 1501 and the motor rotor 6.

[0050] In related technologies, joint modules equipped with encoders 15 typically face the following technical problems: during the operation of the joint module, axial movement of the rotating shaft 14 causes the encoder 15 to be inaccurate; thermal expansion and contraction adversely affect the accuracy of the encoder 15.

[0051] In some embodiments, the left side of the motor rotor 6 is rotatably supported on the module housing via the second bearing 19, and the right side of the motor rotor 6 is rotatably supported on the module housing via the third bearing 20. A disc spring 21 is provided between the third bearing 20 and the module housing, and the disc spring 21 presses against the third bearing 20 to the left.

[0052] By adopting the above technical solution, the disc spring 21 applies axial preload to the motor rotor 6, which can solve the problem of reduced accuracy or error of encoder 15 caused by axial movement of motor rotor 6 during operation, and can offset the problem of reduced accuracy or error of encoder 15 caused by axial deformation of motor rotor 6 due to temperature difference.

[0053] Please see Figures 1 to 8 In specific implementation, the motor rotor 6 includes a rotor body 601 and a rotor support 602. The rotor body 601 is fixedly connected to the outer periphery of the rotor support 602. A first mounting hole is provided at the center of the support wall 102, and a second mounting hole is provided at the center of the partition plate 4. The outer peripheral surface of the second bearing 19 mates with the first mounting hole, and the inner peripheral surface of the second bearing 19 mates with the rotor support 602. The outer peripheral surface of the third bearing 20 mates with the second mounting hole, and the inner peripheral surface of the second bearing 19 mates with the rotor support 602. A third stepped surface facing right is provided at the left end of the first mounting hole, and a fourth stepped surface facing left is provided at the right end of the second mounting hole. A fifth stepped surface facing left and a sixth stepped surface facing right are provided on the rotor support 602. The third and fifth stepped surfaces are located on the left and right sides of the second bearing 19, respectively, and the fourth and sixth stepped surfaces are located on the left and right sides of the third bearing 20, respectively. A disc spring 21 is provided between the fourth stepped surface and the third bearing 20, and the disc spring 21 pushes against the third bearing 20 to the left.

[0054] In some embodiments, the first sun gear 7 and the rotor support 602 are connected by an interference fit and a flat rectangular structure for torque transmission, ensuring structural reliability.

[0055] Please see Figure 1 and Figure 9 , Figure 9 This is a schematic diagram of the driver disclosed in an embodiment of this application. In some embodiments, a detachable end cover 3 is provided at the left end of the module housing, and a motor driver 16 is fixedly connected to the right side of the end cover 3.

[0056] This invention provides a joint module that comprehensively solves the problems of insufficient axial compactness of integrated joint modules, large axial and radial space occupation, complex reducer structure with many parts, axial movement of the rotating shaft 14 causing insufficient accuracy of the encoder 15, and the adverse effects of thermal expansion and contraction on the accuracy of the encoder 15.

[0057] The present invention also proposes a robot comprising the joint module described in any of the preceding claims.

[0058] The above embodiments are merely preferred embodiments provided to fully illustrate the present invention, and the scope of protection of the present invention is not limited thereto. Equivalent substitutions or modifications made by those skilled in the art based on the present invention are all within the scope of protection of the present invention. In the description of this specification, the reference to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., means that a specific feature, structure, material, or characteristic associated with that embodiment or example is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials, or characteristics described can be combined in any suitable manner in one or more embodiments or examples. Furthermore, those skilled in the art can combine and integrate the different embodiments or examples described in this specification.

Claims

1. A joint module, characterized in that, The device includes a module housing, a motor assembly, and a two-stage planetary reduction gear assembly. The motor assembly includes a motor rotor and a motor stator disposed around the motor rotor. The motor stator is fixedly connected to the inner circumference of the module housing. The right end of the motor stator extends to the right beyond the right end of the motor rotor. The right end of the motor stator and the right end of the motor rotor form a first accommodating space with an open right side. The two-stage planetary reduction gear assembly includes a first sun gear, a first planet carrier, multiple first planetary gears, a second sun gear, an internal gear ring, a second planet carrier, and multiple second planetary gears. The internal gear ring is fixedly connected to the inner circumference of the module housing. The multiple first planetary gears are rotatably mounted on the first planet carrier, and the multiple second planetary gears are rotatably mounted on the second planet carrier. The first sun gear is connected to the motor rotor. The multiple first planetary gears mesh between the first sun gear and the left side of the internal gear ring. The second sun gear is connected to the first planet carrier. The multiple second planetary gears mesh between the right side of the internal gear ring and the second sun gear. A portion of the first planet carrier is accommodated in the first accommodating space.

2. The joint module according to claim 1, characterized in that, The first planetary carrier includes a planetary carrier body housed in the first housing space, and a plurality of first planetary gears are connected to the right side of the planetary carrier body.

3. The joint module according to claim 1, characterized in that, Multiple second planetary gears are connected to the left side of the second planetary carrier, and the right side of the second planetary carrier is rotatably supported on the module housing by a first bearing.

4. The joint module according to claim 1, characterized in that, A retaining ring is held between the right end of the internal gear ring and the inner wall of the module housing, and the retaining ring is used to limit the axial position of the left end of the first bearing.

5. The joint module according to claim 1, characterized in that, The module housing includes a motor housing and a reducer housing. The right end of the motor housing is threadedly connected to the left end of the reducer housing. The motor stator is fixedly connected to the inner circumference of the motor housing, and the internal gear ring is fixedly connected to the inner circumference of the reducer housing.

6. The joint module according to claim 5, characterized in that, A partition is provided inside the module housing. The outer periphery of the partition is sandwiched between the motor housing and the reducer housing. The middle part of the partition is recessed into the first receiving space to form a first recessed space for accommodating a part of the first planetary carrier.

7. The joint module according to claim 1, characterized in that, It also includes a rotating shaft connected to the second planetary carrier at its right end. The left end of the motor stator extends to the left of the left end of the motor rotor. The left end of the motor stator and the left end of the motor rotor form a second accommodating space with an open left side. An encoder is provided in the second accommodating space. The encoder includes an encoder stator connected to the module housing, a first encoder rotor connected to the motor rotor, and a second encoder rotor connected to the rotating shaft.

8. The joint module according to claim 7, characterized in that, The left side of the motor rotor is rotatably supported on the module housing by a second bearing, and the right side of the motor rotor is rotatably supported on the module housing by a third bearing. A disc spring is provided between the third bearing and the module housing, and the disc spring presses against the third bearing to the left.

9. The joint module according to claim 1, characterized in that, The left end of the module housing is provided with a detachable end cover, and a motor driver is fixedly connected to the right side of the end cover.

10. A robot, characterized in that, Includes the joint module as described in any one of claims 1-9.

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