Lightweight robot arm structure

Abstract

The utility model discloses a light-weight robot arm structure. The light-weight robot arm structure comprises a shoulder rotating module, a shoulder stretching module, a large arm rotating module, an elbow joint stretching module, a small arm rotating module, a wrist rotating stretching module and a grabbing module which are made of aluminum alloy. The shoulder rotating module is connected with the large arm rotating module through the shoulder stretching module, one end of the large arm rotating module is connected with the small arm rotating module through the elbow joint stretching module, the other end of the small arm rotating module is connected with the wrist rotating stretching module, and the wrist rotating stretching module is connected with the grabbing module. Wherein the shoulder rotating module, the shoulder stretching module, the large arm rotating module, the elbow joint stretching module and the small arm rotating module are each internally provided with a servo driving assembly, and the wrist rotating stretching module comprises two stacked steering engines. Swinging and rotating of seven degrees of freedom can be achieved, under the condition of the same driving torque, the lighter the self structure weight is, the larger the load capable of being borne by the tail end is, the load is relatively large, and installation and debugging are convenient.

Description

Technical Field

[0001] The utility model relates to the technical field of robot arms, in particular to a lightweight robot arm structure. Background Technique

[0002] The description of this part only provides background information related to the disclosure of the utility model, and does not constitute the prior art.

[0003] Most existing humanoid robots have arms with six or seven degrees of freedom. The arms are used for manipulation, grasping, or whole-body movement. Therefore, the arm structure must be able to compensate for the whole-body momentum and be as simple as possible.

[0004] Since the grasping function of the arm is expected to be as powerful as possible, the structure itself needs to be as lightweight as possible. The lighter the arm is under the same driving torque, the greater the load that the end can bear. At the same time, it is required that the arm movement is flexible enough. Therefore, the arm must have at least seven degrees of freedom to achieve the flexibility of the human arm.

[0005] It should be noted that the above introduction to the technical background is only for the convenience of clearly and completely explaining the technical solution of the utility model and facilitating the understanding of those skilled in the art. It cannot be considered that the above technical solutions are well-known to those skilled in the art just because these solutions are described in the background art part of the utility model. Summary of the Utility Model

[0006] The technical problem to be solved by the utility model is to provide a lightweight robot arm structure for the deficiencies of the prior art, which can achieve the swinging and rotation of seven degrees of freedom, has a light self-structure weight, the lighter it is under the same driving torque, the greater the load that the end can bear, has a relatively large load, and is also convenient for installation and debugging.

[0007] An embodiment of the present application discloses a lightweight robot arm structure, including:

[0008] A shoulder rotation module, a shoulder extension module, a large arm rotation module, an elbow joint extension module, a small arm rotation module, a wrist rotation and extension module, and a grasping module made of aluminum alloy material;

[0009] The shoulder rotation module is connected to the large arm rotation module through the shoulder extension module. One end of the large arm rotation module is connected to the small arm rotation module through the elbow joint extension module. The other end of the small arm rotation module is connected to a wrist rotation and extension module, and the wrist rotation and extension module is connected to a grasping module;

[0010] Among them, a servo drive component is provided in each of the shoulder rotation module, the shoulder extension module, the large arm rotation module, the elbow joint extension module, and the small arm rotation module. The wrist rotation and extension module includes two stacked servos.

[0011] Furthermore, for the above-mentioned lightweight robot arm structure, the servo drive assembly includes a motor shaft, a permanent magnet rotor, a wave generator, and a positioning bearing. The permanent magnet rotor is arranged on the motor shaft, the wave generator is fixed on the motor housing, and the wave generator is supported by a set of positioning bearings.

[0012] Furthermore, for the above-mentioned lightweight robot arm structure, the positioning bearing is selected as a four-point contact ball bearing.

[0013] Furthermore, for the above-mentioned lightweight robot arm structure, the motor shaft is of a hollow structure and is made of aluminum material.

[0014] Furthermore, for the above-mentioned lightweight robot arm structure, the plug of the wave generator is made of aluminum or steel material.

[0015] Furthermore, for the above-mentioned lightweight robot arm structure, crossed roller bearings and T-shaped servo actuators are provided in the shoulder extension module and the elbow extension module.

[0016] Furthermore, for the above-mentioned lightweight robot arm structure, torque sensors are provided at the output ends of the shoulder extension module, the upper arm rotation module, and the elbow extension module.

[0017] Furthermore, for the above-mentioned lightweight robot arm structure, the wrist rotation and extension module includes a first servo motor and a second servo motor. The first servo motor is installed on the second servo motor, and the swinging directions of the first servo motor and the second servo motor are inconsistent.

[0018] Furthermore, for the above-mentioned lightweight robot arm structure, the grasping module is connected to the wrist rotation and extension module through a U-shaped part, and the bottom of the U-shaped part is fixedly connected to the grasping module.

[0019] Furthermore, for the above-mentioned lightweight robot arm structure, the robot arm has seven degrees of freedom.

[0020] In summary, the above structure adopted in the embodiments of the present utility model has the following advantages:

[0021] The lightweight robot arm structure described in the present utility model can achieve swinging and rotating of seven degrees of freedom. The shoulder rotation module rotates to achieve the front and back swinging of the entire robot arm, the shoulder extension module moves to achieve the abduction of the arm, the upper arm rotation module rotates to achieve the rotation of the upper arm, the elbow joint extension module rotates to achieve the bending of the forearm, the forearm rotation module rotates to achieve the rotation of the forearm, and the wrist rotation and extension module can achieve two-directional movement similar to that of the wrist through the stacked first servo motor and second servo motor for two-directional degrees of freedom movement. The robot arm of the present utility model has a light self-structure weight. Under the condition of the same driving torque, the lighter the self-weight, the greater the load that the end can bear, and the relatively large load is also convenient for installation and debugging. Aluminum alloy 7075 is selected for the material. On the premise of not affecting the performance in the material selection from the motor shaft to the reducer to the motor housing, aluminum alloy material is preferably used, and the motor housing is mostly designed as a direct connection type, omitting the intermediate transition parts, thereby reducing the overall mass.

[0022] To further understand the features and technical content of the present utility model, please refer to the following detailed description and drawings of the present utility model. However, the provided drawings are only for reference and illustration, and are not used to limit the present utility model. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the technical solutions in the embodiments of this specification or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are only some embodiments recorded in this specification. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0024] Figure 1 and Figure 2 are the structural schematic diagrams of the lightweight robot arm structure in the embodiments of the present utility model.

[0025] Figure 3 is the structural schematic diagram of the servo drive assembly in the embodiments of the present utility model.

[0026] Figure 4 is the schematic diagram of the components inside the shoulder extension station module and the elbow joint extension module in the embodiments of the present utility model.

[0027] The reference numerals of the above drawings: 1. Shoulder rotation module; 2. Shoulder extension module; 3. Upper arm rotation module; 4. Elbow joint extension module; 5. Forearm rotation module; 6. Wrist rotation and extension module; 61. First servo motor; 62. Second servo motor; 7. Gripping module; 71. U-shaped part; 8. Servo drive assembly; 81. Motor shaft; 82. Permanent magnet rotor; 83. Wave generator; 84. Positioning bearing; 91. Crossed roller bearing; 92. T-shaped servo actuator. Detailed implementation manners

[0028] In order to enable those skilled in the art to better understand the technical solutions in this specification, the technical solutions in the embodiments of this specification will be clearly and completely described below with reference to the accompanying drawings in the embodiments of this specification. Obviously, the described embodiments are only a part of the embodiments of this specification, rather than all the embodiments. Based on the embodiments in this specification, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of this specification.

[0029] The following are specific embodiments to illustrate the implementation manners of the present utility model. Those skilled in the art can understand the advantages and effects of the present utility model from the content disclosed in this specification. The present utility model can be implemented or applied through other different specific embodiments, and various details in this specification can also be modified and changed based on different viewpoints and applications without departing from the concept of the present utility model. Additionally, the drawings of the present utility model are only simple schematic illustrations and are not drawn according to actual dimensions. This is stated in advance. The following implementation manners will further detail the related technical content of the present utility model, but the disclosed content is not used to limit the protection scope of the present utility model.

[0030] It should be understood that although terms such as "first", "second", and "third" may be used herein to describe various components or signals, these components or signals should not be limited by these terms. These terms are mainly used to distinguish one component from another, or one signal from another. Additionally, the term "or" used herein may, depending on the actual situation, include any one or a combination of more of the associated listed items.

[0031] Refer to Figures 1 to 4 As shown, an embodiment of the present application discloses a lightweight robot arm structure, including:

[0032] A shoulder rotation module 1, a shoulder extension module 2, a large arm rotation module 3, an elbow joint extension module 4, a small arm rotation module 5, a wrist rotation and extension module 6, and a grasping module 7 made of aluminum alloy material;

[0033] The shoulder rotation module 1 is connected to the large arm rotation module 3 through the shoulder extension module 2. One end of the large arm rotation module 3 is connected to the small arm rotation module 5 through the elbow joint extension module 4. The other end of the small arm rotation module 5 is connected to a wrist rotation and extension module 6, and the wrist rotation and extension module 6 is connected to a grasping module 7;

[0034] Among them, a servo drive assembly 8 is provided in each of the shoulder rotation module 1, shoulder extension module 2, upper arm rotation module 3, elbow joint extension module 4, and forearm rotation module 5, and the wrist rotation and extension module 6 includes two stacked servos.

[0035] Specifically, referring to Figure 3 , in this embodiment, the servo drive assembly 8 includes a motor shaft 81, a permanent magnet rotor 82, a wave generator 83, and a positioning bearing 84. The permanent magnet rotor 82 is disposed on the motor shaft 81, the wave generator 83 is fixed to the motor housing, and the wave generator 83 is supported by a set of positioning bearings 84.

[0036] Specifically, in this embodiment, the positioning bearing 84 is a four-point contact ball bearing. The characteristics of the four-point angular contact ball bearing are as follows: 1. The four-point contact ball bearing is a separable structure, and a single bearing can replace the angular contact ball bearings in the face-to-face combination or back-to-back combination; 2. It can withstand radial loads and bi-directional axial loads, and can limit the axial displacement in two directions, but occupies less axial space than the current standard double-row angular contact ball bearings; 3. Compared with other ball bearings, when the radial clearance is the same, the four-point contact ball bearing has a smaller axial clearance and a higher limiting speed; 4. The four-point contact ball bearing is suitable for bearing pure axial loads or axial and radial combined loads mainly composed of axial loads. Since it has double half inner rings (or outer rings), the number of balls installed increases, and it has a larger load-bearing capacity; 5. Under normal working conditions, when this type of bearing bears axial loads in any direction, a contact angle can be formed, and the steel balls contact the inner and outer raceways at one point each, avoiding large sliding friction in the contact area. Therefore, the bearing is not suitable for bearing radial force-dominated loads.

[0037] Specifically, in this embodiment, the motor shaft 81 is a hollow structure, and the motor shaft 81 is made of aluminum material to reduce the weight of the overall mechanism.

[0038] Specifically, in this embodiment, the plug of the wave generator 83 is made of aluminum or steel material.

[0039] Specifically, referring to Figure 4, in this embodiment, the shoulder extension module 2 and the elbow extension module 4 are provided with crossed roller bearings 91 and T-shaped servo actuators 92. Crossed roller bearings have the following advantages: 1. High load-carrying capacity and stiffness. Crossed roller bearings use rolling supports, which can withstand large radial and axial loads and provide high-stiffness supports; 2. High precision. Due to their rolling support method, no sliding friction occurs during operation, ensuring high precision and stability; 3. Strong adaptability. Suitable for a variety of working environments, including harsh conditions such as high temperature, low temperature, strong acid, and strong alkali; 4. Long service life. The internal rolling friction has a small friction coefficient and a small amount of frictional heat, resulting in a long bearing life; 5. Installation and maintenance. Although the installation requirements are high, once correctly installed, the maintenance is relatively simple and the grease consumption is small.

[0040] Specifically, in this embodiment, torque sensors are provided at the output ends of the shoulder extension module 2, the upper arm rotation module 3, and the elbow extension module 4.

[0041] Specifically, in this embodiment, the wrist rotation and extension module 6 includes a first servo motor 61 and a second servo motor 62. The first servo motor 61 is installed on the second servo motor 62, and the swinging directions of the first servo motor 61 and the second servo motor 62 are inconsistent.

[0042] Specifically, in this embodiment, the grasping module 7 is connected to the wrist rotation and extension module 6 through a U-shaped member 71, and the bottom of the U-shaped member 71 is fixedly connected to the grasping module 7.

[0043] Specifically, in this embodiment, the robotic arm has seven degrees of freedom.

[0044] With the above structure, the robotic arm mechanism has seven degrees of freedom. There is a servo drive component 8 in each of the shoulder rotation module 1, shoulder extension module 2, upper arm rotation module 3, elbow joint extension module 4, and forearm rotation module 5. The servo drive component 8 adopts a low-inertia design. Since the inertia of the motor shaft is mainly determined by the inertia of the permanent magnet rotor and the wave generator, the wave generator is customized for low inertia and mass. The wave generator is made of aluminum or steel, and the coupling of the standard version is cancelled; the permanent magnet rotor is fixed on the motor shaft, while the wave generator is fixed on the motor housing with screws. The motor shaft is made of aluminum and is hollow. It is only supported by a positioning bearing, and the positioning bearing is fixed by adjusting gaskets and snap rings. The positioning bearing adopts a four-point contact ball bearing, which is a thin-walled ball bearing. In order to reduce the total weight of the module, the motor housing needs to be as light as possible on the premise of load calculation. Aluminum alloy 7075 is selected for the material. On the premise of not affecting the performance, aluminum alloy material is preferably used for the selection of materials from the motor shaft to the reducer to the motor housing, and the motor housing is mostly designed as a direct connection type, eliminating the intermediate transition parts, thereby reducing the overall mass. The wrist rotation and extension module 6 includes a first servo 61 and a second servo 62. The housing of the shoulder rotation module 1 is connected to the upper body structure through a flange. The upper arm rotation mechanism 3 is a lightweight servo actuator, and its output end is equipped with a torque sensor. The shoulder extension module 2 and the elbow joint extension module 4 are driven by T-shaped lightweight servo actuators with crossed roller bearings and additional support bearings, and torque sensors are equipped at the output ends. The forearm rotation module 5 is composed of a small lightweight servo drive and a four-point contact ball bearing. The wrist rotation and extension module 6 realizes the two-way swing of the wrist by stacking two servos. The wrist rotation and extension module 6 is connected to the grasping module 7 through a U-shaped part 71. A load is installed at the end of the grasping module 7. The connecting flange of the servo actuator assembly is installed by blind rivets and polyurethane adhesives. All connecting parts are made of aluminum alloy materials except for special requirements; compared with the overall structure of an equivalent seven-degree-of-freedom arm, the weight of this robotic arm mechanism is reduced by about 6 kg, and the maximum load is about 3 kg; for the robotic arm mechanism of this application, the rotation of the shoulder rotation module 1 realizes the front-back swing of the entire robotic arm, the movement of the shoulder extension module 2 realizes the abduction of the arm, the rotation of the upper arm rotation module 3 can realize the rotation of the upper arm, the rotation of the elbow joint extension module 4 can realize the bending of the forearm, the rotation of the forearm rotation module 5 can realize the rotation of the forearm, and the wrist rotation and extension module 6 can realize the two-direction movement similar to the wrist through the two-direction degree-of-freedom movement of the stacked first servo 61 and second servo 62. The robotic arm of this embodiment has a light self-structure weight. Under the same driving torque, the lighter it is, the greater the load that the end can bear. The load is relatively large, and it is also convenient for installation and debugging.

[0045] The content disclosed above is only the preferred and feasible embodiment of the present utility model, and does not limit the scope of the patent application of the present utility model. Therefore, all equivalent technical changes made by using the content of the specification and drawings of the present utility model are included in the scope of the patent application of the present utility model.

[0046] The embodiments in this specification are described in a progressive manner. For the same or similar parts among the embodiments, reference can be made to each other. The key points of each embodiment are the differences from other embodiments.

[0047] Although the present application is depicted through embodiments, those of ordinary skill in the art know that the present application has many variations and changes without departing from the spirit of the present application. It is hoped that the appended embodiments include these variations and changes without departing from the present application.

Claims

1. A lightweight robot arm structure, characterized in that: include: The shoulder rotation module, shoulder extension module, upper arm rotation module, elbow extension module, forearm rotation module, wrist rotation extension module and grasping module are made of aluminum alloy; The shoulder rotation module is connected to the upper arm rotation module through the shoulder extension module, one end of the upper arm rotation module is connected to the lower arm rotation module through the elbow extension module, the other end of the lower arm rotation module is connected to the wrist rotation extension module, and the wrist rotation extension module is connected to the grasping module; Wherein, each of the shoulder rotation module, shoulder extension module, upper arm rotation module, elbow joint extension module and lower arm rotation module is provided with a servo drive assembly, and the wrist rotation extension module includes two stacked servos.

2. The lightweight robot arm structure according to claim 1, characterized in that: The servo drive assembly comprises a motor shaft, a permanent magnet rotor, a wave generator and a locating bearing. The permanent magnet rotor is arranged on the motor shaft. The wave generator is fixed on the motor housing. The wave generator is supported by a group of locating bearings.

3. The lightweight robot arm structure according to claim 2, characterized in that: The locating bearing is a four-point contact ball bearing.

4. The lightweight robot arm structure according to claim 2, characterized in that: The motor shaft is a hollow structure, and the motor shaft is made of aluminum.

5. The lightweight robot arm structure according to claim 2, characterized in that: The plug of the wave generator is made of aluminum or steel.

6. The lightweight robot arm structure according to claim 1, characterized in that: The shoulder extension module and the elbow joint extension module are provided with a cross roller bearing and a T-type servo actuator.

7. The lightweight robot arm structure according to claim 1, characterized in that: The output ends of the shoulder extension module, the upper arm rotation module and the elbow joint extension module are all provided with torque sensors.

8. The lightweight robot arm structure according to claim 1, characterized in that: The wrist rotation and extension module includes a first steering gear and a second steering gear, wherein the first steering gear is installed on the second steering gear, and the swing directions of the first steering gear and the second steering gear are inconsistent.

9. The lightweight robot arm structure according to claim 1, characterized in that: The grabbing module is connected to the wrist rotating and extending module via a U-shaped piece, and the bottom of the U-shaped piece is fixedly connected to the grabbing module.

10. The lightweight robot arm structure according to claim 1, characterized in that: The robot arm has seven degrees of freedom.

Images