End driving structure of multi-joint robot

Abstract

The utility model provides an end driving structure of multi -joint robot belongs to the field of robot technology, it has solved the technical problem of the insufficient precision of existing four -axis robot end transmission, this multi -joint robot includes the casing and movable rod, end driving structure includes Z axle motor, R axle motor, speed reducer subassembly and ball spline subassembly, speed reducer subassembly includes transmission shaft and transmission wheel, transmission wheel coaxial fixed in transmission shaft's upper end, the inner chamber bottom surface of casing has the baffle that sets up vertically, the robot still includes the mount frame that is fixed link with baffle and the inner chamber lateral wall of casing respectively in both sides, transmission shaft and mount frame all are located transmission band one's outside, mount frame has two locating plate that interval is up and down, and the upper and lower ends of this transmission shaft are rotatoryly connected on two locating plate respectively. The utility model is beneficial to make the length of transmission shaft shorter, reduce the influence of stress deflection, in addition, can strengthen the stability of mount frame position, and then guarantee transmission shaft not deflection in the working process, and transmission is accurate all the time.

Description

Technical Field

[0001] This utility model belongs to the field of robotics technology and relates to an end effector structure for a multi-joint robot. Background Technology

[0002] SCARA, also known as Selective Compliant Assembly Robotic Arm, is a cylindrical coordinate industrial robotic arm used for assembly operations. It is capable of positioning and orientation in a plane. A SCARA four-axis robot includes four axes and four degrees of freedom. The four axes are named as follows, from closest to farthest from the robot base: first axis, second axis, third axis, and fourth axis. The four degrees of freedom include three rotational degrees of freedom and one translational degree of freedom.

[0003] For example, patent application number CN201721172919.4 discloses a desktop four-axis robot, including a base, a first rotating arm, a second rotating arm, and a movable rod; one end of the first rotating arm is rotatably connected to the base via an X-axis drive motor, and the other end of the first rotating arm is rotatably connected to one end of the second rotating arm via a Y-axis drive motor; the movable rod is disposed at the other end of the second rotating arm; the second rotating arm is provided with a Z-axis drive motor and an R-axis drive motor; the Z-axis drive motor and the movable rod are connected by a ball spline assembly to enable the movable rod to move linearly along its own axis; the R-axis drive motor and the movable rod are connected by a synchronous belt reduction mechanism to enable the movable rod to rotate around its own axis.

[0004] The aforementioned four-axis robot controls the lifting and rotation of the movable rods through the Z-axis drive motor and the R-axis drive motor, respectively. However, there are still some shortcomings: the drive shaft in the synchronous belt reduction mechanism passes through the inside of the drive belt, and the upper pulley is fixed to the upper end of the drive shaft through a connector. Only the lower end of the drive shaft is fixed to the machine housing. In order to avoid interference between the upper pulley and the drive belt, the length of the drive shaft is relatively long, which makes the upper end of the drive shaft more prone to deformation and skew after continuous force, ultimately affecting the transmission accuracy. Summary of the Invention

[0005] This utility model addresses the aforementioned problems in existing technologies by providing an end-effector drive structure for a multi-joint robot. The technical problem this utility model aims to solve is the insufficient transmission accuracy of existing four-axis robots.

[0006] The objective of this utility model can be achieved through the following technical solutions:

[0007] An end effector structure for a multi-joint robot includes a long, narrow housing and a vertically positioned movable rod at one end of the housing. The end effector structure includes a Z-axis motor, an R-axis motor, a reduction gear assembly, and a ball spline assembly. The ball spline assembly is fitted around the movable rod and can rotate to move the movable rod up and down. The Z-axis motor and R-axis motor are both vertically fixed at the other end of the housing. The output shaft of the R-axis motor is connected to the movable rod via the reduction gear assembly, and the output shaft of the Z-axis motor is connected to the ball spline assembly via a transmission belt. The reduction gear assembly includes a transmission shaft and a transmission wheel, with the transmission wheel coaxially fixed to the upper end of the transmission shaft. The housing has a vertically positioned partition on its inner cavity bottom surface. The robot also includes mounting brackets fixed to the partition and the inner cavity sidewall of the housing on both sides. The transmission shaft and mounting brackets are located outside the transmission belt. The mounting brackets have two positioning plates spaced apart vertically, and the upper and lower ends of the transmission shaft are rotatably connected to the two positioning plates.

[0008] The Z-axis motor drives the existing ball spline assembly to rotate via a transmission belt, thereby achieving vertical lifting and lowering of the movable rod. The R-axis motor, after torque amplification via a reduction assembly, outputs torque to the outer circumference of the movable rod to achieve its circumferential rotation. A vertical partition is installed on the bottom surface of the inner cavity of the machine housing, and a mounting bracket is fixed between the partition and the inner side wall of the housing. The mounting bracket has two positioning plates spaced vertically, allowing the upper and lower ends of the drive shaft to be rotatably connected to the two positioning plates. This ensures that both ends of the drive shaft are radially constrained by the positioning plates, effectively preventing skewness caused by loads in different directions. Furthermore, since the drive shaft and mounting bracket are located outside the transmission belt, the position of the transmission wheel can be designed to be lower, allowing for a shorter drive shaft and reducing the impact of force skewness. In addition, the mounting bracket fully utilizes the constraints of the partition and the inner side wall of the housing on both sides, enhancing the stability of the mounting bracket position and ensuring that the drive shaft does not skew during operation, maintaining precise transmission.

[0009] In the aforementioned end effector structure of the multi-joint robot, the output shaft of the R-axis motor is connected to the transmission wheel via a second transmission belt, and the transmission shaft below the transmission wheel is connected to the movable rod via a third transmission belt. The Z-axis motor and the R-axis motor are arranged horizontally along the width of the casing. This arrangement facilitates the formation of a space on the side of the R-axis motor near the movable rod that does not interfere with the first transmission belt, making it easier to arrange the mounting bracket. It also helps to ensure that the R-axis motor, transmission shaft, and movable rod are arranged in an approximately straight line along the horizontal direction, thereby reducing losses during transmission.

[0010] In the aforementioned end effector structure of the multi-joint robot, the mounting frame is C-shaped with its opening facing the side where the movable rod is located. The upper and lower side walls of the mounting frame form two positioning plates, and the transmission belt is located between the two positioning plates. This makes the mounting frame a more stable, integrated structure, while the opening of the mounting frame allows the transmission belt to extend without interference, thus balancing structural and transmission stability.

[0011] In the end effector structure of the aforementioned multi-joint robot, the positioning plate located at the top has several vertically penetrating, waist-shaped holes arranged along the length of the housing. The positioning plate is fixed to the housing and the partition plate by screws passing through these waist-shaped holes. This facilitates fine-tuning of the mounting bracket's position relative to the length of the housing, allowing for adjustments to the position based on the actual length and condition of the transmission belt to ensure optimal transmission performance.

[0012] In the end effector structure of the aforementioned multi-joint robot, the partition is arranged along the length of the casing. This helps to ensure the strength of the partition while reducing the potential interference of the partition with the transmission belt, which is generally arranged along the length direction.

[0013] In the end effector structure of the aforementioned multi-joint robot, a gap is left between the bottom of the mounting bracket and the bottom surface of the inner cavity of the housing. This helps to avoid contact and friction between the lower end of the drive shaft, which is rotatably connected to the mounting bracket, and the bottom surface of the inner cavity of the housing, thus ensuring transmission efficiency.

[0014] Compared with the prior art, the advantages of this utility model are as follows:

[0015] The end effector structure of this multi-joint robot ensures that both the upper and lower ends of the drive shaft are radially constrained by the positioning plates, effectively preventing the drive shaft from becoming skewed when subjected to loads in different directions. At the same time, the mounting frame makes full use of the constraints of the partition plates and the inner cavity sidewalls of the housing, resulting in high stability and ensuring that the transmission is always accurate. Attached Figure Description

[0016] Figure 1 This is a three-dimensional structural diagram of this embodiment.

[0017] Figure 2 This is a top view of the structure of this embodiment.

[0018] Figure 3 yes Figure 2 A schematic diagram of the AA cross-sectional structure.

[0019] Figure 4 This is a three-dimensional structural diagram of a partial structure in this embodiment.

[0020] Figure 5 This is a three-dimensional structural diagram of a partial structure from another angle in this embodiment.

[0021] Figure 6 This is a three-dimensional structural diagram of the mounting bracket in this embodiment.

[0022] In the diagram, 1. Housing; 11. Partition; 2. Movable rod; 3. Z-axis motor; 4. R-axis motor; 5. Reduction assembly; 51. Drive shaft; 52. Drive wheel; 7. Ball spline assembly; 8. Drive belt one; 9. Mounting bracket; 91. Positioning plate; 92. Waist-shaped hole; 101. Drive belt two; 102. Drive belt three; 103. Screw. Detailed Implementation

[0023] The following are specific embodiments of the present invention, which are described in conjunction with the accompanying drawings. However, the present invention is not limited to these embodiments.

[0024] like Figure 1-6As shown, this multi-joint robot includes a long, narrow housing 1 and a vertically positioned movable rod 2 at one end of the housing 1. The end effector includes a Z-axis motor 3, an R-axis motor 4, a reduction gear assembly 5, and a ball spline assembly 7. The ball spline assembly 7 is fitted around the movable rod 2 and can rotate to move the movable rod 2 up and down. The Z-axis motor 3 and R-axis motor 4 are existing motors, vertically fixed at the other end of the housing 1. The reduction gear assembly 5 includes a drive shaft 51 and a drive wheel 52. The drive wheel 52 is coaxially fixed to the upper end of the drive shaft 51. The R-axis... The output shaft of motor 4 is connected to the movable rod 2 via transmission wheel 52 and transmission shaft 51. The output shaft of Z-axis motor 3 is connected to the ball spline assembly 7 via transmission belt 8. The bottom surface of the inner cavity of the housing 1 has a vertically arranged partition 11. The robot also includes mounting brackets 9 on both sides, which are fixed to the partition 11 and the inner cavity sidewall of the housing 1, respectively. The transmission shaft 51 and the mounting brackets 9 are both located outside the transmission belt 8. The mounting brackets 9 have two positioning plates 91 spaced apart vertically. The upper and lower ends of the transmission shaft 51 are rotatably connected to the two positioning plates 91, respectively. Z-axis motor 3 is used to drive the existing ball spline assembly 7 to rotate via transmission belt 8, thereby realizing the vertical lifting and lowering of the movable rod 2. R-axis motor 4 is used to output torque to the outer periphery of the movable rod 2 by increasing the torque of the torque reduction component 5, thereby realizing its circumferential rotation. Specifically, the output shaft of the R-axis motor 4 is connected to the transmission wheel 52 of the reduction assembly 5 via a second transmission belt 101. The transmission shaft 51 below the transmission wheel 52 is connected to the movable rod 2 via a third transmission belt 102. The Z-axis motor 3 and the R-axis motor 4 are arranged horizontally along the width of the housing 1. The mounting bracket 9 is C-shaped with its opening facing the movable rod 2. The upper and lower side walls of the mounting bracket 9 form two positioning plates 91. The third transmission belt 102 is located between the two positioning plates 91. The first transmission belt 8, the second transmission belt 101, and the third transmission belt 102 are all existing transmission belts. The upper positioning plate 91 has three vertical through-holes 92 on both sides, which are arranged along the length of the housing 1. The positioning plate 91 is fixed to the housing 1 and the partition plate 11 by screws 103 that pass through the through-holes 92. The partition plate 11 is arranged along the length of the housing 1. There is a gap between the bottom of the mounting bracket 9 and the bottom surface of the inner cavity of the housing 1.

[0025] The specific embodiments described herein are merely illustrative examples illustrating the spirit of this utility model. Those skilled in the art to which this utility model pertains may make various modifications or additions to the described specific embodiments or use similar methods to replace them, without departing from the spirit of this utility model or exceeding the scope defined by the appended claims.

Claims

1. An end effector structure for a multi-joint robot, the robot comprising a long, narrow housing (1) and a movable rod (2) vertically disposed at one end of the housing (1), the end effector structure comprising a Z-axis motor (3), an R-axis motor (4), a reduction gear assembly (5), and a ball spline assembly (7), the ball spline assembly (7) being sleeved on the outer periphery of the movable rod (2) and capable of rotating to drive the movable rod (2) to move up and down, the Z-axis motor (3) and the R-axis motor (4) being vertically fixed at the other end of the housing (1), the output shaft of the R-axis motor (4) being connected to the movable rod (2) via the reduction gear assembly (5), the output shaft of the Z-axis motor (3) being connected to the ball spline assembly (7) via a transmission belt (8), the reduction gear assembly (5) comprising a transmission shaft (51) and a transmission wheel (52), the transmission wheel (52) being coaxially fixed to the upper end of the transmission shaft (51), characterized in that, The inner cavity bottom surface of the housing (1) has a vertically arranged partition (11). The robot also includes mounting brackets (9) on both sides, which are fixedly connected to the partition (11) and the inner cavity sidewall of the housing (1). The transmission shaft (5) and the mounting bracket (9) are both located outside the transmission belt (8). The mounting bracket (9) has two positioning plates (91) spaced apart vertically. The upper and lower ends of the transmission shaft (5) are rotatably connected to the two positioning plates (91).

2. The end effector drive structure of the multi-joint robot according to claim 1, characterized in that, The output shaft of the R-axis motor (4) is connected to the transmission wheel (6) via a transmission belt (101). The transmission shaft (5) below the transmission wheel (6) is connected to the movable rod (2) via a transmission belt (102). The Z-axis motor (3) and the R-axis motor (4) are arranged along the width direction of the housing (1).

3. The end effector drive structure of the multi-joint robot according to claim 1, characterized in that, The mounting bracket (9) is C-shaped with its opening facing the side where the movable rod (2) is located. The upper and lower side walls of the mounting bracket (9) form two positioning plates (91), and the transmission belt (102) is located between the two positioning plates (91).

4. The end effector structure of the multi-joint robot according to claim 1, 2, or 3, characterized in that, The positioning plate (91) located above has several vertical through holes (92) arranged along the length of the housing (1). The positioning plate (91) is fixed to the housing (1) and the partition plate (11) by screws (103) passing through the through holes (92).

5. The end effector drive structure of the multi-joint robot according to claim 1, 2, or 3, characterized in that, The partition (11) is arranged along the length of the housing (1).

6. The end effector structure of the multi-joint robot according to claim 1, 2, or 3, characterized in that, There is a gap between the bottom of the mounting bracket (9) and the bottom surface of the inner cavity of the housing (1).

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