A high-precision four-axis robot

Abstract

The present invention discloses a high-precision four-axis robot, comprising a first-axis linear motion pair, a second-axis rotation pair, a third-axis lifting linear motion pair and a fourth-axis rotation pair, wherein the first-axis linear motion pair and the second-axis rotation pair are combined together through a connecting plate, the third-axis lifting linear motion pair and the fourth-axis rotation pair are combined together through a nut guide block, and the second-axis rotation pair, the third-axis lifting linear motion pair and the fourth-axis rotation pair are all connected through a mechanical arm. The first-axis linear motion pair of the present invention adopts a linear motor with an absolute value encoder, the second-axis rotation pair adopts a rotary direct-drive motor with an absolute value encoder, the third axis adopts a servo motor and a lead screw transmission with an absolute value encoder, and the fourth axis rotation pair adopts a rotary direct-drive motor with an absolute value encoder. All axes have no reducers, and therefore have the characteristics of high precision, high speed, low noise, long life and low maintenance.

Description

Technical Field

[0001] The invention relates to a four-axis robot, in particular to a high-precision four-axis robot. Background Art

[0002] Commonly used industrial planar four-axis robots are mainly represented by Scara robots or multi-slide combination structure robots, among which the first and second axes of Scara robots usually use a combination of servo motors and harmonic reducers, and their accuracy and life are completely dependent on the harmonic reducers. The fourth axis uses a synchronous belt drive, so it is not feasible in high-precision applications. As the first, second, and third axes of multi-slide combination structure robots all use slides, on the one hand, the spatial structure is not ideal and it appears very bulky. Due to the large overall inertia, the speed cannot be increased. On the other hand, such robots usually use incremental encoders, which cannot record the position when the power is off and need to be reset to zero, which is very inconvenient to use. Summary of the invention

[0003] The technical problem to be solved by the present invention is to provide a high-precision four-axis robot, in which the linear motion pair of the first axis adopts a linear motor with an absolute encoder, the rotation pair of the second axis adopts a rotary direct-drive motor with an absolute encoder, the third axis adopts a servo motor and a lead screw transmission with an absolute encoder, and the rotation pair of the fourth axis adopts a rotary direct-drive motor with an absolute encoder. Therefore, the robot has the characteristics of high precision, high speed, low noise, long life and low maintenance.

[0004] The present invention is achieved through the following technical solutions: a high-precision four-axis robot, comprising a first-axis linear motion pair, a second-axis rotation pair, a third-axis lifting linear motion pair and a fourth-axis rotation pair, the first-axis linear motion pair and the second-axis rotation pair are combined together through a connecting plate, the third-axis lifting linear motion pair and the fourth-axis rotation pair are combined together through a nut guide block, and the second-axis rotation pair, the third-axis lifting linear motion pair and the fourth-axis rotation pair are all connected through a mechanical arm.

[0005] As a preferred technical solution, the first axis linear motion pair is directly composed of a linear motor;

[0006] The second axis rotary pair is composed of a rotary direct drive motor and a mounting seat, and the third axis lifting linear motion pair is composed of a linear guide pair, a pressure plate, a second angular contact bearing, a lead screw nut, a lead screw, a servo motor, a pulley, a synchronous belt, a lead screw seat, and a motor seat;

[0007] The fourth axis rotary pair is composed of a rotary encoder, a nut, a bearing pressure plate, a first angular contact bearing, a bearing seat, a rotary motor, a spline nut, and a spline shaft;

[0008] The mover of the linear motor is connected to the connecting plate, the connecting plate is connected to the rotor of the rotary direct-drive motor, the housing of the rotary direct-drive motor is connected to the mounting seat, the mounting seat is connected to the robotic arm, the robotic arm is respectively connected to the screw seat, the motor seat and the housing of the rotary motor, the screw is supported by angular contact bearing 2 and mounted on the screw seat, and is pressed by a pressure plate, a pulley is installed at the end of the screw, and a pulley is also installed on the shaft of the servo motor, the two are meshed together with a synchronous belt, and the servo motor is installed on the motor seat.

[0009] As a preferred technical solution, the spline shaft and the spline nut form a linear motion pair, the spline nut is connected to the rotor of the rotary motor, the top end of the spline shaft is supported in the bearing seat through a first angular contact bearing, the inner ring of the first angular contact bearing is locked with a nut, and the outer ring of the first angular contact bearing is pressed with a bearing pressure plate, the shaft of the rotary encoder is connected to the spline shaft, and the outer shell of the rotary encoder is connected to the bearing seat, and the bearing seat is mounted on the screw nut through a nut guide block.

[0010] As a preferred technical solution, the servo motor and the screw seat are distributed side by side in the width direction of the robot arm.

[0011] As a preferred technical solution, the first-axis linear motion pair adopts a linear motor with an absolute encoder, the second-axis rotation pair adopts a rotary direct-drive motor with an absolute encoder, the third-axis lifting linear motion pair adopts a servo motor and screw transmission with an absolute encoder, and the fourth-axis rotation pair adopts a rotary direct-drive motor with an absolute encoder.

[0012] As a preferred technical solution, the rotary encoder and rotary motor of the fourth axis rotary pair are separate structures, which can move up and down with the lead screw nut and rotate with the rotor of the rotary motor of the fourth axis.

[0013] As a preferred technical solution, the rotary direct drive motor of the second axis rotary pair is a hollow type, the rotor of which is mounted on the linear motor, and the housing of which is mounted on the robot arm, allowing the air pipe and the cable to pass through the middle.

[0014] As a preferred technical solution, the servo motor and the screw seat are distributed side by side in the width direction of the robot arm, so as to shorten the length of the robot arm and reduce the inertia of the head.

[0015] The beneficial effects of the present invention are as follows: the first-axis linear motion pair of the present invention adopts a linear motor with an absolute value encoder, the second-axis rotation pair adopts a rotary direct-drive motor with an absolute value encoder, the third axis adopts a servo motor and a lead screw transmission with an absolute value encoder, and the fourth-axis rotation pair adopts a rotary direct-drive motor with an absolute value encoder. Therefore, it has the characteristics of high precision, high speed, low noise, long life and low maintenance. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0017] Figure 1 It is a schematic diagram of the present invention;

[0018] Figure 2 It is a schematic diagram of the structure of the present invention;

[0019] Figure 3 It is a schematic structural diagram of the fourth axis rotation pair of the present invention;

[0020] Figure 4 It is a structural schematic diagram of the third axis lifting linear motion pair of the present invention;

[0021] In the figure: 101, first axis linear motion pair, 102, second axis rotation pair, 103, third axis lifting linear motion pair, 104, fourth axis rotation pair, 1, linear motor, 2, connecting plate, 3, rotary direct drive motor, 4, mounting seat, 5, robotic arm, 6, linear guide pair, 7, nut guide block, 8, rotary encoder, 9, nut, 10, bearing pressure plate, 11, first angular contact bearing, 12, bearing seat, 13, rotary motor, 14, spline nut, 15, spline shaft, 16, pressure plate, 17, second angular contact bearing, 18, screw nut, 19, screw, 20, servo motor, 21, pulley, 22, synchronous belt, 23, screw seat, 24, motor seat. DETAILED DESCRIPTION

[0022] All features disclosed in this specification, or steps in all methods or processes disclosed, except mutually exclusive features and / or steps, can be combined in any manner.

[0023] Any feature disclosed in this specification (including any additional claims, abstract and drawings), unless otherwise stated, may be replaced by other equivalent or alternative features with similar purposes. That is, unless otherwise stated, each feature is only an example of a series of equivalent or similar features.

[0024] like Figure 1 As shown, it includes a first-axis linear motion pair, a second-axis rotation pair, a third-axis lifting linear motion pair and a fourth-axis rotation pair. The first-axis linear motion pair and the second-axis rotation pair are combined together through a connecting plate, the third-axis lifting linear motion pair and the fourth-axis rotation pair are combined together through a nut guide block, and the second-axis rotation pair, the third-axis lifting linear motion pair and the fourth-axis rotation pair are all connected through a robotic arm.

[0025] Specifically, the first axis linear motion pair 101 and the second axis rotation pair 102 are combined together through the connecting plate 2, the third axis lifting linear motion pair 103 and the fourth axis rotation pair 104 are combined together through the nut guide block 7, and the robot arm 5 connects the second axis rotation pair 102, the third axis lifting linear motion pair 103 and the fourth axis rotation pair 104. The first axis linear motion pair 101 is directly composed of a linear motor 1, the second axis rotation pair 102 is composed of a rotary direct drive motor 3 and a mounting seat 4, the third axis lifting linear motion pair 103 is composed of a linear guide pair 6, a pressure plate 16, a second angular contact bearing 17, a screw nut 18, a screw 19, a servo motor 20, a pulley 21, a synchronous belt 22, a screw seat 23, and a motor seat 24, and the fourth axis rotation pair 104 is composed of a rotary encoder 8, a nut 9, a bearing pressure plate 10, a first angular contact bearing 11, a bearing seat 12, a rotary motor 13, a spline nut 14, and a spline shaft 15.

[0026] The mover of the linear motor 1 is connected to the connecting plate 2, the connecting plate 2 is connected to the rotor of the rotary direct drive motor 3, the housing of the rotary direct drive motor 3 is connected to the mounting base 4, the mounting base 4 is connected to the mechanical arm 5, the mechanical arm 5 is respectively connected to the screw base 23, the motor base 24 and the housing of the rotary motor 13, the screw 19 is supported by the angular contact bearing 17 and is mounted on the screw base 23, and is pressed by the pressure plate 16. A pulley 21 is installed at the end of the screw 19, and a pulley 21 is also installed on the shaft of the servo motor 20. The two are meshed together with a synchronous belt 22, and the servo motor 20 is installed on the motor base 24.

[0027] The spline shaft 15 and the spline nut 14 form a linear motion pair, wherein the spline nut 14 is connected to the rotor of the rotary motor 13, the top end of the spline shaft 15 is supported in the bearing seat 12 through an angular contact bearing 11, the inner ring of the angular contact bearing 11 is locked by a nut 9, and the outer ring of the angular contact bearing 11 is pressed by a bearing pressure plate 10, the shaft of the rotary encoder 8 is connected to the spline shaft 15, and the outer shell of the rotary encoder 8 is connected to the bearing seat 12, and the bearing seat 12 is installed on the screw nut 18 through the nut guide block 7.

[0028] Therefore, when the linear motor 1 is driven, the rotary direct drive motor 3 follows to make linear motion, when the rotary direct drive motor 3 is driven, the robot arm 5 follows to rotate, when the servo motor 20 is driven, the spline shaft 15 follows to move up and down, and when the rotary motor 13 is driven, the spline shaft 15 follows to rotate.

[0029] In this embodiment, the rotary encoder 8 serves as the feedback encoder of the rotary motor 13, and it rises and falls together with the spline shaft 15. This requires that the rotational clearance between the spline shaft 15 and the spline nut 14 is very small. The present invention adopts a spline combination with zero rotational backlash.

[0030] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that are not conceived through creative work should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope defined in the claims.

Claims

1. A high-precision four-axis robot, characterized in that: It comprises a first axis linear motion pair, a second axis rotation pair, a third axis lifting linear motion pair and a fourth axis rotation pair, wherein the first axis linear motion pair and the second axis rotation pair are combined together through a connecting plate, the third axis lifting linear motion pair and the fourth axis rotation pair are combined together through a nut guide block, and the second axis rotation pair, the third axis lifting linear motion pair and the fourth axis rotation pair are all connected through a mechanical arm; The first axis linear motion pair is composed of a linear motor; The second axis rotary pair is composed of a rotary direct drive motor and a mounting seat, and the third axis lifting linear motion pair is composed of a linear guide pair, a pressure plate, a second angular contact bearing, a lead screw nut, a lead screw, a servo motor, a pulley, a synchronous belt, a lead screw seat, and a motor seat; The fourth axis rotary pair is composed of a rotary encoder, a nut, a bearing pressure plate, a first angular contact bearing, a bearing seat, a rotary motor, a spline nut, and a spline shaft; The mover of the linear motor is connected to the connecting plate, the connecting plate is connected to the rotor of the rotary direct-drive motor, the housing of the rotary direct-drive motor is connected to the mounting seat, the mounting seat is connected to the mechanical arm, the mechanical arm is respectively connected to the screw seat, the motor seat and the housing of the rotary motor, the screw is installed on the screw seat through the second angular contact bearing and is pressed by the pressure plate, a pulley is installed at the end of the screw, a pulley is also installed on the shaft of the servo motor, the two are meshed with a synchronous belt, and the servo motor is installed on the motor seat; the servo motor and the screw seat are distributed side by side in the width direction of the mechanical arm; the spline shaft and the spline nut constitute a linear motion pair, the spline nut is connected to the rotor of the rotary motor, the top end of the spline shaft is supported in the bearing seat through the first angular contact bearing, the inner ring of the first angular contact bearing is locked with a nut, and the outer ring of the first angular contact bearing is pressed with a bearing pressure plate, the shaft of the rotary encoder is connected to the spline shaft, the housing of the rotary encoder is connected to the bearing seat, and the bearing seat is installed on the screw nut through a nut guide block.

2. The high-precision four-axis robot according to claim 1, characterized in that: The first axis linear motion pair adopts a linear motor with an absolute encoder, the second axis rotation pair adopts a rotary direct drive motor with an absolute encoder, the third axis lifting linear motion pair adopts a servo motor and screw transmission with an absolute encoder, and the fourth axis rotation pair adopts a rotary direct drive motor with an absolute encoder.

3. The high-precision four-axis robot according to claim 2, characterized in that: The rotary encoder and rotary motor of the fourth axis rotary pair are of separate structures, and can move up and down with the lead screw nut and rotate together with the rotor of the rotary motor of the fourth axis.

4. The high-precision four-axis robot according to claim 1, characterized in that: The rotary direct drive motor of the second axis rotary pair is a hollow type, with its rotor mounted on the linear motor and its housing mounted on the robot arm, allowing the air pipe and cable to pass through the middle.

Images