A robot arm

Abstract

The present invention discloses a robot arm, comprising an arm connecting plate, an upper arm and a lower arm; the arm connecting plate has a horizontal connecting plate and a vertical connecting plate perpendicular to each other, the upper surface of the horizontal connecting plate is provided with an upper arm circumferential rotation mechanism, the output end of the upper arm circumferential rotation mechanism is connected to the upper end of the upper arm, and the lower end of the upper arm is hinged to the upper end of the lower arm; the vertical connecting plate is used to connect the shoulder joint of the robot. The robot arm of the technical solution of the present invention can not only realize self-rotation around its own central axis, but also realize bending or straightening of the lower arm relative to the upper arm, and the lower arm can output a large torque.

Description

Technical Field

[0001] The present invention relates to the field of robots, and in particular to a robot arm. Background Art

[0002] With the advancement of technology, the development of robots is no longer limited to early industrial robots. The development of service robots is a trend at this stage. The development of service robots has brought more convenient and comfortable services to humans. For service robots, a suitable humanoid robotic arm is crucial, but many existing robot arms have many shortcomings: (i) The robot arm does not have enough degrees of freedom and cannot rotate around the central axis of the arm like a human arm, so it is not flexible enough; (ii) Due to space limitations, robot arms generally cannot output large torques and cannot carry heavy objects, and can only be used for demonstration; if a large torque needs to be output, increasing the reduction motor will cause the joints to become bloated. Summary of the invention

[0003] In order to solve the above technical problems, the main purpose of the present invention is to provide a robot arm, which realizes the rotation of the arm around its central axis by setting a circumferential rotation mechanism of the upper arm, and realizes the bending and straightening of the forearm relative to the upper arm by setting a forearm bending and extension mechanism.

[0004] In order to achieve the above object, the present invention adopts the following technical solutions to solve it.

[0005] A robot arm comprises an arm connecting plate, an upper arm and a lower arm; the arm connecting plate comprises a horizontal connecting plate and a vertical connecting plate which are perpendicular to each other, the upper surface of the horizontal connecting plate is provided with an upper arm circumferential rotating mechanism, the output end of the upper arm circumferential rotating mechanism is connected to the upper end of the upper arm, and the lower end of the upper arm is hinged to the upper end of the lower arm; the vertical connecting plate is used to connect the shoulder joint of the robot.

[0006] Furthermore, the boom circumferential rotation mechanism includes a boom rotation reduction motor, the boom rotation reduction motor is fixedly connected to the horizontal connecting plate, and the output shaft of the boom rotation reduction motor is fixedly connected to the upper end of the boom.

[0007] Furthermore, a boom hinge hole is provided at the lower end of the boom; a proximal shoulder hinge shaft and a distal shoulder hinge shaft are laterally provided at the upper end of the forearm, and the proximal shoulder hinge shaft is inserted into the boom hinge hole at the lower end of the boom.

[0008] Furthermore, it also includes a forearm flexion and extension mechanism, which is used to drive the forearm to bend or straighten.

[0009] Furthermore, the forearm flexion and extension mechanism includes a forearm flexion and extension reduction motor, a lead screw and a connecting rod; a fixing plate is provided on the upper arm, a through hole is provided on the fixing plate, the forearm flexion and extension reduction motor is fixedly connected to the upper surface of the fixing plate, the output shaft of the forearm flexion and extension reduction motor passes through the through hole and is connected to the lead screw, a nut is screwed on the lead screw, a nut articulation shaft is laterally provided on the side of the nut; an upper articulation hole and a lower articulation hole are respectively provided at the upper and lower ends of the connecting rod; the nut articulation shaft is inserted into the upper articulation hole; the distal shoulder side articulation shaft is inserted into the lower articulation hole.

[0010] Furthermore, a rotation-stopping plane is arranged on the side of the nut, and a rotation-limiting plane abutting against the rotation-stopping plane is arranged on the large arm.

[0011] Furthermore, a vertical distance between the upper arm hinge hole and a center line of the lead screw is greater than or equal to zero.

[0012] Furthermore, the upper arm rotation reduction motor and the lower arm flexion and extension reduction motor are motor-built-in reduction motors; the motor-built-in reduction motor comprises a harmonic reducer, a permanent magnet rotor, a winding stator and a motor housing; the harmonic reducer has an input shaft, a reducer housing and a reducer end cover, the reducer housing is fixedly connected to the reducer end cover, the input shaft is arranged in the reducer housing and extends out of the reducer end cover; the permanent magnet rotor is fixedly connected to the input shaft; the winding stator is fixedly connected in the motor housing, and the motor housing is fixedly connected to the reducer housing.

[0013] Furthermore, a ratio of a height to a diameter of the permanent magnet rotor is less than or equal to 1, and a ratio of a height to a diameter of the winding stator is less than or equal to 1.

[0014] Furthermore, a screw hole is arranged on the end face of the input shaft close to the permanent magnet rotor; the rotor core of the permanent magnet rotor is a hollow cylinder, an inverted inner flange is arranged at one end of the hollow cylinder close to the reducer input shaft, a mounting hole is arranged on the inner flange, and the permanent magnet rotor is mounted on the input shaft by bolts.

[0015] The robot arm of the technical solution of the present invention can not only realize self-rotation around its own central axis, but also realize bending or straightening of the forearm relative to the upper arm, and the forearm can output a large torque. 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 the structures shown in these drawings without paying creative work.

[0017] Figure 1 is a three-dimensional schematic diagram of the robot arm of the present invention;

[0018] Figure 2 is an exploded schematic diagram of the robot arm of the present invention;

[0019] Figure 3 A longitudinal sectional schematic diagram of an embodiment of a motor-built-in reduction motor of the present invention;

[0020] Figure 4 It is an exploded schematic diagram of an embodiment of a motor-built-in reduction motor of the present invention;

[0021] In the above figure: 1 arm connecting plate; 101 horizontal connecting plate; 102 vertical connecting plate;

[0022] 2 upper arm; 201 upper arm hinge hole; 202 fixing plate; 203 through hole; 204 rotation limiting plane;

[0023] 3 forearm; 301 near shoulder side articulation axis; 302 far shoulder side articulation axis;

[0024] 4. Big arm rotation reduction motor;

[0025] 5. Reducer motor for arm bending and extension;

[0026] 6 screws;

[0027] 7 connecting rod; 701 upper hinge hole; 702 lower hinge hole;

[0028] 8 nut; 801 nut hinge shaft; 802 anti-rotation plane 802;

[0029] 9 harmonic reducer; 901 input shaft; 902 reducer housing; 903 screw hole; 904 flexible wheel; 905 wave generator; 906 steel wheel; 907 output flange; 908 first bearing; 909 second bearing; 9010 reducer end cover;

[0030] 10 permanent magnet rotor; 1001 rotor core, 1002 tile-shaped magnet; 1003 mounting hole; 1004 rotor convex ring;

[0031] 11 winding stator;

[0032] 12 motor housing; 1201 motor housing convex ring;

[0033] 13 bolts. DETAILED DESCRIPTION

[0034] In order to make the above-mentioned objects, features and advantages of the present invention more obvious and understandable, the specific embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0035] In the following description, specific details are set forth to facilitate a full understanding of the present invention. However, the present invention can be implemented in a variety of other ways than those described herein, and those skilled in the art can make similar generalizations without violating the connotation of the present invention. Therefore, the present invention is not limited to the specific embodiments disclosed below.

[0036] refer to Figure 1 and Figure 2 A robot arm comprises an arm connecting plate 1, an upper arm 2 and a lower arm 3, wherein the arm connecting plate 1 has a horizontal connecting plate 101 and a vertical connecting plate 102 which are perpendicular to each other, and an upper arm circumferential rotating mechanism is arranged on the upper surface of the horizontal connecting plate 101, wherein the output end of the upper arm circumferential rotating mechanism is connected to the upper end of the upper arm 2, and the lower end of the upper arm 2 is hinged to the upper end of the lower arm 3; the vertical connecting plate 102 is used to connect to the shoulder joint of the robot.

[0037] In the above embodiments, the robot arm is connected to the robot shoulder joint through the vertical connecting plate 102 of the arm connecting plate 1, and a circumferential rotation mechanism of the upper arm is provided on the horizontal connecting plate 101, which can realize the rotation of the upper arm 2 around its central axis, making the robot arm more flexible than existing robots and capable of performing more fine movements similar to human arms.

[0038] Furthermore, the boom circumferential rotation mechanism includes a boom rotation reduction motor 4, the boom rotation reduction motor 4 is fixedly connected to the horizontal connecting plate 101, and the output shaft of the boom rotation reduction motor 4 is fixedly connected to the upper end of the boom 2.

[0039] In the above embodiments, specifically, a boom rotation reduction motor 4 is installed on the horizontal connecting plate 101, and the output shaft of the boom rotation reduction motor 4 is fixedly connected to the upper end of the boom 2. By starting the boom rotation reduction motor 4, the boom 2 can be rotated. Since the forearm 3 is connected to the lower end of the boom 2, the forearm 3 rotates with the boom 2.

[0040] Furthermore, a boom hinge hole 201 is provided at the lower end of the boom 2; a proximal shoulder hinge shaft 301 and a distal shoulder hinge shaft 302 are laterally provided at the upper end of the forearm 3, and the proximal shoulder hinge shaft 301 is inserted into the boom hinge hole 201 at the lower end of the boom 2.

[0041] In the above embodiments, the lower end of the upper arm 2 and the upper end of the forearm 3 are hinged. Specifically, an upper arm hinge hole 201 is provided at the lower end of the upper arm 2, and a proximal shoulder hinge shaft 301 and a distal shoulder hinge shaft 302 are provided at the upper end of the forearm 3. The proximal shoulder hinge shaft 301 of the forearm 3 is inserted into the upper arm hinge hole 201 at the lower end of the upper arm 2 to achieve hinge.

[0042] Furthermore, it also includes a forearm bending and extending mechanism, which is used to drive the forearm 3 to bend or straighten.

[0043] In the above embodiments, a forearm bending and extension mechanism is provided between the upper arm 2 and the lower arm 3 for realizing the bending and straightening of the lower arm 3 relative to the upper arm 2, so that the function of the robot arm is more complete and flexible.

[0044] Furthermore, the forearm flexion and extension mechanism includes a forearm flexion and extension reduction motor 5, a lead screw 6, and a connecting rod 7; a fixed plate 202 is provided on the upper arm 2, a through hole 203 is provided on the fixed plate 202, the forearm flexion and extension reduction motor 5 is fixedly connected to the upper surface of the fixed plate 202, the output shaft of the forearm flexion and extension reduction motor 5 passes through the through hole 203 and is connected to the lead screw 6, a nut 8 is screwed on the lead screw 6, and a nut articulation shaft 801 is laterally provided on the side of the nut 8; an upper articulation hole 701 and a lower articulation hole 702 are respectively provided at the upper and lower ends of the connecting rod 7; the nut articulation shaft 801 is inserted into the upper articulation hole 701; the distal shoulder side articulation shaft 302 is inserted into the lower articulation hole 702.

[0045] In the above embodiments, specifically, the forearm bending and extension mechanism adopts a lead screw nut mechanism and a crank slider mechanism to realize the bending and straightening of the forearm 3. The forearm bending and extension reduction motor 5 is installed on the upper surface of the fixed plate 202 provided with a through hole 203 on the big arm 2, and the output shaft of the forearm bending and extension reduction motor 5 is connected to the lead screw 6, and the nut 8 is screwed on the lead screw 6. When the lead screw 6 rotates, as long as the nut 8 is restricted from rotating, the up and down linear motion of the nut 8 can be realized. A nut hinge shaft 801 is set on the side of the nut 8, the upper hinge hole 701 of the connecting rod 7 is sleeved on the nut hinge shaft 801, and the lower hinge hole 702 of the connecting rod 7 is sleeved on the far shoulder side hinge shaft 302 of the forearm 3. The nut 8, the connecting rod 7, the lead screw 6 and the forearm 3 together constitute a crank slider mechanism, and the nut 8 drives the forearm 3 to rotate around the center line of the near shoulder side hinge shaft 301 along the up and down linear motion of the lead screw 6, so as to realize the bending and straightening of the forearm 3.

[0046] Furthermore, a rotation-stopping plane 802 is provided on the side of the nut 8 , and a rotation-limiting plane 204 abutting against the rotation-stopping plane 802 is provided on the upper arm 2 .

[0047] In the above embodiments, although the nut hinge shaft 801 provided on the side of the nut 8 can prevent the nut 8 from rotating, in order to better prevent the nut 8 from rotating, a rotation-stopping plane 802 is provided on the side of the nut 8 close to the arm 2, and a rotation-limiting plane 204 is provided on the side of the arm 2 close to the nut 8. Under the guiding action of the screw 6, the rotation-stopping plane 802 slides against the rotation-limiting plane 204, which can better prevent the nut 8 from rotating.

[0048] Furthermore, a vertical distance between the upper arm hinge hole 201 and the center line of the lead screw 6 is greater than or equal to zero.

[0049] In the above embodiment, specifically, the upper arm hinge hole 201 is not colinear with the center line of the lead screw 6, that is, an offset crank slider mechanism is formed. The linear motion trajectory of the connecting rod 7 deviates less from the center line of the lead screw 6, so that the joint volume of the upper arm and the forearm is small, which is closer to the state of a human arm.

[0050] Furthermore, the upper arm rotation reduction motor 4 and the lower arm bending and extension reduction motor 5 are motor-built-in reduction motors; Figure 3 and Figure 4 The motor-built-in reduction motor comprises a harmonic reducer 9, a permanent magnet rotor 10, a winding stator 11 and a motor housing 12; the harmonic reducer 9 has an input shaft 901, a reducer housing 902 and a reducer end cover 9010, the reducer housing 902 is fixedly connected to the reducer end cover 9010, the input shaft 901 is arranged in the reducer housing 902 and extends out of the reducer end cover 9010; the permanent magnet rotor 10 is fixedly connected to the input shaft 901; the winding stator 11 is fixedly connected in the motor housing 12, and the motor housing 12 is fixedly connected to the reducer housing 902.

[0051] In the above embodiment, the DC permanent magnet motor and the harmonic reducer 9 are combined into one, the permanent magnet rotor 10 of the DC permanent magnet motor is directly connected to the input shaft 901 of the harmonic reducer 9, the reducer housing 902 is connected to the motor housing 12, and the winding stator 11 is fixedly connected inside the motor housing 12. The motor does not use bearings, and the coaxiality of the winding stator 11 and the permanent magnet rotor 10 is guaranteed by the reducer housing 902 and the reducer input shaft 901, which simplifies the motor structure in structure, reduces the overall size and weight of the reduction device with a built-in motor.

[0052] The permanent magnet rotor comprises a rotor core 1001 and a plurality of tile-shaped magnets 1002 embedded in the rotor core 1001. The rotor core 1001 is fixedly connected to the input shaft 901 of the harmonic reducer 9 by bolts.

[0053] The transmission principle of the harmonic reducer: The harmonic reducer is mainly composed of three basic components: a rigid wheel with an inner gear ring, a flexible wheel with an outer gear ring, and a wave generator. The wave generator is a rod-shaped component with rolling bearings installed at both ends to form rollers, which are pressed against the inner wall of the flexible wheel. The flexible wheel is a thin-walled gear that can produce large elastic deformation, and its inner hole diameter is slightly smaller than the total length of the wave generator. The wave generator is a component that causes the flexible wheel to produce controllable elastic deformation. When the wave generator is installed in the flexible wheel, the cross-section of the flexible wheel is forced to change from the original circle to an ellipse, and the teeth near the two ends of its long axis are completely meshed with the teeth of the rigid wheel, while the teeth near the two ends of the short axis are completely disengaged from the rigid wheel. The teeth in other sections of the circumference are in a transitional state of meshing and disengagement. When the wave generator rotates continuously, the deformation of the flexible wheel keeps changing, so that the meshing state of the flexible wheel and the rigid wheel also keeps changing, from meshing in, meshing in, meshing out, disengaging, and meshing in again..., repeating over and over again, thereby realizing the slow rotation of the flexible wheel relative to the rigid wheel in the opposite direction of the wave generator.

[0054] Normally, the rigid wheel is fixed, the wave generator rotates, and the flexible wheel acts as a driven wheel, outputs rotation, and drives the load to move. It can also be reversed, that is, the flexible wheel is fixed and the steel wheel outputs.

[0055] In this embodiment, the harmonic reducer 9 includes a reducer housing 902, an input shaft 901, a flexible wheel 904, a wave generator 905, a steel wheel 906, and an output flange 907. A first bearing 908 and a second bearing 909 are installed between the two ends of the wave generator 905 and the reducer housing 902, respectively.

[0056] In this embodiment, specifically, the output flange of the boom rotation reduction motor 4 is connected to the upper end of the boom 2 , and the output flange of the arm bending and extending reduction motor 5 is fixedly connected to the upper end of the lead screw 6 .

[0057] The harmonic reducer of this embodiment is installed in a manner that the flexible spline 904 is fixed and the steel wheel 906 rotates relative to the flexible spline 904 .

[0058] Furthermore, a ratio of a height to a diameter of the permanent magnet rotor 10 is less than or equal to 1, and a ratio of a height to a diameter of the winding stator 11 is less than or equal to 1.

[0059] Since the coaxiality of the permanent magnet rotor 10 and the wound stator 11 needs to be ensured by the input shaft 901 and the reducer housing 902, the permanent magnet rotor 10 connected to the input shaft 901 needs to be as short as possible, and a motor with a relatively large height and diameter is not suitable for this combination. In the above embodiment, preferably, the ratio of the height to the diameter of the permanent magnet rotor 10 is less than or equal to 1, and correspondingly, the ratio of the height to the diameter of the wound stator 11 is less than or equal to 1, that is, the motor with a smaller height to diameter ratio is more suitable for integration with the reducer.

[0060] Furthermore, a screw hole 903 is provided on the end surface of the input shaft 901 close to the permanent magnet rotor 10; the rotor core 1001 of the permanent magnet rotor 10 is a hollow cylinder, and an inverted inner flange is provided at one end of the hollow cylinder close to the reducer input shaft 901, and a mounting hole 1003 is provided on the inner flange, and the permanent magnet rotor 10 is mounted on the input shaft 901 by bolts 13.

[0061] In the above embodiment, a screw hole 903 is provided on the end surface of the input shaft 901 close to the permanent magnet rotor 10, and the rotor core 1001 is a hollow cylinder with an inverted inner flange, and the rotor core 1001 is mounted on the input shaft 901 through the mounting hole 1003 provided on the inner flange. The hollow structure can reduce the overall weight of the reduction device of the built-in motor.

[0062] refer to Figure 3 and Figure 4 In order to further improve the coaxiality between the permanent magnet rotor 10 and the wound stator 11, a rotor collar 1004 is provided at one end of the rotor core 1001 close to the input shaft 901, and the inner diameter of the rotor collar 1004 is clearance matched with the outer diameter of the input shaft 901, and the clearance meets the precision requirement. Similarly, a motor housing collar 1201 is provided at one end of the motor housing 12 close to the reducer housing 902, and the inner diameter of the motor housing collar 1201 is clearance matched with the outer diameter of the reducer end cover 9010, and the clearance meets the precision requirement.

[0063] Although the present invention has been described in detail in this specification by means of general description and specific embodiments, it is obvious to those skilled in the art that some modifications or improvements may be made thereto on the basis of the present invention. Therefore, these modifications or improvements made without departing from the present invention all fall within the scope of protection claimed by the present invention.

Claims

1. A robot arm, characterized in that: It comprises an arm connecting plate (1), a large arm (2) and a small arm (3); The arm connecting plate (1) comprises a horizontal connecting plate (101) and a vertical connecting plate (102) which are perpendicular to each other; a large arm circumferential rotating mechanism is arranged on the upper surface of the horizontal connecting plate (101); an output end of the large arm circumferential rotating mechanism is connected to the upper end of the large arm (2); and the lower end of the large arm (2) is hinged to the upper end of the small arm (3); The vertical connecting plate (102) is used to connect the shoulder joint of the robot; The boom circumferential rotation mechanism comprises a boom rotation reduction motor (4); the boom rotation reduction motor (4) is fixedly connected to the horizontal connection plate (101), and the output shaft of the boom rotation reduction motor (4) is fixedly connected to the upper end of the boom (2); The lower end of the upper arm (2) is provided with an upper arm hinge hole (201); the upper end of the lower arm (3) is laterally provided with a proximal shoulder hinge shaft (301) and a distal shoulder hinge shaft (302), and the proximal shoulder hinge shaft (301) is inserted into the upper arm hinge hole (201) at the lower end of the upper arm (2); The forearm bending and extension mechanism is used to drive the forearm (3) to bend or straighten; The forearm bending and extension mechanism comprises a forearm bending and extension reduction motor (5), a lead screw (6) and a connecting rod (7); The upper arm (2) is provided with a fixing plate (202), the fixing plate (202) is provided with a through hole (203), the lower arm flexion and extension reduction motor (5) is fixedly connected to the upper surface of the fixing plate (202), the output shaft of the lower arm flexion and extension reduction motor (5) passes through the through hole (203) and is connected to a lead screw (6), a nut (8) is screwed onto the lead screw (6), and a nut articulation shaft (801) is transversely provided on the side of the nut (8); the upper and lower ends of the connecting rod (7) are respectively provided with an upper articulation hole (701) and a lower articulation hole (702); the nut articulation shaft (801) is inserted into the upper articulation hole (701); the distal shoulder side articulation shaft (302) is inserted into the lower articulation hole (702); A rotation-stopping plane (802) is provided on the side of the nut (8), and a rotation-limiting plane (204) abutting against the rotation-stopping plane (802) is provided on the upper arm (2); The vertical distance between the upper arm hinge hole (201) and the center line of the lead screw (6) is greater than or equal to zero.

2. The robot arm according to claim 1, characterized in that: The upper arm rotation reduction motor (4) and the lower arm bending and extension reduction motor (5) are motor-built-in reduction motors; The motor-mounted reduction motor comprises a harmonic reducer (9), a permanent magnet rotor (10), a winding stator (11) and a motor housing (12); The harmonic reducer (9) comprises an input shaft (901), a reducer housing (902) and a reducer end cover (9010); the reducer housing (902) is fixedly connected to the reducer end cover (9010); the input shaft (901) is arranged in the reducer housing (902) and extends out of the reducer end cover (9010); The permanent magnet rotor (10) is fixedly connected to the input shaft (901); The winding stator (11) is fixedly connected inside the motor housing (12), and the motor housing (12) is fixedly connected to the reducer housing (902).

3. The robot arm according to claim 2, characterized in that: The ratio of the height to the diameter of the permanent magnet rotor (10) is less than or equal to 1, and the ratio of the height to the diameter of the winding stator (11) is less than or equal to 1.

4. The robot arm according to claim 2, characterized in that: A screw hole (903) is provided on the end surface of the input shaft (901) close to the permanent magnet rotor (10); the rotor core (1001) of the permanent magnet rotor (10) is a hollow cylinder, and an inverted inner flange is provided at one end of the hollow cylinder close to the reducer input shaft (901), and a mounting hole (1003) is provided on the inner flange, and the permanent magnet rotor (10) is mounted on the input shaft (901) by means of bolts (13).

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