A servo motor

Abstract

The application provides a servo motor, in particular to a robot. The servo motor comprises a robot body, a main rod arranged on the robot body, a sub rod rotatably connected to the main rod, a joint shell arranged on the main rod, a cover plate detachably connected to the joint shell through a connecting assembly, and a rotor and a stator arranged in the joint shell. The servo motor provided by the application cancels the independent motor shell, directly uses the joint shell as the motor shell, fixes the stator on the inner wall of the joint shell, and inserts the rotor between the rotating shaft and the rotating block through the two end spline rods, so that the rotor shaft and the rotor bearing are not needed, the number of structures and the weight of the motor are reduced, the joint shell and the cover plate are made of aluminum alloy, the weight is further reduced under the premise of ensuring the strength, and the light weight degree is high.

Description

Technical Field

[0001] This invention relates to the field of robotics, specifically to a servo motor. Background Technology

[0002] Robot joint servo motors are key actuators for collaborative robots and humanoid robots. They convert electrical energy into mechanical energy and drive joint rotation through reducers, enabling the robot to move flexibly. As robots develop towards lightweight and high dynamic response, joint servo motors need to reduce their size and weight as much as possible while ensuring output torque, in order to improve the robot's load capacity and energy efficiency.

[0003] In existing robots, the joint servo motors are usually fixedly connected to the main joint, and the output shaft is fixed to the sub-joint. This configuration often uses an independent housing structure, that is, the motor has an independent metal shell, the stator is often glued to the inside of the housing, and the rotor is supported at both ends of the housing by bearings. This structure results in the motor body occupying a large space, and the independent housing, rotor shaft and bearings are heavy. Since the stator and rotor are both fixed inside the housing, the entire motor needs to be removed from the joint during maintenance, which is a cumbersome disassembly and assembly process and is not conducive to on-site maintenance of the robot.

[0004] Therefore, it is necessary to provide a new servo motor to solve the above-mentioned technical problems. Summary of the Invention

[0005] The technical problem this invention aims to solve is to overcome the heavy weight and cumbersome disassembly / assembly issues caused by the independent housing and rotor shaft in existing robot joint servo motors, and to provide a servo motor. This device uses the joint housing as the motor housing, and with the insertion and positioning of the positioning rod and positioning slot, as well as the insertion and transmission of the spline rod, it achieves rapid installation and disassembly of the stator and rotor, realizing the overall replacement of the motor section. This improves the lightweight design and ease of maintenance of the joint, and reduces the difficulty of operation and manufacturing costs.

[0006] To solve the above-mentioned technical problems, the present invention provides a servo motor, including a robot body, and further including: a main rod, which is disposed on the robot body; a secondary rod, which is rotatably connected to the main rod; a joint housing is disposed on the main rod, and a cover plate is detachably connected to the joint housing through a connecting assembly; a rotor and a stator are disposed inside the joint housing; the stator is fixed between the joint housing and the cover plate through a first positioning assembly; the rotor is rotatably connected between the joint housing and the cover plate through a second positioning assembly; multiple positioning rods are fixedly connected to both ends of the stator; the first positioning assembly includes multiple first positioning grooves adapted to the positioning rods on the inner wall surface of the joint housing and multiple second positioning grooves adapted to the positioning rods on the inner wall surface of the cover plate; the positioning rods are used to insert into the first positioning grooves and the second positioning grooves, so that the stator is positioned in the joint housing through the insertion of the positioning rods at both ends.

[0007] Preferably, a rotating shaft is fixedly connected to the auxiliary rod, the rotating shaft passes through the joint housing, a rotating block is rotatably connected to the cover plate, the second positioning component includes a first spline groove formed on the rotating shaft and a second spline groove formed on the rotating block, and spline rods are fixedly connected to both ends of the rotor, and the spline rods at both ends are respectively adapted to the first spline groove and the second spline groove.

[0008] Preferably, an encoder magnetic ring is fixedly connected to the rotating block, and an encoder reading head is fixedly connected to the cover plate, with the encoder reading head corresponding to the encoder magnetic ring.

[0009] Preferably, the connecting assembly includes a plurality of first threaded grooves formed on the cover plate, a plurality of second threaded grooves formed on the joint housing, and a plurality of screws for threaded connection of the first threaded grooves and the second threaded grooves.

[0010] Preferably, the cover plate is provided with multiple anti-misalignment rods, the joint shell is provided with multiple anti-misalignment grooves that are adapted to the size of the anti-misalignment rods, the cover plate is provided with multiple sealing rings, and the end face of the joint shell is provided with multiple sealing grooves.

[0011] Preferably, the end faces of the first spline groove and the second spline groove are each provided with a first guide surface that is inclined, and the end face of the spline rod is provided with a second guide surface that is inclined and adapted to the first guide surface.

[0012] Preferably, the outer wall surface of the joint housing has a plurality of arrayed heat dissipation fins integrally formed thereon.

[0013] Preferably, a brake is provided on the inner wall surface of the joint housing.

[0014] Preferably, both the joint housing and the cover plate are made of aluminum alloy.

[0015] Preferably, the joint housing and the main rod are integrally formed.

[0016] By adopting the above technical solution, the beneficial effects achieved by the present invention are as follows: The servo motor proposed in this invention eliminates the need for a separate motor housing; the joint housing is used directly as the motor housing. The stator is fixed to the inner wall of the joint housing, and the rotor is connected between the rotating shaft and the rotating block via splined rods at both ends. This eliminates the need for a rotor shaft and rotor bearings, reducing the number of components and the weight of the motor. Both the joint housing and the cover plate are made of aluminum alloy, further reducing weight while ensuring strength, achieving a high degree of lightweighting. In addition, the stator is positioned by insertion of positioning rods at both ends, eliminating the need for interference fits or bolt fixation. The rotor achieves torque transmission and automatic alignment through insertion of splined rods at both ends. The stator and rotor can be removed as a whole for maintenance or replacement without disassembling the auxiliary shaft and main shaft, making maintenance very convenient. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the structure of a servo motor according to the present invention; Figure 2 This is a split view of the main rod and auxiliary rod of a servo motor according to the present invention; Figure 3 This is an exploded view of the joint housing and cover plate of a servo motor according to the present invention. Figure 4 This is a split view of the stator and rotor of a servo motor according to the present invention; Figure 5 This is an exploded view of the rotor and cover plate of a servo motor according to the present invention; Figure 6 for Figure 5 Enlarged view of point A in the middle; Figure 7 for Figure 5 Enlarged view of point B in the middle; Figure 8 This is a diagram showing the positional relationship between the rotor and the rotating block of a servo motor according to the present invention.

[0018] Figure label: 101. Robot body; 1. Joint housing; 11. Main rod; 12. Secondary rod; 13. Cover plate; 14. Rotary shaft; 15. Stator; 16. Rotor; 17. Rotating block; 18. Encoder magnetic ring; 181. Encoder reading head; 19. Brake; 110. Heat sink fins; 2. Connecting assembly; 21. First threaded groove; 22. Second threaded groove; 23. Error prevention rod; 24. Error prevention groove; 25. Sealing ring; 26. Sealing groove; 27. Screw; 3. First positioning assembly; 31. Positioning rod; 32. First positioning groove; 33. Second positioning groove; 4. Second positioning assembly; 41. Spline rod; 42. First spline groove; 43. Second spline groove; 44. First guide surface; 45. Second guide surface. Detailed Implementation

[0019] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0020] Furthermore, in this invention, descriptions involving "first," "second," etc., are for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0021] In this invention, unless otherwise explicitly specified and limited, the terms "connection," "fixed," etc., should be interpreted broadly. For example, "fixed" can mean a fixed connection, a detachable connection, or an integral part; it can mean a mechanical connection or an electrical connection; it can mean a direct connection or an indirect connection through an intermediate medium; it can mean the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0022] Please see Figures 1 to 8As shown in the figure, the servo motor provided in this embodiment of the invention includes a robot body 101, a main rod 11, and a secondary rod 12. One end of the main rod 11 is provided with a joint housing 1. The joint housing 1 is cylindrical, closed at one end and open at the other. The closed end and the main rod 11 are integrally die-cast or integrally machined, with no interface between them, forming a single structural component. A cover plate 13 is detachably connected to the open end of the joint housing 1 via a connecting assembly 2. The cover plate 13 is used to close the open end of the joint housing 1. A stator 15 and a rotor 16 are installed inside the joint housing 1. The stator 15 is cylindrical, made of stacked silicon steel sheets, and has windings inside. Multiple positioning rods 31 are fixedly connected to each of the two end faces of the stator 15. The positioning rods 31 are evenly distributed along the circumference of the stator 15, and the cross-section of the positioning rods 31 is circular. Multiple first positioning grooves are formed on the inner wall surface of the closed end of the joint housing 1 corresponding to the positions of the positioning rods 31. 32. The first positioning groove 32 is a blind hole, and its inner diameter is adapted to the outer diameter of the positioning rod 31. Multiple second positioning grooves 33 are opened on the inner wall surface of the cover plate 13 corresponding to the position of the positioning rod 31. The second positioning grooves 33 are also blind holes, and their inner diameter is adapted to the outer diameter of the positioning rod 31. During assembly, the stator 15 is first pushed in from the open end of the joint housing 1, so that the positioning rod 31 at one end of the stator 15 is inserted into the first positioning groove 32 at the closed end of the joint housing 1. Then the cover plate 13 is installed, so that the positioning rod 31 at the other end of the stator 15 is inserted into the second positioning groove 33 of the cover plate 13. The stator 15 is positioned and connected to the joint housing 1 and the cover plate 13 by the insertion of the positioning rods 31 at both ends. The stator 15 is positioned by the insertion of the positioning rods 31 at both ends. During disassembly and assembly, the stator 15 can be pulled out from the joint housing 1 simply by removing the cover plate 13. Moreover, the cooperation between the positioning rod 31 and the positioning groove realizes the automatic centering of the stator 15 without additional adjustment.

[0023] Additionally, a rotating shaft 14 is fixedly connected to the auxiliary rod 12. One end of the rotating shaft 14 is fixedly connected to the auxiliary rod 12, and the other end passes through the central hole of the closed end of the joint housing 1 and extends into the interior of the joint housing 1. A first spline groove 42 is formed at the center of the end face of the rotating shaft 14 extending into the joint housing 1. The first spline groove 42 is an internal spline. A rotating block 17 is rotatably connected to the cover plate 13. A second spline groove 43 is formed at the center of the end face of the rotating block 17 extending into the joint housing 1. The second spline groove 43 is also an internal spline. The rotor 16 is cylindrical, and its outer surface should... When a permanent magnet is attached, a splined rod 41 is fixedly connected to the center of each end of the rotor 16. The splined rod 41 is an external spline, and the two splined rods 41 are respectively adapted to the first spline groove 42 and the second spline groove 43. During assembly, the rotor 16 is first pushed in from the open end of the joint housing 1, so that the splined rod 41 at one end of the rotor 16 is inserted into the first spline groove 42 of the rotating shaft 14. Then the cover plate 13 is installed, so that the splined rod 41 at the other end of the rotor 16 is inserted into the second spline groove 43 of the rotating block 17. The rotor 16, through the insertion of the splined rods 41 at both ends, is connected to the rotating block 17. This achieves coaxial connection and power transmission with the rotating shaft 14 and rotating block 17. When the stator 15 is energized, it generates a rotating magnetic field, driving the rotor 16 to rotate. The rotor 16 drives the rotating shaft 14 to rotate through the spline rod 41 at one end, and the rotating shaft 14 drives the auxiliary rod 12 to rotate, realizing joint movement. At the same time, the rotor 16 drives the rotating block 17 to rotate freely on the cover plate 13 through the spline rod 41 at the other end. The rotating block 17 is used to transmit encoder and braking signals. The entrance end face of the first spline groove 42 is machined into a conical or wedge-shaped inclined surface, serving as the first guide surface 44. The inlet end face of the second spline groove 43 is also machined with a first guide surface 44. The end face of the spline rod 41 is machined into a conical or wedge-shaped inclined surface that matches the first guide surface 44, serving as a second guide surface 45. When the spline rod 41 is inserted into the spline groove, the second guide surface 45 first contacts the first guide surface 44. During the continued insertion process, the inclined surface is guided and automatically guides the spline rod 41 to the center position of the spline groove, completing the alignment. This ensures that there is a certain deviation between the spline rod 41 and the spline groove, and the inclined surface can also guide it to the correct position.

[0024] An encoder magnetic ring 18 is fixedly connected to one end face of the rotating block 17 extending outward from the cover plate 13. The encoder magnetic ring 18 is circular and rotates together with the rotating block 17. An encoder reading head 181 is fixedly connected to the outer side of the cover plate 13 at the position corresponding to the encoder magnetic ring 18. The sensing surface of the encoder reading head 181 faces the end face of the encoder magnetic ring 18. In specific implementation, the encoder reading head 181 should lead out a signal line to be electrically connected to the robot's controller. When the rotor 16 rotates, the rotor 16 drives the rotating block 17 to rotate through the spline rod 41. The encoder magnetic ring 18 on the rotating block 17 rotates accordingly. The encoder reading head 181 detects the rotation angle and speed of the magnetic ring, thereby obtaining the position and speed information of the rotor 16 in real time.

[0025] In addition, a brake 19 is fixedly connected to the inner wall of the joint housing 1. The coil of the brake 19 is electrically connected to the robot's controller through a wire. The armature of the brake 19 should be fixed on the rotating block 17. When the coil of the brake 19 is energized, it generates an electromagnetic force that attracts the armature of the brake 19 to move towards the coil, causing the armature of the brake 19 to disengage from the rotating block 17. The brake 19 is released, and the rotor 16 can rotate freely. When the coil of the brake 19 is de-energized, the electromagnetic force disappears, and the armature of the brake 19 is pressed against the rotating block 17 under the action of a disc spring or spring, generating a frictional torque that prevents the rotating block 17 from rotating. Thus, the rotor 16 is locked through the spline rod 41, thereby achieving joint position holding.

[0026] Furthermore, the edge of the cover plate 13 is evenly provided with a plurality of first threaded grooves 21 along the circumferential direction, and the end face of the joint housing 1 at the opening end is provided with a plurality of second threaded grooves 22 corresponding to the positions of the first threaded grooves 21. During assembly, the screws 27 are passed through the first threaded grooves 21 and screwed into the second threaded grooves 22. After tightening, the cover plate 13 is fixed on the joint housing 1. The screws 27 can be internal hex screws 27 or cross-head screws 27, which are convenient for tightening with tools.

[0027] Multiple anti-misalignment rods 23 are fixedly connected to the inner side of the cover plate 13, such as... Figure 5 As shown, the anti-misalignment rods 23 are not evenly distributed, so that the cover plate 13 can only be installed into the joint housing 1 at the correct angle. Multiple anti-misalignment grooves 24 are provided on the end face of the open end of the joint housing 1 corresponding to the position of the anti-misalignment rods 23. The size and position of the anti-misalignment grooves 24 correspond to the anti-misalignment rods 23. When the angle of the cover plate 13 is incorrect, the anti-misalignment rods 23 and the anti-misalignment grooves 24 are misaligned, and the cover plate 13 cannot be installed. Multiple sealing rings 25 are also provided on the inner side of the cover plate 13. The sealing rings 25 can be made of rubber or silicone material and are embedded in the end face of the cover plate 13. Multiple sealing grooves 26 are provided on the end face of the open end of the joint housing 1 corresponding to the position of the sealing rings 25. When the cover plate 13 is installed and the screws 27 are tightened, the sealing rings 25 are compressed in the sealing grooves 26 to form a reliable seal and prevent external moisture and dust from entering the interior of the joint housing 1.

[0028] Furthermore, the joint housing 1 is made of aluminum alloy by die casting or extrusion molding, and multiple heat dissipation fins 110 are integrally formed on its outer wall surface. The heat dissipation fins 110 are rectangular and evenly arranged in the circumferential direction. The heat dissipation fins 110 increase the contact area between the outer wall of the joint housing 1 and the air, so that the heat generated by the stator 15 and the rotor 16 is conducted through the joint housing 1 to the heat dissipation fins 110, and then dissipated into the surrounding air by the fins.

[0029] In the specific processing, the joint shell 1 and the cover plate 13 are made of aluminum alloy material by die casting or machining. Because aluminum alloy has the characteristics of light weight, high strength and good thermal conductivity, the device can achieve lightweight while having good thermal conductivity.

[0030] Working principle: When the servo motor is working, the stator 15 is energized to generate a rotating magnetic field, driving the rotor 16 to rotate. The rotor 16 drives the shaft 14 to rotate via the spline rod 41 at one end, and the shaft 14 drives the auxiliary rod 12 to rotate, realizing joint movement. At the same time, the rotor 16 drives the rotating block 17 to rotate via the spline rod 41 at the other end. The encoder magnetic ring 18 on the rotating block 17 cooperates with the reading head on the cover plate 13 to detect the position of the rotor 16. The brake coil cooperates with the armature on the rotating block 17 to achieve braking. When maintenance is required, the screws 27 are removed, the cover plate 13 assembly is removed as a whole, the spline rod 41 at one end of the rotor 16 is disengaged from the rotating block 17, then the rotor 16 is pulled out of the joint housing 1, the spline rod 41 at the other end of the rotor 16 is disengaged from the shaft 14, and then the stator 15 is removed. 5. Remove from joint housing 1 for replacement. During assembly, first install the rotating shaft 14 in the bearing seat at the closed end of joint housing 1 through the first bearing. Push the stator 15 into the open end of joint housing 1 so that the positioning rod 31 at one end of the stator 15 is inserted into the first positioning groove 32 at the closed end of joint housing 1. Push the rotor 16 into the open end of joint housing 1 so that the spline rod 41 at one end of the rotor 16 is inserted into the first spline groove 42 of the rotating shaft 14. Then, align the pre-assembled cover plate 13 assembly with the open end of joint housing 1 and install it so that the positioning rod 31 at the other end of the stator 15 is inserted into the second positioning groove 33 of the cover plate 13. At the same time, the spline rod 41 at the other end of the rotor 16 is inserted into the second spline groove 43 of the rotating block 17. The anti-misalignment rod 23 is inserted into the anti-misalignment groove 24. Then tighten the screw 27.

[0031] The above are merely preferred embodiments of the present invention and do not limit the patent scope of the present invention. Any equivalent structural transformations made under the concept of the present invention using the description and drawings of the present invention, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present invention.

Claims

1. A servo motor, comprising a robot body (101), characterized in that, Also includes: The main rod (11) is mounted on the robot body (101); Sub-rod (12), which is rotatably connected to the main rod (11); A joint housing (1) is provided on the main rod (11). A cover plate (13) is detachably connected to the joint housing (1) via a connecting assembly (2). A rotor (16) and a stator (15) are provided inside the joint housing (1). The stator (15) is fixed between the joint housing (1) and the cover plate (13) via a first positioning assembly (3). The rotor (16) is rotatably connected between the joint housing (1) and the cover plate (13) via a second positioning assembly (4). Multiple [unclear] components are fixedly connected to both ends of the stator (15). The first positioning component (3) includes a plurality of first positioning grooves (32) adapted to the positioning rods (31) on the inner wall surface of the joint housing (1) and a plurality of second positioning grooves (33) adapted to the positioning rods (31) on the inner wall surface of the cover plate (13). The positioning rods (31) are used to insert into the first positioning grooves (32) and the second positioning grooves (33) so that the stator (15) is positioned in the joint housing (1) by the insertion of the positioning rods (31) at both ends.

2. The servo motor according to claim 1, characterized in that: A rotating shaft (14) is fixedly connected to the auxiliary rod (12). The rotating shaft (14) passes through the joint shell (1). A rotating block (17) is rotatably connected to the cover plate (13). The second positioning component (4) includes a first spline groove (42) opened on the rotating shaft (14) and a second spline groove (43) opened on the rotating block (17). Spline rods (41) are fixedly connected to both ends of the rotor (16), and the spline rods (41) at both ends are adapted to the first spline groove (42) and the second spline groove (43) respectively.

3. The servo motor according to claim 1, characterized in that: An encoder magnetic ring (18) is fixedly connected to the rotating block (17), and an encoder reading head (181) is fixedly connected to the cover plate (13). The encoder reading head (181) is correspondingly set with the encoder magnetic ring (18).

4. The servo motor according to claim 1, characterized in that: The connecting assembly (2) includes a plurality of first threaded grooves (21) formed on the cover plate (13), a plurality of second threaded grooves (22) formed on the joint housing (1), and a plurality of screws (27) for threaded connection of the first threaded grooves (21) and the second threaded grooves (22).

5. The servo motor according to claim 1, characterized in that: The cover plate (13) is provided with multiple anti-misalignment rods (23), the joint shell (1) is provided with multiple anti-misalignment grooves (24) that are adapted to the size of the anti-misalignment rods (23), the cover plate (13) is provided with multiple sealing rings (25), and the end face of the joint shell (1) is provided with multiple sealing grooves (26).

6. The servo motor according to claim 2, characterized in that: The end faces of the first spline groove (42) and the second spline groove (43) are provided with a first guide surface (44) that is inclined, and the end face of the spline rod (41) is provided with a second guide surface (45) that is inclined and adapted to the first guide surface (44).

7. The servo motor according to claim 1, characterized in that: Multiple arrayed heat dissipation fins (110) are integrally formed on the outer wall surface of the joint shell (1).

8. The servo motor according to claim 1, characterized in that: The joint housing (1) is provided with a brake (19) on its inner wall surface.

9. The servo motor according to claim 1, characterized in that: Both the joint shell (1) and the cover plate (13) are made of aluminum alloy.

10. The servo motor according to claim 1, characterized in that: The joint shell (1) and the main rod (11) are integrally formed.

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