Wrist structure and mechanical arm

Abstract

The utility model relates to the technical field of robots, in particular to a wrist structure and a mechanical arm, the wrist structure comprises a fixed support, a wrist joint, a differential driving assembly, a driven bevel gear and a rotary driving assembly, the wrist joint comprises a rotary support and a deflection support, the rotary support is pivoted to the fixed support, and the deflection support is pivoted to the rotary support; the differential driving assembly comprises a first driving bevel gear and a second driving bevel gear which are both pivoted to the fixing support. The driven bevel gear is fixedly arranged on the deflection bracket and is in transmission connection with the first driving bevel gear and the second driving bevel gear; the rotation driving assembly is fixedly arranged on the deflection support and used for being in transmission connection with the tail end manipulator. According to the wrist structure provided by the utility model, the combination of differential driving and rotary driving is adopted, and the structural size of the wrist can be reduced, so that the motion range of a tail-end manipulator is enlarged, and the flexibility of a mechanical arm is improved.

Description

TECHNICAL FIELD

[0001] The utility model relates to robot technical field, specifically, a wrist structure and mechanical arm. BACKGROUND

[0002] Mechanical arm is widely used in mechanical automation production because it has certain flexibility and endurance, and it can accurately realize positioning and accurately complete various complex work required in industrial field. Among them, the wrist is an important component part connecting the arm and the end manipulator in the mechanical arm, which is used for supporting the end manipulator and adjusting the position and posture of the end manipulator in the working space.

[0003] In the related art, the wrist of the conventional mechanical arm adopts three independent joint motors in the form of series connection to control the rotation of the end manipulator in three directions through the orthogonal arrangement mode. However, there are still the following disadvantages: the wrist is formed by the series connection of three mechanical joints with single direction rotation, which leads to large size and low flexibility of the wrist structure. UTILITY MODEL CONTENT

[0004] One of the purposes of the utility model is to provide a wrist structure, which is used to solve the technical problem of large size and low flexibility of the wrist structure caused by the series connection of three mechanical joints with single direction rotation in the prior art.

[0005] The utility model provides a wrist structure, which comprises:

[0006] A fixed support;

[0007] A wrist joint comprising a rotating support and a deflection support, wherein the rotating support is pivotally connected to the fixed support, and the deflection support is pivotally connected to the rotating support;

[0008] A differential drive assembly comprising a first driving bevel gear and a second driving bevel gear, both of which are pivotally connected to the fixed support;

[0009] A driven bevel gear fixedly arranged on the deflection support, wherein the driven bevel gear is in transmission connection with the first driving bevel gear and the second driving bevel gear; and

[0010] A rotating drive assembly installed on the deflection support and used for transmission connection with an end manipulator.

[0011] Further, the driven bevel gear comprises a first driven bevel gear and a second driven bevel gear, both of which are fixedly arranged on the deflection support;

[0012] The differential drive assembly further comprises an outer drive shaft and an inner drive shaft, the outer drive shaft is pivoted to the fixed support, the upper end of the outer drive shaft is drivingly connected with an outer drive motor, and the lower end of the outer drive shaft is fixed to the first driving bevel gear; the inner drive shaft is pivoted to the fixed support, the inner drive shaft is arranged in the outer drive shaft, and the upper end of the inner drive shaft protrudes from the upper end of the outer drive shaft, the upper end of the inner drive shaft is drivingly connected with the power output end of an inner drive motor, and the lower end of the inner drive shaft is fixed to the second driving bevel gear.

[0013] Further, the differential drive assembly further comprises an outer drive wire transmission shaft, a first outer drive wire, a second outer drive wire and an outer wire wheel, the outer drive wire transmission shaft is drivingly connected with the outer drive motor; the outer wire wheel is fixed to the upper end of the outer drive shaft; the first end of the first outer drive wire is fixed to the outer drive wire transmission shaft and wound on the outer wall surface of the outer drive wire transmission shaft in a clockwise direction, and the second end of the first outer drive wire is fixed to the outer wire wheel and wound on the outer wall surface of the outer wire wheel in a clockwise direction; the first end of the second outer drive wire is fixed to the outer drive wire transmission shaft and wound on the outer wall surface of the outer drive wire transmission shaft in an anticlockwise direction, and the second end of the second outer drive wire is fixed to the outer wire wheel and wound on the outer wall surface of the outer wire wheel in an anticlockwise direction.

[0014] The differential drive assembly further comprises an inner drive wire transmission shaft, a first inner drive wire, a second inner drive wire and an inner wire wheel, the inner drive wire transmission shaft is drivingly connected with the inner drive motor; the inner wire wheel is fixed to the upper end of the inner drive shaft; the first end of the first inner drive wire is fixed to the inner drive wire transmission shaft and wound on the outer wall surface of the inner drive wire transmission shaft in a clockwise direction, and the second end of the first inner drive wire is fixed to the inner wire wheel and wound on the outer wall surface of the inner wire wheel in a clockwise direction; the first end of the second inner drive wire is fixed to the inner drive wire transmission shaft and wound on the outer wall surface of the inner drive wire transmission shaft in an anticlockwise direction, and the second end of the second inner drive wire is fixed to the inner wire wheel and wound on the outer wall surface of the inner wire wheel in an anticlockwise direction.

[0015] Further, the axis direction of the outer drive motor is perpendicular to the axis direction of the outer drive shaft; the differential drive assembly further comprises a first outer guide wheel and a second outer guide wheel which are respectively pivoted to the fixed support, the axis direction of the first outer guide wheel and the second outer guide wheel is perpendicular to the axis direction of the outer drive shaft, and the first outer drive wire is wound on part of the outer wall surface of the first outer guide wheel; the second outer drive wire is wound on part of the outer wall surface of the second outer guide wheel.

[0016] The axis direction of the inner driving motor is perpendicular to the axis direction of the inner driving shaft; the differential driving assembly further comprises a first inner guide wheel and a second inner guide wheel respectively pivoted to the fixed support, the axis direction of the first inner guide wheel and the second inner guide wheel are both perpendicular to the axis direction of the inner driving shaft, the first inner driving wire is wound on the partial outer wall surface of the first inner guide wheel, and the second inner driving wire is wound on the partial outer wall surface of the second inner guide wheel.

[0017] Further, the fixed support is a U-shaped support comprising a support horizontal plate and support side plates, the support side plates are parallel and spaced apart and fixed to the support horizontal plate, and the rotating support is pivoted to the support horizontal plate; the first outer guide wheel and the second outer guide wheel are both pivoted to the support side plate; the first inner guide wheel and the second inner guide wheel are both pivoted to the support side plate.

[0018] Further, the support side plate has a plurality of spaced apart wheel supports, the wheel supports protrude from the inner surface of the support side plate in the direction close to the outer wire wheel and the inner wire wheel, and the first outer guide wheel, the second outer guide wheel, the first inner guide wheel and the second inner guide wheel are respectively pivoted to the corresponding wheel supports.

[0019] Further, the outer driving wire transmission shaft has a first outer wire groove, the first ends of the first outer driving wire and the second outer driving wire are respectively wound and fixed in the first outer wire groove; the outer wall surface of the outer wire wheel has a second outer wire groove, the second ends of the first outer driving wire and the second outer driving wire are respectively wound and fixed in the second outer wire groove.

[0020] The inner driving wire transmission shaft has a first inner wire groove, the first ends of the first inner driving wire and the second inner driving wire are respectively wound and fixed in the first inner wire groove; the outer wall surface of the inner wire wheel has a second inner wire groove, the second ends of the first inner driving wire and the second inner driving wire are respectively wound and fixed in the second inner wire groove.

[0021] Further, the second ends of the first outer driving wire and the second outer driving wire both have outer wire joints; the upper end surface and the lower end surface of the outer wire wheel are both recessed to form outer pre-tightening holes, the outer pre-tightening holes are communicated with the second outer wire groove; the outer wire joint and the outer pre-tightening hole have a limiting part, the limiting part is used for limiting the movement of the outer wire joint along the circumferential direction of the outer pre-tightening hole; the outer wire joint is threadedly connected with a fastener, the fastener can abut against the end surface of the outer pre-tightening hole, and is configured to: tighten the fastener to drive the outer wire joint to move along the axis direction of the outer pre-tightening hole to tension the first outer driving wire and / or the second outer driving wire.

[0022] Both the first inner drive line and the second inner drive line have an inner drive connector at their second ends; the upper and lower end faces of the inner drive wheel are recessed to form an inner pre-tightening hole, which communicates with the second inner drive groove; the inner drive connector and the inner pre-tightening hole have a limiting part, which is used to limit the movement of the inner drive connector along the circumferential direction of the inner pre-tightening hole; the inner drive connector is threadedly connected to a fastener, which can abut against the end face of the inner pre-tightening hole, and is configured to: tighten the fastener to drive the inner drive connector to move along the axial direction of the inner pre-tightening hole to tension the first inner drive line and / or the second inner drive line.

[0023] Furthermore, the rotating bracket is fixedly provided with a rotating shaft, and the first driven bevel gear and the second driven bevel gear are respectively pivotally connected to the rotating shaft;

[0024] Alternatively, the rotating bracket is pivotally connected to the rotating shaft, and the first driven bevel gear and the second driven bevel gear are respectively fixed to the rotating shaft.

[0025] Furthermore, the rotating bracket is fixed with a rotating shaft, which is a T-shaped rotating shaft. The T-shaped rotating shaft includes a horizontal shaft and a vertical shaft. The vertical shaft is vertically connected to the horizontal shaft. The upper end of the vertical shaft is pivotally connected to the inner wall surface of the inner drive shaft. The first driven bevel gear is pivotally connected to the first end of the horizontal shaft, and the second driven bevel gear is pivotally connected to the second end of the horizontal shaft.

[0026] Furthermore, the middle part of the horizontal axis has a connecting portion;

[0027] The deflection bracket includes a deflection plate and a connecting side plate. The deflection plate is pivotally connected to the rotating bracket. The connecting side plates are arranged at intervals. The upper ends of the connecting side plates are all fixed to the deflection plate, and the lower ends of the connecting side plates are all fixed to the connecting portion. A gear receiving space is formed between the deflection plate and the connecting side plate to accommodate the first driving bevel gear and the second driving bevel gear.

[0028] The first driven bevel gear and the second driven bevel gear are respectively fixed to the connecting side plate.

[0029] The wrist structure provided by this utility model has at least the following beneficial technical effects:

[0030] The first and second active bevel gears of the differential drive assembly drive the driven bevel gear to rotate in two directions relative to the vertical and horizontal axes, thereby causing the deflection bracket to rotate in two directions relative to the fixed bracket, giving the wrist joint two degrees of freedom. In addition, the rotation drive assembly drives the end effector to move, which, together with the aforementioned two degrees of freedom of the wrist joint, gives the wrist three degrees of freedom, providing flexible movement capabilities. Compared with related technologies that use three mechanical joints with single-direction rotation in series in the wrist, this invention, by using a combination of differential drive and rotation drive, can reduce the structural size of the wrist, thereby increasing the range of motion of the end effector and the flexibility of the robotic arm.

[0031] This utility model also provides a robotic arm, including an upper arm, an elbow structure, a forearm, and a wrist structure as described in any one of claims. The elbow structure is connected between the upper arm and the forearm. The fixed bracket is fixed to the end of the forearm away from the upper arm. The external drive motor and the internal drive motor are installed at the end of the upper arm away from the forearm.

[0032] The robotic arm provided by this utility model has at least the following beneficial technical effects:

[0033] By incorporating the aforementioned wrist structure into the robotic arm, the robotic arm consequently possesses all the advantages of the aforementioned wrist structure, which will not be elaborated upon here.

[0034] In addition, by placing the external and internal drive motors on the upper arm, the mass of the wrist is reduced, thereby reducing the inertia of the wrist and making the end effector move more smoothly, thus improving the accuracy and stability of the end effector's movement. The end effector has a small inertia during movement, which enables it to respond quickly to control commands. It also reduces the structural size of the wrist, making the wrist structure more compact. Attached Figure Description

[0035] Figure 1 A schematic diagram of a wrist structure assembly provided for an embodiment of this utility model;

[0036] Figure 2 A top view of a wrist structure provided for an embodiment of this utility model;

[0037] Figure 3 for Figure 2 Schematic diagram of the cross-sectional structure of the middle AA section;

[0038] Figures 4(a) and 4(b) illustrate the differential drive principle of a wrist structure provided in an embodiment of this utility model. Figure 1 ;

[0039] Figures 5(a) and 5(b) illustrate the differential drive principle of a wrist structure provided in an embodiment of this utility model. Figure 2 ;

[0040] Figure 6 for Figure 1 An enlarged structural diagram of the circled portion at point B in the middle;

[0041] Figure 7 A partial structural diagram of the outer and inner connectors in a wrist structure provided in this embodiment of the utility model;

[0042] Figure 8 A partial structural diagram of the outer and inner reels in a wrist structure provided for an embodiment of this utility model;

[0043] Figure 9 A schematic diagram of the assembly structure of a robotic arm provided for an embodiment of this utility model;

[0044] Explanation of reference numerals in the attached figures:

[0045] 1. Wrist structure; 2. Upper arm; 3. Elbow structure; 4. Forearm;

[0046] 10. Fixed bracket; 110. Supporting horizontal plate; 120. Supporting side plate; 130. Wheel support; 140. Guide wheel;

[0047] 20. Differential drive assembly; 211. External drive motor; 212. External drive shaft; 213. First drive bevel gear; 214. External drive cable drive shaft; 215. First external drive cable; 2152. External cable connector; 216. Second external drive cable; 217. External cable pulley; 2172. External preload hole; 218. First external guide wheel; 219. Second external guide wheel; 221. Internal drive motor; 222. Internal drive shaft; 223. Second drive bevel gear; 224. Internal drive cable drive shaft; 225. First internal drive cable; 226. Second internal drive cable; 227. Internal cable pulley; 2272. Internal preload hole; 228. First internal guide wheel; 229. Second internal guide wheel;

[0048] 30. Driven bevel gear; 310. First driven bevel gear; 320. Second driven bevel gear;

[0049] 40. Rotary drive assembly;

[0050] 50. Wrist joint; 510. Rotation bracket; 520. Rotation shaft; 530. Deflection bracket; 531. Deflection plate; 532. Connecting side plate. Detailed Implementation

[0051] To make the above-mentioned objectives, features and advantages of this utility model more apparent and understandable, the following description is provided in conjunction with the appendix. Figures 1-9Specific embodiments of this utility model will be described in detail.

[0052] In this utility model, the terms "connection" and "connected" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral structure.

[0053] In this utility model, the terms "inner", "outer", "upper", "lower", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0054] See appendix Figure 1 The OY direction represents the vertical direction, and the OX direction represents the horizontal direction.

[0055] This utility model embodiment provides a wrist structure 1, please refer to the appendix. Figure 1 The wrist structure 1 includes a fixed support 10, a wrist joint 50, a differential drive assembly 20, a driven bevel gear 30, and a rotation drive assembly 40. The wrist joint 50 includes a rotation support 510 and a deflection support 530. The rotation support 510 is pivotally connected to the fixed support 10, and the deflection support 530 is pivotally connected to the rotation support 510. Figure 3 As shown, the differential drive assembly 20 includes a first driving bevel gear 213 and a second driving bevel gear 223, both of which are pivotally connected to the fixed bracket 10; the driven bevel gear 30 is fixed to the deflection bracket 530 and is drivenly connected to the first driving bevel gear 213 and the second driving bevel gear 223; the rotary drive assembly 40 is mounted on the deflection bracket 530 and is used for drive connection to the end effector.

[0056] The wrist structure 1 provided in this embodiment of the utility model is shown in Figures 4(a) and 5(a). If the first driving bevel gear 213 and the second driving bevel gear 223 drive the driven bevel gear 30 to move in the same direction and at the same speed, the driven bevel gear 30 will drive the deflection bracket 530 to move around the vertical axis of the fixed bracket 10, that is, to deflect the deflection bracket 530 relative to the fixed bracket 10. The same direction of movement in the same direction and at the same speed refers to the direction of rotation or rotational tendency of the driven bevel gear 30 under the driving action of the corresponding driving bevel gear, viewed from the direction from the small end to the large end of the driven bevel gear 30, as shown by arrow a in Figure 4(a). In Figure 5(a), arrows a and b indicate that the driven bevel gear 30 rotates either clockwise or counterclockwise. As shown in Figures 4(b) and 5(b), if the first driving bevel gear 213 and the second driving bevel gear 223 drive the driven bevel gear 30 to move in the opposite direction at the same rotational speed, the driven bevel gear 30 drives the deflection bracket 530 to rotate around the transverse axis, that is, it causes the deflection bracket 530 to pitch relative to the fixed bracket 10. Here, the opposite movement in the opposite direction at the same rotational speed refers to the direction of rotation or the direction of rotation tendency of the driven bevel gear 30 under the driving action of the corresponding driving bevel gear, viewed from the direction from the small end of the driven bevel gear 30 to the large end. As shown by arrow a in Figure 4(b) and arrows a and b in Figure 5(b), the driven bevel gear 30 rotates clockwise and counterclockwise, respectively. If the first driving bevel gear 213 and the second driving bevel gear 223 drive the driven bevel gear 30 to move at different speeds, the driven bevel gear 30 will drive the deflection bracket 530 to move around the vertical axis of the fixed bracket 10, and simultaneously drive the deflection bracket 530 to rotate around the horizontal axis, that is, to make the deflection bracket 530 deflect and pitch relative to the fixed bracket 10. Therefore, it can be seen that the first driving bevel gear 213 and the second driving bevel gear 223 of the differential drive assembly 20 drive the driven bevel gear 30 to rotate clockwise and counterclockwise, respectively. The driven bevel gear 20 rotates in both directions relative to the vertical and horizontal axes, thereby driving the deflection bracket 530 to deflect in the vertical direction relative to the fixed bracket 10 and to pitch in the horizontal direction. In addition, the rotary drive assembly 40 drives the end effector to move. Combined with the two degrees of freedom of the wrist joint mentioned above, the wrist joint has three degrees of freedom, giving it flexible movement capabilities. Compared with related technologies, where the wrist uses three mechanical joints with single-direction rotation connected in series, this embodiment of the present invention, by using a combination of differential drive and rotary drive, can reduce the structural size of the wrist, thereby increasing the range of motion of the end effector and the flexibility of the robotic arm.

[0057] Please see the appendix Figure 3 and Figure 9In this embodiment of the present invention, the driven bevel gear 30 includes a first driven bevel gear 310 and a second driven bevel gear 320, both of which are fixed to the deflection bracket 530; the differential drive assembly 20 also includes an outer drive shaft 212 and an inner drive shaft 222, the outer drive shaft 212 is pivotally connected to the fixed bracket 10, the upper end of the outer drive shaft 212 is drivenly connected to an outer drive motor 211, and the lower end is fixed to the first drive bevel gear 213; the inner drive shaft 222 is pivotally connected to the fixed bracket 10, the inner drive shaft 222 passes through the outer drive shaft 212 and the upper end of the inner drive shaft 222 protrudes from the upper end of the outer drive shaft 212, the upper end of the inner drive shaft 222 is drivenly connected to the power output end of the inner drive motor 221, and the lower end is fixed to the second drive bevel gear 223.With this configuration, the external drive motor 211 transmits power to the first driven bevel gear 310 via the external drive shaft 212 and the first driving bevel gear 213, while the internal drive motor 221 transmits power to the second driven bevel gear 320 via the internal drive shaft 222 and the second driving bevel gear 223. As shown in Figure 5(a), if the external drive motor 211 and the internal drive motor 221 move in the same direction and at the same speed, they drive the first driven bevel gear 310 and the second driven bevel gear 320 to move in the same direction and at the same speed via the first driving bevel gear 213 and the second driving bevel gear 223, respectively. In this configuration, the deflection bracket 530 is locked to the rotating bracket 510, and the first driven bevel gear 310 and the second driven bevel gear 320 drive the deflection bracket 530 to drive the rotating bracket 510. 0 moves around the vertical axis of the fixed bracket 10, that is, the deflection bracket 530 deflects relative to the fixed bracket 10. The same direction and rotation speed in this same-direction and same-speed movement refer to the direction from the small end to the large end of the first driven bevel gear 310 and the direction from the small end to the large end of the second driven bevel gear 320. The rotation direction or rotational tendency direction of the first driven bevel gear 310 and the second driven bevel gear 320 under the driving action of the corresponding first driving bevel gear 213 and second driving bevel gear 223 are as shown by arrows a and b in Figure 5(a). Both the first driven bevel gear 310 and the second driven bevel gear 320 rotate clockwise or both rotate counterclockwise. As shown in Figure 5(b), if the external drive motor 2... 11 and the internal drive motor 221 move in the opposite direction and at the same speed. The first driving bevel gear 213 and the second driving bevel gear 223 drive the first driven bevel gear 310 and the second driven bevel gear 320 to move in the opposite direction and at the same speed. The first driven bevel gear 310 and the second driven bevel gear 320 drive the deflection bracket 530 to rotate around the transverse axis, that is, to make the deflection bracket 530 pitch relative to the fixed bracket 10. The "opposite direction" in this reverse same-speed movement refers to the direction from the small end of the first driven bevel gear 310 to the large end and the direction from the small end of the second driven bevel gear 320 to the large end. The rotation direction or rotation tendency of the first driven bevel gear 310 and the second driven bevel gear 320 under the driving action of the corresponding driving bevel gears. As shown by arrows a and b in Figure 5(b), one of the first driven bevel gear 310 and the second driven bevel gear 320 moves clockwise and the other moves counterclockwise. If the external drive motor 211 and the internal drive motor 221 move at different speeds, the first driven bevel gear 310 and the second driven bevel gear 320 are driven at different speeds by the first drive bevel gear 213 and the second drive bevel gear 223, respectively. The first driven bevel gear 310 and the second driven bevel gear 320 drive the deflection bracket 530 to move around the vertical axis and also around the horizontal axis, so that the deflection bracket 530 moves in pitch while deflecting relative to the fixed bracket 10.

[0058] See appendixFigure 6 and Figure 9 In this embodiment of the present invention, the differential drive assembly 20 further includes an external drive wire drive shaft 214, a first external drive wire 215, a second external drive wire 216, and an external drive wheel 217. The external drive wire drive shaft 214 is driveably connected to the external drive motor 211. The external drive wheel 217 is fixed to the upper end of the external drive shaft 212. The first end of the first external drive wire 215 is fixed to the external drive wire drive shaft 214 and wound clockwise around the outer wall of the external drive wire drive shaft 214, and the second end is fixed to the external drive wheel 217 and wound clockwise around the outer wall of the external drive wheel 217. The first end of the second external drive wire 216 is fixed to the external drive wire drive shaft 214 and wound counterclockwise around the outer wall of the external drive wire drive shaft 214, and the second end is fixed to the external drive wheel 217 and wound counterclockwise around the outer wall of the external drive wheel 217.

[0059] The differential drive assembly 20 also includes an inner drive wire drive shaft 224, a first inner drive wire 225, a second inner drive wire 226, and an inner reel 227. The inner drive wire drive shaft 224 is driveably connected to the inner drive motor 221. The inner reel 227 is fixed to the upper end of the inner drive shaft 222. The first end of the first inner drive wire 225 is fixed to the inner drive wire drive shaft 224 and wound clockwise around the outer wall of the inner drive wire drive shaft 224, and the second end is fixed to the inner reel 227 and wound clockwise around the outer wall of the inner reel 227. The first end of the second inner drive wire 226 is fixed to the inner drive wire drive shaft 224 and wound counterclockwise around the outer wall of the inner drive wire drive shaft 224, and the second end is fixed to the inner reel 227 and wound counterclockwise around the outer wall of the inner reel 227. With this configuration, on the one hand, the external drive motor 211 rotates forward or reverse to control the first external drive wire 215 and the second external drive wire 216 to wind around or release from the external drive wire transmission shaft 214 and the outer wire pulley 217, causing the first external drive wire 215 and the second external drive wire 216 to pull the outer wire pulley 217 and drive the external drive shaft 212 to rotate, thereby driving the first drive bevel gear 213 to rotate; on the other hand, the internal drive motor 221 rotates forward or reverse to control the first internal drive wire 225 and the second internal drive wire 226 to wind around or release from the internal drive wire transmission shaft 224 and the internal wire pulley 227, causing the first internal drive wire 225 and the second internal drive wire 226 to drive the internal drive shaft 222 to rotate, thereby driving the internal drive shaft 222 to rotate. The second active bevel gear 223 rotates; that is, the rotation of the first active bevel gear 213 and the second active bevel gear 223 is achieved through line drive, which in turn drives the driven bevel gear 30 to rotate, realizing the single or two-way degrees of freedom of the wrist joint; on the other hand, through line drive, the external drive motor 211 and the internal drive motor 221 can be set on the upper arm or forearm away from the wrist, reducing the mass of the wrist, thereby reducing the inertia of the wrist, making the end effector move more smoothly during movement, and improving the accuracy and stability of the end effector movement; it also makes the end effector have a smaller inertia during movement, and can respond quickly to control commands; in addition, it can reduce the structural size of the wrist, making the wrist structure compact.

[0060] See appendix Figure 6 and Figure 9 In this embodiment of the present invention, the axial direction of the external drive motor 211 is perpendicular to the axial direction of the external drive shaft 212; the differential drive assembly 20 also includes a first external guide wheel 218 and a second external guide wheel 219 respectively pivotally connected to the fixed bracket 10, the axial directions of the first external guide wheel 218 and the second external guide wheel 219 are perpendicular to the axial direction of the external drive shaft 212, the first external drive line 215 is wound around a portion of the outer wall surface of the first external guide wheel 218; the second external drive line 216 is wound around a portion of the outer wall surface of the second external guide wheel 219;

[0061] The axis of the inner drive motor 221 is perpendicular to the axis of the inner drive shaft 222; the differential drive assembly 20 also includes a first inner guide wheel 228 and a second inner guide wheel 229 respectively pivotally connected to the fixed bracket 10. The axes of the first inner guide wheel 228 and the second inner guide wheel 229 are both perpendicular to the axis of the inner drive shaft 222. The first inner drive line 225 is wound around a portion of the outer wall of the first inner guide wheel 228, and the second inner drive line 226 is wound around a portion of the outer wall of the second inner guide wheel 229. This configuration is used to change the direction of the first outer drive line 215, the second outer drive line 216, the first inner drive line 225, and the second inner drive line 226. Specifically, it allows the first outer drive line 215 and the second outer drive line 216 wound around the outer drive line wheel 217 to be wound around the outer drive line drive shaft 214 via the first outer guide wheel 218 and the second outer guide wheel 219, respectively; and it allows the second inner drive line 225 and the second inner drive line 226 wound around the inner drive line wheel 227 to be wound around the inner drive line drive shaft 224 via the first inner guide wheel 228 and the second inner guide wheel 229, respectively.

[0062] See appendix Figure 3 and Figure 6 In this embodiment of the present invention, the fixed bracket 10 is a U-shaped bracket, including a supporting horizontal plate 110 and a supporting side plate 120. The supporting side plate 120 has two parallel and spaced fixed to the supporting horizontal plate 110. The rotating bracket 510 is pivotally connected to the supporting horizontal plate 110. The first outer guide wheel 218 and the second outer guide wheel 219 are both pivotally connected to the supporting side plate 120. The first inner guide wheel 228 and the second inner guide wheel 229 are both pivotally connected to the supporting side plate 120.

[0063] See appendix Figure 6 In this embodiment of the present invention, the supporting side plate 120 has a plurality of spaced wheel supports 130. The wheel supports 130 protrude from the inner surface of the supporting side plate 120 in the direction close to the outer wheel 217 and the inner wheel 227. The first outer guide wheel 218, the second outer guide wheel 219, the first inner guide wheel 228 and the second inner guide wheel 229 are respectively pivotally connected to the corresponding wheel supports 130.

[0064] In this embodiment of the present invention, the outer drive wire drive shaft 214 has a first outer wire groove, and the first ends of the first outer drive wire 215 and the second outer drive wire 216 are respectively wound and fixed in the first outer wire groove; the outer wall surface of the outer wire wheel 217 has a second outer wire groove, and the second ends of the first outer drive wire 215 and the second outer drive wire 216 are respectively wound and fixed in the second outer wire groove; the inner drive wire drive shaft 224 has a first inner wire groove, and the first ends of the first inner drive wire 225 and the second inner drive wire 226 are respectively wound and fixed in the first inner wire groove; the outer wall surface of the inner wire wheel 227 has a second inner wire groove, and the second ends of the first inner drive wire 225 and the second inner drive wire 226 are respectively wound and fixed in the second inner wire groove. With this configuration, the first outer wire groove, the second outer wire groove, the first inner wire groove, and the second inner wire groove allow the first outer drive wire 215, the second outer drive wire 216, the first inner drive wire 225, and the second inner drive wire 226 to be neatly arranged, reducing friction between adjacent drive wires, thereby reducing wear and extending the service life of each drive wire.

[0065] See appendix Figure 2 , Figure 7 and Figure 8 In this embodiment of the present invention, the second ends of the first external drive line 215 and the second external drive line 216 both have external drive line connectors 2152; the upper and lower end faces of the external drive wheel 217 are recessed to form an external pre-tightening hole 2172, which is connected to the second external drive line groove; the external drive line connector 2152 and the external pre-tightening hole 2172 have limiting portions, which are used to restrict the movement of the external drive line connector 2152 along the circumferential direction of the external pre-tightening hole 2172; the external drive line connector 2152 is threadedly connected to a fastener, which can abut against the end face of the external pre-tightening hole 2172, configured to: tighten the fastener to drive the external drive line connector 2152 to move along the axial direction of the external pre-tightening hole 2172 to tension the first external drive line 215 and / or the second external drive line 216;

[0066] The second ends of the first inner drive line 225 and the second inner drive line 226 both have inner drive line connectors; the inner drive line connectors have the same structure as the outer drive line connectors 2152, and the upper and lower end faces of the inner drive line wheel 227 are recessed to form an inner pre-tightening hole 2272, which is connected to the second inner drive line groove; the inner drive line connectors and the inner pre-tightening hole 2272 have limiting portions, which are used to restrict the movement of the inner drive line connectors along the circumferential direction of the inner pre-tightening hole 2272; the inner drive line connectors are threadedly connected to fasteners, which can abut against the end face of the inner pre-tightening hole 2272, and are configured such that: tightening the fasteners drives the inner drive line connectors to move along the axial direction of the inner pre-tightening hole 2272 to tension the first inner drive line 225 and / or the second inner drive line 226. With this setup, the operator can adjust the depth of the fastener's insertion into the outer connector 2152 by tightening the fastener. The fastener causes the outer connector 2152 to move along the axial direction of the outer pre-tightening hole 2172, adjusting the contact length between the outer connector 2152 and the outer pre-tightening hole 2172, thereby pre-tightening the first outer drive line 215 and the second outer drive line 216 respectively. Additionally, by adjusting the depth of the fastener's insertion into the inner connector, the fastener causes the inner connector to move along the axial direction of the inner pre-tightening hole 2272, adjusting the contact length between the inner connector and the inner pre-tightening hole 2272, thereby pre-tightening the first inner drive line 225 and the second inner drive line 226 respectively.

[0067] In this embodiment of the invention, the cross-sectional shape of the outer wall of the external connector 2152 can be various. Specifically, the cross-sectional shape of the outer wall of the external connector 2152 can be triangular, quadrilateral, pentagonal, hexagonal, convex, or concave. Referring to Figure 5, the cross-sectional shape of the outer wall of the external connector 2152 is hexagonal. It should be noted that the cross-sectional shape of the outer wall of the external pre-tightening hole 2172 matches that of the mating section of the external connector 2152. With this configuration, the cross-sectional shapes of the outer walls of the external connector 2152 and the external pre-tightening hole 2172 are polygonal, thereby forming a limiting portion that restricts the movement of the external connector 2152 along the circumferential direction of the external pre-tightening hole 2172.

[0068] In this embodiment of the invention, the cross-sectional shape of the outer wall of the inner connector can be various. Specifically, the cross-sectional shape of the outer wall of the inner connector can be triangular, quadrilateral, pentagonal, hexagonal, convex, or concave. It should be noted that the cross-sectional shape of the outer wall of the inner pre-tightening hole 2272 matches that of the mating section of the inner connector. With this configuration, the cross-sectional shape of the outer walls of the inner connector and the inner pre-tightening hole 2272 is polygonal, thereby forming a limiting portion that restricts the movement of the inner connector along the circumferential direction of the inner pre-tightening hole 2272.

[0069] In this embodiment of the present invention, the connection method between the rotating shaft 520 and the first driven bevel gear 310 and the second driven bevel gear 320 can be various, as follows:

[0070] For the first scenario, please refer to the appendix. Figure 1 The rotating bracket 510 is fixedly provided with a rotating shaft 520, and the first driven bevel gear 310 and the second driven bevel gear 320 are respectively pivotally connected to the rotating shaft 520.

[0071] In the second scenario, the rotating bracket 510 is pivotally connected to the rotating shaft 520, and the first driven bevel gear 310 and the second driven bevel gear 320 are respectively fixed to the rotating shaft 520.

[0072] In this embodiment of the utility model, for the first scenario described above, please refer to the appendix. Figure 1 The rotating bracket 510 is fixed with a rotating shaft 520, which can be a T-shaped rotating shaft. The T-shaped rotating shaft includes a horizontal shaft and a vertical shaft. The vertical shaft is vertically connected to the horizontal shaft. The upper end of the vertical shaft is pivotally connected to the inner wall surface of the inner drive shaft 222. The first driven bevel gear 310 is pivotally connected to the first end of the horizontal shaft, and the second driven bevel gear 320 is pivotally connected to the second end of the horizontal shaft.

[0073] In this embodiment of the invention, the horizontal shaft has a connecting portion in the middle; the deflection bracket 530 includes a deflection plate 531 and a connecting side plate 532. The deflection plate 511 is pivotally connected to the rotating bracket 10. There are two connecting side plates 512 arranged at intervals. The upper ends of the connecting side plates 512 are fixed to the deflection plate 511, and the lower ends of the connecting side plates 512 are fixed to the connecting portion. A gear receiving space is formed between the deflection plate 511 and the connecting side plate 512 to accommodate the first driving bevel gear 213 and the second driving bevel gear 223. The first driven bevel gear 310 and the second driven bevel gear 320 are respectively fixed to the connecting side plate 512. This arrangement improves the stability of the connection between the deflection bracket 530 and the rotating shaft 520.

[0074] This utility model embodiment also provides a robotic arm; please refer to the appendix. Figure 9 The robotic arm includes an upper arm 2, an elbow structure 3, a forearm 4, and the aforementioned wrist structure 1. The elbow structure 3 connects the upper arm 2 and the forearm 4. A fixed bracket 10 is fixed to the end of the forearm 4 away from the upper arm 2. An external drive motor 211 and an internal drive motor 221 are mounted on the end of the upper arm 2 away from the forearm 4. This configuration, by placing the external drive motor 211 and the internal drive motor 221 on the upper arm 2, reduces the mass of the wrist, thereby reducing the inertia of the wrist and making the end effector move more smoothly during movement, thus improving the accuracy and stability of the end effector's movement. The end effector has a smaller inertia during movement, enabling it to respond quickly to control commands. In addition, it can reduce the structural size of the wrist, making the wrist structure more compact.

[0075] While the present invention has been disclosed above, it is not limited thereto. Any person skilled in the art can make various modifications and alterations without departing from the spirit and scope of the present invention; therefore, the scope of protection of the present invention should be determined by the scope defined in the claims.

Claims

1. A wrist structure, characterized by, The wrist joint (50) comprises a rotating support (510) and a deflecting support (530), the rotating support (510) is pivotally connected to the fixed support (10), and the deflecting support (530) is pivotally connected to the rotating support (510). The differential drive assembly (20) comprises a first driving bevel gear (213) and a second driving bevel gear (223), both of which are pivotally connected to the fixed support (10). The driven bevel gear (30) comprises a first driven bevel gear (310) and a second driven bevel gear (320), both of which are fixedly arranged on the deflecting support (530). The differential drive assembly (20) further comprises an outer driving shaft (212) and an inner driving shaft (222), the outer driving shaft (212) is pivotally connected to the fixed support (10), the upper end of the outer driving shaft (212) is drivingly connected with an outer driving motor (211), and the lower end of the outer driving shaft (212) is fixedly arranged on the first driving bevel gear (213); the inner driving shaft (222) is pivotally connected to the fixed support (10), the inner driving shaft (222) is arranged in the outer driving shaft (212) and the upper end of the inner driving shaft (222) protrudes from the upper end of the outer driving shaft (212), the upper end of the inner driving shaft (222) is drivingly connected with the power output end of an inner driving motor (221), and the lower end of the inner driving shaft (222) is fixedly arranged on the second driving bevel gear (223). The differential drive assembly (20) further comprises an outer driving wire transmission shaft (214), a first outer driving wire (215), a second outer driving wire (216) and an outer wire wheel (217), the outer driving wire transmission shaft (214) is drivingly connected with the outer driving motor (211); the outer wire wheel (217) is fixedly arranged on the upper end of the outer driving shaft (212); the first end of the first outer driving wire (215) is fixedly arranged on the outer driving wire transmission shaft (214) and wound on the outer wall surface of the outer driving wire transmission shaft (214) in a clockwise direction, and the second end of the first outer driving wire (215) is fixedly arranged on the outer wire wheel (217) and wound on the outer wall surface of the outer wire wheel (217) in a clockwise direction; the first end of the second outer driving wire (216) is fixedly arranged on the outer driving wire transmission shaft (214) and wound on the outer wall surface of the outer driving wire transmission shaft (214) in a counterclockwise direction, and the second end of the second outer driving wire (216) is fixedly arranged on the outer wire wheel (217) and wound on the outer wall surface of the outer wire wheel (217) in a counterclockwise direction. ​ 2. The wrist structure of claim 1, wherein, ​ ​ 3. The wrist structure of claim 2, wherein, ​ The differential drive assembly (20) further comprises an inner drive line transmission shaft (224), a first inner drive line (225), a second inner drive line (226) and an inner line wheel (227), the inner drive line transmission shaft (224) is in transmission connection with the inner drive motor (221); the inner line wheel (227) is fixedly arranged on the upper end of the inner drive shaft (222); the first end of the first inner drive line (225) is fixedly arranged on the outer wall surface of the inner drive line transmission shaft (224) and wound on the outer wall surface of the inner drive line transmission shaft (224) in a clockwise direction, and the second end is fixedly arranged on the outer wall surface of the inner line wheel (227) and wound on the outer wall surface of the inner line wheel (227) in a clockwise direction; the first end of the second inner drive line (226) is fixedly arranged on the outer wall surface of the inner drive line transmission shaft (224) and wound on the outer wall surface of the inner drive line transmission shaft (224) in a counterclockwise direction, and the second end is fixedly arranged on the outer wall surface of the inner line wheel (227) and wound on the outer wall surface of the inner line wheel (227) in a counterclockwise direction.

4. The wrist structure of claim 3, wherein, The axis direction of the outer drive motor (211) is perpendicular to the axis direction of the outer drive shaft (212); the differential drive assembly (20) further comprises a first outer guide wheel (218) and a second outer guide wheel (219) which are respectively pivotally connected to the fixed support (10), the axis directions of the first outer guide wheel (218) and the second outer guide wheel (219) are perpendicular to the axis direction of the outer drive shaft (212), and the first outer drive line (215) is wound on part of the outer wall surface of the first outer guide wheel (218); the second outer drive line (216) is wound on part of the outer wall surface of the second outer guide wheel (219); The axis direction of the inner drive motor (221) is perpendicular to the axis direction of the inner drive shaft (222); the differential drive assembly (20) further comprises a first inner guide wheel (228) and a second inner guide wheel (229) which are respectively pivotally connected to the fixed support (10), the axis directions of the first inner guide wheel (228) and the second inner guide wheel (229) are both perpendicular to the axis direction of the inner drive shaft (222), the first inner drive line (225) is wound on part of the outer wall surface of the first inner guide wheel (228), and the second inner drive line (226) is wound on part of the outer wall surface of the second inner guide wheel (229).

5. The wrist structure of claim 4, wherein, The fixed support (10) is a U-shaped support comprising a support horizontal plate (110) and support side plates (120), the support side plates (120) are two in number and are fixedly arranged in parallel and spaced apart on the support horizontal plate (110), and the rotating support (510) is pivotally connected to the support horizontal plate (110); the first outer guide wheel (218) and the second outer guide wheel (219) are both pivotally connected to the support side plates (120); the first inner guide wheel (228) and the second inner guide wheel (229) are both pivotally connected to the support side plates (120).

6. The wrist structure of claim 5, wherein, The support side plate (120) has a plurality of spaced wheel supports (130) which protrude from the inner surface of the support side plate (120) in a direction close to the outer line wheel (217) and the inner line wheel (227), and the first outer guide wheel (218), the second outer guide wheel (219), the first inner guide wheel (228) and the second inner guide wheel (229) are respectively pivoted to the corresponding wheel supports (130).

7. The wrist structure of claim 3, wherein, The outer drive line transmission shaft (214) has a first outer line groove, and the first ends of the first outer drive line (215) and the second outer drive line (216) are respectively wound and fixed in the first outer line groove; the outer wall surface of the outer line wheel (217) has a second outer line groove, and the second ends of the first outer drive line (215) and the second outer drive line (216) are respectively wound and fixed in the second outer line groove; The inner drive line transmission shaft (224) has a first inner line groove, and the first ends of the first inner drive line (225) and the second inner drive line (226) are respectively wound and fixed in the first inner line groove; the outer wall surface of the inner line wheel (227) has a second inner line groove, and the second ends of the first inner drive line (225) and the second inner drive line (226) are respectively wound and fixed in the second inner line groove.

8. The wrist structure of claim 7, wherein, The second ends of the first outer drive line (215) and the second outer drive line (216) each have an outer line joint (2152); the upper end surface and the lower end surface of the outer line wheel (217) are recessed to form an outer pre-tightening hole (2172), and the outer pre-tightening hole (2172) is communicated with the second outer line groove; the outer line joint (2152) and the outer pre-tightening hole (2172) have a limiting portion for limiting the movement of the outer line joint (2152) along the circumferential direction of the outer pre-tightening hole (2172); the outer line joint (2152) is threadedly connected with a fastener which can abut against the end surface of the outer pre-tightening hole (2172), and is configured to: tighten the fastener to drive the outer line joint (2152) to move along the axial direction of the outer pre-tightening hole (2172) to tension the first outer drive line (215) and / or the second outer drive line (216); Second ends of the first inner driving line (225) and the second inner driving line (226) are provided with inner wire joints; upper and lower end faces of the inner wire wheel (227) are recessed to form inner pre-tightening holes (2272) which are communicated with the second inner wire grooves; the inner wire joints and the inner pre-tightening holes (2272) are provided with limiting portions for limiting movement of the inner wire joints along a circumferential direction of the inner pre-tightening holes (2272); the inner wire joints are threadedly connected with fasteners which can abut against end faces of the inner pre-tightening holes (2272) and are configured to move the inner wire joints along an axial direction of the inner pre-tightening holes (2272) to tension the first inner driving line (225) and / or the second inner driving line (226) by tightening the fasteners.

9. The wrist structure of any of claims 2-8, wherein, The rotating support (510) is fixedly provided with a rotating shaft (520), and the first driven bevel gear (310) and the second driven bevel gear (320) are respectively pivotally connected to the rotating shaft (520). Alternatively, the rotating support (510) is pivotally provided with the rotating shaft (520), and the first driven bevel gear (310) and the second driven bevel gear (320) are respectively fixedly provided on the rotating shaft (520).

10. The wrist structure of any one of claims 2-8, wherein, The rotating support (510) is fixedly provided with a rotating shaft (520), and the rotating shaft (520) is a T-shaped rotating shaft including a horizontal shaft and a vertical shaft, the vertical shaft is perpendicularly connected to the horizontal shaft, an upper end of the vertical shaft is pivotally connected to an inner wall surface of the inner driving shaft (222), the first driven bevel gear (310) is pivotally connected to a first end of the horizontal shaft, and the second driven bevel gear (320) is pivotally connected to a second end of the horizontal shaft.

11. The wrist structure of claim 10, wherein, A middle portion of the horizontal shaft is provided with a connecting portion. The deflection support (530) includes a deflection plate (531) and connecting side plates (532), the deflection plate (511) is pivotally connected to the rotating support (10), the connecting side plates (512) are provided in two and are oppositely spaced, upper ends of the connecting side plates (512) are fixedly provided on the deflection plate (511), and lower ends of the connecting side plates (512) are fixedly provided on the connecting portion; a gear accommodating space is formed between the deflection plate (511) and the connecting side plates (512) for accommodating the first driving bevel gear (213) and the second driving bevel gear (223); The first driven bevel gear (310) and the second driven bevel gear (320) are respectively fixedly provided on the connecting side plates (512).

12. A robot arm, characterized in that The robot arm (1) comprises a large arm (2), an elbow structure (3), a small arm (4), and the wrist structure (1) according to any one of claims 2-11, the elbow structure (3) is connected between the large arm (2) and the small arm (4), the fixed support (10) is fixedly provided on an end of the small arm (4) away from the large arm (2), and the outer driving motor (211) and the inner driving motor (221) are mounted on an end of the large arm (2) away from the small arm (4).

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