Differential rotation power device

Abstract

The application belongs to the technical field of speed reducer, and particularly relates to a differential rotation power device. The technical scheme is as follows: a differential rotation power device comprises a cross ring, and harmonic speed reducer motors are arranged on the two outer sides of the cross ring; the harmonic speed reducer motor comprises a central shaft arranged in the speed reducer, a motor stator connected to the central shaft, a motor rotor sleeved on the motor stator, a harmonic speed reduction unit connected to the motor rotor, an output end of the harmonic speed reduction unit fixed to the central shaft, a harmonic gear wheel meshed with the output end of the harmonic speed reduction unit, the harmonic gear wheel rotationally connected to the cross ring, a large gear wheel fixed to the harmonic gear wheel, and a small gear wheel rotationally connected to the outer ring of the end portion of the cross ring, and the small gear wheel is meshed with the large gear wheels on the two sides. The application provides a differential rotation power device capable of driving the action end to rotate or compound rotate in two mutually perpendicular planes.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of speed reducer, and particularly relates to a differential rotation power device. BACKGROUND

[0002] The harmonic reducer is widely used in the field of mechanical transmission due to a large transmission ratio. Generally, the harmonic reducer comprises a rigid gear, a flexible gear and a wave generator. The rigid gear is actually an inner ring gear with great rigidity. The flexible gear is in a cylindrical shape and is made of a material with small rigidity. The outer wall of the mouth end of the flexible gear is formed with outer teeth. The mouth end of the flexible gear extends into the rigid gear, and the outer teeth are used to mesh with the inner teeth of the rigid gear. The wave generator is in an elliptical cylindrical shape and extends into the mouth end of the flexible gear. When the wave generator is driven to rotate by a power mechanism, the outer teeth of the flexible gear corresponding to the long axis of the wave generator are continuously meshed with the inner teeth of the rigid gear to drive the flexible gear to rotate.

[0003] Patent No. CN201320170058.1 discloses a hollow harmonic reducer with deep groove ball bearing, which comprises a harmonic reducer, a hollow input shaft and a deep groove ball bearing. The hollow input shaft is arranged in the harmonic reducer. The harmonic reducer is provided with a bearing fixing assembly. The deep groove ball bearing is arranged between the hollow input shaft and the bearing fixing assembly. The bearing fixing assembly comprises a bearing seat and a bearing pressing plate. The bearing seat and the bearing pressing plate fix the two ends of the deep groove ball bearing, respectively. The hollow harmonic reducer with deep groove ball bearing fixes the deep groove ball bearing on the harmonic reducer through the bearing fixing assembly, thereby ensuring the firmness and stability of the harmonic reducer as a whole. The harmonic reducer can meet the use requirements without excessive adjustment during application and installation, thereby saving the installation time and facilitating the later maintenance and repair of the equipment.

[0004] However, the above harmonic reducer can only output rotation in a single direction and cannot realize rotation or compound motion in two mutually perpendicular planes. SUMMARY

[0005] In order to solve the above problems existing in the prior art, the purpose of the present application is to provide a differential rotation power device capable of driving a motion end to rotate or compound rotate in two mutually perpendicular planes.

[0006] The technical scheme adopted by the present application is as follows:

[0007] A differential rotation power device includes a cross ring, and a harmonic reduction motor is provided on both outer sides of the cross ring; the harmonic reduction motor includes a central shaft, a motor stator is connected to the central shaft, a motor rotor is sleeved on the motor stator, and the motor rotor is connected to a harmonic reduction unit, the output end of the harmonic reduction unit is fixed to the central shaft, the output end of the harmonic reduction unit is meshed with a harmonic rigid wheel, the harmonic rigid wheel is rotatably connected to the cross ring, a large gear is fixed to the harmonic rigid wheel, the outer ring of the end of the cross ring is rotatably connected to a small gear, and the small gear is respectively meshed with the large gears on both sides.

[0008] The output speed of the harmonic reduction unit of the present invention is significantly lower than that of the cam, resulting in a stable, low-speed output from the harmonic reduction motor. The harmonic reduction unit meshes with the harmonic rigid gear teeth, ensuring high transmission accuracy relative to the cam. The output of the harmonic reduction unit is fixed to the central shaft, securing the motor stator and ensuring stable rotation of the motor rotor relative to the stator.

[0009] The output ends of the harmonic reduction motors on both sides are connected to the action end, and the fixed end is connected to the pinion. When the motors on both sides rotate in the same direction and at the same speed, the pinion and the large gear will not produce relative rotation, and the action end tilts with the center axis as the rotation axis. When the motors on both sides rotate in opposite directions and at the same speed, the large gears on both sides are respectively engaged with the small gears for transmission and the small gears only rotate on themselves, and the action end rotates with the axis of the small gear as the rotation axis. Under other working conditions, the action end performs compound motion. The reducer of the present invention can realize motion in two mutually perpendicular directions, can simulate human joints, has a compact structure, and can be applied to the joints of robots.

[0010] As a preferred embodiment of the present invention, the harmonic reduction unit includes a cam, which is fixed on the motor rotor. A flexible bearing is installed on the cam. The outer ring of the flexible bearing is provided with a flexible wheel. The flexible wheel is engaged with the teeth of the harmonic rigid wheel. The number of teeth of the flexible wheel is less than the number of teeth of the harmonic rigid wheel. An output flange is fixed on the flexible wheel, and the flexible wheel is fixed to the center shaft.

[0011] When the motor is powered, the motor rotor rotates relative to the motor stator, which in turn drives the cam. The cam, through the flexible bearing, pushes the flexspline into meshing with the harmonic rigid wheel. If the number of teeth on the flexspline is N less than that on the harmonic rigid wheel, the flexspline rotates N teeth relative to the harmonic rigid wheel for each revolution of the cam. This significantly reduces the speed of the output flange connected to the flexspline, ensuring stable output force. Transmission accuracy is also guaranteed through gear transmission.

[0012] As a preferred solution of the present invention, the inner side of the cam is connected to the central shaft via a rolling bearing. The central shaft reliably supports the cam, and the central shaft and the cam can rotate relative to each other.

[0013] As a preferred embodiment of the present invention, the cam and the flexible bearing are both elliptical in shape, and the flexspline meshes with the harmonic rigid wheel at two locations. The flexible bearing pushes the flexspline and the harmonic rigid wheel into meshing transmission from two locations, ensuring stable transmission between the flexspline and the harmonic rigid wheel.

[0014] As a preferred embodiment of the present invention, the harmonic reduction motor further includes a crossed roller bearing, the inner ring of which is integrally formed with or fixedly connected to the output flange, and the outer ring of which is integrally formed with or fixedly connected to the gear. The output end of the harmonic reduction unit can reliably support the gear and can rotate relative to the gear.

[0015] As a preferred embodiment of the present invention, the central shaft is provided with a wiring hole, through which the wiring of the motor stator is passed. Passing the wiring through the wiring hole facilitates wiring. The central shaft has a low rotation speed, a small rotation angle, and is capable of returning to its original position, so that the wiring does not interfere with other structures after passing through the wiring hole.

[0016] As a preferred solution of the present invention, a PCB mounting plate is fixed on the central axis.

[0017] As a preferred embodiment of the present invention, two rotating connectors are provided on the cross ring at positions 180° apart, and the pinion is connected to the cross ring via one of the rotating connectors. The fixed end can be connected to both rotating connectors to ensure the stability of the differential rotary power device of the present invention after being installed on the fixed end.

[0018] As a preferred solution of the present invention, an end cap for limiting position is fixed to the rotating connector, which is used to limit the fixed end to prevent the differential rotation power device from being separated from the fixed end.

[0019] As a preferred embodiment of the present invention, the rotating connector includes a protruding connecting post provided on the cross ring, with a ball or bearing mounted on the connecting post. The pinion is connected to one of the connecting posts via the ball or bearing, one of the connecting heads at the fixed end is connected to the pinion via a bolt, and the other connecting head at the fixed end is connected to the connecting post on the opposite side via the ball or bearing.

[0020] The beneficial effects of the present invention are:

[0021] 1. In the present invention, when the motors on both sides rotate in the same direction and at the same speed, the small gear and the large gear will not rotate relative to each other, and the action end will tilt around the central axis as the rotation axis. When the motors on both sides rotate in opposite directions and at the same speed, the large gears on both sides respectively mesh with the small gears for transmission and the small gears only rotate on their own, and the action end rotates around the cross ring as the rotation axis. Under other working conditions, the action end performs a compound motion. The reducer of the present invention can realize two mutually perpendicular directions of motion, can simulate human joints, has a compact structure, and can be applied to the joints of robots.

[0022] 2. The output speed of the harmonic reduction unit of the present invention is significantly lower than that of the cam, resulting in a stable, low-speed output from the harmonic reduction motor. The harmonic reduction unit meshes with the harmonic rigid gear teeth, ensuring high transmission accuracy of the output of the harmonic reduction motor relative to the cam. The output of the harmonic reduction unit is fixed to the central shaft, securing the motor stator and ensuring stable rotation of the motor rotor relative to the stator. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a structural schematic diagram of the present invention;

[0024] Figure 2 is a cross-sectional view of the present invention;

[0025] Figure 3 yes Figure 2 A partial enlarged view of point A in the middle;

[0026] Figure 4 It is a partial structural diagram of the present invention.

[0027] In the figure: 1- Cross ring; 2- Center shaft; 3- Motor stator; 4- Motor rotor; 5- Harmonic reduction unit; 6- Harmonic rigid wheel; 7- Large gear; 8- Small gear; 9- PCB mounting plate; 11- Rotating connector; 12- End cover; 21- Rolling bearing; 51- Cam; 52- Flexible bearing; 53- Flexible wheel; 54- Output flange; 55- Cross roller bearing. DETAILED DESCRIPTION

[0028] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions of the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings herein can be arranged and designed in various different configurations.

[0029] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but rather merely represents selected embodiments of the present invention. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention. It should be noted that the embodiments of the present invention and the features therein may be combined with each other unless there is a conflict.

[0030] like Figures 1 to 4As shown, a differential rotation power device of this embodiment includes a cross ring 1, and harmonic reduction motors are provided on both outer sides of the cross ring 1; the harmonic reduction motor includes a central shaft 2, a motor stator 3 is connected to the central shaft 2, a motor rotor 4 is sleeved on the motor stator 3, and the motor rotor 4 is connected to a harmonic reduction unit 5, the output end of the harmonic reduction unit 5 is fixed to the central shaft 2, and the output end teeth of the harmonic reduction unit 5 are meshed with a harmonic rigid wheel 6, the harmonic rigid wheel 6 is rotatably connected to the cross ring 1, and the harmonic rigid wheel 6 is fixed with a large gear 7, and the outer ring at the end of the cross ring 1 is rotatably connected to a small gear 8, and the small gear 8 is respectively meshed with the large gear 7 on both sides.

[0031] The output speed of the harmonic reduction unit 5 of the present invention is significantly reduced relative to the speed of the cam 51, resulting in a stable, low-speed output from the harmonic reduction motor. The harmonic reduction unit 5 meshes with the harmonic rigid wheel 6, ensuring high transmission accuracy relative to the cam 51. The output of the harmonic reduction unit 5 is secured to the central shaft 2, thereby securing the motor stator 3 and ensuring stable rotation of the motor rotor 4 relative to the motor stator 3.

[0032] The motor stator 3 and the electronic rotor 4 are built into the flexible spline 53 , which can effectively utilize space, reduce the volume of the harmonic reduction motor, and simplify the structure.

[0033] The output ends of the harmonic reduction motors on both sides are connected to the action end, and the fixed end is connected to the pinion 8. When the motors on both sides rotate in the same direction and at the same speed, the pinion 8 and the large gear 7 will not produce relative rotation, and the action end tilts with the center axis 2 as the rotation axis. When the motors on both sides rotate in opposite directions and at the same speed, the large gears 7 on both sides are respectively engaged with the pinion 8 for transmission and the pinion 8 only rotates on its own, and the action end rotates with the axis of the pinion 8 as the rotation axis. Under other working conditions, the action end performs compound motion. The reducer of the present invention can realize motion in two mutually perpendicular directions, can simulate human joints, has a compact structure, and can be applied to the joints of robots.

[0034] Specifically, if Figure 4 As shown, the harmonic reduction unit 5 includes a cam 51, which is fixed to the motor rotor 4. A flexible bearing 52 is mounted on the cam 51. The outer ring of the flexible bearing 52 is equipped with a flexspline 53. The flexspline 53 meshes with the harmonic rigid wheel 6. The number of teeth on the flexspline 53 is smaller than that on the harmonic rigid wheel 6. An output flange 54 is fixed to the flexspline 53, and the flexspline 53 is fixed to the central shaft 2. The cam 51 and the flexible bearing 52 are both elliptical in shape. The flexspline 53 meshes with the harmonic rigid wheel 6 at two locations. The flexible bearing 52 pushes the flexspline 53 and the harmonic rigid wheel 6 into engagement and transmission from two locations, ensuring stable transmission between the flexspline 53 and the harmonic rigid wheel 6.

[0035] The deceleration principle of the harmonic reduction motor utilizes the relative motion of the flexspline 53, the harmonic rigid wheel 6, and the cam 51, primarily the controllable elastic deformation of the flexspline 53, to achieve motion and power transmission. The elliptical cam 51 rotates within the flexspline 53, causing the flexspline 53 to deform. When the teeth of the flexspline 53 at either end of the elliptical cam 51's major axis engage with those of the harmonic rigid wheel 6, the teeth of the flexspline 53 at either end of the minor axis disengage from those of the harmonic rigid wheel 6. The teeth between the major and minor axes of the cam 51 gradually enter a semi-engaged state within different sections along the circumference of the flexspline 53 and harmonic rigid wheel 6, known as engagement. A semi-engaged state gradually exits engagement is known as disengagement. As the cam 51 rotates continuously, the flexspline 53 continuously deforms, causing the teeth of the two wheels to continuously change their original working states through four motions: engagement, disengagement, and disengagement. This produces staggered tooth motion, enabling motion transmission between the cam 51 and the flexspline 53. The harmonic reduction motor has smooth transmission, low noise, high motion precision and back clearance less than 10 arc seconds.

[0036] When the motor is powered on, the motor rotor 4 rotates relative to the motor stator 3, and the motor rotor 4 drives the cam 51 to rotate. The cam 51 pushes the flexspline 53 to mesh with the harmonic rigid wheel 6 through the flexible bearing 52. The flexible bearing 52 is also elliptical and rotates synchronously with the cam 51. The flexspline 53 is made of a flexible material and is sleeved on the flexspline 53. When the flexible bearing 52 rotates, the teeth of the harmonic rigid wheel 6 block the teeth of the flexspline 53, so that the flexspline 53 slides on the flexible bearing 52. Due to the pressing effect of the flexible bearing 52, the meshing position of the flexspline 53 and the harmonic rigid wheel 6 changes continuously. Since the number of teeth of the flexspline 53 is less than the number of teeth of the harmonic rigid wheel 6, when the cam 51 rotates one circle, the meshing position of the flexspline 53 and the harmonic rigid wheel 6 does not change one circle. If the number of teeth of the flex spline 53 is N less than the number of teeth of the harmonic rigid wheel 6, then when the cam 51 rotates one circle, the flex spline 53 rotates N teeth relative to the harmonic rigid wheel 6, so that the output flange 54 connected to the flex spline 53 is greatly decelerated, ensuring stable output force, and transmission accuracy is guaranteed through gear transmission. Figure 3 In the embodiment, the number of teeth of the flex spline 53 is two less than that of the harmonic rigid wheel 6 . When the cam 51 rotates one circle, the flex spline 53 rotates two teeth, and the output flange 54 rotates a corresponding angle along with the cam 51 .

[0037] To support the cam 51, the inner side of the cam 51 is connected to the central shaft 2 via a rolling bearing 21. The central shaft 2 provides reliable support for the cam 51, and the central shaft 2 and cam 51 can rotate relative to each other. The cam 51 and central shaft 2 are connected by two rolling bearings 21, further enhancing the stability of the cam 51. These rolling bearings 21 can be deep groove ball bearings.

[0038] To support the large gear 7, the harmonic reduction motor further includes a cross roller bearing 55. The inner ring of the cross roller bearing 55 is integrally formed with or fixedly connected to the output flange 54, and the outer ring of the cross roller bearing 55 is integrally formed with or fixedly connected to the large gear 7. The output flange 54 can reliably support the large gear 7 and can rotate relative to the large gear.

[0039] To facilitate wiring connections, the central shaft 2 is provided with a wiring hole through which the wiring for the motor stator 3 is passed. Passing the wiring through the wiring hole facilitates wiring. The central shaft 2 rotates at a low speed, has a narrow rotation angle, and can return to its original position, so the wiring does not interfere with other structures after passing through the wiring hole.

[0040] A PCB mounting plate 9 is fixed on the central shaft 2. The PCB mounting plate 9 is fixed to the side of the central shaft 2 close to the cross ring 1, and a gap is left between the cross ring 1 and the PCB mounting plate 9 to avoid motion interference.

[0041] In order to further reduce the occupied space, the small gear 8 and the large gear 7 are both bevel gears, so that the outer contour of the reducer of the present invention is closer to a sphere, which is convenient for installing it on the joints of the humanoid simulation robot.

[0042] Bolt holes are located at the same position on the flexspline 53 and output flange 54. Connecting bolts pass through the flexspline 53 and output flange 54, respectively, and then connect to the actuating end, further enhancing the stability of the output connection. The fixed connection between the flexspline 53 and the central shaft 2 ensures that the central shaft 2 stably supports the motor stator 3 and that the motor rotor 4 can rotate reliably relative to the motor stator 3.

[0043] Furthermore, two rotating connectors 11 are provided at positions 180° apart on the cross ring 1, and the pinion 8 is connected to the cross ring 1 via one of the rotating connectors 11. The fixed end can be connected to both rotating connectors 11 to ensure the stability of the differential rotary power device of the present invention after being installed on the fixed end.

[0044] like Figure 3 As shown, the rotating connector 11 includes a protruding connecting post provided on the cross ring 1, on which a ball or bearing is mounted. The pinion 8 is connected to one of the connecting posts via a ball or bearing. One of the connectors at the fixed end is connected to the pinion 8 via a bolt, and the other connector at the fixed end is connected to the connecting post on the opposite side via a ball or bearing.

[0045] To ensure the limit, an end cap 12 for limiting the position is fixed on the rotating connector 11. The end cap 12 is used to limit the fixed end to prevent the differential rotation power device from being separated from the fixed end.

[0046] The present invention is not limited to the above-mentioned optional implementation modes. Anyone can derive other forms of products under the inspiration of the present invention. However, no matter what changes are made in the shape or structure, any technical solution that falls within the scope defined by the claims of the present invention falls within the scope of protection of the present invention.

Claims

1. A differential rotary power device, characterized in that: The invention comprises a cross ring (1), and a harmonic reduction motor is arranged on both outer sides of the cross ring (1); the harmonic reduction motor comprises a central shaft (2), a motor stator (3) is connected to the central shaft (2), a motor rotor (4) is sleeved on the motor stator (3), the motor rotor (4) is connected to a harmonic reduction unit (5), an output end of the harmonic reduction unit (5) is fixed to the central shaft (2), a harmonic rigid wheel (6) is meshed with the output end teeth of the harmonic reduction unit (5), the harmonic rigid wheel (6) is rotatably connected to the cross ring (1), a large gear (7) is fixed to the harmonic rigid wheel (6), an outer ring of the end of the cross ring (1) is rotatably connected to a small gear (8), and the small gear (8) is respectively meshed with the large gear (7) on both sides.

2. A differential rotation power device according to claim 1, characterized in that: The harmonic reduction unit (5) includes a cam (51), which is fixed on the motor rotor (4). A flexible bearing (52) is installed on the cam (51). The outer ring of the flexible bearing (52) is provided with a flexible wheel (53). The flexible wheel (53) is engaged with the teeth of the harmonic rigid wheel (6). The number of teeth of the flexible wheel (53) is smaller than the number of teeth of the harmonic rigid wheel (6). An output flange (54) is fixed on the flexible wheel (53). The flexible wheel (53) is fixed to the central shaft (2).

3. A differential rotation power device according to claim 2, characterized in that: The inner side of the cam (51) is connected to the central shaft (2) via a rolling bearing (21).

4. A differential rotation power device according to claim 2, characterized in that: The cam (51) and the flexible bearing (52) are both elliptical in shape, and the flexible wheel (53) is meshed with the harmonic rigid wheel (6) at two positions.

5. The differential rotation power device according to claim 2, characterized in that: The harmonic reduction motor further comprises a cross roller bearing (55), the inner ring of the cross roller bearing (55) is integrally formed with or fixedly connected to the output flange (54), and the outer ring of the cross roller bearing (55) is integrally formed with or fixedly connected to the large gear (7).

6. The differential rotation power device according to claim 1, characterized in that: The central shaft (2) is provided with a wiring hole, and the wiring of the motor stator (3) passes through the wiring hole.

7. The differential rotation power device according to claim 1, characterized in that: A PCB mounting plate (9) is fixed on the central shaft (2).

8. The differential rotation power device according to claim 1, characterized in that: Rotating connectors (11) are provided at two positions on the cross ring (1) spaced 180 degrees apart, and the pinion (8) is connected to the cross ring (1) via one of the rotating connectors (11).

9. The differential rotation power device according to claim 8, characterized in that: An end cap (12) for limiting position is fixed on the rotating connector (11).

10. The differential rotation power device according to claim 8, characterized in that: The rotating connector (11) comprises a protruding connecting column arranged on the cross ring (1), and a ball or a bearing is installed on the connecting column.

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