Hollow robot joint module with adjustable output mode

Abstract

This invention discloses a hollow robotic joint module with adjustable output modes. [Solution] The robot joint module is equipped with an output flange shaft, on which a harmonic reducer, a dual torque motor, a brake, an angle encoder, and a drive controller are mounted in front of the output flange shaft from front to back. The drive controller can switch the output mode by acquiring data from the angle encoder and the dual torque motor in real time and controlling the opening and closing of the brake. The harmonic reducer, dual torque motor, and brake are attached to the output flange shaft by a wave generator, and the output flange shaft and the wave generator are mounted coaxially. By integrating and applying a dual circular spline harmonic reducer, a dual torque motor, a friction brake, and an angle encoder, the present invention ensures structural compactness while realizing two different types of output modes: a low rotational speed / high load mode and a high rotational speed / low load mode, providing an effective solution for applications in various working conditions of robot joints.

Description

[Technical Field]

[0001] The present invention relates to a robot joint module, and more particularly to a hollow robot joint module with adjustable output modes. [Background technology]

[0002] Robot joints are crucial components that enable movement in industrial robots, collaborative robots, and humanoid robots. Currently, in robot joint designs, the power source is generally a servo motor, and the reduction gear is generally a harmonic reducer, with the servo motor driving the reducer to transmit power. As robot application scenarios diversify, the requirements for robot joints demand not only high precision and high load capacity, but also high rotational speed. However, in scenarios requiring high rotational speed, simply increasing the rotational speed of the servo motor significantly increases the volume and cost of the product, as well as shortening the lifespan of the servo motor. While harmonic reducers have advantages such as a compact structure and a large reduction ratio, standard cup-type and hat-type products have a single reduction ratio and, when directly applied, cannot meet the application needs of diverse working conditions. [Overview of the project] [Problems that the invention aims to solve]

[0003] The objective of the present invention is to provide a hollow robot joint module with adjustable output modes, thereby integrating two modes into the robot joint: low rotational speed / high load and high rotational speed / low load. [Means for solving the problem]

[0004] The present invention features an output flange shaft, on which a harmonic reducer, a dual torque motor, a brake, an angle encoder, and a drive controller are mounted in front of the output flange shaft from front to back. The drive controller can acquire data from the angle encoder and the dual torque motor in real time and switch the output mode by controlling the opening and closing of the brake.

[0005] The harmonic reducer, dual torque motor, and brake are mounted on the output flange shaft by a wave generator, and the output flange shaft and wave generator are mounted coaxially.

[0006] The harmonic reducer includes an annular flexspline, a multi-tooth circular spline, and an equal-tooth circular spline, the annular flexspline being mounted outside the wave generator, and the multi-tooth circular spline and the equal-tooth circular spline meshing with the annular flexspline.

[0007] The dual torque motor includes a front motor and a rear motor, the front motor including a front motor stator and a front motor rotor, the front motor stator being mounted inside the front case and the front motor rotor being mounted outside the wave generator.

[0008] The multi-tooth circular spline is bolted to the output flange shaft, and the equal-tooth circular spline is bolted to the front-stage motor rotor, and the front-stage motor drives the equal-tooth circular spline to rotate.

[0009] The aforementioned rear motor includes a rear motor stator and a rear motor rotor. The rear motor stator is mounted inside the rear case, and the rear motor rotor is fixed to the wave generator. The rear motor drives the wave generator to rotate.

[0010] The brake includes a brake rotor and a brake stator, the brake rotor being mounted to a wave generator and the brake stator being mounted to the inner wall of the rear case.

[0011] The angle encoder includes an angle encoder reading head and an angle encoder code disk, the angle encoder reading head being mounted in a rear case and the angle encoder code disk being mounted on an output flange shaft via a transition connecting ring.

[0012] The output modes include low rotational speed / high load and high rotational speed / low load. When the working conditions are low rotational speed / high load, the output mode is such that the drive controller emits a drive signal, the downstream motor rotor rotates, and the upstream motor rotor locks. At this time, the downstream motor rotor drives the wave generator to rotate, causing the annular flexspline to mesh with the multi-tooth circular spline and transmit power, driving the output flange shaft and outputting power. At this time, the transmission ratio i1 is

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Advantages of the Invention

[0013] By integrating and applying the dual circular spline harmonic reducer, dual torque motor, friction brake, and angle encoder, the present invention ensures the compactness of the structure, realizes two different types of output modes, namely, the low rotation speed - high load mode and the high rotation speed - low load mode, and provides an effective solution for the application of robot joints under various working conditions.

Brief Description of the Drawings

[0014] [Figure 1] Figure 1 is an overall structure diagram according to the present invention. [Figure 2] Figure 2 is a structural cross-sectional view according to the present invention. [Figure 3] Figure 3 is a structural diagram of the output flange shaft according to the present invention. [Figure 4] Figure 4 is a structural diagram of the wave generator according to the present invention. [Figure 5] Figure 5 is a structural diagram of the annular flex spline according to the present invention. [Figure 6] Figure 6 is a structural diagram of the multi-tooth circular spline according to the present invention. [Figure 7] Figure 7 is a structural diagram of the equal-tooth circular spline according to the present invention. [Figure 8] Figure 8 is a structural diagram of the rear case according to the present invention.

Modes for Carrying Out the Invention

[0015] The present invention will be further described below with reference to the drawings.

[0016] As shown in Figures 1 to 8, the present invention comprises an output flange shaft 1, on which a harmonic reducer, a dual torque motor, a brake, an angle encoder, and a rear end cover 18 are mounted in front of the output flange shaft 1 in order from front to back. The harmonic reducer, dual torque motor, and brake are attached to the output flange shaft 1 by a wave generator 4, and the output flange shaft 1 and the wave generator 4 are mounted coaxially. The harmonic reducer includes an annular flexspline 2, a multi-tooth circular spline 6, and an equal-tooth circular spline 7. The annular flexspline 2 is mounted to the outside of the wave generator 4 by a flexible bearing 5, the outer ring of the flexible bearing 5 contacts and engages with the inner wall of the annular flexspline 2, the multi-tooth circular spline 6 and the equal-tooth circular spline 7 mesh with the annular flexspline 2, and the multi-tooth circular spline 6 is bolted to the output flange shaft 1. The dual torque motor includes a front motor and a rear motor. The front motor includes a front motor stator 8 and a front motor rotor 9. The rear motor includes a rear motor stator 10 and a rear motor rotor 11. The front motor stator 8 is mounted inside the front case 27 and positioned by a front motor positioning ring 28. The front motor rotor 9 is mounted outside the wave generator 4 by multiple motor deep groove ball bearings 26 and bolted to an equal-tooth circular spline 7. The rear motor stator 10 is mounted inside the rear case 21 and positioned by a rear motor positioning ring 23. The rear motor rotor 11 is fixed to the wave generator 4. The brake is a friction brake and includes a brake rotor 12 and a brake stator 13. The brake rotor 12 is mounted on the wave generator 4 and the brake stator 13 is mounted on the inner wall of the rear case 21. The angle encoder includes an angle encoder reading head 14 and an angle encoder code disk 15, the angle encoder reading head 14 being mounted on the rear case 21 and the angle encoder code disk 15 being mounted on the output flange shaft 1 by a transition connecting ring 16. A drive controller 19 is mounted on the inner wall of the rear end cover 18.

[0017] As shown in Figure 3, the output flange shaft 1 includes a circular flange 1.1, a hollow hole 1.2, an output screw hole 1.3, a hollow shaft 1.4, an angle encoder mounting surface 1.5, an angle encoder screw hole 1.6, and a rear end cover bearing mounting surface 1.7. The circular flange 1.1 is the output end of the output flange shaft 1, and multiple output screw holes 1.3 are arranged in an annular pattern on the circular flange 1.1. The hollow hole 1.2 and hollow shaft 1.4 are used for routing wiring for robot joints. An angle encoder code disk 15 is mounted on the angle encoder mounting surface 1.5, and the angle encoder code disk 15 is fitted into an interlocking fit with the angle encoder mounting surface 1.5 by a transition connecting ring 16 and tightened by the angle encoder screw hole 1.6. When the output flange shaft 1 rotates, the angle encoder code disk 15 rotates in conjunction, and the angle encoder reading head 14 obtains the output accurate angle with an absolute accuracy of 2 arcseconds. The rear end cover 18 is attached to the rear end cover bearing mounting surface 1.7, and the rear end cover 18 is attached to the rear end cover bearing mounting surface 1.7 by the rear end cover bearing 17, and the rear end cover bearing mounting surface 1.7 and the inner ring of the rear end cover bearing 17 form a small clearance fit, thereby ensuring the coaxiality of the rotation of the output flange shaft 1.

[0018] The wave generator 4 employs a stepped shaft structure and, as shown in Figure 4, includes a bearing mating surface 4.1, an outer contour surface 4.2, a motor deep groove ball bearing mounting surface 4.3, a motor rotor mounting surface 4.4, a brake mounting surface 4.5, and a wave generator internal bore 4.6. The bearing mating surface 4.1 is the mounting mating surface for the output end deep groove ball bearing 3, and the wave generator 4 is mounted coaxially with the output flange shaft 1 by the output end deep groove ball bearing 3, and the coaxiality is ensured by the output end deep groove ball bearing 3. The outer contour surface 4.2 is an elliptical contour surface, on which a flexible bearing 5 is mounted and positioned by a flexible bearing snap retainer 29. The annular flexspline 2 is supported in an elliptical shape by the flexible bearing 5, thereby forming a differential gear transmission between the annular flexspline 2, the multi-tooth circular spline 6, and the equal-tooth circular spline 7. Deep groove ball bearings 26 for motors are mounted on the motor mounting surface 4.3, one on each side. The inner and outer rings of the bearings are tightened by bearing inner ring sleeves 24 and bearing outer ring sleeves 25, respectively. The left bearing is positioned by the left shaft flange, and the right bearing is positioned by the motor bearing retaining ring 22. The motor rotor mounting surface 4.4 is the mounting position for the downstream motor rotor 11 and is positioned by the shaft flange on one side. The brake mounting surface 4.5 is used to mount the brake rotor 12. The wave generator 4 is press-fitted into the inner wall of the brake rotor 12, and the brake snap retainer 20 is mounted in the locking groove of the brake mounting surface 4.5 to position the brake rotor 12 axially. The minimum clearance between the wave generator inner hole 4.6 and the outer surface of the hollow shaft 1.4 is 10 mm.

[0019] As shown in Figure 5, the annular flexspline 2 includes a flexspline external gear 2.1 and a flexspline inner wall 2.2. The flexspline inner wall 2.2 fits onto the outer ring of the flexible bearing 5 and undergoes elastic deformation due to the action of its elliptical outer contour surface, thereby causing the flexspline external gear 2.1 to form a differential gear drive with the multi-tooth circular spline 6 and the equal-tooth circular spline 7.

[0020] As shown in Figure 6, the multi-tooth circular spline 6 includes a multi-tooth circular spline screw hole 6.1, a multi-tooth circular spline end face 6.2, and a multi-tooth circular spline internal gear 6.3. The multi-tooth circular spline 6 is bolted to the inner end face of the circular flange 1.1 via the multi-tooth circular spline screw hole 6.1. The multi-tooth circular spline end face 6.2 is perpendicular to the axis of the hollow shaft 1.4. The number of teeth of the multi-tooth circular spline 6 is greater than the number of teeth of the annular flexspline 2, and in this embodiment the difference in the number of teeth is 2. When the wave generator 4 is used as input and the equal-tooth circular spline 7 is fixed, the multi-tooth circular spline internal gear 6.3 and the flexspline external gear 2.1 form a meshing transmission with a small difference in the number of teeth.

[0021] As shown in Figure 7, the equitooth circular spline 7 includes an equitooth circular spline screw hole 7.1, an equitooth circular spline end face 7.2, and an equitooth circular spline internal gear 7.3. The equitooth circular spline 7 is bolted to the pre-motor rotor 9 by the equitooth circular spline screw hole 7.1. The equitooth circular spline end face 7.2 is perpendicular to the axis of the hollow shaft 1.4. The number of teeth of the equitooth circular spline 7 is equal to the number of teeth of the annular flexspline 2, and the pitch circle diameters of the equitooth circular spline 7, the multi-tooth circular spline 6, and the annular flexspline 2 are equal to each other. When the wave generator 4 is fixed and does not move, and the pre-motor rotor 9 is used as input, the equitooth circular spline internal gear 7.3 rotates the multi-tooth circular spline 6 via the annular flexspline 2.

[0022] As shown in FIG. 8, the rear case 21 includes a rear case end face 21.1 and case screw holes 21.2. The rear case end face 21.1 and the front case 27 are fixedly connected by bolts. On the inner wall of the rear case 21, there are mounting surfaces and screw holes for fixing the rear-stage motor stator 10, the brake stator 13, and the angle encoder reading head 14, respectively. On the outer peripheral surface of the rear case 21, a plurality of case screw holes 21.2 for connecting to the robot body are uniformly arranged.

[0023] The drive controller 19 can acquire the angle data of the angle encoder reading head 14, the current data of the front-stage motor and the rear-stage motor in real time, and can control the opening and closing of the brake. The drive controller 19 can freely switch to output mode 1 or output mode 2 based on the acquired data information and working conditions.

[0024] When the working condition is low rotational speed and high load, in output mode 1, the drive controller 19 fixed to the rear end cover 18 transmits a drive signal, the rear-stage motor rotor 11 rotates, and the front-stage motor rotor 9 is locked. At this time, the rear-stage motor rotor 11 drives the wave generator 4 to rotate, whereby the annular flex spline 2 meshes with the multi-tooth circular spline 6 to transmit power, driving the output flange shaft 1 to output power. The transmission ratio i1 in output mode 1 is

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[0025] The rated output torque T out1 in output mode 1 is

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[0026] When the working conditions are high rotational speed and low load, output mode 2 is when the drive controller 19 sends a drive signal, the front motor rotor 9 rotates, and the rear motor rotor 11 is locked. At this time, the front motor rotor 9 drives the equal-tooth circular spline 7 to rotate, the equal-tooth circular spline 7 rotates the multi-tooth circular spline 6 via the annular flex spline 2, and subsequently drives the output flange shaft 1 to output power. The transmission ratio i2 in output mode 2 is,

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[0027] Rated output torque T in output mode 2 out2 teeth,

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[0028] Furthermore, the effects of the present invention will be explained by application examples, and the number of teeth in an equitooth circular spline is N D = 100, and the number of teeth in a multi-tooth circular spline is N S = 102, the rated input torque of the front and rear motors is T1=T2=0.1Nm, and the rated input rotational speed of both the front and rear motors is 3000r / min. The transmission ratio in output mode 1 is

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Claims

1. A hollow robot joint module with adjustable output modes, The output flange shaft has a hollow shaft at its center, and a harmonic reducer, a dual torque motor, a friction brake, an angle encoder, and a drive controller are mounted coaxially on the output flange shaft in the order from front to back. The harmonic reducer includes an annular flexspline, a multi-tooth circular spline, and an equal-tooth circular spline, the multi-tooth circular spline being connected to the flange portion of the output flange shaft, The dual torque motor includes a front motor and a rear motor, the front motor rotor of the front motor is connected to the same-tooth circular spline and mounted via a bearing to the outside of a wave generator located inside the annular flex spline, and the rear motor rotor of the rear motor is fixed to the wave generator. The friction brake includes a brake rotor attached to the wave generator and a brake stator attached to the inner wall of the rear case. The aforementioned drive controller When working conditions are low rotational speed and high load, the first output mode is achieved by fixing and holding the front motor rotor with an electrical servo lock, and rotating the rear motor rotor to drive the wave generator, thereby outputting power from the output flange shaft via the meshing of the annular flex spline and the multi-tooth circular spline. A hollow robot joint module with an adjustable output mode, characterized in that, when working conditions are high rotational speed and low load, the downstream motor rotor is fixed and held by an electrical servo lock to fix the wave generator, and the upstream motor rotor is rotated to drive the equal-tooth circular spline, thereby rotating the multi-tooth circular spline via the annular flex spline and controlling it to output power from the output flange shaft in a second output mode.

2. The hollow robot joint module with adjustable output modes according to claim 1, wherein the angle encoder includes an angle encoder reading head and an angle encoder code disk, the angle encoder reading head is mounted on a rear case, and the angle encoder code disk is mounted on an output flange shaft by a transition connecting ring.

3. If the number of teeth of the equal-tooth circular spline is N D and the rated input torque of the downstream motor is T 1, The transmission ratio i1 in the first output mode is [Math 12] The rated output torque T out1 is, [Number 13] If the number of teeth of the multi-tooth circular spline is N / S and the rated input torque of the preceding motor is T / 2, The transmission ratio i2 in the second output mode is [Number 14] (However, N S = N D + 2) The rated output torque T out2 is, [Number 15] A hollow robot joint module with adjustable output modes as described in claim 1.

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