A dual-stator driving large-torque robot joint

Abstract

The application relates to a double-stator driving large-torque robot joint, which comprises a double-stator driving module and a cycloidal speed reducer module; the double-stator driving module comprises a joint shell, a permanent magnet array one, a permanent magnet array two, a permanent magnet array three, a radial core, a radial coil, an end core, an end coil, an input shaft, a joint cover, a wiring tube and a bearing one; and the cycloidal speed reducer module comprises a crank shaft, a bearing steel sleeve, a cylindrical pin, a cycloidal tooth one, a cycloidal tooth two, an inner ring gear, a back baffle, a cylindrical roller and a bearing two. The double-stator driving large-torque robot joint adopts a layout mode of radial nesting of a motor and a speed reducer, simultaneously realizes electrical connection integration in the structure, increases driving torque and output torque through circumferential and end double stators, simultaneously can reduce torque fluctuation, widens a joint rotating speed range, and improves internal space utilization.

Description

Technical Field

[0001] This invention relates to the field of robotics, and in particular to a dual-stator driven high-torque robot joint. Background Technology

[0002] Modular joints, as core components of the robotics industry, have wide applications in industrial production and biomimetic robots. A modular joint mainly consists of a brushless DC motor, a high-precision reducer, an angle encoder, and a motor driver, forming a highly integrated mechanical structure.

[0003] Traditional modular joints typically employ a series layout of a brushless DC motor, a reducer, and a driver. Brushless DC motors can be categorized into two types based on the direction of their magnetic flux: the first is a radial flux motor, where the flux lines are perpendicular to the axis of rotation; the second is an axial flux motor, also called a disc motor, where the flux lines are parallel to the axis of rotation. Most common brushless DC motors are radial brushless DC motors. Reducers can be further classified into planetary gear reducers and cycloidal pinwheel reducers, among others.

[0004] Radial flux motors have advantages such as small size, low noise, high speed, high power density, and good heat dissipation, but their motor power is lower than that of axial motors. While axial motors have higher power and larger torque, their flat shape and large radial dimension result in a large moment of inertia, and their maximum speed is not as high as that of radial motors.

[0005] Common speed reducers include planetary gear reducers and cycloidal pinwheel reducers. While planetary gear reducers have advantages such as high transmission efficiency and high precision, they have fewer contact teeth, lower torque density, complex structure, and are difficult to manufacture and install. In contrast, cycloidal pinwheel reducers have advantages such as more contact teeth and higher torque density compared to planetary gear reducers.

[0006] Traditional integrated joints typically employ either a radial brushless DC motor + planetary gear reducer + driver or a radial brushless DC motor + cycloidal pinwheel reducer + driver layout. For the former, due to the low torque density of the planetary gear reducer, achieving higher torque necessitates a larger overall joint size. For the latter, while torque density is high, motor power becomes a bottleneck. Furthermore, in traditional layouts, electrical components such as the joint angle encoder are mostly exposed, resulting in a complex structure and poor integration. Summary of the Invention

[0007] Therefore, the technical problem to be solved by the present invention is to overcome the unreasonable structural design of the existing integrated joints, which have problems such as large size or complex structure.

[0008] To solve the above-mentioned technical problems, the present invention provides a dual-stator driven high-torque robot joint, comprising: a dual-stator drive module and a cycloidal pinwheel reducer module, wherein the dual-stator drive module and the cycloidal pinwheel reducer module are assembled together to form a robot joint; the dual-stator drive module includes a joint shell, a first permanent magnet array, a second permanent magnet array, a third permanent magnet array, a radial iron core, a radial coil, an end iron core, an end coil, an input shaft, a joint cover, a wiring tube, and a bearing. The joint shell is cylindrical, the joint cover is disposed at one end along the axial direction of the joint shell, the input shaft is disposed inside the joint shell and is coaxial with the joint shell, one end of the wiring tube is connected to the joint shell and passes through the input shaft, the wiring tube is located at the center line of the input shaft, the radial iron core is disposed on the inner wall of the joint shell, the radial coil is disposed on the radial iron core, the first permanent magnet array is disposed on the outer circumferential wall at one end of the input shaft, and the magnetization direction of the first permanent magnet array is radial. The second permanent magnet array and the third permanent magnet array are both located on the radial end face of the input shaft, and the magnetization directions of both permanent magnet arrays are axial. The circumference of the second permanent magnet array is located outside the circumference of the third permanent magnet array. The end iron core is connected to the radial end face of the joint housing. The end coil is sleeved on the end iron core. The bearing is sleeved on the input shaft, and the input shaft is connected to the joint housing through the bearing. The cycloidal pinwheel reducer module includes a crankshaft, a bearing steel sleeve, a cylindrical pin, and a cycloidal gear. The invention comprises a cycloidal gear, an internal gear ring, a rear baffle, cylindrical rollers, and a second bearing. One end of the crankshaft is inserted into the input shaft, and the second bearing is located at one end of the crankshaft along its axial direction. Both cycloidal gears are connected to the crankshaft, and the crankshaft drives cycloidal gears to perform circular motion. The rear baffle is connected to the crankshaft via the second bearing. The bearing sleeve is fitted onto a cylindrical pin, which passes through both cycloidal gears. The internal gear ring is connected to cycloidal gears one and two via cylindrical rollers. This invention's dual-stator driven high-torque robot joint employs a radially nested layout of the motor and reducer, integrating electrical connections within the structure. It utilizes a hollow wiring method, with the integrated drive board housed within the joint shell, increasing wiring organization and reliability while reducing axial space and avoiding the risk of wiring being dragged and broken. A dual-stator driven high-torque robot joint is proposed. By using circumferential and end-effector dual stators, the driving torque and output torque are increased, while torque fluctuations are reduced, the joint rotational speed range is widened, and the internal space utilization is improved. This design is geared towards high-dynamic legged robots, meeting their requirements of high torque, high impact, and high speed.

[0009] In one embodiment of the present invention, a drive circuit board is provided on the joint housing.

[0010] In one embodiment of the present invention, a sensor is provided on the joint housing.

[0011] In one embodiment of the present invention, a bearing third is provided at the end of the crankshaft that is away from the bearing second in the axial direction.

[0012] In one embodiment of the present invention, an output disk is connected to the outer ring of the bearing three, and the output disk is connected to a cylindrical pin by screws.

[0013] In one embodiment of the present invention, a crossed roller bearing is provided on the outer circumference of the output disk.

[0014] In one embodiment of the present invention, the robot joint further includes an outer end cap, which is disposed at the end of the joint housing away from the joint cover, and the outer end cap is connected to the output disk via a cross roller bearing.

[0015] In one embodiment of the present invention, a sealing ring is provided at the gap between the outer end cap of the joint and the output disk.

[0016] In one embodiment of the present invention, a gap is provided between the crankshaft and the cable conduit.

[0017] In one embodiment of the present invention, the sensor is used to detect the rotation angle information of the permanent magnet array three.

[0018] The technical solution of the present invention has the following advantages compared with the prior art:

[0019] 1. The front middle part of the joint is a cycloidal pinwheel reducer, and the radial outer ring and rear end are the input shafts. Three sets of permanent magnet arrays are arranged on the input shafts for driving the joint and angle detection.

[0020] 2. Two sets of stator coils are provided on the outer periphery and rear end of the joint, which can be independently controlled to generate electromagnetic driving force;

[0021] 3. Permanent magnet arrays are provided on both the circumference and rear end face of the joint input shaft. The circumferential permanent magnet array of the joint input shaft is radially magnetized, generating an electromagnetic coupling force with the stator coil on the outer circumference of the joint to drive the crankshaft rotation. The rear end of the joint input shaft has two rings of permanent magnet arrays that are axially magnetized. One ring generates an electromagnetic coupling force with the stator coil on the rear end face of the joint to drive the crankshaft, while the other ring is used to detect the angle information of the input shaft, serving as position feedback for the actuator. The three sets of permanent magnet arrays have a defined phase relationship. Attached Figure Description

[0022] To make the content of this invention easier to understand, the invention will be further described in detail below with reference to specific embodiments and accompanying drawings, wherein...

[0023] Figure 1This is a cross-sectional view of the dual-stator driven high-torque robot joint of the present invention;

[0024] Figure 2 This is a cross-sectional view of the dual-stator drive module of the present invention;

[0025] Figure 3 This is a cross-sectional view of the cycloidal pinwheel reducer module of the present invention.

[0026] Explanation of reference numerals in the accompanying drawings: Dual stator drive module 100, joint housing 101, permanent magnet array one 102, permanent magnet array two 103, permanent magnet array three 104, radial iron core 105, radial coil 106, end iron core 107, end coil 108, input shaft 109, joint cover 110, cable tray 111, bearing one 112, drive circuit board 113, sensor 114, cycloidal pinwheel reducer module 200, crankshaft 201, bearing sleeve 202, cylindrical pin 203, cycloidal gear one 204, cycloidal gear two 205, internal gear ring 206, rear baffle 207, cylindrical roller 208, bearing two 209, bearing three 210, output disc 211, crossed roller bearing 212, joint outer end cover 213, sealing ring 214. Detailed Implementation

[0027] The present invention will be further described below with reference to the accompanying drawings and specific embodiments, so that those skilled in the art can better understand and implement the present invention. However, the embodiments described are not intended to limit the present invention.

[0028] Reference Figure 1 As shown, the dual-stator driven high-torque robot joint of the present invention includes: a dual-stator drive module 100 and a cycloidal pinwheel reducer module 200, wherein the dual-stator drive module 100 and the cycloidal pinwheel reducer module 200 are assembled together to form a robot joint.

[0029] Reference Figure 2As shown, the dual-stator drive module 100 includes a joint housing 101, a permanent magnet array one 102, a permanent magnet array two 103, a permanent magnet array three 104, a radial iron core 105, a radial coil 106, an end iron core 107, an end coil 108, an input shaft 109, a joint cover 110, a wiring tube 111, and a bearing one 112. The joint housing 101 is cylindrical. The joint cover 110 is located at one end of the joint housing 101 along its axial direction. The input shaft 109 is located inside the joint housing 101 and is coaxial with the joint housing 101. One end of the wiring tube 111 is connected to the joint housing 101 and passes through the input shaft 109. The wiring tube 111 is located at the center line of the input shaft 109. The radial iron core 105... The radial coil 106 is disposed on the radial iron core 105 and the permanent magnet array 102 is disposed on the outer circumference of one end of the input shaft, with the magnetization direction of the permanent magnet array 102 being radial. The permanent magnet arrays 103 and 104 are disposed on the radial end face of the input shaft, with the magnetization directions of the permanent magnet arrays 103 and 104 being axial. The circumference of the permanent magnet array 103 is located outside the circumference of the permanent magnet array 104. The end iron core 107 is connected to the radial end face of the joint housing 101, and the end coil 108 is sleeved on the end iron core 107. The bearing 112 is sleeved on the input shaft 109, and the input shaft 109 is connected to the joint housing 101 through the bearing 112. The joint housing 101 is provided with a drive circuit board 113 and a sensor 114.

[0030] The structure of the dual-stator drive module 100 is as follows: the radial core 105, radial coil 106, end core 107, end coil 108, wiring tube 111, sensor 114, and drive circuit board 113 are all fixed to the joint housing 101 by screws or adhesive. The wiring tube 111 has a certain gap with the crankshaft in the cycloidal pinwheel reducer module 200 to prevent wear and damage to the wiring caused by the rotation of the crankshaft during hollow wiring. Three permanent magnet arrays (permanent magnet array one 102, permanent magnet array two 103, and permanent magnet array three 104) are fixed to the input shaft 109, which can rotate directly with the bearing housing via the bearing. A joint cover 110 is located at the joint end to protect important electronic components.

[0031] The working principle of the drive module is as follows: When current flows through the radial coil 106 and the end coil 108, a magnetic field is generated, which drives the permanent magnet array one 102 and the permanent magnet array two 103 to move, thereby driving the input shaft 109 to rotate and generating torque. The permanent magnet array three 104 is used to generate joint rotation angle information, which is detected by the sensor and used for joint control feedback.

[0032] Reference Figure 3 As shown, the cycloidal pinwheel reducer module 200 includes a crankshaft 201, a bearing sleeve 202, a cylindrical pin 203, a first cycloidal gear 204, a second cycloidal gear 205, an internal gear ring 206, a rear baffle 207, a cylindrical roller 208, and a second bearing 209. One end of the crankshaft 201 is inserted into the input shaft 109, and the second bearing 209 is provided at one end of the crankshaft 201 along its axial direction. Both the first cycloidal gear 204 and the second cycloidal gear 205... The crankshaft 201 is connected to the crankshaft 201, which drives cycloidal gear 204 and cycloidal gear 205 in circular motion. The rear baffle 207 is connected to the crankshaft 201 via bearing 209. The bearing sleeve 202 is fitted onto the cylindrical pin 203, which passes through cycloidal gear 204 and cycloidal gear 205. The internal gear ring 206 is connected to cycloidal gear 204 and cycloidal gear 205 via cylindrical rollers 208. A bearing 210 is provided at the end of the crankshaft 201 away from bearing 209 along its axial direction. An output disc 211 is connected to the outer ring of bearing 210, and the output disc 211 is connected to the cylindrical pin 203 by screws. A crossed roller bearing 212 is provided on the outer circumference of the output disc 211. The robot joint also includes an outer end cap 213, which is located at the end of the joint housing 101 away from the joint cover 110, and is connected to the output disk 211 via a crossed roller bearing 212. A sealing ring 214 is provided at the gap between the outer end cap 213 and the output disk 211.

[0033] The structural principle of the cycloidal pinwheel reducer module 200 is as follows: Due to its eccentric structure, the crankshaft 201 can drive the cycloidal gear 1 204 and cycloidal gear 205 to produce circumferential motion. The two cycloidal gears 1 204 and cycloidal gear 205 are symmetrically distributed (so that the crankshaft is evenly stressed) and perform staggered circumferential rotation. The internal gear ring 206 meshes with the cylindrical roller 208. The internal gear ring 206 is fixed to the rear baffle 207 and the outer end cover 213 of the joint by screws, thereby driving the bearing steel sleeve 202 and the cylindrical pin 203 to rotate. Since the output disc 211 is fixed to the cylindrical pin 203 by screws, the torque is finally output by the output disc 211.

[0034] In the above structure, a gap is provided between the crankshaft 201 and the cable conduit 111.

[0035] In the above structure, the sensor 114 is used to detect the rotation angle information of the permanent magnet array 104. The magnetic ring encoder 114 for detecting the rotation angle of the input shaft can be replaced by a grating sensor or a magnetic rotary encoder.

[0036] The reducer uses a cycloidal pinwheel reducer, which has more contact teeth and higher torque density than a planetary gear reducer. The drive section uses a dual-stator drive scheme, which takes advantage of both radial and axial motors. Compared to a single radial or axial motor scheme, it can output higher motor power at higher speeds and make full use of the internal space of the joint. The entire joint adopts an integrated structure layout, integrating the angle encoder and motor driver into the joint. Important components are protected by a shell. It also uses a magnetic ring type angle encoder. The hollow design of the joint facilitates wiring and results in a neat appearance.

[0037] By setting different pole pair numbers and phase differences for the two permanent magnet arrays on the rotor, the output torque can be improved in some aspects. For example, when the number of pole pairs and the phase difference of the two permanent magnet arrays are the same, the output torque range can be widened; when the number of pole pairs of the two permanent magnet arrays are equal and the phase difference is pi / 2, the output torque can be increased and the torque fluctuation can be reduced; when the number of pole pairs and the phase difference of the two permanent magnet arrays are different, they can be output together or act as impedances to each other, forming a CPG network in conjunction with the circuit.

[0038] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A dual-stator driven high-torque robot joint, characterized in that, include: A dual-stator drive module and a cycloidal pinwheel reducer module are assembled together to form a robot joint; The dual-stator drive module includes a joint housing, permanent magnet array one, permanent magnet array two, permanent magnet array three, radial iron core, radial coil, end iron core, end coil, input shaft, joint cover, wiring conduit, and bearing one. The joint housing is cylindrical, and the joint cover is located at one end along the axis of the joint housing. The input shaft is located inside the joint housing and is coaxial with the joint housing. One end of the wiring conduit is connected to the joint housing and passes through the input shaft. The wiring conduit is located at the center line of the input shaft. The radial iron core is located on the inner wall of the joint housing. The radial coil is disposed on the radial iron core. The first permanent magnet array is disposed on the outer circumferential wall of one end of the input shaft, and the magnetization direction of the first permanent magnet array is radial. The second and third permanent magnet arrays are disposed on the radial end face of the input shaft, and the magnetization directions of the second and third permanent magnet arrays are axial. The circumference of the second permanent magnet array is located outside the circumference of the third permanent magnet array. The end iron core is connected to the radial end face of the joint housing. The end coil is sleeved on the end iron core. The bearing is sleeved on the input shaft, and the input shaft is connected to the joint housing through the first bearing. The cycloidal pinwheel reducer module includes a crankshaft, a bearing sleeve, a cylindrical pin, cycloidal gear one, cycloidal gear two, an internal gear ring, a rear baffle, cylindrical rollers, and bearing two. One end of the crankshaft is inserted into the input shaft, and bearing two is provided at one end of the crankshaft along the axial direction. Cycloidal gear one and cycloidal gear two are both connected to the crankshaft, and the crankshaft drives cycloidal gear one and cycloidal gear two to perform circumferential motion. The rear baffle is connected to the crankshaft through bearing two. The bearing sleeve is fitted on the cylindrical pin, and the cylindrical pin passes through cycloidal gear one and cycloidal gear two. The internal gear ring is connected to cycloidal gear one and cycloidal gear two through cylindrical rollers.

2. The dual-stator driven high-torque robot joint according to claim 1, characterized in that: The joint housing is equipped with a drive circuit board.

3. The dual-stator driven high-torque robot joint according to claim 1 or 2, characterized in that: The joint housing is equipped with sensors.

4. The dual-stator driven high-torque robot joint according to claim 1, characterized in that: Bearing 3 is provided at the end of the crankshaft away from bearing 2 along the axis direction.

5. The dual-stator driven high-torque robot joint according to claim 4, characterized in that: An output disc is connected to the outer ring of the bearing three, and the output disc is connected to a cylindrical pin by screws.

6. The dual-stator driven high-torque robot joint according to claim 5, characterized in that: The output disc is equipped with crossed roller bearings on its outer circumference.

7. The dual-stator driven high-torque robot joint according to claim 6, characterized in that: The robot joint also includes an outer end cap, which is disposed at the end of the joint housing away from the joint cover, and the outer end cap is connected to the output disk via a cross roller bearing.

8. The dual-stator driven high-torque robot joint according to claim 7, characterized in that: A sealing ring is provided at the gap between the outer end cap of the joint and the output plate.

9. The dual-stator driven high-torque robot joint according to claim 1, characterized in that: A gap is provided between the crankshaft and the cable conduit.

10. The dual-stator driven high-torque robot joint according to claim 3, characterized in that: The sensor is used to detect the rotation angle information of the permanent magnet array three.

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