A three-degree-of-freedom spherical joint motor module with integrated reducer

Abstract

The present invention proposes a three-degree-of-freedom spherical joint motor module with an integrated reducer, which belongs to the field of motors and includes a sphere, two sets of outer rotor permanent magnet DC brushless motor modules with integrated single-stage reducers for driving rotation around the X / Y axis, a third axial flux permanent magnet DC brushless motor module with integrated two-stage planetary reducer for driving the sphere and the two sets of outer rotor permanent magnet DC brushless motor modules with integrated single-stage reducers for overall rotation around the Z axis, the two sets of outer rotor permanent magnet DC brushless motor modules being located on the outer surface of the sphere and arranged at 90 degrees in space. The ball joint motor of the present invention enables the two sets of outer rotor permanent magnet DC brushless motor modules to rotate around their respective rotation axes within a certain angle range, significantly expanding the range of motion of the sphere and improving the output torque capacity of the sphere, and has the advantages of compact structure and high space utilization.

Description

Technical Field

[0001] The present invention belongs to the field of motors, and in particular relates to a three-degree-of-freedom spherical joint motor module with an integrated reducer. Background Art

[0002] The shoulder and hip joints of humanoid robots utilize three independent joint motors to form a three-degree-of-freedom joint motor system. While this system can achieve high torque transmission, it suffers from drawbacks such as low integration and large space requirements. As a branch of three-degree-of-freedom systems, spherical joint motor systems with integrated three-degree-of-freedom (DOF) rotations integrate three motors within a sphere or shell to achieve three-rotational coordinate motion. These systems have become a research hotspot in recent years, with applications in areas such as vector lighting, radar seekers, neck joints, and shoulder / hip joints.

[0003] The application with publication number CN115042224A, and invention name "A multi-degree-of-freedom spherical electric joint", discloses a multi-degree-of-freedom spherical electric joint. The working principle is that a connecting shaft is designed on the inner side of the third rotor located in the ball frame, and the output shaft passes through the cross connection of the first rotor and the second rotor. The output shaft is connected to the connecting shaft through a universal joint, which realizes the decoupling of the three-degree-of-freedom motion of the joint, simple control, and improved output torque. The characteristic is that the third rotor only drives the rotation of its own shaft, and is independent of the first rotor and the second rotor. The disadvantage of this application is that the weight of the first motor, the second motor and the third motor in the sphere lacks effective bearing support, and the stator and rotor of each motor lack effective axial positioning and alignment. It is a direct drive mode, no reducer is configured, and the output torque is very small.

[0004] Application Publication No. CN115229839A, entitled "A Three-Degree-of-Freedom Spherical Joint Structure," discloses a three-degree-of-freedom spherical joint structure composed of three joint motors placed within a spherical shell, independently controlling rotation about each axis. Features include a simple structure, compact size, high output torque, easy installation and maintenance, and a wide range of three-degree-of-freedom motion. However, this application suffers from a significant lack of effective utilization of the internal space within the sphere, resulting in a relatively large sphere footprint. Summary of the Invention

[0005] In order to solve the above technical problems, the present invention provides a three-degree-of-freedom spherical joint motor module with an integrated reducer. In order to achieve the above purpose, the technical solution adopted by the present invention is as follows:

[0006] A three-degree-of-freedom spherical joint motor module with an integrated reducer comprises: a sphere, a first outer rotor permanent magnet brushless DC motor module, a second outer rotor permanent magnet brushless DC motor module, a third axial magnetic flux permanent magnet brushless DC motor module, and a first base assembly; wherein the first outer rotor permanent magnet brushless DC motor module is integrated with a first single-stage reducer, the second outer rotor permanent magnet brushless DC motor module is integrated with a second single-stage reducer, and the third axial magnetic flux permanent magnet brushless DC motor module is integrated with a two-stage planetary reducer;

[0007] Among them, the first outer rotor permanent magnet DC brushless motor module and the second outer rotor permanent magnet DC brushless motor module are located on the outer surface of the sphere and are arranged at 90 degrees in space. The first outer rotor permanent magnet DC brushless motor module, the second outer rotor permanent magnet DC brushless motor module and the sphere are placed in the first base assembly. The first outer rotor permanent magnet DC brushless motor module is used to realize the rotation of the sphere around the Y axis; the second outer rotor permanent magnet DC brushless motor module is used to realize the rotation of the sphere around the X axis; the third axial magnetic flux permanent magnet DC brushless motor module drives the first outer rotor permanent magnet DC brushless motor module, the second outer rotor permanent magnet DC brushless motor module, the sphere and the first base assembly to rotate around the Z axis as a whole.

[0008] The present invention has the following beneficial effects:

[0009] The ball joint motor of the present invention enables the outer rotor permanent magnet DC brushless motor module of the first integrated single-stage reducer and the outer rotor permanent magnet DC brushless motor module of the second integrated single-stage reducer to rotate around their respective rotation axes within a certain angle range (±40°), significantly expanding the range of movement of the sphere and improving the output torque capacity of the sphere, and has the advantages of compact structure and high space utilization. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 This is an axonometric view of a three-degree-of-freedom spherical joint motor module with an integrated reducer according to the present invention;

[0011] Figure 2 This is a cross-sectional view of a three-degree-of-freedom spherical joint motor module with an integrated reducer according to the present invention;

[0012] Figure 3 A top view of a three-degree-of-freedom spherical joint motor module with an integrated reducer according to the present invention;

[0013] Figure 4 This is the first structural diagram of the wrapped sphere of the two permanent magnet DC brushless motors of the integrated reducer of the present invention;

[0014] Figure 5 This is the second structural diagram of the wrapped sphere of the two permanent magnet DC brushless motors of the integrated reducer of the present invention;

[0015] Figure 6This is a first exploded view of the spherical joint motor module of the present invention;

[0016] Figure 7 This is a second exploded view of the spherical joint motor module of the present invention;

[0017] Figure 8 This is the structural diagram of the outer rotor permanent magnet DC brushless motor with pinion;

[0018] Figure 9 This is the structural diagram of the two-stage planetary reducer;

[0019] Figure 10 This is a cross-sectional view of an axial flux permanent magnet brushless DC motor module;

[0020] Figure 11 This is a diagram showing the internal structure of a completely sunken sphere of the axial flux permanent magnet brushless DC motor of the present invention;

[0021] Figure 12 This is a diagram showing the internal structure of a partially sunken sphere of the axial flux permanent magnet brushless DC motor of the present invention.

[0022] Wherein: 1 is a sphere, 1a is the first arcuate groove, 1b is the second arcuate groove, 1c is the third arcuate groove, and 1d is the fourth arcuate groove.

[0023] 100 is the first outer rotor permanent magnet DC brushless motor module, 101 is the first guide wheel, 102 is the first pin shaft, 103 is the first guide rail, 104 is the first large gear, 110 is the first outer rotor permanent magnet DC brushless motor, 105 is the first housing, 105a is the first boss wheel shaft, 105b is the first lead hole, 111 is the first rotor, 111a is the first rotor back iron, 111b is the first magnetic steel, 112 is the first stator, 112a is the first stator winding, 112b is the first main shaft, 112c is the first stator core, and 113 is the first pinion.

[0024] 200 is the second outer rotor permanent magnet DC brushless motor module, 201 is the second guide wheel, 202 is the second pin shaft, 203 is the second guide rail, 204 is the second large gear, 210 is the second outer rotor permanent magnet DC brushless motor, 205 is the second housing, 205a is the second boss wheel axle, 205b is the second lead hole, 211 is the second rotor, 211a is the second rotor back iron, 211b is the second magnetic steel, 212 is the second stator, 212a is the second stator winding, 212b is the second main shaft, 212c is the second stator core, and 213 is the second small gear.

[0025] 300 is the first base assembly, 301 is the first base, 301a is the first ear plate, 301b is the second wire outlet hole, and 302 is the first bearing.

[0026] 400 is a two-stage planetary reducer, 401 is a first-stage planetary reducer, 401a is the first ring gear, 401b is the first sun gear, 401c is the first planet gear, and 401d is the first planet carrier; 402 is a second-stage planetary reducer, 402a is the second ring gear, 402b is the second sun gear, 402c is the second planet gear, 402d is the second planet carrier, 403 is the third casing, 404 is the first flange, and 405 is the second flange.

[0027] 500 is an axial flux permanent magnet brushless DC motor, 510 is a third stator, 501 is a third stator winding, 502 is a third stator core, 520 is a third rotor, 503 is a third main shaft, 504 is a third magnetic steel, 505 is a rotor bracket, 506 is a second base, and 506a is a second ear plate.

[0028] 600 is the third axial flux permanent magnet DC brushless motor module. DETAILED DESCRIPTION

[0029] In order to make the objectives, technical solutions, and advantages of the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and examples. It should be understood that the specific examples described herein are merely illustrative of the present invention and are not intended to limit the present invention. In addition, the technical features involved in the various embodiments of the present invention described below may be combined with each other as long as they do not conflict with each other.

[0030] The present invention will be described in detail below with reference to the accompanying drawings.

[0031] In application scenarios with space constraints, high output torque, and requirements for XYZ three-axis rotational freedom, existing multi-motor systems can meet torque, freedom and other indicators, but the cost is often large and bulky. The purpose of the present invention is to develop a highly integrated spherical joint multi-motor system with high output torque and three rotational degrees of freedom.

[0032] like Figure 1 、 Figure 2 、 Figure 3As shown, a three-degree-of-freedom spherical joint motor module with integrated reducer includes: a sphere 1, a first outer rotor permanent magnet brushless DC motor module 100, a second outer rotor permanent magnet brushless DC motor module 200, a first base assembly 300, a two-stage planetary reducer 400, and an axial flux permanent magnet brushless DC motor 500, which together achieve three degrees of freedom rotation about the X, Y, and Z axes. Specifically, the first outer rotor permanent magnet brushless DC motor module 100 integrates a first single-stage reducer, the second outer rotor permanent magnet brushless DC motor module 200 integrates a second single-stage reducer, and the third axial flux permanent magnet brushless DC motor module 600 integrates the axial flux permanent magnet brushless DC motor 500 and the two-stage planetary reducer 400. The first permanent magnet brushless DC motor module 100 and the second outer rotor permanent magnet brushless DC motor module 200 surround the sphere 1, which is designed as a hollow sphere with a flange on the top.

[0033] The spherical shape of the sphere 1 itself serves as a support. A first arcuate groove 1a is machined on the outer surface of the sphere 1, and the second large gear 204 is mounted using screws. A second arcuate groove 1b is machined on the outer surface of the sphere 1, and the first large gear 104 is mounted using screws. A third arcuate groove 1c is machined on the outer surface of the sphere 1 for mounting the second guide rail 203; a fourth arcuate groove 1d is machined for mounting the first guide rail 103. The first and second guide rails 103 and 203 are then secured to the sphere 1 using screws. A third arcuate groove 1c is arranged on each side of the first arcuate groove 1a; a fourth arcuate groove 1d is arranged on each side of the second arcuate groove 1b. The plane of the first arcuate groove 1a is perpendicular to the plane of the second arcuate groove 1b in space.

[0034] like Figure 4 、 Figure 5 The first single-stage reducer includes a first large gear 104 and first small gears 113. Four first small gears 113 are arranged along the circumference of sphere 1. Each first small gear 113 is independently driven by a first outer rotor permanent magnet brushless DC motor 110. The four first small gears 113 simultaneously generate torque, meshing with the first large gear 104 to form the first stage of reduction, achieving a torque-increasing effect similar to a two-stage planetary reducer. The first large gear 104 is fixed to sphere 1 with screws, driving sphere 1 to rotate about the Y-axis.

[0035] Similarly, the second single-stage reducer comprises a second large gear 204 and second small gears 213. Four second small gears 213 are positioned along the circumference of sphere 1. Each second small gear 213 is independently driven by the second outer rotor permanent magnet brushless DC motor 210. The four second small gears 213 simultaneously generate torque, meshing with the second large gear 204 to form the first stage of reduction, achieving a torque-amplifying effect similar to that of a two-stage planetary reducer. The second large gear 204 is secured to sphere 1 with screws, driving its rotation about the X-axis. The first large gear 104 and the second large gear 204 are spatially arranged at 90 degrees.

[0036] like Figure 6 、 Figure 7 As shown, the first base assembly 300 includes a first base 301 having four first lugs 301a along its circumference. Each first lug 301a is designed with a bearing mounting hole and a second cable outlet hole 301b for mounting a first bearing 302 and motor lead wires. The first outer rotor permanent magnet brushless DC motor 110 comprises a first housing 105, and the second outer rotor permanent magnet brushless DC motor 210 comprises a second housing 205. The first bearing 302 is fitted onto the first boss axle 105a of the first housing 105 and the second boss axle 205a of the second housing 205. The first bearing 302 is then mounted into the second cable outlet hole 301b of the first base 301, thereby placing the first outer rotor permanent magnet brushless DC motor module 100, the second outer rotor permanent magnet brushless DC motor module 200, and the sphere 1 within the cavity of the first base assembly 300.

[0037] After driving the first-stage planetary reducer 401 and the second-stage planetary reducer 402, the axial flux permanent magnet brushless DC motor 500 is connected to the first base 301 through the first flange 404, thereby driving the first base assembly 300, the second outer rotor permanent magnet brushless DC motor module 200, the first outer rotor permanent magnet brushless DC motor module 100 and the sphere 1 to rotate around the Z axis.

[0038] A bearing is installed inside the first guide wheel 101. The first guide wheel 101 is mounted on the first pin shaft 102, and the first pin shaft 102 with threads is installed on the side end surface of the first housing 105. The first guide wheel 101 and the first guide rail 103 are matched through a trapezoidal cross-section, limiting the first guide rail 103 to move along the circular arc trajectory of the three first guide wheels 101, that is, to rotate around the Y axis.

[0039] Similarly, a bearing is installed inside the second guide wheel 201. The second guide wheel 201 is mounted on the second pin shaft 202, and the second pin shaft 202 with threads is installed on the side end face of the second housing 205. The second guide wheel 201 is matched with the second guide rail 203 through a trapezoidal cross-section, limiting the second guide rail 203 to move in a circular arc along the three second guide wheels 201, that is, to rotate around the X-axis.

[0040] The weight of the sphere 1 , the first outer rotor permanent magnet brushless DC motor module 100 , and the second outer rotor permanent magnet brushless DC motor module 200 is supported by the four first bearings 302 .

[0041] According to design requirements and taking into account the wire entanglement problem caused by the first outer rotor permanent magnet DC brushless motor module 100 and the second outer rotor permanent magnet DC brushless motor module 200 during a full rotation, a hollow shaft solution is adopted for the first boss axle 105a and the second boss axle 205a, and the lead wires are led out from the hollow shaft to connect the controller assembly and the battery, and the controller assembly and the battery are fixed to the first base 301 using screws.

[0042] The host computer sets the angular range of motion for the first outer rotor permanent magnet brushless DC motor module 100 and the second outer rotor permanent magnet brushless DC motor module 200, ensuring only simple pendulum-like motion (±40°). The third axial flux permanent magnet brushless DC motor module 600 achieves full rotation around the Z axis, eliminating wire entanglement.

[0043] The twelve first guide wheels 101 of the first outer rotor permanent magnet brushless DC motor module 100 cooperate with the first guide rail 103, and the twelve second guide wheels 201 of the second outer rotor permanent magnet brushless DC motor module 200 cooperate with the second guide rail 203 to jointly support the weight of the sphere 1 and limit the movement displacement along the three directions of X, Y, and Z.

[0044] Absolute position encoders are installed according to design requirements and mounted on first and second boss axles 105a, 205a, for position detection of first and second outer rotor permanent magnet brushless DC motor modules 100, 200. Similarly, an absolute position encoder is installed on third axial flux permanent magnet brushless DC motor module 600 for position detection.

[0045] like Figure 8 The first outer rotor permanent magnet brushless DC motor module 100 includes a first outer rotor permanent magnet brushless DC motor 110 and a first gear 104. The first rotor 111 of the first outer rotor permanent magnet brushless DC motor 110 includes a first rotor back iron 111a and a first magnet 112b. The first stator 112 includes a first stator winding 112a, a first main shaft 112b, and a first stator core 112c. The first outer rotor permanent magnet brushless DC motor 110 is located within a first pinion 113, where the first rotor back iron 111a is connected to the first pinion 113 using a key or screws. The first pinion 113 and the first gear 104 form a final reducer.

[0046] Similarly, the second outer rotor permanent magnet brushless DC motor module 200 includes a second outer rotor permanent magnet brushless DC motor 210 and a second large gear 204. The second rotor 211 of the second outer rotor permanent magnet brushless DC motor 210 comprises a second rotor back iron 211a and second magnets 211b. The stator comprises a second stator winding 212a, a second main shaft 212b, and a second stator core 212c. The second outer rotor permanent magnet brushless DC motor 210 is located within the second pinion 203, with the second rotor back iron 211a connected to the second pinion 213 using a key or screws. The second pinion 213 and the second large gear 204 form the final reducer.

[0047] The three-phase lead wires of the first stator winding 112a are led out from the first lead wire hole 105b; the three-phase lead wires of the second stator winding 212a are led out from the second lead wire hole 205b.

[0048] like Figure 9 , Figure 10 The third axial flux permanent magnet DC brushless motor module 600 includes a two-stage planetary reducer 400 and an axial flux permanent magnet DC brushless motor 500, wherein the two-stage planetary reducer 400 is composed of two-stage planetary reducers connected in series, namely a first-stage planetary reducer 401 and a second-stage planetary reducer 402.

[0049] The first-stage planetary reducer 401 includes a first ring gear 401a, a first sun gear 401b, first planetary gears 401c and a first planet carrier 401d. The first ring gear 401a, the first sun gear 401b and the four first planetary gears 401c are meshed with each other, and the four first planetary gears 401c are mounted on the first planet carrier 401d and rotate together.

[0050] Similarly, the second-stage planetary reducer 402 includes a second ring gear 402a, a second sun gear 402b, second planetary gears 402c and a second planet carrier 402d. The second ring gear 402a, the second sun gear 402b and the three second planetary gears 402c are meshed with each other, and the three second planetary gears 402c are mounted on the second planet carrier 402d and rotate together.

[0051] The two-stage planetary reducer 400 also includes a third casing 403, in which the first-stage planetary reducer 401 and the second-stage planetary reducer 402 are installed in series to form a two-stage planetary reducer. The second planetary carrier 402d of the second-stage planetary reducer 402 is connected to the first flange 404 by screws, and the first flange 404 is connected to the first base 301 by screws.

[0052] The third main shaft 503 of the axial flux permanent magnet brushless DC motor 500 is connected to the first sun gear 401 b of the first-stage planetary reducer 401 .

[0053] The axial flux permanent magnet brushless DC motor 500 includes two third stators 510 and a third rotor 520. The third stator 510 includes a third stator winding 501, a third stator core 502, and a second base 506. The second base 506 is designed with a second lug 506a to provide stable support for the axial flux permanent magnet brushless DC motor 500. The third rotor 520 includes a third main shaft 503, a third magnetic steel 504, and a rotor bracket 505.

[0054] The third main shaft 503 is inserted into the cavity of the first sun gear 401b of the first-stage planetary reducer 401, and the extended shaft of the first planet carrier 401d is inserted into the second sun gear 402b. This enables the third rotor 520 of the axial flux permanent magnet brushless DC motor 500 to drive the rotation of the second-stage planetary reducer 400, and the rotation of the second planet carrier 402d drives the first base 301 to rotate about the Z axis.

[0055] by Figure 1 Based on the expansion, such as Figure 11 , Figure 12 , gives the spatial position of the third axial flux permanent magnet DC brushless motor module 600 relative to the sphere 1, Figure 11 This is the internal structure diagram of the third axial flux permanent magnet DC brushless motor module 600, which is completely sunk into the sphere 1. Figure 9 This is a partial internal structure diagram of the spherical body 1. Figure 11 、 Figure 12 In this solution, the first motor base 301 remains stationary, while the first outer rotor permanent magnet brushless DC motor module 100, the second outer rotor permanent magnet brushless DC motor module 200, and the third axial flux permanent magnet brushless DC motor module 600 each rotate about the X, Y, and Z coordinate axes. This layout is applicable to scenarios such as vectored vehicle lights and vectored propellers.

[0056] It will be easily understood by those skilled in the art that the above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A three-degree-of-freedom spherical joint motor module with an integrated reducer, characterized in that: include: A sphere, a first outer rotor permanent magnet brushless DC motor module, a second outer rotor permanent magnet brushless DC motor module, a third axial flux permanent magnet brushless DC motor module, and a first base assembly; wherein the first outer rotor permanent magnet brushless DC motor module is integrated with a first single-stage reducer, the second outer rotor permanent magnet brushless DC motor module is integrated with a second single-stage reducer, and the third axial flux permanent magnet brushless DC motor module is integrated with a two-stage planetary reducer; Among them, the first outer rotor permanent magnet DC brushless motor module and the second outer rotor permanent magnet DC brushless motor module are located on the outer surface of the sphere and are arranged at 90 degrees in space. The first outer rotor permanent magnet DC brushless motor module, the second outer rotor permanent magnet DC brushless motor module and the sphere are placed in the first base assembly. The first outer rotor permanent magnet DC brushless motor module is used to realize the rotation of the sphere around the Y axis; the second outer rotor permanent magnet DC brushless motor module is used to realize the rotation of the sphere around the X axis; the third axial flux permanent magnet DC brushless motor module drives the first outer rotor permanent magnet DC brushless motor module, the second outer rotor permanent magnet DC brushless motor module, the sphere and the first base assembly as a whole to rotate around the Z axis; The first single-stage reducer includes a first large gear and a first small gear. Multiple first small gears are arranged along the circumference of the sphere. The rotation of each first small gear is driven by the first outer rotor permanent magnet DC brushless motor. The first small gear also generates torque and forms the first stage of reduction by meshing with the first large gear. The first large gear is fixed to the sphere and drives the sphere to rotate around the Y axis. The second single-stage reducer includes a second large gear and a second small gear. Multiple second small gears are arranged along the circumference of the sphere. The rotation of each second small gear is driven by the second outer rotor permanent magnet DC brushless motor. Multiple second small gears generate torque simultaneously and form the first stage of reduction by meshing with the second large gear. The second large gear is fixed to the sphere by screws, thereby driving the sphere to rotate around the X-axis.

2. The three-degree-of-freedom spherical joint motor module with integrated reducer according to claim 1, characterized in that: The first outer rotor permanent magnet DC brushless motor module also includes a first outer rotor permanent magnet DC brushless motor. The first rotor of the first outer rotor permanent magnet DC brushless motor has a first rotor back iron and a first magnet. The first stator of the first outer rotor permanent magnet DC brushless motor has a first stator winding, a first main shaft, and a first stator core. The first outer rotor permanent magnet DC brushless motor is located in the first pinion, wherein the first rotor back iron is connected to the first pinion.

3. The three-degree-of-freedom spherical joint motor module with integrated reducer according to claim 1, characterized in that: The second outer rotor permanent magnet DC brushless motor module also includes a second outer rotor permanent magnet DC brushless motor. The second rotor of the second outer rotor permanent magnet DC brushless motor has a second rotor back iron and a second magnetic steel. The stator part has a second stator winding, a second main shaft, and a second stator core. The second outer rotor permanent magnet DC brushless motor is located in the second pinion, wherein the second rotor back iron is connected to the second pinion.

4. The three-degree-of-freedom spherical joint motor module with integrated reducer according to claim 1, characterized in that: The third axial flux permanent magnet brushless DC motor module includes a two-stage planetary reducer and an axial flux permanent magnet brushless DC motor, wherein the two-stage planetary reducer is composed of a two-stage planetary reducer in series, namely a first-stage planetary reducer and a second-stage planetary reducer; the first-stage planetary reducer includes a first ring gear, a first sun gear, a first planetary gear and a first planet carrier, the first ring gear, the first sun gear and the four first planetary gears are meshed with each other, and the four first planetary gears are mounted on the first planet carrier; the second-stage planetary reducer includes a second ring gear, a second sun gear, a second planetary gear and a second planet carrier, the second ring gear, the second sun gear and the three second planetary gears are meshed with each other, and the three second planetary gears are mounted on the second planet carrier; the two-stage planetary reducer also includes a third casing, the first-stage planetary reducer and the second-stage planetary reducer are installed in series inside the third casing, the second planet carrier is connected to the first flange, and the first flange is connected to the first base assembly; the third output shaft of the axial flux permanent magnet brushless DC motor is connected to the first sun gear of the first-stage planetary reducer; The axial flux permanent magnet brushless DC motor includes two third stators and a third rotor, wherein the third stator includes a third stator winding, a third stator core, and a second base; the third rotor includes a third main shaft, a third magnetic steel, and a rotor bracket; the third main shaft is inserted into the cavity of the first sun gear of the first-stage planetary reducer, and the protruding shaft of the first planet carrier is inserted into the second sun gear.

5. The three-degree-of-freedom spherical joint motor module with integrated reducer according to claim 1, characterized in that: The first base assembly includes a first base, which has four first ear plates along the circumference, each first ear plate is provided with a bearing mounting hole and a second wire outlet hole for mounting a first bearing and leading out wires, the first outer rotor permanent magnet DC brushless motor has a first housing, the second outer rotor permanent magnet DC brushless motor includes a second housing, the first boss axle of the first housing and the second boss axle of the second housing are fitted with the first bearing, and then installed in the second wire outlet hole of the first base, the first outer rotor permanent magnet DC brushless motor module, the second outer rotor permanent magnet DC brushless motor module, and the sphere are placed together inside the cavity of the first base assembly.

6. The three-degree-of-freedom spherical joint motor module with integrated reducer according to claim 1, characterized in that: A first arc groove is machined on the outer surface of the sphere for installing the second large gear; a second arc groove is machined on the outer surface of the sphere for the first large gear, and a third arc groove is machined on the outer surface of the sphere for installing the second guide rail; a fourth arc groove is machined on the outer surface of the sphere for installing the first guide rail, and a third arc groove is arranged on each side of the left and right of the first arc groove; a fourth arc groove is arranged on each side of the left and right of the second arc groove, and the plane where the first arc groove is located is perpendicular to the plane where the second arc groove is located in space.

7. The three-degree-of-freedom spherical joint motor module with integrated reducer according to claim 6, characterized in that: A bearing is installed inside the first guide wheel, and the first guide wheel is mounted on the first pin shaft. The first pin shaft with threads is installed on the side end surface of the first housing of the first outer rotor permanent magnet DC brushless motor. The first guide wheel and the first guide rail are matched through a trapezoidal cross-section, limiting the first guide rail to move along the circular arc trajectory of the first guide wheel, that is, to rotate around the Y axis.

8. The three-degree-of-freedom spherical joint motor module with integrated reducer according to claim 7, characterized in that: A bearing is installed inside the second guide wheel, and the second guide wheel is mounted on the second pin shaft. The second pin shaft with threads is installed on the side end surface of the second housing of the second outer rotor permanent magnet DC brushless motor. The second guide wheel and the second guide rail are matched through a trapezoidal cross-section, and the second guide rail is limited to move in a circular arc along the second guide wheel, that is, rotate around the X-axis.

Images