Integrated motion mechanical joint module

Abstract

The application discloses an integrated motion mechanical joint module, which comprises a motor assembly and a speed reduction assembly. The motor assembly comprises a stator assembly, a rotor assembly and a control unit. The stator assembly is provided with a first hollow shaft body, and the rotor assembly is provided with a second hollow shaft body; the two are nested with each other and are provided with a bearing therebetween; the bearing is integrated on the same output end side of the rotor, and the non-output end bearing is cancelled. The rear cover is provided with an embedded connector interface, so that a compact layout is realized. The rotor core is made of die-cast aluminum and a neodymium-iron-boron magnetic ring to form a 0.2-0.38mm gap and fill with heat-conducting glue, so that the thermal expansion matching problem is solved. A plastic magnetic isolation sleeve is arranged to isolate the interference of the magnetically conductive rotor body on the magnetic encoder signal. The speed reduction assembly is internally provided with powder metallurgy small balls to realize long-acting lubrication. The application greatly compresses the axial and radial dimensions of the joint module, reduces the rotational inertia, and improves the reliability and assembly convenience in an extreme environment.

Description

Technical Field

[0001] This invention relates to the field of robot joint drive technology, and in particular to an integrated motion mechanical joint module. Background Technology

[0002] With the rapid development of robotics technology, increasingly higher requirements are being placed on the integration, power density, control precision, and reliability of joint modules. Existing integrated joint modules typically integrate brushless motors, reducers, encoders, and drive control circuits into the same housing to achieve a compact "motor-reduction-control" integrated design.

[0003] However, the existing technology still has the following shortcomings: (1) In the traditional brushless motor driven joint module, the rotor generally adopts a structure in which the front and rear double bearings are supported on both sides of the motor stator respectively: that is, the front end (output end) and the rear end (non-output end) of the rotor shaft are each equipped with a set of independent bearings, and the two sets of bearings are respectively installed on the front and rear end covers or housing structure of the motor stator, so as to realize the radial and axial positioning of the rotor. This "front and rear double bearing" support method results in a significant increase in the axial length of the motor, which limits the application of the joint module in harsh spaces. At the same time, although the use of an external rotor motor can eliminate the need to add a support bearing at the reducer end, the heat dissipation structure of the external rotor motor is complex and cannot provide higher power density.

[0004] (2) The connector interface of traditional joint module usually protrudes from the surface of the housing, which not only occupies additional axial or radial space, but also the protruding connector is easily damaged by external impact during transportation, assembly or use, affecting the reliability and service life of the module.

[0005] (3) To achieve high speed and high power density, the motor magnets are made of neodymium iron boron (NdFeB) die-casting process, forming an integrated magnetic ring structure with a mechanical limit speed of over 13,000 rpm. To reduce the overall weight, the rotor core, which is matched with the NdFeB magnetic ring, does not use traditional silicon steel sheets or steel, but instead uses ADC12 die-cast aluminum. However, the thermal conductivity and coefficient of thermal expansion of die-cast aluminum and NdFeB are vastly different. In extreme temperature environments ranging from -40℃ to 155℃, die-cast aluminum expands violently, which can easily crack the NdFeB magnetic ring, leading to motor failure.

[0006] (4) To improve the structural strength of the rotor body, high-strength magnetic materials are often used to manufacture the rotor body. However, when magnetic rings or beads are directly pasted on the rotor body, the magnetic material will interfere with the magnetic field distribution, causing the magnetic encoder chip to be unable to accurately read the rotor position signal, thus affecting the control accuracy. At the same time, magnetic rings are difficult to disassemble and repair after being directly pasted on the metal surface.

[0007] (5) In existing two-stage planetary reducers, the friction pair between the sun gear and the drive shaft often lacks long-term lubrication design, which leads to rapid loss of grease, increased wear, friction noise, and affects the life of the reducer and user experience.

[0008] (6) Traditional gearboxes are often partially exposed or protrude from the outside of the housing, occupying a large space in the axial and radial directions, and lack effective full-enclosed protection, making them susceptible to dust, water vapor and external impact.

[0009] Therefore, there is an urgent need for an integrated joint module that can further reduce axial and radial dimensions, improve integration, solve the problem of material thermal expansion matching, improve encoder signal reliability, improve lubrication effect and enhance protection performance. Summary of the Invention

[0010] The purpose of this invention is to provide an integrated motion mechanical joint module, which aims to solve problems such as redundant axial dimensions, easily damaged connectors, cracking of magnetic rings due to thermal expansion, interference of encoder signals by the magnetic rotor, and poor lubrication of the reducer in existing robot joint modules.

[0011] The technical solution to achieve the purpose of this invention is as follows: The integrated motion mechanical joint module of this invention includes a motor assembly and a reduction assembly, wherein the motor assembly and the reduction assembly are assembled and connected; the motor assembly includes a stator assembly, a rotor assembly and a control unit; the stator assembly includes a housing, a stator body, an insulated stator core and a stator winding; the insulated stator core is fixedly disposed on the inner circumferential wall of the housing, and the stator winding is disposed on the insulated stator core; The stator body includes a stator disk body and a first hollow shaft body arranged coaxially; the first hollow shaft body is located on the central axis of the stator disk body and extends toward the rotor assembly; the stator body is fixedly connected to the housing and located at the non-output end of the rotor assembly; the stator body is coaxially arranged with the insulated stator core, and the first hollow shaft body extends into the interior of the insulated stator core. The rotor assembly includes a rotor body and a permanent magnet attached to the rotor body; the rotor body includes a rotor core and a second hollow shaft arranged coaxially; the second hollow shaft is located on the central axis of the rotor core; the second hollow shaft constitutes the rotating shaft of the rotor assembly; The first hollow shaft and the second hollow shaft are nested together; the first hollow shaft is at least partially inserted into the interior of the second hollow shaft, or the second hollow shaft is at least partially inserted into the interior of the first hollow shaft; a bearing is provided between the first hollow shaft and the second hollow shaft; the rotor assembly is rotatably supported on the first hollow shaft through the bearing; The permanent magnet is magnetically coupled to the stator winding; the second hollow shaft is connected to the input end of the reduction gear assembly at one end of the output end of the rotor assembly; the control unit is mounted on the stator assembly and electrically connected to the stator winding.

[0012] Preferably, the inner wall of the first hollow shaft is provided with a first annular retaining ring; the outer circumferential surface of the second hollow shaft is provided with a second annular retaining ring and a retaining ring groove; the second hollow shaft is inserted into the first hollow shaft; a first bearing chamber is formed between the first annular retaining ring and the second annular retaining ring; when a retaining ring is installed in the retaining ring groove, a second bearing chamber is formed between the retaining ring and the first annular retaining ring; a first bearing and a second bearing are respectively installed in the first bearing chamber and the second bearing chamber; the rotor assembly is rotatably supported on the first hollow shaft by the first bearing and the second bearing.

[0013] Preferably, the rotor core has an annular groove on the side facing the non-output end of the rotor assembly, the first hollow shaft is at least partially accommodated in the annular groove, and the first hollow shaft and the annular groove are in clearance fit.

[0014] Preferably, the control unit includes a rear cover and a PCBA board; the rear cover is fixedly mounted on the stator body and located at the end of the stator body away from the output end of the motor assembly; a mounting cavity for mounting the PCBA board is formed between the rear cover and the stator body; the PCBA board is fixedly mounted in the mounting cavity; the stator body is provided with a through hole for the stator winding lead wire to pass through; the stator winding lead wire passes through the through hole and enters the mounting cavity, and forms an electrical connection with the PCBA board.

[0015] Preferably, the second hollow shaft is fixedly provided with a magnetic shielding sleeve at one end facing the non-output end; the magnetic shielding sleeve is made of non-magnetic material and is used to isolate the magnetic circuit between the second hollow shaft and the magnetic encoder; a magnetic encoder is fixedly provided on the magnetic shielding sleeve and is coaxially arranged with the second hollow shaft; the magnetic encoder is arranged opposite to the magnetic encoder chip on the PCBA board, and an air gap is left between the two so as to output a position signal through magnetic field coupling when the rotor assembly rotates.

[0016] Preferably, the magnetic coding body is a magnetic ring or a magnetic bead.

[0017] Preferably, the aforementioned reduction assembly includes a sun gear, an internal gear ring, a first-stage planetary reduction assembly, a second-stage planetary reduction assembly, and a front end cover; The housing forms an embedded groove at one end of the output end of the rotor assembly; the internal gear ring is embedded in the embedded groove and is located between the front cover and the housing, and the front cover, the internal gear ring and the housing are fixedly connected together by bolts; the internal gear ring is coaxially arranged with the second hollow shaft. The first-stage planetary reduction assembly includes a planet carrier and a plurality of first-stage planetary gears rotatably mounted on the planet carrier; the second-stage planetary reduction assembly includes an output flange, a plurality of second-stage planetary gears rotatably mounted on the output flange, and a drive shaft. The sun gear is connected to one end of the second hollow shaft located at the output end of the rotor assembly; the sun gear is engaged with the first-stage planetary gear; the first-stage planetary gear is engaged with the internal gear ring; a second-stage sun gear is mounted on the drive shaft; the rotation center of the planet carrier is equipped with a transmission internal gear ring; the planet carrier is mounted on the drive shaft, and its internal gear ring is engaged with the second-stage sun gear; the drive shaft and the output flange are rotatably connected via a third bearing; the second-stage sun gear is engaged with the second-stage planetary gear, and the second-stage planetary gear is engaged with the internal gear ring; The front end cover has a through hole for the output flange to be exposed or extended; the front end cover and the internal gear ring are fitted together with bolts to form a third bearing chamber; a fourth bearing is installed in the third bearing chamber; the fourth bearing is fitted on the outer circumferential wall of the output flange, and the output flange is rotatably supported on the front end cover and the internal gear ring through the fourth bearing.

[0018] Preferably, the drive shaft has a countersunk hole on the end face facing the sun gear; the countersunk hole contains powder metallurgy balls impregnated with lubricating grease; the powder metallurgy balls are in contact with the inner wall of the countersunk hole and the end face of the sun gear facing the drive shaft.

[0019] Preferably, the density of the above-mentioned powder metallurgy microspheres is controlled at 6-6.5 g / cm³. 3 .

[0020] Preferably, the end face of the rear cover away from the output end of the rotor assembly is provided with a polygonal connector for positioning and insertion; the polygonal connector has at least one insertion port.

[0021] Preferably, the rotor core is die-cast aluminum; the permanent magnet is a neodymium iron boron magnetic ring; the neodymium iron boron magnetic ring is fitted onto the outer circumferential surface of the rotor core, forming a clearance fit of 0.2-0.38mm; the gap between the neodymium iron boron magnetic ring and the rotor core is filled with thermally conductive adhesive.

[0022] The present invention has positive effects: (1) By setting up a first hollow shaft and a second hollow shaft nested together and installing the bearing between them, the rotor assembly can achieve rotational support without an independent shaft. The two sets of support bearings are integrated on the same output end side of the rotor, completely eliminating the bearing structure at the non-output end of the rotor, and fundamentally solving the axial dimension redundancy defect of the traditional structure.

[0023] Meanwhile, by eliminating the bearings at the non-output ends and the traditional independent shaft, the mass distribution of the rotor assembly is more concentrated, and the moment of inertia is significantly reduced, thereby improving the motor's dynamic response performance and acceleration capability. Furthermore, this invention centrally mounts all bearings in the hollow shaft nesting position, simplifying the assembly process and making it easier to ensure coaxiality.

[0024] This invention adopts an internal rotor structure to achieve better heat dissipation performance and higher power density. At the same time, through the innovative design of "rotor structure with an appearance similar to an external rotor", the front-end support bearing is placed at the rear, which solves the problem that the internal rotor structure cannot be supported by bearings at the reducer end, forming a hybrid structure of internal and external rotors, with significant innovative features.

[0025] Moreover, the design of the first hollow shaft extending into the interior of the insulated stator core makes full use of the axial unused space inside the stator assembly, further compressing the overall length of the module.

[0026] (2) This invention forms two independent bearing chambers through a first annular retaining ring, a second annular retaining ring, and a retaining ring, which can accommodate two axially arranged first and second bearings. Both bearings are installed between the first hollow shaft and the second hollow shaft, meaning all support points are concentrated in the same nested position (rotor output end side), achieving the core innovation of "dual bearings arranged on the same side". This structure improves the radial and axial load-bearing capacity of the rotor assembly at the output end, ensuring rotor rotation accuracy, while avoiding the increase in axial length caused by traditional double-end support, and minimizing rotational inertia.

[0027] (3) This invention achieves an optimized layout where the mass distribution of the rotor assembly is concentrated at the support point through the clearance fit between the first hollow shaft and the annular groove of the rotor core, and the nested bearing support between the first and second hollow shafts. The center of gravity of the rotor assembly is closer to the bearing support position, reducing the moment of inertia and improving the dynamic response performance. At the same time, shortening the support span effectively suppresses the sway and vibration when the rotor rotates at high speed. This design allows the rotor to maintain good rotational stability even without the non-output end bearing, solving the vibration problem of traditional cantilever rotor structures, reducing operating noise, and extending the service life of the bearings and the entire machine.

[0028] (4) In this invention, an independent mounting cavity is formed between the rear cover and the stator body, in which the PCBA board is fixed. The structure is compact and provides good dust protection. The stator winding leads directly enter the mounting cavity through the wire holes and are electrically connected to the PCBA board. The wiring is short, the path is reliable, and electromagnetic interference is reduced.

[0029] (5) The present invention uses a magnetic shielding sleeve made of non-magnetic material (plastic) to fix the magnetic encoder body to the second hollow shaft, which isolates the magnetic encoder body from the magnetically conductive second hollow shaft, effectively blocking the interference of the rotor material on the encoder magnetic field and ensuring the accuracy of the signal read by the magnetic encoder chip. At the same time, the magnetic encoder body is fixed on the magnetic shielding sleeve instead of being directly pasted on the metal surface. When disassembling, only the magnetic shielding sleeve needs to be removed, without destructive operation, which reduces maintenance costs.

[0030] (6) The present invention limits the magnetic coding body to a magnetic ring or a magnetic bead, providing two mature implementation methods that can be flexibly selected according to accuracy requirements and cost.

[0031] (7) The gearbox of this invention is nested entirely within the internal cavity of the joint module housing. Both the input stage and the transmission stage are completely housed inside the housing, with only the output transmission surface protruding from the outer surface of the housing. This effectively reduces the axial and radial space occupied by the module, achieving a compact layout. Simultaneously, the front end of the housing has an end cover to protect the output surface, forming a fully enclosed protective cavity that effectively isolates dust, moisture, and external impacts, improving the reliability of the module in harsh environments. Furthermore, the use of a first-stage planetary reduction assembly and a second-stage planetary reduction assembly achieves a large reduction ratio. The output flange is supported by the front end cover and the third bearing on the internal gear ring, ensuring stable output, good structural rigidity, and ease of assembly.

[0032] (8) In this invention, a countersunk hole is provided on the end face of the drive shaft facing the sun gear. Powder metallurgy balls impregnated with grease are placed inside the countersunk hole. The porous characteristics of powder metallurgy materials are used to store grease. When rotating, an oil film is formed on the surface of the powder metallurgy balls, which significantly reduces friction noise. The powder metallurgy balls are in contact with the inner wall of the countersunk hole and the end face of the sun gear, achieving long-term lubrication and solving the problem of rapid grease loss in traditional structures, thus extending the life of the reducer.

[0033] (9) The present invention controls the density of the powder metallurgy microspheres to 6-6.5 g / cm³, which is much lower than that of ordinary steel (about 7.8 g / cm³), resulting in a large number of micropores inside the microspheres, which can be fully impregnated with grease. This density range ensures that the microspheres have sufficient oil storage porosity (moderate density and good pore connectivity) and also ensures sufficient mechanical strength to prevent breakage during operation.

[0034] (10) In this invention, the rear cover body is a polygonal (approximately circular) shell with at least two sets of embedded connector interfaces, so that the surface of the connector after installation is flush with or lower than the outer surface of the shell, eliminating redundant gaps in connector installation, realizing overall space compression of the rear cover, and further compressing the axial space.

[0035] (11) The rotor core of this invention adopts ADC12 die-cast aluminum process, and the permanent magnet is a neodymium iron boron magnetic ring. The thermal conductivity and thermal expansion coefficient of the two materials differ greatly. Under extreme temperature environments ranging from -40℃ to 155℃, the expansion of die-cast aluminum can easily cause the neodymium iron boron magnetic ring to crack. This invention has obtained the optimal gap range of 0.2-0.38mm through calculation of the expansion of the two materials under extreme environments and hundreds of cold and hot extreme environment impact tests. The gap is filled with thermally conductive adhesive with a high thermal conductivity. Under extreme environments, the magnetic ring will not detach or crack. At the same time, the thermally conductive adhesive forms a good heat conduction path, which is conducive to heat dissipation of the permanent magnet and prevents demagnetization at high temperatures. The neodymium iron boron magnetic ring is fitted on the outer circumference of the rotor core, and the mechanical limit speed can reach more than 13,000 rpm, which meets the requirements of high speed applications. Attached Figure Description

[0036] 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... Figure 1 This is a schematic diagram of the structure of the present invention; Figure 2 This is a cross-sectional view of the present invention; Figure 3 This is a schematic diagram of the motor assembly in this invention; Figure 4 This is a cross-sectional view of the motor assembly in this invention; Figure 5 This is a schematic diagram of the reduction gear assembly in this invention; Figure 6 This is a cross-sectional view of the deceleration assembly in this invention; Figure 7 This is a schematic diagram of the rotor body in this invention; Figure 8 This is a cross-sectional view of the rotor body in this invention; Figure 9 This is a schematic diagram of the stator structure in this invention; Figure 10 for Figure 2 Enlarged view of point A in the middle; Figure 11 for Figure 2 Enlarged view of point B in the middle.

[0037] In the diagram, the components are: motor assembly 1, stator assembly 11, rotor assembly 12, control unit 13, housing 111, stator body 112, insulated stator core 113, stator winding 114, rotor body 121, permanent magnet 122, rear cover 131, PCBA board 132, stator disc 112-1, first hollow shaft 112-2, first annular retaining ring 112-3, wire hole 112-4, rotor core 121-1, second hollow shaft 121-2, second annular retaining ring 121-3, snap ring groove 121-4, annular groove 121-5, polygonal... 131-1, 131-2, 132-1, 132-1, 2, 2, 2, 2, 2, 2, 2, 3, 2, 3, 2, 2, 3, 2, 3, 4, 5, 6, 7, 8, 9, 10, 10, 11, 11, 12, 11, 12, 13, 14, 15, 16, 17, 18, 19, 10, 11, 12, 13 ... Detailed Implementation

[0038] like Figures 1 to 11 As shown, this embodiment includes a motor assembly 1 and a reduction gear assembly 2, which are assembled and connected together. The motor assembly 1 includes a stator assembly 11, a rotor assembly 12, and a control unit 13.

[0039] The stator assembly 11 includes a housing 111, a stator body 112, an insulated stator core 113, and a stator winding 114. The insulated stator core 113 is fixedly disposed on the inner circumferential wall of the housing 111. The stator winding 114 is disposed on the insulated stator core 113.

[0040] The stator body 112 includes a stator disc 112-1 and a first hollow shaft 112-2 coaxially arranged. The first hollow shaft 112-2 is located on the central axis of the stator disc 112-1 and extends toward the rotor assembly 12. The stator body 112 is fixedly connected to the housing 111 and located at the non-output end of the rotor assembly 12, specifically by bolting, riveting, or welding. The stator body 112 is coaxially arranged with the insulated stator core 113, and the first hollow shaft 112-2 extends into the interior of the insulated stator core 113. In an alternative embodiment, the stator body 112 and the housing 111 can also be integrally cast.

[0041] The rotor assembly 12 includes a rotor body 121 and a permanent magnet 122 attached to the rotor body 121. The rotor body 121 includes a rotor core 121-1 and a second hollow shaft 121-2 arranged coaxially. The second hollow shaft 121-2 is located on the central axis of the rotor core 121-1, and the second hollow shaft 121-2 constitutes the shaft of the rotor assembly 12, that is, the rotor assembly 12 does not require a separate shaft component.

[0042] The rotor core 121-1 is made of die-cast aluminum (such as ADC12). The permanent magnet 122 is a neodymium iron boron (NdFeB) magnetic ring, which is fitted onto the outer circumference of the rotor core 121-1, forming a clearance fit of 0.2-0.38 mm. This clearance range is an optimal range obtained through calculations of the expansion of the two materials under extreme environments (-40℃ to 155℃) and hundreds of thermal shock tests. The gap between the NdFeB magnetic ring and the rotor core 121-1 is filled with thermally conductive adhesive, such as silicone-based or epoxy-based thermally conductive adhesive. Under extreme temperature environments, when the die-cast aluminum expands, the thermally conductive adhesive can act as a buffer, preventing the NdFeB magnetic ring from cracking. At the same time, the thermally conductive adhesive can also conduct the heat generated by the NdFeB magnetic ring to the rotor core 121-1, thus achieving heat dissipation. As an alternative, the permanent magnet 122 can also adopt a segmented magnetic tile structure, with multiple magnetic tiles alternately distributed along the circumference of the rotor core 121-1.

[0043] The first hollow shaft 112-2 and the second hollow shaft 121-2 are nested together. Specifically, the second hollow shaft 121-2 is inserted into the interior of the first hollow shaft 112-2. In an alternative embodiment, the first hollow shaft 112-2 may be at least partially inserted into the interior of the second hollow shaft 121-2.

[0044] A first annular retaining ring 112-3 is provided on the inner wall of the first hollow shaft 112-2. A second annular retaining ring 121-3 and a snap ring groove 121-4 are provided on the outer circumference of the second hollow shaft 121-2. A first bearing chamber is formed between the first annular retaining ring 112-3 and the second annular retaining ring 121-3. When a snap ring 3 is installed in the snap ring groove 121-4, a second bearing chamber is formed between the snap ring 3 and the first annular retaining ring 112-3. A first bearing 4 and a second bearing 5 are respectively installed in the first bearing chamber and the second bearing chamber. The rotor assembly 12 is rotatably supported on the first hollow shaft 112-2 by the first bearing 4 and the second bearing 5. The first bearing 4 and the second bearing 5 can be selected as deep groove ball bearings, angular contact ball bearings, or needle roller bearings. In an alternative, if the load-bearing capacity requirement is not high, only one bearing can be provided.

[0045] With the above structure, both sets of bearings (first bearing 4 and second bearing 5) are integrated on the same output end side of the rotor assembly 12, completely eliminating the bearings located at the non-output end in the traditional structure, thereby greatly reducing the axial dimension of the joint module, reducing the moment of inertia, and simplifying the assembly process.

[0046] The rotor core 121-1 has an annular groove 121-5 on its side facing the non-output end of the rotor assembly 12. The first hollow shaft 112-2 is at least partially accommodated within the annular groove 121-5, and the first hollow shaft 112-2 and the annular groove 121-5 are clearance-fitted. This design achieves an optimized layout where the mass distribution of the rotor assembly 12 is concentrated towards the support point. The center of gravity of the rotor assembly 12 is closer to the support position of the two sets of bearings (first bearing 4 and second bearing 5), reducing the moment of inertia and improving dynamic response performance. At the same time, shortening the support span effectively suppresses the sway and vibration of the rotor body 121 during high-speed rotation. This design allows the rotor body 121 to maintain good rotational stability even without the non-output end bearings, solving the vibration problem of traditional cantilever rotor structures, reducing operating noise, and extending the service life of bearings and the entire machine.

[0047] The control unit 13 includes a rear cover 131 and a PCBA board 132. The rear cover 131 is fixedly mounted on the stator body 112 and located at the end of the stator body 112 away from the output end of the motor assembly 1. A mounting cavity for mounting the PCBA board 113 is formed between the rear cover 131 and the stator body 112, and the PCBA board 113 is fixedly mounted in the mounting cavity. The rear cover 131 and the stator body 112 are connected by bolts. In an alternative embodiment, a sealing ring may also be provided between the rear cover 131 and the stator body 112 to achieve dust and water resistance.

[0048] The stator body 112 is provided with a wire-passing hole 112-4 for the lead wire of the stator winding 114 to pass through. After the lead wire of the stator winding 114 passes through the wire-passing hole 112-4, it enters the mounting cavity and forms an electrical connection with the PCBA board 132.

[0049] The rear cover 131 has a polygonal connector 131-1 on its end face away from the output end of the rotor assembly for positioning and insertion during subsequent joint module installation. The polygonal connector 131-1 has an approximately circular polygonal outline with truncated edges. Two connectors 131-2 are provided on the side of the polygonal connector 131-1, although one or more connectors 131-2 may also be provided.

[0050] When the polygonal connector 131-1 of the integrated motion mechanical shutdown module in this embodiment is inserted into a matching through slot on a connector, the locking block on the side wall of the through slot, which is compatible with the connector 131-2, can be locked into the corresponding connector 131-2, thereby realizing the installation of the integrated motion mechanical joint module in this embodiment (not shown in the attached figure, but its locking block installation method is a traditional locking method, which can be referred to as the conventional locking block and locking slot mating insertion method). When the integrated motion mechanical joint module in this embodiment is inserted and mated with the through slot on the connector, the surface of the through slot is flush with or lower than the outer surface of the rear cover 131. This embedded design eliminates redundant gaps in the insertion installation. The outer contour of the rear cover 131 adopts a chamfered polygonal design, which maximizes the reduction of radial space occupied while ensuring structural strength, realizing the miniaturization and lightweight design of the module.

[0051] The second hollow shaft 121-2 has a magnetic shielding sleeve 6 fixedly provided at its non-output end facing the rotating assembly 12. The magnetic shielding sleeve 6 is made of a non-magnetic material, such as plastic (POM, PA66, PEEK, etc.), ceramic, or aluminum alloy. The magnetic shielding sleeve 6 is used to isolate the magnetic circuit between the second hollow shaft 121-2 and the magnetic encoder 7, preventing the magnetic material of the second hollow shaft 121-2 from interfering with the encoder's magnetic field.

[0052] A magnetic encoder 7, coaxially aligned with the second hollow shaft 121-2, is fixedly mounted on the magnetic shielding sleeve 6. The magnetic encoder 7 is positioned opposite to the magnetic encoder chip 132-1 on the PCBA board 132, with an air gap (e.g., 0.5-2 mm) between them to couple a position signal via magnetic field coupling when the rotor assembly 12 rotates. The magnetic encoder 7 can be a magnetic ring or a magnetic bead. Using a magnetic ring enables high-precision absolute position detection; using a magnetic bead is suitable for switch signals or low-cost applications. Alternatively, the magnetic encoder 7 can be made of injection-molded or bonded permanent magnets.

[0053] The magnetic shielding sleeve 6 solves the problem of interference between the magnetic rotor and the magnetic encoder signal, and also facilitates the disassembly and repair of the magnetic encoder body 7. During maintenance, the magnetic encoder body 7 can be removed together with the magnetic shielding sleeve 6 without any destructive operation.

[0054] The reduction assembly 2 includes a sun gear 21, an internal gear ring 22, a first-stage planetary reduction assembly 23, a second-stage planetary reduction assembly 24, and a front end cover 25. The housing 111 forms an embedded groove at one end of the output end of the rotor assembly 12, and the internal gear ring 22 is embedded in this groove. The front end cover 25 directly mates with the housing 111 to form an annular groove for accommodating the internal gear ring 22. The internal gear ring 22 is located between the front end cover 25 and the housing 111, and is also enclosed within them by the front end cover 25 and the housing 111. The front end cover 25, the internal gear ring 22, and the housing 111 are fixedly connected together by bolts. The internal gear ring 22 is coaxially arranged with the second hollow shaft 121-2.

[0055] The first-stage planetary reduction assembly 23 includes a planet carrier 231 and three first-stage planetary gears 232 rotatably mounted on the planet carrier 231. The second-stage planetary reduction assembly 24 includes an output flange 241, three second-stage planetary gears 242 rotatably mounted on the output flange 241, and a drive shaft 243.

[0056] The sun gear 21 is connected to one end of the second hollow shaft 121-2 located at the output end of the rotor assembly 12, for example, by a key connection, spline connection, or integral molding. The sun gear 21 forms a transmission engagement with the first-stage planetary gear 232, and the first-stage planetary gear 232 forms a transmission engagement with the internal gear ring 22.

[0057] The drive shaft 243 is equipped with a secondary sun gear 243-1. The planet carrier 231 has an internal gear ring at its rotation center. The planet carrier 231 is mounted on the drive shaft 243, and its internal gear ring forms a transmission engagement with the secondary sun gear 243-1. The drive shaft 243 and the output flange 241 are rotatably connected via a third bearing 8. The secondary sun gear 243-1 forms a transmission engagement with the secondary planetary gear 242, and the secondary planetary gear 242 forms a transmission engagement with the internal gear ring 22.

[0058] The front end cover 25 has a through hole for the output flange 241 to be exposed or extended. The front end cover 25 and the internal gear ring 22 are bolted together to form a third bearing chamber, in which a fourth bearing 9 is installed. The fourth bearing 9 is fitted onto the outer circumferential wall of the output flange 241, and the output flange 241 is rotatably supported on the front end cover 25 and the internal gear ring 22 via the fourth bearing 9. The fourth bearing 9 can be a crossed roller bearing or an angular contact ball bearing to improve the radial and axial load capacity of the output end.

[0059] With the above structure, the input stage and transmission stage of the reduction assembly 2 are completely housed within the internal space formed by the housing 111 and the front cover 25, with only the end face of the output flange 241 protruding from the outer surface of the housing 111, effectively reducing the axial and radial space occupied by the joint module. A fully enclosed protective cavity is formed between the front cover 25 and the housing 111, effectively isolating dust, moisture, and external impacts.

[0060] The drive shaft 243 has a countersunk hole 243-2 on its end face facing the sun gear 21. Powder metallurgy microspheres 10, impregnated with grease, are placed inside the countersunk hole 243-2. ​​The powder metallurgy microspheres 10 are in contact with the inner wall of the countersunk hole 243-2 and the end face of the sun gear 21 facing the drive shaft 243-1. The density of the powder metallurgy microspheres 10 is controlled at 6-6.5 g / cm³, which is much lower than that of ordinary steel (approximately 7.8 g / cm³), resulting in numerous micropores inside the microspheres, allowing for thorough impregnation with grease.

[0061] When the reduction assembly 2 is running, the powder metallurgy balls 10 utilize their porous characteristics to slowly release lubricating grease, forming an oil film between the end face of the sun gear 21 and the end face of the drive shaft 243, thereby reducing frictional noise and achieving long-term lubrication.

[0062] During assembly, first assemble the stator assembly 11 (stator winding 114 is wound on the insulated stator core 113, the insulated stator core 113 is fixed to the inner wall of the housing 111, and the stator body 112 is fixed to the housing 111). Then, insert the rotor assembly 12 (permanent magnet 122 is attached to the rotor core 121-1, and the magnetic shielding sleeve 6 and magnetic encoder 7 are fixed to the non-output end of the second hollow shaft 121-2) from the output end direction, so that the second hollow shaft 121-2 is inserted into the first hollow shaft 112-2 and mates with the first bearing 4 and the second bearing 5. Install the retaining ring 3 to complete the axial positioning of the bearings. Then, install the reduction assembly 2 to make the sun gear 21 drively connected to the output end of the second hollow shaft 121-2. Finally, install the PCBA board 132 and the rear cover 131 to complete the overall assembly.

[0063] During operation, PCBA board 132 energizes the stator winding 114, generating a rotating magnetic field that interacts with the permanent magnet 122 to drive the rotor assembly 12 to rotate. The rotor assembly 12 drives the sun gear 21 to rotate via the second hollow shaft 121-2. After two stages of planetary reduction, the increased torque is output through the output flange 243. Simultaneously, the magnetic encoder 7 rotates synchronously with the rotor assembly 12, cooperating with the magnetic encoder chip 132-1 on PCBA board 132 to output rotor position signals, achieving closed-loop control.

[0064] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above descriptions are merely specific embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. An integrated motion mechanical joint module, comprising a motor assembly and a reduction gear assembly, wherein the motor assembly and the reduction gear assembly are assembled and connected; the motor assembly comprises a stator assembly, a rotor assembly, and a control unit; characterized in that: The stator assembly includes a housing, a stator body, an insulated stator core, and stator windings; the insulated stator core is fixedly disposed on the inner circumferential wall of the housing, and the stator windings are disposed on the insulated stator core; The stator body includes a stator disk body and a first hollow shaft body arranged coaxially; the first hollow shaft body is located on the central axis of the stator disk body and extends toward the rotor assembly; the stator body is fixedly connected to the housing and located at the non-output end of the rotor assembly; the stator body is coaxially arranged with the insulated stator core, and the first hollow shaft body extends into the interior of the insulated stator core. The rotor assembly includes a rotor body and a permanent magnet attached to the rotor body; the rotor body includes a rotor core and a second hollow shaft arranged coaxially; the second hollow shaft is located on the central axis of the rotor core; the second hollow shaft constitutes the rotating shaft of the rotor assembly; The first hollow shaft and the second hollow shaft are nested together; the first hollow shaft is at least partially inserted into the interior of the second hollow shaft, or the second hollow shaft is at least partially inserted into the interior of the first hollow shaft; a bearing is provided between the first hollow shaft and the second hollow shaft; the rotor assembly is rotatably supported on the first hollow shaft through the bearing; The permanent magnet is magnetically coupled to the stator winding; the second hollow shaft is connected to the input end of the reduction gear assembly at one end of the output end of the rotor assembly; the control unit is mounted on the stator assembly and electrically connected to the stator winding.

2. The integrated motion mechanical joint module according to claim 1, characterized in that: The inner wall of the first hollow shaft is provided with a first annular retaining ring; the outer circumference of the second hollow shaft is provided with a second annular retaining ring and a snap ring groove; the second hollow shaft is inserted into the first hollow shaft; a first bearing chamber is formed between the first annular retaining ring and the second annular retaining ring; when a snap ring is installed in the snap ring groove, a second bearing chamber is formed between the snap ring and the first annular retaining ring; a first bearing and a second bearing are respectively installed in the first bearing chamber and the second bearing chamber; the rotor assembly is rotatably supported on the first hollow shaft through the first bearing and the second bearing.

3. An integrated motion mechanical joint module according to claim 1 or 2, characterized in that: The rotor core has an annular groove on the side facing the non-output end of the rotor assembly, the first hollow shaft is at least partially accommodated in the annular groove, and the first hollow shaft and the annular groove are in clearance fit.

4. An integrated motion mechanical joint module according to claim 1 or 2, characterized in that: The control unit includes a rear cover and a PCBA board; the rear cover is fixedly mounted on the stator body and located at the end of the stator body away from the output end of the motor assembly; a mounting cavity for mounting the PCBA board is formed between the rear cover and the stator body; the PCBA board is fixedly mounted in the mounting cavity; the stator body is provided with a through hole for the stator winding lead wire to pass through; the stator winding lead wire passes through the through hole and enters the mounting cavity, and forms an electrical connection with the PCBA board.

5. The integrated motion mechanical joint module according to claim 4, characterized in that: The second hollow shaft is fixedly provided with a magnetic shielding sleeve at one end facing the non-output end; the magnetic shielding sleeve is made of non-magnetic material and is used to isolate the magnetic circuit between the second hollow shaft and the magnetic encoder; a magnetic encoder is fixedly provided on the magnetic shielding sleeve and is coaxially arranged with the second hollow shaft; the magnetic encoder is arranged opposite to the magnetic encoder chip on the PCBA board, and an air gap is left between the two so as to output a position signal through magnetic field coupling when the rotor assembly rotates.

6. The integrated motion mechanical joint module according to claim 5, characterized in that: The magnetic coding body is a magnetic ring or a magnetic bead.

7. An integrated motion mechanical joint module according to claim 1 or 2, characterized in that: The reduction assembly includes a sun gear, an internal gear ring, a first-stage planetary reduction assembly, a second-stage planetary reduction assembly, and a front end cover; The housing forms an embedded groove at one end of the output end of the rotor assembly; the internal gear ring is embedded in the embedded groove and is located between the front cover and the housing, and the front cover, the internal gear ring and the housing are fixedly connected together by bolts; the internal gear ring is coaxially arranged with the second hollow shaft. The first-stage planetary reduction assembly includes a planet carrier and a plurality of first-stage planetary gears rotatably mounted on the planet carrier; the second-stage planetary reduction assembly includes an output flange, a plurality of second-stage planetary gears rotatably mounted on the output flange, and a drive shaft. The sun gear is connected to one end of the second hollow shaft located at the output end of the rotor assembly; the sun gear is engaged with the first-stage planetary gear; the first-stage planetary gear is engaged with the internal gear ring; a second-stage sun gear is mounted on the drive shaft; the rotation center of the planet carrier is equipped with a transmission internal gear ring; the planet carrier is mounted on the drive shaft, and its internal gear ring is engaged with the second-stage sun gear; the drive shaft and the output flange are rotatably connected via a third bearing; the second-stage sun gear is engaged with the second-stage planetary gear, and the second-stage planetary gear is engaged with the internal gear ring; The front end cover has a through hole for the output flange to be exposed or extended; the front end cover and the internal gear ring are fitted together with bolts to form a third bearing chamber; a fourth bearing is installed in the third bearing chamber; the fourth bearing is fitted on the outer circumferential wall of the output flange, and the output flange is rotatably supported on the front end cover and the internal gear ring through the fourth bearing.

8. The integrated motion mechanical joint module according to claim 7, characterized in that: The drive shaft has a countersunk hole on the end face facing the sun gear; the countersunk hole contains powder metallurgy balls impregnated with grease; the powder metallurgy balls are in contact with the inner wall of the countersunk hole and the end face of the sun gear facing the drive shaft.

9. The integrated motion mechanical joint module according to claim 8, characterized in that: The density of the powder metallurgy microspheres is controlled at 6-6.5 g / cm³. 3 .

10. The integrated motion mechanical joint module according to claim 4, characterized in that: The end face of the rear cover away from the output end of the rotor assembly is provided with a polygonal connector for positioning and insertion; the polygonal connector has at least one insertion port.

11. The integrated motion mechanical joint module according to claim 1, characterized in that: The rotor core is made of die-cast aluminum; the permanent magnet is a neodymium iron boron magnetic ring; the neodymium iron boron magnetic ring is fitted onto the outer circumferential surface of the rotor core, forming a clearance fit of 0.2-0.38mm; the gap between the neodymium iron boron magnetic ring and the rotor core is filled with thermally conductive adhesive.

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