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CN-122026664-A - Robot joint motor assembly

CN122026664ACN 122026664 ACN122026664 ACN 122026664ACN-122026664-A

Abstract

The invention discloses a robot joint motor assembly, which comprises an axial magnetic field motor and a planetary reducer, wherein the axial magnetic field motor comprises a shell, a stator, a rotor frame, a rotating shaft and a permanent magnet, the planetary reducer comprises a lower planetary frame, an upper planetary frame, a sun gear, a gear ring and a plurality of planetary gears, the shell comprises a shell, an inner cylinder, a lower end cover and an upper end cover, the stator is fixedly arranged on the outer wall of the inner cylinder, the rotor frame is fixedly arranged on the rotating shaft, the gear ring is arranged on the inner wall of the inner cylinder, the lower planetary frame and the upper planetary frame are respectively arranged on the inner cylinder through a first bearing and a second bearing, the rotating shaft is arranged on the lower planetary frame through a third bearing, the first boss is arranged on the upper planetary frame through a fourth bearing, the lower planetary frame and the upper planetary frame are fixed together through a plurality of pin shafts, each pin shaft is respectively provided with one planetary gear through a fifth bearing, and each planetary gear is fixedly arranged on the rotating shaft. The invention has high integration level, small occupied space and high reliability.

Inventors

  • WENG MENGKUN
  • CHEN FANGYUAN
  • WANG PENG

Assignees

  • 深圳市万至达电机制造有限公司

Dates

Publication Date
20260512
Application Date
20260209

Claims (10)

  1. 1. The utility model provides a robot joint motor assembly which characterized in that includes axial magnetic field motor and planetary reducer, wherein: The axial magnetic field motor comprises a shell, a stator, a rotor frame, a rotating shaft and a permanent magnet, and the planetary reducer comprises a lower planetary frame, an upper planetary frame, a sun wheel, a gear ring and a plurality of planetary wheels; the shell comprises a shell, an inner cylinder, a lower end cover and an upper end cover, wherein the inner cylinder is positioned in the shell, the lower end of the inner cylinder is fixedly connected with the shell through the lower end cover, the stator is fixedly arranged on the outer wall of the inner cylinder, the rotor frame is fixedly arranged on the rotating shaft, the upper end of the shell is fixedly arranged on the upper end cover, and the gear ring is arranged on the inner wall of the inner cylinder; the lower planet carrier and the upper planet carrier are arranged along the axial direction of the rotating shaft, and are respectively arranged on the inner wall of the inner cylinder through a first bearing and a second bearing; The rotating shaft is mounted on the lower planet carrier through a third bearing, the rotor carrier comprises a carrier body and a first boss protruding from the lower end of the carrier body, the permanent magnet is mounted on the carrier body, the first boss is mounted on the upper planet carrier through a fourth bearing, the lower planet carrier and the upper planet carrier are fixedly connected together through a plurality of pins and are uniformly distributed along the circumferential direction of the central line of the rotating shaft, each pin is respectively provided with one planet wheel through a fifth bearing, the sun wheel is fixedly mounted on the rotating shaft and is respectively meshed with each planet wheel, and each planet wheel is respectively meshed with the gear ring.
  2. 2. The robot joint motor assembly of claim 1, wherein the upper end cover is provided with an air inlet and outlet, and the lower end cover seals the space between the outer shell and the inner cylinder; The rotor frame is fixedly provided with fan blades, the permanent magnet is positioned between the fan blades and the stator, the rotor frame is provided with ventilation channels at positions corresponding to the fan blades, the fan blades are used for enabling air outside the machine shell to flow into the machine shell from the air inlet and outlet and blow the air to the stator, so that heat exchange between the air inside and outside the machine shell is achieved, heat dissipation of the axial magnetic field motor is achieved, and the air inside the machine shell also flows out of the machine shell from the air inlet and outlet.
  3. 3. The robotic joint motor assembly according to claim 2, wherein the fan blade includes a hub and a plurality of blades circumferentially mounted on the hub, the hub being fixedly mounted on the shaft; along the direction of keeping away from wheel hub, every the thickness of blade reduces gradually, every the blade all includes arc wind-guiding portion and slope radiating portion and the contained angle of the central line of slope radiating portion and pivot is 60~ 75.
  4. 4. The robot joint motor assembly according to claim 2, wherein the rotor frame is provided with an outer ring body, the outer ring body is provided with the permanent magnets through a permanent magnet mounting ring, the permanent magnets comprise a plurality of magnets which are arranged at intervals, a plurality of notch grooves are uniformly formed in the circumference of the permanent magnet mounting ring, and each notch groove is provided with one magnet; one end of each blade, far away from the hub, of each blade is fixedly mounted on the outer ring body of the rotor frame.
  5. 5. The robot joint motor assembly according to claim 1, wherein a second boss is provided on a side of the frame body away from the first boss, the second boss is mounted on the upper end cover through a sixth bearing, and the first boss and the second boss are coaxially arranged.
  6. 6. A robot joint motor assembly according to claim 1, wherein, A first shaft shoulder is arranged on the first boss of the rotor frame and is abutted against the upper end of the inner ring of the fourth bearing; The outer side wall of the upper planet carrier is provided with a second shoulder, and the second shoulder is abutted against the upper end of the inner ring of the second bearing; A third shaft shoulder is arranged on the rotating shaft and is abutted against the upper end of the inner ring of the third bearing; an annular step is arranged on the inner wall of the lower planet carrier and is abutted against the lower end of the outer ring of the third bearing; The inner wall of the inner barrel is provided with an annular groove, a stop ring is arranged at the annular groove, and the stop ring abuts against the lower end of the outer ring of the first bearing.
  7. 7. The robot joint motor assembly of claim 1, wherein an annular gap between the inner barrel and the housing is filled with a thermally conductive gel, and the stator is surrounded by the thermally conductive gel for conducting heat generated by the stator to the housing in a radial direction of the inner barrel.
  8. 8. The robot joint motor assembly of claim 7, wherein the inner wall of the housing is provided with a spiral channel, the inner wall of the housing is further provided with a plurality of sets of teeth, the plurality of sets of teeth are arranged along the axial direction of the rotating shaft, each set of teeth respectively comprises a plurality of teeth arranged circumferentially, the spiral channel is filled with the heat conducting colloid, and each tooth is respectively embedded into the heat conducting colloid.
  9. 9. The robot joint motor assembly of claim 1, wherein the housing is integrally prismatic, and a plurality of positioning keyways are uniformly circumferentially arranged on the outer wall of the housing; or a plurality of arc-shaped positioning ribs are circumferentially arranged on the outer wall of the shell, each arc-shaped positioning rib extends along the axial direction of the rotating shaft, and a connecting hole is formed in each arc-shaped positioning rib.
  10. 10. The robotic joint motor assembly according to claim 1, wherein the lower planet carrier has a plurality of threaded bores circumferentially disposed thereon for connection to a load.

Description

Robot joint motor assembly Technical Field The invention belongs to the field of robots, and particularly relates to a robot joint motor assembly. Background With rapid development of robot technology, particularly wide application of four-legged robots, cooperative robots and humanoid robots, extremely high demands are made on joint motors as power cores thereof. Robotic joints are often required to have high power density, high torque output, high motion accuracy, and compact physical dimensions. In order to achieve speed reduction and torque increase, the current mainstream scheme is to combine a driving motor with a speed reducer (such as a planetary speed reducer, a harmonic speed reducer and the like). However, the existing robot joint motor assembly still has the following significant defects and shortcomings in structural design and performance: 1) The structure compactness is insufficient, the traditional joint motor scheme with oversized axial dimension mostly adopts a serial structure, namely, the motor and the speed reducer module are arranged in sequence in the axial direction, and an output shaft of the motor is connected with the speed reducer module through a coupler or a transition shaft. In addition, the motor and the speed reducer are provided with independent shells, and the repeated structural design not only increases the overall weight, but also further increases the space occupation. 2) The structural rigidity is poor, the shock resistance is weak, and in the existing integrated design, a cantilever support or a simple single-point support is usually adopted for the rotor of the motor and the planet carrier of the speed reducer. For an axial magnetic field motor, the magnetic pulling force between a stator and a rotor is extremely strong and the direction is distributed along the axial direction, and if the supporting rigidity is insufficient, tiny axial displacement or deflection is extremely easy to generate when the motor runs at a high speed or bears alternating load. This not only results in uneven motor air gap, reduced electromagnetic efficiency and noise, but also, in more serious, affects the accuracy of engagement of the gears inside the reducer. In the robot operation scene of frequent start, stop or receive external impact, this structural rigidity defect easily leads to gear tooth breakage or early failure of the bearing. 3) The heat dissipation performance and the thermal reliability are the bottleneck that when the joint motor works under heavy load, a large amount of heat is generated at the meshing position of the stator winding and the gear of the speed reducer. In the prior art, the stator is usually enclosed between double-layer shells, the heat transfer path is long, and the thermal resistance is large. Meanwhile, heat is easily accumulated in a central area inside the planetary reducer due to the existence of grease. If a high-efficiency heat dissipation path (such as active air cooling or optimized radial heat conduction) is lacking, the motor can demagnetize magnetic steel or age an insulating layer due to overhigh temperature rise under continuous operation, so that rated output power of the joint motor is limited. Disclosure of Invention Aiming at the defects or improvement demands of the prior art, the invention provides a robot joint motor assembly which has high integration level, small occupied space and high working reliability. To achieve the above object, according to the present invention, there is provided a robot joint motor assembly including an axial magnetic field motor and a planetary reducer, wherein: The axial magnetic field motor comprises a shell, a stator, a rotor frame, a rotating shaft and a permanent magnet, and the planetary reducer comprises a lower planetary frame, an upper planetary frame, a sun wheel, a gear ring and a plurality of planetary wheels; the shell comprises a shell, an inner cylinder, a lower end cover and an upper end cover, wherein the inner cylinder is positioned in the shell, the lower end of the inner cylinder is fixedly connected with the shell through the lower end cover, the stator is fixedly arranged on the outer wall of the inner cylinder, the rotor frame is fixedly arranged on the rotating shaft, the upper end of the shell is fixedly arranged on the upper end cover, and the gear ring is arranged on the inner wall of the inner cylinder; the lower planet carrier and the upper planet carrier are arranged along the axial direction of the rotating shaft, and are respectively arranged on the inner wall of the inner cylinder through a first bearing and a second bearing; The rotating shaft is mounted on the lower planet carrier through a third bearing, the rotor carrier comprises a carrier body and a first boss protruding from the lower end of the carrier body, the permanent magnet is mounted on the carrier body, the first boss is mounted on the upper planet carrier through a fourth bearing, the lower planet carrier