Actuator having planetary reduction mechanism, and robot joint
By introducing support ribs and clamping elements into the actuator, the problem of inconvenient bearing assembly is solved, making the bearing easy to install and disassemble, and improving the actuator's structural compactness and assembly efficiency.
Patent Information
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- SHANGHAI FOURIER INTELLIGENCE CO LTD
- Filing Date
- 2025-08-12
- Publication Date
- 2026-06-18
AI Technical Summary
In existing actuators, the bearings between the connecting bracket and the internal gear ring are difficult to assemble, making assembly and maintenance inconvenient. Furthermore, the bearings occupy radial space, resulting in an actuator that is not compact enough.
The design employs supporting ribs and clamping components. By using a separate structure of supporting ribs, inner bracket, and outer bracket, and fixing the bearing with bolts, the tight fit between the bearing and the connecting bracket is avoided, simplifying the assembly process. Furthermore, the removable top cover and bushing optimize the structural compactness.
This design facilitates easy assembly and disassembly of the bearings, reduces assembly difficulty, prevents tool damage to the bearings, and reduces the radial and axial dimensions of the actuator, thus improving structural compactness.
Smart Images
Figure CN2025113979_18062026_PF_FP_ABST
Abstract
Description
Actuators and robot joints with planetary reduction mechanisms Technical Field
[0001] This invention relates to the field of robot drive technology, and more specifically to an actuator and robot joint with a planetary reduction mechanism. Background Technology
[0002] The actuator is the core component of a robot joint. It is used to provide power for the relative motion between the two moving parts of the robot joint and to precisely control the motion angle of the two moving parts in the robot joint.
[0003] An actuator generally includes a housing, a motor, and a reduction mechanism. Existing actuators commonly use planetary reduction mechanisms for their reduction mechanisms. Since planetary reduction mechanisms occupy a relatively large amount of radial space in the actuator, a motor chamber is formed between the actuator housing and the internal gear ring of the planetary reduction mechanism. A frameless torque motor is installed in this motor chamber. In order to transmit the power output by the frameless torque motor to the sun gear of the planetary reduction mechanism, a connecting bracket that spans the internal gear ring of the planetary reduction mechanism is required to synchronously connect the rotor of the frameless torque motor and the sun gear of the planetary reduction mechanism.
[0004] To ensure stable rotation of the connecting bracket, stator, and sun gear, bearings are required between the housing and the connecting bracket (or stator) to provide radial support. However, in existing actuators, bearings are placed between the outer periphery of the connecting bracket and the housing. Because the bearings occupy a certain radial space, the radial dimension of the actuator is relatively large, resulting in a less compact overall structure.
[0005] To avoid bearings occupying the radial space of the actuator, some actuators place a bearing between the inner side of the internal gear ring, which is fixedly fitted to the housing, and the connecting bracket to provide radial support for the connecting bracket. However, when assembling the bearing with the connecting bracket and the internal gear ring, it is necessary to press-fit the inner and outer rings of the bearing together with the connecting bracket and the internal gear ring respectively, so that the inner ring of the bearing is tightly fitted with the connecting bracket and the outer ring of the bearing is tightly fitted with the internal gear ring. The press-fit method makes the assembly of the actuator more difficult, and special tools are required to assemble and disassemble the bearing. Furthermore, the bearing is easily damaged during the assembly and disassembly process. Therefore, existing actuators with the above structure have many inconveniences in the assembly and maintenance process. Summary of the Invention
[0006] The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, the purpose of the present invention is to provide an actuator and robot joint with a planetary reduction mechanism to solve the problems of difficult assembly and inconvenient maintenance of the bearing between the actuator connecting bracket and the internal gear ring in the prior art.
[0007] The objective of this invention is achieved through the following technical solution:
[0008] An actuator with a planetary reduction gear includes a housing, a motor, and the planetary reduction gear.
[0009] The planetary reduction mechanism includes an internal gear ring, a sun gear, a planetary carrier, and planetary gears that are fixedly fitted to the outer casing. The sun gear, planetary carrier, and planetary gears are all located inside the internal gear ring. The planetary gears are pivotally connected to the planetary carrier and mesh between the sun gear and the internal gear ring. An installation chamber is formed between the internal gear ring and the outer casing. An annular support rib is provided on the internal gear ring. A clamping member is detachably fixed to the support rib on the inner side of the support rib.
[0010] The motor is placed in the mounting chamber and includes a stator that is fixedly fitted with the housing and a rotor that matches the stator. The rotor is synchronously connected to the sun gear through a connecting bracket.
[0011] The connecting bracket includes an outer bracket and an inner bracket. The outer edge of the outer bracket is fixedly connected to the rotor. The inner edge of the outer bracket extends over the end of the supporting rib and then extends to the inner side of the supporting rib. The outer edge of the inner bracket is fixedly connected to the inner edge of the outer bracket by bolts. The inner bracket can be embedded into the supporting rib along the end opening of the supporting rib. A bearing is provided between the supporting rib and the inner bracket to pivotally connect the connecting bracket and the supporting rib. The outer ring of the bearing is clamped between the clamping member and the supporting rib, and the inner ring of the bearing is clamped between the outer bracket and the inner bracket.
[0012] In this embodiment of the invention, the outer ring of the bearing is fixed to the supporting rib by pressing against both ends of the bearing outer ring with clamping parts and supporting ribs. The inner ring of the bearing is fixed to the connecting bracket by pressing against both ends of the bearing inner ring with outer and inner brackets. The inner and outer rings of the bearing do not need to be tightly fitted with the connecting bracket and supporting ribs, thus eliminating the need for special pressing tools to disassemble and install the bearing. This makes the bearing easy to assemble and disassemble without damaging it during the assembly and disassembly process. Furthermore, the inner and outer brackets of the connecting bracket are of a split structure, which will not interfere with the bearing during installation. This ensures that the connecting bracket and the bearing can be quickly assembled into the inside of the actuator housing from one end without interfering with other components inside the actuator housing, facilitating the overall assembly of the actuator.
[0013] In a preferred embodiment, the housing includes a sidewall and a support wall extending radially inward from the inner surface of the sidewall along the actuator. The lower end of the internal gear ring is connected to the support wall. The mounting chamber is formed by the internal gear ring, the sidewall, and the support wall. The radially extending support wall serves as the fixing base for the internal gear ring, ensuring a fixed fit between the internal gear ring and the housing. When the mounting chamber for the motor has an open top, the motor can be easily placed in the mounting chamber from top to bottom, further facilitating actuator assembly.
[0014] In a preferred embodiment, the outer support includes a first fixing ring located on its outer edge, a second fixing ring located on its inner edge, and a connecting rib connecting the first and second fixing rings. The second fixing ring is positioned above the upper surface of the outer edge of the inner support, and a support rib extending outward is provided at the bottom of the outer edge of the inner support. The top of the inner ring of the bearing abuts against the lower surface of the second fixing ring, and the bottom of the inner ring of the bearing abuts against the support rib. In a preferred embodiment, a bolt passes through the second fixing ring from top to bottom and is screwed onto the outer edge of the inner support. The lower surface of the second fixing ring is clearance-fitted with the upper surface of the outer edge of the inner support. During assembly, the bolt is tightened, pressing the second fixing ring downward. The lower surface of the second fixing ring contacts the top surface of the inner ring of the bearing and continuously pushes the inner ring of the bearing downward until the bottom of the inner ring of the bearing presses against the support rib. Because the lower surface of the second fixing ring is clearance-fitted with the upper surface of the outer edge of the inner support, the second fixing ring can fully press the inner ring of the bearing downward, minimizing the clearance between the bottom of the inner ring of the bearing and the support rib, and preventing axial loosening of the inner ring of the bearing relative to the connecting support.
[0015] In a preferred embodiment, the first fixing ring is positioned above the supporting rib, and a connecting arm extending downward and fixedly connected to the rotor is provided on it. In the radial direction of the actuator, at least a section of the connecting rib gradually slopes downward from the outside to the inside so that the second fixing ring is positioned between the top surface of the supporting rib and the upper surface of the outer edge of the inner support. The second fixing ring is positioned between the top surface of the supporting rib and the upper surface of the outer edge of the inner support. This reduces the height of the lower surface of the second fixing ring, allowing the connecting support to span the internal gear ring while preventing the bearing from being installed too high. The bearing position is as close as possible to the center of gravity of the rotating structure formed by the connecting support and the rotor, improving the stability of rotor rotation. Furthermore, setting the portion of the connecting support located within the inner support as a recessed structure allows space for other components inside the actuator, making the internal structure of the actuator more compact and reducing the axial dimension of the actuator.
[0016] In a preferred embodiment, the inner side of the supporting rib is provided with a supporting step and a groove located above the supporting step. The clamping member is a retaining spring that is clamped in the groove. The top end of the bearing's outer ring abuts against the retaining spring, and the bottom end of the bearing's outer ring abuts against the supporting step. By clamping the retaining spring onto the supporting rib through the groove on the supporting rib, axial movement of the retaining spring can be prevented. This allows the retaining spring to cooperate with the supporting step to fix the outer ring of the bearing onto the supporting rib, preventing axial movement of the bearing's outer ring relative to the supporting rib.
[0017] In a preferred embodiment, the housing further includes a top cover, which is detachably fixed to the upper end of the side wall. By providing a detachable top cover, the motor, planetary reduction gear mechanism, and connecting bracket can be inserted into the internal space of the housing through the opening at the upper end of the side wall. Then, the top cover is fixed to the upper end of the side wall to close the internal space of the housing, thus further facilitating the overall assembly of the actuator.
[0018] In a preferred embodiment, a downwardly extending bushing is provided on the inner support. The axle of the sun gear passes through the bushing, and the upper end face of the sun gear abuts against the lower end face of the bushing. The bushing is keyed to the axle of the sun gear. By providing the bushing, the inner edge of the inner support is sleeved with the axle of the sun gear, increasing the axial dimension of the interaction between the inner support and the sun gear. This makes the synchronous connection between the connecting support and the sun gear more stable and the power transmission between the connecting support and the planetary reduction mechanism smoother.
[0019] In a preferred embodiment, the bottom surface of the inner support is offset upwards by 0-8 mm from the upper end surface of the internal teeth of the internal gear ring, and an upwardly recessed clearance groove is provided on the bottom surface of the inner support, in which at least a portion of the planetary carrier is embedded. By providing a clearance groove on the inner support to avoid interference between the planetary carrier and the connecting support in the axial direction of the actuator, it is also beneficial to reduce the space occupied by the planetary reduction mechanism and the connecting support in the axial direction of the actuator, thereby reducing the axial dimension of the actuator.
[0020] Robotic joints, including the actuators with planetary reduction mechanisms described above.
[0021] The accompanying drawings, which form part of this application, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an improper limitation of the invention. Attached Figure Description
[0022] Figure 1 is a cross-sectional schematic diagram of the actuator with planetary reduction mechanism of the present invention;
[0023] Figure 2 is an enlarged view of point A in Figure 1;
[0024] Figure 3 is a schematic diagram of the assembly of the connecting bracket and the internal gear ring in Figure 1;
[0025] Figure 4 is a cross-sectional view of the connecting bracket and the internal gear ring in step 1;
[0026] Figure 5 is a schematic diagram of the external support structure in Figure 4.
[0027] In the diagram: 11. Side wall; 12. Support wall; 13. Top cover; 20. Motor; 21. Stator; 22. Rotor; 31. Internal gear ring; 311. Support rib; 312. Support step; 313. Snap ring; 314. Snap groove; 315. Upper end face; 32. Sun gear; 33. Planetary support; 34. Planetary gear; 35. Bearing; 40. Connecting bracket; 41. Outer bracket; 411. First fixing ring; 412. Second fixing ring; 4120. Lower surface; 413. Connecting rib; 414. Connecting arm; 42. Inner bracket; 420. Upper surface; 4201. Gap; 421. Support rib; 422. Bushing; 423. Bottom surface; 424. Clearance groove; 43. Bolt. Detailed Implementation
[0028] The present invention will now be further described in conjunction with the accompanying drawings and specific embodiments.
[0029] Please refer to Figures 1-5, which illustrate an actuator with a planetary reduction mechanism according to the present invention. The actuator includes a housing, a motor 20, and a planetary reduction mechanism comprising an internal gear ring 31, a sun gear 32, a planetary carrier 33, and planetary gears 34. The internal gear ring 31 is fixedly fitted to the housing, serving as a fixed component of the planetary reduction mechanism. The sun gear 32, planetary carrier 33, and planetary gears 34 are all located inside the internal gear ring 31 (i.e., within the circular space enclosed by the internal gear ring 31). The planetary gears 34 are pivotally connected to the planetary carrier 33 and are meshed between the sun gear 32 and the internal gear ring 31. An installation chamber is formed between the ring 31 and the outer casing. The top of the internal gear ring 31 is provided with an upwardly protruding and annular support rib 311. The inner side of the support rib 311 is provided with a snap ring 313 that engages with the support rib 311. The installation chamber is annular around the axis of the actuator. The motor 20 is installed inside the installation chamber. It is a frameless torque motor, including a stator 21 and a rotor 22. The stator 21 is fixedly fitted to the outer casing. The stator 21 and the rotor 22 are matched so that the rotor 22 can rotate relative to the stator 21. The rotor 22 is synchronously connected to the sun gear 32 through a connecting bracket 40.
[0030] The connecting bracket 40 includes an outer bracket 41 and an inner bracket 42. The outer edge of the outer bracket 41 is fixedly connected to the rotor 22, and the inner edge extends over the support rib 311 and then to the inner side of the support rib 311. The outer edge of the inner bracket 42 is fixedly connected to the inner edge of the outer bracket 41 by bolts 43. That is, the inner bracket 42 and the outer bracket 41 are detachably fixed together, so that the connecting bracket 40 forms a split structure composed of the inner bracket 42 and the outer bracket 41. The inner bracket 42 can be inserted into the space enclosed by the support rib 311 through the opening formed by the top of the support rib 311. That is, the outer diameter of the inner bracket 42 is smaller than the inner diameter of the support rib 311, so that the inner bracket 42 can be located inside the support rib 311.
[0031] A bearing 35 is provided between the supporting rib 311 and the inner bracket 42. The outer ring of the bearing 35 is fixedly engaged with the supporting rib 311, and the inner ring is fixedly engaged with the connecting bracket 40. Specifically, the outer ring of the bearing 35 is clamped between the retaining spring 313 and the supporting rib 311. The downward pressing force of the retaining spring 313, in conjunction with the supporting rib 311, fixes the outer ring of the bearing 35 to the supporting rib 311. The inner ring of the bearing 35 is clamped between the outer bracket 41 and the inner bracket 42 of the connecting bracket 40. When the outer bracket 41 and the inner bracket 42 are locked with the bolt 43, the inner ring of the bearing 35 is clamped and fixed, thereby fixing the inner ring of the bearing 35 to the connecting bracket 40.
[0032] The bearing 35 of the present invention is placed between the support rib 311 and the connecting bracket 40. The support rib 311 is set on the internal gear ring 31 and fixedly engaged with the outer shell, so that the bearing 35 can provide radial support for the connecting bracket 40, so that the assembly formed by the rotor 22, the connecting bracket 40 and the sun gear 32 can rotate stably and prevent wobbling during rotation.
[0033] During assembly, the bearing 35 is first fitted around the inner bracket 42 and embedded inside the support rib 311. Then, the retaining ring 313 is placed inside the support rib 311. The retaining ring 313 acts as a clamping element and works with the support rib 311 to clamp and fix the outer ring of the bearing 35. Finally, the outer bracket 41 is placed at the end of the support rib 311. The bolt 43 is passed through the outer bracket 41 and the inner bracket 42, and the bolt 43 is tightened. The outer bracket 41 and the inner bracket 42 are used to clamp and fix the inner ring of the bearing 35, thus completing the assembly of the connecting bracket 40, the bearing 35 and the inner gear ring 31.
[0034] The outer ring of the bearing 35 is fixed to the support rib 311 by pressing against both ends of the outer ring of the bearing 35. The inner ring of the bearing 35 is fixed to the connecting bracket 40 by pressing against both ends of the outer bracket 41 and the inner bracket 42. The inner ring of the bearing 35 does not need to be tightly fitted with the connecting bracket 40 and the support rib 311, so there is no need to use special pressing tools to disassemble and install the bearing 35. This makes the bearing 35 easy to assemble and disassemble, and will not cause damage to the bearing 35 during assembly and disassembly. In addition, the inner bracket 42 and the outer bracket 41 of the connecting bracket 40 are of a split structure, which will not interfere with the bearing 35 during installation. This ensures that the connecting bracket 40 and the bearing 35 can be quickly assembled into the inside of the actuator housing from one end, and will not interfere with other components inside the actuator housing during installation, which facilitates the overall assembly of the actuator.
[0035] It should be noted that the clamping member fixed on the support rib 311 for pressing down the outer ring of the bearing 35 is not limited to the aforementioned snap ring 313. The clamping member can also be other components that can press down the outer ring of the bearing 35, such as a pressure ring threaded to the inner side of the support rib 311, or other components that can be detachably connected to the inner side of the support rib 311.
[0036] The housing includes a side wall 11 and a support wall 12. The side wall 11 has a cylindrical structure, and the support wall 12 extends radially inward from the inner surface of the side wall 11 along the actuator. The lower end of the internal gear ring 31 is connected to the support wall 12. The mounting chamber is formed by the internal gear ring 31, the side wall 11, and the support wall 12. The radially extending support wall 12 serves as the fixing base for the internal gear ring 31, so that the internal gear ring 31 is fixedly engaged with the housing. When the mounting chamber for placing the motor 20 forms a structure with an open top, it is convenient to place the motor 20 in the mounting chamber from top to bottom, which further facilitates the assembly of the actuator.
[0037] In other embodiments, the support wall 12 may also be located above the side wall 11, with the top end of the internal gear ring 31 fixed to the lower surface of the support wall 12, and the support rib 311 extending downward from the internal gear ring 31 to form a structure with a lower opening in the mounting chamber. The motor 20 is installed into the mounting chamber from the lower part of the housing. Correspondingly, the inner edge of the outer bracket 41 of the connecting bracket 40 is positioned below the support rib 311.
[0038] The outer support 41 includes a first fixing ring 411 located on its outer edge, a second fixing ring 412 located on its inner edge, and a plurality of connecting ribs 413. The connecting ribs 413 are connected between the first fixing ring 411 and the second fixing ring 412 to connect the first fixing ring 411 and the second fixing ring 412 into one unit. The second fixing ring 412 is placed above the upper surface 420 of the outer edge of the inner support 42. A support rib 421 extending outward is provided at the bottom of the outer edge of the inner support 42. The top end of the inner ring of the bearing 35 abuts against the lower surface 4120 of the second fixing ring 412, and the bottom end of the inner ring of the bearing 35 abuts against the support rib 421.
[0039] During assembly, the bearing 35 can be first fitted onto the inner bracket 42, and the bottom end of the inner ring of the bearing 35 can be supported by the support rib 421. Then, the second fixing ring 412 of the outer bracket 41 is placed above the upper surface 420 of the inner edge of the inner bracket 42. Tightening the bolt 43 will press the top end of the inner ring of the bearing 35 downward by the lower surface 4120 of the second fixing ring 412, so that the bottom end of the inner ring of the bearing 35 finally abuts against the support rib 421. That is, the frictional resistance between the inner ring of the bearing 35 and the outer edge of the inner bracket 42 can be overcome simply by tightening the bolt 43, which facilitates the assembly of the bearing 35.
[0040] The bolt 43 passes through the second fixing ring 412 from top to bottom and is screwed onto the outer edge of the inner bracket 42. The lower surface 4120 of the second fixing ring 412 is in clearance fit with the upper surface 420 of the outer edge of the inner bracket 42, that is, a gap 4201 is formed between the lower surface 4120 of the second fixing ring 412 and the upper surface 420 of the outer edge of the inner bracket 42. During assembly, tighten bolt 43 to press the second retaining ring 412 downwards. The lower surface 4120 of the second retaining ring 412 contacts the top surface of the inner ring of the bearing 35 and continuously pushes the inner ring of the bearing 35 downwards until the bottom end of the inner ring of the bearing 35 presses against the support rib 421. Since the lower surface 4120 of the second retaining ring 412 is in clearance fit with the upper surface 420 of the outer edge of the inner bracket 42, the second retaining ring 412 can fully press the inner ring of the bearing 35 downwards, eliminating as much of the clearance between the bottom end of the inner ring of the bearing 35 and the support rib 421 as possible, and preventing the inner ring of the bearing 35 from axially loosening relative to the connecting bracket 40.
[0041] The first fixing ring 411 is positioned above the supporting rib 311, and multiple downwardly extending connecting arms 414 are provided on it. The multiple connecting arms 414 are positioned on the inner surface of the rotor 22 and are fixedly connected to the rotor 22. The connecting rib 413 located between the first fixing ring 411 and the second fixing ring 412 is inclined. Specifically, in the radial direction of the actuator, the connecting rib 413 gradually slopes downward from the right outer side to the inside, so that the height of the second fixing ring 412 is lower than the height of the first fixing ring 411. The second fixing ring 412 is placed between the top surface of the supporting rib 311 and the upper surface 420 of the outer edge of the inner bracket 42. In this way, the height of the lower surface 4120 of the second fixing ring 412 is reduced in the height direction. This allows the connecting bracket 40 to span the internal gear ring 31 while avoiding the bearing 35 being installed too high. The position of the bearing 35 can be as close as possible to the center of gravity of the rotating structure formed by the connecting bracket 40 and the rotor 22, improving the stability of the rotor 22's rotation. Furthermore, setting the part of the connecting bracket 40 located in the inner bracket 42 as a sunken structure can make room for other components inside the actuator, making the internal structure of the actuator more compact and helping to reduce the axial dimension of the actuator.
[0042] It should be noted that the connecting rib 413 can be set as an entire inclined structure, or a part of the connecting rib 413 can be set as an inclined structure. For example, a part of the connecting rib 413 near the first fixing ring 411 can be set to be radially aligned with the actuator, and a part of the connecting rib 413 near the second fixing ring 412 can be set as a downward inclined structure to ensure that the second fixing ring 412 can be located inside the supporting rib 311. While reducing the installation height of the inner bracket 42, the outer bracket 41 can be straddled above the top of the supporting rib 311 to avoid the supporting rib 311.
[0043] The inner side of the supporting rib 311 is provided with a supporting step 312 and a groove 314 located above the supporting step 312. The distance between the groove 314 and the supporting step 312 is approximately equal to the axial dimension of the outer ring of the bearing 35. The retaining spring 313 is engaged in the groove 314. The top end of the outer ring of the bearing 35 abuts against the retaining spring 313, and the bottom end of the outer ring of the bearing 35 abuts against the supporting step 312. By engaging the retaining spring 313 with the groove 314 on the supporting rib 311, axial movement of the retaining spring 313 can be prevented. This allows the retaining spring 313 to cooperate with the supporting step 312 to fix the outer ring of the bearing 35 onto the supporting rib 311, preventing axial movement of the outer ring of the bearing 35 relative to the supporting rib 311.
[0044] The housing also includes a top cover 13, which is detachably fixed to the upper end of the side wall 11. Specifically, the top cover 13 can be fixed to the upper end of the side wall 11 by screws around its periphery. By providing a detachable top cover 13, the motor 20, the planetary reduction mechanism, and the connecting bracket 40 can be inserted into the interior space of the housing through the opening at the upper end of the side wall 11. Then, the top cover 13 is fixed to the upper end of the side wall 11, thereby sealing the interior space of the housing. This further facilitates the overall assembly of the actuator.
[0045] To facilitate the synchronous connection of the connecting bracket 40 and the sun gear 32, a downwardly extending bushing 422 is provided on the inner bracket 42. The axle of the sun gear 32 extends upward and passes through the bushing 422 from bottom to top. The upper end face of the sun gear 32 abuts against the lower end face of the bushing 422. Keyways are provided on the inner wall of the bushing 422 and the outer surface of the axle of the sun gear 32. A key is provided in the keyway to connect the bushing 422 and the axle of the sun gear 32. By providing the bushing 422, the inner edge of the inner bracket 42 is connected to the axle 422 of the sun gear 32, increasing the axial dimension of the interaction between the inner bracket 42 and the sun gear 32. This makes the synchronous connection between the connecting bracket 40 and the sun gear 32 more stable and the power transmission between the connecting bracket 40 and the planetary reduction mechanism smoother.
[0046] The bottom surface 423 of the inner support 42 is offset upward by 0-8mm from the upper end face 315 of the internal gear ring 31. That is, the bottom surface 423 of the inner support 42 is flush with or slightly higher than the upper end face 315 of the internal gear ring 31. Preferably, the bottom surface 423 of the inner support 42 and the upper end face 315 of the internal gear ring 31 are made flush to make full use of the axial space of the actuator. An upwardly recessed clearance groove 424 is provided on the bottom surface 423 of the inner support 42, and a portion of the top of the planetary carrier 33 is embedded in the clearance groove 424. By providing the clearance groove 424 on the inner support 42, the planetary carrier 33 is avoided in the axial direction of the actuator, thus avoiding interference between the planetary carrier 33 and the connecting support 40. This also helps to reduce the space occupied by the planetary reduction mechanism and the connecting support 40 in the axial direction of the actuator, thereby reducing the axial dimension of the actuator.
[0047] The robot joint of the present invention includes the actuator with planetary reduction mechanism described above. Other structures of the robot joint are the same as those in the prior art and will not be described in detail here.
Claims
1. An actuator with a planetary reduction mechanism, characterized in that, Includes the housing, motor, and planetary gear reducer; The planetary reduction mechanism includes an internal gear ring, a sun gear, a planetary carrier, and planetary gears that are fixedly fitted to the outer casing. The sun gear, planetary carrier, and planetary gears are all located inside the internal gear ring. The planetary gears are pivotally connected to the planetary carrier and mesh between the sun gear and the internal gear ring. An installation chamber is formed between the internal gear ring and the outer casing. An annular support rib is provided on the internal gear ring. A clamping member is detachably fixed to the support rib on the inner side of the support rib. The motor is placed in the mounting chamber and includes a stator that is fixedly fitted with the housing and a rotor that matches the stator. The rotor is synchronously connected to the sun gear through a connecting bracket. The connecting bracket includes an outer bracket and an inner bracket. The outer edge of the outer bracket is fixedly connected to the rotor. The inner edge of the outer bracket extends over the end of the supporting rib and then extends to the inner side of the supporting rib. The outer edge of the inner bracket is fixedly connected to the inner edge of the outer bracket by bolts. The inner bracket can be embedded into the supporting rib along the end opening of the supporting rib. A bearing is provided between the supporting rib and the inner bracket to pivotally connect the connecting bracket and the supporting rib. The outer ring of the bearing is clamped between the clamping member and the supporting rib, and the inner ring of the bearing is clamped between the outer bracket and the inner bracket.
2. The actuator with a planetary reduction mechanism as described in claim 1, characterized in that, The housing includes a sidewall, a support wall extending radially inward from the inner surface of the sidewall along the actuator, the lower end of the internal gear ring being connected to the support wall, and the mounting chamber being formed by the internal gear ring, the sidewall, and the support wall.
3. The actuator with a planetary reduction mechanism as described in claim 2, characterized in that, The outer support includes a first fixing ring located on its outer edge, a second fixing ring located on its inner edge, and a connecting rib connecting the first fixing ring and the second fixing ring. The second fixing ring is placed above the upper surface of the outer edge of the inner support. A support rib extending outward is provided at the bottom of the outer edge of the inner support. The top of the inner ring of the bearing abuts against the lower surface of the second fixing ring, and the bottom of the inner ring of the bearing abuts against the support rib.
4. The actuator with a planetary reduction mechanism as described in claim 3, characterized in that, The bolt passes through the second fixing ring from top to bottom and is screwed onto the outer edge of the inner bracket. The lower surface of the second fixing ring is clearance-fitted with the upper surface of the outer edge of the inner bracket.
5. The actuator with a planetary reduction mechanism as described in claim 3, characterized in that, The first fixing ring is positioned above the supporting rib, and a connecting arm is provided on it that extends downward and is fixedly connected to the rotor. In the radial direction of the actuator, at least one section of the connecting rib is inclined downward from the outside to the inside so that the second fixing ring is positioned between the top surface of the supporting rib and the upper surface of the outer edge of the inner support.
6. The actuator with a planetary reduction mechanism as described in claim 2, characterized in that, The inner side of the supporting rib is provided with a supporting step and a slot located above the supporting step. The clamping element is a retaining spring that is clamped in the slot. The top of the outer ring of the bearing abuts against the retaining spring, and the bottom of the outer ring of the bearing abuts against the supporting step.
7. The actuator with a planetary reduction mechanism as described in claim 2, characterized in that, The housing also includes a top cover, which is detachably attached to the upper end of the side wall.
8. The actuator with a planetary reduction mechanism as described in claim 1, characterized in that, An inner support is provided with a downwardly extending bushing, the axle of the sun gear passes through the bushing, the upper end face of the sun gear abuts against the lower end face of the bushing, and the bushing is keyed to the axle of the sun gear.
9. The actuator with a planetary reduction mechanism as described in claim 1, characterized in that, The bottom surface of the inner support is offset upward by 0~8mm from the upper end of the inner tooth of the inner gear ring, and an upwardly recessed clearance groove is provided on the bottom surface of the inner support, at least a part of the planetary support is embedded in the clearance groove.
10. A robot joint, characterized in that, Includes the actuator with planetary deceleration mechanism as described in any one of claims 1-9.