Actuator and robot joint with planetary reduction mechanism

Abstract

The present invention discloses an actuator and a robot joint with a planetary reduction mechanism, wherein the actuator comprises a housing, a motor, and a planetary reduction mechanism; the planetary reduction mechanism comprises an inner gear ring, a sun gear, a planetary bracket, and a planetary gear; a supporting rib is arranged on the inner gear ring, and a pressing piece is detachably fixed on the inner side surface of the supporting rib; the motor comprises a stator and a rotor, and the rotor is synchronously connected with the sun gear through a connecting bracket; the connecting bracket comprises an outer bracket and an inner bracket, and the outer edge of the inner bracket and the inner edge of the outer bracket are fixedly connected by bolts, and a bearing is arranged between the supporting rib and the inner bracket, and the outer ring of the bearing is clamped between the pressing piece and the supporting rib, and the inner ring of the bearing is clamped between the outer bracket and the inner bracket. The inner ring and the outer ring of the bearing of the present invention do not need to be tightly matched with the connecting bracket and the supporting rib, so there is no need to use a special pressing tool to disassemble and assemble the bearing, so that the bearing is easy to assemble and disassemble, and the assembly of the actuator as a whole is convenient.

Description

Technical Field

[0001] The present invention relates to the technical field of robot driving, and in particular to an actuator with a planetary reduction mechanism and a robot joint. Background Art

[0002] The actuator is the core component of the robot joint, which is used to provide power for the relative movement between the two moving parts of the robot joint and accurately control the movement angle of the two moving parts in the robot joint.

[0003] The actuator generally includes a housing, a motor and a reduction mechanism. The reduction mechanism of existing actuators generally adopts a planetary reduction mechanism. Since the planetary reduction mechanism occupies relatively more radial space of the actuator, a motor chamber is formed between the inside of the actuator housing and the inner gear ring of the planetary reduction mechanism. A frameless torque motor is installed in the 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 spanning the inner gear ring of the planetary reduction mechanism is required to synchronously connect the rotor of the frameless torque motor with the sun gear of the planetary reduction mechanism.

[0004] In order to ensure the stable rotation of the connecting bracket, the stator and the sun gear, a bearing needs to be arranged between the housing and the connecting bracket (or the stator) to provide radial support to the connecting bracket or the stator. However, in the existing actuator, a bearing is arranged between the outer periphery of the connecting bracket and the housing. Since the bearing occupies a certain radial space, the radial size of the actuator is relatively large, and the overall structure of the actuator is not compact enough.

[0005] In order to prevent the bearing from occupying the radial space of the actuator, in some actuators, a bearing is arranged between the inner side of the inner gear ring fixedly matched with the outer shell and the connecting bracket to provide radial support for the connecting bracket. However, when assembling the bearing with the connecting bracket and the inner gear ring, it is necessary to clamp the inner ring and outer ring of the bearing with the connecting bracket and the inner gear ring respectively by press-fitting, so that the inner ring of the bearing is tightly matched with the connecting bracket, and the outer ring of the bearing is tightly matched with the inner gear ring. The press-fitting method makes the assembly of the actuator more difficult, and professional tools are required to assemble and disassemble the bearing. The bearing is easily damaged during the assembly and disassembly process. Therefore, the existing actuators using the above structure have many inconveniences during assembly and maintenance. 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 a robot joint with a planetary reduction mechanism to solve the problem in the prior art that the bearing between the actuator connecting bracket and the inner gear ring is difficult to assemble and inconvenient to maintain.

[0007] The purpose of the present invention is achieved by the following technical solutions:

[0008] An actuator with a planetary reduction mechanism, comprising a housing, a motor and a planetary reduction mechanism;

[0009] The planetary reduction mechanism comprises an inner gear ring, a sun gear, a planetary bracket and a planetary gear fixedly matched with the housing. The sun gear, the planetary bracket and the planetary gear are all located on the inner side of the inner gear ring. The planetary gear is pivotally connected to the planetary bracket and meshes between the sun gear and the inner gear ring. An installation chamber is formed between the inner gear ring and the housing. An annular supporting rib is arranged on the inner gear ring. A pressing piece detachably fixed to the supporting rib is arranged on the inner side surface of the supporting rib.

[0010] The motor is placed in the installation chamber, and includes a stator fixedly matched with the housing, and a rotor matched with the stator, and the rotor is synchronously connected with 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, and the inner edge of the outer bracket spans the end of the supporting rib and extends to the inner side of the supporting rib. The outer edge of the inner bracket and the inner edge of the outer bracket are fixedly connected together by bolts. The inner bracket can be embedded in the supporting rib along the end opening of the supporting rib, and a bearing is arranged 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 piece and the supporting rib, and the inner ring of the bearing is clamped between the outer bracket and the inner bracket.

[0012] The embodiment of the present invention fixes the outer ring of the bearing to the supporting rib by pressing the two ends of the outer ring of the bearing with a clamping piece and a supporting rib, and fixes the inner ring of the bearing to the connecting bracket by pressing the two ends of the inner ring of the bearing with an outer bracket and an inner bracket. The inner ring and the outer ring of the bearing do not need to be tightly matched with the connecting bracket and the supporting rib, so there is no need to use special pressing tools to disassemble the bearing, so that the bearing is easy to assemble and disassemble, and the bearing will not be damaged during the assembly and disassembly process. In addition, the inner bracket and the outer bracket of the connecting bracket are of a split structure, and will not interfere with the bearing during the installation process, ensuring that the connecting bracket and the bearing can be quickly assembled into the interior of the actuator housing from one end of the actuator housing, and will not interfere with other components inside the actuator housing, thereby facilitating the overall assembly of the actuator.

[0013] In a preferred embodiment, the housing includes a side wall, a support wall extending radially inward from the inner surface of the side wall along the actuator, the lower end of the inner gear ring is connected to the support wall, and the installation chamber is surrounded by the inner gear ring, the side wall and the support wall. The support wall extending radially serves as a fixing base for the inner gear ring, so that the inner gear ring is fixedly matched with the housing. When the installation chamber for placing the motor forms a structure with an upper opening, the motor can be conveniently placed in the installation chamber from top to bottom, further facilitating the assembly of the actuator.

[0014] In a preferred embodiment, the outer bracket includes a first fixing ring located at its outer edge, a second fixing ring located at its inner edge, and a connecting rib connected between 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 bracket. The bottom of the outer edge of the inner bracket is provided with a supporting rib extending outward. 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 supporting rib. During the assembly process, the bearing sleeve can be firstly arranged on the inner bracket, and the bottom end of the inner ring of the bearing can be supported by the supporting rib. Then, the second fixing ring of the outer bracket is placed above the upper surface of the inner edge of the inner bracket. By tightening the bolts, the top of the inner ring of the bearing can be pressed downward by the lower surface of the second fixing ring, so that the bottom end of the inner ring of the bearing finally abuts against the supporting rib. That is, the friction resistance between the inner ring of the bearing and the outer edge of the inner bracket can be overcome by tightening the bolts, which facilitates the assembly of the bearing.

[0015] In a preferred embodiment, the bolt passes through the second fixing ring from top to bottom and is screwed to the outer edge of the inner bracket, and the lower surface of the second fixing ring is in clearance with the upper surface of the outer edge of the inner bracket. During the assembly process, the bolt is tightened to press the second fixing ring downward, and 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 end of the inner ring of the bearing presses the support rib. Since the lower surface of the second fixing ring is in clearance with the upper surface of the outer edge of the inner bracket, the second fixing ring can fully press the inner ring of the bearing downward, and the clearance between the bottom end of the inner ring of the bearing and the support rib is eliminated as much as possible, so as to prevent the inner ring of the bearing from axially loosening relative to the connecting bracket.

[0016] In a preferred embodiment, the first fixing ring is placed above the supporting rib, and a connecting arm extending downward and fixedly connected to the rotor is provided on the first fixing ring. In the radial direction of the actuator, at least one section of the connecting rib is gradually inclined downward from the outside to the inside so that the second fixing ring is placed between the top end surface of the supporting rib and the upper surface of the outer edge of the inner bracket. The second fixing ring is placed between the top end surface of the supporting rib and the upper surface of the outer edge of the inner bracket. In this way, in the height direction, the height of the lower surface of the second fixing ring is reduced, and while the connecting bracket can be placed across the inner gear ring, the installation position of the bearing is avoided to be too high. The position of the bearing can be as close as possible to the center of gravity of the rotating structure formed by the connecting bracket and the rotor, thereby improving the stability of the rotor rotation. In addition, the part of the connecting bracket located at the inner bracket is set as a sinking structure, which can make room for other components inside the actuator, making the internal structure of the actuator more compact, which is conducive to reducing the axial size of the actuator.

[0017] In a preferred embodiment, a support step and a clamping groove above the support step are provided on the inner side of the support rib, the pressing member is a clamping spring clamped in the clamping groove, the top end of the outer ring of the bearing abuts against the clamping spring, and the bottom end of the outer ring of the bearing abuts against the support step. The clamping spring is clamped on the support rib through the clamping groove on the support rib, which can prevent the clamping spring from axial movement, so that the clamping spring can cooperate with the support step to fix the outer ring of the bearing on the support rib, preventing the outer ring of the bearing from axial movement relative to the support rib.

[0018] In a preferred embodiment, the housing further comprises an upper cover, which is fixedly connected to the upper end of the side wall in a detachable manner. By providing a detachable upper cover, the motor, the planetary reduction mechanism and the connecting bracket can be installed into the internal space of the housing through the opening of the upper end of the side wall, and then the upper cover is fixed to the upper end of the side wall to close the internal space of the housing, thereby further facilitating the assembly of the actuator as a whole.

[0019] In a preferred embodiment, a shaft sleeve extending downward is provided on the inner bracket, the axle of the sun gear is inserted into the shaft sleeve, the upper end surface of the sun gear gear abuts against the lower end surface of the shaft sleeve, and the shaft sleeve is key-connected with the axle of the sun gear. By providing the shaft sleeve, the inner edge of the inner bracket and the axle of the sun gear are sleeved together, increasing the axial dimension of the inner bracket and the sun gear to cooperate with each other, thereby making the synchronous connection between the connecting bracket and the sun gear more stable, and making the power transmission between the connecting bracket and the planetary reduction mechanism smoother.

[0020] In a preferred embodiment, the bottom surface of the inner bracket is offset upward by 0 to 8 mm compared to the upper end surface of the inner teeth of the inner gear ring, and an upwardly recessed avoidance groove is provided on the bottom surface of the inner bracket, and at least a portion of the planetary bracket is embedded in the avoidance groove. By providing the avoidance groove on the inner bracket, the planetary bracket is avoided in the axial direction of the actuator, and the interference between the planetary bracket and the connecting bracket is avoided, which is also conducive to reducing the space occupied by the planetary reduction mechanism and the connecting bracket in the axial direction of the actuator, thereby reducing the axial size of the actuator.

[0021] A robot joint comprises the above-mentioned actuator with a planetary reduction mechanism.

[0022] The drawings in the specification, which constitute a part of this application, are used to provide a further understanding of the present invention. The illustrative embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute improper limitations on the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 It is a cross-sectional schematic diagram of an actuator with a planetary reduction mechanism according to the present invention;

[0024] Figure 2 for Figure 1 The enlarged schematic diagram of point A in the middle;

[0025] Figure 3 for Figure 1 Schematic diagram of the assembly of the connecting bracket and the inner gear ring;

[0026] Figure 4 It is a cross-sectional schematic diagram of the connection bracket and the inner gear ring in 1;

[0027] Figure 5 for Figure 4 Schematic diagram of the structure of the middle and outer brackets.

[0028] In the figure: 11, side wall; 12, supporting wall; 13, upper cover; 20, motor; 21, stator; 22, rotor; 31, inner ring gear; 311, supporting rib; 312, supporting step; 313, retaining spring; 314, retaining groove; 315, upper end surface; 32, sun gear; 33, planetary bracket; 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, supporting rib; 422, bushing; 423, bottom surface; 424, avoidance groove; 43, bolt. DETAILED DESCRIPTION

[0029] Below, in conjunction with the accompanying drawings and specific embodiments, the present invention is further described. It should be noted that, under the premise of no conflict, the various embodiments described below or the various technical features can be arbitrarily combined to form a new embodiment. Except for special instructions, the materials and equipment used in this embodiment can be purchased from the market. Examples of embodiments are shown in the accompanying drawings, in which the same or similar reference numerals throughout represent the same or similar elements or elements with the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present application, and the limitations of the present application cannot be understood.

[0030] In the description of the present application, it should be understood that the terms "upper", "lower", "front", "back", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific position, be constructed and operated in a specific position, and therefore cannot be understood as a limitation on the present application. In the description of the present application, "plurality" means two or more, unless otherwise precisely and specifically specified.

[0031] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "connected", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, or it can be connected through an intermediary medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0032] The terms "first", "second", etc. in the specification and claims of this application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device that includes a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0033] Please refer to Figure 1-5 As shown, an actuator with a planetary reduction mechanism of the present invention comprises a housing, a motor 20, and a planetary reduction mechanism comprising an inner gear ring 31, a sun gear 32, a planetary carrier 33, and a planetary gear 34. The inner gear ring 31 is fixedly matched with the housing as a fixed component of the planetary reduction mechanism. The sun gear 32, the planetary carrier 33, and the planetary gear 34 are all located on the inner side of the inner gear ring 31 (i.e., located inside the circular space surrounded by the inner gear ring 31). The planetary gear 34 is pivotally connected to the planetary carrier 33, and the planetary gear 34 is meshed between the sun gear 32 and the inner gear ring 31; the inner gear ring 31 An installation chamber is formed between the inner gear ring 31 and the outer shell, and an upwardly protruding and annular support rib 311 is provided on the top of the inner gear ring 31, and a retaining spring 313 engaged with the support rib 311 is provided on the inner side surface of the support rib 311; the installation chamber is a ring surrounding the axis of the actuator, and 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 matched with the outer shell, and the stator 21 and the rotor 22 are matched so that the rotor 22 can rotate relative to the stator 21, and the rotor 22 is synchronously connected with the sun gear 32 through a connecting bracket 40.

[0034] 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 is arranged above the supporting rib 311 and then extends to the inner side of the supporting 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 consisting of the inner bracket 42 and the outer bracket 41. The inner bracket 42 can be embedded in the opening surrounded by the top of the supporting rib 311 into the space surrounded by the supporting rib 311. That is, the outer diameter of the inner bracket 42 is smaller than the inner diameter of the supporting rib 311, so that the inner bracket 42 can be located on the inner side of the supporting rib 311.

[0035] A bearing 35 is arranged between the supporting rib 311 and the inner bracket 42. The outer ring of the bearing 35 is fixedly matched with the supporting rib 311, and the inner ring is fixedly matched 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, and the outer ring of the bearing 35 is fixed to the supporting rib 311 through the downward pressing force of the retaining spring 313 and 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 by the bolt 43, the inner ring of the bearing 35 is clamped and fixed, so that the inner ring of the bearing 35 is fixedly matched with the connecting bracket 40.

[0036] The bearing 35 of the present invention is placed between the supporting rib 311 and the connecting bracket 40. The supporting rib 311 is arranged on the inner gear ring 31 and fixedly matched 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 it from swinging during rotation.

[0037] During assembly, the bearing 35 is first sleeved on the outer periphery of the inner bracket 42, and the bearing 35 is embedded in the inner side of the supporting rib 311, and then the retaining spring 313 is placed on the inner side of the supporting rib 311. The retaining spring 313 acts as a clamping member and cooperates with the supporting rib 311 to clamp the outer ring of the bearing 35. Finally, the outer bracket 41 is placed on the end of the supporting rib 311, and the bolt 43 is passed through the outer bracket 41 and the inner bracket 42. The bolt 43 is tightened, and the inner ring of the bearing 35 is clamped and fixed by the outer bracket 41 and the inner bracket 42, thereby completing the assembly of the connecting bracket 40, the bearing 35 and the inner gear ring 31.

[0038] In the present invention, the outer ring of the bearing 35 is fixed to the supporting rib 311 by pressing the two ends of the outer ring of the bearing 35 against the clamping piece and the supporting rib 311, and the inner ring of the bearing 35 is fixed to the connecting bracket 40 by pressing the two ends of the inner ring of the bearing 35 against the outer bracket 41 and the inner bracket 42. The inner ring and the outer ring of the bearing 35 do not need to be tightly matched with the connecting bracket 40 and the supporting rib 311, so there is no need to use special pressing tools to disassemble the bearing 35, so that the bearing 35 is easy to assemble and disassemble, and the bearing 35 will not be damaged during the assembly and disassembly process. In addition, the inner bracket 42 and the outer bracket 41 of the connecting bracket 40 are of a split structure, and will not interfere with the bearing 35 during the installation process, ensuring that the connecting bracket 40 and the bearing 35 can be quickly assembled into the inside of the actuator housing from one end of the actuator housing, and will not interfere with other components inside the actuator housing during installation, so as to facilitate the assembly of the actuator as a whole.

[0039] It should be pointed out that the clamping member fixed on the supporting rib 311 for pressing down the outer ring of the bearing 35 of the present invention is not limited to the above-mentioned retaining spring 313. The clamping member can also be other components that can press down the outer ring of the bearing 35, for example, it can be a pressure ring threadedly connected to the inner side of the supporting rib 311, or other components detachably connected to the inner side of the supporting rib 311.

[0040] In a preferred embodiment, the outer shell includes a side wall 11 and a support wall 12, the side wall 11 is cylindrical, the support wall 12 extends radially inward from the inner surface of the side wall 11 of the actuator, the lower end of the inner gear ring 31 is connected to the support wall 12, and the installation chamber is surrounded by the inner gear ring 31, the side wall 11 and the support wall 12; the support wall 12 extending radially serves as a fixed base for the inner gear ring 31, so that the inner gear ring 31 is fixedly matched with the outer shell, so that the installation chamber for placing the motor 20 forms a structure with an upper opening, which facilitates the placement of the motor 20 in the installation chamber from top to bottom, and further facilitates the assembly of the actuator.

[0041] In other embodiments, the support wall 12 may also be located above the side wall 11, the top end of the inner gear ring 31 is fixed to the lower surface of the support wall 12, and the supporting rib 311 is formed by extending downward from the inner gear ring 31, so that the installation chamber forms a structure with a lower opening, and the motor 20 is installed into the installation chamber from the lower part of the outer casing. Correspondingly, the inner edge of the outer bracket 41 of the connecting bracket 40 is straddled below the supporting rib 311.

[0042] The outer bracket 41 includes a first fixing ring 411 located at its outer edge, a second fixing ring 412 located at 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, and are used to connect the first fixing ring 411 and the second fixing ring 412 into one. The second fixing ring 412 is placed above the upper surface 420 of the outer edge of the inner bracket 42. A supporting rib 421 extending outward is provided at the bottom of the outer edge of the inner bracket 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 supporting rib 421.

[0043] During the assembly process, the bearing 35 can be first sleeved on the inner bracket 42, and the support rib 421 can be used to support the bottom end of the inner ring of the bearing 35. Then, the second fixing ring 412 of the outer bracket 41 is placed above the inner edge upper surface 420 of the inner bracket 42. By tightening the bolt 43, the top end of the inner ring of the bearing 35 can be pressed 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 rests on the support rib 421. That is, the friction resistance between the inner ring of the bearing 35 and the outer edge of the inner bracket 42 can be overcome by tightening the bolt 43, thereby facilitating the assembly of the bearing 35.

[0044] 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 clearance-matched 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 the assembly process, the bolts 43 are tightened to press the second fixing ring 412 downward. The lower surface 4120 of the second fixing ring 412 contacts the top surface of the inner ring of the bearing 35 and continuously pushes the inner ring of the bearing 35 downward until the bottom end of the inner ring of the bearing 35 presses the support rib 421. Since the lower surface 4120 of the second fixing ring 412 and the upper surface 420 of the outer edge of the inner bracket 42 are clearance-matched, the second fixing ring 412 can fully press the inner ring of the bearing 35 downward, and eliminate the fitting clearance between the bottom end of the inner ring of the bearing 35 and the support rib 421 as much as possible, to prevent the axial loosening of the inner ring 35 of the bearing relative to the connecting bracket 40.

[0045] The first fixing ring 411 is placed above the supporting rib 311, and a plurality of downwardly extending connecting arms 414 are arranged thereon. The plurality of connecting arms 414 are placed on the inner surface of the rotor 22 and fixedly connected to the rotor 22; the connecting rib 413 between the first fixing ring 411 and the second fixing ring 412 is arranged obliquely. Specifically, in the radial direction of the actuator, the connecting rib 413 gradually inclines downward from the right outside to the inside, so that the height of the second fixing ring 412 is lower than that of the first fixing ring 411. The second fixing ring 412 is placed between the top end surface of the supporting rib 311 and the upper surface 420 of the outer edge of the inner bracket 42. In this way, in the height direction, the height of the lower surface 4120 of the second fixing ring 412 is reduced, and while the connecting bracket 40 can be arranged astride the inner gear ring 31, the installation position of the bearing 35 is avoided to be 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, thereby improving the rotation stability of the rotor 22. In addition, the part of the connecting bracket 40 located at the inner bracket 42 is set to a sunken structure, which can make room for other components inside the actuator, making the internal structure of the actuator more compact, which is beneficial to reducing the axial size of the actuator.

[0046] It should be pointed out that the entire connecting rib 413 can be set to an inclined structure, or a part of the connecting rib 413 can be set to an inclined structure. For example, a part of the connecting rib 413 close to the first fixing ring 411 is set to be consistent with the radial direction of the actuator, and a part of the connecting rib 413 close to the second fixing ring 412 is set to a downward inclined structure to ensure that the second fixing ring 412 can be located on the inner side of the supporting rib 311, while lowering the installation height of the inner bracket 42, allowing the outer bracket 41 to straddle the top of the supporting rib 311 to avoid the supporting rib 311.

[0047] The inner side surface of the support convex rib 311 is provided with a support step 312 and a clamping groove 314 located above the support step 312. The distance between the clamping groove 314 and the support step 312 is equivalent to the axial dimension of the outer ring of the bearing 35. The clamping spring 313 is clamped in the clamping groove 314. The top end of the outer ring of the bearing 35 abuts against the clamping spring 313, and the bottom end of the outer ring of the bearing 35 abuts against the support step 312. The clamping spring 313 is clamped on the support convex rib 311 by the clamping groove 314 on the support convex rib 311, which can prevent the clamping spring 313 from axial movement, so that the clamping spring 313 can cooperate with the support step 312 to fix the outer ring of the bearing 35 on the support convex rib 311, and prevent the outer ring of the bearing 35 from axial movement relative to the support convex rib 311.

[0048] The housing further includes an upper cover 13, which is fixedly connected to the upper end of the side wall 11 in a detachable manner. Specifically, the upper cover 13 can be fixed to the upper end of the side wall 11 by screws on its periphery. By providing a detachable upper cover 13, the motor 20, the planetary reduction mechanism and the connecting bracket 40 can be installed into the internal space of the housing from the opening of the upper end of the side wall 11, and then the upper cover 13 is fixed to the upper end of the side wall 11, and the internal space of the housing is closed by the upper cover 13, so that the assembly of the actuator as a whole is further facilitated.

[0049] In order to facilitate the synchronous connection of the connecting bracket 40 and the sun gear 32, a shaft sleeve 422 extending downward is provided on the inner bracket 42, the wheel shaft of the sun gear 32 extends upward and penetrates into the shaft sleeve 422 from bottom to top, the upper end surface of the gear of the sun gear 32 abuts against the lower end surface of the shaft sleeve 422, and the inner wall surface of the shaft sleeve 422 and the outer surface of the wheel shaft of the sun gear 32 are provided with key grooves, and the key grooves are provided with keys to connect the shaft sleeve 422 with the wheel shaft of the sun gear 32. By providing the shaft sleeve 422, the inner edge of the inner bracket 42 is connected with the wheel shaft sleeve 422 of the sun gear 32, and the axial dimension of the inner bracket 42 and the sun gear 32 that cooperate with each other is increased, so that the synchronous connection between the connecting bracket 40 and the sun gear 32 is more stable, and the power transmission between the connecting bracket 40 and the planetary reduction mechanism is smoother.

[0050] The bottom surface 423 of the inner bracket 42 is offset upward by 0-8 mm compared to the upper end surface 315 of the inner teeth of the inner gear ring 31, that is, the bottom surface 423 of the inner bracket 42 is flush with or slightly higher than the upper end surface 315 of the inner teeth of the inner gear ring 31. Preferably, the bottom surface 423 of the inner bracket 42 is set flush with the upper end surface 315 of the inner teeth of the inner gear ring 31 to fully utilize the axial space of the actuator, and an upwardly recessed avoidance groove 424 is provided on the bottom surface 423 of the inner bracket 42, and a part of the top of the planetary bracket 33 is embedded in the avoidance groove 424; by providing the avoidance groove 424 on the inner bracket 42, the planetary bracket 33 is avoided in the axial direction of the actuator, and the interference between the planetary bracket 33 and the connecting bracket 40 is avoided, which is also conducive to reducing the space occupied by the planetary reduction mechanism and the connecting bracket 40 in the axial direction of the actuator, thereby reducing the axial size of the actuator.

[0051] The robot joint of the present invention includes the above-mentioned actuator with a planetary reduction mechanism. Other structures of the robot joint are the same as those in the prior art and will not be described in detail here.

[0052] Although only certain components and embodiments of the present application have been illustrated and described, many modifications and changes may be conceived by those skilled in the art without actually departing from the scope and spirit of the claims, such as changes in the size, dimensions, structure, shape and proportion of the various elements, mounting arrangements, material usage, color, orientation, etc.

[0053] The above implementation modes are only preferred implementation modes of the embodiments of the present invention and cannot be used to limit the protection scope of the embodiments of the present invention. Any non-substantial changes and replacements made by technicians in this field on the basis of the embodiments of the present invention shall fall within the scope of protection required by the embodiments of the present invention.

Claims

1. An actuator with a planetary reduction mechanism, characterized in that: It includes a housing, a motor and a planetary reduction mechanism; The planetary reduction mechanism comprises an inner gear ring, a sun gear, a planetary bracket and a planetary gear fixedly matched with the housing. The sun gear, the planetary bracket and the planetary gear are all located on the inner side of the inner gear ring. The planetary gear is pivotally connected to the planetary bracket and meshes between the sun gear and the inner gear ring. An installation chamber is formed between the inner gear ring and the housing. An annular supporting rib is arranged on the inner gear ring. A pressing piece detachably fixed to the supporting rib is arranged on the inner side surface of the supporting rib. The motor is placed in the installation chamber, and includes a stator fixedly matched with the housing, and a rotor matched with the stator, and the rotor is synchronously connected with 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, and the inner edge of the outer bracket spans the end of the supporting rib and extends to the inner side of the supporting rib. The outer edge of the inner bracket and the inner edge of the outer bracket are fixedly connected together by bolts. The inner bracket can be embedded in the supporting rib along the end opening of the supporting rib, and a bearing is arranged 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 piece 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 according to claim 1, characterized in that: The shell includes a side wall and a support wall extending radially inward from the inner surface of the side wall along the actuator. The lower end of the inner gear ring is connected to the support wall, and the installation chamber is surrounded by the inner gear ring, the side wall and the support wall.

3. The actuator with a planetary reduction mechanism according to claim 2, characterized in that: The outer bracket includes a first fixing ring located at its outer edge, a second fixing ring located at its inner edge, and connecting ribs connected between 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 bracket. A supporting rib extending outward is provided at the bottom of the outer edge of the inner bracket. The top end of the inner ring of the bearing abuts against the lower surface of the second fixing ring, and the bottom end of the inner ring of the bearing abuts against the supporting rib.

4. The actuator with a planetary reduction mechanism according to claim 3, characterized in that: The bolt passes through the second fixing ring from top to bottom and is screwed to the outer edge of the inner bracket. The lower surface of the second fixing ring is clearance-matched with the upper surface of the outer edge of the inner bracket.

5. The actuator with a planetary reduction mechanism according to claim 3, characterized in that: The first fixing ring is placed above the supporting rib, and is provided with a connecting arm extending downward and fixedly connected to the rotor. In the radial direction of the actuator, at least one section of the connecting rib is gradually inclined downward from the outside to the inside so that the second fixing ring is placed between the top end surface of the supporting rib and the upper surface of the outer edge of the inner bracket.

6. The actuator with a planetary reduction mechanism according to claim 2, characterized in that: The inner side surface of the supporting rib is provided with a supporting step and a slot located above the supporting step. The clamping piece is a retaining spring clamped in the slot. The top end of the outer ring of the bearing abuts against the retaining spring, and the bottom end of the outer ring of the bearing abuts against the supporting step.

7. The actuator with a planetary reduction mechanism according to claim 2, characterized in that: The shell also includes an upper cover which is fixedly connected to the upper end of the side wall in a detachable manner.

8. The actuator with a planetary reduction mechanism according to claim 1, characterized in that: A shaft sleeve extending downward is arranged on the inner bracket, the wheel shaft of the sun gear is inserted into the shaft sleeve, the upper end surface of the gear of the sun gear abuts against the lower end surface of the shaft sleeve, and the shaft sleeve is key-connected with the wheel shaft of the sun gear.

9. The actuator with a planetary reduction mechanism according to claim 1, characterized in that: The bottom surface of the inner bracket is offset upward by 0-8 mm compared to the upper end surface of the inner teeth of the inner gear ring, and an upwardly recessed avoidance groove is arranged on the bottom surface of the inner bracket, and at least a part of the planetary bracket is embedded in the avoidance groove.

10. A robot joint, characterized in that An actuator with a planetary reduction mechanism comprising any one of claims 1 to 9.

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