Actuator and robot joint

Abstract

The utility model discloses an actuator and a robot joint. The actuator comprises a shell, a motor and a planetary reducer. The planetary reducer comprises an inner gear ring, a sun gear, a planet gear and a planet support, and the inner gear ring is fixedly matched with the shell; the shell comprises a side wall, a motor cavity is formed between the inner surface of the side wall and the outer edge face of the inner gear ring, the motor is arranged in the motor cavity and comprises a stator and a rotor, the stator is fixed to the inner surface of the side wall and matched with the side wall in a heat transfer mode, and the rotor is arranged between the stator and the inner gear ring and is in clearance fit with the stator and the inner gear ring. One end of the rotor is connected with a connecting support, and the connecting support extends in the radial direction of the actuator and is synchronously connected with the sun gear. A plurality of heat dissipation convex ribs are arranged on the outer surface of the side wall, and a heat dissipation groove is formed between every two adjacent heat dissipation convex ribs. According to the utility model, heat generated by the stator can be timely and rapidly dissipated to the outer surface of the side wall, and the motor is prevented from working in a high-temperature environment.

Description

TECHNICAL FIELD

[0001] The utility model relates to robot drive technical field, concretely relates to an actuator and robot joint. BACKGROUND

[0002] The actuator is an important component of the robot joint, which is used to provide power for the relative movement between two movable parts of the robot joint, and accurately control the movement angle of the two movable parts in the robot joint; the current actuator generally includes a shell, a motor and a reducer, in order to make the structure inside the actuator more compact, the motor usually adopts a frameless torque motor, the motor will generate a certain amount of heat in the working process, and the heat generated by the motor during operation is difficult to dissipate in time due to the relatively compact structure inside the shell, the motor works in a high temperature environment, which greatly reduces the performance of the motor and makes it difficult to meet the driving requirements of the components at the robot joint. SUMMARY

[0003] The utility model aims at solving one of the technical problems existing in the prior art, and therefore, the purpose of the utility model is to provide an actuator and robot joint, so as to solve the problem of poor heat dissipation efficiency of the motor in the prior art.

[0004] The purpose of the utility model is realized by the following technical scheme:

[0005] The actuator comprises a shell, a motor and a planetary reducer.

[0006] The planetary reducer comprises an inner ring gear, a sun gear, a planet wheel and a planet support, the inner ring gear is located inside the shell and fixedly matched with the shell, the planet wheel is pivotally connected to the planet support and engaged between the sun gear and the inner ring gear.

[0007] The shell comprises a side wall, a motor cavity is formed between the inner surface of the side wall and the outer edge surface of the inner ring gear, the motor is arranged in the motor cavity, the motor comprises a stator and a rotor, the stator is fixed to the inner surface of the side wall and matched with the side wall in a heat transfer manner, the rotor is arranged between the stator and the inner ring gear and matched with the stator and the inner ring gear in a gap manner, one end of the rotor is connected with a connecting support, the connecting support extends along the radial direction of the actuator and is synchronously connected with the sun gear, and the outer surface of the side wall is provided with a plurality of heat dissipation ribs, and a heat dissipation groove is formed between adjacent heat dissipation ribs.

[0008] According to the actuator of the embodiment of the utility model, the stator of the motor is fixedly attached to the inner surface of the side wall of the shell, the stator is cooperated with the side wall in a heat transfer mode, and a plurality of heat dissipation ribs and a plurality of heat dissipation grooves are arranged on the outer surface of the side wall in a spaced manner, the heat dissipation area of the outer side of the side wall is increased through the heat dissipation ribs and the heat dissipation grooves, the heat transfer cooperation mode of the stator and the inner surface of the side wall is matched, the heat generated by the stator can be timely and quickly dissipated to the outer surface of the side wall, the motor can work in a high temperature environment, and the motor can meet the driving requirements of the related components at the joint of the robot.

[0009] In the preferred embodiment, the shell further comprises a support wall extending inwardly along the radial direction of the actuator from the inner surface of the side wall, the inner ring gear is fixedly connected to the support wall by bolts, and the support wall is sealed to the lower end of the motor cavity. The inner ring gear is fixed by the radially extending support wall, so that the inner ring gear is fixedly cooperated with the shell, and the motor cavity is formed by the inner ring gear, the support wall and the side wall, so that the motor can be embedded into the motor cavity from top to bottom, the stator and the inner surface of the side wall are fixed, and then the motor and the shell are assembled.

[0010] In the preferred embodiment, a heat insulation gap is formed between the lower end of the stator and the upper surface of the support wall, and the lower end of the rotor is gap cooperated with the upper surface of the support wall. The rotor is gap cooperated with the upper surface of the support wall to avoid interference between the support wall and the rotor. In addition, the heat insulation gap between the stator and the upper surface of the support wall can prevent the heat generated by the stator from being transmitted to the inside of the actuator through the support wall.

[0011] In the preferred embodiment, the outer edge of the connecting bracket is fixedly connected to the upper end of the rotor, and the inner edge of the connecting bracket is sleeved on the shaft of the sun gear and is connected with the sun gear. The rotor and the sun gear are synchronously connected through the connecting bracket, so that the power output by the motor can be smoothly transmitted to the input end of the planetary reducer, and the assembly of the actuator is facilitated.

[0012] In the preferred embodiment, the top end of the inner ring gear is provided with an upward extending blocking wall, the connecting bracket is provided with a matching part inside the blocking wall, and a first bearing is arranged between the matching part and the blocking wall to pivotally connect the connecting bracket to the blocking wall. The first bearing supports the connecting bracket in the radial and axial directions of the actuator, so that the rotation of the connecting bracket is more stable, and the power transmission loss between the motor and the planetary reducer is reduced.

[0013] In the preferred embodiment, the outer edge of the connecting bracket is provided with a connecting wall extending axially along the actuator shaft and fixed to the inner edge surface of the rotor, and a connecting portion connecting the connecting wall and the matching portion, the connecting portion extending upward from the top of the connecting wall and then downward at the inner side of the blocking wall to connect to the top of the matching portion. In this way, the connecting portion is in the form of an arc protruding upward from the middle portion, so that the lower part of the connecting portion can avoid the top of the blocking wall, avoiding interference between the connecting bracket and the inner gear ring, and reducing the axial size of the connecting bracket after being matched with the inner gear ring, which is conducive to reducing the overall axial size of the actuator.

[0014] In the preferred embodiment, the upper surface of the support wall is provided with a positioning protruding rib protruding upward, the bottom surface of the inner gear ring is provided with a plurality of positioning protruding blocks extending downward and supported on the upper surface of the support wall, and the outer edge surface of the positioning protruding rib abuts against the inner side of the plurality of positioning protruding blocks. The positioning structure is formed by the cooperation of the plurality of positioning protruding blocks and the positioning protruding rib, the inner gear ring and the support wall are positioned, and the matching precision of the inner gear ring and the outer shell is improved.

[0015] In the preferred embodiment, a second bearing is arranged between the inner edge of the planet carrier and the support wall to pivotally connect the planet carrier to the support wall, the inner edge bottom of the support wall is provided with a support protruding rib, and the planet carrier is provided with a stepped surface, the inner ring top of the second bearing abuts against the stepped surface, and the outer ring bottom of the second bearing abuts against the support protruding rib. The planet carrier is pivotally connected to the support wall by the second bearing, and the support wall provides axial and radial support for the planet carrier, so that the planet carrier as the output end of the planetary reducer can rotate more stably.

[0016] In the preferred embodiment, the outer shell further comprises an upper cover located at the top thereof, and the upper cover is detachably fixed to the top of the side wall by screws. The upper cover can protect the motor and the planetary reducer inside the outer shell, and the detachable connection between the upper cover and the side wall enables the motor and the planetary reducer to be loaded into the outer shell from the top of the side wall, facilitating the assembly of the entire actuator.

[0017] A robot joint comprising the actuator described above.

[0018] The drawings accompanying the specification of this application form a part thereof, serve to provide further understanding of the present application, and together with the description of the exemplary embodiments of the present application, serve to explain the present application, and do not constitute an improper limitation of the present application. BRIEF DESCRIPTION OF DRAWINGS

[0019] Figure 1 It is a sectional structure schematic view of the actuator of the present application;

[0020] Figure 2 It is a sectional structure schematic view of the actuator of the present application; Figure 1 It is an enlarged structure schematic view of position A in FIG. 6;

[0021] Figure 3 As Figure 1 Structure diagram of the inner gear ring;

[0022] Figure 4 As Figure 1 Enlarged structure diagram at B.

[0023] In the figure: 10, the shell; 11, the side wall; 110, the inner surface; 111, the heat dissipation convex rib; 112, the heat dissipation groove; 12, the support wall; 121, the positioning convex rib; 122, the support convex rib; 123, the heat insulation gap; 13, the upper cover; 14, the bolt; 20, the motor; 21, the stator; 22, the rotor; 23, the connecting bracket; 231, the matching part; 232, the connecting wall; 233, the connecting part; 31, the inner gear ring; 311, the blocking wall; 312, the positioning convex block; 32, the sun gear; 33, the planet gear; 34, the planet bracket; 341, the step surface; 40, the first bearing; 50, the second bearing. DETAILED DESCRIPTION

[0024] Hereinafter, the present application will be further described in conjunction with the drawings and the specific embodiments, it should be noted that the following described embodiments or the technical features between each of the embodiments can be combined to form a new embodiment without conflict. Except for the special description, the materials and equipment used in the embodiments can be purchased from the market. The examples of the embodiments are shown in the drawings, wherein the same or similar reference signs represent the same or similar elements or elements with the same or similar functions throughout. The embodiments described below by referring to the drawings are exemplary and are only used to explain the present application, and cannot be understood as a limitation on the present application.

[0025] In the description of the present application, it should be understood that the terms "upper", "lower", "front", "back", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like indicate the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, therefore cannot be understood as a limitation on the present application. In the description of the present application, the meaning of "a plurality of" is two or more, unless otherwise specifically specified.

[0026] In the description of the present application, it should be noted that unless otherwise explicitly specified and limited, the terms "connected", "communicated", "connected" should be understood in a broad sense, for example, it can be fixedly connected, or connected through an intermediate medium, or the internal communication of two elements or the interaction relationship between two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0027] The terms "first", "second", and the like in the description and in the claims of the present application and in the above-described drawings are used to distinguish similar objects, and are not necessarily used to describe a particular sequential or chronological order. Moreover, the terms "comprising", "having", and any variations thereof in the present application are intended to cover a non-exclusive inclusion, for example, a process, method, system, product, or apparatus that includes a list of steps or units not necessarily limited to those clearly identified, but can include other not clearly recited steps or units inherent in such processes, methods, products, or apparatus.

[0028] Please refer to Figures 1-4 The present application is an actuator, which comprises a housing 10, a motor 20, and a planetary reducer, wherein the motor 20 and the planetary reducer are mounted inside the housing 10, and the planetary reducer comprises an inner ring gear 31, a sun gear 32, a planet gear 33, and a planet carrier 34, the inner ring gear 31 is fixedly connected with the housing 10, the sun gear 32, the planet gear 33, and the planet carrier 34 are located inside the space surrounded by the inner ring gear 31, the planet gear 33 is pivotally connected with the planet carrier 34, the outer side of the planet gear 33 is engaged with the inner ring gear 31, and the inner side of the planet gear 33 is engaged with the sun gear 32.

[0029] The housing 10 comprises a side wall 11 extending along the axial direction of the actuator, and a motor cavity is formed between the inner surface 110 of the side wall 11 and the outer edge surface of the inner ring gear 31, the motor 20 is arranged in the motor cavity, the motor 20 comprises a stator 21 and a rotor 22, both the stator 21 and the rotor 22 are configured in a ring shape, the outer peripheral surface of the stator 21 abuts against the inner surface 110 of the side wall 11 after being arranged in the motor cavity, and the stator 21 can be fixed to the inner surface 110 of the side wall 11 by means of adhesion.

[0030] For example, the stator 21 is fixedly connected with the inner surface 110 of the side wall 11 by means of heat-conducting silica gel or other connecting means, so that the stator 21 and the side wall 11 are connected in a heat-conducting manner; the rotor 22 is arranged between the stator 21 and the inner ring gear 31, and the rotor 22 is gap-connected with the inner ring gear 31 and the stator 21, so that the rotor 22 can rotate relative to the stator 21 and avoid interference between the rotor 22 and the stator 21 and the inner ring gear 31; one end of the rotor 22 is connected with a connecting carrier 23 extending along the radial direction of the actuator, and the connecting carrier 23 is synchronously connected with the sun gear 32, so that the power of the rotor 22 is transmitted to the sun gear 32 through the connecting carrier 23 to drive the sun gear 32 to rotate.

[0031] A plurality of heat dissipation ribs 111 are arranged on the outer surface of the side wall 11 of the shell 10, and a heat dissipation groove 112 is formed between adjacent heat dissipation ribs 111. The plurality of heat dissipation ribs 111 are arranged along the axial direction of the actuator, that is, each heat dissipation rib 111 extends in the circumferential direction of the actuator; in other embodiments, the heat dissipation rib 111 can extend in the axial direction of the actuator, and the plurality of heat dissipation ribs 111 are arranged in the circumferential direction of the actuator.

[0032] In the utility model, the stator 21 of the motor 20 is fixedly attached to the inner surface 110 of the side wall 11 of the shell 10, so that the stator 21 cooperates with the side wall 11 in a heat transfer manner. A plurality of heat dissipation ribs 111 and a plurality of heat dissipation grooves 112 are arranged on the outer surface of the side wall 11 in a spaced-apart manner. The heat dissipation ribs 111 and the heat dissipation grooves 112 increase the heat dissipation area of the outer side of the side wall 11. In combination with the heat transfer cooperation mode of the stator 21 and the inner surface 110 of the side wall 11, the heat generated by the stator 21 can be dissipated in a timely and rapid manner to the outer surface of the side wall 11. This avoids the motor 20 from working in a high-temperature environment, so that the motor 20 can meet the driving requirements of the related components at the joint of the robot.

[0033] In a preferred embodiment, the shell 10 further comprises a support wall 12 extending radially inward from the inner surface 110 of the side wall 11 along the actuator. The inner ring gear 31 is arranged above the support wall 12, with the bottom end abutting the upper surface of the support wall 12. The inner ring gear 31 is fixedly connected to the support wall 12 by screwing the bolt 14 from bottom to top through the support wall 12 and then to the inner ring gear 31. In this way, the support wall 12 is sealed at the lower end of the motor cavity, that is, the inner ring gear 31, the support wall 12, and the side wall 11 form a motor cavity with a U-shaped cross-section and an opening at the top. The radially extending support wall 12 is used to fix the inner ring gear 31, so that the inner ring gear 31 is fixedly connected to the shell 10. The motor cavity is formed by the inner ring gear 31, the support wall 12, and the side wall 11, so that the motor 20 can be embedded into the motor cavity from top to bottom. This facilitates the fixation of the stator 21 to the inner surface 110 of the side wall 11, and then facilitates the assembly of the motor 20 and the shell 10.

[0034] In addition, a heat insulation gap 123 is formed between the lower end of the stator 21 and the upper surface of the support wall 12, and the lower end of the rotor 22 is in gap cooperation with the upper surface of the support wall 12. The gap cooperation between the rotor 22 and the upper surface of the support wall 12 avoids interference between the support wall 12 and the rotor 22. In addition, the heat insulation gap 123 between the stator 21 and the upper surface of the support wall 12 prevents the heat generated by the stator 21 from being transmitted to the interior of the actuator through the support wall 12.

[0035] The outer edge of the connecting bracket 23 is fixedly connected to the upper end of the rotor 22, and the inner edge of the connecting bracket 23 is sleeved on the wheel shaft of the sun gear 32 and is keyed together with the sun gear 32; the connecting bracket 23 synchronously connects the rotor 22 and the sun gear 32, so that the power output by the motor 20 can be smoothly transmitted to the input end of the planetary reducer, and the assembly of the actuator is facilitated.

[0036] The top end of the inner ring gear 31 is provided with an upwardly extending blocking wall 311, the connecting bracket 23 is provided with a matching portion 231 inside the blocking wall 311, and a first bearing 40 is arranged between the matching portion 231 and the blocking wall 311. The inner ring of the first bearing 40 is fixed to the matching portion 231, and the outer ring of the first bearing 40 is fixed to the blocking wall 311. Thus, the connecting bracket 23 is pivoted to the inner ring gear 31 by the first bearing 40, and then the connecting bracket 23 is pivotally matched with the housing 10. The connecting bracket 23 is supported in the radial and axial directions of the actuator by the first bearing 40, so that the rotation of the connecting bracket 23 is more stable, and the power transmission loss between the motor 20 and the planetary reducer is reduced.

[0037] The outer edge of the connecting bracket 23 is provided with a connecting wall 232 extending in the axial direction of the actuator and a connecting portion 233. The connecting wall 232 is arranged inside the rotor 22 and is fixedly connected to the inner edge surface of the rotor 22. The connecting portion 233 extends upward from the top of the connecting wall 232 and then extends downward inside the blocking wall 311 to connect to the top of the matching portion 231. In this way, the connecting portion 233 is in an arc-shaped structure with the middle portion protruding upward, so that the lower part of the connecting portion 233 can avoid the top of the blocking wall 311, avoiding interference between the connecting bracket 23 and the inner ring gear 31, and reducing the axial dimension of the connecting bracket 23 after being matched with the inner ring gear 31, which is beneficial to reducing the overall axial dimension of the actuator.

[0038] In order to improve the assembly precision, a positioning protruding rib 121 protruding upward is arranged on the upper surface of the support wall 12, and the positioning protruding rib 121 is arranged around the support wall 12 to form a closed circular structure. The bottom surface of the inner ring gear 31 is provided with a plurality of positioning protrusions 312 extending downward, and the plurality of positioning protrusions 312 are supported on the upper surface of the support wall 12, and the outer edge surface of the positioning protruding rib 121 abuts against the inner side of the plurality of positioning protrusions 312. The plurality of positioning protrusions 312 and the positioning protruding rib 121 form a positioning structure to position the inner ring gear 31 and the support wall 12, thereby improving the matching precision of the inner ring gear 31 and the housing 10.

[0039] A second bearing 50 is arranged between the planet carrier 34 and the inner edge of the support wall 12, the outer ring of the second bearing 50 is fixedly matched with the inner edge of the support wall 12, and the inner ring of the second bearing 50 is fixedly matched with the planet carrier 34, so that the planet carrier 34 is pivoted to the support wall 12 by the second bearing 50, a support boss 122 is arranged at the bottom of the inner edge of the support wall 12, a stepped surface 341 is arranged on the planet carrier 34, the top of the inner ring of the second bearing 50 abuts against the stepped surface 341, and the bottom of the outer ring of the second bearing 50 abuts against the support boss 122. The planet carrier 34 is pivoted to the support wall 12 by the second bearing 50, the support wall 12 provides axial and radial support for the planet carrier 34, so that the planet carrier 34 as the output end of the planetary reducer can rotate more stably.

[0040] In the utility model, the shell 10 further includes an upper cover 13 located at the top thereof, the upper cover 13 is detachably fixed at the top of the side wall 11 by screws, the upper cover 13 is arranged to protect the motor 20 and the planetary reducer inside the shell 10, and the upper cover 13 is detachably connected with the side wall 11, so that the motor 20 and the planetary reducer can be loaded into the shell 10 from the top of the side wall 11, and the assembly of the entire actuator is facilitated.

[0041] The robot joint of the utility model comprises the actuator, other structures of the robot joint are the same as those of the prior art, and will not be described in detail here.

[0042] Although only some parts and embodiments of the present application have been illustrated and described, many modifications and changes can be conceived by those skilled in the art without departing from the scope and spirit of the claims, for example, changes in size, dimension, structure, shape and proportion, mounting arrangement, material use, color, orientation, etc.

[0043] The above embodiment is only a preferred embodiment of the robot joint of the utility model, and cannot be used to limit the protection scope of the robot joint of the utility model, and any non-essential changes and replacements made by those skilled in the art on the basis of the robot joint of the utility model all belong to the protection scope of the robot joint of the utility model.

Claims

1. An actuator, characterized in that, Includes housing, motor, and planetary gear reducer; The planetary gear reducer includes an internal gear ring, a sun gear, planet gears, and a planet carrier. The internal gear ring is located inside the housing and is fixedly fitted to the housing. The planet gears are pivotally connected to the planet carrier and mesh between the sun gear and the internal gear ring. The housing includes a sidewall, and a motor cavity is formed between the inner surface of the sidewall and the outer edge of the internal gear ring. The motor is placed inside the motor cavity and includes a stator and a rotor. The stator is fixed to the inner surface of the sidewall and engages with the sidewall in a way that allows for heat transfer. The rotor is placed between the stator and the internal gear ring and is in clearance fit with the stator and the internal gear ring. One end of the rotor is connected to a connecting bracket, which extends radially along the actuator and is synchronously connected to the sun gear. The outer surface of the sidewall is provided with multiple heat dissipation ribs, and a heat dissipation groove is formed between adjacent heat dissipation ribs.

2. The actuator as described in claim 1, characterized in that, The housing also includes a support wall extending radially inward from the inner surface of the sidewall along the actuator. The internal gear ring is fixedly connected to the support wall by bolts, and the support wall seals the lower end of the motor cavity.

3. The actuator as described in claim 2, characterized in that, A heat-insulating gap is formed between the lower end of the stator and the upper surface of the support wall, and the lower end of the rotor is clearance-fitted with the upper surface of the support wall.

4. The actuator as described in claim 2, characterized in that, The outer edge of the connecting bracket is fixedly connected to the upper end of the rotor, and the inner edge of the connecting bracket is sleeved on the axle of the sun gear and keyed to the sun gear.

5. The actuator as described in claim 4, characterized in that, The top of the internal gear ring is provided with an upwardly extending baffle, and the connecting bracket is provided with a mating part located inside the baffle. A first bearing is provided between the mating part and the baffle to pivotally connect the connecting bracket to the baffle.

6. The actuator as described in claim 5, characterized in that, The outer edge of the connecting bracket is provided with a connecting wall that extends along the actuator axis and is fixed to the inner edge of the rotor, and a connecting part that connects the connecting wall and the mating part. The connecting part extends upward from the top of the connecting wall and then downward from the inner side of the baffle wall to connect with the top of the mating part.

7. The actuator as claimed in claim 2, characterized in that, The upper surface of the support wall is provided with an upwardly protruding positioning rib, and the bottom surface of the internal gear ring is provided with multiple downwardly extending positioning protrusions that support the upper surface of the support wall. The outer edge of the positioning rib abuts against the inner side of the multiple positioning protrusions.

8. The actuator as claimed in claim 2, characterized in that, A second bearing is provided between the planetary support and the inner edge of the support wall to pivotally connect the planetary support to the support wall. A support rib is provided at the bottom of the inner edge of the support wall. A stepped surface is provided on the planetary support. The top of the inner ring of the second bearing abuts against the stepped surface, and the bottom of the outer ring of the second bearing abuts against the support rib.

9. The actuator as claimed in claim 1, characterized in that, The housing also includes a top cover located on top of it, which is detachably secured to the top of the side wall by screws.

10. A robot joint, characterized in that, Includes the actuator as described in any one of claims 1-9.

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