Servo module, joint and robot

Abstract

The application provides a servo module, a joint and a robot, and relates to the field of robots.The servo module comprises a motor, a planetary reduction assembly and a servo driver.The motor comprises a shell, an end cover, a stator and a rotor.The shell has an annular housing portion and an inner housing portion.The inner wall of the inner housing portion is provided with a plurality of teeth.The stator is arranged around the inner housing portion.The rotor is arranged between the stator and the housing portion.The planetary reduction assembly comprises a planet carrier, a planet wheel and a sun wheel.The planet carrier is in rotational cooperation with the inner wall of the inner housing portion.The planet wheel is arranged on the planet carrier and is in meshing cooperation with the teeth.The sun wheel is in meshing cooperation with the planet wheel and is connected with the rotor.The servo driver is arranged on the side of the end cover facing the shell and is electrically connected with the stator.The integrated design of the motor, the planetary reduction assembly and the servo driver makes the whole servo module more compact and smaller in size.The torque parameter of the motor is estimated by the current of the winding of the stator, which simplifies the structure of the servo module and better meets the demand of the robot for light weight and small size.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of robots, in particular to a servo module, a joint and a robot. BACKGROUND

[0002] According to whether it is driven alone, the joint of the robot can be divided into active joint and passive joint. In the active joint, the servo module as an actuator is the core component of the robot.

[0003] The servo module used in the existing robot joint is generally a harmonic servo module, which has high reduction ratio and large torque, but the torque cannot be directly observed or estimated by the current of the driver, and a torque sensor must be installed in the occasion requiring force control, which has the defects of complex structure and large volume, and does not meet the demand of lightweight and small volume of robots. SUMMARY

[0004] In order to solve the problems in the prior art, one of the purposes of the present application is to provide a servo module.

[0005] The present application provides the following technical solutions:

[0006] A servo module comprises:

[0007] A motor comprises a shell, an end cover, a stator and a rotor, the shell has an annular housing portion and an inner housing portion, the inner wall of the inner housing portion is provided with a plurality of teeth in the circumferential direction, the end cover is connected with the housing portion, the stator is arranged around the inner housing portion and is fixedly connected with the inner housing portion, and the rotor is rotatably arranged between the stator and the housing portion;

[0008] A planetary reduction assembly comprises a planet carrier, a planet wheel and a sun wheel, the planet carrier is rotatably connected with the inner wall of the inner housing portion, the planet wheel is rotatably arranged on the planet carrier and is engaged with the teeth on the inner housing portion, and the sun wheel is engaged with the planet wheel and is connected with the rotor; and

[0009] A servo driver is arranged on the side of the end cover facing the shell, the servo driver is connected with the end cover and is electrically connected with the stator.

[0010] As a further optional scheme of the servo module, the end cover is made of heat-conducting material, a heat-conducting member is arranged between the servo driver and the end cover, and the servo driver abuts against the end cover through the heat-conducting member.

[0011] As a further optional scheme of the servo module, the end cover has a protruding portion, a containing cavity is formed in the protruding portion, and the servo driver is located in the containing cavity.

[0012] As a further optional solution to the servo module, the servo driver comprises a board card and a control module, the board card is connected with the end cover, and the control module is arranged on the board card and electrically connected with the stator to collect the current signal of the stator.

[0013] As a further optional solution to the servo module, the servo driver further comprises a coding and decoding module, the coding and decoding module is electrically connected with the control module, the coding and decoding module is arranged on the side of the board card facing the sun gear and directly opposite the sun gear, and a magnet is arranged at one end of the sun gear close to the coding and decoding module.

[0014] As a further optional solution to the servo module, the inner wall of the inner shell part is provided with a first bearing and a second bearing, the first bearing and the second bearing are arranged along the axial direction of the inner shell part, and the planet carrier is rotationally connected with the inner wall of the inner shell part through the first bearing and the second bearing.

[0015] As a further optional solution to the servo module, the motor further comprises a rotor holder, the rotor holder is connected with the rotor, and the rotor holder has a sleeve part, the sleeve part is sleeved on one end of the sun gear and connected with the sun gear.

[0016] As a further optional solution to the servo module, a third bearing is arranged between one end of the sun gear away from the sleeve part and the planet carrier, and a fourth bearing is arranged between the sleeve part and the planet carrier.

[0017] Another object of the present application is to provide a joint.

[0018] The present application provides the following technical solutions:

[0019] A joint comprises the above-mentioned servo module.

[0020] Another object of the present application is to provide a robot.

[0021] The present application provides the following technical solutions:

[0022] A robot comprises the above-mentioned joint.

[0023] Embodiments of the present application have the following beneficial effects:

[0024] In the servo module, the motor housing has an annular outer shell part and an inner shell part. The stator is arranged around the inner shell part, and the rotor is rotatably arranged between the stator and the outer shell part, which can ensure normal operation of the motor and form a space for embedding and installing the planetary reduction assembly on the inner side of the inner shell part. On this basis, the planet carrier is rotatably connected with the inner wall of the inner shell part and is installed by relying on the motor housing. The planet wheel is engaged with the teeth on the inner wall of the inner shell part, and the inner shell part acts as a gear ring. In addition, the servo driver is arranged on the side of the end cover facing the motor housing and is installed and fixed by the end cover, so that the motor, the planetary reduction assembly and the servo driver are integrated, and the entire servo module is more compact in the radial and axial directions and has a smaller volume.

[0025] In use, the rotor of the motor drives the sun gear to rotate, which in turn drives the meshing planet wheel to rotate. In the case that the inner shell part acting as a gear ring is fixed, the planet wheel drives the planet carrier to rotate, and the planet carrier serves as the output end of the entire servo module. Compared with the existing harmonic servo module, the reduction ratio of the planetary reduction assembly is smaller, the torque parameter of the motor can be more accurately estimated by the current of the winding of the stator, so that a torque sensor does not need to be arranged, the structure of the servo module is simplified, and the volume of the entire servo module is reduced, which can better meet the demand for lightweight and small volume of robots.

[0026] In order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the following preferred embodiments are described in detail below, and the accompanying drawings are described as follows. BRIEF DESCRIPTION OF DRAWINGS

[0027] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following will briefly introduce the drawings needed to be used in the embodiments. It should be understood that the following drawings only show some embodiments of the present application, and therefore should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can also be obtained without creative labor on the basis of these drawings.

[0028] Figure 1 The overall structure of a servo module provided by an embodiment of the present application is shown in the schematic diagram;

[0029] Figure 2 The schematic diagram of an explosion of a servo module provided by an embodiment of the present application is shown;

[0030] Figure 3 The cross-sectional schematic diagram of a motor in a servo module provided by an embodiment of the present application is shown;

[0031] Figure 4 The schematic diagram of an explosion of a motor in a servo module provided by an embodiment of the present application is shown;

[0032] Figure 5 An exploded schematic view of a planetary reduction assembly in a servo module is shown according to an embodiment of the present application;

[0033] Figure 6 A schematic view of the cooperation between a planet carrier and a case in a servo module is shown according to an embodiment of the present application;

[0034] Figure 7 A schematic view of the cooperation between a sun gear, a rotor carrier and a planet carrier in a servo module is shown according to an embodiment of the present application;

[0035] Figure 8 A schematic view of the connection between an end cover and a servo driver in a servo module is shown according to an embodiment of the present application;

[0036] Figure 9 A schematic view of the structure of a servo driver in a servo module is shown according to an embodiment of the present application.

[0037] Main component symbol explanation:

[0038] 100 - motor; 110 - case; 111 - outer shell part; 112 - inner shell part; 113 - tooth; 114 - first bearing; 115 - second bearing; 120 - end cover; 121 - heat conducting part; 122 - protruding part; 130 - stator; 140 - rotor; 150 - rotor carrier; 151 - sleeve part; 152 - fourth bearing; 200 - planetary reduction assembly; 210 - planet carrier; 211 - first carrier body; 211a - first shaft shoulder; 212 - second carrier body; 212a - second shaft shoulder; 213 - support column; 220 - planet gear; 230 - sun gear; 231 - third bearing; 232 - fixed block; 233 - magnet; 300 - servo driver; 310 - board card; 320 - control module; 330 - power module; 340 - encoding and decoding module; 350 - digital output interface; 360 - emergency stop control interface; 370 - temperature sensor. DETAILED DESCRIPTION

[0039] Embodiments of the present application are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals represent the same or similar elements or elements having the same or similar functions throughout. The embodiments described below by reference to the drawings are exemplary only, and are used only for explaining the present application, and cannot be understood as limiting the present application.

[0040] It should be noted that when an element is referred to as being "on" another element, it can be directly on the other element or intervening elements can also be present. In contrast, when an element is referred to as being "directly on" another element, there are no intervening elements present. It will be understood that, although the terms "first," "second," etc. can be used herein to describe various elements, these elements should not be limited by these terms since such terms are only used to distinguish one element from another. For example, a first element could be termed a second element, and, similarly, a second element could be termed a first element without departing from the scope of the application.

[0041] In this application, terms of "mounting", "connecting", "connecting", "fixing" and the like should be understood in a broad sense, for example, it can be fixedly connected, or it can be detachably connected, or it can be integrated; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be 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.

[0042] In addition, the terms "first", "second" are only used for descriptive purposes and should not be construed as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first", "second" can explicitly or implicitly include one or more of the features. In the description of the present application, the meaning of "multiple" is two or more, unless otherwise explicitly specified.

[0043] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used in the description of the template herein is only for the purpose of describing specific embodiments and is not intended to limit the present application. The term "and / or" used herein includes any and all combinations of one or more of the associated listed items.

[0044] Embodiment 1

[0045] Please refer to Figure 1 and Figure 2 The embodiment provides a servo module, which comprises a motor 100, a planetary reduction assembly 200 and a servo driver 300.

[0046] Please refer to Figure 3 and Figure 4The motor 100 comprises a casing 110, an end cover 120, a stator 130 and a rotor 140. The casing 110 has an annular outer shell part 111 and an inner shell part 112, and the inner wall of the inner shell part 112 is provided with a plurality of teeth 113 in the circumferential direction. The end cover 120 is connected with the outer shell part 111. The stator 130 is arranged around the inner shell part 112 and fixedly connected with the inner shell part 112, and the rotor 140 is rotatably arranged between the stator 130 and the outer shell part 111. In addition, the stator 130 is electrically connected with the servo driver 300.

[0047] Please refer to Figure 5 , Figure 6 and Figure 7 , the planetary reduction assembly 200 comprises a planet carrier 210, a planet wheel 220 and a sun wheel 230. The planet carrier 210 is rotatably matched with the inner wall of the inner shell part 112. The planet wheel 220 is rotatably arranged on the planet carrier 210 and engaged with the teeth 113 on the inner shell part 112. The sun wheel 230 is engaged with the planet wheel 220 and connected with the rotor 140.

[0048] Please refer to Figure 2 again, in addition, the servo driver 300 is arranged on the side of the end cover 120 facing the casing 110 and connected with the end cover 120.

[0049] In the above servo module, the casing 110 of the motor 100 has an annular outer shell part 111 and an inner shell part 112. The stator 130 is arranged around the inner shell part 112, and the rotor 140 is rotatably arranged between the stator 130 and the outer shell part 111, which not only ensures the normal operation of the motor 100, but also forms a space inside the inner shell part 112 for embedding and installing the planetary reduction assembly 200. On this basis, the planet carrier 210 is rotatably matched with the inner wall of the inner shell part 112 and installed relying on the casing 110. The planet wheel 220 is engaged with the teeth 113 on the inner wall of the inner shell part 112, and the inner shell part 112 acts as a gear ring. In addition, the servo driver 300 is arranged on the side of the end cover 120 facing the casing 110 and installed and fixed by the end cover 120, thereby realizing the integrated design of the motor 100, the planetary reduction assembly 200 and the servo driver 300, making the entire servo module more compact in the radial and axial directions and smaller in size.

[0050] In use, the rotor 140 of the motor 100 drives the sun gear 230 to rotate, and the sun gear 230 drives the meshed planetary gears 220 to rotate. In the case that the inner shell part 112 serving as the gear ring is fixed, the planetary gears 220 drive the planet carrier 210 to rotate, and the planet carrier 210 serves as the output end of the entire servo module. Compared with the existing harmonic servo module, the reduction ratio of the planetary reduction assembly 200 is smaller, the torque parameter of the motor 100 can be more accurately estimated through the current of the winding of the stator 130, and thus it is not necessary to set a torque sensor, the structure of the servo module is simplified, and at the same time, the volume of the entire servo module is reduced, which can better meet the demand of the robot for light weight and small volume.

[0051] Embodiment 2

[0052] Please refer to Figure 1 and Figure 2 , the embodiment provides a servo module, in particular to a quasi-torque servo module, which is applied to the joint of a robot, and the servo module is composed of a motor 100, a planetary reduction assembly 200 and a servo driver 300.

[0053] Please refer to Figure 3 and Figure 4 , in particular, the motor 100 is composed of a casing 110, an end cover 120, a stator 130, a rotor 140 and a rotor holder 150.

[0054] The casing 110 has an annular outer shell part 111 and an annular inner shell part 112, the axis of the outer shell part 111 coincides with the axis of the inner shell part 112, and the outer shell part 111 is located outside the inner shell part 112. One end of the outer shell part 111 and the inner shell part 112 is closed along the axis direction, and the other end is open and opposite to the end cover 120.

[0055] In addition, the inner wall of the inner shell part 112 is integrally formed with a plurality of teeth 113, and each tooth 113 is uniformly distributed along the circumference of the inner shell part 112.

[0056] The end cover 120 is fixedly connected with the outer shell part 111 through bolts, and a gap is left between the end cover 120 and the inner shell part 112.

[0057] The stator 130 includes a core and a winding, the core is arranged around the inner shell part 112 and is fixedly bonded with the inner shell part 112 through a high-strength adhesive, and the winding is arranged on the core. In addition, the winding of the stator 130 is electrically connected with the servo driver 300.

[0058] The rotor 140 is arranged between the stator 130 and the outer shell part 111, and can freely rotate relative to the stator 130 and the outer shell part 111.

[0059] The rotor holder 150 is arranged on the side of the end cover 120 facing the inner housing 112 and passes through the gap between the end cover 120 and the inner housing 112, and the outer edge of the rotor holder 150 is fixedly connected with the rotor 140.

[0060] In use, the servo driver 300 supplies power to the windings of the stator 130, so that the motor 100 is driven to rotate the rotor holder 150 by the rotor 140. At the same time, the torque parameters of the motor 100 can be accurately estimated by the current passing through the windings of the stator 130.

[0061] Please refer to Figure 5 , specifically, the planetary reduction assembly 200 is embeddedly installed on the inner side of the inner housing 112 and is composed of a planetary carrier 210, a planetary gear 220 and a sun gear 230.

[0062] Please refer to Figure 6 and Figure 7 , wherein the planetary carrier 210 is rotationally fitted with the inner wall of the inner housing 112. The planetary gear 220 is rotationally arranged on the planetary carrier 210 and is engaged with the teeth 113 on the inner wall of the inner housing 112. The sun gear 230 is engaged with the planetary gear 220 and is connected with the rotor 140 through the rotor holder 150.

[0063] In some embodiments, the rotor holder 150 has a sleeve portion 151. The sleeve portion 151 is sleeved on one end of the sun gear 230 and is in interference fit with the sun gear 230, so as to keep relative fixation with the sun gear 230.

[0064] In use, the rotor 140 drives the sun gear 230 to rotate, and the sun gear 230 drives the engaged planetary gear 220 to rotate. In the case that the inner housing 112 serving as a gear ring is fixed, the planetary gear 220 drives the planetary carrier 210 to rotate, and the planetary carrier 210 serves as the output end of the entire servo module.

[0065] Please refer to Figure 6 , further, the inner wall of the inner housing 112 is provided with a first bearing 114 and a second bearing 115. The first bearing 114 and the second bearing 115 are arranged along the axial direction of the inner housing 112 and are respectively located on the two sides of the teeth 113. The planetary carrier 210 is rotationally fitted with the inner wall of the inner housing 112 through the first bearing 114 and the second bearing 115.

[0066] The first bearing 114 and the second bearing 115 can reduce the frictional resistance of the planetary carrier 210 during relative rotation with the inner housing 112, improve the energy transmission efficiency, and avoid wear caused by direct contact between the planetary carrier 210 and the inner housing 112.

[0067] Please refer to Figure 5In some embodiments, the planet carrier 210 is composed of a first carrier body 211, a second carrier body 212 and support columns 213. The first carrier body 211 and the second carrier body 212 are both annularly arranged, and the axis of the first carrier body 211 and the axis of the second carrier body 212 are both coincident with the axis of the inner shell 112, and the first carrier body 211 and the second carrier body 212 are arranged along the axis direction of the inner shell 112.

[0068] The support columns 213 are at least two in number and are located between the first carrier body 211 and the second carrier body 212. Each support column 213 is parallel to the axis of the first carrier body 211, and each support column 213 is arranged along the circumferential direction of the first carrier body 211. One end of the support column 213 is integrally formed with the first carrier body 211, and the other end of the support column 213 abuts against the second carrier body 212 and is fixedly connected with the second carrier body 212, thereby forming a complete planet carrier 210.

[0069] In addition, the outer side wall of the end of the first carrier body 211 away from the second carrier body 212 is provided with a first shaft shoulder 211a, and the outer side wall of the end of the second carrier body 212 away from the first carrier body 211 is provided with a second shaft shoulder 212a.

[0070] On the one hand, the first shaft shoulder 211a abuts against the side of the first bearing 114 away from the tooth 113, and can limit the first bearing 114. The second shaft shoulder 212a abuts against the side of the second bearing 115 away from the tooth 113, and can limit the second bearing 115. On the other hand, the split arrangement of the first carrier body 211 and the second carrier body 212 makes the installation of the first bearing 114 and the second bearing 115 more convenient. The support column 213 can be connected with the second carrier body 212 after the first bearing 114, the second bearing 115, the first carrier body 211 and the second carrier body 212 are installed.

[0071] Along the axis direction of the first carrier body 211, the planet wheel 220 is located between the first carrier body 211 and the second carrier body 212. Along the circumferential direction of the first carrier body 211, the planet wheel 220 is located between two adjacent support columns 213. In addition, one end of the wheel shaft of the planet wheel 220 penetrates into the first carrier body 211 and rotationally cooperates with the first carrier body 211, and the other end penetrates into the second carrier body 212 and rotationally cooperates with the second carrier body 212.

[0072] Due to the split arrangement of the first carrier body 211 and the second carrier body 212, the planet wheel 220 can be placed between the first carrier body 211 and the second carrier body 212 during installation, and the wheel shafts of the planet wheel 220 can penetrate into the first carrier body 211 and the second carrier body 212, and then the support column 213 can be connected with the second carrier body 212. At this time, the first carrier body 211 and the second carrier body 212 limit the planet wheel 220.

[0073] Optionally, the number of support columns 213 and the number of planet wheels 220 are both three, and the three support columns 213 and the three planet wheels 220 are uniformly distributed and arranged at intervals along the circumference of the first frame body 211.

[0074] Please refer to Figure 7 Further, the sun gear 230 is sleeved with a third bearing 231 at one end away from the sleeve portion 151, and is rotationally matched with the inner wall of the first frame body 211 through the third bearing 231. The sleeve portion 151 is sleeved with a fourth bearing 152, and is rotationally matched with the inner wall of the second frame body 212 through the fourth bearing 152.

[0075] The third bearing 231 and the fourth bearing 152 can reduce the frictional resistance suffered by the sun gear 230 and the sleeve portion 151 during relative rotation with the planet carrier 210, improve the energy transmission efficiency, and at the same time avoid the wear caused by the direct contact and cooperation of the sun gear 230 with the planet carrier 210 and the sleeve portion 151 with the planet carrier 210.

[0076] Optionally, the sun gear 230 is bolted with a fixing block 232 at the end face away from the sleeve portion 151, and the fixing block 232 abuts against the third bearing 231 to limit the third bearing 231.

[0077] In the above motor 100 and planetary reduction assembly 200, the inner shell portion 112 of the casing 110 serves as a mounting base. The stator 130 is arranged around the inner shell portion 112 and fixedly connected with the inner shell portion 112, so as to ensure the coaxiality of the stator 130 and the inner shell portion 112. The planet carrier 210 is rotatably mounted on the inner wall of the inner shell portion 112 through the first bearing 114 and the second bearing 115, and has good coaxiality with the inner shell portion 112. The sun gear 230 and the rotor carrier 150 are rotatably mounted on the inner wall of the planet carrier 210 through the third bearing 231 and the fourth bearing 152, and have good coaxiality with the planet carrier 210, and further have good coaxiality with the inner shell portion 112. The rotor 140 is fixedly connected with the sun gear 230 through the rotor carrier 150, and is mounted on the planet carrier 210 together with the sun gear 230, and also has good coaxiality with the inner shell portion 112, and further has good coaxiality with the stator 130, which is conducive to the stable operation of the motor 100.

[0078] Please refer to Figure 8 and Figure 9 Specifically, the servo driver 300 is arranged on the side of the end cover 120 facing the casing 110, and includes a board card 310, a control module 320 and a power module 330.

[0079] It should be noted that the conventional motor driver includes a drive board, a power board and a control board, etc. The drive board includes a drive circuit and a protection circuit, and the power board includes power devices and bus support capacitors. In operation, the control board outputs a control signal to the drive board, and the drive board further drives the power board to output current to the motor 100.

[0080] Compared with the conventional motor driver, the servo driver 300 integrates the drive board, the power board and the control board on the board card 310, and has a small volume. The structure of the drive board and the power board is the same as that of the conventional motor driver, and will not be described here. The control module 320 and the power module 330 belong to the control board, and will be described below.

[0081] The board card 310 is connected with the end cover 120, and the control module 320 and the power module 330 are arranged on the board card 310. The control module 320 is electrically connected with the power module 330, and the power module 330 converts the battery voltage into a suitable voltage to supply power to the control module 320. In addition, the control module 320 is electrically connected with the winding of the stator 130 through a conditioning circuit module.

[0082] In use, the conditioning circuit module converts the current signal of the winding into a voltage signal of 0-3V and transmits it to the control module 320. The control module 320 indirectly calculates the current signal of the winding according to the voltage signal, and then calculates the torque parameter of the motor 100 according to the actual current of the winding. In addition, the control module 320 can also receive communication data.

[0083] In some specific embodiments, the control module 320 adopts an MCU (Microcontroller Unit) main chip.

[0084] Please refer to Figure 7 Further, the control board of the servo driver 300 further includes a coding and decoding module 340. The coding and decoding module 340 is electrically connected with the control module 320, and the coding and decoding module 340 is arranged on the side of the board card 310 facing the sun gear 230 and faces the end face of the sun gear 230. Correspondingly, the end of the sun gear 230 close to the coding and decoding module 340 is embedded with a magnet 233, and the magnet 233 is spaced apart from the coding and decoding module 340 by 1mm.

[0085] When the motor 100 is running, the magnet 233 rotates with the sun gear 230. The position information of the motor 100 can be decoded by the rotation of the magnet 233, and the position information of the motor 100 is further sent to the control module 320 by the encoding and decoding module 340. The control module 320 controls the drive board and the power board according to the position information of the motor 100, and controls the rotation angle and speed of the motor 100 by controlling the current output by the power board, to realize the closed-loop control of "position-control-position".

[0086] In some embodiments, the encoding and decoding module 340 adopts a magnetic encoder.

[0087] Further, the control board of the servo driver 300 further comprises a digital output interface 350, an emergency stop control interface 360 and a temperature sensor 370. The servo module outputs power to the outside through the digital output interface 350, realizing the power supply or logic control function. The emergency stop control interface 360 can realize the shutdown in emergency. The temperature sensor 370 is used to detect the temperature of the motor 100, realizing the temperature protection of the motor 100, and effectively exerting the limit performance of the motor 100.

[0088] Further, the end cover 120 is made of heat-conducting material, such as metal, ceramic and the like. The servo driver 300 is provided with a heat-conducting piece 121 between the servo driver 300 and the end cover 120, and the servo driver 300 abuts against the end cover 120 through the heat-conducting piece 121.

[0089] The heat generated by the power device of the power board of the servo driver 300 in the working process is transmitted to the end cover 120 through the heat-conducting piece 121, which can effectively solve the problem of heat dissipation of the power device. In other words, the servo driver 300 not only uses the end cover 120 for installation and fixation, but also uses the end cover 120 for heat dissipation, which is conducive to reducing the radial and axial dimensions of the entire servo module, realizing a servo module with smaller volume.

[0090] Further, the middle part of the end cover 120 has a protruding part 122. The protruding part 122 forms an accommodating cavity, and the servo driver 300 is located in the accommodating cavity, maintaining sufficient spacing with the rotor holder 150 and the sun gear 230.

[0091] In addition, in the radial plane of the end cover 120, the size of the protruding part 122 fits the size of the servo driver 300. The area of the end cover 120 other than the protruding part 122 is close to the rotor holder 150, so that the structure of the entire servo module is more compact.

[0092] In summary, in the servo module, the motor housing 110 of the motor 100 has an annular outer shell part 111 and an inner shell part 112. The stator 130 is arranged around the inner shell part 112, and the rotor 140 is rotatably arranged between the stator 130 and the outer shell part 111, which can ensure normal operation of the motor 100 and form a space inside the inner shell part 112 for embedding and installing the planetary reduction assembly 200. On this basis, the planetary carrier 210 is rotatably matched with the inner wall of the inner shell part 112 and is installed by relying on the motor housing 110. The planetary gear 220 is meshed with the teeth 113 on the inner wall of the inner shell part 112, and the inner shell part 112 acts as a gear ring. In addition, the servo driver 300 is arranged on the side of the end cover 120 facing the motor housing 110 and is installed and fixed by using the end cover 120, so as to realize the integrated design of the motor 100, the planetary reduction assembly 200 and the servo driver 300, and make the entire servo module more compact in the radial and axial directions and smaller in size.

[0093] In use, the rotor 140 drives the sun gear 230 to rotate, and the sun gear 230 drives the meshed planetary gear 220 to rotate. In the case that the inner shell part 112 acting as a gear ring is fixed, the planetary gear 220 drives the planetary carrier 210 to rotate, and the planetary carrier 210 acts as an output end of the entire servo module. Compared with the existing harmonic servo module, the planetary reduction assembly 200 has a smaller reduction ratio, the torque parameter of the motor 100 can be more accurately estimated through the current of the winding of the stator 130, so that a torque sensor does not need to be arranged, the structure of the servo module is simplified, and the volume of the entire servo module is reduced, which can better meet the demand of the robot for light weight and small size. The light weight means that the weight of the servo module can be reduced and the motion performance can be improved. The small size can make the key components compact in size, improve the appearance of the robot, and make the robot more flexible.

[0094] Compared with the direct drive motor, the servo module has higher torque density. Based on the combination of the high-power-density motor 100 and the small-reduction-ratio planetary reduction assembly 200, high rotation speed can be achieved. Based on the current loop to realize torque control, high torque control bandwidth can be achieved, so as to ensure that the servo module has high dynamic performance. Considering that the servo module has a small effective inertia at the end, the servo module has good anti-drive performance and can cope with dynamic collision.

[0095] In addition, the servo module realizes modular design, can realize reuse and large-scale manufacturing, and has good economic benefits.

[0096] The embodiment also provides a joint, specifically an active joint, applied to a robot, and the joint comprises the servo module.

[0097] Optionally, the joint is a rotary joint.

[0098] The embodiment also provides a robot, comprising the joint.

[0099] In some specific embodiments, the robot is a humanoid robot.

[0100] In some other specific embodiments, the robot is a legged robot. Through the design of the servo driver 300 with a very small volume, the weight of the leg of the legged robot can be effectively reduced.

[0101] In all examples shown and described herein, any specific values should be interpreted as merely exemplary and not as a limitation, and thus other examples of the example embodiments can have different values.

[0102] It should be noted that similar reference numbers and letters refer to similar items in the following drawings, and thus, once an item is defined in one drawing, it need not be further defined and explained in subsequent drawings.

[0103] The above-described embodiments are merely some embodiments of the present application, and the description is relatively specific and detailed, but should not be understood as limiting the scope of the present application. It should be noted that for those skilled in the art, several modifications and improvements can be made without departing from the concept of the present application, and these are within the scope of the present application.

Claims

1. A servo module, characterized by, The motor comprises a motor housing, an end cover, a stator and a rotor, the motor housing has an annular outer shell part and an inner shell part, an inner wall of the inner shell part is provided with a plurality of teeth in the circumferential direction, the end cover is connected with the outer shell part, the stator is arranged around the inner shell part and is fixedly connected with the inner shell part, and the rotor is rotatably arranged between the stator and the outer shell part. The planetary reduction assembly comprises a planet carrier, a planet wheel and a sun wheel, the planet carrier is rotatably connected with the inner wall of the inner shell part, the planet wheel is rotatably arranged on the planet carrier and is engaged with the teeth on the inner shell part, and the sun wheel is engaged with the planet wheel and is connected with the rotor. The servo driver is arranged on the side of the end cover facing the motor housing, the servo driver is connected with the end cover and is electrically connected with the stator. The inner wall of the inner shell part is provided with a first bearing and a second bearing, the first bearing and the second bearing are arranged along the axial direction of the inner shell part, and the planet carrier is rotatably connected with the inner wall of the inner shell part through the first bearing and the second bearing. The motor further comprises a rotor holder, the rotor holder is connected with the rotor, and the rotor holder has a sleeve part, the sleeve part is sleeved on one end of the sun wheel and is connected with the sun wheel. A third bearing is arranged between the end, of the sun wheel, away from the sleeve part, and the planet carrier, and a fourth bearing is arranged between the sleeve part and the planet carrier. The end cover is made of a heat-conductive material, a heat-conductive member is arranged between the servo driver and the end cover, and the servo driver is in abutment with the end cover through the heat-conductive member. The end cover has a protruding part, an accommodating cavity is formed in the protruding part, and the servo driver is located in the accommodating cavity.

2. The servo module of claim 1, wherein The servo driver comprises a board card and a control module, the board card is connected with the end cover, the control module is arranged on the board card, and the control module is electrically connected with the stator to collect the current signal of the stator.

3. The servo module of claim 1, wherein the first and second servo modules are configured to be mounted on a common substrate. The servo driver further comprises a coding and decoding module, the coding and decoding module is electrically connected with the control module, the coding and decoding module is arranged on the side of the board card facing the sun wheel and is opposite to the sun wheel, and a magnet is arranged on the end of the sun wheel close to the coding and decoding module.

4. The servo module according to any one of claims 1 to 3, wherein The servo module comprises any one of the servo modules according to claims 1-5.

5. The servo module of claim 4, wherein the first and second servo modules are configured to be mounted on a common substrate. The joint comprises the joint according to claim 6.

6. A joint, characterized by ​ 7. A robot, characterized in that ​

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