CN114810951A - Robot brushless outer rotor actuator with built-in speed reducer - Google Patents

Abstract

The invention discloses a brushless outer rotor actuator for a robot with a built-in speed reducer, which comprises a shell, a front end cover and a rear plate, wherein a motor rotor, a motor stator and the speed reducer are arranged in the shell, the speed reducer comprises a speed reducer inner gear ring, a planet wheel assembly and a sun wheel shaft, the first end surface of the shell is connected with the front end cover, the second end surface of the shell is connected with the rear plate, the connected front end cover, the shell and the rear plate form a first accommodating space, the motor rotor, an electrode stator and the speed reducer are arranged in the first accommodating space, the speed reducer is arranged in the motor stator, the motor stator is directly connected to the outer circumferential surface of the speed reducer inner gear ring, and the speed reducer inner gear ring is used for forming a part of a planetary speed reducing mechanism and also used for installing the motor stator. The structure is deeply integrated with the motor, the number of parts is reduced, the radial and axial sizes of the whole machine are effectively controlled, the whole structure is more compact, the mounting process is simple, the assembly precision is high, and the reliability is high.

Description

Robot brushless outer rotor actuator with built-in speed reducer

Technical Field

The invention relates to the technical field of robots, in particular to a brushless outer rotor actuator for a robot with a built-in speed reducer.

Background

The rapid development of industrial robots has been widely involved in various fields, and a four-legged robot is one of the industrial robots. The quadruped robot is a highly intelligent autonomous mobile robot with four legs, navigation, image recognition, voice transmission, autonomous path planning and the like, can autonomously recognize various objects and intelligently cross obstacles according to the surrounding environment, autonomously navigate and autonomously plan a motion path, returns images and voice interaction in real time, and is mainly used in the fields of security patrol, monitoring security, logistics distribution and the like.

The work load capacity and the self-motion flexibility of the quadruped robot are important factors influencing the performance of the quadruped robot. In addition to the weight of the robot, the robot also has additional loads in work, such as logistics distribution and self-carried lithium battery, and the four-footed motion of the robot is driven by a plurality of actuators at different parts of the robot in a coordinated manner, so that the actuators are basically required to be small in size (light and thin), large in torque, high in efficiency and light in weight. Most of the prior art is that a brushless motor is matched with a speed reducer, so that the motor works in a high-rotating-speed and high-efficiency area, and a large output torque is provided by depending on the speed reduction of the speed reducer. The conventional technical scheme is as follows: the motor and the speed reducer are designed and manufactured respectively, and the last two assemblies are assembled in series in the axial direction, but the scheme has the problems of large size, heavy weight, more parts, high cost and the like, and does not meet the application requirements in the field.

Disclosure of Invention

Therefore, the invention provides a brushless outer rotor actuator for a robot with a built-in speed reducer, which better meets the application requirements of small size (compact structure), light weight and more parts required by the actuator.

The invention mainly adopts the following technical scheme:

a brushless outer rotor actuator for a robot with a built-in speed reducer comprises a shell, a front end cover and a rear plate, wherein a motor rotor, a motor stator and the speed reducer are arranged in the shell; the motor rotor, the electrode stator and the speed reducer are arranged in the first accommodating space; the speed reducer is arranged in the motor stator, and the motor stator is directly connected to the outer circumferential surface of the inner gear ring of the speed reducer.

Preferably, the speed reducer ring gear is used for both the component of the planetary speed reducer mechanism and the installation of the motor stator.

Preferably, the planet wheel assembly is connected with an output flange, and a crossed roller bearing is arranged on the outer side of the output flange and used for bearing loads of the power output end in all directions.

Preferably, the actuator further includes a motor driving plate, and the motor driving plate is disposed on an outer side surface of the back plate opposite to the first accommodating space.

Preferably, the actuator further comprises a circuit board cover, and the circuit board cover is arranged on the outer side of the motor driving board and used for covering the motor driving board.

Preferably, the sun gear shaft is a supporting shaft for an integral structure, a ring of gear teeth are processed on the outer surface of the sun gear shaft and used for being in meshing transmission with the planet gear assembly, and one end, close to the rear plate, of the sun gear shaft is rigidly connected with the motor rotor.

Preferably, the whole structure of the actuator comprises three bearings: the device comprises a cross roller bearing, a first deep groove ball bearing and a second deep groove ball bearing; the cross roller bearing and the second deep groove ball bearing are used for supporting the whole rotating parts of the speed reducer, and the first deep groove ball bearing and the second deep groove ball bearing are used for supporting the rotation of the motor rotor.

Preferably, the screws used in the whole structure of the actuator are all countersunk head screws.

Preferably, the housing is uniformly distributed with arc-shaped protrusions along the circumferential direction of the outer side of the housing, and a wire through hole is formed in one of the protrusions.

Compared with the prior art, the invention has the beneficial effects that: the outer circumferential surface of the inner gear ring of the speed reducer is directly connected with the inner hole of the motor stator, the inner gear ring of the speed reducer is not only a component of a planetary speed reducing mechanism but also a mounting seat of the motor stator, and the functions of a plurality of parts are simultaneously replaced by a single part to realize the deep fusion with the motor. The crossed roller bearings are arranged on the side of the output flange, can resist loads in all directions, safely transmit stress to the shell, protect transmission parts and motor parts in the speed reducer from being affected by external loads, and enable the whole structure to be high in reliability and long in service life.

Drawings

Fig. 1 is an exploded view of a brushless outer rotor actuator for a robot with a built-in speed reducer according to the present invention;

FIG. 2 is a cross-sectional view of a brushless outer rotor actuator for a robot with a built-in reducer according to the present invention;

FIG. 3 is a schematic structural diagram of a stator of a motor according to an embodiment of the present invention;

FIG. 4 is an enlarged view of a portion of FIG. 2 at A;

fig. 5 is a schematic diagram of an actuator self-assembly structure according to an embodiment of the invention.

Detailed Description

The following describes in more detail embodiments of the present invention with reference to the schematic drawings. The advantages and features of the present invention will become more apparent from the following description. It should be noted that the drawings are in a very simplified form and all use non-precise scales, and are only used for convenience and clarity to assist in explaining the embodiment of the present invention, the application object of the embodiment is selected from a quadruped robot, but the actuator is not limited to be applied to other types of robots.

The invention provides a brushless outer rotor actuator for a robot with a built-in speed reducer, which is known from a figure 1 and a figure 2 and comprises a motor stator 1, a motor rotor 2, a speed reducer 3, a shell 4, a front end cover 5, a rear plate 6, a motor drive plate 7 and a circuit board cover 8, wherein the motor is a brushless outer rotor motor, and the speed reducer 3 adopts a planetary speed reducing mechanism. The first terminal surface 4A of shell 4 connects front end housing 5, and back plate 6 is connected to second terminal surface 4B, and the back of connecting front end housing 5, shell 4 and back plate 6 constitute first accommodation space, contain motor rotor 2, motor stator 1 and speed reducer 3 in the first accommodation space. Inside motor stator 1 was located to speed reducer 3, motor rotor 2 was connected as power input end and was located one side that is close to back plate 6 in the first accommodation space to the one end of speed reducer 3, and the other end of speed reducer 3 just is located one side that is close to front end housing 5 in the first accommodation space as power output end. The motor driving plate 7 is arranged on the outer side surface of the rear plate 6 corresponding to the first accommodating space, and a circuit board cover 8 is arranged on the outer side of the motor driving plate 7.

As can be seen from the sectional view of the brushless outer rotor actuator for a robot with a built-in speed reducer in fig. 2, the speed reducer 3 adopts a planetary speed reduction mechanism, and mainly comprises a speed reducer inner gear ring 30, a planetary wheel assembly, a sun gear shaft 32 and an inner gear ring rear end cover 33, the planetary wheel assembly comprises a planetary wheel 35, a planetary wheel shaft 36 and a planetary carrier 37, the sun gear shaft 32 is a power input assembly in the transmission process, the speed reducer inner gear ring 30 is fixed, the planetary wheel assembly is a power output assembly, the rotation of the sun gear shaft 32 drives the planetary wheel assembly to rotate, and the transmission mode enables the motor rotor 2 connected with the sun gear shaft 32 to rotate at a high speed and realize speed reduction output through the planetary wheel assembly at a certain speed reduction ratio, so as to increase the output torque. It can be known from the partial enlarged view at a position in fig. 4 that the speed reducer 3 is arranged in the motor stator 1, the outer circumferential surface of the speed reducer ring gear 30 is directly connected with the inner hole of the motor stator 1, the inner circumferential surface of the speed reducer ring gear is provided with inner teeth and is in meshed connection with the teeth of the planet wheels 35, the speed reducer ring gear 30 is not only a component of the planetary speed reducing mechanism but also a mounting seat of the motor stator 1, so that the depth fusion with the motor is realized, and a shell and a separate mounting seat of the motor stator 1 which are separately required by the speed reducer 3 are reduced. One end of the speed reducer ring gear 30 is fixedly connected with the front end cover 5, in this embodiment, a screw connection is preferred, and connection modes such as a bolt, a stud and the like can be selected, and the connection mode is not limited here; the other end of the inner gear ring 30 of the speed reducer is fixedly connected with an inner gear ring rear end cover 33, and an inner space formed by the inner gear ring and the inner gear ring mainly contains the planet wheel assembly. In the transmission process, the planet wheel assembly realizes speed reduction transmission of the rotating speed of the sun wheel shaft 32. One end of the planetary wheel assembly, which is close to the rear end cover 33 of the inner gear ring, is connected with a planetary carrier 37 through a planetary wheel shaft 36, and the other end is connected with an output flange 34 through the planetary wheel shaft 36 to realize power output. A ring of gear teeth are processed on the outer surface of the sun gear shaft 32 and are used for being meshed with the planet gears 35 for transmission, namely, the ring gear teeth are used as the sun gear for power transmission. The sun gear shaft 32 is not only positioned at the center of the planetary speed reducing mechanism and belongs to a part of the planetary transmission of the speed reducer 3, but also positioned on the rotating axis of the motor rotor 2, and one end of the sun gear shaft 32 close to the rear plate 6 is rigidly connected with the motor rotor 2 and also belongs to a part of a rotating body of the motor rotor 2. It can be seen that the sun gear shaft 32 integrates the motor shaft and the reducer shaft into a whole and is the only supporting shaft of the whole structure, so that the whole axial length is determined by only one supporting length, and the structure enables the whole axial structure to be more flat and compact and reduces the cost. The second deep groove ball bearing 11 is mounted in the ring gear rear end cover 33, and the bearing is not only an important component for supporting the speed reducer 3, but also a supporting bearing of the motor rotor 2.

Brushless motor includes outside electric motor rotor 2 and inside electric motor stator 1, brushless motor's electric motor stator 1 is folded by flaky silicon steel sheet and is pressed and form, stator punching 101 designs into a lot of teeth, the alternate structure of groove, at stator punching's surface coating one deck epoxy layer, the winding coil 102 of motor is on every tooth by the enameled wire coiling, and connect and constitute three-phase motor winding, change the magnetic field that electric motor stator 1 formed through external circuit, thereby driving motor rotor 2 encircles electric motor stator 1 and rotates. The motor rotor 2 is rigidly connected with one end of a sun gear shaft 32 in the speed reducer, and the motor rotor 2 drives the sun gear shaft 32 to rotate when rotating. As can be seen from fig. 3, the motor stator 1 has a large inner bore 103, and the inside of the motor stator is used for mounting the speed reducer 3. The inner circumferential surface of the stator inner hole 103 is directly and fixedly connected with the outer circumferential surface of the speed reducer ring gear 30, and the connection mode between the two can be interference press-fitting or viscose glue, and the connection mode is not limited here. The structure realizes the full utilization of a single part, the stator mounting seat, the speed reducer shell and the inner gear ring can be combined into a single part, which is called as the inner gear ring of the speed reducer, one part of the inner gear ring 30 of the speed reducer replaces the functions of a plurality of parts at the same time, and the number of the parts of the shell and the single mounting seat of the motor stator 1 required by the speed reducer 3 is reduced. The whole structure of the actuator mainly depends on the outer diameter and the stacking thickness of the motor, the planetary reduction mechanism is completely or partially arranged in an inner hole of the motor stator 1 when being installed, only the output flange 34 of the planetary reduction mechanism protrudes a little outwards in the axial direction, the structure has little influence on the whole structure of the actuator, the axial size of the whole actuator is ensured to be flat and compact, the radial structure of the whole actuator is compact, and the radial size is effectively reduced.

The shell 4 of the actuator is fixedly connected with the front end cover 5 and the rear plate 6 to form a first accommodating space, so that the built-in motor structure of the speed reducer 3 is integrally coated, and the size of the shell 4 is determined by the outer diameter of the motor. In this embodiment, the outer shell 4 is provided with arc-shaped protrusions uniformly distributed along the outer circumferential direction, the protrusions are provided with mounting holes 401 for matching with screws, the front end cover 5 and the rear plate 6 are respectively mounted on two end faces of the outer shell 4 by penetrating the mounting holes 401 through the screws, and the connection is firm. In the provided projections, a through hole with a certain space and a smooth surface is arranged in one of the projections to serve as a wire through hole 402, and the wire through hole 402 is mainly used for arranging related circuits in the actuator, so that the wiring of the internal circuits is clear and concise.

The front end cover 5 of the actuator is fixedly connected to one end face of the shell 4 through a screw, an arc-shaped bulge correspondingly connected with the shell 4 is also arranged on the outer side of the front end cover in the circumferential direction, and a circular through hole is formed in the center of the front end cover. And the cross roller bearing 9, the output flange 34 and the first deep groove ball bearing 10 are sequentially arranged in the through hole from outside to inside, and the first deep groove ball bearing 10 is used for being matched and connected with one end of the sun wheel shaft 32. And one end of the through hole far away from the first accommodating space is also correspondingly provided with an outer baffle 13 of the crossed roller and an oil seal 12. One side of the front end cover 5, which is positioned in the first accommodating space, is used for connecting the inner gear ring 30 of the speed reducer, and the front end cover and the inner gear ring are combined with the rear end cover 33 of the inner gear ring to be integrally assembled and disassembled as a combined component, so that the structure is simple, and the installation process is convenient and quick.

The crossed roller bearing 9 is installed on the output flange 34 side of the speed reducer, and in the application scene of the actuator in the four-legged robot, the power output end (the output flange 34 of the speed reducer) can frequently bear axial push load, pull load, radial load and torsional load. The cross roller bearing 9 can bear loads (such as axial, radial or momentum loads) in various directions because the rollers are arranged at right angles to each other with the inner ring and the outer ring being alternately crossed, has a high load-bearing capacity because the rollers are in linear contact with the raceway surface, and is minimized in the size of the inner and outer rings, particularly in the extremely thin type, which is a size close to the limit, has high rigidity, and is most suitable for the joint portion or the rotating portion of an industrial robot. In the invention, the crossed roller bearing 9 is arranged at the output flange 34 side of the speed reducer, so that the load in each direction can be resisted, and the stress is safely transmitted to the shell 4, thereby ensuring that the sun gear shaft 32, the planet wheel assembly, the speed reducer inner gear ring 30, the motor stator 1 and the motor rotor 2 in the speed reducer are not influenced by external load, and ensuring that the integral structure has high reliability and long service life.

In the invention, the rotation of the whole structure of the actuator uses three bearings in total: a cross roller bearing 9, a first deep groove ball bearing 10 and a second deep groove ball bearing 11. The crossed roller bearing 9 and the second deep groove ball bearing 11 form a two-end supporting structure, the rotating parts of the whole speed reducer are supported together, and the reliability of two-end supporting is high. The rotary support of the motor rotor 2 is performed by a first deep groove ball bearing 10 and a second deep groove ball bearing 11, and also forms a two-end support. The second deep groove ball bearing 11 is not only a support bearing of the speed reducer 3, but also a support bearing of the motor rotor 2, so that the using amount of the bearings can be reduced from four to three, and the cost is reduced. And the first deep groove ball bearing 10 of the motor support is arranged at the inner side of the crossed roller bearing of the speed reducer, namely the double-end support of the motor is sleeved in the double-end support of the speed reducer, so that the whole axial length is determined by only one support length. The speed reducer 3 and the motor are combined more simply and conveniently, so that the cost is reduced, and the actuator is compact in overall structure, simple and reliable.

A back plate 6 of the actuator is fixedly connected to the other end face of the shell 4 through screws, and a motor driving plate 7 is installed on the outer side face, opposite to the first accommodating space, of the back plate 6. The motor drive board 7 controls the rotation of the motor rotor 2 and is arranged on the outer side surface of the rear plate 6, and is far away from main heating components (stator winding coils 102) of the motor, so that the environmental temperature of electronic components on the motor drive board 7 is reduced, and the service life and the reliability are improved. In addition, set up circuit board cover 8 in motor drive board 7 outside, circuit board cover 8 covers motor drive board 7 is whole, can prevent dust, rainwater, the invasion of foreign matter, improves system reliability and environmental suitability.

The integral structure operation principle of the actuator of the invention is as follows: the motor driving plate 7 controls the operation of the motor, the motor stator 1 drives the motor rotor 2 outside the motor stator 1 to rotate through current commutation according to design requirements, the motor rotor 2 is rigidly connected with the sun gear shaft 32, and the electronic rotor 2 drives the sun gear shaft 32 (sun gear) to rotate. The sun gear shaft 32 rotates to drive the speed reducer 3 positioned in the motor stator 1, the sun gear is a driving wheel, the inner gear ring 30 of the speed reducer is fixed as a mounting seat of the motor stator 1, the sun gear drives the planetary wheel assembly to operate, the rotating speed of the planetary wheel assembly is output through the output flange 34 connected to the end part of the planetary wheel shaft 36, and the purposes of reducing the rotating speed of the motor rotor 2 and outputting and increasing the torque are achieved in the transmission process.

Fig. 5 is a schematic diagram of the actuator self-assembly structure according to the embodiment of the invention, and the overall size of the actuator of the invention is determined by the dimensions of the housing 4 (the outer diameter dimension of the motor), the lamination thickness of the stator 1 of the motor, the motor driving plate 7, the circuit board cover 8 and the like, and mainly depends on the outer diameter and the lamination thickness of the motor. The speed reducer 3 is completely or partially embedded in an inner hole of the motor stator 1, only the output flange 34 of the speed reducer 3 protrudes a little axially, wherein the outer circumferential surface of the speed reducer inner gear ring 30 is directly connected with the motor stator inner hole 103, the inner circumferential surface of the speed reducer inner gear ring is provided with inner teeth and is in meshed connection with the gear teeth of the planet wheel 35, the speed reducer inner gear ring 30 is not only a component of a planet speed reducing mechanism but also a mounting seat of the motor stator 1, one part of the speed reducer inner gear ring 30 simultaneously replaces the functions of a plurality of parts to realize the deep fusion with the motor, the structure effectively controls the radial and axial dimensions of the whole machine, the whole structure is more compact, the mounting process is simple, and the operation assembly precision and the reliability are high. The actuator is more convenient to be applied to the fields with high requirements on size and structure, such as robot arms, joints and the like. The screws used in the installation of the whole actuator are countersunk screws, so that the outer surface of the whole actuator is regular and attractive, and the installation and the use are convenient.

In summary, the invention provides a brushless outer rotor actuator for a robot with a built-in speed reducer. The outer circumferential surface of the speed reducer inner gear ring 30 is directly connected with the motor stator inner hole 103, the inner circumferential surface of the speed reducer inner gear ring is provided with inner teeth and is in meshed connection with the gear teeth of the planet wheel 35, and the speed reducer inner gear ring 30 is not only a component of a planet speed reducing mechanism but also a mounting seat of the motor stator 1, so that the whole structure is more compact, the mounting process is simple, and the operation assembly precision and the reliability are high. In addition, the crossed roller bearing 9 is installed on the side of the output flange 34, so that the load in each direction can be resisted, the stress is safely transmitted to the shell, and a transmission part and a motor part in the speed reducer are protected from being influenced by external load, so that the reliability of the whole structure is high, and the service life is long.

The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention, and those skilled in the art can make various changes, modifications, substitutions and alterations without departing from the principle and spirit of the present invention, and the scope of the present invention is defined by the appended claims and their equivalents.

Claims (9)

1. A brushless outer rotor actuator for a robot with a built-in speed reducer comprises a shell, a front end cover and a rear plate, wherein a motor rotor, a motor stator and the speed reducer are arranged in the shell; the motor rotor, the electrode stator and the speed reducer are arranged in the first accommodating space; the speed reducer is arranged in the motor stator, and the motor stator is directly connected to the outer circumferential surface of the inner gear ring of the speed reducer.

2. The brushless outer rotor actuator for a robot with a built-in speed reducer of claim 1, wherein the speed reducer ring gear is used for both a component of a planetary speed reduction mechanism and for mounting of a motor stator.

3. The brushless external rotor actuator for the robot with the built-in speed reducer as claimed in claim 1, wherein the planetary wheel assembly is connected with an output flange, and a crossed roller bearing is arranged outside the output flange and used for bearing the load of the power output end in each direction.

4. The brushless outer rotor actuator for a robot with a built-in speed reducer according to claim 1, further comprising a motor drive plate, wherein the motor drive plate is disposed on an outer side surface of the back plate opposite to the first accommodating space.

5. The brushless outer rotor actuator for a robot with a built-in speed reducer of claim 1, further comprising a circuit board cover disposed outside the motor drive board for covering the motor drive board.

6. The brushless external rotor actuator for the robot with the built-in speed reducer as claimed in claim 1, wherein the sun gear shaft is a supporting shaft for an integral structure, a ring of gear teeth are arranged on the outer surface of the sun gear shaft for meshing transmission with the planetary gear assembly, and one end of the sun gear shaft, which is close to the rear plate, is rigidly connected with the motor rotor.

7. The brushless external rotor actuator for the robot with the built-in speed reducer of claim 1, wherein the whole structure of the actuator comprises three bearings: the device comprises a cross roller bearing, a first deep groove ball bearing and a second deep groove ball bearing; the cross roller bearing and the second deep groove ball bearing are used for supporting the whole rotating parts of the speed reducer, and the first deep groove ball bearing and the second deep groove ball bearing are used for supporting the rotation of the motor rotor.

8. The brushless external rotor actuator for a robot with a built-in speed reducer of claim 1, wherein the screws used in the whole structure of the actuator are countersunk screws.

9. The brushless external rotor actuator for a robot with a built-in speed reducer of claim 1, wherein the housing is provided with arc-shaped protrusions uniformly distributed along a circumferential direction of an outer side of the housing, and a wire through hole is formed in one of the protrusions.

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