Double-rotor single-stator planetary speed reduction type joint module

Abstract

The invention discloses a double-rotor single-stator planetary speed reduction type joint module which comprises a hollow shaft, a driver assembly, an axial magnetic flux motor, a planetary speed reducer and an output shaft, and the driver assembly, the axial magnetic flux motor and the planetary speed reducer are sequentially arranged on the hollow shaft in the axial direction; the axial magnetic flux motor comprises a rotor support, a stator assembly and two rotor assemblies, the two rotor assemblies are symmetrically arranged on the two different sides of the stator assembly in the axial direction respectively, and the two rotor assemblies are in transmission connection with the power input end of the planetary reducer through the rotor support. The power output end of the planetary reducer, the output shaft and the hollow shaft are in transmission connection in sequence; the stator assembly comprises a plurality of stator units which are circumferentially arranged; each of the two rotor assemblies comprises a rotor supporting plate and a plurality of magnetic steels. Wiring arrangement of the joint module can be facilitated, the integration degree is improved, and the torque density of the joint module is effectively improved.

Description

TECHNICAL FIELD

[0001] The present application relates to a robot electric drive joint, in particular to a double-rotor single-stator planetary reduction joint module. BACKGROUND

[0002] At present, the motor of the robot joint module mainly adopts a radial flux motor. Compared with the radial motor, the axial flux motor can provide higher torque density and power density, and the axial dimension of the axial flux motor is two-thirds shorter than that of the radial flux motor under the same power. The main technical routes of the reducer for the rotating actuator of the joint module are divided into three categories: harmonic reducer electric drive joint, RV reducer electric drive joint and planetary reduction electric drive joint, each having advantages and disadvantages, and the market will coexist for a long time. The planetary reduction electric drive joint has the advantages of strong anti-torque impact capacity, high efficiency, long service life and low manufacturing cost, and the market mainstream planetary reduction electric drive joint adopts 2K-H planetary transmission (NGW type simple planetary transmission and NW type composite planetary transmission belong to the 2K-H planetary transmission category), which is usually not hollow. However, the market development demand is to need a hollow structure, which is convenient for wiring arrangement, and the application scene requires the electric drive joint to achieve high torque density, thereby putting forward the demand for high reduction ratio of the reducer. The hollow structure and the high reduction ratio are a pair of contradictory for the planetary reduction electric drive joint. SUMMARY

[0003] Therefore, the purpose of the present application is to provide a double-rotor single-stator planetary reduction joint module, which can facilitate the wiring arrangement of the joint module, improve the integration and effectively improve the torque density of the joint module.

[0004] The double-rotor single-stator planetary reduction joint module in the present application comprises a hollow shaft, a driver assembly, an axial flux motor, a planetary reducer and an output shaft, wherein the driver assembly, the axial flux motor and the planetary reducer are sequentially arranged on the hollow shaft in the axial direction; The axial flux motor comprises a rotor support, a stator assembly and two rotor assemblies, the two rotor assemblies are symmetrically arranged on different sides of the stator assembly in the axial direction, the two rotor assemblies are drivingly connected with the power input end of the planetary reducer through the rotor support, and the power output end of the planetary reducer, the output shaft and the hollow shaft are sequentially drivingly connected. The stator assembly comprises a plurality of stator units arranged in a circle, each of the plurality of stator units comprises a stator core and a stator winding wound on the stator core; each of the two rotor assemblies comprises a rotor support plate and a plurality of magnetic steels, and the plurality of magnetic steels are arranged in a circle on one side of the rotor support plate facing the stator units.

[0005] Further, the magnetic steel is a surface-mounted segmented magnetic steel, the rotor support plate is a circular steel plate, and the stator winding is a round wire winding or a flat wire winding.

[0006] Further, the driver assembly comprises a driver housing, the axial flux motor further comprises a motor rear housing and a stator outer housing, the planetary reducer comprises a gear ring fixing housing and a reducer main housing; the driver housing, the motor rear housing, the stator outer housing, the gear ring fixing housing and the reducer main housing are sequentially connected in the axial direction, and an opening structure is arranged on a side of the reducer main housing away from the motor outer housing.

[0007] Further, the axial flux motor further comprises a first stator plate and a second stator plate, the first stator plate and the second stator plate are arranged on two sides of the stator unit different in the axial direction respectively, and the first stator plate and the second stator plate are fixedly connected with the stator outer housing.

[0008] Further, the driver assembly further comprises a driver body, a magnetic encoder inner rotor, a magnetic encoder outer rotor and a magnetic encoder stator, the magnetic encoder stator is fixed on the motor rear housing, the magnetic encoder inner rotor is fixed on the hollow shaft, the magnetic encoder outer rotor is fixed on a power input end of the planetary reducer, and the magnetic encoder inner rotor, the magnetic encoder outer rotor and the magnetic encoder stator are in communication connection with the driver body.

[0009] Further, the planetary reducer comprises a sun shaft, a first planetary gear, a fixed gear ring, a second planetary gear, a planet carrier and an output gear ring. The sun shaft comprises a main shaft body and a sun gear arranged on one side of the main shaft body in a coaxial synchronous rotation mode, the rotor support is in transmission connection with the main shaft body, and the sun shaft is rotatably sleeved on the hollow shaft; the fixed gear ring is position-fixed; the first planetary gear is engaged between the sun gear and the fixed gear ring; the first planetary gear and the second planetary gear are connected in a coaxial synchronous rotation mode and are rotatably installed on the planet carrier; the second planetary gear is engaged with the output gear ring; the sun shaft serves as the power input end, and the output gear ring serves as the power output end.

[0010] Further, the hollow shaft has a through hole in the axial direction, one end of the hollow shaft is in rotation connection with the driver assembly, the middle part of the hollow shaft passes through the sun shaft and the planet carrier, and the other end of the hollow shaft is fixedly connected with the output shaft.

[0011] Further, the first planetary gear and the second planetary gear form a double planetary gear, which is rotatably mounted on a planet shaft pin through a planet bearing, and the planet pin is fixedly connected with the planet carrier.

[0012] Further, the output shaft comprises an inner connecting cylinder, a mounting seat, a connecting arm and an outer connecting cylinder arranged in sequence from inside to outside in the radial direction; and the planet carrier comprises a first mounting part, a main carrier body and a second mounting part arranged in sequence in the axial direction. The driver housing is located on the radial outside of the hollow shaft, and a first bearing is arranged between the driver housing and the hollow shaft; The motor rear housing is located on the radial outside of the main shaft body, and a second bearing is arranged between the motor rear housing and the main shaft body; the first mounting part is located on the radial outside of the main shaft body, and a third bearing is arranged between the first mounting part and the main shaft body; and the second bearing and the third bearing are respectively located on two different sides of the rotor support in the axial direction. The second mounting part is located on the radial inside of the inner connecting cylinder, and a fourth bearing is arranged between the second mounting part and the inner connecting cylinder; the inner connecting cylinder is connected with the hollow shaft; and the outer connecting cylinder is connected with the output gear ring. The limiting seat is located on the radial inside of the reducer main housing, and a fifth bearing is arranged between the limiting seat and the reducer main housing.

[0013] Further, the fifth bearing is a cross-roller bearing, and the cross-roller bearing is axially positioned through a fixed ring and a retainer.

[0014] The joint module of the present application has the following advantages: (1) The driver assembly, the axial flux motor and the planetary reducer are arranged in sequence in the axial direction along the hollow shaft, and the hollow shaft has a hollow structure, so that the wiring arrangement of the joint module can be facilitated, and the driver assembly, the axial flux motor and the planetary reducer do not affect the wiring.

[0015] (2) The driver assembly, the axial flux motor and the planetary reducer are coaxially arranged in sequence, so that there is basically no axial space waste between the driver assembly and the axial flux motor, between the axial flux motor and the planetary reducer, the axial space utilization rate is improved, the axial dimension of the joint module can be reduced, and in the radial direction, the driver assembly, the axial flux motor and the planetary reducer do not occupy space with each other, the radial dimension is only related to the shell of the driver assembly, the axial flux motor and the planetary reducer, and the radial dimension of the joint module can be greatly reduced. Therefore, the joint module of the present application can improve the integration, realize a larger speed ratio under the condition of a larger hollow size and smaller radial and axial dimensions, and effectively improve the torque density of the joint module.

[0016] (3) The magnetic field of the double-rotor single-stator axial flux motor of the application passes through the stator core along the axial direction, passes through the next stator core through the magnetic steel and the rotor support plate, and thus forms a complete magnetic circuit through the stator core, the magnetic steel and the rotor support plate. The double-rotor structure provides more magnetic steel in a limited space, greatly increases the magnetic flux area of the motor, increases the output torque of the motor, and improves the torque density of the motor.

[0017] (4) The surface-mounted segmented magnetic steel of the application is fixed on the surface of the rotor support plate by the magnetic steel fixing glue, which can ensure that the magnetic steel will not fall off due to excessive centrifugal force during high-speed operation, and realize the high-speed operation of the motor. At the same time, since the rotor support plate is a circular steel plate, the rotor support plate can greatly reduce the eddy current loss caused by the radial magnetic leakage of the magnetic steel while guiding the magnetic field in the circumferential direction; the magnetic steel is segmented and bonded, which reduces the eddy current loss of the magnetic steel during the operation of the motor, reduces the temperature of the magnetic steel, and further improves the output torque of the motor.

[0018] (5) The double-rotor single-stator planetary reduction type joint module of the application applied in the robot joint can achieve a speed ratio of 99 under the condition of an outer diameter of Φ125mm and a hollow size of Φ10mm, which is much higher than the current market products. The actual joint assembly weight is 2.2kg, the peak torque is 496Nm, and the peak torque density can reach 225Nm / kg, which realizes the high torque density of the joint module. BRIEF DESCRIPTION OF DRAWINGS

[0019] In order to make the purpose, technical scheme and beneficial effects of the application more clear, the application provides the following drawings for illustration: Figure 1 is a structural schematic view of the application; Figure 2 is a sectional schematic view of the application; Figure 3 is a schematic view of the transmission principle of the application; Figure 4 is an exploded schematic view of the axial flux motor and the sun gear shaft of the application; Figure 5 is a structural schematic view of the rotor assembly of the application; Figure 6 is a schematic view of the magnetic field of the double-rotor single-stator axial flux motor of the application; Figure 7 is an exploded schematic view of the planetary reducer of the application; Figure 8 is a structural schematic view of the double planetary gear composed of the first planetary gear and the second planetary gear of the application.

[0020] The marks in the drawings are as follows: 1 - hollow shaft; 2-Driver assembly, 21-Driver housing, 22-Driver body, 23-Inner rotor of magnetic encoder, 24-Outer rotor of magnetic encoder, 25-Stator of magnetic encoder; 3-Axial flux motor, 31-Rotor support, 32-Stator core, 33-Stator winding, 34-Rotor support plate, 35-Magnet, 36-Motor rear housing, 37-Stator outer housing, 38-First stator plate, 39-Second stator plate; 4-Planetary reducer, 41-Ring gear fixed housing, 42-Reducer main housing, 43-Sun gear shaft, 431-Main shaft body, 432-Sun gear, 44-First planetary gear, 45-Fixed ring gear, 46-Second planetary gear, 47-Planet carrier, 471-First mounting part, 472-Main carrier body, 473-Second mounting part, 48-Output ring gear, 49-Planet shaft pin, 410-Planet gear bearing; 5-Output shaft, 51-Inner connecting cylinder, 52-Mounting base, 53-Connecting arm, 54-Outer connecting cylinder; 61-First bearing, 62-Second bearing, 63-Third bearing, 64-Fourth bearing, 65-Fifth bearing, 66-Retaining ring, 67-Retaining ring. Detailed Implementation

[0021] The technical solution of the present invention will be described in detail below with reference to the accompanying drawings and embodiments.

[0022] like Figures 1-8 As shown, a dual-rotor single-stator planetary reduction joint module in this embodiment includes a hollow shaft 1, a driver assembly 2, an axial flux motor 3, a planetary reducer 4, and an output shaft 5. The driver assembly 2, the axial flux motor 3, and the planetary reducer 4 are sequentially arranged on the hollow shaft 1 along the axial direction.

[0023] The axial flux motor 3 includes a rotor support 31, a stator assembly, and two rotor assemblies. The two rotor assemblies are symmetrically arranged on different sides of the stator assembly in the axial direction. The two rotor assemblies are connected to the power input end of the planetary reducer 4 through the rotor support 31. The power output end of the planetary reducer 4, the output shaft 5, and the hollow shaft 1 are sequentially connected. The rotor support 31 is fixedly connected to the rotor support plate 34, and the sun gear shaft 43 is rotated through the rotor support 31.

[0024] The stator assembly includes a plurality of stator units arranged in a circular pattern, each stator unit including a stator core 32 and a stator winding 33 wound on the stator core 32; both rotor assemblies include a rotor support plate 34 and a plurality of magnets 35, the plurality of magnets 35 being arranged in a circular pattern on the side of the rotor support plate 34 facing the stator unit.

[0025] The driver assembly 2, the axial flux motor 3 and the planetary reducer 4 are arranged in sequence along the axis of the hollow shaft 1, and the hollow shaft 1 is hollow, so that the wiring arrangement of the joint module can be facilitated, and the driver assembly 2, the axial flux motor 3 and the planetary reducer 4 do not affect the wiring.

[0026] The coaxial arrangement of the driver assembly 2, the axial flux motor 3 and the planetary reducer 4 makes it possible that there is basically no axial space waste between the driver assembly 2 and the axial flux motor 3 and between the axial flux motor 3 and the planetary reducer 4, the axial space utilization is improved, the axial dimension of the joint module can be reduced, and in the radial direction, the driver assembly 2, the axial flux motor 3 and the planetary reducer 4 do not occupy space with each other, the radial dimension is only related to the shell of the driver assembly 2, the axial flux motor 3 and the planetary reducer 4, and the radial dimension of the joint module can be greatly reduced. Therefore, the joint module in the embodiment can improve the integration, realize a larger speed ratio under the condition of a larger hollow dimension and smaller radial and axial dimensions, and effectively improve the torque density of the joint module.

[0027] The magnetic field of the double-rotor single-stator axial flux motor 3 is shown in Figure 6 The magnetic field passes through the stator core 32 along the axis, passes through the magnetic steel 35 and the rotor support plate 34 and then passes through the next stator core 32, and the magnetic field forms a complete magnetic circuit by passing through the stator core 32, the magnetic steel 35 and the rotor support plate 34. The double-rotor structure provides more magnetic steel 35 in a limited space, greatly increases the magnetic flux area of the motor, increases the output torque of the motor and improves the torque density of the motor.

[0028] In the embodiment, the magnetic steel 35 is a surface-mounted segmented magnetic steel, the rotor support plate 34 is a circular steel plate, and the stator winding 33 is a round wire winding or a flat wire winding.

[0029] The surface-mounted segmented magnetic steel is fixed on the surface of the rotor support plate 34 by a magnetic steel fixing adhesive, so that the magnetic steel 35 cannot fall off due to excessive centrifugal force during high-speed operation, and high-speed operation of the motor is realized. At the same time, since the rotor support plate 34 is a circular steel plate, the rotor support plate 34 can greatly reduce the eddy current loss caused by the radial magnetic leakage of the magnetic steel 35 while guiding the magnetic field in the circumferential direction; the magnetic steel 35 is segmented and bonded, which reduces the eddy current loss of the magnetic steel 35 during operation of the motor, reduces the temperature of the magnetic steel 35 and further improves the output torque of the motor.

[0030] In the embodiment, the driver assembly 2 comprises a driver housing 21, the axial flux motor 3 further comprises a motor rear housing 36 and a stator outer housing 37, the planetary reducer 4 comprises a ring gear fixing housing 41 and a reducer main housing 42; the driver housing 21, the motor rear housing 36, the stator outer housing 37, the ring gear fixing housing 41 and the reducer main housing 42 are connected in sequence along the axial direction, and an opening structure is arranged on the side of the reducer main housing 42 away from the motor outer housing.

[0031] The driver housing 21, the motor rear housing 36, the stator outer housing 37, the ring gear fixing housing 41 and the reducer main housing 42 are connected in sequence along the axial direction, which means that the housings of the joint module form a multi-section split structure, and the housings are connected in a detachable manner, so that the assembly is more convenient. The stator outer housing 37 is used for accommodating the stator assembly, and the ring gear fixing housing 41 is used for mounting and fixing the ring gear 45. The opening structure is used for accommodating the output shaft 5.

[0032] In the embodiment, the axial flux motor 3 further comprises a first stator plate 38 and a second stator plate 39, the first stator plate 38 and the second stator plate 39 are arranged on the two sides of the stator unit in the axial direction respectively, and the first stator plate 38 and the second stator plate 39 are fixedly connected with the stator outer housing 37.

[0033] Meanwhile, the stator outer housing 37, the first stator plate 38 and the second stator plate 39 jointly form a space for accommodating the stator assembly, and the plurality of stator units are arranged in the space in a circumferential direction.

[0034] The space between the motor rear housing 36 and the first stator plate 38 can accommodate one of the rotor assemblies, and the space between the second stator plate 39 and the ring gear fixing housing 41 can accommodate the other rotor assembly, the fixed ring gear 45 and part of the planet carrier 47. There is no partition structure between the rotor assembly and the planet carrier 47, and the weight of the housing can be reduced by reducing the partition structure, thereby reducing the total weight of the joint module.

[0035] In the embodiment, the driver assembly 2 further comprises a driver body 22, a magnetic encoder inner rotor 23, a magnetic encoder outer rotor 24 and a magnetic encoder stator 25, the magnetic encoder stator 25 is fixed on the motor rear housing 36, the magnetic encoder inner rotor 23 is fixed on the hollow shaft 1, the magnetic encoder outer rotor 24 is fixed on the power input end of the planetary reducer 4, and the magnetic encoder inner rotor 23, the magnetic encoder outer rotor 24 and the magnetic encoder stator 25 are in communication connection with the driver body 22. The power input end of the planetary reducer 4 is the sun gear shaft 43.

[0036] The magnetic encoder stator 25 serves as a static reference datum, the magnetic encoder inner rotor 23 can collect the rotating speed and position signal of the hollow shaft 1, the magnetic encoder outer rotor 24 can collect the rotating speed and position signal of the sun gear shaft 43, and the driver body 22 can monitor the rotating speed and direction of the hollow shaft 1 and the sun gear shaft 43 after receiving the signals sent by the magnetic encoder stator 25, the magnetic encoder inner rotor 23 and the magnetic encoder outer rotor 24, so as to facilitate high-precision position control of the joint module. In addition, abnormality monitoring can also be performed, and when the speed ratio of the hollow shaft 1 and the sun gear shaft 43 is abnormal, a fault alarm can be sent in time to improve the reliability of the joint module.

[0037] In the embodiment, the planetary reducer 4 includes a sun gear shaft 43, a first planetary gear 44, a fixed ring gear 45, a second planetary gear 46, a planet carrier 47 and an output ring gear 48. The sun gear shaft 43 includes a main shaft body 431 and a sun gear 432 arranged on one side of the main shaft body 431 in a coaxial synchronous rotating manner, the rotor support 31 is in transmission connection with the main shaft body 431, and the sun gear shaft 43 is rotatably sleeved on the hollow shaft 1; the fixed ring gear 45 is position-fixed; the first planetary gear 44 is engaged between the sun gear 432 and the fixed ring gear 45; the first planetary gear 44 and the second planetary gear 46 are connected in a coaxial synchronous rotating manner and are both rotatably installed on the planet carrier 47; the second planetary gear 46 is engaged with the output ring gear 48; the sun gear shaft 43 serves as the power input end, and the output ring gear 48 serves as the power output end.

[0038] The planetary reducer 4 is a 3K planetary reduction mechanism. The main shaft body 431 of the sun gear shaft 43 extends into the rotor support 31, the motor torque is input to the main shaft body 431 of the planetary reducer 4 through the rotor support 31, and then is reduced and increased in torque through the 3K planetary reduction mechanism composed of the sun gear shaft 43, the first planetary gear 44, the fixed ring gear 45, the second planetary gear 46, the planet carrier 47 and the output ring gear 48, and then the power is output by the output shaft 5 connected with the output ring gear 48. The 3K planetary reduction mechanism can realize large speed ratio reduction. The maximum speed ratio of the existing hollow planetary reducer 4 is less than 25, which cannot meet the market demand, and the planetary reducer 4 is a 3K planetary reduction mechanism which can achieve a large speed ratio of 99.

[0039] And, the 3K planetary reduction mechanism of the planetary reducer 4 and the axial flux motor 3 are arranged in an axial manner, which reduces the radial size of the joint, and the same joint diameter is provided with a larger reduction ratio, the sun shaft 43 of the 3K planetary reduction mechanism extends into the rotor assembly of the motor, and there is no axial space waste between the planetary reducer 4 and the axial flux motor 3, which reduces the axial size of the joint module, has high integration, and has small envelope size, and higher torque density can be achieved under the same envelope size.

[0040] In the embodiment, the hollow shaft 1 has a through hole in the axial direction, one end of the hollow shaft 1 is rotationally connected with the driver assembly 2, the middle part of the hollow shaft 1 passes through the sun shaft 43 and the planet carrier 47, and the other end of the hollow shaft 1 is fixedly connected with the output shaft 5.

[0041] The through hole in the axial direction makes the hollow shaft 1 hollow, which facilitates the wiring arrangement of the joint module and prevents the driver assembly 2, the axial flux motor 3 and the planetary reducer 4 from affecting the wiring.

[0042] In the embodiment, the first planetary gear 44 and the second planetary gear 46 form a double planetary gear, the double planetary gear is rotationally installed on the planet shaft pin 49 through the planetary gear bearing 410, and the planet pin is fixedly connected with the planet carrier 47.

[0043] The coaxial synchronous rotation connection of the first planetary gear 44 and the second planetary gear 46 means that the first planetary gear 44 and the second planetary gear 46 can be integrally formed to form a double planetary gear, and the double planetary gear is rotationally installed on the planet shaft pin 49 through the planetary gear bearing 410. The connection mode of the first planetary gear 44 and the second planetary gear 46 can also be a spline combined axial limiting structure to fix the two on the same gear shaft to realize the connection of the two, and the gear shaft is rotationally installed on the planet shaft pin 49 through the planetary gear bearing 410.

[0044] In the embodiment, the output shaft 5 includes an inner connecting barrel 51, a mounting seat 52, a connecting arm 53 and an outer connecting barrel 54 arranged in the radial direction from inside to outside in sequence; and the planet carrier 47 includes a first mounting part 471, a main carrier body 472 and a second mounting part 473 arranged in the axial direction in sequence. The driver housing 21 is located on the radial outer side of the hollow shaft 1, and the first bearing 61 is arranged between the driver housing 21 and the hollow shaft 1. The motor rear shell 36 is located radially outside the main shaft body 431, and the second bearing 62 is arranged between the motor rear shell 36 and the main shaft body 431; the first mounting portion 471 is located radially outside the main shaft body 431, and the third bearing 63 is arranged between the first mounting portion 471 and the main shaft body 431; the second bearing 62 and the third bearing 63 are respectively located on two axially different sides of the rotor support 31; The second mounting portion 473 is located radially inside the inner connecting cylinder 51, and the fourth bearing 64 is arranged between the second mounting portion 473 and the inner connecting cylinder 51; the inner connecting cylinder 51 is connected with the hollow shaft 1, and the outer connecting cylinder 54 is connected with the output gear ring 48; The limiting seat is located radially inside the reducer main shell 42, and the fifth bearing 65 is arranged between the limiting seat and the reducer main shell 42.

[0045] In the embodiment, the fifth bearing 65 is a crossed roller bearing, and the crossed roller bearing is axially positioned by a fixed ring 66 and a retainer 67.

[0046] The first bearing 61, the second bearing 62, the third bearing 63, and the fourth bearing 64 can be conventional deep groove ball bearings.

[0047] The first bearing 61 enables the hollow shaft 1 and the driver shell 21 to relatively rotate.

[0048] The second bearing 62 enables the sun gear shaft 43 and the motor rear shell 36 to relatively rotate.

[0049] The third bearing 63 and the fourth bearing 64 respectively provide support for the inner and outer sides of the planet carrier 47; the third bearing 63 enables the planet carrier 47 and the sun gear shaft 43 to relatively rotate, and the third bearing 63 can provide a radially outward support force for the side of the planet carrier 47 close to the sun gear shaft 43; the fourth bearing 64 enables the planet carrier 47 and the output shaft 5 to relatively rotate, and the fourth bearing 64 can provide a radially inward support force for the side of the planet carrier 47 close to the output shaft 5, and the support from the inner and outer sides can improve the stability of the planet carrier 47.

[0050] The fifth bearing 65 is a crossed roller bearing, the fifth bearing 65 is located between the limiting seat and the reducer main shell 42, the fifth bearing 65 enables the output shaft 5 and the reducer main shell 42 to relatively rotate, and the fifth bearing 65 can provide a radially inward support force for the limiting seat of the output shaft 5.

[0051] The relative rotation between the relative motion members can be achieved through the first bearing 61, the second bearing 62, the third bearing 63, the fourth bearing 64 and the fifth bearing 65. Meanwhile, the second bearing 62, the third bearing 63, the fourth bearing 64 and the fifth bearing 65 also have certain axial limiting effect, so that the axial relative positions of the motor rear shell 36, the second bearing 62, the rotor support 31, the third bearing 63, the planet carrier 47, the fourth bearing 64, the output shaft 5, the fifth bearing 65 and the reducer main shell 42 are accurate.

[0052] There is no bearing structure between the planet carrier 47 and the hollow shaft 1, which can reduce the number of bearings and simplify the structure of the joint module.

[0053] In summary, the double-rotor single-stator planetary reduction type joint module in the embodiment can achieve a large speed ratio of 99 under the condition of an outer diameter Φ125mm and a hollow size Φ10mm, which is much higher than the current market products. The actual joint assembly weight is 2.2kg, the peak torque is 496Nm, and the peak torque density can reach 225Nm / kg, which realizes the high torque density of the joint module.

[0054] Finally, it should be pointed out that the above embodiments are only used to illustrate the technical solutions of the present application and are not limiting. Although the present application has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solutions of the present application can be modified or replaced equivalently without departing from the purpose and scope of the present application, and they should be covered in the scope of the claims of the present application.

Claims

1. A dual-rotor single-stator planetary reduction joint module, characterized in that: It includes a hollow shaft, a driver assembly, an axial flux motor, a planetary reducer, and an output shaft, wherein the driver assembly, the axial flux motor, and the planetary reducer are sequentially arranged on the hollow shaft along the axial direction. The axial flux motor includes a rotor support, a stator assembly, and two rotor assemblies. The two rotor assemblies are symmetrically arranged on different sides of the stator assembly in the axial direction. The two rotor assemblies are connected to the power input end of the planetary reducer through the rotor support. The power output end of the planetary reducer, the output shaft, and the hollow shaft are sequentially connected. The stator assembly includes a plurality of stator units arranged in a circular pattern, each stator unit including a stator core and a stator winding wound on the stator core; both rotor assemblies include a rotor support plate and a plurality of magnets, the plurality of magnets being arranged circumferentially on the side of the rotor support plate facing the stator unit.

2. The dual-rotor single-stator planetary reduction joint module according to claim 1, characterized in that: The magnet is a surface-mounted segmented magnet, the rotor support plate is a circular steel plate, and the stator winding is a round wire winding or a flat wire winding.

3. The dual-rotor single-stator planetary reduction joint module according to claim 1, characterized in that: The driver assembly includes a driver housing, the axial flux motor further includes a motor rear housing and a stator housing, and the planetary reducer includes a gear ring fixing housing and a reducer main housing; the driver housing, motor rear housing, stator housing, gear ring fixing housing and reducer main housing are connected sequentially along the axial direction, and the side of the reducer main housing away from the motor housing is provided with an opening structure.

4. The dual-rotor single-stator planetary reduction joint module according to claim 3, characterized in that: The axial flux motor further includes a first stator plate and a second stator plate, which are respectively disposed on different sides of the stator unit in the axial direction. Both the first stator plate and the second stator plate are fixedly connected to the stator housing.

5. The dual-rotor single-stator planetary reduction joint module according to claim 3, characterized in that: The drive assembly also includes a drive body, an inner rotor of a magnetic encoder, an outer rotor of a magnetic encoder, and a stator of a magnetic encoder. The stator of the magnetic encoder is fixed on the rear housing of the motor, the inner rotor of the magnetic encoder is fixed on the hollow shaft, and the outer rotor of the magnetic encoder is fixed on the power input end of the planetary reducer. The inner rotor, outer rotor, and stator of the magnetic encoder are all communicatively connected to the drive body.

6. The dual-rotor single-stator planetary reduction joint module according to claim 3, characterized in that: The planetary reducer includes a sun gear shaft, a first planetary gear, a fixed gear ring, a second planetary gear, a planet carrier, and an output gear ring. The sun gear shaft includes a main shaft and a sun gear coaxially and synchronously mounted on one side of the main shaft. The rotor support is drive-connected to the main shaft. The sun gear shaft is rotatably fitted onto the hollow shaft. The fixed gear ring is fixed in position. The first planetary gear meshes between the sun gear and the fixed gear ring. The first planetary gear and the second planetary gear are coaxially and synchronously connected and are both rotatably mounted on the planet carrier. The second planetary gear meshes with the output gear ring. The sun gear shaft serves as the power input end, and the output gear ring serves as the power output end.

7. The dual-rotor single-stator planetary reduction joint module according to claim 6, characterized in that: The hollow shaft has a through hole along the axial direction. One end of the hollow shaft is rotatably connected to the drive assembly. The middle part of the hollow shaft passes through the sun gear shaft and the planet carrier. The other end of the hollow shaft is fixedly connected to the output shaft.

8. The dual-rotor single-stator planetary reduction joint module according to claim 6, characterized in that: The first planetary gear and the second planetary gear form a double planetary gear, which is rotatably mounted on the planetary shaft pin via planetary gear bearings, and the planetary gear pin is fixedly connected to the planet carrier.

9. The dual-rotor single-stator planetary reduction joint module according to claim 6, characterized in that: The output shaft includes an inner connecting cylinder, a mounting base, a connecting arm, and an outer connecting cylinder arranged radially from the inside to the outside; the planetary carrier includes a first mounting part, a main frame body, and a second mounting part arranged axially. The drive housing is located radially outside the hollow shaft and a first bearing is provided between them; The rear housing of the motor is located radially outside the main shaft and a second bearing is provided between them. The first mounting part is located radially outside the main shaft and a third bearing is provided between them. The second bearing and the third bearing are located on different sides of the rotor support in the axial direction. The second mounting part is located on the radially inner side of the inner connecting cylinder and a fourth bearing is provided between them. The inner connecting cylinder is connected to the hollow shaft, and the outer connecting cylinder is connected to the output gear ring. The limiting seat is located radially inside the main housing of the reducer, and a fifth bearing is provided between the two.

10. The dual-rotor single-stator planetary reduction joint module according to claim 9, characterized in that: The fifth bearing is a crossed roller bearing, which is axially positioned by a retaining ring and a retaining ring.

Images