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

Abstract

The invention discloses a double-stator single-rotor planetary reduction type joint module which comprises a hollow shaft, a driver assembly, an axial magnetic flux motor, a planetary reducer and an output shaft, and the driver assembly, the axial magnetic flux motor and the planetary reducer are sequentially arranged on the hollow shaft in the axial direction; the axial magnetic flux motor comprises a rotor assembly and two stator assemblies. The two stator assemblies are symmetrically arranged on the two different sides of the rotor assembly in the axial direction. The rotor assembly comprises a rotor supporting plate and a plurality of magnetic steels, and the plurality of magnetic steels are circumferentially distributed on the rotor supporting plate; the stator assembly comprises a stator iron core and a plurality of stator windings, the stator iron core comprises a yoke part iron core and a plurality of tooth part iron cores, and each stator winding is wound on the corresponding tooth part iron core. According to the joint module, wiring can be facilitated, the integration level can be improved, the torque density of the joint module is effectively improved, and the heat dissipation performance is good.

Description

TECHNICAL FIELD

[0001] The present application relates to a robot electric drive joint, in particular to a double-stator single-rotor 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 2K-H planetary transmission category), which is usually not hollow. However, the market development demand is to need hollow structure, which is convenient for wiring arrangement, and the application scene requires the electric drive joint to achieve large torque density, thereby putting forward the demand for large reduction ratio of the reducer. The large reduction ratio and the hollow structure 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-stator single-rotor planetary reduction joint module, which can facilitate the wiring arrangement of the joint module, improve the integration, effectively improve the torque density of the joint module, and has good heat dissipation performance.

[0004] The double-stator single-rotor 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 assembly and two stator assemblies, and the two stator assemblies are symmetrically arranged on different sides of the rotor assembly in the axial direction. The rotor assembly comprises a rotor support plate and a plurality of magnetic steels, and the plurality of magnetic steels are circumferentially arranged on the rotor support plate; the rotor support plate is in transmission connection with the power input end of the planetary reducer, and the power output end of the planetary reducer, the output shaft and the hollow shaft are sequentially in transmission connection. The stator assembly comprises a stator core and a plurality of stator windings, the stator core comprises a yoke core and a plurality of tooth cores arranged on the side of the yoke core facing the magnetic steels, and each stator winding is wound on the corresponding tooth core.

[0005] Further, the rotor support plate is a circular plastic plate, and the plurality of magnetic steels are embedded in the rotor support plate through a plastic embedding process, and the stator winding is a round wire winding or a flat wire winding.

[0006] Further, the axial flux motor further comprises a motor rear shell and a stator front mounting plate, the motor rear shell has a cavity opening towards the planetary reducer, the motor rear shell is provided with a heat dissipation reinforcing rib outside, and one of the stator cores is connected with the motor rear shell, and the other stator core is connected with the stator front mounting plate.

[0007] Further, the driver assembly comprises a driver shell, the planetary reducer comprises a gear ring fixing shell and a reducer main shell; the driver shell, the motor rear shell, the gear ring fixing shell and the reducer main shell are connected in sequence along the axial direction; and the reducer main shell is provided with an opening structure away from the motor rear shell.

[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 shell, the magnetic encoder inner rotor is fixed on the hollow shaft, the magnetic encoder outer rotor is fixed on the 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 rotating manner, 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 fixed in position; 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 rotating manner and are both 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 along the axial direction, one end of the hollow shaft is in rotational 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, the double planetary gear is rotatably installed on a planetary shaft pin through a planetary wheel bearing, and the planetary wheel pin is fixedly connected with the planet carrier.

[0012] Further, the output shaft comprises, from inside to outside along the radial direction, an inner connecting cylinder, a mounting seat, a connecting arm and an outer connecting cylinder; and the planet carrier comprises, along the axial direction, a first mounting part, a main carrier body and a second mounting part. 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 plate 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 the hollow shaft in sequence along the axial direction, 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 in the present embodiment can improve the integration, and a larger speed ratio can be achieved under the condition of a larger hollow size and smaller radial and axial dimensions, so that the torque density of the joint module is effectively improved.

[0016] (3) The magnetic field of the double-rotor single-stator axial flux motor of the application passes through the stator core in the axial direction, passes through the next stator core through the magnetic steel and the rotor support plate, and forms a complete magnetic circuit through the stator core, the magnetic steel and the rotor support plate. At the same time, the two stator assemblies are connected by the motor rear shell with heat dissipation reinforcing ribs, greatly increasing the heat dissipation area of the motor and effectively improving the heat dissipation capacity of the joint module.

[0017] (4) The magnetic steel is arranged in a circle on the rotor support plate, and the plastic packaging process fixes the magnetic steel, ensuring that the magnetic steel will not fall off due to excessive centrifugal force during high-speed operation, realizing high-speed operation of the motor. The rotor support plate is made of high-strength plastic, which does not produce eddy current loss and can effectively reduce the temperature of the magnetic steel, further improving the output torque of the motor. In addition, the stator winding is wound with flat copper wire, which completely fills the entire stator, improving the occupancy rate of the flat copper wire. Therefore, the motor can withstand a larger current under the same volume, greatly improving the torque density of the motor. At the same time, the higher occupancy rate of the flat copper wire, the better heat dissipation of the motor, further improving the heat dissipation capacity of the joint module.

[0018] (5) The double-stator single-rotor planetary reduction 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 450Nm, and the peak torque density reaches 205Nm / kg, realizing high torque density of the joint assembly. At the same time, the surface temperature of the joint module under continuous operation is about 80℃ (the surface temperature of the existing mainstream scheme is about 100℃), the temperature of the joint module in the embodiment is reduced by 20%, effectively improving the heat dissipation of the joint module and improving the reliability of the joint module under long-time heavy load operation. 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 motor rear shell of the application; Figure 6 is a schematic view of the magnetic field of the double-stator single-rotor axial flux motor of the application; Figure 7 This is an exploded schematic diagram of the planetary reducer of the present invention; Figure 8 This is a schematic diagram of the structure of the first planetary gear and the second planetary gear of the invention, which together form a double planetary gear.

[0020] The following labels are shown in the attached diagram: 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-Stator core, 311-Yoke core, 312-Tooth core, 32-Stator winding, 33-Rotor support plate, 34-Magnet, 35-Motor rear housing, 351-Heat dissipation reinforcing rib, 36-Stator front mounting 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-stator single-rotor 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. The axial flux motor 3 includes a rotor assembly and two stator assemblies, with the two stator assemblies symmetrically arranged on different sides of the rotor assembly in the axial direction. The rotor assembly includes a rotor support plate 33 and a plurality of magnets 34, which are arranged in a circumferential manner on the rotor support plate 33. The rotor support plate 33 is connected to the power input end of the planetary reducer 4, and the power output end of the planetary reducer 4, the output shaft 5, and the hollow shaft 1 are connected in sequence. The stator assembly includes a stator core 31 and a plurality of stator windings 32, the stator core 31 includes a yoke core 311 and a plurality of tooth cores 312 arranged on the side of the yoke core 311 facing the magnetic steel 34, and each stator winding 32 is wound on the corresponding tooth core 312.

[0023] The driver assembly 2, the axial flux motor 3 and the planetary reducer 4 are arranged in the hollow shaft 1 in sequence along the axial direction, and the hollow shaft 1 has a hollow structure, 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.

[0024] 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 size 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 size is only related to the shell of the driver assembly 2, the axial flux motor 3 and the planetary reducer 4, and the radial size of the joint module can be greatly reduced. Therefore, the joint module in the embodiment can improve the integration, and a larger speed ratio can be achieved under the condition of a larger hollow size and smaller radial size and axial size, and the torque density of the joint module is effectively improved.

[0025] 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 31 along the axial direction, passes through the magnetic steel 34 and the rotor support plate 33, and then passes through the next stator core 31, and the magnetic field forms a complete magnetic circuit by passing through the stator core 31, the magnetic steel 34 and the rotor support plate 33. At the same time, the two stator assemblies are connected by a motor rear shell 35 with a heat dissipation reinforcing rib 351, as shown in Figure 5 The heat dissipation area of the motor is greatly increased, and the heat dissipation capacity of the joint module is effectively improved.

[0026] In the embodiment, the rotor support plate 33 is a circular plastic plate, and a plurality of magnetic steels 34 are embedded in the rotor support plate 33 by a plastic embedding process, and the stator winding 32 is a round wire winding or a flat wire winding.

[0027] The magnetic steels 34 are arranged on the rotor support plate 33 in a circumferential direction, and the plastic embedding process fixes the magnetic steels 34, so that the magnetic steels 34 will not fall off due to excessive centrifugal force during high-speed operation, and high-speed operation of the motor is realized. The rotor support plate 33 is made of high-strength plastic, the rotor support plate 33 does not generate eddy current loss, the temperature of the magnetic steel 34 can be effectively reduced, and the output torque of the motor is further improved.

[0028] Preferably, the stator winding 32 adopts a flat copper wire winding, which is fully filled in the entire stator, so as to improve the filling rate of the flat copper wire, and thus the motor can bear a larger current under the same volume, and the torque density of the motor is greatly improved. Meanwhile, the higher filling rate of the flat copper wire can improve the heat dissipation of the motor, and further improve the heat dissipation capacity of the joint module.

[0029] In the embodiment, the axial flux motor 3 further comprises a motor rear shell 35 and a stator front mounting plate 36, the motor rear shell 35 has a cavity opening towards the planetary reducer 4, the motor rear shell 35 is provided with a heat dissipation reinforcing rib 351, and the stator front mounting plate 36 is arranged on the side of the motor rear shell 35 facing the planetary reducer 4, one of the stator cores 31 is connected with the motor rear shell 35, and the other stator core 31 is connected with the stator front mounting plate 36.

[0030] The space for accommodating the double-stator single-rotor is formed between the motor rear shell 35 and the stator front mounting plate 36. The heat dissipation reinforcing rib 351 on the outside of the motor rear shell 35 can enhance the heat dissipation effect.

[0031] In the embodiment, the driver assembly 2 comprises a driver shell 21, the planetary reducer 4 comprises a gear ring fixing shell 41 and a reducer main shell 42, the driver shell 21, the motor rear shell 35, the gear ring fixing shell 41 and the reducer main shell 42 are connected in sequence along the axial direction, and the side of the reducer main shell 42 away from the motor rear shell is provided with an opening structure.

[0032] The driver shell 21, the motor rear shell 35, the stator outer shell, the gear ring fixing shell 41 and the reducer main shell 42 are connected in sequence along the axial direction, that is, the shells of the joint module form a multi-section split structure, the shells are connected in a detachable manner, and the assembly is more convenient. The gear ring fixing shell 41 is used for mounting and fixing the gear ring 45. The opening structure is used for accommodating the output shaft 5.

[0033] 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 shell 35, 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.

[0034] 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.

[0035] 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 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.

[0036] 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, the motor torque is input to the main shaft body 431 of the planetary reducer 4 through the rotor support plate 33, 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 of the planetary reducer 4, 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.

[0037] 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.

[0038] 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.

[0039] 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.

[0040] 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.

[0041] 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.

[0042] 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 a first bearing 61 is arranged between the driver housing 21 and the hollow shaft 1. The motor rear shell 35 is located radially outside the main shaft body 431, and the second bearing 62 is arranged between the motor rear shell 35 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 plate 33; 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.

[0043] 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.

[0044] The first bearing 61, the second bearing 62, the third bearing 63, and the fourth bearing 64 can adopt a conventional deep groove ball bearing.

[0045] The first bearing 61 enables the hollow shaft 1 and the driver shell 21 to relatively rotate.

[0046] The second bearing 62 enables the sun gear shaft 43 and the motor rear shell 35 to relatively rotate.

[0047] 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.

[0048] The fifth bearing 65 is a crossed roller bearing, and 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.

[0049] 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 35, the second bearing 62, the rotor support plate 33, 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.

[0050] 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.

[0051] In summary, the double-stator single-rotor planetary reduction type joint module in the embodiment can achieve a speed ratio of 99 in 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 450Nm, the peak torque density is 205Nm / kg, the high torque density of the joint assembly is realized, at the same time, the surface temperature of the joint module under continuous work is about 80℃ (the surface temperature of the existing mainstream scheme is about 100℃), the temperature of the joint module in the embodiment is reduced by 20%, which effectively improves the heat dissipation of the joint module and improves the reliability of the joint module under long-time and heavy load operation.

[0052] 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 by equivalents without departing from the purpose and scope of the present application, which should be covered in the scope of the claims of the present application.

Claims

1. A dual-stator single-rotor 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 assembly and two stator assemblies, the two stator assemblies being symmetrically arranged on different sides of the rotor assembly in the axial direction; The rotor assembly includes a rotor support plate and multiple magnets, which are arranged in a circumferential manner on the rotor support plate. The rotor support plate is driven to the power input end of the planetary reducer, and the power output end of the planetary reducer, the output shaft, and the hollow shaft are driven to the same extent in sequence. The stator assembly includes a stator core and multiple stator windings. The stator core includes a yoke core and multiple toothed cores disposed on the side of the yoke core facing the magnet. Each stator winding is wound on the corresponding toothed core.

2. The dual-stator single-rotor planetary reduction joint module according to claim 1, characterized in that: The rotor support plate is a circular plastic plate, and multiple magnets are embedded in the rotor support plate through a plastic coating process. The stator winding is a round wire winding or a flat wire winding.

3. The dual-stator single-rotor planetary reduction joint module according to claim 2, characterized in that: The axial flux motor further includes a rear housing and a front stator mounting plate. The rear housing has a cavity facing the planetary reducer. Heat dissipation reinforcing ribs are provided on the outside of the rear housing. The front stator mounting plate is located on the side of the rear housing facing the planetary reducer. One stator core is connected to the rear housing, and the other stator core is connected to the front stator mounting plate.

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

5. The dual-stator single-rotor planetary reduction joint module according to claim 4, 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-stator single-rotor planetary reduction joint module according to claim 5, 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-stator single-rotor 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-stator single-rotor 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-stator single-rotor 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 plate 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 the two. 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-stator single-rotor 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.

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