Axial magnetic flux linear actuator

Abstract

The invention provides an axial magnetic flux linear actuator which comprises an execution assembly, and the execution assembly comprises a reverse planetary lead screw, a double-row angular contact bearing, a threaded sleeve, a rotor disc, a stator iron core, a sealing end cover, two supporting bearings, a stator winding, magnetic steel and a connecting ring. And the double-row angular contact bearing is mounted on the outer side wall of the threaded sleeve. Power is supplied to a stator winding, a stator generates a magnetic field and acts on magnetic steel, at the moment, a rotor disc rotates to drive a threaded sleeve to rotate through a connecting ring, a driving part of a reverse rotation type planetary lead screw pushes an execution knuckle bearing, and robot joints can be driven; compared with the prior art, the radial force bearing capacity can be improved, accurate control over the position is achieved, the axial magnetic flux driving mode is adopted, higher power density and higher torque density can be provided, the overall size is reduced, and the working efficiency is improved.

Description

Technical Field

[0001] The invention relates to a linear actuator, in particular to an axial magnetic flux linear actuator, and belongs to the technical field of actuators. Background Art

[0002] A linear actuator is a device that can convert rotational motion into linear motion, usually composed of components such as a motor, a reducer, a guide rail, and a slider. According to its driving method, linear actuators can be divided into stepper motor linear actuators, linear motor linear actuators, hydraulic linear actuators, and pneumatic linear actuators.

[0003] Linear actuators play an important role in robots. They work in collaboration with other parts of the robot to achieve various functions of the robot. Linear actuators can be used to drive the joints of the robot to achieve linear motion of the joints. For example, in humanoid robots, linear actuators are used for single-degree-of-freedom joints with small swing angles such as knees and elbows, and two double-degree-of-freedom but compact joints such as wrists and ankles to provide precise motion control.

[0004] Current linear actuators generally use radial motors as the driving mechanism, and the motor's rotor drives the ball bearings to achieve linear drive; For example, the Chinese public authorized patent (publication number: CN221263543U) discloses a linear actuator, which controls the rotation of a servo motor after receiving an operation instruction from a servo control module, and the servo motor drives a harmonic reducer, which in turn drives a ball screw to rotate to generate linear motion, thereby realizing motion control; For another example, a Chinese public authorized patent (publication number: CN220915010U) discloses a positioning linear actuator, which is composed of a stator assembly, a rotor assembly and other structures to form a motor, and drives the output shaft through the rotor to achieve linear motion control; Although the above patent can realize the linear motion control of the robot shutdown, its technical solution still has the following shortcomings: (1) Low working efficiency: When the linear actuator is driven by a radial motor, the overall volume of the linear actuator will be larger, and the power density and torque density will be lower, which will reduce the working efficiency; (2) Poor load-bearing capacity: When using a ball screw structure or a single output shaft for transmission, the radial force it can bear is small, and its service life is short when used under high load conditions; To this end, an axial flux linear actuator is proposed. Summary of the invention

[0005] In view of this, the present invention provides an axial flux linear actuator to solve or alleviate the technical problems existing in the prior art and at least provide a beneficial option.

[0006] The technical solution of the embodiment of the present invention is implemented as follows: an axial flux linear actuator includes an actuator assembly, wherein the actuator assembly includes a reversing planetary screw, a double-row angular contact bearing, a threaded sleeve, a rotor disk, a stator core, a sealing end cover, two support bearings, a stator winding, a magnetic steel and a connecting ring; The double-row angular contact bearing is mounted on the outer side wall of the threaded sleeve, the two support bearings are symmetrically mounted on the outer side wall of the threaded sleeve, the outer side wall of the reversing planetary screw is threadedly connected to the inner side wall of the threaded sleeve, the two stator cores are symmetrically located on both sides of the rotor disk, the magnetic steel is symmetrically mounted on both sides of the rotor disk, the stator winding is mounted inside the stator core, the connecting ring is fixedly connected to the outer side wall of the threaded sleeve, the rotor disk is fixedly connected to the outer side wall of the connecting ring, and the sealing end cover is fixedly connected to one end of the threaded sleeve.

[0007] Further preferably, the two stator cores are located between the two support bearings, and the reversing planetary screw comprises a driving portion and a threaded connection portion; The outer side wall of the threaded connection part is threadedly connected to the inner side wall of the threaded sleeve, and one end of the driving part away from the threaded connection part is located outside the threaded sleeve.

[0008] Further preferably, the actuator assembly further includes two limit rings, a first end cover and a second end cover; The two limiting rings are symmetrically fixedly connected to the outer side wall of the threaded sleeve, the two limiting rings are symmetrically located on both sides of the double-row angular contact bearing, and the first end cover is fixedly connected to the second end cover by bolts.

[0009] Further preferably, the two stator cores are symmetrically mounted on the inner side wall of the first end cover and the inner side wall of the second end cover, the rotor disk is located inside the first end cover and the second end cover, and the stator core is sleeved on the outside of the threaded sleeve.

[0010] Further preferably, the first end cover and the second end cover are both located outside the threaded sleeve, and the threaded sleeve is rotatably connected to the inside of the first end cover and the second end cover through the two support bearings.

[0011] Further preferably, a shell assembly is installed outside the threaded sleeve, and the shell assembly includes an outer tube, a limit end cover, a connecting end cover, a threaded connection hole and a tension sensor; The outer tube is fixedly connected to the second end cover by bolts, the connecting end cover is fixedly connected to the first end cover by bolts, the limiting end cover is fixedly connected to the outer tube by bolts, the threaded connection hole is opened inside the connecting end cover, and one end of the tension sensor is fixedly connected to the inner wall of the threaded connection hole.

[0012] Further preferably, the threaded sleeve is rotatably connected to the inner wall of the outer tube through the double-row angular contact bearing, and the outer side wall of the reversing planetary screw is slidably connected to the inner side wall of the limiting end cover.

[0013] Further preferably, an end of the driving portion away from the threaded connection portion is fixedly connected to an actuator joint bearing.

[0014] Further preferably, one end of the tension sensor away from the connecting end cover is fixedly connected to a connecting joint bearing.

[0015] Further preferably, a mounting plate is fixedly connected to the interior of the connecting end cover, and a microcontroller is mounted on a side of the mounting plate away from the connecting end cover.

[0016] Since the embodiment of the present invention adopts the above technical scheme, it has the following advantages: the present invention forms the stator of the axial flux motor through the stator winding and the stator core, and forms the rotor of the axial flux motor through the rotor disk and the magnetic steel. By supplying power to the stator winding, the stator generates a magnetic field and acts on the magnetic steel. At this time, the rotor disk drives the threaded sleeve to rotate through the connecting ring. Since the threaded sleeve is threadedly connected with the reversing planetary screw, the reversing planetary screw moves linearly in the threaded sleeve. The driving part of the reversing planetary screw pushes the actuator joint bearing to realize the driving of the robot joint. By adopting the combination of the threaded sleeve and the reversing planetary screw, its radial force bearing capacity can be improved, the position can be accurately controlled, and the service life is extended. By adopting the axial flux drive method, higher power density and torque density can be provided, and the overall volume is reduced, thereby improving work efficiency.

[0017] The above summary is for illustrative purposes only and is not intended to be limiting in any way. In addition to the illustrative aspects, embodiments and features described above, further aspects, embodiments and features of the present invention will be readily apparent by reference to the accompanying drawings and the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0019] Figure 1 It is a structural diagram of the axial flux linear actuator of the present invention; Figure 2 is a cross-sectional view of the present invention; Figure 3 It is a structural diagram of the execution components of the present invention; Figure 4 An exploded view of the components of the present invention; Figure 5 The stator core structure diagram of the present invention; Figure 6 It is a structural diagram of the connection end cover of the present invention; Figure 7 It is a structural diagram of the housing assembly of the present invention; Figure 8 This is a structural diagram of the reverse planetary screw of the present invention.

[0020] Figure numerals: 101, actuator; 11, reverse planetary screw; 111, drive unit; 112, threaded connection; 12, double-row angular contact bearing; 13, threaded sleeve; 14, rotor disk; 15, stator core; 16, sealing end cover; 17, support bearing; 18, limit ring; 19, stator winding; 20, magnet; 21, first end cover; 22, second end cover; 23, connecting ring; 301, housing assembly; 31, outer tube; 32, limit end cover; 33, connecting end cover; 34, threaded connection hole; 35, actuator joint bearing; 36, connecting joint bearing; 37, tension sensor; 38, mounting plate; 39, microcontroller. DETAILED DESCRIPTION

[0021] In the following, only some exemplary embodiments are briefly described. As those skilled in the art will appreciate, the described embodiments may be modified in various ways without departing from the spirit or scope of the present invention. Therefore, the drawings and descriptions are considered to be exemplary and non-restrictive in nature.

[0022] The embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0023] like Figure 1-8As shown, an embodiment of the present invention provides an axial flux linear actuator, including an actuator assembly 101, wherein the actuator assembly 101 includes a reversing planetary screw 11, a double-row angular contact bearing 12, a threaded sleeve 13, a rotor disk 14, a stator core 15, a sealing end cover 16, two support bearings 17, a stator winding 19, a magnetic steel 20 and a connecting ring 23; The double-row angular contact bearing 12 is installed on the outer wall of the threaded sleeve 13, the two support bearings 17 are symmetrically installed on the outer wall of the threaded sleeve 13, the outer wall of the reversing planetary screw 11 is threadedly connected to the inner wall of the threaded sleeve 13, the two stator cores 15 are symmetrically located on both sides of the rotor disk 14, the magnetic steel 20 is symmetrically installed on both sides of the rotor disk 14, the stator winding 19 is installed inside the stator core 15, the connecting ring 23 is fixedly connected to the outer wall of the threaded sleeve 13, the rotor disk 14 is fixedly connected to the outer wall of the connecting ring 23, and the sealing end cover 16 is fixedly connected to one end of the threaded sleeve 13. The stator of the axial flux motor can be formed by the stator winding 19 and the stator core 15, and the rotor of the axial flux motor can be formed by the rotor disk 14 and the magnetic steel 20. When the stator winding 19 is powered, the stator generates a magnetic field and acts on the magnetic steel 20, so that the rotor disk 14 can be rotated to realize the linear drive of the robot joint.

[0024] In one embodiment, the two stator cores 15 are located between the two support bearings 17 , and the inverted planetary screw 11 includes a driving portion 111 and a threaded connection portion 112 ; The outer wall of the threaded connection part 112 is threadedly connected to the inner wall of the threaded sleeve 13, and the end of the driving part 111 away from the threaded connection part 112 is located outside the threaded sleeve 13. Through the cooperation between the threaded sleeve 13 and the reversing planetary screw 11, its radial force bearing capacity can be improved and precise control of the position can be achieved.

[0025] In one embodiment, the actuator assembly 101 further includes two limit rings 18, a first end cover 21 and a second end cover 22; Two limit rings 18 are symmetrically fixedly connected to the outer wall of the threaded sleeve 13, and the two limit rings 18 are symmetrically located on both sides of the double-row angular contact bearing 12. The first end cover 21 is fixedly connected to the second end cover 22 by bolts. The two stator cores 15 are symmetrically installed on the inner wall of the first end cover 21 and the inner wall of the second end cover 22. The rotor disk 14 is located inside the first end cover 21 and the second end cover 22. The stator core 15 is sleeved on the outside of the threaded sleeve 13. By adopting the double-row angular contact bearing 12, the overall bearing capacity can be increased. The position of the double-row angular contact bearing 12 can be limited by the limit ring 18, and the position of the stator core 15 can be limited by the first end cover 21 and the second end cover 22. When the stator winding 19 is energized, the stator generates a magnetic field and acts on the magnetic steel 20, and the rotor disk 14 rotates at this time.

[0026] In one embodiment, the first end cover 21 and the second end cover 22 are both located outside the threaded sleeve 13, and the threaded sleeve 13 is rotatably connected to the inside of the first end cover 21 and the second end cover 22 through two support bearings 17. When the rotor disk 14 rotates, it drives the connecting ring 23, and the connecting ring 23 drives the threaded sleeve 13. The threaded sleeve 13 rotates through the support bearing 17, and the friction between the threaded sleeve 13 and the first end cover 21 and the second end cover 22 can be reduced by the support bearing 17.

[0027] In one embodiment, a housing assembly 301 is installed outside the threaded sleeve 13, and the housing assembly 301 includes an outer tube 31, a limiting end cover 32, a connecting end cover 33, a threaded connection hole 34 and a tension sensor 37; The outer tube 31 is fixedly connected to the second end cover 22 by bolts, the connecting end cover 33 is fixedly connected to the first end cover 21 by bolts, the limiting end cover 32 is fixedly connected to the outer tube 31 by bolts, and the threaded connection hole 34 is opened inside the connecting end cover 33. One end of the tension sensor 37 is fixedly connected to the inner wall of the threaded connection hole 34. The tension condition of the actuator can be fed back at any time through the tension sensor 37.

[0028] In one embodiment, the threaded sleeve 13 is rotatably connected to the inner wall of the outer tube 31 through a double-row angular contact bearing 12, and the outer wall of the reversing planetary screw 11 is slidably connected to the inner wall of the limiting end cover 32. The position of the reversing planetary screw 11 can be limited by the limiting end cover 32 to enhance the overall stability of the structure.

[0029] In one embodiment, the end of the driving part 111 away from the threaded connection part 112 is fixedly connected to an actuator joint bearing 35, and the end of the tension sensor 37 away from the connection end cover 33 is fixedly connected to a connecting joint bearing 36. The actuator can be connected to an external robot joint through the actuator joint bearing 35 and the connecting joint bearing 36, and the movement of the robot joint can be controlled by the actuator.

[0030] In one embodiment, a mounting plate 38 is fixedly connected to the inside of the connecting end cover 33, and a microcontroller 39 is installed on the side of the mounting plate 38 away from the connecting end cover 33. The signal sending end of the tension sensor 37 is connected to the signal receiving end of the microcontroller 39, and the signal sending end of the microcontroller 39 is connected to the control system of the robot, thereby realizing data transmission.

[0031] When the present invention is working: the stator winding 19 and the stator core 15 constitute the stator of the axial flux motor, the rotor disk 14 and the magnetic steel 20 constitute the rotor of the axial flux motor, the stator winding 19 is powered, the stator generates a magnetic field and acts on the magnetic steel 20, at this time the rotor disk 14 rotates, the rotor disk 14 drives the connecting ring 23, the connecting ring 23 drives the threaded sleeve 13 to rotate, the threaded sleeve 13 rotates in the outer tube 31 through the double-row angular contact bearing 12, the threaded sleeve 13 rotates in the first end cover 21 and the second end cover 22 through two support bearings 17, because the threaded sleeve 13 is threadedly connected with the reversing planetary screw 11, the reversing planetary screw 11 can be driven by the thread to move linearly in the threaded sleeve 13, the driving part 111 of the reversing planetary screw 11 pushes the execution joint bearing 35, and then the driving of the robot joint can be realized; The tension sensor 37 can be used to provide feedback on the tension condition of the actuator at any time. By adopting the axial flux motor drive method, higher power density and torque density can be provided, and the overall volume can be reduced, making it more advantageous in the robot joint and improving work efficiency.

[0032] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art can easily think of various changes or substitutions within the technical scope disclosed by the present invention, which should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. An axial flux linear actuator, comprising an actuator assembly (101), characterized in that: The actuator assembly (101) comprises a reversing planetary screw (11), a double-row angular contact bearing (12), a threaded sleeve (13), a rotor disk (14), a stator core (15), a sealing end cover (16), two support bearings (17), a stator winding (19), a magnetic steel (20), and a connecting ring (23); The double-row angular contact bearing (12) is mounted on the outer wall of the threaded sleeve (13), the two support bearings (17) are symmetrically mounted on the outer wall of the threaded sleeve (13), the outer wall of the reversing planetary screw (11) is threadedly connected to the inner wall of the threaded sleeve (13), the two stator cores (15) are symmetrically located on both sides of the rotor disk (14), the magnetic steel (20) is symmetrically mounted on both sides of the rotor disk (14), the stator winding (19) is mounted inside the stator core (15), the connecting ring (23) is fixedly connected to the outer wall of the threaded sleeve (13), the rotor disk (14) is fixedly connected to the outer wall of the connecting ring (23), and the sealing end cover (16) is fixedly connected to one end of the threaded sleeve (13).

2. An axial flux linear actuator according to claim 1, characterized in that: The two stator cores (15) are located between the two support bearings (17); the reversing planetary screw (11) comprises a driving portion (111) and a threaded connection portion (112); The outer wall of the threaded connection portion (112) is threadedly connected to the inner wall of the threaded sleeve (13), and one end of the driving portion (111) away from the threaded connection portion (112) is located outside the threaded sleeve (13).

3. An axial flux linear actuator according to claim 2, characterized in that: The actuator assembly (101) further comprises two limit rings (18), a first end cover (21) and a second end cover (22); The two limiting rings (18) are symmetrically fixedly connected to the outer wall of the threaded sleeve (13), the two limiting rings (18) are symmetrically located on both sides of the double-row angular contact bearing (12), and the first end cover (21) is fixedly connected to the second end cover (22) by bolts.

4. An axial flux linear actuator according to claim 3, characterized in that: The two stator cores (15) are symmetrically mounted on the inner side wall of the first end cover (21) and the inner side wall of the second end cover (22); the rotor disk (14) is located inside the first end cover (21) and the second end cover (22); and the stator core (15) is sleeved on the outside of the threaded sleeve (13).

5. An axial flux linear actuator according to claim 4, characterized in that: The first end cover (21) and the second end cover (22) are both located outside the threaded sleeve (13), and the threaded sleeve (13) is rotatably connected to the inside of the first end cover (21) and the second end cover (22) via the two support bearings (17).

6. An axial flux linear actuator according to claim 5, characterized in that: A housing assembly (301) is installed outside the threaded sleeve (13), and the housing assembly (301) comprises an outer tube (31), a limiting end cover (32), a connecting end cover (33), a threaded connection hole (34), and a tension sensor (37); The outer tube (31) is fixedly connected to the second end cover (22) by bolts, the connecting end cover (33) is fixedly connected to the first end cover (21) by bolts, the limiting end cover (32) is fixedly connected to the outer tube (31) by bolts, the threaded connection hole (34) is opened inside the connecting end cover (33), and one end of the tension sensor (37) is fixedly connected to the inner wall of the threaded connection hole (34).

7. An axial flux linear actuator according to claim 6, characterized in that: The threaded sleeve (13) is rotatably connected to the inner side wall of the outer tube (31) via the double-row angular contact bearing (12), and the outer side wall of the reversing planetary screw (11) is slidably connected to the inner side wall of the limiting end cover (32).

8. An axial flux linear actuator according to claim 2, characterized in that: An end of the driving portion (111) away from the threaded connection portion (112) is fixedly connected to an actuator joint bearing (35).

9. The axial flux linear actuator according to claim 6, characterized in that: One end of the tension sensor (37) away from the connecting end cover (33) is fixedly connected to a connecting joint bearing (36).

10. An axial flux linear actuator according to claim 9, characterized in that: A mounting plate (38) is fixedly connected to the interior of the connecting end cover (33), and a microcontroller (39) is mounted on a side of the mounting plate (38) away from the connecting end cover (33).

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