Linear stepping motor, bionic finger and bionic dexterous hand

Abstract

A linear stepping motor, a bionic finger and a bionic dexterous hand. The linear stepping motor comprises a housing (10), and a stator (6), a driving nut (1), a rotor (7) and a lead screw (2), which are disposed inside the housing (10), wherein the stator (6) is fixed to an inner wall of the housing (10); the driving nut (1) is rotationally disposed inside the housing (10) and passes through an inner ring of the stator (6); the rotor (7) is wound around an outer peripheral portion of the driving nut (1); and the lead screw (2) is slidably disposed in the housing (10) in the axial direction of the housing (10), one end of the lead screw (2) extends out of the housing (10), the driving nut (1) is threadedly connected to the lead screw (2), and when energized, the stator (6) drives the rotor (7) and the driving nut (1) to rotate together, so as to drive the lead screw (2) to linearly extend and retract relative to the housing (10).

Description

Linear stepper motor, bionic finger and bionic dexterous hand

[0001] This application claims priority to the Chinese patent application No. 202410686173.7 filed on May 30, 2024 with the Chinese Patent Office, the whole content of the above application is incorporated herein by reference TECHNICAL FIELD

[0002] The present application relates to the technical field of mechanical hand, for example, to a linear stepper motor, a bionic finger and a bionic dexterous hand. BACKGROUND

[0003] The bionic dexterous hand is a complex device integrating multiple bionic fingers, aiming to simulate the overall function and flexibility of human hands. Through advanced control algorithms and sensing technology, the bionic dexterous hand can perform precise object manipulation and grasping in complex operating environments.

[0004] At present, the grasping action of the bionic finger is realized by rotating multiple knuckles driven by a motor through tendon ropes. This driving form requires continuous power input to the motor to maintain the grasping posture, and there are problems of poor transmission efficiency and positioning accuracy, low space utilization and low output power.

[0005] SUMMARY

[0006] The present application provides a linear stepper motor with self-locking performance, higher transmission efficiency and positioning accuracy, suitable for high-speed and high-precision grasping action control of bionic fingers and bionic dexterous hands, compact structure, conducive to miniaturization design;

[0007] The present application provides a bionic finger and a bionic dexterous hand, which realizes the grasping action of the bionic finger through the linear stepper motor. The outer shell of the linear stepper motor is integrally arranged with the outer shell of the driving knuckle to improve the space utilization and the motor power.

[0008] In a first aspect, the present application provides a linear stepper motor, comprising an outer shell and a:

[0009] stator fixed to the inner wall of the outer shell;

[0010] a drive nut rotatably arranged in the outer shell, and the drive nut is arranged in the inner ring of the stator;

[0011] a rotor arranged around the outer peripheral portion of the drive nut;

[0012] A screw rod is arranged in the outer housing along the axial direction of the outer housing, one end of the screw rod extends out of the outer housing, the drive nut is threadedly connected to the screw rod, and the stator drives the rotor and the drive nut to rotate together after being energized to drive the screw rod to linearly extend and retract relative to the outer housing.

[0013] Optionally, the linear stepping motor further comprises:

[0014] A radial bearing is arranged at the end of the drive nut away from the extension of the screw rod, the inner ring of the radial bearing is sleeved on the outer periphery of the drive nut, and the outer ring of the radial bearing is fixed to the inner wall of the outer housing.

[0015] A thrust bearing is arranged at the end of the drive nut close to the extension of the screw rod, the outer housing is provided with an inner flange corresponding to the opening through which the screw rod extends, the thrust shaft piece of the thrust bearing abuts against the thrust step, and the thrust seat piece of the thrust bearing is fixed to the inner flange.

[0016] Optionally, the linear stepping motor further comprises a locking block, the locking block is clamped in the outer housing and extends into the inner cavity of the outer housing, and the locking block abuts against the end of the outer ring of the radial bearing away from the extension of the screw rod.

[0017] Optionally, the end of the drive nut away from the extension of the screw rod is provided with a limiting step, and the inner ring of the radial bearing abuts against the limiting step close to the extension of the screw rod.

[0018] Optionally, the inner diameter of the inner flange is smaller than the inner diameter of the thrust bearing, and the inner flange completely covers the thrust bearing to completely shield the thrust bearing.

[0019] Optionally, the radial bearing is a deep groove ball bearing.

[0020] Optionally, the thrust bearing is a thrust roller bearing or a thrust sliding bearing.

[0021] Optionally, the rotor is made of a magnetic steel.

[0022] The stator comprises an iron core and a coil, the iron core is fixed to the inner wall of the outer housing, the iron core is provided with a winding groove on the side facing the outer housing, and the coil is wound on the winding groove.

[0023] Optionally, the drive nut is made of a high polymer plastic material.

[0024] Optionally, the screw rod is made of a metal alloy material.

[0025] In a second aspect, the application provides a bionic finger, comprising a terminal knuckle and a plurality of driving knuckles connected in turn, wherein the driving knuckle comprises the linear stepper motor as described above, the end of the lead screw extending out of the outer shell is in transmission connection with the adjacent driving knuckle or terminal knuckle to drive the driving knuckle or the terminal knuckle to rotate, and the outer shell of the linear stepper motor is integrally arranged with the outer shell of the driving knuckle.

[0026] In a third aspect, the application provides a bionic dexterous hand, comprising the bionic finger as described above and a palm structure, wherein the bionic finger is in movable connection with the palm structure. BRIEF DESCRIPTION OF DRAWINGS

[0027] Fig. 1 is a partial structure sectional view of the linear stepper motor provided by the application.

[0028] In the drawings:

[0029] 10, outer shell; 101, inner flange;

[0030] 1, driving nut; 11, thrust step; 12, limiting step; 2, lead screw; 3, radial bearing; 31, inner ring; 32, outer ring; 4, thrust bearing; 41, thrust shaft piece; 42, thrust seat piece; 5, locking block; 6, stator; 61, iron core; 610, winding groove; 62, coil; 7, rotor. DETAILED DESCRIPTION

[0031] The application will be described in detail below in conjunction with the drawings and embodiments. It can be understood that the specific embodiments described herein are only used to explain the application, and not to limit the application. In addition, in order to facilitate the description, only the parts related to the application are shown in the drawings, not all the structures.

[0032] In the description of the application, unless otherwise explicitly specified and limited, the terms "connected", "connected", "fixed" should be understood broadly, for example, it can be fixed connection, or detachable connection, or integral; it can be mechanical connection, or electrical connection; it can be directly connected, or indirectly connected through intermediate medium, it can be the internal communication of two elements or the interaction relationship between two elements. For those skilled in the art, the specific meaning of the above terms in the application can be understood according to the specific circumstances.

[0033] In the present application, unless specifically defined and limited otherwise, the first feature is "on" or "under" the second feature can include that the first feature and the second feature are in direct contact, or that the first feature and the second feature are not in direct contact but are in contact through another feature between them. Moreover, the first feature is "on", "above" and "over" the second feature includes that the first feature is directly above and obliquely above the second feature, or only indicates that the horizontal height of the first feature is higher than that of the second feature. The first feature is "under", "below" and "underneath" the second feature includes that the first feature is directly below and obliquely below the second feature, or only indicates that the horizontal height of the first feature is less than that of the second feature.

[0034] In the description of the present embodiment, the terms "upper", "lower", "right", "left" and the like orientation or position relationship are based on the orientation or position relationship shown in the drawings, only for the convenience of description and simplification of operation, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application. In addition, the terms "first", "second" are only used to distinguish in description, and have no special meaning.

[0035] The present embodiment provides a bionic dexterous hand, which comprises a bionic finger and a palm structure, and the bionic finger is movably connected with the palm structure. The bionic finger comprises a terminal knuckle and a plurality of driving knuckles connected in turn, and the driving knuckle comprises a linear stepper motor, which is in transmission connection with the adjacent driving knuckle or terminal knuckle to drive the latter to rotate.

[0036] As shown in FIG. 1, the linear stepper motor comprises an outer shell 10, a stator 6, a rotor 7, a drive nut 1 and a screw rod 2 arranged in the outer shell 10, wherein the stator 6 is fixed to the inner wall of the outer shell 10, the drive nut 1 is arranged in rotation in the outer shell 10, and the drive nut 1 is arranged through the inner ring of the stator 6, and the rotor 7 is arranged around the outer peripheral part of the drive nut 1; the screw rod 2 is arranged in sliding along the axis direction of the outer shell 10 in the outer shell 10, one end of the screw rod 2 (i.e. the upper end of the screw rod 2 in FIG. 1) extends out of the outer shell 10 and is in transmission connection with the adjacent driving knuckle or terminal knuckle; the drive nut 1 is threadedly connected to the screw rod 2, and the stator 6 drives the rotor 7 and the drive nut 1 to rotate together after being energized, so as to drive the screw rod 2 to linearly extend and retract relative to the outer shell 10, thereby driving the connected driving knuckle or terminal knuckle to rotate, and the outer shell 10 of the linear stepper motor is integrally arranged with the outer shell of the driving knuckle.

[0037] The bionic finger and the bionic dexterous hand provided by the embodiment realize the gripping action of the bionic finger through a linear stepping motor. In a first aspect, the linear stepping motor drives the rotation of the rotor 7 and the drive nut 1 by energizing the stator 6, the drive nut 1 drives the screw rod 2 connected with it in a threaded manner to slide relative to the outer shell 10 to realize the conversion of rotary power to linear power, the self-locking between the drive nut 1 and the screw rod 2 can realize the position keeping of extension and contraction without continuous power input; and the drive nut 1 drives the screw rod 2 to extend and contract with higher rigidity, which can effectively improve the transmission efficiency and positioning accuracy, is very suitable for the high-speed and high-precision gripping action control of the bionic finger and the bionic dexterous hand, and the drive nut 1 acts as the rotation shaft of the linear stepping motor, simplifies the structure of the linear stepping motor, makes the structure more compact and small, and is conducive to the miniaturization design and application in the bionic finger. In a second aspect, the outer shell 10 of the linear stepping motor is integrally arranged with the outer shell of the drive knuckle, that is, the outer shell 10 of the linear stepping motor acts as the outer shell structure of the bionic finger, the overall structure is more compact, the space utilization rate is improved, the linear stepping motor with larger output power can be arranged in the limited space, the output power is improved, and larger and more stable gripping force can be output.

[0038] For example, the rotor 7 is made of magnetic steel, and the rotor 7 and the outer peripheral part of the drive nut 1 are integrally connected by adhesive fastening; as shown in FIG. 1, the stator 6 includes an iron core 61 and a coil 62, the iron core 61 is tightly fitted and fixed to the inner wall of the outer shell 10, the iron core 61 is provided with a winding groove 610 on the side facing the outer shell 10, and the coil 62 is wound on the winding groove 610; after the coil 62 is connected to alternating current, the rotor 7 and the drive nut 1 are driven to rotate together.

[0039] For example, as shown in FIG. 1, the drive nut 1 is rotatably arranged in the outer shell 10 through a bearing. The linear stepping motor further includes a radial bearing 3 and a thrust bearing 4.

[0040] For example, as shown in FIG. 1, the radial bearing 3 is arranged at the end of the drive nut 1 away from the extension of the screw rod 2, the inner ring 31 of the radial bearing 3 is tightly sleeved on the outer periphery of the drive nut 1, the outer ring 32 of the radial bearing 3 is fixed to the inner wall of the outer shell 10, and the radial bearing 3 can bear the radial load of the drive nut 1.

[0041] For example, as shown in FIG. 1, the linear stepping motor further includes a locking block 5, the locking block 5 is clamped in the outer shell 10 and extends into the inner cavity of the outer shell 10, the end of the drive nut 1 away from the extension of the screw rod 2 is provided with a limiting step 12, the locking block 5 is pressed against the side of the outer ring 32 of the radial bearing 3 away from the extension of the screw rod 2, and the inner ring 31 of the radial bearing 3 is pressed against the limiting step 12 on the side close to the extension of the screw rod 2, so as to lock the radial bearing 3 between the outer shell 10 and the drive nut 1, and when maintenance and adjustment are needed, the radial bearing 3 can be removed by removing the locking block 5.

[0042] In the present embodiment, the radial bearing 3 is a deep groove ball bearing. In other embodiments of the present application, the radial bearing 3 can also be an angular contact ball bearing, a needle bearing, etc.

[0043] As shown in FIG. 1, the thrust bearing 4 is arranged at the end of the drive nut 1 close to the extension of the screw rod 2. The drive nut 1 is provided with a thrust step 11 at the end close to the extension of the screw rod 2. The outer housing 10 is provided with an inner flange 101 corresponding to the opening through which the screw rod 2 extends. The thrust shaft 41 of the thrust bearing 4 abuts against the thrust step 11, and the thrust seat 42 of the thrust bearing 4 is fixed to the inner flange 101. The thrust bearing 4 can bear the axial load of the drive nut 1.

[0044] Since the linear stepper motor is arranged to drive the gripping action of the bionic finger, the action resistance mainly exists in the stage of retraction of the screw rod 2. Therefore, the axial load of the screw rod 2 on the outer housing 10 at the opening end is the largest. The thrust bearing 4 arranged at this position can effectively bear the one-way axial force generated in the gripping process, thereby improving the bearing capacity. The thrust bearing 4 cooperates with the radial bearing 3 to realize the functions of centering and bearing.

[0045] As shown in FIG. 1, the inner diameter of the inner flange 101 is smaller than the inner diameter of the thrust bearing 4, and the inner flange 101 completely covers the thrust bearing 4 to completely shield the thrust bearing 4.

[0046] For example, the thrust bearing 4 can be a thrust roller bearing or a thrust sliding bearing.

[0047] For example, the drive nut 1 can be made of a high-molecular plastic material such as polytetrafluoroethylene or polyurethane, which has excellent high-temperature resistance and wear resistance. The screw rod 2 can be made of a metal alloy material such as S45C steel or SUJ2 steel, which has high strength, wear resistance, and high-temperature resistance. The selection of the materials of the drive nut 1 and the screw rod 2 can improve the transmission efficiency between them, reduce structural wear, and prolong the service life of the linear stepper motor.

[0048] For example, as shown in FIG. 1, the outer housing 10 is arranged in a cylindrical structure, the extension direction of the screw rod 2 is the same as the axial direction of the outer housing 10, and the cylindrical structure of the outer housing 10 is adapted to the shape of the knuckles of the bionic finger.

Claims

1. A linear stepping motor comprising an outer housing (10) and the following components arranged in the outer housing (10): a stator (6) fixed to the inner wall of the outer housing (10); a drive nut (1) rotatably arranged in the outer housing (10), and the drive nut (1) penetrating the inner ring of the stator (6); a rotor (7) arranged around the outer periphery of the drive nut (1); a screw rod (2) slidably arranged in the outer housing (10) along the axial direction of the outer housing (10), one end of the screw rod (2) extending out of the outer housing (10), the drive nut (1) being threadedly connected to the screw rod (2), and the stator (6) driving the rotor (7) and the drive nut (1) to rotate together when energized, so as to drive the screw rod (2) to linearly extend and retract relative to the outer housing (10).

2. The linear stepping motor according to claim 1, further comprising: a radial bearing (3) arranged at the end of the drive nut (1) away from the extension of the screw rod (2), the inner ring (31) of the radial bearing (3) being sleeved on the outer periphery of the drive nut (1), and the outer ring (32) of the radial bearing (3) being fixed to the inner wall of the outer housing (10); a thrust bearing (4), a thrust step (11) being arranged at the end of the drive nut (1) close to the extension of the screw rod (2), an inner flange (101) being arranged on the outer housing (10) corresponding to the opening for the extension of the screw rod (2), the thrust pad (41) of the thrust bearing (4) abutting against the thrust step (11), and the thrust seat (42) of the thrust bearing (4) being fixed to the inner flange (101).

3. The linear stepping motor according to claim 2, further comprising a locking block (5) clamped to the outer housing (10) and extending into the inner cavity of the outer housing (10), and the locking block (5) abutting against the end of the outer ring (32) of the radial bearing (3) away from the extension of the screw rod (2).

4. The linear stepper motor of claim 3, wherein, a limiting step (12) being arranged at the end of the drive nut (1) away from the extension of the screw rod (2), and the inner ring (31) of the radial bearing (3) abutting against the limiting step (12) close to the extension of the screw rod (2).

5. The linear stepper motor of claim 2, wherein, The inner diameter of the inner flange (101) is smaller than the inner diameter of the thrust bearing (4), and the inner flange (101) completely covers the thrust bearing (4).

6. The linear stepper motor of claim 2, wherein, The radial bearing (3) is a deep groove ball bearing.

7. The linear stepper motor of claim 2 or 6, wherein, The thrust bearing (4) is a thrust roller bearing or a thrust sliding bearing.

8. The linear stepper motor according to any one of claims 1-7, wherein, The rotor (7) is made of magnetic steel. The stator (6) comprises an iron core (61) and a coil (62), the iron core (61) being fixed to the inner wall of the outer housing (10), the iron core (61) being provided with a winding groove (610) on the side facing the outer housing (10), and the coil (62) being arranged around the winding groove (610).

9. The linear stepper motor according to any one of claims 1-7, wherein, The drive nut (1) is made of high polymer plastic material.

10. The linear stepper motor according to any one of claims 1-7, wherein, The screw rod (2) is made of metal alloy material.

11. A bionic finger comprising a terminal phalanx and a plurality of driving phalanges connected in turn, the driving phalanges comprising the linear stepper motor of any one of claims 1-10, the lead screw (2) extending out of one end of the outer shell (10) and being in transmission connection with an adjacent driving phalanx or terminal phalanx to drive the driving phalanx or the terminal phalanx to rotate, the outer shell (10) of the linear stepper motor being integrally arranged with the outer shell of the driving phalanx.

12. A bionic dexterous hand comprising the bionic finger of claim 11 and a palm structure, the bionic finger being movably connected with the palm structure.

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