Self-locking ball screw

Abstract

The application discloses a self-locking ball screw and belongs to the ball screw field. The self-locking ball screw comprises a base, a screw rod which is rotationally connected with the base and vertically arranged at two ends, and a nut assembly which is connected with the outer thread of the screw rod through balls. The outer end of the base is provided with a self-locking cavity, the length direction of the self-locking cavity is the same as the length direction of the screw rod, and the self-locking cavity is provided with a bearing module. The inner end of the nut assembly is provided with a feeler, the feeler is embedded in the self-locking cavity and abuts against the bearing module. The part of the bearing module which is located on the upper side of the feeler has the ability to move and / or deform away from the feeler, so that the feeler can move upward. The part of the bearing module which is located on the lower side of the feeler has the ability to move and / or deform close to the feeler, so that the feeler cannot move downward and forms self-locking. The self-locking ball screw can realize multi-gear self-locking when the nut of the ball screw moves.

Description

TECHNICAL FIELD

[0001] The application belongs to the field of ball screws, and more particularly relates to a self-locking ball screw. BACKGROUND

[0002] Ordinary ball screws do not have self-locking capability. For a ball screw vertically placed and reciprocally moving in the vertical direction with a load, after the screw motor stops rotating, the nut bearing the weight of the load will move downward due to gravity, providing a reverse rotating driving force to the screw, which will cause damage to the screw motor.

[0003] Patent No. CN201910699568.X discloses a ball screw with a self-locking structure, which comprises a bearing seat, a proximity switch, a round nut, a lock, a compression spring, an electromagnet, a sleeve, a sliding pin, a screw nut, and a screw shaft. When the round nut moves to the top end, the sliding pin is located in the groove of the lock, so that the round nut does not have a moving pair to move downward, forming self-locking.

[0004] However, the above-mentioned scheme can only ensure that the round nut can be self-locked when it moves to the top end of the screw, and cannot be self-locked during movement. Moreover, the self-locking point is only one, and the application range is too small. In addition, the self-locking structure is designed at both ends of the screw, and in general production line arrangement, the distance between devices is compact. If the ball screw is modified, the length of the ball screw will change, and the safety distance between devices cannot be guaranteed, and even the installation of the ball screw modified by the above-mentioned scheme cannot be accommodated. SUMMARY

[0005] The technical problem to be solved by the present application is to provide a self-locking ball screw which can realize multi-gear self-locking when the nut of the ball screw moves.

[0006] The self-locking ball screw of the present application comprises a base, a screw vertically arranged at both ends of the base and rotatably connected to the base, and a nut assembly connected to the outer thread of the screw through balls;

[0007] A self-locking cavity is formed at the outer end of the base, the length direction of the self-locking cavity is the same as the length direction of the screw, and a receiving module is arranged in the self-locking cavity;

[0008] A probe hand is arranged at the inner end of the nut assembly, the probe hand is embedded in the self-locking cavity and abuts against the receiving module;

[0009] The part of the receiving module located above the probe hand has the ability to move away from the probe hand and / or deform, so that the probe hand can move upward; the part of the receiving module located below the probe hand has the ability to move towards the probe hand and / or deform, so that the probe hand cannot move downward and forms self-locking.

[0010] As a further improvement of the present application, the nut assembly comprises a nut connected with the outer thread of the screw rod through balls, a supporting plate fixedly arranged at the outer end of the nut, and a probe hand arranged at the inner end of the nut.

[0011] As a further improvement of the present application, the upper end surface and the lower end surface of the probe hand are mutually symmetrical inclined surfaces.

[0012] As a further improvement of the present application, the receiving module comprises a plurality of baffle assemblies distributed along the vertical direction; each baffle assembly comprises a fixed plate and a rotating plate; the fixed plate is fixedly arranged on the inner wall of the self-locking cavity; the rotating plate is elastically connected to the outer end of the fixed plate, and the rotating plate is located within the moving range of the probe hand; the outer end of the fixed plate and the inner end of the rotating plate are in stepped abutment, so that the rotating plate cannot be turned downward; in the unloaded state, the fixed plate and the rotating plate are coaxial, and the baffle assembly is inclined upward relative to the horizontal plane; the rotating plates of adjacent baffle assemblies abut each other to realize linkage of the plurality of rotating plates; in the self-locking state, the outer end surface of the rotating plate located on the lower side of the probe hand abuts against the lower end surface of the probe hand to form self-locking.

[0013] As a further improvement of the present application, in the unloaded state, the outer end surface of the rotating plate is parallel to the lower end surface of the probe hand.

[0014] As a further improvement of the present application, the inner end of the probe hand is a probe head, and the upper end surface and the lower end surface of the probe head are mutually symmetrical horizontal surfaces; the inner end of the probe head is a round head.

[0015] As a further improvement of the present application, the receiving module comprises a plurality of pressure receiving assemblies distributed along the vertical direction; each pressure receiving assembly comprises a pressure receiving frame and a return assembly; the return assembly is fixedly arranged between the pressure receiving frame and the inner wall of the self-locking cavity, and the return assembly at least has an elastic member, and the compression direction of the elastic member is horizontal, so that the pressure receiving frame can move horizontally; adjacent pressure receiving frames are in stepped abutment to realize linkage of the plurality of pressure receiving frames; in the unloaded state, the pressure receiving frame is located within the moving range of the probe head, so that the probe head can press the pressure receiving frame to move; in the self-locking state, the upper end surface of the pressure receiving frame located on the lower side of the probe hand abuts against the lower end surface of the probe head to form self-locking.

[0016] As a further improvement of the present application, the upper end surface of the probe head is a horizontal surface to be parallel to the lower end surface of the probe head.

[0017] As a further improvement of the application, the return assembly comprises a sleeve, a spring, a permanent magnet block and an electromagnet; the sleeve is fixedly arranged on the inner wall of the self-locking cavity; the spring is located in the sleeve; the permanent magnet block is fixedly arranged on the inner end of the pressure-bearing frame, the inner end of the pressure-bearing frame is embedded in the sleeve and is in sliding connection with the sleeve, and the spring is located between the electromagnet and the permanent magnet block; the electromagnet is controlled by the on-off circuit of the external control system, and the electromagnet and the permanent magnet block are attracted or repelled when the current is connected; when the electromagnet and the permanent magnet block are attracted, the pressure-bearing frame is not located in the moving range of the probe.

[0018] As a further improvement of the application, the lower end of the probe is provided with an attracting magnetic block; the outer end surface of the pressure-bearing frame is fixedly provided with a magnetic flow bag, the magnetic flow bag is filled with magnetic fluid, and the magnetic flow bag is made of a bag membrane of elastic or flexible material; in the no-load state, the outer end surface of the magnetic flow bag is located outside the inner end of the probe, so that when the probe moves to the height of the magnetic flow bag, the magnetic flow bag is deformed, the part of the magnetic flow bag located on the lower side of the probe corresponds to the attracting magnetic block and is kept inflated to abut against the lower end surface of the probe.

[0019] Compared with the prior art, the application has the following beneficial effects:

[0020] 1. The present application sets up a probe and a plurality of abutting plate groups. When the probe moves upward, it can drive the rotating plate to rotate, but once it completely passes a certain rotating plate, the rotating plate abuts against the lower end surface of the probe. Since the abutting plate group does not have the ability to turn or move downward, the abutting plate group supports the probe from moving downward. If the screw motor stops rotating at this time, the abutting plate group can support the probe from moving downward, reducing the pressure on the screw itself and prolonging the service life of the screw. At the same time, the more abutting rod groups on the lower side of the probe, the more abutting rod groups indirectly supporting the probe, which can further enhance the support ability of the probe.

[0021] 2. The present application sets up a probe and a plurality of pressure-bearing frames. When the probe moves upward, it can press the pressure-bearing frame to move, but once it completely passes a certain pressure-bearing frame, the pressure-bearing frame is returned by elastic force, the upper end surface of the pressure-bearing frame abuts against the lower end surface of the probe, supporting the probe from moving downward. If the screw motor stops rotating at this time, the pressure-bearing frame can support the probe from moving downward, reducing the pressure on the screw itself and prolonging the service life of the screw. At the same time, the more pressure-bearing frames on the lower side of the probe, the more pressure-bearing frames indirectly supporting the probe, which can further enhance the support ability of the probe.

[0022] 3. After the electromagnet in the return assembly is energized, the pressure-bearing frame can be attracted to move inward, so that the self-locking state can be released, the nut assembly can smoothly move downward, or the pressure-bearing frame can be repelled outward to enhance the support ability of the pressure-bearing frame.

[0023] 4. The pressure-bearing frame of the present application is provided with magnetic flow bags at the outer end surface, when the probe passes through, the magnetic flow bags on the upper side of the probe can be deformed, the magnetic flow bags on the lower side of the probe are rigidly enhanced by the attracting magnetic blocks, and play the role of supporting the probe, so that the probe can realize self-locking effect at any position. BRIEF DESCRIPTION OF DRAWINGS

[0024] Figure 1 It is a three-dimensional structure schematic diagram of the specific embodiment one of the present application;

[0025] Figure 2 It is a partial three-dimensional structure schematic diagram of the nut assembly of the specific embodiment one of the present application;

[0026] Figure 3 It is a position structure schematic diagram of the probe and the bearing module when the load is zero of the specific embodiment one of the present application;

[0027] Figure 4 It is a position structure schematic diagram of the probe and the bearing module when the probe just contacts the bearing module of the specific embodiment one of the present application;

[0028] Figure 5 It is a position structure schematic diagram of the probe and the bearing module when the probe is self-locked of the specific embodiment one of the present application;

[0029] Figure 6 It is a partial three-dimensional structure schematic diagram of the nut assembly of the specific embodiment two of the present application;

[0030] Figure 7 It is a position structure schematic diagram of the probe and the bearing module when the load is zero of the specific embodiment two of the present application;

[0031] Figure 8 It is a position structure schematic diagram of the probe and the bearing module when the probe just contacts the bearing module of the specific embodiment two of the present application;

[0032] Figure 9 It is a position structure schematic diagram of the bearing module when the bearing module is linked and moved of the specific embodiment two of the present application;

[0033] Figure 10 It is a position structure schematic diagram of the probe and the bearing module when the probe is self-locked of the specific embodiment two of the present application;

[0034] Figure 11 It is a plane structure schematic diagram of the return assembly of the specific embodiment three of the present application;

[0035] Figure 12 It is a position structure schematic diagram of the probe and the bearing module when the load is zero of the specific embodiment four of the present application;

[0036] Figure 13Fig. 1 is a schematic diagram of the position structure of the probe and the receiving module when they are in contact with each other according to the fourth embodiment of the present application;

[0037] Figure 14 Fig. 2 is a schematic diagram of the position structure of the probe and the receiving module when they are in self-locking state according to the fourth embodiment of the present application.

[0038] Fig. 1 is a schematic diagram of the position structure of the probe and the receiving module when they are in contact with each other according to the fourth embodiment of the present application;

[0039] Base 1, self-locking cavity 11, screw rod 2, nut assembly 3, nut 31, supporting plate 32, probe 33, probe head 331, suction magnetic block 332, receiving module 4, one abutting plate group 41, two abutting plate groups 42, three abutting plate groups 43, guide frame 44, pressure bearing frame 45, magnetic flow bag 451, return assembly 46, sleeve 461, spring 462, permanent magnet block 463, electromagnet 464. DETAILED DESCRIPTION

[0040] Specific embodiment one: please refer to Figures 1-5 A self-locking ball screw, comprising a base 1, a screw rod 2 vertically arranged and rotationally connected to the base 1 at both ends, and a nut assembly 3 connected with the screw rod 2 through balls.

[0041] The base 1 is vertically placed when in use, and in this application, the direction close to the base 1 is the inner side, and the direction away from the base 1 is the outer side; a guide rail is arranged on the outer side surface of the base 1; a bearing wall is arranged on the upper and lower ends of the base 1, and a bearing is arranged in the bearing wall; a screw motor (not shown in the figure) is arranged on the upper side or the lower side of the base 1; a self-locking cavity 11 is opened on the outer side surface of the guide rail, and the self-locking cavity 11 is not through the base 1, and the length direction of the self-locking cavity 11 is vertical.

[0042] The screw rod 2 is vertically placed when in use, and the screw rod 2 is embedded in the corresponding bearing at both ends, and one end is fixedly connected with the output end of the screw motor to rotate under the driving of the screw motor.

[0043] The nut assembly 3 comprises a nut 31, a supporting plate 32, and a probe 33; the nut 31 is threadedly matched with the screw rod 2, and balls are arranged in the thread grooves; the supporting plate 32 is arranged at the outer end of the nut assembly 3 to connect the carried object; the probe 33 is arranged at the inner end of the nut 31, and the probe 33 is embedded in the self-locking cavity 11; the outer periphery of the nut 31 is further provided with a limiting piece (not shown in the figure) matched with the guide rail, so that the nut assembly 3 can move vertically.

[0044] The above connection of the base 1, the screw rod 2, and the nut assembly 3 constitutes a ball screw structure, and the ball screw is a transmission member well known to those skilled in the art, so the remaining unexpressed matching relationship is not described here.

[0045] The self-locking cavity 11 of the present application is provided with a receiving module 4; the part of the probe hand 33 located in the self-locking cavity 11 abuts against the receiving module 4; in the present embodiment, the receiving module 4 is a plurality of baffle assemblies distributed along the vertical direction; since the number of baffle assemblies has any number of setting modes, the present embodiment takes three baffle assemblies as an example for description; the three baffle assemblies are respectively a first abutting plate group 41, a second abutting plate group 42 and a third abutting plate group 43 from bottom to top; the baffle assemblies all include a fixed plate and a rotating plate; the first abutting plate group 41, the second abutting plate group 42 and the third abutting plate group 43 have the same structure and the same overall size, except that the sizes of the fixed plates and the rotating plates of each are different; the first abutting plate group 41 includes a first fixed plate and a first rotating plate; the inner end of the first fixed plate is fixedly connected with the inner wall of the self-locking cavity 11; the inner end of the first rotating plate is elastically rotatably connected with the outer end of the first fixed plate; the outer end of the first fixed plate and the inner end of the first rotating plate are in stepped abutment (as shown in Figure 3 ), so that the first rotating plate has the ability to turn upward, but does not have the ability to turn downward; in the no-load state, the first abutting plate group 41 as a whole is in a plate shape (as shown in Figure 3 ); the second abutting plate group 42 is located above the first abutting plate group 41; the second abutting plate group 42 includes a second fixed plate and a second rotating plate; the inner end of the second fixed plate is fixedly connected with the inner wall of the self-locking cavity 11; the inner end of the second rotating plate is elastically rotatably connected with the outer end of the second fixed plate; the outer end of the second fixed plate and the inner end of the second rotating plate are in stepped abutment (as shown in Figure 3 ), so that the second rotating plate has the ability to turn upward, but does not have the ability to turn downward; in the no-load state, the second abutting plate group 42 as a whole is in a plate shape (as shown in Figure 3 ); among them, the lower end surface of the second fixed plate abuts and fits with the upper end surface of the first fixed plate, and the outer end of the second fixed plate is lower than the rotating position of the first fixed plate, so that the first rotating plate can turn upward without being limited; in the no-load state, the lower end surface of the second rotating plate abuts and fits with the upper end surface of the first rotating plate, so that when the first rotating plate is rotated, the second rotating plate will also be indirectly rotated; the third abutting plate group 43 includes a third fixed plate and a third rotating plate; the inner end of the third fixed plate is fixedly connected with the inner wall of the self-locking cavity 11; the inner end of the third rotating plate is elastically rotatably connected with the outer end of the third fixed plate; the outer end of the third fixed plate and the inner end of the third rotating plate are in stepped abutment (as shown in Figure 3 ), so that the third rotating plate has the ability to turn upward, but does not have the ability to turn downward; in the no-load state, the third abutting plate group 43 as a whole is in a plate shape (as shown in Figure 3 ); among them, the lower end surface of the third fixed plate abuts and fits with the upper end surface of the second fixed plate, and the outer end of the third fixed plate is lower than the rotating position of the second fixed plate, so that the second rotating plate can turn upward without being limited; in the no-load state, the lower end surface of the third rotating plate abuts and fits with the upper end surface of the second rotating plate, so that when the second rotating plate is rotated, the third rotating plate will also be indirectly rotated.

[0046] In the embodiment, the upper end face and the lower end face of the feeler 33 are mutually symmetrical inclined surfaces, and the inner end of the feeler 33 is a rounded corner (as shown in Figure 2 In the idle state, the outer end face of the rotating plate is parallel to the lower end face of the feeler 33 (as shown in Figure 3 For example, if the angle of the outer end face of the rotating plate is 135°, and the angle of the lower end face of the feeler 33 is -45°, the two faces can be completely abutted.

[0047] The moving range of the feeler 33 covers at least part of the range where the rotating plate is located, so that when the feeler 33 moves from bottom to top, it will abut against the rotating plate one by one and drive the rotating plate to flip upward. Since the rotating plate has a rotating pair that flips upward, the upward movement of the feeler 33 will not be restricted. However, when the feeler 33 completely passes through a certain rotating plate, for example, the first rotating plate, the first rotating plate automatically returns to the lower side of the feeler 33 due to the elastic effect. Since the first rotating plate does not have the ability to flip downward at this time, when the feeler 33 stops moving at this time, the abutted plate group 41 can provide a supporting force to hinder the downward movement of the feeler 33 due to gravity, thereby forming a self-locking.

[0048] Specific embodiment two: different from the specific embodiment one, please refer to Figures 6-10 A self-locking ball screw, the inner end of the feeler 33 is a probe 331, the upper end face and the lower end face of the probe 331 are mutually symmetrical horizontal surfaces; the inner end of the probe 331 is a rounded corner;

[0049] In the embodiment, the receiving module 4 includes a plurality of pressure receiving assemblies distributed in the vertical direction. Since the number of pressure receiving assemblies has any number of setting modes, the embodiment takes three pressure receiving assemblies as an example for description. The three pressure receiving assemblies are a guide frame 44, two pressure receiving frames 45 from bottom to top, and the two pressure receiving frames 45 are a first pressure receiving frame and a second pressure receiving frame from bottom to top. The inner ends of the guide frame 44, the first pressure receiving frame, and the second pressure receiving frame are connected with the inner wall of the self-locking cavity 11 through corresponding return assemblies 46. The return assembly 46 includes an elastic member, and the compression direction of the elastic member is horizontal.

[0050] The guide frame 44 includes a main rod, a lower plate, and an upper plate. The upper end face of the lower plate is fixedly connected with the lower end face of the main rod, the outer side face of the lower plate is an inwardly inclined inclined surface, the outer end of the lower plate is flush with the outer end of the main rod, the lower end of the inclined surface is flush with the cavity end face of the self-locking cavity 11, and the probe 331 starts to move upward from abutting on the cavity end face, that is, in the initial state, the inner end of the probe 331 is located on the inner side of the outer end of the main rod, and the lower end face of the lower plate abuts against the lower inner wall of the self-locking cavity 11. The lower end face of the upper plate is fixedly connected with the upper end face of the main rod, the outer end face of the upper plate is flush with the outer end face of the main rod, and the outer end face of the upper plate is flush with the lower end of the inclined surface.

[0051] The pressure bearing one frame comprises a main two-bar, a lower two-plate, and an upper two-plate; the lower two-plate is fixedly connected with the lower end surface of the main two-bar, and the outer side surface of the lower two-plate is a vertical plane; the lower end surface of the upper two-plate is fixedly connected with the upper end surface of the main two-bar, the outer end surface of the upper two-plate is flush with the outer end surface of the main two-bar, and the inner end surface of the upper two-plate is flush with the outer end surface of the lower two-plate; in the unloaded state, the outer end surface of the main one-bar is flush with the outer end surface of the main two-bar, the upper end surface of the upper one-plate is in abutment with the lower end surface of the main two-bar, the inner end surface of the upper one-plate is in abutment with the outer end surface of the lower two-plate, and the lower end surface of the lower two-plate is in abutment with the upper end surface of the main one-bar.

[0052] The pressure bearing two frame has the same structure as the pressure bearing one frame, and the matching relationship of the pressure bearing two frame and the pressure bearing one frame is consistent with the matching relationship of the pressure bearing one frame and the guide frame 44, which is described in detail in Figure 7 , and thus is not described here.

[0053] When the probe 331 moves from bottom to top, the inner end of the probe 331 first contacts the inclined surface of the guide frame 44, the guide frame 44 moves to the inner side under pressure, at this time all the pressure bearing components move to the inner side, the probe 331 continues to move upwards until it contacts the outer side surface of the guide frame 44, when the probe 331 continues to move until it completely passes through the guide frame 44, the guide frame 44 moves to the outer side under the elastic force of the return component 46, at this time the lower end surface of the probe 331 is in abutment with the upper end surface of the guide frame 44, if the probe 331 stops moving at this time, the guide frame 44 can provide a supporting force to hinder the probe 331 from moving downward due to gravity, since the lower end surface of the guide frame 44 is in abutment with the lower inner wall of the self-locking cavity 11, thus the strength of supporting the probe 331 is greater, and it can adapt to a heavier load.

[0054] Specific embodiment three: on the basis of the specific embodiment two, please refer to Figure 11 A self-locking ball screw, the return component 46 comprises a sleeve 461, a spring 462, a permanent magnet block 463, and an electromagnet 464; the sleeve 461 is fixedly arranged on the inner wall of the self-locking cavity 11; the spring 462 is located in the sleeve 461; the permanent magnet block 463 is fixedly arranged on the inner end of the pressure bearing frame, the inner end of the pressure bearing frame is embedded in the sleeve 461 and is in sliding connection with the sleeve 461, and the spring 462 is located between the electromagnet 464 and the permanent magnet block 463; the electromagnet 464 is controlled by the on-off of the control circuit of the external control system, and the electromagnet 464 is in attraction or repulsion with the permanent magnet block 463 when the current is connected; when the electromagnet 464 and the permanent magnet block 463 are in attraction, the pressure bearing frame is not located in the moving range of the probe 331.

[0055] Such a setting can ensure the contact in the self-locking state, can allow the probe 331 to move from top to bottom, realize the reciprocating movement of the probe 331, and also ensure the formation of the self-locking state.

[0056] Specific embodiment four: on the basis of the specific embodiment three, please refer toFigures 12-14 A self-locking ball screw of the application, the lower end of the probe 331 is provided with an attracting magnetic block 332, the inner end of the attracting magnetic block 332 is located outside the inner end of the probe 331; the outer end surface of the pressure bearing frame is fixedly provided with a magnetic flow bag 451, the magnetic flow bag 451 is filled with magnetic fluid, and the magnetic flow bag 451 is made of a bag film of elastic or flexible material; in the no-load state, the outer end surface of the magnetic flow bag 451 is located outside the inner end of the probe 331, so that when the probe 331 moves to the height of the magnetic flow bag 451, the magnetic flow bag 451 is compressed to deform, and the part of the magnetic flow bag 451 located on the lower side of the probe 331 corresponds to the attracting magnetic block 332 and keeps swelling to abut against the lower end surface of the probe 331.

[0057] Since the attracting magnetic block 332 can attract the magnetic fluid in the magnetic flow bag 451 to move, the magnetic fluid in the magnetic flow bag 451 located on the lower side of the probe 331 is more than that in the magnetic flow bag 451 located on the upper side of the probe 331, and due to the action of the magnetic field, the magnetic fluid in the magnetic flow bag 451 located on the lower side of the probe 331 tends to be solid, thereby ensuring that the probe 331 is supported by the magnetic fluid in the magnetic flow bag 451, and ensuring that the probe 331 can be upwardly supported at any height to form self-locking.

Claims

1. A self-locking ball screw, comprising a base (1), a screw (2) with both ends rotatably connected to the base (1) and vertically arranged, and a nut assembly (3) threadedly connected to the outer side of the screw (2) by balls; Its features are: The base (1) has a self-locking cavity (11) at its outer end. The length direction of the self-locking cavity (11) is the same as the length direction of the screw (2). The self-locking cavity (11) is provided with a receiving module (4). The nut assembly (3) has a probe (33) at its inner end. The probe (33) is embedded in the self-locking cavity (11) and abuts against the receiving module (4). The portion of the receiving module (4) located above the probe (33) has the ability to move and / or deform away from the probe (33) so that the probe (33) can move upward; the portion of the receiving module (4) located below the probe (33) has the ability to move and / or deform towards the probe (33) so that the probe (33) cannot move downward and forms a self-locking mechanism. The nut assembly (3) includes a probe (33) disposed at the inner end of the nut (31); The inner end of the probe (33) is the probe (331), and the upper and lower end faces of the probe (331) are symmetrical horizontal planes; the inner end of the probe (331) is round. The receiving module (4) includes multiple pressure-bearing components distributed vertically; each pressure-bearing component includes a pressure frame and a return component (46); the return component (46) is fixedly installed between the pressure frame and the inner wall of the self-locking cavity (11), and the return component (46) has at least an elastic element, the compression direction of which is horizontal, so that the pressure frame can move horizontally; adjacent pressure frames abut against each other in a stepped manner to realize the linkage of multiple pressure frames; in the unloaded state, the pressure frame is located within the movement range of the probe (331) so that the probe (331) can press the pressure frame to move; in the self-locking state, the upper end face of the pressure frame located below the probe (33) abuts against the lower end face of the probe (331) to form a self-lock; The return assembly (46) includes a sleeve (461), a spring (462), a permanent magnet (463), and an electromagnet (464). The sleeve (461) is fixedly installed on the inner wall of the self-locking cavity (11). The spring (462) is located inside the sleeve (461). The permanent magnet (463) is fixedly installed at the inner end of the pressure frame. The inner end of the pressure frame is embedded in the sleeve (461) and slidably connected to the sleeve (461). The spring (462) is located between the electromagnet (464) and the permanent magnet (463). The electromagnet (464) is controlled by the external control system circuit. When the current is connected, the electromagnet (464) and the permanent magnet (463) are attracted or repelled. When the electromagnet (464) and the permanent magnet (463) are attracted, the pressure frame is not within the movement range of the probe (331).

2. The self-locking ball screw according to claim 1, characterized in that: The nut assembly (3) includes a nut (31) that is threaded to the outside of the screw (2) by a ball bearing, and a support plate (32) fixedly disposed at the outer end of the nut (31); the support plate (32) is used to support the movable part.

3. The self-locking ball screw according to claim 1, characterized in that: The upper surface of the probe (331) is horizontal, so as to be parallel to the lower surface of the probe (331).

4. The self-locking ball screw according to claim 1, characterized in that: The lower end of the probe (331) is provided with an attraction magnet (332); a magnetic fluid bag (451) is fixedly provided on the outer end face of the pressure frame. The magnetic fluid bag (451) is filled with magnetic fluid and is made of a membrane of elastic or flexible material. In the unloaded state, the outer end face of the magnetic fluid bag (451) is located outside the inner end of the probe (331) so that when the probe (331) moves to the height of the magnetic fluid bag (451), the magnetic fluid bag (451) is compressed and deformed. The part of the magnetic fluid bag (451) located on the lower side of the probe (331) corresponds to the attraction magnet (332) and is kept expanded to abut against the lower end face of the probe (331).

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