A large-stroke nut push rod device

Abstract

The present invention relates to the field of ball screw transmission structure, and in particular to a large-stroke nut push rod device, including a main transmission mechanism and a nut push rod mechanism; the main transmission mechanism includes a driven gear and a screw drive rod; the nut push rod mechanism includes a rotating push rod, a reverser, a screw nut barrel and a ball. The present invention drives the screw drive rod to rotate by the driven gear, and the rotating push rod can rotate synchronously with the screw drive rod and can slide linearly relative to the screw drive rod along the length direction, so the rotating push rod can complete rotational motion and linear motion at the same time. In the process of the rotating push rod completing the rotational motion and linear motion, the ball and the reverser cooperate to realize the static state of the screw nut barrel. The rotating push rod in the present invention has both rotational motion and linear motion, and the screw nut barrel is located in the outer cylinder of the rotating cylinder and remains stationary, and has the structural characteristics of short rotating push rod thread, long screw nut barrel thread, and the reverser located on the rotating push rod.

Description

Technical Field

[0001] The invention relates to the field of ball screw transmission structures, and in particular to a long-stroke nut push rod device. Background Art

[0002] The ball screw transmission structure is a traditional mechanism for converting rotational motion into linear motion. In order to achieve long-stroke transmission, the current ball screw transmission structure has the characteristics of a long screw track and a short nut track. The screw is connected to the motor through a reducer, that is, the screw performs rotational motion; the nut installed outside the screw performs linear motion. In this movement, the motion is transmitted between the screw and the nut through the rolling friction of the ball, and the reverser is located on the nut. Due to the long screw track, its own weight is large, and vibration and abnormal noise are prone to occur during movement; the processing precision required for the screw with a long track is high, and the manufacturing process is complex, which increases the manufacturing cost to a certain extent. Summary of the invention

[0003] In order to solve the problems of heavy screw weight and high machining precision requirement in the current ball screw transmission structure with long-stroke rotation, the present invention provides a long-stroke nut push rod device.

[0004] The present invention is realized by the following technical scheme: a large-stroke nut push rod device, comprising a main transmission mechanism and a nut push rod mechanism;

[0005] A main transmission mechanism, which includes a driven gear and a lead screw drive rod;

[0006] A nut push rod mechanism, which includes a rotating push rod, a reverser, a lead screw nut barrel and a ball;

[0007] The center of the rotating push rod has a first sliding hole that is clearance-matched with the screw drive rod, and the driven gear is coaxially fixed to one end of the screw drive rod outside the rotating push rod; the rotating push rod can rotate synchronously with the screw drive rod and can slide and cooperate with the screw drive rod along the length direction through the first sliding hole; the outer wall of the rotating push rod close to one end of the driven gear is provided with a first threaded raceway, and at least one reverse hole for installing a reverser is provided on the outer wall of the rotating push rod located at the first threaded raceway, and a second threaded raceway is provided on the inner wall of the screw nut tube, and the thread length of the second threaded raceway is greater than the thread length of the first threaded raceway. The first threaded raceway and the second threaded raceway are combined to form a raceway for ball motion, and the body of the reverser is provided with a return ball groove for returning the ball.

[0008] As a further improvement of the technical solution of the present invention, the main transmission mechanism also includes a transmission screw and a sensing rod; the nut push rod mechanism also includes a sensor trigger connecting rod; the lead screw drive rod is provided with a first mounting hole along the center line, the transmission screw is screwed to one end of the first mounting hole close to the driven gear, the transmission screw is provided with a second mounting hole along the center line, the sensing rod is inserted into the second mounting hole, the sensor trigger connecting rod is movably inserted into the first mounting hole, and the end of the sensor trigger connecting rod away from the driven gear extends out of the lead screw drive rod and is fixedly installed on the inner wall of the rotating push rod, and the sensor trigger connecting rod can contact and cooperate with the sensing rod.

[0009] As a further improvement of the technical solution of the present invention, the second mounting hole is a stepped hole, the end of the sensing rod has a rod cap that cooperates with the end of the transmission screw, and a spring is movably sleeved on the rod body of the sensing rod, and the two ends of the spring are respectively limited by the end face of the rod cap and the shoulder of the stepped hole of the second mounting hole.

[0010] As a further improvement of the technical solution of the present invention, the main transmission mechanism also includes a sliding sleeve, the middle of the sliding sleeve has a third mounting hole that slides and frictionally cooperates with the screw drive rod, and the outside of the sliding sleeve has a first external thread that is screwed to the first sliding hole.

[0011] As a further improvement of the technical solution of the present invention, the nut push rod mechanism also includes a rotating cylinder outer cylinder barrel, and the rotating cylinder outer cylinder barrel is fixedly sleeved on the outer wall of the screw nut barrel.

[0012] As a further improvement of the technical solution of the present invention, the main transmission mechanism also includes a first bearing fixedly sleeved on the screw drive rod between the driven gear and the rotating push rod, a bearing seat ring is fixedly sleeved on the outer ring of the first bearing, and the outer wall of the bearing seat ring has a stepped portion that is positioned and matched with the inner wall of the outer cylinder barrel of the rotating cylinder.

[0013] As a further improvement of the technical solution of the present invention, it also includes an angle adjustment mechanism, which includes an inner ring of an outer cylinder front bearing and an inner ring of a universal joint; the inner ring of the outer cylinder front bearing is screwed onto the outer wall of the outer cylinder of the rotating cylinder away from the driven gear, and the outer wall of the inner ring of the outer cylinder front bearing has at least one first annular groove along the circumferential direction; the inner ring of the universal joint is sleeved on the outside of the inner ring of the outer cylinder front bearing, and the inner wall of the inner ring of the universal joint has at least one second annular groove along the circumferential direction, and the first annular groove and the second annular groove are combined to form a track for the movement of the steel ball group.

[0014] As a further improvement of the technical solution of the present invention, the angle adjustment mechanism also includes a universal joint frame, the outer wall of the universal joint inner ring is extended outwardly to be provided with at least one clamping portion, the universal joint frame is sleeved on the outside of the universal joint inner ring, and the frame body of the universal joint frame is provided with a clamping hole that is engaged with the corresponding clamping portion, and the frame body of the universal joint frame is connected to be provided with at least one ear shaft seat.

[0015] As a further improvement of the technical solution of the present invention, the nut push rod mechanism also includes a front guide sleeve, which is slidably sleeved on the outer wall of the end of the rotating push rod away from the driven gear, and the front guide sleeve is fixedly connected to the inner ring of the front bearing of the outer cylinder.

[0016] As a further improvement of the technical solution of the present invention, the end of the rotating push rod away from the driven gear has a fourth mounting hole connected to the first sliding hole, the inner wall of the fourth mounting hole has a shrinkage hole portion that cooperates with the end of the sensor trigger connecting rod to limit the position, and the fourth mounting hole outside the sensor trigger connecting rod is provided with a mounting plug that seals and cooperates with the end face of the sensor trigger connecting rod.

[0017] The long-stroke nut push rod device provided by the present invention has the following advantages compared with the prior art:

[0018] 1. In the present invention, the driven gear drives the lead screw drive rod to rotate, and the rotary push rod can rotate synchronously with the lead screw drive rod and can slide linearly relative to the lead screw drive rod along the length direction, so the rotary push rod can complete rotary motion and linear motion at the same time. In the process of the rotary push rod completing rotary motion and linear motion, the ball and the reverser cooperate to achieve the stillness of the lead screw nut tube. The rotary push rod in the present invention has both rotary motion and linear motion, and the lead screw nut tube is located in the outer cylinder barrel of the rotary cylinder and remains stationary. It has the structural characteristics of short rotary push rod thread, long lead screw nut tube thread, and the reverser is located on the rotary push rod, and the transmission process of the present invention does not require the addition of a connecting plate. The problems of large weight and high processing precision of the long lead screw track are solved.

[0019] 2. In the present invention, the spring is in a compressed state, and the transmission screw keeps the sensing rod in contact with the sensor trigger connecting rod. The sensor trigger connecting rod rotates and moves linearly with the rotating push rod. When the rotating push rod extends from the screw nut barrel, the spring is in a natural state, and the sensor trigger connecting rod moves outward with the rotating push rod. The sensor trigger connecting rod and the sensing rod are in a disconnected state. This structure can ensure that the stroke position of the rotating push rod is detected in time. The entire structure is compact and reliable and convenient to install.

[0020] 3. In the present invention, the inner ring of the universal joint cooperates with the inner ring of the front bearing of the outer cylinder barrel so that the main transmission mechanism and the nut push rod mechanism have an angle adjustment function. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the invention and, together with the description, serve to explain the principles of the invention.

[0022] In order to more clearly illustrate the embodiments of the present invention 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, for ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0023] Figure 1 The figure is a schematic diagram of the external structure of a long-stroke nut push rod device according to the present invention.

[0024] Figure 2 It is a cross-sectional view of a long-stroke nut push rod device according to the present invention.

[0025] Figure 3 It is a schematic diagram of the connection between the rotary push rod and the screw drive rod.

[0026] Figure 4 It is a schematic diagram of the installation of the sliding sleeve.

[0027] Figure 5 It is a cross-sectional view of the screw nut tube.

[0028] Figure 6 It is a cross-sectional view of the rotary push rod.

[0029] Figure 7 It is a schematic structural diagram of the inner ring of the front bearing of the outer cylinder.

[0030] Figure 8 It is a schematic structural diagram of the inner ring of the universal joint.

[0031] Fig. 9 It is a structural schematic diagram of the universal joint frame.

[0032] Fig.10 It is a schematic diagram of the cooperation between the inner ring of the universal joint and the universal joint frame.

[0033] Fig.11 for Figure 2 A partial enlargement of one part.

[0034] Fig.12 for Figure 2 A partial enlargement of another part.

[0035] Fig.13 It is a schematic diagram of the installation of the sensing rod.

[0036] In the figure: 1-main transmission mechanism; 2-nut push rod mechanism; 3-angle adjustment mechanism; 11-screw drive rod; 111-first mounting hole; 12-driven gear; 13-transmission screw; 131-second mounting hole; 14-sensing rod; 141-rod cap; 15-spring; 16-sliding sleeve; 161-third mounting hole; 162-first external thread; 171-first bearing; 172-bearing race; 173-second bearing; 21-rotating push rod; 211-first sliding hole; 212-first thread raceway; 213- The fourth mounting hole; 214-shrinkage portion; 215-mounting plug; 22-reverser; 221-return ball groove; 23-screw nut tube; 231-second thread raceway; 24-ball; 25-sensor trigger connecting rod; 26-rotating cylinder outer steel cylinder; 261-mounting portion; 27-front guide sleeve; 31-front bearing inner ring of outer cylinder; 311-first annular groove; 32-universal joint inner ring; 321-clamping portion; 322-second annular groove; 33-universal joint frame; 331-clamping hole; 332-ear shaft seat; 34-steel ball group. DETAILED DESCRIPTION

[0037] In order to more clearly understand the above-mentioned objectives, features and advantages of the present invention, the scheme of the present invention will be further described below. It should be noted that the embodiments of the present invention and the features in the embodiments can be combined with each other without conflict.

[0038] In the description, it should be noted that the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance. It should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected" and "connected" should be understood in a broad sense. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to specific circumstances.

[0039] In the following description, many specific details are set forth to facilitate a full understanding of the present invention, but the present invention may also be implemented in other ways different from those described herein; it is obvious that the embodiments in the specification are only part of the embodiments of the present invention, rather than all of the embodiments.

[0040] The specific embodiments of the present invention are described in detail below.

[0041] like Figures 1 to 13 As shown, the present invention provides a specific embodiment of a large-stroke nut push rod device, comprising a main transmission mechanism 1 and a nut push rod mechanism 2;

[0042] The main transmission mechanism 1 includes a driven gear 12 and a lead screw drive rod 11:

[0043] The nut push rod mechanism 2 includes a rotating push rod 21, a reverser 22, a lead screw nut cylinder 23 and a ball 24;

[0044] The center of the rotary push rod 21 has a first sliding hole 211 that is clearance-matched with the screw drive rod 11, and the driven gear 12 is coaxially fixed to one end of the screw drive rod 11 outside the rotary push rod 21; the rotary push rod 21 can rotate synchronously with the screw drive rod 11 and can slide and cooperate with the screw drive rod 11 along the length direction through the first sliding hole 211; the outer wall of the rotary push rod 21 close to one end of the driven gear 12 is provided with a first threaded raceway 212, and at least one reverse hole for installing the reverser 22 is provided on the outer wall of the rotary push rod 21 located at the first threaded raceway 212, and the inner wall of the screw nut tube 23 is provided with a second threaded raceway 231, the thread length of the second threaded raceway 231 is greater than the thread length of the first threaded raceway 212, the first threaded raceway 212 and the second threaded raceway 231 are combined to form a raceway for the movement of the ball 24, and the body of the reverser 22 has a return ball groove 221 for returning the ball 24.

[0045] It is well known in the art that the number of reversers 22 is determined according to the bearing capacity of the screw pair (e.g. Figure 3 As shown, there are four deflectors 22 in this embodiment). The arrangement method of the deflectors 22 in the axial direction of the rotating push rod 21 is related to the structure of the lead of the screw pair and the screw nut tube 23. The return ball groove 221 connects the two adjacent first thread raceways 212. The return ball groove 221 in this embodiment is used to complete the circulation of the ball 24. It should be noted that the screw nut tube 23 can be combined by docking multiple ball screw nuts, or it can be made in an integrated molding manner. After testing, the rotating push rod 21 in this embodiment can achieve a large stroke linear displacement of 700mm while rotating.

[0046] The specific principle of the transmission working of this embodiment:

[0047] The driven gear 12 obtains power by meshing with the external driving gear. In this embodiment, the driven gear 12 is a spur gear with a keyway in the middle, which is connected to the lead screw drive rod 11 through a flat key. Figure 4As shown, the outer cross-section of the rod body of the lead screw driving rod 11 in this embodiment is hexagonal, and the first sliding hole 211 on the rotating push rod 21 is a hexagonal shape adapted to the lead screw driving rod 11, while the outer cross-section of the rod body of the lead screw driving rod 11 on which the driven gear 12 is mounted is circular. The lead screw driving rod 11 plays a positioning role for the rotating push rod 21, and the lead screw nut cylinder 23 in this embodiment is kept fixed by connecting with the external structure. When the driven gear 12 drives the screw drive rod 11 to rotate, the rotating push rod 21 rotates synchronously due to the limiting effect of the screw drive rod 11 on the rotating push rod 21; since the screw nut tube 23 remains fixed, when the rotating push rod 21 rotates, the ball 24 runs in the raceway and the return movement of the ball 24 is completed through the reverser 22. At this time, the rotating push rod 21 realizes linear motion through the reverser 22, and the rotating push rod 21 extends out of the screw nut tube 23; when the rotating push rod 21 needs to be retracted, the driven gear 12 can be rotated in the reverse direction.

[0048] In order to facilitate timely detection of the stroke position of the rotating push rod 21, the main transmission mechanism 1 of this embodiment further includes a transmission screw 13 and a sensing rod 14; the nut push rod mechanism 2 further includes a sensor triggering connecting rod 25; the lead screw driving rod 11 is provided with a first mounting hole 111 along the center line, the transmission screw 13 is screwed to one end of the first mounting hole 111 close to the driven gear 12, the transmission screw 13 is provided with a second mounting hole 131 along the center line, the sensing rod 14 is inserted into the second mounting hole 131, the sensor triggering connecting rod 25 is movably inserted into the first mounting hole 111, and the end of the sensor triggering connecting rod 25 away from the driven gear 12 extends out of the lead screw driving rod 11 and is fixedly installed on the inner wall of the rotating push rod 21, and the sensor triggering connecting rod 25 can contact and cooperate with the sensing rod 14. The end of the sensor triggering connecting rod 25 in this embodiment is installed inside the rotating push rod 21, and performs rotational motion and linear motion with the rotating push rod 25. When the rotating push rod 21 is located inside the screw nut tube 23, the sensor triggers the connecting rod 25 to contact the sensing rod 14. The sensing rod 14 senses the contact signal, and the driven gear 12 stops rotating, thereby controlling the rotating push rod 21 to stop moving. In this embodiment, the limiting effect is achieved through the contact signal. When the rotating push rod 21 performs rotational motion and linear motion and extends from the inside of the screw nut tube 23, the sensor triggers the connecting rod 25 and the sensing rod 14 are in a disconnected state.

[0049] In one example of the present embodiment, the second mounting hole 131 of the present embodiment is a stepped hole, the end of the sensing rod 14 has a rod cap 141 that matches the end of the screw rod of the transmission screw 13, and a spring 15 is movably sleeved on the rod body of the sensing rod 14, and the two ends of the spring 15 are respectively limited with the end surface of the rod cap 141 and the shoulder of the stepped hole of the second mounting hole 131. When the rotating push rod 21 is located inside the lead screw nut barrel 23, the sensor trigger connecting rod 25 contacts the sensing rod 14, and the spring 15 is compressed, and the contact effectiveness of the sensor trigger connecting rod 25 and the sensing rod 14 can be achieved through the action of the spring force. When the rotating push rod 21 extends from the inside of the lead screw nut barrel 23 through rotational motion and linear motion, the spring force is released, and the spring 15 gradually returns to a natural state.

[0050] In another embodiment of the present embodiment, the main transmission mechanism 1 further comprises a sleeve 16, wherein the middle portion of the sleeve 16 comprises a third mounting hole 161 which is frictionally matched with the lead screw drive rod 11, and the outer portion of the sleeve 16 comprises a first external thread 162 which is threadedly connected with the first sliding hole 211. The sleeve 16 in the present embodiment can reduce the contact area between the lead screw drive rod 11 and the rotating push rod 21 by frictionally matching with the lead screw drive rod 11, thereby reducing the friction between the lead screw drive rod 11 and the rotating push rod 21. Specifically, as Figure 4 As shown, the third mounting hole 161 of the sliding sleeve 16 in this embodiment is hexagonal.

[0051] In a specific implementation, the nut push rod mechanism 2 further includes a rotating cylinder outer cylinder barrel 26, and the rotating cylinder outer cylinder barrel 26 is fixedly sleeved on the outer wall of the screw nut barrel 23. Specifically, the fixed sleeve method can be a bonding method. It can be understood that the rotating cylinder outer cylinder barrel 26 in this embodiment is connected to the external structure to keep the screw nut barrel 23 fixed. Further, as Figure 2 As shown, a mounting portion 261 is disposed outside the outer cylinder barrel 26 of the rotary cylinder in this embodiment. A plurality of mounting holes are evenly distributed along the circumferential direction on the mounting portion 261, and the mounting portion 261 can be connected to an external structure through different mounting holes.

[0052] In order to support the screw drive rod 11 so that the screw drive rod 11 is located at the center of the rotating cylinder outer cylinder barrel 26, the main transmission mechanism 1 also includes a first bearing 171 fixedly sleeved on the screw drive rod 11 between the driven gear 12 and the rotating push rod 21, and a bearing race 172 is fixedly sleeved on the outer ring of the first bearing 171, and the outer wall of the bearing race 172 has a stepped portion that is positioned and matched with the inner wall of the rotating cylinder outer cylinder barrel 26. The first bearing 171 and the bearing race 172 are supported between the screw drive rod 11 and the rotating cylinder outer cylinder barrel 26 to achieve the center positioning of the screw drive rod 11.

[0053] like Fig.12As shown, in order to achieve axial positioning of the driven gear 12 , a second bearing 173 is provided on the screw drive rod 11 in this embodiment, and the second bearing 173 is located between the driven gear 12 and the nut of the transmission screw 13 .

[0054] In order to further realize the characteristic of adjustable cylinder rotation angle of the large-stroke nut push rod device, the present embodiment also includes an angle adjustment mechanism 3, which includes an outer cylinder front bearing inner ring 31 and a universal joint inner ring 32; the outer cylinder front bearing inner ring 31 is screwed on the outer wall of the outer cylinder 26 of the rotating cylinder away from the driven gear 12, and the outer wall of the outer cylinder front bearing inner ring 31 has two first annular grooves 311 along the circumferential direction; the universal joint inner ring 32 is sleeved on the outside of the outer cylinder front bearing inner ring 31, and the inner wall of the universal joint inner ring 32 has two second annular grooves 322 along the circumferential direction, and the corresponding first annular groove 311 and the second annular groove 322 are combined to form a track for the movement of the steel ball group 34. In this embodiment, before rotating the outer cylinder barrel 26 of the rotating cylinder, the connection between the mounting hole on the mounting portion 261 and the external structure is released; then the outer cylinder barrel 26 of the rotating cylinder is rotated, and the inner ring 31 of the front bearing of the outer cylinder barrel can be rotated in the inner ring 32 of the universal joint through the steel ball group 34, and then the corresponding mounting hole on the mounting portion 261 is connected to the external structure, so as to realize the adjustable angle of the outer cylinder barrel 26 of the rotating cylinder.

[0055] In order to facilitate the installation of the angle adjustment mechanism 3, the angle adjustment mechanism 3 also includes a universal joint frame 33, the outer wall of the universal joint inner ring 32 is extended outwardly and provided with two clamping parts 321, the universal joint frame 33 is sleeved on the outside of the universal joint inner ring 32, the frame body of the universal joint frame 33 is provided with a clamping hole 331 that is clamped and matched with the corresponding clamping part 321, and the frame body of the universal joint frame 33 is connected with two trunnion seats 332. In this embodiment, the installation of the angle adjustment mechanism 3 is achieved by connecting the trunnion seat 332 with the external structure, and the angle adjustment of the outer cylinder barrel 26 of the rotating cylinder can be achieved by only releasing the connection between the mounting hole on the mounting part 261 and the external structure.

[0056] like Fig.11 As shown, in order to ensure the position accuracy of the rotary push rod 21 during linear motion, the nut push rod mechanism 2 further includes a front guide sleeve 27, which is slidably sleeved on the outer wall of the end of the rotary push rod 21 away from the driven gear 12, and the front guide sleeve 27 is fixedly connected to the inner ring 31 of the front bearing of the outer cylinder. When the rotary push rod 21 extends or retracts from the inside of the lead screw nut barrel 23 for rotational and linear motion, the front guide sleeve 27 in this embodiment slides and frictionally cooperates with the rotary push rod 21, and supports and guides the rotary push rod 21.

[0057] This embodiment also provides a way to install the sensor trigger link 25, that is, the end of the rotating push rod 21 away from the driven gear 12 has a fourth installation hole 213 connected to the first sliding hole 211, the inner wall of the fourth installation hole 213 has a shrinkage hole portion 214 that matches the end of the sensor trigger link 25, and the fourth installation hole 213 outside the sensor trigger link 25 is provided with a mounting plug 215 that matches the end face of the sensor trigger link 25. Fig.11 As shown, the installation plug 215 and the fourth installation hole 213 are screwed to achieve a sealing function.

[0058] The above is only a specific implementation of the present invention, which enables those skilled in the art to understand or implement the present invention. Although detailed descriptions are given with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions recorded in the aforementioned embodiments, or replace some or all of the technical features therein by equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments, and they should all be covered by the protection scope of the claims.

Claims

1. A long-stroke nut push rod device, characterized in that: It comprises a main transmission mechanism (1) and a nut push rod mechanism (2); A main transmission mechanism (1), comprising a driven gear (12) and a lead screw drive rod (11); A nut push rod mechanism (2), comprising a rotating push rod (21), a reverser (22), a lead screw nut tube (23) and a ball (24); The center of the rotary push rod (21) has a first sliding hole (211) which is clearance-matched with the lead screw drive rod (11); the driven gear (12) is coaxially fixedly arranged at one end of the lead screw drive rod (11) outside the rotary push rod (21); the rotary push rod (21) can rotate synchronously with the lead screw drive rod (11) and can slide and match with the lead screw drive rod (11) along the length direction through the first sliding hole (211); the outer wall of one end of the rotary push rod (21) close to the driven gear (12) is provided with a first thread raceway (212), and the first thread raceway is located on the outer wall of the first thread raceway. At least one reversing hole for mounting a reversing device (22) is provided on the outer wall of the rotating push rod (21) at (212), a second threaded raceway (231) is provided on the inner wall of the lead screw nut tube (23), the thread length of the second threaded raceway (231) is greater than the thread length of the first threaded raceway (212), the first threaded raceway (212) and the second threaded raceway (231) are combined to form a raceway for the movement of the ball (24), and the body of the reversing device (22) is provided with a return ball groove (221) for returning the ball (24); The main transmission mechanism (1) further comprises a transmission screw (13) and a sensing rod (14); the nut push rod mechanism (2) further comprises a sensor trigger connecting rod (25); the lead screw driving rod (11) is provided with a first mounting hole (111) along the center line; the transmission screw (13) is screwed to one end of the first mounting hole (111) close to the driven gear (12); the transmission screw (13) is provided with a second mounting hole (131) along the center line; the sensing rod (14) is inserted into the second mounting hole (131); the sensor trigger connecting rod (25) is movably inserted into the first mounting hole (111); and one end of the sensor trigger connecting rod (25) away from the driven gear (12) extends out of the lead screw driving rod (11) and is fixedly mounted on the inner wall of the rotating push rod (21); the sensor trigger connecting rod (25) is capable of contacting and cooperating with the sensing rod (14).

2. A long-stroke nut push rod device according to claim 1, characterized in that: The second mounting hole (131) is a stepped hole, the end of the sensing rod (14) has a rod cap (141) which is stop-matched with the end of the screw rod of the transmission screw (13), a spring (15) is movably sleeved on the rod body of the sensing rod (14), and the two ends of the spring (15) are respectively stop-matched with the end surface of the rod cap (141) and the shoulder of the stepped hole of the second mounting hole (131).

3. A long-stroke nut push rod device according to claim 2, characterized in that: The main transmission mechanism (1) further comprises a sliding sleeve (16), wherein the middle portion of the sliding sleeve (16) comprises a third mounting hole (161) for sliding and frictionally engaging with the lead screw drive rod (11), and the exterior of the sliding sleeve (16) comprises a first external thread (162) for threaded engagement with the first sliding hole (211).

4. A long-stroke nut push rod device according to claim 3, characterized in that: The nut push rod mechanism (2) further comprises a rotating cylinder outer cylinder barrel (26), wherein the rotating cylinder outer cylinder barrel (26) is fixedly sleeved on the outer wall of the lead screw nut barrel (23).

5. A long-stroke nut push rod device according to claim 4, characterized in that: The main transmission mechanism (1) further comprises a first bearing (171) fixedly sleeved on the lead screw drive rod (11) between the driven gear (12) and the rotating push rod (21); a bearing race (172) is fixedly sleeved on the outer ring of the first bearing (171); the outer wall of the bearing race (172) comprises a stepped portion for positioning and matching with the inner wall of the outer cylinder barrel (26) of the rotating cylinder.

6. A long-stroke nut push rod device according to claim 5, characterized in that: The invention also comprises an angle adjustment mechanism (3), the angle adjustment mechanism (3) comprising an inner ring of a front bearing of an outer cylinder (31) and an inner ring of a universal joint (32); the inner ring of the front bearing of the outer cylinder (31) is threadedly connected to the outer wall of the outer cylinder (26) of the rotating cylinder away from the driven gear (12), and the outer wall of the inner ring of the front bearing of the outer cylinder (31) has at least one first annular groove (311) along the circumferential direction; the inner ring of the universal joint (32) is sleeved on the outside of the inner ring of the front bearing of the outer cylinder (31), and the inner wall of the inner ring of the universal joint (32) has at least one second annular groove (322) along the circumferential direction, and the first annular groove (311) and the second annular groove (322) are combined to form a track for the movement of the steel ball group (34).

7. A long-stroke nut push rod device according to claim 6, characterized in that: The angle adjustment mechanism (3) further comprises a universal joint frame (33); the outer wall of the universal joint inner ring (32) is provided with at least one clamping portion (321) extending outward; the universal joint frame (33) is sleeved outside the universal joint inner ring (32); a clamping hole (331) for clamping and cooperating with a corresponding clamping portion (321) is provided on a frame body of the universal joint frame (33); and at least one trunnion seat (332) is connected to the frame body of the universal joint frame (33).

8. A long-stroke nut push rod device according to claim 7, characterized in that: The nut push rod mechanism (2) further comprises a front guide sleeve (27), the front guide sleeve (27) being slidably sleeved on the outer wall of an end of the rotary push rod (21) away from the driven gear (12), and the front guide sleeve (27) being fixedly connected to the inner ring (31) of the front bearing of the outer cylinder.

9. A long-stroke nut push rod device according to claim 8, characterized in that: The end of the rotary push rod (21) away from the driven gear (12) has a fourth mounting hole (213) in communication with the first sliding hole (211); the inner wall of the fourth mounting hole (213) has a shrinkage hole portion (214) for limited engagement with the end of the sensor trigger connecting rod (25); and a mounting plug (215) for sealed engagement with the end surface of the sensor trigger connecting rod (25) is provided in the fourth mounting hole (213) outside the sensor trigger connecting rod (25).

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