Circulating type tail end heavy-load electric cylinder

Abstract

The invention discloses a circulating type tail end large-load electric cylinder, and relates to the technical field of electric cylinders. Comprising a cylinder body, an inner cavity of the cylinder body is provided with a guide limiting groove, the guide limiting groove is formed in the axial direction of the inner side wall of the cylinder body in a folded-back mode, and the guide limiting groove extends in the circumferential direction of the cylinder body and is communicated end to end; the piston rod is matched with the cylinder body and is of a hollow structure; the screw mechanism comprises a non-self-locking lead screw and a nut assembly, the non-self-locking lead screw is installed in the cylinder body and can be arranged in the cavity of the piston rod in a penetrating mode, the non-self-locking lead screw can rotate along the axis of the non-self-locking lead screw, the nut assembly is matched with the non-self-locking lead screw, the nut assembly is connected with the piston rod, and the non-self-locking lead screw can rotate along the axis of the non-self-locking lead screw. The nut assembly is provided with a guide protrusion, and the guide protrusion is matched with the guide limiting groove. Wherein the guide protrusion abuts against one side of the guide limiting groove and can circularly move in the length direction of the guide limiting groove. According to the invention, a large load can be borne at the tail end of the stroke.

Description

Technical Field

[0001] This invention relates to the field of electric cylinder technology, and specifically to a cyclic end-load electric cylinder. Background Technology

[0002] An electric cylinder is a linear actuator that converts the rotational motion of a motor shaft into the linear extension and retraction motion of a push rod through a lead screw and nut pair. It is widely used in automation fields that require precise linear motion, such as industrial robots, CNC machine tools, production line automation, testing equipment (vibration tables, fatigue testing), military equipment (servo motors, hatches), medical devices, and stage entertainment equipment.

[0003] Existing electric cylinders directly bear negative pressure (both compressive and non-compressive) through the lead screw and nut. The load they can withstand throughout the entire extension and retraction stroke depends on the strength of the lead screw and nut, making it impossible to withstand a larger load at a specific position during the extension and retraction stroke. If it is necessary to bear the load during the stroke, a corresponding locking mechanism must be configured to lock the lead screw and nut and prevent relative rotation between them. However, such mechanisms are complex and inconvenient for the maintenance and repair of electric cylinders. Summary of the Invention

[0004] To address the technical problem that existing electric cylinders cannot withstand large loads, this invention provides a cyclic end-load electric cylinder. Through the cooperation of the guide protrusion and the cylinder guide groove, it can withstand large loads at the end of the stroke. It also features a simple structure, high reliability, and easy maintenance.

[0005] This invention is achieved through the following technical solution:

[0006] This invention provides a cyclic end-load electric cylinder, comprising: a cylinder body with a guide limiting groove on the inner cavity sidewall, the guide limiting groove being axially folded back along the inner sidewall of the cylinder body and extending circumferentially along the cylinder body and communicating head-to-tail; a piston rod adapted to the cylinder body and having a hollow structure; and a helical mechanism including a non-self-locking screw and a nut assembly, the non-self-locking screw being installed in the cylinder body and capable of passing through the cavity of the piston rod, and the non-self-locking screw being rotatable along its own axis, the nut assembly being adapted to the non-self-locking screw and connected to the piston rod, and the nut assembly having a guide protrusion adapted to the guide limiting groove; wherein, during the process of the non-self-locking screw driving the nut assembly to move axially, the guide protrusion abuts against the side of the guide limiting groove away from the helix angle of the non-self-locking screw, and is capable of cyclically moving along the length direction of the guide limiting groove.

[0007] The present invention provides a circulating end-load electric cylinder, comprising a cylinder body, a piston rod, and a screw mechanism. The inner cavity sidewall of the cylinder body is provided with a guide limiting groove that is connected end to end and axially reversed. The non-self-locking screw of the screw mechanism is installed in the cylinder body and passes through the cavity of the piston rod. The nut assembly is adapted to the non-self-locking screw and connected to the piston rod. At the same time, the guide protrusion of the nut assembly is adapted to the guide limiting groove.

[0008] When the non-self-locking screw rotates in the forward direction, the guide protrusion abuts against the guide limiting groove on the side away from the helix angle of the non-self-locking screw under the action of the non-self-locking screw thread, so that the nut assembly cannot rotate with the non-self-locking screw. Thus, the rotation of the non-self-locking screw drives the nut assembly to move axially, thereby driving the piston rod to extend. When the guide protrusion moves to the end of the extension stroke, the guide protrusion is located at the connection between the axial section and the return section of the guide limiting groove. The side wall of the guide limiting groove no longer limits the guide protrusion. Under the action of the non-self-locking screw thread, the nut assembly rotates with the non-self-locking screw, causing the guide protrusion to move to the return section. At this time, the non-self-locking screw stops rotating. Under the action of internal pressure load, the guide protrusion abuts against the side wall of the return section of the guide limiting groove, thereby providing support for the piston rod through the cylinder body, so that the entire electric cylinder has sufficient compressive load resistance.

[0009] When the piston rod needs to retract, the non-self-locking screw is controlled to rotate in the opposite direction. The non-self-locking screw thread then confines the guide protrusion between the guide limiting groove on the side away from the non-self-locking screw helix angle and the direction of the non-self-locking screw helix angle. The nut assembly does not rotate with the non-self-locking screw, thus retracting the piston rod. When the guide protrusion reaches the end of its retraction stroke, it is located at the connection between the axial section and the return section of the guide limiting groove. The side wall of the guide limiting groove no longer limits the guide protrusion. Under the action of downward pressure or its own weight, the guide protrusion rotates relative to the non-self-locking screw and moves into the return section of the guide limiting groove. The non-self-locking screw stops rotating. Under the action of external tensile load, the guide protrusion abuts against the side wall of the return section of the guide limiting groove, thereby providing a limit to the piston rod through the cylinder body, ensuring the entire electric cylinder has sufficient tensile load resistance.

[0010] Since the guide limiting groove is connected end to end and is axially reversible, when the piston rod needs to be extended again, the non-self-locking screw can be rotated forward again, so that the guide protrusion can circulate within the guide limiting groove without additional control.

[0011] Therefore, this invention, through the cooperation of the guide protrusion and the cylinder guide groove, transmits the load to the cylinder, which can withstand a large load at the end of the stroke. It has excellent guiding and load-bearing capacity, so as to bear a large load in a narrow space. Compared with locking mechanism, it has a simple structure, high reliability, and is easy to maintain. It can also make electric cylinders smaller and lighter.

[0012] The extension and retraction of the piston rod are achieved entirely by the rotation of the lead screw, without the need for a switch / locking mechanism, making electrical control simpler and easier; the extension and retraction motion driven by the lead screw mechanism is smooth and without impact or vibration.

[0013] In an optional embodiment of this application, the guide limiting groove includes: a circumferential segment, which has multiple segments, the multiple circumferential segments being evenly distributed along the circumference of the cylinder body, and adjacent two circumferential segments being respectively located at both ends of the axial direction of the cylinder body; and a vertical segment, which has multiple segments, and each vertical segment is connected to adjacent two circumferential segments so that the guide limiting groove can be connected end to end, and is folded back along the inner sidewall of the cylinder body.

[0014] In an optional embodiment of this application, the arc length of the circumferential segment is greater than the axial width of the guide protrusion to ensure that the circumferential segment can provide sufficient support and limiting area for the guide protrusion.

[0015] In an optional embodiment of this application, the helical mechanism is a ball screw mechanism to reduce the frictional force during the operation of the helical mechanism, while ensuring that the guide protrusion can reliably abut against the side of the guide limiting groove away from the helical angle of the non-self-locking screw during operation.

[0016] In an optional embodiment of this application, the nut assembly includes: a lead screw nut, screwed to the non-self-locking lead screw; a connecting sleeve, spaced apart and fitted over the non-self-locking lead screw, and fixedly connected to the lead screw nut; and a guide locking member, fitted over the piston rod and the connecting sleeve, and rotatable relative to the piston rod; wherein the guide protrusion is provided on the side wall of the guide locking member to ensure that while the nut assembly can drive the piston rod to extend and retract, the guide locking member can rotate relative to the piston rod.

[0017] In an optional embodiment of this application, the nut assembly further includes a thrust bearing assembly disposed between the piston rod and the connecting sleeve, and the guide locking member is sleeved outside the thrust bearing assembly to ensure that the guide assembly can rotate stably relative to the piston rod.

[0018] In an optional embodiment of this application, a drive assembly is further included. The drive assembly is connected to the non-self-locking screw and is capable of driving the non-self-locking screw to rotate along its own axis, so as to directly drive the piston rod to extend and retract via the drive assembly.

[0019] In an optional embodiment of this application, a cylinder head and a cylinder seat are respectively adapted to the two axial ends of the cylinder body, and the drive assembly is mounted on the cylinder seat.

[0020] In an optional embodiment of this application, the drive assembly includes: a drive motor mounted on the cylinder base and arranged parallel to the cylinder body; and a transmission mechanism mounted on the cylinder base and connected to the drive motor and the non-self-locking screw respectively, to ensure that the drive assembly can drive the piston rod to extend and retract.

[0021] In an optional embodiment of this application, the drive assembly further includes a speed reducer connected between the drive motor and the transmission mechanism to reduce the speed of the drive motor and increase the torque.

[0022] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0023] 1. The present invention provides a circulating end-load electric cylinder, comprising a cylinder body, a piston rod, and a screw mechanism. The inner cavity sidewall of the cylinder body is provided with a guide limiting groove that is connected end-to-end and axially reversible. The non-self-locking screw of the screw mechanism is installed in the cylinder body and passes through the cavity of the piston rod. The nut assembly is adapted to the non-self-locking screw and connected to the piston rod. At the same time, the guide protrusion of the nut assembly is adapted to the guide limiting groove. During the axial movement of the nut assembly driven by the non-self-locking screw, the guide protrusion abuts against the side of the guide limiting groove away from the helix angle of the non-self-locking screw and can move along the length of the guide limiting groove. The cylinder moves in a cyclic motion. When the guide protrusion reaches the end of its extended stroke, it abuts against the side wall of the guide limiting groove's return section, providing support to the piston rod via the cylinder body. When the guide protrusion reaches the end of its retracted stroke, it abuts against the side wall of the guide limiting groove's return section, again limiting the piston rod via the cylinder body. This ensures the entire electric cylinder has sufficient tensile and compressive load resistance, exhibiting excellent guiding and load-bearing capacity, enabling it to withstand large loads in confined spaces. Compared to locking mechanisms, it features a simpler structure, higher reliability, and easier maintenance, allowing for miniaturization and weight reduction of the electric cylinder.

[0024] 2. The cyclic end high-load electric cylinder provided by the present invention achieves the extension and retraction of the piston rod entirely by the rotation of the lead screw, without the need for a switch / locking mechanism, making electrical control simpler and easier; the extension and retraction motion driven by the lead screw mechanism is smooth and without impact or vibration. Attached Figure Description

[0025] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0026] In the attached diagram:

[0027] Figure 1 This is an exploded structural diagram of a cyclic end-load electric cylinder provided in an embodiment of the present invention;

[0028] Figure 2 A schematic diagram of the force transmission process in the extension and retraction state of a cyclic end-load electric cylinder provided in an embodiment of the present invention;

[0029] Figure 3 This is a schematic diagram of the cylinder block unfolding structure and the guide protrusion movement process provided in an embodiment of the present invention;

[0030] Figure 4 A schematic diagram of the force transmission process after the extension and locking of a cyclic end-load electric cylinder provided in an embodiment of the present invention;

[0031] Figure 5 This is a schematic diagram of the force transmission process after the retraction and locking of a cyclic end-load electric cylinder provided in an embodiment of the present invention.

[0032] The attached diagram shows the markings and corresponding component names:

[0033] 1-Cylinder block, 2-Guide limiting groove, 2a-Circumferential section, 2b-Vertical section, 3-Piston rod, 4-Non-self-locking screw, 5-Screw nut, 6-Connecting sleeve, 7-Guide locking component, 8-Guide protrusion, 9-Thrust bearing assembly, 10-Cylinder head, 11-Bushing, 12-Cylinder seat, 13-Drive motor, 14-Transmission mechanism, 15-Reducer.

[0034] Specific implementation party

[0035] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. It should be noted that similar reference numerals and letters in the following drawings indicate similar items. Therefore, once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings.

[0036] In the description of the embodiments of this application, the indicated orientation or positional relationship is based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship that the device of this application is usually placed in when in use, or the orientation or positional relationship that is commonly understood by those skilled in the art. It is only for the convenience of describing this application and simplifying the description, and is not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation of this application.

[0037] In the description of this application, unless otherwise expressly specified and limited, the terms "set up," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0038] It should be noted that the load-bearing capacity of existing electric cylinders depends on the strength of the lead screw and nut, making it difficult to bear large loads in confined spaces and achieve miniaturization and weight reduction. To address this, the inventors have creatively proposed a cyclic, high-load-bearing end-effector electric cylinder, which solves the aforementioned problems. The specific technical solution is as follows: Example

[0039] Combination Figure 1 , Figure 2 and Figure 3 This embodiment provides a cyclic end-load electric cylinder, comprising: a cylinder body 1, with a guide limiting groove 2 provided on the inner cavity sidewall, the guide limiting groove 2 being axially folded back along the inner sidewall of the cylinder body 1, and the guide limiting groove 2 extending circumferentially along the cylinder body 1 and communicating head-to-tail; a piston rod 3, adapted to the cylinder body 1, having a hollow structure; and a screw mechanism, including a non-self-locking screw 4 and a nut assembly, the non-self-locking screw 4 being installed inside the cylinder body 1 and capable of passing through the cavity of the piston rod 3, and the non-self-locking screw 4 being... The self-locking screw 4 can rotate along its own axis. The nut assembly is adapted to the non-self-locking screw 4. The nut assembly is connected to the piston rod 3, and the nut assembly is provided with a guide protrusion 8. The guide protrusion 8 is adapted to the guide limiting groove 2. During the process of the non-self-locking screw 4 driving the nut assembly to move axially, the guide protrusion 8 abuts against the side of the guide limiting groove 2 away from the helix angle of the non-self-locking screw 4, and can move cyclically along the length direction of the guide limiting groove 2.

[0040] It is understood that this embodiment also includes a drive assembly, which is connected to the non-self-locking screw 4 and can drive the non-self-locking screw 4 to rotate along its own axis so as to directly drive the piston rod 3 to extend and retract through the drive assembly.

[0041] Recombined Figure 1 The cylinder body 1 has a cylinder head 10 and a cylinder seat 12 adapted to its two axial ends, respectively, and the drive assembly is mounted on the cylinder seat 12. The piston rod 3 can pass through the middle of the cylinder head 10, and the piston rod 3 is fitted with a bushing 11, which is mounted on one end of the cylinder body 1 through the cylinder head 10. One end of the piston cylinder is usually provided with a connecting lug to facilitate the connection of corresponding structural components.

[0042] Combination Figure 3 The guide limiting groove 2 includes: a circumferential segment 2a, which is provided in multiple segments, and the multiple circumferential segments 2a are evenly distributed along the circumference of the cylinder body 1, and adjacent two circumferential segments 2a are respectively located at the two ends of the axial direction of the cylinder body 1; and a vertical segment 2b, which is provided in multiple segments, and each vertical segment 2b is connected to two adjacent circumferential segments 2a so that the guide limiting groove 2 can be connected end to end, and is folded back along the inner sidewall of the cylinder body 1.

[0043] Preferably, the arc length of the circumferential segment 2a is greater than the axial width of the guide protrusion 8, so as to ensure that the circumferential segment 2a can provide sufficient support and limiting area for the guide protrusion 8.

[0044] It should be understood that the spiral mechanism is a ball screw mechanism to reduce the frictional force during the operation of the spiral mechanism, and at the same time, to ensure that the guide protrusion 8 can reliably abut against the side of the guide limiting groove 2 away from the helix angle of the non-self-locking screw 4 during operation.

[0045] Combination Figure 2 The nut assembly includes: a lead screw nut 5, which is screwed to the non-self-locking lead screw 4; a connecting sleeve 6, which is spaced out and fitted around the non-self-locking lead screw 4 and fixedly connected to the lead screw nut 5; and a guide locking member 7, which is fitted around the piston rod 3 and the connecting sleeve 6 and is rotatable relative to the piston rod 3; wherein, the guide protrusion 8 is provided on the side wall of the guide locking member 7 to ensure that the nut assembly can drive the piston rod 3 to extend and retract while the guide locking member 7 can rotate relative to the piston rod 3.

[0046] In this embodiment, the nut assembly further includes a thrust bearing assembly 9 (such as a thrust roller combination bearing), the thrust bearing assembly 9 is disposed between the piston rod 3 and the connecting sleeve 6, and the guide locking member 7 is sleeved outside the thrust bearing assembly 9 to ensure that the guide assembly can rotate stably relative to the piston rod 3.

[0047] It is understood that the drive assembly includes: a drive motor 13, mounted on the cylinder base 12 and arranged parallel to the cylinder body 1; and a transmission mechanism 14 (such as a gear mechanism, pulley, sprocket mechanism, etc.), mounted on the cylinder base 12 and respectively connected to the drive motor 13 and the non-self-locking screw 4, to ensure that the drive assembly can drive the piston rod 3 to extend and retract, and to make the electric cylinder parallel / reverse type, thereby shortening the overall length of the electric cylinder, making the structure more compact, and the installation more flexible.

[0048] Of course, the drive assembly also includes a speed reducer 15, which is connected between the drive motor 13 and the transmission mechanism 14 to reduce the speed of the drive motor 13 and increase the torque.

[0049] That is, the electric cylinder uses electricity as the direct power source, and the screw is driven to rotate by a motor and a reducer 15. The screw nut 5 and the guide locking member 7 are fixed together by screws. The rotational movement of the guide locking member 7 is restricted by the limiting effect of the guide limit inside the cylinder body 1, so that the helical motion of the screw can be converted into the linear motion of the nut assembly. The guide locking member 7 and the piston rod 3 transmit power to the piston rod 3 through a thrust roller combination bearing, which can ensure that the guide locking member 7 and the piston rod 3 can rotate relative to each other.

[0050] In summary, the circulating end-load electric cylinder provided in this embodiment includes a cylinder body 1, a piston rod 3, a screw mechanism, and a drive assembly. The inner cavity sidewall of the cylinder body 1 is provided with a guide limiting groove 2 that is connected end to end and axially reversed. The non-self-locking screw 4 of the screw mechanism is installed in the cylinder body 1 and passes through the cavity of the piston rod 3. The nut assembly is adapted to the non-self-locking screw 4 and connected to the piston rod 3. At the same time, the guide protrusion 8 of the nut assembly is adapted to the guide limiting groove 2. The drive assembly is connected to the screw mechanism for transmission.

[0051] Combination Figure 2 The force transmission route during the extension and retraction of piston rod 3 is as follows: drive motor 13 → reducer → driving pulley → driven pulley → non-self-locking screw 4 → screw nut 5 → connecting sleeve 6 → thrust bearing assembly 9 → piston rod 3 → load.

[0052] Combination Figure 4 When the electric cylinder extends and locks, the load force transmission route is as follows: load → piston rod 3 → thrust bearing assembly 9 → connecting sleeve 6 → lead screw nut 5 → screw → guide locking component 7 → cylinder body 1 → cylinder seat 12 → mounting bracket.

[0053] Combination Figure 5 When the electric cylinder retracts and locks, the load force transmission route is: load → piston rod 3 → guide locking component 7 → cylinder body 1 → cylinder seat 12 → mounting bracket.

[0054] Specifically:

[0055] When the non-self-locking screw 4 rotates in the forward direction, the guide protrusion 8 abuts against the side of the guide limiting groove 2 away from the helix angle of the non-self-locking screw 4 under the action of the thread of the non-self-locking screw 4, so that the nut assembly cannot rotate with the non-self-locking screw 4. Thus, the rotation of the non-self-locking screw 4 drives the nut assembly to move axially, thereby driving the piston rod 3 to extend. When the guide protrusion 8 moves to the end of the extension stroke, the guide protrusion 8 is located at the connection between the axial section and the return section of the guide limiting groove 2. The side wall of the guide limiting groove 2 no longer limits the guide protrusion 8. Under the action of the thread of the non-self-locking screw 4, the nut assembly rotates with the non-self-locking screw 4, causing the guide protrusion 8 to move to the return section. At this time, the non-self-locking screw 4 stops rotating. Under the action of the internal pressure load, the guide protrusion 8 abuts against the side wall of the return section of the guide limiting groove 2, thereby providing support for the piston rod 3 through the cylinder body 1, so that the entire electric cylinder has sufficient compressive load resistance.

[0056] When the piston rod 3 needs to retract, the non-self-locking screw 4 is controlled to rotate in the opposite direction. Under the action of the thread of the non-self-locking screw 4, the guide protrusion 8 is limited between the side of the guide limiting groove 2 away from the helix angle of the non-self-locking screw 4 and the direction of the helix angle of the non-self-locking screw 4. The nut assembly does not rotate with the non-self-locking screw 4, so the piston rod 3 retracts. When the guide protrusion 8 moves to the end of the retraction stroke, the guide protrusion 8 is located at the connection between the axial section and the return section of the guide limiting groove 2. The side wall of the guide limiting groove 2 no longer limits the guide protrusion 8. Under the action of the downward pressure load or its own weight, the guide protrusion 8 rotates and moves relative to the non-self-locking screw 4 into the return section of the guide limiting groove 2. The non-self-locking screw 4 stops rotating. Under the action of the external tensile load, the guide protrusion 8 abuts against the side wall of the return section of the guide limiting groove 2, thereby providing a limit to the piston rod 3 through the cylinder body 1, so that the entire electric cylinder has sufficient tensile load resistance.

[0057] Since the guide limiting groove 2 is connected end to end and is axially reversible, when the piston rod 3 needs to be extended again, the non-self-locking screw 4 can be controlled to rotate in the forward direction again, so that the guide protrusion 8 can move cyclically in the guide limiting groove 2 without additional control.

[0058] Combination Figure 3 To facilitate understanding of the locking state of the electric cylinder, this application describes the electric cylinder body 1 unfolded into a plane. The guide limit groove 2 has a beveled sidewall to make the entire step trapezoidal, thereby increasing the contact area of ​​the guide protrusion 8. Eight contact microswitches are installed on the wall of the cylinder body 1 (installed on...). Figure 3 (At the red dot), thus accurately monitoring the position of the guide protrusion 8. Two microswitches are installed at each deceleration and locking position to increase the accuracy and reliability of motion position monitoring.

[0059] In this configuration, the guide protrusion 8 is initially stationary at position A. When the non-self-locking screw 4 begins to rotate, its helical surface (inclined surface) moves to the right, causing the guide protrusion 8 to move towards position B. It stops at position B, where it can withstand a large load. The protrusion then moves to position C, where the microswitch at point I contacts the guide protrusion 8, indicating it is in a locked state. When the large load disappears, the guide protrusion 8 unlocks, and the piston rod 3 bears the heavy working load. The guide protrusion 8 then slides on the helical surface of the non-self-locking screw 4 to position D, and the switch at point I releases. Subsequently, driven by the non-self-locking screw 4, the guide protrusion 8 slides upward along the guide surface of the guide limiting groove 2 and quickly moves to position E. After the upper deceleration point I contacts the guide protrusion 8, the program controls the drive motor 13 to reduce the transmission speed. The guide protrusion 8 moves along the guide limiting groove 2 on the inclined surface of the non-self-locking screw 4 to position F. The switch at the upper arrival point I contacts the guide protrusion 8, indicating that the guide protrusion 8 has moved to the locking point, and the drive motor 13 stops running. At this time, the guide protrusion 8 of the guide locking member 7 contacts the guide limiting groove 2 and can withstand a large pressure load. After the work is completed, the non-self-locking screw 4 rotates forward, thereby bringing the guide protrusion 8 out of the side wall of the guide limiting groove 2 and into position G. At this time, the contact switch at the upper arrival point I is disconnected. Then the program controls the non-self-locking screw 4 to start reversing, and the guide protrusion 8 will reach position H. As the non-self-locking screw 4 continues to reverse, it slides along the groove surface of the cylinder body 1 to position J, thereby entering the next cycle state.

[0060] In summary, the cyclic end-load electric cylinder provided in this embodiment transmits the load to the cylinder body 1 through the cooperation of the guide protrusion 8 and the guide groove of the cylinder body 1. It can withstand a large load at the end of the stroke and has excellent guiding and load-bearing capacity, so as to bear a large load in a narrow space. Compared with locking mechanism, it has a simple structure, high reliability, and is easy to maintain. It can also make the electric cylinder smaller and lighter.

[0061] The extension and retraction of the piston rod 3 are achieved entirely by the rotation of the lead screw, without the need for a switch / locking mechanism, making electrical control simpler and easier; the extension and retraction motion driven by the lead screw mechanism is smooth and without impact or vibration.

[0062] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above description is only a specific embodiment of the present invention and is not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A circulating end-load electric cylinder, characterized in that, include: The cylinder body (1) has a guide limiting groove (2) on its inner cavity sidewall. The guide limiting groove (2) is folded back along the inner sidewall of the cylinder body (1) and extends along the circumference of the cylinder body (1) and is connected head to tail. The piston rod (3) is adapted to the cylinder body (1) and has a hollow structure; The screw mechanism includes a non-self-locking screw (4) and a nut assembly. The non-self-locking screw (4) is installed in the cylinder (1) and can pass through the cavity of the piston rod (3). The non-self-locking screw (4) can rotate along its own axis. The nut assembly is adapted to the non-self-locking screw (4) and is connected to the piston rod (3). The nut assembly is provided with a guide protrusion (8), which is adapted to the guide limiting groove (2). During the process of the non-self-locking screw (4) driving the nut assembly to move axially, the guide protrusion (8) abuts against the side of the guide limiting groove (2) away from the helix angle of the non-self-locking screw (4) and can move cyclically along the length direction of the guide limiting groove (2).

2. The circulating end-load electric cylinder according to claim 1, characterized in that, The guide limiting groove (2) includes: The circumferential segment (2a) is provided in multiple segments, and the multiple circumferential segments (2a) are evenly distributed along the circumferential interval of the cylinder body (1), and two adjacent circumferential segments (2a) are respectively located at the two ends of the axial direction of the cylinder body (1). The vertical segment (2b) is provided in multiple segments, and each of the vertical segments (2b) is connected to two adjacent circumferential segments (2a).

3. The circulating end-load electric cylinder according to claim 2, characterized in that, The arc length of the circumferential segment (2a) is greater than the axial width of the guide protrusion (8).

4. The circulating end-load electric cylinder according to claim 1, characterized in that, The screw mechanism is a ball screw mechanism.

5. The circulating end-load electric cylinder according to claim 1, characterized in that, The nut assembly includes: The lead screw nut (5) is screwed to the non-self-locking lead screw (4); The connecting sleeve (6) is spaced out and fitted outside the non-self-locking screw (4), and is fixedly connected to the screw nut (5); The guide locking member (7) is sleeved outside the piston rod (3) and the connecting sleeve (6) and is rotatable relative to the piston rod (3); The guide protrusion (8) is disposed on the side wall of the guide locking member (7).

6. The circulating end-load electric cylinder according to claim 5, characterized in that, The nut assembly also includes a thrust bearing assembly (9), which is disposed between the piston rod (3) and the connecting sleeve (6), and the guide locking member (7) is sleeved on the thrust bearing assembly (9).

7. The cyclic end-load electric cylinder according to any one of claims 1 to 6, characterized in that, It also includes a drive assembly, which is connected to the non-self-locking screw (4) and is capable of driving the non-self-locking screw (4) to rotate along its own axis.

8. The circulating end-load electric cylinder according to claim 7, characterized in that, The cylinder body (1) is fitted with a cylinder head (10) and a cylinder seat (12) at its two axial ends, respectively, and the drive assembly is mounted on the cylinder seat (12).

9. The circulating end-load electric cylinder according to claim 8, characterized in that, The driving component includes: A drive motor (13) is mounted on the cylinder base (12) and is arranged parallel to the cylinder body (1); The transmission mechanism (14) is mounted on the cylinder seat (12) and is connected to the drive motor (13) and the non-self-locking screw (4) respectively.

10. The circulating end-load electric cylinder according to claim 9, characterized in that, The drive assembly also includes a speed reducer (15) connected between the drive motor (13) and the transmission mechanism (14).

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