Anti-impact electric cylinder

Abstract

The utility model provides an anti-impact electric cylinder, which belongs to the technical field of engineering machinery and comprises a lead screw pair mounted in an outer pipe, a lead screw in the lead screw pair is driven by a servo motor to rotate, the lead screw drives a nut to do reciprocating rectilinear motion along the surface of the lead screw when rotating, a connecting pipe is fixed at the upper end of the nut, and a push rod is sleeved at the upper end of the lead screw. The push rod is matched with an extension block at the upper end of the connecting pipe in a hooking and pulling mode, the surface of the connecting pipe is sleeved with a compression spring, the upper end of the compression spring makes contact with the lower end face of the push rod, and when the nut pushes the push rod to do forward linear movement through the compression spring, impact energy can be absorbed and converted into elastic potential energy; direct damage of impact to core components such as a lead screw pair and a gear pair is effectively reduced, component failure caused by impact is avoided, and the service life of the electric cylinder under the high-impact working condition is remarkably prolonged.

Description

Technical Field

[0001] This utility model relates to the field of engineering machinery technology, specifically to an impact-resistant electric cylinder. Background Technology

[0002] An electric cylinder is a precision mechatronic device that converts electrical energy into linear motion. It uses a servo motor to drive a lead screw or belt drive mechanism to convert rotary motion into high-precision, controllable linear displacement. As a typical representative of modern linear motion mechanisms, electric cylinders have been widely used in many important fields such as industrial processing, simulation instruments, medical machinery, and engineering vehicles. With the continuous expansion of application fields, the working conditions of electric cylinders are becoming more and more complex. In recent years, fields such as engineering machinery have also been gradually replacing hydraulic cylinders with electric cylinders. Their working conditions are characterized by multiple impacts, such as excavators, bulldozers, and crushers, which means that electric cylinders need to withstand large impact loads during operation.

[0003] However, due to its rigid mechanical connection transmission characteristics, most existing electric cylinders do not have the ability to buffer impacts and cannot directly drive heavy loads and withstand impact loads, which greatly limits their use in impact-resistant applications.

[0004] In moving equipment such as excavators, the push rod of the electric cylinder will be subjected to impact loads multiple times during its movement. These repeated high-intensity impact loads will be transmitted to the inside of the electric cylinder through the push rod, causing failure of the force-bearing components of the electric cylinder, affecting the performance of the force-bearing components, and reducing the service life of the electric cylinder. Utility Model Content

[0005] In view of this, the present invention provides an impact-resistant electric cylinder. When the push rod is subjected to a reverse impact load, the impact energy is absorbed by the compression spring and converted into elastic potential energy, which effectively reduces the direct damage of the impact to core components such as the lead screw pair and gear pair, avoids component failure caused by impact, and significantly extends the service life of the electric cylinder under high impact conditions.

[0006] To solve the above-mentioned technical problems, this utility model provides an impact-resistant electric cylinder, including a lead screw assembly installed inside an outer tube. The lead screw in the lead screw assembly is driven to rotate by a servo motor. The nut forms a linear sliding fit with the inner wall of the outer tube through a key block. When the lead screw rotates, it drives the nut to reciprocate linearly along the surface of the lead screw. A connecting tube is fixed to the upper end of the nut. An extension block extends outward from the upper end of the connecting tube. A push rod is sleeved on the upper end of the lead screw. The push rod forms a hook-pull fit with the extension block at the upper end of the connecting tube. A compression spring is sleeved on the surface of the connecting tube. The upper end of the compression spring is connected to the push rod. When the lower end faces are in contact, and the nut moves forward in the direction of the push rod, the nut drives the push rod to move forward synchronously through the compression spring. If the push rod is subjected to a reverse impact force during its movement, the push rod can compress the compression spring with the cooperation of the compression spring, so that the compression spring absorbs the impact energy and converts it into elastic potential energy to buffer the impact on the push rod. Subsequently, when the nut moves back to its original position on the screw surface, the compression spring rebounds, and at the same time, the nut drives the connecting tube to move synchronously. The connecting tube hooks the push rod through its outer extension block, so that the connecting tube can drive the push rod to its original position.

[0007] The push rod has an internal cavity, through which it is fitted onto the surface of the lead screw. The lower end face of the push rod has an inner extension block that hooks and engages with the outer extension block on the upper end face of the connecting tube. This creates a meshing engagement between the inner extension block of the push rod and the outer extension block of the connecting tube. When the nut moves back to its original position and causes the compression spring to rebound, the nut drives the connecting tube to move synchronously. The hooking and engaging between the outer extension block of the connecting tube and the inner extension block of the push rod allows the connecting tube to drive the push rod to its original position.

[0008] A transmission mechanism is provided at the lower end of the outer tube. The servo motor drives the lead screw in the lead screw pair to rotate through the gear transmission mechanism.

[0009] The gear transmission mechanism includes a primary gear pair and a secondary gear pair, each consisting of two meshing gears. The primary gear pair is connected to the output shaft of the servo motor, and the secondary gear pair is connected to the lead screw of the lead screw pair. When the output shaft of the servo motor rotates, it drives the two meshing gears in the primary gear pair to rotate, causing one gear in the secondary gear pair, which is linked by the connecting shaft, to rotate synchronously. This causes the two gears in the secondary gear pair to drive the lead screw to rotate, which in turn drives the nut in the lead screw pair to move axially.

[0010] The gear transmission mechanism also includes a gearbox housing located at the lower end of the outer tube, a secondary gear pair located on the upper side of one side of the housing, and one of the gears of the secondary gear pair connected to the lower end of the lead screw. The secondary gear pair is located on the lower side of the other side of the housing, and a servo motor is mounted on the upper side of the gearbox housing. The servo motor drives the lead screw to rotate through the primary gear pair and the secondary gear pair.

[0011] The gearbox is equipped with a thrust bearing, which bears the axial force generated by the lead screw during rotation, making the lead screw rotation process more stable. There is also a bearing on one side of the gearbox, and the bearing on the output shaft of the servo motor can improve the stability of the servo motor movement.

[0012] The gearbox body and the outer tube are connected by bolts. The outer ring surface at both ends of the outer tube has through holes, and the gearbox body has threaded holes at the contact positions with the through holes of the outer ring. After the screw is passed through the through holes of the outer ring, it is threaded into the threaded holes of the gearbox body. The outer tube is installed on the housing. The detachable connection between the outer tube and the housing makes the whole equipment easier to maintain later.

[0013] The bottom of the gearbox body is bolted to a gearbox cover. The outer surface of the gearbox cover also has a through hole. The bottom of the gearbox body has a threaded hole that fits into the through hole of the gearbox cover. After the screw is passed through the through hole of the gearbox cover, it is threaded into the threaded hole of the gearbox body, thus completing the splicing and installation of the gearbox cover and the gearbox body, thereby further improving the convenience of later maintenance of the equipment.

[0014] The outer wall of the outer tube is equipped with a trunnion, which is hinged to the machine body, such as a crusher, bulldozer, or excavator. The upper end of the push rod is fixed with a movable support lug, which is connected to a moving part of the machine body, such as the robotic arm of an excavator. The movable support lug can be installed on a designated moving part of the machine body for operation.

[0015] The connecting pipe and the nut are connected by a threaded fit. The inner wall of the nut has an internal thread surface, and the lower end of the outer side of the connecting pipe has an external thread surface that matches the internal thread surface of the nut. This allows the connecting pipe to be threaded into the nut through the external thread surface, making it easy to assemble and disassemble.

[0016] In summary, compared with the prior art, this application includes at least one of the following beneficial technical effects:

[0017] 1. When this utility model is used, a compression spring is set on the upper end of the nut of the lead screw pair. When the push rod is subjected to reverse impact load, the compression spring is compressed to absorb the impact energy and convert it into elastic potential energy. This effectively reduces the direct damage of the impact to the core components such as the lead screw pair and gear pair, avoids component failure caused by impact, and significantly extends the service life of the electric cylinder under high impact conditions.

[0018] 2. When this utility model is used, the gear transmission mechanism adopts a design in which the first-stage gear pair and the second-stage gear pair are linked by a connecting shaft. It works in conjunction with the thrust bearing and the servo motor output shaft bearing in the gearbox. The thrust bearing bears the axial load of the lead screw and prevents the lead screw from moving, while the servo motor bearing reduces the resistance of the output shaft. The two work together to ensure smooth power transmission, reduce transmission error, and improve the motion accuracy and reliability of the electric cylinder.

[0019] 3. When using this utility model, the outer tube and the gearbox body are detachably connected by bolts. The bottom of the gearbox body is equipped with a detachable gearbox cover. During maintenance, there is no need to disassemble the entire equipment. Only the bolts need to be removed to separate the gearbox body from the outer tube and open the cover. This facilitates the lubrication, replacement or repair of internal components such as gear pairs and bearings, greatly reducing maintenance costs and time.

[0020] 4. When this utility model is used, the outer wall of the outer tube is provided with a trunnion hinged to the machine body, and the movable support ear at the upper end of the push rod is connected to the moving parts of the machine body to form a hinged installation structure, which allows the electric cylinder to swing flexibly with the body under complex working conditions, adapting to the high-frequency impact scenarios of engineering machinery such as crushers and bulldozers, while meeting the installation space and motion trajectory requirements of different equipment. Attached Figure Description

[0021] Figure 1 This is a schematic diagram of the structure of Embodiment 1 of the present utility model;

[0022] Figure 2 This is an enlarged schematic diagram of the structure at point A in Embodiment 1 of this utility model;

[0023] Figure 3 This is a schematic diagram of the structure of Embodiment 2 of this utility model;

[0024] Figure 4 This is a schematic diagram of the structure of Embodiment 3 of this utility model.

[0025] Explanation of reference numerals in the attached figures:

[0026] 100. Outer tube; 101. Trunnion; 200. Lead screw; 300. Nut; 400. Servo motor; 500. Push rod; 501. Moving support lug; 600. Connecting pipe; 601. Compression spring; 602. Tension spring; 700. Gearbox body; 701. Primary gear transmission; 702. Secondary gear pair; 703. Thrust bearing; 704. Bearing; 800. Gearbox cover. Detailed Implementation

[0027] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the following will be described in conjunction with the accompanying drawings of the embodiments of this utility model. Figure 1 The technical solutions of the embodiments of this utility model are clearly and completely described herein. Obviously, the described embodiments are only some, not all, of the embodiments of this utility model. All other embodiments obtained by those skilled in the art based on the described embodiments of this utility model are within the protection scope of this utility model.

[0028] Example 1:

[0029] An impact-resistant electric cylinder, such as Figure 1 and Figure 2 As shown: It includes an outer tube 100, inside which a lead screw pair is installed. The lead screw pair consists of a lead screw 200 and a nut 300 that are threaded together. The lead screw 200 is driven to rotate by a servo motor 400. The outer wall of the nut 300 is provided with a guide key, and the inner wall of the outer tube 100 is provided with a sliding groove that matches the guide key. When the lead screw 200 rotates, it drives the nut 300 to reciprocate linearly along the surface of the lead screw 200. A connecting tube 600 is fixed to the upper end of the nut 300. An extension block extends outward from the upper end of the connecting tube 600. A push rod 500 is sleeved on the upper end of the lead screw 200. The push rod 500 forms a hook-and-pull engagement with the extension block at the upper end of the connecting tube 600. A compression spring 601 is sleeved on the surface of the connecting tube 600. The upper end of the compression spring 601 abuts against the lower end of the push rod 500, and the lower end of the compression spring 601 abuts against the upper end of the nut 300.

[0030] When the nut 300 moves forward toward the push rod 500, the nut 300 drives the push rod 500 to move forward synchronously via the compression spring 601. If the push rod 500 is subjected to a reverse impact force during its movement, the push rod 500 can compress the compression spring 601 with the cooperation of the compression spring 601 to convert the impact energy into elastic potential energy for storage, thereby reducing damage to mechanical parts such as the lead screw pair, bearing 704, and gear pair. When the reverse impact on the push rod 500 disappears, the compression spring 601 will release the stored elastic potential energy under its own elastic force, thus playing a buffering role to protect the lead screw pair and other internal parts. Subsequently, when the nut 300 moves in the reverse reset direction on the surface of the lead screw 200, the compression spring 601 rebounds, and at the same time, the nut 300 drives the connecting tube 600 to move synchronously. The connecting tube 600 hooks the push rod 500 through its extension block, enabling the connecting tube 600 to drive the push rod 500 to reset.

[0031] Specifically, the push rod 500 has an internal cavity, which is sleeved on the surface of the lead screw 200. The lower end face of the push rod 500 has an inner extension block that hooks and engages with the outer extension block of the upper end face of the connecting pipe 600, creating a meshing fit between the inner extension block of the push rod 500 and the outer extension block of the connecting pipe 600. When the nut 300 pushes the push rod 500 to move via the compression spring 601, and the push rod 500 is subjected to an impact force in the opposite direction of movement, the push rod... The rod 500 compresses the spring 601, and the push rod 500 slides on the surface of the connecting tube 600, so that the connecting tube 600 guides the push rod 500 to improve the stability of the moving process of the connecting tube 600. When the nut 300 returns to its original position and causes the spring 601 to rebound, the nut 300 drives the connecting tube 600 to move synchronously. Through the mutual hooking of the outer extension block of the connecting tube 600 and the inner extension block of the push rod 500, the connecting tube 600 can drive the push rod 500 to return to its original position.

[0032] Furthermore, the connecting pipe 600 and the nut 300 are connected by a threaded connection. The inner wall of the nut 300 has an internal thread surface, and the lower end of the outer side of the connecting pipe 600 has an external thread surface that matches the internal thread surface of the nut 300, so that the connecting pipe 600 is threadedly connected to the nut 300 through the external thread surface, which facilitates disassembly and assembly.

[0033] according to Figure 1 As shown, a transmission mechanism is provided at the lower end of the outer tube 100. The servo motor 400 drives the lead screw 200 in the lead screw pair to rotate through the transmission mechanism. The transmission mechanism can be a gear transmission or a synchronous belt transmission. In this embodiment, a gear transmission is used. When the output end of the servo motor 400 rotates, it drives the lead screw 200 to rotate through the transmission mechanism.

[0034] Specifically, the gear transmission mechanism includes a primary gear pair and a secondary gear pair 702. Each of the primary gear pair and the secondary gear pair 702 consists of two meshing gears. One of the gears in the primary gear pair is connected to the output shaft of the servo motor 400, and one of the gears in the secondary gear pair 702 is connected to the lead screw 200 of the lead screw pair. The other gear in the primary gear pair and the other gear in the secondary gear pair 702 are connected to each other through a connecting shaft.

[0035] When the output shaft of the servo motor 400 rotates, it drives the two meshing gears in the primary gear pair to rotate, causing one gear in the secondary gear pair 702, which is linked by the connecting shaft, to rotate synchronously. This causes the two gears in the secondary gear pair 702 to drive the lead screw 200 to rotate, which in turn drives the nut 300 in the lead screw pair to move axially.

[0036] Specifically, the gear transmission mechanism also includes a gearbox 700, which is located at the lower end of the outer tube 100. A secondary gear pair 702 is located on the upper side of one side of the gearbox, and one of the gears of the secondary gear pair 702 is connected to the lower end of the lead screw 200. The secondary gear pair 702 is located on the lower side of the other side of the gearbox, and the servo motor 400 is installed on the upper side of the gearbox 700.

[0037] Specifically, a thrust bearing 703 is installed inside the gearbox 700. The outer ring of the thrust bearing 703 is fixed to the inner wall of the gearbox, while the end of the lead screw 200 is fixed to the inner ring of the thrust bearing 703. The thrust bearing 703 bears the axial force generated by the lead screw 200 during rotation, making the rotation of the lead screw 200 more stable. A bearing 704 is also provided on one side inside the gearbox 700, and the bearing 704 is sleeved on the output shaft of the servo motor 400. The bearing 704 on the output shaft of the servo motor 400 can improve the stability of the movement of the servo motor 400.

[0038] according to Figure 1As shown, the gearbox body 700 and the outer tube 100 are connected by bolts. The two ends of the outer tube 100 have outer rings. The surface of the outer rings is provided with through holes, and the gearbox body 700 is provided with threaded holes at the contact positions with the through holes of the outer rings. After the screws are passed through the through holes of the outer rings, they are threaded into the threaded holes of the gearbox body 700. The housing is used to install the outer tube 100. The detachable connection between the outer tube 100 and the housing makes the overall equipment easier to maintain later.

[0039] Specifically, the bottom of the gearbox body 700 is bolted to the gearbox cover 800. The outer surface of the gearbox cover 800 also has a through hole. The bottom of the gearbox body 700 has a threaded hole that fits into the through hole of the gearbox cover 800. After the screw is passed through the through hole of the gearbox cover 800, it is threaded into the threaded hole of the gearbox body 700, thus completing the splicing and installation of the gearbox cover 800 and the gearbox body 700, thereby further improving the convenience of later maintenance of the equipment.

[0040] according to Figure 1 As shown, the outer wall of the outer tube 100 is provided with a trunnion 101, which is hinged to the machine body. The machine body can be, for example, a crusher, bulldozer, or excavator. The upper end of the push rod 500 is fixed with a movable support ear 501, which is connected to the moving parts of the machine body, such as the mechanical arm of an excavator. If rotation is required, the movable support ear 501 can be installed in the moving parts of the designated machine body.

[0041] Example 2:

[0042] according to Figure 3 As shown, the difference from Embodiment 1 is that in this embodiment, the compression spring 601 in Embodiment 1 is replaced with a tension spring 602, and the tension spring 602 is set at the hooking position of the outer extension block of the connecting tube 600 and the inner extension block of the push rod 500.

[0043] The upper end of the tension spring 602 is fixed to the outer extension block of the connecting tube 600, and the lower end of the tension spring 602 is fixed to the inner extension block of the push rod 500. When the nut 300 drives the connecting tube 600 to move forward in the direction of the push rod 500, the connecting tube 600 will drive the push rod 500 to move synchronously through the tension spring 602. If the push rod 500 is subjected to a reverse impact force in the direction of movement, the push rod 500 will stop moving, while the nut 300 and the connecting tube 600 will continue to move, thereby causing the outer extension block of the connecting tube 600 and the inner extension block of the push rod 500 to move away from each other, thus stretching the tension spring 602. The tension force of the tension spring 602 is used to buffer the impact force on the push rod 500. By setting the tension spring 602 inside the push rod 500, the push rod 500 and the connecting tube 600 can protect the tension spring 602.

[0044] Example 3:

[0045] according to Figure 4 As shown, the difference from Embodiment 1 and Embodiment 2 is that in this embodiment, tension spring 602 and compression spring 601 are used simultaneously. Tension spring 602 is set at the hook position of the outer extension block of connecting tube 600 and the inner extension block of push rod 500, and compression spring 601 is sleeved on the outer surface of connecting tube 600. When push rod 500 moves and is subjected to a reverse impact force, push rod 500 and connecting tube 600 stretch tension spring 602 and compress compression spring 601, thereby achieving double buffering and improving the buffering effect.

[0046] The above description is the preferred embodiment of this utility model. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of this utility model, and these improvements and modifications should also be considered within the protection scope of this utility model.

Claims

1. An impact-resistant electric cylinder, comprising a lead screw assembly installed within an outer tube (100), wherein the lead screw (200) in the lead screw assembly is driven to rotate by a servo motor (400), and when the lead screw (200) rotates, it drives a nut (300) to reciprocate linearly along the surface of the lead screw (200), characterized in that: A connecting tube (600) is fixed to the upper end of the nut (300), and a push rod (500) is sleeved on the upper end of the lead screw (200). The push rod (500) forms a hook-and-pull engagement with the outer extension block at the upper end of the connecting tube (600). A compression spring (601) is sleeved on the surface of the connecting tube (600). The upper end of the compression spring (601) is in contact with the lower end face of the push rod (500). When the nut (300) pushes the push rod (500) to move linearly in the forward direction through the compression spring (601), when the push rod (500) is subjected to reverse impact pressure during its movement, the push rod (500) can compress the compression spring (601). When the nut (300) moves linearly in the reverse direction on the surface of the lead screw (200), the connecting tube (600) hooks and pulls with the push rod (500) through its outer extension block, and the connecting tube (600) can drive the push rod (500) to reset.

2. The impact-resistant electric cylinder as described in claim 1, characterized in that: The push rod (500) has a cavity inside, and the push rod (500) is sleeved on the surface of the lead screw (200) through the cavity. The lower end face of the push rod (500) is provided with an inner extension block that hooks and engages with the outer extension block of the upper end face of the connecting pipe (600).

3. The impact-resistant electric cylinder as described in claim 1, characterized in that: The lower end of the outer tube (100) is provided with a transmission mechanism, and the servo motor (400) drives the lead screw (200) in the lead screw pair to rotate through the transmission mechanism.

4. The impact-resistant electric cylinder as described in claim 3, characterized in that: The gear transmission mechanism includes a primary gear pair and a secondary gear pair (702). The primary gear pair is connected to the output shaft of the servo motor (400), and the secondary gear pair (702) is connected to the lead screw (200) of the lead screw pair.

5. The impact-resistant electric cylinder as described in claim 4, characterized in that: The gear transmission mechanism also includes a gearbox (700), the first-stage gear pair and the second-stage gear pair (702) are respectively disposed on both sides inside the gearbox (700), and the servo motor (400) is installed on the upper side of the gearbox (700).

6. The impact-resistant electric cylinder as described in claim 5, characterized in that: A thrust bearing (703) is provided inside the gearbox (700), and the thrust bearing (703) is sleeved on the end of the lead screw (200) in the lead screw pair. A bearing (704) is also provided on one side inside the gearbox (700), and the bearing (704) is sleeved on the output shaft of the servo motor (400).

7. The impact-resistant electric cylinder as described in claim 5, characterized in that: The gearbox body (700) is connected to the outer tube (100) by bolts.

8. The impact-resistant electric cylinder as described in claim 5, characterized in that: The bottom of the gearbox body (700) is bolted to a gearbox cover (800).

9. The impact-resistant electric cylinder as described in claim 1, characterized in that: The outer wall of the outer tube (100) is provided with a trunnion (101), which is hinged to the body. The upper end of the push rod (500) is fixed with a movable support (501), which is connected to the moving part of the body.

10. An impact-resistant electric cylinder as described in claim 1, characterized in that: The connecting pipe (600) and the nut (300) are connected by a threaded connection.

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