A balanced guide screw-driven two-stage rotary thrust cylinder

Abstract

This invention discloses a balanced, guided, helical-driven two-stage rotary thrust cylinder, belonging to the field of hydraulic cylinder technology. It includes: a cylinder B with an oil port at one end; a helical guide sleeve fixedly connected to one end of the cylinder; a secondary piston rod disposed within the cylinder, one end of which is fixedly connected to piston A, and the other end is connected to the helical guide sleeve via a trapezoidal thread; a primary piston rod disposed within the secondary piston rod, one end of which is fixedly connected to piston B, and the other end connected to a piston rod head; and a guide rod disposed within the primary piston rod, the guide rod being hollow, with its end near the piston rod head closed and fixedly connected to piston C, and one end of the hollow inner cavity of the guide rod serving as the oil port A. The advantages of this invention compared to existing technologies are: the primary piston rod achieves linear telescopic motion, the secondary piston rod achieves rotary telescopic linear motion, and the primary and secondary piston rods together achieve sequential telescopic and long-stroke technical actions.

Description

Technical Field

[0001] This invention relates to the field of hydraulic cylinder technology, specifically to a balanced guide screw-driven two-stage rotary thrust cylinder. Background Technology

[0002] Hydraulic cylinders, as the actuators of hydraulic systems, are widely used in engineering machinery due to their simple transmission structure, flexible operation, and ability to transmit force.

[0003] Conventional hydraulic cylinders are mostly ordinary double-acting hydraulic cylinders, which can only provide thrust and pull force on one side. However, in applications such as the leveling mechanism of aerial work platforms that require rotational output force, a long stroke rotational output force with a small installation space is needed, along with meeting various complex load conditions and stability requirements. Traditional mechanical products generally achieve the above-mentioned rotational force output function not through hydraulic pressure conversion, but through electric motors. However, electric motors often have limited output force, making it difficult to provide large rotational power and achieve effective locking.

[0004] Meanwhile, the installation of ordinary multi-stage hydraulic cylinders is often limited by their own space and material specifications, and the power oil circuit and pressure range provided by the system are relatively limited. Therefore, it is difficult to have a highly stable output force structure and cannot realize the rotational movement of the rod.

[0005] Currently, there are no hydraulic cylinders in mechanical main units or structural components that can achieve the above functions. Most are combined splicing structures with complex rotary conversion mechanisms. They generally adopt a single-stage cylinder structure and vertical rotation output (i.e., through a screw and ball screw structure, the motion mode is converted through a transmission type). The structure is complex, prone to jamming during transmission, and the force cannot be achieved on the same piston rod, resulting in relatively low stability. The system needs to provide multiple power sources, requires many external oil circuits, occupies a lot of space, and cannot reduce the weight of the main unit, thus failing to achieve the purpose of energy saving and consumption reduction. Summary of the Invention

[0006] The present invention addresses the technical problems mentioned in the background section by providing a balanced guide screw-driven two-stage rotary thrust cylinder, which can achieve stable stiffness of the rod and high-load output telescopic motion, while saving installation space, improving overall cylinder stability, and enhancing mechanical locking safety.

[0007] The technical solution provided by this invention is as follows: a balanced guide spiral driven two-stage rotary thrust cylinder, comprising: a cylinder barrel, one end of which is provided with an oil port B; a spiral guide sleeve fixedly connected to one end of the cylinder barrel; a secondary piston rod disposed within the cylinder barrel, one end of which is fixedly connected to a piston A, and the other end is connected to the spiral guide sleeve via a trapezoidal thread, the piston A being disposed within the cylinder barrel and slidably connected to the cylinder barrel; a primary piston rod disposed within the secondary piston rod, one end of which is fixedly connected to a piston B, and the other end connected to a piston rod head; and a guide rod disposed within the primary piston rod, the guide rod having a hollow structure, the end of which near the piston rod head is closed and fixedly connected to a piston C, the piston C being disposed within the primary piston rod and slidably connected to it, the hollow inner cavity of the guide rod having an oil port A at one end.

[0008] Furthermore, the guide rod is slidably connected to piston B.

[0009] Furthermore, the guide rod is fixedly connected to the cylinder bottom.

[0010] Furthermore, the piston rod head is connected to the structural components of the application scenario.

[0011] Furthermore, the oil port B is connected to the inner cavity of the secondary piston rod at the end of the primary piston rod.

[0012] Furthermore, the oil port B is connected to the cylinder cavity at the end of the secondary piston rod.

[0013] Furthermore, the oil port A is connected to the inner cavity of the guide rod, and the inner cavity of the guide rod is connected to the inner cavity of the first-stage piston rod between piston B and piston C.

[0014] The advantages of this invention compared to existing technologies are as follows: 1. It realizes a two-stage piston rod thrust telescopic structure, which can solve and achieve ultra-long stroke under limited installation space conditions, meeting the requirements of large stroke; 2. The first-stage piston rod realizes linear telescopic motion, and the second-stage piston rod realizes rotary telescopic linear motion. The first and second-stage piston rods together realize sequential telescopic and long stroke technical actions; 3. An oil return passage is provided inside the first-stage piston rod, which can realize the retraction motion of the thrust cylinder, thus reducing the external oil passage and effectively reducing the space occupied; 4. The screw drive can achieve good positioning accuracy, realize the rotation of the rod body, and especially realize mechanical locking in the case of loss of oil pressure, ensuring the safety and sealing of the piston rod body under heavy load movement, and facilitating disassembly and assembly.

[0015] The advantages of this invention are as follows: 1. With the assistance of the internal support guide rod, the first-stage piston rod can achieve bilateral stability during rod movement, improving stability by 40% compared to single-sided support, meeting the high stability requirements under different thrust magnitudes, and enhancing the rigidity of the piston rod; 2. The first-stage piston rod has oil flowing through its inner cavity, which also increases the stability of the rod. Because of the oil inside the cavity, the inner wall of the cavity does not need to undergo anti-corrosion internal plating treatment, saving on electroplating processes and costs; 3. In addition to the piston seal support at one end, the second-stage piston rod is connected to the thrust cylinder guide sleeve screw at the other end. The smoothness of the screw drive is the most stable among force and motion transmissions. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of a balanced guide screw-driven two-stage rotary thrust cylinder structure according to an embodiment of the present invention.

[0017] In the attached diagram: 1. Oil port A; 2. Oil port B; 3. Piston A; 4. Piston B; 5. Guide rod; 6. First-stage piston rod; 7. Second-stage piston rod; 8. Cylinder; 9. Piston C; 10. Guide sleeve; 11. Piston rod head; 12. Cylinder bottom. Detailed Implementation

[0018] The present invention will now be described in further detail with reference to the accompanying drawings.

[0019] like Figure 1 As shown, in this embodiment, the entire thrust cylinder consists of a cylinder barrel 8, a first-stage piston rod 6, a second-stage piston rod 7, a cylinder bottom 12, pistons at each stage, and a guide sleeve 10. When there is pressurized oil, the linear motion extension and retraction of the first-stage piston rod 6 and the rotary linear motion extension and retraction of the first and second-stage piston rods 7 can be realized, thereby generating thrust and achieving stable power output.

[0020] One end of the internal guide rod 5 is fixedly connected to the cylinder bottom 12, and the other end is fixed to the guide piston C9. Its rod body can extend and retract within the piston B to achieve support and guidance. The guide rod 5 has a hollow structure, and the left end of the hollow inner cavity of the guide rod 5 is the oil port A1.

[0021] The end of the first-stage piston rod 6 is connected to the piston rod head 11. The piston rod head 11 can be connected to other structures (referring to the cylinder and the mechanism or structural component to be connected to it, which is the active component in the application of this cylinder). With its pistons B4 and C9 as guides, supports and seals, it realizes the telescopic action. The inner cavity of the first-stage piston rod 6 between pistons B4 and C9 is connected to the inner cavity of the guide rod 5. The guide rod 5 is slidably connected to the piston B4.

[0022] One end of the secondary piston rod 7 is fixedly connected to the piston A3, and the other end is connected to the guide sleeve 10 through a trapezoidal thread to realize the rotational extension and retraction of the rod body. The piston A3 is located inside the cylinder 8 and is slidably connected to the cylinder 8.

[0023] The left end of the cylinder 8 is provided with an oil port B2, which is connected to the inner cavity of the second-stage piston rod 7 at the left end of the first-stage piston rod 6. The oil port B2 is connected to the inner cavity of the cylinder 8 at the left end of the second-stage piston rod 7.

[0024] Based on the different hydraulic pressure conditions required for the extension of the first and second stage piston rods 7, the first and second stage piston rods 7 can achieve sequential extension and retraction.

[0025] In specific implementation of this invention:

[0026] like Figure 1 As shown, the hydraulic cylinder has a cylinder bottom 12 and a piston rod head 11 at its two ends, which are connected to the structural components of the application scenario. This structure consists of a central support guide rod inside the thrust cylinder, a primary piston rod 6, and a secondary trapezoidal spiral piston rod. The central support guide rod can be circulated with hydraulic oil; one end is fixed to the cylinder bottom 12, and the other end has a piston, which supports and guides the primary piston rod 6. Simultaneously, oil circulation within the rod allows the primary piston rod 6 to retract. The primary piston rod 6 has a closed inner cavity and a guide sleeve 10 at one end for sealing and guiding. The rod can extend under hydraulic pressure, and a detachable spherical end face is provided at the end of the rod for contact connection with structural components. The secondary piston rod 7 has a piston at one end, which seals the hydraulic fluid and provides support and guidance. The entire rod has trapezoidal transmission threads that cooperate with the thrust cylinder guide sleeve 10. Under the thrust of the hydraulic fluid, it performs a screw-feed rotational motion, exhibiting high stability and smoothness. Under pressure holding conditions, the first and second stage piston rods 7 can always be in the output state, and due to the screw screw and helical engagement, they can be effectively mechanically locked.

[0027] When the piston rod needs to move to the right to generate thrust, hydraulic oil enters through port B2. The oil enters the main cylinder's large chamber through the oil passage at the bottom of the cylinder 12. Under the action of pressure difference, it pushes the piston B4 to move to the right, thereby pushing the entire first-stage piston rod 6 to move to the right.

[0028] At the same time, when the first-stage piston rod 6 extends to a certain load or fully extends, the pressure increases, pushing the piston A3 to the right, which in turn pushes the second-stage piston rod 7 to rotate and extend.

[0029] Conversely, when the thrust cylinder needs to retract, oil enters through port A1 and returns through port B2. The oil flows through the guide rod 5 into the inner cavity of the first-stage piston rod 6, pushing the first-stage piston rod 6 to retract. When it reaches the end of its stroke, it further pushes the second-stage piston rod 7 to retract, thus achieving one cycle of motion.

[0030] When stationary, the secondary piston rod 7 achieves self-locking under the action of the trapezoidal thread.

[0031] In summary, the advantages of this invention are: it allows for the selection of appropriate configurations to meet the diverse needs of various mechanical hosts or mechanisms under different operating conditions, achieving both rotary and linear feed thrust requirements; its stability and mechanical locking reliability are its outstanding features; its simple structure reduces the system's requirements for hydraulic circuits, eliminating the need for multiple external hydraulic lines (inlet and return), thus reducing the system's power source and achieving energy saving and consumption reduction; simultaneously, due to the innovative support and guide design, the piston rod experiences more uniform force, improving its stability, and the oil-filled inner cavity design of the piston rod increases its rigidity, making it less prone to bending. The overall structure is easy to assemble and disassemble, highly maintainable, occupies little space, and effectively reduces system weight.

[0032] As can be seen from the above description, the present invention provides a balanced guide screw-driven two-stage rotary thrust cylinder. The screw drive in this thrust cylinder has the smoothest stability among force and motion transmissions. At the same time, the screw drive can achieve excellent positioning accuracy, realize the rotation of the rod, and especially realize mechanical locking in the case of loss of oil pressure, ensuring the safety and sealing of the piston rod under heavy load movement, providing a good solution for systems with rotary output requirements.

[0033] Although embodiments of the invention have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the claims and their equivalents.

Claims

1. A balanced guide screw-driven two-stage rotary thrust cylinder, characterized in that, include: Cylinder (8), one end of which is provided with oil port B (2); A spiral guide sleeve (10) is fixedly connected to one end of the cylinder (8); A secondary piston rod (7) is provided inside the cylinder (8). One end of the secondary piston rod (7) is fixedly connected to a piston A (3), and the other end is connected to a spiral guide sleeve (10) through a trapezoidal thread. The piston A (3) is provided inside the cylinder (8) and is slidably connected to the cylinder (8). A first-stage piston rod (6) is provided inside the second-stage piston rod (7). One end of the first-stage piston rod (6) is fixedly connected to a piston B (4), and the other end is connected to a piston rod head (11). A guide rod (5) is provided inside the first-stage piston rod (6). The guide rod (5) has a hollow structure. One end of the guide rod (5) near the piston rod head (11) is closed and fixedly connected to a piston C (9). The piston C (9) is provided inside the first-stage piston rod (6) and is slidably connected to it. One end of the hollow inner cavity of the guide rod (5) is an oil port A (1). The guide rod (5) is slidably connected to the piston B (4); The guide rod (5) is fixedly connected to the cylinder bottom (12); The oil port B (2) is connected to the inner cavity of the secondary piston rod (7) at the end of the primary piston rod (6); The oil port B (2) is connected to the inner cavity of the cylinder (8) at the end of the secondary piston rod (7); The oil port A (1) is connected to the inner cavity of the guide rod (5), and the inner cavity of the guide rod (5) is connected to the inner cavity of the first-stage piston rod (6) between piston B (4) and piston C (9).

2. The balanced guide screw-driven two-stage rotary thrust cylinder according to claim 1, characterized in that: The piston rod head (11) is connected to the structural components of the application scenario.

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