A shaft center anti-rotation sleeve oil cylinder

Abstract

The utility model discloses a kind of axle center anti-rotation sleeve oil cylinder, including central structural member and the outer side of sequentially superimposed sleeve of several barrel;The inner wall of the barrel is equipped with annular cavity, the outer wall of the central structural member and the barrel is equipped with annular piston structure, the annular piston structure is slidably matched in adjacent the annular cavity, constitutes hydraulic unit;The barrel is equipped with radial extension piece, the central structural member and the barrel are equipped with axially extending guide slot, the radial extension piece is slidably matched in adjacent the guide slot, to limit relative circumferential rotation.The utility model is integrated in the built-in anti-rotation mechanism of barrel wall, the mechanism is while realizing efficient circumferential limiting, completely not extra occupies radial space, to realize the high compactness on the overall structure of hydraulic cylinder.

Description

Technical Field

[0001] This utility model relates to the field of hydraulic actuator technology, and in particular to a shaft anti-rotation sleeve cylinder. Background Technology

[0002] Hydraulic cylinders, as common hydraulic actuators, are widely used in various engineering machinery and industrial equipment. Traditional single-stage piston hydraulic cylinders have limited strokes. To obtain a longer working stroke, the cylinder length usually needs to be increased, making them difficult to use in applications with limited installation space. Multi-stage sleeve hydraulic cylinders achieve long strokes by axially stacking sleeves, but their radial dimensions are difficult to control. Traditional hydraulic cylinders typically have one or more anti-rotation pins axially fixed at one end of the piston. The protruding part of this anti-rotation pin is precisely embedded in an axial groove at the end of the cylinder or a specific location to achieve anti-rotation. However, the anti-rotation pin must be robust enough to withstand the shear force generated by the anti-rotation torque, which occupies radial space. At the same time, the pressure-bearing strength of the piston structure itself must be ensured, resulting in limitations on the overall radial compactness of the structure. The additional anti-rotation parts further increase the complexity of the structure and the difficulty of assembly, contradicting the goal of compact design. Therefore, there is an inherent contradiction between the anti-rotation design of existing multi-stage hydraulic cylinders and the requirement for compactness. Summary of the Invention

[0003] Purpose of the invention: In order to overcome the shortcomings of the existing technology, this utility model provides a shaft anti-rotation sleeve cylinder. Through the built-in anti-rotation mechanism integrated into the cylinder wall, the mechanism can achieve efficient circumferential limiting without occupying any additional radial space, thereby achieving a highly compact overall structure of the hydraulic cylinder.

[0004] Technical Solution: To achieve the above objectives, this utility model provides a axial anti-rotation sleeve cylinder, comprising a central structural component and several cylinders sequentially stacked and fitted onto its outer side; the inner wall of each cylinder is provided with an annular cavity, and the outer walls of the central structural component and the cylinders are provided with an annular piston structure, the annular piston structure being slidably fitted into adjacent annular cavities to form a hydraulic unit; each cylinder is provided with a radial extension, and the central structural component and the cylinders are provided with axially extending guide grooves, the radial extension being slidably fitted into adjacent guide grooves to restrict relative circumferential rotation.

[0005] Furthermore, the cylinder includes a wall portion and an end cap. One end of the wall portion is provided with a countersunk hole, and the end cap is installed in the countersunk hole and forms the annular cavity with the inner wall of the countersunk hole.

[0006] Furthermore, the guide groove is located at the end of the cylinder away from the end cap.

[0007] Furthermore, the guide groove has an opening on the end face of the cylinder, and the radial extension can be inserted into the guide groove through the opening.

[0008] Furthermore, the radial extension is detachably connected to the cylindrical body.

[0009] Furthermore, the radial extension is a pin structure, the cylinder has a radial hole for insertion, the outer end of the radial extension is provided with an end cap, and it is fixed to the cylinder by fasteners.

[0010] Furthermore, the inner end of the radial extension is provided with two parallel limiting surfaces for fitting against the two side walls of the guide groove.

[0011] Furthermore, the outer wall of the cylinder is provided with a positioning groove that matches the shape of the end cap. When the end cap is installed in the positioning groove, the limiting surface is parallel to the axis of the cylinder.

[0012] Beneficial Effects: This utility model discloses a axial anti-rotation sleeve cylinder, which adopts a sleeve nesting design and an annular piston mating with the annular cavity. This integrates multiple hydraulic units within a radially overlapping space, significantly reducing the axial dimension in the retracted state while ensuring a large stroke. Furthermore, the radial extension and guide groove are integrated within the cylinder wall thickness, achieving a concealed anti-rotation function. This means the outer diameter of the hydraulic cylinder is determined solely by strength and sealing requirements, eliminating the need to reserve any additional radial dimension for the anti-rotation mechanism. This results in a highly compact overall structure.

[0013] By integrating the piston function with the cylinder structure and the anti-rotation function with the connecting parts, a high degree of structural integration is achieved, reducing the number of parts, manufacturing costs, and assembly complexity.

[0014] The design of the guide groove end opening and the detachable radial extension allows the cylinder to be assembled and disassembled sequentially from the axial direction, simplifying the assembly process and facilitating subsequent maintenance and seal replacement.

[0015] The built-in anti-rotation mechanism also serves as an axial guide, achieving two goals at once. This further eliminates the need for external guide components, simplifies the overall structure, and improves compactness. Attached Figure Description

[0016] Figure 1 This is a schematic cross-sectional view of one embodiment of the present invention. Detailed Implementation

[0017] The present invention will be further described below with reference to the accompanying drawings.

[0018] As attached Figure 1The aforementioned axial anti-rotation sleeve cylinder comprises a central structural component 1 and multiple (in the figure, a single-stage example) cylinders 2. These cylinders 2 are sequentially fitted onto the outside of the central structural component 1 in order of increasing diameter. The central structural component 1 can be a rod-shaped or cylindrical structure, used to connect with the object to be driven, thereby forming a rod-shaped or cylindrical multi-stage hydraulic cylinder to adapt to different application scenarios.

[0019] Each cylinder 2 has an annular cavity 3 machined into its inner wall, while an outwardly protruding annular piston structure 4 is formed on the central structural component 1 and the outer wall of each cylinder 2. Each annular piston structure 4 is slidably fitted and sealed within the annular cavity 3 of the adjacent outer cylinder 2, thus forming an independent hydraulic unit 5. By introducing hydraulic oil into different annular cavities 3, the corresponding annular piston structure 4 can be driven to move, thereby realizing the progressive extension or retraction of each stage of the cylinder 2. The design of nested sleeves and annular pistons fitting with annular cavities integrates multiple hydraulic units in a radially overlapping space, greatly shortening the axial dimension in the retracted state while ensuring a large stroke.

[0020] To prevent relative rotation of each stage of the cylinder 2 during expansion and contraction, this design incorporates an anti-rotation mechanism. This anti-rotation mechanism consists of a radial extension 6 and an axial guide groove 7, and is completely contained within the projected wall thickness of the cylinder.

[0021] like Figure 1 As shown, a radial extension 6 is installed on the wall portion 21 of each cylinder 2. A guide groove 7 extending axially is machined on the central structural member 1 and the outer wall of each cylinder 2. The radial extension 6 slidably fits into adjacent guide grooves 7 to restrict relative circumferential rotation. For any two adjacent stages, the inner end of the radial extension 6 on the outer member is slidably embedded in the guide groove 7 on the inner member (which may be the central structural member 1 or the inner cylinder 2). The side walls of the guide groove 7 form a circumferential constraint on the radial extension 6, thereby effectively transmitting torque and preventing rotation. Based on this, no other components need to be installed on the annular piston structure 4; only the overall thickness needs to meet the pressure-bearing strength, and the radial dimension is effectively compressed.

[0022] In summary, both the radial extension 6 and the guide groove 7 are integrated within the space of the cylinder wall thickness, achieving a "stealth" effect for the anti-rotation function. This allows the outer diameter of the hydraulic cylinder to be determined solely by strength and sealing requirements, eliminating the need to reserve any additional radial dimensions for the anti-rotation mechanism. Consequently, the entire hydraulic actuator achieves extreme compactness in both the axial and radial directions.

[0023] In a preferred embodiment, the cylinder 2 adopts a split design, including a wall portion 21 and an end cap 22. One end of the wall portion 21 has a countersunk hole, and the end cap 22 is fixed in the countersunk hole by means of threads or welding. The inner end face of the end cap 22 and the inner stepped surface of the countersunk hole together form the annular cavity 3 for accommodating the upper-stage annular piston structure 4. This structure facilitates machining and the installation of seals. This makes the hydraulic actuator of this solution a modular structure, which can be freely selected or modified into a multi-stage hydraulic cylinder with different numbers of stages as needed. While achieving the largest possible stroke or greater flexibility and controllability, its radial and axial dimensions in the contracted state are greatly reduced, meeting the design requirements of compactness and suitable for applications with limited installation space.

[0024] The guide groove 7 is preferably located at the end of the cylinder 2 away from the end cap 22. The guide groove 7 has an opening on the end face of the cylinder 2, allowing the radial extension 6 to be inserted into the guide groove 7 through the opening. This design allows the inner component (the assembled single-stage or multi-stage hydraulic cylinder) to be axially inserted into the outer cylinder 2 with a countersunk hole during assembly. This allows the inner end of the radial extension 6 to naturally slide into the guide groove 7, achieving synchronous integration and assembly of the anti-rotation function. Once the outermost piston structure of the inner component falls into the countersunk hole at the end of the outer cylinder 2, the end cap is installed to complete the final assembly. The entire installation process is simple and quick, and easy to modularly modify.

[0025] The radial extension 6 is detachably connected to the cylindrical body 2. Specifically, the radial extension 6 is a pin structure, and the cylindrical body 2 has a radial hole for insertion. The radial extension 6 is inserted into this hole from the outside, and the outer end of the radial extension 6 is provided with an end cap 61. The end cap 61 is pressed against the outer wall of the cylindrical body 2 by a fastening screw, thereby achieving fixation. This structure facilitates disassembly and maintenance. The pin is replaced periodically to maintain its stable anti-rotation function.

[0026] To ensure a good limiting effect, the inner end of the radial extension 6 extending into the guide groove 7 is machined to have two mutually parallel limiting surfaces 62. These two limiting surfaces 62 are in close contact with the two side surfaces of the guide groove 7, providing more stable torsional resistance through planar contact.

[0027] To ensure that the limiting surface 62 of the radial extension 6 is parallel to the axis after installation, a positioning groove 23 adapted to the shape of the end cap 61 is machined on the outer cylindrical surface of the cylinder 2. During installation, the end cap 61 is first placed into the positioning groove 23 and then tightened with screws. This ensures that the circumferential angle of the radial extension 6 is correct, thereby ensuring that the limiting surface 62 fits perfectly with the side wall of the guide groove 7. This design not only ensures anti-rotation rigidity but also incorporates all connecting structures within the cylinder contour, avoiding any form of radial protrusion.

[0028] Working principle:

[0029] The hydraulic drive process is no different from that of a conventional multi-stage cylinder. As high-pressure oil drives each stage of the cylinder to extend sequentially, the built-in anti-rotation mechanism works synchronously: the radial extension 6 slides within the axial guide groove 7, allowing free axial movement, but strictly restricting circumferential rotation through the contact of the limiting surface 62 with the groove wall. Throughout the entire process, this mechanism remains hidden within the cylinder wall, requiring zero external radial space.

[0030] The above are merely preferred embodiments 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. A shaft anti-rotation sleeve hydraulic cylinder, characterized in that: It includes a central structural component (1) and several cylindrical bodies (2) that are stacked and fitted on its outer side in sequence; The inner wall of the cylinder (2) is provided with an annular cavity (3), and the outer wall of the central structural component (1) and the cylinder (2) is provided with an annular piston structure (4). The annular piston structure (4) is slidably fitted into the adjacent annular cavity (3) to form a hydraulic unit (5). The cylinder (2) is provided with a radial extension (6), and the central structural member (1) and the cylinder (2) are provided with axially extending guide grooves (7). The radial extension (6) is slidably fitted into the adjacent guide grooves (7) to restrict relative circumferential rotation.

2. The shaft anti-rotation sleeve cylinder according to claim 1, characterized in that: The cylinder (2) includes a wall portion (21) and an end cap (22). One end of the wall portion (21) is provided with a countersunk hole, and the end cap (22) is installed in the countersunk hole and forms the annular cavity (3) with the inner wall of the countersunk hole.

3. The shaft anti-rotation sleeve cylinder according to claim 2, characterized in that: The guide groove (7) is located at one end of the cylinder (2) away from the end cap (22).

4. The shaft anti-rotation sleeve cylinder according to claim 3, characterized in that: The guide groove (7) has an opening on the end face of the cylinder (2), and the radial extension (6) can be inserted into the guide groove (7) through the opening.

5. A shaft anti-rotation sleeve cylinder according to claim 4, characterized in that: The radial extension (6) is detachably connected to the cylinder (2).

6. A shaft anti-rotation sleeve cylinder according to claim 5, characterized in that: The radial extension (6) is a pin structure, the cylinder (2) is provided with a radial hole for insertion, and the outer end of the radial extension (6) is provided with an end cap (61) and is fixed to the cylinder (2) by fasteners.

7. A shaft anti-rotation sleeve cylinder according to claim 6, characterized in that: The inner end of the radial extension (6) is provided with two parallel limiting surfaces (62) for fitting with the two side walls of the guide groove (7).

8. A shaft anti-rotation sleeve cylinder according to claim 7, characterized in that: The outer wall of the cylinder (2) is provided with a positioning groove (23) that matches the shape of the end cap (61). When the end cap (61) is installed in the positioning groove (23), the limiting surface (62) is parallel to the axis of the cylinder (2).

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