A servo hydraulic cylinder piston rod anti-rotation device

Abstract

The invention discloses a piston rod rotation prevention device of a servo hydraulic cylinder. The servo hydraulic cylinder comprises a base, a protection barrel and a lower end cover, wherein the protection barrel is installed on the base, the lower end cover is installed on the protection barrel, and the lower end of a piston rod is placed in the protection barrel. The piston rod rotation prevention device comprises a rotation prevention plate in the horizontal direction and a guide rod in the vertical direction. The rotation prevention plate is fixedly installed at the lower end of the piston rod. A vertical through hole for allowing the guide rod to penetrate through is formed in the rotation prevention plate. The two ends of the guide rod are installed on the lower end cover and the base respectively. The guide rod penetrates through the vertical through hole and is located in interlayer space between the piston rod and the protection barrel. The guide rod structure is additionally arranged in the protection barrel, the goal of preventing the piston rod from rotating is achieved, the appearance size of the hydraulic cylinder is not increased, the piston rod and a sealing structure of a universal hydraulic cylinder are unchanged, and therefore the influence on the characteristics of the hydraulic cylinder is small, and the hydraulic cylinder still has the advantages of being long in service life and maintenance period. The piston rod rotation prevention device is simple in structure, convenient to machine and maintain, and suitable for servo hydraulic cylinders of various models.

Description

technical field [0001] The invention relates to a piston rod anti-rotation device for a servo hydraulic cylinder, in particular to a piston rod anti-rotation device installed inside the servo hydraulic cylinder. Background technique [0002] At present, there are three structures for the anti-rotation of the piston rod of the servo hydraulic cylinder: (1) non-circular piston rod anti-rotation; (2) the guide groove processed on the piston rod, the positioning pin processed on the lower end cover, the guide groove and the Positioning pin cooperates with anti-rotation; (3) Increase anti-rotation guide rod at the top of piston rod, enlarge upper end cover and process guide hole on upper end cover, guide rod and guide hole cooperate anti-rotation. [0003] The respective characteristics and defects of the above three traditional structures are as follows: [0004] (1) Adopt non-circular piston rod anti-rotation structure: it has minimal impact on the performance of the hydraulic...

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Problems solved by technology

[0004] (1) Non-circular piston rod anti-rotation structure: it has minimal impact on the performance of the hydraulic cylinder, can be used without maintenance, has a long service life, and does not need to increase the size of the hydraulic cylinder, but its processing cost is high, and special design guidance is required And sealing, not universal, currently less use of this method;

[0005] (2) Using guide groove and positioning pin anti-rotation structure: Although the processing requirements are low, an additional guide stroke needs to be added. The friction between the guide groove and the positioning pin is large, which has a great impact on the performance of the hydraulic cylinder. It will cause the positioning pin to heat up, cause the positioning pin to deform and accelerate wear, and its service life is short. Once damaged, it is not easy to repair, so it is only suitable for hydraulic cylinders that run at low speed and have a short working stroke;

[0006] (3) The top of the piston rod is used to increase the anti-rotation guide rod anti-rotation structure: the processing requirements are low. After the guide ring is lubricated, its friction and mechanical wear can be reduced to a satisfactory level, but this structure not only increases the hydraulic cylinder. Dimensions, and because the guide rod and the guide ring are in an open environment, the lubricating oil is easy to enter the dust and volatilize. Once it is not maintained in time, the friction between the guide rod and the guide ring will increase, which will affect the performance of the hydraulic cylinder. Characterizes and accelerates mechanical wear of guide rods and guide rings

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