Two-stage servo hydraulic cylinder

Abstract

The invention relates to a two-stage servo hydraulic cylinder. The technical scheme is that: the hydraulic cylinder consists of a static pressure cylinder and a dynamic pressure cylinder, wherein the cylinder bodies (2) of the static pressure cylinder and the dynamic pressure cylinder are integrated; a static pressure piston rod (33) is concentrically arranged in a static pressure cavity (27) of the static pressure cylinder; the working end of the static pressure piston rod (33) passes through a left end cover (1); a static pressure piston (5) is arranged on the static pressure piston rod (33); a dynamic pressure piston rod (34) is concentrically arranged in a dynamic pressure cavity (21) of the dynamic pressure cylinder; the working end of the dynamic pressure piston rod (34) passes through a cylinder body partition wall and the hollow part of the static pressure piston rod (33); and the width of a first leakage oil annular groove (32) formed on the inner wall of a through hole of the left end cover (1) is 1.3 to 2 times the travel of the static pressure piston (5). The hydraulic cylinder has the characteristics of small friction force, high dynamic response, energy saving and capability of outputting high vibration frequency and high excitation force which change up and down near large constant force according to a certain rule.

Description

technical field [0001] The invention belongs to the technical field of hydraulic cylinders, and in particular relates to a two-stage servo hydraulic cylinder. Background technique [0002] In some working conditions, it is necessary to output a high-frequency force that changes up and down according to a certain law around a large constant force, such as 200kN±100sinωtkN, 200kN is a large constant force, and 100sinωtkN is a high-frequency dynamic force that changes according to a certain law. When the cylinder outputs this kind of force, there are the following problems: [0003] 1. Due to the large load, the natural frequency of the hydraulic cylinder becomes smaller, the response speed is poor, and it is difficult to meet the requirements of outputting high-frequency changing force; [0004] 2. The pressure in the working chamber of the hydraulic cylinder is high, the deformation of the sealing ring between the piston and the cylinder body of the hydraulic cylinder is lar...

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Problems solved by technology

[0003] 1. Due to the large load, the natural frequency of the hydraulic cylinder becomes smaller, the response speed is poor, and it is difficult to meet the requirements of outputting high-frequency changing force;

[0004] 2. The pressure in the working chamber of the hydraulic cylinder is high, the deformation of the sealing ring between the piston and the cylinder body of the hydraulic cylinder is large, and the friction between the piston and the cylinder body is large, which increases the running resistance of the piston and is difficult to meet the requirements of outputting high-frequency changing force;

[0005] 3. Due to the high frequency and large force output, the piston area of ​​the hydraulic cylinder is large, the maximum operating speed of the piston is large, and the working flow required by the hydraulic cylinder is large, which is not conducive to energy saving

[0006] Based on the above reasons, due to the large friction force and poor dynamic response, ordinary hydraulic cylinders cannot meet the requirements of high vibration frequency and high excitation force whose output changes according to a certain rule around a large constant force.

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