Detailed Explanation of Hydraulic Cylinder Technical Parameters and Selection Guide

 

As the core executive component of the hydraulic system, the technical parameters of the hydraulic cylinder directly affect the performance and reliability of the equipment. This article systematically analyzes the design specifications and key technical conditions of the hydraulic cylinder to help users master the key points of selection.

 

I. Pressure Parameter Specifications

1. Nominal Pressure: The reference pressure for the long - term stable operation of the hydraulic cylinder, which needs to comply with the sequence values stipulated by industry standards, such as 16 MPa, 25 MPa, 31.5 MPa, etc.

2. Maximum Permissible Pressure: The short - term load - bearing limit pressure, usually 1.5 times the nominal pressure. In special working conditions, it can be increased to more than 2 times.

3. Test Pressure: During quality inspection, it is necessary to pass a pressure - holding test at 1.5 times the nominal pressure. The pressure - holding time should be no less than 10 minutes to ensure no leakage or deformation.

4. Working Pressure: It is dynamically adjusted according to the actual load and needs to be comprehensively designed in combination with the system flow and the requirements of the actuating mechanism.

5. Starting Pressure: The minimum pressure required when the hydraulic cylinder starts. The specification requires it to be ≤ 0.3 MPa to ensure response sensitivity.

 

II. Dimension Parameter Standards

1. Cylinder Bore Diameter: The core dimension determining the output force. Common specifications include 125 mm, 160 mm, 200 mm, etc., which need to match the system pressure and load requirements.

2. Piston Rod Diameter: It affects the pushing and pulling force and the motion stability. Typical specifications are 100 mm, 125 mm, 140 mm, etc., and the bending strength needs to be checked.

3. Stroke Accuracy: The standard stipulates that the stroke deviation should be controlled within ± 1 mm, and higher requirements are needed for precision equipment.

4. Installation Method: It includes flange type, earring type, foot type, etc. It needs to be selected according to the mechanical structure layout to ensure uniform force.

 

III. Performance Index Requirements

1. Motion Characteristics: In low - speed working conditions, it is necessary to achieve non - crawling motion. In high - speed motion, a buffer device needs to be configured to reduce the impact.

2. Leakage Control: The internal leakage should be ≤ 0.2 ml/min, and the external seals should not show leakage after 10 reciprocating motions.

3. Temperature Resistance Range: The hydraulic cylinder needs to operate stably in an environment from - 60°C to 200°C. The sealing material needs to be resistant to high temperatures and anti - aging.

4. Medium Compatibility: It is recommended to use 46# anti - wear hydraulic oil. The sealing system needs to match the chemical properties of the oil.

 

IV. Manufacturing and Inspection Specifications

1. Material Selection: The cylinder barrel is made of high - strength carbon steel, and the surface of the piston rod needs to be hard - chrome plated to improve wear resistance.

2. Cleanliness Standard: The internal cleanliness needs to reach NAS7 level or above. Ultrasonic cleaning is required before assembly.

3. Surface Treatment: Spray anti - rust primer and topcoat. The appearance should be free of defects such as scratches and bubbles.

4. Factory Test: Conduct full - item tests such as pressure resistance, leakage, and stroke according to the GB/T test method, and keep the test reports.

 

V. Design Key Points for Special Working Conditions

1. Heavy - Load Equipment: The safety factor should be ≥ 3. It is recommended to use double - acting cylinders and install displacement sensors.

2. High - Frequency Reciprocating Scenarios: Adopt a combined sealing ring and guide ring structure to reduce friction loss.

3. Corrosive Environment: Select stainless - steel materials or perform surface phosphating treatment to extend the service life.

 

The selection of hydraulic cylinders needs to comprehensively consider the pressure level, motion accuracy, environmental adaptability, and maintenance cost. It is recommended to give priority to products that meet national standards and have passed authoritative certifications. At the same time, regularly replace the seals and conduct pressure tests to ensure the long - term efficient operation of the system.