What are the names of the sealing rings of thrust cylinders?

2025-08-01 14:32:51

### What are the Core Differences Between Thrust cylinders and Pull Cylinders?   Although both thrust cylinders and pull cylinders belong to the category of hydraulic or pneumatic cylinders, they differ significantly in force direction, structural characteristics, and application scenarios due to their different design objectives. The core differences lie in **the direction of force action** and **structural adaptability**, and understanding these differences is crucial for correct selection.   ### Essence from the Perspective of Force Direction: Thrust vs. Pull   - **Thrust Cylinder**:    Its core function is to output **axial thrust**, that is, to push external loads when the piston rod extends. Its design focuses on enhancing the load-bearing capacity when the piston rod extends. Usually, the piston rod is thick, and the bottom of the cylinder barrel bears large pressure.    For example, the pressing action of hydraulic presses and the mold-clamping process of injection molding machines rely on thrust cylinders to provide positive pressure.   - **Pull Cylinder**:    It mainly outputs **axial pulling force**. When the piston rod retracts, it pulls the load, and the force-bearing points are concentrated at the head of the piston rod and the cylinder cover. Therefore, the connection strength between the cylinder cover and the piston rod needs special reinforcement. The piston rod may be designed to be hollow to reduce weight while ensuring tensile strength.    It is commonly used in scenarios requiring pulling actions, such as the lifting mechanism of cranes and the tensioning device of conveyor belts.   ### Targeted Structural Differences   The structural differences between the two serve their respective force-bearing characteristics, as detailed in the following comparison:   | **Comparison Item**       | **Thrust Cylinder**                              | **Pull Cylinder**                              |   |---------------------------|--------------------------------------------------|------------------------------------------------|   | **Piston Rod**            | Thick, solid, with strong bending and compression resistance | Can be hollow, slender, with high tensile strength |   | **Cylinder Barrel Bottom**| Thickened design to bear the reaction force generated by thrust | Relatively simple structure, with main force-bearing points on the cylinder cover |   | **Sealing System**        | Focus on preventing oil leakage when the piston rod extends | Focus on preventing negative pressure suction when the piston rod retracts |   | **Installation Method**   | Mostly cylinder barrel fixed (e.g., flange fixed at the bottom of the cylinder barrel) | Mostly piston rod fixed (e.g.,耳环 fixed at the piston rod end) |   ### Typical Distinctions in Application Scenarios   - **Applicable Scenarios for Thrust Cylinders**: Load driving requiring "pushing" actions, such as:    - Feeding movement of machine tools    - Closing action of gates    - Ejection and conveying of materials   - **Applicable Scenarios for Pull Cylinders**: Load driving requiring "pulling" actions, such as:    - Traction of steel wire ropes (e.g., elevator traction)    - Opening action of molds    - Tightening adjustment of tensioning devices   ### Summary: Core Differences and Key Selection Factors   The essential difference between thrust cylinders and pull cylinders lies in **the direction of force output**, which leads to targeted differences in structural design and application scenarios. When selecting, it is necessary to clarify the force direction of the load: if the load needs to be pushed, priority should be given to thrust cylinders; if the load needs to be pulled, focus on pull cylinders. Meanwhile, parameters such as load size and movement speed should be combined to match the cylinder strength and sealing performance, ensuring stable operation of the equipment.