The copper bushing in the hydraulic cylinders of concrete pump trucks manufactured by Sany Heavy Industry and Zoomlion Heavy Industry serves several important functions:

1. Reducing friction: The copper bushing acts as a bearing surface between the moving parts of the hydraulic cylinder, such as the piston and the cylinder barrel. It helps to minimize friction and wear between these components, allowing for smooth and efficient movement of the cylinder.

2. Providing structural support: The copper bushing provides stability and support to the hydraulic cylinder assembly. It helps to maintain proper alignment and positioning of the moving parts, ensuring reliable and consistent operation of the cylinder.

3. Absorbing shock and vibration: During the operation of the concrete pump truck, there can be substantial shock and vibration generated due to the hydraulic forces and dynamic loads. The copper bushing helps to absorb and dampen these impacts, protecting the hydraulic cylinder and other components from excessive stress and damage.

4. Facilitating heat dissipation: The copper material of the bushing has good thermal conductivity properties. It helps in dissipating heat generated during the operation of the hydraulic cylinder, preventing overheating and maintaining optimal operating temperatures.

Overall, the copper bushing in the hydraulic cylinders of concrete pump trucks plays a crucial role in ensuring smooth movement, structural integrity, shock absorption, and heat dissipation. It contributes to the reliable and efficient functioning of the hydraulic system in the pump truck.