Concrete pumps use alternating pistons that drive cups to move concrete through a boom and hose that is used to pour the concrete in the desired location. These pistons, in turn, are connected to hydraulic cylinders that are powered with high pressure oil. A hydraulic pump runs the entire set of components, delivering energy and power to pump the concrete. Normal hydraulic circuits are comprised of many components, such as the hydraulic pump, hoses, blocks, valve filters and tanks. From an engineering perspective, there are essentially two types of circuits — open hydraulic circuit and closed hydraulic circuits.
Liebherr has typically used an open hydraulic circuit on its concrete pumps, as this configuration is simple, highly reliable and powerful. Both circuit types have pros and cons. The open setup takes up more space and weighs more, and a large amount of oil is required. A closed setup incorporates more components and is therefore more complex.
The Liebherr Powerbloc is a solution that combines the best attributes of open and closed systems, resulting in a system that weighs less and is more efficient, with a longer service life. Yet, it also meets strict noise and health and safety regulations. This product is innovative and unique as it is a half closed hydraulic circuit. It combines the best elements of the two designs into one powerful and reliable unit with a lean design, easy maintenance and smooth operation.
As this set was designed specifically for application on concrete pumps, hydraulic hoses have been replaced with rigid piping. Hydraulic blocks are optimized and less oil is needed, which results in a more compact, lighter unit. Additional features are embedded, such as switching and measuring elements.
Switching cylinders on a concrete pump can cause significant wear and tear, violent, hard vibrations and extreme noise. It can also result in component damage and require more frequent maintenance. On the Powerbloc, moving parts switch smoothly, preventing intense friction wear. This enables a longer lifetime for pump components. A measuring system, also part of this innovative design, transmits signals from the exact position of the hydraulic cylinders to the computer to control the entire function of the pump.