The role of the hydraulic power unit
During the course of the project, it became clear that the required speed control can only be achieved using a hydraulic system. An electric motor is unable to achieve the same. The pupils sought expert knowledge and contacted the development managers at Bucher Hydraulics Klettgau, who agreed to offer specialist, competent support for their challenge. After producing the 3D model of the pellet press, the specialists developed a solution. In light of the challenges with the drive's low speeds at both medium to high pressures and an output of 5 kW, they decided upon an advanced combination of hydraulic components: a hydraulic power unit, a flow control valve, an internal gear motor, and electronics.
Interestingly, the hydraulic power unit came from the Bucher site in Grand Rapids, USA, where it is normally used in applications such as lathes, injection molding machines, presses, and heavy lifting gear. The flow control valves manufactured by Bucher Hydraulics are typically used in winter road maintenance applications. The use of these technologies in a pellet press demonstrates the diverse possibilities of hydraulic systems within different sectors.
