Voith offered the HPD punch drive – the company's newest development in the field of punching and nibbling machines – recently at EuroBLECH 2016 in Hannover, Germany. The compact and economic hybrid servo drive is a culmination of 30 years of hydraulics experience combined with the advantages of a servo drive. This drive technology is ideally suited for a medium power range.
The HPD is a versatile drive used in punching and nibbling machines. The transmitted force can be adapted individually to meet the specific operation profile. When power requirements are low, the HPD uses a partial load operation at high speed in order to achieve high productivity. During punching or forming, it automatically switches to full load operation delivering up to 300 kN at any time and at any point of the cylinder stroke. Despite its flexibility, the HPD requires only 4 kW of power at 600 strokes/min.
The functional principle of the HPD is that of a closed loop hydraulic system without directional valves or servo valves. The pump connects directly to the cylinder allowing it to operate as a hydrostatic gear – without friction or wear. Together with the linear cylinder, it is also virtually wear-free, operators benefit from an extremely robust and low-maintenance solution. The system is absolutely overload-safe because it has no mechanical gear.
Voith uses a modular design and standardized components to make system integration of the HPD remarkably easy. The standardized electronic and mounting interface is easily recognizable as it is found throughout the Voith punch drive offering. This includes the proven Voith HS4 controller, an integrated electronic controller that recognizes even complex parameter structures independently.
The self-adaptive hydraulic gear reduces the inverter capacities and servomotor power required for the HPD. The system requires no additional cooling as there is no a brake resistor and significantly reduced heat loss is achieved. The complexity and space requirements in the control cabinet are therefore further reduced. In contrast to servo-mechanical alternatives, which operate with a peak current input of 200 A, the innovative Voith drive requires only 50 A.