SERVOTRON® - The most energy efficient high pressure pump
for waterjet cutting!
Generally in mechanical engineering the term servo refers to a mechanism the purpose of which is to convert a small effort into a large effect with the aid of external energy. In electrical engineering a servo is considered to be a combination of a control and a drive unit. If this knowledge is transferred to high pressure pumps for waterjet cutting, the following results:
The classical concept of high pressure pumps for waterjet cutting is based on an asynchronous motor that drives a wobble plate type axial piston pump. By adjusting the plate, the flow rate, and consequently the operating pressure, are adjusted. If the plate is perpendicular to the pump axle, this equates to idling operation and hence zero flow. As soon as the plate swings out, the pressure builds up and the pressure intensifier starts to operate.
With the new SERVOTRON® type high pressure pump, this principle has been inverted. A gear pump with a constant flow rate is connected with a highly dynamic, frequency-controlled servo drive. In approximately 60 milliseconds, the motor is accelerated from zero to up to 2,700 rpm. This drive concept has a decisive advantage, i.e. improved energy efficiency! In comparison with asynchronous motors, the efficiency of this new drive concept with a frequency-controlled servomotor is approximately 15% higher. A standard pump consumes approximately 23 amps during idle mode. With the new SERVOTRON® high pressure pump, if the waterjet valve is closed, then the servo drive is also stationary and hence consumes no power. If an average cutting operation with a ratio of 75 % cutting time and 25 % closed cutting head is assumed, then it is possible to save more than 24% on energy. This is also confirmed and certified by TUV Austria.