Cost-cutting pressures relieved

March 2015

When engineering its latest series of high-pressure pumps systems for water jet cutting, Projet System placed its bets on hydraulics by Rexroth. To achieve a quieter, energy-saving version, one new component is all that was needed.

Regardless of whether it’s a question of metal, acrylic glass or textiles, industry makes use of water jet cutting for a wide range of materials. That is why one Swedish company, Projet System, has specialized in high-pressure pump systems for a broad variety of applications. The ProLine series is available in a number of versions with differing specifications and these can also be modified to suit special needs. Ever since these pumps were introduced to the market, the manufacturer has placed its faith in the portfolio of hydraulic components made by Rexroth. “Since the company’s clientele is demanding energy-saving versions ever more often, Projet System began to expand the model range,” recalls Bjarne Restedt, application support manager at Bosch Rexroth in Sweden. Several competitors engaged in a search for a suitable solution. “We had an idea that did away with the need for an entirely new configuration but, in spite of that, was able to achieve the targets,” says Restedt.

The magic words: demand-driven

Restedt suggested to the engineers at Projet System that they leave the hydraulics in place, including the motor and pump assembly, but to operate them with an intelligent Sytronix drive controller. The great advantage here: With this custom solution Sytronix regulates the motor speed in order to maintain the pump swivel angle and pump displacement volumes to the optimum. So the solution always delivers exactly the amount of power needed – exactly in line with demands. To accomplish this, the system calculates the pump’s actual swivel angle in three different ways and a pressure transducer continuously registers the required flow rate and the pressure prevailing in the system. Where the load varies, this configuration can reduce energy consumption. Results from long-term field testing shows an energy reduction of more than 50 percent. One side effect, no less important to the customers, is that the noise is also reduced at lower speeds. Beyond the drive controller, no other components are needed to achieve this improvement.

Projet System found this solution persuasive and the new ProLine Sytronix Eco line was born. “In order to increase delivery and control convenience even further, Projet System replaced the previous third-party controls with the drive-based IndraMotion MLD and our new HMI VR2107 control device,” says Restedt. The control software associated with this was customized during joint programming efforts. Users have been more than excited about this overall package. Right now, Projet System is forecasting 30 systems per year. And there’s more: Projet System is also planning to market energy-saving versions in other lines.