HYDRAULICS Drive controllers make servo pumps more efficient Performance, pump protection and high precision control without compromise – all this is provided by the servo pump control function integrated in KEB Automation’s drive controllers. In combination with KEB’s DL4 and TA series servo motors, they can also save energy. By controlling the pump drive, pressure and flow can be optimally adapted to the requirements of servohydraulic machines at any time. This is the case, for example, in injection moulding machines where cycle times are key. Here, the COMBIVERT F6 drive controller and S6 servo drives from KEB come in. With the precise and highperformance solution for pump control, the company says they ensure continuous control, as well as faster cycle times, to increase the productivity of injection moulding machines. Another goal of the control: the hydraulic valves are to be protected and the service life of the pump is to be extended. For this purpose, there are various parameters in the firmware of the drive controllers whereby the lifetime and availability of the injection moulding machines can be significantly increased. Various features that have been specifically integrated into KEB’s drive controller firmware are proving useful in practice. “Among other things, we have considered ‘anti-cogging’ in our solution”, says Michael Schulz, application engineer at KEB. He added: “This enables KEB’s inverters to equalise disturbing cogging torques, which are system-immanent in permanent magnet motors. The result is significantly improved concentricity on the motor axis. In combination with the notch filter from the Wizard, which serves to avoid resonances in the hydraulic circuit, the result is highly precise and very good control of flow and pressure. Furthermore, there is the additional feature that the PQ control can be switched on and off by setting a bit. The user therefore has a regular KEB drive in place. This can lead to cost savings.” The choice of servo pumps is always a sensible idea when hydraulic systems are confronted with highly dynamic or highly constant control requirements. These include various areas of plastics processing, hydraulics and bending presses, but also applications in the field of lifting technology. According to Schulz, the stability of the KEB system and the performance of the software solution are particularly evident in the control of pressure and flow. For more information, please visit: www.keb.co.uk Service time reduced with new shut-off device for agitators Sulzer has launched a new shut-off device SOD for horizontal SALOMIX SSA agitators that significantly reduces the time spent on servicing the seal. The device enables seal maintenance without emptying the tank, which makes the feature especially useful for very large tanks, wastewater treatment plants, and other critical processes. After shutting down the agitator, SOD is activated by pressure, which expands a rubber element that clamps around the shaft. The pressure can be applied with a simple hand pump, and either by air or water. There is no need to remove the shaft or unlock the bearings, which significantly speeds up the maintenance process. The simple structure also minimizes the chances of misuse. SOD is designed for a longer seal lifetime. Outside maintenance periods, the large radial clearance between the shaft sleeve and SOD’s cartridge provides an open seal environment that prevents clogging and drying out. Especially with contaminated liquids and slurries this is a key feature in maximizing seal lifetime. After extensive testing, the company says that the patented construction of SOD has proven to be extremely reliable. It enables a tight seal and works robustly even with impurities in the liquid. As a result, the device is especially suitable for paper pulp, wastewater, biofuels, metals, and mineral applications. SOD represents the latest in Sulzer’s continuous efforts to finalise its agitator selection: “In the past few years, we have developed the portfolio of our side-mounted agitators by combining our expertise with the customers’ needs, which has led to market leading hydraulics and a comprehensive agitator range packed with smart features. SOD is a good match with our objective to always serve our customers with innovative and reliable technology,” says Patrik Kolmodin, product manager of agitators at Sulzer. SOD suits most industrial applications. It is globally available for all sizes of the side-mounted SALOMIX™ SSA agitators in either EPDM or FKM rubber. The devices can be combined with gland packings or split mechanical seals. They endure high temperatures up to 90˚C (195°F) and pressures up to 4 bars (58 psi). For further information please visit: https://www.sulzer.com 18 HYDRAULICS & PNEUMATICS October 2023 www.hpmag.co.uk SOD has a large radial clearance to the shaft, which provides long seal lifetime
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