NKK Marketing Energy-Saving Direct-Drive Hydro System
The direct-drive hydro system introduced at the bloom continuous caster of NKK's Fukuyama Works
NKK has begun selling a new direct-drive hydro system (DDHS) which incorporates an actuator,pump, tank and drive motor in a composite unit.Unlike conventional hydraulic systems, the hybrid DDHS features a simple structure that contains virtually no piping and valves and is directly driven by a CPU-controlled servomotor. The high-performance DDHS is capable of driving cylinders only when activated, thus reducing energy loss to a range of one-fifth to one-tenth that of conventional systems. It also incorporates a low-noise design. Combining all components in a composite unit, the system consumes only one-tenth to one-twentieth the oil of conventional systems, while allowing use of mineral oil even in high-temperature environments. A CPU-controlled servomotor activates a sensor-equipped actuator so synchronizing multiple cylinders is simple. NKK's DDHS is rated at a maximum pressure of 600kg/cm2 with thrust ranging from about 500kg to 10,000 tons and is targeted at cylinders with a maximum diameter of 400mm. A standard model is priced at ¥1-5 million. The technology for the DDHS was originally developed by Dai-ichi Denki Co. based in Fujisawa.NKK obtained the right to sell the system and applied products from Primetech, Dai-ichi's subsidiary,which manufactures the system. Basic patents for the system have already been obtained in the U.S. and U.K., with application patents being filed in Japan. In the future, NKK intends to focus on the applied engineering and manufacturing of new systems that take maximum advantage of this technology's special features. Applicable fields include industrial and construction machinery,aircraft and ships. NKK put the energy-saving DDHS into practical use at the Fukuyama Works in October 1997 to run the molten steel level control stopper at the works' bloom continuous caster. Results have been positive in terms of the system's high performance and ease of maintenance. |
