Oil baths eliminate cylinder maintenance
SEW-Eurodrive has applied an oil bath lubrication technology originally developed for gearmotors to an expanded range of electric cylinders, resulting in improved efficiency, uniform heating, and minimal maintenance.
Usually, the threaded spindles in electric cylinders are lubricated using grease which inevitably leaks, requiring relubrication. In the new design, two sealing systems isolate the oil bath from the exterior. The oil bath reduces friction and heating, and is said to prolong the lives of spindle nuts, bearings and guides. Heat from the internal components is dissipated via the housing.
The cylinder is driven by a servomotor with linear components integrated into its rotor, producing a smaller actuator than conventional designs in which the linear components are connected to the motor via adapters and couplings. Start-up from idle is said to be easier than normal and does not suffer from the stick-slip effect. The CMS63 cylinders, hermetically sealed to IP65, can be used in hygienic applications or where there are high levels of dust or moisture. They are fitted with resolvers, with encoder feedback as an option.
The cylinders can deliver up to 7.2kN of thrust, and can provide strokes up to 600mm and top speeds of 500mm/s.