The system uses a planetary threaded drive, a gear unit and a servomotor. The spindle transfers the drive of the planetary gear directly via the gear unit. The gear unit is responsible for the power and the clamping force adjustment and the servomotor is only used for the actual clamping movement. Hydraulics, which can be very maintenance intensive, are usually responsible for the lion's share of most cylinders total energy consumption. This is reflected in high leakage rates, large fluid use and a correspondingly high consumption of energy. In addition the power losses for hydraulic rotary feeds with large through-bores are extremely high. HAINBUCH have produced a totally new, high energy-efficient generation of hollow clamping cylinders. The electromechanical actuator from HAINBUCH maintains the stroke position and hence the clamping force, even if there is an abrupt speed change as during spindle braking, or even a complete spindle direction change. Using the servomotor the clamping force can also be varied to suit the part being machined and can be used to give a very light or a very heavy grip. It can also be used to counteract centrifugal forces actually during the machining ¬process. This is the only time the electromechanical actuator switches on, is when a change in stroke position is required. There is a smaller load on the machine drive as the mass and size is smaller than existing cylinders, and at the same time more sensitive clamping force control can be achieved during the mach¬ining process, greater positioning accuracy, and faster actuation of different stroke lengths. The stroke can also be adjusted to move no more than the necessary during the opening and clamping stroke. What's more it can be adapted to new and existing machine tools. HAINBUCH will be in Hall 4, stand 4311, at MACH 2010.