Piezo motor specialist PI (Physik Instrumente) has introduced a new family of ultrasonic piezo-motor-driven linear stages. Models M-663, M-664 and M-682 provide travel ranges to 50mm in a very compact package, with vacuum compatible and non-magnetic versions available.
Key features of the linear stages include easy integration due to a very small footprint and only 15mm profile height, and high acceleration to 20g for fast start/stop and high speed scanning. For improved guiding accuracy, crossed roller bearings are mounted on precision ground aluminum profiles. A direct metrology linear encoder with 0.1micron resolution provides high linearity and positioning accuracy. The integrated ceramic linear motors can generate push/pull forces up to 7N, at speeds to 400 mm/sec. Travel ranges are 20, 25 and 50mm.
The ultrasonic piezo linear motor drive is based on an ultra-compact standing-wave PZT ceramic element. At the heart of the system is a rectangular monolithic piezoceramic plate (the stator), segmented on one side by two electrodes. Depending on the desired direction of motion, the left or right electrode of the piezoceramic plate is excited to produce high-frequency eigenmode oscillations of tens to hundreds of kilohertz. An alumina friction tip (pusher) attached to the plate moves along an inclined linear path at the eigenmode frequency.
For optimum performance the highly specialized C-886 motion controller is available. This sophisticated controller also integrates the drive electronics. A number of special features, including dynamic parameter switching for an optimized high-speed motion and settling behavior, take into account the motion characteristics typical of piezomotors. The broad-band encoder input (35MHz) supports the high accelerations and velocities intrinsic to the PILine piezo motors.
