After a run-in phase of over 10 – 15 km, the drive achieves an exceptionally stable step size. The constant step size is a measure for the high load capacity and endurance of the drive.
PiezoWalk® drives were developed more than 10 years ago for the semiconductor industry, which is a very demanding industry when it comes to reliability, position resolution and long-term stability. PI received the SEMI Technology Innovation Showcase Award for the PiezoWalk® technology in 2005. The drives are continuously developed further, and a large number of variants are now available for different areas of application.
High-load walking drives combine piezo clamping and shear actuators, in order to move a rod. The drives feature particularly high forces and stiffnesses at feed forces of several 100 N. They are capable of dynamically compensating oscillations in the range of a few micrometers with nanometer resolution, are designed for higher positioning and holding forces of up to 800 N, and work at lower velocities.
Precision walking drives convert the walking motion by means of piezo bending elements. These drives are more compact and achieve higher velocities, developing forces in the range from 10 to 20 N.
A suitable selection of the piezo elements optimizes step size, clamping force, velocity, and stiffness for the respective applications.
Operating Principles of PiezoWalk® Linear Motors
As essential components, these piezo walking drives have several piezo actuators that are preloaded against a guided runner.
These piezo actuators perform a walking motion during operation that causes a forward feed of the runner. The piezo actuators can be operated to perform very small walking and feed motion so that a high motion resolution of far below one nanometer is achieved.