Physik Instrumente UK

M-674 PILine® RodDrives represent a level of integration between PILine® OEM piezo linear motors such as P-664 and guided micropositioning systems such as the M-682 series stages.

• Drive-Component for Integration into MicropositioningSystems
• Travel Ranges to 150 mm
• Push/Pull Forces to 7 N
• Min. Incremental Motion to 0.05 µm
• Velocity to 450 mm/s
• Self-Locking at Rest

M-674 PILine® RodDrive Piezo Linear Drive

RodDrives may replace classical drive elements like rotary motor/leadscrew assemblies, or magnetic linear drives integrated into a micropositioner. They consist of a rod which is preloaded by piezo linear motors from two sides. Depending on the way of integration, either the rod or the motor block is coupled to the moving platform.

Advantages of PILine Micropositioning Systems

The ultrasonic piezoceramic drives used in PILine® micropositioners have a number of advantages over classical drives:

• Higher Accelerations, up to 10g
• Speeds up to 500 mm/s
• Small Form Factor
• Self-Locking When Powered Down
• No Shafts, Gears or Other Rotating Parts
• Non-Magnetic and Vacuum Compatible Drive Principle

Working Principle

RodDrives employ a patented ultrasonic drive developed by PI. The highly compact, integrated P-664 piezomotors can provide velocities of 450 mm/s,together with high resolution and holding force. The maximum travel is determined by the length of the rod and is basically unlimited. Customizedadaptations in terms of operating and holding force are feasible by varyingtype and number of motors used. Because the integrated ceramic motors are preloaded against the rod, RodDrives resist motion with an intrinsic holdingforce when at rest. The result is very high position stability without the heat dissipation common with conventional linear motors. Furthermore, there are no gears, leadscrews or other mechanical components to contribute play or backlash.

Variety of Drivers / Controllers

PILine® piezomotors require a drive electronics for exciting the ultrasonic oscillations. The drive electronics is available as OEM board, stand-alone device or integrated inside a closedloop motion controller and therefore not included in the delivery.

Closed-Loop Operation: Optimized for High Velocity and Rapid Step/Settling

Together with a position sensor, RodDrives can be operated in closed-loop with the C-866.D64 piezo motor controller. This specialized servocontroller also integrated the motor drive electronics and enables highly constant speeds up to 350 mm/s with very short settling times (10´s of msecs). RodDrives can also be operated with conventional servocontrollers. In this case, the C-185 (to be ordered separately) external drive electronics is required which accepts a ±10 V analog signal from the controller.

Note

The products described in this document are in part protected by the following patents: US-Pat. No. 6,765,335

*The minimum incremental motion is a typical value that can be achieved in the open-loop mode of a piezomotor stage. To reach the specs it is important to follow the mounting guidelines of the OEM-motors.

**Stiffness at 25°C.

***The operating voltage is supplied by the drive electronics.