Posted to News on 25th Oct 2006, 19:59
Linear actuators perform sub-micron movements
For precision levelling and alignment in industrial machinery, Lambda Photometrics is introducing a comprehensive range of high-load motorised linear actuators from PI. The actuators, which incorporate a low-friction, heavy-duty ballscrew, can move and hold loads of up to 40kg to within a step size of 0.1 microns. A non-rotating tip design, built-in Hall-effect limit and reference switches, and a line driver that allows a cable length of up to 10m, all help to simplify the integration process.
Three different designs of standard actuator are detailed on the PI website. The M-238 has a travel of 50mm and can hold a load of up to 40kg; it features a low-stiction, low-friction construction that allows motion increments as small as 0.3 microns. A direct metrology, linear encoder option produces the highest precision, achieving a unidirectional repeatability of 0.3 microns and a backlash of only 1 micron. A direct drive DC motor produces a velocity of up to 30mm/s.
The M-235 series, with 20mm and 50mm of travel, can hold loads of up to 10kg and can move in increments as small as 0.1 microns. Three drive options are available, a DC motor direct drive, a DC motor gearhead drive and a two-phase stepper motor drive. The rugged construction of the M-238 and M-235 drives ensures that under normal operating conditions an MTBF of >20,000 hours is achieved.
The M-230 series, for low-force applications, is available with 10mm or 25mm of travel. When driven by either a DC motor gearhead or a two-phase stepper motor, a minimum incremental motion of 0.05 microns is specified, making the M-230 drive excellent for high-precision applications.
For design engineers, the non-rotating tip ensures that torque-induced positioning error, tip wear, sinusoidal motion error, and tip-induced wobble are all eliminated.
Each actuator is supplied with a selection of end tips, an integrated 0.5m cable with 15-pin D-sub connector and a 3m extension cable. An optional 10m extension cable can be supplied on request.
PI controllers such as the C-843 PCI bus board and the C-862 Mercury can drive geared versions of the actuators without the need for any external voltage amplification. An external power supply is required for the higher-voltage direct-drive motors. The new C-663 Mercury Step is a low-cost single-channel stepper motor controller that is suitable for driving the two-phase stepper versions. The actuators are also compatible with a range of industry-standard controllers.
About PI
PI is a global manufacturer of high-precision positioning equipment based on piezoelectric, DC and stepper motor drives. Key technologies include Hexapod six-axis robots, ultrasonic piezo motor drives, piezo driven nanopositioning stages and piezo linear actuators.
