Magnetically preloaded single-axis linear stepper motors from H2W
Engineering360 News Desk | July 07, 2020Single axis linear stepper motors from H2W Technologies are designed for high-speed open loop positioning applications and can perform at speeds of up to 80 in/sec [2 m/sec] and strokes of up to 68 in [1.7 m]. Linear stepper motors are capable of very precise position, velocity and acceleration control when coupled with a micro-stepping drive and indexer.
The moving assembly called the forcer is supported by magnetically preloaded air bearings that are embedded in the active surface of the forcer, and on a single side of the platen to minimize the physical contact of bearings on the platen. The bearings are designed to support the user's payload and to maintain the required 0.0005 in
Source: H2W Technologiesto 0.0010 in [12 to 25 micron] air gap between the platen and the forcer.
The step and direction signal comes from a micro-stepping drive (two or four phase). An indexer is required to send step and direction signals to the driver. For two-phase motors, the full step is 0.010 in [250 microns] and for four-phase motors the full step is 0.005 in [125 microns]. With micro-stepping, resolutions on the order of 0.5 to 1 micron are achievable.
The single axis linear stepper motor is a complete air bearing positioning system with the motor, the bearings, and the positioning system all built into one compact package. Integrating a linear encoder with the stepper motor allows for a hybrid, closed-loop positioning system.
Advantages include a low profile and small cross section, high speed, no servo tuning required and multiple forcers on a single platen. Typical applications include pick and place machines, wire bonders, parts transfer and fiber optics.