June 24, 2020 - H2W Technologies introduced single axis linear stepper motors for high-speed open loop positioning applications. They 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 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 customer’s payload and to maintain the required 0.0005 in to 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 (2 or 4 phase). An indexer is required to send step and direction signals to the driver.
For 2 phase motors, the full step is 0.010 in [250 microns] and for 4 phase motors the full step is 0.005 in [125 microns]. With micro-stepping, resolutions in 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.
