H2W engineers have developed a new Single Rail Stage (SRS-006-04-030-A) that is capable of generating 30 pounds at 100% Duty Cycle. The SR stage is a compact, small footprint, open type positioning stage. It is used in closed loop positioning applications that require high speed and high accelerations of lighter loads. The ironless core coil assembly has no magnetic attractive force to the stationary magnet assembly, which reduces the load on and increases life of the bearing system. The low overall weight of the stage makes it ideal as a Y axis (top axis) in a multi-axis system. The lower moving mass of the stage allows for much higher accelerations of light payloads.
The stage includes a three-phase brushless linear motor. The short encapsulated moving coil assembly moves thru a gap in the long "U" shaped magnet assembly. A customer supplied bearing system is required to guide the moving coil assembly and to maintain a .025 in [0.63 mm] clearance between the magnet and the coil assembly. The power to the motor (from a customer supplied PWM 3-phase brushless servo amplifier) is supplied to the moving secondary via a power cable. Larger motors with higher forces are available, consult factory for details and drawings.
There is a long stationary "U" shaped magnet assembly made with nickel-plated steel back iron and Neodymium permanent magnets. The magnets are bonded to the 2 parallel steel plates and the plates are bolted to a steel spacer bar. Threaded and thru holes are available in the steel back iron for mounting the magnet assembly to the customer supplied base plate. The length of the magnet assembly is a function of the stroke.
The Single Rail Stages incorporate state of the art high quality linear motion products. Linear guidance is achieved by using a single linear rail with 1 or 2 linear recirculating ball bearing guides. The bearing is sealed with wipers to contain the lubrication and to keep out debris. A non-contact glass, metal, or magnetic scale linear encoders are used for position feedback, which includes a reference mark for homing. Multiple reference marks are available and are spaced every 50 mm down the length of the scale. Typical encoder output is A and B square wave signals but sinusoidal output is available as an option. End of travel limit switches are included at both ends of the stroke. The switches can be either active high (5V to 24V) or active low. The switches can be used to shut down the amplifier or to signal the controller that an error has occurred. The limit switches are typically an integral part of the encoder, but can be mounted separately if required. Cable guidance is achieved by using a cable carrier. Cable carriers are over sized to allow for routing of customers hoses and cables. Hard stops are incorporated into the ends of the stage to prevent over travel damage in the event of servo system failure.
Advantages: Small Footprint and Cross Section, Lowest Weight per unit Length, Low Cost, High Acceleration of light loads, High Speed
Applications: Pick and Place, Vision Inspection, Parts Transfer, Clean room
High Acceleration, Precise Motion Control SR Positioning Stage
Published July 27, 2011