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OES' linear step motors
are ideal for open loop positioning applications with light
payloads. They can be used at speeds up to 80 in /sec (2 m/sec)
and strokes up to 144" (3.6 m). Linear step motors are capable
of very precise position, velocity and acceleration control when
coupled with a micro-stepping drive and indexer.
The short moving assembly called a "forcer"
is guided by either roller or air-bearings along he precision
ground track called a "platen". The bearings are designed to
support the customer's payload and to maintain the required
.001" (0.025 mm) gap between the platen and the forcer.
The forcer conveniently connects to any
commercially available 2-phase micro-stepper driver. The motion
achieved with a full step is .010" (250 microns) and with a
micro-step of 250 it's 0.00004" (1 micron).
These motors are also available with 4
windings to be used with a 4 phase step motor driver s. The
advantage of using a 4-phase motor is higher resolution and
lower velocity ripple.
The linear step motors a complete positioning
stage with the motor, the bearings and the positioning system
all built into one compact package.
Integrating a linear encoder with the
stepping provides a closed loop system. |
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Advantages:
- Low profile and small cross section
- High Speed
- Low cost positioning stage solution
- No servo tuning required
- Multiple forcers on a single platen
Applications:
- Pick and Place
- Wire bonders
- Parts transfer
- Fiber optic
The Linear Stepper Motorconsists of 2 main parts
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Moving Forcer Assembly: The forcer is made up of an aluminum
housing that contains the motor windings, lamination stacks, and permanent
magnets. The active surface of the lamination is slotted to form teeth with
a pitch of .040" (1 mm). The ends of the coil are brought out to either
a "D" connector or to flying leads. Mounting holes on the top
surface of the forcer are for attaching the customer's payload. The forcer
comes in different widths and lengths, depending on the required force.
Multiple forcers can be supplied with a single platen to allow for
independent moving heads.
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Long Stationary Platen: The platen is a precision ground steel bar
or tube that is slotted to form .020" (0.50 mm) wide teeth on the
surface. The bar is hard chrome plated and filled with epoxy to provide a
flat air-bearing surface for the platen. The platen is available in widths
from 1.25" to 3.0 " (31.8 mm to 76.2 mm). The length of the platen
is a function of the stroke. Single piece platens are available as long as
144 inches (3.6 m). For longer strokes the platens will be supplied in
sections.
Operating Information:
Required Electronics:
With full stepping, the forcer will move .010" (0.25 mm) for
each step. With micro-stepping the forcer will divide the full step by the number
of Micro-steps. With 256 Micro-steps per full step, each micro-step will be .010"
(0.25 mm) / 256 = 0.00004" (1 micron)
Environmental Considerations:
The linear stepper motors a precision device and should not be mounted in an
environment that is wet or excessively dirty. Debris should not be allowed to
accumulate on the platen.
Mounting:
The platen should be mounted to a flat (better than .003"/ ft (246 microns
/ m) and stiff surface. Threaded holes on the bottom of the platen are present
for mounting to the customers system. The forcer has threaded holes on the top
surface for attaching the payload. The linear stepper motor may be mounted in
any orientation. When mounting the platen with the forcer moving vertical, it
should be noted that the forcer will be required to generate additional force
due to gravity and that the ball bearing forcer will slide down to the bottom
when power fails. Turning off the air to an air bearing forcer will lock the
forcer in place.
Product Information:
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Travel |
144 inches
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(3.6 m)
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Velocity |
80 inches/sec
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(2 m/s)
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Acceleration |
1 G's
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1 G's
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Peak Force |
65 lbs
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(289 N)
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Continuous Force |
50 lbs
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(222 N)
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Dimensions:
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5-lb Linear Stepping
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Ordering Information:
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Model #
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Force cont
lbs (N)
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Force peak
lbs (N)
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# of Phases
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Bearing Type
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STPM-SL-05-Length-R |
5
(22) |
8
(36) |
2 |
Roller |
For example,
STPM-SL-05-10-R
is a 5.0 lbs continuous force stepping with 10.0 inches of travel.
Note: This is a partial listing; other models with different forces and
strokes are available. Optimal Engineering Systems, Inc. single axis linear stepper motors can be
custom designed to meet your specifications.
please contact us for a prompt quotation.
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