Chicago-Today, everyone is making products smaller and
more versatile. And essentially, that's what a host of power transmission
suppliers at last week's National Design Engineering Show were doing-combining
components to come up with more compact designs that cost less and are easier
put together. Here are a few examples.
The ELCOM ST(tm) slotted brushless dc motors from Pittman (http://www.pittmannet.com/300000.html?id=188)
now include control electronics inside the motor housing. The company claims
the result is a smaller, more versatile motor that's less expensive to operate
than conventional brushless dc motors that typically require more complex
The motor's flexible design allows Pittman to configure
it as either a two-wire, single-polarity motor with open-loop speed control,
or as a reversible motor just by changing the windings. The company can even
incorporate other functional components such as closed-loop motor speed
control, and encoders for velocity feedback and enhanced motor
Targeted at engineers seeking the simplicity of a motor with on-board
electronics, but without the expense of an indexer on each axis, the IMS
Motor+Driver from Intelligent Motion Systems Inc. (http://www.imshome.com) consists of a NEMA
17 frame size 1.8-degree motor mounted to a microstepping motor drive. It's
also available in multiple configurations, including a single-shaft
stand-alone device, a standard motor with optical encoder, and an Acme screw
"With prices starting at $113.73 each/100 piece
quantity, it allows the system designer to choose the best method of control
for the application," says IMS President David Coutu. Various setup parameters
can be changed on-the-fly or downloaded and stored in non-volatile memory. And
the motor is available in three different stack lengths. "It's a small,
powerful, and inexpensive solution that offers 'cost-effective versatility,'
and reduces design and assembly time in low-power stepping motor
applications," says Coutu.
Designed for limited space applications, the series 44M100D permanent-
magnet stepper motor weighs in at just 80g (2.82 oz), but it's no lightweight
in terms of power, according to Thomson Airpax Mechatronics (http://www.thomsonindustries.com/airpax/airpax.htm).
Its "super-thin" design measures just 44 mm (1.7 inches) by 12 mm (0.48
inches) long, yet it produces 30 mNm (4.25 oz-in) of pullout torque.
Engineers designing electronic assembly equipment such as component
delivery systems, tape and label feeders, and precision-testing
instrumentation will appreciate its super-thin profile, high torque to inertia
ratio, and low cost of $9.95 for 500 units. Flexible options include custom
mounting/lead egress positions, changes in coil design, and different bearing
Californiaís plan to mandate an electric vehicle market isnít the first such undertaking and certainly wonít be the last. But as the Golden State ratchets up for its next big step toward zero-emission vehicle status in 2018, it might be wise to consider a bit of history.