March 23, 1998 Design News
Tubular linear motors accept three
by Norman Bartlett, UK
Recent introduction of a three-phase tubular linear
motor from Linear Drives Ltd. allows greater flexibility
in system design. "The three-phase output of virtually
any industry-standard servo amplifier can be converted
into a direct-thrust linear motion with twice the performance
of previous motors," claims CEO Hugh-Peter Kelly.
By using three-phase, the new LD Series motors are
considerably more responsive and have higher peak performance
than two-phase units. Higher voltages can be used which
translate to faster top speeds--for example, 8 m/sec
on short-duty cycles. Better acceleration/deceleration
accompanies improved speed.
Key components include a thrust rod and motor thrust
block. The thrust rod contains a series of permanent
magnets that form the magnet core. The motor thrust
block functions as the load-bearing housing, enclosing
the motor coil. A large air gap between rod and motor
eliminates precision alignment while the design's inherent
magnetic flux maintains even force.
Depending on application, the core technology is available
as a powered version suitable for a machine builder
with an existing bearing setup
Additional details, contact: Linear Drives Ltd.,
Luckyn Lane, Basildon, Essex SS14 3BW, UK, Tel: +44
1268 287070, FAX: +44 1268 293344.