FORKLIFT
BRAKE
TECHNOLOGY
odern materials handling
equipment needs to run
rapidly, efficiently and
reliably. It must also stop
when required. That’s
called for the development of a range
of sophisticated braking solutions from
leading manufacturers like Warner Electric.
M
Forklift trucks, stackers, order pickers and
reach trucks are mainstays of warehouse
operations. Businesses around the world
depend on these machines to keep
products and materials flowing. For more
than 60 years, Warner Electric – part of the
Altra Industrial Motion Corporation – has
been developing a vital, but inconspicuous
component of the forklift: brakes.
Unlike the brakes fitted to road-going
vehicles, forklift brakes tend to require
spring applied operation. That means
the braking force is provided by passive
components and actuation is required to
release the brake. In the event a truck loses
power or the operator loses control, the
vehicle will be brought to a stop and held
in a stationary condition.
One of the most common methods used
to provide this functionality on forklifts is
the electrically released dynamic brake,
like the Warner ERD range. These brakes
use an electromagnetic coil, sized to suit
the operating voltage of the truck, that
works against a set of springs to pull the
brake armature away from a disc when
power is applied. ERD brakes come in
eight standard sizes and a range of torque
capacities from 5Nm to 300Nm. The size of
brake for a particular application is chosen
based on the maximum operating load
and speed of the truck.
While a constant torque brake like the
ERD is ideal for many applications, the
approach has limitations where the weight
of the load may be high relative to the
weight of an unloaded machine. That’s
often true of ride-on pallet trucks and
order pickers, for example. In these cases,
the torque required to stop a fully loaded
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truck would decelerate an unloaded one
too rapidly, and risk unbalancing the
operator.
For these applications hydraulically
amplified brakes, like the Warner ERDH
range, may prove more suitable. In this
design, the braking force
provided by the springs is
augmented by an additional
integrated hydraulic actuator. Pressure
for the actuator is provided by a piston
integrated into the shell of the truck’s mast
cylinder.