• Maximum diameter of 2 inches
• Voltage range: 16 VDC to 32 VDC
• Ability to withstand 500 emergency
• Ability to operate in a radiation
When the designer discovered the
need for the brake, he also realized that
these specifications would limit brake
options. Further, given the requirement
to adhere to original production sched-
ules, he needed to move quickly, adding
further urgency to the situation.
Meeting the spec
The designer translated the specifications into a set of requirements he’d
use to select the braking system using
a straightforward application of the
inertia-time equation (See the sidebar
“Selecting Friction Brakes and Clutches”).
An Internet search led him to Thom-
son who was able to meet all technical
specifications. Thomson supplied a
Deltran SB19 series spring set friction
brake, which met requirements in all of
the following areas:
• Low backlash: Precision machin-
ing helped meet the backlash re-
quirement. Play is all but undetect-
able when the system is at rest due
to the tightly machined tolerances
of the spline design.
• Torque density: In most cases,
the available 2” X 1.2” available
space would have limited the
torque to around 10 inch pounds
(approximately 1 Nm). The Deltran
brake, however, provided 18 inch
pounds (approximately 2 Nm).
The increased torque density is the
result of a high performance sole-
noid, which can overcome stronger
Figure 2: Cutaway of an electromechanical brake.
Reliable. Available. Now. tracopower.com
New 40 and 65 Watt models, most
compact and highly efficient
in metal enclosure or open frame.