BENDIX SINGLE ANCHOR PIN CAM BRAKE General Description Manual

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Bendix Single Anchor Pin Cam Brake
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FIGURE 1

GENERAL DESCRIPTION

The Bendix 15" x 4" single anchor pin cam brake is designed
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for use on heavy duty highway vehicles. It is a mechanically
actuated, leading/trailing shoe brake with a fixed position
cam and anchor.
The brake consists of two fabricated steel shoe assemblies
anchored to a cast iron torque spider and actuated by a
single forged S-cam shaft. Two retaining springs secure
the shoe assemblies to the anchor pin. The twin webs of
each shoe assembly are keyed to the anchor pin on one
end and the cam roller on the other. A single shoe to shoe
return spring is used to maintain constant contact between
the shoe, cam roller and cam.

OPERATION

The Bendix cam brake operates in the following manner
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during a braking application. The force of the push rod of
the actuator is converted from a linear force to a rotary
torque. This is accomplished by use of the slack adjuster.
This torque is transferred to the cam shaft of the foundation
brake due to the spline of the cam shaft being connected to
the gear of the slack adjuster. On the opposite end of the
cam shaft is the S-cam which when rotated lifts the cam
rollers. This spreads the brake shoe ends apart equally
and pivots the shoes about the anchor pin so the brake
lining comes in contact with the rotating brake drum. The
friction created by the lining pressure against the drum
generates the torque necessary to provide a retarding force
to slow down the vehicle. The energy of the vehicle in motion
is converted to heat at the surface of the drum and lining.
This heat raises the temperature of the drum. The heat is
stored in the drum, and finally dissipated to the air.
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