BENDIX SD-22-3260 User Manual

®

The Bendix 16-1/2” x 7” double anchor pin cam brake is
designed for use on heavy duty highway vehicles. It is a
mechanically actuated, leading /trailing shoe brake with a
fixed position cam and anchors.

The brake consists of two fabricated steel shoe assemblies
individually anchored to a cast iron torque spider and
actuated by a single forged cam shaft. Two retaining springs
secure the shoe assemblies to their respective anchor pins.
The twin webs of each shoe assembly engages 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.

The Bendix cam brake operates in the following manner
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 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. The heat raises
the temperature of the drum. The heat is stored in the drum
and finally dissipated to the air.