The Positorq® brakes use multiple
disc oil shear technology with a continual supply of cooling and lubricating
fluid like all other Force Control units. The main difference is that
the Positorq® Brake is a constant slip device. It is normally force lubricated
for smooth accurate torque control over the entire speed range, even to
0 RPM. Tension torque is transmitted through the viscous shear of the
fluid between the friction surfaces.
Torque
is proportional to air or hydraulic pressure supplied to the piston. Teflon
piston liners produce smooth controllable piston movement for precise
control and quick brake response.
Web tension control and dynamometer (dyno) brakes are essentially energy
absorbers. Rotary motion is transformed through the brake to heat, so
a critical function of the brake is its ability to dissipate heat. In
the Positorq® brake, fluid is pumped through the brake shaft to furnish
a continuous supply of fluid between the friction surfaces. The fluid
lubricates the surfaces at the point of engagement, and removes engagement
heat. The fluid is then circulated through a cooling unit and cooled fluid
is returned to the Positorq® brake.