BRAKE THERMAL CAPACITY
When a brake stops a load, the energy required to stop is converted to heat. This heat is absorbed by the brake and the wheel. The ability to absorb and dissipate heat without exceeding temperature limitations is known as thermal capacity.
 
There are two types of thermal capacity. The first is referred to as the maximum energy the brake can absorb in one stop, or emergency stop. The second is the heat dissipation capability of the brake if it is for frequent stopping.
 
The kinetic energy that must be absorbed and dissipated by the brake can be determined as follows:
 
      Rotational Loads:
            

where:	KEr	=	Kinetic energy of rotating load (ft-lb)
	WKT2	=	Inertia of the rotating load reflected to brake shaft (Ib-ft2)
	NB	=	Shaft speed at brake (RPM)
	5875	=	Constant

 
      Linear Loads:
              

where:	KEL	=	Kinetic energy (ft-lb)
	W	=	Weight of load (lb.)
	V	=	Linear velocity of load, (ft/sec.)
	g	=	Gravitational constant (32.2 ft/sec2)